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Alexander Lyman Holley contributed significantly to the success of Bessemer steel in the United States. His A Treatise on Ordnance and Armor is an important work on contemporary weapons manufacturing and steel-making practices. In 1862, he visited Bessemers Sheffield works, and became interested in licensing the process for use in the US. Upon returning to the US, Holley met with two iron producers from Troy, New York, John F. Winslow and John Augustus Griswold, who asked him to return to the United Kingdom and negotiate with the Bank of England on their behalf. Holley secured a license for Griswold and Winslow to use Bessemers patented processes and returned to the United States in late 1863.
The trio began setting up a mill in Troy, New York in 1865. The factory contained a number of Holleys innovations that greatly improved productivity over Bessemers factory in Sheffield, and the owners gave a successful public exhibition in 1867. The Troy factory attracted the attention of the Pennsylvania Railroad, which wanted to use the new process to manufacture steel rail. It funded Holley's second mill as part of its Pennsylvania Steel subsidiary. Between 1866 and 1877, the partners were able to license a total of 11 Bessemer steel mills.
One of the investors they attracted was Andrew Carnegie, who saw great promise in the new steel technology after a visit to Bessemer in 1872, and saw it as a useful adjunct to his existing businesses, the Keystone Bridge Company and the Union Iron Works. Holley built the new steel mill for Carnegie, and continued to improve and refine the process. The new mill, known as the Edgar Thomson Steel Works, opened in 1875, and started the growth of the United States as a major world steel producer. Using the Bessemer process, Carnegie Steel was able to reduce the costs of steel railroad rails from $100 per ton to $50 per ton between 1873 and 1875. The price of steel continued to fall until Carnegie was selling rails for $18 per ton by the 1890s. Prior to the opening of Carnegie's Thomson Works, steel output in the United States totaled around 157,000 tons per year. By 1910, American companies were producing 26 million tons of steel annually.
William Walker Scranton, manager and owner of the Lackawanna Iron & Coal Company in Scranton, Pennsylvania, had also investigated the process in Europe. He built a mill in 1876 using the Bessemer process for steel rails and quadrupled his production.
Bessemer steel was used in the United States primarily for railroad rails. During the construction of the Brooklyn Bridge, a major dispute arose over whether crucible steel should be used instead of the cheaper Bessemer steel. In 1877, Abram Hewitt wrote a letter urging against the use of Bessemer steel in the construction of the Brooklyn Bridge. Bids had been submitted for both crucible steel and Bessemer steel; John A. Roeblings Sons submitted the lowest bid for Bessemer steel, but at Hewitts direction, the contract was awarded to J. Lloyd Haigh Co. | 0 | Metallurgy |
UIT enables life extension of steel bridges. This technique has been employed in numerous US states as well as other nations. The result is a greatly reduced cost of infrastructure. UIT has been certified for this use by AASHTO.
The use of UIT on draglines and other heavy equipment in the mining industry has resulted in increased production and has decreased downtime and maintenance costs.
UIT is employed on drive shafts and crank shafts in a number of industries. Results show that UIT increases shaft life by over a factor of 3.
The US Navy uses UIT to address cracked areas in certain aluminum decks. Without UIT, crack repairs resulted in almost immediate re-cracking. With UIT, repairs have shown to last over eight months without cracks. | 0 | Metallurgy |
The frequency of introns within different genomes is observed to vary widely across the spectrum of biological organisms. For example, introns are extremely common within the nuclear genome of jawed vertebrates (e.g. humans, mice, and pufferfish (fugu)), where protein-coding genes almost always contain multiple introns, while introns are rare within the nuclear genes of some eukaryotic microorganisms, for example bakers/brewers yeast (Saccharomyces cerevisiae). In contrast, the mitochondrial genomes of vertebrates are entirely devoid of introns, while those of eukaryotic microorganisms may contain many introns.
A particularly extreme case is the Drosophila dhc7 gene containing a ≥3.6 megabase (Mb) intron, which takes roughly three days to transcribe. On the other extreme, a 2015 study suggests that the shortest known metazoan intron length is 30 base pairs (bp) belonging to the human MST1L gene. The shortest known introns belong to the heterotrich ciliates, such as Stentor coeruleus, in which most (> 95%) introns are 15 or 16 bp long. | 1 | Gene expression + Signal Transduction |
Casting is a solidification process, which means the solidification phenomenon controls most of the properties of the casting. Moreover, most of the casting defects occur during solidification, such as gas porosity and solidification shrinkage.
Solidification occurs in two steps: nucleation and crystal growth. In the nucleation stage, solid particles form within the liquid. When these particles form, their internal energy is lower than the surrounded liquid, which creates an energy interface between the two. The formation of the surface at this interface requires energy, so as nucleation occurs, the material actually undercools (i.e. cools below its solidification temperature) because of the extra energy required to form the interface surfaces. It then recalescences, or heats back up to its solidification temperature, for the crystal growth stage. Nucleation occurs on a pre-existing solid surface because not as much energy is required for a partial interface surface as for a complete spherical interface surface. This can be advantageous because fine-grained castings possess better properties than coarse-grained castings. A fine grain structure can be induced by grain refinement or inoculation, which is the process of adding impurities to induce nucleation.
All of the nucleations represent a crystal, which grows as the heat of fusion is extracted from the liquid until there is no liquid left. The direction, rate, and type of growth can be controlled to maximize the properties of the casting. Directional solidification is when the material solidifies at one end and proceeds to solidify to the other end; this is the most ideal type of grain growth because it allows liquid material to compensate for shrinkage. | 0 | Metallurgy |
Similar mechanism of action for enhancer-blocking insulators; chromatin loop domains are formed in the nucleus that separates the enhancer and the promoter of a target gene. Loop domains are formed through the interaction between enhancer-blocking elements interacting with each other or securing chromatin fibre to structural elements within the nucleus. The action of these insulators is dependent on being positioned between the promoter of the target gene and the upstream or down stream enhancer. The specific way in which insulators block enhancers is dependent on the enhancers mode of action. Enhancers can directly interact with their target promoters through looping (direct-contact model), in which case an insulator prevents this interaction through the formation of a loop domain that separates the enhancer and promoter sites and prevents the promoter-enhancer loop from forming. An enhancer can also act on a promoter through a signal (tracking model of enhancer action). This signal may be blocked by an insulator through the targeting of a nucleoprotein complex at the base of the loop formation. | 1 | Gene expression + Signal Transduction |
The metals involved in a bimetallic strip can vary in composition so long as their thermal expansion coefficients differ. The metal of lower thermal expansion coefficient is sometimes called the passive metal, while the other is called the active metal. Copper, steel, brass, iron, and nickel are commonly used metals in bimetallic strips. Metal alloys have been used in bimetallic strips as well, such as invar and constantan. Material selection has a significant impact on the working temperature range of a bimetallic strip, with some having a temperature limit up to 500°C, with others only reaching 150°C before failing. | 0 | Metallurgy |
Countertop components fabricated out of granite and other natural stones are sometimes reinforced with metal rods inserted into grooves cut into the underside of the stone, and bonded in place with various resins. This procedure is called "rodding" by countertop fabricators. Most commonly, these rods will be placed near sink cutouts to prevent cracking of the brittle stone countertop during transportation and installation. Data published by the Marble Institute of America shows that this technique results in a 600% increase in the deflection strength of the component.
However, if a metal rod subject to oxidation or other forms of corrosion is used, and moisture from a sink or faucet reaches the rod, oxide jacking can crack the countertop directly above the rod. Mild steel and some grades of aluminium rods are known to cause oxide jacking failures in granite countertops. Skilled stone repair professionals can disassemble the cracked stone, remove the metal rod, and reassemble the stone using various resins tinted to match the colors of the stone. This type of problem can be prevented by using reinforcing rods made of stainless steel or fiberglass in the rodding procedure. | 0 | Metallurgy |
The LPB process includes a unique and patented way of analyzing, designing, and testing metallic components in order to develop the unique metal treatment necessary to improve performance and reduce metal fatigue, SCC, and corrosion fatigue failures. Lambda modifies the process and tooling for each component to provide the best results possible and to ensure that the apparatus reaches every inch on the component. With this practice of customization along with the closed-loop process control system, LPB has been shown to produce a maximum compression of 12mm, although the average is around 1-7+mm. LPB has even been shown to have the ability to produce through-thickness compression in blades and vanes, greatly increasing their damage tolerance over 10-fold, effectively mitigating most FOD and reducing inspection requirements. No material is removed during this process, even when correcting corrosion damage. LPB smooths surface asperities during machining, leaving an improved, almost mirror-like surface finish that is vastly better looking and better protected than even a newly manufactured component. | 0 | Metallurgy |
The adaptor protein Grb2 forms a complex with Sos by the Grb2 SH3 domain. Grb2 (or the Grb2/Sos complex) is recruited to the membrane by the Grb2 SH2 domain binding to activated PDGFR-bound SHP2 (also known as PTPN11, a cytosolic PTP), thereby allowing interaction with Ras and the exchange of GDP for GTP on Ras. Whereas the interaction between Grb2 and PDGFR occurs through interaction with the SHP2 protein, Grb2 instead binds to activated EGFR through Shc, another adaptor protein that forms a complex with many receptors via its PTB domain. Once activated, Ras interacts with several proteins, namely Raf. Activated Raf stimulates MAPK-kinase (MAPKK or MEK) by phosphorylating a serine residue in its activation loop. MAPKK then phosphorylates MAPK (ERK1/2) on T and Y residues at the activation-loop leading to its activation. Activated MAPK phosphorylates a variety of cytoplasmic substrates, as well as transcription factors, when translocated into the nucleus. MAPK family members have been found to regulate various biological functions by phosphorylation of particular target molecules (such as transcription factors, other kinases etc.) located in cell membrane, cytoplasm and nucleus, and thus contribute to the regulation of different cellular processes such as cell proliferation, differentiation, apoptosis and immunoresponses. | 1 | Gene expression + Signal Transduction |
PKA is also commonly known as cAMP-dependent protein kinase, because it has traditionally been thought to be activated through release of the catalytic subunits when levels of the second messenger called cyclic adenosine monophosphate, or cAMP, rise in response to a variety of signals. However, recent studies evaluating the intact holoenzyme complexes, including regulatory AKAP-bound signalling complexes, have suggested that the local sub cellular activation of the catalytic activity of PKA might proceed without physical separation of the regulatory and catalytic components, especially at physiological concentrations of cAMP. In contrast, experimentally induced supra physiological concentrations of cAMP, meaning higher than normally observed in cells, are able to cause separation of the holoenzymes, and release of the catalytic subunits.
Extracellular hormones, such as glucagon and epinephrine, begin an intracellular signalling cascade that triggers protein kinase A activation by first binding to a G protein–coupled receptor (GPCR) on the target cell. When a GPCR is activated by its extracellular ligand, a conformational change is induced in the receptor that is transmitted to an attached intracellular heterotrimeric G protein complex by protein domain dynamics. The Gs alpha subunit of the stimulated G protein complex exchanges GDP for GTP in a reaction catalyzed by the GPCR and is released from the complex. The activated Gs alpha subunit binds to and activates an enzyme called adenylyl cyclase, which, in turn, catalyzes the conversion of ATP into cAMP, directly increasing the cAMP level. Four cAMP molecules are able to bind to the two regulatory subunits. This is done by two cAMP molecules binding to each of the two cAMP binding sites (CNB-B and CNB-A) which induces a conformational change in the regulatory subunits of PKA, causing the subunits to detach and unleash the two, now activated, catalytic subunits.
