The short version of lyophilization fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-01 and is reviewed periodically as new material appears.
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.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Purity assessment | RP-HPLC | Reported as percent area, often ≥95% |
| Identity confirmation | Mass spectrometry | Observed mass compared with ~390 Da |
| Typical storage temperature | -20 °C or below | Lyophilized powder, desiccated |
| Reconstitution solvent | Sterile water or buffer | Acidic residues aid dissolution |
| Common synonyms | AEDG; epithalon | Spelling varies in literature |
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.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
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.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
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.
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.
February 3 – The government shutdown ends with a bill that funds DHS for two weeks. February 4 The Central Intelligence Agency announces it will no longer publish The World Factbook. Decline of newspapers: The Washington Post announces 300 journalist layoffs, roughly one-third of its employees, as part of a major restructuring. February 5 The New START treaty limiting strategic nuclear weapons with Russia expires. Three people are killed and seven others are injured when a car crashes into a 99 Ranch Market in Westwood, Los Angeles, California. February 6 – Trump shares a video on social media depicting Barack and Michelle Obama as apes. Trump receives bipartisan condemnation. February 8 – Super Bowl LX is played at Levi's Stadium in Santa Clara, California, with the Seattle Seahawks prevailing over the New England Patriots. Bad Bunny headlines the halftime show with special guests Lady Gaga and Ricky Martin, while Kid Rock performs at the Turning Point alternate All-American Halftime Show. February 10 – Trump threatens the opening of the Gordie Howe International Bridge, saying the U.S. should be "fully compensated for everything" it has given to Canada, and demanding that Ottawa "treats the United States with the Fairness and Respect that we deserve". February 11 – The Federal Aviation Administration abruptly announces a 10-day temporary flight restriction (TFR) over El Paso, Texas and surrounding areas (specifically a 10-mile radius surrounding El Paso International Airport).
Analgesics are frequently used in combination, such as the paracetamol and codeine preparations found in many non-prescription pain relievers. They can also be found in combination with vasoconstrictor drugs such as pseudoephedrine for sinus-related preparations, or with antihistamine drugs for people with allergies. While the use of paracetamol, aspirin, ibuprofen, naproxen, and other NSAIDs concurrently with weak to mid-range opioids (up to about the hydrocodone level) has been said to show beneficial synergistic effects by combating pain at multiple sites of action, several combination analgesic products have been shown to have few efficacy benefits when compared to similar doses of their individual components. Moreover, these combination analgesics can often result in significant adverse events, including accidental overdoses, most often due to confusion that arises from the multiple (and often non-acting) components of these combinations.
It is synthesized from lathosterol by the enzyme lathosterol oxidase (lathosterol 5-desaturase). This is the next-to-last step of cholesterol biosynthesis. Defective synthesis results in the human inherited disorder lathosterolosis resembling Smith–Lemli–Opitz syndrome. Mice where this gene has been deleted lose the ability to increase vitamin D3 in the blood following UV exposure of the skin. The skin consists of two primary layers: an inner layer, the dermis, comprising largely connective tissue, and an outer, thinner epidermis. The thickness of the epidermis ranges from 0.04 mm to greater than 0.6 mm. The epidermis comprises five strata; from outer to inner, they are the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. The highest concentrations of 7-dehydrocholesterol are found in the epidermal layer of skin—specifically in the stratum basale and stratum spinosum. The production of pre-vitamin D3 is, therefore, greatest in these two layers.
