This is a working overview of Semax, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-10-04. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Dry storage temperature | -20 C or below | Sealed, desiccated, protected from light |
| Solution stability | Hours to days at 2-8 C | Depends on buffer and microbial load |
| Preferred pH range | Near neutral to slightly acidic | Alkaline pH accelerates hydrolysis |
| Main degradation routes | Hydrolysis and deamidation | No cysteine or methionine in sequence |
| Identity confirmation | Electrospray mass spectrometry | Observed mass compared with 751.9 Da |
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.
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.
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.
== Jeewanu protocell == A further protocell model is the Jeewanu. First synthesized in 1963 from simple minerals and basic organics while exposed to sunlight, it is reported to have some metabolic capabilities, the presence of a semipermeable membrane, amino acids, phospholipids, carbohydrates and RNA-like molecules. However, the nature and properties of the Jeewanu remains to be clarified. Electrostatic interactions induced by short, positively charged, hydrophobic peptides containing 7 amino acids in length or fewer can attach RNA to a vesicle membrane, the basic cell membrane.
This marked the first time in post-World War II history that the United States had withdrawn from a major international arms treaty. Russian president Vladimir Putin stated that American withdrawal from the ABM Treaty was a mistake. Bush emphasized a careful approach to the conflict between Israel and the Palestinians; he denounced Palestine Liberation Organization leader Yasser Arafat for his support of violence, but sponsored dialogues between Prime Minister Ariel Sharon and Palestinian National Authority president Mahmoud Abbas. Bush supported Sharon's unilateral disengagement plan, and lauded the democratic elections held in Palestine after Arafat's death. Bush also expressed U.S. support for the defense of Taiwan following the stand-off in April 2001 with China over the Hainan Island incident, when an EP-3E Aries II surveillance aircraft collided with a People's Liberation Army Air Force jet, leading to the detention of U.S. personnel. From 2003 to 2004, Bush authorized U.S. military intervention in Haiti and Liberia to protect U.S. interests. Bush condemned the militia attacks in Darfur and denounced the killings in Sudan as genocide. Bush said an international peacekeeping presence was critical in Darfur, but he opposed referring the situation to the International Criminal Court. On June 10, 2007, Bush met with Albanian Prime Minister Sali Berisha and became the first president to visit Albania. He later voiced his support for the independence of Kosovo.
== General overview == In its earliest manifestations, molecular biology—the name was coined by Warren Weaver of the Rockefeller Foundation in 1938—was an idea of physical and chemical explanations of life, rather than a coherent discipline. Following the advent of the Mendelian-chromosome theory of heredity in the 1910s and the maturation of atomic theory and quantum mechanics in the 1920s, such explanations seemed within reach. Weaver and others encouraged (and funded) research at the intersection of biology, chemistry and physics, while prominent physicists such as Niels Bohr and Erwin Schrödinger turned their attention to biological speculation. Schrödinger's 1944 book What Is Life? in particular inspired many to enter the emerging field, including guiding James Watson towards DNA research. However, in the 1930s and 1940s it was by no means clear which—if any—cross-disciplinary research would bear fruit; work in colloid chemistry, biophysics and radiation biology, crystallography, and other emerging fields all seemed promising. In 1940, George Beadle and Edward Tatum demonstrated the existence of a precise relationship between genes and proteins. In the course of their experiments connecting genetics with biochemistry, they switched from the genetics mainstay Drosophila to a more appropriate model organism, the fungus Neurospora; the construction and exploitation of new model organisms would become a recurring theme in the development of molecular biology.