Once released from inhibitory regulatory subunit, the catalytic subunits can go on to phosphorylate a number of other proteins in the minimal substrate context Arg-Arg-X-Ser/Thr., although they are still subject to other layers of regulation, including modulation by the heat stable pseudosubstrate inhibitor of PKA, termed PKI.
Below is a list of the steps involved in PKA activation:
# Cytosolic cAMP increases
# Two cAMP molecules bind to each PKA regulatory subunit
# The regulatory subunits move out of the active sites of the catalytic subunits and the R2C2 complex dissociates
# The free catalytic subunits interact with proteins to phosphorylate Ser or Thr residues. | 1 | Gene expression + Signal Transduction |
Regions of the short arm of chromosome 8 are frequently deleted in a range of solid tumors, indicating that tumor suppressor genes reside at these loci. Caldwell et al. have shown frequent interstitial deletions in a series of prostate cancers, squamous cell head and neck cancers and colorectal carcinomas. There was also an association between 8p11.2 deletion and local invasion.
The first coding exon contains the whole of the frizzled-related cysteine rich domain (CRD), while the third exon (COOH-terminal domain) contains the netrin-related domain. Netrin is a regulator of apoptosis; the SFRP1 netrin-related motif is also found in a range of other proteins that is thought to mediate protein-protein interactions. The middle exon most likely represents a spacer between the first and third exon. There are 2 introns present within the coding sequence of SFRP1. | 1 | Gene expression + Signal Transduction |
The affinity of an antagonist for its binding site (K), i.e. its ability to bind to a receptor, will determine the duration of inhibition of agonist activity. The affinity of an antagonist can be determined experimentally using Schild regression or for competitive antagonists in radioligand binding studies using the Cheng-Prusoff equation. Schild regression can be used to determine the nature of antagonism as beginning either competitive or non-competitive and K determination is independent of the affinity, efficacy or concentration of the agonist used. However, it is important that equilibrium has been reached. The effects of receptor desensitization on reaching equilibrium must also be taken into account. The affinity constant of antagonists exhibiting two or more effects, such as in competitive neuromuscular-blocking agents that also block ion channels as well as antagonising agonist binding, cannot be analyzed using Schild regression. Schild regression involves comparing the change in the dose ratio, the ratio of the EC of an agonist alone compared to the EC in the presence of a competitive antagonist as determined on a dose response curve. Altering the amount of antagonist used in the assay can alter the dose ratio. In Schild regression, a plot is made of the log (dose ratio-1) versus the log concentration of antagonist for a range of antagonist concentrations. The affinity or K is where the line cuts the x-axis on the regression plot. Whereas, with Schild regression, antagonist concentration is varied in experiments used to derive K values from the Cheng-Prusoff equation, agonist concentrations are varied. Affinity for competitive agonists and antagonists is related by the Cheng-Prusoff factor used to calculate the K (affinity constant for an antagonist) from the shift in IC that occurs during competitive inhibition. The Cheng-Prusoff factor takes into account the effect of altering agonist concentration and agonist affinity for the receptor on inhibition produced by competitive antagonists. | 1 | Gene expression + Signal Transduction |
On April 17, 2005, the Millstone Nuclear Power Plant in Connecticut was shut down due to a "false alarm" that indicated an unsafe pressure drop in the reactor's steam system when the steam pressure was actually nominal. The false alarm was caused by a tin whisker that short circuited the logic board responsible for monitoring the steam pressure lines in the power plant. | 0 | Metallurgy |
In Alabama, industrialization was generating a ravenous appetite for the states coal and iron ore. Production was booming, and unions were attempting to organize unincarcerated miners. Convicts provided an ideal captive work force: cheap, usually docile, unable to organize and available when unincarcerated laborers went on strike." The Southern agrarian economy did not accommodate convict leasing as well as the industrial economy did, whose jobs were often unappealing or dangerous, offering hard-labor and low pay. The competition, expansion, and growth of mining and steel companies also created a high demand for labor, but union labor posed a threat to expanding companies. As unions bargained for higher wages and better conditions, often organizing strikes in order to achieve their goals, the growing companies would be forced to agree to union demands or face abrupt halts in production. The rate companies paid for convict leases, which paid the laborer nothing, was regulated by government and state officials who entered the labor contracts with companies. "The companies built their own prisons, fed and clothed the convicts, and supplied guards as they saw fit." (Blackmon 2001) Alabamas use of convict leasing was commanding; 51 of its 67 counties regularly leased convicts serving for misdemeanors at a rate of about $5–20 per month, equal to about $160–500 in 2015. Although the influence of labor unions forced some states to move away from the profitable convict lease agreements and run traditional prisons, plenty of companies began substituting convict labor in their operations in the twentieth century. "The biggest user of forced labor in Alabama at the turn of the century was Tennessee Coal, Iron & Railroad Co., [of] U.S. Steel" | 0 | Metallurgy |
The beginning of the 1970s saw the first investigations of the effects of pulsed laser irradiation within the target material. L. I. Mirkin observed twinning in ferrite grains in steel under the crater created by laser irradiation in vacuum. S. A. Metz and F. A. Smidt, Jr. irradiated nickel and vanadium foils in air with a pulsed laser at a low power density and observed voids and vacancy loops after annealing the foils, suggesting that a high concentration of vacancies was created by the stress wave. These vacancies subsequently aggregated during post-iradiation annealing into the observed voids in nickel and dislocation loops in vanadium.
In 1971, researchers at Battelle Memorial Institute in Columbus, Ohio began investigating whether the laser shocking process could improve metal mechanical properties using a high-energy pulsed laser. In 1972, the first documentation of the beneficial effects of laser shocking metals was published, reporting the strengthening of aluminum tensile specimens using a quartz overlay to confine the plasma. Subsequently, the first patent on laser shock peening was granted to Phillip Mallozzi and Barry Fairand in 1974. Research into the effects and possible applications of laser peening continued throughout the 1970s and early 1980s by Allan Clauer, Barry Fairand, and coworkers, supported by funding from the National Science Foundation, NASA, Army Research Office, U.S. Air Force, and internally by Battelle. This research explored the in-material effects in more depth and demonstrated the creation of deep compressive stresses and the accompanying increase in fatigue and fretting fatigue life achieved by laser peening. | 0 | Metallurgy |
The proposed mechanism of how this mRNA secondary structure and the trp leader peptide could regulate transcription of the trp biosynthetic enzymes includes the following.
*RNAP initiates transcription of the trp promoter.
*RNAP pauses at about nucleotide 90 at a secondary structure (?the first one shown above?).
*Ribosomes engage this nascent mRNA and initiate translation of the leader peptide.
**RNAP is then "released" from its pause and continues transcription.
*When RNAP reaches the region of the potential terminator, whether it continues or not is dependent on the position of the ribosome "trailing behind".
**If the ribosome stalls at the tandem Trp codons, waiting for the appropriate tRNA, region 1 is sequestered within the ribosome and thus cannot base pair with region 2. This means that region 2 and 3 become based paired before region 4 can be transcribed. This forces region 4 when it is made to be single stranded, preventing the formation of the region 3/4 terminator structure. Transcription will then continue.
**If the ribosome translates the leader peptide with no hesitation, it then covers a portion of region 2 preventing it from base pairing with region 3. Then when region 4 is transcribed, it forms a stem and loop with region 3 and transcription is terminated, generating a ca. 140 base transcript.
*This mechanism of control measures the amount of available, charged Trp-tRNA.
The location of ribosomes determines which alternate secondary structures form. | 1 | Gene expression + Signal Transduction |
A durable plaster intermediate is often used as a stage toward the production of a bronze sculpture or as a pointing guide for the creation of a carved stone. With the completion of a plaster, the work is more durable (if stored indoors) than a clay original which must be kept moist to avoid cracking. With the low cost plaster at hand, the expensive work of bronze casting or stone carving may be deferred until a patron is found, and as such work is considered to be a technical, rather than artistic process, it may even be deferred beyond the lifetime of the artist.
In waste molding a simple and thin plaster mold, reinforced by sisal or burlap, is cast over the original clay mixture. When cured, it is then removed from the damp clay, incidentally destroying the fine details in undercuts present in the clay, but which are now captured in the mold. The mold may then at any later time (but only once) be used to cast a plaster positive image, identical to the original clay. The surface of this plaster may be further refined and may be painted and waxed to resemble a finished bronze casting. | 0 | Metallurgy |
Plants have many protection mechanisms to cope with stresses from the environment, which include ultraviolet light, cold or hot weather, windy days, and mechanical wounding. There are multiple pathways, but one pathway that plants have been able to develop is a self-defense mechanism by recognize pathogens through pathogen-associated molecular patterns (PAMPs) via cell surface-located pathogen-recognition receptors. These receptors induce intracellular signal pathways within the plant cells, while also resulting in PAMP-triggered immunity. Responses to PAMPs target broadly instead of specifically. This immunity requires downstream components via the MAPK cascade to activate the MAP kinases. The flagellin, a peptide of flg22, triggers a rapid and strong activation of MPK3, MPK4, and MPK6. MPK4 and MPK6 can be activated by harpin proteins. MPK3 and MPK6 are very similar proteins and have a function as regulators in abscission, stomatal development, signaling various abiotic stresses, and defense responses to certain pathogens. Experimentation has proposed that the MAPK module MEKK1-MKK4/MKK5-MPK3/MPK6 may be responsible for flg22 signal transmission. All of the proposed modules appear to be correct expect for MEKK1 because plants with mekk1 mutated have a compromised flg22-triggered activation of MPK4, yet they have normal activation of MPK3 and MPK6. Data has shown that MAPK cascade is composed of MKK4/MKK5 and MPK3/MPK6 in response to fungal pathogens. The observation shows that the activation of MPK3/MPK6 in conditional gain-of-function plants for MKK4/MKK5 or MEKK1/MKKKa is sufficient to induce camalexin, which is a major phytoalexin in Arabidopsis. The stomata are considered to be the entry point for pathogenic invaders because microbial invaders enter the plant at the stomata. A recent study has shown that MAPK cascades play a role in abiotic and biotic stress responses. The main pathways in stomatal development and dynamics are MPK3 and MPK6. During a drought, the stomata closes and is believed to be mediated by the phytohormone, abscisic acid, and involves MKK1, MPK3, and MPK6. Another way of closing the stomata is through a closing process that is called pathogen-induced, which is an innate response from the plant. Campestris (Xcc) excretes a chemical that reverts stomatal closure that was caused by bacteria and abscisic acid (ABA). Most stomata close in the presence of ABA, but some are unresponsive to bacteria. In Arabidopsis Xcc does not revert bacteria-induced or ABA-induced stomatal closure. Scientists are not certain if MAPK cascades are responsible for the signaling, so further investigation is needed for this. | 1 | Gene expression + Signal Transduction |
Hot corrosion can affect gas turbines operating in high salt environments (e.g., near the ocean). Salts, including chlorides and sulfates, are ingested by the turbines and deposited in the hot sections of the engine; other elements present in fuels also form salts, e.g. vanadates. The heat from the engine melts these salts which then can flux the passivating oxide layers on the metal components of the engine, allowing corrosion to occur at an accelerated rate. | 0 | Metallurgy |
The copper-based and NiTi-based shape-memory alloys are considered to be engineering materials. These compositions can be manufactured to almost any shape and size.
