neurotrophic factor raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-04-14. Anything still debated is marked as such rather than presented as settled.
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。
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.
| Property | Value | Notes |
|---|---|---|
| 化学类别 | 合成七肽 | ACTH(4-10) 结构类似物 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | 单字母写作 MEHFPGP |
| 分子量 | 约 813.9 Da | 随确切形式和盐型略有变化 |
| 常见同义词 | ACTH(4-10) 类似物 | 俄语文献称 Семакс |
| 开发来源 | 俄罗斯 | 二十世纪八十年代 |
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.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
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.
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.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
=== Category:EC 3.5 (act on carbon–nitrogen bonds, other than peptide bonds) === Category:EC 3.5.1 (In linear amides) Urease (EC 3.5.1.5) Category:EC 3.5.2 (In cyclic amides) Beta-lactamase (EC 3.5.2.6) Category:EC 3.5.3 (In linear amidines) Arginase (EC 3.5.3.1) Category:EC 3.5.4 (In cyclic amidines) Adenosine deaminase (EC 3.5.4.4) GTP cyclohydrolase I (EC 3.5.4.16) Category:EC 3.5.5 (In nitriles) Nitrilase (EC 3.5.5.1)
==== Controversy over Juan Silva ==== On 3 November 2021, Transportation Minister Juan Silva announced an agreement with transport unions. Prior to the agreement, the transport unions of Lima and Callao had announced plans to strike. The agreement involved the replacement of the president of the Urban Transportation Authority, and the head of the Superintendence of Land Transport of People, Cargo and Goods (Sutran). The new head of the Sutran resigned 6 days later, following the revelation that 3 police complaints had been filed against her for alleged robberies at shopping centers. On 11 November 2021, Congress voted against interpelling Silva, in part due to Popular Force abstaining. Since Popular Force and its Fujmorist ideology are seen as being staunchly opposed to Castillo, their decision to abstain drew much criticism from anti-Castillo hardliners. Popular Force's spokesperson, Hernando Guerra García, responded to the criticism by saying that the "spotlight" shouldn't be on two things at once, referring to the pressure campaign against the then Defense Minister Walter Ayala and this case. Guerra García said that interpellation would go "minister by minister." On 18 November 2021, Congress accepted a new motion to interpellate Juan Silva. The motion was proposed by Popular Force.
Yale University entered into its own licensing agreement with a private company, leading Fenn to file a lawsuit against the school in 1996. Yale countersued, requesting damages and reassignment of the patent. The two parties did not reach an out of court settlement, despite repeated attempts at mediation. In 2005, U.S. District Judge Christopher Droney ruled against Fenn, awarding Yale $545,000 in royalties and $500,000 in legal fees. Judge Droney was critical of Fenn, saying "Dr. Fenn only obtained the patent through fraud, civil theft, and breach of fiduciary duty." Evidence presented in the case indicated that Fenn had served on panels at Yale University that reviewed the institution's policy on intellectual property. A spokesperson for Yale said, "We are pleased by the result in this case and, in particular, by the court's vindication of the Yale patent policy." The ruling, and Yale's response produced a mixed reaction from some of Fenn's colleagues and former students, who wrote a letter to the Yale Daily News stating, "'Vindicating the Yale patent policy' is a poor excuse for treating a Nobel Laureate with a 68-year association with and dedicated service to the University, in such a contemptible manner."
Sources: en.wikipedia.org
==== Types of 3D printing used in manufacturing vascularized organs ==== Extrusion Extrusion based printing is a type of printing in which material is pushed through a nozzle and extruded onto a surface or medium. While material is being extruded, either the nozzle or the print bed is moved so that the material can be placed in complex shapes across it medium. Layers upon layers of material are placed until a 3D structure is formed. The extruded material comes out as a liquid and is solidified through varies means depending on the chemical or physical properties of the material. For example, the material could be solidified through the use of photoreceptive polymerization, in which light activates the material to solidify. The material could also be hardened through the use of chemicals or enzymes. Some examples of bioinks used in extrusion based printing include some alginates, hyaluronic acid, and gellan gum.
Trails Through Daybreak follows Van Arkride, a mix of a detective and bounty hunter known as a Spriggan, and high schooler Agnes Claudel, who hires Van to search for eight artifacts that hold the key to solving an apocalyptic mystery. The arc is set in Calvard and is considered the start of the second half of the series. The first game, Trails Through Daybreak, was released in Japan for the PlayStation 4 in 2021. It features an action-based battle system as well as updates to the traditional turn-based system. An English version was released by NIS America in July 2024 in addition to a Nintendo Switch version. A sequel, Trails Through Daybreak II, was released in Japan for the PlayStation 4 and PlayStation 5 in September 2022 and for the Switch in July 2024. The English version released in February 2025. A third game, Trails Beyond the Horizon, was released in Japan in September 2024 and worldwide in January 2026. A sequel to Trails Beyond the Horizon is planned to end the Calvard arc.
