If you have been reading about Neurotrophic signalling 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.
Last reviewed on 2026-02-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
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.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
=== Hybrid === When the parent anticyclone is weaker or not ideally located, the diabatic process must start to contribute in order to develop CAD. In scenarios where there is an equal contribution from dry synoptic forcing and diabatic processes, it is considered a hybrid damming event. The 250-mb jet is weaker and slightly farther south relative to a classical composite 24 hours prior to CAD onset. With the surface parent high farther west, it builds in eastward into the northern Great Plains and western Great Lakes region, located beneath a region of confluent flow from the 250-mb jet.
== Single-cell protein and gasohol projects == Even greater expectations of biotechnology were raised during the 1960s by a process that grew single-cell protein. When the so-called protein gap threatened world hunger, producing food locally by growing it from waste seemed to offer a solution. It was the possibilities of growing microorganisms on oil that captured the imagination of scientists, policy makers, and commerce. Major companies such as BP staked their futures on it. In 1962, BP built a pilot plant at Cap de Lavera in Southern France to publicize its product, Toprina. Initial research work at Lavera was done by Alfred Champagnat, In 1963, construction started on BP's second pilot plant at the Grangemouth Refinery in Scotland. As there was no well-accepted term to describe the new foods, in 1966 the term "single-cell protein" (SCP) was coined at MIT to provide an acceptable and exciting new title, avoiding the unpleasant connotations of microbial or bacterial. The "food from oil" idea became quite popular by the 1970s, when facilities for growing yeast fed by n-paraffins were built in a number of countries. The Soviets were particularly enthusiastic, opening large "BVK" (belkovo-vitaminny kontsentrat, i.e., "protein-vitamin concentrate") plants next to their oil refineries in Kstovo (1973) and Kirishi (1974). By the late 1970s, however, the cultural climate had completely changed, as the growth in SCP interest had taken place against a shifting economic and cultural scene (136).
=== In mines === 222Rn decay products have been classified by the International Agency for Research on Cancer as being carcinogenic to humans, and as a gas that can be inhaled, lung cancer is a particular concern for people exposed to elevated levels of radon for sustained periods. During the 1940s and 1950s, when safety standards requiring expensive ventilation in mines were not widely implemented, radon exposure was linked to lung cancer among non-smoking miners of uranium and other hard rock materials in what is now the Czech Republic, and later among miners from the Southwestern US and South Australia. Despite these hazards being known in the early 1950s, this occupational hazard remained poorly managed in many mines until the 1970s. During this period, several entrepreneurs opened former uranium mines in the US to the general public and advertised alleged health benefits from breathing radon gas underground. Health benefits claimed included relief from pain, sinus problems, asthma, and arthritis, but the government banned such advertisements in 1975, and subsequent works have debated the truth of such claimed health effects, citing the documented ill effects of radiation on the body. Since that time, ventilation and other measures have been used to reduce radon levels in most affected mines that continue to operate. In recent years, the average annual exposure of uranium miners has fallen to levels similar to the concentrations inhaled in some homes.
The variance is infinite. In a real reactor, diffusion will eventually mix the layers so that the tail of the RTD becomes exponential and the variance finite; but laminar flow reactors can have variance greater than 1, the maximum for CTSD reactors.
=== E3 subunit === The E3 component is a flavoprotein, and it re-oxidizes the reduced lipoyl sulfur residues of E2 using FAD (a catalytic cofactor) as the oxidant. FAD then transfers these protons and electrons to NAD+ (a stoichiometric cofactor) to complete the reaction cycle.
Sources: en.wikipedia.org
Woods assures Biko that he will meet with a Government official to discuss the matter. Woods then meets with Jimmy Kruger (John Thaw), the South African Minister of Justice, in his house in Pretoria in an attempt to prevent further abuses. Minister Kruger first expresses discontent over their actions; however, Woods is later harassed at his home by security forces, who insinuate that their orders came directly from Kruger. Later, Biko travels to Cape Town to speak at a student-run meeting. En route, security forces stop his car and arrest him asking him to say his name, and he says, "Bantu Stephen Biko". He is held in harsh conditions and beaten, causing a severe brain injury. A doctor recommends consulting a nearby specialist in order to best treat his injuries, but the police refuse out of fear that he might escape. The security forces instead decide to take him to a police hospital in Pretoria, around 700 miles (1,100 km) away from Cape Town. He is thrown into the back of a prison van and driven on a bumpy road, aggravating his brain injury and resulting in his death. Woods then works to expose the police's complicity in Biko's death. He attempts to expose photographs of Biko's body that contradict police reports that he died of a hunger strike, but he is prevented just before boarding a plane to leave and informed that he is now 'banned', therefore not able to leave the country.
=== Mechanical ventilation === Isolated mechanical forces may not adequately explain ventilator induced lung injury (VILI). The damage is affected by the interaction of these forces and the pre-existing state of the lung tissues, and dynamic changes in alveolar structure may be involved. Factors such as plateau pressure and positive end-expiratory pressure (PEEP) alone do not adequately predict injury. Cyclic deformation of lung tissue may play a large part in the cause of VILI, and contributory factors probably include tidal volume, positive end-expiratory pressure and respiratory rate. There is no protocol guaranteed to avoid all risk in all applications.
UNC Rex Hospital is a general hospital located in Raleigh, North Carolina. It is the capital city's oldest hospital, founded by a bequest from John T. Rex (1771–1839), a local tanner, planter, and owner of enslaved families, and named in his honor. Originally located on what is now Dorothea Dix campus, and later on St. Mary's Street, Rex is now located in west Raleigh at the corner of Blue Ridge Road and Lake Boone Trail. Rex Health Care's services include oncology, heart and vascular, surgical services (including bariatric, heartburn, GI, orthopedic, neuro, and spinal), rehabilitation, emergency department, urgent care, women's services, and wound healing. Rex is a member of the UNC Health Care system, a non-profit integrated health care system, owned by the state of North Carolina and based in Chapel Hill, North Carolina. Rex is located just 2 miles from the Lenovo Center, and is the official healthcare provider of the Carolina Hurricanes and NC State Wolfpack.
This perspective implies that the processes that lead to El Niño and La Niña also eventually bring about their end, making ENSO a self-sustaining process. Other theories view the state of ENSO as being changed by irregular and external phenomena such as the Madden–Julian oscillation, tropical instability waves, and westerly wind bursts.
Sources: en.wikipedia.org
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.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
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。