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Proline-, glutamic acid- and leucine-rich protein 1 (PELP1) also known as modulator of non-genomic activity of estrogen receptor (MNAR) and transcription factor HMX3 is a protein that in humans is encoded by the PELP1 gene. is a transcriptional corepressor for nuclear receptors such as glucocorticoid receptors and a coactivator for estrogen receptors.
Proline-, glutamic acid-, and leucine-rich protein 1 (PELP1) is transcription coregulator and modulates functions of several hormonal receptors and transcription factors. PELP1 plays essential roles in hormonal signaling, cell cycle progression, and ribosomal biogenesis. PELP1 expression is upregulated in several cancers; its deregulation contributes to hormonal therapy resistance and metastasis; therefore, PELP1 represents a novel therapeutic target for many cancers. | 1 | Gene expression + Signal Transduction |
In molecular biology, a two-component regulatory system serves as a basic stimulus-response coupling mechanism to allow organisms to sense and respond to changes in many different environmental conditions. Two-component systems typically consist of a membrane-bound histidine kinase that senses a specific environmental stimulus, and a corresponding response regulator that mediates the cellular response, mostly through differential expression of target genes. Although two-component signaling systems are found in all domains of life, they are most common by far in bacteria, particularly in Gram-negative and cyanobacteria; both histidine kinases and response regulators are among the largest gene families in bacteria. They are much less common in archaea and eukaryotes; although they do appear in yeasts, filamentous fungi, and slime molds, and are common in plants, two-component systems have been described as "conspicuously absent" from animals. | 1 | Gene expression + Signal Transduction |
During the Song Dynasty, Chinese copper output from domestic mining was in decline and the resulting shortages caused miners to seek alternative methods for extracting copper. The discovery of a new “wet process” for extracting copper from mine water was introduced between the eleventh and twelfth century, which helped to mitigate their loss of supply.
Similar to the Anglo-Saxon method for cupellation, the Chinese employed the use of a base metal to extract the target metal from its impurities. First, the base metal, iron, is hammered into thin sheets. The sheets are then placed into a trough filled with “vitriol water” i.e., copper mining water which is then left to steep for several day. The mining water contains copper salts in the form of copper sulfate . The iron then reacts with the copper, displacing it from the sulfate ions, causing the copper to precipitate onto the iron sheets, forming a "wet" powder. Finally, the precipitated copper is collected and refined further through the traditional smelting process. This is the first large-scale use of a hydrometallurgical process. | 0 | Metallurgy |
Model organisms have been used in the study of TCF7L2 function. A conditional knockout mouse line called Tcf7l2 was generated at the Wellcome Trust Sanger Institute. Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Additional screens performed: - In-depth immunological phenotyping
Variations of the protein encoding gene are found in rats, zebra fish, drosophila, and budding yeast. Therefore, all of those organisms can be used as model organisms in the study of TCF7L2 function. | 1 | Gene expression + Signal Transduction |
The converting process occurs in a converter. Two kinds of converters are widely used: horizontal and vertical.
Horizontal (which are an improvement of the ) prevail in the metallurgy of non-ferrous metals. Such a converter is a horizontal barrel lined with refractory material inside. A hood for the purpose of the loading/unloading operations is located on the upper side of the converter. Two belts of tuyeres come along the axis on either sides of the converter.
Molten sulfide material, referred to as matte, is poured through the hood into the converter during the operation of loading. Air is distributed to tuyeres from the two tuyere collectors which are located on opposite sides of the converter. Collector pipes vary in diameter with distance from the connection to air supplying trunk; this is to provide equal pressure of air in each tuyere.
This high temperature roasting allows oxygen in the air to replace sulfide compounds in the minerals. Unless carefully captured, these oxidized sulfur compounds such as sulfur trioxide leave the converter as a noxious acidic vapor, along with other dangerous volatile elements such as arsenic trioxide. | 0 | Metallurgy |
As early as 1895 in the UK it was being noted that the heyday of the Bessemer process was over and that the open hearth method predominated. The Iron and Coal Trades Review said that it was "in a semi-moribund condition. Year after year, it has not only ceased to make progress, but it has absolutely declined." It has been suggested, both at that time and more recently, that the cause of this was the lack of trained personnel and investment in technology rather than anything intrinsic to the process itself. For example, one of the major causes of the decline of the giant ironmaking company Bolckow Vaughan of Middlesbrough was its failure to upgrade its technology. The basic process, the Thomas-Gilchrist process, remained in use longer, especially in Continental Europe, where iron ores were of high phosphorus content and the open-hearth process was not able to remove all phosphorus; almost all inexpensive construction steel in Germany was produced with this method in the 1950s and 1960s. It was eventually superseded by basic oxygen steelmaking.
In the U.S., commercial steel production using this method stopped in 1968. It was replaced by processes such as the basic oxygen (Linz–Donawitz) process, which offered better control of final chemistry. The Bessemer process was so fast (10–20 minutes for a heat) that it allowed little time for chemical analysis or adjustment of the alloying elements in the steel. Bessemer converters did not remove phosphorus efficiently from the molten steel; as low-phosphorus ores became more expensive, conversion costs increased. The process permitted only limited amount of scrap steel to be charged, further increasing costs, especially when scrap was inexpensive. Use of electric arc furnace technology competed favourably with the Bessemer process resulting in its obsolescence.
Basic oxygen steelmaking is essentially an improved version of the Bessemer process (decarburization by blowing oxygen as gas into the heat rather than burning the excess carbon away by adding oxygen carrying substances into the heat). The advantages of pure oxygen blast over air blast were known to Henry Bessemer, but 19th-century technology was not advanced enough to allow for the production of the large quantities of pure oxygen necessary to make it economical. | 0 | Metallurgy |
Due to its material properties, Terfenol-D is excellent for use in the manufacturing of low frequency, high powered underwater acoustics. Its initial application was in naval sonar systems. It sees application in magnetomechanical sensors, actuators, and acoustic and ultrasonic transducers due to its high energy density and large bandwidth capabilities, e.g. in the SoundBug device (its first commercial application by FeONIC). Its strain is also larger than that of another normally used material (PZT8), which allows Terfenol-D transducers to reach greater depths for ocean explorations than past transducers. Its low Young's modulus brings some complications due to compression at large depths, which are overcome in transducer designs that may reach 1000 ft in depth and only lose a small amount of accuracy of around 1 dB. Due to its high temperature range, Terfenol-D is also useful in deep hole acoustic transducers where the environment may reach high pressure and temperatures like oil holes. Terfenol-D may also be used for hydraulic valve drivers due to its high strain and high force properties. Similarly, magnetostrictive actuators have also been considered for use in fuel injectors for diesel engines because of the high stresses that can be produced. | 0 | Metallurgy |
#Curves in the Ellingham diagrams for the formation of metallic oxides are basically straight lines with a positive slope. The slope is proportional to ΔS, which is approximately constant with temperature.
#The lower the position of a metal's line in the Ellingham diagram, the greater is the stability of its oxide. For example, the line for Al (oxidation of aluminium) is found to be below that for Fe (formation of ) meaning that aluminium oxide is more stable than iron(III) oxide.
#Stability of metallic oxides decreases with increase in temperature. Highly unstable oxides like and HgO easily undergo thermal decomposition.
#The formation free energy of carbon dioxide () is almost independent of temperature, while that of carbon monoxide (CO) has negative slope and crosses the line near 700 °C. According to the Boudouard reaction, carbon monoxide is the dominant oxide of carbon at higher temperatures (above about 700 °C), and the higher the temperature (above 700 °C) the more effective a reductant (reducing agent) carbon is.
#If the curves for two metals at a given temperature are compared, the metal with the lower Gibbs free energy of oxidation on the diagram will reduce the oxide with the higher Gibbs free energy of formation. For example, metallic aluminium can reduce iron oxide to metallic iron, the aluminium itself being oxidized to aluminium oxide. (This reaction is employed in thermite.)
#The greater the gap between any two lines, the greater the effectiveness of the reducing agent corresponding to the lower line.
#The intersection of two lines implies an oxidation-reduction equilibrium. Reduction using a given reductant is possible at temperatures above the intersection point where the ΔG line of that reductant is lower on the diagram than that of the metallic oxide to be reduced. At the point of intersection the free energy change for the reaction is zero, below this temperature it is positive and the metallic oxide is stable in the presence of the reductant, while above the point of intersection the Gibbs energy is negative and the oxide can be reduced. | 0 | Metallurgy |
An iron founder (also iron-founder or ironfounder) in its more general sense is a worker in molten ferrous metal, generally working within an iron foundry. However, the term iron founder is usually reserved for the owner or manager of an iron foundry, a person also known in Victorian England as a master. Workers in a foundry are generically described as foundrymen; however, the various craftsmen working in foundries, such as moulders and pattern makers, are often referred to by their specific trades.
Historically the appellation "founder" was given to the supervisor of a blast furnace, and persons who made castings in iron or other heavy metal. The term is also often applied to the company or works in which an iron foundry operates. | 0 | Metallurgy |
During the 1950s, Bernard Katz and Paul Fatt observed spontaneous miniature synaptic currents at the frog neuromuscular junction. Based on these observations, they developed the quantal hypothesis that is the basis for our current understanding of neurotransmitter release as exocytosis and for which Katz received the Nobel Prize in Physiology or Medicine in 1970. In the late 1960s, Ricardo Miledi and Katz advanced the hypothesis that depolarization-induced influx of calcium ions triggers exocytosis.
Sir Charles Scott Sherringtonin coined the word synapse and the history of the word was given by Sherrington in a letter he wrote to John Fulton: | 1 | Gene expression + Signal Transduction |
Steel is an alloy composed of between 0.2 and 2.0 percent carbon, with the balance being iron. From prehistory through the creation of the blast furnace, iron was produced from iron ore as wrought iron, 99.82–100 percent Fe, and the process of making steel involved adding carbon to iron, usually in a serendipitous manner, in the forge, or via the cementation process. The introduction of the blast furnace reversed the problem. A blast furnace produces pig iron — an alloy of approximately 90 percent iron and 10 percent carbon. When the process of steel-making is started with pig iron, instead of wrought iron, the challenge is to remove a sufficient amount of carbon to reduce it to the 0.2 to 2 percentage for steel.
Before about 1860, steel was an expensive product, made in small quantities and used mostly for swords, tools and cutlery; all large metal structures were made of wrought or cast iron. Steelmaking was centered in Sheffield and Middlesbrough, Britain, which supplied the European and American markets. The introduction of cheap steel was due to the Bessemer and the open hearth processes, two technological advances made in England. In the Bessemer process, molten pig iron is converted to steel by blowing air through it after it was removed from the furnace. The air blast burned the carbon and silicon out of the pig iron, releasing heat and causing the temperature of the molten metal to rise. Henry Bessemer demonstrated the process in 1856 and had a successful operation going by 1864. By 1870 Bessemer steel was widely used for ship plate. By the 1850s, the speed, weight, and quantity of railway traffic was limited by the strength of the wrought iron rails in use. The solution was to turn to steel rails, which the Bessemer process made competitive in price. Experience quickly proved steel had much greater strength and durability and could handle the increasingly heavy and faster engines and cars.
