Everything below concerns Selank. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-05-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
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.
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.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
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.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Langer–Giedion syndrome is a very rare genetic disorder caused by a deletion of chromosomal material. Diagnosis is usually made at birth or in early childhood. The features associated with this condition include mild to moderate learning difficulties, short stature, unique facial features, small head and skeletal abnormalities including bony growths projecting from the surfaces of bones.
Ibogaine is derived from the root of Tabernanthe iboga, a plant known to exhibit hallucinogenic effects in people who consume it. It is described as having a typical dose range of 1,000 to 1,500 mg orally, with these doses producing hallucinogenic effects, and a duration of 18 to 36 hours. However, lower doses like 200 to 400 mg orally are also active and said to be hallucinogenic. In addition, very low doses of ibogaine, like 8 to 50 mg orally, have been used and reported to produce stimulant or "antidepressant" effects. The onset of the drug is 1 to 3 hours and peak effects have been described as being reached after 2 hours. With full hallucinogenic doses, ibogaine is described as having three different phases of effects. The first phase is the acute or visionary phase, which onsets after 1 to 3 hours and has a duration of 4 to 8 hours; the second phase is the evaluative or introspective phase, which starts after 4 to 8 hours and has a duration of 8 to 20 hours; and the third phase is residual stimulation, which onsets after 12 to 24 hours and has a duration of 24 to 72 hours or longer. Each of these phases is described as having distinct qualitative effects. The visionary phase is a dream-like, conscious state called oneirophrenia. Visual effects are almost always present and are often described as films or slideshows. These may be accompanied by increases in long-term visual memory, resulting in autobiographical content. Other changes to sensation and perception may occur, including auditory hallucinations or distortions. Nausea and vomiting can be severe.
Overview of all the structural information available in the PDB for UniProt: P0DPI1 (Botulinum neurotoxin type A) at the PDBe-KB. Overview of all the structural information available in the PDB for UniProt: P10844 (Botulinum neurotoxin type B) at the PDBe-KB. Overview of all the structural information available in the PDB for UniProt: A0A0X1KH89 (Bontoxilysin A) at the PDBe-KB. "AbobotulinumtoxinA Injection". MedlinePlus. "IncobotulinumtoxinA Injection". MedlinePlus. "OnabotulinumtoxinA Injection". MedlinePlus. "PrabotulinumtoxinA-xvfs Injection". MedlinePlus. "RimabotulinumtoxinB Injection". MedlinePlus.
Detailed statistics were not released by the Singapore government between 2000 and 2006. Singapore's Prime Minister Goh Chok Tong told the BBC in September 2003 that he believed there were "in the region of about 70 to 80" hangings in 2003. Two days later he retracted his statement, saying the number was in fact ten. In total, at the end of 2003, 19 people were hanged. While no information is issued on the race and ethnicity of death row inmates, it was noted in 2021, during an appeal from a number of Malay death row inmates who alleged racism on the part of the government, that there were a large number of Malays among those on death row, with only handfuls of other minority races. Between 2010 and 2021, Malays made up 66 of the 120 prosecuted for capital drug offences, with 76% of cases concluding with the death sentence. 50 out of 77 people sentenced to death between 2010 and 2021 were Malays, with a remaining 15 Indians, 10 Chinese and two from other races. Since 2010, of all the 77 sentenced to death, there were 14 Malaysians being condemned to death row, with eleven of them ethnic Indians, two Malays and one Chinese. Former chief executioner, Darshan Singh, who died from COVID-19 complications on 31 October 2021, stated that he had executed more than 850 people during his service, which began in 1959. When conducting the executions, he would use the phrase: "I am going to send you to a better place than this.
This abnormal chromosome was dubbed the Philadelphia chromosome - as both scientists were doing their research in Philadelphia, Pennsylvania. Thirteen years later, with the development of more advanced techniques, the abnormal chromosome was shown by Janet Rowley to be the result of a translocation of chromosomes 9 and 22. Identification of the Philadelphia chromosome by cytogenetics is diagnostic for CML. More than 780 leukemias and hundreds of solid tumors (lung, prostate, kidney, etc.) are now characterized by an acquired chromosomal abnormality, whose prognostic value is crucial. The identification of these chromosomal abnormalities has led to the discovery of a very large number of "cancer genes" (or oncogenes). The increasing knowledge of these cancer genes now allows the development of targeted therapies, which transforms the prospects of patient survival. Thus, cytogenetics has had and continues to have an essential role in the progress of cancer understanding. Large databases (Atlas of Genetics and Cytogenetics in Oncology and Haematology, COSMIC cancer database, Mitelman Database of Chromosome Aberrations and Gene Fusions in Cancer) allow researchers and clinicians to have the necessary corpus for their work in this field.
Sources: en.wikipedia.org
, respectively. Michaelis–Menten kinetics relies on the law of mass action, which is derived from the assumptions of free diffusion and thermodynamically driven random collision. Many biochemical or cellular processes deviate significantly from these conditions, because of macromolecular crowding and constrained molecular movement. More recent, complex extensions of the model attempt to correct for these effects.
