Everything below concerns Intranasal route. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-12-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| 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 |
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
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.
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
== Effects on chronic pain == Data obtained from using P2 receptor-selective antagonists has produced evidence supporting ATP's ability to initiate and maintain chronic pain states after exposure to noxious stimuli. It is believed that ATP functions as a pronociceptive neurotransmitter, acting at specific P2X and P2Y receptors in a systemized manner, which ultimately (as a response to noxious stimuli) serve to initiate and sustain heightened states of neuronal excitability. This recent knowledge of purinergic receptors' effects on chronic pain provide promise in discovering a drug that specifically targets individual P2 receptor subtypes. While some P2 receptor-selective compounds have proven useful in preclinical trials, more research is required to understand the potential viability of P2 receptor antagonists for pain. Recent research has identified a role for microglial P2X receptors in neuropathic pain and inflammatory pain, especially the P2X4 and P2X7 receptors.
==== CIA assessment ==== At the latest, the successful start of Sputnik 2 with the satellite weighing more than 500 kg proved that the USSR had achieved a leading advantage in rocket technology. The CIA, initially astonished, estimated the launch weight of the rocket at 500 metric tons, requiring an initial thrust exceeding 1,000 tons, and assumed the use of a three-stage rocket. In a classified report, the agency described the event as a "stupendous scientific achievement" and concluded that the USSR had likely perfected an intercontinental ballistic missile (ICBM) capable of accurately targeting any location. In reality, the launch weight of the Soviet rocket was 267 metric tons with an initial thrust of 410 tons with one and a half stages. The CIA's misjudgement was caused by extrapolating the parameters of the US Atlas rocket developed at the same time (launch weight 82 tons, initial thrust 135 tons, maximum payload of 70 kg for low Earth orbit). In part, the favourable data of the Soviet launcher was based on concepts proposed by the German rocket scientists headed by Helmut Gröttrup on Gorodomlya Island, such as, among other things, the rigorous weight saving, the control of the residual fuel quantities and a reduced thrust to weight relation of 1.4 instead of usual factor 2. The CIA had heard about such details already in January 1954 when it interrogated Göttrup after his return from the USSR but did not take him seriously.
=== Emulsifier === Only a limited number of emulsifiers are commonly regarded as safe to use for parenteral administration, of which the most important is lecithin. Lecithin can be biodegraded and metabolized, since it is an integral part of biological membranes, making it virtually non-toxic. Other emulsifiers can only be excreted via the kidneys, creating a toxic load. The emulsifier of choice for most fat emulsions used for parenteral nutrition is a highly purified egg lecithin, due to its low toxicity and complete integration with cell membranes. Use of egg-derived emulsifiers is not recommended for people with an egg allergy due to the risk of reaction. In situations where there is no suitable emulsifying agent for a person at risk of developing essential fatty acid deficiency, cooking oils may be spread upon large portions of available skin for supplementation by transdermal absorption. Another type of fat emulsion Omegaven is being used experimentally within the US primarily in the pediatric population. It is made of fish oil instead of the soybean oil based formulas more widely in use. Research has shown use of Omegaven may reverse and prevent liver disease and cholestasis.
Moscow contains more than 21,500 Wi-Fi access points in student dormitories; in parks; at cultural and sports institutions; and within the Garden Ring and the Third Transport Ring. From September 2020 to August 2021, 1,700 public Wi-Fi access points were launched in Moscow. The structure of the city's Wi-Fi network allows residents to use the Internet without reauthorization.
2 glutathione + lipid–hydroperoxide → glutathione disulfide + lipid–alcohol + H2O This reaction occurs at the selenocysteine within the catalytic center of GPX4. During the catalytic cycle of GPX4, the active selenol (-SeH) is oxidized by peroxides to selenenic acid (-SeOH), which is then reduced with glutathione (GSH) to an intermediate selenodisulfide (-Se-SG). GPX4 is eventually reactivated by a second glutathione molecule, releasing glutathione disulfide (GS-SG).
Sources: en.wikipedia.org
=== Structural elucidation === The elucidation of the chemical structure is critical to avoid the re-discovery of a chemical agent that is already known for its structure and chemical activity. Mass spectrometry is a method in which individual compounds are identified based on their mass/charge ratio, after ionization. Chemical compounds exist in nature as mixtures, so the combination of liquid chromatography and mass spectrometry (LC-MS) is often used to separate the individual chemicals. Databases of mass spectra for known compounds are available and can be used to assign a structure to an unknown mass spectrum. Nuclear magnetic resonance spectroscopy is the primary technique for determining chemical structures of natural products. NMR yields information about individual hydrogen and carbon atoms in the structure, allowing detailed reconstruction of the molecule's architecture.
