Everything below concerns Semax. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-12-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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 |
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
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.
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.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
On June 26, 2025, Pritzker announced he would seek a third term as governor. With incumbent Lieutenant Governor Juliana Stratton running for U.S. Senate, Pritzker chose former state representative Christian Mitchell as his running mate. Pritzker and Mitchell ran unopposed in the March Democratic primary, winning 100% of the vote. Pritzker faces the Republican nominee, former state senator Darren Bailey, in a rematch in the November general election. Should Pritzker win, he will be first Illinois governor to win a third term since Jim Thompson in 1986, and the first Democrat to do so in Illinois history.
Most terrestrial helium present today is created by the natural radioactive decay of heavy radioactive elements (thorium and uranium, although there are other examples), as the alpha particles emitted by such decays consist of helium-4 nuclei. This radiogenic helium is trapped with natural gas in concentrations as great as 7% by volume, from which it is extracted commercially by a low-temperature separation process called fractional distillation. Terrestrial helium is a non-renewable resource because once released into the atmosphere, it promptly escapes into space. Its supply is thought to be rapidly diminishing. However, some studies suggest that helium produced deep in the Earth by radioactive decay can collect in natural gas reserves in larger-than-expected quantities, in some cases having been released by volcanic activity.
=== Increasing permeability === Scientists previously believed that the skin was an effective barrier to inorganic particles. Damage from mechanical stressors was believed to be the only way to increase its permeability. Recently, simpler and more effective methods for increasing skin permeability have been developed. Ultraviolet radiation (UVR) slightly damages the surface of skin and causes a time-dependent defect allowing easier penetration of nanoparticles. The UVR's high energy causes a restructuring of cells, weakening the boundary between the stratum corneum and the epidermal layer. The damage of the skin is typically measured by the transepidermal water loss (TEWL), though it may take 3–5 days for the TEWL to reach its peak value. When the TEWL reaches its highest value, the maximum density of nanoparticles is able to permeate the skin. While the effect of increased permeability after UVR exposure can lead to an increase in the number of particles that permeate the skin, the specific permeability of skin after UVR exposure relative to particles of different sizes and materials has not been determined.
In the United States, methamphetamine hydrochloride, sold under the brand name Desoxyn, is FDA-approved for the treatment of attention deficit hyperactivity disorder (ADHD); however, the FDA notes that the limited therapeutic usefulness of methamphetamine should be weighed against the risks associated with its use. To avoid toxicity and risk of side effects, FDA guidelines recommend an initial dose of methamphetamine at doses 5–10 mg/day for ADHD in adults and children over six years of age, which may be increased at weekly intervals of 5 mg, up to 25 mg/day, until optimum clinical response is found; the usual effective dose is around 20–25 mg/day. Methamphetamine is sometimes prescribed off-label for obesity, narcolepsy, and idiopathic hypersomnia. In the United States, methamphetamine's levorotary form is available in some over-the-counter (OTC) nasal decongestant products. Although the pharmaceutical name "methamphetamine hydrochloride" may suggest a racemic mixture, Desoxyn contains enantiopure dextromethamphetamine, which is a more potent stimulant than both levomethamphetamine and racemic methamphetamine. This naming convention deviates from the standard practice observed with other stimulants, such as Adderall and dextroamphetamine, where the dextrorotary enantiomer is explicitly identified as an active ingredient in both generic and brand-name pharmaceuticals. As methamphetamine is associated with a high potential for misuse, the drug is regulated under the Controlled Substances Act and is listed under Schedule II in the United States.
12 June to 6 July The 1st Battalion, 9th Marines, elements of the 1st Brigade, 5th Infantry Division and the ARVN 2nd Regiment launch Operation Utah Mesa against the PAVN 24th Regiment near Khe Sanh. The operation results in 309 PAVN killed and 14 U.S. killed.
