nasal formulation raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-05-27. Anything still debated is marked as such rather than presented as settled.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
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。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
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.
Although the clitoris (and clitoral prepuce/sheath) exists in all mammal species, there are few detailed studies of the anatomy of the clitoris in non-humans. Studies have been done on the clitoris of cats, sheep and mice. Some mammals have clitoral glands. The clitoris is especially developed in fossas, non-human apes, lemurs, moles, and often contains a small bone known as the os clitoridis. Many species of talpid moles exhibit peniform clitorises that are tunneled by the urethra and are found to have erectile tissue. The clitoris is contained in fossa, which is a small pouch of tissue in horses and dogs. The clitoris is found in other amniotic creatures including reptiles such as turtles and crocodilians, and birds such as ratites (e.g., cassowaries, ostriches) and anatids (e.g., swans, ducks). The hemiclitoris is one-half of a paired structure in squamates (lizards and snakes). Scientists state that female spotted hyenas are the only non-intersex female mammals devoid of an external vaginal opening, and whose sexual anatomy is distinct from intersex cases.
== Limitations of MRS == The major limitation to MRS is its low available signal due to the low concentration of metabolites as compared to water. As such, it has inherently poor temporal and spatial resolution. Nevertheless, no alternate technique is able to quantify metabolism in vivo non-invasively and thus MRS remains a valuable tool for research and clinical scientists. In addition, despite recent efforts toward international expert consensus on methodological details like shimming, motion correction, spectral editing, spectroscopic neuroimaging, other advanced acquisition methods, data processing and quantification, application to brain, proton spectroscopy application to skeletal muscle, phosphorus application to skeletal muscle, methods description, results reporting, and other considerations, currently published implementations of in vivo magnetic resonance spectroscopy cluster into literatures exhibiting a broad variety of individualized acquisition, processing, quantification, and reporting techniques. This situation may contribute to a low sensitivity and specificity of, for example, in vivo proton magnetic resonance spectroscopy to disorders such as multiple sclerosis, that continue to fall below clinically beneficial thresholds for, e.g., diagnosis.
The white paper that led to the Local Government Act 1972 proposed as "area 2" a metropolitan county including Newcastle and Sunderland, extending as far south down the coast as Seaham and Easington, and bordering "area 4" (which would become Tees Valley). The Bill as presented in November 1971 pruned back the southern edge of the area, and gave it the name "Tyneside". The name "Tyneside" proved controversial on Wearside, and a government amendment changed the name to "Tyne and Wear" at the request of Sunderland County Borough Council.
== Function == Phosphorylation of a protein by GSK-3 usually inhibits the activity of its downstream target. GSK-3 is active in a number of central intracellular signaling pathways, including cellular proliferation, migration, glucose regulation, and apoptosis. GSK-3 was originally discovered in the context of its involvement in regulating glycogen synthase. After being primed by casein kinase 2 (CK2), glycogen synthase gets phosphorylated at a cluster of three C-terminal serine residues, reducing its activity. In addition to its role in regulating glycogen synthase, GSK-3 has been implicated in other aspects of glucose homeostasis, including the phosphorylation of insulin receptor IRS1 and of the gluconeogenic enzymes phosphoenolpyruvate carboxykinase and glucose 6 phosphatase. However, these interactions have not been confirmed, as these pathways can be inhibited without the up-regulation of GSK-3. GSK-3 has also been shown to regulate immune and migratory processes. GSK-3 participates in a number of signaling pathways in the innate immune response, including pro-inflammatory cytokine and interleukin production. The inactivation of GSK3B by various protein kinases also affects the adaptive immune response by inducing cytokine production and proliferation in naïve and memory CD4+ T cells.
13 December The UK economy shrinks for the second month in a row, with a 0.1% drop in GDP reported for October. The City of London grants planning approval for 1 Undershaft, a new skyscraper that will be tied with the Shard as western Europe's tallest building. 14 December Roisin Quinn, operations director of National Grid plc, confirms that power has been restored to all its customers who experienced outages during Storm Darragh. A number of Irish-themed pubs in the UK have told the BBC they have run out of Guinness after the brewery's owners, Diageo, imposed a limit on supplies in the run up to Christmas. A woman is killed and two men are injured in a shooting in Harlesden, West London. 15 December – UK Foreign Secretary David Lammy says that the British government has made "diplomatic contact" with the Syrian rebel group that overthrew the Assad regime. A £50m humanitarian aid package is announced for vulnerable Syrians. 16 December BBC News reports that Prince Andrew will not join the Royal family at Sandringham for Christmas following revelations about his links to an alleged Chinese spy. Yang Tengbo is named as the alleged Chinese spy with links to Prince Andrew. Archbishop of York Stephen Cottrell, who is to take temporary charge of the Church of England following the resignation of Justin Welby as Archbishop of Canterbury, faces calls for his resignation over his handling of a sexual abuse case while he was Bishop of Chelmsford.
