Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-06-24. 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 chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
=== Other dextran hydrogel targeted sites === Dextran conjugate hydrogels can also target other desirable sites. Paclitaxel-loaded dextran-sericin hydrogels can effectively target tumor growth in mice. Hydrogels composed of translocator protein (TSPO) ligands conjugated to dextran have the potential to induce apoptosis in tumor cells via the TSPO receptor on the mitochondria. Dextran/polyacrylamide hydrogels with covalently bound silver nanoparticles can effectively release ornidazole to treat infections. Dextran conjugated with oligolactide chains through a disulfide bond can form hydrogels that have potential applications in cancer treatment drug delivery systems. Dextran hydrogels that release drugs in response to an external electrical field can also be synthesized.
=== Surface-to-air missiles === Thunderbird (missile) – In use till 1977 for mobile high-altitude air defence. Bloodhound (missile) – Fixed air defence in UK from 1958 till 1991. Blowpipe (missile) – Man portable surface-to-air missile from 1975 till 1985 Rapier (missile) – Came into service at the start of 1970s and at the end replaced Bofors and thunderbird. Used until 2022. Javelin (surface-to-air missile) – Man portable surface-to-air missile replacing Blowpipe in use from 1984 to 1993.
Patrick Brenan, Finance Director, Minories Finance Ltd. For services to Banking. Linda Broadhead, Senior Management Pay Band 2, the Employment Service, Department for Education and Employment. Rosemary Anne Brown, Member, Occupational Pensions Board. For services to Pensions Legislation. Barbara Kathleen Bryant, Grade 7, Department of Social Security. Keith Patrick Burke, Managing Director, Dana Spicer Europe Ltd., Dana Corporation. For services to Industry and to the Environment. David Burnett. For services to the Development and Application of Biochemistry to Health Care. William John Burnison. For public service. Derek Harold Calam, Member and Vice Chairman, British Pharmacopoeia Commission. For services to the Control of Medicines. Libby Campbell, Executive Director, Nursing and Quality, West Lothian NHS Trust. For services to Health Care. Dennis Duncan Carmichael, Honorary Treasurer, Lawn Tennis Association. For services to Lawn Tennis. Enid Castle, lately Principal, Cheltenham Ladies' College. For services to Education. Jonathan Joseph Chadwick, Secretary to the Imperial War Museum. Christopher Charlton, Director, Cromford Mill Project, Derbyshire. For services to Conservation. Professor Dennis Child. For services to Deaf People. Edward Samuel Childs, Executive Producer, Carlton UK Television. For services to Television Broadcasting. Brian James Clark, Principal Specialist Inspector, Health and Safety Executive, Department of the Environment. Harold Clarke, District Inspector, Board of Inland Revenue. Seamus Anthony Close. For public service.
The primary function of the thyroid is the production of the iodine-containing thyroid hormones, triiodothyronine (T3) and thyroxine or tetraiodothyronine (T4) and the peptide hormone calcitonin. The thyroid hormones are created from iodine and tyrosine. T3 is so named because it contains three atoms of iodine per molecule and T4 contains four atoms of iodine per molecule. The thyroid hormones have a wide range of effects on the human body. These include:
Sources: en.wikipedia.org
An independent 2024 assembly of the same strain using a new technique (PacBio HiFi) produced an extra 4.17 million base pairs total and 8.0 million base pairs on chromosome arms. In 2024, a near-complete "telomere-to-telomere" genome assembly was produced for D. melanogaster strain Canton S, closing 93.28% of gaps in the release 6 genome. This was enabled by a combination of PacBio HiFi, Oxford Nanopore ultra-long reads, and Hi-C data. It measured 161.63 million base pairs, though a lot of the increase relative to reference appear to reflect actual strain-to-strain variation (and not an error in the R6 genome). D. melanogaster originated in sub-Saharan Africa and populations diverged as the species expanded across the globe. As of 2024, there are more than 1439 genome sequences representing the global diversity of this species, allowing for a detailed estimate of its global evolutionary history.
This interpretation remained controversial until NMR techniques demonstrated information transfer between hydrogen-bonded nuclei, a feat that would only be possible if the hydrogen bond contained some covalent character.
As an example of a model safety evaluation, a 2024 test by Apollo Research found that when given certain prompts as input, models would engage in deceptive behavior at a rate between 0.3% - 10% depending on the model and wording of the input prompt. Types of model safety evaluations include benchmarking and capability testing. Benchmarks typically consist of a static list of prompts which models can be graded on and assigned a score compared to other models.
