intranasal route raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
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.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
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。
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.
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.
end-group A constitutional unit that occupies a terminal position within or is at an extremity of a macromolecule or polymer, and thus by definition is connected to only one other constitutional unit of the molecule.
The effects of glaciation were global. Antarctica was ice-bound throughout the Pleistocene and the preceding Pliocene. The Andes were covered in the south by the Patagonian ice cap. There were glaciers in New Zealand and Tasmania. The decaying glaciers of Mount Kenya, Mount Kilimanjaro, and the Ruwenzori Range in east and central Africa were larger. Glaciers existed in the mountains of Ethiopia and to the west in the Atlas Mountains. In the northern hemisphere, many glaciers fused into one. The Cordilleran Ice Sheet covered the North American northwest; the Laurentide covered the east. The Fenno-Scandian ice sheet covered northern Europe, including Great Britain; the Alpine ice sheet covered the Alps. Scattered domes stretched across Siberia and the Arctic shelf. The northern seas were frozen. During the late Upper Paleolithic (Latest Pleistocene) c. 18,000 BP, the Beringia land bridge between Asia and North America was blocked by ice, which may have prevented early Paleo-Indians such as the Clovis culture from directly crossing Beringia to reach the Americas. According to Mark Lynas (through collected data), the Pleistocene's overall climate could be characterized as a continuous El Niño with trade winds in the south Pacific weakening or heading east, warm air rising near Peru, warm water spreading from the west Pacific and the Indian Ocean to the east Pacific, and other El Niño markers. The Paleolithic is often held to finish at the end of the ice age (the end of the Pleistocene epoch), and Earth's climate became warmer.
Chromatography columns Gravity-flow columns Chromatography cartridges Centrifuge columns Centrifuge plates Gravity-flow, or drip, columns use head-pressure from a buffer-chase to push the sample through the gel filtration matrix. Sample is loaded into the top of an upright column and allowed to flow into the resin bed. The sample is then chased through the column by adding additional buffer or water to the top of the column. During this process, small fractions are typically collected and each is tested for the macromolecules of interest. In some cases, several fractions might contain the protein and may have to be pooled to improve yield. In order to eliminate the time and monitoring assorted with drip columns, fractions often equal to the full exclusion volume of the column are collected regardless of sample volume resulting in significant dilution of sample. Sealed chromatography cartridges or columns work similarly except the sample and buffer is pumped into and through the resin by an external device such as a liquid chromatographic (LC) system, also requiring collection and monitoring of several fractions. Even though this method is often semi-automated, using chromatography cartridges is typically limited to processing one sample at a time and some sample dilution from the chase buffer is still likely to occur. To eliminate sample dilution and the collecting and monitoring of fractions, centrifuge column or plate -based gel filtration, also referred to as spin desalting, methods are commonly used.
Grifols, S.A. (Catalan: [ˈɡɾifuls]) is a global healthcare company and leading producer of plasma-derived medicines founded in Barcelona, Catalonia, Spain, in 1909. With a workforce of over 23,800 employees, Grifols serves more than 110 countries and regions and maintains a direct presence in over 30. Principally a producer of blood plasma–based products and other biopharmaceuticals, the company also operates in transfusion medicine, supplying devices, instruments and reagents for clinical testing laboratories, as well as clinical diagnostic technologies. Furthermore, it provides biological supplies for life-science research, clinical trials and the manufacturing of pharmaceutical and diagnostic products. It has a portfolio on four therapeutic areas: immunology, infectious diseases, pulmonology and critical care.
== History == The first scholars to propose that there are three primary colors for painters were Scarmiglioni (1601), Savot (1609), de Boodt (1609) and Aguilonius (1613). From these, the most influential was the work of Franciscus Aguilonius (1567–1617), although he did not arrange the colors in a wheel. Jacob Christoph Le Blon was the first to apply the RYB color model to printing, specifically mezzotint printing, and he used separate plates for each color: yellow, red and blue plus black to add shades and contrast. In 'Coloritto', Le Blon asserted that “the art of mixing colours…(in) painting can represent all visible objects with three colours: yellow, red and blue; for all colours can be composed of these three, which I call Primitive”. Le Blon added that red and yellow make orange; red and blue, make purple; and blue and yellow make green (Le Blon, 1725, p6). In the 18th century, Moses Harris advocated that a multitude of colors can be created from three "primitive" colors – red, yellow, and blue. Mérimée referred to "three simple colours (yellow, red, and blue)" that can produce a large gamut of colors and details. "United in pairs, these three primitive colours give birth to three other colours as distinct and brilliant as their originals; thus, yellow mixed with red, gives orange; red and blue, violet; and green is obtained by mixing blue and yellow" (Mérimée, 1839, p245).
Sources: en.wikipedia.org
Notch signaling is triggered via direct cell-to-cell contact, mediated by interactions between the Notch receptor protein in the signal receiving cell and a ligand in an adjacent signal transmitting cell. These type 1 single-pass transmembrane proteins fall into the Delta/Serrate/Lag-2 (DSL) family of proteins which is named after the three canonical Notch ligands. Delta and Serrate are found in Drosophila while Lag-2 is found in C. elegans. Humans contain 3 Delta homologs, Delta-like 1, 3, and 4, as well as two Serrate homologs, Jagged 1 and 2. Notch proteins consist of a relatively short intracellular domain and a large extracellular domain with one or more EGF motifs and a N-terminal DSL-binding motif. EGF repeats 11-12 on the Notch extracellular domain have been shown to be necessary and sufficient for trans signaling interactions between Notch and its ligands. Additionally, EGF repeats 24-29 have been implicated in inhibition of cis interactions between Notch and ligands co-expressed in the same cell.
