If you have been reading about tuftsin and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-01-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid form |
| Solubility class | Freely soluble in water | Hydrophilic heptapeptide |
| Dry storage temperature | -20 degrees Celsius or lower | Sealed, desiccated, protected from light |
| Solution storage | 2 to 8 degrees Celsius short term | Avoid repeated freeze-thaw cycles |
| Common identification method | Reversed-phase HPLC with mass spectrometry | Confirms purity and molecular mass |
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.
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.
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.
Amazake, beer, bread, choujiu, gamju, injera, kvass, makgeolli, murri, ogi, rejuvelac, sake, sikhye, sourdough, sowans, rice wine, malt whisky, grain whisky, idli, dosa, Bangla (drink), vodka, boza, and chicha, among others.
The failure of the January Uprising in Poland caused a major psychological trauma and became a historic watershed; indeed, it sparked the development of modern Polish nationalism. The Poles, subjected within the territories under the Russian and Prussian administrations to still stricter controls and increased persecution, sought to preserve their identity in non-violent ways. After the uprising, Congress Poland was downgraded in official usage from the "Kingdom of Poland" to the "Vistula Land" and was more fully integrated into Russia proper, but not entirely obliterated. The Russian and German languages were imposed in all public communication, and the Catholic Church was not spared from severe repression. Public education was increasingly subjected to Russification and Germanisation measures. Illiteracy was reduced, most effectively in the Prussian partition, but education in the Polish language was preserved mostly through unofficial efforts. The Prussian government pursued German colonization, including the purchase of Polish-owned land. On the other hand, the region of Galicia (western Ukraine and southern Poland) experienced a gradual relaxation of authoritarian policies and even a Polish cultural revival. Economically and socially backward, it was under the milder rule of the Austro-Hungarian Monarchy and from 1867 was increasingly allowed limited autonomy. Stańczycy, a conservative Polish pro-Austrian faction led by great land owners, dominated the Galician government. The Polish Academy of Learning (an academy of sciences) was founded in Kraków in 1872.
It was protected through NAFTA in Canada and the United States until July 2020 and through bilateral agreements with individual countries such as Japan and Israel, and it has been a protected designation of origin product in the European Union since 1997. Tequila is commonly served neat in Mexico and as a shot with salt and lime around the world.
== Sports == Canberra Raiders, Australian rugby league football club Chitwan Rhinos, a professional Twenty20 cricket franchise representing Chitwan District, Nepal in the Nepal Premier League (NPL) Colorado Rockies, a Major League Baseball team Cincinnati Reds, another Major League Baseball team Colorado Rockies (NHL), a former National Hockey League team Cristiano Ronaldo, Portuguese footballer Commonwealth record in athletics Commonwealth record in swimming
=== Missing and identification === According to UNICEF, the standard system for identifying, documenting, tracing and reuniting children with relatives or siblings was barely functional in early December 2023. Additional difficulties arose from the intensity of the fighting and the rapidly changing conditions in Gaza, which hindered efforts to communicate with hospitals and medical staff. Four months into the conflict, the UN estimated that about 40% of all people in Gaza had lost identification cards and documents due to the war, making it more difficult to identify unaccompanied children and reunite them with their families. Humanitarian organizations also reported difficulties with orphaned children who were too young to know their own names. A UNICEF spokesman said: "The youngest ones very often cannot say their name and even the older ones are usually in shock so it can be extremely difficult to identify them". Hospital and emergency workers in Gaza noted that parents and relatives of some children wrote on children's bodies, mostly on their legs and abdomens, so the children would be identifiable if found in the rubble or get lost. One employee stated: "Many of the children are missing, many get here with their skulls broken… and it’s impossible to identify them, only through that writing do they get identified." In June 2024, Save the Children stated approximately 21,000 children were missing in Gaza, including 4,000 children believed to be buried under rubble. The bodies of some of these children remained unrecovered.
Sources: en.wikipedia.org
Surrounds heart and bases of pulmonary artery and aorta. Deep to sternum and anterior chest wall. The right phrenic nerve passes to the right of the pericardium. The left phrenic nerve passes over the pericardium of the left ventricle. Pericardial arteries supply blood to the dorsal portion of the pericardium.
