If you have been reading about lyophilised powder and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-12-30. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
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.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
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.
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.
In August 2021, Nando's UK was forced to temporarily close 45 of its 450 restaurants due to a shortage of chicken. A Nando's spokesperson said: "The UK food industry has been experiencing disruption across its supply chain in recent weeks due to staff shortages and Covid isolations, and a number of our restaurants have been impacted." The UK is Nando's largest market.
The male is slender, and the blue line is straighter. The female is rounder, producing a bent blue line. Some aquarists say the females look plumper when viewed from above. However, the straightness of the line and the plumpness of the female might occasionally be due to the eggs she is carrying. A neon tetra can appear slightly plump in the belly due to having overeaten. Neon tetras need dim lighting, a DH less than one, about 5.5 pH, and a temperature of 75 °F (24 °C) to breed. There also needs to be a lot of tannins in the water. Neon tetras are old enough to breed at 12 weeks. Breeding neon tetras is considered to be difficult in home aquariums. However, it is becoming more common, with less than 5% of specimens currently sold in America caught in the wild, and more than 1.5 million specimens imported to America each month from fish farms.
=== Other endocrine conditions === Endocrine diseases that may lead to ketoacidosis include severe forms of hypothyroidism, thyrotoxicosis and adrenal failure. In all cases, the hormone-sensitive lipase in cells is phosphorylated and over-active, resulting in unrestrained lipolysis. Ketonemia and even ketoacidosis may arise from endocrine (non-diabetic) conditions alone, but the combination of endocrine and diabetic ketoacidosis leads to an especially unfavourable prognosis.
In ibritumomab tiuxetan, the chelator tiuxetan is a modified version of DTPA whose carbon backbone contains an isothiocyanatobenzyl and a methyl group. In capromab pendetide and satumomab pendetide, the chelator pendetide (GYK-DTPA) is a modified DTPA containing a peptide linker used to connect the chelate to an antibody. Pentetreotide is a modified DTPA attached to a peptide segment. DTPA and derivatives are used to chelate gadolinium to form an MRI contrast agent, such as Magnevist. Technetium-99m is chelated with DTPA for ventilation perfusion (V/Q) scans and radioisotope renography nuclear medicine scans.
For the ninth patient, they introduced a surgical instrument called a leucotome; this was a cannula that was 11 centimetres (4.3 in) in length and 2 centimetres (0.79 in) in diameter. It had a retractable wire loop at one end that, when rotated, produced a 1 centimetre (0.39 in) diameter circular lesion in the white matter of the frontal lobe. Typically, six lesions were cut into each lobe, but, if they were dissatisfied with the results, Lima might perform several procedures, each producing multiple lesions in the left and right frontal lobes. By the conclusion of this first run of leucotomies in February 1936, Moniz and Lima had operated on twenty patients with an average period of one week between each procedure; Moniz published his findings with great haste in March of the same year. The patients were aged between 27 and 62 years of age; twelve were female, and eight were male. Nine of the patients were diagnosed with depression, six with schizophrenia, two with panic disorder, and one each with mania, catatonia and manic-depression. Their most prominent symptoms were anxiety and agitation. The duration of their illness before the procedure varied from as little as four weeks to as much as 22 years, although all but four had been ill for at least one year. Patients were normally operated on the day they arrived at Moniz's clinic and returned within ten days to the Miguel Bombarda Mental Hospital. A perfunctory post-operative follow-up assessment took place anywhere from one to ten weeks following surgery.
Sources: en.wikipedia.org
==== The 12 nidanas in Mahāyāna sutras and tantras ==== Alex Wayman writes that Mahāyāna texts such as Śrīmālādevī Siṃhanāda Sūtra present an alternative interpretation of the twelve nidanas. According to Wayman, this interpretation holds that arhats, pratyekabuddhas, and bodhisattvas have eliminated the four kinds of clinging (nidana # 9), which are the usual condition for existence (or "gestation", nidana #10) and rebirth (#11) in one of the three realms. Instead of being reborn, they have a "body made of mind" (manōmaya kāya), which is a special consciousness (vijñana). This consciousness is projected by ignorance (nidana #1) and purified by a special kind of samskara (# 2) called "nonfluxional karma" (anāsrava-karma). These mind-made bodies produce a reflected image in the three worlds, and thus they appear to be born. According to Wayman, this view of dependent origination posits "a dualistic structure of the world, in the manner of heaven and earth, where the "body made of mind" is in heaven and its reflected image, or coarser equivalent, is on earth. Otherwise stated, the early members of Dependent Origination apply to the superior realm, the later members to the inferior realm. But the Śrī-mālā-Sūtra does not clarify how those members are allotted to their respective realms." According to Wayman, similar interpretations appear in tantric texts, such as the Caṇḍamahāroṣaṇatantra.