Sources: en.wikipedia.org
=== Wound healing and fibrosis === In skin wound healing, CCN1 is highly expressed in the granulation tissue by myofibroblasts, which proliferate and rapidly synthesize ECM to maintain tissue integrity and to promote regeneration of parenchymal cells. However, excessive matrix deposition can lead to fibrosis, scarring, and loss of tissue function. In skin wounds, CCN1 accumulates in the granulation tissue as myofibroblasts proliferate, and eventually reaches a sufficiently high level to drive the myofibroblasts themselves into senescence, whereupon these cells cease to proliferate and express matrix-degrading enzymes. Thus, CCN1 limits synthesis and deposition of ECM by myofibroblasts, reducing the risk of fibrosis during wound healing. In addition to skin wound healing, CCN1 expression is elevated in remodeling cardiomyocytes after myocardial infarction, in vascular injury, and in the long bones during fracture repair. Blockade of CCN1 by antibodies inhibits bone fracture healing in mice. In the kidney, CCN1 is expressed in podocytes in normal adult and embryonic glomeruli, but expression is decreased in IgA nephropathy, diabetic nephropathy, and membranous nephropathy, particularly in diseased kidneys with severe mesangial expansion. CYR61 induction of cellular senescence in the kidney is a potential therapy to limit fibrosis.
=== Space exploration === As humans begin venturing into space for a longer time, the nutritional requirements for maintaining crew health is critical. Currently NASA is exploring ways of integrating 3D printing food into space in order to sustain the crew's dietary requirements. The vision is to 3D print powdered food layers that have a shelf life of 30 years instead of using traditional freeze dried food that have a shelf life of 5 years. In addition to dietary requirements, 3D printing food in space could provide a morale boost, as the astronauts would be able to design custom meals that are aesthetically pleasing. In September 2019, Russian cosmonauts, along with Israeli startup Aleph Farms, grew meat from cow cells, then 3D printed the cells into steaks.
== Professional contribution == Kalra established Bharti Hospital in Karnal, which offers clinical care, research, training, and education in endocrinology. As executive editor (2011–15), he played a role in strengthening the Indian Journal of Endocrinology and Metabolism (IJEM), which became recognised as India's second-highest-ranked scientific journal according to Google Metrics. He also serves as executive editor of Thyroid Research and Practice and associate editor of Diabetic Medicine (UK). In addition, he is an international advisory board member for several journals, including US Endocrinology, the Sri Lankan Journal of Diabetes, Endocrinology and Metabolism (SLJDEM), the Journal of Pakistan Medical Association, and the Journal of Diabetes and Endocrinology Association of Nepal (JDEAN). As a founder member and past president, Kalra has contributed to the establishment and growth of the South Asian Federation of Endocrine Societies (SAFES). His contributions have been recognised in neighbouring countries, and he has been awarded Fellowship and Life Membership of the Sri Lanka College of Endocrinologists (SLCE), as well as life membership of the Pakistan Endocrine Society (PES).
== Secondary ion mass spectrometry == Secondary ion mass spectrometry (SIMS) is a method very similar to FAB in that a beam of particles is fired against the surface of a sample in order to cause sputtering, in which the molecules of the sample ionize and leave the surface, thus allowing for the ions or the sample to be analyzed. The primary difference is that in SIMS, an ion beam is fired against the surface, but in FAB, an atom beam is fired against the surface. The other primary difference, of more interest to this page, is that, unlike FAB, SIMS is typically performed on a solid sample with little sample preparation required. The main consideration with SIMS is ensuring that the sample is stable under ultra-high vacuum, or pressures less than 10−8 torr. The nature of the ultra-high vacuum is that it ensures the sample remains constant during analysis as well as ensuring the high energy ion beam strikes the sample. Ultra-high vacuum solves many of the problems that need to be considered during sample preparation. When preparing the sample for analysis, another thing that should be considered is the thickness of the film. Typically, if a thin monolayer can be deposited onto the surface of a noble metal, analysis should be successful. If the film thickness is too large, which is common in real world analysis, the problem can be solved by methods such as depositing a perforated silver foil over a nickel grid onto the film surface. This yields similar results to thin films deposited directly onto a noble metal.