After 1890 the Bessemer process was gradually supplanted by open-hearth steelmaking and by the middle of the 20th century was no longer in use. The open-hearth process originated in the 1860s in Germany and France. The usual open-hearth process used pig iron, ore, and scrap, and became known as the Siemens-Martin process. Its process allowed closer control over the composition of the steel; also, a substantial quantity of scrap could be included in the charge. The crucible process remained important for making high-quality alloy steel into the 20th century. By 1900 the electric arc furnace was adapted to steelmaking and by the 1920s, the falling cost of electricity allowed it to largely supplant the crucible process for specialty steels. | 0 | Metallurgy |
From the formation of the Roman Empire, Rome was an almost completely closed economy, not reliant on imports although exotic goods from India and China (such as gems, silk and spices) were highly prized (Shepard 1993). Through the recovery of Roman coins and ingots throughout the ancient world (Hughes 1980), metallurgy has supplied the archaeologist with material culture through which to see the expanse of the Roman world. | 0 | Metallurgy |
Last but not least prof. E.J.Zoqui has summarized in his work the approach proposed by several researchers in the criteria for semi-solid processing, which involves the stability of the solid phase fs with the temperature; to process semisolid alloys the sensitivity to variation of solid fraction with temperature should be minimal: in one direction it could evolve to a difficult to deform solid, on the other to a liquid which may be difficult to shape without proper moulding. It turns out that we can express this criterion again by evaluating the slope of the solidification curve, in fact ∂(fS)/∂T should be less than a certain threshold, which is commonly accepted in the scientific and technical literature to be below 0.03 1/K. Mathematically this may be expressed by an inequation, ∂(fS)/∂T < 0.03 (1/K) - where K stands for Kelvin degrees - could be equally assumed for a rough estimate of the two main semi-solid casting processing: both rheocasting ( 0.3<fs<0.4 ) and thixoforming (0.6<fs<0.7). If one would go back just to the (numerical) and functional approaches above, one should consider the reciprocal value i.e. ∂T/∂(fS)> 33 (K) | 0 | Metallurgy |
James Marrow was born on 23 November 1966 in Bromborough, Wirral to John Williams Marrow and Mary Elizabeth Marrow. He attended Wirral Grammar School for Boys, then graduated with a 1st Class Honours Master of Arts (M.A) in Natural Sciences (Materials Science) from the University of Cambridge in 1988, where he was a student at Clare College, Cambridge before pursuing and completing a Doctor of Philosophy degree in 1991. During his PhD, he studied the Fatigue mechanisms in embrittled duplex stainless steel and was supervised by Julia King. | 0 | Metallurgy |
This method relies on the idea that deoxidation of slag will lead to the deoxidation of steel.
The chemical equilibrium equation used for this process is:
where a is the activity of the oxygen in the slag, and a is the activity of oxygen in the steel.
Reducing the activity in the slag (a) will lower the oxygen levels in the slag. Afterwards, oxygen will diffuse from the steel into the lesser concentrated slag. This method is done by using deoxidizing agents on the slag, such as coke or silicon. As these agents do not come into direct contact with the steel, non-metallic inclusions will not form in the steel itself. | 0 | Metallurgy |
Targeted drug delivery is one of many ways researchers seek to improve drug delivery systems' overall efficacy, safety, and delivery. Within this medical field is a special reversal form of drug delivery called chemotactic drug targeting. By using chemical agents to help guide a drug carrier to a specific location within the body, this innovative approach seeks to improve precision and control during the drug delivery process, decrease the risk of toxicity, and potentially lower the required medical dosage needed. The general components of the conjugates are designed as follows: (i) carrier – regularly possessing promoter effect also on internalization into the cell; (ii) chemotactically active ligands acting on the target cells; (iii) drug to be delivered in a selective way and (iv) spacer sequence which joins drug molecule to the carrier and due to it enzyme labile moiety makes possible the intracellular compartment specific release of the drug. Careful selection of chemotactic component of the ligand not only the chemoattractant character could be expended, however, chemorepellent ligands are also valuable as they are useful to keep away cell populations degrading the conjugate containing the drug. In a larger sense, chemotactic drug-targeting has the potential to improve cancer, inflammation, and arthritis treatment by taking advantage of the difference in environment between the target site and its surroundings. Therefore, this Wikipedia article aims to provide a brief overview of chemotactic drug targeting, the principles behind the approach, possible limitations and advantages, and its application to cancer and inflammation. | 1 | Gene expression + Signal Transduction |
Recrystallization is prevented or significantly slowed by a dispersion of small, closely spaced particles due to Zener pinning on both low- and high-angle grain boundaries. This pressure directly opposes the driving force arising from the dislocation density and will influence both the nucleation and growth kinetics. The effect can be rationalized with respect to the particle dispersion level where is the volume fraction of the second phase and r is the radius. At low the grain size is determined by the number of nuclei, and so initially may be very small. However the grains are unstable with respect to grain growth and so will grow during annealing until the particles exert sufficient pinning pressure to halt them. At moderate the grain size is still determined by the number of nuclei but now the grains are stable with respect to normal growth (while abnormal growth is still possible). At high the unrecrystallized deformed structure is stable and recrystallization is suppressed. | 0 | Metallurgy |
Enhancer-FACS-seq (eFS), developed by the Bulyk lab at Brigham and Women’s Hospital and Harvard Medical School, is a highly parallel enhancer assay that aims for the identification of active, tissue-specific transcriptional enhancers, in the context of whole Drosophila melanogaster embryos. This technology replaces the use of microscopy to screen for tissue-specific enhancers with fluorescence activated cell sorting (FACS) of dissociated cells from whole embryos, combined with identification by high-throughput Illumina sequencing. | 1 | Gene expression + Signal Transduction |
As a reference, molten sodium chloride, table salt has a melting point (m.p.) of 801 °C (1474 °F). A variety of eutectic mixtures have been developed with lower melting points: | 0 | Metallurgy |
Deoxidization is a method used in metallurgy to remove the oxygen content during steel manufacturing. In contrast, antioxidants are used for stabilization, such as in the storage of food. Deoxidation is important in the steelmaking process as oxygen is often detrimental to the quality of steel produced. Deoxidization is mainly achieved by adding a separate chemical species to neutralize the effects of oxygen or by directly removing the oxygen. | 0 | Metallurgy |
Genetic evidence suggesting that RNAP was the target of ppGpp came from the discovery that M+ mutants (also called stringent RNAP mutants) display in vitro and in vivo mimicry of physiology and transcription regulation conferred by (p)ppGpp, even in its absence. Cross-linking ppGpp to RNAP reinforced this notion. Structural details of an association between ppGpp and RNAP came from the analysis of cocrystals that positioned ppGpp in the secondary channel of RNAP near the catalytic center. | 1 | Gene expression + Signal Transduction |
While the lead ISASMELT 5 t/h pilot plant was being designed in 1982–1983, MIM continued to use the 120 kg/h test rig to develop other processes, including the dross treatment process previously mentioned, and the treatment of lead-acid battery paste for lead recycling.
The MIM Holdings Board of Directors approved the construction of an ISASMELT plant at Britannia Refined Metals, the company's lead refinery at Northfleet in the United Kingdom, for commercial recovery of lead from battery paste to supplement the existing plant, which used a short rotary furnace to produce 10,000 t/y of lead. The new plant increased annual production to 30,000 t/y of recycled lead, and was commissioned in 1991. The ISASMELT furnace was used to produce low-antimony lead bullion from the battery paste and an antimony-rich slag that contained 55–65% lead oxide. While it was possible to recover the lead from the slag in the ISASMELT furnace by a reduction step, the total throughput of the plant was increased by treating the slag in the short rotary furnace when sufficient quantities of the slag had been generated. The plant was designed to treat 7.7 t/h of battery paste, but routinely treated 12 t/h. The plant was shut down in 2004 when Xstrata Zinc, which took over the MIM Holdings lead operations, decided to leave the lead recycling business.
A second lead ISASMELT plant for recovering lead from recycled batteries was commissioned in 2000 in Malaysia at Metal Reclamation Industries’ Pulau Indah plant. This ISASMELT plant has a design capacity of 40,000 t/y of lead bullion. | 0 | Metallurgy |
CeCoIn ("Cerium-Cobalt-Indium 5") is a heavy-fermion superconductor with a layered crystal structure, with somewhat two-dimensional electronic transport properties. The critical temperature of 2.3 K is the highest among all of the Ce-based heavy-fermion superconductors. | 0 | Metallurgy |
In many magnetic ferrous alloys, the Curie point, the temperature at which magnetic materials cease to behave magnetically, occurs at nearly the same temperature as the austenite transformation. This behavior is attributed to the paramagnetic nature of austenite, while both martensite and ferrite are strongly ferromagnetic. | 0 | Metallurgy |
PARP1 is involved in base excision repair (BER), single- and double-strand break repair, and chromosomal stability. It is also involved in transcriptional regulation through its facilitation of protein–protein interactions. PARP1 uses NAD in order to perform its function in apoptosis. If a PARP becomes overactive the cell will have decreased levels of NAD cofactor as well as decreased levels of ATP and thus will undergo necrosis. This is important in carcinogenesis because it could lead to the selection of PARP1 deficient cells (but not depleted) due to their survival advantage during cancer growth.
Susceptibility to carcinogenesis under PARP1 deficiency depends significantly on the type of DNA damage incurred. There are many implications that various PARPs are involved in preventing carcinogenesis. As stated previously, PARP1 and PARP2 are involved in BER and chromosomal stability. PARP3 is involved in centrosome regulation. Tankyrase is another (ADP-ribosyl)polymerase that is involved in telomere length regulation.
PARP1 inhibition has also been widely studied in anticancer therapeutics. The mechanism of action of a PARP1 inhibitor is to enhance the damage done by chemotherapy on the cancerous DNA by disallowing the reparative function of PARP1 in BRCA1/2 deficient individuals .
PARP14 is another ADP-ribosylating enzyme that has been well-studied in regards to cancer therapy targets; it is a signal transducer and activator of STAT6 transcription-interacting protein, and was shown to be associated with the aggressiveness of B-cell lymphomas. | 1 | Gene expression + Signal Transduction |
Anisomycin, also known as flagecidin, is an antibiotic produced by Streptomyces griseolus which inhibits eukaryotic protein synthesis. Partial inhibition of DNA synthesis occurs at anisomycin concentrations that effect 95% inhibition of protein synthesis. Anisomycin can activate stress-activated protein kinases, MAP kinase and other signal transduction pathways. | 1 | Gene expression + Signal Transduction |
Mediator is a multiprotein complex that functions as a transcriptional coactivator in all eukaryotes. It was discovered in 1990 in the lab of Roger D. Kornberg, recipient of the 2006 Nobel Prize in Chemistry. Mediator complexes interact with transcription factors and RNA polymerase II. The main function of mediator complexes is to transmit signals from the transcription factors to the polymerase.
Mediator complexes are variable at the evolutionary, compositional and conformational levels. The first image shows only one "snapshot" of what a particular mediator complex might be composed of, but it certainly does not accurately depict the conformation of the complex in vivo. During evolution, mediator has become more complex. The yeast Saccharomyces cerevisiae (a simple eukaryote) is thought to have up to 21 subunits in the core mediator (exclusive of the CDK module), while mammals have up to 26.