We thus come to the remarkable conclusion that, beyond doubt, Van Leeuwenhoek in his experiment with the fully closed tube had cultivated and seen genuine anaerobic bacteria, which would happen again only after 200 years, namely about 1862 by Pasteur. That Leeuwenhoek, one hundred years before the discovery of oxygen and the composition of air, was not aware of the meaning of his observations is understandable. But the fact that in the closed tube he observed an increased gas pressure caused by fermentative bacteria and, in addition, saw the bacteria, prove, in any case, that he not only was a good observer but also was able to design an experiment from which a conclusion could be drawn.
According to helium conservationists like Nobel laureate physicist Robert Coleman Richardson, writing in 2010, the free market price of helium has contributed to "wasteful" usage (e.g. for helium balloons). Prices in the 2000s had been lowered by the decision of the U.S. Congress to sell off the country's large helium stockpile by 2015. Richardson posited that the price of helium needed to be multiplied by 20 to eliminate excessive wasting of the gas. In a 2012 paper by Nuttall and colleagues titled "Stop squandering helium", they proposed to create an International Helium Agency that would build a sustainable helium market.
Spiral multidetector CT uses 16, 64, 254, or more detectors during continuous motion of the patient through the radiation beam to obtain fine detail images in a short exam time. With rapid administration of intravenous contrast during the CT scan, ...these fine detail images can be reconstructed into three-dimensional (3D) images of carotid, cerebral, coronary or other arteries. The introduction of computed tomography in the early 1970s revolutionized diagnostic radiology by providing front-line clinicians with detailed images of anatomic structures in three dimensions. CT scanning has become the test of choice in diagnosing some urgent and emergent conditions, such as cerebral hemorrhage, pulmonary embolism (clots in the arteries of the lungs), aortic dissection (tearing of the aortic wall), appendicitis, diverticulitis, and obstructing kidney stones. Before the development of CT imaging, risky and painful exploratory surgery was often the only way to obtain a definitive diagnosis of the cause of severe abdominal pain, which could not be otherwise ascertained from external observation. Continuing improvements in CT technology, including faster scanning times and improved resolution, have dramatically increased the accuracy and usefulness of CT scanning, which may partially account for increased use in medical diagnosis.
Sibabrata Mukhopadhyay, Mumu Chakraborty, Arun Bandyopadhyay, Dipak Kar, Tanima Banerjee, Aditya Konar, Debaprasad Jana, Siddhartha Roy, Santu Bandyopadhyay, Balram Ghosh, Mabalirajan Ulaganathan, Rakesh Johri, Subhash Sharma, Gurdarshan Singh, Bholanath Paul, Vasanta Madhava Sharma Gangavaram, Jhillu Singh Yadav, Radha Krishna Palakodety (August 2013). "Method for treatment of bronchial asthma (Patent US8519154B2)". {{cite journal}}: Cite journal requires |journal= (help)CS1 maint: multiple names: authors list (link) Sujoy K Das Gupta, Abhik Saha, Archana Sharma, Siddhartha Roy, Bhabatarak Bhattacharya (January 2012). "Peptide antagonists for inhibiting heat shock protein (Hsp 16.3) of Mycobacterium tuberculosis (Patent 7569537)". Retrieved 15 October 2016.{{cite web}}: CS1 maint: multiple names: authors list (link) S. Bandyopadhay, B. Ghosh, Parasuraman Jaisankar, Bikas C Pal, Siddhartha Roy, Nath Paul, Arjun Ram, U. Mabalirajan, Nahid Ali, Arun Bandyopadhyay, Aditya Konar, J. B. Chakraborty, I. C. Mukherjee, Jaydeep Chaudhuri, Sanjit Kumar Mahato, A. Manna, Roma Sinha, Pradyot Bhattacharya, J. Vinayagam, Sudeshna Chowdhury (January 2012). "Substituted catechols as inhibitors of IL-4 and IL-5 for the treatment of bronchial asthma (WO Patent 2,012,140,574)". doi:10.13140/RG.2.1.2784.6488. Retrieved 15 October 2016. {{cite journal}}: Cite journal requires |journal= (help)CS1 maint: multiple names: authors list (link) 1st S. Bandyopadhay, B. Ghosh, Parasuraman Jaisankar, Bikas C Pal, Siddhartha Roy, Nath Paul, Arjun Ram, U.
