The short version of epithalamin fits in a sentence. The long version — which is the one that helps — is below.
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The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Synthetic tetrapeptide, four residues |
| Nominal mass | Approximately 390 Da | Free peptide; salt forms differ |
| Appearance | White to off-white powder | Commonly supplied lyophilised |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffer |
| Typical storage | −20 °C, desiccated | Cold packs used during transport |
Published studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than settled.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9, and its calculated molar mass is approximately 390.35 grams per mole. The compound is a short fragment related to a peptide fraction isolated from bovine pineal gland extracts, and it is normally supplied as a lyophilised powder intended for laboratory research. It is not a registered pharmaceutical product in most countries.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
Some research has shown that sea ice diatoms can use an ancient bacterial metabolic pathway known as the Entner−Doudoroff pathway (EDP) to maintain metabolism and energy production during light limitation. The ability of diatoms to use light for energy also depends on air temperature. As it gets colder, the thylakoid membranes within the microalgae plastids can become dense and compact, which influences how certain photosynthetic proteins (such as the proteins necessary for Photosystems I & II) function and self-assemble. Sea ice diatoms can alter the saturation of the fatty acids that compose the thylakoid membranes as temperatures decrease, which can provide more fluidity to these membranes and result in proper folding of photosynthetic proteins at subzero temperatures. As temperatures within brine pockets decrease, organisms that survive within brine pockets produce substances that can help prevent freezing. Some sea ice diatoms can produce specialized ice-binding proteins and extracellular polymeric substances, which can help increase the habitat space available within a brine pocket by preventing ice formation and reducing the freezing temperature of the brine. Decreased temperatures can also reduce the efficiency of important physiological processes within many microorganisms. Psychrophilic diatoms and bacteria have the ability to regulate their production of proteins, DNA, and enzymes required for metabolism to help maintain metabolic efficiency in colder temperatures.
Fallout: After a Nuclear Attack – slideshow by Life magazine The Effects of Nuclear War Archived 2016-08-28 at the Wayback Machine (1979) — handbook produced by the United States Office of Technology Assessment (hosted by the Federation of American Scientists) Nuclear Attack Planning Base – 1990 (1987) — assessment of the effects of a major Soviet attack on the United States produced by the Federal Emergency Management Agency (hosted by the Federation of American Scientists) Nuclear War Survival Skills (1979/1987) — handbook produced by Oak Ridge National Laboratory (use menu at left to navigate) Ground Zero: A Javascript simulation of the effects of a nuclear explosion in a city British RAF manual on the effects of nuclear explosions dated 1955 20 Mishaps That Might Have Started Accidental Nuclear War by Alan F. Philips, M.D. Nuclear Files.org Archived 2013-03-29 at the Wayback Machine Interactive Timeline of the Nuclear Age Annotated bibliography on nuclear warfare from the Alsos Digital Library for Nuclear Issues DeVolpi, Alexander, Vladimir E. Minkov, Vadim A. Simonenko, and George S. Stanford. 2004. Nuclear Shadowboxing: Contemporary Threats from Cold War Weaponry, Vols. 1 and 2. Fidlar Doubleday. Air Weapons for the Cold War Archived 2013-07-24 at the Wayback Machine An in depth history of American air weapons and nuclear bombs from the reference book American Combat Planes of the 20th Century by Ray Wagner Nuclear Emergency and Radiation Resources NUKEMAP3D – a 3D nuclear weapons effects simulator powered by Google Maps.
== Research career == Garcia's research integrates approaches in structural biology, biochemistry and protein engineering to understand how cell surface receptors sense environmental cues through the engagement of extracellular ligands, and transduce signals. The overarching theme of the laboratory is to elucidate the structural and mechanistic basis of receptor activation in systems relevant to human disease, and to exploit this information to design and engineer new molecules with therapeutic properties. Thus there is a close integration of basic science discovery with translation. Garcia's laboratory at Stanford has published numerous scientific articles describing the molecular structure and signaling mechanisms of proteins important for immunity, neurobiology and development.
Aryl nitriles can be synthesized via the Sandmeyer reaction of diazonium salts with copper(I) cyanide or by the Rosenmund-von Braun reaction (direct reaction of an aryl bromide with copper(I) cyanide). Conversion of thiocyanate with aromatic carboxylic acids, known as Letts nitrile synthesis, can be carried out using potassium thiocyanate; lead thiocyanate generally provides higher yields. Aryl iodides can be converted into aromatic nitriles under palladium catalysis with trimethylsilyl cyanide. For example, iodobenzene reacts with trimethylsilyl cyanide in the presence of tetrakis(triphenylphosphine)palladium(0) (Pd(PPh3)4) to form benzonitrile. Another palladium-catalyzed route (also employing Pd(PPh3)4) is the decarbonylation of aromatic acyl cyanides. Palladium-catalyzed cyanation of aryl chlorides with potassium cyanide or potassium hexacyanidoferrate(II) has likewise been reported. Quinones can react with trimethylsilyl cyanide to give silylated cyanohydrins, which are subsequently aromatized using phosphorus tribromide. A further approach involves reaction of aryl Grignard or aryllithium reagents with dimethylmalonitrile. Aromatic nitriles are often prepared in the laboratory from the aniline via diazonium compounds. This is the Sandmeyer reaction. It requires transition metal cyanides.