Individual subunits can be absent or replaced by other subunits under different conditions. Also, there are many intrinsically disordered regions in mediator proteins, which may contribute to the conformational flexibility seen both with and without other bound proteins or protein complexes. A more realistic model of a mediator complex without the CDK module is shown in the second figure.
The mediator complex is required for the successful transcription by RNA polymerase II. Mediator has been shown to make contacts with the polymerase in the transcription preinitiation complex. A recent model showing the association of the polymerase with mediator in the absence of DNA is shown in the figure to the left. In addition to RNA polymerase II, mediator must also associate with transcription factors and DNA. A model of such interactions is shown in the figure to the right. Note that the different morphologies of mediator do not necessarily mean that one of the models is correct; rather those differences may reflect the flexibility of mediator as it interacts with other molecules. For example, after binding the enhancer and core promoter, the mediator complex undergoes a compositional change in which the kinase module dissociates from the complex to allow association with RNA polymerase II and transcriptional activation.
The Mediator complex is located within the cell nucleus. It is required for the successful transcription of nearly all class II gene promoters in yeast. It works in the same manner in mammals. The mediator functions as a coactivator and binds to the C-terminal domain of RNA polymerase II holoenzyme, acting as a bridge between this enzyme and transcription factors. | 1 | Gene expression + Signal Transduction |
The period of the iconoclasts synchronised with the reign of the Frankish emperor Charlemagne, whose power was felt throughout western Europe. Some of the craftsmen who were forced to leave Byzantium were welcomed by him in his capitals of Cologne and Aix-la-Chapelle and their influence was also felt in France. Another stream passed by way of the Mediterranean to Italy, where the old classical art had decayed owing to the many national calamities, and here it brought about a revival. In the Rhineland and elsewhere in Europe the terms "Rhenish-Byzantine" and "Romanesque" applied to architecture and works of art generally, testify to the provenance of the style of this and the succeeding period. The bronze parapet of Aachen Cathedral is of classic design and probably dates from Charlemagne's time.
All through the Middle Ages the use of bronze continued on a great scale, particularly in the 11th and 12th centuries. Bernward, bishop of Hildesheim, a great patron of the arts, had bronze doors, the Bernward Doors, made for St Nicholas' church (afterwards removed to the cathedral) which were set up in 1015; great doors were made for Augsburg somewhere between 1060 and 1065, and for Mainz shortly after the year 1000. A prominent feature on several of these doors is seen in finely modelled lion jaws, with conventional manes and with ring hanging from their jaws. These have their counterpart in France and Scandinavia as well as in England, where they are represented by the so-called Sanctuary Knocker at Durham Cathedral.
Provision of elaborate tomb monuments and church furniture gave much work to German and Netherlandish founders. Mention may be made of the seven-branch candlestick at Essen Cathedral made for the Abbess Matilda about the year 1000, and another at Brunswick completed in 1223; also of the remarkable font of the 13th century made for Hildesheim Cathedral at the charge of Wilbernus, a canon of the cathedral. Other fonts are found at Brandenburg and Würzburg. Vast numbers of bronze and brass ewers, holy-water vessels, reliquaries and candelabra were produced in the Middle Ages. In general, most of the finest work was executed for the Church. An important centre of medieval copper and brass casting (Dutch: geelgieten; literally "yellow casting") was the Meuse Valley, especially in the 12th century. The city of Dinant gave its name to the French term for all types of artistic copper and brass work: dinanderie (see also section "Brass"). After the destruction of the town by Charles the Bold in 1466, many brass workers moved to Maastricht, Aachen and other towns in Germany and even England.
The end of the Gothic period saw some great craftsmen in Germany and the Habsburg Netherlands. The brass worker Aert van Tricht was based in Maastricht but worked in St. Johns Cathedral, s-Hertogenbosch and Xanten Cathedral. A bronze lectern for St. Peter's Church, Leuven is now in the collection of The Cloisters in New York. Peter Vischer of Nuremberg, and his sons, working on the bronze reliquary of Saint Sebald, a finely conceived monument of architectural form, with rich details of ornament and figures; among the latter appearing the artist in his working dress. The shrine was completed and set up in the year 1516. This great craftsman executed other fine works at Magdeburg, Römhild and Breslau. Reference should be made to the colossal monument at Innsbruck, the tomb of the Emperor Maximilian I, with its 28 bronze statues of more than life size. Large fountains in which bronze was freely employed were set up, such as those at Munich and Augsburg. The tendency was to use this metal for large works of an architectural or sculpturesque nature; while at the same time smaller objects were produced for domestic purposes. By the late 15th to 16th centuries, a style of ornamental brass bowls called Beckenschlägerschüssel had developed. | 0 | Metallurgy |
MECP2 duplication syndrome (M2DS) is a rare disease that is characterized by severe intellectual disability and impaired motor function. It is an X-linked genetic disorder caused by the overexpression of MeCP2 protein. | 1 | Gene expression + Signal Transduction |
Signal peptides function to prompt a cell to translocate the protein, usually to the cellular membrane. In prokaryotes, signal peptides direct the newly synthesized protein to the SecYEG protein-conducting channel, which is present in the plasma membrane. A homologous system exists in eukaryotes, where the signal peptide directs the newly synthesized protein to the Sec61 channel, which shares structural and sequence homology with SecYEG, but is present in the endoplasmic reticulum. Both the SecYEG and Sec61 channels are commonly referred to as the translocon, and transit through this channel is known as translocation. While secreted proteins are threaded through the channel, transmembrane domains may diffuse across a lateral gate in the translocon to partition into the surrounding membrane. | 1 | Gene expression + Signal Transduction |
In eukaryotic somatic cells, the poly(A) tails of most mRNAs in the cytoplasm gradually get shorter, and mRNAs with shorter poly(A) tail are translated less and degraded sooner. However, it can take many hours before an mRNA is degraded. This deadenylation and degradation process can be accelerated by microRNAs complementary to the 3′ untranslated region of an mRNA. In immature egg cells, mRNAs with shortened poly(A) tails are not degraded, but are instead stored and translationally inactive. These short tailed mRNAs are activated by cytoplasmic polyadenylation after fertilisation, during egg activation.
In animals, poly(A) ribonuclease (PARN) can bind to the 5′ cap and remove nucleotides from the poly(A) tail. The level of access to the 5′ cap and poly(A) tail is important in controlling how soon the mRNA is degraded. PARN deadenylates less if the RNA is bound by the initiation factors 4E (at the 5′ cap) and 4G (at the poly(A) tail), which is why translation reduces deadenylation. The rate of deadenylation may also be regulated by RNA-binding proteins. Additionally, RNA triple helix structures and RNA motifs such as the poly(A) tail 3’ end binding pocket retard deadenylation process and inhibit poly(A) tail removal. Once the poly(A) tail is removed, the decapping complex removes the 5′ cap, leading to a degradation of the RNA. Several other proteins are involved in deadenylation in budding yeast and human cells, most notably the CCR4-Not complex. | 1 | Gene expression + Signal Transduction |
Early diffusion models postulated that atomic motion in substitutional alloys occurs via a direct exchange mechanism, in which atoms migrate by switching positions with atoms on adjacent lattice sites. Such a mechanism implies that the atomic fluxes of two different materials across an interface must be equal, as each atom moving across the interface causes another atom to move across in the other direction.
Another possible diffusion mechanism involves lattice vacancies. An atom can move into a vacant lattice site, effectively causing the atom and the vacancy to switch places. If large-scale diffusion takes place in a material, there will be a flux of atoms in one direction and a flux of vacancies in the other.
The Kirkendall effect arises when two distinct materials are placed next to each other and diffusion is allowed to take place between them. In general, the diffusion coefficients of the two materials in each other are not the same. This is only possible if diffusion occurs by a vacancy mechanism; if the atoms instead diffused by an exchange mechanism, they would cross the interface in pairs, so the diffusion rates would be identical, contrary to observation. By Fick's 1st law of diffusion, the flux of atoms from the material with the higher diffusion coefficient will be larger, so there will be a net flux of atoms from the material with the higher diffusion coefficient into the material with the lower diffusion coefficient. To balance this flux of atoms, there will be a flux of vacancies in the opposite direction—from the material with the lower diffusion coefficient into the material with the higher diffusion coefficient—resulting in an overall translation of the lattice relative to the environment in the direction of the material with the lower diffusion constant.
Macroscopic evidence for the Kirkendall effect can be gathered by placing inert markers at the initial interface between the two materials, such as molybdenum markers at an interface between copper and brass. The diffusion coefficient of zinc is higher than the diffusion coefficient of copper in this case. Since zinc atoms leave the brass at a higher rate than copper atoms enter, the size of the brass region decreases as diffusion progresses. Relative to the molybdenum markers, the copper-brass interface moves toward the brass at an experimentally measurable rate. | 0 | Metallurgy |
The reaction of calcium carbide with water, producing acetylene and calcium hydroxide, was discovered by Friedrich Wöhler in 1862.
:CaC(s) + 2HO(l) → CH(g) + Ca(OH)(aq)
This reaction was the basis of the industrial manufacture of acetylene, and is the major industrial use of calcium carbide.
Today acetylene is mainly manufactured by the partial combustion of methane or appears as a side product in the ethylene stream from cracking of hydrocarbons. Approximately 400,000 tonnes are produced this way annually (see acetylene preparation).
In China, acetylene derived from calcium carbide remains a raw material for the chemical industry, in particular for the production of polyvinyl chloride. Locally produced acetylene is more economical than using imported oil. Production of calcium carbide in China has been increasing. In 2005 output was 8.94 million tons, with the capacity to produce 17 million tons.
In the United States, Europe, and Japan, consumption of calcium carbide is generally declining. Production levels in the US during the 1990s were 236,000 tons per year. | 0 | Metallurgy |
Transcriptional noise is a primary cause of the variability (noise) in gene expression occurring between cells in isogenic populations (see also cellular noise) . A proposed source of transcriptional noise is transcriptional bursting although other sources of heterogeneity, such as unequal separation of cell contents at mitosis are also likely to contribute considerably. Bursting transcription, as opposed to simple probabilistic models of transcription, reflects multiple states of gene activity, with fluctuations between states separated by irregular intervals, generating uneven protein expression between cells. Noise in gene expression can have tremendous consequences on cell behaviour, and must be mitigated or integrated. In certain contexts, such as establishment of viral latency, the survival of microbes in rapidly changing stressful environments, or several types of scattered differentiation, the variability may be essential. Variability also impacts upon the effectiveness of clinical treatment, with resistance of bacteria and yeast to antibiotics demonstrably caused by non-genetic differences. Variability in gene expression may also contribute to resistance of sub-populations of cancer cells to chemotherapy and appears to be a barrier to curing HIV. | 1 | Gene expression + Signal Transduction |
Arner et al. identified 65,423 transcribed enhancers (producing eRNA) among 33 different cell types under different conditions and different timings of stimulation. The transcription of enhancers generally preceded transcription of transcription factors which, in turn, generally preceded messenger RNA(mRNA) transcription of genes.
