peptide synthesis raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-07-02. Anything still debated is marked as such rather than presented as settled.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
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.
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.
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.
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.
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 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.
=== Antibiotics === The length of antibiotic courses depends on the severity of the infection and whether bone infection is involved, but can range from 1 week to 6 weeks or more. Current recommendations are that antibiotics are only used when there is evidence of infection and continued until there is evidence that the infection has cleared, instead of evidence of ulcer healing. The choice of antibiotic depends on common local bacterial strains known to infect ulcers. Microbiological swabs are believed to be of limited value in identifying the causative strain. Microbiological investigation is of value in cases of osteomyelitis. Most ulcer infections involve multiple microorganisms. There is limited safety and efficacy data on topical antibiotics in treating diabetic foot ulcers.
The post–Cold War era is a period of history that has been ongoing since the dissolution of the Soviet Union, which began in 1988 and marked the end of the Cold War by 1991, thereby leaving the United States as the world's sole superpower. At the same time, Europe experienced the collapse of communism alongside the fall of the "Iron Curtain" between the American-aligned Western Bloc and the Soviet-aligned Eastern Bloc, which gradually embraced market economies. The establishment of the European Union (EU) in 1993 effectively reversed the continent's Cold War divide by absorbing most of Eastern Europe and integrating it with Western Europe over the course of three enlargements. Relative to the Cold War, the period is characterized by stabilization and disarmament. Both Russia (the Soviet Union's legal successor state) and the United States significantly reduced their nuclear weapons stockpiles, and most Eastern Bloc countries became democratic and were integrated into the global economy. In the first two decades of the post–Cold War era, the North Atlantic Treaty Organization (NATO) underwent three enlargements and France re-integrated into the NATO command, while Russia founded the Collective Security Treaty Organization (CSTO) to replace the Warsaw Pact. More recently, China has become a rising power and has likewise consolidated a greater role on the international stage while building a strategic partnership with Russia, with both countries working in BRICS and the Shanghai Cooperation Organization.
The Earth's cold trap is located about 12 km above sea level, well below the height at which water vapor would be permanently split apart into hydrogen and oxygen by solar UV rays, with the former irreversibly being lost to space. Because of the cold trap in the Earth's atmosphere, the Earth is losing water to space at a rate of only about 1 millimeter of ocean every 1 million years. At that rate, it would take trillions of years for all of its water to disappear, a timescale far longer than Earth's remaining life expectancy. A warmer atmosphere can hold more moisture, consistent with the Clausius–Clapeyron relation. Even with localized warming, the modern cold trap remains robust enough to prevent significant water vapor from being lost to space. However, the gradual luminosity increase of the Sun as it ages will weaken the cold trap over the next billion years by driving a warmer troposphere and stratosphere. This will elevate the mixing ratio of water vapor at the tropopause, allowing moisture to bypass the freeze-drying effect and ascend into the upper atmosphere where it will be dissociated by solar UV rays, leaving hydrogen to escape into space. As a result, the Earth is projected to ultimately lose its oceans to space in approximately 1 to 1.3 billion years, well before the Sun expands into a red giant.
Battle of Hébuterne — French attacks on the southern flanks became disorganized, with one German patrol able to take 100 French prisoners. U.S. President Woodrow Wilson sent Germany the second of three letters related to the sinking of the RMS Lusitania in May, rejecting Germany's argument the British blockade was illegal and that the Lusitania was carrying munitions. United States Secretary of State William Jennings Bryan resigned over disagreement regarding his nation's handling of the RMS Lusitania sinking. Second Battle of Garua — After nearly 10 days of siege from British and French forces, close to half of the native colonial troops under German command in forts around Garua, German Cameroon began to mutiny or desert their posts. British colonial force cracked down on rioters in Ceylon, resulting in 116 dead. British cruiser HMS Dublin was torpedoed and damaged in the Adriatic Sea off Albania by Austro-Hungarian submarine SM U-4 with the loss of 12 of her 440 crew. HMS Dublin was subsequently repaired and returned to service. The Georgia Prison Commission denied an application to commute the death sentence of Leo Frank in a 2–1 vote, who was convinced in 1913 for the murder of 13-year old Mary Phagan. British naval forces occupied the island of Kamaran in the Red Sea off the coast what is now Yemen. The French Army established the Marine Infantry Tank Regiment. Born: Les Paul, American musician, inventor of the solid body electric guitar; as Lester William Polsfuss, in Waukesha, Wisconsin, United States (d. 2009)
symporter Any of a class of transmembrane transporter proteins which facilitate the transport of two or more different molecules across the membrane at the same time and in the same direction; e.g. glucose and sodium ions. Contrast antiporter and uniporter.
