ACTH fragment raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-05-11. Anything still debated is marked as such rather than presented as settled.
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
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 corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
| Property | Value | Notes |
|---|---|---|
| 外观 | 白色至类白色粉末 | 常见于冻干制剂 |
| 溶解度 | 易溶于水 | 在极性溶剂中一般也可溶 |
| 建议储存温度 | -20 °C | 冻干粉，避光密封 |
| 常见分析手段 | 反相高效液相色谱 | 常与质谱联用 |
| 主要降解路径 | 水解与氧化 | 溶液状态更显著 |
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
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.
==== 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.
=== Industries and economic zones === Ningxia was a major recipient of China's investment in industrial capacity during the Third Front campaign. Yinchuan Economic and Technological Development Zone was established in 1992. Spanning 32 km2 (12 sq mi), it has an annual economic output Rmb23.7 billion (25.1% up) (US$3.5 billion). Major investors are mainly local enterprises such as Kocel Steel Foundry, FAG Railway Bearing (Ningxia), Ningxia Little Giant Machine Tools, etc. Major industries include machinery and equipment manufacturing, new materials, fine chemicals and the animation industry. Desheng Industrial Park (in Helan County) is a base for about 400 enterprises. The industrial park has industrial chains from Muslim food and commodities to trade and logistics, new materials and bio-pharmaceuticals that has 80 billion yuan in fixed assets. Desheng is looking to be the most promising industrial park in the city. It achieved a total output value of 4.85 billion in 2008, up 40 percent year-on-year. The local government plans to cut taxes and other fees to reduce the burden on local enterprises. The industrial output value reached 2.68 billion yuan in 2008, an increase of 48 percent from a year earlier.
ClCH2CO2H + Na2S2O3 → Na[O3S2CH2CO2H] + NaCl Na[O3S2CH2CO2H] + H2O → HSCH2CO2H + NaHSO4 Organolithium compounds and Grignard reagents react with sulfur to give the thiolates, which are readily hydrolyzed:
The Cochrane reviews on the treatment of ADHD in children, adolescents, and adults with pharmaceutical amphetamines stated that short-term studies have demonstrated that these drugs decrease the severity of symptoms, but they have higher discontinuation rates than non-stimulant medications due to their adverse side effects. However, a 2025 meta-analytic systematic review of 113 randomized controlled trials found that stimulant medications were the only intervention with robust short-term efficacy, and were associated with lower all-cause treatment discontinuation rates than non-stimulant medications (e.g., atomoxetine). A Cochrane review on the treatment of ADHD in children with tic disorders such as Tourette syndrome indicated that stimulants in general do not make tics worse, but high doses of dextroamphetamine could exacerbate tics in some individuals.
Sources: en.wikipedia.org
== Design considerations == Fabricating artificial skin has the difficulty of mimicking living tissue with similar biological and mechanical performance. As outlined by Integra founders Yannas and Burke, there are three key factors to consider in the creation of artificial skin: material, bio/physiochemical properties, and mechanical properties.
=== Liver === Bridging fibrosis – an advanced stage of liver fibrosis, seen in the progressive form of chronic liver diseases. The term bridging refers to the formation of a "bridge" by a band of mature and thick fibrous tissue from the portal area to the central vein. This form of fibrosis leads to the formation of pseudolobules. Long-term exposure to hepatotoxins, such as thioacetamide, carbon tetrachloride, and diethylnitrosamine, has been shown to cause bridging fibrosis in experimental animal models. Senescence of hepatic stellate cells could prevent progression of liver fibrosis, although has not yet been implemented as a therapy due to risks associated with hepatic dysfunction.
She has released two albums on the Karaoke Kalk label: Kids with Sticks in 2001 and the collaboration Kuchen Meets Mapstation in 2003 with Stefan Schneider of To Rococo Rot (who also records as Mapstation). Horner is a film producer based in Newcastle upon Tyne. Browne went on to play with Warm Jets, Rialto, and White Hotel (with Jean-Marc Butty, longtime drummer for PJ Harvey) before briefly returning to Canada in 2001, then relocating to San Francisco in 2002. There she played with local rock noir chanteuse Rykarda Parasol, appearing on her Here She Comes EP and the Our Hearts First Meet album, then went on to record and tour with The Wronglers, an old-time band with Warren Hellman, founder and financer of San Francisco's free Hardly Strictly Bluegrass festival, who also made an album with Jimmie Dale Gilmore called "Heirloom Music".
