The short version of Khavinson fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-31 and is reviewed periodically as new material appears.
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.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Calculated from the four residues with three water losses |
| Molecular mass | About 390.35 g/mol | Monoisotopic mass near 390.14, used for mass-spectrometric identification |
| Peptide sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG; no disulfide bonds or modified residues |
| Appearance | White to off-white solid | Supplied as a dried powder |
| Isoelectric point | Around 4 | Estimated from aspartate and glutamate side-chain pKa values |
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
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.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
Droplet countercurrent chromatography (DCCC or DCC) was introduced in 1970 by Tanimura, Pisano, Ito, and Bowman. DCCC is considered to be a form of liquid-liquid separation, which includes countercurrent distribution and countercurrent chromatography, that employs a liquid stationary phase held in a collection of vertical glass columns connected in series. The mobile phase passes through the columns in the form of droplets. The DCCC apparatus may be run with the lower phase stationary and the upper phase being introduced to the bottom of each column. Or it may be run with the upper phase stationary and the lower phase being introduced from the top of the column. In both cases, the work of gravity is allowed influence the two immiscible liquids of different densities to form the signature droplets that rise or descend through the column. The mobile phase is pumped at a rate that will allow droplets to form that maximize the mass transfer of a compound between the upper and lower phases. Compounds that are more soluble in the upper phase will travel quickly through the column, while compounds that are more soluble in the stationary phase will linger. Separation occurs because different compounds distribute differently, in a ratio called the partition coefficient, between the two phases. The biphasic solvent system must be carefully formulated so that it will perform appropriately in the DCCC column. The solvent system must form two phases without excess emulsification in order to form droplets.
The Foreign Ministry also confirmed that no Malaysians in the country were affected by the strikes, stating that the situation is closely monitored and actively obtaining updates to ensure safety of Malaysians. Prime Minister Anwar Ibrahim described the operation on Facebook as "unusual in scope and nature" as well as constitutes a "clear violation of international law and amounts to an unlawful use of force against a sovereign state". Oman: The Ministry of Foreign Affairs stated that it respects state sovereignty and independence and fully supports international law. In order to avoid escalation and bring about reconciliation, it urged all sides to use moderation and promote communication. Pakistan: The Ministry of Foreign Affairs stated that it attaches "great importance" to the wellbeing of the Venezuelan people, and urges the need for restraint and de-escalation in line with the principles of the Charter of the United Nations. It added that it is engaged with the situation on the ground to ensure the safety and security of Pakistanis in Venezuela. Philippines: The Department of Foreign Affairs stated that it is monitoring the situation in Venezuela and urged "concerned parties to resolve disputes through peaceful means, and to exercise restraint to prevent escalation of conflict". It said the Philippine Embassy in Bogotá, the non-resident mission for Venezuela, had "issued a travel and safety advisory to Filipinos in Venezuela" and was prepared to provide assistance.
==== East and South ==== Heroin is increasingly trafficked from Afghanistan to Europe and America through eastern and southern African countries. This path is known as the "southern route" or "smack track". Repercussions of this trade include burgeoning heroin use and political corruption in intermediary African nations.
Omics.org Archived 2014-01-02 at the Wayback Machine Omics terms and concepts home page. Probably the first omics web page created. List of omics Archived 2015-07-09 at the Wayback Machine, including references/origins. Maintained by the (CHI) Cambridge Health Institute.
Sources: en.wikipedia.org
Although Jim works as a coffee house barista, he is also a well known poetry writer. Damien (Eduardo Rioseco) was Amber's boyfriend in Fresno, who Amber wants to live with in the series premiere, but Sarah forcibly prevents it. He briefly comes to Berkeley to see Amber, despite the fact that Sarah and Zeek dislike him. Amber eventually tells Damien to return to Fresno. Phil Lessing (Phil Abrams) is married to Suze Lessing and father of Noel, a child diagnosed with Asperger's. Suze Lessing (Amanda Foreman) is married to Phil Lessing. Noel Lessing (Nicholas Lobue) is Phil and Suze Lessing's son who has Asperger's, and requires constant stimulation and food. Mark Cyr (Jason Ritter) is Amber's English teacher who has a brief relationship with Sarah. Mark helps Amber study for the SAT after school hours; Amber likely had a crush on Mr. Cyr, so Sarah decides to postpone her relationship with him because it hurt Amber's feelings, and Sarah wants to focus on her family. Sarah and Mark restart their relationship after Sarah asked Mark to read a story she wrote (which Mark said was a play that needed an Act II). The relationship continues, and Sarah and Drew move in with Mark, until season 4, episode 10 "Trouble in Candyland", where Mark breaks up with Sarah because he thought she was getting involved with her boss Hank Rizzoli, and due to her habit of running away from things that make her feel good about herself. Later in season 4, he decides to fight for her, but she decides to try to make it work with Hank.