Carullo et al. examined one particular cell type, neurons (from primary neuron cultures). They exhibited 28,492 putative enhancers generating eRNAs. These eRNAs were often transcribed from both strands of the enhancer DNA in opposite directions. Carullo et al. used these cultured neurons to examine the timing of specific enhancer eRNAs compared to the mRNAs of their target genes. The cultured neurons were activated and RNA was isolated from those neurons at 0, 3.75, 5, 7.5, 15, 30, and 60 minutes after activation. In these experimental conditions, they found that 2 of the 5 enhancers of the immediate early gene (IEG) FOS, that is FOS enhancer 1 and FOS enhancer 3, became activated and initiated transcription of their eRNAs (eRNA1 and eRNA3). FOS eRNA1 and eRNA3 were significantly up-regulated within 7.5 minutes, whereas FOS mRNA was only upregulated 15 minutes after stimulation. Similar patterns occurred at IEGs FOSb and NR4A1, indicating that for many IEGs, eRNA induction precedes mRNA induction in response to neuronal activation.
While some enhancers can activate their target promoters at their target genes without transcribing eRNA, most active enhancers do transcribe eRNA during activation of their target promoters. | 1 | Gene expression + Signal Transduction |
MgCu is a binary intermetallic compound of magnesium (Mg) and copper (Cu) adopting cubic crystal structure, more specifically the C15 Laves phase. The space group of MgCu is Fdm with lattice parameter a = 7.04 Å. | 0 | Metallurgy |
DNA is extracted from cells used to create test fragments. These test fragments are added to a solution containing a variety of microsphere beads. Each type of microsphere bead contains a known DNA probe with a unique fluorescent identity. Test fragments and probes on the microsphere beads are allowed to hybridize to each other. Once hybridized, the microsphere beads are sorted, usually using flow cytometry. This allows for the detection of each of the gene variants from the original sample. The resulting data collected will indicate the relative abundance of each hybridized sample to the microsphere. | 1 | Gene expression + Signal Transduction |
In the field of genomics, GeneCalling is an open-platform mRNA transcriptional profiling technique. The GeneCalling protocol measures levels of cDNA, which are correlated with gene expression levels of specific transcripts. Differences between gene expression in healthy tissues and disease or drug responsive tissues are examined and compared in this technology. The technique has been applied to the study of human tissues and plant tissues. | 1 | Gene expression + Signal Transduction |
The American biochemist George Wald and others had outlined the visual cycle by 1958. For his work, Wald won a share of the 1967 Nobel Prize in Physiology or Medicine with Haldan Keffer Hartline and Ragnar Granit. | 1 | Gene expression + Signal Transduction |
Recent excavations in Middle Ganges Valley conducted by archaeologist Rakesh Tewari show iron working in India may have begun as early as 1800 BCE. Archaeological sites in India, such as Malhar, Dadupur, Raja Nala Ka Tila and Lahuradewa in the state of Uttar Pradesh show iron implements in the period between 1800 BCE-1200 BCE. Sahi (1979: 366) concluded that by the early 13th century BCE, iron smelting was definitely practiced on a bigger scale in India, suggesting that the date the technology's early period may well be placed as early as the 16th century BCE.
Some of the early iron objects found in India are dated to 1400 BCE by employing the method of radio carbon dating. Spikes, knives, daggers, arrow-heads, bowls, spoons, saucepans, axes, chisels, tongs, door fittings etc. ranging from 600 BCE—200 BCE have been discovered from several archaeological sites. In Southern India (present day Mysore) iron appeared as early as the 12th or 11th century BCE. These developments were too early for any significant close contact with the northwest of the country.
The earliest available Bronze age swords of copper discovered from the Harappan sites in Pakistan date back to 2300 BCE. Swords have been recovered in archaeological findings throughout the Ganges-Jamuna Doab region of India, consisting of bronze but more commonly copper. Diverse specimens have been discovered in Fatehgarh, where there are several varieties of hilt. These swords have been variously dated to periods between 1700 and 1400 BCE, but were probably used more extensively during the opening centuries of the 1st millennium BCE.
The beginning of the 1st millennium BCE saw extensive developments in iron metallurgy in India. Technological advancement and mastery of iron metallurgy was achieved during this period of peaceful settlements. The years between 322 and 185 BCE saw several advancements being made to the technology involved in metallurgy during the politically stable Maurya period (322—185 BCE). Greek historian Herodotus (431—425 BCE) wrote the first western account of the use of iron in India.
Perhaps as early as 300 BCE—although certainly by 200 CE—high quality steel was being produced in southern India by what Europeans would later call the crucible technique. In this system, high-purity wrought iron, charcoal, and glass were mixed in a crucible and heated until the iron melted and absorbed the carbon. The first crucible steel was the wootz steel that originated in India before the beginning of the common era. Wootz steel was widely exported and traded throughout ancient Europe, China, the Arab world, and became particularly famous in the Middle East, where it became known as Damascus steel. Archaeological evidence suggests that this manufacturing process was already in existence in South India well before the common era.
Zinc mines of Zawar, near Udaipur, Rajasthan, were active during 400 BCE. There are references of medicinal uses of zinc in the Charaka Samhita (300 BCE). The Rasaratna Samuccaya (800 CE) explains the existence of two types of ores for zinc metal, one of which is ideal for metal extraction while the other is used for medicinal purpose. The Periplus Maris Erythraei mentions weapons of Indian iron and steel being exported from India to Greece. | 0 | Metallurgy |
In order to confer to the pellets high resistance metallurgic mechanics and appropriate characteristics, the pellets are subjected to thermal processing, which involves stages of drying, preheating, firing, after-firing and cooling. The duration of each stage and the temperature that the pellets are subjected to have a strong influence on the final product quality. | 0 | Metallurgy |
GPCRs become desensitized when exposed to their ligand for a long period of time. There are two recognized forms of desensitization: 1) homologous desensitization, in which the activated GPCR is downregulated; and 2) heterologous desensitization, wherein the activated GPCR causes downregulation of a different GPCR. The key reaction of this downregulation is the phosphorylation of the intracellular (or cytoplasmic) receptor domain by protein kinases. | 1 | Gene expression + Signal Transduction |
The hepatitis B virus (HBV) genome encodes its own DNA polymerase for replication. Biomics Biotechnologies has evaluated around 5000 siRNA sequences of this gene for effective knockdown; five sequences were chosen for further investigation and shown to have potent silencing activity when converted into shRNA expression cassettes. A multi-cassette construct, Hepbarna, is under preclinical development for delivery by an adeno-associated virus 8 (AAV-8) liver-targeting vector. | 1 | Gene expression + Signal Transduction |
In metallurgy, alpha case is the oxygen-enriched surface phase that occurs when titanium and its alloys are exposed to heated air or oxygen. Alpha case is hard and brittle, and tends to create a series of microcracks that will reduce the metal's performance and its fatigue properties. Alpha case can be minimized or avoided by processing titanium at very deep vacuum levels. However once present on the surface, the currently applied method to remove the alpha case is by the subtractive methods of machining and/or chemical milling.
An emerging technique is to subject the metal to an electrochemical treatment in molten salts, such as calcium chloride or lithium chloride at elevated temperatures. This method removes the dissolved oxygen from the alpha case, hence restoring the oxygen-free metal. However, an unwanted consequence of the high temperature treatment is the growth of the grains in the metal. Grain growth may be limited by lowering the molten salt temperature. Alternatively, the metal may be rolling-pressed again to break the large grains into smaller ones. | 0 | Metallurgy |
The secret of bulat manufacturing had been lost by the beginning of the 19th century. It is known that the process involved dipping the finished weapon into a vat containing a special liquid of which spiny restharrow extract was a part (the plants name in Russian, stalnik', reflects its historical role), then holding the sword aloft while galloping on a horse, allowing it to dry and harden against the wind.
Pavel Anosov eventually managed to duplicate the qualities of that metal in 1838, when he completed ten years of study into the nature of Damascus steel swords.
Anosov had entered the Saint Petersburg Mine Cadet School in 1810, where a Damascus steel sword was stored in a display case. He became enchanted with the sword, and was filled with stories of them slashing through their European counterparts. In November 1817, he was sent to the factories of Zlatoust mining region in the southern Urals, where he was soon promoted to the inspector of the "weapon decoration department".
Here he again came into contact with Damascus steel of European origin (which was in fact pattern welded steel, and not at all similar), but quickly found that this steel was quite inferior to the original forged in the Middle East from wootz steel from India. Anosov had been working with various quenching techniques, and decided to attempt to duplicate Damascus steel with quenching. He eventually developed a methodology that greatly increased the hardness of his steels.
Bulat became popular in cannon manufacturing, until the Bessemer process was able to make the same quality steels for far less money. | 0 | Metallurgy |
Sinter roasting involves heating the fine ores at high temperatures, where simultaneous oxidation and agglomeration of the ores take place. For example, lead sulfide ores are subjected to sinter roasting in a continuous process after froth flotation to convert the fine ores to workable agglomerates for further smelting operations. | 0 | Metallurgy |
Metrnl participates in the control of inflammatory responses and is a critical regulator of muscle regeneration. | 1 | Gene expression + Signal Transduction |
With the end of the war and the adoption of the New Economic Policy (NEP) in March 1921, the restoration of the Ural industry began. Uralplan was created, under whose auspices the development of a program for the integrated development of the region was carried out. Most of the enterprises switched to a self-supporting scheme, which led to the emergence of industrial trusts, which united factories according to industry characteristics. 5 metallurgical trusts were formed in geographical areas, as well as separate trusts "Uralzoloto," "Uralmed," and trusts for the extraction of coal. In 1925, Uralplan developed a "Three-Year Program for the Development of the Metallurgical Industry in the Urals," then a plan for the development of the Urals for 1925-1930 was drawn up, which included, among other things, the construction of the Magnitogorsk Metallurgical Complex. Concession contracts for the smelting of metals and the extraction of minerals operated with varying degrees of success. In 1927, the number of concession contracts in the Urals included 12 companies. Subsequently, the trusts were downsized with the allocation of iron ore trusts. In total, on October 1, 1925, there were 31 trusts in the Urals. After the adoption of the first five-year plan, in 1929 the trust system was abolished.
In the 1920s-1930s, the concentration of production and specialization of factories, which began at the beginning of the 20th century, continued in the metallurgy of the Urals. The Nadezhdinsky Plant focused on rolling of all Ural rails, the Nizhny Salda Plant switched to the production of shaped rolled products, the production of pipes was concentrated at the Pervouralsk Plant, the Verkh-Isetsky Plant switched to the production of transformer steel. Machine-building and mechanical enterprises were separated from metallurgical enterprises. Small mines were actively closed, ore mining was concentrated at the large deposits of Bakalsky, Tagilo-Kushvinsky, Nadezhdinsky, and Alapaevsky districts. Geological exploration work began in 1920 in the Urals, and by 1933 the explored reserves of iron ore amounted to about 2 billion tons, including 478 million tons along Magnitnaya Mountain. There was an acute shortage of fuel resources, which forced metallurgists to switch to mineral fuel. The first successful blast-furnace smelting in the Urals of Kuznetsk coke took place on June 13, 1924 at the Nizhnesaldinsky Plant. Later, Kushvinsky, Nizhnetagilsky, and other plants switched to using coke. By 1926, 37% of the Ural pig iron was smelted using coke, the number of operating blast furnaces was 32, open-hearth furnaces was 47 (in 1913 - 61 and 75, respectively), and their productivity increased 1.5 and 1.7 times, respectively, to the level of production in 1913.