The yield strength of shape-memory alloys is lower than that of conventional steel, but some compositions have a higher yield strength than plastic or aluminum. The yield stress for Ni Ti can reach . The high cost of the metal itself and the processing requirements make it difficult and expensive to implement SMAs into a design. As a result, these materials are used in applications where the super elastic properties or the shape-memory effect can be exploited. The most common application is in actuation.
One of the advantages to using shape-memory alloys is the high level of recoverable plastic strain that can be induced. The maximum recoverable strain these materials can hold without permanent damage is up to for some alloys. This compares with a maximum strain for conventional steels. | 0 | Metallurgy |
The last model involves transcriptional regulation by eRNAs at distant chromosomal locations. Through the differential recruitment of protein complexes, eRNAs can affect the transcriptional competency of specific loci. Evf-2 represents a good example of such trans regulatory eRNA as it can induce the expression of Dlx2, which in turn can increase the activity of the Dlx5 and Dlx6 enhancers. Trans-acting eRNAs might also be working in cis, and vice versa. | 1 | Gene expression + Signal Transduction |
The metallothermic reduction of anhydrous rare-earth fluorides to rare-earth metals is also referred to as the Ames process.
The study of rare earths was also advanced during World War II: Synthetic plutonium was believed to be rare-earth-like, it was assumed that knowledge of rare earths would assist in planning for and the study of transuranic elements; ion-exchange methods developed for actinide processing were forerunners to processing methods for rare-earth oxides; methods used for uranium were modified for plutonium, which were subsequently the basis for rare-earth metal preparation. | 0 | Metallurgy |
Shape-memory alloys have different shape-memory effects. The two common effects are one-way SMA and two-way SMA. A schematic of the effects is shown below.
The procedures are very similar: starting from martensite, adding a deformation, heating the sample and cooling it again. | 0 | Metallurgy |
A bloomery consists of a pit or chimney with heat-resistant walls made of earth, clay, or stone. Near the bottom, one or more pipes (made of clay or metal) enter through the side walls. These pipes, called tuyeres, allow air to enter the furnace, either by natural draught or forced with bellows or a trompe. An opening at the bottom of the bloomery may be used to remove the bloom, or the bloomery can be tipped over and the bloom removed from the top.
The first step taken before the bloomery can be used is the preparation of the charcoal and the iron ore. Charcoal is nearly pure carbon, which, when burned, both produces the high temperature needed for the smelting process and provides the carbon monoxide needed for reduction of the metal.
The ore is broken into small pieces and usually roasted in a fire, to make rock-based ores easier to break up, bake out some impurities, and (to a lesser extent) to remove any moisture in the ore. Any large impurities (as silica) in the ore can be removed as it is crushed. The desired particle size depends primarily on which of several ore types may be available, which will also have a relationship to the layout and operation of the furnace, of which a number of regional, historic/traditional forms exist. Natural iron ores can vary considerably in oxide form ( / / ), and importantly in relative iron content. Since slag from previous blooms may have a high iron content, it can also be broken up and may be recycled into the bloomery with the new ore.
In operation, after the bloomery is heated typically with a wood fire, shifting to burning sized charcoal, iron ore and additional charcoal are introduced through the top. Again, traditional methods vary, but normally smaller charges of ore are added at the start of the main smelting sequence, increasing to larger amounts as the smelt progresses. Overall, a typical ratio of total charcoal to ore added is in a roughly one-to-one ratio. Inside the furnace, carbon monoxide from the incomplete combustion of the charcoal reduces the iron oxides in the ore to metallic iron without melting the ore; this allows the bloomery to operate at lower temperatures than the melting temperature of the ore. As the desired product of a bloomery is iron that is easily forgeable, it requires a low carbon content. The temperature and ratio of charcoal to iron ore must be carefully controlled to keep the iron from absorbing too much carbon and thus becoming unforgeable. Cast iron occurs when the iron absorbs 2% to 4% carbon. Because the bloomery is self-fluxing, the addition of limestone is not required to form a slag.
The small particles of iron produced in this way fall to the bottom of the furnace, where they combine with molten slag, often consisting of fayalite, a compound of silicon, oxygen, and iron mixed with other impurities from the ore. The hot liquid slag, running to the bottom of the furnace, cools against the base and lower side walls of the furnace, effectively forming a bowl still containing fluid slag. As the individual iron particles form, they fall into this bowl and sinter together under their own weight, forming a spongy mass referred to as the bloom. Because the bloom is typically porous, and its open spaces can be full of slag, the extracted mass must be beaten with heavy hammers to both compress voids and drive out any molten slag remaining. This process may require several additional heating and compaction cycles, working at high welding temperatures. Iron treated this way is said to be wrought (worked), and the resulting iron, with reduced amounts of slag, is called wrought iron or bar iron. Because of the creation process, individual blooms can often have differing carbon contents between the original top and bottom surfaces, differences that will also be somewhat blended together through the flattening, folding, and hammer-welding sequences. Intentionally producing blooms that are coated in steel (i.e. iron with a higher carbon content) by manipulating the charge of and air flow to the bloomery is also possible.
As the era of modern commercial steelmaking began, the word "bloom" was extended to another sense referring to an intermediate-stage piece of steel, of a size comparable to many traditional iron blooms, that was ready to be further worked into billet. | 0 | Metallurgy |
Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U).
Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), Valine (Val, V). | 1 | Gene expression + Signal Transduction |
In order to get a good quality product, removing the inclusion becomes necessary. Liquid metal filtration through a ceramic medium is an efficient way to clean the metal. Different types of ceramic media are used in-line in foundries, such as ceramic foam filters, porous tube filters, bonded ceramic filters, and deep bed filters. | 0 | Metallurgy |
STAT2 has been shown to interact with:
* CREB-binding protein,
* IFNAR1
* IFNAR2,
* IRF9,
* MED14,
* SMARCA4, and
* STAT1. | 1 | Gene expression + Signal Transduction |
The tandem affinity purification (TAP) method allows the high-throughput identification of proteins interactions. In contrast with the Y2H approach, the accuracy of the method can be compared to those of small-scale experiments (Collins et al., 2007) and the interactions are detected within the correct cellular environment as by co-immunoprecipitation. However, the TAP tag method requires two successive steps of protein purification, and thus can not readily detect transient protein–protein interactions. Recent genome-wide TAP experiments were performed by Krogan et al., 2006, and Gavin et al., 2006, providing updated protein interaction data for yeast organisms.
Chemical crosslinking is often used to "fix" protein interactions in place before trying to isolate/identify interacting proteins. Common crosslinkers for this application include the non-cleavable [NHS-ester] crosslinker, [bis-sulfosuccinimidyl suberate] (BS3); a cleavable version of BS3, [dithiobis(sulfosuccinimidyl propionate)](DTSSP); and the [imidoester] crosslinker [dimethyl dithiobispropionimidate] (DTBP) that is popular for fixing interactions in ChIP assays. | 1 | Gene expression + Signal Transduction |
The adsorption of particles to bubbles is essential to separating the minerals from the slurry, but the minerals must be purified from the additives used in separation, such as the collectors, frothers, and modifiers. The product of the cleaning, or desorption process, is known as the cleaner concentrate.
The detachment of a particle and bubble requires adsorption bond cleavage driven by shear forces. Depending on the flotation cell type, shear forces are applied by a variety of mechanical systems. Among the most common are impellers and mixers. Some systems combine the functionalities of these components by placing them at key locations where they can take part in multiple froth flotation mechanisms. Cleaning cells also take advantage of gravitational forces to improve separation efficiency.
Desorption itself is a chemical phenomenon where compounds are just physically attached to each other without having any chemical bond. | 0 | Metallurgy |
When comparing initiation in eukaryotes to prokaryotes, perhaps one of the first noticeable differences is the use of a larger 80S ribosome. Regulation of this process begins with the supply of methionine by a tRNA anticodon that basepairs AUG. This base pairing comes about by the scanning mechanism that ensues once the small 40S ribosomal subunit binds the 5 untranslated region (UTR) of mRNA. The usage of this scanning mechanism, in opposition to the Shine-Dalgarno sequence that was referenced in prokaryotes, is the ability to regulate translation through upstream RNA secondary structures. This inhibition of initiation through complex RNA structures may be circumvented in some cases by way of internal ribosomal entry sites (IRESs) that localize pre-initiation complexes (PIC) to the start site. In addition to this, the guidance of the PIC to the 5 UTR is coordinated by subunits of the PIC, known as eukaryotic initiation factors (eIFs). When some of these proteins are down-regulated through stresses, translation initiation is reduced by inhibiting cap dependent initiation, the activation of translation by binding eIF4E to the 5' 7-methylguanylate cap. eIF2 is responsible for coordinating the interaction between the Met-tRNA and the P-site of the ribosome. Regulation by phosphorylation of eIF2 is largely associated with the termination of translation initiation. Serine kinases, GCN2, PERK, PKR, and HRI are examples of detection mechanisms for differing cellular stresses that respond by slowing translation through eIF2 phosphorylation. | 1 | Gene expression + Signal Transduction |
Noble metals tend to be highly resistant to oxidation and other forms of corrosion, and this corrosion resistance is often considered to be a defining characteristic. Some exceptions are described below.
Copper is dissolved by nitric acid and aqueous potassium cyanide.
Ruthenium can be dissolved in aqua regia, a highly concentrated mixture of hydrochloric acid and nitric acid, only when in the presence of oxygen, while rhodium must be in a fine pulverized form. Palladium and silver are soluble in nitric acid, while silver's solubility in aqua regia is limited by the formation of silver chloride precipitate.
Rhenium reacts with oxidizing acids, and hydrogen peroxide, and is said to be tarnished by moist air. Osmium and iridium are chemically inert in ambient conditions. Platinum and gold can be dissolved in aqua regia. Mercury reacts with oxidising acids.
In 2010, US researchers discovered that an organic "aqua regia" in the form of a mixture of thionyl chloride SOCl and the organic solvent pyridine CHN achieved "high dissolution rates of noble metals under mild conditions, with the added benefit of being tunable to a specific metal" for example, gold but not palladium or platinum. | 0 | Metallurgy |
Using a glia-conditioned medium to treat glia-free purified rat retinal ganglion microcultures has been shown to significantly increase the number of autapses per neuron compared to a control. This suggests that glia-derived soluble, proteinase K-sensitive factors induce autapse formation in rat retinal ganglion cells. | 1 | Gene expression + Signal Transduction |
Modern steel making in India began with the setting of first blast furnace of India at Kulti in 1870 and production began in 1874, which was set up by Bengal Iron Works. The Ordnance Factory Board established Metal & Steel Factory (MSF) at Calcutta, in 1872 The Tata Iron and Steel Company (TISCO) was established by Dorabji Tata in 1907, as part of his father's conglomerate. By 1939 Tata operated the largest steel plant in the British Empire, and accounted for a significant proportion of the 2 million tons pig iron and 1.13 of steel produced in British India annually. | 0 | Metallurgy |
In genetics, a silencer is a DNA sequence capable of binding transcription regulation factors, called repressors. DNA contains genes and provides the template to produce messenger RNA (mRNA). That mRNA is then translated into proteins. When a repressor protein binds to the silencer region of DNA, RNA polymerase is prevented from transcribing the DNA sequence into RNA. With transcription blocked, the translation of RNA into proteins is impossible. Thus, silencers prevent genes from being expressed as proteins.
