Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-02-18. Numbers and descriptions here follow the published literature rather than marketing material.
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 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。
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.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
| 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. 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.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
=== Chemical detection === NASA contracted with Intelligent Optical Systems (IOS) to develop moisture- and pH-sensitive sensors to warn of corrosive conditions in aircraft before damage occurs. This sensor changes color in response to contact with its target. After completing the work with NASA, IOS was tasked by the U.S. Department of Defense to further develop the sensors for detecting chemical warfare agents and potential threats, such as toxic industrial compounds and nerve agents. IOS has sold the chemically sensitive fiber optic cables to major automotive and aerospace companies, who are finding a variety of uses for the devices such as aiding experimentation with nontraditional power sources, and as an economical "alarm system" for detecting chemical release in large facilities.
Keepers should be careful of the combination of light and heat radiated from composite UV‑A and UV‑B lamps; typical lamps emit high levels of UV‑A with low levels of UV‑B that are often have different fixed strengths at different wavelengths that are difficult to adjust to meet different reptiles' metabolic needs. A better strategy is to use separate lamps for separate UV bands so that keepers can place and control the lamps' intensity for best animal health.
In the African-American slave community, slaves quickly adopted funeral procedures and the location of gravesites of family and friends. Specific slaves were assigned to prepare dead bodies, build coffins, dig graves, and construct headstones. Slave funerals were typically at night when the workday was over, with the master present to view all the ceremonial procedures. Slaves from nearby plantations were regularly in attendance. At death, a slave's body was wrapped in cloth. The hands were placed across the chest, and a metal plate was placed on top of their hands. The reasoning for the plate was to hinder their return home by suppressing any spirits in the coffin. Often, personal property was buried with slaves to appease spirits. The coffins were nailed shut once the body was inside, and carried by hand or wagon, depending on the property designated for the slave burial site. Slaves were buried oriented east to west, with feet at the eastern end and head at the western end and the person thus rising facing east. According to Christian doctrine, this orientation permitted rising to face the return of Christ without having to turn around upon the call of Gabriel's trumpet. Gabriel's trumpet would be blown near the eastern sunrise.
Sources: en.wikipedia.org
=== Blood deserts === Since blood products acquisition, storage, transportation, and administration requires extensive infrastructure, there are several regions in which there is no blood, colloquially referred to as blood deserts. In these regions, blood transfusion is often not possible, and communities may have to rely on the commonly illegal practice of drawing blood directly from other community members. Blood deserts are a serious global health crisis that affects many people every year.
PSSM is most prevalent in American Quarter Horses and their related breeds (Paint horse, Appaloosa, Appendix Quarter Horse), Draft horse breeds (especially Belgian Draft and Percherons), and Warmblood breeds. The Belgian Draft been shown to have a 36% prevalence of PSSM. Other breeds that have been diagnosed with PSSM include the Arabian, Lipizzaner, Morgan, Mustang, Peruvian Paso, Rocky Mountain Horse, Standardbred, Tennessee Walking Horse, Thoroughbred, and National Show Horse. It has been suggested that the GSY1 mutation provided some benefit to hard working animals with poor-quality diets, and is now damaging members of those "thrifty" breeds that are managed with moderate to low levels of work and diets high in non-structural carbohydrates. PSSM Type 1 (homozygous or heterozygous for the GSY1 mutation) is more common in Quarter Horses and their related breeds, and draft breeds, while PSSM Type 2 (negative for the GSY1 mutation) is more commonly seen in other breeds, including warmbloods. There is no sex predilection to the disease.
March 15: Education Law mandates girls' schools in communes with over 800 inhabitants. Curricula share similarities but differ by sex. Single-sex schooling is the rule, with teachers matching students' sex, except in communes under 800 inhabitants with prefect approval. Children from indigent families receive free education.
Sources: en.wikipedia.org
== Commercial syntheses of amino acids == The commercial production of amino acids usually relies on mutant bacteria that overproduce individual amino acids using glucose as a carbon source. Some amino acids are produced by enzymatic conversions of synthetic intermediates. 2-Aminothiazoline-4-carboxylic acid is an intermediate in the industrial synthesis of L-cysteine for example. Aspartic acid is produced by the addition of ammonia to fumarate using a lyase.
In addition, Kuwait had been producing oil above treaty limits established by OPEC. By the eve of the Iraqi invasion, Kuwait had set production quotas to almost 1.9 million barrels per day (300,000 m3/d), which coincided with a sharp worldwide drop in the price of oil. By the summer of 1990, Kuwaiti overproduction had become a serious point of contention with Iraq. Some analysts have speculated that one of Saddam Hussein's main motivations in invading Kuwait was to punish the ruling al-Sabah family in Kuwait for not stopping its policy of overproduction, as well as his reasoning behind the destruction of said wells. It is also hypothesized that Iraq decided to destroy the oil fields to achieve a military advantage, believing the intense smoke plumes serving as smoke screens created by the burning oil wells would inhibit Coalition offensive airstrikes, foil allied precision guided weapons and spy satellites, and could screen Iraq's military movements. Furthermore, it is thought that Iraq's military leaders may have regarded the heat, smoke, and debris from hundreds of burning oil wells as presenting a formidable area denial obstacle to Coalition forces. The onset of the oil well destruction supports this military dimension to the sabotage of the wells; for example, during the early stage of the Coalition air campaign, the number of oil wells afire was relatively small but the number increased dramatically in late February with the arrival of the ground war.
A protein kinase is a kinase which selectively modifies other proteins by covalently adding phosphates to them (phosphorylation) as opposed to kinases which modify lipids, carbohydrates, or other molecules. Phosphorylation usually results in a functional change of the target protein (substrate) by changing enzyme activity, cellular location, or association with other proteins. The human genome contains about 500 protein kinase genes and they constitute about 2% of all human genes. There are two main types of protein kinase. The great majority are serine/threonine kinases, which phosphorylate the hydroxyl groups of serines and threonines in their targets. Most of the others are tyrosine kinases, although additional types exist. Protein kinases are also found in bacteria and plants. Up to 30% of all human proteins may be modified by kinase activity, and kinases are known to regulate the majority of cellular pathways, especially those involved in signal transduction.
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。
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.