Everything below concerns ACTH analog. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-07-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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。
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
| 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 |
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
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。
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
=== Todd Barber === Todd Barber (Branden Cook) is Harper's ex-boyfriend from New York. The two remain sexually involved after their breakup, and he helps her forge her university transcripts when she is hired to Pierpoint. Todd later visits Harper in London; the two have a fight after Harper discovers he stole an expensive jacket from a patron at the nightclub they went to, where Todd calls Harper a coward and a hypocrite. Harper cuts ties with him for good.
== Biology and Uses == Pisolithus arhizus is made up of networks of hyphae, the thin filamentous structures that compose the its mycelium. In Pisolithus fungi, spores are produced in basidia on the fungus's fruiting body. A recent study testing arhizus compounds looked into the cellular compounds and discovered twenty new "triterpenoid" compounds that had never before been documented, as well as assorted pigments and phenolic acids. As its chemical composure continues to be researched, studies have claimed significant medical potential for the Pisolithus group in general. A study on the broader genus revealed compounds with significant antibiotic properties and killed resistant strains of bacteria from real patients' wounds. Also, certain triterpenoids yielded impressive results in killing leukemia, melanoma, and brain cancer cells without harming healthy human blood cells they were with. A paper that hones in on Pisolithus arhizus specifically notes that arhizus had anti-genotoxic properties in addition to the antibacterial effects found from using methanol and ethanol extracts of the fungus (in comparison to the specific isolated compounds from the study mentioned before). The fungus also showed strong cytotoxicity (at high concentrations eliminated up to 97% cancer cells) against a colon cancer cell line. Although the study didn't give results of the testing on healthy human cells, it's findings are promising for future research.
== Mechanism of action == α-Arbutin's mechanism of action as a skin lightening agent is primarily through the competitive enzymatic inhibition of tyrosinase, leading to a decrease in melanin production without affecting the mRNA gene expression of tyrosinase. It is more potent an inhibitor of tyrosinase than arbutin. α-Arbutin directly inhibits the enzymatic activity of tyrosinase, which is essential for melanin synthesis. Tyrosinase catalyzes the first two steps in melanin production: the hydroxylation of tyrosine to l-DOPA and the oxidation of l-DOPA to dopaquinone. By inhibiting tyrosinase, α-arbutin reduces the formation of melanin in melanocytes. α-Arbutin does not affect the gene expression of tyrosinase mRNA. This means that while α-arbutin inhibits the activity of the tyrosinase enzyme, it does not decrease the enzyme's production at the genetic level. This reduction in melanin leads to lighter skin tones and can help in the treatment of hyperpigmentation disorders. The efficacy of α-arbutin in reducing melanin synthesis was demonstrated in cultured human melanoma cells and a three-dimensional human skin model, where it effectively reduced melanin synthesis.
Sources: en.wikipedia.org
=== Preservation of bog bodies === The preservation of bog bodies is dependent on a set of specific physical conditions, which can occur in peat bogs. A sphagnum moss bog must have a temperature lower than 4 °C (39 °F) at the time of deposition of the body. The subsequent average annual temperature must be lower than 10 °C (50 °F). Moisture must be stable in the bog year-round: it cannot dry out. Sphagnum moss affects the chemistry of nearby water, which becomes highly acidic (a pH of roughly 3.3 to 4.5) relative to a more ordinary environment. The concentration of dissolved minerals also tends to be low. Dying moss forms layers of sediment and releases sugars and humic acids which consume oxygen. Since the surface of the water is covered by living moss, water becomes anaerobic. As a result, human tissues buried in the bog tend to tan rather than decay.
While there is a lack of geochemical observations to constrain the exact composition of the prebiotic atmosphere, recent models point to an early "weakly reducing" atmosphere; that is, early Earth's atmosphere was likely dominated by CO2 and N2 and not CH4 and NH3 as used in the original Miller–Urey experiment. This is explained, in part, by the chemical composition of volcanic outgassing. Geologist William Rubey was one of the first to compile data on gases emitted from modern volcanoes and concluded that they are rich in CO2, H2O, and likely N2, with varying amounts of H2, sulfur dioxide (SO2), and H2S. Therefore, if the redox state of Earth's mantle — which dictates the composition of outgassing – has been constant since formation, then the atmosphere of early Earth was likely weakly reducing, but there are some arguments for a more-reducing atmosphere for the first few hundred million years. While the prebiotic atmosphere could have had a different redox condition than that of the Miller–Urey atmosphere, the modified Miller–Urey experiments described in the above section demonstrated that amino acids can still be abiotically produced in less-reducing atmospheres under specific geochemical conditions.
