nootropic raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-08-21. Anything still debated is marked as such rather than presented as settled.
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。
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。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构，不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
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.
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 normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Hegseth had announced on 10 October the formation of a new counternarcotics joint task force, to operate in Latin America, the Western hemisphere, and the area of the United States Southern Command (USSOUTHCOM), to be headed by the II Marine Expeditionary Force, intended "to crush the cartels, stop the poison and keep America safe". On 13 November 2025, Hegseth announced the unveiling of Operation Southern Spear, led by Joint Task Force Southern Spear and using a fleet with robotics and autonomous systems to target Latin American drug trafficking, with operations to begin later in November. A US official told a reporter in November that Hegseth's 13 November unveiling was "a formal operation naming for what the Joint Task Force Southern Spear ... and Southcom have already been doing in theater".
== The genome of Elusimicrobium minutum == The 1.64 Mbp genome of E. minutum reveals the presences of several genes required for uptake and fermentation of sugars via the Embden–Meyerhof pathway, including several hydrogenases, and an unusual peptide degradation pathway comprising transamination reactions. It also reveals the presence of genes coding for peptidoglycan and lipopolysaccharide biosynthesis. The genome also seems to encode 60 PilE genes putatively involved in pilus assembly, polyketide synthesis, non-ribosomal peptide synthesis and many other still undiscovered metabolic traits.
The Environmental Investigation Agency in 2016 estimated that 34 species of fish were being traded on the wider Chinese fish maw market. Sciaenidae (croakers/drums) are typically the most valued, due to their similarity to the historically prized and critically endangered Chinese bahaba. Other targeted fishes include eels, stonefishes, lates perch, groupers, threadfins and sturgeon.
Sources: en.wikipedia.org
Heat or ionizing irradiation can be used to kill the bacteria that cause decomposition. Heat is applied by cooking, blanching or microwave heating in a manner that pasteurizes or sterilizes fish products. Cooking or pasteurizing does not completely inactivate microorganisms and may need to be followed with refrigeration to preserve fish products and increase their shelf life. Sterilised products are stable at ambient temperatures up to 40 °C, but to ensure they remain sterilized they need packaging in metal cans or retortable pouches before the heat treatment.
It acts by interfering with the signal transmission between vestibular apparatus of the inner ear and the vomiting centre of the hypothalamus by limiting the activity of the vestibular hair cells which send signals about movement. The disparity of signal processing between inner ear motion receptors and the visual senses is abolished, so that the confusion of brain whether the individual is moving or standing is reduced. Vomiting in motion sickness could be a physiological compensatory mechanism of the brain to keep the individual from moving so that it can adjust to the signal perception, but the true evolutionary reason for this malady is currently unknown. When prescribed for balance problems and vertigo, cinnarizine is typically taken two or three times daily depending on the amount of each dose and when used to treat motion sickness, the pill is taken at least two hours before travelling and then again every four hours during travel. However, a recent 2012 study comparing the effects of cinnarizine to transdermal scopolamine for the treatment of seasickness, concluded that scopolamine was reported as significantly more effective and as having fewer adverse side effects than cinnarizine. This led to the conclusion that transdermal scopolamine is likely a better option for the treatment of motion sickness in naval crew and other sea travelers. However, due to increased levels of drowsiness caused by the medication, it is generally of limited use in pilots and aircrew who must be dependably alert.
The sarcoplasmic reticulum has a large calcium buffering capacity partially due to a calcium-binding protein called calsequestrin. The near synchronous activation of thousands of calcium sparks by the action potential causes a cell-wide increase in calcium giving rise to the upstroke of the calcium transient. The Ca2+ released into the cytosol binds to Troponin C by the actin filaments, to allow crossbridge cycling, producing force and, in some situations, motion. The sarco/endoplasmic reticulum calcium-ATPase (SERCA) actively pumps Ca2+ back into the sarcoplasmic reticulum. As Ca2+ declines back to resting levels, the force declines and relaxation occurs.
Sources: en.wikipedia.org
1948: Canadian plant pathologist and mycologist Margaret Newton became the first woman to be awarded the Flavelle Medal from the Royal Society of Canada, in recognition of her extensive research in wheat rust fungal disease. Her experiments led to the development of rust-resistant strains of wheat. 1948: American limnologist Ruth Patrick of the Academy of Natural Sciences of Philadelphia led a multidisciplinary team of scientists on an extensive pollution survey of the Conestoga River watershed in Pennsylvania. Patrick would become a leading authority on the ecological effects of river pollution, receiving the Tyler Prize for Environmental Achievement in 1975. 1949: Botanist Valida Tutayug became the first Azerbaijani woman to receive a PhD in biological studies. She went on to write the first national Azerbaijani-language textbooks on botany and biology. 1949: American paleontologist Winifred Goldring became the first female president of the Paleontological Society. Her work included a description of stromatolites, as well as the study of Devonian crinoids. She was the first woman in the US to be appointed as a State Paleontologist.
=== Sources === Beynon, Erdmann Doane (May 1, 1938). "The Voodoo Cult among Negro migrants in Detroit". American Journal of Sociology. 43 (6): 894–907. doi:10.1086/217872. JSTOR 2768686. S2CID 144039917. Evanzz, Karl (2011) [1999]. The Messenger: The Rise and Fall of Elijah Muhammad (3 ed.). New York City, New York, United States: Knopf Doubleday. ISBN 9780307805201 – via Google Books. Gardell, Mattias (1996). In the Name of Elijah Muhammad: Louis Farrakhan and The Nation of Islam. Durham: Duke University Press. ISBN 978-0822318453.
Replacing natural polyunsaturated fatty acids (PUFA) with deuterated PUFA (dPUFA), which have deuterium in place of the bis-allylic hydrogens, can prevent cell death induced by erastin or RSL3. These deuterated PUFAs effectively inhibit ferroptosis and various chronic degenerative diseases associated with ferroptosis. Live-cell imaging has been used to observe the morphological changes that cells undergo during ferroptosis. Initially the cell contracts and then begins to swell. Perinuclear lipid assembly is observed immediately before ferroptosis occurs. After the process is complete, lipid droplets are redistributed throughout the cell (see GIF on right side).
Sources: en.wikipedia.org
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。
Semax 对应 ACTH 第 4 至第 10 位的片段，并在两端做了替换与延长，使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物，需要医生开具处方。多数其他国家把它当作研究化合物，不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
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。