The short version of elevated plus maze fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-18. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| 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 |
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.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
The company was founded in Pittsburgh, Pennsylvania, in 1902 by Chester Garfield Fisher (1881–1965), originally called the "Scientific Materials Co.". After obtaining his degree in engineering at Western University of Pennsylvania (now University of Pittsburgh), C.G. Fisher purchased the stockroom of the Pittsburgh Testing Laboratory. Fisher became a supplier of lab equipment and reagents for the area's industrial research. Early products included microscopes, burets, pipettes, litmus, balances, colorimeters, dissecting kits, and anatomical models. The first catalog, the 400 page Scientific Materials Co. Catalog of Laboratory Apparatus & Supplies, was published in 1904. Fisher established an R&D lab at his company in 1915. Edwin Fisher, Chester's brother, developed the Meker-Fisher burner in 1921, an advancement on the design of the Bunsen burner. The company manufactured an electric-combustion furnace and combustion train for analyzing carbon levels in steel, and an electrically heated and thermostatically controlled bacteriological incubator. In 1925, the company purchased Montreal-based Scientific Supplies, Ltd. The same year, the company was renamed Fisher Scientific. In 1940, Fisher Scientific acquired the New York supply company Eimer & Amend, which was founded in 1851 by Bernard G. Amend. Aiken Fisher, Chester's oldest son, became president of the company in 1949. In 1955, Fisher established a chemical manufacturing facility in Fair Lawn, New Jersey. In 1957, the company purchased the New York–based medical apparatus supply company E. Machlett & Sons.
The purpose of using the vacuum is to eliminate background signal and avoid intermolecular collision events, therefore, providing a long mean free path for the ions. The vacuum system, including the vacuum pumps and the vacuum manifold with its various interfaces, is often the heaviest part and consumes the most power in a mass spectrometer. In the case of TOF, if the length of drift region is decreased, the pressure inside region can be operated at higher value because the free collision region is still maintained for a short traveling distance of the ions. As a result, the vacuum system requires less power to run the system. For a trap-type mass analyzer, because the ions are trapped in the device for long periods and the accumulated trajectory length is much longer than the size of the mass analyzer, the size reduction of the mass analyzer may not directly affect the adequate operating pressure. Miniature rough-turbo pump configurations similar to lab-scale instruments have been developed to be compatible with MMS. For high-vacuum pumping, turbomolecular pumps are also upgraded. A Thermo Fisher Orbitrap used three turbo pumps in LC-MS modes to achieve a vacuum below 10−10 torr. Recently, a turbo pump from Creare, Inc.TM weighs only 500g and needs below 18 W power to run. The pump can provide the ultimate vacuum below 10−8 torr, which is much lower than the operating pressure necessary for a MMS.
== Packaging machines == A choice of packaging machinery requires consideration of technical capabilities, labor requirements, worker safety, maintainability, serviceability, reliability, ability to integrate into the packaging line, capital cost, floorspace, flexibility (change-over, materials, etc.), energy usage, quality of outgoing packages, qualifications (for food, pharmaceuticals, etc.), throughput, efficiency, productivity, and ergonomics, at a minimum. Packaging machines may be of the following general types:
== Bioremediation properties == Pseudomonas fluorescens is increasingly recognized for its bioremediation potential, particularly in the degradation of environmental pollutants such as hydrocarbons. A study has shown that biostimulation and bioaugmentation with P. fluorescens can significantly contribute to the removal of total petroleum hydrocarbons (TPHs) from contaminated soil. This process is facilitated by the bacterium's production of biosurfactants, which increase the bioavailability of hydrocarbons for degradation. Further research has explored the biofilm-forming and denitrification capabilities of Pseudomonas species, including P. fluorescens, in eutrophic waters. The ability to form biofilms and produce extracellular polymeric substances (EPS) enhances the bioremediation potential of these bacteria. Specifically, strains that exhibit strong biofilm-forming and EPS production capabilities show higher nitrate removing capacity, which is crucial for combating water pollution. These findings underscore the importance of Pseudomonas fluorescens in environmental cleanup efforts and its potential application in treating oil-contaminated and nutrient-poor soils as well as nitrate-polluted water.
Sources: en.wikipedia.org
== Pelvic diaphragm == The muscular pelvic diaphragm is composed of the bilateral levator ani and coccygeus muscles and these attach to the inner pelvic surface. The iliococcygeus and pubococcygeus make up the levator ani muscle. The muscles pass behind the rectum. The levator ani surrounds the opening which the urethra, rectum and vagina pass. The pubococcygeus muscle is subdivided into the pubourethralis, pubovaginal muscle and the puborectalis muscle. The names describe the attachments of the muscles to the urethra, vagina, anus, and rectum. The names are also called the pubourethralis, pubovaginalis, puboanalis, and puborectalis muscles and sometimes the pubovisceralis since it attaches to the viscera.