Sources: en.wikipedia.org
Large portions of the book involve detailed discussions of mathematics, physics, and philosophy. Most of these discussions use fictional Arbran terminology, but treat ideas from actual science and philosophy. Stephenson acknowledges the work of author Julian Barbour as the source for much of this material. A major theme of the novel is the many-worlds interpretation of quantum mechanics based on a directed acyclic graph, which accounts for the various "worldtracks" and "narratives" explored by Fraa Orolo and manipulated by Fraa Jad. Another major theme is the recurring philosophical debate between characters espousing mathematical Platonic realism (called "Halikaarnians" in the novel and associated with Incanters) and characters espousing nominalism (called "Procians" in the novel and who are the Rhetors). Stephenson cites the work of Roger Penrose as a major influence on the novel. Specific ideas from Penrose's work include: the idea that the human mind operates in certain fundamental ways as a quantum computer, espoused in Penrose's The Emperor's New Mind; Platonic realism as a philosophical basis for works of fiction, as in stories from Penrose's The Road to Reality; and the theory of aperiodic tilings, which appear in the Teglon puzzle in the novel. Stephenson also cites as an influence the works of Kurt Gödel and Edmund Husserl, both of whom the character Durand mentions by name in the novel. Much of the Geometers' technology seen in the novel reflects existing scientific concepts. The alien ship moves by means of nuclear pulse propulsion.
July 29: Decree-law on family and French natality. November 29: The conversion of legal separation into divorce sees its delay temporarily reduced to one year during the war (Second World War). November 29: Decree concerning the prevention of venereal diseases. Vichy Regime (July 1940-August 1944) October 11, 1940: Law on women's work — aimed at combating unemployment; notably prohibits the hiring of married women in the administration. 1941
==== Taxation of e-commerce ==== In early 2023 the government announced plans to remove tax exemptions for international purchases up to US$50 between individuals. After negative reactions the government maintained the rule, but later introduced the “Remessa Conforme” program in August 2023.
An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity. Enzymes are proteins that speed up chemical reactions necessary for life, in which substrate molecules are converted into products. An enzyme facilitates a specific chemical reaction by binding the substrate to its active site, a specialized area on the enzyme that accelerates the most difficult step of the reaction. An enzyme inhibitor stops ("inhibits") this process, either by binding to the enzyme's active site (thus preventing the substrate itself from binding) or by binding to another site on the enzyme such that the enzyme's catalysis of the reaction is blocked. Enzyme inhibitors may bind reversibly or irreversibly. Irreversible inhibitors form a chemical bond with the enzyme such that the enzyme is inhibited until the chemical bond is broken. By contrast, reversible inhibitors bind non-covalently and may spontaneously leave the enzyme, allowing the enzyme to resume its function. Reversible inhibitors produce different types of inhibition depending on whether they bind to the enzyme, the enzyme-substrate complex, or both. Enzyme inhibitors play an important role in all cells, since they are generally specific to one enzyme each and serve to control that enzyme's activity. For example, enzymes in a metabolic pathway may be inhibited by molecules produced later in the pathway, thus curtailing the production of molecules that are no longer needed. This type of negative feedback is an important way to maintain balance in a cell.
=== Anxiety disorders === Recent studies have linked smoking to anxiety disorders, suggesting the correlation (and possibly mechanism) may be related to the broad class of anxiety disorders, and not limited to just depression. Current and ongoing research attempts to explore the addiction-anxiety relationship. Data from multiple studies suggest that anxiety disorders and depression play a role in cigarette smoking. A history of regular smoking was observed more frequently among individuals who had experienced a major depressive disorder at some time in their lives than among individuals who had never experienced major depression or among individuals with no psychiatric diagnosis. People with major depression are also much less likely to quit due to the increased risk of experiencing mild to severe states of depression, including a major depressive episode. Depressed smokers appear to experience more withdrawal symptoms on quitting, are less likely to be successful at quitting, and are more likely to relapse.
Sources: en.wikipedia.org
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.
Reversed-phase HPLC establishes purity, while mass spectrometry confirms the expected molecular mass. Sequence confirmation may use tandem mass spectrometry or peptide mapping. A certificate of analysis typically reports these results alongside the analytical method applied.
In Russia it is a registered medicine available by prescription. In many other countries it is not approved for human use and is supplied only as a research chemical. Import and possession rules differ by jurisdiction, and buyers are responsible for checking local requirements.
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.