Everything below concerns Peptide mapping. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-09-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
| Property | Value | Notes |
|---|---|---|
| 化学类别 | 合成七肽 | ACTH(4-10) 结构类似物 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | 单字母写作 MEHFPGP |
| 分子量 | 约 813.9 Da | 随确切形式和盐型略有变化 |
| 常见同义词 | ACTH(4-10) 类似物 | 俄语文献称 Семакс |
| 开发来源 | 俄罗斯 | 二十世纪八十年代 |
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.
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.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
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.
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.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The General dumps the cargo module Archer is hiding in to gain speed and leaves the AI facility's science team behind to die. As Archer progresses through the facility, he learns that the Mainframe's primary battle is with a major Xenome infestation that the humans brought onto the moon. Fighting both attack drones and Xenomes alike, Archer makes his way through the facility. Despite the Mainframe's best efforts, Archer manages to destroy most of the "kata-space anchors" that keep the moon from falling to the planet below. Archer survives the destruction of the anchors, but is stranded on the falling moon. Archer eventually finds the Mainframe and they form an uneasy alliance: the Mainframe will provide an aerial drone for Major Archer to escape in, but only if he takes the Mainframe's core with him. Major Archer agrees, and they battle through hordes of Xenome forces with the help of the Mainframe's attack drones. Major Archer and the AI successfully reach and board the aerial drone, but fail to navigate through an asteroid field on their way into kata-space and crash land on a desert planet called Icnus, encountering and fighting rogue Gunmen. Icnus turns out to be the location of the General's main Xenome facility. Archer battles his way through the facility with the help of the Mainframe, accidentally causing a captured Worm Xenome, one of the most dangerous Xenomes in existence, to break loose. The Mainframe helps Archer to the General's location and they engage in a firefight, where the AI's newly constructed Super Drone defeats the General's Kata-Drone.
== Further reading == Hagedorn, Henry H.; Kunkel, Joseph G. (1979). "Vitellogenin and Vitellin in Insects". Annual Review of Entomology. 24 (4): 475–505. doi:10.1146/annurev.en.24.010179.002355. Wheeler, Diana E.; Kawooya, John K. (1990). "Purification and characterization of honey bee vitellogenin". Archives of Insect Biochemistry and Physiology. 14 (4): 253–267. doi:10.1002/arch.940140405. PMID 2134180. "Vitellogenin Gene Expression in Male Fathead Minnow as an Indicator of Exposure to Endocrine Disrupting Chemicals (EDC) in an Aquatic Environment". EPA.gov. 2006. Amdam, G. V.; Norberg, K.; Omholt, S. W.; Kryger, P.; Lourenço, A. P.; Bitondi, M. M. G.; Simões, Z. L. P. (November 2005). "Higher vitellogenin concentrations in honey bee workers may be an adaptation to life in temperate climates". Insectes Sociaux. 52 (4): 316–319. doi:10.1007/s00040-005-0812-2. S2CID 25197924. Seehuus, S.-C.; Norberg, K.; Gimsa, U.; Krekling, T.; Amdam, G. V. (17 January 2006). "Reproductive protein protects functionally sterile honey bee workers from oxidative stress". Proceedings of the National Academy of Sciences. 103 (4): 962–7. doi:10.1073/pnas.0502681103. PMC 1347965. PMID 16418279. Nelson, C. Mindy; Ihle, Kate E; Fondrk, M. Kim; Page, Robert E; Amdam, Gro V; Chittka, Lars (6 March 2007). "The Gene vitellogenin Has Multiple Coordinating Effects on Social Organization". PLOS Biology. 5 (3): e62. doi:10.1371/journal.pbio.0050062. PMC 1808115. PMID 17341131. Corona, M.; Velarde, R. A.; Remolina, S.; Moran-Lauter, A.; Wang, Y.; Hughes, K. A.; Robinson, G. E. (16 April 2007).