RNA polymerase, a DNA-dependent enzyme, transcribes the DNA sequences, called nucleotides, in the 3 to 5 direction while the complementary RNA is synthesized in the 5 to 3 direction. RNA is similar to DNA, except that RNA contains uracil, instead of thymine, which forms a base pair with adenine. An important region for the activity of gene repression and expression found in RNA is the 3 untranslated region. This is a region on the 3 terminus of RNA that will not be translated to protein but includes many regulatory regions.
Not much is yet known about silencers but scientists continue to study in hopes to classify more types, locations in the genome, and diseases associated with silencers. | 1 | Gene expression + Signal Transduction |
The International Deep Drawing Research Group ([http://www.iddrg.com IDDRG]) focuses on sheet metal research in industry and academia. It was started 1957 as an organization of national groups. The original focus was on the fabrication of cups hence the name Deep Drawing Research Group. At the initial meeting the purpose was enlarged to do cooperative research on tests, materials, and processes. Such work included for example, methods for determining the strain hardening exponent n, the anisotropy-values (lankford coefficient), as well as other tests for sheet metal formability and, later, forming limit diagrams.
Starting in 1960, a schedule was established for working group meetings every year with open Congresses in every second, even numbered years. The working group meetings were closed sessions made up of delegations from the National Groups that comprised the IDDRG. The reason for these closed sessions was to allow experts to informally review critical issues related to materials, tests, and processes.
As some of the initial technical issues were resolved, the working groups became progressively more informal, and over the years became mini conferences. By 1998, it had become obvious that the former format of the IDDRG has to be changed. This evolution took time, but starting in 2003, the meeting schedule shifted to yearly Conferences with both regular papers and poster presentations that are included in conference proceedings. | 0 | Metallurgy |
The tool has a crucial part to creation of the final product. The tool consists of two main functions:
# Localized heating
# Material flow
The tool at its most simplest form consist of a shoulder, a small cylinder with a diameter of 50 mm, and a pin, a small threaded cylinder similar to a drill. The tool itself has been modified to reduce displaced volume of the metals as they merged. Recently two new pin geometries have arisen:
# Flared-Triflute – introducing flutes (large carving vertically on the pin)
#A-skew – the pin axis being inclined to the axis of the spindle. | 0 | Metallurgy |
Different types of heterotrimeric G proteins share a common mechanism. They are activated in response to a conformational change in the GPCR, exchanging GDP for GTP, and dissociating in order to activate other proteins in a particular signal transduction pathway. The specific mechanisms, however, differ between protein types. | 1 | Gene expression + Signal Transduction |
Many coactivators also function as corepressors under certain circumstances. Cofactors such as TAF1 and BTAF1 can initiate transcription in the presence of an activator (act as a coactivator) and repress basal transcription in the absence of an activator (act as a corepressor). | 1 | Gene expression + Signal Transduction |
Faced with competition from cheaper British iron production, the Swedish iron industry needed to find a new cheaper method of making iron. In the 1810s, experiments were made with puddling, but this proved unsatisfactory, as it needed coal of which Sweden had none. After visited Britain, he published a report of his observations. He had seen closed finery hearths in south Wales and near Ulverston, then in Lancashire (now Cumbria). Those in south Wales were similar to puddling furnaces, but in Lancashire, he saw closed furnaces, where the metal was in contact with the fuel. On his return to Sweden, Ekman experimented and built furnaces similar to what he had seen near Ulverston, most probably at Newland ironworks.
In 1829-30, Waern installed a furnace of the south Wales type at Backefors ironworks, while independently Ekman built Lancashire hearths at Dormsjö and Söderfors. From there the process spread to other forges. Charcoal consumption by the metallurgical industry in Sweden peaked about 1885. In 1887, 406 hearths made 210,500 tons of iron. The last Lancashire forge in Sweden was at Ramnäs, closed in 1964.
In Shropshire, charcoal iron production continued on a significant scale, but declined after 1870, rods for wire-drawing being a significant product. However most charcoal forges were probably closed by 1890. | 0 | Metallurgy |
In prokaryotes, structural genes of related function are typically adjacent to one another on a single strand of DNA, forming an operon. This permits simpler regulation of gene expression, as a single regulatory factor can affect transcription of all associated genes. This is best illustrated by the well-studied lac operon, in which three structural genes (lacZ, lacY, and lacA) are all regulated by a single promoter and a single operator. Prokaryotic structural genes are transcribed into a polycistronic mRNA and subsequently translated.
In eukaryotes, structural genes are not sequentially placed. Each gene is instead composed of coding exons and interspersed non-coding introns. Regulatory sequences are typically found in non-coding regions upstream and downstream from the gene. Structural gene mRNAs must be spliced prior to translation to remove intronic sequences. This in turn lends itself to the eukaryotic phenomenon of alternative splicing, in which a single mRNA from a single structural gene can produce several different proteins based on which exons are included. Despite the complexity of this process, it is estimated that up to 94% of human genes are spliced in some way. Furthermore, different splicing patterns occur in different tissue types.
An exception to this layout in eukaryotes are genes for histone proteins, which lack introns entirely. Also distinct are the rDNA clusters of structural genes, in which 28S, 5.8S, and 18S sequences are adjacent, separated by short internally transcribed spacers, and likewise the 45S rDNA occurs five distinct places on the genome, but is clustered into adjacent repeats. In eubacteria these genes are organized into operons. However, in archaebacteria these genes are non-adjacent and exhibit no linkage. | 1 | Gene expression + Signal Transduction |
This book describes smelting, which Agricola describes as perfecting the metal by fire. The design of furnaces is first explained.
These are very similar for smelting different metals, constructed of brick or soft stone with a brick front and mechanically driven bellows at the rear. At the front is a pit called the fore-hearth to receive the metal. The furnace is charged with beneficiated ore and crushed charcoal and lit. In some gold and silver smelting a lot of slag is produced because of the relative poverty of the ore and the tap hole has to be opened at various times to remove different slag materials. When the furnace is ready, the forehearth is filled with molten lead into which the furnace is tapped. In other furnaces the smelting can be continuous, and lead is placed into the furnace if there is none in the ore. The slag is skimmed off the top of the metal as it is tapped. The lead containing the gold is separated by cupellation, the metal rich slags are re-smelted. Other smelting processes are similar, but lead is not added. Agricola also describes making crucible steel and distilling mercury and bismuth in this book. | 0 | Metallurgy |
eRNAs are transcribed from DNA sequences upstream and downstream of extragenic enhancer regions. Previously, several model enhancers have demonstrated the capability to directly recruit RNA Pol II and general transcription factors and form the pre-initiation complex (PIC) prior to the transcription start site at the promoter of genes. In certain cell types, activated enhancers have demonstrated the ability to both recruit RNA Pol II and also provide a template for active transcription of their local sequences.
Depending on the directionality of transcription, enhancer regions generate two different types of non-coding transcripts, 1D-eRNAs and 2D-eRNAs. The nature of the pre-initiation complex and specific transcription factors recruited to the enhancer may control the type of eRNAs generated. After transcription, the majority of eRNAs remain in the nucleus. In general, eRNAs are very unstable and actively degraded by the nuclear exosome. Not all enhancers are transcribed, with non-transcribed enhancers greatly outnumbering the transcribed ones in the order of magnitude of dozens of thousands in every given cell type. | 1 | Gene expression + Signal Transduction |
Three successive generations of the same family all bearing the name Abraham Darby are renowned for their contributions to the development of the English iron industry. Their works at Coalbrookdale in Shropshire nurtured the start of improvements in metallurgy that allowed large-scale production of the iron that made the development of steam engines and railways possible, although their most notable innovation was The Iron Bridge. | 0 | Metallurgy |
ADP-ribosylation can affect gene expression at nearly every level of regulation, including chromatin organization, transcription factor recruitment and binding, and mRNA processing.
The organization of nucleosomes is key to regulation of gene expression: the spacing and organization of nucleosomes changes what regions of DNA are available for transcription machinery to bind and transcribe DNA. PARP1, a poly-ADP ribose polymerase, has been shown to affect chromatin structure and promote changes in the organization of nucleosomes through modification of histones.
PARPs have been shown to affect transcription factor structure and cause recruitment of many transcription factors to form complexes at DNA and elicit transcription. Mono(ADP-ribosyl)transferases are also shown to affect transcription factor binding at promoters. For example, PARP14, a mono (ADP-ribosyl)transferase, has been shown to affect STAT transcription factor binding.
Other (ADP-ribosyl)transferases have been shown to modify proteins that bind mRNA, which can cause silencing of that gene transcript. | 1 | Gene expression + Signal Transduction |
The majority of eukaryotic genes are transcribed by RNA polymerase II, proceeding in the 5 to 3 direction. In eukaryotes, specific subunits within the RNA polymerase II complex allow it to carry out multiple functions. General transcription factors help binding RNA polymerase II to DNA. Promoters are cites where RNA polymerase II binds to start transcription and, in eukaryotes, transcription starting point is positioned at +1 nucleotide. Like all RNA polymerases, it travels along the template DNA, in the 3 to 5 direction and synthesizes a new RNA strand in the 5 to 3 direction, by adding new bases to the 3' end of the new RNA. A transcription bubble occurs as a result of the double stranded DNA unwinding. After about 25 base pairs of the DNA double strand are unwound, RNA synthesis takes place within the transcription bubble region. Supercoiling is also part of this process since DNA regions in front of the RNA polymerase II are unwinding, while DNA regions behind it are rewinding, forming a double helix again.
The RNA polymerase carries out the majority of the steps during the transcription cycle, especially in maintaining the transcription bubble open for the complementary base pairing. There are some steps of the transcription cycle that require more proteins, such as the Rpb4/7 complex and the RNA polymerase attached to the elongation factor transcription factor IIS (TFIIS). | 1 | Gene expression + Signal Transduction |
Methods of MAE detection are based on the difference between alleles, which can be distinguished either by the sequence of expressed mRNA or protein structure. Methods of MAE detection can be divided into single gene or whole genome MAE analysis. Whole genome MAE analysis cannot be performed based on protein structure yet, so these are completely NGS based techniques.
Single-gene analysis
Genome-wide analysis | 1 | Gene expression + Signal Transduction |
Depletion gilding is a decorative process, with no significant industrial applications. It is not widely used in modern times, having been superseded by processes more suited to mass production, such as electroplating. Some individual artisans and small shops continue to practice it.
However, depletion gilding was widely used in antiquity. While it requires skill to execute it well, the process itself is technologically simple, and uses materials that are readily available to most ancient civilizations. Some form of depletion gilding has been used by nearly every culture that developed metalworking. The South American Sican culture in particular developed depletion gilding to a high art. Some ancient alloys, such as tumbaga, may have been developed specifically for use in depletion gilding. The technique was not known to be used by Anglo-Saxons until detailed examination with electron microscopes of treasures such as the Staffordshire Hoard revealed its use in the twenty-first century.
Certain cultures are thought to have attached mythical or spiritual significance to the process. Gold was considered sacred in many early civilizations and was highly valued in nearly all of them, and anything relating to it had the potential to take on cultural importance. Moreover, the ability to turn what appeared to be an object made of copper into what seemed to be pure gold would be very impressive. There is some speculation that depletion gilding may have contributed to the concepts of alchemy, a major goal of which was to physically transform one metal into another. | 0 | Metallurgy |
* Ciliata: Oxytricha and Stylonychia, Paramecium, Tetrahymena, Oxytrichidae and probably Glaucoma chattoni.
* Dasycladaceae: Acetabularia, and Batophora.
