Everything below concerns AEDG tetrapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
The compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
Identity and purity are established with reversed-phase high-performance liquid chromatography and mass spectrometry. The chromatogram shows the main peak and any truncated or oxidised by-products, while the mass spectrum confirms the expected 390 dalton mass. Amino acid analysis can corroborate composition when a sample's origin is uncertain. Counterion content, particularly residual trifluoroacetate from purification, is frequently reported alongside purity because it shifts the net mass of the solid.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Computed for the free acid of Ala-Glu-Asp-Gly |
| Molecular mass | About 390.35 g/mol | Free peptide; salt forms shift the value |
| Appearance | White to off-white solid | Typical of short peptides after freeze-drying |
| Solubility class | Freely soluble in water | Aqueous buffers are also commonly used |
| Common synonyms | Epitalon, epithalone, AEDG | AEDG is the single-letter sequence |
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
Typical storage for the lyophilized powder is −20 °C or lower, in a sealed container protected from light and moisture. Hygroscopic material should be allowed to equilibrate to room temperature before the vial is opened, which limits condensation on the contents. Working solutions are commonly divided into single-use aliquots and frozen to avoid repeated freeze-thaw cycles. Dilute solutions are more prone to adsorption onto plastic surfaces and to loss during filtration, so procedures that minimize transfers and use low-binding labware are preferable.
Reversed-phase high-performance liquid chromatography is the standard approach for assessing purity, usually with ultraviolet detection near 214 nm, where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the molecular mass and helps reveal truncation or deletion byproducts. Amino acid analysis can verify composition, and counterion content is sometimes measured because peptides purified with trifluoroacetic acid retain variable amounts of that salt. Purity figures reported without a stated method and detection wavelength are difficult to interpret.
Heart tissue, like all cells in the body, needs to be supplied with oxygen, nutrients and a way of removing metabolic wastes. This is achieved by the coronary circulation, which includes arteries, veins, and lymphatic vessels. Blood flow through the coronary vessels occurs in peaks and troughs relating to the heart muscle's relaxation or contraction. Heart tissue receives blood from two arteries which arise just above the aortic valve. These are the left main coronary artery and the right coronary artery. The left main coronary artery splits shortly after leaving the aorta into two vessels, the left anterior descending and the left circumflex artery. The left anterior descending artery supplies heart tissue and the front, outer side, and septum of the left ventricle. It does this by branching into smaller arteries—diagonal and septal branches. The left circumflex supplies the back and underneath of the left ventricle. The right coronary artery supplies the right atrium, right ventricle, and lower posterior sections of the left ventricle. The right coronary artery also supplies blood to the atrioventricular node (in about 90% of people) and the sinoatrial node (in about 60% of people). The right coronary artery runs in a groove at the back of the heart and the left anterior descending artery runs in a groove at the front. There is significant variation between people in the anatomy of the arteries that supply the heart. The arteries divide at their furthest reaches into smaller branches that join at the edges of each arterial distribution.
The average lifespan of inactivated human neutrophils in the circulation has been reported by different approaches to be between 5 and 135 hours. Upon activation, they marginate (position themselves adjacent to the blood vessel endothelium) and undergo selectin-dependent capture followed by integrin-dependent adhesion in most cases, after which they migrate into tissues, where they survive for 1–2 days. Neutrophils have also been demonstrated to be released into the blood from a splenic reserve following myocardial infarction. The distribution ratio of neutrophils in bone marrow, blood and connective tissue is 28:1:25. Neutrophils are much more numerous than the longer-lived monocyte/macrophage phagocytes. A pathogen (disease-causing microorganism or virus) is likely to first encounter a neutrophil. Some experts hypothesize that the short lifetime of neutrophils is an evolutionary adaptation. The short lifetime of neutrophils minimizes propagation of those pathogens that parasitize phagocytes (e.g. Leishmania) because the more time such parasites spend outside a host cell, the more likely they will be destroyed by some component of the body's defenses. Also, because neutrophil antimicrobial products can also damage host tissues, their short life limits damage to the host during inflammation. Neutrophils will be removed after phagocytosis of pathogens by macrophages. PECAM-1 and phosphatidylserine on the cell surface are involved in this process.
