If you have been reading about intranasal route and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-12-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 |
|---|---|---|
| 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 |
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 was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
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.
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。
Unlike the related medication eplerenone, spironolactone is said to not be metabolized by CYP3A4. However, hepatic CYP3A4 is likely responsible for the 6β-hydroxylation of 7α-TMS into 6β-OH-7α-TMS. 7α-TMS may also be hydroxylated at the C3α and C3β positions. Spironolactone is dethioacetylated into canrenone. Finally, the C17 γ-lactone ring of spironolactone is hydrolyzed by the paraoxonase PON3. It was originally thought to be hydrolyzed by PON1, but this was due to contamination with PON3.
Pyruvate is plentiful in muscle due to extensive glycolysis. Amino groups in skeletal muscles are transferred to a product of glycolysis, pyruvate, forming alanine. This transamination reaction is catalyzed by alanine aminotransferase. Alanine is then transported to the liver, where it is converted back into pyruvate (used for gluconeogenesis) by transferring its amino group to α-ketoglutarate, forming glutamate. Simultaneously, glucose is being transported from the liver (where it's more abundant due to gluconeogenesis) to the muscle, where it is consumed. This is the glucose-alanine cycle.
In September 2010, Iran was attacked by the Stuxnet worm, thought to specifically target its Natanz nuclear enrichment facility. It was a 500-kilobyte computer worm that infected at least 14 industrial sites in Iran, including the Natanz uranium-enrichment plant. Although the official authors of Stuxnet haven't been officially identified, Stuxnet is believed to be developed and deployed by the United States and Israel. The worm is said to be the most advanced piece of malware ever discovered and significantly increases the profile of cyberwarfare. Iranian Cyber Police department, FATA, was dismissed one year after its creation in 2011 because of the arrest and death of Sattar Behesti, a blogger, in the custody of FATA. Since then, the main responsible institution for the cyberwarfare in Iran is the "Cyber Defense Command" operating under the Joint Staff of Iranian Armed Forces. The Iranian state sponsored group MuddyWater is active since at least 2017 and is responsible for many cyber attacks on various sectors.
A DNA construct is an artificially-designed segment of DNA borne on a vector that can be used to incorporate genetic material into a target tissue or cell. A DNA construct contains a DNA insert, called a transgene, delivered via a transformation vector which allows the insert sequence to be replicated and/or expressed in the target cell. This gene can be cloned from a naturally occurring gene, or synthetically constructed. The vector can be delivered using physical, chemical or viral methods. Typically, the vectors used in DNA constructs contain an origin of replication, a multiple cloning site, and a selectable marker. Certain vectors can carry additional regulatory elements based on the expression system involved. DNA constructs can be as small as a few thousand base pairs (kbp) of DNA carrying a single gene, using vectors such as plasmids or bacteriophages, or as large as hundreds of kbp for large-scale genomic studies using an artificial chromosome. A DNA construct may express wildtype protein, prevent the expression of certain genes by expressing competitors or inhibitors, or express mutant proteins, such as deletion mutations or missense mutations. DNA constructs are widely adapted in molecular biology research for techniques such as DNA sequencing, protein expression, and RNA studies.
DMT is inactive when ingested orally due to metabolism by monoamine oxidase (MAO), and DMT-containing drinks such as ayahuasca have been found to contain monoamine oxidase inhibitors (MAOIs), in particular, harmine and harmaline. Life-threatening lethalities such as serotonin syndrome (SS) may occur when MAOIs are combined with certain serotonergic medications such as selective serotonin reuptake inhibitor (SSRI) antidepressants. Serotonin syndrome has also been reported with tricyclic antidepressants (TCAs), certain opioids, certain analgesics, and antimigraine drugs; it is advised to exercise caution when an individual has used dextromethorphan (DXM), MDMA, ginseng, or St. John's wort recently. Chronic use of SSRIs, TCAs, and MAOIs diminish subjective effects of psychedelics due to presumed serotonin 5-HT2A receptors downregulation and/or desensitization secondary to elevated serotonin levels. However, a clinical study of people with depression found that SSRIs did not diminish the effects of DMT and instead resulted in greater mystical experience, emotional breakthrough, and ego dissolution scores with DMT than in people with depression not on antidepressants. This was in contrast to previous research finding that SSRIs diminished the effects of serotonergic psychedelics. The interaction between psychedelics and antipsychotics and anticonvulsants are not well documented; however, reports reveal that co-use of psychedelics with mood stabilizers such as lithium may provoke seizure and dissociative effects in individuals with bipolar disorder.