* Diplomonadida: Hexamita inflata, Diplomonadida ATCC50330, and ATCC50380. | 1 | Gene expression + Signal Transduction |
In 1960 Almin was bought by Imperial Aluminium Company (Impalco), a company formed between the Aluminium Company of America (Alcoa) and Imperial Chemical Industries (ICI) which incorporated the whole of ICIs aluminium facilities. Impalcos primary interest in buying Almin was to acquire the facilities of International Alloys, a member of the Almin group. Thus Fulmer was acquired incidentally and it did not fit easily into the Impalco group. Since Impalco had huge research facilities in-house, it had no need of Fulmers services. Impalcos rival companies were also reluctant to place large contracts with Fulmer under this ownership. | 0 | Metallurgy |
Since cyclic AMP is a second messenger and plays vital role in cell signalling, it has been implicated in various disorders but not restricted to the roles given below: | 1 | Gene expression + Signal Transduction |
STAT5 has been found to be constitutively phosphorylated in cancer cells, implying that the protein is always present in its active form. This constant activation is brought about either by mutations or by aberrant expressions of cell signalling, resulting in poor regulation, or complete lack of control, of the activation of transcription for genes influenced by STAT5. This leads to constant and increased expression of these genes. For example, mutations may lead to increased expression of anti-apoptotic genes, the products of which actively prevent cell death. The constant presence of these products preserves the cell in spite of it having become cancerous, causing the cell to eventually become malignant. | 1 | Gene expression + Signal Transduction |
In the early to mid-1850s, the American inventor William Kelly experimented with a method similar to the Bessemer process. Wagner
writes that Kelly may have been inspired by techniques introduced by Chinese ironworkers hired by Kelly in 1854. The claim that both Kelly and Bessemer invented the same process remains controversial. When Bessemers patent for the process was reported by Scientific American, Kelly responded by writing a letter to the magazine. In the letter, Kelly states that he had previously experimented with the process and claimed that Bessemer knew of Kellys discovery. He wrote that "I have reason to believe my discovery was known in England three or four years ago, as a number of English puddlers visited this place to see my new process. Several of them have since returned to England and may have spoken of my invention there." It is suggested Kellys process was less developed and less successful than Bessemers process.
Sir Henry Bessemer described the origin of his invention in his autobiography written in 1890. During the outbreak of the Crimean War, many English industrialists and inventors became interested in military technology. According to Bessemer, his invention was inspired by a conversation with Napoleon III in 1854 pertaining to the steel required for better artillery. Bessemer claimed that it "was the spark which kindled one of the greatest revolutions that the present century had to record, for during my solitary ride in a cab that night from Vincennes to Paris, I made up my mind to try what I could to improve the quality of iron in the manufacture of guns." At the time, steel was used to make only small items like cutlery and tools, but was too expensive for cannons. Starting in January 1855, he began working on a way to produce steel in the massive quantities required for artillery and by October he filed his first patent related to the Bessemer process. He patented the method a year later in 1856. William Kelley was awarded priority patent in 1857.
Bessemer licensed the patent for his process to four ironmasters, for a total of £27,000, but the licensees failed to produce the quality of steel he had promised—it was "rotten hot and rotten cold", according to his friend, William Clay—and he later bought them back for £32,500. His plan had been to offer the licenses to one company in each of several geographic areas, at a royalty price per ton that included a lower rate on a proportion of their output in order to encourage production, but not so large a proportion that they might decide to reduce their selling prices. By this method he hoped to cause the new process to gain in standing and market share.
He realised that the technical problem was due to impurities in the iron and concluded that the solution lay in knowing when to turn off the flow of air in his process so that the impurities were burned off but just the right amount of carbon remained. However, despite spending tens of thousands of pounds on experiments, he could not find the answer. Certain grades of steel are sensitive to the 78% nitrogen which was part of the air blast passing through the steel.
The solution was first discovered by English metallurgist Robert Forester Mushet, who had carried out thousands of experiments in the Forest of Dean. His method was to first burn off, as far as possible, all the impurities and carbon, then reintroduce carbon and manganese by adding an exact amount of spiegeleisen, an alloy of iron and manganese with trace amounts of carbon and silicon. This had the effect of improving the quality of the finished product, increasing its malleability—its ability to withstand rolling and forging at high temperatures and making it more suitable for a vast array of uses. Mushets patent ultimately lapsed due to Mushets inability to pay the patent fees and was acquired by Bessemer. Bessemer earned over 5 million dollars in royalties from the patents.
The first company to license the process was the Manchester firm of W & J Galloway, and they did so before Bessemer announced it at Cheltenham in 1856. They are not included in his list of the four to whom he refunded the license fees. However, they subsequently rescinded their license in 1858 in return for the opportunity to invest in a partnership with Bessemer and others. This partnership began to manufacture steel in Sheffield from 1858, initially using imported charcoal pig iron from Sweden. This was the first commercial production.
A 20% share in the Bessemer patent was also purchased for use in Sweden and Norway by Swedish trader and Consul Göran Fredrik Göransson during a visit to London in 1857. During the first half of 1858, Göransson, together with a small group of engineers, experimented with the Bessemer process at Edsken near Hofors, Sweden before he finally succeeded. Later in 1858 he again met with Henry Bessemer in London, managed to convince him of his success with the process, and negotiated the right to sell his steel in England. Production continued in Edsken, but it was far too small for the industrial-scale production needed. In 1862 Göransson built a new factory for his Högbo Iron and Steel Works company on the shore of Lake Storsjön, where the town of Sandviken was founded. The company was renamed Sandviken's Ironworks, continued to grow and eventually became Sandvik in the 1970s. | 0 | Metallurgy |
Chakrabarti (1976) has identified six early iron-using centres in India: Baluchistan, the Northwest, the Indo-Gangetic divide and the upper Gangetic valley, eastern India, Malwa and Berar in central India and the megalithic south India. The central Indian region seems to be the earliest iron-using centre.
According to Tewari, iron using and iron "was prevalent in the Central Ganga Plain and the Eastern Vindhyas from the early 2nd millennium BC."
The earliest evidence for smelted iron in India dates to 1300 to 1000 BCE. These early findings also occur in places like the Deccan and the earliest evidence for smelted iron occurs in Central India, not in north-western India. Moreover, the dates for iron in India are not later than in those of Central Asia, and according to some scholars (e.g. Koshelenko 1986) the dates for smelted iron may actually be earlier in India than in Central Asia and Iran. The Iron Age did however not necessary imply a major social transformation, and Gregory Possehl wrote that "the Iron Age is more of a continuation of the past then a break with it".
Archaeological data suggests that India was "an independent and early centre of iron technology." According to Shaffer, the "nature and context of the iron objects involved [of the BRW culture] are very different from early iron objects found in Southwest Asia." In Central Asia, the development of iron technology was not necessarily connected with Indo-Iranian migrations either.
J.M. Kenoyer (1995) also remarks that there is a "long break in tin acquisition" necessary for the production of "tin bronzes" in the Indus Valley region, suggesting a lack of contact with Baluchistan and northern Afghanistan, or the lack of migrants from the north-west who could have procured tin. | 0 | Metallurgy |
The proopiomelanocortin gene (POMC) is expressed in the hypothalamus, in the pituitary gland. It yields a range of biologically active peptides and hormones and undergoes tissue-specific posttranslational processing to yield a range of biologically active peptides producing adrenocorticotropic hormone (ACTH), b-endorphin, and a-, b- and c-melanocyte-stimulating hormone (MSH). These peptides then interact with different melanocortin receptors (MCRs) and are involved in a wide range of processes including the regulation of body weight (MC3R and MC4R), adrenal steroidogenesis (MC2R) and hair pigmentation (MC1R). Published in the British Associations of Dermatologists in 2012, Lack of red hair phenotype in a North-African obese child homozygous for a novel POMC null mutation showed nonsense-mediated decay RNA evaluation in a hair pigment chemical analysis. They found that inactivating the POMC gene mutation results in obesity, adrenal insufficiency, and red hair. This has been seen in both in humans and mice. In this experiment they described a 3-year-old boy from Rome, Italy. He was a source of focus because he had Addison's disease and early onset obesity. They collected his DNA and amplified it using PCR. Sequencing analysis revealed a homozygous single substitution determining a stop codon. This caused an aberrant protein and the corresponding amino acid sequence indicated the exact position of the homozygous nucleotide. The substitution was localized in exon 3 and nonsense mutation at codon 68. The results from this experiment strongly suggest that the absence of red hair in non-European patients with early onset obesity and hormone deficiency does not exclude the occurrence of POMC mutations. By sequencing the patients DNA they found that this novel mutation has a collection of symptoms because of a malfunctioning nonsense-mediated mRNA decay surveillance pathway. | 1 | Gene expression + Signal Transduction |
Index inducer or just inducer predictably induce metabolism via a given pathway and are commonly used in prospective clinical drug-drug interaction studies.
Strong, moderate, and weak inducers are drugs that decreases the AUC of sensitive index substrates of a given metabolic pathway by ≥80%, ≥50% to <80%, and ≥20% to <50%, respectively. | 1 | Gene expression + Signal Transduction |
A disintegrin and metalloprotease 17 (ADAM17), also called TACE (tumor necrosis factor-α-converting enzyme), is a 70-kDa enzyme that belongs to the ADAM protein family of disintegrins and metalloproteases, activated by substrate presentation. | 1 | Gene expression + Signal Transduction |
During the synthesis of proteins, polypeptide chains, which are created by ribosomes translating mRNA, must be processed before assuming a mature conformation. The dephosphorylation of proteins is a mechanism for modifying behavior of a protein, often by activating or inactivating an enzyme. Components of the protein synthesis apparatus also undergo phosphorylation and dephosphorylation and thus regulate the rates of protein synthesis.
As part of posttranslational modifications, phosphate groups may be removed from serine, threonine, or tyrosine. As such, pathways of intracellular signal transduction depend on sequential phosphorylation and dephosphorylation of a wide variety of proteins. | 1 | Gene expression + Signal Transduction |
To be effective on a given ore slurry, the collectors are chosen based upon their selective wetting of the types of particles to be separated. A good collector will adsorb, physically or chemically, with one of the types of particles. The wetting activity of a surfactant on a particle can in principle be quantified by measuring the contact angles of the liquid/bubble interface. Another important measure for attachment of bubbles to particles is induction time, the time required for the particle and bubble to rupture the thin film separating the particle and bubble. This rupturing is achieved by the surface forces between the particle and bubble.
The mechanisms for the bubble-particle attachment is complex but is viewed as consisting of three steps: collision, attachment, and detachment. The collision is achieved by particles being within the collision tube of a bubble and this is affected by the velocity of the bubble and radius of the bubble. The collision tube corresponds to the region in which a particle will collide with the bubble, with the perimeter of the collision tube corresponding to the grazing trajectory.
The attachment of the particle to the bubble is controlled by the induction time of the particle and bubble. The particle and bubble need to bind and this occurs if the time in which the particle and bubble are in contact with each other is larger than the required induction time. This induction time is affected by the fluid viscosity, particle and bubble size and the forces between the particle and bubbles.
The detachment of a particle and bubble occurs when the force exerted by the surface tension is exceeded by shear forces and gravitational forces. These forces are complex and vary within the cell. High shear will be experienced close to the impeller of a mechanical flotation cell and mostly gravitational force in the collection and cleaning zone of a flotation column.