to Cuba while he was working for it. Noriega also undertook a number of activities while nominally working for the CIA that served his own ends at the expense of the U.S. government. Journalist Frederick Kempe wrote in 1990 that Noriega had been linked to a series of bombings targeting the U.S. territory in the Panama Canal Zone during the prelude to the U.S. Presidential election in 1976 after the administration of U.S. President Gerald Ford stepped back from negotiations about the Panama Canal. The bombings highlighted to the U.S. government the difficulty of holding on to the Panama Canal Zone in the face of hostility within Panama. Kempe stated that the U.S. knew of Noriega's involvement in the bombings but decided to turn a blind eye toward them. In a December 1976 meeting with George H. W. Bush, then Director of Central Intelligence, Noriega flatly denied involvement, instead suggesting that the CIA was responsible. During negotiations for the Panama Canal treaties, the U.S. government ordered its military intelligence to wiretap Panamanian officials. Noriega discovered this operation in early 1976, and instead of making it public, bribed the U.S. agents and bought the tapes in person; the incident came to be known as the "Singing Sergeants affair". Although some intelligence officials wanted Bush to prosecute the soldiers involved, he declined, because doing so would have exposed Noriega's role in the matter. The CIA did not report this incident to either the National Security Agency or the U.S. Justice Department.
=== Perforated === Perforated steel belts enable the drying media, for example hot air, to be transferred 'through' the belt, so that the air is in contact with all parts of the product on the belt. Normally, manufacturers offer perforated belts with five standard perforation patterns which cover most requirements. Other patterns, with a minimum hole diameter of 0.8 mm (0.03 in.) and different spacing, can be provided to suit specific applications.
Sources: en.wikipedia.org
where w refers to the water, and l refers to the lipids. While the δD of source water is the biggest influence on the δD of lipids, discrepancies between fractionation factor values obtained from the slope and from the intercept of the regression suggest that the relationship is more complex than a two-pool fractionation. In other words, there are multiple fractionation steps that must be taken into account in understanding the isotopic composition of lipids.
Glycolysis – The first stage is known as glycolysis, which produces 2 ATP molecules, 2 reduced molecules of nicotinamide adenine dinucleotide (NADH) and 2 pyruvate molecules that move on to the next stage – the Krebs cycle. Glycolysis takes place in the cytoplasm of normal body cells, or the sarcoplasm of muscle cells. The Krebs cycle – This is the second stage, and the products of this stage of the aerobic system are a net production of one ATP, one carbon dioxide molecule, three reduced NAD+ molecules, and one reduced flavin adenine dinucleotide (FAD) molecule. (The molecules of NAD+ and FAD mentioned here are electron carriers, and if they are reduced, they have had one or two H+ ions and two electrons added to them.) The metabolites are for each turn of the Krebs cycle. The Krebs cycle turns twice for each six-carbon molecule of glucose that passes through the aerobic system – as two three-carbon pyruvate molecules enter the Krebs cycle. Before pyruvate enters the Krebs cycle it must be converted to acetyl coenzyme A. During this link reaction, for each molecule of pyruvate converted to acetyl coenzyme A, a NAD+ is also reduced. This stage of the aerobic system takes place in the matrix of the cells' mitochondria. Oxidative phosphorylation – The last stage of the aerobic system produces the largest yield of ATP – a total of 34 ATP molecules. It is called oxidative phosphorylation because oxygen is the final acceptor of electrons and hydrogen ions (hence oxidative) and an extra phosphate is added to ADP to form ATP (hence phosphorylation).
The city of Johannesburg sprang up nearly overnight as a shanty town. Uitlanders (foreigners, white outsiders) poured in and settled around the mines. The influx was so rapid that uitlanders quickly outnumbered the Boers in Johannesburg and along the Rand, although they remained a minority in the Transvaal. The Boers, nervous and resentful of the uitlanders' growing presence, sought to contain their influence through requiring lengthy residential qualifying periods before voting rights could be obtained; by imposing taxes on the gold industry; and introducing controls through licensing, tariffs and administrative requirements. Among the issues giving rise to tension between the Transvaal government on the one hand and the uitlanders and British interests on the other, were:
The layers of the body can be approximated as a thin layer of epidermis, dermis, adipose tissue (subcutaneous fat), and muscle tissue. At dozens of gigahertz, the radiation is absorbed in the top fraction to top few millimeters of skin. Muscle tissue is a much more efficient absorber than fat, so at lower frequencies that can penetrate sufficiently deep, most energy gets deposited there. In a homogeneous medium, the energy-depth dependence is an exponential curve with the exponent depending on the frequency and tissue. For 2.5 GHz, the first millimeter of muscle tissue absorbs 11% of the heat energy, the first two millimeters together absorb 20%. For lower frequencies, the attenuation factors are much lower, the achievable heating depths are higher, and the temperature gradient within the tissue is lower.
