This is a working overview of anxiolytic, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-02-10. Anything still debated is marked as such rather than presented as settled.
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.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Principal proposed target | GABA-A receptor complex | Hypothesis derived mainly from animal pharmacology |
| Common behavioral assay | Elevated plus maze | Rodent test for anxiety-like behavior |
| Reported molecular marker | Hippocampal BDNF expression | Measured by immunoassay or mRNA quantification |
| Typical dosing route | Intranasal | Chosen to reduce first-pass metabolism |
| Reported plasma half-life | Minutes | Based on limited peptide stability data |
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.
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.
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.
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.
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.
==== Reserve ==== On 1 September 2014, 21 and 23 SAS were moved from UKSF. They were placed under command of 1st Intelligence, Surveillance and Reconnaissance Brigade. In 2019 they were moved back to UKSF.
Nevertheless, other enzymes (peroxidases) including peroxiredoxins and glutathione peroxidases, which use thioredoxins or glutaredoxins as reducing substrates, also contribute to H2O2 removal in plants.
==== MeSH E05.196.941 – ultracentrifugation ==== MeSH E05.196.941.336 – centrifugation, density gradient MeSH E05.196.941.336.253 – centrifugation, isopycnic MeSH E05.196.941.336.419 – centrifugation, zonal
=== In Vivo Translation Tracking === The techniques above require lysis of cells and thus cannot be performed in living cells. Single-molecule fluorescence resonance energy transfer (smFRET) and Nascent chain tracking (NCT) use fluorescence to track translational activity. Both methods track elongation rates of the polypeptides on single mRNAs. Neither technique, however, is capable of high throughput.
Sources: en.wikipedia.org
=== Environmental controls === Many libraries monitor a building's atmosphere through the use of HVAC systems. These built-in ventilation systems help to combat mold growth that occurs as a result of relative humidity levels greater than 65% and temperature greater than 70 °F (21 °C), as well poor air circulation. Proper use and monitoring of HVAC systems can help to prevent mold problems before they occur. Air ventilation removes existing mold spores from the air and keeps the atmosphere relatively dry and cool. Effective HVAC systems have a good system design and the ability to provide environmental control over entire building areas. Proper maintenance of equipment also lowers the chances that issues will arise due to system outages . At 70 °F (21 °C) and 50% relative humidity, the equilibrium moisture content of the environment would be 9.2%, low enough to prevent mold growth. However, proper air flow and air exchange is required to effectively disrupt the boundary layers of air around room contents, which can have high water vapor levels within the surrounding dry air and promote mold amplification.
=== Nationality and travel history === Many nations implement border controls restricting the entry of people of certain nationalities or who have visited certain countries. For instance, Georgia refuses entry to holders of passports issued by the Republic of China. Similarly, since April 2017, nationals of Bangladesh, Pakistan, Sudan, Syria, Yemen, and Iran have been banned from entering the parts of eastern Libya under the control of the Tobruk government. The majority of Arab countries, as well as Iran and Malaysia, ban Israeli citizens, however exceptional entry to Malaysia is possible with approval from the Ministry of Home Affairs. Certain countries may also restrict entry to those with Israeli stamps or visas in their passports. As a result of tension over the Artsakh dispute, Azerbaijan currently forbids entry to Armenian citizens as well as to individuals with proof of travel to Artsakh. Between September 2017 and January 2021, the United States did not issue new visas to nationals of Iran, North Korea, Libya, Somalia, Syria, or Yemen pursuant to restrictions imposed by the Trump administration, which were subsequently repealed by the Biden administration on 20 January 2021. While in force, the restrictions were conditional and could be lifted if the countries affected meet the required security standards specified by the Trump administration, and dual citizens of these countries could still enter if they presented a passport from a non-designated country.
Legionnaires' disease is caused by a waterborne bacterium Legionella that grows best in slow-moving or still, warm water. The primary route of exposure is through the creation of an aerosol effect, most commonly from evaporative cooling towers or showerheads. A common source of Legionella in commercial buildings is from poorly placed or maintained evaporative cooling towers, which often release water in an aerosol which may enter nearby ventilation intakes. Outbreaks in medical facilities and nursing homes, where patients are immuno-suppressed and immuno-weak, are the most commonly reported cases of Legionellosis. More than one case has involved outdoor fountains at public attractions. The presence of Legionella in commercial building water supplies is highly underreported, as healthy people require heavy exposure to acquire infection. Legionella testing typically involves collecting water samples and surface swabs from evaporative cooling basins, shower heads, faucets/taps, and other locations where warm water collects. The samples are then cultured and colony forming units (cfu) of Legionella are quantified as cfu/liter. Legionella is a parasite of protozoans such as amoeba, and thus requires conditions suitable for both organisms. The bacterium forms a biofilm which is resistant to chemical and antimicrobial treatments, including chlorine.
for the 2D (linear) ion trap were also given in literature. There are at least two postulates about the nature of the DC component. The first, of which has been attributed to Ding, assumes for the DIT that the DC component, U depends on not only the mid-level of the AC voltages, V1and V2, but also the duty cycle, d of the waveform:
It was nominated for numerous awards and won "Best VR/AR" at the 2020 Game Awards. Valve acknowledged that the audience for VR games was limited, and Gabe Newell, Valve's president, described Alyx as a long-term investment into new technologies. As of 2024, it had sold more than two million copies. In 2026, Valve ported Alyx to its standalone Steam Frame headset.
