This is a working overview of heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-30 and is reviewed periodically as new material appears.
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 is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
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。
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
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 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.
"Standard weapon grade plutonium requires a 240Pu content of no more than 6.5%." which is 65,000 ppm, and the analogous 238Pu was produced in levels of 0.5% (5,000 ppm) or less). Gun-type fission weapons additionally need low levels (1 ppm range) of light impurities, to keep the neutron generation low. The production of "clean" 233U, low in 232U, requires a few factors: 1) obtaining a relatively pure 232Th source, low in 230Th (which also transmutes to 232U), 2) moderating the incident neutrons to have an energy not higher that 6 MeV (too-high energy neutrons cause the 232Th (n,2n) → 231Th reaction) and 3) removing the thorium sample from neutron flux before the 233U concentration builds up to a too high level, in order to avoid fissioning the 233U itself (which would produce energetic neutrons). The Molten-Salt Reactor Experiment (MSRE) used 233U that contained 222 ppm 232U.
== Synthesis == The oxygen atom in these molecules can in many cases be dispensed with as well; substitution of sulfur for nitrogen affords a molecule whose salient biologic properties are those of a sedative and tranquilizer.
After the ousting of Maduro on 3 January, the United States began increasing its pressure on Mexico to reduce its oil sales to Cuba with President Donald Trump threatening tariffs against any country supplying Cuba with oil. On 9 January, the most recent (as of September 2026) oil shipment from Mexico arrived in Cuba, delivering 85,000 barrels of fuel. Mexico temporarily halted shipments of oil to Cuba by 27 January and Mexican President Claudia Sheinbaum said that the decision to halt oil deliveries was "a sovereign decision". In February 2026, Mexico sent two ships of humanitarian aid to Cuba to help alleviate the impacts of the U.S. embargo.
== Use == Once extracted, oil is refined and separated, most easily by distillation, into numerous products for direct use or use in manufacturing, such as gasoline (petrol), diesel and kerosene to asphalt and chemical reagents (ethylene, propylene, butene, acrylic acid, para-xylene) used to make plastics, pesticides and pharmaceuticals. In terms of volume, most petroleum is converted into fuels for combustion engines. In terms of value, petroleum underpins the petrochemical industry, which includes many high value products such as pharmaceuticals and plastics. By volume, 84% of hydrocarbons present in petroleum are converted into fuels.
Sources: en.wikipedia.org
== Production == As 225Ac does not occur in any appreciable quantities in nature, it must be synthesized in specialized nuclear reactors or accelerators. The majority of 225Ac results from the alpha decay of 229Th, but this supply is limited because the decay of 229Th (half-life 7920 years) is slow. It is also possible to breed 225Ac from radium-226 in the 226Ra(p,2n) reaction. This was first done in 2005, though the production and handling of 226Ra are difficult because of the respective cost of extraction and hazards of decay products such as radon-222. Alternatively, 225Ac can be produced in spallation reactions on a 232Th target irradiated with high-energy proton beams. Current techniques enable the production of millicurie quantities of 225Ac; however, it must then be separated from other reaction products. This is done by allowing some of the shorter-lived nuclides to decay; actinium isotopes are then chemically purified in hot cells and 225Ac is concentrated. Special care must be taken to avoid contamination with the longer-lived beta-emitting actinium-227. For decades, most 225Ac was produced in one facility—the Oak Ridge National Laboratory in Tennessee—further reducing this isotope's availability even with smaller contributions from other laboratories. Additional 225Ac is now produced from 232Th at Los Alamos National Laboratory and Brookhaven National Laboratory. The TRIUMF facility and Canadian Nuclear Laboratories have formed a strategic partnership around the commercial production of actinium-225.
(CH2CH2)O + CH3CONH2 → HOCH2CH2NHC(O)CH3 Addition of ethylene oxide to higher carboxylic acids is carried out at elevated temperatures (typically 140–180 °C (284–356 °F)) and pressure (0.3–0.5 MPa (44–73 psi)) in an inert atmosphere, in presence of an alkaline catalyst (concentration 0.01–2%), such as hydroxide or carbonate of sodium or potassium. The carboxylate ion acts as nucleophile in the reaction:
great-granddaughter of Joseph Hertz (Chief Rabbi of the British Empire) Chaim Herzog(Hebrew: חיים הרצוג; 17 September 1918 – 17 April 1997) Northern-Irish-born Israeli politician, general, lawyer and author of over five books on the Arab-Israeli conflict, who served as the sixth President of Israel; born in Belfast, raised in Dublin, the son of Ireland's Chief Rabbi Yitzhak HaLevi Herzog, he immigrated to Mandatory Palestine in 1935 and served in Haganah Jewish paramilitary group during the 1936–1939 Arab revolt; returned to Palestine after the war and, following the end of the British Mandate and Israel's Declaration of Independence in 1948, fought in the Battles of Latrun during the 1948 Arab–Israeli War; retired from Israel Defence Forces in 1962 with rank of major-general.His son Isaac Herzog is the incumbent President of Israel, the first father–son pair to serve as the nation's president, and led the Israeli Labor Party and the parliamentary Opposition in the Knesset between 2013 and 2017.