== Partial EMT or a hybrid E/M phenotype == Not all cells undergo a complete EMT, i.e. losing their cell-cell adhesion and gaining solitary migration characteristics. Instead, most cells undergo partial EMT, a state in which they retain some epithelial traits such as cell-cell adhesion or apico-basal polarity, and gain migratory traits, thus cells in this hybrid epithelial/mesenchymal (E/M) phenotype are endowed with special properties such as collective cell migration. Single-cell tracking contributes to enabling the visualization of morphological transitions during EMT, the discernment of cell migration phenotypes, and the correlation of the heritability of these traits among sister cells. Two mathematical models have been proposed, attempting to explain the emergence of this hybrid E/M phenotype, and its highly likely that different cell lines adopt different hybrid state(s), as shown by experiments in MCF10A, HMLE and H1975 cell lines. Although a hybrid E/M state has been referred to as 'metastable' or transient, recent experiments in H1975 cells suggest that this state can be stably maintained by cells.
=== 19th century === Mary Watson (1856–1933), one of the first two female chemistry students at the University of Oxford Margaret Seward (1864–1929), one of the first two female chemistry students at the University of Oxford; signed the 1904 petition to the Chemical Society Vera Bogdanovskaia (1868–1897), one of the first female Russian chemists Martina Casiano y Mayor (1881–1958), first female member of the Spanish Society of Physics and Chemistry Gerty Cori (1896–1957) Jewish Czech-American biochemist who was the first American to win a Nobel Prize in science Margot Dorenfeldt (1895–1986) First woman to graduate from Norwegian Institute of Technology (1919) Ida Freund (1863–1914), first woman to be a university chemistry lecturer in the United Kingdom Ellen Gleditsch (1879–1968), Norwegian radiochemist; Norway's second female professor Louise Hammarström (1849–1917), Swedish mineral chemist, first formally educated female Swedish chemist Edith Humphrey (1875–1978), Inorganic chemist, probably the first British woman to gain a doctorate in chemistry Julia Lermontova (1846–1919), Russian chemist, first Russian female doctorate in chemistry Laura Linton (1853–1915), American chemist, teacher, and physician Rachel Lloyd (1839–1900), First American female to earn a doctorate in chemistry, first regularly admitted female member of the American Chemical Society, studied sugar beets Muriel Wheldale Onslow (1880–1932), British biochemist Marie Pasteur (1826–1910), French chemist and bacteriologist Mary Engle Pennington (1872–1952), American chemist Agnes Pockels (1862–1935), German chemist Anna Sundström (1785–1871), Swedish chemist Clara Immerwahr (1870–1915), First woman to get her doctorate in chemistry in Germany Ellen Swallow Richards (1842–1911), American industrial and environmental chemist Anna Volkova (1800–1876), Russian chemist Nadezhda Olimpievna Ziber-Shumova (died 1914), Russian chemist Fanny Rysan Mulford Hitchcock (1851–1936), one of thirteen (American) women to graduate with a degree in chemistry in the 1800s, and the first to graduate with a doctorate in philosophy of chemistry. Her areas of focus were in entomology, fish osteology, and plant pathology.
=== War on Want === From November 1983 to 1987, Galloway was the general secretary of War on Want, a British charity campaigning against poverty worldwide. In this post he travelled widely, and wrote eye-witness accounts of the famine in Eritrea in 1985 which were published in The Sunday Times and The Spectator. His deputy at the charity, Simon Stocker, recalled: "If you went into a fight with George, you knew you would never walk out with a win." On 28 October 1986, the Daily Mirror, in a front-page story by Alastair Campbell, alleged Galloway had spent £20,000 in expenses and had been "enjoying a life of luxury". An internal investigation, and later, an independent auditor, both cleared him of the accusation of any misuse of funds, although he did repay £1,720 in contested expenses. The official history of War on Want comments about Galloway that "even though the problems were not all of his own making, his way of dealing with them heightened tensions".