=== Youth === East German Junior Championship (de) Winners: 1961, 1971, 1974, 1976, 1977 Runners-up: 1964, 1972, 1982 East German Youth Championship (de) Winners: 1969, 1971, 1979, 1981, 1984 (record) Runners-up: 1966, 1970, 1978, 1980 East German Junior Cup (Junge Welt-Pokal) (de) Winners: 1971, 1974, 1975, 1988 East German Youth Cup (Youth FDGB-Pokal) Winners: 1959, 1968
Sources: en.wikipedia.org
Isotopic reference materials are compounds (solids, liquids, gasses) with well-defined isotopic compositions and are the ultimate sources of accuracy in mass spectrometric measurements of isotope ratios. Isotopic references are used because mass spectrometers are highly fractionating. As a result, the isotopic ratio that the instrument measures can be very different from that in the sample's measurement. Moreover, the degree of instrument fractionation changes during measurement, often on a timescale shorter than the measurement's duration, and can depend on the characteristics of the sample itself. By measuring a material of known isotopic composition, fractionation within the mass spectrometer can be removed during post-measurement data processing. Without isotope references, measurements by mass spectrometry would be much less accurate and could not be used in comparisons across different analytical facilities. Due to their critical role in measuring isotope ratios, and in part, due to historical legacy, isotopic reference materials define the scales on which isotope ratios are reported in the peer-reviewed scientific literature. Isotope reference materials are generated, maintained, and sold by the International Atomic Energy Agency (IAEA), the National Institute of Standards and Technology (NIST), the United States Geologic Survey (USGS), the Institute for Reference Materials and Measurements (IRMM), and a variety of universities and scientific supply companies.
{\displaystyle {\begin{aligned}&{\frac {dS}{dt}}=-a(t)SI-v(t)S+b(t)[\mu (t)I+v(t)S],\\[6pt]&{\frac {dI}{dt}}=a(t)SI-\mu (t)I,\\[6pt]&{\frac {dR}{dt}}=[1-b(t)]\mu (t)I,\\[6pt]&{\frac {dV}{dt}}=[1-b(t)]v(t)S,\\[6pt]\end{aligned}}}
=== August === 1 August: The second Donald Trump administration raises tariffs on New Zealand exports to the United States to 15 percent. Visual effects company Wētā FX proposes laying off 100 jobs in its support departments based in Wellington. 4 August: The New Zealand Government announces plans to scrap the National Certificate of Educational Achievement (NCEA) secondary school qualification. A name suppression order lapses for former Deputy Commissioner of Police Jevon McSkimming, who was charged in June 2025 with eight counts of possessing objectionable material including child sexual exploitation and bestiality over a four-year period. 5–6 August — An RNZAF C-130J Hercules evacuated three personnel of the United States National Science Foundation from McMurdo Station. 6 August: The Christchurch-based wool factory Wild Earth Yarns acquires the woollen dye house and spinning mill of the liquidated Napier-based company Design Spun. Hato Hone St John proposes scrapping various community voluntary programmes including hospital volunteers, community carers and pet therapy services as part of a review of its services; affecting about 1,100 people. 8 August – The Japanese Navy makes a stop-over in Wellington for the first time since 1936. 9–10 August – Prime Minister Luxon hosts Australian Prime Minister Anthony Albanese in Queenstown for annual bilateral head of government talks. 10 August — Gloriavale Christian Community's Overseeing Shepherd Howard Temple resigns after pleading guilty to 12 charges of sexual offending against women and girls last month.
Sources: en.wikipedia.org
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。
Semax 被描述为 ACTH(4-10) 的结构类似物，两者共享部分序列特征。它保留了该片段的部分神经相关活性方向，但去除了完整片段带来的激素释放效应。二者并非同一物质，也不能互相替代。
加入的 Pro-Gly-Pro 三肽被普遍认为能提升分子对蛋白水解酶的稳定性。这种设计让短肽在体内维持时间更长。具体延长的程度以及不同组织中是否一致，文献中仍存在不同报告。
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.