If you have been reading about ACTH 片段 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 2026-05-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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。
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.
| 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 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。
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
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.
Carbon monoxide and phosphorus trifluoride are poisonous to humans because they bind to hemoglobin similarly to oxygen, but with much more strength, so that oxygen can no longer be transported throughout the body. Hemoglobin bound to carbon monoxide is known as carboxyhemoglobin. This effect also plays a minor role in the toxicity of cyanide, but there the major effect is by far its interference with the proper functioning of the electron transport protein cytochrome a. The cytochrome proteins also involve heme groups and are involved in the metabolic oxidation of glucose by oxygen. The sixth coordination site is then occupied by either another imidazole nitrogen or a methionine sulfur, so that these proteins are largely inert to oxygen—with the exception of cytochrome a, which bonds directly to oxygen and thus is very easily poisoned by cyanide. Here, the electron transfer takes place as the iron remains in low spin but changes between the +2 and +3 oxidation states. Since the reduction potential of each step is slightly greater than the previous one, the energy is released step-by-step and can thus be stored in adenosine triphosphate. Cytochrome a is slightly distinct, as it occurs at the mitochondrial membrane, binds directly to oxygen, and transports protons as well as electrons, as follows:
== Causes == The cause of IBM is unknown. IBM likely results from the interaction of a number of genetic and environmental factors. There are two major theories about how sIBM is caused. One hypothesis suggests that the inflammation-immune reaction, caused by an unknown trigger – likely an undiscovered virus or an autoimmune disorder – is the primary cause of sIBM and that the degeneration of muscle fibers and protein abnormalities are secondary features. Despite the arguments "in favor of an adaptive immune response in sIBM, a purely autoimmune hypothesis for sIBM is untenable because of the disease's resistance to most immunotherapy." The second school of thought advocates the theory that sIBM is a degenerative disorder related to aging of the muscle fibers and that abnormal, potentially pathogenic protein accumulations in myofibrils play a key causative role in sIBM (apparently before the immune system comes into play). This hypothesis emphasizes the abnormal intracellular accumulation of many proteins, protein aggregation and misfolding, proteosome inhibition, and endoplasmic reticulum (ER) stress. One review discusses the "limitations in the beta-amyloid-mediated theory of IBM myofiber injury." Dalakas (2006) suggested that a chain of events causes IBM – some sort of virus, likely a retrovirus, triggers the cloning of T cells. These T cells appear to be driven by specific antigens to invade muscle fibers.
Sensory neurons (afferent): Relay sensory information in the form of an action potential (nerve impulse) from the PNS to the CNS Motor neurons (efferent): Relay an action potential out of the CNS to the proper effector (muscles, glands) Interneurons: Cells that form connections between neurons and whose processes are limited to a single local area in the brain or spinal cord Structural classification:
Sources: en.wikipedia.org
The illegal trade for tiger parts in China has driven the species to near-extinction because of its popularity in traditional medicine. Laws protecting even critically endangered species such as the Sumatran tiger fail to stop the display and sale of these items in open markets. Shark fin soup is traditionally regarded in Chinese medicine as beneficial for health in East Asia, and its status as an elite dish has led to huge demand with the increase of affluence in China, devastating shark populations. The shark fins have been a part of traditional Chinese medicine for centuries. Shark finning is banned in many countries, but the trade is thriving in Hong Kong and China, where the fins are part of shark fin soup, a dish considered a delicacy, and used in some types of traditional Chinese medicine. Restrictions are made on the accumulation and export of endangered species not raised in captivity. Australian scientists have developed methods to identify medicines containing DNA traces of endangered species. Finally, although not an endangered species, sharp rises in exports of donkeys and donkey hide from Africa to China to make the traditional remedy ejiao have prompted export restrictions by some African countries.
The professional tagmata regiments, first introduced in the mid-700s and consisting of native Byzantine units alongside foreign forces such as the Varangian Guard, had completely replaced them by the 11th century. The mobile tagmata, suitable for offensive warfare, evolved new tactical and strategic structures; the late 10th-century army, perhaps the highest-quality force the empire produced, numbered approximately 140,000, up from below 100,000 in the late 700s. However, its defensive capacities were neglected, especially during the 11th-century civil wars, leading to the loss of Anatolia to the Seljuks. The navy had also been reduced, as the empire increasingly relied on potentially hostile powers such as Venice. Post-1081 reforms re-established an effective army; the institution of feudal-like pronoia grants provided revenue to individuals in exchange for soldiers. The new army heavily relied on foreign mercenaries alongside indigenous Byzantine troops, but the financial demands of a standing army proved too much for the Byzantine state, which succumbed to the Fourth Crusade in 1204. The army of the Palaiologan dynasty, which retook Constantinople in 1261, was generally composed of a similar mix of mercenaries and indigenous troops, but it had lost all offensive capability by the late 1200s. The empire's continued survival depended on foreign armies; attempts in the 1340s to rebuild the fleet, unwisely disbanded in 1284, were forcibly halted by Genoa.
=== Free triiodothyronine === Free triiodothyronine (fT3 or free T3) is generally elevated in hyperthyroidism and decreased in hypothyroidism. Reference ranges depend on the method of analysis. Results should always be interpreted using the range from the laboratory that performed the test. Example values are:
Sources: en.wikipedia.org
=== Examples === Black-box (stimulus/response) loggers: A flight data recorder (FDR) is a piece of recording equipment used to collect specific aircraft performance data. The term may also be used, albeit less accurately, to describe the cockpit voice recorder (CVR), another type of data recording device found on board aircraft. An event data recorder (EDR) is a device installed by the manufacturer in some automobiles which collects and stores various data during the time-frame immediately before and after a crash. A voyage data recorder (VDR) is a data recording system designed to collect data from various sensors on board a ship. A train event recorder is a device that records data about the operation of train controls and performance in response to those controls and other train control systems. An accident data recorder (ADR) is a device for triggering accidents or incidents in most kind of land vehicles and recording the relevant data. In automobiles, all diagnostic trouble codes (DTCs) are logged in engine control units (ECUs) so that at the time of service of a vehicle, a service engineer will read all the DTCs using Tech-2 or similar tools connected to the on-board diagnostics port, and will come to know problems occurred in the vehicle. Sometimes a small OBD data logger is plugged into the same port to continuously record vehicle data. In embedded system and digital electronics design, specialized high-speed digital data logger help overcome the limitations of more traditional instruments such as the oscilloscope and the logic analyzer.
=== Tempe kering === Also known as kering tempe (lit: 'dry tempeh'), or sambal goreng tempe if mixed with plenty of hot and spicy sambal chili pepper sauce. It is a crispy, sweet and spicy, fried tempeh. The raw tempeh is cut into small sticks and thoroughly deep-fried until no longer moist, and then mixed with palm sugar, chili pepper or other spices, or with sweet soy sauce. Often it is mixed with separately fried peanuts and anchovies (ikan teri). This dry tempeh will keep for up to a month if cooked and stored properly.
{\displaystyle T\leq {\frac {abc}{2}}{\sqrt {\frac {a+b+c}{a^{3}+b^{3}+c^{3}+abc}}}\leq {\frac {1}{4}}{\sqrt[{6}]{\frac {3(a+b+c)^{3}(abc)^{4}}{a^{3}+b^{3}+c^{3}}}}\leq {\frac {\sqrt {3}}{4}}(abc)^{\frac {2}{3}}.}
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。
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.