In 2022, more than 1 billion adolescent girls and women suffered from undernutrition, according to UNICEF's 2023 report "Undernourished and Overlooked: A Global Nutrition Crisis in Adolescent Girls and Women". The gender gap in food insecurity more than doubled between 2019 (49 million) and 2021 (126 million). The report shows that globally, 30% of women aged 15–49 years are living with anaemia while 10 per cent of women aged 20–49 years suffer from underweight. South Asia, West and Central Africa and Eastern and Southern Africa are home to 60% of women with anaemia and 65% of women being underweight. In contrast, overweight is affecting more than 35% of women aged 20–49 years, of which 13% are living with obesity. The Middle East and North Africa has the highest prevalence of overweight with 61% affected. North America closely follows at 60%. Fewer than 1 in 3 adolescent girls and women have diets meeting the minimum dietary diversity in the Sudan (10%), Burundi (12%), Burkina Faso (17%) and Afghanistan (26%). In Niger, the percentage of women accessing a minimally diverse diet fell from 53% to 37% between 2020 and 2022. Researchers from the Centre for World Food Studies in 2003 found that the gap between levels of undernutrition in men and women is generally small, but that the gap varies from region to region and from country to country. These small-scale studies showed that female undernutrition prevalence rates exceeded male undernutrition prevalence rates in South/Southeast Asia and Latin America and were lower in Sub-Saharan Africa.
Article LV of Title III of the Concordat specified that "the registers kept by religious ministers, being and only concerning the administration of sacraments, cannot under any circumstances replace the registers required by law to document the civil status of French citizens." Nevertheless, these religious registers were largely used to reconstruct Paris's civil records after the 1871 disaster.
Sources: en.wikipedia.org
The pulmonary trunk divides into pulmonary arteries and progressively smaller arteries throughout the lungs, until it reaches capillaries. As these pass by alveoli carbon dioxide is exchanged for oxygen. This happens through the passive process of diffusion. In the left heart, oxygenated blood is returned to the left atrium via the pulmonary veins. It is then pumped into the left ventricle through the mitral valve and into the aorta through the aortic valve for systemic circulation. The aorta is a large artery that branches into many smaller arteries, arterioles, and ultimately capillaries. In the capillaries, oxygen and nutrients from blood are supplied to body cells for metabolism, and exchanged for carbon dioxide and waste products. Capillary blood, now deoxygenated, travels into venules and veins that ultimately collect in the superior and inferior vena cavae, and into the right heart.
==== Cardiotoxins / Cytotoxins ==== Cardiotoxins are components that are specifically toxic to the heart. They bind to particular sites on the surface of muscle cells and cause depolarisation → the toxin prevents muscle contraction. These toxins may cause the heart to beat irregularly or stop beating, causing death. An example is the three-fingered cardiotoxin III from Chinese cobra, an example of the short three-fingered family (InterPro: IPR003572). Snake example: mambas, and some Naja species
=== Canine osteoarthritis === LTCI increases the immune response to foreign antigens and dampens the immune-mediated response to self-antigens by increasing the number of precursors of a regulatory T-Cell population. In a double-blind placebo-controlled study, 11 of the 12 LTCI-treated canines had a 40 percent increase in function while the placebo group had a 17 percent decrease in function. Following the study, LTCI was approved by the USDA to treat osteoarthritis in dogs in 2016.
However, in the 2025 study, time to maximal effects was about 2.5 hours orally and about 1.2 hours intravenously. In an earlier 2016 study, intravenous LSD effects similarly peaked after about 1.7 hours. For comparison, intravenous dimethyltryptamine (DMT) given as a bolus has been found to produce maximal effects after about 2 minutes and intravenous psilocybin given over 60 seconds produces peak effects after about 4 minutes. Doses of LSD are said to be similar by oral and injectable routes, with the exception of intrathecal injection, in which the dose is reduced to about one-third of usual. The plasma protein binding of LSD in humans is unknown, but it is 65 to 90% bound to plasma proteins in guinea pigs.
