The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-17 and is reviewed periodically as new material appears.
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.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
== Principle == Modified Russell–Movat staining highlights numerous tissue components in histological slides. It is obtained by a mix of five stains: alcian blue, Verhoeff hematoxylin and crocein scarlet combined with acidic fuchsine and saffron. At pH 2.5, alcian blue is fixed by electrostatic binding with the acidic mucopolysaccharides. The Verhoeff hematoxylin has a high affinity for nuclei and elastin fibers, negatively charged. The combination of crocein scarlet with acidic fuchsine stains acidophilic tissue components in red. Then, collagen and reticulin fibers are unstained by a reaction with phosphotungstic acid and stained in yellow by saffron.
== Gas separation == MOFs are predicted to be effective media for separating gases with low energy cost using computational high throughput screening from adsorption or gas breakthrough/diffusion properties. One example is NbOFFIVE-1-Ni (KAUST-7) which can separate propane and propylene via diffusion at nearly 100% selectivity. The specific molecule selectivity properties provided by Cu-BDC surface mounted metal organic framework (SURMOF-2) growth on alumina layer on top of back gated graphene field effect transistor (GFET) can provide a sensor that is sensitive only to ethanol, but not to methanol or isopropanol.
==== Princes of the Royal Secret ==== In April 1818, a member of the Grand Orient de France named Louis de Clouet, who went by the Masonic codename d'Obernay, established a Grand Consistory of the Scottish Rite in Havana, Principes del Real Secreto (English: Princes of the Royal Secret). D'Obernay authorized the Grand Consistory to establish Lodges, chapters, and councils. He also authorized it to confer the 32nd Degree. The Grand Orient of France further authorized this work under the charter of the Grand Consistory dated April 7, 1819. Exactly how many Lodges were merged to create Principes del Real Secreto is debated. However, D'Obernay and this Grand Consistory did create several lodges, including L'Humanite, and La Constante Sophie, which received its charter directly from the Grand Orient of France. The Blue Lodges of the Grand Consistory were formed under the Gran Oriente Simbolico de la Nueva Thebaida (English: Symbolic Grand Orient of New Thebes), which was also known as the Gran Oriente Simbolico de la Isla de Cuba (English: Symbolic Grand Orient of the Island of Cuba). When the Grand Consistory was established, the Grand Orient of France relinquished their authority, handing it over to the National Grand Oriente of Spain. However, because the Grand Orient of Spain was bifurcated politically, the Cubans rejected its authority, preferring to remain autochthonous, instead of finding themselves on either side of the mainland Spanish divisions.
Sources: en.wikipedia.org
Instant coffee (Two packets) Coffee creamer (One packet, four grams) Sugar (One packet, six grams) Candy-coated gum (Two pieces) Compressed fruitcake bar or Tropical Bar Toilet paper Cardboard matches (One book) Cigarettes (Four sticks; eliminated in 1975) Although compact, the LRP daily ration was 'energy depleted', supplying 5,000 kilojoules (1,200 kcal) less energy per day than the MCI.
Important factors for well-being are self-esteem, or how a person evaluates themselves, and authenticity, or the degree to which a person's behavior is subjectively consistent with their sense of self. A further area explores the role of social and physical circumstances. This includes the effects of trust and cooperation on group well-being and dilemmas in which self-interest conflicts with group interest. Having close relationships and engaging in altruistic behavior are generally beneficial to a person's well-being. In addition to the study of the different components and causes of well-being, positive psychologists seek to understand how well-being changes over time. For example, they examine the effects of major negative events, such as the death of a child or bankruptcy, and the psychological features that help some people maintain their level of well-being despite significant adversity, such as self-regulation and an optimistic outlook. Another key topic is the problem of interventions or how to design and implement methods to reliably increase well-being. Researchers explore a wide range of strategies, including cognitive reframing, cultivating gratitude, acts of kindness toward others, and different forms of meditation. The possibility of creating long-term gains in well-being is challenged by the set-point theory—the hypothesis that each person has a stable level of subjective well-being.
== Personal life == Nasatir was one of four children: three boys and a girl. He married Ida Hirsch; they had no children. He actively supported the activities of the California Jewish community. He died on January 18, 1991, from complications of pneumonia at Mercy Hospital in Los Angeles, California.
Sources: en.wikipedia.org
dry box A chamber or container in which the interior is maintained at very low humidity, often by filling it with argon or with air lacking carbon dioxide, in order to provide an inert atmosphere in which manipulation of very reactive chemicals or moisture-sensitive procedures can be carried out in the laboratory.
18 September – A study published in Nature Neuroscience, using mouse embryos and human pluripotent stem cells, finds that the forebrain and midbrain develop from a different progenitor cell lineage from the hindbrain, challenging the long-standing model of a single progenitor population for the entire brain. The authors propose that the brain is a composite organ arising from two developmentally distinct systems that may have been evolutionarily conserved for more than 550 million years.
== See also == Resonance-enhanced multiphoton ionization Rydberg ionization spectroscopy Photoionization Atmospheric-pressure laser ionization Radiometric dating Electron excitation Tunable lasers Cosmochemistry
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.