Sources: en.wikipedia.org
==== Neural ==== Oxytocin secretion in response to suckling or vagino-cervical stimulation is mediated by some of these pathways; vasopressin secretion in response to cardiovascular stimuli arising from chemoreceptors in the carotid body and aortic arch, and from low-pressure atrial volume receptors, is mediated by others. In the rat, stimulation of the vagina also causes prolactin secretion, and this results in pseudo-pregnancy following an infertile mating. In the rabbit, coitus elicits reflex ovulation. In the sheep, cervical stimulation in the presence of high levels of estrogen can induce maternal behavior in a virgin ewe. These effects are all mediated by the hypothalamus, and the information is carried mainly by spinal pathways that relay in the brainstem. Stimulation of the nipples stimulates release of oxytocin and prolactin and suppresses the release of LH and FSH. Cardiovascular stimuli are carried by the vagus nerve. The vagus also conveys a variety of visceral information, including for instance signals arising from gastric distension or emptying, to suppress or promote feeding, by signalling the release of leptin or gastrin, respectively. Again, this information reaches the hypothalamus via relays in the brainstem. In addition, hypothalamic function is responsive to—and regulated by—levels of all three classical monoamine neurotransmitters, noradrenaline, dopamine, and serotonin (5-hydroxytryptamine), in those tracts from which it receives innervation.
Bophuthatswana (, lit. 'gathering of the Tswana people'), officially the Republic of Bophuthatswana (Tswana: Repaboleki ya Bophuthatswana; Afrikaans: Republiek van Bophuthatswana), colloquially referred to as the Bop and by outsiders as Jigsawland (In reference to its enclave-ridden borders) was a Bantustan (also known as "Homeland", an area set aside for members of a specific ethnicity) that was declared (nominally) independent by the apartheid regime of South Africa in 1977. However, like the other Bantustans of Ciskei, Transkei and Venda, its independence was not recognized by any country other than South Africa. Bophuthatswana was the second Bantustan to be declared an independent state by the Apartheid government, after Transkei. Its territory constituted a scattered patchwork of enclaves spread across what was then Cape Province, Orange Free State and Transvaal. Its seat of government was Mmabatho, which is now a suburb of Mahikeng. On 27 April 1994, it was reintegrated into South Africa with the coming into force of the country's interim constitution. Its territory was distributed between the new provinces of the Free State, Gauteng, Mpumalanga and North West Province.
A mammary gland is a specific type of apocrine gland specialized for manufacture of colostrum (first milk) when giving birth. Mammary glands can be identified as apocrine because they exhibit striking "decapitation" secretion. Many sources assert that mammary glands are modified sweat glands.
== Etymology == The proposed name for the toxin is U7-ctenitoxin-Pn1a. Here, 'ctenitoxin' refers to toxins found in the venom of spiders from the Ctenidae family. 'Pn' is an acronym for Phoneutria nigriventer, referring to the genus and species of the animal it was isolated from. A commonly used alternative name for U7-CNTX-Pn1a is PnTx3-5, which is an acronym for Phoneutria nigriventer Toxin 3–5. Here, 3 refers to it being part of the third toxic protein fraction that was isolated from the venom using a technique involving a combination of gel filtration and reverse phase fast protein liquid chromatography. Similarly, 5 refers to it being the fifth peptide that was separated from this fraction through reverse phase and ion-exchange high-performance liquid chromatography.
Potter (1842), officer during the American Civil War Augustus van Horne Ellis* (1844), Civil War general William Cutting* (1851), lawyer and soldier Henry Eugene Davies (1857), Civil War general William McNeill Whistler* (1857), Confederate soldier and surgeon, brother of James Abbott McNeill Whistler Alfred Thayer Mahan* (1858), president, U.S. Naval War College and author of The Influence of Sea Power Upon History William Jay (1859), soldier and lawyer, 40th president of the Saint Nicholas Society of the City of New York and great-grandson of first U.S. chief justice John Jay Alister Greene (1875), soldier and leader during the Gilded Age Duncan Elliot (1884), soldier and banker Hamilton Fish II (1895), first American killed in the Spanish–American War Ulysses S. Grant III* (1902), grandson of Ulysses S. Grant, entered with the class of 1902 but transferred to United States Military Academy Donald Armstrong (1909), brigadier general and commandant of the Army Industrial College John H. Hilldring* (1916), U.S. major general and former assistant secretary of state for occupied areas Melvin Krulewitch (1916), U.S. major general and president of the New York State Athletic Commission John F. "Jack" Hasey* (1940), American captain in the French Foreign Legion; recipient of the Order of Liberation
Sources: en.wikipedia.org
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.
Behavioral endpoints include time spent in open arms of the elevated plus maze and avoidance latencies. Biochemical endpoints include BDNF concentration, cytokine levels, and monoamine metabolite ratios in brain tissue.
Most published studies are small, originate from a limited number of laboratories, and lack independent replication. Dose-response relationships, measured brain exposure, and long-term outcomes are not well characterized.
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.