If you have been reading about lyophilised powder 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 2026-05-08. 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 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.
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.
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
=== Takeshita === The Takeshita geometry consists of a 54.43° electric sector, and short drift length, a second electric sector of the same curvature direction followed by another drift length before a 180° magnetic sector of opposite curvature direction.
== Further reading == Dean L (2017). "Risperidone Therapy and CYP2D6 Genotype". In Pratt VM, McLeod HL, Rubinstein WS, et al. (eds.). Medical Genetics Summaries. National Center for Biotechnology Information (NCBI). PMID 28520384. Bookshelf ID: NBK425795.
== Life == Sun Yaoting was born in a village near Tianjin, about 60 miles southeast of Beijing. Born into poverty, his father was a jianbing peddler. When he was young, his family's home was burned down and their fields were stolen by a landlord in their village. Inspired by an older eunuch from his village who had become rich, coupled with the family's hope that they would gain Imperial influence and get revenge on the landlord, the family decided to emasculate Sun. In 1911, at the age of eight, Sun was emasculated by his father at home on their bed with a single razor cut, without the use of anesthesia. A piece of oil-soaked paper was used as a bandage, while a goose quill was inserted in Sun's urethra to prevent it from getting blocked as the wound healed. Sun remained unconscious for three days and could barely move for two months. However, the emperor he had hoped to serve, Puyi, had abdicated several weeks before his recovery during the Xinhai Revolution. Nonetheless, Sun went to Beijing at age 14. His rank initially was so low that he was not even given a name, and worked as a servant to another, higher ranking eunuch. He then rose through the ranks, becoming a palace eunuch serving under one of the emperor’s uncles, eventually becoming an attendant to the Qing empress. Corruption amongs the eunuchs working in the Forbidden City was rampant, as they constantly stole treasures and sold it on the black market.
demonstrated DE sorting and isolation on-chip followed by FACS that allows for high sorting throughput of encapsulated mammalian cells, from which genetic material can later be extracted. While fluorogenic labeling is a powerful tool for tracking and sorting, it is not always compatible with droplet-based microfluidic systems and experimental design. New label-free and non-fluorescence-based detection techniques have recently been reported. In 2016, Gielen et al. published an absorbance-activated droplet sorting (AADS) microfluidic device and demonstrated its functionality by directing the evolution of a phenylalanine dehydrogenase. In 2016, Sun et al. demonstrated the use of SE droplets and high-throughput MS to screen enzyme activators and inhibitors by screening a transaminase library. In 2019, Pan et al. showed sorting of droplets by interfacial tensions, which are affected by droplet content. In 2020, Haidas et al. presented a microfluidic approach that uses both matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and fluorescence microscopy, which the authors used to measure the concentration and activity of phytase, respectively, in yeast cells. In 2020, Holland-Moritz et al. published their mass activated droplet sorting (MADS) method, which integrates MS analysis with fluorescence-activated droplet sorting (FADS). Using this method, droplets are split and analyzed separately by both MS and FADS. The power of this method was demonstrated by screening the activity of a transaminase library expressed in vitro.
Sources: en.wikipedia.org
==== Juan Alberto Kessel Linares and Viñas Alonso arrested ==== On July 4, 2025, agents from the State Security Unit issued summons to Acting Grand Mater Kessel Linares and Acting Grand Secretary Víctor Bravo Cabañas at the Picota Police Station, where they were again officially arrested by Lieutenant Colonel Kenia María Morales Larrea, but they were later released with warning notices. Filema Duarte called a special session of the High Chamber to occur on July 6. Many Cuban Freemasons considered this an illegal act, because they had voted him out of office, and believed that he did not have the authority to call sessions. After they were released, Kessel Linares and Bravo Cabañas both posted to Facebook that they were concerned about the intimidation tactics used by the government, and called for a peaceful demonstration on July 6.
=== Thailand === In Thailand, postgraduate medical training is monitored by the Medical Council of Thailand (TMC) and conducted by their respective "Royal Colleges". Thailand has a significant issue with an imbalance of medical personnel between Bangkok and the remaining 76 provinces. As a primate city, the majority of specialists wish to remain in Bangkok after training. Each year, the TMC outlines the requirements for application to a certain specialty, depending on the needs of the country for staff within that field. Specialities are therefore classified into tiers depending on national demand. The duration spent in the national internship program depends on the specialty the graduate wishes to study. Specialties classified as 'lacking' may require only one year of internship, whilst more competitive specialties often require the full three-year duration of internship to meet the application criteria. Fields classified as 'severely lacking' may not require internship training at all. Application to residency may be done on contract with a government hospital or without a contract, namely 'free-training'. Government hospitals may sign contracts to sponsor residency training for specialist doctors they require. In these cases, the duration for internship required in more popular fields may be reduced. For example, a residency in internal medicine requires three years of internship if applying without contract, but is reduced to two years if applying under contract.
=== Detection in body fluids === Acetylfentanyl may be quantitated in blood, plasma, or urine by liquid chromatography-mass spectrometry to confirm a diagnosis of poisoning in hospitalized patients or to provide evidence in a medicolegal death investigation. Postmortem peripheral blood acetylfentanyl concentrations have been in a range of 89–945 μg/L in victims of acute overdosage.
In the 1980s, researchers at the National Cancer Institute's Center for Cancer Research (CCR) began exploring the then-heretical idea that a patient's immune system could be harnessed to fight cancer. These researchers included Michael Potter, Ira Pastan, and Steven Rosenberg who developed approaches including monoclonal antibody-based immunotoxins, checkpoint inhibitors, cytokine-based therapies, and adoptive cell therapy studies.
Other options instead of death include conversion of an individual's consciousness into an AI, joining of a group mind (which can include biological and non-biological consciousnesses), or subliming (usually in association with a group mind). Concerning the lifespan of drones and Minds, given the durability of Culture technology and the options of mindstate backups, it is reasonable to assume that they live as long as they choose. Even Minds, with their utmost complexity, are known to be backed up (and reactivated if they for example die in a risky mission, see GSV Lasting Damage). It is noted that even Minds themselves do not necessarily live forever either, often choosing to eventually sublime or even killing themselves (as does the double-Mind GSV Lasting Damage due to its choices in the Culture-Idiran war).
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。