These are difficult times for big-screen entertainment. As the medium declines and TV grows ascendant, authentic spectacles—as opposed to lavish embellishments of smallish ideas—threaten to become a thing of the fabled past. All the more reason, then, to cherish what Marvel has achieved, even though befuddling stumbles have occurred along the way. The studio has kept the faith by smartening up most of its films, not dumbing them down, by banking on, and raking in profits from, the audience's appetite for surprise, its capacity for complexity. When the final battle comes at the end of Avengers: Endgame, it's inevitably unwieldy—every Marvel character you can think of from the past decade shows up for one more assault on cosmic evil—but thrilling all the same, and followed by a delicate coda. So many stories. So many adventures. So much to sort out before the next cycle starts. Many famous filmmakers have expressed different views on both the success and quality of the MCU. In October 2019, filmmaker Martin Scorsese openly criticized Marvel films in an interview and during a David Lean lecture in London, later expanded in an op-ed in The New York Times, asserting that these films are not cinema, but are instead the equivalent of theme park rides that lack "mystery, revelation or genuine emotional danger".
Before her trial, Joan confronts Bea about Allie, calling her "collateral damage." Although Franky manages to stop Shane from killing Nils, Jake hijacks Nils van and shoots him, setting the van on fire. Joan's charges are dropped and she is released. On her way out, she is confronted by Bea, who plans to kill her due to the attack on Allie. Joan overpowers Bea and takes hold of her screwdriver. Bea then thrusts herself into the screwdriver, making it appear that Joan has killed her.
Iodine-125 (125I) is a radioisotope of iodine which has uses in biological assays, nuclear medicine imaging and in radiation therapy as brachytherapy to treat a number of conditions, including prostate cancer, uveal melanomas, and brain tumors. It is the second longest-lived radioisotope of iodine, after iodine-129. Its half-life is 59.392 days and it decays by electron capture to an excited state of tellurium-125. This state is not the metastable 125mTe, but a much shorter-lived excited state that decays either by (7% chance) emitting a gamma ray with energy of 35 keV, or more likely (93% chance), undergoing internally conversion and ejecting an electron (of lower energy than 35 keV). The resulting electron vacancy leads to emission of characteristic X-rays (27–32 keV) and Auger electrons (50 to 500 eV). In either case stable ground state 125Te is the product. In medical applications, the internal conversion and Auger electrons cause little damage outside the cell which contains the isotope atom. The X-rays and gamma rays are of low enough energy to deliver a higher radiation dose selectively to nearby tissues, in "permanent" brachytherapy where the isotope capsules are left in place (125I competes with palladium-103 in such uses). Because of its relatively long half-life and emission of low-energy photons which can be detected by gamma-counter crystal detectors, 125I is a preferred isotope for tagging antibodies in radioimmunoassay and other gamma-counting procedures involving proteins outside the body.
== Adverse effects == The most common adverse event reported in phase III trials for ripasudil was mild conjunctival hyperemia. Additionally, up to 3.8% of trial participants reported ocular irritation after using the drug with up to 5.7% reporting conjunctival hemorrhage. There were several cases of “abnormal sensation in the eye” reported. On a cellular level, Okumura et al. found that ripasudil produced "guttae-like" formations in ocular endothelial cells post-administration, which was attributed to, "protrusion formation along intracellular borders caused by the reduction in actomyosin contractility of the CECs." However, these morphological changes to the eye were considered transient and therefore quick to reverse, unlike symptoms Fuchs endothelial corneal dystrophy, a disorder for which these short-lived symptoms could be mistaken.