Sources: en.wikipedia.org
Fully aquatic mammals, the cetaceans and sirenians, have lost their legs and have a tail fin to propel themselves through the water. Flipper movement is continuous. Whales swim by moving their tail fin and lower body up and down, propellling themselves through vertical movement, while their flippers are mainly used for steering. Their skeletal anatomy allows them to be fast swimmers. Most species have a dorsal fin to prevent themselves from turning upside-down in the water. The flukes of sirenians are raised up and down in long strokes to move the animal forward, and can be twisted to turn. The forelimbs are paddle-like flippers which aid in turning and slowing. Semi-aquatic mammals, like pinnipeds, have two pairs of flippers on the front and back, the fore-flippers and hind-flippers. The elbows and ankles are enclosed within the body. Pinnipeds have several adaptions for reducing drag. In addition to their streamlined bodies, they have smooth networks of muscle bundles in their skin that may increase laminar flow and make it easier for them to slip through water. They also lack arrector pili, so their fur can be streamlined as they swim. They rely on their fore-flippers for locomotion in a wing-like manner similar to penguins and sea turtles. Fore-flipper movement is not continuous, and the animal glides between each stroke. Compared to terrestrial carnivorans, the fore-limbs are reduced in length, which gives the locomotor muscles at the shoulder and elbow joints greater mechanical advantage; the hind-flippers serve as stabilizers.
=== Hazards === When taken in prescribed quantities, codeine-promethazine syrup is quite safe, but dangers arise in higher doses since it can cause one to stop breathing. Using alcohol and other drugs alongside lean increases the chance of serious adverse effects. The drink does not appear to cause seizures itself, but can increase their likelihood in those already susceptible to them. It has been suggested that the promethazine in the drink may heighten the euphoric effects of the codeine. The addictive nature of the drink means that trying to discontinue regular usage can bring about symptoms of opioid withdrawal. In a 2008 interview with MTV News, Lil Wayne described the withdrawal as feeling "like death in your stomach when you stop. Everybody wants me to stop all this and all that. It ain't that easy."
=== Lineup change, Azzouni's death and Leaving Paris (2008–2011) === Cédric Toufouti was a guitarist in the band Inhatred. In 2008, Hangman's Chair were joined by Hanvic, who became the bassist, and Toufouti, who took over as singer-guitarist. In 2010, Azzouni died in a car accident. "One Love Reunion", an evening paying homage to Azzouni, took place at Glazart on 11 March 2010, featuring concerts by Hangman's Chair, Es La Guerilla, Knockoutz and L'Esprit du Clan. Leaving Paris, the band's second album, was released the same year, through Bones Brigade Records, with Chanut, Thépegnier, Hanvic, Toufouti, and Lederer in the lineup. In 2011, Hanvic was busy for a few months with L'Esprit du Clan and was replaced by Every Reason To... bassist Christophe Marconato for concert dates.
Machine learning uses both discriminative models and generative models to predict or generate data. Beginning in the late 2000s and early 2010s, advances in deep learning led to major improvements in image classification, speech recognition, and natural language processing. Neural networks in this period were typically trained as discriminative models due to the relative difficulty of training generative models. In 2014, the introduction of models such as the variational autoencoder (VAE) and generative adversarial network (GAN) enabled effective deep generative modeling of complex data such as images. In 2017, the paper "Attention Is All You Need" proposed that transformer architecture could enable further advances in generative modeling compared to earlier long short-term memory (LSTM) networks. This led to the development of generative pre-trained transformer (GPT) models, beginning with GPT-1 in 2018.
== Available forms == AzM is often used as active ingredient in organophosphate pesticides like Guthion, Gusathion (GUS), Gusathion-M, Crysthyron, Cotnion, Cotnion-methyl, Metriltrizotion, Carfene, Bay 9027, Bay 17147, and R-1852. This is why Guthion is often used as a nickname for AzM. Studies have shown that pure AzM is less toxic than GUS. This increased toxicity can be explained by the interactions between the different compounds in the mixture.
Sources: en.wikipedia.org
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.
Hydrolysis of peptide bonds and deamidation of arginine and proline residues are the main degradation routes. Alkaline pH and higher temperatures accelerate both processes. Buffered, near-neutral solutions stored cold generally degrade more slowly than unbuffered ones.
Reverse-phase chromatography gives the clearest single view of related impurities and truncated sequences. Mass spectrometry then confirms that the main peak carries the expected mass. Neither test detects enantiomeric impurities, which require a separate chiral assay.
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.