Regulatory peptide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-11-27. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
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.
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.
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.
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.
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.
Hatching is an exhausting effort for the neonates, which break out of their eggshells with an egg tooth that falls off before long. After cutting themselves out, the hatchlings may lie in their eggshells for hours before starting to dig out of the nest. They are born quite defenseless and are vulnerable to predation. Sixteen youngsters from a single nest were on average 46.5 cm long and weighed 105.1 grams.
Agmatine is a cationic amine formed by decarboxylation of L-arginine by the mitochondrial enzyme arginine decarboxylase (ADC). Agmatine degradation occurs mainly by hydrolysis, catalyzed by agmatinase into urea and putrescine, the diamine precursor of polyamine biosynthesis. An alternative pathway, mainly in peripheral tissues, is by diamine oxidase-catalyzed oxidation into agmatine-aldehyde, which is in turn converted by aldehyde dehydrogenase into guanidinobutyrate and secreted by the kidneys.
After the resignation of Labour MP Marsha Singh due to ill health, Galloway returned to parliament at the March 2012 Bradford West by-election in an unexpected landslide result, with Galloway calling it "the most sensational victory in British political history." His 36% swing, defeating the Labour candidate Imran Hussain, was amongst the largest in modern British political history. Jeremy Corbyn, then a backbench Labour MP, congratulated him in a tweet. Galloway described the result as a "Bradford spring" (after the Arab Spring) and said that it showed the "total rejection" by voters of the three leading political parties. The election campaign was marked by controversy, in particular over the role of sectarianism, Baradari (clan) networks, and allegations about rivals' lack of "Islamic values" Andrew Gilligan noted in The Daily Telegraph that Galloway had won in wards with a predominantly white electorate as well as those with a majority Muslim population. Nick Robinson, the BBC's political editor, believed it was "a one-off political coup by a political one-off" in a seat which has not followed national trends in the past. The novelist Howard Jacobson in The Independent wrote that Galloway's "campaign shamelessly courted Muslim prejudice in smaller matters such as alcohol – where Galloway painted himself as more Muslim than the Muslim Labour candidate whom he accused of liking, shock horror, a tipple." Patrick Cockburn in The Independent on Sunday commented: "It says something about the comatose nature of British politics that an effective critic of ...
== Other == HMF is an intermediate in the titration of hexoses in the Molisch's test. In the related Bial's test for pentoses, the hydroxymethylfurfural from hexoses may give a muddy-brown or gray solution, but this is easily distinguishable from the green color of pentoses. Acetoxymethyl furfural (AMF) is also bio-derived green platform chemicals as an alternative to HMF.
Sources: en.wikipedia.org
In fantasy fiction, a lich () is a type of undead creature with magical powers. Various works of fantasy fiction, such as Clark Ashton Smith's "The Empire of the Necromancers" (1932), had used lich as a general term for any corpse, animate or inanimate, before the term's specific use in fantasy role-playing games. The more recent use of the term lich for a specific type of undead creature originates from the 1976 Dungeons & Dragons role-playing game booklet Greyhawk, written by Gary Gygax and Rob Kuntz. Often such a creature is the result of a willful transformation, as a powerful wizard skilled in necromancy who seeks eternal life uses rare substances in a magical ritual to become undead. Unlike zombies, which are often depicted as mindless, liches are sapient revenants, retaining their previous intelligence and magical abilities. Liches are often depicted as holding power over lesser mindless undead soldiers and servants. A lich's most commonly depicted distinguishing feature, compared to other undead in fantasy fiction, is the method by which it achieves immortality: liches surrender their souls to create "soul-artifacts" (often called a "soul gem" or "phylactery" in other fantasy works), which serve as the source of their magic and immortality. Many liches take precautions to hide and/or protect one or more of these soul-artifacts, which anchor parts of their souls to the material world.
== Substrate specificity == APX enzymes show high specificity for ascorbate as an electron donor, but most APXs will also oxidise other organic substrates that are more characteristic of the class III peroxidases (such as horseradish peroxidase), in some cases at rates comparable to that of ascorbate itself. This means that defining an enzyme as an APX is not straightforward, but is usually applied when the specific activity for ascorbate is higher than that for other substrates. Some proteins from the APX family lack the ascorbate-binding amino acid residues suggesting that they might oxidize other molecules than ascorbate.
