The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-23. Anything still debated is marked as such rather than presented as settled.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
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.
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.
Cryopreservation of whole moss plants, especially Physcomitrella patens, has been developed by Ralf Reski and coworkers and is performed at the International Moss Stock Center. This biobank collects, preserves, and distributes moss mutants and moss ecotypes.
Dietary restrictions are not used by the highly urban Brazilian ayahuasca church União do Vegetal, suggesting the risk is much lower than perceived and probably non-existent. The ritual use of ayahuasca by the Achuar people is featured in the Bruce Parry 2008 documentary series Amazon, in which Parry participates in the rite.
Researchers cautioned against causal interpretation from this study, citing confounding effects, methodological concerns and a 2020 meta-analysis of randomized controlled trials which showed no increased risk.
"Chemical Composition of Vintage Preban Absinthe with Special Reference to Thujone, Fenchone, Pinocamphone, Methanol, Copper, and Antimony Concentrations". Journal of Agricultural and Food Chemistry. 56 (9): 3073–3081. Bibcode:2008JAFC...56.3073L. doi:10.1021/jf703568f. PMID 18419128. Lachenmeier, Dirk W.; Walch, Stephan G.; Padosch, Stephan A.; Kröner, Lars U. (2006). "Absinthe – A Review". Critical Reviews in Food Science and Nutrition. 46 (5): 365–377. doi:10.1080/10408690590957322. PMID 16891209. S2CID 43251156.
Sources: en.wikipedia.org
Evolution of cells refers to the evolutionary origin and subsequent evolutionary development of cells. Cells first emerged at least 3.8 billion years ago approximately 750 million years after Earth was formed.
== RSKSOP-175 analysis of petroleum gases == A widely used methods for headspace analysis is described by the United States Environmental Protection Agency (USEPA) was developed as a "high quality, defendable, and documented way to measure" methane, ethane, and ethene, RSKSOP-175 is a standard operating procedure (SOP) and an unofficial method employed by the USEPA to detect and quantify dissolved gases in water. This method has been used to quantify dissolved hydrogen, methane, ethylene, ethane, propane, butane, acetylene, nitrogen, nitrous oxide, and oxygen. The method uses headspace gas injected into a gas chromatographic column (GC) to determine the original concentration in a water sample.
== Case studies: environmental impact on hemocyanin levels == A 2003 study of the effect of culture conditions of blood metabolites and hemocyanin of the white shrimp Litopenaeus vannamei found that the levels of hemocyanin, oxyhemocyanin in particular, are affected by the diet. The study compared oxyhemocyanin levels in the blood of white shrimp housed in an indoor pond with a commercial diet with that of white shrimp housed in an outdoor pond with a more readily available protein source (natural live food) as well. Oxyhemocyanin and blood glucose levels were higher in shrimp housed in outdoor ponds. It was also found that blood metabolite levels tended to be lower in low activity level species, such as crabs, lobsters, and the indoor shrimp when compared to the outdoor shrimp. This correlation is possibly indicative of the morphological and physiological evolution of crustaceans. The levels of these blood proteins and metabolites appear to be dependent on energetic demands and availability of those energy sources.
With the death of Stalin and ensuing de-Stalinisation, Marxism–Leninism underwent revisions and adaptations such as Guevarism, Titoism, Ho Chi Minh Thought, Hoxhaism, and Maoism, with the latter two constituting anti-revisionist Marxism–Leninism. These adaptations caused splits between communist states, resulting in the Tito–Stalin split, the Sino-Soviet split, and the Sino-Albanian split. As the Cold War concluded with the demise of much of the socialist world, many surviving communist states reformed their economies and embraced market socialism. Complementing this economic shift, the Communist Party of China developed Maoism into Deng Xiaoping Theory. Today this comprises part of China's governing ideology, with the latest developments including Xi Jinping Thought. Meanwhile, the Communist Party of Peru developed Maoism into Marxism–Leninism–Maoism. The latest developments to Marxism–Leninism–Maoism include Gonzaloism, Maoism-Third Worldism, National Democracy, and Prachanda Path. Ongoing Marxist–Leninist (Maoist) insurgencies include those waged in the Philippines, India, and Turkey. The Nepalese Civil War, fought by Marxist–Leninist–Maoists, ended in their victory in 2006. Criticism of Marxism–Leninism overlaps with criticism of communist party rule and focuses on the actions and policies of Marxist–Leninist leaders, notably Stalin and Mao Zedong. Communist states have been marked by centralised state control by the communist party, political repression, state atheism, collectivisation and labour camps.
