Everything below concerns nootropic. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-02-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
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.
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 |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
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.
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.
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.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
At the initial stage of opening, the restaurants did not offer every menu item they had originally planned due to supply chain issues and packaging logistics. According to quality manager Alexander Merkulov, the dishes contain the same ingredients and are prepared with the same equipment used when McDonald's operated the restaurants, but are served in different packaging. In 2022, Vkusno i tochka started selling shrimp in all of its restaurants (with some locations having previously sold shrimp before the conversion). Due to some restrictions, Vkusno i tochka did not serve its equivalent to the Big Mac (The Big Hit) until February 2023, after the sauce and composition were modified to avoid infringing on McDonald's trademarks. Due to The Coca-Cola Company's departure from Russia, supplies for Coca-Cola were running low as of June 2022. In September, Vkusno i tochka replaced Coca-Cola brand drinks with analogous drinks of the brand Dobry (which is also produced by the Russian subsidiary of Coca-Cola HBC).
Studies have shown that regular low-moderate aerobic exercise increases peak power output, increases peak oxygen uptake (V̇O2peak), lowers heart rate, and lowers serum CK in individuals with McArdle disease. Regardless of whether the patient experiences symptoms of muscle pain, muscle fatigue, or cramping, the phenomenon of second wind having been achieved is demonstrable by the sign of an increased heart rate dropping while maintaining the same speed on the treadmill. Inactive patients experienced second wind, demonstrated through relief of typical symptoms and the sign of an increased heart rate dropping, while performing low-moderate aerobic exercise (walking or brisk walking). Conversely, patients that were regularly active did not experience the typical symptoms during low-moderate aerobic exercise (walking or brisk walking), but still demonstrated second wind by the sign of an increased heart rate dropping. For the regularly active patients, it took more strenuous exercise (very brisk walking/jogging or bicycling) for them to experience both the typical symptoms and relief thereof, along with the sign of an increased heart rate dropping, demonstrating second wind. In young children (<10 years old) with McArdle disease (GSD-V), it may be more difficult to detect the second wind phenomenon. They may show a normal heart rate, with normal or above normal peak cardio-respiratory capacity (V̇O2max). That said, patients with McArdle disease typically experience symptoms of exercise intolerance before the age of 10 years, with the median symptomatic age of 3 years.
An insulin pump delivers insulin subcutaneously. The insulin pump body itself can also contain the algorithm used in an AID system, or it can connect via Bluetooth with a separate mobile device (such as a phone) to send data and receive commands to adjust insulin delivery. Algorithm The algorithm for each AID system differs. In commercial systems (see below), little is known about the details of how the control algorithm works. In open source systems, the code and algorithm are openly available. In general, all algorithms do the same basic functionality of taking in CGM data and based on predicted glucose level's and the user's personal settings (for basal rates, insulin sensitivity, and carbohydrate ratio, for example) then recommends insulin dosing to help bring or maintain glucose levels in target range. Depending on the system, users may have the ability to adjust the target for the system, and may have different settings to ask the system to give more or less insulin in general.
== External links == Table of radioactive isotopes, K-40 The Lund/LBNL Nuclear Data Search Potassium-40 Section, Radiological and Chemical Fact Sheets to Support Health Risk Analyses for Contaminated Areas
Sources: en.wikipedia.org
=== Russia === Russian authorities stated that Russia reacted to the numerous casualties among the South Ossetian civilian population caused by the Georgian attack. According to Russia, its aim was defence of Russian citizens and Russian peacekeepers in South Ossetia. According to the Russian military, the Russian peacekeepers in South Ossetia suffered casualties on August 8. Initially, Russia went as far as accusing Georgia of committing "genocide" against Ossetians. Defending Russia's decision to launch attack in uncontested Georgia, Russian Foreign Minister Sergey Lavrov said that Russian targeting of military infrastructure used for the Georgian attack was legally warranted. It was claimed that Georgia codenamed its attack Operation "Clear Field". Russia also claimed that Georgia was planning to launch a two-day Operation "Rock" to retake Abkhazia. Russia codenamed its military action "Operation to Force Georgia to Peace". The term "enforcing to peace" for describing the war against Georgia allegedly has been coined by General Anatoliy Nogovitsyn. Three years after the August War, President of Russia Dmitry Medvedev stated that NATO would have admitted Post-Soviet states if Russia had not invaded Georgia. "If you...had faltered back in 2008, the geopolitical situation would be different now," Medvedev declared at a Vladikavkaz military base. In response, the Georgian authorities claimed that Medvedev had admitted that Russia started the war with Georgia.
College of Allied Health Sciences College of Medicine College of Nursing James L. Winkle College of Pharmacy Hoxworth Blood Center Metabolic Diseases Institute Cincinnati Diabetes and Obesity Center UC Cancer Institute UC Neuroscience Institute UC Heart, Lung and Vascular Institute
The four main classes of molecules in biochemistry (often called biomolecules) are carbohydrates, lipids, proteins, and nucleic acids. Many biological molecules are polymers: chains of smaller repeating units called monomers. When monomers are linked together to synthesize a biological polymer, they undergo a process called dehydration synthesis. Macromolecules can assemble in larger complexes with other molecules of the same or different type, often required for biological activity.
