If you have been reading about lyophilized 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.
Last reviewed on 2025-08-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffers |
| Typical storage temperature | -20 °C | Dry, desiccated, protected from light |
| Typical analytical method | RP-HPLC with UV detection | Often paired with LC-MS |
| Water content | Reported as Karl Fischer value | Freeze-dried material is hygroscopic |
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
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。
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。
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
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.
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.
A reliable means of propulsion for the submerged vessel was only made possible in the 1880s with the advent of the necessary electric battery technology. The first electrically powered boats were built by Isaac Peral y Caballero in Spain (who built Peral), Dupuy de Lôme (who built Gymnote) and Gustave Zédé (who built Sirène) in France, and James Franklin Waddington (who built Porpoise) in England. Peral's design featured torpedoes and other systems that later became standard in submarines.
When the mixed sulfates were pure enough, they were once more converted to mixed chlorides; barium and radium thereafter were separated by fractional crystallisation while monitoring the progress using a spectroscope (radium gives characteristic red lines in contrast to the green barium lines), and the electroscope. After the isolation of radium by Marie and Pierre Curie from uranium ore from Jáchymov, several scientists started to isolate radium in small quantities. Later, small companies purchased mine tailings from Jáchymov mines and started isolating radium. In 1904, the Austrian government nationalised the mines and stopped exporting raw ore. Until 1912, when radium production increased, radium availability was low. The formation of an Austrian monopoly and the strong urge of other countries to have access to radium led to a worldwide search for uranium ores. The United States took over as leading producer in the early 1910s, producing 70 g total from 1913 to 1920 in Pittsburgh alone. The Curies' process was still used for industrial radium extraction in 1940, but mixed bromides were then used for the fractionation. If the barium content of the uranium ore is not high enough, additional barium can be added to carry the radium. These processes were applied to high grade uranium ores but may not have worked well with low grade ores. Small amounts of radium were still extracted from uranium ore by this method of mixed precipitation and ion exchange as late as the 1990s, but as of 2011, it is extracted only from spent nuclear fuel.
=== Soluble (sRAGE) === The soluble form of RAGE (sRAGE) only includes the extracellular domain and lacks both the transmembrane and cytoplasmic domains. sRAGE can be generated through two primary mechanisms:
Sources: en.wikipedia.org
Valve was named as a defendant in two lawsuits in June and July 2016 related to third-party gambling sites that use the Steamworks API to allow betting with the virtual currency of cosmetic weapon replacement textures, better known as "skins", from Counter-Strike: Global Offensive, which through these sites can be converted from or to real-world money. Both suits assert Valve aiding in underaged gambling. Valve subsequently stated it has no commercial ties with these sites, and that it would demand these sites cease their use of the Steamworks API as they violate the authorized use policies. In October 2016, the Washington State Gambling Commission required Valve to stop the use of virtual skins for gambling on Steam, stating they would face legal repercussions if they failed to co-operate. On October 17, 2016, Valve sent a letter to the Washington State Gambling Commission stating that it had "no business relationship with such gambling sites", asserting that they come into existence, operate, and go out of existence without its knowledge and consent, adding that it was not aware of any such law that Steam or any of its games were violating.
Pauses a rule issued under the Biden administration to cancel student loans if schools engaged in deceptive recruiting; Caps unsubsidized student loans for graduate students at $20,500 per year and $100,000 lifetime; Caps student loans for students seeking professional degrees, such as medical school or law school, at $50,000 per year and $200,000 lifetime, and eliminates graduate PLUS loans; Establishes a lifetime student loan borrowing limit of $257,000; Restructures income-based repayment programs; and Expands Pell Grants to cover workforce-training programs.
== Privacy and security concerns == Privacy concerns have been brought up regarding the app. TikTok's privacy policy lists that the app collects usage information, IP addresses, a user's mobile carrier, unique device identifiers, keystroke patterns, and location data, among other data. Other information collected includes users inferred interests based on the content they view as well as content created by users. TikTok is also able to track information about web users even if they are not users of the TikTok app. It collects information such as IP address, online browsing habits and web search history. TikTok can share data with its corporate group, including ByteDance. The company says that it employs access control and approval process overseen by a US-based team. In June 2021, TikTok updated its privacy policy to include potential collection of biometric data, including "faceprints and voiceprints", for special effects and other purposes. The terms said that user authorization would be requested if local law demands such. Experts considered them to be "vague" and their implications "problematic" for the United States due to the country's general lack of robust data privacy laws. In a November 2022 update to its European privacy policy, TikTok stated that its global corporate group employees from China and other countries could gain remote access to the user information of accounts from Europe based on "demonstrated need".
