elevated plus maze raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-10-03. Anything still debated is marked as such rather than presented as settled.
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.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
| Property | Value | Notes |
|---|---|---|
| Common route | Intranasal | Also injected in some animal work |
| Solubility class | Freely soluble in water | Solid form is hygroscopic |
| Typical storage | About -20 degrees Celsius | Keep desiccated and dark |
| Purity method | Reverse-phase HPLC | Reported as area percent |
| Confirmatory method | Mass spectrometry | Verifies expected molecular mass |
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.
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.
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.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
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.
== Beginnings (1942–1958) == Ron was born on September 11, 1942, in Syracuse, New York, to George and Helen Lauback. There is a long musical history in the Lauback family (with Ron's mother Helen Lauback being a music teacher in the East Syracuse School District in the 1940s), with young Ron being exposed to jazz, classical and pop music as a child. Ron's first musical instrument was a ukulele, which he started learning in his pre-teens. It would take the influence of rock and roll in the mid-1950s to make young Ron take up the electric guitar. Early musical influences include Duane Eddy, The Everly Brothers and most importantly Chuck Berry. By 1958 Ron had formed East Syracuse's first rock and roll band The Sabres. The Sabres specialized in instrumental music and early rock artists like the afore-mentioned Chuck Berry, The Ventures and Dale Hawkins.
=== ENSO Costero === Coined by the Peruvian Comité Multisectorial Encargado del Estudio Nacional del Fenómeno El Niño (ENFEN), ENSO Costero, or ENSO Oriental, is the name given to the phenomenon where the sea-surface temperature anomalies are mostly focused on the South American coastline, especially from Peru and Ecuador. Studies point many factors that can lead to its occurrence, sometimes accompanying, or being accompanied, by a larger EP ENSO occurrence, or even displaying opposite conditions from the observed ones in the other Niño regions when accompanied by Modoki variations. ENSO Costero events usually present more localized effects, with warm phases leading to increased rainfall over the coast of Ecuador, northern Peru and the Amazon rainforest, and increased temperatures over the northern Chilean coast, and cold phases leading to droughts on the Peruvian coast, and increased rainfall and decreased temperatures on its mountainous and jungle regions. Because they don't influence the global climate as much as the other types, these events present lesser and weaker correlations to other significant ENSO features, neither always being triggered by Kelvin waves, nor always being accompanied by proportional Southern Oscillation responses. According to the Coastal Niño Index (ICEN), strong El Niño Costero events include 1957, 1982–83, 1997–98 and 2015–16, and La Niña Costera ones include 1950, 1954–56, 1962, 1964, 1966, 1967–68, 1970–71, 1975–76 and 2013.
φ29’s DNA packaging system, using pRNA, incorporates a motor for the delivery of therapeutic molecules like ribozymes and aptamers. The small size of pRNA-derived nanoparticles also helps to deliver drugs in tight spaces like blood vessels. The main difficulty in using aptamer-based drug delivery is sourcing unique aptamers and other multimers for specific treatments for diseases that potentially degrade therapeutic multimers and nanoparticles in vivo. Nanoparticles need to be stabilized as delivery mechanisms in order to adapt to microenvironments that may result in loss of therapeutic cargo.
=== Material considerations === It is common to reduce a wood sample to just the cellulose component before testing, but since this can reduce the volume of the sample to 20% of its original size, testing of the whole wood is often performed as well. Charcoal is often tested but is likely to need treatment to remove contaminants. Unburnt bone can be tested; it is usual to date it using collagen, the protein fraction that remains after washing away the bone's structural material. Hydroxyproline, one of the constituent amino acids in bone, was once thought to be a reliable indicator as it was not known to occur except in bone, but it has since been detected in groundwater. For burnt bone, testability depends on the conditions under which the bone was burnt. If the bone was heated under reducing conditions, it (and associated organic matter) may have been carbonized. In this case, the sample is often usable. Shells from both marine and land organisms consist almost entirely of calcium carbonate, either as aragonite or as calcite, or some mixture of the two. Calcium carbonate is very susceptible to dissolving and recrystallizing; the recrystallized material will contain carbon from the sample's environment, which may be of geological origin. If testing recrystallized shell is unavoidable, it is sometimes possible to identify the original shell material from a sequence of tests. It is also possible to test conchiolin, an organic protein found in shell, but it constitutes only 1–2% of shell material. The three major components of peat are humic acid, humins, and fulvic acid.