Rhabdomyolysis (shortened as rhabdo) is a condition in which damaged skeletal muscle breaks down rapidly. Symptoms may include muscle pains, weakness, vomiting, and confusion. There may be tea-colored urine or an irregular heartbeat. Some of the muscle breakdown products, such as the protein myoglobin, are harmful to the kidneys and can cause acute kidney injury. The muscle damage is usually caused by a crush injury, strenuous exercise, medications, or a substance use disorder. Other causes include infections, seizure, electrical injury, heat stroke, prolonged immobilization, lack of blood flow to a limb, or snake bites as well as intense or prolonged exercise, particularly in hot conditions. Rhabdomyolysis can occur in athletes Statins (a class of prescription drugs to lower cholesterol) are considered a small risk. Some people have inherited muscle conditions that increase the risk of rhabdomyolysis. The diagnosis is supported by a urine test strip which is positive for "blood" but the urine contains no red blood cells when examined with a microscope. Blood tests show a creatine kinase activity greater than 1000 U/L, with severe disease being above 5000–15000 U/L. The mainstay of treatment is large quantities of intravenous fluids. Other treatments may include dialysis or hemofiltration in more severe cases. Once urine output is established, sodium bicarbonate and mannitol are commonly used but they are poorly supported by the evidence. Outcomes are generally good if treated early.
Smith, a farmer from the Midlands town of Selukwe who had been seriously wounded while serving in the British Royal Air Force during the Second World War, was Southern Rhodesia's first native-born Prime Minister. Regarded in British political circles as a "raw colonial"—when he took over, Smith's personal experience of the UK comprised four brief visits—he promised a harder line than Field in independence talks. The RF's replacement of Field drew criticism from the British Labour Party, whose leader Harold Wilson called it "brutal", while Nkomo described the new Smith Cabinet as "a suicide squad ... not interested in the welfare of all the people but only in their own". Smith said he was pursuing a middle course between black Rhodesian rule and apartheid so that there would still be "a place for the white man" in Southern Rhodesia; this would benefit the blacks too, he claimed. He held that the government should be based "on merit, not on colour or nationalism", and insisted that there would be "no African nationalist government here in my lifetime". Salisbury's blunt refusal to be part of the Wind of Change caused the Southern Rhodesian military's traditional British and American suppliers to impose an informal embargo, and prompted Whitehall and Washington to stop sending Southern Rhodesia financial aid around the same time.
=== Operating systems === AI agents have also been integrated into operating systems developed by Microsoft, Apple, ByteDance, and Google. In November 2025, Microsoft released a test software build of Windows 11 that included agents to run background tasks, with the ability to read and write personal files. In December 2025, ByteDance released Doubao, an AI agent that can be integrated into smartphone operating systems, particularly the Nubia M153 by ZTE. Several apps in China blocked or restricted the agent, citing privacy and security concerns, including WeChat, Alipay, Taobao, Pinduoduo, Ele.me, and local banks.
Sources: en.wikipedia.org
== Renal == In addition to increasing the risk of kidney cancer, smoking can also contribute to additional kidney damage. Smokers are at a significantly increased risk for chronic kidney disease than non-smokers. A history of smoking encourages the progression of diabetic nephropathy.
=== Glycogen synthesis === The phosphorylation of glucose to glucose 6-phosphate has role in regulating glycogen synthase. Glucose is phosphorylated to glucose 6-phosphate to allow its transport across the membrane by ATP-D-glucose 6-phosphotransferase and non-specific hexokinase (ATP-D-hexose 6-phosphotransferase). Liver cells are freely permeable to glucose, and the initial rate of phosphorylation of glucose is the rate-limiting step in glucose metabolism by the liver. The liver's crucial role in controlling blood sugar concentrations by breaking down glucose into carbon dioxide and glycogen is characterized by the negative Gibbs free energy (ΔG) value, which indicates that this is a point of regulation with. The hexokinase enzyme has a low Michaelis constant (Km), indicating a high affinity for glucose, so this initial phosphorylation can proceed even when glucose levels at nanoscopic scale within the blood. The phosphorylation of glucose can be enhanced by the binding of fructose 6-phosphate (F6P), and lessened by the binding fructose 1-phosphate (F1P). Fructose consumed in the diet is converted to F1P in the liver. This negates the action of F6P on glucokinase, which ultimately favors the forward reaction. The capacity of liver cells to phosphorylate fructose exceeds capacity to metabolize fructose-1-phosphate. Consuming excess fructose ultimately results in an imbalance in liver metabolism, which indirectly exhausts the liver cell's supply of ATP.
Some analysts were attracted to the hypothesis that the uprising had been instigated or even planned by the African National Congress (ANC), an organisation which had played an important role in opposing apartheid before 1960, when it was banned by the government and went into exile in Lusaka, Zambia. Harvard Law School's Stephen M. Davis provided the paradigmatic statement of this hypothesis in Apartheid's Rebels, which argued that the unrest was the result of "a massive transformation of the black public" wrought by the ANC by means of "a widening clandestine network of cells to politicize blacks and school them in confrontation". Anthea Jefferey of the South African Institute of Race Relations made a similar argument, in terms less complimentary to the ANC, in her People's War.
Sources: en.wikipedia.org
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。