ACTH 片段 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-08-30. Numbers and descriptions here follow the published literature rather than marketing material.
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 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。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
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。
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.
The 4th Panzer Army (German: 4. Panzerarmee), operating as Panzer Group 4 (Panzergruppe 4) from its formation on 15 February 1941 to 1 January 1942, was a German panzer formation during World War II. As a key armoured component of the Wehrmacht, the army took part in the crucial battles of the German-Soviet war of 1941–45, including Operation Barbarossa, the Battle of Moscow, the Battle of Stalingrad, the Battle of Kursk, and the 1943 Battle of Kiev. The army was destroyed during the Battle of Stalingrad, but later reconstituted.
In 1966, E. O. Wilson and his colleagues identified the fossil remains of an ant (Sphecomyrma) that lived in the Cretaceous period. The specimen, trapped in amber dating back to around 92 million years ago, has features found in some wasps, but not found in modern ants. The oldest fossils of ants date to the mid-Cretaceous, around 113–100 million years ago, which belong to extinct stem-groups such as the Haidomyrmecinae, Sphecomyrminae and Zigrasimeciinae, with modern ant subfamilies appearing towards the end of the Cretaceous around 80–70 million years ago. Ants diversified extensively during the Angiosperm Terrestrial Revolution and assumed ecological dominance around 60 million years ago. Some groups, such as the Leptanillinae and Martialinae, are suggested to have diversified from early primitive ants that were likely to have been predators underneath the surface of the soil. During the Cretaceous period, a few species of primitive ants ranged widely on the Laurasian supercontinent (the Northern Hemisphere). Their representation in the fossil record is poor, in comparison to the populations of other insects, representing only about 1% of fossil evidence of insects in the era. Ants became dominant after adaptive radiation at the beginning of the Paleogene period. By the Oligocene and Miocene, ants had come to represent 20–40% of all insects found in major fossil deposits. Of the species that lived in the Eocene epoch, around one in 10 genera survive to the present.
In their development in the thymus, T lymphocytes are selected to recognize the host's own MHC molecules, but not other self antigens. Following selection, each T lymphocyte shows dual specificity: The TCR recognizes self MHC, but only non-self antigens. MHC restriction occurs during lymphocyte development in the thymus through a process known as positive selection. T cells that do not receive a positive survival signal — mediated mainly by thymic epithelial cells presenting self peptides bound to MHC molecules — to their TCR undergo apoptosis. Positive selection ensures that mature T cells can functionally recognize MHC molecules in the periphery (i.e. elsewhere in the body). The TCRs of T lymphocytes recognise only sequential epitopes, also called linear epitopes, of only peptides and only if coupled within an MHC molecule. (Antibody molecules secreted by activated B cells, though, recognize diverse epitopes—peptide, lipid, carbohydrate, and nucleic acid—and recognize conformational epitopes, which have three-dimensional structure.)
Sources: en.wikipedia.org
== Gameplay == Day of Defeat is a multiplayer first-person shooter that simulates squad-level infantry combat between the adversaries of World War II's European Theatre; the Allies and the Axis powers. Players can choose to join either the Allied or Axis armies, with the Allies including the United States or Great Britain and the Axis including Germany. A round begins with two opposing teams starting simultaneously in their respective spawn area of a map, both acting towards the goal of achieving their respective objectives whilst preventing the enemy team from accomplishing theirs. A round ends when one team accomplishes all of its objectives, with that team claiming victory. Eventually, the game ends with the expiration of a set time limit, and the team with the most objectives achieved is the winning team regardless of kills or casualties, except in the case of both teams having not achieved any objectives or having achieved the same number of objectives. Weaponry in the game attempts to realistically portray those that would be found in World War II, and the gameplay reflects this aesthetic choice. Recoil can be heavy and the game does not allow the player to fire while running or jumping. The game also features a stamina bar, preventing the player from sprinting for long periods of time and forcing them to actively conserve energy.
=== Intravenous injection === The administration of estradiol by intravenous injection has been studied. It achieves extremely high peak levels of estradiol but has a very short duration. Kuhnz et al. (1993) reported that a single intravenous injection of 0.3 mg estradiol resulted in peak estradiol concentrations of 8,321 pg/mL at 5 minutes post-injection. Estradiol levels decreased to 1,628 pg/mL after 30 minutes, to 778 pg/mL after 1 hour, and to 23 pg/mL after 6 hours. Leyendecker et al. (1975) reported that a single intravenous injection of 20 mg estradiol resulted in estradiol levels of 2,950 pg/mL at 12 hours after the injection (earlier time points were not measured). Following this, estradiol levels decreased to around 400 pg/mL by 24 hours post-injection and reached near-baseline levels of 45 pg/mL after 48 hours. The ratio of estradiol to estrone is very high initially (e.g., around 10:1 at peak) but becomes smaller as estradiol levels decline. The distribution half-life of intravenous estradiol is about 6 minutes and the terminal half-life of intravenous estradiol is about 0.5 to 2 hours. The peak estradiol levels are far higher and the duration far shorter when estradiol is given by intravenous injection than when estradiol esters are administered by intramuscular or subcutaneous injection. The administration of estradiol valerate by intravenous injection has been studied as well. It has been found to be very rapidly cleaved into estradiol in the blood. The metabolism of estradiol valerate does not differ with intravenous versus intramuscular injection.
