This is a working overview of GABA-A modulation, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-12-13. Anything still debated is marked as such rather than presented as settled.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
| Property | Value | Notes |
|---|---|---|
| Dry storage temperature | -20 C or below | Sealed, desiccated, protected from light |
| Solution stability | Hours to days at 2-8 C | Depends on buffer and microbial load |
| Preferred pH range | Near neutral to slightly acidic | Alkaline pH accelerates hydrolysis |
| Main degradation routes | Hydrolysis and deamidation | No cysteine or methionine in sequence |
| Identity confirmation | Electrospray mass spectrometry | Observed mass compared with 751.9 Da |
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
== History == Surgery was used to treat hyperthyroidism until the advent of drug therapies in the 1940s. In 1942, thiourea was used by Edwin B. Astwood to treat a patient with the condition. He later published evidence that thiouracil was more effective and began a search for analogues with higher potency and less toxicity. In 1949 he published his work on thiamazole which showed its superiority to previous therapies. The compound had been known since 1889, and was developed as a drug by Eli Lilly and Company under the trade name Tapazole.
In analytical chemistry, ashing or ash content determination is the process of mineralization by complete combustion for preconcentration of trace substances prior to a chemical analysis, such as chromatography, or optical analysis, such as spectroscopy.
=== Translation === Ninety of the Bloomberg tablets have been translated. This is the highest number of translated artefacts from any comparable archaeological site in London, surpassing the previous record of 19. Alongside the 90 translated tablets are another 91 stylus tablets, all which have been inscribed but are considered illegible. The 90 translated tablets have been grouped according to the content translated within, 43 of these tablets contained general correspondence, 25 of them were financial or legal documentation, 8 tablets were book keeping accounts showing what people owed and the remaining 14 are miscellaneous. The tablets were translated by Dr Roger Tomlin, an expert in Roman cursive, the writing style in which the tablets were written. Tablets vary in content, including the oldest financial document from London (dating to 8 January 57 AD), about 3 to 4 years before the city was destroyed by Boudica. It also documents how the Roman government responded with their military and how soon the city recovered thereafter. Legal documents include a judge calling a pretrial hearing, and educational material. One tablet shows the alphabet written out, indicating the presence of perhaps the first school in Britain. Additionally, among the tablets there are over 100 names of people of all different professions and social classes who lived in London at the time, such as slaves, merchants, soldiers, and politicians. One prominent figure that is named is Julius Classicus, who was a commander in the Roman auxiliaries.
Sources: en.wikipedia.org
End-to-end mobile development A new lightweight edition (ColdFusion Express) Language enhancements WebSocket enhancements PDF generation enhancements Security enhancements Social enhancements REST enhancements Charting enhancements Compression enhancements ColdFusion 11 also removed many features previously identified simply as "deprecated" or no longer supported in earlier releases. For example, the CFLOG tag long offered date and time attributes which were deprecated (and redundant, as the date and time is always logged). As of CF11, their use would not cause the CFLOG tag to fail.
=== Frazier === On September 29, 2025, Seth Frazier, then 41 years old, pleaded guilty to four counts of first degree murder, one count of attempted first degree murder, six counts of assault with a deadly weapon with the intent to kill inflicting serious injury, and one count each of burning a public building, inciting riot, attempting escape and assault with a deadly weapon. As a result of his plea of guilt, Frazier was spared the death sentence and instead sentenced to four consecutive life sentences without parole for all four murder charges, plus 93 to 116 years for all the lesser offences he admitted to. Similarly to his co-defendants, Frazier was transferred into the federal prison system and is currently at USP Terre Haute.
A positive screen warrants an antibody panel/investigation to determine if it is clinically significant. An antibody panel consists of commercially prepared group O red cell suspensions from donors that have been phenotyped for antigens that correspond to commonly encountered and clinically significant alloantibodies. Donor cells may have homozygous (e.g. K+k+), heterozygous (K+k-) expression or no expression of various antigens (K−k−). The phenotypes of all the donor cells being tested are shown in a chart. The patient's serum is tested against the various donor cells using an indirect Coombs test. Based on the reactions of the patient's serum against the donor cells, a pattern will emerge to confirm the presence of one or more antibodies. Not all antibodies are clinically significant (i.e. cause transfusion reactions, HDN, etc.). Once the patient has developed a clinically significant antibody it is vital that the patient receive antigen-negative red blood cells to prevent future transfusion reactions. If there is no antibody present, an immediate spin crossmatch may be performed where the recipient serum and donor rbc are incubated. In the immediate spin method, two drops of patient serum are tested against a drop of 3–5% suspension of donor cells in a test tube and spun in a serofuge. Agglutination or hemolysis (i.e., positive Coombs test) in the test tube is a positive reaction. If the crossmatch is positive, then further investigation is needed.
Sources: en.wikipedia.org
==== NATO ==== The foreign secretary, Geoffrey Howe, spoke highly of Heseltine's contribution to NATO and WEU conferences. Heseltine was as angry as Thatcher at the US invasion of Grenada, a Commonwealth country. He wanted warmer relations with the Soviets and was sceptical about the US Strategic Defense Initiative ("Star Wars"), putting in a brief and grudging appearance at Caspar Weinberger's Ditchley Park Conference about the topic in 1985. Heseltine came close to misleading the House of Commons over the meeting of NATO defence ministers at Montebello, Quebec, in October 1983. He stated that no "specific" proposals had been made to update NATO short range and tactical nuclear weapons. In fact a decision had been made in principle to do so. Crick describes Heseltine's answers as "highly disingenuous and deceitful". At the time NATO was claiming to be cutting back on such weapons, and the peace movement was still powerful in Germany where such weapons might be used.
== External links == HPRD Human Protein Reference Database, a (manually) curated database of human protein information with visualization tools IntAct Interaction Database, a public repository for manually curated molecular interaction data from the literature DIP Database of Interacting Proteins, a manual and automatic catalog of experimentally determined interactions between proteins MIPS Mammalian Protein–Protein Interaction Database, the MIPS mammalian protein–protein interaction database
=== Reactions === Crisis services for the LGBTQ+ community saw a sharp increase in usage during the election week. The Trevor Project's crisis lines saw a 125% increase since around midnight on election night according to a statement by CEO Jaymes Black on November 6, and followed an about 200% increase in election related conversations that had been seen November 3–4. By November 8, it was reported that the organization saw an overall increase by 700%. The Crisis Text Line also reported that 56% of their users reported as LGBTQ+ on election day. A company that assists wealthy Americans in securing foreign citizenship saw a 200× jump in inquiries following the election.
In contrast, the accidental forms of S are its non-essential properties—properties that S can lose or gain without changing into a different kind of substance: the chick can lose its feathers (due to, e.g., parasites or the like) without ceasing to be an individual chicken.
Sources: en.wikipedia.org
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.
Hydrolysis of peptide bonds and deamidation of arginine and proline residues are the main degradation routes. Alkaline pH and higher temperatures accelerate both processes. Buffered, near-neutral solutions stored cold generally degrade more slowly than unbuffered ones.
Reverse-phase chromatography gives the clearest single view of related impurities and truncated sequences. Mass spectrometry then confirms that the main peak carries the expected mass. Neither test detects enantiomeric impurities, which require a separate chiral assay.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.