This is a working overview of Certificate of analysis, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-09-27 and is reviewed periodically as new material appears.
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。
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。
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.
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.
| 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。
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。
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.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
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.
=== Clearance in PNS === The response of Schwann cells to axonal injury is rapid. The time period of response is estimated to be prior to the onset of axonal degeneration. Neuregulins are believed to be responsible for the rapid activation. They activate ErbB2 receptors in the Schwann cell microvilli, which results in the activation of the mitogen-activated protein kinase (MAPK). Although MAPK activity is observed, the injury sensing mechanism of Schwann cells is yet to be fully understood. The 'sensing' is followed by decreased synthesis of myelin lipids and eventually stops within 48 hrs. The myelin sheaths separate from the axons at the Schmidt-Lanterman incisures first and then rapidly deteriorate and shorten to form bead-like structures. Schwann cells continue to clear up the myelin debris by degrading their own myelin, phagocytose extracellular myelin and attract macrophages to myelin debris for further phagocytosis. However, the macrophages are not attracted to the region for the first few days; hence the Schwann cells take the major role in myelin cleaning until then. Schwann cells have been observed to recruit macrophages by release of cytokines and chemokines after sensing of axonal injury. The recruitment of macrophages helps improve the clearing rate of myelin debris. The resident macrophages present in the nerves release further chemokines and cytokines to attract further macrophages. The degenerating nerve also produce macrophage chemotactic molecules. Another source of macrophage recruitment factors is serum.
==== Emotional health ==== Researcher Dianne Hales described an emotionally healthy person as someone who exhibits flexibility and adaptability to different circumstances, a sense of meaning and affirmation in life, an "understanding that the self is not the center of the universe", compassion and the ability to be unselfish, an increased depth and satisfaction in intimate relationships, and a sense of control over the mind and body.
He remained director of the NIH facility until the NIH no longer funded such facilities and retired from his teaching position in 2006. The MS Facility continued to operate after funding stopped through the efforts of Watson, the Biochemistry and Chemistry Departments.
Sources: en.wikipedia.org
The mathematics of the preadaptation model assume that the distribution of fitness effects is bimodal, with new sequences of mutations tending to break something or tinker, but rarely in between. Following this logic, populations may either evolve local solutions, in which selection operates on each individual locus and a relatively high error rate is maintained, or a global solution with a low error rate which permits the accumulation of deleterious cryptic sequences. De novo gene birth is thought to be favored in populations that evolve local solutions, as the relatively high error rate will result in a pool of cryptic variation that is "preadapted" through the purging of deleterious sequences. Local solutions are more likely in populations with a high effective population size. In support of the preadaptation model, an analysis of ISD in mice and yeast found that young genes have higher ISD than old genes, while random non-genic sequences tend to show the lowest levels of ISD. Although the observed trend may have partly resulted from a subset of young genes derived by overprinting, higher ISD in young genes is also seen among overlapping viral gene pairs. With respect to other predicted structural features such as β-strand content and aggregation propensity, the peptides encoded by proto-genes are similar to non-genic sequences and categorically distinct from canonical genes.
==== Post-mastectomy fat-graft reconstruction ==== The reconstruction of the breast(s) with grafts of autologous fat is a non-implant alternative to further surgery after a breast cancer surgery, be it a lumpectomy or a breast removal – simple (total) mastectomy, radical mastectomy, modified radical mastectomy, skin-sparing mastectomy, and subcutaneous (nipple sparing) mastectomy. The breast is reconstructed by first applying external tissue expansion to the recipient-site tissues (adipose, glandular) to create a breast-tissue matrix that can be injected with autologous fat grafts (adipocyte tissue); the reconstructed breast has a natural form, look, and feel, and is generally sensate throughout and in the nipple-areola complex (NAC). The reconstruction of breasts with fat grafts requires a three-month treatment period – begun after 3–5 weeks of external vacuum expansion of the recipient-site tissues. The autologous breast-filler fat is harvested by liposuction from the patient's body (buttocks, thighs, abdomen), is refined and then is injected (grafted) to the breast-tissue matrices (recipient sites), where the fat will thrive. One method of non-implant breast reconstruction is initiated at the concluding steps of the breast cancer surgery, wherein the oncological surgeon is joined by the reconstructive plastic surgeon, who immediately begins harvesting, refining, and seeding (injecting) fat grafts to the post-mastectomy recipient site.