Infrequent ADRs associated with the use of lidocaine include: hypotension, bradycardia, arrhythmias, cardiac arrest, muscle twitching, seizures, coma, and/or respiratory depression. It is generally safe to use lidocaine with vasoconstrictors such as adrenaline, including in regions such as the nose, ears, fingers, and toes. While concerns of tissue death, if used in these areas, have been raised, the evidence does not support these concerns. The use of lidocaine for spinal anesthesia may lead to an increased risk of transient neurological symptoms, a painful condition that is sometimes experienced immediately after surgery. There is some weak evidence to suggest that the use of alternative anesthetic medications such as prilocaine, procaine, bupivacaine, ropivacaine, or levobupivacaine may decrease the risk of a person developing transient neurological symptoms. Low-quality evidence suggests that 2‐chloroprocaine and mepivacaine when used for spinal anesthetic have a similar risk of the person developing transient neurological symptoms as lidocaine.
Economist Martin Wolf explained in July 2012 that government fiscal balance is one of three major financial sectoral balances in the U.S. economy, the others being the foreign financial sector and the private financial sector. The sum of the surpluses or deficits across these three sectors must be zero by definition. Since the foreign and private sectors are in surplus, the government sector must be in deficit. Wolf argued that the sudden shift in the private sector from deficit to surplus due to the global economic conditions forced the government balance into deficit, writing: "The financial balance of the private sector shifted towards surplus by the almost unbelievable cumulative total of 11.2 percent of gross domestic product between the third quarter of 2007 and the second quarter of 2009, which was when the financial deficit of US government (federal and state) reached its peak...No fiscal policy changes explain the collapse into massive fiscal deficit between 2007 and 2009, because there was none of any importance. The collapse is explained by the massive shift of the private sector from financial deficit into surplus or, in other words, from boom to bust." Economist Paul Krugman also explained in December 2011 the causes of the sizable shift from private sector deficit to surplus: "This huge move into surplus reflects the end of the housing bubble, a sharp rise in household saving, and a slump in business investment due to lack of customers."
The 25-NB compounds are mostly N-benzylphenethylamines, though in some cases the phenyl ring of the N-benzyl group is replaced by other heterocycles such as thiophene, pyridine, furan, tetrahydrofuran, benzodioxole or naphthalene, among others. Generally speaking, they have methoxy groups at the 2 and 5 positions of the phenyl ring, a substitution such as a halogen or alkyl group at the 4 position of the phenyl ring, and a methoxy or other substitution (e.g., hydroxyl, fluoro) at the 2 position of the N-benzyl ring. More rarely, other substitution patterns may be present (see e.g. NBOMe-mescaline, 2,4,6-TMPEA-NBOMe, 25G-NBOMe, 2CBFly-NBOMe, 25C-NB3OMe). They differ from the 2C series by the presence of the N-benzyl moiety. Rarely an alpha-methyl group is present making them N-benzyl amphetamines rather than N-benzyl phenethylamines, but this greatly reduces potency and activity. However in some cases where a side chain methyl group is cyclised back to the ring (e.g. in 2CBCB-NBOMe) or links the two alpha positions (e.g. in DMBMPP), this can improve selectivity for the 5-HT2A receptor subtype.
== Origin and occurrence == Diamondoids are found in mature high-temperature petroleum fluids (volatile oils, condensates and wet gases). These fluids can have up to a spoonful of diamondoids per US gallon (3.78 liters). A review by Mello and Moldowan in 2005 showed that although the carbon in diamonds is not biological in origin, the diamondoids found in petroleum are composed of carbon from biological sources. This was determined by comparing the ratios of carbon isotopes present.