The recovery of the copper and gold-platinum industries was much slower due to the greater damage inflicted during the Civil War. In 1921-1922, the extraction of copper ore in the Urals amounted to only 2.2% of the level of 1913, gold - 1.9%, and platinum - 4.3%. By 1928, production amounted to 585.4 thousand tons (88.7% of the level of 1913), and 15 copper mines were able to resume operation.
At the end of the 1920s, Soviet design institutes, with the involvement of foreign companies, began designing the giants of the Ural metallurgy and mechanical engineering — Magnitogorsk, Chelyabinsk and Novotagilsky metallurgical plants, Ural Heavy Machinery Plant, Uralvagonzavod and Pyshminsky Copper-Electrolyte Plant. On May 15, 1930, the Central Committee of the CPSU(b) issued a resolution "On the work of Uralmet," which emphasized the need to create a coal and metallurgical center in the East of the USSR on the basis of coal and ore deposits of the Urals and Siberia. Investments in the construction of new and reconstruction of old plants have increased dramatically. In 1925-1926, 52.6 million rubles were disbursed, and in 1932 — already 1447.7 million rubles. The management of the metallurgical industry was also centralized. In 1931, the Main Directorate of the Metallurgical Industry of the VSNH was liquidated, the main committees were created: Glavchermet, Glavspetsstal, Glavmetiz, and Glavtrubostal. Later, in 1939, the People's Commissariats of Ferrous and Non-Ferrous Metallurgy of the USSR were established.
During the 1st and 2nd five-year plans, mining, ore dressing and ore preparation for smelting developed intensively. Flotation and melting of concentrates in water packs and reverberatory furnaces have been successfully applied in non-ferrous metallurgy. By 1934, 62% of all mined ore was being enriched in the Urals. By the beginning of the 2nd five-year plan, drilling at the mines was fully mechanized. Iron ore production by 1937 reached 8.7 million tons (31% of production in the USSR), and copper ore by 1935 had reached 2.96 million tons. The conversion of blast furnaces to mineral fuel continued: in 1940 86.8% of Ural pig iron was smelted on coke. Only 8 furnaces worked on charcoal, producing special and high-quality cast iron. During the same period, non-ferrous metallurgy plants were built: Krasnouralsky and Sredneuralsky copper smelters, Pyshminsky Copper Electrolytic, Ural Aluminum, Chelyabinsk Zinc, Ufaleysky, Rezhsky and Yuzhno-Uralsky Nickel, Solikamsk and Berezniki Magnesium. Most of the equipment of the new plants was purchased abroad. In 1931, 600 million rubles were spent on the purchase of imported equipment, in 1932 — 270 million rubles, in 1933 — 60 million rubles.
In 1933 and 1937, the People's Commissar of Heavy Industry of the USSR, G.K. Ordzhonikidze issued orders for the development of the gold-platinum industry. The measures taken made it possible in 1936 to extract in the Urals a record 12.8 tons of gold (156.3% compared to the level of 1913) and 4.8 tons of platinum (97.8% compared to the level of 1913). | 0 | Metallurgy |
Ideal grain growth is a special case of normal grain growth where boundary motion is driven only by local curvature of the grain boundary. It results in the reduction of the total amount of grain boundary surface area i.e. total energy of the system. Additional contributions to the driving force by e.g. elastic strains or temperature gradients are neglected. If it holds that the rate of growth is proportional to the driving force and that the driving force is proportional to the total amount of grain boundary energy, then it can be shown that the time t required to reach a given grain size is approximated by the equation
where d is the initial grain size, d is the final grain size and k is a temperature dependent constant given by an exponential law:
where k is a constant, T is the absolute temperature and Q is the activation energy for boundary mobility. Theoretically, the activation energy for boundary mobility should equal that for self-diffusion but this is often found not to be the case.
In general these equations are found to hold for ultra-high purity materials but rapidly fail when even tiny concentrations of solute are introduced. | 0 | Metallurgy |
When water flows through cracks present in concrete, water may dissolve various minerals present in the hardened cement paste or in the aggregates, if the solution is unsaturated with respect to them. Dissolved ions, such as calcium (Ca), are leached out and transported in solution some distance. If the physico-chemical conditions prevailing in the seeping water evolve with distance along the water path and water becomes supersaturated with respect to certain minerals, they can further precipitate, making calthemite deposits (predominately calcium carbonate) inside the cracks, or at the concrete outer surface. This process can cause the self-healing of fractures in particular conditions.
Fagerlund (2000) determined that, “About 15% of the lime has to be dissolved before strength is affected. This corresponds to about 10% of the cement weight, or almost all of the initially formed Ca(OH).” Therefore, a large amount of "calcium hydroxide" (Ca(OH)) must be leached from the concrete before structural integrity is affected. The other issue however is that leaching away Ca(OH) may allow the corrosion of reinforcing steel to affect structural integrity. | 0 | Metallurgy |
hnRNPs affect several aspects of the cell cycle by recruiting, splicing, and co-regulating certain cell cycle control proteins. Much of hnRNPs' importance to cell cycle control is evidenced by its role as an oncogene, in which a loss of its functions results in various common cancers. Often, misregulation by hnRNPs is due to splicing errors, but some hnRNPs are also responsible for recruiting and guiding the proteins themselves, rather than just addressing nascent RNAs. | 1 | Gene expression + Signal Transduction |
All of these forms of crack development are the result of the cylinder being subject to high pressure for prolonged periods. The cracks are intergranular and occur at grain boundaries. There is no evidence of stress corrosion or fatigue.
The presence of a relatively high lead content has been identified as a contributory factor. Cracking at the grain boundaries is accelerated in the presence of lead. The presence of bismuth is also suspected to be contributory.
Alloy composition has also been found to be a factor. Alloy 6061 has shown good resistance to SLC, as have alloys 5283 and 7060.
Manufacturing defects such as folds on the inside surface have been shown to be harmful, particularly for parallel-threaded cylinders.
Grain size has been shown to be of relatively minor importance. | 0 | Metallurgy |
Thermocouples are often used at high temperatures and in reactive furnace atmospheres. In this case, the practical lifetime is limited by thermocouple aging. The thermoelectric coefficients of the wires in a thermocouple that is used to measure very high temperatures may change with time, and the measurement voltage accordingly drops. The simple relationship between the temperature difference of the junctions and the measurement voltage is only correct if each wire is homogeneous (uniform in composition). As thermocouples age in a process, their conductors can lose homogeneity due to chemical and metallurgical changes caused by extreme or prolonged exposure to high temperatures. If the aged section of the thermocouple circuit is exposed to a temperature gradient, the measured voltage will differ, resulting in error.
Aged thermocouples are only partly modified; for example, being unaffected in the parts outside the furnace. For this reason, aged thermocouples cannot be taken out of their installed location and recalibrated in a bath or test furnace to determine error. This also explains why error can sometimes be observed when an aged thermocouple is pulled partly out of a furnace—as the sensor is pulled back, aged sections may see exposure to increased temperature gradients from hot to cold as the aged section now passes through the cooler refractory area, contributing significant error to the measurement. Likewise, an aged thermocouple that is pushed deeper into the furnace might sometimes provide a more accurate reading if being pushed further into the furnace causes the temperature gradient to occur only in a fresh section. | 0 | Metallurgy |
The lost-wax casting tradition was developed by the peoples of Nicaragua, Costa Rica, Panama, Colombia, northwest Venezuela, Andean America, and the western portion of South America. Lost-wax casting produced some of the regions typical gold wire and delicate wire ornament, such as fine ear ornaments. The process was employed in prehispanic times in Colombias Muisca and Sinú cultural areas. Two lost-wax moulds, one complete and one partially broken, were found in a shaft and chamber tomb in the vereda of Pueblo Tapado in the municipio of Montenegro (Department of Quindío), dated roughly to the pre-Columbian period. The lost-wax method did not appear in Mexico until the 10th century, and was thereafter used in western Mexico to make a wide range of bell forms. | 0 | Metallurgy |
According to R. Balasubramaniam and A. V. Ramesh Kumar (2003), the pillar shows "excellent" atmospheric corrosion resistance.
Ray et al. (1997) analyzed portions of the two smaller fragments. Their analysis revealed the following chemical composition (weight %):
Balasubramaniam (2002) also obtained a small portion of the pillar with ASI's permission, and used an electron probe microanalyzer to analyze its chemical composition. He found that "the composition varied from one location to another":
The typical composition of the slag was 55.8% iron, 27.8% silicon, 16.3% phosphorus, and 0.1% manganese. | 0 | Metallurgy |
Orphan MTases are common in bacteria and archea CcrM is found in almost every group of Alphaproteobacteria, excepting in Rickettsiales and Magnetococcales, and homologs can be found in Campylobacterota and Gammaproteobacteria. Alphaproteobacteria are organisms with different life stages from free living to substrate associated, some of them are intracellular pathogens of plants, animal and even human, in those groups the CcrMs must have an important role in cell cycle progression.
CcrM miss regulation have shown to produce severe miss control of cell cycle regulation and differentiation in various Alphaproteobacteria; C. crescentus , the plant symbiont Sinorhizobium meliloti and in the human pathogen Brucella abortus. Also CcrM gene has proven to be essential for the viability of various Alphaproteobacteria. | 1 | Gene expression + Signal Transduction |
Engineers can use the Brinell hardness of materials in their calculations to avoid this mode of failure. A rolling element bearing's static load rating is defined to avoid this failure type. Increasing the number of elements can provide better distribution of the load, so bearings intended for a large load may have many balls, or use needles instead. This decreases the chances of brinelling, but increases friction and other factors. However, although roller and ball bearings work well for radial and thrust loading, they are often prone to brinelling when very high impact loading, lateral loading, or vibration are experienced. Babbitt bearings or bronze bushings are often used instead of roller bearings in applications where such loads exist, such as in automotive crankshafts or pulley sheaves, to decrease the possibility of brinelling by distributing the force over a very large surface area.
A common cause of brinelling is the use of improper installation procedures. Brinelling often occurs when pressing bearings into holes or onto shafts. Care must usually be taken to ensure that pressure is applied to the proper bearing race to avoid transferring the pressure from one race to the other through the balls or rollers. If pressing force is applied to the wrong race, brinelling can occur to either or both of the races. The act of pressing or clamping can also leave brinell marks, especially if the vise or press has serrated jaws or roughened surfaces. Flat pressing plates are often used in the pressing of bearings, while soft copper, brass, or aluminum jaw covers are often used in vises to help avoid brinell marks from being forced into the workpiece. | 0 | Metallurgy |
Many maritime accidents have been caused by corrosion, and this has led to stringent regulations concerning protective coatings for ballast tanks. The Coating Performance Standard for Ballast Tank Coatings (PSPC), became effective in 2008. It specifies how protective coatings should be applied during vessel construction with the intention of giving a coating a 15-year service life. Additional regulations, such as those established by The International Convention for the Control and Management of Ships Ballast Water & Sediments (SBWS) sought to avoid introducing invasive species throughout the world through ship's ballast tanks. The methods used to avoid having these invasive species surviving in ballast tanks however greatly increased the rate of corrosion. Therefore ongoing research attempts to find water treatment systems that kill invasive species, while not having a destructive effect on the ballast tank coatings. As double-hulled tankers were introduced it meant that there was more ballast tank area had to be coated and therefore a greater capital investment for ship owners. With the onset of the OPA 90 and later the amendments to MARPOL annex 1, single hull tankers (without alternative method) have basically phased out.
