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Arsenic containing concentrates are roasted in a fluidized bed to remove 60% to 70% of the arsenic present as arsenic oxide (AsO). The roasted ores can be treated with hydrochloric acid and chlorine or with sulfuric acid to give a leach solution that can be purified by hydrometallurgical methods and from which cobalt can be recovered by electro refining or by carbonate precipitation. If hydrochloric acid is used then cobalt may be extracted using alamine 336 in meta-xylene. Cobalt can be extracted also using dialkylphosphinic acid. When cobalt carbonate (CoCO) is heated (calcined) above 400 °C it decomposes into carbon dioxide (CO) and cobalt(II) oxide (CoO) and can be refined as an oxide concentrate (see above). | 0 | Metallurgy |
Amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease, is a motor neuron disease that affects the brain and spinal cord. The disease causes motor neurons to degenerate, which eventually leads to neuron death and muscular degeneration. Hundreds of mutations in the Cu/Zn superoxide dismutase (SOD1) gene have been found to cause ALS. Gene silencing has been used to knock down the SOD1 mutant that is characteristic of ALS. In specific, siRNA molecules have been successfully used to target the SOD1 mutant gene and reduce its expression through allele-specific gene silencing. | 1 | Gene expression + Signal Transduction |
From their earliest days both Fulmer and Yarsley Testing Laboratories had carried out a wide variety of tests for clients and had designed and constructed specialized test equipment. In 1982 both Fulmer Technical Services and Yarsley Technical Centre were awarded accreditation from the National Testing Laboratory Accreditation Scheme (NATLAS).
By the late 1970s American and European governments and business leaders had become increasingly concerned about competition from Japan. Many decided to adopt some Japanese industrial practices, including quality management, which was thought to have played a large part in the Japanese economic miracle. Beginning in the early 1980s, the quality standard BS 5750 (1979) became widely adopted by British companies. In 1985, Yarsley Technical Centre, which already had a strong background in standards and accreditation, established Yarsley Quality Assured Firms (YQAF) as an independent certification body, supported by the UK Department of Trade and Industry. YQAF assessed conformity to BS 5750 and certified conforming companies. Its certification service was overseen by an independent Certification Board under an independent chairman, thus ensuring that there was no conflict of interest with YQAF's consultancy services.
YQAF was successful and grew rapidly by establishing a network of regional offices throughout the UK. It was incorporated in 1987 and gained accreditation from the National Accreditation Council for Certification Bodies (NACCB). | 0 | Metallurgy |
Unlike viruses, bacteria are not as susceptible to silencing by siRNA. This is largely due to how bacteria replicate. Bacteria replicate outside of the host cell and do not contain the necessary machinery for RNAi to function. However, bacterial infections can still be suppressed by siRNA by targeting the host genes that are involved in the immune response caused by the infection or by targeting the host genes involved in mediating the entry of bacteria into cells. For instance, siRNA was used to reduce the amount of pro-inflammatory cytokines expressed in the cells of mice treated with lipopolysaccharide (LPS). The reduced expression of the inflammatory cytokine, tumor necrosis factor α (TNFα), in turn, caused a reduction in the septic shock felt by the LPS-treated mice. In addition, siRNA was used to prevent the bacteria, Psueomonas aeruginosa, from invading murine lung epithelial cells by knocking down the caveolin-2 (CAV2) gene. Thus, though bacteria cannot be directly targeted by siRNA mechanisms, they can still be affected by siRNA when the components involved in the bacterial infection are targeted. | 1 | Gene expression + Signal Transduction |
Stop codons were historically given many different names, as they each corresponded to a distinct class of mutants that all behaved in a similar manner. These mutants were first isolated within bacteriophages (T4 and lambda), viruses that infect the bacteria Escherichia coli. Mutations in viral genes weakened their infectious ability, sometimes creating viruses that were able to infect and grow within only certain varieties of E. coli. | 1 | Gene expression + Signal Transduction |
Memory metal has been utilized in orthopedic surgery as a fixation-compression device for osteotomies, typically for lower extremity procedures. The device, usually in the form of a large staple, is stored in a refrigerator in its malleable form and is implanted into pre-drilled holes in the bone across an osteotomy. As the staple warms it returns to its non-malleable state and compresses the bony surfaces together to promote bone union. | 0 | Metallurgy |
Ancient slag is difficult to date. It has no organic material with which to perform radiocarbon dating. There are no cultural artifacts like pottery shards in the slag with which to date it. Direct physical dating of slag through thermoluminescence dating could be a good method to solve this problem. Thermoluminescence dating is possible if the slag contains crystal elements such as quartz or feldspar. However, the complex composition of slag can make this technique difficult unless the crystal elements can be isolated. | 0 | Metallurgy |
Non-metallic inclusions arise because of many physical-chemical effects that occur in molten and consolidated metal during production.
Non-metallic inclusions that arise because of different reactions during metal production are called natural or indigenous. They include oxides, sulfides, nitrides and phosphides.
Apart from natural inclusions there are also parts of slag, refractories, material of a casting mould (the material the metal contacts during production) in the metal. Such non-metallic inclusions are called foreign, accidental or exogenous.
Most inclusions in the reduction smelting of metal formed because of admixture dissolubility decreasing during cooling and consolidation.
The present-day level of steel production technology allows the elimination of most natural and foreign inclusions from the metal. However its general content in different steels can vary between wide limits and has a big influence on the metal properties. | 0 | Metallurgy |
Metallurgy derives from the Ancient Greek , , "worker in metal", from , , "mine, metal" + , , "work" The word was originally an alchemists term for the extraction of metals from minerals, the ending -urgy signifying a process, especially manufacturing: it was discussed in this sense in the 1797 Encyclopædia Britannica'.
In the late 19th century, metallurgys definition was extended to the more general scientific study of metals, alloys, and related processes. In English, the pronunciation is the more common one in the United Kingdom. The pronunciation is the more common one in the United States US and is the first-listed variant in various American dictionaries, including Merriam-Webster Collegiate and American Heritage'. | 0 | Metallurgy |
The similarity to histone H1 explains how fork head factors are able to bind chromatin by interacting with the major groove of only the one available side of DNA wrapped around a nucleosome. Fork head domains also have a helix that confers sequence specificity unlike linker histone. The C terminus is associated with higher mobility around the nucleosome than linker histone, displacing it and rearranging nucleosomal landscapes effectively. This active re-arrangement of the nucleosomes allows for other transcription factors to bind the available DNA. In thyroid cell differentiation FoxE binds to compacted chromatin of the thyroid peroxidase promoter and opens it for NF1 binding. | 1 | Gene expression + Signal Transduction |
Among the diverse scientific content of this text is:
* Systematic approach to the Science. (Rasaratna Samuccaya 6/2)
* Philosophy of scientific explanation.
* Two kinds of mineral with zinc: calamine and Smithsonite. (Rasaratna Samuccaya 2-149)
* Color and nature of the mineral. (Artha-sastra '2 -30)
* Color of minerals with copper.
* Properties of some chemicals, such as calcium carbonate. (Rasaratna Samuccaya 3 / 130-131)
* Distillation of mercury. (Rasaratna Samucchaya 3/144)
* Explanation of the corrosion (Rasārṇava 7/97)
* The color of the flame (Rasārṇava 4/51)
* Three types of iron (Rasaratna Samuccaya 5/69)
* Two kinds of tin (Rasaratna Samuccaya 5 / 153-154)
* The lead (Rasaratna Samuccaya 5/170)
* The zinc metal (Rasataraṅgiṇi 19/95)
* The brass (Rasendra Cūḍāmaṇi14 / 154)
* The bronze (Rasaratna Samuccaya 5/205)
* Conditions of a laboratory and the people who work within it. | 0 | Metallurgy |
Structures built of concrete and reinforced with metal rebar are also subject to damage by oxide jacking. Expansion of corroded rebar causes spalling of the concrete. Structures exposed to a marine environment, or where salt is used for de-icing purposes, are especially susceptible to this type of damage. This may also be caused by concrete having been installed without sufficient cover for the rebars, allowing moisture to reach the metal and cause oxidation.
Research in the 1960s showed that 22 percent of concrete bridge decks in Pennsylvania showed signs of spalling due to oxide jacking within four years of construction. Oxide jacking caused widespread damage to concrete council houses built in the United Kingdom in the post World War II era.
According to an expert in the field, the problem resulted in "intensive worldwide research into the causes and repair of reinforcement corrosion, which in turn led to a vast output of research papers, conferences and publications on the subject." | 0 | Metallurgy |
CKLF-like MARVEL transmembrane domain-containing protein 2 (i.e. CMTM2), previously termed chemokine-like factor superfamily 2 ( i.e. CKLFSF2), is a member of the CKLF-like MARVEL transmembrane domain-containing family (CMTM) of proteins. In humans, it is encoded by the CMTM2 gene located in band 22 on the long (i.e. "q") arm of chromosome 16. CMTM2 protein is expressed in the bone marrow and various circulating blood cells. It is also highly expressed in testicular tissues: The CMTM2 gene and CMTM2 protein, it is suggested, may play an important role in testicular development.
Studies find that the levels of CMTM2 protein in hepatocellular carcinoma tissues of patients are lower higher than their levels in normal liver tissues. CMTM2 protein levels were also lower in the hepatocellular carcinoma tissues that had a more aggressive pathology and therefore a possible poorer prognosis. Finally, the forced overexpression of CMTM2 protein in cultured hepatocellular tumor cells inhibited their invasiveness and migration. These findings suggest that CMTM2 protein suppresses the development and/or progression of hepatocellular carcinoma and therefore that the CMTM2 gene acts as a tumor suppressor in this cancer. Patients with higher CMTM2 levels in their linitis plastica stomach cancer (i.e. a type of gastric cancer also termed diffuse-type gastric cancer or diffuse type adenocarcinoma of the stomach) tissues had better prognoses than patients with lower CMTM2 levels in their linitis plastica tissues. And, the CMTM2 gene has been found to be more highly expressed in the salivary gland adenoid cystic carcinoma tissues of patients who did not develop tumor recurrences or perineural invasion of their carcinomas compared to the expression of this gene in patients whose adenoid cystic carcinoma tissues went on to develop these complications. These findings suggest that the CMTM2 gene may act as a tumor suppressor not only in hepatocellular carcinoma but also in linitis plastica and salivary gland adenoid cystic carcinoma. Further studies are needed to confirm these findings and determine if CMTM2 protein can serve as a marker for the severity of these three cancers and/or as a therapeutic target for treating them. | 1 | Gene expression + Signal Transduction |
Geometric dynamic recrystallization occurs in grains with local serrations. Upon deformation, grains undergoing GDRX elongate until the thickness of the grain falls below a threshold (below which the serration boundaries intersect and small grains pinch off into equiaxed grains). The serrations may predate stresses being exerted on the material, or may result from the material’s deformation.