During the early 1980s, Jean-Pierre Raufman worked as a postdoctoral researcher at the National Institutes of Health for John Pisano, an "eccentric biochemist" who specialized in collecting venoms from various animals and looking for novel substances that could affect human physiology. In the course of this work, Raufman focused on investigating the Gila monster because he was curious about how it only eats once or twice per year. He discovered molecules in the monster's saliva "that caused inflammation of the pancreas in test animals". He later recalled: "We got a tremendous response from Gila monster venom". When Raufman gave a lecture about his findings, his research piqued the curiosity of John Eng, an endocrinologist at the Veterans Administration Medical Center in New York City. Eng had trained under Rosalyn Sussman Yalow, who shared the 1977 Nobel Prize in Physiology or Medicine for development of the radioimmunoassay technique. In 1992, Eng used that technique to isolate a novel substance from Gila monster venom which he called exendin-4. He tested exendin-4 on diabetic mice and discovered that it was not only effective for reducing blood glucose but was effective for several hours. This was an enormously significant clinical finding, because it was GLP-1's extremely short half-life which had defeated earlier attempts to turn that substance into a drug.
Sources: en.wikipedia.org
A vitamin is an organic compound required by an organism as a vital nutrient in limited amounts. An organic chemical compound (or related set of compounds) is called a vitamin when it cannot be synthesized in sufficient quantities by an organism and must be obtained from the diet. The term is conditional both on the circumstances and on the particular organism. For example, ascorbic acid (vitamin C) is a vitamin for anthropoid primates, humans, guinea pigs and bats, but not for other mammals. Vitamin D is not an essential nutrient for people who get sufficient exposure to ultraviolet light, either from the sun or an artificial source, as they synthesize vitamin D in skin. Humans require thirteen vitamins in their diet, most of which are actually groups of related molecules, "vitamers", (e.g., vitamin E includes tocopherols and tocotrienols, vitamin K includes vitamin K1 and K2). The list: vitamins A, C, D, E, K, Thiamine (B1), Riboflavin (B2), Niacin (B3), Pantothenic Acid (B5), Vitamin B6, Biotin (B7), Folate (B9) and Vitamin B12. Vitamin intake below recommended amounts can result in signs and symptoms associated with vitamin deficiency. There is little evidence of benefit when vitamins are consumed as a dietary supplement by those who are healthy and have a nutritionally adequate diet. The U.S. Institute of Medicine sets tolerable upper intake levels (ULs) for some of the vitamins. This does not prevent dietary supplement companies from selling products with content per serving higher than the ULs.
=== Industrial === Major potassium chemicals are potassium hydroxide, potassium carbonate, potassium sulfate, and potassium chloride. Megatons of these compounds are produced annually. KOH is a strong base, which is used in industry to neutralize strong and weak acids, to control pH and to manufacture potassium salts. It is also used to saponify fats and oils, in industrial cleaners, and in hydrolysis reactions, for example of esters. Potassium nitrate (KNO3) or saltpeter is obtained from natural sources such as guano and evaporites or manufactured via the Haber process; it is the oxidant in gunpowder (black powder) and an important agricultural fertilizer. Potassium cyanide (KCN) is used industrially to dissolve copper and precious metals, in particular silver and gold, by forming complexes. Its applications include gold mining, electroplating, and electroforming of these metals; it is also used in organic synthesis to make nitriles. Potassium carbonate (K2CO3 or potash) is used in the manufacture of glass, soap, color TV tubes, fluorescent lamps, textile dyes and pigments. Potassium permanganate (KMnO4) is an oxidizing, bleaching and purification substance and is used for production of saccharin. Potassium chlorate (KClO3) is added to matches and explosives. Potassium bromide (KBr) was formerly used as a sedative and in photography.
== Composition == Whole leaf protein concentrate is a dark green substance with a texture similar to cheese. Approximately 60% of this is water, while the remaining dry matter is 9-11% nitrogen, 20-25% lipid, 5-10% starch and a variable amount of ash. It is a mixture of many individual proteins. Its flavour has been compared to spinach or tea. Because the colour and taste may make it unpalatable for humans, LPC can instead be separated into green and white fractions. The green fraction has proteins mainly originating from the chloroplasts, while the white fraction has proteins mainly originating from the cytoplasm.