The weakening of the fibrous cap of atheromatous plaques by apoptosis of smooth muscle cells has also been linked to granzyme B. More recently, a key role for extracellular granzyme B has been forwarded for a number of autoimmune (e.g. arthritis, autoimmune blistering, scleroderma, lupus)(Reviewed in ) and/or age-related chronic inflammatory disorders (Photoaging, aneurysm, atherosclerosis, COPD, macular degeneration, etc.)(Reviewed in ). In many of these conditions, proof-of-concept has been demonstrated through the use of experimental models, genetic approaches and/or pharmacologic approaches.
Sources: en.wikipedia.org
Speaking publicly about Biko's death, the country's police minister Jimmy Kruger initially implied that it had been the result of a hunger strike, a statement he later denied. His account was challenged by some of Biko's friends, including Woods, who said that Biko had told them that he would never kill himself in prison. Publicly, he stated that Biko had been plotting violence, a claim repeated in the pro-government press. South Africa's attorney general initially stated that no one would be prosecuted for Biko's death. Two weeks after the funeral, the government banned all Black Consciousness organisations, including the BCP, which had its assets seized. Both domestic and international pressure called for a public inquest to be held, to which the government agreed. It began in Pretoria's Old Synagogue courthouse in November 1977, and lasted for three weeks. Both the running of the inquest and the quality of evidence submitted came in for extensive criticism. An observer from the Lawyers' Committee for Civil Rights Under Law stated that the affidavit's statements were "sometimes redundant, sometimes inconsistent, frequently ambiguous"; David Napley described the police investigation of the incident as "perfunctory in the extreme". The security forces alleged that Biko had acted aggressively and had sustained his injuries in a scuffle, in which he had banged his head against the cell wall. The presiding magistrate accepted the security forces' account of events and refused to prosecute any of those involved.
conjugative - mediate DNA transfer through conjugation and therefore spread rapidly among the bacterial cells of a population; e.g., F plasmid, many R and some col plasmids. nonconjugative - do not mediate DNA through conjugation, e.g., many R and col plasmids.
Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is mainly used as a precursor to polymers. Being polar and having a wide liquid range, THF is a versatile solvent. It is an isomer of another solvent, butanone.
=== Tracking of Fusion Proteins === Many different fusion proteins have been created using EosFP and its engineered variants. These fusion proteins allow for the tracking of proteins within living cells while retaining complex biological functions like protein-protein interactions and protein-DNA interactions. Eos fusion constructs include those with recombination signal-binding protein (RBP) and cytokeratin. Studies have shown that it is favourable to attach the protein of interest to the N-terminal side of the EosFP label. These fusion constructs have been used to visualize nuclear translocation with androgen receptors, dynamics of the cytoskeleton with actin and vinculin and intranuclear protein movement with RBP.
== Biography == Mikhail Tsvet was born on 14 May 1872 in Asti, Italy. His mother was Italian, and his father was a Russian official. His mother died soon after his birth, and he was raised in Geneva, Switzerland. He received his BS degree from the Department of Physics and Mathematics at the University of Geneva in 1893. However, he decided to dedicate himself to botany and received his PhD degree in 1896 for his work on cell physiology. He moved to Saint Petersburg, Russia, in 1896 because his father was recalled from the foreign service. There, he started to work at the Biological Laboratory of the Russian Academy of Sciences. His Geneva degrees were not recognized in Russia, and he had to earn Russian degrees. In 1897, he became a teacher of botany courses for women. In 1902, he became a laboratory assistant at the Institute of Plant Physiology of the Warsaw University (now in Poland). In 1903, he became an assistant professor and also taught at other Warsaw universities. After the beginning of World War I, the Warsaw University of Technology was evacuated to Moscow, Russia, and in 1916 again to Gorki near Moscow. In 1917, he became a Professor of Botany and the director of the botanical gardens at the University of Tartu (then Yuryev). In February 1918, before German troops conquered the Estonian city, Tsvet along with most of the Russian academic staff of the university evacuated to Voronezh in Central Russia. Tsvet died of a chronic inflammation of the throat on 26 June 1919 at the age of 47.
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.
The most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.