Geometric Dynamic Recrystallization has 6 main characteristics:
* It generally occurs with deformation at elevated temperatures, in materials with high stacking fault energy
* Stress increases and then declines to a steady state
* Subgrain formation requires a critical deformation
* Subgrain misorientation peaks at 2˚
* There is little texture change
* Pinning of grain boundaries causes an increase in the required strain
While GDRX is primarily affected by the initial grain size and strain (geometry-dependent), other factors that occur during the hot working process complicate the development of predictive modeling (which tend to oversimplify the process) and can lead to incomplete recrystallization. The equiaxed grain formation does not occur immediately and uniformly along the entire grain once the threshold stress is reached, as individual regions are subjected to different strains/stresses. In practice, a generally sinusoidal edge (as predicted by Martorano et al.) gradually forms as the grains begin to pinch off as they each reach the threshold. More sophisticated models consider complex initial grain geometries, local pressures along grain boundaries, and hot working temperature, but the models are unable to make accurate predictions throughout the entire stress regime and the evolution of the overall microstructure. Additionally, grain boundaries may migrate during GDRX at high temperatures and GB curvatures, dragging along subgrain boundaries and resulting in unwanted growth of the original grain. This new, larger grain will require far more deformation for GDRX to occur, and the local area will be weaker rather than strengthened. Lastly, recrystallization can be accelerated as grains are shifted and stretched, causing subgrain boundaries to become grain boundaries (angle increases). The affected grains are thinner and longer, and thus more easily undergo deformation. | 0 | Metallurgy |
Etching has applications in the printed circuit board and semiconductor fabrication industries. It is also used in the aerospace industry to remove shallow layers of material from large aircraft components, missile skin panels, and extruded parts for airframes. Etching is used widely to manufacture integrated circuits and Microelectromechanical systems. In addition to the standard, liquid-based techniques, the semiconductor industry commonly uses plasma etching. | 0 | Metallurgy |
In physical chemistry and materials science, texture is the distribution of crystallographic orientations of a polycrystalline sample (it is also part of the geological fabric). A sample in which these orientations are fully random is said to have no distinct texture. If the crystallographic orientations are not random, but have some preferred orientation, then the sample has a weak, moderate or strong texture. The degree is dependent on the percentage of crystals having the preferred orientation.
Texture is seen in almost all engineered materials, and can have a great influence on materials properties. The texture forms in materials during thermo-mechanical processes, for example during production processes e.g. rolling. Consequently, the rolling process is often followed by a heat treatment to reduce the amount of unwanted texture. Controlling the production process in combination with the characterization of texture and the materials microstructure help to determine the materials properties, i.e. the processing-microstructure-texture-property relationship'. Also, geologic rocks show texture due to their thermo-mechanic history of formation processes.
One extreme case is a complete lack of texture: a solid with perfectly random crystallite orientation will have isotropic properties at length scales sufficiently larger than the size of the crystallites. The opposite extreme is a perfect single crystal, which likely has anisotropic properties by geometric necessity. | 0 | Metallurgy |
The Superstack was built by Inco Limited (and later purchased by Vale) at an estimated cost of 25 million dollars. Construction on the structure was underway during the Sudbury tornado of August 20, 1970; the structure swayed heavily in the wind, but remained standing and suffered only minor damage. Six workers were on top of the construction platform when the storm hit, and all survived. The same day was the final day of construction on the stack, with the construction fully completed by the evening of August 21, 1970.
The stack entered into full operation in 1972. From the date of its completion until the Ekibastuz GRES-2 chimney was constructed in 1987, it was the world's tallest smokestack. Between the years 1972–75 it was the tallest freestanding structure in Canada.
Prior to the construction of the Superstack, the waste gases contributed to severe local ecological damage. The Copper Cliff smelter was already home to some of the world's tallest stacks, including two chimneys constructed in 1928-29 and 1936. However, these proved to be insufficient and compounded by open coke beds in the early to mid-20th century and logging for fuel, an inevitable near-total loss of native vegetation occurred. Of particular interest to geologists are the now exposed rocky outcrops, which have been permanently stained charcoal black, first by the pollution wafting over the decades from the roasting yards, then by the acid rain in a layer which penetrates up to three inches into the once pink-grey granite.
The Superstack was built to disperse sulphur gases and other byproducts of the smelting process away from the city of Sudbury. It did this by placing the gases high in the air, where they normally blew right past the city on the prevailing winds. As a result, these gases can be detected in the atmosphere around Greater Sudbury in a radius of the Inco plant. During the 1970s and 80s, the sulphur dioxide plume formed a permanent, opaque, cloud-like formation running across the entire horizon as seen from a distance. Periodic inversions would cause the plume to fall into the city.
Construction of the Superstack was followed by an environmental reclamation project which has included rehabilitation of existing landscapes and selected water bodies such as Lake Ramsey. An ambitious regreening plan has seen over three million new trees planted within the Greater Sudbury area. In 1992, Inco and the city were given an award by the United Nations in honour of their environmental rehabilitation programmes.
On November 3, 2014, Vale announced that they may decide to stop using the stack, following a $1 billion project to reduce emissions by 85% that negates the need for the stack. If no other use for it is found, Vale may decommission the superstack, demolish it, and replace it with a much smaller chimney. In 2017, Vale announced plans to decommission the Superstack upon the construction of two smaller, more energy efficient stacks. On July 28, 2020, Vale updated that news, stating that the stack at its Copper Cliff Complex had been taken out of service. It would remain on "hot standby" for about two months while the replacement flue connections were tested but the stack would then be demolished over the years. | 0 | Metallurgy |
RASSLs and DREADDs are families of designer G-protein-coupled receptors (GPCRs) built specifically to allow for precise spatiotemporal control of GPCR signaling in vivo. These engineered GPCRs are unresponsive to endogenous ligands but can be activated by nanomolar concentrations of pharmacologically inert, drug-like small molecules. Currently, RASSLs exist for the interrogation of several GPCR signaling pathways, including those activated by Gs, Gi, Gq, Golf and β-arrestin. A major cause for success of RASSL resources has been open exchange of DNA constructs, and RASSL related resources.
The hM4Di-DREADDs inhibitory effects are a result of the CNOs stimulation and resulting activation of the G-protein inwardly rectifying potassium (GIRK) channels. This causes hyperpolarization of the targeted neuronal cell and thus attenuates subsequent activity. | 1 | Gene expression + Signal Transduction |
Attempts at treatment for cancer cells with constitutively phosphorylated STAT5 have included both indirect and direct inhibition of STAT5 activity. While more medicinal work has been done in indirect inhibition, this approach can lead to increased toxicity in cells and can also result in non-specific effects, both of which are better handled by direct inhibition.
Indirect inhibition targets kinases associated with STAT5, or targets proteases that carry out terminal truncation of proteins. Different inhibitors have been designed to target different kinases:
* Inhibition of BCR/ABl constitutes the basis of the functioning of drugs like imatinib
* Inhibition of FLT3 is carried out by drugs like lestaurtinib
* Inhibition of JAK2 is carried out by the drug CYT387, which was successful in preclinical trials and is currently undergoing clinical trials.
Direct inhibition of STAT5 activity makes use of small molecule inhibitors that prevent STAT5 from properly binding to DNA or prevent proper dimerization. The inhibiting of DNA binding utilizes RNA interference, antisense oligodeoxynucleotide, and short hairpin RNA. The inhibition of proper dimerization, on the other hand, is brought about by the use of small molecules that target the SH2 domain. Recent work on drug development in the latter field have proved particularly effective. | 1 | Gene expression + Signal Transduction |
The Broken Hill Associated Smelters Proprietary Limited (“BHAS”) lead smelter, now owned by Nyrstar NV, has been the world’s largest lead smelter. Its staff was responsible for many significant technical developments in the lead smelting industry, including the updraft sinter plant and continuous lead refining.
Until 1990, BHAS recovered silver in a two-stage reverberatory cupellation process. This process suffered from low recoveries (80–83%), a long cycle time (4–5 days) that caused large in-process inventories, inefficient use of labor and energy, and poor workplace hygiene. After a test work program undertaken at Ausmelt’s facilities in Melbourne, BHAS switched to using a process based on the Sirosmelt top-submerged lance in June 1990.
The change to the lance-based furnace increased oxygen utilization to 95% and the cycle time was reduced to a little less than eight hours, “but the grade of the doré which could be economically produced was poor.” The doré from the new furnace still contained about 0.8% lead and 0.4% copper. It was also found impractical to cast anode plates of doré directly from the Sirosmelt furnace, so the Sirosmelt doré had to undergo a further refining step in a reverberatory furnace, together with a sodium nitrate flux.
Then, in 1996, BHAS decided to modernize the refining circuit and replaced the Sirosmelt silver refining furnace with a BBOC furnace. Commissioning of the modernized refining circuit was completed in 1999, and the lead throughput was increased by 11%, with the silver refining capacity increasing to over 400 t/y.
The BBOC process proved to be “generally successful”, although it did suffer some problems with the lance jamming that were attributed to higher than expected levels of zinc in the feed, due to problems removing the zinc in earlier stages of the refinery circuit. The higher levels of zinc also caused higher than expected refractory wear and excessive lance consumption, because the heat generated by oxidizing the zinc was greater than that of oxidizing lead.
The BBOC furnace proved to be capable of producing doré containing as little as 0.01% lead and less than 0.1% copper at a temperature around 1050 °C, but BHAS wanted to cast the doré directly into anode plates using an existing doré casting conveyor. Casting using the existing conveyor proved impossible at an operating temperature of 1050 °C, because the high thermal conductivity of the silver resulted in it freezing before it reached the molds. Consequently, BHAS decided to increase the operating temperature to 1100–1150 °C so that the silver remained liquid until cast into the anode molds. A side effect of this is that the lead and copper content of the product doré are higher than if the furnace is operated at 1050 °C, at 0.2% lead and 0.6% copper. Thermodynamic calculations have shown that this is unavoidable at this higher operating temperature. | 0 | Metallurgy |
A thermocouple can be used as a vacuum gauge over the range of approximately 0.001 to 1 torr absolute pressure. In this pressure range, the mean free path of the gas is comparable to the dimensions of the vacuum chamber, and the flow regime is neither purely viscous nor purely molecular. In this configuration, the thermocouple junction is attached to the centre of a short heating wire, which is usually energised by a constant current of about 5 mA, and the heat is removed at a rate related to the thermal conductivity of the gas.
