semax comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-12-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 化学类别 | 合成七肽 | ACTH(4-10) 结构类似物 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | 单字母写作 MEHFPGP |
| 分子量 | 约 813.9 Da | 随确切形式和盐型略有变化 |
| 常见同义词 | ACTH(4-10) 类似物 | 俄语文献称 Семакс |
| 开发来源 | 俄罗斯 | 二十世纪八十年代 |
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.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
== Election process == The president is not directly elected by Burmese voters; instead, they are indirectly elected by the Presidential Electoral College (သမ္မတရွေးချယ်တင်မြှောက်ရေးအဖွဲ့), an electoral body made of three separate committees. One committee is composed of MPs who represent the proportions of MPs elected from each Region or State; another is composed of MPs who represent the proportions of MPs elected from each township population; the third is of military-appointed MPs personally nominated by the Defence Services' commander-in-chief. Each of the three committees nominates a presidential candidate. Afterward, all the Pyidaungsu Hluttaw MPs vote for one of three candidates—the candidate with the highest number of votes is elected president, while the other two are elected as vice-presidents. The president serves for a term of 5 years. Should a president resign for any reason or die in office, the Presidential Electoral College will meet and each of the three committees will nominate a candidate to finish out the prior President's term so that the terms of the legislature and presidency are synchronised. The candidate who receives the most votes from the nominees is elected. This process is similar to the one prescribed by the 1947 Constitution, in which MPs from the Parliament's Chamber of Nationalities and Chamber of Deputies elected the president by secret ballot. The President was then responsible for appointing a prime minister (on the advice of the Chamber of Deputies), who was constitutionally recognised as the head of government and led the Cabinet.
Fishmeal and oil from residues instead of whole fish have a different composition with more ash and less protein, which may limit its potential use for aquaculture. As the salmon farming industry expands, it requires more wild forage fish for feed, at a time when seventy-five percent of the world's monitored fisheries are already near to or have exceeded their maximum sustainable yield. The industrial-scale extraction of wild forage fish for salmon farming then impacts the survivability of the wild predator fish who rely on them for food. An important step in reducing the impact of aquaculture on wild fish is shifting carnivorous species to plant-based feeds. Salmon feeds, for example, have gone from containing only fishmeal and oil to containing 40 percent plant protein. The USDA has also experimented with using grain-based feeds for farmed trout. When properly formulated (and often mixed with fishmeal or oil), plant-based feeds can provide proper nutrition and similar growth rates in carnivorous farmed fish. Another impact aquaculture production can have on wild fish is the risk of fish escaping from coastal pens, where they can interbreed with their wild counterparts, diluting wild genetic stocks. Escaped fish can become invasive, out-competing native species.
The Fifth Coalition (1809) of Britain and Austria against France formed as Britain engaged in the Peninsular War in Spain and Portugal. The sea became a major theatre of war against Napoleon's allies. Austria, previously an ally of France, took the opportunity to attempt to restore its imperial territories in Germany as held prior to Austerlitz. During the time of the Fifth Coalition, the Royal Navy won a succession of victories in the French colonies. On land the major battles included Battles of Raszyn, Eckmuhl, Raab, Aspern-Essling, and Wagram. On land, the Fifth Coalition attempted few extensive military endeavours. One, the Walcheren Expedition of 1809, involved a dual effort by the British Army and the Royal Navy to relieve Austrian forces under intense French pressure. It ended in disaster after the Army commander, John Pitt, 2nd Earl of Chatham, failed to capture the objective, the naval base of French-controlled Antwerp. For the most part of the years of the Fifth Coalition, British military operations on land (apart from the Iberian Peninsula) remained restricted to hit-and-run operations executed by the Royal Navy, which dominated the sea after having beaten down almost all substantial naval opposition from France and its allies and blockading what remained of France's naval forces in heavily fortified French-controlled ports. These rapid-attack operations were aimed mostly at destroying blockaded French naval and mercantile shipping and the disruption of French supplies, communications, and military units stationed near the coasts.
