semax comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-11-13. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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。
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.
| Property | Value | Notes |
|---|---|---|
| 外观 | 白色至类白色粉末 | 常见于冻干制剂 |
| 溶解度 | 易溶于水 | 在极性溶剂中一般也可溶 |
| 建议储存温度 | -20 °C | 冻干粉，避光密封 |
| 常见分析手段 | 反相高效液相色谱 | 常与质谱联用 |
| 主要降解路径 | 水解与氧化 | 溶液状态更显著 |
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。
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。
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.
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.
Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in the formation of normal, healthy bone tissue: Intramembranous ossification is the direct laying down of bone into the primitive connective tissue (mesenchyme), while endochondral ossification, also known as intracartilaginous ossification, involves cartilage as a precursor. In fracture healing, endochondral osteogenesis is the most commonly occurring process, for example in fractures of long bones treated by plaster of Paris, whereas fractures treated by open reduction and internal fixation with metal plates, screws, pins, rods and nails may heal by intramembranous osteogenesis. Heterotopic ossification is a process resulting in the formation of bone tissue that is often atypical, at an extraskeletal location. Calcification is often confused with ossification. Calcification is synonymous with the formation of calcium-based salts and crystals within cells and tissue. It is a process that occurs during ossification, but not necessarily vice versa. The exact mechanisms by which bone development is triggered remains unclear, but growth factors and cytokines appear to play a role.
The first use of microwaves to pop corn kernels was when Raytheon engineer Percy Spencer further tested his observation of a nut candy bar melting in his pocket while working with radar tubes during WWII.
=== Second Military Occupation === Estrada Palma's presidency ended with the Little August War and his resignation in 1906. This began the Provisional Government of Cuba, a second period of military occupation by the United States in Cuba lasting until 1909. President Theodore Roosevelt was a highly active Freemason, but his first Provisional Governor William Howard Taft would not be initiated until 1909, several years after Taft left the country. No evidence exists to suggest that Taft was involved in the Brotherhood at this time. His successor, Charles Edward Magoon, was never a Freemason. In the 1908 Cuban general election, both of the leading Presidential candidates, from opposing political parties, were Freemasons; José Miguel Gómez of the Liberal Party, and Rafael Montoro, of the Conservative Party. They were featured on the cover of the Grand Lodge's bi-weekly magazine, La Gran Logia. From the leadership of the new independent Cuba had emerged two oppositional political ideologies for its direction, and the Grand Lodge of Cuba was then fractured in the same manner. A large portion of the Freemasonic leadership in Cuba promoted that "Masonic virtue," should be the guiding light for all of Cuba, not just for Freemasons. Like a half-century earlier, debates about if Freemasons should be involved in politics raged. On March 22, 1908, Grand Master Fernando Figueredo Socarás published a message complaining that the political situation in Cuba was hindering the work of the Grand Lodge, and that it had "corrupted everything, including Freemasonry...
== Scope of accreditation == NABL's scope for accreditation extends to:- Testing Laboratories: Biological, Chemical, Diagnostic Radiology QA testing, Electrical, Electronics, Fluid-Flow, Forensic, Mechanical, Non-Destructive testing, Photometry, Radiological and Software & IT system testing. Calibration Laboratories: Electro-Technical, Mechanical, Fluid Flow, Thermal & Optical, Radiological, Thermal. Medical Laboratories: Clinical Biochemistry, Clinical Pathology, Haematology & Immunohaematology, Microbiology and Infectious Disease Serology, Molecular Diagnostics, Histocompatibility & Immunogenetics, Medical Imaging, Histopathology, Cytopathology, Flow cytometry, Cytogenetics.
Sources: en.wikipedia.org
== Production and styles == Meat floss is made by stewing lean meat finely cut along the grain in a broth until the meat is very tender and individual muscle fibers can be teased apart. This happens when the water-insoluble collagen that holds the muscle fibers of the meat together has been converted into water-soluble gelatin. The meat is then separated from the broth and shredded into fibrous strips. It is then added back into the broth which is enriched with soy sauce, sugar, fennel, ginger, rice wine or other ingredients. The mixture is then cooked at low heat and stirred continuously until the floss is dried. There are different regional styles of meat floss, which differ in whether oil is added during the last process of production. Jiangsu style rousong is dry-cooked and the product is slightly chewy, while Fujian style bak hu is fried with oil and the product is mildly crispy. Five kilograms (11 lb) of meat will usually yield about one kilogram (2.2 lb) of floss. Taiwanese pork floss is made by cutting pork along the muscle fibers then boiling it for around 80 minutes to reduce moisture and soften collagen. The meat is then pressed into a paddle to loosen fibers, then transferred to a gas-fired frypan with mechanical scrapers to aid in drying and reducing the meat into long fibers. Sucrose, dehydrated starch and salt is then added at a specific time and ratio to enhance flavor and texture without hindering moisture removal. Once the desired consistency and dryness is obtained, the floss is stored briefly at room temperature and reheated in the scraping-frypan.