Sources: en.wikipedia.org
The observation of the longest carbon nanotubes grown so far, around 0.5 metre (550 mm) long, was reported in 2013. These nanotubes were grown on silicon substrates using an improved chemical vapor deposition (CVD) method and represent electrically uniform arrays of single-walled carbon nanotubes. The shortest carbon nanotube can be considered to be the organic compound cycloparaphenylene, which was synthesized in 2008 by Ramesh Jasti. Other small molecule carbon nanotubes have been synthesized since.
== S == S1 end mapping - S1 nuclease - satellite DNA - screening - SDS-PAGE - secondary structure - selection - selenium responsive proteins - sense strand - sequence - sequence motif - sequence polymorphism - sequence-tagged site - sequential epitope - severe combined immunodeficiency - sex chromosome - sex-linked - Shine-Dalgarno sequence - shotgun cloning - shotgun cloning or sequencing - shotgun sequencing - shuttle vector - Siah interacting protein N-terminal domain - sickle-cell disease - side chain - sigma factor - signal peptidase - signal sequence - silent mutation - single nucleotide polymorphism - siRNA - site-directed mutagenesis - site-specific recombination - Slc22a21 - slot blot - SNP - Slc22a21 - SMCR2 - snRNA - snRNP - solution hybridization - somatic cells - Southern blot - southwestern blot - SP6 RNA polymerase - SpAB protein domain - spectral karyotype - splicing - Simple Sequence Repeats (SSR) - SPR domain - SQ2397 - SRG1 RNA - ST7-AS2 - ST7-OT3 - stable transfection - start codon - stem-loop - sticky end - stomoxyn - stop codon - streptavidin - stringency - structural motif - sub-cloning - substitution - succinate—citramalate CoA-transferase - suicide gene - sulfate-transporting ATPase - suPARnostic - supercoil - SurE, survival protein E - Syb-prII-1 - syndrome -
Nazi architecture was designed to make the individual feel small and insignificant through its use of high ceilings. For example, at Nuremberg rallies, the feeling produced by the use of massed groups coupled with the architecture of the Zepplintribune architecture was to create wonder and a powerful feeling of community. Indeed, Hitler stated in one of his Nuremberg rally speeches, "Not every one of you sees me and I do not see every one of you. But I feel you and you feel me!". At the Nuremberg rallies, the overall effect of architecture was further enhanced through the use of many searchlights pointed directly upward to create a "Cathedral of Light" that even further served to invite the individual to buy into the Nazi worldview. Another prominent conceptual feature of Nazi architecture was the "Theory of Ruin Value", first put forward by Albert Speer, Hitler's personal architect. This theory postulated that for a civilization's influence to pass beyond the existence of the civilization itself, it was important that aesthetically pleasing and impressive ruins be left by the dilapidated buildings of that civilization. This theory, too, took inspiration from the ancient Romans and Greeks in attempting to emulate the even architectural remains of their civilizations with Nazi ones in thousands of years. Since the original inspiration for Nazi architecture was itself, the ancient Romans and Greeks, it was important to Hitler that at the end of the Thousand Year Reich, the remains would inspire others as Roman ruins had done for him.
=== Selected overdoses === A mysterious woman, known as the Isdal Woman, was found dead in Bergen, Norway, on 29 November 1970. Her death was caused by some combination of burns, phenobarbital, and carbon monoxide poisoning; many theories about her death have been posited, and it is believed that she may have been a spy. British veterinarian Donald Sinclair, the inspiration for the character Siegfried Farnon in the All Creatures Great and Small book series by James Herriot, committed suicide at the age of 84 by injecting himself with an overdose of phenobarbital. Activist Abbie Hoffman also committed suicide by consuming phenobarbital, combined with alcohol, on 12 April 1989; the residue of around 150 pills was found in his body at autopsy. Thirty-nine members of the Heaven's Gate UFO cult committed mass suicide in March 1997 by drinking a lethal dose of phenobarbital and vodka "and then lay down to die" hoping to enter an alien spacecraft.
Sources: en.wikipedia.org
=== Psychological support === Psychological support, often in the form of cognitive-behavioral therapy (CBT), family-based treatment, or psychotherapy aims to change distorted thoughts and behaviors around food, body image, and self-worth, with family-based therapy also being a key approach for younger patients.
