The short version of elevated plus maze fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-10. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid form |
| Solubility class | Freely soluble in water | Hydrophilic heptapeptide |
| Dry storage temperature | -20 degrees Celsius or lower | Sealed, desiccated, protected from light |
| Solution storage | 2 to 8 degrees Celsius short term | Avoid repeated freeze-thaw cycles |
| Common identification method | Reversed-phase HPLC with mass spectrometry | Confirms purity and molecular mass |
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
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.
=== Portland cement blend === Portland cement blends are often available as inter-ground mixtures from cement producers, but similar formulations are often also mixed from the ground components at the concrete mixing plant. Portland blast-furnace slag cement, or blast furnace cement (ASTM C595 and EN 197-1 nomenclature respectively), contains up to 95% ground granulated blast furnace slag, with the rest Portland clinker and a little gypsum. All compositions produce high ultimate strength, but as slag content is increased, early strength is reduced, while sulfate resistance increases and heat evolution diminishes. Used as an economic alternative to Portland sulfate-resisting and low-heat cements. Portland-fly ash cement contains up to 40% fly ash under ASTM standards (ASTM C595), or 35% under EN standards (EN 197–1). The fly ash is pozzolanic, so that ultimate strength is maintained. Because fly ash addition allows a lower concrete water content, early strength can also be maintained. Where good quality cheap fly ash is available, this can be an economic alternative to ordinary Portland cement. Portland pozzolan cement includes fly ash cement, since fly ash is a pozzolan, but also includes cements made from other natural or artificial pozzolans. In countries where volcanic ashes are available (e.g., Italy, Chile, Mexico, the Philippines), these cements are often the most common form in use. The maximum replacement ratios are generally defined as for Portland-fly ash cement. Portland silica fume cement.
=== Negative symptoms === Negative symptoms are those for which function is lost: muscle weakness, atrophy, numbness, diminished or absent reflexes. These symptoms represent a conduction blockade where nerve signals can't be adequately transmitted along the length of the nerve. These symptoms are caused specifically by metabolic blocks, demyelination, and axonmetesis. A metabolic block is the temporary deprivation of nourishment from the blood supply which is readily reversed if the ischema does not last too long. Demyelination will interfere with conduction of signals along the nerve. Axonmetesis will result in a complete conduction block as Wallerian degeneration will destroy every part of the axon distal to the lesion if/until the axon regrows completely to its most distal innervation target.
Current models of addiction from chronic drug use involve alterations in gene expression in certain parts of the brain, particularly the nucleus accumbens. The most important transcription factors that produce these alterations are ΔFosB, cAMP response element binding protein (CREB), and nuclear factor kappa B (NFκB). ΔFosB plays a crucial role in the development of drug addictions, since its overexpression in D1-type medium spiny neurons in the nucleus accumbens is necessary and sufficient for most of the behavioral and neural adaptations that arise from addiction. Once ΔFosB is sufficiently overexpressed, it induces an addictive state that becomes increasingly more severe with further increases in ΔFosB expression. It has been implicated in addictions to alcohol, cannabinoids, cocaine, methylphenidate, nicotine, opioids, phencyclidine, propofol, and substituted amphetamines, among others. ΔJunD, a transcription factor, and G9a, a histone methyltransferase enzyme, both directly oppose the induction of ΔFosB in the nucleus accumbens (i.e., they oppose increases in its expression). Sufficiently overexpressing ΔJunD in the nucleus accumbens with viral vectors can completely block many of the neural and behavioral alterations seen in chronic drug use (i.e., the alterations mediated by ΔFosB). ΔFosB also plays an important role in regulating behavioral responses to natural rewards, such as palatable food, sex, and exercise.
10 June The VC announced that it had selected leaders for its "Provisional Revolutionary Government of the Republic of South Vietnam" (PRG), a "government in exile" to assume leadership if the VC and North Vietnam were successful in conquering South Vietnam. Former South Vietnamese lawyer and VC president Nguyễn Hữu Thọ was named as chairman of the advisory council to the PRG, and Huỳnh Tấn Phát was named the PRG Council President.
Sources: en.wikipedia.org
== Unlikely scenarios == While the scientific consensus is that SARS-CoV-2 derived from viruses hosted in bats, the precise means by which this occurred has been sometimes subject to speculation. Below are some scenarios judged to be unlikely.
==== Cold Climate Ration ==== The Cold Climate Ration (CCR) is a specialist and lightweight, high calorie 24 hour ration designed for use by troops above the snow line or in the high Arctic. It comprises mainly dehydrated main meals with a range of snacks designed to be eaten on the go. There are 8 menu choices available. The cold climate ration provides a minimum of 5500 kcals (23,030 kJ) a day.
