Everything below concerns peptidase cleavage. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-06-05. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Monocytes respond to bacterial pathogen-associated molecular patterns (PAMPs), or damage-associated molecular patterns (DAMPs) by activating the extrinsic pathway of coagulation. Neutrophils facilitate the blood coagulation by NETosis, while platelets facilitate neutrophils' NETosis. NETs bind tissue factor, binding the coagulation centers to the location of infection. They also activate the intrinsic coagulation pathway by providing a negatively charged surface for factor XII. Other neutrophil secretions, such as proteolytic enzymes which cleave coagulation inhibitors, also bolster the process. In case of imbalance in the regulation of immunothrombosis, this process can become aberrant. Regulatory defects in immunothrombosis are suspected to be a major factor in pathological thrombosis in forms such as disseminated intravascular coagulation (DIC) or deep vein thrombosis. DIC in sepsis is a prime example of both the dysregulated coagulation process and an undue systemic inflammatory response. It results in a multitude of microthrombi. These are similar in composition to the thrombi produced in native immunothrombosis — they are made up of fibrin, platelets, neutrophils and NETs.
Due to backstreaming, oil diffusion pumps are not suitable for use with highly sensitive analytical equipment or other applications which require an extremely clean vacuum environment, but mercury diffusion pumps may be in the case of ultra high vacuum chambers used for metal deposition. Often cold traps and baffles are used to minimize backstreaming, although this results in some loss of pumping speed. The oil of a diffusion pump cannot be exposed to the atmosphere when hot. If this occurs, the oil will oxidise and has to be replaced. If a fire occurs, the smoke and residue may contaminate other parts of the system.
This hypothesis was opposed by French palaeontologist Marcellin Boule, who authored several publications starting in 1908 describing the French Neanderthal specimen La Chapelle-aux-Saints 1 ("The Old Man") as a slouching, ape-like creature distantly related to modern man. Boule's ideas would define discussions of Neanderthals for some time. Boule suggested two different lineages existed in Ice Age Europe: a more evolved one descending from the British Piltdown Man (a hoax) to the French Grimaldi Man (a Cro-Magnon) which would culminate with modern Europeans; and a less evolved dead-end lineage leading from the German Heidelberg Man to Neanderthal Man. As the focus of human origins shifted from Europe to East Asia ("Out of Asia" hypothesis) by the 1930s and 40s with discoveries such as Java Man and Peking Man (as well as the marginalisation of Piltdown Man), the question of a "Neanderthal phase" in human evolution once again became a topic of discussion. The definition of "Neanderthal" expanded to include several anatomically variable specimens around the Old World. In the contextual debate between monogenism and polycentrism, some specimens were described as "progressive" Neanderthals which would evolve into some local subspecies of H. sapiens (polycentricism), while the "classic" Neanderthals of the Western European Würm glaciation would not. In the 1970s, with the formulation of cladistics and the consequent refinement of the anatomical definitions of species, this "global morphological pattern" fell apart.
Since 1947, the Doomsday Clock of the Bulletin of the Atomic Scientists has visualized how close the world is to a nuclear war. The Doomsday Clock reached a high point in 1953, when the Clock was set to two minutes until midnight after the U.S. and the Soviet Union began testing hydrogen bombs, and in 2018, following the failure of world leaders to address tensions relating to nuclear weapons and climate change issues. Since 2026, the Clock has been set at 85 seconds to midnight, the closest it has ever been.
Sources: en.wikipedia.org
Cathodic arc deposition Electron-beam physical vapor deposition (EBPVD) Ion plating Ion-beam–assisted deposition (IBAD) Magnetron sputtering Pulsed laser deposition Sputter deposition Vacuum deposition Vacuum evaporation, evaporation (deposition) Pulsed electron deposition (PED)
Cyclic amines—Cyclic amines are either secondary or tertiary amines. Examples of cyclic amines include the 3-membered ring aziridine and the six-membered ring piperidine. N-methylpiperidine and N-phenylpiperidine are examples of cyclic tertiary amines.
=== Consolidating leadership: 1969–1973 === The 12-member central committee of the Free Officers proclaimed themselves the Revolutionary Command Council (RCC), the government of the new republic. Gaddafi became chairman, and therefore de facto head of state, also appointing himself colonel and becoming commander-in-chief of the armed forces. Jalloud became Prime Minister, while a civilian Council of Ministers headed by Sulaiman Maghribi was founded to implement RCC policy. Libya's administrative capital was moved from al-Beida to Tripoli.