==== Cultivation in the UK ==== In late 2006, the British government permitted the pharmaceutical company MacFarlan Smith (a Johnson Matthey company) to cultivate opium poppies in England for medicinal reasons, after Macfarlan Smith's primary source, India, decided to increase the price of export opium latex. This move is well received by British farmers, with a major opium poppy field located in Didcot, England. The British government has contradicted the Home Office's suggestion that opium cultivation can be legalized in Afghanistan for exports to the United Kingdom, helping lower poverty and internal fighting while helping the NHS to meet the high demand for morphine and heroin. Opium poppy cultivation in the United Kingdom does not need a licence, but a licence is required for those wishing to extract opium for medicinal products.
Kay Mason Billig, the leader of Norfolk County Council, apologises "unreservedly" for posting a picture of a steak dinner on Facebook with the words: "Wonder what all the poor people are doing?" 21 June – An Ipsos poll gives Reform UK its highest poll rating so far, with 34%, nine points ahead of Labour on 25%, and 19 points ahead of the Conservatives on 15%. 22 June – Former Pembrokeshire councillor Andrew Edwards is disqualified from holding public office for four years over a racist voice note he posted on WhatsApp. 23 June – Reform UK announces that it would give people with non-domicile tax status the chance to avoid some UK taxes by paying a £250,000 fee, with the proceeds going to people on the lowest incomes. 25 June – Buckingham Palace confirms that US President Donald Trump will make a full state visit to the UK later in the year. Starmer says the government will press ahead with a parliamentary vote on welfare reform on 1 July, despite a growing rebellion among backbench Labour MPs that could see the proposed legislation defeated. Reform councillor Rob Howard resigns as leader of Warwickshire County Council citing his health, and leaving his 18-year-old deputy, George Finch, as interim leader. 29 June – Conservative MP George Freeman refers himself to the Parliamentary Commissioner for Standards after allegations a company he works for asked him to ask a question in Parliament. 30 June – Two Reform UK breakaway parties are formed by past Reform members. Advance UK is established by Ben Habib, and Restore Britain is started by Rupert Lowe.
Sources: en.wikipedia.org
In March 2015, Teva acquired Auspex Pharmaceuticals for $3.5 billion growing its CNS portfolio. In April, Teva offered to acquire Mylan for $40 billion, only a fortnight after Mylan offered to buy Perrigo for $29 billion. Teva's offer for Mylan was contingent on Mylan abandoning its pursuit of Perrigo. Mylan stated in June 2015 that Teva's disclosure that it had a 1.35 percent stake in Mylan violated US antitrust rules. In October, the company acquired Mexico-based Representaciones e Investigaciones Medicas (Rimsa) for around $2.3 billion. In the same month Teva acquired Gecko Health Innovations. In November 2015, the company announced it would collaborate with Heptares Therapeutics with its work on small-molecule calcitonin gene-related peptide antagonists for migraine treatment, with the deal generating up to $410 million. Teva Active Pharmaceutical Ingredients (TAPI) operates within Teva as a stand-alone business unit. In 2009, TAPI's sales to third parties totaled $565 million, and in 2010 sales rose by 13% to a total of $641 million. In July 2017, it was reported that Pascal Soriot, CEO of AstraZeneca since 2012, would become the next CEO of Teva, succeeding Erez Vigodman, however this was soon refuted. As of August 2017, the company has struggled to attract a new CEO, leading to mounting questions for the board. In August 2017, the board of directors announced a 75% cut in the dividend, reflecting declining profitability, and the share price fell by almost half in the days following.
Studies have found a significant correlation between cellular hCTR1 levels and cisplatin accumulation and sensitivity to the drug. Raising extracellular copper can reduce cisplatin uptake and toxicity, likely by downregulating hCTR1 at the membrane. Conversely, copper chelation or deficiency might increase hCTR1 levels and potentially enhance cisplatin import.
The South African Defence Force (SADF) (Afrikaans: Suid-Afrikaanse Weermag) comprised the armed forces of South Africa from 1957 until 1994. Shortly before the state reconstituted itself as a republic in 1961, the former Union Defence Force was officially succeeded by the SADF, which was established by the Defence Act (No. 44) of 1957. The SADF, in turn, was superseded by the South African National Defence Force in 1994.
Type 1: Antigenically Ran2+, GFAP+, FGFR3+, A2B5−, thus resembling the "type 1 astrocyte" of the postnatal day 7 rat optic nerve. These can arise from the tripotential glial restricted precursor cells (GRP), but not from the bipotential O2A/OPC (oligodendrocyte, type 2 astrocyte precursor, also called Oligodendrocyte progenitor cell) cells. Type 2: Antigenically A2B5+, GFAP+, FGFR3−, Ran 2−. These cells can develop in vitro from the either tripotential GRP (probably via O2A stage), from bipotential O2A cells, or in vivo when these progenitor cells are transplanted into lesion sites (but probably not in normal development, at least not in the rat optic nerve). Type 2 astrocytes are the major astrocytic component in postnatal optic nerve cultures that are generated by O2A cells grown in the presence of fetal calf serum but are not thought to exist in vivo. Some researchers think bipotential O2A cells in turn have been derived from the GRP.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
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.