Significant issues of entrainment of fine particles occurs as these particles experience low collision efficiencies as well as sliming and degradation of the particle surfaces. Coarse particles show a low recovery of the valuable mineral due to the low liberation and high detachment efficiencies. | 0 | Metallurgy |
Silverquant is a labeling and detection method for DNA microarrays or protein microarrays. A synonym is <colorimetric> detection.
In contrast to the classical signal detection on microarrays by using fluorescence, the colorimetric detection is more sensitive and ozone-stable. | 1 | Gene expression + Signal Transduction |
The first description of what would come to be called paramutation was given by William Bateson and Caroline Pellew in 1915, when they described "rogue" peas that always passed their "rogue" phenotype onto their progeny. However, the first formal description of paramutation was given by R.A. Brink at the University of Wisconsin–Madison in the 1950s, who did his work in maize (Zea mays). Brink noticed that specific weakly expressed alleles of the red1 (r1) locus in maize, which encodes a transcription factor that confers red pigment to corn kernels, can heritably change specific strongly expressed alleles to a weaker expression state. The weaker expression state adopted by the changed allele is heritable and can, in turn, change the expression state of other active alleles in a process termed secondary paramutation. Brink showed that the influence of the paramutagenic allele could persist for many generations. | 1 | Gene expression + Signal Transduction |
Corrosion loop(s) are systematized analysis "loops" used during Risk-based inspection analysis.
Both terms “RBI Corrosion loops” or “RBI corrosion circuits” are generic terms used to indicate the systematization of piping systems into usable and understandable parts associated with corrosion.
Systematized piping loops or circuits are systems used in Risk Based Inspection analysis to assess the likelihood and consequence of failure.
Other systematization may also prove useful, such as, i.e. inspection, consequence, materials of construction and chemistry.
The system (or sub systems) maybe used to identify, pressure / temperature, subsequent failure mechanism and possible failure rate.
They may be based upon Construction drawings, Process Flow diagrams or Piping & Instrument diagrams as required. Each loop or circuit maybe identified using a unique code, with description about; process, material & degradation mode, material, cladding, C.A, specs.
See system model comes under the general heading of system analysis the terms analysis and synthesis come from Greek where they mean respectively "to take apart" and "to put together". See also systems theory:
Note the exact definition of the systematized risk analysis " loop" is left to the reader and their requirements of the system analysis required, however to ensure consistency and that the expected results is produced, this should be defined before they are constructed.
It is suggested that a “true” corrosion loop should be a grouping were the degradation mechanism is "likely" to be the same i.e.
*Material of Construction,
*Process fluid (similar stream properties),
*Temperature (roughly, or at least within the damage mechanisms susceptibility thresholds),
*Pressure (if the damage mechanism/s of concern is/are reliant upon pressure), and
*Velocity (again (if the damage mechanism of concern is reliant upon velocity).
By defining the barrier limits of Damage Susceptible Areas, the susceptibility of any part is similar to that of the whole. | 0 | Metallurgy |
Insulators have two main functions:
# Enhancer-blocking insulators prevent distal enhancers from acting on the promoter of neighbouring genes
# Barrier insulators prevent silencing of euchromatin by the spread of neighbouring heterochromatin
While enhancer-blocking is classified as an inter-chromosomal interaction, acting as a barrier is classified as an intra-chromosomal interaction. The need for insulators arises where two adjacent genes on a chromosome have very different transcription patterns; it is critical that the inducing or repressing mechanisms of one do not interfere with the neighbouring gene. Insulators have also been found to cluster at the boundaries of topologically associating domains (TADs) and may have a role in partitioning the genome into "chromosome neighborhoods" - genomic regions within which regulation occurs.
Some insulators can act as both enhancer blocker and barriers, and some just have one of the two functions. Some examples of different insulators are:
* Drosophila melanogaster insulators gypsy and scs scs are both enhancer-blocking insulators
* Gallus gallus have insulators, Lys 5 A that have both enhancer-blocking and barrier activity, as well as HS4' that have only enhancer-blocking activity
* Saccharomyces cerevisiae insulators STAR and UAS are both barrier insulators
* Homo sapiens HS5 insulator acts as an enhancer-blocker | 1 | Gene expression + Signal Transduction |
Myogenin has been shown to interact with:
* MDFI,
* POLR2C,
* Serum response factor
* Sp1 transcription factor, and
* TCF3. | 1 | Gene expression + Signal Transduction |
As compared to sodium-based liquid metal coolants such as liquid sodium or NaK, lead-based coolants have significantly higher boiling points, meaning a reactor can be operated without risk of coolant boiling at much higher temperatures. This improves thermal efficiency and could potentially allow hydrogen production through thermochemical processes.
Lead and LBE also do not react readily with water or air, in contrast to sodium and NaK which ignite spontaneously in air and react explosively with water. This means that lead- or LBE-cooled reactors, unlike sodium-cooled designs, would not need an intermediate coolant loop, which reduces the capital investment required for a plant.
Both lead and bismuth are also an excellent radiation shield, absorbing gamma radiation while simultaneously being virtually transparent to neutrons. In contrast, sodium forms the potent gamma emitter sodium-24 (half-life 15 hours) following intense neutron radiation, requiring a large radiation shield for the primary cooling loop.
As heavy nuclei, lead and bismuth can be used as spallation targets for non-fission neutron production, as in accelerator transmutation of waste (see energy amplifier).
Both lead-based and sodium-based coolants have the advantage of relatively high boiling points as compared to water, meaning it is not necessary to pressurise the reactor even at high temperatures. This improves safety as it reduces the probability of a loss of coolant accident (LOCA), and allows for passively safe designs. The thermodynamic cycle (Carnot cycle) is also more efficient with a larger difference of temperature. However, a disadvantage of higher temperatures is also the higher corrosion rate of metallic structural components in LBE due to their increased solubility in liquid LBE with temperature (formation of amalgam) and to liquid metal embrittlement. | 0 | Metallurgy |
Near Eastern development of bronze technology spread across Central Asia by way of the Eurasian Steppes, and with it came the knowledge and technology for tin prospection and extraction. By 2000 to 1500 BC Uzbekistan, Afghanistan, and Tajikistan appear to have exploited their sources of tin, carrying the resources east and west along the Silk Road crossing Central Asia. This trade link likely followed an existing trade route of lapis lazuli, a highly prized semi-precious blue gemstone, and chlorite vessels decorated with turquoise from Central Asia that have been found as far west as Egypt and that date to the same period.
In China, early tin was extracted along the Yellow River in Erlitou and Shang times between 2500 and 1800 BC. By Han and later times, China imported its tin from what is today Yunnan province. This has remained China's main source of tin throughout history and into modern times.
It is unlikely that Southeast Asian tin from Indochina was widely traded around the world in ancient times as the area was only opened up to Indian, Muslim, and European traders around 800 AD.
Indo–Roman trade relations are well known from historical texts such as Plinys Natural History' (book VI, 26), and tin is mentioned as one of the resources being exported from Rome to South Arabia, Somaliland, and India. | 0 | Metallurgy |
Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction:
:ATP = 3′,5′-cyclic AMP + diphosphate
It has key regulatory roles in essentially all cells. It is the most polyphyletic known enzyme: six distinct classes have been described, all catalyzing the same reaction but representing unrelated gene families with no known sequence or structural homology. The best known class of adenylyl cyclases is class III or AC-III (Roman numerals are used for classes). AC-III occurs widely in eukaryotes and has important roles in many human tissues.
All classes of adenylyl cyclase catalyse the conversion of adenosine triphosphate (ATP) to 3,5-cyclic AMP (cAMP) and pyrophosphate. Magnesium ions are generally required and appear to be closely involved in the enzymatic mechanism. The cAMP produced by AC then serves as a regulatory signal via specific cAMP-binding proteins, either transcription factors, enzymes (e.g., cAMP-dependent kinases), or ion transporters. | 1 | Gene expression + Signal Transduction |
Some histidine kinases are hybrids that contain an internal receiver domain. In these cases, a hybrid HK autophosphorylates and then transfers the phosphoryl group to its own internal receiver domain, rather than to a separate RR protein. The phosphoryl group is then shuttled to histidine phosphotransferase (HPT) and subsequently to a terminal RR, which can evoke the desired response. This system is called a phosphorelay. Almost 25% of bacterial HKs are of the hybrid type, as are the large majority of eukaryotic HKs. | 1 | Gene expression + Signal Transduction |
Georg Jacob Tysland (13 February 1890 – 14 February 1932) was a Norwegian engineer and metallurgist. Tysland is known as the originator of a successful electric smelting furnace for the production of pig iron, a semi-finished product for the production of steel. | 0 | Metallurgy |
The 5′ untranslated region (also known as 5′ UTR, leader sequence, transcript leader, or leader RNA) is the region of a messenger RNA (mRNA) that is directly upstream from the initiation codon. This region is important for the regulation of translation of a transcript by differing mechanisms in viruses, prokaryotes and eukaryotes. While called untranslated, the 5′ UTR or a portion of it is sometimes translated into a protein product. This product can then regulate the translation of the main coding sequence of the mRNA. In many organisms, however, the 5′ UTR is completely untranslated, instead forming a complex secondary structure to regulate translation.
The 5′ UTR has been found to interact with proteins relating to metabolism, and within the 5′ UTR. In addition, this region has been involved in transcription regulation, such as the sex-lethal gene in Drosophila. Regulatory elements within 5′ UTRs have also been linked to mRNA export. | 1 | Gene expression + Signal Transduction |
The analysis of slag is based on its shape, texture, isotopic signature, chemical and mineralogical characteristics. Analytical tools like Optical Microscope, scanning electron microscope (SEM), X-ray Fluorescence (XRF), X-ray diffraction (XRD) and inductively coupled plasma-mass spectrometry (ICP-MS) are widely employed in the study of slag. | 0 | Metallurgy |
The vertebrate mitochondrial code (translation table 2) is the genetic code found in the mitochondria of all vertebrata. | 1 | Gene expression + Signal Transduction |
Drugs have long been considered crucial targets for transmitter-gated ion channels. The majority of medications utilized to treat schizophrenia, anxiety, depression, and sleeplessness work at chemical synapses, and many of these pharmaceuticals function by binding to transmitter-gated channels. For instance, some drugs like barbiturates and tranquilizers bind to GABA receptors and enhance the inhibitory effect of GABA neurotransmitter. Thus, reduced concentration of GABA enables the opening of Cl- channels.
Furthermore, psychoactive drugs could potentially target many other synaptic signalling machinery components. In fact, numerous neurotransmitters are released by Na+-driven carriers and are subsequently removed from the synaptic cleft. By inhibiting such carriers, synaptic transmission is strengthened as the action of the transmitter is prolonged. For example, Prozac is one of antidepressant medications that works by preventing the absorption of serotonin neurotransmitter. Also, other antidepressants operate by inhibiting the reabsorption of both serotonin and norepinephrine. | 1 | Gene expression + Signal Transduction |
The origin is the word lixiviate, meaning to leach or to dissolve out, deriving from the Latin lixivium. A lixiviant assists in rapid and complete leaching, for example during in situ leaching. The metal can be recovered from it in a concentrated form after leaching. | 0 | Metallurgy |
Although all bun ingots share the same basic morphology, the details of their form and the texture of their convex base is dependent on the mould in which they cooled. Bun ingots made in purpose-dug depressions in sand can be highly variable in form even on the same site, whereas ingots cast in reusable moulds will form sets of identical “mould siblings”.