Modern double hull tankers, with their fully "segregated ballast tanks" propose another problem. Empty tanks act as insulation from the cold sea and allow the warm cargo areas to retain their heat longer. Corrosion rates increase with differences in temperature. Consequently, the cargo side of the ballast tank corrodes more quickly than it did with single hull tankers. | 0 | Metallurgy |
Protein Ser/Thr phosphatases were originally classified using biochemical assays as either, type 1 (PP1) or type 2 (PP2), and were further subdivided based on metal-ion requirement (PP2A, no metal ion; PP2B, Ca stimulated; PP2C, Mg dependent) (Moorhead et al., 2007). The protein Ser/Thr phosphatases PP1, PP2A and PP2B of the PPP family, together with PP2C of the PPM family, account for the majority of Ser/Thr PP activity in vivo (Barford et al., 1998). In the brain, they are present in different subcellular compartments in neuronal and glial cells, and contribute to different neuronal functions. | 1 | Gene expression + Signal Transduction |
Apart from some production of puddled steel, English steel continued to be made by the cementation process, sometimes followed by remelting to produce crucible steel. These were batch-based processes whose raw material was bar iron, particularly Swedish oregrounds iron.
The problem of mass-producing cheap steel was solved in 1855 by Henry Bessemer, with the introduction of the Bessemer converter at his steelworks in Sheffield, England. (An early converter can still be seen at the city's Kelham Island Museum). In the Bessemer process, molten pig iron from the blast furnace was charged into a large crucible, and then air was blown through the molten iron from below, igniting the dissolved carbon from the coke. As the carbon burned off, the melting point of the mixture increased, but the heat from the burning carbon provided the extra energy needed to keep the mixture molten. After the carbon content in the melt had dropped to the desired level, the air draft was cut off: a typical Bessemer converter could convert a 25-ton batch of pig iron to steel in half an hour.
In the 1860s development of regenerative furnaces and higher temperature refractory lining allowed to melt steel in an open hearth. That was slow and energy intensive, but allowed to better control the chemical makeup of the product and recycle iron scrap.
The acidic refractory lining of Bessemer converters and early open hearths didn't allow to remove phosphorus from steel with lime, which prolonged the life of puddling furnaces in order to utilize phosphorous iron ores abundant in Continental Europe. However in the 1870s Gilchrist–Thomas process was developed, and later basic lining was adopted for the open hearths as well.
Finally, the basic oxygen process was introduced at the Voest-Alpine works in 1952; a modification of the basic Bessemer process, it lances oxygen from above the steel (instead of bubbling air from below), reducing the amount of nitrogen uptake into the steel. The basic oxygen process is used in all modern steelworks; the last Bessemer converter in the U.S. was retired in 1968. Furthermore, the last three decades have seen a massive increase in the mini-mill business, where scrap steel only is melted with an electric arc furnace. These mills only produced bar products at first, but have since expanded into flat and heavy products, once the exclusive domain of the integrated steelworks.
Until these 19th-century developments, steel was an expensive commodity and only used for a limited number of purposes where a particularly hard or flexible metal was needed, as in the cutting edges of tools and springs. The widespread availability of inexpensive steel powered the Second Industrial Revolution and modern society as we know it. Mild steel ultimately replaced wrought iron for almost all purposes, and wrought iron is no longer commercially produced. With minor exceptions, alloy steels only began to be made in the late 19th century. Stainless steel was developed on the eve of World War I and was not widely used until the 1920s. | 0 | Metallurgy |
Until the latter half of the 20th century, smelting sulfide ores was almost the sole means of producing copper metal from mined ores (primary copper production). As of 2002, 80% of global primary copper production was from copper–iron–sulfur minerals, and the vast majority of these were treated by smelting.
Copper was initially recovered from sulfide ores by directly smelting the ore in a furnace. The smelters were initially located near the mines to minimize the cost of transport. This avoided the prohibitive costs of transporting the waste minerals and the sulfur and iron present in the copper-containing minerals. However, as the concentration of copper in the ore bodies decreased, the energy costs of smelting the whole ore also became prohibitive, and it became necessary to concentrate the ores first.
Initial concentration techniques included hand-sorting and gravity concentration. These resulted in high losses of copper. Consequently, the development of the froth flotation process was a major step forward in mineral processing. It made the development of the giant Bingham Canyon mine in Utah possible.
In the twentieth century, most ores were concentrated before smelting. Smelting was initially undertaken using sinter plants and blast furnaces, or with roasters and reverberatory furnaces. Roasting and reverberatory furnace smelting dominated primary copper production until the 1960s.
Copper smelting technology gave rise to the Copper Age, aka Chalcolithic Age, and then the Bronze Age. The Bronze Age would not have been possible without the development of smelting technology.
The modern froth flotation process was independently invented in the early 1900s in Australia by C.V Potter and around the same time by G. D. Delprat. | 0 | Metallurgy |
Change in intracellular Ca levels is used as a signature for diverse responses towards mechanical stimuli, osmotic and salt treatments, and cold and heat shocks. Different root cell types show a different Ca response to osmotic and salt stresses and this implies the cellular specificities of Ca patterns. In response to external stress CaM activates glutamate decarboxylase (GAD) that catalyzes the conversion of -glutamate to GABA. A tight control on the GABA synthesis is important for plant development and, hence, increased GABA levels can essentially affect plant development. Therefore, external stress can affect plant growth and development and CaM are involved in that pathway controlling this effect. | 1 | Gene expression + Signal Transduction |
Bimetal strips are used in miniature circuit breakers to protect circuits from excess current. A coil of wire is used to heat a bimetal strip, which bends and operates a linkage that unlatches a spring-operated contact. This interrupts the circuit and can be reset when the bimetal strip has cooled down.
Bimetal strips are also used in time-delay relays, gas oven safety valves, thermal flashers for older turn signal lamps, and fluorescent lamp starters. In some devices, the current running directly through the bimetal strip is sufficient to heat it and operate contacts directly. It has also been used in mechanical PWM voltage regulators for automotive uses. | 0 | Metallurgy |
Incoherent grain boundaries are those in which there is a significant mismatch in crystallographic orientation between adjacent grains. This results in a discontinuity in the crystal lattice across the boundary, and the formation of a variety of defects such as dislocations, stacking faults, and grain boundary ledges.The presence of these defects creates a barrier to the motion of dislocations and leads to a strengthening effect. This effect is more pronounced in materials with smaller grain sizes, as there are more grain boundaries to impede dislocation motion. In addition to the barrier effect, incoherent grain boundaries can also act as sources and sinks for dislocations. This can lead to localized plastic deformation and affect the overall mechanical response of a material.
When small particles are formed through precipitation from supersaturated solid solutions, their interphase boundaries may not be coherent with the matrix. In such cases, the atomic bonds do not match up across the interface and there is a misfit between the particle and the matrix. This misfit gives rise to a non-coherency strain, which can cause the formation of dislocations at the grain boundary. As a result, the properties of the small particle can be different from those of the matrix. The size at which non-coherent grain boundaries form depends on the lattice misfit and the interfacial energy. | 0 | Metallurgy |
In the most simplified quorum sensing systems, bacteria only need two components to make use of autoinducers. They need a way to produce a signal and a way to respond to that signal. These cellular processes are often tightly coordinated and involve changes in gene expression. The production of autoinducers generally increases as bacterial cell densities increase. Most signals are produced intracellularly and are subsequently secreted in the extracellular environment. Detection of autoinducers often involves diffusion back into cells and binding to specific receptors. Usually, binding of autoinducers to receptors does not occur until a threshold concentration of autoinducers is achieved. Once this has occurred, bound receptors alter gene expression either directly or indirectly. Some receptors are transcription factors themselves, while others relay signals to downstream transcription factors. In many cases, autoinducers participate in forward feedback loops, whereby a small initial concentration of an autoinducer amplifies the production of that same chemical signal to much higher levels. | 1 | Gene expression + Signal Transduction |
pRb is known to interact with more than 300 proteins, some of which are listed below:
* Abl gene
* Androgen receptor
* Apoptosis-antagonizing transcription factor
* ARID4A
* Aryl hydrocarbon receptor
* BRCA1
* BRF1
* C-jun
* C-Raf
* CDK9
* CUTL1
* Cyclin A1
* Cyclin D1
* Cyclin T2
* DNMT1
* E2F1
* E2F2,
* E4F1
* EID1
* ENC1
* FRK
* HBP1
* HDAC1
* HDAC3
* Histone deacetylase 2
* Insulin
* JARID1A
* Large tumor antigen
* LIN9
* MCM7
* MORF4L1
* MRFAP1,
* MyoD
* NCOA6
* PA2G4
* Peroxisome proliferator-activated receptor gamma
* PIK3R3
* Plasminogen activator inhibitor-2
* Polymerase (DNA directed), alpha 1
* PRDM2
* PRKRA
* Prohibitin
* Promyelocytic leukemia protein
* RBBP4
* RBBP7
* RBBP8
* RBBP9
* SNAPC1
* SKP2
* SNAPC3
* SNW1
* SUV39H1
* TAF1
* THOC1
* TRAP1
* TRIP11
* UBTF
* USP4. | 1 | Gene expression + Signal Transduction |
Iron ore in the form of siderite, commonly known as iron stone or historically as mine, occurs in patches or bands in the Cretaceous clays of the Weald. Differing qualities of ore were extracted and mixed by experienced smelters to give the best results. Sites of opencast quarries survive from the pre-Roman and Roman eras, but medieval ore extraction was mainly done by digging a series of minepits about five metres in diameter and up to twelve metres deep with material being winched up in baskets suspended from a wooden tripod. This was less destructive of the land as spoil from one pit was used to backfill the previous pit allowing continued land use.
The fuel for smelting was charcoal, which needed to be produced as close as possible to the smelting sites because it would crumble to dust if transported far by cart over rough tracks. Wood was also needed for pre-roasting the ore on open fires, a process which broke down the lumps or nodules and converted the carbonate into oxide. Large areas of woodland were available in the Weald and coppicing woodlands could provide a sustainable source of wood. Sustainable charcoal production for a post-medieval blast furnace required the timber production from a radius of a furnace in a landscape that was a quarter to a third wooded. Forging and finishing of the iron from bloomeries and blast furnaces also required large quantities of charcoal and was usually carried out at a separate site.
Water power became important with the introduction of blast furnaces and finery forges in the late medieval period. Blast furnaces needed to operate continuously for as long as possible and a series of ponds were often created in a valley to give a sustainable flow for the waterwheel. A campaign, as the production run was known, usually ran from October through to late spring when streams began to dry up, although Lamberhurst Furnace driven by the River Teise ran continuously for more than three years in the 1740s. Finery forges with three or four waterwheels to drive bellows and hammers needed more water than a furnace at times, although continuity was not as important. They tended to be sited downstream from a furnace if they were in the same valley. Ponds were created by building a dam known as a pond bay, which often served as a road, across one of the many valleys in the undulating Wealden landscape. In 1754 one furnace was so drought-stricken that its manager considered hiring workmen to turn the wheel as a treadmill. This need for continuous water power was an incentive in the development of the water-returning engine, a waterwheel driven by water raised by a steam engine pump. | 0 | Metallurgy |
Gene silencing is the regulation of gene expression in a cell to prevent the expression of a certain gene. Gene silencing can occur during either transcription or translation and is often used in research. In particular, methods used to silence genes are being increasingly used to produce therapeutics to combat cancer and other diseases, such as infectious diseases and neurodegenerative disorders.
