A practical reference on Lyophilisation: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-01-08. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| 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 |
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.
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.
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.
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.
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.
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.
The Bergmann degradation begins with benzoylation at the alpha-group of a peptide and subsequent conversion to an acyl azide. As in the Curtius rearrangement, the acyl azide, in the presence of benzyl alcohol and heat, rearranges to a highly reactive isocyanate intermediate, releasing nitrogen gas in the process. The isocyanate in turn reacts with benzyl alcohol to form a benzylurethane (also referred to as carboxybenzyl), a compound possessing a carbamate amine protecting group. Subsequent removal of the carbamate protecting group is carried out by catalytic hydrogenation in the presence of hydrochloric acid followed by addition to boiling water, yielding an unstable intermediate that rapidly rearranges to release carbon dioxide, driving the reaction forward. This leads to further rearrangement and subsequent hydrolysis, ultimately resulting in the formation of an aldehyde bearing the next amino acid residue in the sequencing series and the expulsion of the residual peptide in amide form.
c7orf26 (accession: NM_024067 / NP_076972; alias: MGC-2178) is located on the long arm of chromosome 7 (7p22.1), starting at 6590021 and ending at 6608726. The c7orf26 gene spans 2178 base pairs and is orientated on the + strand. The coding region is made up of a protein sequence measuring 449 amino acids long. It is divided into 6 transcripts containing a total of 24 exons on the forward strand and has 5952 unique Single Nucleotide Polymorphisms (SNPs). Genes ZDHHC4, ZNF853 and ZNF316 neighbor c7orf26 on chromosome 7. Gene ZDHHC4 is a zinc-finger protein involved with cytochrome-c oxidase activity and protein-cysteine S-palmitoyltransferase activity and has overlapping regions with c7orf26. Gene GRID2IP lies upstream by >2000 bp of c7orf26, and is heavily involved with in synaptogenesis and synaptic plasticity. c7orf26 is highly expressed in lymphatic, reproductive, and nervous tissue. These include the brain (frontal and occipital cortex), thymus glands, salivary glands, endometrium, cervix, and prostate. It is intermediately expressed in the lungs.
input from rivers sulfate reduction and sulfide re-oxidation on continental shelves and slopes burial of anhydrite and pyrite in the oceanic crust. The primary natural source of sulfur to the atmosphere is sea spray or windblown sulfur-rich dust, neither of which is long lived in the atmosphere. In recent times, the large annual input of sulfur from the burning of coal and other fossil fuels has added a substantial amount of SO2 which acts as an air pollutant. In the geologic past, igneous intrusions into coal measures have caused large scale burning of these measures, and consequential release of sulfur to the atmosphere. This has led to substantial disruption to the climate system, and is one of the proposed causes of the Permian–Triassic extinction event. Dimethylsulfide [(CH3)2S or DMS] is produced by the decomposition of dimethylsulfoniopropionate (DMSP) from dying phytoplankton cells in the ocean's photic zone, and is the major biogenic gas emitted from the sea, where it is responsible for the distinctive “smell of the sea” along coastlines. DMS is the largest natural source of sulfur gas, but still only has a residence time of about one day in the atmosphere and a majority of it is redeposited in the oceans rather than making it to land. However, it is a significant factor in the climate system, as it is involved in the formation of clouds.
== Hazards == As a radioactive material, 226Ra and its decay products can present serious health hazards. Factory workers who worked with radium-containing luminous paint, known as the Radium Girls, often licked the tips of their paintbrushes in order to produce a finer point. In doing so, the workers ingested some of the radioactive paint; this eventually led to serious health problems including cancer, bone damage, and anemia. Several of these workers died from illnesses caused by radium exposure. Many rocks and soils contain low concentrations of 226Ra, which forms from the radioactive decay of naturally occurring uranium. The decay of 226Ra produces radon-222, a radioactive gas that can accumulate in inadequately ventilated homes and other enclosed spaces. Radon exposure is the second leading cause of lung cancer in the United States.
planets in the habitable zones of stars with low metallicity are the best targets to search for complex life on land." A university reports a study (29 Mar) affirming the high level of economic losses from biological invasions, showing they have risen to the level of economic damage costs from floods or earthquakes, which are also rising. 19 April A bolide is observed over Ukraine and Belarus for about five seconds. It is first observed at an altitude of 98 km above Velyka Dymerka, then passes directly above Kyiv at an altitude of 80 km and continues to the southwest with a speed of 29 km/s. A bright flare occurs at an altitude of 38 km, when the bolide's absolute magnitude reaches approximately −18. The likely cause of grey hair is shown to be pigment-making cells losing their ability to mature into melanocytes. Researchers show parrots can and enjoy to use a videocalling system. A study with mice shows that microplastics pass the blood–brain barrier (BBB), entering and accumulating in the brain, and identifies a key determinant for whether or not they pass the BBB. 20 April A new 29-year record of ice sheet mass in Greenland and Antarctica is published as part of the IMBIE collaboration. It finds that the combined ice loss in these regions has more than tripled since the early 1990s, with 2019 seeing the greatest losses of any year on record. These findings have implications for future sea level rise.