A Pakistani newspaper, citing military sources, reported that seven TTP hideouts in Nangarhar, Paktika, and Khost provinces were destroyed and that more than 80 militants were killed; however, Taliban officials only reported airstrikes in the Nangarhar and Paktika provinces, adding that an airstrike in Bihsud District killed 18 civilians, including 11 children. Taliban officials condemned the airstrikes and warned of a calculated response at an appropriate time. Shayesteh Jan Ahadi, former head of the Paktia Provincial Council, stated that Pakistani airstrikes in several districts were very widespread and powerful. The United Nations Assistance Mission in Afghanistan (UNAMA) reported that Pakistan carried out airstrikes between 11:45 p.m. on 21 February and 12:15 a.m. on 22 February. UNAMA also reported that airstrikes in Paktika province damaged or destroyed infrastructure. On 23 February, UNAMA confirmed that over 13 civilians had been killed by the Pakistani airstrikes, with an additional seven injured. Pakistan described the operation as a retributive response to a series of suicide bombings inside Pakistan, including the 6 February bombing of a Shia mosque in Islamabad that killed 31 worshippers (claimed by ISIS–K), and attacks in Bajaur and Bannu districts in Khyber Pakhtunkhwa during the early days of Ramadan. Pakistan also claimed that the strikes were "intelligence-based, selective operations" against seven camps and hideouts belonging to the Tehreek-e-Taliban Pakistan (TTP), its affiliates, and the Islamic State – Khorasan Province (ISKP).
=== Size and length === There is no identified correlation between the size of the glans or clitoris as a whole, and a woman's age, height, weight, use of hormonal contraception, or being postmenopausal, although women who have given birth may have significantly larger clitoral measurements. Centimetre and millimetre measurements of the clitoris show variations in size. The clitoral glans has been cited as typically varying from 2 mm to 1 cm (less than an inch) and usually being estimated at 4 to 5 mm in both the transverse and longitudinal planes. A 1992 study concluded that the total clitoral length, including glans and body, is 16.0 ± 4.3 mm (0.63 ± 0.17 in), where 16 mm (0.63 in) is the mean and 4.3 mm (0.17 in) is the standard deviation. Concerning other studies, researchers from the Elizabeth Garrett Anderson and Obstetric Hospital in London measured the labia and other genital structures of 50 women from the age of 18 to 50, with a mean age of 35.6., from 2003 to 2004, and the results given for the clitoral glans were 3–10 mm for the range and 5.5 [1.7] mm for the mean. Other research indicates that the clitoral body can measure 5–7 centimetres (2.0–2.8 in) in length, while the clitoral body and crura together can be 10 centimetres (3.9 in) or more in length.
Emissions from vehicles such as cars and trucks can be a substantial outdoor source of PAHs in particulate air pollution. Geographically, major roadways are thus sources of PAHs, which may distribute in the atmosphere or deposit nearby. Catalytic converters are estimated to reduce PAH emissions from gasoline-fired vehicles by 25-fold. People can also be occupationally exposed from using fossil fuels or their derivatives, wood-burning, carbon electrodes, or exposure to diesel exhaust. Industrial activity that can produce and distribute PAHs includes aluminum, iron, and steel manufacturing; coal gasification, tar distillation, shale oil extraction; production of coke, creosote, carbon black, and calcium carbide; road paving and asphalt manufacturing; rubber tire production; manufacturing or use of metal working fluids; and activity of coal or natural gas power stations. In industrial countries, people who smoke tobacco products, or who are exposed to second-hand smoke, are among the most highly exposed groups; tobacco smoke contributes to 90% of indoor PAH levels in the homes of smokers. For the general population in developed countries, the diet is otherwise the dominant source of PAH exposure, particularly from smoking or grilling meat or consuming PAHs deposited on plant foods, especially broad-leafed vegetables, during growth. Exposure also occurs through drinking alcohol aged in charred barrels, flavored with peat smoke, or made with roasted grains. PAHs are typically at low concentrations in drinking water.
Mandelbaum (1956), professor at the University of Pennsylvania School of Design Kenneth Silverman (1956), professor at New York University and Pulitzer Prize-winning biographer Robert Alter (1957), professor of Hebrew and comparative literature at the University of California, Berkeley; president of the Association of Literary Scholars, Critics, and Writers Stanley Corngold (1957), professor of literature at Princeton University George Dargo (1957), legal scholar, professor at New England Law Boston Erich S. Gruen (1957), classicist and ancient historian; president of the Society for Classical Studies in 1992 Stanley Insler (1957), philologist and professor at Yale University Jonathan Lubin (1957), professor of mathematics at Brown University; introduced Lubin–Tate formal group law Robert Chazan (1958), professor of Judaic studies at New York University Gerald Feldman (1958), historian who specializes in 20th-century German history; professor at University of California, Berkeley Robert M. Fogelson (1958), urban historian at Massachusetts Institute of Technology Robert W.
Sources: en.wikipedia.org
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。