Matrikines are a large and somewhat loosely defined group of peptides and small proteins, encompassing both endogenous signalling factors important in wound healing and tissue remodeling, and synthetically produced versions of these along with related analogues and derivatives, which are used mainly for cosmetic applications as well as for scientific research and with some medical indications.
Sources: en.wikipedia.org
Parmotrema perlatum, commonly known as the powdered ruffle lichen, is a common species of foliose lichen in the family Parmeliaceae. The species has a cosmopolitan distribution and occurs throughout the Northern and Southern Hemispheres. Parmotrema perlatum is a prominent and widely recognised species within its genus across primarily temperate zones, preferring humid, oceanic-suboceanic habitats. It is found in diverse geographic areas including Africa, North and South America, Asia, Australasia, Europe, and islands in the Atlantic and Pacific oceans. It usually grows on bark, but occasionally occurs on siliceous rocks, often among mosses. The thallus of Parmotrema perlatum is large, light-grey to pale-blue patch-shaped with rounded and ruffled lobes and often with black hair-cilia at the edges. Distinguishing features of the lichen include its conspicuous soralia (reproductive structures) near the lobe edges, curled leaf-like lobes, and a narrow, shiny, and sometimes wrinkly area on the underside near the margin. This species is known for producing certain secondary metabolites, namely atranorin and a group of substances known as the stictic acid complex, which includes stictic and constictic acids, among other related compounds. These morphological and chemical characteristics help distinguish P. perlatum from several other potential lookalikes. Parmotrema perlatum has a complex taxonomic history, having undergone multiple reclassifications since its original description in 1762.
3,114km of high-pressure petroleum and gas pipelines An inland accumulation facility at Jameson Park, Gauteng (TM2), with a capacity of 180Ml A tank farm in Tarlton, Gauteng, for storage and distribution via rail and road, with a capacity of 29Ml A coastal terminal at Island View in Durban, for continuously supplying jet fuel to O.R. Tambo International Airport The Transnet pipeline network transports over 80% of refined fuel products for use in the inland market, and over 70% of the jet fuel used at O.R. Tambo International Airport. Approximately three-quarters of South Africa's fuel imports flow through Island View Precinct, which forms part of the Port of Durban. The Precinct serves as the country's main fuel storage and supply hub. Data for Transnet's pipeline fuel logistics is in the table below.
For most of the history of wine, winemakers did not know the mechanism that somehow converted sugary grape juice into alcoholic wine. They could observe the fermentation process which was often described as "boiling", "seething" or the wine being "troubled" due to release of carbon dioxide that gave the wine a frothy, bubbling appearance. This history is preserved in the etymology of the word "yeast" itself which essentially means "to boil". In the mid-19th century, the French scientist Louis Pasteur was tasked by the French government to study what made some wines spoil. His work, which would later lead to Pasteur being considered one of the "Fathers of Microbiology", would uncover the connection between microscopic yeast cells and the process of the fermentation. It was Pasteur who discovered that yeast converted sugars in the must into alcohol and carbon dioxide, though the exact mechanisms of how the yeast would accomplish this task was not discovered till the 20th century with the Embden–Meyerhof–Parnas pathway. The yeast species commonly known as Saccharomyces cerevisiae was first identified in late 19th century enology text as Saccharomyces ellipsoideus due to the elliptical (as opposed to circular) shape of the cells. Throughout the 20th century, more than 700 different strains of Saccharomyces cerevisiae were identified. The differences between the vast majority of these strains are mostly minor, though individual winemakers will develop a preference for particular strains when making certain wines or working with particular grape varieties.
== Composition == Diatomaceous earth consists of the fossilized remains of diatoms that accumulated over millions of years. It is usually composed of 80% to 90% silica, 2% to 4% alumina minerals, and 0.5% to 2% iron oxide, although the precise composition of every deposit is different. Deposits may contain different amounts of silica depending on the sedimentation conditions, the presence of other sediments (clay, sand, volcanic ashes), and the age of the deposit (diagenesis, silica (SiO2) dissolution/precipitation, diatoms tests ageing). The species of diatom may also differ among deposits. The species of diatom is dependent upon the age and paleoecology of the deposit. In turn, the shape of a diatom is determined by its species. Many deposits throughout British Columbia, such as Red Lake Earth, are from the Miocene epoch and contain a species of diatom known as Melosira granulata. These diatoms have a small globular shape. A deposit containing diatoms from this epoch can provide certain benefits over others. For example, diatoms from the Eocene epoch are not as effective in their ability to absorb fluids because as older diatoms recrystallize, their small pores become filled with silica.
Sources: en.wikipedia.org
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。
Semax 被描述为 ACTH(4-10) 的结构类似物，两者共享部分序列特征。它保留了该片段的部分神经相关活性方向，但去除了完整片段带来的激素释放效应。二者并非同一物质，也不能互相替代。
加入的 Pro-Gly-Pro 三肽被普遍认为能提升分子对蛋白水解酶的稳定性。这种设计让短肽在体内维持时间更长。具体延长的程度以及不同组织中是否一致，文献中仍存在不同报告。
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.