Naturally occurring niobium (41Nb) is composed of one stable isotope (93Nb). The most stable radioisotope is 92Nb with a half-life of 34.7 million years, followed by 94Nb at a half-life of 20,400 years and 91Nb at 680 years. Other radioisotopes that have been synthesized range from 82Nb to 110Nb; these have half-lives that are less than two hours, except 95Nb (34.991 days), 96Nb (23.35 hours) and 90Nb (14.60 hours). The most stable of the meta states is 93mNb with excitation energy 31 keV and a 16.1 year half-life; this is produced in the decay of 93Zr. The primary decay mode before stable 93Nb is electron capture to zirconium isotopes and the primary mode after is beta emission, with delayed neutron emission starting at 104Nb, leading to molybdenum isotopes. Only 95Nb, along with 97Nb (72 minutes) and heavier isotopes (seconds) are fission products in significant quantity, as the other isotopes are shadowed by stable or very long-lived (93) isotopes of the preceding element zirconium from the usual mode of production through beta decay of neutron-rich fission fragments. 95Nb is the decay product of 95Zr (64 days), so disappearance of 95Nb in used nuclear fuel is slower than would be expected from its own 35-day half-life alone.
Sources: en.wikipedia.org
(2026) study the evolution of amphibious hearing in pinnipeds on the basis of data from extant and extinct representatives of the group and their relatives, link its evolution to the evolution of cavernous tissue in pinniped ear canal and middle ear, and report evidence of presence of amphibious hearing in the last common ancestor of "enaliarctines" and modern pinnipeds but not in more basal members of the pinniped stem group. The first pinniped fossil from Taiwan (a femur of a member of the genus Zalophus from the Pleistocene strata from the bottom of the Taiwan Strait) is described by Sun et al. (2026). Dewaele et al. (2026) study the long bone variability of extant earless seals, finding no evidence of consistently clear genus- or species-specific shapes, and note the need for reevaluation of validity of fossil taxa described on the basis of isolated long bones. Postcranial earless seal bones with distinctive morphology are reported from the Miocene strata from Hrytsiv (Ukraine; the type locality of Planopusa semenovi) by Otriazhyi et al. (2026). Dewaele (2026) revises the fossil record of earless seals from the Miocene strata of the Chesapeake Group (Maryland and Virginia, United States), reporting evidence of presence of three seal morphotypes in the studied fossil material.
=== Layers === The peritoneum is one continuous sheet, forming two layers and a potential space between them: the peritoneal cavity. The outer layer, the parietal peritoneum, is attached to the abdominal wall and the pelvic walls. The tunica vaginalis, the serous membrane covering the male testis, is derived from the vaginal process, an outpouching of the parietal peritoneum. The inner layer, the visceral peritoneum, is wrapped around the visceral organs, located inside the intraperitoneal space for protection. It is thinner than the parietal peritoneum. The mesentery is a double layer of visceral peritoneum that attaches to the gastrointestinal tract. There are often blood vessels, nerves, and other structures between these layers. The space between these two layers is technically outside of the peritoneal sac, and thus not in the peritoneal cavity. The potential space between the parietal and visceral peritoneum is the peritoneal cavity, filled with a small amount (about 50 mL) of slippery serous fluid that allows the two layers to slide freely over each other. The right paracolic gutter is continuous with the right and left subhepatic spaces. The epiploic foramen allows communication between the greater sac and the lesser sac. The peritoneal space in males is closed, while the peritoneal space in females is continuous with the extraperitoneal pelvis through openings of the fallopian tubes, the uterus, and the vagina.
==== Timber rattlesnake ==== The timber rattlesnake, (Crotalus horridus), is a species of venomous pit viper endemic to eastern North America. This is the only rattlesnake species in most of the populous northeastern United States and is second only to its cousins to the west, the prairie rattlesnake, as the most northerly distributed venomous snake in North America. No subspecies are currently recognized.