The composition of the metal and its cooling conditions affect structure. As the ingot cools gases are released giving the upper surface a “blistered” texture and if cooling takes place outside of the furnace, the outer surface often becomes oxidised. Casting in a warm mould or reheating furnace gives the ingot an even columnar structure running in the direction of cooling, whereas ingots cast in a cold mould have a distinctive two stage cooling structure with an outer chilled layer reflecting the rapid cooling of the bottom when it came into contact with the mould. A slightly concave upper surface can be produced if the top of the ingot cools more slowly than the bottom. | 0 | Metallurgy |
Protein-RNA interactions may prevent or stabilize the formation of an anti-terminator structure. .. karima eric discovery | 1 | Gene expression + Signal Transduction |
Heap leaching is an industrial mining process used to extract precious metals, copper, uranium, and other compounds from ore using a series of chemical reactions that absorb specific minerals and re-separate them after their division from other earth materials. Similar to in situ mining, heap leach mining differs in that it places ore on a liner, then adds the chemicals via drip systems to the ore, whereas in situ mining lacks these liners and pulls pregnant solution up to obtain the minerals. Heap leaching is widely used in modern large-scale mining operations as it produces the desired concentrates at a lower cost compared to conventional processing methods such as flotation, agitation, and vat leaching.
Additionally, dump leaching is an essential part of most copper mining operations and determines the quality grade of the produced material along with other factors
Due to the profitability that the dump leaching has on the mining process, i.e. it can contribute substantially to the economic viability of the mining process, it is advantageous to include the results of the leaching operation in the economic overall project evaluation.
The process has ancient origins; one of the classical methods for the manufacture of copperas (iron sulfate) was to heap up iron pyrite and collect the leachate from the heap, which was then boiled with iron to produce iron(II) sulfate. | 0 | Metallurgy |
Nickel–cadmium batteries (Ni-Cd) use nickel oxide hydroxide and metallic cadmium electrodes with an electrolyte of potassium hydroxide. Sealed Ni-Cd batteries were widely used in photography equipment, handheld power tools, and radio-controlled toys from the early 1940s until the early 1990s, when nickel–metal hydride batteries supplanted them (like how alkaline batteries replaced zinc–carbon batteries). In personal computers, Ni-Cd batteries first saw use in the mid-1980s as a cheaper alternative to lithium batteries for powering real-time clocks and preserving BIOS settings. Nickel–cadmium batteries were also briefly used in laptop battery packs, until the advent of commercially viable nickel–metal hydride batteries in the early 1990s. Ni-Cd batteries are still used in some uninterruptible power supplies and emergency lighting setups.
Except in aeronautical or other high-risk applications, Ni-Cd batteries are intentionally not hermetically sealed and include pressure vents for safety if the batteries are charged improperly. With age and sufficient thermal cycles the seal will degrade and allow electrolyte to leak through. The leakage usually travels down the positive and/or negative terminals onto any surrounding circuitry (see the top image).
Like with alkaline battery leakage, Ni-Cd leakage can be effectively neutralized with lemon juice or distilled white vinegar. | 0 | Metallurgy |
It has been shown in previous studies that the only types of RNA editing seen in the plants mitochondria and plastids are conversion of C-to-U and U-to-C (very rare). RNA-editing sites are found mainly in the coding regions of mRNA, introns, and other non-translated regions. In fact, RNA editing can restore the functionality of tRNA molecules. The editing sites are found primarily upstream of mitochondrial or plastid RNAs. While the specific positions for C to U RNA editing events have been fairly well studied in both the mitochondrion and plastid, the identity and organization of all proteins comprising the editosome have yet to be established. Members of the expansive PPR protein family have been shown to function as trans'-acting factors for RNA sequence recognition. Specific members of the MORF (Multiple Organellar RNA editing Factor) family are also required for proper editing at several sites. As some of these MORF proteins have been shown to interact with members of the PPR family, it is possible MORF proteins are components of the editosome complex. An enzyme responsible for the trans- or deamination of the RNA transcript remains elusive, though it has been proposed that the PPR proteins may serve this function as well.
RNA editing is essential for the normal functioning of the plant's translation and respiration activity. Editing can restore the essential base-pairing sequences of tRNAs, restoring functionality. It has also been linked to the production of RNA-edited proteins that are incorporated into the polypeptide complexes of the respiration pathway. Therefore, it is highly probable that polypeptides synthesized from unedited RNAs would not function properly and hinder the activity of both mitochondria and plastids.
C-to-U RNA editing can create start and stop codons, but it cannot destroy existing start and stop codons. A cryptic start codon is created when the codon ACG is edited to be AUG. | 1 | Gene expression + Signal Transduction |
X-chromosome inactivation (XCI), is the most striking and well-studied example of RME. XCI leads to the transcriptional silencing of one of the X chromosomes in female cells, which results in expression of the genes that located on the other, remaining active X chromosome. XCI is critical for balanced gene expression in female mammals. The allelic choice of XCI by individual cells takes place randomly in epiblasts of the preimplantation embryo, which leads to mosaic gene expression of the paternal and maternal X chromosome in female tissues. XCI is a chromosome-wide monoallelic expression, that includes expression of all genes that are located on X chromosome, in contrast to autosomal RME (aRME) that relates to single genes that are interspersed over the genome. aRME's can be fixed or dynamic, depending whether or not the allele-specific expression is conserved in daughter cells after mitotic cell division. | 1 | Gene expression + Signal Transduction |
The excavations at Hammeh are part of the Deir 'Alla Regional Project, a joint undertaking of Yarmouk University in Irbid, Jordan, and Leiden University in the Netherlands, in collaboration with the Jordanian Department of Antiquities.
The site's most intriguing feature is the presence of a substantial and very early iron smelting operation, as evidence by large quantities of slag, technical ceramics, furnace remnants etc. This activity dates to 930 BC.
Fieldwork at Tell Hammeh took place in 1996, 1997, and 2000. The first two (rescue) seasons were directed by Dr E.J. van der Steen; the third season was directed by Dr H.A. Veldhuijzen. A fourth season, planned in 2003, had to be abandoned due to the invasion of Iraq. As with the third season, the focus of new excavation would primarily be on the iron smelting evidence. A new excavation was to start in May 2009. | 0 | Metallurgy |
The 5′ UTR begins at the transcription start site and ends one nucleotide (nt) before the initiation sequence (usually AUG) of the coding region. In prokaryotes, the length of the 5′ UTR tends to be 3–10 nucleotides long, while in eukaryotes it tends to be anywhere from 100 to several thousand nucleotides long. For example, the ste11 transcript in Schizosaccharomyces pombe has a 2273 nucleotide 5′ UTR while the lac operon in Escherichia coli only has seven nucleotides in its 5′ UTR. The differing sizes are likely due to the complexity of the eukaryotic regulation which the 5′ UTR holds as well as the larger pre-initiation complex that must form to begin translation.
The 5′ UTR can also be completely missing, in the case of leaderless mRNAs. Ribosomes of all three domains of life accept and translate such mRNAs. Such sequences are naturally found in all three domains of life. Humans have many pressure-related genes under a 2–3 nucleotide leader. Mammals also have other types of ultra-short leaders like the TISU sequence. | 1 | Gene expression + Signal Transduction |
Zinc is rarely anodized, but a process was developed by the International Lead Zinc Research Organization and covered by MIL-A-81801. A solution of ammonium phosphate, chromate and fluoride with voltages of up to 200 V can produce olive green coatings up to 80 μm thick. The coatings are hard and corrosion resistant.
Zinc or galvanized steel can be anodized at lower voltages (20–30 V) as well as using direct currents from silicate baths containing varying concentration of sodium silicate, sodium hydroxide, borax, sodium nitrite and nickel sulphate. | 0 | Metallurgy |
When a cell is subjected to stressful conditions, the ATF4 gene is expressed. The ATF4 transcription factor has the ability to form dimers with many different proteins that influence gene expression and cell fate. ATF4 binds to C/EBP‐ATF response element (CARE) sequences which work together to increase the transcription of stress-responsive genes. However, when undergoing amino acid starvation, the sequences will act as amino acid response elements instead.
ATF4 will work together with other transcription factors, such as CHOP and ATF3, by forming homodimers or heterodimers, resulting in numerous observed effects. The proteins that ATF4 interacts with determines the outcome of the cell during the integrated stress response. For example, ATF4 and ATF3 work to establish homeostasis inside of the cell following stressful conditions. On the other hand, ATF4 and CHOP work together to induce cell death, as well as regulating amino acid biosynthesis, transport and metabolic processes. The presence of a leucine zipper domain (bZIP) allows ATF4 to work together with many other proteins, thus creating specific responses to different types of stressors. When a cell is undergoing the stress of hypoxia, ATF4 will interact with PHD1 and PHD3 to decrease its transcriptional activity. In addition, when a cell is undergoing amino acid starvation or endoplasmic reticulum stress, TRIP3 also interacts with ATF4 to decrease activity.
One result of ATF4 and stress-response proteins expression is the induction of autophagy. During this process, the cell forms autophagosomes, or double membraned vesicles, that allow for transportation of material throughout the cell. These autophagosomes can carry unneeded organelles and proteins, as well as damaged or harmful components in an attempt by the cell to maintain homeostasis. | 1 | Gene expression + Signal Transduction |
A hydrogen analyzer can be used for direct measurement of hydrogen in liquid aluminium. Direct monitoring of hydrogen is possible using an on-line quantitative measurement technology based on a closed-loop gas recirculation method though a porous ceramic probe.
Since its introduction in 1989, this gas recirculation method has been increasingly used by major aluminum producers.
An example of analyzer for direct hydrogen measurement in liquid aluminium is the Accurity. It works with a probe immersed in liquid aluminium and it uses the closed-loop recirculation method. | 0 | Metallurgy |
DNA printing can thus be used to produce DNA parts, which are defined as sequences of DNA that encode a specific biological function (for example, promoters, transcription regulatory sequences or open reading frames). However, because oligonucleotide synthesis typically cannot accurately produce oligonucleotides sequences longer than a few hundred base pairs, DNA assembly methods have to be employed to assemble these parts together to create functional genes, multi-gene circuits or even entire synthetic chromosomes or genomes. Some DNA assembly techniques only define protocols for joining DNA parts, while other techniques also define the rules for the format of DNA parts that are compatible with them. These processes can be scaled up to enable the assembly of entire chromosomes or genomes. In recent years, there has been proliferation in the number of different DNA assembly standards with 14 different assembly standards developed as of 2015, each with their pros and cons. Overall, the development of DNA assembly standards has greatly facilitated the workflow of synthetic biology, aided the exchange of material between research groups and also allowed for the creation of modular and reusable DNA parts.
The various DNA assembly methods can be classified into three main categories – endonuclease-mediated assembly, site-specific recombination, and long-overlap-based assembly. Each group of methods has its distinct characteristics and their own advantages and limitations. | 1 | Gene expression + Signal Transduction |
The idea that the electrical activity generated by nervous tissue may influence the activity of surrounding nervous tissue is one that dates back to the late 19th century. Early experiments, like those by Emil du Bois-Reymond, demonstrated that the firing of a primary nerve may induce the firing of an adjacent secondary nerve (termed "secondary excitation"). This effect was not quantitatively explored, however, until experiments by Katz and Schmitt in 1940, when the two explored the electric interaction of two adjacent limb nerves of the crab Carcinus maenas. Their work demonstrated that the progression of the action potential in the active axon caused excitability changes in the inactive axon. These changes were attributed to the local currents that form the action potential. For example, the currents that caused the depolarization (excitation) of the active nerve caused a corresponding hyperpolarization (depression) of the adjacent resting fiber. Similarly, the currents that caused repolarization of the active nerve caused slight depolarization in the resting fiber. Katz and Schmitt also observed that stimulation of both nerves could cause interference effects. Simultaneous action potential firing caused interference and resulted in decreased conduction velocity, while slightly offset stimulation resulted in synchronization of the two impulses.
