合成七肽 raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-12-08. Anything still debated is marked as such rather than presented as settled.
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。
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.
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构,不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
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.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
== Composition == Most hotspot volcanoes are basaltic (e.g., Hawaii, Tahiti). As a result, they are less explosive than subduction zone volcanoes, in which water is trapped under the overriding plate. Where hotspots occur in continental regions, basaltic magma rises through the continental crust, which melts to form rhyolites which can form violent eruptions. For example, the Yellowstone Caldera was formed by some of the most powerful volcanic explosions in geologic history. However, when the rhyolite is completely ejected, it may be followed by eruptions of basaltic magma rising through the same lithospheric fissures (cracks in the lithosphere). An example of this activity is the Ilgachuz Range in British Columbia, which was created by an early complex series of trachyte and rhyolite eruptions, and late extrusion of a sequence of basaltic lava flows. The hotspot hypothesis is now closely linked to the mantle plume hypothesis. The detailed compositional studies now possible on hotspot basalts have allowed linkage of samples over the wider areas often implicate in the later hypothesis, and its seismic imaging developments.
The effects of 2C-B were reported by Shulgin to include sensory enhancement, brightened colors, visual richness, mental imagery, psychedelic visuals including kaleidoscopic and organic forms, sound distortion, increased appreciation of art and music, passivity, relaxation, emotional changes, euphoria, increased body awareness, tactile enhancement, feeling like waves of energy are flowing through oneself, feeling like one's body is flooded with orgasms, and sexual enhancement. He has succinctly described 2C-B as having "a luxury of sensory enhancement (visual, sexual, gustatory) with a minimum of introspective demands". The drug was one of his favorite psychedelics and one of his "magical half-dozen" most important psychedelic phenethylamines. At doses of 8 to 10 mg, 2C-B was described as consistently producing substantial sensory enhancement, but as not "superimposing hallucinogenesis" or as having "no hallucinogenic effects", with the state being described as quite distinct from that usually associated with psychedelics. It was also said to lack the lassitude that can be associated with psilocybin.
== Career == McLain provides voices for many characters in several video games from Valve. Among them are GLaDOS, the primary antagonist of the Portal video game series (for which she won an AIAS Interactive Achievement Award for Outstanding Achievement in Character Performance), the announcer in Team Fortress 2, and the voice of the Combine Overwatch for the Half-Life series. McLain sang "Still Alive" and "Want You Gone", the ending credits songs to Portal and Portal 2, respectively, both of which were written by Jonathan Coulton. She also sang "Cara Mia Addio" at the end of Portal 2. In December 2011, McLain won the Spike Video Game Award in the category "Best Performance by a Human Female" for her voice acting as GLaDOS in Portal 2. In 2013, she lent her public support to gathering donations for the Kickstarter-funded LGBT gaming convention GaymerX. She later was a special guest at the convention in August 2013. In 2014, she portrayed Fairy Godmother in the online video series [Wish It Inc.]. In 2015, she portrayed Lisa Clarke in the gay independent film, Winning Dad. This film was also promoted on McLain's YouTube channel. McLain has played roles in many radio dramas on the radio program Imagination Theatre. In 2021, McLain provided the voice of GLaDOS non-canonically, singing a verse in The Chalkeaters’ song "Count to Three" as a cameo.
Sources: en.wikipedia.org
=== Capillary rise of liquid between two glass plates === The product of layer thickness (d) and elevation height (h) is constant (d·h = constant), the two quantities are inversely proportional. The surface of the liquid between the planes is hyperbola.
To better compete with more diversified manufacturers, in 1955 Whirlpool acquired Seeger Refrigerator Company and RCA's air conditioner and cooking range lines. The company changed its name to Whirlpool-Seeger Corporation and began using the RCA-Whirlpool brand name. Whirlpool acquired International Harvester Company's refrigeration plant in Evansville, Indiana, in 1955. In 1956, a 100-acre (0.40 km2) administrative center was opened in Benton Harbor, Michigan. In 1957, the RCA Whirlpool Miracle Kitchen was introduced with an estimated 15 million television viewers. The company changed its name back to Whirlpool Corporation and brought in Robert Elton Brooker as president. At the 1959 American National Exhibition at Sokolniki Park, Moscow, Brooker presided over the Whirlpool kitchen. The Whirlpool kitchen inspired the Kitchen Debate between then Vice President Richard Nixon and Soviet Premier Nikita Khrushchev.
== Clinical evidence == In a six-month randomized trial published in The New England Journal of Medicine in 2019, 168 people with type 1 diabetes were assigned either Control-IQ with a t:slim X2 and Dexcom G6 or a sensor-augmented pump. Mean time with glucose in the target range of 70–180 mg/dL rose from 61% to 71% in the Control-IQ group and remained about 59% in the control group, an adjusted difference of 11 percentage points, or 2.6 hours per day. No severe hypoglycemic events occurred; one participant using the closed-loop system developed diabetic ketoacidosis after an infusion-set failure. The trial was funded by the National Institute of Diabetes and Digestive and Kidney Diseases; Tandem supplied systems and technical support but, according to the publication, did not control the study design, conduct or analysis. A 13-week randomized trial published in the same journal in 2025 enrolled 319 adults with insulin-treated type 2 diabetes. Time in the target range increased from 48% to 64% with Control-IQ, compared with 51% to 52% in a control group that continued its previous insulin method; the adjusted difference was 14 percentage points. Glycated hemoglobin fell by 0.9 percentage points in the automated-delivery group and by 0.4 points in the control group. One severe hypoglycemic event occurred in the automated-delivery group. The study was funded by Tandem.
Sources: en.wikipedia.org
不存在。它是依据 ACTH 的一段序列人工设计的分子,天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号,而非天然物质名。
Semax 对应 ACTH 第 4 至第 10 位的片段,并在两端做了替换与延长,使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物,需要医生开具处方。多数其他国家把它当作研究化合物,不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
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.