The short version of Certificate of analysis fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-24. Anything still debated is marked as such rather than presented as settled.
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
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 |
|---|---|---|
| 外观 | 白色至类白色粉末 | 常见于冻干制剂 |
| 溶解度 | 易溶于水 | 在极性溶剂中一般也可溶 |
| 建议储存温度 | -20 °C | 冻干粉，避光密封 |
| 常见分析手段 | 反相高效液相色谱 | 常与质谱联用 |
| 主要降解路径 | 水解与氧化 | 溶液状态更显著 |
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.
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.
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.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Diazepam is mainly used to treat anxiety, insomnia, panic attacks, and symptoms of acute alcohol withdrawal. It is also used as a premedication for inducing sedation, anxiolysis, or amnesia before certain medical procedures (e.g., endoscopy). In 2020, it was approved for use in the United States as a nasal spray to interrupt seizure activity in people with epilepsy. Diazepam is the most commonly used benzodiazepine for "tapering" benzodiazepine dependence due to diazepam's comparatively long half-life, allowing for more efficient dose reduction. Benzodiazepines have a relatively low toxicity in overdose. Diazepam has several uses, including:
Peukert saw his work as a "warning against the fallacious notion that the normality of industrial society is harmless" and urged historians to consider the "dark side of modernity", instead of seeing modernity as a benign development that was always for the best. Peukert wrote: "The view that National Socialism was...one of the pathological development forms of modernity does not imply that barbarism is the inevitable logical outcome of modernization. The point, rather, is that we should not analyse away the tensions between progressive and aberrant features by making a glib opposition between modernity and tradition: we should call attention to the rifts and danger-zones which result from the civilizing process itself, so that the opportunities for human emancipation which it simultaneously creates can be more thoroughly charted. The challenges of Nazism shows that the evolution to modernity is not a one-way trip to freedom. The struggle for freedom must always be resumed afresh, both in inquiry and in action". Peukert argued that though völkisch racism was extreme, it was by no means exceptional, and instead reflected the logic promoted by the social sciences throughout the West which had argued that the state can and should foster "normality" while identifying "the non-conformity that is to be segregated and eliminated". Seen in this perspective, for Peukert the genocide against the Jews and Romany were only part of a wider project to eliminate all unhealthy genes from the volksgemeinschaft.
Indian childhood cirrhosis is a form of neonatal cholestasis characterized by deposition of copper in the liver Alpha-1 antitrypsin deficiency is an autosomal co-dominant disorder of low levels of the enzyme alpha-1 antitrypsin Cardiac cirrhosis is due to chronic right-sided heart failure, which leads to liver congestion Galactosemia Glycogen storage disease type IV Cystic fibrosis Hepatotoxic drugs or toxins, such as acetaminophen (paracetamol), methotrexate, or amiodarone
=== Connection with Cancer treatment === hCTR1 is upregulated in various cancer types, and it's associated with prognosis in several solid tumors. Atox1 and ATP7B were found to be important for Pt-based drug resistance. hCTR1 plays a role in oncology, hCTR1 facilitates uptake of platinum-based chemotherapeutic agents, such as cisplatin. Yeast and mammalian cells lacking CTR1 were resistant to cisplatin, while cells overexpressing CTR1 accumulated more of the drug. Tumor cells when exposed to cisplatin often react by increased degradation of hCTR1, thereby they become drug-resistant while simultaneously exhibiting signs of perturbed copper homeostasis. Studies of Atox1 in cancer cells demonstrated that this copper chaperone is crucial for cancer cell proliferation and survival. Small molecules targeting Atox1 have been proved to effectively block Cu-trafficking. For that reason reduce cell proliferation in lung, leukemia, breast, head, and neck cancer cell lines by elevating cellular ROS levels and reducing cellular NADPH and GSH levels. In contrast, healthy cells were barely affected by these small molecules.
Sources: en.wikipedia.org
=== Neurodevelopmental disorders === Astrocytes have emerged as important participants in various neurodevelopmental disorders. This view states that astrocyte dysfunction may result in improper neural circuitry, which underlies certain psychiatric disorders such as autism spectrum disorders and schizophrenia.
