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 2025-11-23 and is reviewed periodically as new material appears.
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.
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。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
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.
Singapore has a generally efficient healthcare system, having achieved high quality of care while also keeping expenditures low. The World Health Organisation ranks Singapore's healthcare system as 6th overall in the world in its World Health Report. Singapore has had the lowest infant mortality rates in the world for the past two decades. In 2019, Singaporeans had the longest life expectancy of any country at 84.8 years. Women can expect to live an average of 87.6 years with 75.8 years in good health. The averages are lower for men. Singapore is ranked 1st on the Global Food Security Index. As of December 2011 and January 2013, 8,800 foreigners and 5,400 Singaporeans were respectively diagnosed with HIV, but there are fewer than 10 annual deaths from HIV per 100,000 people. Adult obesity is below 10%. There is a high level of immunisation. In 2013, the Economist Intelligence Unit ranked Singapore as having the best quality of life in Asia and sixth overall in the world. The government's healthcare system is based upon the "3M" framework. This has three components: Medifund, which provides a safety net for those not able to otherwise afford healthcare; Medisave, a compulsory national medical savings account system covering about 85% of the population; and Medishield, a government-funded health insurance programme. Public hospitals in Singapore have considerable autonomy in their management decisions, and notionally compete for patients, but remain in government ownership. A subsidy scheme exists for those on low income.
== Uses of animal guts == Intestines from animals other than humans are used in a number of ways. From each species of livestock that is a source of milk, a corresponding rennet is obtained from the intestines of milk-fed calves. Pig and calf intestines are eaten, and pig intestines are used as sausage casings. Calf intestines supply calf-intestinal alkaline phosphatase (CIP), and are used to make goldbeater's skin. Other uses are:
The Indian cobra (Naja naja) is a moderately venomous species, but has a rapid-acting venom. In mice, the SC LD50 for this species is 0.80 mg/kg and the average venom yield per bite is between 169 and 250 mg. Though it is responsible for many bites, only a small percentage are fatal if proper medical treatment and antivenom are given. The mortality rate for untreated bite victims can vary from case to case, depending upon the quantity of venom delivered and by the individual involved. According to one study, it is approximately 15–20% but in another study, with 1,224 bite cases, the mortality rate was only 6.5%. Estimated fatalities as a result of this species is approximately 15,000 per year, but they are responsible for an estimated 100,000–150,000 non-fatal bites per year.
Resurgence of train ridership in the 21st century pushed the current Pennsylvania Station under Madison Square Garden to capacity, leading to several proposals to renovate or rebuild the station, often characterized as correcting for the 1960s demolition of the original facility. The Times noted in 2025 that a succession of elected officials over several decades—including Governors Pataki, Spitzer, Cuomo, and Hochul—had made gestures at reconstructing the station, though no such reconstruction ultimately materialized. Among the reasons, the Times cited the controlling interests of multiple transit companies—Amtrak, which owns the station, along with NJ Transit and the MTA, which operate within it—and the influence of James Dolan, whose company owns Madison Square Garden and the air rights above the station. Several of the failed plans were entangled with questions of if and how to move the Garden; in 2008, Eliot Spitzer induced the Garden to sign a memorandum of understanding to move one block west as part of a planned station reconstruction, although his plan fizzled after he was felled by a prostitution scandal only a week later. In 2013, the Regional Plan Association and Municipal Art Society formed the Alliance for a New Penn Station, advocating for limiting the extension of Madison Square Garden's operating permit to ten years and soliciting designs to move the arena.
== Components == Honey bee venom is a complex mixture of proteins and smaller molecules. The main component is melittin, which amounts to 52% of venom peptides. One of the main allergens is phospholipase A2, which amounts to 12% and is an enzyme that catalyzes the hydrolysis of phospholipids, causing degradation of cell membranes, causing cell death. Adolapin contributes 2–5% of the peptides. Further protein components include apamin (2%), a neurotoxin, hyaluronidase (2%), which dilates blood vessels, increasing their permeability and facilitating the spread of the venom, mast cell degranulating peptide (2%), tertiapin, and secapin. Small molecules in bee venom include histamine (0.1–1%), dopamine and noradrenaline.
Sources: en.wikipedia.org
Paralytic peptides are a family of short (23 amino acids) insect peptides that halt metamorphosis of insects from larvae to pupae. These peptides contain one disulphide bridge. The family includes growth-blocking peptide (GBP) of Mythimna separata (Oriental armyworm) and the paralytic peptides from Manduca sexta (tobacco hawkmoth), Heliothis virescens (noctuid moth), and Spodoptera exigua (beet armyworm) as well as plasmatocyte-spreading peptide (PSP1).
Erythema annulare centrifugum (deep gyrate erythema, erythema perstans, palpable migrating erythema, superficial gyrate erythema) Erythema gyratum repens (Gammel's disease) Erythema migrans (erythema chronicum migrans) Erythema multiforme Erythema multiforme minor (herpes simplex-associated erythema multiforme) Erythema palmare Generalized erythema Necrolytic acral erythema Necrolytic migratory erythema (glucagonoma syndrome)
While results vary slightly across reputable studies, the consensus is that the mean human penis, when erect, is in the range 5–6 in (13–15 cm) in length. The 2015 review (measured by staff) found average flaccid, stretched, and erect lengths of 9.16 cm (3.61 in), 13.24 cm (5.21 in), and 13.12 cm (5.17 in), respectively, and average flaccid and erect circumferences of 9.31 cm (3.67 in) and 11.66 cm (4.59 in), respectively. Erect length in the studies was measured by pushing the pre-pubic fat pad to the bone, and flaccid or erect girth (circumference) was measured at the base or mid-shaft of the penis.
Biological carbon fixation, or carbon assimilation, is the process by which living organisms convert inorganic carbon (particularly carbon dioxide, CO2) to organic compounds. These organic compounds are then used to store energy and as structures for other biomolecules. Carbon is primarily fixed through photosynthesis, but some organisms use chemosynthesis in the absence of sunlight. Chemosynthesis is carbon fixation driven by chemical energy rather than from sunlight. The process of biological carbon fixation plays a crucial role in the global carbon cycle, as it serves as the primary mechanism for removing CO2 from the atmosphere and incorporating it into living biomass. The primary production of organic compounds allows carbon to enter the biosphere. Carbon is considered essential for life as a base element for building organic compounds. The flow of carbon from the Earth's atmosphere, oceans and lithosphere into lifeforms and then back into the air, water and soil is one of the key biogeochemical cycles (or nutrient cycles). Understanding biological carbon fixation is essential for comprehending ecosystem dynamics, climate regulation, and the sustainability of life on Earth. Organisms that grow by fixing carbon, such as most plants and algae, are called autotrophs. These include photoautotrophs (which use sunlight) and lithoautotrophs (which use inorganic oxidation). Heterotrophs, such as animals and fungi, are not capable of carbon fixation but are able to grow by consuming the carbon fixed by autotrophs or other heterotrophs.
Sources: en.wikipedia.org
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.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
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。