The neighbouring powers took advantage of the situation: the Habsburg Monarchy annexed the northwestern part of Moldavia, or Bukovina, in 1775, and the Russian Empire seized the eastern half of Moldavia, or Bessarabia, in 1812. A census revealed that the Romanians were more numerous than any other ethnic group in Transylvania in 1733, but legislation continued to use contemptuous adjectives (such as "tolerated" and "admitted") when referring to them. The Uniate bishop, Inocențiu Micu-Klein, who demanded recognition of the Romanians as the fourth privileged nation, was forced into exile. Uniate and Orthodox clerics and laymen jointly signed a plea for the Transylvanian Romanians' emancipation in 1791, but the monarch and the local authorities refused to grant their requests.
== Career and research == He moved to the Department of Pharmaceutical Chemistry the University of California, San Francisco in the early 1970s. He founded the Molecular Design Institute at UCSF in 1993. He was awarded the UCSF medal in 2018.
Sources: en.wikipedia.org
Marcelino Arroyo, Francisco José de Caldas and Domingo de Petrés were great representatives of neo-classical architecture. The National Capitol is a great representative of romanticism. Wood was extensively used in doors, windows, railings, and ceilings during the colonization of Antioquia. The Caribbean architecture acquires a strong Arabic influence. The Teatro Colón in Bogotá is a lavish example of architecture from the 19th century. The quintas houses with innovations in the volumetric conception are some of the best examples of the Republican architecture; the Republican action in the city focused on the design of three types of spaces: parks with forests, small urban parks and avenues and the Gothic style was most commonly used for the design of churches. Deco style, modern neoclassicism, eclecticism folklorist and art deco ornamental resources significantly influenced the architecture of Colombia, especially during the transition period. Modernism contributed with new construction technologies and new materials (steel, reinforced concrete, glass and synthetic materials) and the topology architecture and lightened slabs system also have a great influence. The most influential architects of the modern movement were Rogelio Salmona and Fernando Martínez Sanabria. The contemporary architecture of Colombia is designed to give greater importance to the materials, this architecture takes into account the specific natural and artificial geographies and is also an architecture that appeals to the senses.
29 June – A spokesman for Reform UK confirms the party has dropped three candidates for making offensive comments. They are Edward Oakenfull (Derbyshire Dales), Robert Lomas (Barnsley North), and Leslie Lilley (Southend East and Rochford), but the candidates will still appear on the ballot paper as Reform candidates because it is too late for them to be removed. East Lothian Council becomes the third local authority to establish an emergency facility for people who have not received their postal votes. The Northern Ireland Conservatives launch their election manifesto with the help of Chris Heaton-Harris, the Secretary of State for Northern Ireland. Policies include upholding the Good Friday Agreement and continuing to invest in Northern Ireland. The Conservatives are fielding five candidates in Northern Ireland. 30 June – The Sunday Times endorses the Labour Party for the first time since the 2001 general election. Liam Booth-Isherwood, the Reform UK candidate for Erewash, disowns the party, citing a "significant moral issue" following recent reports of "widespread racism and sexism", and gives his backing to the Conservatives.
== History == TMA was first synthesized by Gordon Alles around 1937. He assessed it in both animal studies and self-experiments and documented its effects, but these were not reported until 1959. The drug was first described in the scientific literature in 1947 and its psychedelic effects were first described in 1955. TMA was studied at Edgewood Arsenal under the code name EA‐1319 in 1953 and 1954. The drug was further characterized by Alexander Shulgin and described in his 1991 book PiHKAL (Phenethylamines I Have Known and Loved).
Recent studies have shown that SK channels do not only regulate afterhyperpolarization, they also have an effect on synaptic plasticity. This is the activity-dependent adaptation of the strength of synaptic transmission. Synaptic plasticity is an important mechanism underlying learning and memory processes. Apamin is expected to influence these processes by inhibiting SK channels. It has been shown that apamin enhances learning and memory in rats and mice. This may provide a basis for the use of apamin as a treatment for memory disorders and cognitive dysfunction. However, due to the risk of toxic effects, the therapeutic window is very narrow. SK channel blockers may have a therapeutic effect on Parkinson's disease. Dopamine, which is depleted in this disease, will be released from midbrain dopaminergic neurons when these SK channels are inhibited. SK channels have also been proposed as targets for the treatment of epilepsy, emotional disorders and schizophrenia. Apamin at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
Sources: en.wikipedia.org
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.
Reported human trials are few, brief and originate mainly from one country. They describe effects on anxiety-related measures, but sample sizes are small and reporting is limited. The results are widely regarded as preliminary rather than confirmed.
Reverse-phase liquid chromatography is used to assess purity and separation of related impurities. Mass spectrometry confirms that the observed molecular mass matches the expected peptide. A certificate of analysis from the supplier is the usual document of record.
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.