Everything below concerns nootropic. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
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.
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.
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.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
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.
== Cultural references == British archaeologist and anthropologist Don Brothwell's The Bog Man and the Archaeology of People provides an account of the modern scientific techniques employed to conserve and analyse Lindow Man. Celtic history, language and lore scholar Anne Ross and archaeological chemist Don Robins's The Life and Death of a Druid Prince provides an account of the circumstances surrounding Lindow Man's life and death, in part hypothesising that he had lived as a highborn, perhaps even as a druid who was sacrificed to the gods at the time of the Menai Massacre and Boudica's rebellion.
Materials and samples from the original experiments remained in 2017 under the care of Miller's former student, Jeffrey Bada, a professor at the UCSD, Scripps Institution of Oceanography who also conducts origin of life research. As of 2013, the apparatus used to conduct the experiment was on display at the Denver Museum of Nature and Science.
Until May 1943, almost all penicillin was produced using the shallow-pan method pioneered by the Oxford team, but NRRL mycologist Kenneth Bryan Raper experimented with deep submergence production, in which penicillin mould was grown in a vat instead of a shallow dish. The initial results were disappointing; penicillin cultured in this manner yielded only three to four Oxford units per cubic centimetre, compared to twenty for surface cultures. He got the help of U.S. Army's Air Transport Command to search for similar mould in different parts of the world. Good moulds were found in samples from Chongqing, Bombay and Cape Town. The best sample, however, was from a cantaloupe sold in a Peoria fruit market in 1943. The mould was identified as Penicillium chrysogenum and designated as "NRRL 1951" or "cantaloupe strain". The spores may have escaped from the NRRL. Between 1941 and 1943, Moyer, Coghill and Raper developed methods for industrialized penicillin production and isolated higher-yielding strains of the Penicillium fungus. To improve upon that strain, researchers at the Carnegie Institution of Washington subjected NRRL 1951 to X-rays to produce a mutant strain designated X-1612 that produced 300 milligrams of penicillin per litre of mould culture, twice as much as NRRL 1951. In turn, researchers at the University of Wisconsin used ultraviolet radiation on X-1612 to produce a strain designated Q-176. This produced more than twice the penicillin of X-1612, but in the form of the less desirable penicillin K.
Birds have one of the most complex respiratory systems of all animal groups. Upon inhalation, 75% of the fresh air bypasses the lungs and flows directly into a posterior air sac which extends from the lungs and connects with air spaces in the bones and fills them with air. The other 25% of the air goes directly into the lungs. When the bird exhales, the used air flows out of the lungs and the stored fresh air from the posterior air sac is simultaneously forced into the lungs. Thus, a bird's lungs receive a constant supply of fresh air during both inhalation and exhalation. Sound production is achieved using the syrinx, a muscular chamber incorporating multiple tympanic membranes which diverges from the lower end of the trachea; the trachea being elongated in some species, increasing the volume of vocalisations and the perception of the bird's size. In birds, the main arteries taking blood away from the heart originate from the right aortic arch (or pharyngeal arch), unlike in the mammals where the left aortic arch forms this part of the aorta. The postcava receives blood from the limbs via the renal portal system. Unlike in mammals, the circulating red blood cells in birds retain their nucleus.
Officers / Ceremonial dress (מדי שרד madei srad) – worn by officers, or during special events/ceremonies. Dress uniform and mess dress – worn only abroad. There are several dress uniforms depending on the season and the branch. The service uniform for all ground forces personnel is olive green. The uniforms consist of a two-pocket shirt, combat trousers, sweater, jacket or blouse, and shoes or boots. The green fatigues are the same for winter and summer and heavy winter gear is issued as needed. Women's dress parallels the men's but may substitute a skirt for the trousers. Headgear included a service cap for dress and semi-dress and a field cap or "Kova raful" bush hat worn with fatigues. IDF personnel generally wear berets in lieu of the service cap and there are many beret colors issued to IDF personnel. Paratroopers are issued a maroon beret, Golani brown, Givati purple, Nahal lime green, Kfir camouflage, Combat Engineers gray. Other beret colors are: black for armored corps, turquoise for artillery personnel. For all other ground personnel, except combat units, the beret for men was green and for women, black. In combat uniforms the Orlite helmet has replaced the British Brodie helmet Mark II/Mark III, RAC Mk II modified helmet with chin web jump harness used by paratroopers and similar to the HSAT Mk II/Mk III paratrooper helmets, US M1 helmet, and French Modèle 1951 helmet – previously worn by Israeli infantry and airborne troops from the late 1940s to the mid-1970s and early 1980s.