In 1941 Angélique Arvanitaki explored the same topic and proposed the usage of the term "ephapse" (from the Greek and meaning "to touch") to describe this phenomenon and distinguish it from synaptic transmission. Over time the term ephaptic coupling has come to be used not only in cases of electric interaction between adjacent elements, but also more generally to describe the effects induced by any field changes along the cell membrane. | 1 | Gene expression + Signal Transduction |
Knockouts are accomplished through a variety of techniques. Originally, naturally occurring mutations were identified and then gene loss or inactivation had to be established by DNA sequencing or other methods. | 1 | Gene expression + Signal Transduction |
An intermetallic (also called intermetallic compound, intermetallic alloy, ordered intermetallic alloy, long-range-ordered alloy) is a type of metallic alloy that forms an ordered solid-state compound between two or more metallic elements. Intermetallics are generally hard and brittle, with good high-temperature mechanical properties. They can be classified as stoichiometric or nonstoichiometic intermetallic compounds.
Although the term "intermetallic compounds", as it applies to solid phases, has been in use for many years, Hume-Rothery has argued that it gives misleading intuition, suggesting a fixed stoichiometry and even a clear decomposition into species. | 0 | Metallurgy |
Loss-of-function mutations in females can lead to infertility. In 46, XY individuals severe inactivation can cause male pseudohermaphroditism, as fetal Leydig cells during may not respond and thus interfere with masculinization. Less severe inactivation can result in hypospadias or a micropenis. | 1 | Gene expression + Signal Transduction |
SMA have many advantages over traditional actuators, but do suffer from a series of limitations that may impede practical application. In numerous studies, it was emphasised that only a few of patented shape memory alloy applications are commercially successful due to material limitations combined with a lack of material and design knowledge and associated tools, such as improper design approaches and techniques used. The challenges in designing SMA applications are to overcome their limitations, which include a relatively small usable strain, low actuation frequency, low controllability, low accuracy and low energy efficiency. | 0 | Metallurgy |
PNRC1 functions as a coactivator for several nuclear receptors including AR, ERα, ERRα, ERRγ, GR, SF1, PR, TR, RAR and RXR. The interaction between PNRC1 with nuclear receptors occurs through the SH3 domain of PNRC1. | 1 | Gene expression + Signal Transduction |
Although other cells lines, such as African green monkey kidney (COS) and baby hamster kidney (BHK), can be used for recombinant protein production, the most commonly employed host system in transient expression of mammalian cells involves derivatives of the HEK293 cell line, which is based on the human embryonic kidney cell line established in 1977 by Graham et al. The HEK293 cell line was created via transformation with sheared Adenovirus 5 DNA. Advantages of using this cell line include their high rates of transfection and ability to grow in a serum-free medium, which results in reduced cost and lowered risk of contamination with animal-derived material typically found in serum.
Several engineered sublines were later developed by incorporating viral elements derived from mammalian viruses, such as SV40 virus or Epstein–Barr virus (EBV), which are notable for their high retention of plasmid DNA in an episomal state and their capacity to increase transcription and translation via specific viral properties. These later sublines were consequently identified to have two interacting components: the SV40 large T-antigen binding to the SV20 origin of replication (SV40ori) and the EBV-derived nuclear antigen-1 (EBNA-1) protein to its associated origin of replication (oriP).
Typical historical yields of transient expression in HEK293 cells transfected using PEI-25kDa was 20-40 mg/L of recombinant antibody protein. In 2008, Backliwal et. al reported for the first time yields crossing 1 g/L of recombinant antibody protein. | 1 | Gene expression + Signal Transduction |
The role of endoglin plays in angiogenesis and the modulation of TGF beta receptor signaling, which mediates cellular localization, cellular migration, cellular morphology, cell proliferation, cluster formation, etc., makes endoglin an important player in tumor growth and metastasis. Being able to target and efficiently reduce or halt neoangiogenesis in tumors would prevent metastasis of primary cancer cells into other areas of the body. Also, it has been suggested that endoglin can be used for tumor imaging and prognosis.
The role of endoglin in cancer can be contradicting at times since it is needed for neoangiogenesis in tumors, which is needed for tumor growth and survival, yet the reduction in expression of endoglin has in many cancers correlated with a negative outcome of that cancer. In breast cancer, for example, the reduction of the full form of endoglin, and the increase of the soluble form of endoglin correlate with metastasis of cancer cells. The TGF beta receptor-endoglin complex relay contradicting signals from TGF beta as well. TGF beta can act as a tumor suppressor in the premalignant stage of the benign neoplasm by inhibiting its growth and inducing apoptosis. However, once the cancer cells have gone through the Hallmarks of Cancer and lost inhibitory growth responses, TGF beta mediates cell invasion, angiogenesis (with the help of endoglin), immune system evasion, and their ECM composition, allowing them to become malignant. | 1 | Gene expression + Signal Transduction |
* Birch, Alan. Economic History of the British Iron and Steel Industry (Routledge, 2013).
* Burn, D. L. “Recent Trends in the History of the Steel Industry.” Economic History Review, 17#2 1947, pp. 95–102. [https://www.jstor.org/stable/2590552 online].
* Burn, Duncan. The Steel Industry, 1939–1959: A Study in Competition and Planning (1961)
* Burn, Duncan. The Economic History of Steelmaking, 1867–1939: A Study in Competition. Cambridge University Press, 1961
* Carr, J. C. and W. Taplin; History of the British Steel Industry Harvard University Press, 1962
* Tweedale, Geoffrey. Steel City: Entrepreneurship, Strategy, and Technology in Sheffield, 1743–1993. (Oxford U.P. 1995)
* Vaizy, John. The history of British steel (1974), well illustrated
* Warren, Kenneth. British Iron and Sheet Steel Industry since 1840 (1970) Economic geography. | 0 | Metallurgy |
The receptor has a broad tissue distribution but is especially abundant in the cerebellum. Most of the InsP3Rs are found integrated into the endoplasmic reticulum. | 1 | Gene expression + Signal Transduction |
The free-living bioluminescent marine bacterium, Vibrio harveyi, uses another signaling molecule in addition to an acylated homoserine lactone. This molecule, termed Autoinducer-2 (or AI-2), is a furanosyl borate diester. AI-2, which is also produced and used by a number of Gram-negative and Gram-positive bacteria, is believed to be an evolutionary link between the two major types of quorum sensing circuits. | 1 | Gene expression + Signal Transduction |
In true corrosion fatigue, the fatigue-crack-growth rate is enhanced by corrosion; this effect is seen in all three regions of the fatigue-crack growth-rate diagram. The diagram on the left is a schematic of crack-growth rate under true corrosion fatigue; the curve shifts to a lower stress-intensity-factor range in the corrosive environment. The threshold is lower (and the crack-growth velocities higher) at all stress-intensity factors. Specimen fracture occurs when the stress-intensity-factor range is equal to the applicable threshold-stress-intensity factor for stress-corrosion cracking.
When attempting to analyze the effects of corrosion fatigue on crack growth in a particular environment, both corrosion type and fatigue load levels affect crack growth in varying degrees. Common types of corrosion include filiform, pitting, exfoliation, intergranular; each will affect crack growth in a particular material in a distinct way. For instance, pitting will often be the most damaging type of corrosion, degrading a materials performance (by increasing the crack-growth rate) more than any other kind of corrosion; even pits of the order of a materials grain size may substantially degrade a material. The degree to which corrosion affects crack-growth rates also depends on fatigue-load levels; for instance, corrosion can cause a greater increase in crack-growth rates at a low loads than it does at a high load. | 0 | Metallurgy |
Some industrial-level sprays (with teflon or leather needle packing, variable speed agitator in pressure pot, separate air and fluid pressure regulators) can also be used for Dimetcote. | 0 | Metallurgy |
In normal operation, a rolling-element bearing has the rollers and races separated by a thin layer of lubricant such as grease or oil. Although these lubricants normally appear liquid (not solid), under high pressure they act as solids and keep the bearing and race from touching.
If the lubricant is removed, the bearings and races can touch directly. While bearings and races appear smooth to the eye, they are microscopically rough. Thus, high points of each surface can touch, but "valleys" do not. The bearing load is thus spread over much less area increasing the contact stress, causing pieces of each surface to break off or to become pressure-welded then break off when the bearing rolls on.
The broken-off pieces are also called wear debris. Wear debris is bad because it is relatively large compared to the surrounding surface finish and thus creates more regions of high contact stress. Worse, the steel in ordinary bearings can oxidize (rust), producing a more abrasive compound which accelerates wear. | 0 | Metallurgy |
The two major types of austenitic stainless steels are characterized by the oxide layer that forms on the steel surface: either chromia-forming or alumina-forming. Cr-forming stainless steel is the most common type. However, Cr-forming steels do not exhibit high creep resistance at high temperatures, especially in environments with water vapor. Exposure to water vapor at high temperatures can increase internal oxidation in Cr-forming alloys and rapid formation of volatile Cr (oxy)hydroxides, both of which can reduce durability and lifetime.
Al-forming austenitic stainless steels feature a single-phase matrix of austenite iron (FCC) with an Al-oxide at the surface of the steel. Al is more thermodynamically stable in oxygen than Cr. More commonly, however, precipitate phases are introduced to increase strength and creep resistance. In Al-forming steels, NiAl precipitates are introduced to act as Al reservoirs to maintain the protective alumina layer. In addition, Nb and Cr additions help form and stabilize Al by increasing precipitate volume fractions of NiAl.
At least 5 grades of alumina-forming austenitic (AFA) alloys, with different operating temperatures at oxidation in air + 10% water vapor have been realized:
* AFA Grade: (50-60)Fe-(20-25)Ni-(14-15)Cr-(2.5-3.5)Al-(1-3)Nb wt.% base
** 750-800 °C operating temperatures at oxidation in air + 10% water vapor
* Low Nickel AFA Grade: 63Fe-12Ni-14Cr-2.5Al-0.6Nb-5Mn3Cu wt.% base
** 650 °C operating temperatures at oxidation in air + 10% water vapor
* High Performance AFA Grade: (45-55)Fe-(25-30)Ni-(14-15)Cr(3.5-4.5)Al-(1-3)Nb-(0.02-0.1)Hf/Y wt.% base
** 850-900 °C operating temperatures at oxidation in air + 10% water vapor
* Cast AFA Grade: (35-50)Fe-(25-35)Ni-14Cr-(3.5-4)Al-1Nb wt.% base
** 750-1100 °C operating temperatures at oxidation in air + 10% water vapor, depending upon Ni wt.%
* AFA superalloy (40-50)Fe-(30-35)Ni-(14-19)Cr-(2.5-3.5)Al-3Nb
** 750-850 °C operating temperatures at oxidation in air + 10% water vapor
Operating temperatures with oxidation in air and no water vapor are expected to be higher. In addition, an AFA superalloy grade exhibits creep strength approaching that of nickel alloy UNS N06617. | 0 | Metallurgy |