A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-05-11 and is reviewed periodically as new material appears.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
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。
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 |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Check valves are often part of common household items. Although they are available in a wide range of sizes and costs, check valves generally are very small, simple, and inexpensive. Check valves work automatically and most are not controlled by a person or any external control; accordingly, most do not have any valve handle or stem. The bodies (external shells) of most check valves are made of plastic or metal. An important concept in check valves is the cracking pressure which is the minimum differential upstream pressure between inlet and outlet at which the valve will operate. Typically the check valve is designed for and can therefore be specified for a specific cracking pressure.
As such, the yeasts involved in what has been typically called top-cropping or top-fermenting ale may be both Saccharomyces cerevisiae and complex hybrids of Saccharomyces cerevisiae and Saccharomyces kudriavzevii. Three notable ales, Chimay, Orval and Westmalle, are fermented with these hybrid strains, which are identical to wine yeasts from Switzerland.
Additionally, microscopy is based on single-particle measurements, meaning that large numbers of individual particles must be characterized to estimate their bulk properties. Spectroscopy, which measures the particles' interaction with electromagnetic radiation as a function of wavelength, is useful for some classes of nanoparticles to characterize concentration, size, and shape. X-ray, ultraviolet–visible, infrared, and nuclear magnetic resonance spectroscopy can be used with nanoparticles. Light-scattering methods using laser light, X-rays, or neutron scattering are used to determine particle size, with each method suitable for different size ranges and particle compositions. Some miscellaneous methods are electrophoresis for surface charge, the Brunauer–Emmett–Teller method for surface area, and X-ray diffraction for crystal structure, as well as mass spectrometry for particle mass, and particle counters for particle number. Chromatography, centrifugation, and filtration techniques can be used to separate nanoparticles by size or other physical properties before or during characterization.
Sources: en.wikipedia.org
A precarious number of people managed to return to responsible work, while at the other extreme, people were left with severe and disabling impairments. Most people fell into an intermediate group, left with some improvement of their symptoms but also with emotional and intellectual deficits to which they made a better or worse adjustment. On average, there was a mortality rate of approximately 5% during the 1940s. A survey of British lobotomy patients lobotomised between 1942 and 1954 found that 13% of patients were deemed to have made a full recovery and a further 28% were deemed to have made a significant recovery; for 25% lobotomy was deemed to have made no change and 4% died as a result of the surgery. Patients after lobotomy can have a lowering and stabilising of blood pressure. They may have inertia, struggle to complete test problems, and might suffer from metabolic disorders. They may also be considered dispassionate about their feelings because they lack a strong emotional component. It is reported that the patients face less anxiety and stress, but have a constant feel of depression. The frontal lobotomy procedure could have severe negative effects on a patient's personality and ability to function independently. Lobotomy patients often show a marked reduction in initiative and inhibition. They may also exhibit difficulty imagining themselves in the position of others because of decreased cognition and detachment from society. Walter Freeman coined the term "surgically induced childhood" and used it constantly to refer to the results of lobotomy.
On 7 August 2022, Petro was sworn in, becoming the country's first leftist president. Later that month, Colombia and Venezuela formally reestablished bilateral diplomatic relations. The 21 June 2026 election run-off vote ended in a win for right-wing candidate, Abelardo de la Espriella, taking 49.7% of the vote compared to 48.7% of left-wing Iván Cepeda. On 7 August 2026, Abelardo de la Espriella was sworn in as Colombia’s president.
=== Wastewater treatment === A majority of silver nanoparticles in consumer products go down the drain and are eventually released into sewer systems and reach wastewater treatment plants. Primary screening and grit removal in wastewater treatment does not completely filter out silver nanoparticles, and coagulation treatment may lead to further condensation into wastewater sludge. The secondary wastewater treatment process involves suspended growth systems which allow bacteria to decompose organic matter within the water. Any silver nanoparticles still suspended in the water may collect on these microbes, potentially killing them due to their antimicrobial effects. After passing through both treatment processes, the silver nanoparticles are eventually deposited into the environment. A majority of the submerged portions of wastewater treatment plants are anoxic and rich in sulfur. During the wastewater treatment process, silver nanoparticles either remain the same, are converted into free silver ions, complex with ligands, or agglomerate. Silver nanoparticles can also attach to wastewater biosolids found in both the sludge and the effluent. Silver ions in wastewater are removed efficiently because of their strong complexation with chloride or sulfide. A majority of the silver found in wastewater treatment plant effluent is associated with reduced sulfur as organic thiol groups and inorganic sulfides. Silver nanoparticles also tend to accumulate in activated sludge, and the dominant form of the silver found in sewage sludge is Ag2S.
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
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。