This is a working overview of Semax, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-08 and is reviewed periodically as new material appears.
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.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
| 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 |
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.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
2 CmF3 + F2 → 2 CmF4 A series of ternary fluorides are known of the form A7Cm6F31 (A = alkali metal). The colorless curium(III) chloride (CmCl3) is made by reacting curium hydroxide (Cm(OH)3) with anhydrous hydrogen chloride gas. It can be further turned into other halides such as curium(III) bromide (colorless to light green) and curium(III) iodide (colorless), by reacting it with the ammonia salt of the corresponding halide at temperatures of ~400–450 °C:
Researchers in the 1960s and the 1970s were convinced that their methods would eventually succeed in creating a machine with general intelligence and considered this the goal of their field. In 1965 Herbert Simon predicted, "machines will be capable, within twenty years, of doing any work a man can do".In 1967 Marvin Minsky agreed, writing that "within a generation ... the problem of creating 'artificial intelligence' will substantially be solved". They had, however, underestimated the difficulty of the problem. In 1974, both the U.S. and British governments cut off exploratory research in response to the criticism of Sir James Lighthill and ongoing pressure from the U.S. Congress to fund more productive projects. Minsky and Papert's book Perceptrons was understood as proving that artificial neural networks would never be useful for solving real-world tasks, thus discrediting the approach altogether. The "AI winter", a period when obtaining funding for AI projects was difficult, followed. In the early 1980s, AI research was revived by the commercial success of expert systems, a form of AI program that simulated the knowledge and analytical skills of human experts. By 1985, the market for AI had reached over a billion dollars. At the same time, Japan's fifth generation computer project inspired the U.S. and British governments to restore funding for academic research. However, beginning with the collapse of the Lisp Machine market in 1987, AI once again fell into disrepute, and a second, longer-lasting winter began.
==== Invasion preparedness ==== The Greenlandic government has asked citizens to prepare for a possible attack on Greenland by the United States, including by stockpiling supplies. According to a report by Danish broadcaster DR, published in March 2026, Danish forces also prepared defensive measures in early 2026, including the deployment of special forces units and the pre-positioning of medical supplies such as blood for potential casualties. Troops reportedly brought explosives intended to disable key airstrips in Nuuk and Kangerlussuaq to prevent American landings.
== Synthesis == The synthesis (in this case, of carbon-14-labelled material) can be seen in figure 1. In the first step, o-nitroaniline (compound 1) is purified through dissolution in hot water-ethanol mixture in relation 2:1. [Activated carbon] is added and the result is filtrated for clarifying. The filtrate is chilled while kept in movement to generate crystals, usually at 4 °C, but if needed it can also be cooled to −10 °C. The crystals are then collected, washed and dried. If it is pure enough it is used for the following steps, which take place at 0 till 5 °C. To produce o-Nitrobenzonitrile-14C (compound 2), the first component o-nitroaniline and (concentrated reagent grade) hydrochloric acid are put together with ice and water. Sodium nitrite, dissolved in water, is added to this thin slurry. After the formation of a pale-yellow solution, which indicates the completion of the diazotization reaction, the pH should be adjusted to 6. After this, the solution is introduced to a mixture of cuprous cyanide and toluene. At room temperature the toluene layer is removed. The aqueous layer is washed and dried and the purified product is isolated by crystallization. The third product is Anthranilamide-14C (compound 3). It is formed out of o-Nitrobenzonitrile-14C, which is first solved in ethanol and hydrazine hydrate. The solvent is heated subsequently, treated in a well-ventilated hood with small periodic charges, smaller than 10 mg, of Raney nickel. Under nitrogen atmosphere the ethanolic solution is clarified and dried.
=== Bulgaria === Following the 2013 Bulgarian protests against the Borisov cabinet of Prime Minister Boyko Borisov over government austerity measures encouraged by the European Union and the International Monetary Fund during the recession and high utility bills, the Borisov government resigned and brought forward the Bulgarian parliamentary election, 2013, which saw a very low voter turnout. Though Borisov's party Citizens for European Development of Bulgaria (GERB) won a plurality with 97 deputies in the National Assembly, it could not form a government and gave up its mandate. The Bulgarian Socialist Party (BSP) led the government under technocratic prime minister Plamen Oresharski. The left-wing government of Plamen Oresharski was approved by the 120 members of the BSP and the Movement for Rights and Freedoms. Outside support to the Oresharski Government was also given by nationalist party Ataka, dubbed by some sources as the "hidden coalition partner", or Siderov's "golden finger", and regarded as a key instrument for allowing the Parliament to proceed with its functions, until June 2014.
Sources: en.wikipedia.org
Non-professional antigen presenting cells include all nucleated cell types in the body. They use an MHC class I molecule coupled to beta-2 microglobulin to display endogenous peptides on the cell membrane. These peptides originate within the cell itself, in contrast to the exogenous antigen displayed by professional APCs using MHC class II molecules. Cytotoxic T cells are able to interact with endogenous antigen presented using an MHC class I molecule. Non-professional APCs do not typically express MHC class II molecules. However, it has been observed that antigen presentation to CD4+ cells via MHC class II is not restricted to the classically professional APCs. Other leukocytes, including granulocytes such as mast cells and neutrophils, can be induced to do so, as can endothelial and epithelial cells under certain circumstances. Even so, there is little evidence that these atypical APCs are able to activate naive CD4+ T cells.