The cause of Fukuyama congenital muscular dystrophy is rooted in the FKTN gene, located at human chromosome 9q31, encoding the protein fukutin. Mutations in this gene, and therefore the fukutin protein, are the cause of FCMD. The disease is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome (chromosome 9 is an autosome), and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene but usually do not experience any signs or symptoms of the disorder. Two mutations have been identified. The first and most common is an SVA retrotransposal insertion in the 3'-untranslated region. The second is a deep-intronic point mutation c.647+2084G>T. This second mutation has only been found to date in the presence of the first mutation.
Coagulation, the formation of a blood clot or thrombus, occurs when the proteins of the coagulation cascade are activated, either by contact with a damaged blood vessel wall and exposure to collagen in the tissue space (intrinsic pathway) or by activation of factor VII by tissue activating factors (extrinsic pathway). Both pathways lead to the generation of thrombin, an enzyme that turns the soluble blood protein fibrinogen into fibrin, which aggregates into protofibrils. Another thrombin-generated enzyme, factor XIII, then crosslinks the fibrin protofibrils at the D fragment site, leading to the formation of an insoluble gel that serves as a scaffold for blood clot formation. The circulating enzyme plasmin, the main enzyme of fibrinolysis, cleaves the fibrin gel in a number of places. The resultant fragments, "high molecular weight polymers", are digested several times more by plasmin to lead to intermediate and then to small polymers (fibrin degradation products or FDPs). The cross-link between two D fragments remains intact, however, and these are exposed on the surface when the fibrin fragments are sufficiently digested. The structure of D-dimer is either a 180 kDa or 195 kDa molecule of two D domains, or a 340 kDa molecule of two D domains and one E domain. The half-life of D-dimer in blood is approximately 6 to 8 hours. D-dimers are not normally present in human blood plasma, except when the coagulation system has been activated, for instance, because of the presence of thrombosis or disseminated intravascular coagulation.
Sources: en.wikipedia.org
=== Biological actions === β-TG is a chemoattractant, strongly for fibroblasts and weakly for neutrophils. It is a stimulator of mitogenesis, extracellular matrix synthesis, glucose metabolism, and plasminogen activator synthesis in human fibroblasts. β-TG also affects megakaryocyte maturation, and thus helps in regulating platelet production.
Some hormonal birth control methods utilize cervical drug delivery methods. The earliest example of such dates to 1850 Ancient Egypt when acadia gum was inserted into the vagina, releasing spermicidal components. Examples in the modern era include vaginal rings and intrauterine devices (IUDs) that release hormones into the reproductive system to prevent fertilization. Vaginal rings are plastic ring-shaped devices that are inserted into the vaginal canal and slowly release hormones such as estradiol or progestin. Hormonal IUDs are T-shaped devices inserted into the uterus, releasing progestin over extended periods of time. These hormones work to thicken the cervical mucus to prevent sperm from penetrating and reaching the fallopian tubes. Copper IUDs are another form of intrauterine devices that release copper ions instead of hormones. The copper ions are toxic to sperm and therefore prevents successful fertilization.
=== 1987 Goiânia, Goiás, Brazil === In the Goiânia accident of 1987, an improperly disposed of radiation therapy system from an abandoned clinic in Goiânia, Brazil, was removed, then cracked to be sold in junkyards. The glowing caesium salt was then sold to curious, unaware buyers. This led to four confirmed deaths and several serious injuries from radiation contamination.
3 May Drug company Eli Lilly reports that donanemab can slow the pace of Alzheimer's disease by 35%, following a Phase 3 study in human patients. Astronomers using the Gemini South telescope report the first direct evidence of an exoplanet being swallowed by an ancient Sun-like star, a fate that likely awaits the Earth in five billion years. 4 May – Westinghouse Electric's nuclear division announces the AP300, a miniature version of its signature AP1000 nuclear reactor. 5 May – The World Health Organization announces that COVID-19 is no longer considered a global health emergency. 8 May The first infrared image of an asteroid belt outside the Solar System is captured by the James Webb Space Telescope. Three distinct rings of debris are shown to exist around Fomalhaut, a young star 25 light years away. AI successfully identifies people at the highest risk for pancreatic cancer up to three years before diagnosis, using solely the patients' medical records. 10 May A rough draft of the human "pan-genome" is presented, consisting of 47 genomes from a cohort of genetically diverse individuals. This aims to improve medical research by building on the earlier Human Genome Project. Scientists demonstrate with experimental evolution how macroscopic multicellularity could have emerged on Earth. 11 May – The discovery of 62 new moons of Saturn is reported, taking its total confirmed number to 145 and overtaking Jupiter. 15 May The National Institutes of Health begins a Phase 1 trial of an mRNA-based universal influenza vaccine, enrolling 50 volunteers.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。