Sources: en.wikipedia.org
The 3D crystallographic structures of the seven transmembrane helical domain (7TM) and the extracellular domain (ECD) and an electron microscopy (EM) map of full length glucagon receptor have been determined. Furthermore, the structural dynamics of an active state complex of the Glucagon receptor, Glucagon, the Receptor activity-modifying protein, and the G-protein C-terminus has been determined using a computational and experimental approach.
Beta decay does not change the number (A) of nucleons in the nucleus, but changes only its charge Z. Thus the set of all nuclides with the same A can be introduced; these isobaric nuclides may turn into each other via beta decay. For a given A there is one that is most stable. It is said to be beta stable, because it presents a local minimum of the mass excess: if such a nucleus has (A, Z) numbers, the neighbour nuclei (A, Z−1) and (A, Z+1) have higher mass excess and can beta decay into (A, Z), but not vice versa. For all odd mass numbers A, there is only one known beta-stable isobar. For even A, there are up to three different beta-stable isobars experimentally known; for example, 12450Sn, 12452Te, and 12454Xe are all beta-stable. There are about 350 known beta-decay stable nuclides.
Bukele announced at the Bitcoin 2021 conference on 5 June 2021 that he would introduce a bill to the Legislative Assembly that would make bitcoin legal tender, saying that it would "generate jobs" and promote "financial inclusion" in the short term. The Legislative Assembly approved the bill three days later. Although the World Bank rejected a request from the Salvadoran government to assist it with the implementation of bitcoin as legal tender, citing concerns about transparency and the environmental effects of bitcoin mining, Athena Bitcoin announced that it would invest $1 million to install 1,500 bitcoin ATMs. This would allow users to exchange U.S. dollars for bitcoin and vice versa. Bitcoin became legal tender on 7 September 2021 in El Salvador, the first country to do so. It became legal tender alongside the United States dollar, which had been adopted in 2001 and replaced the Salvadoran colón. About 1,000 people marched in the streets of San Salvador to protest the country's adoption of bitcoin, though other citizens saw the adoption as an "opportunity." According to The New York Times, bitcoin adoption has allowed Salvadorans without bank accounts to "access digital payments, invest savings or boost earnings." The day before bitcoin became legal tender, Bukele announced that the Salvadoran government had bought its first 200 bitcoins. Economist Steve Hanke stated that El Salvador had "the most distressed sovereign debt in the world" due to its adoption of bitcoin, and other economists predicted that the country would likely default on its debt.
== Development == Half-Life: Opposing Force was announced by developer Gearbox Software on April 15, 1999. In their press release, founder Randy Pitchford stated that "our number one goal is to preserve the integrity of Half-Life and provide new experiences that expand upon the sensation of the original". The name Opposing Force has a double meaning, referring both to the fact that the player is one of the enemies in the original game, as well as to Newton's third law of motion. In a later interview, Pitchford stated that he believed that Valve offered Gearbox the chance to make a Half-Life expansion was from a wish "to focus on their future titles". In addition, Pitchford commented that Valve and Gearbox had agreed not to "severely modify" the game engine used by Half-Life and Opposing Force as it "risks breaking all of the wonderful work" that the game's custom content community was creating. Substantial information on Opposing Force's development direction, as well as new locations, characters and story were revealed at the 1999 Electronic Entertainment Expo convention. The official website for Opposing Force, hosted by publisher Sierra Studios, was put online in July 1999. Opposing Force was developed in 8 months by a team of more than 15 people. Over the course of development, Gearbox acquired various outside talent to assist in designing some aspects. In June 1999, Gearbox announced that level designer Richard Gray would be assisting in developing the multiplayer aspects.
Sources: en.wikipedia.org
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.
It is not recognised as an endogenous peptide hormone. The four-residue sequence can appear inside larger proteins and in digestive fragments of dietary protein, but no dedicated pathway producing it as a signalling molecule has been identified.
Several cell-culture reports describe increased telomerase activity after treatment, measured by enzyme assays or by transcript levels. Results differ between cell types and laboratories, and measured telomere lengthening has been reported in some studies but not in others, which leaves the physiological relevance open.
The usual approach is reversed-phase HPLC with ultraviolet detection, reported as a percentage of total peak area. Mass spectrometry is used alongside chromatography to confirm identity rather than purity alone.