{\displaystyle T\leq {\frac {abc}{2}}{\sqrt {\frac {a+b+c}{a^{3}+b^{3}+c^{3}+abc}}}\leq {\frac {1}{4}}{\sqrt[{6}]{\frac {3(a+b+c)^{3}(abc)^{4}}{a^{3}+b^{3}+c^{3}}}}\leq {\frac {\sqrt {3}}{4}}(abc)^{\frac {2}{3}}.}
The jacket harness, also known as AR vest, is a waistcoat (vest) style garment with strong adjustable webbing straps which are adjustable and securely buckled over the shoulders, across the chest and waist, and through the crotch or around each thigh, so that the diver can not slide out under any predictable circumstance. The harness is fitted with several heavy duty D-rings, fixed to the webbing in such a way that the full weight of the diver and all their equipment can be safely supported. A minimum strength for a safe working load of 500 kgf is recommended or required by some codes of practice. A jacket harness is usually provided with webbing straps or a cloth pocket on the back to support the bailout cylinder, may have a variety of pockets to carry tools, and may also carry ditchable or fixed main weights. There are usually several strong D-rings to secure the umbilical and other equipment.
He received a B.S. in physics in 1943. He did not attend graduate school, instead deciding to join the Fighting Vehicles Research Establishment where he served between 1943 and 1947 developing tank fire-control systems.
Sources: en.wikipedia.org
Half-Life: Alyx received "universal acclaim", according to the review aggregator website Metacritic. According to the review aggregator OpenCritic, it was recommended by 97% of critics. By April 2020, it was one of the 20 highest-rated PC games on Metacritic. VG247, TechRadar and Video Games Chronicle described it as VR's "killer app". The announcement trailer was watched more than 10 million times within the first 24 hours of its release. Though most fans expressed excitement, some were disappointed that Alyx was only available in VR, a small but growing market in 2019. Vic Hood of TechRadar expressed enthusiasm but wrote that "we forever live in hope" for Half-Life 3. Kevin Webb of Business Insider wrote that Alyx could "spark fresh interest in an industry [VR] that has struggled to win over hardcore gamers". Andrew King of USGamer suggested that Alyx would test whether the modding community would embrace VR, a difficult area to work in. In IGN, Dan Stapleton wrote that Alyx was one of the best shooter games and the best VR shooter by far. He felt that Valve "set a new bar for VR in interactivity, detail, and level design ... It feels like a game from the future, and one that the rest of VR gaming will likely take a good long while to match, much less surpass." In Polygon, Ben Kuchera wrote of how Alyx transformed FPS systems. For example, he felt that reloading guns, traditionally performed with a button press, was more fun in VR. He wrote: "The magic lies in being inside the world, being able to touch it, and interact with it, directly.
=== Development === Parafollicular cells are derived from pharyngeal endoderm. Embryologically, they associate with the ultimopharyngeal body, which is a ventral derivative of the fourth (or fifth) pharyngeal pouch. Parafollicular cells were previously believed to be derived from the neural crest based on a series of experiments in quail-chick chimeras. However, lineage tracing experiments in mice revealed that parafollicular cells are derived from the endoderm origin.
=== Symmetrical flow === Of these techniques flow FFF was the first to be offered commercially. Flow FFF separates particles based on size, independent of density and can measure macromolecules in the range of 1 nm to 1 μm. In this respect it is the most versatile FFF sub-technique available. The cross flow in Flow FFF enters through a porous frit at the top of the channel, exiting through a semi-permeable membrane outlet frit on the accumulation wall (i.e. the bottom wall). Symmetrical flow has been replaced by asymmetrical flow in the last two decades.
Local flaps are created by freeing a layer of tissue and then stretching the freed layer to fill a defect. This is the least complex type of flap and includes advancement flaps, rotation flaps, and transposition flaps, from least to most complex respectively. With an advancement flap, incisions are extended out parallel from the wound, creating a rectangle with one edge remaining intact. This rectangle is freed from the deeper tissues and then stretched (or advanced) forward to cover the wound. The flap is disconnected from the body, except for the uncut edge which contains the blood supply which feeds in horizontally. A rotation flap is similar except that, instead of being stretched in a straight line, the flap is stretched in an arc. The more complex transposition flap involves rotating an adjacent piece of tissue, resulting in the creation of a new defect that must then be closed. Regional or interpolation flaps are not immediately adjacent to the defect. Instead, the freed tissue "island" is moved over or underneath normal tissue to reach the defect to be filled, with the blood supply still connected to the donor site via a pedicle. The pedicle can be removed after a new blood supply has formed. Examples: pectoralis major myocutaneous flap and deltopectoral flap for head and neck defects, and latissimus dorsi flap and traverse rectus abdominal muscle (TRAM) flap for breast reconstruction. Distant flaps are used when the donor site is far from the defect. These are the most complex class of flap.
Sources: en.wikipedia.org
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.
Reversed-phase HPLC establishes purity, while mass spectrometry confirms the expected molecular mass. Sequence confirmation may use tandem mass spectrometry or peptide mapping. A certificate of analysis typically reports these results alongside the analytical method applied.
In Russia it is a registered medicine available by prescription. In many other countries it is not approved for human use and is supplied only as a research chemical. Import and possession rules differ by jurisdiction, and buyers are responsible for checking local requirements.
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.