Sources: en.wikipedia.org
NADPH deficiency can cause a dysfunction in glutathione peroxidase which is an enzyme that converts hydrogen peroxide (a reactive oxygen species) into water. G6PD (glucose-6-phosphate dehydrogenase) deficiency exacerbated by administration of oxidant drugs (e.g., primaquine, dapsone, quinidine) can also result in Heinz bodies. G6PD deficient red cells in combination with high levels of oxidants causes a cross-linking of sulfhydryl groups on globin chains which causes a denaturing and formation of Heinz body precipitates. Heinz bodies can also be found in chronic liver disease. Alpha-thalassemia. Normal adult hemoglobin is composed of two alpha and two beta chains. Alpha thalassemia patients have partial or complete defects in alpha globin production, leading to a relative abundance of beta globin chains in the cell. These excess beta globin chains aggregate to form HbH, which has decreased solubility and precipitates in the red blood cell cytoplasm. This is not direct damage to hemoglobin per se, but rather a perturbation in the quaternary structure of hemoglobin. The presence of Heinz bodies may also be a feature of hyposplenism or asplenia, when a damaged or absent spleen cannot remove these damaged cells from circulation.
So, Stan Lee as a guy who is working for the Watchers was something that I thought was fun for the MCU." Feige added that Lee "clearly exists, you know, above and apart from the reality of all the films. So the notion that he could be sitting there on a cosmic pit stop during the jump gate sequence in Guardians...really says, so wait a minute, he's this same character who's popped up in all these films?" Following Lee's death, Marvel Studios chose not to create any new Lee cameos in future projects. NY1 news anchor Pat Kiernan has also appeared in multiple MCU films and television series as himself.
== Caesium-134 == Caesium-134 has a half-life of 2.0650 years. It is produced both directly (at a very small yield because 134Xe is stable) as a fission product and via neutron capture from nonradioactive 133Cs (neutron capture cross section 29 barns), which is a common fission product. It is not produced by nuclear weapons because 133Cs is created by beta decay of original fission products long after the nuclear explosion is over. The combined yield of 133Cs and 134Cs is given as 6.7896%. The proportion between the two will change with continued neutron irradiation. 134Cs also captures neutrons with a cross section of 140 barns, becoming long-lived radioactive 135Cs. Caesium-134 undergoes beta decay (β−), producing stable 134Ba after emitting on average 2.23 gamma ray photons (mean energy 0.698 MeV).
=== Mechanism of action === Insulin glargine differs from human insulin by replacing asparagine with glycine in position 21 of the A-chain and by carboxy-terminal extension of B-chain by 2 arginine residues. The arginine amino acids shift the isoelectric point from a pH of 5.4 to 6.7, making the molecule more soluble at an acidic pH and less soluble at physiological pH. The isoelectric shift also allows for the subcutaneous injection of a clear solution. The glycine substitution prevents deamidation of the acid-sensitive asparagine at acidic pH. In the neutral subcutaneous space, higher-order aggregates form, resulting in a slow, peakless dissolution and absorption of insulin from the site of injection.
{\displaystyle P(t)=e^{Qt}={\begin{pmatrix}p_{\mathrm {AA} }(t)&p_{\mathrm {AC} }(t)&p_{\mathrm {AG} }(t)&p_{\mathrm {AT} }(t)\\p_{\mathrm {CA} }(t)&p_{\mathrm {CC} }(t)&p_{\mathrm {CG} }(t)&p_{\mathrm {CT} }(t)\\p_{\mathrm {GA} }(t)&p_{\mathrm {GC} }(t)&p_{\mathrm {GG} }(t)&p_{\mathrm {GT} }(t)\\p_{\mathrm {TA} }(t)&p_{\mathrm {TC} }(t)&p_{\mathrm {TG} }(t)&p_{\mathrm {TT} }(t)\end{pmatrix}}}
Sources: en.wikipedia.org
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.