Sources: en.wikipedia.org
Zinc is an essential element for all known forms of life. In humans, zinc is required for the function of over 300 enzymes and 1000 transcription factors, and is stored and transferred in metallothioneins. It is the second most abundant trace metal in humans after iron. It is the only metal which appears in all enzyme classes. In proteins, zinc ions are often coordinated to the amino acid side chains of aspartic acid, glutamic acid, cysteine and histidine. The theoretical and computational description of this zinc binding in proteins (as well as that of other transition metals) is difficult. Roughly 2–4 grams of zinc are distributed throughout the human body. Most zinc is in the brain, muscle, bones, kidney, and liver, with the highest concentrations in the prostate and parts of the eye. Semen contains a particularly high amount of zinc, a key factor in prostate gland function and reproductive organ growth. Zinc homeostasis of the body is mainly controlled by the intestine. Here, ZIP4 and especially TRPM7 were linked to intestinal zinc uptake essential for postnatal survival. In humans, the biological roles of zinc are ubiquitous. It interacts with "a wide range of organic ligands", and has roles in the metabolism of RNA and DNA, signal transduction, and gene expression. It also regulates apoptosis. A review from 2015 indicated that about 10% of human proteins (~3000) bind zinc, in addition to hundreds more that transport and traffic zinc; a similar in silico study in the plant Arabidopsis thaliana found 2367 zinc-related proteins.
the Kurchatov Institute, Russia's leading research and development institution in nuclear energy, where the first nuclear reactor in Europe was built the Landau Institute for Theoretical Physics the Institute for Theoretical and Experimental Physics the Kapitza Institute for Physical Problems the Steklov Institute of Mathematics The city contains 452 libraries, including 168 for children. The Russian State Library, founded in 1862, is the national library of Russia. This library contains more than 275 kilometers (171 mi) of shelves and 42 million items—including more than 17 million books and serial volumes, 13 million journals, 350,000 music scores and sound records, and 150,000 maps—making it the country's largest library and one of the world's largest. Items in 247 languages other than Russian account for 29% of the library's collection. The State Public Historical Library, founded in 1863, is the largest library specialising in Russian history. Its collection contains four million items in 112 languages, mostly on Russian and world history, heraldry, numismatics, and the history of science. On the subject of primary and secondary education, journalist Clifford J. Levy of The New York Times newspaper wrote in 2011:
=== Energy use === Early assessments of energy use in grey matter signaling suggested that 95% was attributed to neurons and 5% to astrocytes. However, after discovering that action potentials were more efficient than initially believed, the energy budget was adjusted: 70% for dendrites, 15% for axons, and 7% for astrocytes. Previous accounts assumed that astrocytes captured synaptic K+ solely via Kir4.1 channels. However, it's now understood they also utilize Na+/K+ ATPase. Factoring in this active buffering, astrocytic energy demand increases by >200%. This is supported by 3D neuropil reconstructions indicating similar mitochondrial densities in both cell types, as well as cell-specific transcriptomic and proteomic data, and tricarboxylic acid cycle rates. Therefore "Gram-per-gram, astrocytes turn out to be as expensive as neurons".
Blanche absinthe ("white" in French, also referred to as la Bleue in Switzerland) is bottled directly following distillation and reduction and is uncoloured (clear). Blanches tend to have a clean, smooth flavour with strongly individuated tasting notes. The name la Bleue was originally a term used for Swiss bootleg absinthe, which was bottled colourless so as to be visually indistinct from other spirits during the era of absinthe prohibition, but has become a popular term for post-ban Swiss-style absinthe in general. Blanches are often lower in alcohol content than vertes, though this is not necessarily so; the only truly differentiating factor is that blanches are not put through a secondary maceration stage, and thus remain colourless like other distilled liquors. Verte absinthe ("green" in French, sometimes called la fée verte) begins as a blanche and is altered by a secondary maceration stage, in which a separate mixture of herbs is steeped into the clear distillate before bottling. This confers an intense, complex flavor as well as a peridot green hue. Vertes represent the prevailing type of absinthe that was found in the 19th century. Vertes are typically more alcoholic than blanches, as the high amounts of botanical oils conferred during the secondary maceration only remain miscible at lower concentrations of water, thus vertes are usually bottled at closer to still strength. Artificially colored green absinthes may also be claimed to be verte, though they lack the characteristic herbal flavors that result from maceration in whole herbs.
Sources: en.wikipedia.org
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。
公开资料对此没有统一答案。普遍建议现配现用，或冷藏并在数日内用完。含甲硫氨酸的序列更易氧化，放置时间越长风险越高。
反相高效液相色谱是最常用的手段，配合质谱确认分子量。氨基酸组成分析和肽图分析可补充序列层面的验证。
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.