== History == The condition was first described in 1561 in correspondence between Andreas Vesalius and Gabriele Falloppio and separately by Gabriele Falloppio. The condition is named after François Gigot de la Peyronie, who described it in 1743. Peyronie was the personal physician of King Louis XV and cofounder of the Académie Royale de Chirurgie, which was later included in the French Académie nationale de médecine.
while fresh citrus (particularly lemons) cured scurvy, lime juice that had been exposed to light, air, and copper tubing did not – thus undermining the theory that citrus cured scurvy; fresh meat (especially organ meat and raw meat, consumed in arctic exploration) also cured scurvy, undermining the theory that fresh vegetable matter was essential to preventing and curing scurvy; increased marine speed via steam shipping, improved nutrition on land, reduced the incidence of scurvy – and thus the ineffectiveness of copper-piped lime juice compared to fresh lemons was not immediately revealed. In the resulting confusion, a new hypothesis was proposed, following the new germ theory of disease – that scurvy was caused by ptomaine, a waste product of bacteria, particularly in tainted tinned meat. Infantile scurvy emerged in the late 19th century because children were fed pasteurized cow's milk, particularly in the urban upper class. While pasteurization killed bacteria, it also destroyed vitamin C. This was eventually resolved by supplementing with onion juice or cooked potatoes. Native Americans helped save some newcomers from scurvy by directing them to eat wild onions.
All isotopes ranging from 242Cm to 248Cm, as well as 250Cm, undergo a self-sustaining nuclear chain reaction and thus in principle can be a nuclear fuel in a reactor. As in most transuranic elements, nuclear fission cross section is especially high for the odd-mass curium isotopes 243Cm, 245Cm and 247Cm. These can be used in thermal-neutron reactors, whereas a mixture of curium isotopes is only suitable for fast breeder reactors since the even-mass isotopes are not fissile in a thermal reactor and accumulate as burn-up increases. The mixed-oxide (MOX) fuel, which is to be used in power reactors, should contain little or no curium because neutron activation of 248Cm will create californium. Californium is a strong neutron emitter, and would pollute the back end of the fuel cycle and increase the dose to reactor personnel. Hence, if minor actinides are to be used as fuel in a thermal neutron reactor, the curium should be excluded from the fuel or placed in special fuel rods where it is the only actinide present.
Affective computing is a field that comprises systems that recognise, interpret, process, or simulate human affect (feeling, emotion, and mood). For example, some virtual assistants are programmed to speak conversationally or even banter humorously; it makes them appear more sensitive to the emotional dynamics of human interaction, or to otherwise facilitate human–computer interaction. However, this tends to give naïve users an unrealistic conception of the intelligence of existing computer agents. Moderate successes related to affective computing include textual sentiment analysis and, more recently, multimodal sentiment analysis, wherein AI classifies the effects displayed by a videotaped subject.
Sources: en.wikipedia.org
(2026) provide a direct comparison between brain and endocast characteristics in the same individuals on the basis of data from the study of 75 volunteers, reporting the discovery of endocranial marks unrelated to cerebral sulci, and propose a new standardised approach to the study of fossil endocasts and reconstruction of brains of fossil hominins. Review of virtual anatomy methods used in paleoanthropological studies is published by Aramendi & de Jager (2026). A new method for reconstruction of missing landmarks in the studies of hominin long bones is presented by Courtenay & Aramendi (2026). Keevil et al. (2026) provide measurement data from bone surface modifications resulting from simulated stone tool and percussive butchery, carnivore feeding trials and ungulate trampling, facilitating identification of bone modifications in the studies on the origin and evolution of human carnivory. Hobaiter & Dominy (2026) argue that the emergence of spoken language and the replacement of ape-like gestural systems by speech as the default mode of human communication might have resulted from fireside storytelling.
== Herbalism == A. mongholicus is used in traditional Chinese medicine (TCM). A. mongholicus is a component in Lectranal, a food supplement used in treatment of seasonal allergic rhinitis, though there is limited evidence of its effectiveness.
Milk thistle (Silybum marianum) extract (70–80% Silymarin) (225 mg) Bacopa (Bacopa monnieri) extract (45% bacosides) (150 mg) Ashwagandha (Withania somnifera) powder (150 mg) Green tea (Camellia sinensis) extract (98% polyphenols, 45% EGCG) (75 mg) Turmeric (Curcuma longa) extract (95% curcumin) (75 mg)
The organisation was formed by the BSAC in 1889 as a paramilitary, mounted infantry force in order to provide protection for the Pioneer Column of settlers which moved into Mashonaland in 1890. In common with several colonial police forces such as the Royal Canadian Mounted Police (RCMP), it was modelled on the Royal Irish Constabulary (RIC), and its early officers were trained at the Police Depot in the Phoenix Park in Dublin. The unit played a central role in both the First Matabele War (1893) and the Second Matabele War (1896/97) with many troopers serving in the Jameson Raid. Until 1896 the force was called the British South Africa Company's Police. The BSAP operated originally in conjunction with the Southern Rhodesia Constabulary (SRC), the town police force for Salisbury (now Harare) and Bulawayo, but amalgamated with the SRC in 1909.
Sources: en.wikipedia.org
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.