The temperature detected at the thermocouple junction depends on the thermal conductivity of the surrounding gas, which depends on the pressure of the gas. The potential difference measured by a thermocouple is proportional to the square of pressure over the low- to medium-vacuum range. At higher (viscous flow) and lower (molecular flow) pressures, the thermal conductivity of air or any other gas is essentially independent of pressure. The thermocouple was first used as a vacuum gauge by Voege in 1906. The mathematical model for the thermocouple as a vacuum gauge is quite complicated, as explained in detail by Van Atta, but can be simplified to:
where P is the gas pressure, B is a constant that depends on the thermocouple temperature, the gas composition and the vacuum-chamber geometry, V is the thermocouple voltage at zero pressure (absolute), and V is the voltage indicated by the thermocouple.
The alternative is the Pirani gauge, which operates in a similar way, over approximately the same pressure range, but is only a 2-terminal device, sensing the change in resistance with temperature of a thin electrically heated wire, rather than using a thermocouple. | 0 | Metallurgy |
In Twin Roll Melt Spinning two rollers or drums are used instead of one. The rollers are placed side by side, and rotated such that the one to the left spins clockwise, and the one on the right spins counter-clockwise. This configuration results in material passing between the rollers being pulled down. The melt is jetted between the rollers where it is cooled and ejected as a ribbon. The advantage of twin-roll melt spinning is that it gives a high degree of control over the thickness of the resulting ribbon. With a single roller, controlling ribbon thickness is complicated involving close control over the flow rate of the melt, rotational speed of the wheel, and temperature of the melt. With the twin roller setup, a particular and consistent thickness can be achieved by simply changing the distance between the rollers.
To date, twin roll melt spinning is still limited almost exclusively to laboratory scales. | 0 | Metallurgy |
Fluxing salt, like chlorides are also liquid inclusions. They come from flux treatments added to the melt for cleaning. | 0 | Metallurgy |
In the early 1950s two groundbreaking series of papers were written independently on the relationship between grain boundaries and strength.
In 1951, while at the University of Sheffield, E. O. Hall wrote three papers which appeared in volume 64 of the Proceedings of the Physical Society. In his third paper, Hall showed that the length of slip bands or crack lengths correspond to grain sizes and thus a relationship could be established between the two. Hall concentrated on the yielding properties of mild steels.
Based on his experimental work carried out in 1946–1949, N. J. Petch of the University of Leeds, England published a paper in 1953 independent from Halls. Petchs paper concentrated more on brittle fracture. By measuring the variation in cleavage strength with respect to ferritic grain size at very low temperatures, Petch found a relationship exact to that of Hall's. Thus this important relationship is named after both Hall and Petch. | 0 | Metallurgy |
Lost-wax castingalso called investment casting, precision casting, or cire perdue (; borrowed from French)is the process by which a duplicate sculpture (often a metal, such as silver, gold, brass, or bronze) is cast from an original sculpture. Intricate works can be achieved by this method.
The oldest known examples of this technique are approximately 6,500-year-old (4550–4450 BC) and attributed to gold artefacts found at Bulgaria's Varna Necropolis. A copper amulet from Mehrgarh, Indus Valley civilization, in Pakistan, is dated to circa 4,000 BC. Cast copper objects, found in the Nahal Mishmar hoard in southern Israel, which belong to the Chalcolithic period (4500–3500 BC), are estimated, from carbon-14 dating, to date to circa 3500 BC. Other examples from somewhat later periods are from Mesopotamia in the third millennium BC. Lost-wax casting was widespread in Europe until the 18th century, when a piece-moulding process came to predominate.
The steps used in casting small bronze sculptures are fairly standardized, though the process today varies from foundry to foundry (in modern industrial use, the process is called investment casting). Variations of the process include: "lost mould", which recognizes that materials other than wax can be used (such as tallow, resin, tar, and textile); and "waste wax process" (or "waste mould casting"), because the mould is destroyed to remove the cast item. | 0 | Metallurgy |
SpliceInfo is a database for the four major alternative-splicing modes (exon skipping, 5-alternative splicing, 3-alternative splicing and intron retention) in the human genome.
This resource appears to be no longer available. | 1 | Gene expression + Signal Transduction |
Mitochondrial genes in some vertebrates (including humans) have incomplete stop codons ending in U or UA, which become complete termination codons (UAA) upon subsequent polyadenylation. | 1 | Gene expression + Signal Transduction |
Extensive worldwide tests have proved that uncoated copper and copper alloys (e.g., brass, bronze, copper nickel, copper-nickel-zinc) have strong intrinsic antimicrobial properties with efficacies against a wide range of disease-resistant bacteria, molds, fungi and viruses. After years of testing, the U.S. approved the registration of over 300 different copper alloys (copper, brasses, bronzes, copper-nickels, and nickel-silvers) as antimicrobial materials. These developments are creating markets for antimicrobial copper and copper alloys in interior architecture. To meet the design needs for building surfaces, structures, fixtures, and components, antimicrobial copper-based products are available in a wide range of colors, finishes, and mechanical properties. Copper handrails, counter tops, hallways, doors, push plates, kitchens, and bathrooms are just some of the antimicrobial products approved for hospitals, airports, offices, schools, and army barracks to kill harmful bacteria. See: a list of products approved in the U.S. | 0 | Metallurgy |
The diagram shows a ceramic crucible with a steel cylinder suspended within. Both cathode (C) and anode (A) are made of iron or nickel. The temperature is cooler at the bottom and hotter at the top so that the sodium hydroxide is solid in the neck (B) and liquid in the body of the vessel. Sodium metal forms at the cathode but is less dense than the fused sodium hydroxide electrolyte. Wire gauze (G) confines the sodium metal to accumulating at the top of the collection device (P). The cathode reaction is
:2 Na + 2 e → 2Na
The anode reaction is
:4 OH → O + 2 HO + 4 e
Despite the elevated temperature, some of the water produced remains dissolved in the electrolyte. This water diffuses throughout the electrolyte and results in the reverse reaction taking place on the electrolyzed sodium metal:
:2 Na + 2 HO → H + 2 Na + 2 OH
with the hydrogen gas also accumulating at (P). This, of course, reduces the efficiency of the process. | 0 | Metallurgy |
In the 1980s and 1990s, silicon carbide was studied in several research programs for high-temperature gas turbines in Europe, Japan and the United States. The components were intended to replace nickel superalloy turbine blades or nozzle vanes. However, none of these projects resulted in a production quantity, mainly because of its low impact resistance and its low fracture toughness.
Like other hard ceramics (namely alumina and boron carbide), silicon carbide is used in composite armor (e.g. Chobham armor), and in ceramic plates in bulletproof vests. Dragon Skin, which was produced by Pinnacle Armor, used disks of silicon carbide. Improved fracture toughness in SiC armor can be facilitated through the phenomenon of abnormal grain growth or AGG. The growth of abnormally long silicon carbide grains may serve to impart a toughening effect through crack-wake bridging, similar to whisker reinforcement. Similar
AGG-toughening effects have been reported in Silicon nitride (SiN).
Silicon carbide is used as a support and shelving material in high temperature kilns such as for firing ceramics, glass fusing, or glass casting. SiC kiln shelves are considerably lighter and more durable than traditional alumina shelves.
In December 2015, infusion of silicon carbide nano-particles in molten magnesium was mentioned as a way to produce a new strong and plastic alloy suitable for use in aeronautics, aerospace, automobile and micro-electronics. | 0 | Metallurgy |
Traditional active cancellation techniques for tremor reduction use electrical, hydraulic, or pneumatic systems to actuate an object in the direction opposite to the disturbance. However, these systems are limited due to the large infrastructure required to produce large amplitudes of power at human tremor frequencies. SMAs have proven to be an effective method of actuation in hand-held applications, and have enabled a new class active tremor cancellation devices. One recent example of such device is the Liftware spoon, developed by Verily Life Sciences subsidiary Lift Labs. | 0 | Metallurgy |
Andrew Handyside (1805–1887) was born in Edinburgh and set up works in Derby where he made ornamental items, bridges and pillar boxes, many of which survive today. | 0 | Metallurgy |
Normally, when a metallic material cools, the individual atoms solidify in strong, repeating patterns to form a crystalline solid. However, in melt spinning, the melt is quenched (cooled) so rapidly that the atoms don't have time to form these ordered structures before they completely solidify. Instead, the atoms are solidified in positions resembling their liquid state. This physical structure gives rise to the magnetic and electric properties of amorphous metals. | 0 | Metallurgy |
One of the remarkable features of plasma electrolyte coatings is the presence of micro pores and cracks on the coating surface. Plasma electrolytic oxide coatings are generally recognized for high hardness, wear resistance, and corrosion resistance. However, the coating properties are highly dependent on the substrate used, as well as on the composition of the electrolyte and the electrical regime used (see Equipment used section, above).
Even on aluminium, the coating properties can vary strongly according to the exact alloy composition. For instance, the hardest coatings can be achieved on 2XXX series aluminium alloys, where the highest proportion of crystalline phase corundum (α-AlO) is formed, resulting in hardnesses of ~2000 HV, whereas coatings on the 5XXX series have less of this important constituent and are hence softer. Extensive work is being pursued by Prof. T. W. Clyne at the University of Cambridge to investigate the fundamental electrical and plasma physical processes involved in this process, having previously elucidated some of the micromechanical (& pore architectural), mechanical and thermal characteristics of PEO coatings. | 0 | Metallurgy |
Detonation gun spraying like any other industrial process carries with it a number of safety hazards that need to be managed correctly in order to ensure operator safety whilst in use. These safety precautions primarily fall into the following categories and the hazard minimisation techniques suggested, in some cases have a positive effect on the resultant detonation spray coating. For example, having to automate the spraying process means that a very even and consistent spray coating can be achieved. | 0 | Metallurgy |
There is significant correlation of phosphorylated mTOR with the survival rate for patients with stages I and II TNBC. A patient-derived xenograft TNBC model testing the mTOR inhibitor rapamycin showed 77–99% tumor-growth inhibition, which is significantly more than has been seen with doxorubicin; protein phosphorylation studies indicated that constitutive activation of the mTOR pathway decreased with treatment. | 1 | Gene expression + Signal Transduction |
Almost all functional transcripts are derived from known genes. The only exceptions are a small number of transcripts that might play a direct role in regulating gene expression near the prompters of known genes. (See Enhancer RNA.)