=== Structure determination === Incorporation of selenomethionine into proteins in place of methionine aids the structure elucidation of proteins by X-ray crystallography using single- or multi-wavelength anomalous diffraction (SAD or MAD). The incorporation of heavy atoms such as selenium helps solve the phase problem in X-ray crystallography. Incorporation is achieved with the help of a selenomethionine-tolerant microbial expression system: the recombinant DNA for the protein in question is put into a microbe, which is then given large amounts of selenomethionine.
== Lactation == No human data is available if the drug is distributed into human milk. Nursing women should either discontinue breast-feeding or Neumega, the decision should take into account the importance of the drug to the mother.
Sources: en.wikipedia.org
Sulfite reductase (NADPH) (EC 1.8.1.2, sulfite (reduced nicotinamide adenine dinucleotide phosphate) reductase, NADPH-sulfite reductase, NADPH-dependent sulfite reductase, H2S-NADP oxidoreductase, sulfite reductase (NADPH2)) is an enzyme with systematic name hydrogen-sulfide:NADP+ oxidoreductase. This enzyme catalises the following chemical reaction:
=== Chemistry === The aforementioned chemical shift came as a disappointment to physicists who had hoped that the resonance frequency of each nuclear species would be constant in a given magnetic field. But about 1951, chemist S. S. Dharmatti pioneered a way to determine the structure of many compounds by studying the peaks of nuclear magnetic resonance spectra. It can be a very selective technique, distinguishing among many atoms within a molecule or collection of molecules of very similar type but which differ only in terms of their local chemical environment. NMR spectroscopy is used to unambiguously identify known and novel compounds, and as such, is usually required by scientific journals for identity confirmation of synthesized new compounds. See the articles on carbon-13 NMR and proton NMR for detailed discussions. A chemist can determine the identity of a compound by comparing the observed nuclear precession frequencies to known or predicted frequencies. Further structural data can be elucidated by observing spin–spin coupling, a process by which the precession frequency of a nucleus can be influenced by the spin orientation of a chemically bonded nucleus. Spin–spin coupling is easily observed in NMR of hydrogen-1 (1H NMR) since its natural abundance is nearly 100%. Because the nuclear magnetic resonance timescale is rather slow, compared to other spectroscopic methods, changing the temperature of a T2* experiment can also give information about fast reactions, such as the Cope rearrangement or about structural dynamics, such as ring-flipping in cyclohexane.
== Episode 2: Second Opinions == Sadie Gonzalez is a 7 year old little girl from Queens, NY, with a severe brain disorder. Sadie suffers from very frequent seizures that have resulted in a slight speech and mobility impediment. Her mother recounts the first time Sadie had a seizure being the morning of the 29th of December, when Sadie was 6 years old. The seizures stopped for two months and in late February Sadies seizures started to violently progress into daily visible seizures that will affect different parts of her body at a time. At the time of recording the episode, Sadie was having a motor seizure almost every couple of minutes. Sadie was admitted into the Columbia Presbyterian where multiple MRI’s were done showing no signs of brain damage or brain tumors. These results along with her symptoms led some physicians to believe she had Rasmussen’s. Rasmussen’s Encephalitis, explained by Dr. Lisa Sanders, is characterized by the chronic inflammation caused by T-Lymph white blood cells to invade half of the brain and destroy it. The only sure treatment for Rasmussen’s is a hemispherectomy, where the corpus callosum is severed and separated the diseased side of the brain from the healthy side. This procedure can result in loss of vision in one eye, losing the ability to move one half of her body, or losing the ability to speak. If Sadie actually does have this disorder and undergoes the procedure, then half of the brain can spread into the second half, causing the brain to deteriorate. The parents of Sadie reach out to Dr.
With the German entry into World War I, the party also used the debates about war bonds to push for a repeal of the last remnants of anti-Jesuit laws. In 1916, the Reichstag adopted a resolution introduced by the Centre Party, calling on the government to follow the Oberste Heeresleitung (OHL)'s recommendation on the use of submarines. The OHL's policy of resuming unrestricted submarine warfare was supposed to break the deadlock of the war but instead led to the United States entry into the war. As the war continued, many of the leaders of the Centre's left wing, particularly Matthias Erzberger, came to support a negotiated settlement, and Erzberger was key in the passage of the Reichstag Peace Resolution of 1917. The same year, the Centre's Georg von Hertling, formerly Minister-President of Bavaria, was appointed Chancellor, but he could not overcome the dominance of the military leadership of Hindenburg and Ludendorff. When a parliamentary system of government was introduced in October 1918, the new chancellor Max von Baden appointed representatives from the Centre party, the Social Democrats and the left-liberals as ministers. After the fall of the monarchy in the German Revolution of 1918–1919, conflict arose between the party and the new Social Democratic government. Adolf Hofmann, the Free State of Prussia minister for culture, attempted to decree a total separation of church and state, forcing religion out of schools.
Sources: en.wikipedia.org
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。
公开资料对此没有统一答案。普遍建议现配现用，或冷藏并在数日内用完。含甲硫氨酸的序列更易氧化，放置时间越长风险越高。
反相高效液相色谱是最常用的手段，配合质谱确认分子量。氨基酸组成分析和肽图分析可补充序列层面的验证。
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.