== Corporate history == KCI was founded in 1976 in San Antonio, Texas, by James R. Leininger, then an emergency room physician who wanted to help prevent the pulmonary complications associated with immobility. Over time, the company developed or acquired a line of therapeutic specialty beds, introducing a specialty bed for acute care patients with pulmonary complications. Initially KCI's product development focused on therapeutic beds and surfaces then expanded to introduce the first commercial negative pressure wound therapy products in the mid-1990s. KCI acquired regenerative medicine company, LifeCell, in 2008 in a non-hostile transaction for US$1.7 billion. In January 2012, LifeCell was made a sister company to KCI. In 2013, LifeCell and KCI recombined into one company.
=== Viruses === Viral infections make up perhaps one third of cases of food poisoning in developed countries. Norovirus is the leading cause of foodborne illness in the United States, responsible for approximately 58% of foodborne illnesses acquired domestically and about 50% of all foodborne disease outbreaks. Each year, norovirus causes an estimated 19 to 21 million illnesses and approximately 2,500 reported outbreaks in the United States, with outbreaks most common between November and April. Infected food workers are a frequent source of contamination, often through direct handling of ready-to-eat foods. Foodborne viral infections are usually of intermediate (1–3 days) incubation period, causing illnesses which are self-limited in otherwise healthy individuals.
Sources: en.wikipedia.org
Kazuaki Kiriya's action-thriller Last Knights was Freeman's first film of 2015, starring opposite Clive Owen. The plot centers on a band of warriors who seek to avenge the loss of their master at the hands of a corrupt minister. Reviews were largely underwhelming; Sara Stewart of New York Post called it "bloody bad", adding: "Once-proud box office names are its first casualties." Freeman next joined the cast of Ted 2, a comedy sequel to Ted, directed by Seth MacFarlane. The story follows the talking teddy bear Ted as he fights for civil rights in order to be recognized as a person. Freeman portrays Patrick Meighan, a highly respected civil rights attorney. A television series, Madam Secretary, also occupied Freeman's time. He played Chief Justice Frawley of the United States Supreme Court in a recurring role in the series. He and his producing partner Lori McCreary were executive producers. Freeman directed the first episode; McCreary remarked of his directing style, "What's riveting is that he can achieve a complete tonal change in performance with the least amount of direction ... Everybody behaves better when Morgan is there ... but he's very fun." At the end of 2015, Freeman played a U.S. senator in the thriller Momentum. Reprising his role as Allan Trumbull, Freeman appeared in London Has Fallen, the 2016 sequel to Olympus Has Fallen. The film follows a plot to assassinate the world leaders of the G7 as they attend the British Prime Minister's funeral in London, as well as Secret Service agent Mike Banning's efforts to protect U.S.
Indigenous people traded obsidian throughout the Americas. Each volcano and in some cases each volcanic eruption produces a distinguishable type of obsidian allowing archaeologists to use methods such as non-destructive energy dispersive X-ray fluorescence to select minor element compositions from both the artifact and geological sample to trace the origins of a particular artifact. Obsidian cores and blades were traded far inland from the coast. A particularly distant examples of traded obsidian are pieces from the Yellowstone Region found at Hopewell sites, such as Hopewell Culture National Historical Park, Ohio, over 1500 miles away.
== Benefits of TPMS == The dynamic behavior of a pneumatic tire is closely connected to its inflation pressure. Key factors like braking distance and lateral stability require the inflation pressures to be adjusted and kept as specified by the vehicle manufacturer. Extreme under-inflation can even lead to thermal and mechanical overload caused by overheating and subsequent, sudden destruction of the tire itself. Additionally, fuel efficiency and tire wear are severely affected by under-inflation. Tires do not only leak air if punctured, they also leak air naturally, and over a year, even a typical new, properly mounted tire can lose from 20 to 60 kPa (3 to 9 psi), roughly 10% or even more of its initial pressure. The claimed benefits of TPMS include:
are convenient for the patients who have difficulty in swallowing (children, old people, bed-ridden and psychiatric patients); are fast to absorb; don't require water to consume; have good taste (mouth feel); don't provoke choking or suffocation; have high microbial resistance ("due to the low moisture content in the final product, the Zydis formulation does not allow microbial growth").
Sources: en.wikipedia.org
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.