Sources: en.wikipedia.org
Barrow's inequality strengthens the Erdős–Mordell inequality, which has identical form except with PU, PV, and PW replaced by the three distances of P from the triangle's sides. It is named after David Francis Barrow. Barrow's proof of this inequality was published in 1937, as his solution to a problem posed in the American Mathematical Monthly of proving the Erdős–Mordell inequality. This result was named "Barrow's inequality" as early as 1961. A simpler proof was later given by Louis J. Mordell.
A single-chain variable fragment (scFv) is not actually a fragment of an antibody, but instead is a fusion protein of the variable regions of the heavy (VH) and light chains (VL) of immunoglobulins, connected with a short peptide linker of ten to about 25 amino acids. Each variable fragment contains framework regions (FWRs), providing stability to the structure, and complementarity-determining regions (CDRs), which are the regions responsible for antigen recognition. The linker is usually rich in glycine, which provides flexibility, as well as serine or threonine, that provides solubility. The peptide linker can either connect the N-terminus of the VH with the C-terminus of the VL, or vice versa, but changes in the orientation of the VH, peptide linker and VL have been described to affect scFv’s affinity and specificity. This protein retains the specificity of the original immunoglobulin, despite removal of the constant regions and the introduction of the linker. The image to the right shows how this modification usually leaves the specificity unaltered. These molecules were created to facilitate phage display, where it is highly convenient to express the antigen-binding domain as a single peptide. As an alternative, scFv can be created directly from subcloned heavy and light chains derived from a hybridoma. ScFvs have many uses, e.g., flow cytometry, immunohistochemistry, and as antigen-binding domains of CAR-T cells. Unlike monoclonal antibodies, which are often produced in mammalian cell cultures, scFvs are more often produced in bacteria cell cultures such as E. coli.
Oxygen-containing compounds – are typically hydrophilic and polar, including materials such as silica gel, limestone (calcium carbonate), and zeolites. Carbon-based compounds – are typically hydrophobic and non-polar, including materials such as activated carbon and graphite. Polymer-based compounds – are polar or non-polar, depending on the functional groups in the polymer matrix.
=== Use in structural biology === The transpeptidase activity of sortase is taken advantage of by structural biologists to produce fusion proteins in vitro. The recognition motif (LPXTG) is added to the C-terminus of a protein of interest while an oligo-glycine motif is added to the N-terminus of the second protein to be ligated. Upon addition of sortase to the protein mixture, the two peptides are covalently linked through a native peptide bond. This reaction is employed by NMR spectroscopists to produce NMR invisible solubility tags and by X-ray crystallographers to promote complex formation.
The definitive breakthrough came from the Russian chemist Dmitri Mendeleev. Although other chemists (including Meyer) had found some other versions of the periodic system at about the same time, Mendeleev was the most dedicated to developing and defending his system, and it was his system that most affected the scientific community. On 17 February 1869 (1 March 1869 in the Gregorian calendar), Mendeleev began arranging the elements and comparing them by their atomic weights. He began with a few elements, and over the course of the day his system grew until it encompassed most of the known elements. After he found a consistent arrangement, his printed table appeared in May 1869 in the journal of the Russian Chemical Society. When elements did not appear to fit in the system, he boldly predicted that either valencies or atomic weights had been measured incorrectly, or that there was a missing element yet to be discovered. In 1871, Mendeleev published a long article, including an updated form of his table, that made his predictions for unknown elements explicit. Mendeleev predicted the properties of three of these unknown elements in detail: then-missing heavier homologues of boron, aluminium, and silicon; he named them eka-boron, eka-aluminium, and eka-silicon ("eka" being Sanskrit for "one"). In 1875, the French chemist Paul-Émile Lecoq de Boisbaudran, working without knowledge of Mendeleev's prediction, discovered a new element in a sample of the mineral sphalerite, and named it gallium. He isolated the element and began determining its properties.
