The short version of ACTH 片段 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-16 and is reviewed periodically as new material appears.
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.
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.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
| 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 |
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
The WHO model list of essential in vitro diagnostics, or WHO list of essential diagnostic tests (EDL) is a World Health Organization (WHO) priority list of medical tests that provides guidance for individual countries on which tests to use and which not to. It was first published in 2018, then revised in 2019, and a third edition was published in 2020. Tests in community settings where there is no laboratory, are divided into general tests and tests that are disease-specific. Diseases that can be tested for in the community without laboratory facilities include: Chagas disease, cholera, COVID-19, diabetes mellitus, hepatitis B and C, HIV, influenza, malaria, Streptococcal pharyngitis, sickling disorders, syphilis, tuberculosis and visceral leishmaniasis. Where there is a health care facility with laboratories, tests are divided into either general tests or disease-specific tests for clinical laboratories, and disease-specific tests for blood screening laboratories. For each group of tests, the EDL specifies the test's name, purpose, assay format and type of specimen.
=== Contactless atmospheric pressure ionization === Contactless atmospheric pressure ionization is a technique used for analysis of liquid and solid samples by mass spectrometry. Contactless API can be operated without an additional electric power supply (supplying voltage to the source emitter), gas supply, or syringe pump. Thus, the technique provides a facile means for analyzing chemical compounds by mass spectrometry at atmospheric pressure.
=== Residential units === The capacity of a refrigerator is measured in either liters or cubic feet. Typically the volume of a combined refrigerator-freezer is split with 1/3 to 1/4 of the volume allocated to the freezer although these values are highly variable. Temperature settings for refrigerator and freezer compartments are often given arbitrary numbers by manufacturers (for example, 1 through 9, warmest to coldest), but generally 3 to 5 °C (37 to 41 °F) is ideal for the refrigerator compartment and −18 °C (0 °F) for the freezer. Some refrigerators must be within certain external temperature parameters to run properly. This can be an issue when placing units in an unfinished area, such as a garage. Some refrigerators are now divided into four zones to store different types of food:
Dehydrated eggs advertisements appeared in the late 1890s in the United States. Powdered eggs appear in literature as a staple of camp cooking at least as early as 1912. Powdered eggs, known also as dried eggs, were widely used in the United Kingdom during World War II when food (including both fresh and dried eggs) was rationed. While nutritious, they were not a culinary treat; Esther Rantzen, reminiscing about the time, wrote that there were few real eggs, and "I can still remember the disgusting taste of powdered egg". It was also part of military rations. Bob Hope joked during a USO show, "Fellows, the folks at home are having a terrible time about eggs. They can't get any powdered eggs at all. They've got to use the old-fashioned kind you break open".
For South Africa and the Soviet Union—the two parties which had previously refrained from joining the US-mediated talks—the point had now been reached where the costs of continuing the war exceeded its anticipated benefits. This necessitated a change in perceptions in both nations, which began warming to the possibility of a negotiated peace. The Soviet government agreed to jointly sponsor with the US a series of renewed peace talks on 3 and 4 May 1988. For its part, South Africa made its first bid to join the tripartite negotiations and agreed to send a delegation of diplomats, intelligence chiefs, and senior SADF officers. The Soviet and US diplomats in attendance, including Crocker, made it clear to the South Africans that they wanted peace in Angola and a political settlement in South West Africa. They were also agreed on the need to bring pressure on their respective allies to bring about a solution. South Africa would be expected to comply with United Nations Security Council Resolution 435, in exchange for the complete withdrawal of Cuban troops from Angola. The Cuban and Angolan delegations had already assented to a complete Cuban withdrawal, and under US pressure produced an extremely precise timetable which extended this process over three to four years. South Africa found this unacceptable but conceded that the withdrawal could be timed to certain benchmarks in the Namibian independence process. According to Crocker, the US decision to use Security Council Resolution 435 as the basis and pivot for a regional settlement provided leverage over the discussions.
Sources: en.wikipedia.org
nick A break or discontinuity in the phosphate backbone of one strand of a double-stranded DNA molecule, i.e. where a phosphodiester bond is hydrolyzed but no nucleotides are removed; such a molecule is said to be nicked. A nick is a single-strand break, where despite the break the DNA molecule is not ultimately broken into multiple fragments, which contrasts with a cut, where both strands are broken. Nicks may be caused by DNA damage or by dedicated nucleases known as nicking enzymes, which nick DNA at random or specific sites. Nicks are frequently placed by the cell as markers identifying target sites for enzyme activity, including in DNA replication, transcription, and mismatch repair, and also to release torsional stress from overwound DNA molecules, making them important in manipulating DNA topology.
== Research == Polyphenols are a large, diverse group of compounds, which makes it challenging to determine their biological effects. They are not considered nutrients, as they do not contribute to growth, survival, or reproduction, nor do they provide dietary energy. Therefore, they do not have recommended daily intake levels, such as those for macronutrients and micronutrient (vitamins and minerals). In the United States, the Food and Drug Administration issued guidance to manufacturers that polyphenols cannot be mentioned on food labels as antioxidant nutrients unless physiological evidence exists to verify such a qualification and a Dietary Reference Intake value has been established – characteristics which have not been determined for polyphenols. In the European Union, two health claims were authorized between 2012 and 2015: 1) flavanols in cocoa solids at doses exceeding 200 mg per day may contribute to maintenance of vascular elasticity and normal blood flow; and 2) olive oil polyphenols (5 mg of hydroxytyrosol and its derivatives such as oleuropein complex and tyrosol) may "contribute to the protection of blood lipids from oxidative damage", if consumed daily. As of 2022, clinical trials that assessed the effect of polyphenol-rich diets on health biomarkers are limited, with results difficult to interpret due to the wide variation of intake values for both individual polyphenols and total polyphenols. Polyphenols were once considered as antioxidants, but this concept is obsolete.
=== 29 May === Two people were killed in a Russian rocket attack on Krasnopillia, Sumy Oblast. Two people were killed in separate attacks in Nikopol. Explosions near Kerch and the Crimean Bridge were reported. Russian officials claimed that two ferries were damaged by falling missile debris. Sweden pledged ASC 890 AWACS aircraft for Ukraine as part of an aid package valued at 13.3 Swedish krona ($1.3 billion), as well as its "entire stock" of Pansarbandvagn 302, which Sweden pulled from frontline service, artillery shells and anti-aircraft missiles. US officials warned Ukraine against strikes on Voronezh radars, fearing such attacks hurt the "strategic stability" between the US and Russia.
In 3+1 programs, the student attends classroom courses for three years and complete a clinical rotation their final year of study. In 2+2 programs, students have already completed their lower division coursework and return to complete their last two years of study in a CLS program. In 4+1 program, students who have already completed an undergraduate program return to complete a year of medical laboratory training. The training is typically completed at a clinical site rather than a college. The core curriculum in medical technology generally comprises 20 credits in clinical chemistry, 20 credits in hematology, and 20 credits in clinical microbiology. During clinical rotations, the student experiences hands-on learning in each discipline of the laboratory and performs diagnostic testing in a functioning laboratory under supervision. With limited or no compensation, a student in the clinical phase of training usually works 40 hours per week for 20 to 52 weeks. Some programs in the United States have halved the time students spend completing their clinical rotation reduced due to staffing shortages. For example, in 2015, the MLS program at the University of Minnesota reduced the clinical rotation portion of the program from 22 weeks to 12 weeks. In the United States, a two-year academic program (associate's degree) qualifies the graduate to work as a medical laboratory technician (MLT).
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.
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.