Many animals can learn behaviours by imitation, but ants may be the only group apart from mammals where interactive teaching has been observed. A knowledgeable forager of Temnothorax albipennis can lead a naïve nest-mate to newly discovered food by the process of tandem running. The follower obtains knowledge through its leading tutor. The leader is acutely sensitive to the progress of the follower and slows down when the follower lags and speeds up when the follower gets too close. Controlled experiments with colonies of Cerapachys biroi suggest that an individual may choose nest roles based on her previous experience. An entire generation of identical workers was divided into two groups whose outcome in food foraging was controlled. One group was continually rewarded with prey, while it was made certain that the other failed. As a result, members of the successful group intensified their foraging attempts while the unsuccessful group ventured out fewer and fewer times. A month later, the successful foragers continued in their role while the others had moved to specialise in brood care.
Sources: en.wikipedia.org
Even the territorial integrity of the country was in danger: On 7 March 1849, an imperial proclamation was issued in the name of the Emperor Francis Joseph, according to the new proclamation, the territory of Kingdom of Hungary would be carved up and administered by five military districts, while the Principality of Transylvania would be reestablished. These events represented a clear and obvious existential threat for the Hungarian state. The stadion constitution abolished Hungary’s separate constitutional statehood and reduced the Hungarian state to the status of a typical Habsburg province/crownland within a centralized Austrian Empire. The new constrained Stadion Constitution of Austria, the revocation of the April laws and the Austrian military campaign against the Kingdom of Hungary resulted in the fall of the pacifist Batthyány government (which sought agreement with the court) and led to the sudden emergence of Lajos Kossuth's followers in the Hungarian parliament, who demanded the full independence of Hungary. The Austrian military intervention in the Kingdom of Hungary resulted in strong anti-Habsburg sentiment among Hungarians, thus the events in Hungary grew into a war for total independence from the Habsburg dynasty.
=== Freshwater ecosystems === Whole-lake experiments carried out at the Experimental Lakes Area in Ontario, Canada, have displayed the potential for cage aquaculture to source numerous changes in freshwater ecosystems. Following the initiation of an experimental rainbow trout cage farm in a small boreal lake, dramatic reductions in mysis concentrations associated with a decrease in dissolved oxygen were observed. Significant increases in ammonium and total phosphorus, a driver for eutrophication in freshwater systems, were measured in the hypolimnion of the lake. Annual phosphorus inputs from aquaculture waste exceeded that of natural inputs from atmospheric deposition and inflows, and phytoplankton biomass has had a fourfold annual increase following the initiation of the experimental farm.
== Use of military intelligence == Intelligence played a pivotal factor throughout the Napoleonic Wars and could very well have changed the tide of war. The use and misuse of military intelligence dictated the course of many major battles during the Napoleonic Wars. Some of the major battles that were dictated by the use of intelligence include: The Battle of Waterloo, Battle of Leipzig, Battle of Salamanca, and the Battle of Vitoria. A major exception to the greater use of superior military intelligence to claim victory was the Battle of Jena in 1806. At the Battle of Jena even Prussian superior military intelligence was not enough to counter the sheer military force of Napoleons' armies. The use of intelligence varied greatly across the major world powers of the war. Napoleon at this time had more supply of intelligence given to him than any French general before him. However, Napoleon was not an advocate of military intelligence at this time as he often found it unreliable and inaccurate when compared to his own preconceived notions of the enemy. Napoleon rather studied his enemy via domestic newspapers, diplomatic publications, maps, and prior documents of military engagements in the theaters of war in which he would operate. It was this stout and constant study of the enemy which made Napoleon the military mastermind of his time. Whereas, his opponents—Britain, Austria, Prussia, and Russia—were much more reliant on traditional intelligence-gathering methods and were much quicker and more willing to act on them.
== Function == The activity of GSTs is dependent upon a steady supply of GSH from the synthetic enzymes gamma-glutamylcysteine synthetase and glutathione synthetase, as well as the action of specific transporters to remove conjugates of GSH from the cell. The primary role of GSTs is to detoxify xenobiotics by catalyzing the nucleophilic attack by GSH on electrophilic carbon, sulfur, or nitrogen atoms of said nonpolar xenobiotic substrates, thereby preventing their interaction with crucial cellular proteins and nucleic acids. Specifically, the function of GSTs in this role is twofold: to bind both the substrate at the enzyme's hydrophobic H-site and GSH at the adjacent, hydrophilic G-site, which together form the active site of the enzyme; and subsequently to activate the thiol group of GSH, enabling the nucleophilic attack upon the substrate. The glutathione molecule binds in a cleft between N- and C-terminal domains - the catalytically important residues are proposed to reside in the N-terminal domain. Both subunits of the GST dimer, whether hetero- or homodimeric in nature, contain a single nonsubstrate binding site, as well as a GSH-binding site. In heterodimeric GST complexes such as those formed by the cytosolic mu and alpha classes, however, the cleft between the two subunits is home to an additional high-affinity nonsubstrate xenobiotic binding site, which may account for the enzymes' ability to form heterodimers.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
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。