Additionally, the increased levels of P4 can also cause side effects such as weight gain, fatigue, and mood swings (extreme or rapid changes in mood). In prostate cancer, removal of testicular T through castration (surgical or chemical removal or inactivation of testicles) helps eliminate the growth-promoting effects of androgens. However, in some cases, metastatic tumors can develop into castration-resistant prostate cancer (CRPC). While castration reduces serum T levels by 90-95%, it only decreases DHT in the prostate gland by 50%. This difference between the magnitude of androgen levels confirms that the prostate has enzymes capable of producing DHT even without testicular T. In addition to DHT production within the prostate, researchers found that 11-oxygenated androgens play a role in maintaining total circulating androgen pool levels which are relevant to the amounts of clinically significant androgens in the body. These 11-oxygenated androgens contribute greatly to reactivating androgen signaling in patients with CRPC. 11-oxygenated androgens make up around 60% of the total active androgen pool in such patients. Unlike T or DHT, these levels of 11-oxygenated androgens remain unaffected by castration therapy.
Sources: en.wikipedia.org
=== Meat === Salting, either with dry salt or brine, was a common method of preserving meat until the middle of the 20th century, becoming less popular after the advent of refrigeration. Meat that had been preserved in this way was frequently called "junk" or "salt horse". One early method of salt-curing meat was corning, or applying large, coarse pellets of salt, which were rubbed into the meat to keep it from spoiling and to preserve it. This term originates from Old English and references the large corns or grains of salt used (see wiktionary:corn). Corned beef retains this name, although it is typically brined today. Salt inhibits the growth of microorganisms by drawing water out of microbial cells through osmosis. Concentrations of salt up to 20% are required to kill most species of unwanted bacteria. Smoking, often used in the process of curing meat, adds chemicals to the surface of meat that reduce the concentration of salt required. Various types of salted meat are staples of the diets of people in North Africa, Southern China, Scandinavia, coastal Russia, and in the Arctic. Some of those salted meats (or foods that contain salted meat) are bacon, biltong, cecina, corned beef, ham, jamón, jerky, pastrami, and salt pork.
==== Drugs ==== A number of medications have been identified which may cause hypoglycemia, through a variety of ways. Moderate quality evidence implicates the non-steroidal anti-inflammatory drug indomethacin and the anti-malarial quinine. Low quality evidence implicates lithium, used for bipolar disorder. Finally, very low quality evidence implicates a number of hypertension medications including angiotensin converting enzyme inhibitors (also called ACE-inhibitors), angiotensin receptor blockers (also called ARBs), and β-adrenergic blockers (also called beta blockers). Other medications with very low quality evidence include the antibiotics levofloxacin and trimethoprim-sulfamethoxazole, progesterone blocker mifepristone, anti-arrhythmic disopyramide, anti-coagulant heparin, and chemotherapeutic mercaptopurine. If a person without diabetes accidentally takes medications that are traditionally used to treat diabetes, this may also cause hypoglycemia. These medications include insulin, glinides, and sulfonylureas. This may occur through medical errors in a healthcare setting or through pharmacy errors, also called iatrogenic hypoglycemia.
At the time, only poisons required a doctor's prescription, and self-treatment was a real possibility. Legislation was passed in the UK in 1947 to require a prescription for antibiotics. The United States followed in 1951. Elsewhere in the world, the export of Western pharmaceuticals diffused faster than Western medical knowledge and practices, and penicillin was often dispensed by practitioners of traditional medicine. As late as 1999, a study in the UK found that 39 per cent of respondents erroneously believed that antibiotics could cure colds and flu, and 12 per cent believed that they were the best treatment for them. The misplaced faith in antibiotics had serious consequences. It reduced the status of doctors to providers of pills. Many more people sought medical attention for ailments they would have ignored before, and they often demanded antibiotics. For their part, overworked doctors were increasingly willing to provide them even if not asked to do so. By 1942, some strains of Staphylococcus aureus had developed a strong resistance to penicillin and many strains were resistant by the 1960s. In 1946, bacteriologist Mary Barber began a study of penicillin resistance through natural selection at Hammersmith Hospital in London. She found that in 1946, seven out of eight bacterial infections were susceptible to penicillin, but two years later only three out of eight were. Nurses were exposed to both bacteria and penicillin and harboured and transmitted bacterial infections.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
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。