Gene silencing is often considered the same as gene knockdown. When genes are silenced, their expression is reduced. In contrast, when genes are knocked out, they are completely erased from the organism's genome and, thus, have no expression. Gene silencing is considered a gene knockdown mechanism since the methods used to silence genes, such as RNAi, CRISPR, or siRNA, generally reduce the expression of a gene by at least 70% but do not eliminate it. Methods using gene silencing are often considered better than gene knockouts since they allow researchers to study essential genes that are required for the animal models to survive and cannot be removed. In addition, they provide a more complete view on the development of diseases since diseases are generally associated with genes that have a reduced expression. | 1 | Gene expression + Signal Transduction |
Mineral separation is hampered by several factors, with particle size being particularly important. As the slurry feed grainsize increases, the efficiency of separation tends to decrease. Separation efficiency is also affected by the stroke of the table (frequency and length); fine feed requires a higher speed and shorter stroke than a coarse feed. A frequency of 200 to 325 strokes per minute is typical.
When Wilfley tables were originally employed to rework tailing dumps, the tables were found to enhance mineral recovery by some 3540% percent compared to existing processes, though this is not always the case.
Optimisation of table setup can have a significant impact on the recovery of ore. Using magnetite as a synthetic ore to test recovery on a Wilfley Table, Mackay et al. (2015) found that an optimised table setup (i.e. table inclination, wash-water flow rate, material feed rate, table speed, stroke amplitude, feed grade and feed density) increased magnetite recovery by a factor of 3.7.
The Wilfley table, like any wet table, is one of the most metallurgically efficient forms of gravity concentration, being used to treat the smaller, more difficult flow-streams, and to produce finished concentrates from the products of other forms of gravity system. Additional efficiencies are gained in the treatment of low grade feeds where two or even three decks are stacked one above the other allowing for continuous feeding. | 0 | Metallurgy |
3′-UTR mutations can be very consequential because one alteration can be responsible for the altered expression of many genes. Transcriptionally, a mutation may affect only the allele and genes that are physically linked. However, since 3′-UTR binding proteins also function in the processing and nuclear export of mRNA, a mutation can also affect other unrelated genes. Dysregulation of ARE-binding proteins (AUBPs) due to mutations in AU-rich regions can lead to diseases including tumorigenesis (cancer), hematopoietic malignancies, leukemogenesis, and developmental delay/autism spectrum disorders. An expanded number of trinucleotide (CTG) repeats in the 3’-UTR of the dystrophia myotonica protein kinase (DMPK) gene causes myotonic dystrophy. Retro-transposal 3-kilobase insertion of tandem repeat sequences within the 3′-UTR of fukutin protein is linked to Fukuyama-type congenital muscular dystrophy. Elements in the 3′-UTR have also been linked to human acute myeloid leukemia, alpha-thalassemia, neuroblastoma, Keratinopathy, Aniridia, IPEX syndrome, and congenital heart defects. The few UTR-mediated diseases identified only hint at the countless links yet to be discovered. | 1 | Gene expression + Signal Transduction |
The UN and business communities developed an international standard for tailings management in 2020 after the critical failure of the Brumadinho dam disaster. The program was convened by United Nations Environment Programme (UNEP), International Council on Mining and Metals (ICMM) and the Principles for Responsible Investment. | 0 | Metallurgy |
The euplotid nuclear code (translation table 10) is the genetic code used by Euplotidae. The euplotid code is a socalled "symmetrical code", which results from the symmetrical distribution of the codons. This symmetry allows for arythmic exploration of the codon distribution. In 2013, shCherbak and Makukov, reported that "the patterns are shown to match the criteria of an intelligent signal." | 1 | Gene expression + Signal Transduction |
For cellular processes that are not directly related to pathogen resistance or defense, BIK1 does not utilize traditional defense-mediating hormones such as SA, JA, or ACC, but instead utilizes an herbicide, known as paraquat which produces ROIs. It is believed that SA, JA, and ACC have no effect on BIK1 induction because they are likely located downstream from the BIK1 gene, or it is possible that BIK1 operates completely independently. However, it is believed that BIK1 does play a vital role in the ET signaling pathway. Based on the signaling function of BIK1 in ET responses, it is believed that Botrytis-induced kinase1 accumulates response signals that it receives from upstream regulators and then integrates them into its own resistance mechanism.
BIK1 is a receptor-like cytoplasmic kinase (RLCK) that associates with a cell-surface receptor, FLS2, and a co-receptor kinase, BAK1 to transduce signals when a PAMP is detected. In order for BIK1 to be activated, site-specific phosphorylation must occur. | 1 | Gene expression + Signal Transduction |
In humans, DNA methylation occurs at the 5' position of the pyrimidine ring of the cytosine residues within CpG sites to form 5-methylcytosines. The presence of multiple methylated CpG sites in CpG islands of promoters causes stable silencing of genes. Silencing of a gene may be initiated by other mechanisms, but this is often followed by methylation of CpG sites in the promoter CpG island to cause the stable silencing of the gene. | 1 | Gene expression + Signal Transduction |
From alpha iron undergoes a phase transition from body-centered cubic (BCC) to the face-centered cubic (FCC) configuration of gamma iron, also called austenite. This is similarly soft and ductile but can dissolve considerably more carbon (as much as 2.03% by mass at ). This gamma form of iron is present in the most commonly used type of stainless steel for making hospital and food-service equipment. | 0 | Metallurgy |
The concept of plotting the free energies of reaction of various elements with a given gas-phase reactant may be extended beyond oxidation reactions. The original paper by Ellingham explicitly to the reduction of both oxygen and sulfur by metallurgical processes, and anticipated the use of such diagrams for other compounds, including chlorides, carbides, and sulfates. The concept is generally useful for studying the comparative stability of compounds across a range of partial pressures and temperatures. The construction of an Ellingham diagram is especially useful when studying the stability of compounds in the presence of a reductant. Ellingham diagrams are now available for bromides, chlorides, fluorides, hydrides, iodides, nitrides, oxides, sulfides, selenides, and tellurides. | 0 | Metallurgy |
The usage of the term canonical sequence to refer to a promoter is often problematic, and can lead to misunderstandings about promoter sequences. Canonical implies perfect, in some sense.
In the case of a transcription factor binding site, there may be a single sequence that binds the protein most strongly under specified cellular conditions. This might be called canonical.
However, natural selection may favor less energetic binding as a way of regulating transcriptional output. In this case, we may call the most common sequence in a population the wild-type sequence. It may not even be the most advantageous sequence to have under prevailing conditions.
Recent evidence also indicates that several genes (including the proto-oncogene c-myc) have G-quadruplex motifs as potential regulatory signals. | 1 | Gene expression + Signal Transduction |
Although as a general rule, dietary supplement labeling and marketing are not allowed to make disease prevention or treatment claims, the FDA has for some foods and dietary supplements reviewed the science, concluded that there is significant scientific agreement, and published specifically worded allowed health claims. An initial ruling allowing a health claim for calcium dietary supplements and osteoporosis was later amended to include calcium and vitamin D supplements, effective January 1, 2010. Examples of allowed wording are shown below. In order to qualify for the calcium health claim, a dietary supplement must contain at least 20% of the Reference Dietary Intake, which for calcium means at least 260 mg/serving.
*"Adequate calcium throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis."
*"Adequate calcium as part of a healthful diet, along with physical activity, may reduce the risk of osteoporosis in later life."
*"Adequate calcium and vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis."
*"Adequate calcium and vitamin D as part of a healthful diet, along with physical activity, may reduce the risk of osteoporosis in later life."
In 2005 the FDA approved a Qualified Health Claim for calcium and hypertension, with suggested wording "Some scientific evidence suggests that calcium supplements may reduce the risk of hypertension. However, FDA has determined that the evidence is inconsistent and not conclusive." Evidence for pregnancy-induced hypertension and preeclampsia was considered inconclusive. The same year the FDA approved a QHC for calcium and colon cancer, with suggested wording "Some evidence suggests that calcium supplements may reduce the risk of colon/rectal cancer, however, FDA has determined that this evidence is limited and not conclusive." Evidence for breast cancer and prostate cancer was considered inconclusive. Proposals for QHCs for calcium as protective against kidney stones or against menstrual disorders or pain were rejected.
The European Food Safety Authority (EFSA) concluded that "Calcium contributes to the normal development of bones." The EFSA rejected a claim that a cause-and-effect relationship existed between the dietary intake of calcium and potassium and maintenance of normal acid-base balance. The EFSA also rejected claims for calcium and nails, hair, blood lipids, premenstrual syndrome and body weight maintenance. | 1 | Gene expression + Signal Transduction |
Melid, also known as Arslantepe, was an ancient city on the Tohma River, a tributary of the upper Euphrates rising in the Taurus Mountains. It has been identified with the modern archaeological site of Arslantepe near Malatya, Turkey.
It was named a UNESCO World Heritage Site under the name Arslantepe Mound on 26 July 2021. | 0 | Metallurgy |
The main effect of chloride ions on reinforced concrete is to cause pitting corrosion of the steel reinforcement bars (rebar). It is a surreptitious and dangerous form of localized corrosion because the rebar sections can be decreased to the point that the steel reinforcement are no longer capable to withstand to the tensile efforts they are supposed to resist by design. When the rebar sections are too small or the rebar are locally broken, the reinforcements are lost, and concrete is no longer reinforced concrete.
Chlorides, particularly calcium chloride, have been used to shorten the setting time of concrete.
However, calcium chloride and (to a lesser extent) sodium chloride have been shown to leach calcium hydroxide and cause chemical changes in Portland cement, leading to loss of strength, as well as attacking the steel reinforcement present in most concrete. The ten-storey Queen Elizabeth hospital in Kota Kinabalu contained a high percentage of chloride causing early failure. | 0 | Metallurgy |
Glucosylceramides (GluCer) are the most widely distributed glycosphingolipids in cells serving as precursors for the formation of over 200 known glycosphingolipids. GluCer is formed by the glycosylation of ceramide in an organelle called Golgi via enzymes called glucosylceramide synthase (GCS) or by the breakdown of complex glycosphingolipids (GSLs) through the action of specific hydrolase enzymes. In turn, certain β-glucosidases hydrolyze these lipids to regenerate ceramide. GluCer appears to be synthesized in the inner leaflet of the Golgi. Studies show that GluCer has to flip to the inside of the Golgi or transfer to the site of GSL synthesis to initiate the synthesis of complex GSLs. Transferring to the GSL synthesis site is done with the help of a transport protein known as four phosphate adaptor protein 2 (FAPP2) while the flipping to the inside of the Golgi is made possible by the ABC transporter P-glycoprotein, also known as the multi-drug resistance 1 transporter (MDR1). GluCer is implicated in post-Golgi trafficking and drug resistance particularly to chemotherapeutic agents. For instance, a study demonstrated a correlation between cellular drug resistance and modifications in GluCer metabolism.