Sources: en.wikipedia.org
==== Race ==== Mental health impacts individuals of all ethnic and racial backgrounds across the world. Asian Americans often experience extreme levels of self-stigma, created from the intersection of cultural and societal factors. Cultural pressures lead to self-isolation and shame surrounding the inability to exceed expectations and maintain high achievement. Latino Americans face societal discrimination and report heightened levels of shame when speaking about mental health struggles. Latino communities face structural barriers such as documentation, low rates of English proficiency, and difficulties understanding the steps needed to navigate the healthcare system, ultimately limiting accessibility to mental health services. Latino men often face deep-rooted shame regarding mental health issues due to the cultural expectation of leading communities or a household. Immigration status, language barriers, or cultural beliefs cause many Latino Americans to avoid seeking professional care. The stigma surrounding mental health results in delayed professional care, embarrassment, and social rejection.
Drug recycling is a relatively new concept, but in some places it happens. Sometimes, an individual or organization will have valuable medicine which they do not intend to use. If that medication could be used by other people before its expiration, then sometimes, interested parties discuss drug recycling to transfer ownership of the drugs away from the party which will not use them to the party which needs them. In such discussions, anyone considering the transfer of drugs will also consider if drugs could be used before their expiration. In the United States, there is a growing movement for medication reclamation and reuse, particularly for high-cost specialty drugs such as oral chemotherapies. This practice is increasingly viewed as an opportunity to reduce pharmaceutical waste and help patients who cannot afford necessary medications. In the U.S., programs for drug reclamation and donation are regulated on a state-by-state basis, with some states allowing the donation and/or dispensing of approved unused prescriptions. Tennessee law, for example, permits programs based in the state to accept donations of approved unused prescriptions from individuals and clinics from anywhere in the United States. It also allows dispensing of approved donated medications to patients in need. Dispensing donated medications is currently allowed, in various forms, in 42 U.S. states.
In chemical terms, polystyrene is a long chain hydrocarbon wherein alternating carbon centers are attached to phenyl groups (a derivative of benzene). Polystyrene's chemical formula is (C8H8)n; it contains the chemical elements carbon and hydrogen. The material's properties are determined by short-range van der Waals attractions between polymer chains. Since the molecules consist of thousands of atoms, the cumulative attractive force between the molecules is large. When heated (or deformed at a rapid rate, due to a combination of viscoelastic and thermal insulation properties), the chains can take on a higher degree of confirmation and slide past each other. This intermolecular weakness (versus the high intramolecular strength due to the hydrocarbon backbone) confers flexibility and elasticity. The ability of the system to be readily deformed above its glass transition temperature allows polystyrene (and thermoplastic polymers in general) to be readily softened and molded upon heating. Extruded polystyrene is about as strong as an unalloyed aluminium but much more flexible and much less dense (1.05 g/cm3 for polystyrene vs. 2.70 g/cm3 for aluminium).
== Diagnosis == In terms of the diagnosis of Ullrich congenital muscular dystrophy upon inspection follicular hyperkeratosis, may be a dermatological indicator, additionally also serum creatine kinase may be mildly above normal. Other exams/methods to ascertain if the individual has Ullrich congenital muscular dystrophy are:
==== Retinoids ==== Retinoids, a class of natural and synthetic vitamin A analogues, are widely utilized for their anti-aging effects, specifically in the reduction of facial wrinkles and fine lines. Tretinoin (Retin-A) and tazarotene (Tazorac) are the only topical retinoids approved as medical agents for the treatment of wrinkles and fine lines from photodamage. Other retinoids, such as retinol, retinaldehyde, and retinyl palmitate, are commonly found in over-the-counter cosmeceuticals and have some evidence for reducing wrinkles and fine lines but are regulated as cosmetics rather than medicines. Retinoids function by binding to retinoic acid receptors (RAR) and retinoid-X receptors (RXR), which promotes keratinocyte proliferation, increases epithelial cell turnover, stimulates collagen synthesis, and inhibits collagen degradation. Retinoids also appear to improve the epidermal barrier and reduce transepithelial water loss.
Sources: en.wikipedia.org
No. Epithalamin is a heterogeneous peptide fraction obtained from pineal gland extract and contains many components. Epitalon is a single synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly. Researchers synthesised the shorter peptide while attempting to identify active sequences within the extract.
No endogenous peptide with this exact sequence has been described as a circulating hormone or signalling molecule. The tetrapeptide was designed as a synthetic analogue based on fragments observed in pineal preparations. Any activity discussed in the literature therefore refers to administered material rather than to a natural pool of the compound.
It is not an approved medicine in major jurisdictions and does not appear in the major pharmacopoeias. Material is usually distributed as a research chemical or laboratory reagent. Such labelling places handling responsibility on the purchaser and does not indicate that a regulatory body has reviewed the substance.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.