== History == The first modern report of sickle cell disease may have been in 1846, where the autopsy of an executed runaway slave was discussed; the key finding was the absence of the spleen. Reportedly, African slaves in the United States exhibited resistance to malaria, but were prone to leg ulcers. The abnormal characteristics of the red blood cells, which later lent their name to the condition, were first described by Ernest E. Irons (1877–1959), intern to Chicago cardiologist and professor of medicine James B. Herrick (1861–1954), in 1910. Irons saw "peculiar elongated and sickle-shaped" cells in the blood of a man named Walter Clement Noel, a 20-year-old first-year dental student from Grenada. Noel had been admitted to the Chicago Presbyterian Hospital in December 1904 with anaemia. Noel was readmitted several times over the next three years for "muscular rheumatism" and "bilious attacks" but completed his studies and returned to the capital of Grenada (St. George's) to practice dentistry. He died of pneumonia in 1916 and is buried in the Catholic cemetery at Sauteurs in the north of Grenada. Shortly after the report by Herrick, another case appeared in the Virginia Medical Semi-Monthly with the same title, "Peculiar Elongated and Sickle-Shaped Red Blood Corpuscles in a Case of Severe Anemia." This article is based on a patient admitted to the University of Virginia Hospital on 15 November 1910. In the later description by Verne Mason in 1922, the name "sickle cell anemia" is first used.
Sources: en.wikipedia.org
There are also a few thousand Druze immigrants from Lebanon in the United States of America, who have converted to Christianity. In the period of Egyptian rule in the Levant in the 1830s, many Druze converted to Christianity to avoid enlistment into the Egyptian army. The baptism of children in accordance with Christian custom was usual in large, well-known Lebanese Druze families, according to historian Aharon Layish there is also explicit evidence of Druzes in Lebanon under the Ottoman rule were posing Christians for practical reasons. The early Druze migrants from Levant to Venezuela tended to mix well with the local population, and some Druze converted to Catholicism. By one estimate made by Elisabe Granli from University of Oslo, around 1,920 Syrian Druze converted to Christianity; according to the same study, Christians with a Druze background (Druze converts to Christianity) still regard themselves as Druze, and claim that there is no contradiction between being Druze and being Christian. According to the Druze religious courts, between 1952 and 2009, around 10% of Israeli Druze who left the Druze faith converted to Christianity. According to Open Doors, there is a small but growing community of Druze converts to Christianity in Syria and Lebanon, with most converting to Evangelical Protestantism. These converts have established churches specifically for Christians of Druze background, primarily comprising women, girls, and young men who have abandoned the Druze religion they were raised in.
In August 2020, scientists described one way cells—in particular cells of a slime mold and mouse pancreatic cancer-derived cells—are able to navigate efficiently through a body and identify the best routes through complex mazes: generating gradients after breaking down diffused chemoattractants which enable them to sense upcoming maze junctions before reaching them, including around corners.
==== The Ringmaster and birth of "Stone Cold" (1996) ==== Austin joined the WWE at the end of 1995 after Diesel and Jim Ross helped convince WWF's owner Vince McMahon to hire him. He debuted in WWF on December 18, 1995, which was broadcast on the January 8, 1996, episode of Raw, using the moniker "The Ringmaster" and was awarded the Million Dollar Championship by his manager, Ted DiBiase. In his debut match on Raw he defeated Matt Hardy. While making his first pay-per-view (PPV) appearance at the Royal Rumble, he was scripted to be among the final four wrestlers in the ring, which could have given him an early push; however, The Ringmaster failed to hang onto the ropes after Fatu clotheslined him over and slipped out of the ring early. Austin soon thought the Ringmaster gimmick was weak and asked for a change. Having battled thinning hair for a few years, he decided to shave his head in early 1996. He later said in a 2017 interview, "After watching the Pulp Fiction movie with Bruce Willis, that's the haircut that inspired me. I was traveling on the road to Pittsburgh with Dustin Rhodes and before I went to the show, I said fuck it. I went into the bathroom with a razor blade and shaved all my hair off. Then I grew the goatee and everything came full circle." By March 11, having thankfully missed out on the "opportunity" to be renamed Fang McFrost, among others, his Ringmaster moniker (now merely a prefix to his ring name) would be discarded in favor of his most famous ring name, "Stone Cold" Steve Austin, in a match against Savio Vega.
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.