Sources: en.wikipedia.org
February 9 The second impeachment trial of Donald Trump begins. He is acquitted four days later, February 13 with a 57–43 vote in the Senate, ten votes short of the required two-thirds majority for conviction. COVID-19 drug development: The FDA issues an emergency use authorization (EUA) for bamlanivimab and etesevimab. February 11 President Biden terminates the national emergency declaration on the US-Mexico border which President Trump had used to pay for the wall. In Fort Worth, Texas, at least six people are killed in an accident involving 133 vehicles on Interstate 35W, affected by weather conditions left by a snowstorm system. February 12 The United States Senate votes by unanimous consent to award United States Capitol Police officer Eugene Goodman the Congressional Gold Medal for keeping rioters away from the Senate chamber during the storming of the United States Capitol. The U.S. Food and Drug Administration approves Cosela as the first therapy in its class to reduce the frequency of chemotherapy-induced bone marrow suppression. February 15 – House Speaker Nancy Pelosi announces that Congress will establish a 9/11-styled commission to investigate the January 6 riot at the United States Capitol. February 13–17 – A major winter storm kills 58 people in the United States (and 12 in Mexico) and causes over 9,724,000 power outages across 13 states in the Midwest and Southwest, with Southwest Power Pool declaring an "energy emergency". February 17 COVID-19 pandemic: North Dakota confirms their first case of the UK variant of SARS-CoV-2.
== Purpose == Breakthrough T1D was founded to support and accelerate breakthroughs in medical science to cure, prevent, and treat type 1 diabetes and its complications. These goals are pursued both through scientific research and public advocacy campaigns.
In November 1965 the government of the British colony of Southern Rhodesia issued an illegal Unilateral Declaration of Independence. This government represented the country's small white minority and was led by Prime Minister Ian Smith. The black majority of the population had little influence on the government, which sought to continue white racial privileges. At the time of independence the Rhodesian Security Forces were relatively large and well trained and equipped. Two groups with armed elements emerged as the opposition to the white Rhodesian regime. These were the Zimbabwe African National Union (ZANU), whose military wing was the Zimbabwe African National Liberation Army (ZANLA), and the Zimbabwe African People's Union (ZAPU) and its armed wing the Zimbabwe People's Revolutionary Army (ZIPRA). Both groups were initially based in Zambia, and from the late 1960s began dispatching insurgents into Rhodesia who used guerrilla tactics. These attacks initially proved ineffective and the Rhodesian military, which had been bolstered by forces from South Africa, was able to effectively counter them. Rhodesia's security situation began to deteriorate from late 1972, when the guerrilla armies began making more effective attacks in the north-east of the country. The collapse of the Portuguese Empire in 1975 that led to the independence of Mozambique led to a further increase to the challenges facing the Rhodesian regime, with the guerrillas using that country as well as Botswana as bases.
It is recommended that a water concentration of 2 μg Se/L be considered highly hazardous to sensitive fish and aquatic birds. Selenium poisoning can be passed from parents to offspring through the egg, and selenium poisoning may persist for many generations. Reproduction of mallard ducks is impaired at dietary concentrations of 7 μg Se/L. Many benthic invertebrates can tolerate selenium concentrations up to 300 μg/L of selenium in their diet. Bioaccumulation of selenium in aquatic environments causes fish kills depending on the species in the affected area. There are, however, a few species that have been seen to survive these events and tolerate the increased selenium. It has also been suggested that the season could have an impact on the harmful effects of selenium on fish. Substantial physiological changes may occur in fish with high tissue concentrations of selenium. Fish affected by selenium may experience swelling of the gill lamellae, which impedes oxygen diffusion across the gills and blood flow within the gills. Respiratory capacity is further reduced due to selenium binding to hemoglobin. Other problems include degeneration of liver tissue, swelling around the heart, damaged egg follicles in ovaries, cataracts, and accumulation of fluid in the body cavity and head. Selenium often causes a malformed fish fetus which may have problems feeding or respiring; distortion of the fins or spine is also common. Adult fish may appear healthy despite their inability to produce viable offspring.
Sources: en.wikipedia.org
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.