This is a working overview of Research chemical, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-25 and is reviewed periodically as new material appears.
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.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
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.
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.
====== Turnout ====== An analysis released by Democratic-leaning data firm Catalist in May 2025 found that Trump's victory rested on support from voters who were less engaged with politics, as well as weakened support and turnout for Harris from a range of Democratic-leaning groups. Nearly half of the 2024 electorate cast ballots in the previous four federal elections, representing an increase of nine points from 2020 and seven points from 2016, and Harris won under 50 percent of these voters, outperforming Biden's and Hillary Clinton's respective performances. In contrast, Harris won 48 percent of voters who only voted in two or fewer of the previous four federal elections, underperforming Biden and Clinton, both of whom won at least 54 percent of those voters. Harris also won less than half of voters who did not cast a vote in 2020 but did so in 2024, compared to Biden and Clinton each winning roughly 55 percent of new voters in their respective elections; Catalist considered this Democratic underperformance to be unprecedented in their history of election analysis. Jennifer Agiesta of CNN reported that new and infrequent voters in 2024 were more likely to be from Democratic-leaning groups but also less likely to have college degrees, a trait increasingly tied to Republican support.
==== Neurological model ==== The theoretical underpinnings of Moniz's psychosurgery were largely commensurate with the nineteenth-century ones that had informed Burckhardt's decision to excise matter from the brains of his patients. Although in his later writings, Moniz referenced both the neuron theory of Ramón y Cajal and the conditioned reflex of Ivan Pavlov, in essence he simply interpreted this new neurological research in terms of the old psychological theory of associationism. He differed significantly from Burckhardt, however in that he did not think there was any organic pathology in the brains of the mentally ill, but rather that their neural pathways were caught in fixed and destructive circuits leading to "predominant, obsessive ideas". As Moniz wrote in 1936:
The photosynthetic partners, or photobionts, of X. parietina belong to the green algal genus Trebouxia, including Trebouxia arboricola and T. irregularis. These algae also exist independently in nature, occurring on both lichen-colonized and lichen-free bark. A study found that the photobiont occupies 7% of the thallus volume in X. parietina. Pigmentation density in the upper cortex varies, regulating light exposure to the algae. The Trebouxia photobiont adjusts its photosynthetic activity seasonally, supporting X. parietina in sunlit environments. As sunlight increases in spring, the photobiont reduces chlorophyll levels and produces protective pigments to dissipate excess light as heat. Chlorophyll concentrations are lowest in spring and peak in winter, balancing light absorption and photoprotection throughout the year. X. parietina associates with diverse photobionts. It primarily partners with Trebouxia decolorans when growing on bark and with T. arboricola on rock. Even within local populations, genetically distinct photobionts often coexist in adjacent thalli. One study identified 36 algal genotypes among 38 epiphytic samples from a single site. Despite T. decolorans being assumed to reproduce asexually, multiple algal strains sometimes occur within a single thallus, suggesting photobiont switching or thallus fusion. This diversity may contribute to X. parietina's adaptability across varied environments. Although free-living algae are abundant, X. parietina selectively associates with Trebouxia species.
== Discovery == RGD was identified as the minimal recognition sequence within fibronectin required for cell attachment by Ruoslahti and Pierschbacher in the early 1980s. To do this, the authors synthesized various peptides based on the hypothesized cell attachment site of fibronectin. They then coupled those peptides to protein-coated plastic and tested each for cell attachment-promoting activity. Only those that contained the RGD sequence were found to enhance cell attachment. Further, they showed that peptides containing RGD were able to inhibit cell attachment to fibronectin-coated substrates, whereas peptides not containing RGD did not. These foundational studies also identified the cellular receptors that recognize the sequence. These studies utilized a synthetic RGD-containing peptide to isolate the putative receptors, and then demonstrated that liposomes containing the isolated proteins could bind to fibronectin, in much the same way as cells with surface receptors. The discovered receptors were later named integrins. The RGD motif is presented in slightly different ways in different proteins, making it possible for the many RGD-binding integrins to selectively distinguish individual adhesion proteins.
Sources: en.wikipedia.org
The president of the Republic of the Union of Myanmar (Burmese: နိုင်ငံတော်သမ္မတ, MLCTS: nuing ngam tau samma.ta., lit. 'President of the State') is the head of state and head of government of Myanmar. The president chairs the National Defence and Security Council and leads the Union Government (Cabinet), the executive branch of the Myanmar government. The presidency was established in 1948, when Burma gained its independence from the British Empire. During this period, the president was the ceremonial head of state while prime minister is the actual head of government. The presidency was abolished following the 1962 coup d'etat, when Ne Win assumed the powers of both head of state and head of government as the Chairman of the Revolutionary Council and the Revolutionary Government. The 1974 Constitution reintroduced the presidency, to be held by the Chairman of the Council of State. The 1988 coup d'etat again led to the presidency's abolishment, with the Chairman of the State Law and Order Restoration Council (reconstituted in 1997 as the State Peace and Development Council) assuming the functions of the head of state. The 2008 Constitution introduced a presidential system, where the president is both the head of state and government. Thein Sein assumed the presidency in 2011. After the 2015 election, the extraconstitutional post of State Counsellor of Myanmar was created for Aung San Suu Kyi, the leader of the majority party, the National League for Democracy, because she was ineligible for the presidency.