== Venom == Bites from H. hypnale, although previously thought to be innocuous, are now known to cause serious complications such as coagulopathy and acute renal failure (ARF). If not treated within a few hours, bites can potentially be fatal for human beings. While not initially included in the list of highly venomous snakes in Sri Lanka, it is now considered highly venomous, and one of the medically important venomous snakes in Sri Lanka and on the south western coast of India. As of November 2016, an antivenom is currently being developed by the Costa Rican Clodomiro Picado Institute, and clinical trial phase in Sri Lanka.
Sources: en.wikipedia.org
Of these, only the longest form conserved all functionally important domains (such as three fibronectin type III domains, the Ig C2-like domain, a pair of WSXWS motifs, two JAK2-binding motif boxes, and a STAT-binding domain), while the other four forms have only the intra-cellular region. The long form of mammalian LepR has a function for full signal transduction through the JAK/STAT pathways, whereas the shorter forms exhibit partial or no signaling capabilities. The biological importance of long form LepR via the JAK/STAT pathway in maintaining body weight and energy homeostasis has been demonstrated. Previous studies in teleosts have only identified a single lepr. Rønnestad et al., is the first to report that plural LepR transcripts in any ectotherm species. When looking at the available motif for lepr, the model suggests that it would bind easily to lepa1 and not lepa2 (Fig. 2). Furthermore, the relatively ubiquitous expression of lepr in salmon tissues supports diverse roles of lep in teleosts.
=== 2004—2008: Third Michelin star and international acclaim === In 2004, the Fat Duck became the third restaurant in the UK to receive three Michelin stars, after the Waterside Inn, also in Bray, and Restaurant Gordon Ramsay in London. It was the fastest that a British restaurant had gone from one to three stars. At the time he received his third star, Blumenthal said it was the closest he had been to bankruptcy, with enough money only to cover the following week's staff wages. Immediately after receiving the third star, the Fat Duck began receiving hundreds of phone calls seeking reservations a day. Blumenthal hired Tony Baker as managing director to help deal with the demand. In the same year, the Fat Duck was ranked second in the world behind the French Laundry by the World's 50 Best Restaurants. It also received the title of Square Meal BMW Best UK Restaurant 2004. That year, food and safety officers found "borderline" levels of listeria in the foie gras and expressed concern that "no core temperatures of the meat are taken". The Daily Telegraph reported that the Fat Duck dealt with the problem and introduced "stringent procedures." In 2005, the World's 50 Best Restaurants named the Fat Duck the best restaurant in the world. At the first Front of House Awards in 2007, it won the awards for Overall Service and Front Desk of the Year. As of 2007, the Fat Duck employed 32 chefs, with a weekly wage bill of around £35,000. It seated 46 people for lunch and dinner six days a week, with an average spend of around £175 per head and an annual turnover of more than £4 million.
Without proofreading, DNA replication is inherently somewhat error-prone, but by introducing error-prone polymerases, droplet-based PCR utilizes higher than normal mutation output to build a mutation library more quickly and efficiently than normal. This makes droplet-based PCR more attractive than slower, traditional PCR. In a similar application, highly multiplexed, microdroplet PCR has been developed that allows for the screening of large numbers of target sequences enabling applications such as bacterial identification. On-chip PCR allows for an excess of 15 x 15 multiplexing, which means that multiple target DNA sequences could be run on the same device at the same time. This multiplexing was made possible with immobilized DNA primer fragments placed in the base of the individual wells of the chips. Combining droplet-based PCR with polydimethylsiloxane (PDMS) devices has allowed for novel enhancements of droplet PCR as well as remedying some preexisting problems with droplet PCR including high liquid loss due to evaporation. Droplet-based PCR is highly sensitive to air bubbles as they create temperature differentials hindering DNA replication while also dislodging reagents from the replication chamber. Now, droplet-based PCR has been carried out in PDMS devices to transfer reagents into droplets through a PDMS layer in a more controlled manner that better maintains replication progress and stability than traditional valves.
== Beta-2 agonists == All beta-2 agonists and their D- and L-isomers, are banned. However, formoterol, salbutamol, salmeterol, and terbutaline may be used with a "therapeutic use exemption", only in the inhaled form.
The president The vice-president The secretary-general The deputy secretary-general The founding president of SWAPO as a permanent member 13 SWAPO Party regional coordinators 54 members elected at the party congress 10 members appointed by the party president The current 100 Central Committee members are:
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 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.