Gene occupy most of prokaryotic genomes so most of their genomes are transcribed. Many eukaryotic genomes are very large and known genes may take up only a fraction of the genome. In mammals, for example, known genes only account for 40-50% of the genome. Nevertheless, identified transcripts often map to a much larger fraction of the genome suggesting that the transcriptome contains spurious transcripts that do not come from genes. Some of these transcripipts are known to be non-functional because they map to transcribed pseudogenes or degenerative transposons and viruses. Others map to unidentified regions of the genome that may be junk DNA.
Spurious transcription is very common in eukaryotes, especially those with large genomes that might contain a lot of junk DNA. Some scientists claim that if a transcript has not been assigned to a known gene then the default assumption must be that it is junk RNA until it has been shown to be functional. This would mean that much of the transcriptome in species with large genomes is probably junk RNA. (See Non-coding RNA)
The transcriptome includes the transcripts of protein-coding genes (mRNA plus introns) as well as the transcripts of non-coding genes (functional RNAs plus introns).
*Ribosomal RNA/rRNA: Usually the most abundant RNA in the transcriptome.
*Long non-coding RNA/lncRNA: Non-coding RNA transcripts that are more than 200 nucleotides long. Members of this group comprise the largest fraction of the non-coding transcriptome other than introns. It is not known how many of these transcripts are functional and how many are junk RNA.
*transfer RNA/tRNA
*micro RNA/miRNA: 19-24 nucleotides (nt) long. Micro RNAs up- or downregulate expression levels of mRNAs by the process of RNA interference at the post-transcriptional level.
*small interfering RNA/siRNA: 20-24 nt
*small nucleolar RNA/snoRNA
*Piwi-interacting RNA/piRNA: 24-31 nt. They interact with Piwi proteins of the Argonaute family and have a function in targeting and cleaving transposons.
*enhancer RNA/eRNA: | 1 | Gene expression + Signal Transduction |
Genetic codes is a simple ASN.1 database hosted by the National Center for Biotechnology Information and listing all the known Genetic codes. | 1 | Gene expression + Signal Transduction |
Diglycerides are a minor component of many seed oils and are normally present at ~1–6%; or in the case of cottonseed oil as much as 10%. Industrial production is primarily achieved by a glycerolysis reaction between triglycerides and glycerol. The raw materials for this may be either vegetable oils or animal fats. | 1 | Gene expression + Signal Transduction |
Inorganic fluxes contain components playing the same role as in organic fluxes. They are more often used in brazing and other high-temperature applications, where organic fluxes have insufficient thermal stability. The chemicals used often simultaneously act as both vehicles and activators; typical examples are borax, borates, fluoroborates, fluorides and chlorides. Halogenides are active at lower temperatures than borates, and are therefore used for brazing of aluminium and magnesium alloys; they are however highly corrosive. | 0 | Metallurgy |
* On a prepared mould surface as a sample, permeability can be checked with use of a mould permeability attachment to permeability meter, readings such obtained are of relative permeability, and not absolute permeability. The relative permeability reading on a mould surface is only used to gauge sample-to-sample variation.
* On standard specimen as a sample
** For sands that can be compressed, e.g.: bentonite-bonded sand, also known as green sand, a compressed or rammed sample is used to check permeability.
** For sand that cannot be compressed, e.g.: Resin-coated sands, a freely filled sample is used. To check such a sample, user may have to use an attachment to the permeability meter called a core permeability tube.
The absolute permeability number, which has no units, is determined by the rate of flow of air, under standard pressure, through a rammed cylindrical specimen. DIN standards define the specimen dimensions to be 50 mm in diameter and 50 mm tall, while the American Foundry Society defines it to be two inches in diameter and two inches tall. rammed cylindrical specimen.
formula is
PN = (VxH)/PxAxT
where
* V = volume of air in ml passing through the specimen
* H = Height of the specimen in cm
* A = Cross sectional area of specimen in cm2
* P = Pressure of air in cm of water
* T = Time in minutes
American Foundry Society has also released a chart where back pressure (P) from a rammed specimen placed on a permeability meter is correlated with a Permeability number. The Permeability number so measured is used in foundries for recording permeability value. | 0 | Metallurgy |
The theory behind experimental archaeology comes from the new archaeology technique of the 1950s to use modern day examples in the form of experiments and ethnologies as analogues to past processes. Experimental archaeometallurgy is considered a part of general experimental archaeology and is rarely separated in the literature and as such, many of the principles stay the same while there is a greater focus on a single subject.
Archaeometallurgy works as a good field for experimental reproduction because of the evidence that is provided from excavation is a good starting point for reconstruction. Metallurgical remains provide a durable product that has relatively durable evidence of production methods such as slag and refractory ceramic remains. Experimentation comes in a varied amount of forms including object replication, system replication, behavioral replication, and process replication. | 0 | Metallurgy |
Adenylyl cyclase is regulated by G proteins, which can be found in the monomeric form or the heterotrimeric form, consisting of three subunits. Adenylyl cyclase activity is controlled by heterotrimeric G proteins. The inactive or inhibitory form exists when the complex consists of alpha, beta, and gamma subunits, with GDP bound to the alpha subunit. In order to become active, a ligand must bind to the receptor and cause a conformational change. This conformational change causes the alpha subunit to dissociate from the complex and become bound to GTP. This G-alpha-GTP complex then binds to adenylyl cyclase and causes activation and the release of cAMP. Since a good signal requires the help of enzymes, which turn on and off signals quickly, there must also be a mechanism in which adenylyl cyclase deactivates and inhibits cAMP. The deactivation of the active G-alpha-GTP complex is accomplished rapidly by GTP hydrolysis due to the reaction being catalyzed by the intrinsic enzymatic activity of GTPase located in the alpha subunit. It is also regulated by forskolin, as well as other isoform-specific effectors:
* Isoforms I, III, and VIII are also stimulated by Ca/calmodulin.
* Isoforms V and VI are inhibited by Ca in a calmodulin-independent manner.
* Isoforms II, IV and IX are stimulated by alpha subunit of the G protein.
* Isoforms I, V and VI are most clearly inhibited by Gi, while other isoforms show less dual regulation by the inhibitory G protein.
* Soluble AC (sAC) is not a transmembrane form and is not regulated by G proteins or forskolin, instead acts as a bicarbonate/pH sensor. It is anchored at various locations within the cell and, with phosphodiesterases, forms local cAMP signalling domains.
In neurons, calcium-sensitive adenylyl cyclases are located next to calcium ion channels for faster reaction to Ca influx; they are suspected of playing an important role in learning processes. This is supported by the fact that adenylyl cyclases are coincidence detectors, meaning that they are activated only by several different signals occurring together. In peripheral cells and tissues adenylyl cyclases appear to form molecular complexes with specific receptors and other signaling proteins in an isoform-specific manner. | 1 | Gene expression + Signal Transduction |
Human proteins containing this domain include:
* ABL1; ABL2
* BCAR3; BLK; BLNK; BMX; BTK
* CHN2; CISH; CRK; CRKL; CSK
* DAPP1
* FER; FES; FGR; FRK; FYN
* GRAP; GRAP2; GRB10; GRB14; GRB2; GRB7
* HCK; HSH2D
* INPP5D; INPPL1; ITK; JAK2; LCK; LCP2; LYN
* MATK; NCK1; NCK2
* PIK3R1; PIK3R2; PIK3R3; PLCG1; PLCG2; PTK6; PTPN11; PTPN6; RASA1
* SH2B1; SH2B2; SH2B3; SH2D1A; SH2D1B; SH2D2A; SH2D3A; SH2D3C; SH2D4A; SH2D4B; SH2D5; SH2D6; SH3BP2; SHB; SHC1; SHC3; SHC4; SHD; SHE
* SLA; SLA2
* SOCS1; SOCS2; SOCS3; SOCS4; SOCS5; SOCS6; SOCS7
* SRC; SRMS
* STAT1; STAT2; STAT3; STAT4; STAT5A; STAT5B; STAT6
* SUPT6H; SYK
* TEC; TENC1; TNS; TNS1; TNS3; TNS4; TXK
* VAV1; VAV2; VAV3
* YES1; ZAP70 | 1 | Gene expression + Signal Transduction |
The pulse-induction method is based on electromagnetic pulse induction technology to detect rebars. Coils in the probe are periodically charged by current pulses and thus generate a magnetic field. On the surface of any electrically conductive material which is in the magnetic field eddy currents are produced. They induce a magnetic field in opposite directions. The resulting change in voltage can be utilized for the measurement. Rebars that are closer to the probe or of larger size produce a stronger magnetic field.
Modern rebar detectors use different coil arrangements to generate several magnetic fields. Advanced signal processing supports not only the localization of rebars but also the determination of the cover and the estimation of the bar diameter. This method is unaffected by all non conductive materials such as concrete, wood, plastics, bricks, etc. However any kind of conductive materials within the magnetic field will have an influence on the measurement.
Advantages of the pulse induction method:
* high accuracy
* not influenced by moisture and heterogeneities of the concrete
* unaffected by environmental influences
* low costs
Disadvantage of the pulse induction method:
* Limited detection range
* Minimum bar spacing depends on cover depths | 0 | Metallurgy |
The pillar carries a number of inscriptions of different dates, some of which have not been studied systematically despite the pillar's prominent location and easy access. | 0 | Metallurgy |
URhGes critical temperature (T') is normally about 280 millikelvins.
