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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.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
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.
| 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 |
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
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.
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.
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.
Since DisplayPort's introduction in 2006, it has gained popularity within the computer industry and is featured on many graphics cards, displays, and notebook computers. Dell was the first company to introduce a consumer product with a DisplayPort connector, the Dell UltraSharp 3008WFP, which was released in January 2008. Soon after, AMD and Nvidia released products to support the technology. AMD included support in the Radeon HD 3000 series of graphics cards, and Nvidia first introduced support in the GeForce 9 series starting with the GeForce 9600 GT.
== Adverse effects == Protamine has been reported to cause allergic reactions in patients who are allergic to fish, diabetics using insulin preparations containing protamine, and vasectomized or infertile men. These occur at rates ranging from 0.28% to 6%. Avoiding rapid infusion of protamine sulfate and pre-treating at-risk patients with histamine receptor antagonists (H1 and H2) and steroids may minimize these reactions. A 5 to 10 mg test dose is recommended following pretreatment before administering the full dose.
One way is to fuse modular binding sites (e.g., MS2 RNA tagging system, or RIDD-RIAD dock-and-lock system) to the phase-separating domain (e.g., synthetic RNA repeat, or IDP) that recruit "solute" or "client" of interest. Such a modular design enables engineering, optimization, and reusability of each fusion molecule, thus commonly applied in synthetic biology and metabolic engineering. Moreover, by applying a relatively slower binding system (e.g., split GFP), the recruitment of target into synthetic condensate can be fine-tuned by growth and division rates of the living cells. Another way to gain temporal control over the formation and dissolution of biomolecular condensates is by using optogenetic tools. Several different systems have been developed which allow for control of condensate formation and dissolution which rely on chimeric protein expression, and light or small molecule activation. In one system, proteins are expressed in a cell which contain light-activated oligomerization domains fused to IDRs. Upon irradiation with a specific wavelength of light, the oligomerization domains bind each other and form a 'core', which also brings multiple IDRs close together because they are fused to the oligomerization domains. The recruitment of multiple IDRs effectively creates a new biopolymer with increased valency. This increased valency allows for the IDRs to form multivalent interactions and trigger LLPS. When the activation light is stopped, the oligomerization domains disassemble, causing the dissolution of the condensate.
The fifth chain reversal occurs in the region of residues 22–28, which fulfill the criteria for an i2-loop. The C-terminal extension, stabilized by the Cys16-Cys42 disulfide bond, consists of three y-turns, VI-VIII, that are, respectively, an inverse turn, centered on Thr33, a classic turn centered on Ile35 and an inverse turn centered on Phe39. All three of the y-turn hydrogen bonds have slowly exchanging amide protons (although this is not the case for the other turns). The only slowly exchanging amide proton not accounted for by consensus hydrogen bonds in any secondary structure element is that of Gly37 (which hydrogen bonds to Thr34 in one of the structures). The conformations of the Cys1-Cys15 and Cys8-Cys20 disulfide bonds are well defined and have negative and positive Xss, respectively; the other two bonds have lower order parameters. The hydrophobic core of RBX is limited, consisting of essentially the disulfide knot cystine residues and the buried Met18. The 22-28 loop contains one apolar residue, Ala23, and three aromatics, Tyr22, Trp24 and Tyr25, and is flanked by Ile21 at its N-terminus and Trp7 near its C-terminus, so this region represents a significant non-polar surface on the molecule. RBX is highly positively charged, with one Arg (sequence position 5) and six Lys (3, 4, 10, 19, 40 and 41) residues, balanced only by Glu12 and Asp13. These charged residues form three patches on the surface.
