The short version of Semax fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-13. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| 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 |
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
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.
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.
The JWP considered that the JINR–LLNL collaborations of 2004 and 2007, producing element 113 as the daughter of element 115, did not meet the discovery criteria as they had not convincingly determined the atomic numbers of their nuclides through cross-bombardments, which were considered necessary since their decay chains were not anchored to previously known nuclides. They also considered that the previous JWP's concerns over their chemical identification of the dubnium daughter had not been adequately addressed. The JWP recognised the JINR–LLNL–ORNL–Vanderbilt collaboration of 2010 as having discovered elements 117 and 115, and accepted that element 113 had been produced as their daughter, but did not give this work shared credit. After the publication of the JWP reports, Sergey Dimitriev, the lab director of the Flerov lab at the JINR where the discoveries were made, remarked that he was happy with IUPAC's decision, mentioning the time Riken spent on their experiment and their good relations with Morita, who had learnt the basics of synthesising superheavy elements at the JINR. The sum argument advanced by the JWP in the approval of the discovery of element 113 was later criticised in a May 2016 study from Lund University and the GSI, as it is only valid if no gamma decay or internal conversion takes place along the decay chain, which is not likely for odd nuclei, and the uncertainty of the alpha decay energies measured in the 278113 decay chain was not small enough to rule out this possibility.
=== Controversy === Several Hardee's ad campaigns in the 2000s have been criticized by groups including Parents Television Council for their sexually suggestive nature. A campaign titled "More Than a Piece of Meat" featured scantily clad women appearing to receive sexual gratification from consuming Hardee's products, and "Name Our Holes" – an ad campaign and website promoting Hardee's Biscuit Holes. In January 2015, Carl's Jr. released a commercial online featuring model Charlotte McKinney advertising its new All Natural Burger to air regionally during Super Bowl XLIX. The ad features McKinney walking around a farmers' market, implying that she is "all natural" and uses double entendres to suggest that she is naked with strategically placed items in the market until it reveals McKinney in a bikini eating the All Natural Burger. Critics suggested that the ad "sets feminism back four decades," while others, including McKinney's elderly grandfather, enjoyed the ad. Until the YouTube video of the ad was privatized by Carl's Jr. in March 2017, it had over 13 million views and 10 thousand likes.
== Further reading == Biot, René. (1962). The Enigma of the Stigmata. Hawthorn Books. Carroll, Robert Todd. (2003). Stigmata. In The Skeptic's Dictionary. Wiley. ISBN 978-0-471-27242-7 Harrison, Ted. (1994). Stigmata: A Medieval Phenomenon in a Modern Age. St Martins Press. ISBN 0-312-11372-2 Mazzoni, Cristina. (1996). Saint Hysteria: Neurosis, Mysticism, and Gender in European Culture. Cornell University Press. ISBN 0-8014-3229-4 Nickell, Joe. (1993). Looking for a Miracle: Weeping Icons, Relics, Stigmata, Visions & Healing Cures. Prometheus Books. ISBN 1-57392-680-9 Radford, Benjamin. (2014). What is Stigmata?. LiveScience. Retrieved 12 May 2016. Wilson, Ian. (1988). The Bleeding Mind: An Investigation into the Mysterious Phenomena of Stigmata. Weidenfeld & Nicolson. ISBN 0-297-79099-4 Yarom, Nitza. (1992). Body, Blood, and Sexuality: A Psychoanalytic Study of St. Francis' Stigmata and Their Historical Context. Peter Lang Publisher. Van Osselaer, Tina; Graus, Andrea; Rossi, Leonardo; Smeyers, Kristof (12 October 2020). The Devotion and Promotion of Stigmatics in Europe c. 1800–1950, between Saints and Celebrities (PDF). Numen Book Series-Studies in the History of Religions. Vol. 167. Leiden, Boston: Brill. p. 487. ISBN 978-90-04-43935-1. ISSN 0169-8834. LCCN 2020031449. Archived (PDF) from the original on September 9, 2021.
In its oxidized form, azurin (Cu2+Az) receives an electron from its redox partner and is reduced according to the following reaction: Cu2+Az + e− → Cu+Az The redox potential is 310 mV. The highly interconnected beta-sheet structure of azurin is strongly coupled with its electron-transfer center (the copper-binding side). Considerable experimental evidence exists to suggest that hydrogen bonds play a role in the long-distance electron transfer mechanism of azurin. Taken together, these observations suggest that electrons tunnel through the protein along its polypeptide and hydrogen bonds, making azurin a useful model system for studying long-range, intraprotein electron transfer (LRET).
TNP refers to the chemical compound 2,4,6-trinitrophenol, also known as Picric acid. It is a primary constituent of many unexploded landmines, and is a cousin to TNT, but less stable. It is recognized as an environmental contaminant and is toxic to many organisms. It is still commonly used in the manufacturing of fireworks, explosives, and rocket fuels, as well as in leather, pharmaceutical, and dye industries. ATP is an essential mediator of life. It is used to overcome unfavorable energy barriers to initiate and fuel chemical reactions. It is also used to drive biological machinery and regulate a number of processes via protein-phosphorylation. However, the proteins that bind ATP for both regulation and enzymatic reactions are very diverse—many yet undiscovered—and for many proteins their relationship to ATP in terms of number of binding sites, binding constants, and dissociation constants remain unclear.