The Grenoble team in France, headed by Andrew D. Huxley, first cooled down the sample below its critical temperature and raised the magnetic field to 2 T. As expected, the sample's superconducting properties vanished. However, when the team raised the magnetic field to 8 T, the superconducting behavior continued. The critical temperature at that field strength increased to about 400 millikelvins. The sample retained the superconducting state until 13 T. They also found that at 12 T, the URhGe sample experienced a magnetic phase transition. | 0 | Metallurgy |
After a surface has been abrasion blasted and/or machined a thin layer of molybdenum, nickel-chromium alloys or nickel aluminide can be spayed before the final detonation spray coating to improve the bond strength. This is known as a bond coating. Bond coatings are often used when spray coating materials of ceramic composites are being applied. The component may need to be machined and/or abrasion blasted slightly deeper for the purpose of allowing space for the bond coating and spray coating to fit flush on the component surface.
Areas that are not to be sprayed must be covered in stop-off chemicals (chemicals that stop the spay from bonding) or tape. The chemicals and tape are then removed after the coating has cooled. | 0 | Metallurgy |
Identification of predictive biomarkers of efficacy for tumor types that are sensitive to mTOR inhibitors remains a major issue.
Possible predictive biomarkers for tumor response to mTOR inhibitors, as have been described in glioblastoma, breast and prostate cancer cells, may be the differential expression of mTOR pathway proteins, PTEN, AKT, and S6. Thus, this data is based on preclinical assays, based on in vitro cultured tumor cell lines, which suggest that the effects of mTOR inhibitors may be more pronounced in cancers displaying loss of PTEN functions or PIK3CA mutations. However, the use of PTEN, PIK3CA mutations, and AKT–phospho status for predicting rapalog sensitivity has not been fully validated in clinic. To date, attempts to identify biomarkers of rapalog response have been unsuccessful. | 1 | Gene expression + Signal Transduction |
Gold cyanidation (also known as the cyanide process or the MacArthur–Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore by converting the gold to a water-soluble coordination complex. It is the most commonly used leaching process for gold extraction. Cyanidation is also widely used in the extraction of silver, usually after froth flotation.
Production of reagents for mineral processing to recover gold represents more than 70% of cyanide consumption globally. Other metals are recovered from the process include copper, zinc, and silver, but gold is the main driver of this technology. Due to the highly poisonous nature of cyanide, the process is controversial and its use is even banned in some parts of the world. Cyanide can be safely used in the gold mining industry. A key feature for safe use of cyanide is to ensure adequate pH control at an alkaline pH level above 10.5. At industrial scale, pH control is mainly achieved using lime, as an important enabling reagent in gold processing. | 0 | Metallurgy |
Twenty-two DNA repair genes with hypermethylated promoters, and reduced or absent expression, were found to occur among 17 types of cancer, as listed in two review articles. Promoter hypermethylation of MGMT occurs frequently in a number of cancers including 93% of bladder cancers, 88% of stomach cancers, 74% of thyroid cancers, 40%-90% of colorectal cancers and 50% of brain cancers. That review also indicated promoter hypermethylation of LIG4, NEIL1, ATM, MLH1 or FANCB occurs at frequencies between 33% and 82% in one or more of head and neck cancers, non-small-cell lung cancers or non-small-cell lung cancer squamous cell carcinomas. The article Epigenetic inactivation of the premature aging Werner syndrome gene in human cancer indicates the DNA repair gene WRN has a promoter that is frequently hypermethylated in a number of cancers, with hypermethylation occurring in 11% to 38% of colorectal, head and neck, stomach, prostate, breast, thyroid, non-Hodgkin lymphoma, chondrosarcoma and osteosarcoma cancers (see WRN). | 1 | Gene expression + Signal Transduction |
Small amounts of yttrium (0.1 to 0.2%) have been used to reduce the grain sizes of chromium, molybdenum, titanium, and zirconium. Yttrium is used to increase the strength of aluminium and magnesium alloys. The addition of yttrium to alloys generally improves workability, adds resistance to high-temperature recrystallization, and significantly enhances resistance to high-temperature oxidation (see graphite nodule discussion below).
Yttrium can be used to deoxidize vanadium and other non-ferrous metals. Yttria stabilizes the cubic form of zirconia in jewelry.
Yttrium has been studied as a nodulizer in ductile cast iron, forming the graphite into compact nodules instead of flakes to increase ductility and fatigue resistance. Having a high melting point, yttrium oxide is used in some ceramic and glass to impart shock resistance and low thermal expansion properties. Those same properties make such glass useful in camera lenses. | 0 | Metallurgy |
TCF7L2 is a transcription factor influencing the transcription of several genes thereby exerting a large variety of functions within the cell. It is a member of the TCF family that can form a bipartite transcription factor (β-catenin/TCF) alongside β-catenin. Bipartite transcription factors can have large effects on the Wnt signalling pathway. Stimulation of the Wnt signaling pathway leads to the association of β-catenin with BCL9, translocation to the nucleus, and association with TCF7L2, which in turn results in the activation of Wnt target genes. The activation of the Wnt target genes specifically represses proglucagon synthesis in enteroendocrine cells. The repression of TCF7L2 using HMG-box repressor (HBP1) inhibits Wnt signalling. Therefore, TCF7L2 is an effector in the Wnt signalling pathway. TCF7L2's role in glucose metabolism is expressed in many tissues such as gut, brain, liver, and skeletal muscle. However, TCF7L2 does not directly regulate glucose metabolism in β-cells, but regulates glucose metabolism in pancreatic and liver tissues. That said, TCF7L2 directly regulates the expression of multiple transcription factors, axon guidance cues, cell adhesion molecules and ion channels in the thalamus.
The TCF7L2 gene encoding the TCF7L2 transcription factor, exhibits multiple functions through its polymorphisms and thus, is known as a pleiotropic gene. Type 2 diabetes T2DM susceptibility is exhibited in carriers of TCF7L2 rs7903146C>T and rs290481T>C polymorphisms. TCF7L2 rs290481T>C polymorphism, however, has shown no significant correlation to the susceptibility to gestational diabetes mellitus (GDM) in a Chinese Han population, whereas the T alleles of rs7903146 and rs1799884 increase susceptibility to GDM in the Chinese Han population. The difference in effects of the different polymorphisms of the gene indicate that the gene is indeed pleiotropic. | 1 | Gene expression + Signal Transduction |
Other uses include making custom-shaped apertures and blocks (for example, electron-beam cutouts and lung blocks) for medical radiation treatment, and making casts of keys that are hard to otherwise duplicate.
Like other fusible alloys, e.g. Roses metal, Woods metal can be used as a heat-transfer medium in hot baths. Hot baths with Roses and Woods metals are not used routinely but are employed at temperatures above .
Wood's metal has a modulus of elasticity of 12.7 GPa and a yield strength of 26.2 MPa. | 0 | Metallurgy |
It is convenient to categorize grain boundaries according to the extent of misorientation between the two grains. Low-angle grain boundaries (LAGB) or subgrain boundaries are those with a misorientation less than about 15 degrees. Generally speaking they are composed of an array of dislocations and their properties and structure are a function of the misorientation. In contrast the properties of high-angle grain boundaries, whose misorientation is greater than about 15 degrees (the transition angle varies from 10 to 15 degrees depending on the material), are normally found to be independent of the misorientation. However, there are special boundaries at particular orientations whose interfacial energies are markedly lower than those of general high-angle grain boundaries.
The simplest boundary is that of a tilt boundary where the rotation axis is parallel to the boundary plane. This boundary can be conceived as forming from a single, contiguous crystallite or grain which is gradually bent by some external force. The energy associated with the elastic bending of the lattice can be reduced by inserting a dislocation, which is essentially a half-plane of atoms that act like a wedge, that creates a permanent misorientation between the two sides. As the grain is bent further, more and more dislocations must be introduced to accommodate the deformation resulting in a growing wall of dislocations – a low-angle boundary. The grain can now be considered to have split into two sub-grains of related crystallography but notably different orientations.
An alternative is a twist boundary where the misorientation occurs around an axis that is perpendicular to the boundary plane. This type of boundary incorporates two sets of screw dislocations. If the Burgers vectors of the dislocations are orthogonal, then the dislocations do not strongly interact and form a square network. In other cases, the dislocations may interact to form a more complex hexagonal structure.
These concepts of tilt and twist boundaries represent somewhat idealized cases. The majority of boundaries are of a mixed type, containing dislocations of different types and Burgers vectors, in order to create the best fit between the neighboring grains.
If the dislocations in the boundary remain isolated and distinct, the boundary can be considered to be low-angle. If deformation continues, the density of dislocations will increase and so reduce the spacing between neighboring dislocations. Eventually, the cores of the dislocations will begin to overlap and the ordered nature of the boundary will begin to break down. At this point the boundary can be considered to be high-angle and the original grain to have separated into two entirely separate grains.
In comparison to low-angle grain boundaries, high-angle boundaries are considerably more disordered, with large areas of poor fit and a comparatively open structure. Indeed, they were originally thought to be some form of amorphous or even liquid layer between the grains. However, this model could not explain the observed strength of grain boundaries and, after the invention of electron microscopy, direct evidence of the grain structure meant the hypothesis had to be discarded. It is now accepted that a boundary consists of structural units which depend on both the misorientation of the two grains and the plane of the interface. The types of structural unit that exist can be related to the concept of the coincidence site lattice, in which repeated units are formed from points where the two misoriented \
In coincident site lattice (CSL) theory, the degree of fit (Σ) between the structures of the two grains is described by the reciprocal of the ratio of coincidence sites to the total number of sites.
In this framework, it is possible to draw the lattice for the two grains and count the number of atoms that are shared (coincidence sites), and the total number of atoms on the boundary (total number of site). For example, when Σ=3 there will be one atom of each three that will be shared between the two lattices. Thus a boundary with high Σ might be expected to have a higher energy than one with low Σ. Low-angle boundaries, where the distortion is entirely accommodated by dislocations, are Σ1. Some other low-Σ boundaries have special properties, especially when the boundary plane is one that contains a high density of coincident sites. Examples include coherent twin boundaries (e.g., Σ3) and high-mobility boundaries in FCC materials (e.g., Σ7). Deviations from the ideal CSL orientation may be accommodated by local atomic relaxation or the inclusion of dislocations at the boundary. | 0 | Metallurgy |
Although RNA polymerase holoenzyme shows high affinity to non-specific sites of the DNA, this characteristic does not allow us to clarify the process of promoter location. This process of promoter location has been attributed to the structure of the holoenzyme to DNA and sigma 4 to DNA complexes. | 1 | Gene expression + Signal Transduction |
Functional selectivity has been proposed to broaden conventional definitions of pharmacology.