Sources: en.wikipedia.org
[...] None of the participants to the conflict saw the events of 7–8 August in isolation, nor present them as isolated. How those events are interconnected is essential to determining the story." Fawn and Nalbandov paid attention to the report that during the military exercise "Kavkaz 2008" in the North Caucasus, which concluded in early August, a leaflet entitled "Soldier, know your probable enemy" (describing Georgia), was distributed among the Russian trainees. Fawn and Nalbandov argued: "The Russian military measures were part of a Russian strategy and possibly a genuine belief that Moscow was acting in accordance with, and upholding, international law and norms." Fawn and Nalbandov also argued, "Different events, and different interlinkages, create the story. What is common is that every event is used rhetorically as the ‘start’, which justifies retaliation." The researchers noted that "each military clash led to mutual blame by the belligerent parties: each side accused the other of opening the first salvo and characterized its actions only as a response." The researchers concluded, "The August war did not come out of nowhere. [...] The precise ignition of the war rests on specific timing in the late hours of 7 August and early hours of 8 August, and when and why Russian armor traveled through the Roki tunnel from the Russian Federation into Georgia." In August 2012, Scott C. Monje, senior editor of the Encyclopedia Americana, argued: "Thus, provocations and incidents had become commonplace over the course of several years, and they frequently occurred in the summer.
== Growth and morphology == The filamentous non-soil associated fungus does not require any specific growth condition in culture. E. floccosum does not grow on urease culture, has low osmotolerance, and is unable to form perforating organs. The colonies have khaki suede-like flat surfaces and grow moderately rapidly, reaching maturity within 10 days. The reverse is reddish-brown. Colonies are initially flat, but the centre of which later becomes raised and folded, with the periphery submerged. On rich media like Sabouraud agar, colonies usually degenerate into white pleomorphic tufts within several weeks, and sometimes exude a red-brown pigment into its agar. E. floccosum has septate, hyaline hyphae. Its key features are the smooth, thin-walled, club-shaped macroconidia and the absence of microconidia. The macroconidia are borne singly or in clusters of 2 or 3; they are 20–40 μm in length and 7–12 μm in width, consisting of 1 to 9 septa. The narrow base and broad, club-shaped apex of the macroconidium have been compared in shape to a beaver tail. The fungus reproduces asexually through chlamydoconidia, which are resting spores that are abundant in culture. Arthroconidia are also abundant in the culture, emerging as swollen cells alongside macroconidia formation; these thick-walled spores are resistant to heat and drying conditions.
== Structure == Some brands may have a pellet (spheroid) formulations (made by extrusion and spheronization) can be used for controlled release of the drug in the body whereas powder filled pellets generally cannot. The plastic spheres containing powder have micropores that open at varying pH levels, to maintain a mostly constant release during transit through the digestive tract. The spheres themselves, the outer shells, pass undigested in most patients. Other brands are thought to use ethylcellulose coatings to control drug release from pellets. Another use these medications have is that they can be given via NG tube, the pellets being very small. This makes them one of the few extended release oral medications that can be given by feeding tube.
The Global Cold Chain Alliance (GCCA) is an international trade association representing industries engaged in temperature-controlled warehousing, logistics and transportation. The alliance is headquarter in Arlington, Virginia in the United States. In 2007 the Global Cold Chain Alliance was formed through the merger of the International Association of Refrigerated Warehouses (IARW) and International Refrigerated Transportation Association (IRTA), when leaders of both organisations realised that global supply chain depends on transportation and warehousing working closely together. The World Food Logistics Organization (WFLO) would later join as a core partner of the alliance as well as the Controlled Environment Building Association (CEBA). The GCCA serves as the central coordinating body for these associations, promoting best practices, advocacy, and industry development worldwide.
Taxidermy is the art of preserving an animal's body by mounting (over an armature) or stuffing, for the purpose of display or study. Animals are often, but not always, portrayed in a lifelike state. The word taxidermy describes the process of preserving the animal, but the word is also used to describe the end product, which are called taxidermy mounts or referred to simply as "taxidermy". The word taxidermy is derived from the Ancient Greek words τάξις taxis (order, arrangement) and δέρμα derma (skin). Thus taxidermy translates to "arrangement of skin". Taxidermy is practiced primarily on vertebrates (mammals, birds, fish, reptiles, and less commonly on amphibians) but can also be done to larger insects and arachnids under some circumstances. Taxidermy takes on a number of forms and purposes including hunting trophies and natural history museum displays. Unlike meat harvesting, taxidermy does not require killing an animal that could have otherwise remained alive. Museums use taxidermy as a method to record species, including those that are extinct and threatened, in the form of study skins and life-size mounts. Taxidermy is sometimes also used as a means to memorialize pets. A person who practices taxidermy is called a taxidermist. They may practice professionally, catering to museums and sportspeople (hunters and fishers), or as amateurs (hobbyists). A taxidermist is aided by familiarity with anatomy, sculpture, painting, and tanning.
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.
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.