In addition to their role as building blocks of biological membranes, glycosphingolipids have long attracted attention because of their supposed involvement in cell growth, differentiation, and formation of tumors. The production of GluCer from Cer was found to be important in the growth of neurons or brain cells. On the other hand, pharmacological inhibition of GluCer synthase is being considered a technique to avoid insulin resistance. | 1 | Gene expression + Signal Transduction |
There has been conflicting ideas to the purpose of the 800 copper plates. Although they have been assumed to be scales of armor from an Egyptian army unit, as proposed by archaeologist Shmuel Yeivin, recent reevaluations have confuted this claim. Archaeologist William A. Ward proposed that the scales were means of barter or a reserve supply of metal from the Syro-Palestinian area. Ward arrived at this conclusion through several pieces of evidence: the scales were not attached to any jacket, body armor was generally not used by the Egyptians until the New Kingdom, copper was still very rare, and the plates were too thin for body armor. | 0 | Metallurgy |
Transcription factor TFA is a nuclear protein involved in the RNA polymerase II-dependent transcription of DNA. TFA is one of several general (basal) transcription factors (GTFs) that are required for all transcription events that use RNA polymerase II. Other GTFs include TFD, a complex composed of the TATA binding protein TBP and TBP-associated factors (TAFs), as well as the factors TFB, TFE, TFF, and TFH. Together, these factors are responsible for promoter recognition and the formation of a transcription preinitiation complex (PIC) capable of initiating RNA synthesis from a DNA template. | 1 | Gene expression + Signal Transduction |
Tin is an essential metal in the creation of tin-bronzes, and its acquisition was an important part of ancient cultures from the Bronze Age onward. Its use began in the Middle East and the Balkans around 3000 BC. Tin is a relatively rare element in the Earth's crust, with about two parts per million (ppm), compared to iron with 50,000 ppm, copper with 70 ppm, lead with 16 ppm, arsenic with 5 ppm, silver with 0.1 ppm, and gold with 0.005 ppm. Ancient sources of tin were therefore rare, and the metal usually had to be traded over very long distances to meet demand in areas which lacked tin deposits.
Known sources of tin in ancient times include the southeastern tin belt that runs from Yunnan in China to the Malay Peninsula; Cornwall and Devon in Britain; Brittany in France; the border between Germany and the Czech Republic; Spain; Portugal; Italy; and central and South Africa. Syria and Egypt have been suggested as minor sources of tin, but the archaeological evidence is inconclusive. | 0 | Metallurgy |
In the case of a translating ribosome, a frameshift can either result in Nonsense mutation, a premature stop codon after the frameshift, or the creation of a completely new protein after the frameshift. In the case where a frameshift results in nonsense, the nonsense-mediated mRNA decay (NMD) pathway may destroy the mRNA transcript, so frameshifting would serve as a method of regulating the expression level of the associated gene.
If a novel or off-target protein is produced, it can trigger other unknown consequences. | 1 | Gene expression + Signal Transduction |
In humans, about 70% of promoters located near the transcription start site of a gene (proximal promoters) contain a CpG island. CpG islands are generally 200 to 2000 base pairs long, have a C:G base pair content >50%, and have regions of DNA where a cytosine nucleotide is followed by a guanine nucleotide and this occurs frequently in the linear sequence of bases along its 5′ → 3′ direction.
Genes may also have distant promoters (distal promoters) and these frequently contain CpG islands as well. An example is the promoter of the DNA repair gene ERCC1, where the CpG island-containing promoter is located about 5,400 nucleotides upstream of the coding region of the ERCC1 gene. CpG islands also occur frequently in promoters for functional noncoding RNAs such as microRNAs. | 1 | Gene expression + Signal Transduction |
Iron oxides are reduced in the following sequence:
O → FeO → FeO
Each transition from one oxide to the next is due to two simultaneous high-temperature reduction reactions by carbon monoxide CO or dihydrogen H:
These temperatures differ from those predicted by the Ellingham diagram. In reality, there is a coupling between carbon monoxide reduction and dihydrogen, so that these reactions work together, with hydrogen significantly improving the efficiency of CO reduction. | 0 | Metallurgy |
Hormonal effects are dependent on where they are released, as they can be released in different manners. Not all hormones are released from a cell and into the blood until it binds to a receptor on a target. The major types of hormone signaling are: | 1 | Gene expression + Signal Transduction |
Inositol hexaphosphate (IP6) is the most abundant inositol phosphate isomer found. IP6 is solely involved in various biological activities such as neurotransmission, immune response, regulation of kinase and phosphatase proteins as well as activation of calcium channels. IP6 is also involved in ATP regeneration seen in plants as well as insulin exocytosis in pancreatic β cells.
Inositol hexaphosphate also facilitates the formation of the six-helix bundle and assembly of the immature HIV-1 Gag lattice. IP6 makes ionic contacts with two rings of lysine residues at the centre of the Gag hexamer. Proteolytic cleavage then unmasks an alternative binding site, where IP6 interaction promotes the assembly of the mature capsid lattice. These studies identify IP6 as a naturally occurring small molecule that promotes both assembly and maturation of HIV-1. | 1 | Gene expression + Signal Transduction |
pRb is able to be localize to sites of DNA breaks during the repair process and assist in non-homologous end joining and homologous recombination through complexing with E2F1. Once at the breaks, pRb is able to recruit regulators of chromatin structure such as the DNA helicase transcription activator BRG1. pRb has been shown to also be able to recruit protein complexes such as condensin and cohesin to assist in the structural maintenance of chromatin.
Such findings suggest that in addition to its tumor suppressive role with E2F, pRb is also distributed throughout the genome to aid in important processes of genome maintenance such as DNA break-repair, DNA replication, chromosome condensation, and heterochromatin formation. | 1 | Gene expression + Signal Transduction |
As the result of substrate effects producing preferred crystallite orientations, pronounced textures tend to occur in thin films. Modern technological devices to a large extent rely on polycrystalline thin films with thicknesses in the nanometer and micrometer ranges. This holds, for instance, for all microelectronic and most optoelectronic systems or sensoric and superconducting layers. Most thin film textures may be categorized as one of two different types: (1) for so-called fiber textures the orientation of a certain lattice plane is preferentially parallel to the substrate plane; (2) in biaxial textures the in-plane orientation of crystallites also tend to align with respect to the sample. The latter phenomenon is accordingly observed in nearly epitaxial growth processes, where certain crystallographic axes of crystals in the layer tend to align along a particular crystallographic orientation of the (single-crystal) substrate.
Tailoring the texture on demand has become an important task in thin film technology. In the case of oxide compounds intended for transparent conducting films or surface acoustic wave (SAW) devices, for instance, the polar axis should be aligned along the substrate normal. Another example is given by cables from high-temperature superconductors that are being developed as oxide multilayer systems deposited on metallic ribbons. The adjustment of the biaxial texture in YBaCuO layers turned out as the decisive prerequisite for achieving sufficiently large critical currents.
The degree of texture is often subjected to an evolution during thin film growth and the most pronounced textures are only obtained after the layer has achieved a certain thickness. Thin film growers thus require information about the texture profile or the texture gradient in order to optimize the deposition process. The determination of texture gradients by x-ray scattering, however, is not straightforward, because different depths of a specimen contribute to the signal. Techniques that allow for the adequate deconvolution of diffraction intensity were developed only recently. | 0 | Metallurgy |
KAP1 forms a complex with MDM2 (a ubiquitin E3 ligase) that binds to p53. The complex marks the bound p53 for degradation. p53 is a known precursor of apoptosis that facilitates the synthesis of proteins necessary for cell death so its degradation results in apoptosis inhibition. | 1 | Gene expression + Signal Transduction |
There are two types of target peptides directing to peroxisome, which are called peroxisomal targeting signals (PTS). One is PTS1, which is made of three amino acids on the C-terminus. The other is PTS2, which is made of a 9-amino-acid sequence often present on the N-terminus of the protein. | 1 | Gene expression + Signal Transduction |
One example of controlling the environment to prevent or reduce corrosion is the practice of storing aircraft in deserts. These storage places are usually called aircraft boneyards. The climate is usually arid so this and other factors make it an ideal environment. | 0 | Metallurgy |
Plasmid vectors are circular strands of DNA, found in virions, that are used in genetic engineering to integrate new genes into a host cell genome.
The small T intron is an intron, that is used in some plasmid vectors, in order to induce gene expression in mammalian cells. | 1 | Gene expression + Signal Transduction |
In double knockout STAT2 mice, an increased proliferation of M1, M2, and M1/M2 coexpressing macrophages during influenza-bacterial super-infection is observed. The bacterial clearance was also impaired by neutralization of IFN-γ (M1) and Arginase-1 (M2) what suggests that pulmonary macrophages expressing a mixed M1/M2 phenotype promote bacterial control during influenza-bacterial super-infection. Therefore the STAT2 signaling is associated with suppressing macrophage activation and bacterial control during influenza-bacterial super-infection. These mice demonstrate no developmental defects. The knockout STAT2 and double knockout STAT mice in Vesicular stromatitis Indiana virus (VSV) model produce at least 10 times more virus plaque-forming units than the wild type (WT). IFN-α pretreatment supplied protection in WT and STAT2 cells but not in double knockout STAT2 cells. IFN-γ pretreatment did not provide any antiviral response during infection of VSV. This finding could be explained by the reduced level of STAT1 in cells of STAT2 knockout mice. Additionally, the double knockout STAT2 mice are more sensitive to mouse cytomegalovirus (MCMV), severe fever thrombocytopenia syndrome virus, influenza virus, dengue virus (DNV) and Zika virus than control mice, which suggests that STAT2 plays a critical role in the suppression of virus replication in mice. | 1 | Gene expression + Signal Transduction |
This salt is used as a flotation agent in the purification of molybdenite (MoS) from other components of the ores, where it is usually known as "Nokes reagent" (after Charles M. Nokes, who patented it in 1948). The salt is generated by the reaction of phosphorus pentasulfide with sodium hydroxide, often using impure reagents to obtain a mixture of the desired salt and related thiophosphates and oxidized species. Molybdenite particles, which are normally hydrophobic, become hydrophilic in the presence of this salt. In this context, the Nokes reagent is called a "depressant," because it suppresses the flotation tendency of the solids other than molybdenite. | 0 | Metallurgy |
While the romantic picture of gold mining focuses on nuggets, the reality is that gold is typically recovered from ores containing >10 ppm of the metal. Thus, the main challenge is concentrating this trace amount. | 0 | Metallurgy |
Hollywood is a RNA splicing database containing data for the splicing of orthologous genes in different species. | 1 | Gene expression + Signal Transduction |
Despite being a powerful model organism for biology and the study of transcriptional enhancers, the tissue specific activity of less than 5% of the estimated 50,000 transcriptional enhancers in Drosophila melanogaster have been discovered. Over the past decade, the main method for detection of tissue- or cell-type specific activities of enhancers in Drosophila melanogaster was to test candidate enhancers by traditional reporter assays, which are low-throughput and costly. Over the past few years, even though enhancer discovery has been improved and other parallel reporter assays have been developed, none so far allowed the direct identification of enhancer activity in a genomic context in cell types of interest in a whole embryo. | 1 | Gene expression + Signal Transduction |
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