Sources: en.wikipedia.org
The word yeast comes from Old English gist, gyst, and from the Indo-European root *yes-, meaning "boil", "foam", or "bubble". Yeast microbes are probably one of the earliest domesticated organisms. Archaeologists digging in Egyptian ruins found early grinding stones and baking chambers for yeast-raised bread, as well as drawings of 4,000-year-old bakeries and breweries. Vessels studied from several archaeological sites in Israel (dating to around 5,000, 3,000 and 2,500 years ago), which were believed to have contained alcoholic beverages (beer and mead), were found to contain yeast colonies that had survived over the millennia, providing the first direct biological evidence of yeast use in early cultures. In 1680, Dutch naturalist Anton van Leeuwenhoek first microscopically observed yeast, but at the time did not consider them to be living organisms, but rather globular structures as researchers were doubtful whether yeasts were algae or fungi. Theodor Schwann recognized them as fungi in 1837.
== Biosynthesis == Ibotenic acid's biosynthetic genes are organized in a physically linked biosynthetic gene cluster. The biosynthetic pathway is initiated by hydroxylation of glutamic acid by a dedicated Fe(II)/2-oxoglutarate-dependent oxygenase. The reaction yields threo-3-hydroxyglutamic acid, which is converted into ibotenic acid, likely by enzymes encoded in the biosynthetic gene cluster.
=== Site hosting === Planet Half-Life also offered free web hosting for Half-Life themed websites. The web hosting was regulated through GameSpy, though the address of hosted sites were subsets of the Planet Half-Life domain. This was a major attraction of the site in its early days and many original Half-Life mod teams took advantage of the offer. However this feature has not been utilized nearly as much since the release of Half-Life 2. A directory of the old sites still exists, although most have been abandoned by their creators.
Sources: en.wikipedia.org
== Statement == Let P be an arbitrary point inside the triangle ABC. From P and ABC, define U, V, and W as the points where the angle bisectors of BPC, CPA, and APB intersect the sides BC, CA, AB, respectively. Then Barrow's inequality states that
=== Metatropic dysplasia === Metatropic means "changing form" and refers to this form of skeletal dysplasia as there is an abnormality in the growth plates. Skeletal changes continue over time and may need surgical intervention to help protect the lungs. Symptoms starting at birth may be mild or can be fatal. There are recognizable features in individuals with this genetic disorder. Some are short stature, narrow chest, "facial features such as a prominent forehead, underdevelopment of the upper jaw, cheekbones and eye sockets (midface hypoplasia), and a squared-off jaw." It is considered a more severe skeletal dysplasia, but is very rare, with the exact number of those affected unknown. Prognosis is largely on a case-by-case basis depending on the severity, and life expectancy may not be impacted unless there are respiratory complications.
NMR quantum computing uses the spin states of nuclei within molecules as qubits. NMR differs from other implementations of quantum computers in that it uses an ensemble of systems; in this case, molecules.
Progestogens are the precursors of all other human steroids, and all human tissues which produce steroids must first convert cholesterol to pregnenolone. This conversion is the rate-limiting step of steroid synthesis, which occurs inside the mitochondrion of the respective tissue. The conversion is catalyzed by the mitochondrial P450scc system. Cortisol, corticosterone, aldosterone are produced in the adrenal cortex. Estradiol, estrone and progesterone are made primarily in the ovary, estriol in placenta during pregnancy, and testosterone primarily in the testes (some testosterone may also be produced in the adrenal cortex). Estradiol is converted from testosterone directly (in males), or via the primary pathway DHEA – androstenedione – estrone and secondarily via testosterone (in females). Stromal cells have been shown to produce steroids in response to signaling produced by androgen-starved prostate cancer cells. Some neurons and glia in the central nervous system (CNS) express the enzymes required for the local synthesis of pregnenolone, progesterone, DHEA and DHEAS, de novo or from peripheral sources.
Sources: en.wikipedia.org
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。
Semax 被描述为 ACTH(4-10) 的结构类似物，两者共享部分序列特征。它保留了该片段的部分神经相关活性方向，但去除了完整片段带来的激素释放效应。二者并非同一物质，也不能互相替代。
加入的 Pro-Gly-Pro 三肽被普遍认为能提升分子对蛋白水解酶的稳定性。这种设计让短肽在体内维持时间更长。具体延长的程度以及不同组织中是否一致，文献中仍存在不同报告。
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.