=== Sociological === Anorexia nervosa has been increasingly diagnosed since 1950; the increase has been linked to vulnerability and internalization of body ideals. People in professions where there is a particular social pressure to be thin (such as models and dancers) were more likely to develop anorexia, and those with anorexia have much higher contact with cultural sources that promote weight loss. Internet usage heavily leads to deep societal practices of the upkeep of slender body types. Thus leading many to have symptoms of body dissatisfaction and low body image satisfaction. This trend can also be observed for people who partake in certain sports, such as jockeys and wrestlers. There is a higher incidence and prevalence of anorexia nervosa in sports with an emphasis on aesthetics, where low body fat is advantageous, and sports in which one has to make weight for competition. Family group dynamics can play a role in the perpetuation of anorexia including negative expressed emotion in overprotective families where blame is frequently experienced among its members. In the face of constant pressure to be thin, often perpetuated by teasing and bullying, feelings of low self-esteem and self-worth can arise, including the perception that one is not "deserving" of food.
The currency of Singapore is the Singapore dollar (SGD or S$), issued by the Monetary Authority of Singapore (MAS). It has been interchangeable with the Brunei dollar at par value since 1967. MAS manages its monetary policy by allowing the Singapore dollar exchange rate to rise or fall within an undisclosed trading band. This is different from most central banks, which use interest rates to manage policy. Singapore has the world's eleventh largest foreign reserves, and one of the highest net international investment position per capita. Singapore has been identified as a tax haven for the wealthy due to its low tax rates on personal income and tax exemptions on foreign-based income and capital gains. Individuals such as Australian millionaire retailer Brett Blundy and multi-billionaire Facebook co-founder Eduardo Saverin are two examples of wealthy individuals who have settled in Singapore. In 2009, Singapore was removed from the Organisation for Economic Co-operation and Development (OECD) "liste grise" of tax havens, and ranked fourth on the Tax Justice Network's 2015 Financial Secrecy Index of the world's off-shore financial service providers, banking one-eighth of the world's offshore capital, while "providing numerous tax avoidance and evasion opportunities". In August 2016, The Straits Times reported that Indonesia had decided to create tax havens on two islands near Singapore to bring Indonesian capital back into the tax base.
Sources: en.wikipedia.org
If a customer has the right to receive additional goods or services in exchange for a voluntary tip, the tip is not eligible. The tax deduction is not allowed if the individual is married and files their federal income tax return separately from their spouse. The tax deduction is not allowed if the individual does not include their social security number on their federal income tax return or if the social security number was issued on or after the due date, including extensions, of the federal income tax return . For a self-employed individual who receives tips in the course of their trade or business, eligible tips are tax deductible but they cannot create a net loss for the trade or business.
==== Underage users ==== As with other platforms popular with children, underage users may inadvertently reveal their daily routine and whereabouts, raising concerns of potential misuse by sexual predators. At the time of reporting (2018), TikTok had only two privacy settings, either private or completely public, without any middle ground. Comment sections of "sexy" videos, such as young girls dancing in revealing clothes, were found to contain requests for nude pictures. Despite safety concerns, TikTok began rolling out photo, video, and voice messaging around 2025. As of January 2026, the features are only available in certain regions, including the United States and Canada. In recent years, the US has charged and sentenced sexual predators for illegal activities on TikTok against underage girls. On 22 January 2021, the Italian Data Protection Authority demanded that TikTok temporarily suspend Italian users whose age could not be established. The order came after the death of a 10-year-old Sicilian girl involved in an Internet challenge. TikTok asked its users in Italy to confirm again that they were over 13 years old. By May, over 500,000 accounts had been removed for failing the age check. In July 2021, the Dutch Data Protection Authority fined TikTok €750,000 for offering privacy statements only in English but not in Dutch.
Edith died on 29 November 1971, at the age of 82. Ronald returned to Oxford, where Merton College gave him convenient rooms near the High Street. He missed Edith, but enjoyed being back in the city. Tolkien was made a Commander of the Order of the British Empire in the 1972 New Year Honours and received the insignia of the Order at Buckingham Palace on 28 March 1972. In the same year Oxford University gave him an honorary Doctorate of Letters. He was further awarded an honorary Doctorate of Letters from the University of Edinburgh on 22 July 1973. He had the name Luthien [sic] engraved on Edith's tombstone at Wolvercote Cemetery, Oxford. When Tolkien died 21 months later on 2 September 1973 from a bleeding ulcer and chest infection, at the age of 81, he was buried in the same grave, with "Beren" added to his name. Tolkien's will was proven on 20 December 1973, with his estate valued at £190,577 (equivalent to £2,991,790 in 2026).
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.
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.