Everything below concerns semax. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-05-16. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
However, in a preprint study, Carnegie Mellon University researchers tested the behavior of agents in a simulated software company and found that none of the agents could complete a majority of the tasks assigned to them. Other researchers had similar findings with Devin AI and other agents in both formal business settings and freelance work. In June 2025, CNN argued that CEOs's statements on AI replacing their employees were a strategy to "[keep] workers working by making them afraid of losing their jobs." Tech companies have pressured employees to use generative AI models in their work, including AI coding agents. Brian Armstrong, the CEO of Coinbase, fired several employees who did not. Some business leaders have replaced some of their employees with agents, but have said that the agents would need more supervision than those employees. In October 2025, Futurism questioned whether Amazon's previously announced efforts to replace parts of its workforce with generative AI and AI agents could have led to the October 2025 outage of Amazon Web Services. Large technology companies such as Salesforce, Klarna and IBM announced layoffs in 2025, replacing hundreds of their employees in human resources or customer service with AI agents. However, Klarna later rehired several human employees. Yoshua Bengio warned at the 2025 World Economic Forum that "all of the catastrophic scenarios with AGI or superintelligence happen if we have agents". Financial authorities have warned that more complex and autonomous "agentic" AI could become a channel for systemic risk in finance.
== Resistance == Resistance to zalcitabine develops infrequently compared with other nRTIs, and generally only occurs at a low level. The most common mutation observed in vivo is T69D, which does not appear to give rise to cross-resistance to other nRTIs; mutations at positions 65, 74, 75, 184 and 215 in the pol gene are observed more rarely.
Arginylglycylaspartic acid (RGD) is the most common peptide motif responsible for cell adhesion to the extracellular matrix (ECM), found in species ranging from Drosophila to humans. Cell adhesion proteins called integrins recognize and bind to this sequence, which is found within many matrix proteins, including fibronectin, fibrinogen, vitronectin, osteopontin, and several other adhesive extracellular matrix proteins. The discovery of RGD and elucidation of how RGD binds to integrins has led to the development of a number of drugs and diagnostics, while the peptide itself is used ubiquitously in bioengineering. Depending on the application and the integrin targeted, RGD can be chemically modified or replaced by a similar peptide which promotes cell adhesion.
=== Energy === Most civilian nuclear reactors, as well as all naval reactors, require fuel containing concentrated 235U, and production of that fuel generates depleted uranium as residue. Some power-generating reactors design are able to use unenriched fuel, for example the pressurized heavy-water reactors such as the CANDU design. However, as of 2013, about 10% of those built use that technology. Travelling wave reactors are a proposed type of reactor which can use depleted uranium as fuel.
Sources: en.wikipedia.org
Throughout its history, the Hydropower corps has been involved in the construction of over 50 hydropower projects, including the Three Gorges Dam, Wan'an Dam and Longtan Dam, along with providing aid and rescue to many disasters, such as the 2014 Ludian earthquake and 2015 Shenzhen landslide. The Hydropower corps was deployed for search and rescue after the 2013 Qingdao oil pipeline explosion. After the 2014 Ludian earthquake, the 1st Hydropower Corps deployed 263 personnel to conduct an emergency demolition operation of Changhai Dam, which after the earthquake had huge risk of a dam failure. The Hydropower corps was officially disbanded on 30 August 2018, and was handed over to the China Anneng Construction Group in April 2019.
The magnitude of sensory impairment may vary in people of differing weights. The NIAAA defines the term "binge drinking" as a pattern of drinking that brings a person's blood alcohol concentration (BAC) to 0.08 grams percent or above.
Homochirality is the uniformity of materials composed of chiral (non-mirror-symmetric) units. Living organisms use molecules with the same chirality: with almost no exceptions, amino acids are left-handed while nucleotides and sugars are right-handed. Chiral molecules can be synthesized, but in the absence of a chiral source or a chiral catalyst, they are formed in a 50/50 (racemic) mixture of both forms. Non-racemic mixtures can arise from racemic materials by asymmetric physical laws such as the electroweak interaction, or in asymmetric environments, such as those in which molecules are exposed to circularly polarized light of a given handedness. It has been hypothesized that the solar nebula was such an environment, exposed to circularly-polarized radiation from an external source before or during the epoch of planet formation. This proposal is consistent with the finding that some amino acids delivered to Earth in meteorites exhibit a chiral asymmetry of the same sign as terrestrial life. Once established, a chirality imbalance may influence subsequent chemical evolution. A small bias in the population can be amplified by asymmetric autocatalysis, as in the Soai reaction, where a chiral molecule catalyzes its own production.
