If you have been reading about neurotrophic factor and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
| 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 |
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。
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。
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。
The station is at 750 m (2,460 ft) and the surrounding mountains at 1,100 m (3,600 ft), causing cold air to pool in the valley: recent studies show that winter temperatures in the area increase with elevation by as much as 10 °C (18 °F). The average temperature in Oymyakon has risen about 2.7 degrees Celsius since preindustrial times. On December 22, 1991, the Klinck Automatic Weather Station (AWS) (located at 72°31′N 40°48′W, altitude 3,105 metres (10,187 ft)) in Greenland recorded a temperature of −69.6 °C (−93.3 °F). The WMO validated the metadata and observations and was able to conclude that the observation was credible in terms of instrument calibration, monitoring of the station and the synoptic situation. The WMO Rapporteur accepted the observation as the officially lowest observed near‐surface air temperature for the Northern and Western Hemispheres.
GSH + R• → RH + GS• → 1/2 GSSG Thiyl radicals (such as glutathionyl radicals) are themselves oxidizing species in biology, with a single-electron reduction potential sufficient for oxidation of nucleic acids, proteins and polyunsaturated lipids. Therefore, GSH itself may not be effective at direct reduction of reactive oxygen species under physiological conditions. Under oxidizing conditions, hydrogen sulfide may react with glutathione (or other electrophilic oxidized forms of glutathione) to form glutathione hydropersulfide (GS–SH), which is a superior radical-trapping antioxidant and reductant. GSH is a highly important indirect antioxidant by acting as a coenzyme for various enzymes that couple GSH-to-GSSG oxidation to the reduction of harmful oxidizing species. Such enzymes include the glutathione peroxidase family, the glutaredoxin family, the peroxiredoxin family, and others.
== Properties == PAW contains reactive oxygen and nitrogen species, with a pH lower than untreated water along with higher electrical conductivity. PAW has disinfective properties: the oxidative stress that it causes on the cell membranes of the bacterial cells results in disruption of the cell membrane, followed by further damage that leads to cell death.
=== Test patch for child food allergies === The team from DBV Technologies has developed a patented, innovative process, the E-Patch, which is used to determine allergies in children. The ready-to-use, standardised patch tests are highly reliable and conserve the allergic agents in their optimal state. This innovative technique uses the principal of freeze drying and electrification to retain the allergic agents on the patch, without using solvent or glue. The E-patch is then conditioned so that it remains air and water tight. Once applied to the child the allergic agents are rapidly hydrated by body transpiration and liberated from the patch. They enter into contact with the skin and create, if positive, a reaction which can be seen by the doctor 48 hours later.
Sources: en.wikipedia.org
A positive result, in the absence of unequivocal high blood sugar, should be confirmed by a repeat of any of the above methods on a different day. It is preferable to measure a fasting glucose level because of the ease of measurement and the considerable time commitment of formal glucose tolerance testing, which takes two hours to complete and offers no prognostic advantage over the fasting test. According to the current definition, two fasting glucose measurements at or above 7.0 mmol/L (126 mg/dL) is considered diagnostic for diabetes mellitus. Per the WHO, people with fasting glucose levels from 6.1 to 6.9 mmol/L (110 to 125 mg/dL) are considered to have impaired fasting glucose. People with plasma glucose at or above 7.8 mmol/L (140 mg/dL), but not over 11.1 mmol/L (200 mg/dL), two hours after a 75 gram oral glucose load are considered to have impaired glucose tolerance. Of these two prediabetic states, the latter in particular is a major risk factor for progression to full-blown diabetes mellitus, as well as cardiovascular disease. The American Diabetes Association (ADA) since 2003 uses a slightly different range for impaired fasting glucose of 5.6 to 6.9 mmol/L (100 to 125 mg/dL). Glycated hemoglobin is better than fasting glucose for determining risks of cardiovascular disease and death from any cause.
The absence of salt in the seasoning is justified by the fact that the salt present in the butter at the time was sufficient. Lancelot de Casteau makes no comment on the vegetable, its origin, its price, or the ease or difficulty of finding it on the market. However, he has been using potatoes since at least December 12, 1557, since the dish "boiled potato" appears in the third course of the banquet that he organized on that date for the Joyous Entry of Prince-Bishop Robert of Berghes. As a court cook, he had to use quality products while keeping a reasonable budget, as he worked on his own funds and was only paid after presenting his statement of fees. The potato was cooked in the Principality of Liege sixty years before being offered "as a rarity at the table of the king" of France Louis XIII, in 1616.