==== Indirect routes of production of 99Mo ==== Other particle accelerator-based isotope production techniques have been investigated. The supply disruptions of 99Mo in the late 2000s and the ageing of the producing nuclear reactors forced the industry to look into alternative methods of production. The use of cyclotrons or electron accelerators to produce 99Mo from 100Mo via (p,pn) or (γ,n) reactions, respectively, has been further investigated. The (n,2n) reaction on 100Mo yields a higher reaction cross-section for high energy neutrons than of (n,γ) on 98Mo with thermal neutrons. In particular, this method requires accelerators that generate fast neutron spectrums, such as ones using D-T or other fusion-based reactions, or high energy spallation or knock out reactions. A disadvantage of these techniques is the necessity for enriched 100Mo targets, which are significantly more expensive than natural isotopic targets and typically require recycling of the material, which can be costly, time-consuming, and arduous.
=== Subcutaneous === Insulin is usually taken as subcutaneous injections by single-use syringes with needles, an insulin pump, or by repeated-use insulin pens with needles. People who wish to reduce repeated skin puncture of insulin injections often use an injection port in conjunction with syringes. The use of subcutaneous injections of insulin is designed to mimic the natural physiological cycle of insulin secretion, while taking into account the various properties of the formulations used such as half-life, onset of action, and duration of action. In many people, both a rapid- or short-acting insulin product as well as an intermediate- or long-acting product are used to decrease the amount of injections per day. In some, insulin injections may be combined with other injection therapy such as incretin mimetics (eg, semaglutide). Cleansing of the injection site and injection technique are required to ensure effective insulin therapy.
The Ministry of Foreign Affairs of Georgia was also criticized since "there is no special action plan and written instructions for ambassadors on how to act in the emergency situations; the activities of ambassadors are not controlled properly either." According to the report, "serious shortcomings" in the defense system had been found out, such as problems in the communication system, "inadequacy" of the reserve troops and inability of the Ministry of Defense of Georgia "to carry out strategic planning properly". The Prosecutor's Office of Georgia was urged to investigate all breaches of international humanitarian law.
Sources: en.wikipedia.org
Using various modifiers, the activity of the enzyme can be regulated, enabling control of the biochemistry of the cell as a whole. The structure of proteins is traditionally described in a hierarchy of four levels. The primary structure of a protein consists of its linear sequence of amino acids; for instance, "alanine-glycine-tryptophan-serine-glutamate-asparagine-glycine-lysine-...". Secondary structure is concerned with local morphology (morphology being the study of structure). Some combinations of amino acids will tend to curl up in a coil called an α-helix or into a sheet called a β-sheet; some α-helixes can be seen in the hemoglobin schematic above. Tertiary structure is the entire three-dimensional shape of the protein. This shape is determined by the sequence of amino acids. In fact, a single change can change the entire structure. For example, the beta chain of hemoglobin contains 146 amino acid residues; substitution of the glutamate residue at position 6 with a valine residue changes the behavior of hemoglobin so much that it results in sickle-cell disease. Finally, quaternary structure is how separately polypeptide chains interact with one another to form the final protein. This applies only to proteins composed of multiple chains, such as hemoglobin with its four subunits, whereas many others have only one chain.
Minimal follow-up was three years. Metacarpophalangeal joint (MP) contractures were corrected at an average of 99% and proximal interphalangeal joint (PIP) contractures at an average of 89% immediately post procedure. At final follow-up, 72% of the correction was maintained for MP joints and 31% for PIP joints. The difference between the final corrections for MP versus PIP joints was statistically significant. When comparing people aged below and above 55 years of age there was a statistically significant difference at both MP and PIP joints, with greater correction maintained in the older group. Gender differences were not statistically significant. Needle aponeurotomy provided successful correction to 5° or less contracture immediately post procedure in 98% (791) of MP joints and 67% (350) of PIP joints. There was recurrence of 20° or less over the original post-procedure corrected level in 80% (646) of MP joints and 35% (183) of PIP joints. Complications were rare except for skin tears, which occurred in 3.4% (34) of digits. This study showed that NA is a safe procedure that can be performed in an outpatient setting. The complication rate was low, but recurrences were frequent in younger people and for PIP contractures.
Integrin alpha-2, or CD49b (cluster of differentiation 49b), is a transmembrane protein which in humans is encoded by the CD49b gene. The CD49b protein is an integrin alpha subunit. It makes up half of the α2β1 integrin duplex. Integrins are heterodimeric integral membrane glycoproteins composed of a distinct alpha chain and a common beta chain. They are found on a wide variety of cell types including T cells (the NKT cells), NK cells, fibroblasts and platelets. Integrins are involved in cell adhesion and also participate in cell-surface-mediated signalling. The α2β1 integrin functions primarily as a recepter for collagen, making it important in tissues like the skin, bone, and blood vessels. Expression of CD49b in conjunction with LAG-3 has been used to identify type 1 regulatory (Tr1) cells. The DX5 monoclonal antibody recognizes mouse CD49b.
305200: type 5 130080: type 8 – unspecified gene, locus 12p13 225310: type 10 – unspecified gene, locus 2q34 608763: Beasley–Cohen type 130070: progeroid form – B4GALT7 130090: type unspecified 601776: D4ST1-deficient Ehlers–Danlos syndrome (adducted thumb-clubfoot syndrome) CHST14
Some of this pool of 238Pu was used in a multi-mission radioisotope thermoelectric generator (MMRTG) for the 2020 Mars Rover mission and two additional MMRTGs for a notional 2024 NASA mission. 21 kg (46 lb) would remain after that, including approximately 4 kg (8.8 lb) just barely meeting the NASA specification. Since isotope content in the material is lost over time to radioactive decay while in storage, this stock could be brought up to NASA specifications by blending it with a smaller amount of freshly produced 238Pu with a higher content of the isotope, and therefore energy density.
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.
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。