=== Category:EC 5.1 (racemases and epimerases) === Category:EC 5.1.1 Amino-acid racemase: Phenylalanine racemase (ATP-hydrolysing) Serine racemase Category:EC 5.1.2 Mandelate racemase Category:EC 5.1.3 UDP-glucose 4-epimerase Category:EC 5.1.99 Methylmalonyl CoA epimerase
Sources: en.wikipedia.org
{\displaystyle {\frac {1}{\sqrt {f_{\mathrm {D} }}}}=-2\,\log _{10}\left({\frac {2.51}{\mathrm {Re} {\sqrt {f_{\mathrm {D} }}}}}\left\{1+0.305R_{*}\;\left(1-\exp {\frac {-R_{*}}{26}}\right)\right\}\right),}
Angiotensin II also acts on the smooth muscle in the walls of the arterioles causing these small diameter vessels to constrict, thereby restricting the outflow of blood from the arterial tree, causing the arterial blood pressure to rise. This, therefore, reinforces the measures described above (under the heading of "Arterial blood pressure"), which defend the arterial blood pressure against changes, especially hypotension. The angiotensin II-stimulated aldosterone released from the zona glomerulosa of the adrenal glands has an effect on particularly the epithelial cells of the distal convoluted tubules and collecting ducts of the kidneys. Here it causes the reabsorption of sodium ions from the renal tubular fluid, in exchange for potassium ions which are secreted from the blood plasma into the tubular fluid to exit the body via the urine. The reabsorption of sodium ions from the renal tubular fluid halts further sodium ion losses from the body, and therefore preventing the worsening of hyponatremia. The hyponatremia can only be corrected by the consumption of salt in the diet. However, it is not certain whether a "salt hunger" can be initiated by hyponatremia, or by what mechanism this might come about. When the plasma sodium ion concentration is higher than normal (hypernatremia), the release of renin from the juxtaglomerular apparatus is halted, ceasing the production of angiotensin II, and its consequent aldosterone-release into the blood. The kidneys respond by excreting sodium ions into the urine, thereby normalizing the plasma sodium ion concentration.
Cochran (born 1929), American chemist, known for pioneering studies on the nature of free radicals Ernst Cohen (1869–1944 Auschwitz), Dutch chemist known for work on the allotropy of metals) Mildred Cohn (1913–2009), American chemist, a pioneer in the applying nuclear magnetic resonance to enzyme reactions, particularly reactions of adenosine triphosphate David Collison (PhD 1980), British chemist known for development of electron paramagnetic resonance spectroscopy Vicki Colvin (born 1965), American chemist known for work on the synthesis and characterization of nanomaterials James Bryant Conant (1893–1978), American organic chemist who explored the complex relationship between chemical equilibrium and the reaction rate of chemical processes, Priestley Medal 1944 Elias James Corey (born 1928), American organic chemist, winner of the 1990 Nobel Prize in Chemistry for developing the theory and methodology of organic synthesis, specifically retrosynthetic analysis Robert Corey (1897–1971), American biochemist known for co-discovery of the α-helix and the β-sheet Carl Ferdinand Cori (1896–1984), Czech biochemist, Nobel Prize in physiology or medicine 1947 for discovering how glycogen is broken down and resynthesized Gerty Cori (1896–1957), American biochemist, Nobel Prize in physiology or medicine 1947 for discovering how glycogen is broken down and resynthesized John Cornforth (1917–2013), Australian-British chemist, 1975 Nobel Prize in Chemistry for work on the stereochemistry of enzyme-catalysed reactions Athel Cornish-Bowden (born 1943).
The next step is to form 1,2,3-Benzotriazin-4(3H)-one-14C (compound 4). In water dissolved sodium nitrite is added to anthranilamide and hydrochloric acid in ice water. Because this is a diazotization reaction, the product is pale-yellow again. After this the pH is adjusted to 8,5. This causes the ring closure to form 1,2,3-Benzotriazin-4(3H)-one-14C. This results in a sodium salt slurry that can be treated with hydrochloric acid, what lowers the pH down to 2 till 4. The 1,2,3-Benzotriazin-4(3H)-one-14C is collected, washed and dried. In the following step 1,2,3-Benzotriazin-4-(3-chloromethyl)-one-14C has to be formed. Therefore, 1,2,3-Benzotriazin-4(3H)-one-14C and paraformaldehyde are added to ethylene dichloride and heated to 40 °C. Then thionyl chloride is added and the whole solvent is further heated to 65 °C. After four hours of heating the solution is cooled down to room temperature. Water is added and the solution is neutralized. The ethylene dichloride layer is removed and put together with the result of the washed aqueous layer. The solvent was filtered and dried. The last step is the actual synthesis of Azinphos methyl. Ethylene dichloride is added to the compound resulting from the fifth step, 1,2,3-Benzotriazin-4-(3-chloromethyl)-one-14C. This mixture is heated to 50 °C and sodium bicarbonate and O,O-dimethyl phosphorodithioate sodium salt in water are added. The ethylene dichloride layer is removed, reextracted with ethylene dichloride and purified by filtration. The pure filtrate is dried.
=== Business practices === In November 2016, Feige explained that the studio would often put together a "lookbook" of influences from the comics and art by Marvel's visual development department, to create a visual template for a project. These are put together at company retreats, which the studio holds approximately every 18 months to plan out future projects and develop the phases of the MCU. However, these lookbooks are not always shown to directors, with Marvel sometimes preferring to let the director offer their own ideas first. When choosing a director for a project, Marvel Studios looks for filmmakers to hire who can guide a film. Some of their choices for directors have been considered "out-of-left-field" based on those directors' previous work. On this, Feige remarked that "you don't have to have directed a big, giant visual-effects movie to do a big, giant visual-effects movie for us. You just have to have done something singularly sort of awesome."
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.
Dry lyophilised powder is generally kept at minus twenty degrees Celsius, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they encourage aggregation and moisture uptake. Solutions are less stable than the solid form and degrade faster at room temperature.
A certificate documents what the supplier measured, not what an independent party confirmed. Methods, instruments and acceptance criteria can differ between suppliers. Third-party testing is the usual way to resolve discrepancies.
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.