Explorers, traders and missionaries arrived from Russia beginning in 1741. In 1741 the Russian government sent Vitus Bering, a Danish-born Russian, and Aleksei Chirikov, a Russian, in the ships Saint Peter and Saint Paul on a voyage of discovery in the Northern Pacific. After the ships were separated by a storm; Chirikov discovered several eastern islands of the Aleutian group, and Bering discovered several of the western islands. Bering was shipwrecked and died in the Komandorski Islands (Commander Islands); one of which now bears his name (Bering Island), along with the surrounding Bering Sea. The survivors of Bering's party reached the Kamchatka Peninsula in a boat constructed from the wreckage of their ship, and reported the islands were rich in fur-bearing animals. Siberian fur hunters flocked to the Commander Islands and gradually moved eastward across the Aleutian Islands to North America. In this manner, Russia gained a foothold on the northwestern coast of North America. The Aleutian Islands consequently belonged to Russia, until that country transferred all its possessions in North America to the U.S. in the 1867 Alaska Purchase. In the 1780s Russian merchant and seafarer Grigory Shelikhov established a company based on the systematic exploitation of the indigenous peoples, with whom there was sporadic conflict with the native population, for example the Awa'uq Massacre.
Peptidoglycan recognition protein 2 (PGLYRP2) is an enzyme (EC 3.5.1.28), N-acetylmuramoyl-L-alanine amidase (NAMLAA), that hydrolyzes bacterial cell wall peptidoglycan and is encoded by the PGLYRP2 gene.
=== Canonical and noncanonical pathways === The three best characterized Wnt signaling pathways are the canonical Wnt pathway, the noncanonical planar cell polarity pathway, and the noncanonical Wnt/calcium pathway. As their names suggest, these pathways belong to one of two categories: canonical or noncanonical. The difference between the categories is that a canonical pathway involves the protein beta-catenin (β-catenin) while a noncanonical pathway operates independently of it.
Sources: en.wikipedia.org
The division had been so rushed to get this brigade to the battlefront that it ignored individual deployment criteria. Paratroopers who had just returned from Vietnam now found themselves suddenly going back. The howl of soldier complaints was so vehement that the Department of the Army was soon forced to give each trooper who had deployed to Vietnam with the 3d Brigade the option of returning to Fort Bragg or remaining with the unit. To compensate for the abrupt departures from home for those who elected to stay with the unit, the Army authorized a month leave at the soldiers' own expense or a two-week leave with government aircraft provided for special flights back to North Carolina. Of the 3,650 paratroopers who had deployed from Fort Bragg, 2,513 elected to return to the United States at once. MACV had no paratroopers to replace them, and overnight the brigade was transformed into a separate light infantry brigade, airborne in name only.
One of the basic tenets of TCM is that the body's qi (sometimes translated as vital energy) is circulating through channels called meridians having branches connected to bodily organs and functions. The concept of vital energy is pseudoscientific. Concepts of the body and of disease used in TCM reflect its ancient origins and its emphasis on dynamic processes over material structure, similar to Classical humoral theory. TCM has also been controversial within China. In 2006, the Chinese philosopher Zhang Gongyao triggered a national debate with an article entitled "Farewell to Traditional Chinese Medicine", arguing that TCM was a pseudoscience that should be abolished in public healthcare and academia. The Chinese government took the stance that TCM is a science and continued to encourage its development. There are concerns about a number of potentially toxic plants, animal parts, and mineral compounds from China, as well as the facilitation of disease. Trafficked and farm-raised animals used in TCM are a source of several fatal zoonotic diseases. There are additional concerns over the illegal trade and transport of endangered species including rhinoceroses and tigers, and the welfare of specially farmed animals, including bears. Many TCM remedies are effective because they are combined with modern Western medicine. An example is the popular over-the-counter cold medication Ganmaoling Keli (Chinese: 感冒灵颗粒; pinyin: Gǎnmàolíng Kēlì; lit.
=== Type I === A civilization "close to the level currently achieved on Earth, with an energy consumption of ≈4×1019 erg/s" (≈4×1012 watts). A Type I civilization is usually defined as one that can harness all the energy that reaches its home planet from its parent star (for Earth, this value is about 2×1017 watts), which is about four orders of magnitude higher than the amount currently achieved on Earth, with an energy consumption of ≈2×1013 watts by 2020. The astronomer Guillermo A. Lemarchand defined Type I as a level close to today's terrestrial civilization, with an energy capacity equivalent to Earth's solar irradiance, between 1016 and 1017 watts.
Ultramicrotomy is a method of preparing extremely thin sections for transmission electron microscope (TEM) analysis. Tissues are commonly embedded in epoxy or other plastic resin. Very thin sections (less than 0.1 micrometer in thickness) are cut using diamond or glass knives on an ultramicrotome.
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.
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.