=== Heart === T3 increases the heart rate and force of contraction, thus increasing cardiac output, by increasing β-adrenergic receptor levels in myocardium. This results in increased systolic blood pressure and decreased diastolic blood pressure. The latter two effects act to produce the typical bounding pulse seen in hyperthyroidism. It also upregulates the thick filament protein myosin, which helps to increase contractility. A helpful clinical measure to assess contractility is the time between the QRS complex and the second heart sound. This is often decreased in hyperthyroidism.
Sources: en.wikipedia.org
Pombal's industrialisation efforts failed, and his education policies weakened human-capital formation. The expulsion of the Jesuits reduced student numbers and contributed to Portugal's decline in literacy. Pombal's instrumentalisation of the Inquisition for political purposes helped to entrench an extractive system that outlasted his rule. The nature of the existing political institutions contributed to Portugal's sustained divergence from Western Europe despite comparable family values and high state capacity, with partial recovery beginning from around the mid-20th century alongside the continuation of colonialism.
== Distribution and habitat == The Liliaceae are widely distributed, but mainly in the temperate regions of the Northern Hemisphere. The centre of diversity is from southwest Asia to China. Their distribution is diverse, mainly in plains, steppes, and alpine meadows, but also in deciduous forests, Mediterranean scrub and arctic tundra. Tulipa and Gagea provide examples of ornamental geophyte biomorphological types representing continental thermoperiodic zones (Irano-Turanian region), characterised by cessation of underground growth at high temperatures in early summer and requiring low winter temperatures for spring flowering. While some genera are shade-dwelling, such as the Medeoleae, and Streptopoideae, Tricyrtis, and Cardiocrinum, others prefer a more open habitat.
At the next performance on 25 October, his fellow actors realised that Thomas was very ill: "He was desperately ill…we didn't think that he would be able to do the last performance because he was so ill…Dylan literally couldn't speak he was so ill…still my greatest memory of it is that he had no voice." On the evening of 27 October, Thomas attended his 39th birthday party but felt unwell and returned to his hotel after an hour. The next day, he took part in Poetry and the Film, a recorded symposium at Cinema 16. A turning point came on 2 November. Air pollution in New York had risen significantly and exacerbated chest illnesses such as Thomas's. By the end of the month, over 200 New Yorkers had died from the smog. On 3 November, Thomas spent most of the day in his room, entertaining various friends. He went out in the evening to keep two drink appointments. After returning to the hotel, he went out again for a drink at 2 am. After drinking at the White Horse, Thomas returned to the Hotel Chelsea, declaring, "I've had 18 straight whiskies. I think that's the record!" The barman and the owner of the pub who served him later commented that Thomas could not have drunk more than half that amount. Thomas had an appointment at a clam house in New Jersey with Ruthven Todd on 4 November. When Todd telephoned the Chelsea that morning, Thomas said he was feeling ill and postponed the engagement. Todd thought he sounded "terrible". The poet, Harvey Breit, was another to phone that morning. He thought that Thomas sounded "bad". Thomas's voice, recalled Breit, was "low and hoarse".
=== Viruses === Brine pockets can support a wide variety of bacteria, and they are also home to high concentrations of marine viruses. Marine viruses in brine pockets may play a major role in regulating the population dynamics of their hosts and influencing biogeochemical cycles within the pocket. As viruses are highly specific to their hosts, viruses in brine pockets include bacteriophages, which infect bacteria, and archaeal viruses, which infect archaea. Algal viruses and other eukaryotic viruses can also be present in brine pockets, which influences the productivity and diversity of these microorganisms. Marine viruses in brine pockets can also influence biogeochemical processes by releasing nutrients through the lysis of infected cells, and by facilitating horizontal gene transfer between hosts. Infections caused by viruses can also trigger changes in the host metabolism, leading to altered nutrient uptake and production of metabolites, which in turn can influence the surrounding environment. The few studies on viral abundance and composition in brine pockets focus mainly on the diverse concentrations of viruses, separated by molecular size. Brine pockets in the Antarctic lakes have been found to have three groups of viruses at different abundances. In the Arctic waters, viral concentrations were found to vary from 1.6 to 82 × 106 ml−1, with the highest concentrations found in the coldest brine pockets (–24 to –31 °C).
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。
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.