This is a working overview of Selank, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
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.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
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.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Whether it expanded the person's ability to socialize or gave the person a chance to contribute to the multiethnic goals of the Soviet Union, many people saw the benefit of learning Russian. While other languages were spoken, Russian became the lingua franca of the USSR. During World War II, some minority languages were banned, and their speakers accused of collaborating with the enemy. As the most widely spoken of the Soviet Union's many languages, Russian de facto functioned as an official language, as the 'language of interethnic communication' (Russian: язык межнационального общения), but only assumed the de jure status as the official national language in 1990.
=== North America === In North America, medical physics training is offered at the master's, doctorate, post-doctorate and/or residency levels. A professional doctorate has also been recently introduced as an option. Several universities in Canada and the United States offer these degrees. As of October 2013, over 70 universities in North America have medical physics graduate programs or residencies that are accredited by The Commission on Accreditation of Medical Physics Education Programs (CAMPEP). The majority of residencies are therapy, but diagnostic and nuclear have also been on the rise in the past several years. In the United States, professional certification is obtained from the American Board of Radiology (for all 4 areas) the American Board of Medical Physics (for MRI), the American Board of Science in Nuclear Medicine (for Nuc Med and PET). As of 2012, enrollment in a CAMPEP-accredited residency or graduate program is required to start the ABR certification process. As of 2013, completion of a CAMPEP-accredited residency is required to advance to part 2 of the ABR certification process. In Canada, professional certification is obtained from the Canadian College of Physicists in Medicine (for all 4 areas and Mammography). Since 2016, eligibility requirements for Radiation Oncology Physics certification includes graduation and post-graduate training from a CAMPEP accredited institution.
where I(iM)is the count rate of the isotope iM of element M. The counting rate of the isotope is dependent on the concentration, XM and the element's isotopic abundance, denoted Ai. Because the primary ion beam determines the secondary ions, Y, that are sputtered, the density of the primary ion beam, db, which is defined as the amount of ions per second per unit of surface area, will affect a portion of the surface area of the sample, S, with an even distribution of the primary ions. Of the sputtered secondary ions, there is only a fraction that will be ionized, Yi. The probability that any ion will be successfully transferred from mass spectrometer to detector is T. The product of Yi and T determines the amount of isotopes that will be ionized, as well as detected, so it is considered the useful yield.
== Regional research stations == Captain Pawan Kumar Extension campus, Jind: Captain Pawan Kumar Extension campus is at Badhana village in Jind district for which INR46 crore (460 million) was released in 2018. Regional Research Station, Ambala: It is located at Naraingarh in Ambala district. Regional Research Station, Jhajjar: located at Jhajjar district. RMRC Mushroom Research Center, Murthal in Sonepat
Viserys I Targaryen is a fictional character in American author George R. R. Martin's the A Song of Ice and Fire series of epic fantasy novels, appearing in the 2013 novella The Princess and the Queen, the 2014 novella The Rogue Prince and the 2018 novel Fire & Blood. In the HBO television adaptation House of the Dragon, he is portrayed by English actor Paddy Considine. Viserys was the fifth king from the Targaryen dynasty to sit on the Iron Throne, ruling from 103 AC to 129 AC. He inherited the throne from his grandfather Jaehaerys I Targaryen, who had lost several previous heirs of his own issue. He is the older brother of Prince Daemon Targaryen, husband of queens Aemma Arryn and Alicent Hightower, and father of Queen Rhaenyra Targaryen and King Aegon II Targaryen. Ruling in a peacetime period, Viserys remained open-minded and approachable in addressing problems across the realm, and many lords and smallfolk praised him for his generosity. He hosted many tournaments, balls, and banquets in the Red Keep, a source of both unity and division depending on the occasion. He was not very physically active like Daemon, and dealt with various health problems that continued to worsen towards the end of his reign. The issue of succession caused much friction in Viserys' court, as he struggled to stabilize relations between the green faction led by Alicent and black faction led by Rhaenyra.
Sources: en.wikipedia.org
In 2018, the International Union for Conservation of Nature (IUCN) assessed the white shark as vulnerable worldwide, citing a population decline of 30–49% since approximately 1859. The species was further described as "moderately depleted" in 2021. The biggest threats to white sharks are accidental catching in fishing nets and the use of shark control measures—such as nets and traps—near beaches in Australia and South Africa. They nevertheless maintain a high survival rate when released from such gear. To regulate international trade, the species is listed under CITES Appendix II, requiring permits for the exchange of any specimens or parts. While a 2025 study estimated the global population at a minimum of roughly 5,800 individuals, co-author Gavin Naylor suggests the actual figure may be closer to 20,000.
The set nature of species, and thus the absoluteness of creatures' places in the great chain, came into question during the 18th century. The dual nature of the chain, divided yet united, had always allowed for seeing creation as essentially one continuous whole, with the potential for overlap between the links. Radical thinkers like Jean-Baptiste Lamarck saw a progression of life forms from the simplest creatures striving towards complexity and perfection, a schema accepted by zoologists like Henri de Blainville. The very idea of an ordering of organisms, even if supposedly fixed, laid the basis for the idea of transmutation of species, whether progressive goal-directed orthogenesis or Charles Darwin's undirected theory of evolution. The chain of being continued to be part of metaphysics in 19th-century education, and the concept was well known. The geologist Charles Lyell used it as a metaphor in his 1851 Elements of Geology description of the geological column, where he used the term "missing links" about missing parts of the continuum. The term "missing link" later came to signify transitional fossils, particularly those bridging the gulf between man and beasts.
==== Partitioning ==== ParM: this protein forms dynamic filaments that push plasmid copies to opposite poles of the cell ParR: recruits ParM to the plasmid by acting as a DNA-binding protein that recognizes the ParC centromere-like site. ParC: the centromere-like site where ParR binds.
== Diagnosis == A seroma may be diagnosed based on signs on the skin. On CT scans, seromas have a radiodensity of 0–20 Hounsfield units, generally in the lower part of this range, consistent with clear fluid.
== Benefits of TPMS == The dynamic behavior of a pneumatic tire is closely connected to its inflation pressure. Key factors like braking distance and lateral stability require the inflation pressures to be adjusted and kept as specified by the vehicle manufacturer. Extreme under-inflation can even lead to thermal and mechanical overload caused by overheating and subsequent, sudden destruction of the tire itself. Additionally, fuel efficiency and tire wear are severely affected by under-inflation. Tires do not only leak air if punctured, they also leak air naturally, and over a year, even a typical new, properly mounted tire can lose from 20 to 60 kPa (3 to 9 psi), roughly 10% or even more of its initial pressure. The claimed benefits of TPMS include:
Sources: en.wikipedia.org
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.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
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.