If you have been reading about ACTH(4-10) 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 2026-07-19. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 |
|---|---|---|
| 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 |
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.
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.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
. In other words, as a rule, there is an infection-free steady state. This solution, also usually ensures that the disease-free equilibrium is also an equilibrium of the system. There is another fixed point known as an Endemic Equilibrium (EE) where the disease is not totally eradicated and remains in the population. Mathematically,
=== Grhl3 === Much the same as the previous two orthologues, Grhl3 is involved in the regulation of epidermal tissue, such as the formation of the jaw, neural tube and other craniofacial features, and does so across both land and aquatic organisms. Grhl3 is a downstream target of Irf6, and plays a key role in processes involving fusion during development much like Grhl2, especially so in the oral palate and spinal cord. A mutation of Grhl3, that causes an increase or a decrease in expression, can lead to Van der Woude syndrome, which is characterized by phenotypes that include cleft lip and/or palate and spina bifida. Primarily, Grhl3 appears to play a vital role for regulating the development of the craniofacial skeleton. A genome-wide association study found that Grhl3 is an etiological variant for a nonsyndromic form of cleft palate, ~50% of all cleft palate cases, highlighting the level of impact that dysregulation of Grhl3 has on development. Apart from the defects that are physically noticeable, Grhl3 is also expressed in the brain of mice embryos and has been shown to regulate the impulsiveness and anxiety levels of mice. Furthermore, it appears that grhl3 regulates the enveloping layer of zebrafish and axial extension as well as cell size and identity during embryonic development. If expression is disrupted during the early stages of disruption it will lead to severe defects that can lead to the death of the embryo before epiboly is complete.
The proton–proton chain is more prominent in stars the mass of the Sun or less. This difference stems from temperature dependency differences between the two reactions; pp-chain reaction starts at temperatures around 4×106 K (4 megakelvins), making it the dominant energy source in smaller stars. A self-maintaining CNO chain starts at approximately 15×106 K, but its energy output rises much more rapidly with increasing temperatures so that it becomes the dominant source of energy at approximately 17×106 K. The Sun has a core temperature of around 15.7×106 K, and only 1.7% of 4He nuclei produced in the Sun are born in the CNO cycle. The CNO-I process was independently proposed by Carl von Weizsäcker and Hans Bethe in the late 1930s. The first reports of the experimental detection of the neutrinos produced by the CNO cycle in the Sun were published in 2020 by the BOREXINO collaboration. This was also the first experimental confirmation that the Sun had a CNO cycle, that the proposed magnitude of the cycle was accurate, and that von Weizsäcker and Bethe were correct.
A glycogen storage disease (GSD, also glycogenosis and dextrinosis) is a metabolic disorder caused by a deficiency of an enzyme or transport protein affecting glycogen synthesis, glycogen breakdown, or glucose breakdown, typically in muscles and/or liver cells. GSDs are caused by Inborn errors of carbohydrate metabolism (genetically defective enzymes or transport proteins) involved in these processes. In livestock, a defect in glycogen storage is caused by intoxication with the alkaloid castanospermine. However, not every inborn error of carbohydrate metabolism has been assigned a GSD number, even if it is known to affect the muscles or liver. For example, phosphoglycerate kinase deficiency (gene PGK1) has a myopathic form. Also, Fanconi-Bickel syndrome (gene SLC2A2) and Danon disease (gene LAMP2) were declassed as GSDs due to being defects of transport proteins rather than enzymes; however, GSD-1 subtypes b, c, and d are due to defects of transport proteins (genes SLC37A4, SLC17A3) yet are still considered GSDs. Phosphoglucomutase deficiency (gene PGM1) was declassed as a GSD due to it also affecting the formation of N-glycans; however, as it affects both glycogenolysis and glycosylation, it has been suggested that it should re-designated as GSD-XIV. Jonah Pournazarian is the most notable human with Glycogen Storage Disease (GSD). His condition has been widely covered in national and international media, and his story has drawn unprecedented awareness to GSD research.