Sources: en.wikipedia.org
== Illness and death == In June 2026, Chase was admitted to the Los Angeles General Medical Center for treatment of severe malnutrition following a period of extreme weight loss. During her hospitalization, her condition became increasingly critical after she was diagnosed with bacterial meningitis, several bloodstream infections, and AIDS. Doctors stated that she did not have much time left to live. To help manage rising medical expenses and support Chase in regaining stability, her alleged boyfriend, Roy Hernandez, created a GoFundMe crowdfunding campaign. In the campaign description, Hernandez said that Chase had faced significant personal difficulties in her post-acting life, including systemic bullying, a painful estrangement from her family, and ongoing housing instability in downtown Los Angeles. Chase died hours after the fundraising page was launched on June 16, from organ failure caused by her infections, substance abuse and AIDS. She was 35. A secondary cause of death was chronic polysubstance use. Hernandez publicly announced her death through TMZ the following day, June 17, stating that her bloodstream infections had led to septic complications that caused her body to shut down. Following her death, a dispute emerged regarding her final arrangements and the crowdfunding campaign, which Hernandez claimed was intended to help fund her cremation. Chase's former manager, John Ryan, and her father, John Schwallier, publicly denounced the fundraiser, advising fans not to donate.
The energy associated with a particular wavefunction, perhaps the most important information contained in a wavefunction, can be extracted by solving the Schrödinger equation (above, Ψ is the wavefunction, E is the energy, and Ĥ is the Hamiltonian operator) in which an appropriate Hamiltonian operator is applied. In the various forms of the Schrödinger equation, the overall size of a particle's probability distribution increases with decreasing particle mass. For this reason, nuclei are of negligible size in relation to much lighter electrons and are treated as point charges in practical applications of quantum chemistry. Due to complex interactions which arise from electron-electron repulsion, algebraic solutions of the Schrödinger equation are only possible for systems with one electron such as the hydrogen atom, H2+, H32+, etc.; however, from these simple models arise all the familiar atomic (s,p,d,f) and bonding (σ,π) orbitals. In systems with multiple electrons, an overall multielectron wavefunction describes all of their properties at once. Such wavefunctions are generated through the linear addition of single electron wavefunctions to generate an initial guess, which is repeatedly modified until its associated energy is minimized. Thousands of guesses are often required until a satisfactory solution is found, so such calculations are performed by powerful computers. Importantly, the solutions for atoms with multiple electrons give properties such as diameter and electronegativity which closely mirror experimental data and the patterns found in the periodic table.
Dirt spawned five singles that reached the top 30 on the Billboard Mainstream Rock chart: "Would?", "Rooster", "Them Bones", "Angry Chair", and "Down in a Hole", and remained on the charts for nearly two years. Alice in Chains was added as openers to Ozzy Osbourne's No More Tours tour. Days before the tour began, Layne Staley broke his foot in an ATV accident, forcing him to use crutches on stage. Starr left the band after the release of Dirt. Staley told Rolling Stone in 1994 about Starr leaving the band, "It was just a difference in priorities. We wanted to continue intense touring and press. Mike was ready to go home." Years later, Starr claimed that he was fired due to his drug addiction. Starr was replaced by former Ozzy Osbourne bassist Mike Inez. Inez had met Alice in Chains during Ozzy Osbourne's No More Tours tour and became friends with them. When the band was in Brazil, they called Inez to join them and he accepted. Inez wanted to do the shows in Brazil and even got his immunization shots, but the band called him back saying that Starr wanted to do the last two shows in Brazil, so they would meet Inez in London instead. Inez ended up getting sick with his vaccination shots for a couple of days. Inez played his first concert with Alice in Chains on January 27, 1993, at the Camden Underworld in London. In April 1993, the band recorded two songs with Inez, "What the Hell Have I" and "A Little Bitter", for the Last Action Hero soundtrack.
Sources: en.wikipedia.org
Identity is normally confirmed by mass spectrometry, which checks the measured mass against the expected value near 390 daltons. Reverse-phase high-performance liquid chromatography is used alongside it to assess purity. Amino acid analysis can provide additional composition data.
The powder is generally kept refrigerated or frozen, protected from light and moisture. Vials should reach room temperature before opening to prevent condensation. Reconstituted solutions are usually stored cold and used within a limited window because dilute solutions can degrade or support microbial growth.
Epitalon is not an approved drug in major Western regulatory jurisdictions. Its legal status differs between countries, and it is often distributed as a research chemical. This means product documentation and purity vary considerably between suppliers.
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.