Sources: en.wikipedia.org
North Carolina State University's College of Veterinary Medicine in Raleigh, North Carolina, uses both plastic coating (PC) and plastination (PN) to investigate and compare the difference in the two methods. The PC method was simple and inexpensive, but the PN specimens were more flexible, durable, and lifelike than those preserved by the PC method. The use of plastination allowed the use of many body parts such as muscle, nerves, bones, ligaments, and central nervous system to be preserved. The University of Texas Health Science Center at San Antonio was the first school in the United States to use this technique to prepare gross organ specimens for use in teaching. The New York University College of Dentistry, Philadelphia College of Osteopathic Medicine, University of Warwick, and University of Northumbria use collections of plastinates as teaching aids. The University of Vienna and the University of Sheffield have their own plastination laboratories. The first medical school in India to have a plastination lab was A.I.I.M.S, New Delhi with others following suit like Christian Medical College, Vellore, Government Institute of Medical Sciences, Greater Noida etc.
they contain all the element's isotopes in unnatural abundances, calculations of enrichment of multiple isotope tracers must account for the perturbation of each isotope ratio by the presence of the other tracers. Due to the prevalence of mineral deficiencies and their critical impact on human health and well-being in resource-poor countries, the International Atomic Energy Agency has recently published detailed and comprehensive descriptions of stable isotope methods to facilitate the dissemination of this knowledge to researchers beyond western academic centers.
Graphene is chemically dormant, mechanically sturdy, and non-permeable to gas or liquid. So, carbon plays a major role for fabrication of nanomaterials with porous nature. Graphene membranes that are formed by graphene oxide molecules or chemically converted graphene that is adhered with 2D nano mediated arrays have the ability to efficiently separate molecules in a gas or in a liquid phase. Graphene-coated nanomembranes are said to be more applicable in water treatment due to its unique properties. Graphene membranes are obtained from vacuum filtration or coating of graphene oxide solution as Graphene oxide sheets. The graphene coated nanofiltration membrane showed a higher water flux range. The graphene embedded with carbon nanotubes to serve as nanofilters is more useful for dye rejection in water effluent, removal of salt ions, and also acts as antifouling agent. Graphene nanofilter membranes possess effective antifouling agent due to its strong bond between graphene sheets and proteins. Also, graphene oxide coated nanofilter membranes helps in dechlorination of water. In addition to this, ultrathin nanofilter coated with graphene is the most potent filter that could be commercialized for water purification. Graphene oxide membranes can be used in various forms such as free, surface modified, and graphene cast in membranes in the range of micro, nano, or ultrafilters. Among which nanofilters is more efficient for water desalination due to its mechanical strength and physiochemical properties of the membrane.
However, insulin therapy may be conducted without CGM and although there is not yet an automated insulin-regulation feedback mechanism between measure and infusion to control the amount and timing of insulin, this is clearly a future objective. Any change in basal or bolus is patient-driven by programming the pump using the Bolus Wizard. The latest model pumps are the MiniMed Paradigm 522 and 722, which differ in reservoir size, 176 versus 300 units, respectively. In 2007 the FDA approved a pediatric model for patients 7 to 17 years old.
After the war, part of the Great Chain was saved for posterity and the rest relegated to the West Point Foundry furnaces near Cold Spring, New York, to be melted down. A saved portion was first displayed at the West Point ordnance compound, along with a captured mortar, as shown in a 1905 drawing. Thirteen links are displayed at Trophy Point, one for each of the Thirteen Colonies. Also included are a swivel and clevis. The exhibit is maintained and preserved by the West Point Museum. A section of boom recovered from the river in 1855 is displayed at Washington's Headquarters State Historic Site in Newburgh, New York. Two links of the original chain are also at Raynham Hall in Oyster Bay, New York, the home of Robert Townsend, a cousin of iron works owner Peter Townsend, and (as "Culper Jr") a member of George Washington’s Culper spy ring. Bilking the gullible, John C. Abbey, and later Pollepel Island owner Francis Bannerman, sold counterfeit chain links to collectors and museums.
