Everything below concerns tuftsin. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
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.
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.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
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.
La Niña causes mostly the opposite effects of El Niño: above-average precipitation across the northern Midwest, the northern Rockies, Northern California, and the Pacific Northwest's southern and eastern regions. Meanwhile, precipitation in the southwestern and southeastern states, as well as southern California, is below average. This also allows for the development of many stronger-than-average hurricanes in the Atlantic and fewer in the Pacific. ENSO is linked to rainfall over Puerto Rico. During an El Niño, snowfall is greater than average across the southern Rockies and Sierra Nevada mountain range, and is well-below normal across the Upper Midwest and Great Lakes states. During a La Niña, snowfall is above normal across the Pacific Northwest and western Great Lakes. In Canada, La Niña will, in general, cause a cooler, snowier winter, such as the near-record-breaking amounts of snow recorded in the La Niña winter of 2007–2008 in eastern Canada. In the spring of 2022, La Niña caused above-average precipitation and below-average temperatures in the state of Oregon. April was one of the wettest months on record, and La Niña effects, while less severe, were expected to continue into the summer. Over North America, the main temperature and precipitation impacts of El Niño generally occur in the six months between October and March. In particular, the majority of Canada generally has milder than normal winters and springs, with the exception of eastern Canada where no significant impacts occur.
This involves inspection of a polished slice of a material to determine the density of "track" markings left in it by the spontaneous fission of uranium-238 impurities. The uranium content of the sample has to be known, but that can be determined by placing a plastic film over the polished slice of the material, and bombarding it with slow neutrons. This causes induced fission of 235U, as opposed to the spontaneous fission of 238U. The fission tracks produced by this process are recorded in the plastic film. The uranium content of the material can then be calculated from the number of tracks and the neutron flux. This scheme has application over a wide range of geologic dates. For dates up to a few million years micas, tektites (glass fragments from volcanic eruptions), and meteorites are best used. Older materials can be dated using zircon, apatite, titanite, epidote and garnet which have a variable amount of uranium content. Because the fission tracks are healed by temperatures over about 200 °C the technique has limitations as well as benefits. The technique has potential applications for detailing the thermal history of a deposit.
== Clinical significance == Current scientific evidence indicates that both up- and down-regulation of the expression of proprotein convertases are part of the multiple changes occurring in gynecological tumors. PCs activate crucial substrates implicated in the progression of gynecological cancers, including adhesion molecules, metalloproteinases, and viral proteins. Experimental evidences suggest that careful targeting of PCs in gynecological cancer may represent a feasible strategy to deter tumor progression. Variants of PCSK9 can reduce or increase circulating cholesterol. Furin plays a role in the activation of several different virus proteins, and inhibitors of furin have been explored as antiviral agents.
Sources: en.wikipedia.org
The Sharpe series by Bernard Cornwell stars the character Richard Sharpe, a soldier in the British Army, who fights throughout the Napoleonic Wars. It was adapted into the Sharpe TV Series starring Sean Bean. The Bloody Jack book series by Louis A. Meyer is set during the Second Coalition of the Napoleonic Wars, and retells many famous battles of the age. The heroine, Jacky, meets Bonaparte. The Napoleonic Wars provide the backdrop for The Emperor, The Victory, The Regency and The Campaigners, Volumes 11, 12, 13 and 14 respectively of The Morland Dynasty, a series of historical novels by the author Cynthia Harrod-Eagles. The Richard Bolitho series by Alexander Kent novels portray this period of history from a naval perspective. G.S. Beard, author of two novels (2010) about John Fury, British naval officer during the Napoleonic Wars. Napoleon's Blackguards, a novel by Stephen McGarry, set in Spain during the Napoleonic Wars about the travails of an elite unit of Napoleon's Irish Legion. Robert Challoner, author of three novels in the series about Charles Oakshott, British naval officer in Napoleonic Wars. David Donachie's John Pearce series about a pressed seaman who becomes a British naval officer during the French Revolution wars and Napoleonic Wars. Julian Stockwin's Thomas Kydd series portrays one man's journey from pressed man to Admiral in the time of the French and Napoleonic Wars. Simon Scarrow – Napoleonic series. Rise of Napoleon and Wellington from humble beginnings to history's most remarkable and notable leaders. Four books in the series.