Traditional pharmacology posits that a ligand can be either classified as an agonist (full or partial), antagonist or more recently an inverse agonist through a specific receptor subtype, and that this characteristic will be consistent with all effector (second messenger) systems coupled to that receptor. While this dogma has been the backbone of ligand-receptor interactions for decades now, more recent data indicates that this classic definition of ligand-protein associations does not hold true for a number of compounds; such compounds may be termed as mixed agonist-antagonists.
Functional selectivity posits that a ligand may inherently produce a mix of the classic characteristics through a single receptor isoform depending on the effector pathway coupled to that receptor. For instance, a ligand can not easily be classified as an agonist or antagonist, because it can be a little of both, depending on its preferred signal transduction pathways. Thus, such ligands must instead be classified on the basis of their individual effects in the cell, instead of being either an agonist or antagonist to a receptor.
It is also important to note that these observations were made in a number of different expression systems and therefore functional selectivity is not just an epiphenomenon of one particular expression system. | 1 | Gene expression + Signal Transduction |
Shen Kuo's written work of 1088 contains, among other early descriptions of inventions, a method of repeated forging of cast iron under a cold blast similar to the modern Bessemer process.
Chinese metallurgy was widely practiced during the Middle Ages; during the 11th century, the growth of the iron industry caused vast deforestation due to the use of charcoal in the smelting process. To remedy the problem of deforestation, the Song Chinese discovered how to produce coke from bituminous coal as a substitute for charcoal. Although hydraulic-powered bellows for heating the blast furnace had been written about since Du Shi's (d. 38) invention of them in the 1st century CE, the first known illustration of a bellows in operation is found in a book written in 1313 by Wang Zhen (fl. 1290–1333). | 0 | Metallurgy |
• DIN EN ISO 6988 Metallic and other inorganic coatings - Test with sulfur dioxide with general moisture condensation, March 1997.
• DIN 50018 testing in an alternating condensation climate with an atmosphere containing sulfur dioxide, June 1997.
• The importance of corrosion test procedures with special consideration of the SO test according to DIN 50018, Wilhelm Kesternich, published in Materials and Corrosion Volume 16, Issue 3, pages 193-201, March 1965. | 0 | Metallurgy |
In production engineering, metallurgy is concerned with the production of metallic components for use in consumer or engineering products. This involves production of alloys, shaping, heat treatment and surface treatment of product. The task of the metallurgist is to achieve balance between material properties, such as cost, weight, strength, toughness, hardness, corrosion, fatigue resistance and performance in temperature extremes. To achieve this goal, the operating environment must be carefully considered.
Determining the hardness of the metal using the Rockwell, Vickers, and Brinell hardness scales is a commonly used practice that helps better understand the metal's elasticity and plasticity for different applications and production processes. In a saltwater environment, most ferrous metals and some non-ferrous alloys corrode quickly. Metals exposed to cold or cryogenic conditions may undergo a ductile to brittle transition and lose their toughness, becoming more brittle and prone to cracking. Metals under continual cyclic loading can suffer from metal fatigue. Metals under constant stress at elevated temperatures can creep. | 0 | Metallurgy |
The transduction of the signal through the membrane by the receptor is not completely understood. It is known that in the inactive state, the GPCR is bound to a heterotrimeric G protein complex. Binding of an agonist to the GPCR results in a conformational change in the receptor that is transmitted to the bound G subunit of the heterotrimeric G protein via protein domain dynamics. The activated G subunit exchanges GTP in place of GDP which in turn triggers the dissociation of G subunit from the G dimer and from the receptor. The dissociated G and G subunits interact with other intracellular proteins to continue the signal transduction cascade while the freed GPCR is able to rebind to another heterotrimeric G protein to form a new complex that is ready to initiate another round of signal transduction.
It is believed that a receptor molecule exists in a conformational equilibrium between active and inactive biophysical states. The binding of ligands to the receptor may shift the equilibrium toward the active receptor states. Three types of ligands exist: Agonists are ligands that shift the equilibrium in favour of active states; inverse agonists are ligands that shift the equilibrium in favour of inactive states; and neutral antagonists are ligands that do not affect the equilibrium. It is not yet known how exactly the active and inactive states differ from each other. | 1 | Gene expression + Signal Transduction |
While the two previous models implied that eRNAs were not functionally relevant, this mechanism states that eRNAs are functional molecules that exhibit cis activity. In this model, eRNAs can locally recruit regulatory proteins at their own site of synthesis. Supporting this hypothesis, transcripts originating from enhancers upstream of the Cyclin D1 gene are thought to serve as adaptors for the recruitment of histone acetyltransferases. It was found that depletion of these eRNAs led to Cyclin D1 transcriptional silencing. | 1 | Gene expression + Signal Transduction |
A number of organism-specific transcriptome databases have been constructed and annotated to aid in the identification of genes that are differentially expressed in distinct cell populations.
RNA-seq is emerging (2013) as the method of choice for measuring transcriptomes of organisms, though the older technique of DNA microarrays is still used. RNA-seq measures the transcription of a specific gene by converting long RNAs into a library of cDNA fragments. The cDNA fragments are then sequenced using high-throughput sequencing technology and aligned to a reference genome or transcriptome which is then used to create an expression profile of the genes. | 1 | Gene expression + Signal Transduction |
In 1972, C.W. Horsting of the RCA Corporation published a paper which reported test results on the reliability of semiconductor devices in which the connections were made using aluminium wires bonded ultrasonically to gold plated posts. His paper demonstrated the importance of the Kirkendall effect in wire bonding technology, but also showed the significant contribution of any impurities present to the rate at which precipitation occurred at the wire bonds. Two of the important contaminants that have this effect, known as Horsting effect (Horsting voids) are fluorine and chlorine. Both Kirkendall voids and Horsting voids are known causes of wire bond fractures, though historically this cause is often confused with the purple colored appearance of one of the five different gold-aluminium intermetallics, commonly referred to as "purple plague" and less often "white plague". | 0 | Metallurgy |
The following classification method is based on the American AISI/SAE standard. Other international standards including DIN (Germany), GB (China), BS/EN (UK), AFNOR (France), UNI (Italy), SS (Sweden) , UNE (Spain), JIS (Japan), ASTM standards, and others.
Carbon steel is broken down into four classes based on carbon content: | 0 | Metallurgy |
The third and last stop codon in the standard genetic code was discovered soon after, and corresponds to the nucleotide triplet "UGA".
To continue matching with the theme of colored minerals, the third nonsense codon came to be known as "opal", which is a type of silica showing a variety of colors. Nonsense mutations that created this premature stop codon were later called opal mutations or umber mutations. | 1 | Gene expression + Signal Transduction |
*SDHA NM_004168 Succinate Dehydrogenase subunit A
*SDHAF2 NM_017841
*SDHB NM_002973 Iron-sulfur protein (IP) subunit of succinate dehydrogenase (SDH) that is involved in complex II of the mitochondrial electron transport chain and is responsible for transferring electrons from succinate to ubiquinone (coenzyme Q)
*SDHC NM_003000 Membrane-anchoring subunit of succinate dehydrogenase (SDH) that is involved in complex II of the mitochondrial electron transport chain and is responsible for transferring electrons from succinate to ubiquinone (coenzyme Q).
*SDHD NM_003001 | 1 | Gene expression + Signal Transduction |
In biochemistry, dephosphorylation is the removal of a phosphate (PO) group from an organic compound by hydrolysis. It is a reversible post-translational modification. Dephosphorylation and its counterpart, phosphorylation, activate and deactivate enzymes by detaching or attaching phosphoric esters and anhydrides. A notable occurrence of dephosphorylation is the conversion of ATP to ADP and inorganic phosphate.
Dephosphorylation employs a type of hydrolytic enzyme, or hydrolase, which cleaves ester bonds. The prominent hydrolase subclass used in dephosphorylation is phosphatase, which removes phosphate groups by hydrolysing phosphoric acid monoesters into a phosphate ion and a molecule with a free hydroxyl (-OH) group.
The reversible phosphorylation-dephosphorylation reaction occurs in every physiological process, making proper function of protein phosphatases necessary for organism viability. Because protein dephosphorylation is a key process involved in cell signalling, protein phosphatases are implicated in conditions such as cardiac disease, diabetes, and Alzheimer's disease. | 1 | Gene expression + Signal Transduction |
Chamber construction, testing procedure and testing parameters are standardized under national and international standards, such as ASTM B 117 and ISO 9227. These standards describe the necessary information to carry out this test; testing parameters such as temperature, air pressure of the sprayed solution, preparation of the spraying solution, concentration, pH, etc. Daily checking of testing parameters is necessary to show compliance with the standards, so records shall be maintained accordingly. ASTM B117 and ISO 9227 are widely used as reference standards. Testing cabinets are manufactured according to the specified requirements here.
However, these testing standards neither provide information of testing periods for the coatings to be evaluated, nor the appearance of corrosion products in form of salts. Requirements are agreed between customer and manufacturer. In the automotive industry requirements are specified under material specifications. Different coatings have different behavior in salt spray test and consequently, test duration will differ from one type of coating to another. For example, a typical electroplated zinc and yellow passivated steel part lasts 96 hours in salt spray test without white rust. Electroplated zinc-nickel steel parts can last more than 720 hours in NSS test without red rust (or 48 hours in CASS test without red rust) Requirements are established in test duration (hours) and coatings shall comply with minimum testing periods.
Artificial seawater which is sometimes used for Salt Spray Testing can be found at ASTM International. The standard for Artificial Seawater is ASTM D1141-98 which is the standard practice for the preparation of substitute ocean water. | 0 | Metallurgy |
Several nucleoside analogues are used as antiviral or anticancer agents. The viral polymerase incorporates these compounds with non-canonical bases. These compounds are activated in the cells by being converted into nucleotides, they are administered as nucleosides since charged nucleotides cannot easily cross cell membranes. | 1 | Gene expression + Signal Transduction |
In continuum mechanics, a material is said to be under plane stress if the stress vector is zero across a particular plane. When that situation occurs over an entire element of a structure, as is often the case for thin plates, the stress analysis is considerably simplified, as the stress state can be represented by a tensor of dimension 2 (representable as a 2×2 matrix rather than 3×3). A related notion, plane strain, is often applicable to very thick members.