Sources: en.wikipedia.org
Diagnostic criteria of MFS were agreed upon internationally in 1996. However, Marfan syndrome is often difficult to diagnose in children, as they typically do not show symptoms until reaching pubescence. A diagnosis is based on family history and a combination of major and minor indicators of the disorder, rare in the general population, that occur in one individual – for example: four skeletal signs with one or more signs in another body system such as ocular and cardiovascular in one individual. The following conditions may result from MFS, but may also occur in people without any known underlying disorder.
Atkins, P. W. Galileo's Finger (Oxford University Press) ISBN 0-19-860941-8 Atkins, P. W. Atkins' Molecules (Cambridge University Press) ISBN 0-521-82397-8 Kean, Sam. The Disappearing Spoon – and Other True Tales from the Periodic Table (Black Swan) London, England, 2010 ISBN 978-0-552-77750-6 Levi, Primo The Periodic Table (Penguin Books) [1975] translated from the Italian by Raymond Rosenthal (1984) ISBN 978-0-14-139944-7 Stwertka, A. A Guide to the Elements (Oxford University Press) ISBN 0-19-515027-9 "Dictionary of the History of Ideas". Archived from the original on 10 March 2008. "Chemistry" . Encyclopædia Britannica. Vol. 6 (11th ed.). 1911. pp. 33–76. Introductory undergraduate textbooks
An acid is a molecule or ion capable of either donating a proton (i.e. hydrogen cation, H+), known as a Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid. The first category of acids are the proton donors, or Brønsted–Lowry acids. In the special case of aqueous solutions, proton donors form the hydronium ion H3O+ and are known as Arrhenius acids. Brønsted and Lowry generalized the Arrhenius theory to include non-aqueous solvents. A Brønsted–Lowry or Arrhenius acid usually contains a hydrogen atom bonded to a chemical structure that is still energetically favorable after loss of H+. Aqueous Arrhenius acids have characteristic properties that provide a practical description of an acid. Acids form aqueous solutions with a sour taste, can turn blue litmus red, and react with bases and certain metals (like calcium) to form salts. The word acid is derived from the Latin acidus, meaning 'sour'. An aqueous solution of an acid has a pH less than 7 and is colloquially also referred to as "acid" (as in "dissolved in acid"), while the strict definition refers only to the solute. A lower pH means a higher acidity, and thus a higher concentration of hydrogen cations in the solution. Chemicals or substances having the property of an acid are said to be acidic.
At community gatherings, target shooting was a major sport; they practised shooting at targets, such as hens' eggs perched on posts 100 metres (110 yd) away. They made expert mounted infantry, using cover, from which they could pour in a destructive fire using modern, smokeless, Mauser rifles. In preparation for hostilities, the Boers had acquired around 100 of the latest Krupp field guns, all horse-drawn and dispersed among the Kommando groups and several Le Creusot "Long Tom" siege guns. The Boers' skill in adapting themselves to become first-rate artillerymen shows that they were a versatile adversary. The Transvaal had an intelligence service that stretched across South Africa, and of whose extent and efficiency the British were as yet unaware.
Sources: en.wikipedia.org
=== Available forms === PSGAG is first administered as a series of injections over several weeks, and can be continued once or twice a month thereafter. It is normally injected intramuscularly, though can also be injected intra-articularily (directly into the joint) in horses or subcutaneously in off-label uses. Giving PSGAG intra-articularily requires it to be given aseptically, and is sometimes supplemented by the antibiotic amikacin to prevent infection. There are no generic or human-labeled equivalents of PSGAG in the US.
Source 2 was announced by Valve as the successor to Source at the Game Developers Conference in March 2015. There, Valve stated that it would be free to use for developers, with support for the Vulkan graphical API, as well as using a new in-house physics engine called Rubikon. In June 2015, Valve announced that Dota 2, originally developed with Source, would be ported over to Source 2 in an update called Dota 2 Reborn. Reborn was first released to the public as an opt-in beta update that same month before officially replacing the original client in September 2015, making it the first game to use the engine. The engine had succeeded Source by the late 2010s.
Low-density lipoprotein receptor-related protein 5 is a protein that in humans is encoded by the LRP5 gene. LRP5 is a key component of the LRP5/LRP6/Frizzled co-receptor group that is involved in canonical Wnt pathway. Mutations in LRP5 can lead to considerable changes in bone mass. A loss-of-function mutation causes osteoporosis pseudoglioma syndrome with a decrease in bone mass, while a gain-of-function mutation causes drastic increases in bone mass.
Sources: en.wikipedia.org
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
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。