== Treatment == Ciguatera poisoning is a treatable condition. Genetically susceptible individuals can develop a long-term illness due to inability to clear the Ciguatera toxins; these people can be treated using the protocol for Chronic Inflammatory Response Syndrome (CIRS). Acutely, the mainstay of treatment is supportive care, but once the toxin is identified, CIRS treatment should start as soon as possible, as it will speed recovery, even for those without the genetic susceptibility. There is some evidence that calcium channel blockers like nifedipine and verapamil are effective in treating some of the symptoms that remain after the initial sickness passes, such as poor circulation and shooting pains through the chest. These symptoms are due to vasoconstriction caused by maitotoxin and/or palytoxin. Ciguatoxin lowers the threshold for opening voltage-gated sodium channels in synapses of the nervous system. Opening a sodium channel causes depolarization, which could sequentially cause paralysis, vasoconstriction, and changing the senses of hot and cold. Some medications such as amitriptyline may reduce some symptoms, such as fatigue and paresthesia, although benefit does not occur in every case.
==== Due to use of medication ==== Urine tests can be falsely positive in those that are taking the medications: chlorpromazine, promethazine, phenothiazines, methadone, aspirin, carbamazepine and drugs that cause high urinary pH.
Mashing is the process of combining a mix of milled grain (typically malted barley with supplementary grains such as corn, sorghum, rye or wheat), known as the "grist" or "grain bill", and water, known as "liquor", and heating this mixture in a vessel called a "mash tun". Mashing is a form of steeping, and defines the act of brewing, such as with making tea, sake, and soy sauce. Technically, wine and cider are not brewed but rather vinified, as there is no steeping process involving solids. Mead is also fermented directly without a steeping stage, and is conventionally described as being "made" rather than brewed. Mashing allows the enzymes in the malt to break down the starch in the grain into sugars, typically maltose, producing a malty, sugar-rich liquid called wort. There are two main methods – infusion mashing, in which the grains are heated in one vessel; and decoction mashing, in which a proportion of the grains are boiled and then returned to the mash, raising the temperature. Mashing may involve rests at certain temperatures - traditionally 45–62–73 °C or 113–144–163 °F, though modern, fully modified malt is often mashed with a single infusion held at around 65–68 °C (149–154 °F), where both major starch-converting enzymes are active without further steps. This takes place in a "mash tun" – an insulated brewing vessel with a false bottom. Mashing usually takes 1 to 2 hours, and during this time enzymes in the malt break down components of the grain.
Sources: en.wikipedia.org
The present Ordre des Palmes académiques was instituted on 4 October 1955 by President René Coty. In 1963 the French system of orders was reformed under President Charles de Gaulle. A number of so-called "ministerial orders" were consolidated into the Ordre national du Mérite. De Gaulle, however, was fond of the Ordre des Palmes académiques and decided to keep it as a separate order. Since 1955, the Ordre des Palmes académiques has had three grades, each with a fixed annual number of new recipients or promotions:
=== Approval process and advocacy === In June 2010, a federal advisory panel to the US Food and Drug Administration (FDA) unanimously voted against recommending approval of flibanserin, citing an inadequate risk-benefit ratio. The committee acknowledged the validity of hypoactive sexual desire as a diagnosis, but expressed concern with the drug's side effects and insufficient evidence for efficacy, especially the drug's failure to show a statistically significant effect on the co-primary endpoint of sexual desire. Ahead of the votes, Boehringer Ingelheim had mounted a publicity campaign to promote the controversial disorder of "hypoactive sexual desire". In 2010, the FDA issued a Complete Response Letter, stating that the new drug application could not be approved in its current form. The letter cited several concerns, including the failure to demonstrate a statistical effect on the co-primary endpoint of sexual desire and overly restrictive entry criteria for the two phase III trials. The FDA recommended performing a new phase III trial with less restrictive entry criteria. In October 2010, Boehringer announced that it would discontinue its development of flibanserin in light of the FDA's decision. Sprout responded to the FDA's cited deficiencies and refiled the new drug application in 2013. The submission included data from a new phase III trial and several phase I drug-drug interaction studies. The FDA again refused the application, citing an uncertain risk/benefit ratio.
=== Addiction === NF-κB is one of several induced transcriptional targets of ΔFosB which facilitates the development and maintenance of an addiction to a stimulus. In the caudate putamen, NF-κB induction is associated with increases in locomotion, whereas in the nucleus accumbens, NF-κB induction enhances the positive reinforcing effect of a drug through reward sensitization.
Sources: en.wikipedia.org
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.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
Identity is confirmed by matching the retention time in reversed-phase chromatography against a reference standard and by measuring the molecular mass with mass spectrometry. Tandem mass spectrometry or amino acid analysis can verify the sequence of the seven residues. Because the peptide contains no aromatic amino acids, detection at 280 nm is not useful.