The short version of Neurotrophic factor fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-06-22. Anything still debated is marked as such rather than presented as settled.
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.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
| Property | Value | Notes |
|---|---|---|
| Route studied | Intranasal | Predominant route in published reports |
| Circulation stability | Short, minutes scale | Peptidases cleave it; the tail slows the process |
| Analytical method | RP-HPLC with mass spectrometry | Used for identity and purity assessment |
| Reported outcome domains | Anxiety and cognitive measures | Derived from small, mostly regional trials |
| Regulatory status | Marketed in Russia | Availability outside that market is limited |
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Infants can be infected during passage through the birth canal; nevertheless, newborns who acquire GBS through this route may only become colonized, and these colonized infants typically do not develop EOD. Roughly 50% of newborns to GBS colonized mothers are also GBS colonized, and (without prevention measures) 1–2% of these newborns will develop EOD. In the past, the incidence of EOD ranged from 0.7 to 3.7 per thousand live births in the US and from 0.2 to 3.25 per thousand in Europe.Multistate surveillance 2006-2015 shows a decline in EOD from 0.37 to 0.23 per 1000 live births in the US, but LOD remains steady at 0.31 per 1000 live births. In 2021 had been estimated a total of 1970 deaths (0.59/100,000 population) in the US were estimated to be caused by GBS neonatal infections. It was estimated that 226 infants (49 per 100,000) in the United States had a clinically significant GBS infection, and that approximately 11 (2.4%) of those cases resulted in death. The widespread use of intrapartum antibiotic prophylaxis (IAP) has resulted in a decline in the incidence of early neonatal GBS infection in the United States of more than 85%, from 1.8‰ of cases in live births in the 1990s to 0.23‰ in 2015, and to 0.18‰ in 2023.
According to the contract, the RDIF as a seller is not liable for any adverse events following administering of the vaccine, nor its effectiveness. According to the Slovak lawyers, the contract is explicitly disadvantageous for Slovakia. On 8 May 2021, the Russian Direct Investment Fund sent a letter to the Denník N newspaper requesting the removal of the statements of the drug regulator, calling them "unsubstantiated and false" and "fake news". RDIF threatened the newspaper with legal action if they didn't comply with the demand by 9 May. The newspaper's editors refused. After the samples were sent to the EU-certified laboratory in Hungary and it was stated that "the results were satisfactory", the Slovak government approved the vaccine, and announced that vaccination with Sputnik V would begin in June 2021, despite the negative review by Slovakia's drug regulator. Vaccinations started on 7 June, but without significant interest in the Sputnik V vaccine. Slovakia had no plans to order new batches and planned to sell or donate unused vaccines to Balkans countries. The registrations for vaccination were closed on 30 June. In July 2021, 160,000 doses of the vaccine from the first batch of 200,000 were shipped back to Russia. Temporary government approval for Sputnik V expired on 31 August 2021. In total, 18,500 people have been vaccinated. The purchase of Sputnik V, which led to a political crisis and contributed to a fall of Igor Matovič's Cabinet was investigated by Slovak Police Force with the investigation levered against Marek Krajčí.
28 October 2014: Wilkinson A/L Primus, a Malaysian convicted of trafficking heroin in 2008 and sentenced to death in 2009. When changes to the law took effect in 2013, he applied for re-sentencing and was re-sentenced to life imprisonment in 2014 on the grounds that he was intellectually challenged and suffering from depression at the time of the crime. 20 April 2015: Cheong Chun Yin, a Malaysian convicted of trafficking heroin in 2008 and sentenced to death in 2010. He lost his appeal to the Court of Appeal in 2010. When changes to the law took effect in 2013, he applied for re-sentencing and was re-sentenced in 2015 to life imprisonment and 15 strokes of the cane. His boss and accomplice, Pang Siew Fum, was also re-sentenced to life imprisonment on the same day, due to Pang suffering from depression at the time of the crime. 1 July 2015: Kester Ng Wei Ren, a 47-year-old Singaporean caught trafficking in 23.38g of heroin on 12 August 2008. He tried to argue that he only meant to import only 9.92g of heroin while the rest of his drug supply was only meant for his own consumption. Ng was given the mandatory death penalty in 2010 and he also lost his appeal in the same year. After changes to the law took effect in 2013, Ng applied for re-sentencing but he did not meet the criteria to be re-sentenced to life imprisonment. Hence he lost his appeal to be re-sentenced on 1 July 2015 since he was not certified as a courier. He was presumably executed sometime following the loss of his re-sentencing application.
Sources: en.wikipedia.org
=== Mechanism of action === Elbasvir targets the NS5A protein, which effectively prevents the transcription of the HCV RNA and also prevents virion assembly. "Median EC50 values range from 0.2 to 3600 pmol/L, based on genotype." Grazoprevir is an protease inhibitor targeting HCV NS3/4A serine protease. Effectively grazoprevir prevents cleavage of the necessary polyproteins for replication.
== Titanium-44 == Titanium-44 (44Ti) is a radioactive isotope of titanium that undergoes electron capture with a half-life of 59.1 years to an excited state of scandium-44, before reaching the ground state of 44Sc and ultimately of 44Ca. Because titanium-44 can decay only through electron capture, its half-life increases slowly with its ionization state and it becomes stable in its fully ionized state (that is, having a charge of +22), though as astrophysical environments never lack electrons completely, it will always decay. Titanium-44 is produced in relative abundance in the alpha process in stellar nucleosynthesis and the early stages of supernova explosions. It is produced when stable calcium-40 adds an alpha particle (helium-4), as nickel-56 is the result of adding three more. The age of supernova remnants (even though nickel-56 has died away to iron) may be determined through measurements of gamma-ray emissions from the relatively long-lived titanium-44 and of its abundance. It was observed in the Cassiopeia A supernova remnant and SN 1987A at a relatively high concentration, enhanced by the delayed decay in the ionizing conditions.
After the Second World War, the United States and the Soviet Union were doomed to be antagonists. ... There probably was never any real possibility that the post-1945 relationship could be anything but hostility verging on conflict. ... Traditions, belief systems, propinquity, and convenience ... all combined to stimulate antagonism, and almost no factor operated in either country to hold it back. From that view of "post-revisionism" emerged a line of inquiry that examines how Cold War actors perceived various events and the degree of misperception involved in the failure of the two sides to reach common understandings of their wartime alliance and their disputes. After the opening of the Soviet archives, John Lewis Gaddis began to argue that the Soviets should be held more accountable for conflict. According to Gaddis, Stalin was in a much better position to compromise than his Western counterparts, given his much broader power within his own regime than Truman, who was often undermined by vociferous political opposition at home. Asking if it would have been possible to predict that the wartime alliance would fall apart within a matter of months, leaving in its place nearly a half century of cold war, Gaddis wrote in his 1997 book We Now Know: Rethinking Cold War History the following:
Sources: en.wikipedia.org
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.
Intranasal delivery is the route described in most published work. It is used because the peptide is degraded quickly once it reaches circulation. Direct evidence of brain penetration in humans is lacking.
Most trials are small, regionally concentrated, and often lack rigorous blinding or placebo control. Independent replication is limited. Reviews in English generally rate the evidence as preliminary.
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.