British biochemist at the National Institute for Medical Research in Mill Hill, London, specializing in thyroid biochemistry. David Andrew Phoenix (b. 1966). British biochemist at London South Bank University, where he studies properties of biologically active amphiphilic peptides. Rodney Porter FRS (1917–1985). British biochemist at Oxford known for determining the chemical structure of antibodies. Addy Pross (b. 1945), Israeli-Australian researcher of abiogenesis from a chemistry perspective Frank W. Putnam (1917–2006). American biochemist at the Indiana University, who worked on the structure and function of blood proteins. Member Natl. Acad. Sci. USA.
In computing, FLOPS (FLoating point Operations Per Second) is a measure of a computer's computing power. It is also common to see measurements of kilo, mega, giga, and teraFLOPS. It is also used to compare the performance of computers in practice.
Sources: en.wikipedia.org
==== Family-based therapy ==== Family-based treatment (FBT) may be more successful than individual therapy for adolescents with AN. Various forms of family-based treatment have been proven to work in the treatment of adolescent AN including conjoint family therapy (CFT), in which the parents and child are seen together by the same therapist, and separated family therapy (SFT) in which the parents and child attend therapy separately with different therapists. Proponents of family therapy for adolescents with AN assert that it is important to include parents in the adolescent's treatment. The evidence supporting family based therapy for adults is weak and despite the evidence that it is effective and the primary choice for treatment in adolescents, there is no evidence it is helpful for adults. A four- to five-year follow up study of the Maudsley family therapy, an evidence-based manualized model, showed full recovery at rates up to 90%. The Maudsley model of family therapy is problem focused, and the treatment targets re-establishing regular eating, weight restoration, and the reduction of illness behaviors like purging. The Maudsley model is split into three phases, with phase one focusing on the parents implementing weight restoration in the child; phase two transitioning control over food back to the individual at an age-appropriate level; and phase three focusing on other issues related to typical adolescent development (e.g., social and other psychological developments), and helps parents learn how to interact with their child.
In Rolf Singer's classification of the Agaricales mushrooms, it is also the type species of section Boletus, a grouping of about 30 related boletes united by several characteristics: a mild-tasting, white flesh that does not change colour when exposed to air; a smooth to distinctly raised, netted pattern over at least the uppermost portion of the stem; a yellow-brown or olive-brown spore print; white tubes that later become yellowish then greenish, which initially appear to be stuffed with cotton; and cystidia that are not strongly coloured. Molecular analysis published in 1997 established that the bolete mushrooms are all derived from a common ancestor, and established the Boletales as an order separate from the Agaricales. The generic name is derived from the Latin term bōlētus "mushroom", which was borrowed in turn from the Ancient Greek βωλίτης, "terrestrial fungus". Ultimately, this last word derives from bōlos/βῶλος "lump", "clod", and, metaphorically, "mushroom". The βωλίτης of Galen, like the boletus of Latin writers like Martial, Seneca and Petronius, is often identified as the much prized Amanita caesarea. The specific epithet edulis in Latin means "eatable" or "edible".
=== Fabrication === The electrostatic potential needed to create a quantum dot can be realized with several methods. These include external electrodes, doping, strain, or impurities. Self-assembled quantum dots are typically between 5 and 50 nm in size. Quantum dots defined by lithographically patterned gate electrodes, or by etching on two-dimensional electron gases in semiconductor heterostructures can have lateral dimensions between 20 and 100 nm. The formation of quantum dots can be spontaneous when a semiconductor material is deposited on a substrate and a difference in lattice space exists between them. By means of advanced nanofabrication technologies it is possible to manipulate properties of the quantum dots, such as their interactions, shape, size and transparency. For example, when negative voltage is applied to a metal gate around a QD, as response, its diameter starts to be gradually squeezed, as a consequence, the number of electrons on the dot starts to decrease one by one, this could be made until there are no more left. The previous property allows to record the current flow as the number of electrons on the dot, this implies that the energy variates.
Trump has said repeatedly that he wanted to end "ridiculous" wars and prevent the start of new ones. Ahmed Fouad Alkhatib, a Gazan analyst and Atlantic Council fellow, said that Trump's vision could not believably be considered an option and that it was transparently impossible. He wrote that Trump may be trying to pressure Arab nations into action through threatening to take over the Strip and communicating that he would become involved if there was not Arab initiative, including finance from Gulf nations. Alkhatib added that regardless of Trump's intentions, his statements have been damaging and have further contributed to the perception of the unhelpfulness of the United States.
==== MeSH D06.347.360 – estrogen receptor modulators ==== MeSH D06.347.360.315 – estrogen antagonists MeSH D06.347.360.315.300 – estradiol antagonists MeSH D06.347.360.827 – selective estrogen receptor modulators
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.