Absinthe (, French: [apsɛ̃t] ) is an anise-flavoured spirit derived from several plants, including the flowers and leaves of Artemisia absinthium ("grand wormwood"), together with green anise, sweet fennel, and other medicinal and culinary herbs. Historically described as a highly alcoholic spirit, it is 45–74% ABV or 90–148 proof in the US. Absinthe traditionally has a natural green colour but may also be colourless. It is commonly referred to in historical literature as la fée verte 'the green fairy'. While sometimes casually referred to as a liqueur, absinthe is not traditionally bottled with sugar or sweeteners. Absinthe is traditionally bottled at a high level of alcohol by volume, but it is normally diluted with water before being consumed. Absinthe was created in the canton of Neuchâtel in Switzerland in the late 18th century by the French physician Pierre Ordinaire. It rose to great popularity as an alcoholic drink in late 19th- and early 20th-century France, particularly among Parisian artists and writers. The consumption of absinthe was opposed by social conservatives and prohibitionists, partly due to its association with bohemian culture. From Europe and the Americas, notable absinthe drinkers included Ernest Hemingway, James Joyce, Lewis Carroll, Charles Baudelaire, Paul Verlaine, Arthur Rimbaud, and Henri de Toulouse-Lautrec. Absinthe has often been portrayed as a dangerously addictive psychoactive drug and hallucinogen, which gave birth to the term absinthism.
== Gene == Humanin is encoded in the mitochondrial genome by the 16S ribosomal RNA gene, MT-RNR2. Multiple paralogs are found in the nuclear genome (due to nuclear mitochondrial DNA segments) and are named MTRNR2L followed by a number. It is not known whether these paralogous isoforms are completely unexpressed.
Sources: en.wikipedia.org
When the recombinant MBP includes a signal peptide, the fusion protein can be exported into the periplasmic space, which facilitates its purification since the periplasmic fluid contains only a limited number of proteins and can be recovered either by an osmotic shock or by permeabilization of the bacterial outer membrane with antibiotics such as Polymyxin B. Such an export of the fusion protein into the periplasmic space enables the formation of disulfide bonds in the passenger protein, for example antibody fragments. Foreign proteins that are exported or secreted in their native organism, can usually be exported into the E. coli periplasm by fusion with MBP. Examples of cytoplasmic proteins that could be exported by fusion with MBP, include the monomeric Klenow polymerase and the dimeric Gene V protein of phage M13. When the recombinant MBP includes either a defective or no signal peptide the fusion protein remains within the bacterial cytoplasm from where it can be recovered by breaking open the cells. The fusion of proteins with MBP usually enhances their solubility and facilitates their proper folding so that the fusion proteins are most often bifunctional. In addition, such fusions can facilitate the crystallisation of difficult proteins, e.g. membrane proteins. The crystallized protein can often have their structures solved by X-ray crystallography using molecular replacement on a known MBP structure.
The use of ACE can provide specific details in binding, separation, and detection of analytes and is proven to be highly practical for studies in life sciences. Aptamer-based affinity capillary electrophoresis is utilized for the analysis and modifications of specific affinity reagents. Modified aptamers ideally exhibit and high binding affinity, specificity, and nuclease resistance. Ren et al. incorporated modified nucleotides in aptamers to introduce new confrontational features and high affinity interactions from the hydrophobic and polar interactions between IL-1α and the aptamer. Huang et al. uses ACE to investigate protein-protein interactions using aptamers. A α-thrombin binding aptamer was labeled with 6-carboxyfluorescein for use as a selective fluorescent probe and was studied to elucidate information on binding sites for protein-protein and protein-DNA interactions. Capillary electrophoresis (CE) has become an important, cost-effective approach to do DNA sequencing that provides high throughput and high accuracy sequencing information. Woolley and Mathies used a CE chip to sequence DNA fragments with 97% accuracy and a speed of 150 bases in 540 seconds. They used a 4-color labeling and detection format to collect fluorescent data. Fluorescence is used to view the concentrations of each part of the nucleic acid sequence, A, T, C and G, and these concentration peaks that are graphed from the detection are used to determine the sequence of the DNA.
== External links == Proprotein+Convertase+1 at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural information available in the PDB for UniProt: P63239 (Mouse Neuroendocrine convertase 1) at the PDBe-KB.
==== 2001 White House shooting ==== On February 7, 2001, while Bush was in the residence area of the White House, Robert W. Pickett, standing outside the perimeter fence, discharged a number of shots from a Taurus .38 Special revolver "in the general direction" of the White House. Pickett was shot in the knee by a U.S. Secret Service agent and arrested. Furthermore, he was initially charged with discharging a firearm during a crime, carrying a 10-year mandatory sentence, but following a plea agreement, Pickett instead entered a guilty plea to a firearms violation and an Alford plea to assaulting a federal officer. He was sentenced to three years at the Federal Medical Center, Rochester followed by three years of probation.
Sources: en.wikipedia.org
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。
公开资料对此没有统一答案。普遍建议现配现用，或冷藏并在数日内用完。含甲硫氨酸的序列更易氧化，放置时间越长风险越高。
反相高效液相色谱是最常用的手段，配合质谱确认分子量。氨基酸组成分析和肽图分析可补充序列层面的验证。
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.