Merchandising can be extremely lucrative too: The Lion King also sold $3 billion of merchandise, while Pixar's Cars—which earned $462 million in theatrical revenues and was only a modest hit by comparison to other Pixar films—generated global merchandise sales of over $8 billion in the five years after its 2006 release. Pixar had another huge hit with Toy Story 3, which generated almost $10 billion in merchandise retail sales in addition to the $1 billion it earned at the box office. On this chart, films are ranked by the revenues from theatrical exhibition at their nominal value, along with the highest positions they attained. Eight films in total have grossed in excess of $2 billion worldwide, with Avatar ranked in the top position. All of the films have had a theatrical run (including re-releases) in the 21st century, and films that have not played during this period do not appear on the chart because of ticket-price inflation, population size and ticket purchasing trends not being considered.
Sources: en.wikipedia.org
=== Argentina === In 2011, Argentina introduced a catalogue of drugs covered by its national drug traceability scheme, listing more than 3,000 drugs that require the placing of unique serial numbers and tamper-evident features on the secondary packaging. The drugs listed are recorded in real time in a central database managed by the National Administration of Drugs, Foods, Medical Devices of Argentina (ANMAT), Regulation 3683, which uses Global Location Numbers (GLNs) to identify the various actors in the supply chain. The purpose of this program is to actively limit the use of illegal drugs.
So much so that it was considered an aphrodisiac and given to the Inca soldiers during campaigns to make them forget about their spouses. Other roots that could be found in the Inca cuisine were the maka (Lepidium meyenii) and the yacón (Polymnia sonchifolia). Maka was capable of surviving in the coldest and highest areas of the Andes, thus giving it high value. Yacón was documented to be similar to a turnip in texture but was very sweet and kept well, making them popular on sea voyages. The insipid, starchy root ullucu, and arracacha, something like a cross between carrot and celery, were, like potatoes, used in stews and soup. Achira, a species of Canna, was a sweet, starchy root that was baked in earth ovens. Since it had to be transported up to the power center of Cuzco, it is considered to have been food eaten as part of a tradition. Although the roots and tubers provided the staples of the Inca, they were still considered lower in rank than maize (Zea mays). It has been found that the Inca-conquered lands were often transitioned from potato fields to maize fields, more than likely due to maize being the main ingredient of chicha. Several species of seaweed, such as Porphyra, Durvillaea antarctica, and Ulva lactuca were part of the Inca diet and could be eaten fresh or dried. Some freshwater algae and blue algae of the genus Nostoc were eaten raw or processed for storage. In post-colonial times it has been used to make a dessert by boiling it in sugar.
==== Tandem Diabetes Care t:Slim X2 with Control IQ ==== The Tandem Diabetes Care t:Slim X2 was approved by the U.S. Food and Drug Administration in 2019 and is the first insulin pump to be designated as an alternate controller enabled (ACE) insulin pump. ACE insulin pumps allow users to integrate continuous glucose monitors, automated insulin dosing (AID) systems, and other diabetes management devices with the pump to create a personalized diabetes therapy system. Many users of the t:slim X2 integrate the pump with the Dexcom G6, a continuous glucose monitor approved by the FDA in 2018. It was the first CGM authorized for use in an integrated therapy system. The device does not require fingerstick calibrations.
While most cephalopods can move by jet propulsion, this is a very energy-consuming way to travel compared to the tail propulsion used by fish. The efficiency of a propeller-driven waterjet (i.e. Froude efficiency) is greater than a rocket. The relative efficiency of jet propulsion decreases further as animal size increases; paralarvae are far more efficient than juvenile and adult individuals. Since the Paleozoic era, as competition with fish produced an environment where efficient motion was crucial to survival, jet propulsion has taken a back role, with fins and tentacles used to maintain a steady velocity. Whilst jet propulsion is never the sole mode of locomotion, the stop-start motion provided by the jets continues to be useful for providing bursts of high speed – not least when capturing prey or avoiding predators. Indeed, it makes cephalopods the fastest marine invertebrates, and they can out-accelerate most fish. The jet is supplemented with fin motion; in the squid, the fins flap each time that a jet is released, amplifying the thrust; they are then extended between jets (presumably to avoid sinking). Oxygenated water is taken into the mantle cavity to the gills and through muscular contraction of this cavity, the spent water is expelled through the hyponome, created by a fold in the mantle. The size difference between the posterior and anterior ends of this organ control the speed of the jet the organism can produce. The velocity of the organism can be accurately predicted for a given mass and morphology of animal.
Sources: en.wikipedia.org
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.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.