Up to the 20th century, alcoholic spirits were assessed in the UK by mixing with gunpowder and testing the mixture to see whether it would still burn; spirit that just passed the test was said to be at 100° proof. The UK now uses percentage alcohol by volume (ABV) at 20 °C (68.0 °F), where spirit at 100° proof is approximately 57.15% ABV. In the US, "proof number" is defined as twice the ABV at 60 °F (15.6 °C).
Sources: en.wikipedia.org
Broadly referred to as arrayed primer extension (APEX), this technology has several benefits over methods based on differential hybridization of probes. Comparatively, APEX methods have greater discriminating power than methods using this differential hybridization, as it is often impossible to obtain the optimal hybridization conditions for the thousands of probes on DNA microarrays (usually this is addressed by having highly redundant probes). However, the same density of probes cannot be achieved in APEX methods, which translates into lower output per run. Illumina Incorporated's Infinium assay is an example of a whole-genome genotyping pipeline that is based on primer extension method. In the Infinium assay, over 100,000 SNPs can be genotyped. The assay uses hapten-labelled nucleotides in a primer extension reaction. The hapten label is recognized by anti-bodies, which in turn are coupled to a detectable signal. APEX-2 is an arrayed primer extension genotyping method which is able to identify hundreds of SNPs or mutations in parallel using efficient homogeneous multiplex PCR (up to 640-plex) and four-color single-base extension on a microarray. The multiplex PCR requires two oligonucleotides per SNP/mutation generating amplicons that contain the tested base pair. The same oligonucleotides are used in the following step as immobilized single-base extension primers on a microarray (Krjutskov et al. 2008).
In May 2026, he allowed two immigration bills to into effect without his signature: the Community Trust Act, which prohibits correctional officers from contacting ICE agents for the deportation of an undocumented individual unless the person is a convicted felon, a registered sex offender, or meets other parameters; and the Data Privacy Act, which prohibits state and local agencies from sharing certain personal information for federal immigration enforcement.
General technique for NPWT is as follows: A dressing or filler material is fitted to the contours of a wound to protect the periwound and the overlying foam or gauze is then sealed with a transparent film. A drainage tube is then connected to the dressing through an opening of the transparent film. Tubing is connected through an opening in the film drape to a canister on the side of a vacuum pump. This turns an open wound into a controlled, closed wound with an airtight seal while removing excess fluid from the wound bed to enhance circulation and remove wound fluids. This creates a moist healing environment and reduces edema. There are four types of dressings used over the wound surface: foam or gauze, a transparent film, and a non-adherent (woven or non-woven) contact layer if necessary. Foam dressings or woven gauze are used to fill open cavity wounds. Foam can be cut to size to fit wounds. Once the wound is filled, then a transparent film is applied over the top to create a seal around the dressing. The tubing is then attached and connected to the pump. Once the dressing is sealed, the vacuum pump can be set to deliver continuous or intermittent pressures, with levels of pressure depending on the device used, varying between −200 and −40 mmHg depending on the material used and patient tolerance. Pressure can be applied constantly or intermittently. The dressing type used depends on the type of wound, clinical objectives and patient.
False negative results for antibody testing can occur in people who are immunosuppressed, as they produce lower amounts of antibodies, and in people who receive antimicrobial drugs early in the course of the infection.
Sources: en.wikipedia.org
It is a four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine. The chain is unmodified and contains only standard proteinogenic residues, which makes it straightforward to produce by solid-phase synthesis and to characterise by standard peptide methods.
Epitalon and epithalon both circulate, and the difference reflects transliteration of a name coined in Russian-language publications. Reference to the extract it derives from, epithalamin, explains the shared stem. Databases and suppliers are inconsistent, so a search for one spelling alone may miss relevant entries.
No. Epithalamin is a multi-component preparation obtained from pineal tissue, and its exact composition is not fully characterised. Epitalon is a single defined tetrapeptide described as a short synthetic counterpart of that extract, so the two are related in origin but not interchangeable in identity.
Sealed lyophilised powder is normally kept at minus twenty degrees Celsius or below, away from light and moisture. Vials are allowed to reach room temperature before opening to limit condensation. Repeated warming and cooling of the same vial is discouraged.