The short version of selank fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-04-26. Anything still debated is marked as such rather than presented as settled.
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.
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.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues; tuftsin plus a Pro-Gly-Pro tail |
| Molecular formula | C33H57N11O9 | Commonly reported value for the free peptide |
| Monoisotopic mass | Roughly 751.4 Da | Average molecular mass near 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid |
| Solubility class | Freely soluble in water | Also dissolves in saline and other polar solvents |
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.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
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 a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
A 1995 study found that daily consumption of water treated with 4 tablets containing tetraglycine hydroperiodide reduced the uptake of radioactive iodine in human subjects to a mean of 1.1 percent, from a baseline mean of 16 percent, after a week of treatment. At 90 days of daily treatment, uptake was further reduced to a mean of 0.5 percent. However, unlike KI, tetraglycine hydroperiodide is not recommended by the WHO for this purpose. Iodine should be allowed at least 30 minutes to kill Giardia.
== Bacterial short-chain fatty acids == Certain bacteria in the gastrointestinal tract ferment fecal fiber into SC-FAs and excrete them as waste products. The excreted SC-FAs enter the gastrointestinal walls, diffuse into the portal venous system, and ultimately flow into the systemic circulation. During this passage, they can activate the FFAR3 on cells in the intestinal wall as well as throughout the body. This activation may: suppress the appetite for food and thereby reduce overeating and the development of obesity; inhibit the liver's accumulation of fatty acids and thereby the development of fatty liver diseases; decrease blood pressure and thereby the development of hypertension and hypertension-related cardiac diseases; modulate insulin secretion and thereby the development and/or symptoms of type 2 diabetes; reduce heart rate and blood plasma norepinephrine levels and thereby lower total body energy expenditures; and suppress or delay the development of allergic asthma. The specific types of bacteria in the intestines can be modified to increase the number which make SC-FAs by using foods that stimulate the growth of these bacteria (i.e., prebiotics), preparations of SC-FA-producing bacteria (i.e., probiotics), or both methods (see synbiotics).
One of the first common applications of surface plasmon resonance spectroscopy was the measurement of the thickness (and refractive index) of adsorbed self-assembled nanofilms on gold substrates. The resonance curves shift to higher angles as the thickness of the adsorbed film increases. This example is a 'static SPR' measurement. When higher speed observation is desired, one can select an angle right below the resonance point (the angle of minimum reflectance), and measure the reflectivity changes at that point. This is the so-called 'dynamic SPR' measurement. The interpretation of the data assumes that the structure of the film does not change significantly during the measurement.
Sources: en.wikipedia.org
=== Financing === In May 2016, Cerebras raised $27 million in a series A round led by Benchmark, Foundation Capital and Eclipse Ventures. In December 2016, the company raised a series B round led by Coatue Management. In January 2017, it raised a series C round led by VY Capital. In November 2018, Cerebras raised $88 million in a series D round, making the company a unicorn. Investors in this round included Altimeter, VY Capital, Coatue, Foundation Capital, Benchmark, and Eclipse. In November 2019, Cerebras raised $270 million in a series E round at a valuation of $2.4 billion. In November 2021, Cerebras raised $250 million in a Series F round, valuing the company at over $4 billion and bringing its total financing to $720 million. The Series F financing round was led by Alpha Wave Ventures and Abu Dhabi Growth Fund (ADG). In July, August, and September 2024, the company raised $85 million in a series F-1 round, selling shares for $14.66 each. In September 2025, the company raised $1.1 billion in a Series G round, selling shares for $36.23 each, or a valuation of $8.1 billion. In January 2026, the company raised $1.0 billion in a Series H round, selling shares for $89.01 each. In this round, Benchmark invested $225 million, while Alpha Wave and funds managed by Fidelity Investments each invested $100 million. On May 14, 2026, the company became a public company via the largest U.S. technology initial public offering since 2019, raising $5.55 billion by selling 30 million shares at $185 each and opening on Nasdaq at $350, valuing the company at $95 billion.
glycolysis The metabolic pathway in which carbohydrate sugars such as glucose are broken down into simpler molecules, releasing chemical energy which can then be used for various cellular functions. In a series of ten enzyme-catalyzed reactions, each molecule of glucose is converted into two molecules of pyruvate, with the free energy liberated in this process simultaneously being used to form high-energy bonds in two molecules of reduced nicotinamide adenine dinucleotide (NADH) and two molecules of adenosine triphosphate (ATP). In aerobic conditions pyruvate and NADH are further oxidized in the mitochondria; in anaerobic conditions NADH itself subsequently reduces pyruvate to lactate.