Sources: en.wikipedia.org
The medical uses of silver include its use in wound dressings, creams, and as an antibiotic coating on medical devices. Wound dressings containing silver sulfadiazine or silver nanomaterials may be used to treat external infections. The limited evidence available shows that silver coatings on endotracheal breathing tubes may reduce the incidence of ventilator-associated pneumonia. There is tentative evidence that using silver-alloy indwelling catheters for short-term catheterizing will reduce the risk of catheter-acquired urinary tract infections. Silver generally has low toxicity, and minimal risk is expected when silver is used in approved medical applications. Alternative medicine products such as colloidal silver are controversial.
miR-324-5p is a reverse strand miRNA, meaning it is produced from the 5' end of the associated RNA, and spans from position 7,223,342 to 7,223,364 on chromosome 17. Its sequence is CGCAUCCCCUAGGGCAUUGGUG. miRNA forms following cleavage of pre-miRNA at the hairpin loop by the enzyme dicer within the cytosol. Interestingly, both strands of miR-324's pre-miRNA hairpin loop structure, miR-324-5p and miR-324-3p, become active miRNAs with distinct targets and functions. miR-324-5p has between 166 and 469 predicted targets, including regulators of cell growth, proliferation, survival, cytoskeletal structure, ATP transport, and ion channels. Though miR-324-5p is found on chromosome 17, its targets span across all chromosomes.
15. Biofizika. 2014 Sep-Oct;59(5):1023-6. [Main mechanisms of rhabdomyolysis-caused kidney injury and their correction by organospecific peptides]. [Article in Russian] Zamorskiĭ II, Shchudrova TS. The influence of the organospecific peptides--kidney tripeptides T-31 and T-35, pineal tetrapeptide epitalon on the main mechanisms of kidney injury caused by experimental rhabdomyolysis--toxic injury of tubular cells, development of oxidative stress and energetic misbalance, leading to significant disturbances of the functional state of kidneys and development of acute kidney failure was studied. The renoprotective effect of oligopeptides realized by impact on all of the indicated mechanisms of kidney injury and confirmed by correlation between them was estimated.
They are used in cosmetics, pigments, and a few pharmaceuticals, notably bismuth subsalicylate, used to treat diarrhea. Bismuth's unusual propensity to expand as it solidifies is responsible for some of its uses, as in the casting of printing type. Bismuth, when in its elemental form, has unusually low toxicity for a heavy metal. As the toxicity of lead and the cost of its environmental remediation became more apparent during the 20th century, suitable bismuth alloys have gained popularity as replacements for lead. Presently, around a third of global bismuth production is dedicated to needs formerly met by lead.
Sources: en.wikipedia.org
=== Crack tip plastic zone === In theory the stress at the crack tip where the radius is nearly zero, would tend to infinity. This would be considered a stress singularity, which is not possible in real-world applications. For this reason, in numerical studies in the field of fracture mechanics, it is often appropriate to represent cracks as round tipped notches, with a geometry dependent region of stress concentration replacing the crack-tip singularity. In actuality, the stress concentration at the tip of a crack within real materials has been found to have a finite value but larger than the nominal stress applied to the specimen. Nevertheless, there must be some sort of mechanism or property of the material that prevents such a crack from propagating spontaneously. The assumption is, the plastic deformation at the crack tip effectively blunts the crack tip. This deformation depends primarily on the applied stress in the applicable direction (in most cases, this is the y-direction of a regular Cartesian coordinate system), the crack length, and the geometry of the specimen. To estimate how this plastic deformation zone extended from the crack tip, Irwin equated the yield strength of the material to the far-field stresses of the y-direction along the crack (x direction) and solved for the effective radius. From this relationship, and assuming that the crack is loaded to the critical stress intensity factor, Irwin developed the following expression for the idealized radius of the zone of plastic deformation at the crack tip:
=== Nerve anatomy === Each nerve is composed of a bundle of axons. Each axon is surrounded by the endoneurium connective tissue layer. These axons are bundled into fascicles surrounded by the perineurium connective tissue layer. Multiple fascicles are then surrounded by the epineurium, which is the outermost connective tissue layer of the nerve. The axons of myelinated nerves have a myelin sheath made up of Schwann cells that coat the axon.
is the so-called shoving volume, i.e. it is the characteristic volume of the group of atoms involved in the shoving event by which an atom/molecule escapes from the cage of nearest-neighbours, typically on the order of the volume occupied by few atoms. Furthermore,
The Masonic historian Emanuel Rebold wrote:"In no place except Cuba has one seen Freemasonry exposed to such atrocious persecution as in this Catholic reign par excellence, persecution founded on the bulls of Clement XII (April 27, 1738) and Benedict XIV (March 18, 1751), and the edict of Cardinal Consalvi (August 12, 1814), in all of which Freemasons are excommunicated and the severest punishments, including that of death, were inflicted upon them."Historians debate the impact that Freemasonry had on Cuban revolutionary movements, with some Masonic historians explaining that while most revolutionaries in Cuba were Freemasons, their connection to Freemasonry was coincidental. Other historians, however, state that the two movements were directly connected. In an empire where Freemasonry would land you in prison, the very act of joining the brotherhood was itself a political act, as much as modern Freemasonry strives to remain apolitical. In Cuba, from the very beginning, Freemasonry was political. There is broad consensus that the Ten Years' War was started by Freemasons and developed in Masonic Lodges. The Cuban Revolution of 1895, though, is less directly impacted by Freemasonry, despite the fact that all of its leaders were Freemasons. Over the centuries, the Freemasonic movements and currents in Cuba bifurcated themselves along distinct lines; those Lodges that had been planted by Spaniards from the mainland, and those that existed as autochthonist Lodges risen within Cuba.
=== Greece === In Greece, licensed physicians are eligible to apply for a position in a residency program. To be a licensed physician, one must finish a medical training program which in Greece lasts for six years. A one-year obligatory rural medical service (internship) is necessary to complete the residency training. Applications are made individually in the prefecture where the hospital is located, and the applicants are positioned on first-come, first-served basis. The duration of the residency programs varies between three and seven years.
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.
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.