Plane stress typically occurs in thin flat plates that are acted upon only by load forces that are parallel to them. In certain situations, a gently curved thin plate may also be assumed to have plane stress for the purpose of stress analysis. This is the case, for example, of a thin-walled cylinder filled with a fluid under pressure. In such cases, stress components perpendicular to the plate are negligible compared to those parallel to it.
In other situations, however, the bending stress of a thin plate cannot be neglected. One can still simplify the analysis by using a two-dimensional domain, but the plane stress tensor at each point must be complemented with bending terms. | 0 | Metallurgy |
Rapamycin and rapalogs crosslink the immunophilin FK506 binding protein, tacrolimus or FKBP-12, through its methoxy group. The rapamycin-FKBP12 complex interferes with FRB domain of mTOR. Molecular interaction between FKBP12, mTOR, and rapamycin can last for about three days (72 hours). The inhibition of mTOR blocks the binding of the accessory protein raptor (regulatory-associated protein of mTOR) to mTOR, but that is necessary for downstream phosphorylation of S6K1 and 4EBP1.
As a consequence, S6K1 dephosphorylates, which reduces protein synthesis and decreases cell mortality and size. Rapamycin induces dephosphorylation of 4EBP1 as well, resulting in an increase in p27 and a decrease in cyclin D1 expression. That leads to late blockage of G1/S cell cycle. Rapamycin has shown to induce cancer cell death by stimulating autophagy or apoptosis, but the molecular mechanism of apoptosis in cancer cells has not yet been fully resolved. One suggestion of the relation between mTOR inhibition and apoptosis might be through the downstream target S6K1, which can phosphorylate BAD, a pro-apoptotic molecule, on Ser136. That reaction breaks the binding of BAD to BCL-XL and BCL2, a mitochondrial death inhibitors, resulting in inactivation of BAD and decreased cell survival. Rapamycin has also shown to induce p53-independent apoptosis in certain types of cancer. | 1 | Gene expression + Signal Transduction |
Figure 2 shows the positions of the BBOC at various stages of the operating cycle.
The BBOC is held in an upright position during the charging stage. A solid or liquid charge is added using an overhead crane. The furnace is then tilted forward so that the lance is above the charge, and the charge is melted using an oil or natural gas burner that is inserted near the top of the furnace. Once the charge has been melted, the furnace is tilted back into the blowing position and oxygen is blown into the bath. Slag formed from the oxidation of lead and zinc is removed periodically by tilting the furnace forward again and pouring it off.
The oxygen flow rate during blowing for a three tonne capacity furnace is 20–30 Nm/h. Zinc is initially oxidized to form a zinc oxide dross on the surface of the charge, but as lead oxide subsequently forms, a fluid slag of zinc and lead oxides is created. Most of the copper is removed at the same time as the lead. The final removal of copper to a level of 0.04% is undertaken at the end of the process by further additions of lead to collect the copper.
If the lance needs to be replaced at any time during operation, this is done by tilting the furnace forward until the lance is above the surface of the bath, where it can be removed and replaced without the contents of the furnace draining through the hole in the furnace lining.
The cupellation process finishes when the silver is about 99.7% pure. At this point, the silver is poured from the furnace and transferred to another furnace, where a flux is added to upgrade and remove the oxygen from the silver to produce market bullion of 99.9% purity. | 0 | Metallurgy |
The proteins in these excitable domains of neuron when injured may result in cognitive disorders and various neuropathic ailments. | 1 | Gene expression + Signal Transduction |
Rotation of the reduction furnace may be a design choice intended to circulate the ore through the furnace. It can also play an active part in the chemical reaction by ensuring mixing between the reactants present. Rotary hearth processes, where the ore rests on a fixed bed and travels through a tunnel, fall into the first category. Rotary kiln processes, where the ore is mixed with coal at high temperature, constitute the second category. | 0 | Metallurgy |
The Sherritt process is a hydrometallurgical process named for Sherritt Gordon Mines Ltd. (now Sherritt International) of Sherridon and Lynn Lake Manitoba Canada, based on the older Forward process developed by Dr. Frank Forward for the recovery of copper and nickel from those same mines. Nickel sulfide concentrates can be treated by either roasting or flash smelting to produce matte from which nickel and cobalt can be recovered hydrometallurgically, or they may be treated by an ammonia solution pressure leach. The residue is removed. A feed of matte and sulfide concentrate containing approximately 0.4% cobalt and 30% sulfur is pressure leached at elevated temperature and pressure in an ammoniacal solution to produce a solution of nickel, copper and cobalt. By boiling away the ammonia; copper is precipitated as a sulfide and sent to a smelter. Hydrogen sulfide is added to the autoclave to remove nickel sulfide and copper sulfide which is fed back to the leaching process. Air is then passed through the solution in the autoclave for oxyhydrolysis. The solution is then reduced with hydrogen, again at high temperature and pressure, to precipitate nickel powder (>99%). The remaining solution (containing approximately equal proportions of nickel and cobalt sulfides), is then adjusted (to a lower temperature and pressure) to precipitate the mixed sulfides and the fluid is concentrated and crystallized into ammonium sulfate ((NH)SO). The mixed sulfides are pressure leached with air and sulfuric acid. Ammonia is then added to remove potassium and iron as jarosite (KFe (OH)(SO)). More ammonia and air is added for oxidation. The solution is removed from the autoclave and sulfuric acid added to remove nickel as nickel(II) sulfate-ammonium sulfate hexahydrate ([NiSO]•[(NH)SO]•6HO) which is then sent to have its nickel recovered. The solution is then further reduced with more sulfuric acid and cobalt metal powder is added to aid in the nucleation of precipitants (seeding). Addition of hydrogen gas to saturation precipitates cobalt powder with a purity of approximately 99.6%. | 0 | Metallurgy |
Long non-coding RNA (LncRNA) are a type of RNA which is usually defined as transcripts which are greater than 200 base-pairs in length and not translated into proteins. This limitation distinguishes lncRNA from small non-coding RNAs which encompasses microRNAs (miRNAs), small interfering RNAs (siRNAs), Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), and other short RNAs. Long non-coding RNAs include lincRNAs, intronic ncRNAs, circular and linear ncRNA. | 1 | Gene expression + Signal Transduction |
Copper was the first metal in common use for tools and containers since it is one of the few metals available in non-oxidized form, not requiring the smelting of an ore. Copper is easily softened by heating and then cooling (it does not harden by quenching, e.g., quenching in cool water). In this annealed state it may then be hammered, stretched and otherwise formed, progressing toward the desired final shape but becoming harder and less ductile as work progresses. If work continues beyond a certain hardness the metal will tend to fracture when worked and so it may be re-annealed periodically as shaping continues. Annealing is stopped when the workpiece is near its final desired shape, and so the final product will have a desired strength and hardness. The technique of repoussé exploits these properties of copper, enabling the construction of durable jewelry articles and sculptures (such as the Statue of Liberty). | 0 | Metallurgy |
Although cyanide is cheap, effective, and biodegradable, its high toxicity has incentivized to alternative methods for extracting gold. Other extractants have been examined including thiosulfate (SO), thiourea (SC(NH)), iodine/iodide, ammonia, liquid mercury, and alpha-cyclodextrin. Challenges include reagent cost and the efficiency of gold recovery. Thiourea has been implemented commercially for ores containing stibnite. Yet another alternative to cyanidation is the family of glycine-based lixiviants. | 0 | Metallurgy |
There is now more than one two-phase region. The tie line drawn is from the solid alpha to the liquid and by dropping a vertical line down at these points the mass fraction of each phase is directly read off the graph, that is the mass fraction in the x axis element. The same equations can be used to find the mass fraction of alloy in each of the phases, i.e. w is the mass fraction of the whole sample in the liquid phase. | 0 | Metallurgy |
Certain materials especially refractories which are processed at high temperatures end up with excessively large grain size and poor mechanical properties at room temperature. To mitigate this problem in a common sintering procedure, a variety of dopants are often used to inhibit grain growth. | 0 | Metallurgy |
Human genes encoding heterogeneous nuclear ribonucleoproteins include:
* HNRNPA0, HNRNPA1, HNRNPA1L1, HNRNPA1L2, HNRNPA3, HNRNPA2B1
* HNRNPAB
* HNRNPB1
* HNRNPC, HNRNPCL1
* HNRNPD (AUF1), HNRPDL
* HNRNPF
* HNRNPG (RBMX)
* HNRNPH1, HNRNPH2, HNRNPH3
* HNRNPI (PTB)
* HNRNPK
* HNRNPL, HNRPLL
* HNRNPM
* HNRNPP2 (FUS/TLS)
* HNRNPR
* HNRNPQ (SYNCRIP)
* HNRNPU, HNRNPUL1, HNRNPUL2, HNRNPUL3
* FMR1 | 1 | Gene expression + Signal Transduction |
Coupling of RNA polymerase II (pol II) transcription can influence processing reactions in three ways.
# localization
#* positions mRNA processing factors at the elongation complex, which raises their local concentration in the vicinity of the nascent transcript
# kinetic coupling
#* the rate of transcript can have profound effects on RNA folding and the assembly of RNA-protein complexes
# allosteric
#* contact between the pol II elongation complex and mRNA processing factors can allosterically inhibit or activate mRNA processing factors | 1 | Gene expression + Signal Transduction |
When abscisic acid signals the guard cells, free Ca ions enter the cytosol from both outside the cell and internal stores, reversing the concentration gradient so the K+ ions begin exiting the cell. The loss of solutes makes the cell flaccid and closes the stomatal pores. | 1 | Gene expression + Signal Transduction |
Pseudogenes are mostly former genes that have become non-functional due to mutation but the term also refers to inactive DNA sequences that are derived from RNAs produced by functional genes (processed pseudogenes). Pseudogenes are only a small fraction of noncoding DNA in prokaryotic genomes because they are eliminated by negative selection. In some eukaryotes, however, pseudogenes can accumulate because selection is not powerful enough to eliminate them (see Nearly neutral theory of molecular evolution).
The human genome contains about 15,000 pseudogenes derived from protein-coding genes and an unknown number derived from noncoding genes. They may cover a substantial fraction of the genome (~5%) since many of them contain former intron sequences.