Sources: en.wikipedia.org
== Lead-212 == Lead-212 (212Pb) is a radioactive isotope of lead that has gained significant attention in nuclear medicine, particularly in targeted alpha therapy (TAT). This isotope is part of the thorium decay series and serves as an important intermediate in various radioactive decay chains. 212Pb is produced through the decay of radon-220 (220Rn), an intermediate product of thorium-228 (228Th) decay. It undergoes radioactive decay through beta emission to form bismuth-212 (212Bi), which further decays to emit alpha particles. This decay chain is particularly important in medical applications, as it is an in-vivo generator system of alpha particles, that can be utilized for therapeutic purposes, particularly TAT, by delivering potent, localized radiation to cancer cells. The isotope is part of the thorium decay series, which begins with natural thorium-232. Its beta decay (10.627 hours) results in the formation of bismuth-212 (212Bi), which then emits alpha particles (6.1 MeV), crucial for the effectiveness of TAT in cancer treatment. While in aqueous solutions, free Pb2+ tends to hydrolyze under physiological pH conditions to form species like Pb(OH)+, which can impact its biodistribution if not properly chelated, chelator-modified complexes have demonstrated high stability in saline and serum environments for extended periods (e.g., 24–72 hours), which is critical for therapeutic applications. Lead-212 can be synthesized through several methods, with generator-based production utilizing the decay of 228Th being the most common.
Fisher formulate a zinc insulin mixture at Connaught Laboratories in Toronto and license it to Novo 1936 Hagedorn discovers that adding protamine to insulin prolongs the duration of action of insulin 1946 Nordisk formulates Isophane porcine insulin aka Neutral Protamine Hagedorn or NPH insulin 1946 Nordisk crystallizes a protamine and insulin mixture 1950 Nordisk markets NPH insulin 1953 Novo formulates Lente porcine and bovine insulins by adding zinc for longer lasting insulin 1955 Frederick Sanger determines the amino acid sequence of insulin 1965 Synthesized by total synthesis by Wang Yinglai, Chen-Lu Tsou, et al. 1969 Dorothy Crowfoot Hodgkin characterizes and describes the crystal structure of insulin by X-ray crystallography 1973 Purified monocomponent (MC) insulin is introduced 1973 The US officially "standardized" insulin sold for human use in the US to U-100 (100 units per milliliter). Prior to that, insulin was sold in different strengths, including U-80 (80 units per milliliter) and U-40 formulations (40 units per milliliter), so the effort to "standardize" the potency aimed to reduce dosage errors and ease doctors' job of prescribing insulin for people. Other countries also followed suit.
Mirror-image life (also called mirror life) is a hypothetical form of life using mirror-reflected molecular building blocks. The successful creation of mirror-image life had previously been the goal of some scientists as a scientific achievement and a potential tool for biomanufacturing of mirror-image molecules. In 2024, a team of 38 scientists, including two Nobel laureates and several researchers previously involved in developing mirror-image life, published a report suggesting that mirror-image life could pose catastrophic risks to health and the environment. Unlike simple mirror-image molecules, mirror-image organisms such as bacteria could reproduce and might irreversibly spread through ecosystems. Such bacteria might be able to evade many components of immune systems, causing fatal infections in humans, animals, and plants. Some scientists, bioethicists, policymakers, and civil society groups have recommended that governance be established to ensure that mirror-image life is not created, and some funders have refused to support research with the goal of creating mirror-image life. Discussions are ongoing about the risks of mirror life and appropriate governance. Certain mirror-image components of molecular machinery have been synthesized in laboratories and efforts to chemically synthesize a mirror-image ribosome have been ongoing since 2016. Although entire mirror organisms could in principle be created, some scientists estimate 10 to 30 years before the creation of mirror-image life is possible.
Another similar characterization concerns the exradii ra, rb, rc, and rd in the same four triangles (the four excircles are each tangent to one side of the quadrilateral and the extensions of its diagonals). A quadrilateral is tangential if and only if
== Methods of production == LPC production processes are two-staged, with the first focusing on the expression of leaf juice or production of a leaf extract, and the second being the purification or protein recovery stage that recovers protein from the solution. The most commonly employed method of leaf protein extraction is pulping/juicing. Other assisted extraction methods have also been reported such as alkali treatment, pressurised extraction, and enzyme treatment. Each method comes with its own advantages although pulping produces the most "native" protein composition and does not require significant investment in complex machinery. Alkali extraction has been employed with some success although it significantly affects lysine and threonine residues in the protein. Pressurised extraction have limited success. Enzyme treatment is another well reported method which targets the plant cell wall to aid the release of bound proteins. However, enzymes are generally more expensive compared to physical or chemical methods of protein extraction. Recovering the protein from the extract however is most critical to the nutritive value of the LPC. Commonly reported methods were heat coagulation, acid precipitation, ultrafiltration, solvent precipitation and chromatography. Heat coagulation is the easiest and the oldest method of protein recovery, albeit the least preferred as most of the nutritive value of the LPC is lost. Acid precipitation is the most commonly employed method of protein recovery although it results in the loss of methionine and tryptophan in the LPC.
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.
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。