=== Adhesives/coatings === Charged surfaces are often useful in creating surfaces that will not adsorb certain molecules (for example, in order to prevent the adsorption of basic proteins, a positively charged surface should be used). Polymers are very useful in this respect in that they can be functionalized so that they contain ionizable groups, which serve to provide a surface charge when submerged in an aqueous solution.
== June 2012 reconstitution == On 29 June 2012, the Ministry was reconstituted. This followed the retirement of Liz Constable (Education), the removal of Rob Johnson (Police; Road Safety) and the earlier resignation on 12 June of Christian Porter (Treasurer; Attorney General), whose duties had been temporarily split between Premier Colin Barnett and senior minister Norman Moore. Three new ministers were appointed from amongst the parliamentary secretary ranks, and three new secretaries were appointed to replace them. The list below is ordered by decreasing seniority within the Cabinet, as indicated by the Government Gazette and the Hansard index. Blue entries indicate members of the Liberal Party, while green entries indicate members of the National Party.
Pork heart can be stewed, poached, braised, or made into sausage. The Balinese oret is a sort of blood sausage made with pig heart and blood. A French recipe for cœur de porc à l'orange is made of braised heart with an orange sauce. Snake heart, called tim rắn in Vietnam, is sometimes a delicacy consumed in wine.
) to identify patterns such as sudden jumps or drops in stream power, these features can help identify locations where the local terrain controls the flow or widens out as well as areas prone to erosion.
Sources: en.wikipedia.org
Jake Carlisle (born 1 October 1991) is a former professional Australian rules footballer who played 66 games for the St Kilda Football Club in the Australian Football League (AFL) until his retirement at the end of the 2021 season. He previously played 85 games for the Essendon Football Club from 2010 to 2015.
LSD's psychedelic properties were discovered 5 years later when Hofmann himself accidentally ingested an unknown quantity of the chemical. The first intentional ingestion of LSD occurred on April 19, 1943, when Hofmann ingested 250 μg of LSD. He said this would be a threshold dose based on the doses of other ergot alkaloids; however, Hofmann found the effects to be much stronger than he anticipated. Information about synthesizing LSD was first published in scientific literature by Hofmann and his colleague, psychiatrist Werner Stoll in 1943; a description of LSD's hallucinogenic effects was later published by Stoll in 1947.
Gerald W. Hart, a founding figure of the field of glycobiology, discovered and performed much of the pioneering work on intracellular O-GlcNAcylation beginning in the 1980s at Johns Hopkins School of Medicine. Hart and colleagues were probing for terminal GlcNAc residues on the surfaces of thymocytes and lymphocytes. Bovine milk β-1,4-galactosyltransferase, which reacts with terminal GlcNAc residues, was used to perform radiolabeling with UDP-[3H]galactose. Loss of signal from the labeled galactose following β-elimination of serine and threonine residues demonstrated that most of it was attached to proteins O-glycosidically; chromatography revealed that the major β-elimination product was Galβ1-4GlcNAcitol. Insensitivity to peptide N-glycosidase treatment provided additional evidence for O-linked GlcNAc. Permeabilizing cells with detergent prior to radiolabeling greatly increased the amount of [3H]galactose incorporated into Galβ1-4GlcNAcitol, leading the authors to conclude that most of the O-linked GlcNAc monosaccharide residues were intracellular. This was in stark contrast to the prevailing understanding that protein glycosylation was nearly or entirely exclusive to the secretory pathway, as the topic was dominated by research of highly abundant extracellular mucin-type O-glycans.
Theories suggest the claustrum may act to bind and integrate multisensory information, or else to encode sensory stimuli as salient or nonsalient (Mathur, 2014). One theory suggests the claustrum harmonizes and coordinates activity in various parts of the cortex, leading to the seamless integrated nature of subjective conscious experience (Crick and Koch, 2005; Stiefel et al., 2014). Disrupting claustral activity may lead to conscious experiences of disintegrated or unusually bound sensory information, perhaps including synesthesia. Such theories are in part corroborated by the fact that [salvia divinorum], which functions almost exclusively on the KOR system, can cause consciousness to be decoupled from external sensory input, leading to experiencing other environments and locations, perceiving other "beings" besides those actually in the room, and forgetting oneself and one's body in the experience. From this perspective, disrupting claustral activity might lead to conscious experiences of disintegrated or unusually bound sensory information, including synesthesia. However, even early formulations acknowledged that their assumptions are merely tentative and that "KORs are not exclusive to the claustrum; there is also a fairly high density of receptors located in the prefrontal cortex, hippocampus, nucleus accumbens and putamen", and that "disruptions to other brain regions could also explain the consciousness-altering effects [of salvinorin A]".
Sources: en.wikipedia.org
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.