Pseudogenes are junk DNA by definition and they evolve at the neutral rate as expected for junk DNA. Some former pseudogenes have secondarily acquired a function and this leads some scientists to speculate that most pseudogenes are not junk because they have a yet-to-be-discovered function. | 1 | Gene expression + Signal Transduction |
The ShapiroSenapathy algorithm (S&S) is an algorithm for predicting splice junctions in genes of animals and plants. This algorithm has been used to discover disease-causing splice site mutations and cryptic splice sites. | 1 | Gene expression + Signal Transduction |
Local hormones are a large group of signaling molecules that do not circulate within the blood. Local hormones are produced by nerve and gland cells and bind to either neighboring cells or the same type of cell that produced them. Local hormones are activated and inactivated quickly. They are released during physical work and exercise. They mainly control smooth and vascular muscle dilation. Strength of response is dependent upon the concentration of receptors of target cell and the amount of ligand ( the specific local hormone).
Eicosanoids (ī′kō-să-noydz; eicosa = twenty, eidos = formed) are a primary type of local hormone. These local hormones are polyunsaturated fatty acid derivatives containing 20 carbon atoms and fatty acids derived from phospholipids in the cell membrane or from diet. Eicosanoids initiate either autocrine stimulation or paracrine stimulation. There are two main types of eicosanoids: prostaglandins and leukotrienes, which initiate either autocrine stimulation or paracrine stimulation. Eicosanoids are the result of a ubiquitous pathway which first produces arachidonic acid, and then the eicosanoid product.
Prostaglandins are the most diverse category of eicosanoids and are thought to be synthesized in most tissues of the body. This type of local hormone stimulates pain receptors and increases the inflammatory response. Nonsteroidal anti-inflammatory drugs stop the formation of prostaglandins, thus inhibiting these responses.
Leukotrienes are a type of eicosanoids that are produced in leukocytes and function in inflammatory mediation.
Paracrines (para- = beside or near) are local hormones that act on neighboring cells. This type of signaling involves the secretion of paracrine factors, which travel a short distance in the extracellular environment to affect nearby cells. These factors can be excitatory or inhibitory. There are a few families of factors that are very important in embryo development including fibroblast growth factor secreted them.
Juxtacrines (juxta = near) are local hormones that require close contact and act on either the cell which emitted them or on adjacent cells. | 1 | Gene expression + Signal Transduction |
The main advantage of electroforming is that it accurately replicates the external shape of the mandrel. Generally, machining a cavity accurately is more challenging than machining a convex shape, however the opposite holds true for electroforming because the mandrel's exterior can be accurately machined and then used to electroform a precision cavity.
Compared to other basic metal forming processes (casting, forging, stamping, deep drawing, machining and fabricating) electroforming is very effective when requirements call for extreme tolerances, complexity or light weight. The precision and resolution inherent in the photo-lithographically produced conductive patterned substrate, allows finer geometries to be produced to tighter tolerances while maintaining superior edge definition with a near optical finish. Electroformed metal can be extremely pure, with superior properties over wrought metal due to its refined crystal structure. Multiple layers of electroformed metals can be bonded together, or to different substrate materials to produce complex structures with "grown-on" flanges and bosses.
Tolerances of 1.5 to 3 nanometres have been reported.
A wide variety of shapes and sizes can be made by electroforming, the principal limitation being the need to part the product from the mandrel. Since the fabrication of a product requires only a single model or mandrel, low production quantities can be made economically. | 0 | Metallurgy |
The SH2 (Src Homology 2) domain is a structurally conserved protein domain contained within the Src oncoprotein and in many other intracellular signal-transducing proteins. SH2 domains bind to phosphorylated tyrosine residues on other proteins, modifying the function or activity of the SH2-containing protein. The SH2 domain may be considered the prototypical modular protein-protein interaction domain, allowing the transmission of signals controlling a variety of cellular functions. SH2 domains are especially common in adaptor proteins that aid in the signal transduction of receptor tyrosine kinase pathways. | 1 | Gene expression + Signal Transduction |
In a medical laboratory, flocculation is the core principle used in various diagnostic tests, for example the rapid plasma reagin test. | 0 | Metallurgy |
Metals can be heat-treated to alter the properties of strength, ductility, toughness, hardness and resistance to corrosion. Common heat treatment processes include annealing, precipitation strengthening, quenching, and tempering:
* Annealing process softens the metal by heating it and then allowing it to cool very slowly, which gets rid of stresses in the metal and makes the grain structure large and soft-edged so that, when the metal is hit or stressed it dents or perhaps bends, rather than breaking; it is also easier to sand, grind, or cut annealed metal.
* Quenching is the process of cooling metal very quickly after heating, thus "freezing" the metal's molecules in the very hard martensite form, which makes the metal harder.
* Tempering relieves stresses in the metal that were caused by the hardening process; tempering makes the metal less hard while making it better able to sustain impacts without breaking.
Often, mechanical and thermal treatments are combined in what are known as thermo-mechanical treatments for better properties and more efficient processing of materials. These processes are common to high-alloy special steels, superalloys and titanium alloys. | 0 | Metallurgy |
Mediator was originally discovered because it was important for RNA polymerase II function, but it has many more functions than just interactions at the transcription start site. | 1 | Gene expression + Signal Transduction |
An early medieval writer Theophilus Presbyter, believed to be the Benedictine monk and metalworker Roger of Helmarshausen, wrote a treatise in the early-to-mid-12th century that includes original work and copied information from other sources, such as the Mappae clavicula and Eraclius, De dolorous et artibus Romanorum. It provides step-by-step procedures for making various articles, some by lost-wax casting: "The Copper Wind Chest and Its Conductor" (Chapter 84); "Tin Cruets" (Chapter 88), and "Casting Bells" (Chapter 85), which call for using "tallow" instead of wax; and "The Cast Censer". In Chapters 86 and 87 Theophilus details how to divide the wax into differing ratios before moulding and casting to achieve accurately tuned small musical bells. The 16th-century Florentine sculptor Benvenuto Cellini may have used Theophilus writings when he cast his bronze Perseus with the Head of Medusa'. | 0 | Metallurgy |
PKA phosphorylates proteins that have the motif Arginine-Arginine-X-Serine exposed, in turn (de)activating the proteins. Many possible substrates of PKA exist; a list of such substrates is available and maintained by the NIH.
As protein expression varies from cell type to cell type, the proteins that are available for phosphorylation will depend upon the cell in which PKA is present. Thus, the effects of PKA activation vary with cell type: | 1 | Gene expression + Signal Transduction |
The school of metalwork in Mosul is believed to have been founded in the early 13th century under Zengid patronage. During this time, the Zengid region was operating as a vassal under the Ayyubid Sultanate. Control over Mosul as a city central to trade between China, the Mediterranean, Anatolia, and Mesopotamia was contested between the Zengids and the Ayyubid sultan, Saladin, throughout the early acquisitions of the Ayyubid Sultanate in Syria and Iraq after the decline of Fatimid rule. However, the Zengids remained in Mosul and were allowed some degree of authority under the Sultanate.
Around 1256, the Mongol occupation of Iraq began, and the region became a part of the Ilkhanate. Of the artifacts agreed to be "nabish al-Mawsili" (of Mosul), approximately 80% were produced after the commencement of Mongol rule in Mosul. However, it is unclear as to whether or not all of these artifacts were produced within Mosul and later exported as esteemed gifts, or created elsewhere by Mosulian artisans who relocated but maintained the "al-Mawsili" signature. | 0 | Metallurgy |
Twintrons were discovered by Donald W. Copertino and Richard B. Hallick as a group II intron within another group II intron in Euglena chloroplast genome. They found that splicing of both the internal and external introns occurs via lariat intermediates. Additionally, twintron splicing was found to proceed by a sequential pathway, the internal intron being removed prior to the excision of the external intron.
Since the original discovery, there have been other reports of Group III twintrons and GroupII/III twintrons in the chloroplast of Euglena gracilis. In 1993 a new type of complex twintron composed of four individual group III introns has been characterized. The external intron was interrupted by an internal intron containing two additional introns. In 1995 scientists discovered the first non-Euglena twintron in cryptomonad alga Pyrenomonas salina. In 2004, several twintrons were discovered in Drosophila. | 1 | Gene expression + Signal Transduction |
Native iron in the metallic state occurs rarely as small inclusions in certain basalt rocks. Besides meteoritic iron, Thule people of Greenland have used native iron from the Disko region. | 0 | Metallurgy |
MITF is phosphorylated on several serine and tyrosine residues. Serine phosphorylation is regulated by several signaling pathways including MAPK/BRAF/ERK, receptor tyrosine kinase KIT, GSK-3 and mTOR. In addition, several kinases including PI3K, AKT, SRC and P38 are also critical activators of MITF phosphorylation. In contrast, tyrosine phosphorylation is induced by the presence of the KIT oncogenic mutation D816V. This KIT pathway is dependent on SRC protein family activation signaling. The induction of serine phosphorylation by the frequently altered MAPK/BRAF pathway and the GSK-3 pathway in melanoma regulates MITF nuclear export and thereby decreasing MITF activity in the nucleus. Similarly, tyrosine phosphorylation mediated by the presence of the KIT oncogenic mutation D816V also increases the presence of MITF in the cytoplasm. | 1 | Gene expression + Signal Transduction |
The fundamental way to prevent fretting is to design for no relative motion of the surfaces at the contact. Surface roughness plays an important role as fretting normally occurs by the contact of the asperities of the mating surfaces. Lubricants are often employed to mitigate fretting because they reduce friction and inhibit oxidation. This may however, also cause the opposite effect as a lower coefficient of friction may lead to more movement. Thus, a solution must be carefully considered and tested.
In the aviation industry, coatings are applied to cause a harder surface and/or influence the friction coefficient.
Soft materials often exhibit higher susceptibility to fretting than hard materials of a similar type. The hardness ratio of the two sliding materials also has an effect on fretting wear. However, softer materials such as polymers can show the opposite effect when they capture hard debris which becomes embedded in their bearing surfaces. They then act as a very effective abrasive agent, wearing down the harder metal with which they are in contact. | 0 | Metallurgy |
The term refining is used in a narrower context. Henry Corts original puddling process only worked where the raw material was white cast iron, rather than the grey pig iron that was the usual raw material for finery forges. To use grey pig iron, a preliminary refining process was necessary to remove silicon. The pig iron was melted in a running out furnace and then run out into a trough. This process oxidised the silicon to form a slag, which floated on the iron and was removed by lowering a dam at the end of the trough. The product of this process was a white metal, known as finers metal or refined iron'. | 0 | Metallurgy |
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