ACTH 片段 raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-07-11 and is reviewed periodically as new material appears.
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 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。
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 |
|---|---|---|
| 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. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
It was not discovered to act as a very weak (3.5 orders of magnitude less potent) gabapentinoid until 2015. Baclofen marketed under the brandname of Lioresal was introduced in the United States in 1977 for the treatment of spasticity is chemically similar to phenibut but is usually not considered a gabapentinoid. Mirogabalin, under the brand name Tarlige, was approved for the treatment of neuropathic pain and postherpetic neuralgia in Japan in January 2019. Gabapentenoid consumption appears to be increasing; between 2008 and 2018, gabapentenoid use increased by over 17% averaged worldwide, led by growing consumption in the US, Canada, and northern Europe.
== Adverse effects == People have had severe infusion-related reactions to pembrolizumab. There have also been severe immune-related adverse effects including lung inflammation (including fatal cases) and inflammation of endocrine organs that caused inflammation of the pituitary gland, of the thyroid (causing both hypothyroidism and hyperthyroidism in different people), and pancreatitis that caused Type 1 diabetes and diabetic ketoacidosis; some people have had to go on lifelong hormone therapy as a result (e.g. insulin therapy or thyroid hormones). People have also had colon inflammation, liver inflammation, kidney inflammation due to the drug. The common adverse reactions have been fatigue (24%), rash (19%), itchiness (pruritus) (17%), diarrhea (12%), nausea (11%) and joint pain (arthralgia) (10%). Other adverse effects occurring in between 1% and 10% of people taking pembrolizumab have included anemia, decreased appetite, headache, dizziness, distortion of the sense of taste, dry eye, high blood pressure, abdominal pain, constipation, dry mouth, severe skin reactions, vitiligo, various kinds of acne, dry skin, eczema, muscle pain, pain in a limb, arthritis, weakness, edema, fever, chills, myasthenia gravis, and flu-like symptoms.
=== Electricity demand and grid capacity === The proliferation of AI has driven a surge in data centre construction and power requirements. According to the National Energy System Operator (NESO), UK data centres consumed 5.0 TWh of electricity in 2023, equivalent to 2% of total UK electricity demand and 7% of commercial sector consumption. However, Oxford Economics forecasts that total demand could grow more than fivefold by 2030, reaching 26.2 TWh, which would represent 8.8% of total UK electricity demand and 30.4% of commercial electricity consumption. This rapid growth has created friction with the UK's net zero targets. In February 2026, the Environmental Audit Committee raised concerns that the government had not adequately factored data centre energy consumption into the draft Seventh Carbon Budget. The energy regulator Ofgem disclosed that developers of new data centres had enquired about grid connections that would require more energy at peak times than the whole of Britain consumes on some days.
Sources: en.wikipedia.org
Trump further announced that month a plan for a new fleet of naval vessels, to be called Trump-class battleships, although battleships have long been obsolete in naval warfare and the Navy's last one in service was decommissioned in 1992. For many years, the National Park Service's annual general pass depicted natural landscapes, but the new 2026 pass design for U.S. residents has a photo of Donald Trump. The redesign triggered a popular backlash of passholders' covering his photo with stickers; the Park Service responded by updating its ban on defaced passes to include anything obscuring the front. The year also marked the Treasury's announcement that Trump's own signature would replace that of the treasurer on paper currency, another first for a president; the State Department’s issuance of a new passport design with a portrait of Trump, the first living president to appear on a U.S. passport, offered as an option to in-person applicants at the Washington, D.C., Passport Agency; and Florida Gov. Ron DeSantis's consent to renaming Palm Beach International Airport after Trump, a change the president had reportedly sought in 2020. Other measures bearing Trump’s name are Trump accounts, tax-advantaged investment accounts for American minors rolled out as part of the One Big Beautiful Bill Act; TrumpRx, a prescription drug website run by the federal government; and the Trump Gold Card, a program offering foreign nationals expedited U.S. residency in exchange for donations of $1 million or more to the Commerce Department and denounced by U.S. Sen.
=== Proteins === Arginine's side chain is amphipathic, because at physiological pH it contains a positively charged guanidinium group, which is highly polar, at the end of a hydrophobic aliphatic hydrocarbon chain. Because globular proteins have hydrophobic interiors and hydrophilic surfaces, arginine is typically found on the outside of the protein, where the hydrophilic head group can interact with the polar environment, for example taking part in hydrogen bonding and salt bridges. For this reason, it is frequently found at the interface between two proteins. The aliphatic part of the side chain sometimes remains below the surface of the protein. Arginine residues in proteins can be deiminated by PAD enzymes to form citrulline, in a post-translational modification process called citrullination. This is important in fetal development, is part of the normal immune process, as well as the control of gene expression, but is also significant in autoimmune diseases. Another post-translational modification of arginine involves methylation by protein methyltransferases.
The two substrates of this enzyme are L-idonic acid and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are 5-oxo-D-gluconic acid, reduced NADH, and a proton. The enzyme can also use the alternative cofactor, nicotinamide adenine dinucleotide phosphate. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-idonate:NAD(P)+ oxidoreductase.
Sources: en.wikipedia.org
==== Galápagos Islands ==== The Galápagos Islands are a chain of volcanic islands, nearly 600 miles west of Ecuador, South America. in the Eastern Pacific Ocean. These islands support a wide diversity of terrestrial and marine species. The ecosystem is based on the normal trade winds which influence upwelling of cold, nutrient rich waters to the islands. During an El Niño event the trade winds weaken and sometimes blow from west to east, which causes the Equatorial current to weaken, raising surface water temperatures and decreasing nutrients in waters surrounding the Galápagos. El Niño causes a trophic cascade which impacts entire ecosystems starting with primary producers and ending with critical animals such as sharks, penguins, and seals. The effects of El Niño can become detrimental to populations that often starve and die back during these years. Rapid evolutionary adaptations are displayed amongst animal groups during El Niño years to mitigate El Niño conditions.
=== Radiogenic === Some 209Bi was created radiogenically from the neptunium decay chain. Neptunium-237 is an extinct radionuclide, but it can be found in traces in uranium ores because of neutron capture reactions. This is also ultimately due to the r-process, as every (4n+1) nucleus formed (and not fissioned) ultimately decayed to bismuth.
== Signs and symptoms == People with antidepressant discontinuation syndrome have been on an antidepressant for at least four weeks and have recently stopped taking the medication, whether abruptly, after a fast taper, or each time the medication is reduced on a slow taper. Commonly reported symptoms include flu-like symptoms (e.g., nausea, vomiting, diarrhea, headaches, sweating) and sleep disturbances (e.g., insomnia, nightmares, constant sleepiness). Sensory and movement disturbances have also been reported, including imbalance, tremors, vertigo, dizziness, and electric-shock-like experiences in the brain, often described by people who have them as brain zaps. These "brain zaps" have been described as an electric shock felt in the skull, potentially triggered by lateral eye movement, and at times accompanied by vertigo, pain, or dissociative symptoms. Some individuals consider it as a pleasant experience akin to an orgasm, however it is more often reported as an unpleasant experience that interferes with daily function. Mood disturbances such as dysphoria, anxiety, or agitation are also reported, as are cognitive disturbances such as confusion and hyperarousal. In cases associated with sudden discontinuation of MAO inhibitors (MAOIs), acute psychosis has been observed. Over fifty symptoms have been reported. The SNRI venlafaxine has been reported to have a higher incidence in withdrawal symptoms after discontinuation when compared to other SNRIs. Venlafaxine has also been implicated to create withdrawal symptoms regardless of dosage.
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。
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。