In November 1965, when asked to comment by Time after the number of Americans killed in Vietnam passed 1,000, Kissinger praised Johnson for having to make "difficult and lonely decisions". Kissinger compared Johnson to the sheriff played by Gary Cooper in the 1952 film High Noon, depicting Johnson as a heroic figure making necessary, but unpopular decisions. In a 1967 peace initiative, he would mediate between Washington and Hanoi. In June 1967, at an academic conference in Paris, Kissinger met a French biologist, Herbert Marcovitch, who mentioned that one of his friends was Raymond Aubrac, a Communist hero of the French resistance, who in turn was one of the few Westerners who were friends with Ho Chi Minh. Ho had something of an aversion to Westerners and tried to avoid meeting them as much as possible, and Aubrac was unique in being allowed to correspond with Ho. Wanting to play a role in diplomacy, Kissinger contacted the State Department with a plan for Marovitch and Aubrac to go to Hanoi with a peace offer. The Secretary of State, Dean Rusk, was opposed to Kissinger's plan. However, W. Averell Harriman of the "peace shop" was interested and got President Johnson to approve the approach, which was code-named Operation Pennsylvania. In July 1967, Aubrac and Marcovitch went to Hanoi to see Ho, who told him that he was willing to open peace talks with the United States, provided that the Americans "unconditionally" stopped bombing North Vietnam.
Microchimerism is the presence of a small number of cells in an individual that have originated from another individual and are therefore genetically distinct. This phenomenon may be related to certain types of autoimmune diseases although the responsible mechanisms are unclear. The term comes from the prefix "micro" + "chimerism" based on the hybrid Chimera of Greek mythology. The concept was first discovered in the 1960s with the term gaining usage in the 1970s.
Sources: en.wikipedia.org
As pointed out by Peter Ward and Donald Brownlee in their book The Life and Death of Planet Earth, the process of ocean loss has only been documented twice: first during the Apollo 16 Moon mission, when the mission's astronauts observed Earth using a unique Carruthers camera, and again during the 1990s through studies based on observations made by astronauts aboard the Space Shuttle. Saturn's moon Titan has a very weak cold trap that is only able to retain some of its atmospheric methane. Thus, it has been suggested that Titan is the closest analog to what Earth's atmosphere will look like as Earth's cold trap fails, with methane instead of water and hydrocarbon products of photochemistry instead of oxygen and ozone. Cold traps are thought to function for oxygen on Ganymede.
The 1981 Springboks tour of New Zealand was compromised by demonstrations, and the tourists had to be kept under strict security throughout their visit. Two games had to be cancelled. The game at Hamilton in the first week of the tour saw 200 protestors rip down a chain fence, sprinkle tacks all over the pitch and then staged a sit-in on the halfway line. At the time, a crowd of 25,000 was watching them playing Waikato. Subsequent matches saw the arrival of barbed wire, and police with batons. The match against South Canterbury at Timaru was cancelled because the authorities thought that they would not be able to control the demonstrations there. The final test of the tour was buzzed by a Cessna aircraft - some in fact nicknamed it the "Crazy Biggles Test". The plane continually strafed the pitch, and dropped flour bombs, flares and leaflets. All-Black prop Gary Knight was temporarily stunned by a flour bomb. Musician Bruce Russell received two police convictions as a student leader of protests against the tour. He was at the University of Otago at the time. It was a tight game, with Allan Hewson, the New Zealand full-back kicking a long range penalty to win the game 25–22. As Rod Chester and Nev McMillan described the scene:
==== In adolescence ==== There has been a significant focus in past research on adulthood, in regards to well-being and development and although eudaimonia is not a new field of study, there has been little research done in the areas of adolescence and youth. Research that has been done on this age group had previously explored more negative aspects than well-being, such as problem and risk behaviours (i.e. drug and alcohol use). Researchers who conducted a study in 2013 recognized the absence of adolescents in eudaimonic research and the importance of this developmental stage. Adolescents rapidly face cognitive, social and physical changes, making them prime subjects to study for development and well-being. The eudaimonic identity theory was used in their research to examine the development of identity through self-discovery and self-realization. They emphasize the personal value found in discovering and appeasing one's "daimon" (daemon) through subjective experiences that develop eudaimonic happiness from aligning with one's true self. Researchers focused their studies on PYD (positive youth development) and the eudaimonic identity theory in the context of three developmental elements: self-defining activities, personal expressiveness and goal-directed behaviours. They determined that adolescents sample multiple self-defining activities; these activities aid in identity formation, as individuals choose activities that they believe represents who they are. These self-defining activities also help determine the adolescent's social environments.
Sources: en.wikipedia.org
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.
No peptide with this exact sequence has been identified as an endogenous substance. It is a laboratory-designed analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The Pro-Gly-Pro extension has no known natural source.
Proline introduces conformational constraints that make a peptide less accessible to common peptidases. This is a standard stabilization strategy in peptide design. The added residues also increase the distance between the active tuftsin portion and typical cleavage sites.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.