Sources: en.wikipedia.org
In 2011 the committee concluded that the presence of numerous uncertainties and knowledge gaps regarding the effects of heroin treatment meant that it could not recommend the introduction of heroin maintenance treatment in Norway. Critics of heroin maintenance programmes object to the high costs of providing heroin to people who use it. The British heroin study cost the British government £15,000 per participant per year, roughly equivalent to average person who uses heroin's expense of £15,600 per year. Drug Free Australia contrast these ongoing maintenance costs with Sweden's investment in, and commitment to, a drug-free society where a policy of compulsory rehabilitation of people who are experiencing drug addiction is integral, which has yielded to one of the lowest reported illicit drug use levels in the developed world, a model in which successfully rehabilitated people who use substances present no further maintenance costs to their community, as well as reduced ongoing health care costs. King's Health Partners notes that the cost of providing free heroin for a year is about one-third of the cost of placing the person in prison for a year.
=== Beta-carotene === Sunless-tanning pills often contain β-carotene. The American Cancer Society states that "Although the US Food and Drug Administration (FDA) has approved some of these additives for coloring food, they are not approved for use in tanning agents." Also that "They may be harmful at the high levels that are used in tanning pills." Chronic, high doses of synthetic β-carotene supplements have been associated with increased rate of lung cancer among those who smoke.
Molybdenum(II) chloride MoCl2, which exists as the hexamer Mo6Cl12 and the related dianion [Mo6Cl14]2-. Molybdenum(III) chloride MoCl3, a dark red solid, which converts to the anion trianionic complex [MoCl6]3-. Molybdenum(IV) chloride MoCl4, a black solid, which adopts a polymeric structure. Molybdenum(V) chloride MoCl5 dark green solid, which adopts a dimeric structure. Molybdenum(VI) chloride MoCl6 is a black solid, which is monomeric and slowly decomposes to MoCl5 and Cl2 at room temperature. The accessibility of these oxidation states depends quite strongly on the halide counterion: although molybdenum(VI) fluoride is stable, molybdenum does not form a stable hexachloride, pentabromide, or tetraiodide. Like chromium and some other transition metals, molybdenum forms quadruple bonds, such as in Mo2(CH3COO)4 and [Mo2Cl8]4−. The Lewis acid properties of the butyrate and perfluorobutyrate dimers, Mo2(O2CR)4 and Rh2(O2CR) 4, have been reported. The oxidation state 0 and lower are possible with carbon monoxide as ligand, such as in molybdenum hexacarbonyl, Mo(CO)6.
== Biosafety == Xenobiological systems are designed to convey orthogonality to natural biological systems. A (still hypothetical) organism that uses XNA, different base pairs and polymerases and has an altered genetic code will hardly be able to interact with natural forms of life on the genetic level. Thus, these xenobiological organisms represent a genetic enclave that cannot exchange information with natural cells. Altering the genetic machinery of the cell leads to semantic containment. In analogy to information processing in IT, this safety concept is termed a "genetic firewall". The concept of the genetic firewall seems to overcome a number of limitations of previous safety systems. A first experimental evidence of the theoretical concept of the genetic firewall was achieved in 2013 with the construction of a genomically recoded organism (GRO). In this GRO all known UAG stop codons in E.coli were replaced by UAA codons, which allowed for the deletion of release factor 1 and reassignment of UAG translation function. The GRO exhibited increased resistance to T7 bacteriophage, thus showing that alternative genetic codes do reduce genetic compatibility. This GRO, however, is still very similar to its natural "parent" and cannot be regarded to have a genetic firewall. The possibility of reassigning the function of large number of triplets opens the perspective to have strains that combine XNA, novel base pairs, new genetic codes, etc. that cannot exchange any information with the natural biological world.
It has also been shown to possess significant neutralizing activity against gram-positive and gram-negative bacteria, with slightly higher activity against gram-positive organisms. Many plant derived compounds have demonstrated potential as therapeutic tools. In one study sugiol showed efficacy in treating Leishmania infantum, a parasite that can cause Leishmaniasis in humans. Free sugiol was able to induce cell-death in the parasitic bacteria, and when encased in cell walls obtained from yeast was able to enter a parasitized macrophage and inhibit the L. infantum within. Because sugiol has shown so many protective effects in therapeutic trials, it is likely that in plants it acts as a chemical defense agent. Sugiol present in the resins of conifers may help to protect the plant against ROS generated during metabolism, as well as against any pathogenic viruses or bacteria.
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.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.