A fleet of opium clippers on the River Ganges Confessions of a Poppy Tea addict DEA drug information: Opium, morphine, and heroin From Flowers to Heroin, CIA publication Erowid: Opium Opium in India Opium Made Easy by Michael Pollan (originally appeared in Harper's.) House of Opium museum BLTC Research: Speculations on the future of opioids Thailex photo: Traditional method of using opium in Thailand Tsur Shezaf, Writer, The Opium Growers of Sinai Archived November 20, 2009, at the Wayback Machine UNODC – United Nations Office on Drugs and Crime – Afghan Opium Survey 2009 "The Alkaloids of Opium", Scientific American, 20 July 1878, p. 36, historical account on the physiological effects of the first 16 known alkaloids
8 October – Conservative Party leader Kemi Badenoch delivers her keynote speech to the Conservative Party Conference on its final day. 9 October – Kensington Palace announces that Prince William will attend the COP30 conference in Brazil in November. Former prime minister Rishi Sunak takes up paid adviser roles with Microsoft and Anthropic, the earnings from which will be donated to the charity to tackle numeracy problems in the UK that he and his wife founded. Councillor Rowland O'Connor resigns as deputy leader of the Reform UK group on Cornwall Council. 10 October – Ash Regan resigns from the Alba Party in order to "focus" on her efforts to criminalise prostitution. Bristol City councillor Fabian Breckels is suspended from the Labour Party over an alleged racist comment posted on Facebook. 12 October – Starmer arrives in Egypt ahead of an international summit on the Gaza peace process where Downing Street says he will pay "particular tribute" to the US president, Donald Trump. 13 October – MI5 warns MPs they are being targeted in espionage operations by Russia, China and Iran. The Scottish National Party conference is held in Aberdeen. Councillor Rob Parsonage resigns as leader of the Reform UK group on Cornwall Council. 14 October – The Northern Ireland Troubles Bill, designed to replace the Northern Ireland Troubles (Legacy and Reconciliation) Act 2023, receives its first reading in the House of Commons.
Sources: en.wikipedia.org
== Legal issues == On June 25, 2010, Bayer sued Teva for falsely claiming that Teva's Gianvi was stabilized by betadex as a clathrate, and could consequently be advertised as a generic of Yaz. The settlement resulted in Teva changing its product marketing to remove the claim that it used the same ingredients as Yaz. Bayer's method specifically prevents oxidative degradation of the estrogen, while Teva's does not. In January 2015, the Supreme Court of the United States decided for Teva on the Copaxone patent in Teva Pharmaceuticals USA, Inc. v. Sandoz, Inc. In December 2016, the attorneys general of 20 states filed a civil complaint accusing Teva of a coordinated scheme to artificially maintain high prices for a generic antibiotic and diabetes drug. The complaint alleged price collusion schemes between six pharmaceutical firms including informal gatherings, telephone calls, and text messages. In January 2019, the Supreme Court of the United States decided for Teva in Helsinn Healthcare S.A. v. Teva Pharmaceuticals USA Inc. On May 11, 2019, Teva Pharmaceuticals USA was one of 19 drug companies sued for price fixing in the United States by 44 states for inflating its prices, sometimes up to 1000%, in an illegal agreement among it and its competitors. In June 2021, Teva agreed to pay $925M to settle allegations it had engaged in price fixing in Mississippi. In January 2022, Teva agreed to pay $425M to settle allegations that it had concealed price fixing practices from shareholders. In May 2019, Teva Pharmaceuticals USA agreed to pay $85 million to the U.S.
The article cites the attempts to replicate Hamer's work, some supportive and some not. It concludes, "Although it is encouraging that the largest study replicated some findings from smaller studies, the case is not closed. Still larger studies are needed to provide the degree of certainty now expected in molecular genetics, and in any case, the mapping case is not closed in molecular genetics until one has identified the genes that affect a trait." Hamer and colleagues also investigated the genetic roots of anxiety and found that a promoter region polymorphism in the gene for the serotonin transporter, which is the target of antidepressant drugs such as Prozac, is associated with mood and personality. This finding has been extensively replicated and extended and its activity has been confirmed by direct brain imaging studies. In 2004, Hamer used data from ongoing behavioral genetics studies in his lab to explore the possibility of genetic influences on spirituality. In The God Gene: How Faith is Hardwired into our Genes, he proposed that a quantitative measure of self-transcendence is partially heritable and may be correlated to a specific gene, VMAT2, involved in monamine metabolism. Hamer's speculations on the possible role of genetics in religious experience were featured in a cover story in Time magazine.
== Personnel == Permanent Forces — full-time active members National Servicemen — Initially called up for 1 year national service, later extended to 2 years national service in 1977, with ongoing short term service requirements. Troops were generally fully trained for operational duty within the space of 4–7 months. Citizen Forces — Conventional Reserve (Motorised and Mechanised) and other units — fully trained part-time members Commando Forces — Light Infantry and Rear Area Defence — fully trained members Special Forces — composed of the Reconnaissance Regiments and support personnel Voluntary Term Service — created in 1992 to replace the National Service Service Volunteers — non-permanent full-time members Auxiliary Service — limited duty personnel who did not meet the academic or physical requirements for national service but performed guard, COIN, labour, and driving duties Prior to amalgamation, the SADF had 585,000 personnel divided as follows:
== Chemical reactions == Being multifunctional, cysteine undergoes a variety of reactions. Much attention has focused on protecting the thiol group. Methylation of cysteine gives S-methylcysteine. Treatment with formaldehyde gives the thiazolidine thioproline. With phosgene and related carbonylating agents, cysteine gives procysteine. Cysteine forms a variety of coordination complexes upon treatment with metal ions. This coordination behavior is seen in many metal-cysteine metalloenzymes.
== Physiology == MC5R is necessary for normal sebum production. Stimulation of MC5R promotes fatty acid oxidation in skeletal muscle and lipolysis in adipocytes. MC5R is essential for erythrocyte differentiation. MC5R is involved in inflammation. MC5R helps maintain thermal homeostasis. Stimulation of the MC5R in skeletal muscle causes glucose uptake. In vitro, MC5R agonism is cardioprotective and kidney protective. MC5R is expressed in the brain at different levels depending on physical activity.
Sources: en.wikipedia.org
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.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
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。