The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-12-05. Anything still debated is marked as such rather than presented as settled.
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。
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。
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
| 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 heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
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.
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。
The developer of the Half-Life series, Valve, was founded in 1996 in Kirkland, Washington by the former Microsoft employees Mike Harrington and Gabe Newell. Valve began working on the first Half-Life soon after formation, and settled on a concept for a horror-themed 3D action game, using the Quake engine as licensed by id Software. The game was a hit at the 1997 E3 convention, where its animation system and artificial intelligence were demonstrated. The success led to its first expansion pack, Half-Life: Opposing Force, which was developed by Gearbox Software, a new company based in Plano, Texas, and announced on April 15, 1999. The Gearbox founder, Randy Pitchford, said Valve gave them the project to allow Valve to focus on future games. Opposing Force was demonstrated at the 1999 E3 convention, where new locations, characters and the story were revealed. The second Half-Life expansion pack, Half-Life: Blue Shift, was again developed by Gearbox Software and announced by its publisher, Sierra Entertainment, on August 30, 2000. Sierra intended to release Blue Shift for the Dreamcast, and it was set to include higher detail models and textures that were double the polygon count of the models from Half-Life. However, after several months of delays, Sierra terminated the Dreamcast version of Blue Shift on June 16, 2001, and instead released it for Windows on June 12. Afterward, Gearbox began working on a Half-Life game for the PlayStation 2.
Between 280 and 275 BCE the Tarentine War was fought between Rome and Taranto. The latter sought help from Pyrrhus, king of Epirus, who in 280, together with his allies, the Bruttians and Lucanians, defeated the Romans at the Battle of Heraclea, thanks to the use of elephants. But Pyrrhus was later defeated by the Romans at Maluentum (current Benevento) in 275 and retreated to Sicily, where Syracuse needed help against the Carthaginians. Transiting through Calabria, Pyrrhus' army is said to have sacked the shrine of Persephone in Locri, triggering the wrath of the gods. This, combined with the fact that Rome had formed alliances with some of the last poleis of Magna Graecia, including Reggio, caused Pyrrhus to return home. After Pyrrhus was eventually defeated, to avoid Roman revenge the Bruttii submitted willingly and gave up half of the Sila, a mountainous plateau valuable for pitch and timber. Rome subjugated southern Italy by means of treaties with the cities.
Ultraviolet-fluorescence observations in some bloodstain regions have been interpreted as indicating that blood-related fluids may have reduced or prevented body-image formation in those areas, implying that the blood predated the image-forming process. This is further supported by microchemical tests in which, after protein material from blood-area fibers was removed, the linen fibers appeared similar to non-image fibers rather than to the body-image fibers.
Sources: en.wikipedia.org
Caesium-137 has a half-life of about 30.04 years, decaying by beta emission to stable barium-137. About 94.6% of the decays go to a metastable nuclear isomer of barium: barium-137m (137mBa) and the remainder directly to the ground state. Barium-137m has a half-life of about 153 seconds, its dropping to the ground state usually (85.1% of all 137Cs decays) emitting photons having energy 0.6617 MeV. This is responsible for all of the gamma ray emissions in samples of 137Cs.
== Further reading == Davidson JA, Sloan L (January 2017). "Fixed-Dose Combination of Canagliflozin and Metformin for the Treatment of Type 2 Diabetes: An Overview". Adv Ther. 34 (1): 41–59. doi:10.1007/s12325-016-0434-2. PMC 5216068. PMID 27854055.
=== National acceptance and symbolic meaning === By the period leading to independence, the name "Ghana" was accepted and adopted as a symbol of precolonial prestige, cultural unity, and national legitimacy.
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。
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.