Sources: en.wikipedia.org
Narrated by Paul Daneman, directed by Julian Nott, made by Peninsula Films 9 October The Rubber Universe, in 1929 Hubble's law was discovered, but the Hubble constant was not fully known - about the Hubble constant, which could be between 50 and 85, which meant that the universe could be 14 billion years old, not 8 billion years old, for a constant of 50; scientists were highly protective of any discoveries that they made, or not, but that did not always lead to good outcomes for all concerned - such as the relationship between Allan Sandage, who thought the Hubble constant was about 50, and the French Gérard de Vaucouleurs; Canadian Sidney van den Bergh looked at the Hubble constant as well; Tod R.
The spatial arrangement of the C-C and C-H bonds are described by the torsion angles of the molecule, known as its conformation. In ethane, the simplest case for studying the conformation of alkanes, there is nearly free rotation about a carbon–carbon single bond. Two limiting conformations are important: eclipsed conformation and staggered conformation. The staggered conformation is 12.6 kJ/mol (3.0 kcal/mol) lower in energy (more stable) than the eclipsed conformation (the least stable). In highly branched alkanes, the bond angle may differ from the optimal value (109.5°) to accommodate bulky groups. Such distortions introduce a tension in the molecule, known as steric hindrance or strain. Strain substantially increases reactivity.
A typical bicycle chain (for derailleur gears) uses narrow 1⁄2-inch-pitch chain. The width of the chain is variable, and does not affect the load capacity. The more sprockets at the rear wheel (historically 3–6, nowadays 7–12 sprockets), the narrower the chain. Chains are sold according to the number of speeds they are designed to work with, for example, "10 speed chain". Hub gear or single speed bicycles use 1/2 x 1/8 inch chains, where 1/8 inch refers to the maximum thickness of a sprocket that can be used with the chain. Typically chains with parallel shaped links have an even number of links, with each narrow link followed by a broad one. Chains built up with a uniform type of link, narrow at one and broad at the other end, can be made with an odd number of links, which can be an advantage to adapt to a special chainwheel-distance; on the other side such a chain tends to be not so strong. Roller chains made using ISO standard are sometimes called "isochains".
=== Early life === Logan Roy's early life is elaborated in an animation made for the episode "Dundee" that was eventually cut and replaced by a scene where Kendall performs a rap song exalting his father. Roy was born on 29 October in Dundee, Scotland, United Kingdom in 1938, in a working-class family. His father died from a brain hemorrhage several years later. During World War II, he was sent with his older brother Ewan to live with his uncle Noah in Quebec, Canada. In the episode "Church and State," Ewan recalls in a eulogy that during the journey, the two brothers were stranded at sea after their ship's engines had failed. Fearing attacks by German submarines, the two did not speak or move for three days. While Logan was enrolled at a boarding school, his baby sister, Rose, arrived to Canada. After falling ill and returning home, Rose died of polio, which would cause immense guilt for the rest of Logan's life as he believed he was responsible. In the episode "Austerlitz," he claims that Noah was physically abusive towards him throughout his childhood, which is indicated by scars across Logan's back.
Sources: en.wikipedia.org
== Structure and properties == As for most amides, the spectroscopic evidence indicates partial double bond character for the C−N and C−O bonds.Thus, the infrared spectrum shows a C=O stretching frequency at only 1675 cm−1, whereas a ketone would absorb near 1700 cm−1. DMF is a classic example of a fluxional molecule.
Additionally, protein binding triggers a metachromatic reaction, evidenced by the emergence of a species that absorbs light around 595 nm, indicative of the unprotonated form This dye creates strong noncovalent bonds with the proteins, via electrostatic interactions with the amino and carboxyl groups, as well as Van Der Waals interactions. Only the molecules that bind to the proteins in solution exhibit this change in absorption, which eliminates the concern that unbound molecules of the dye might contribute to the experimentally obtained absorption reading. This process is more beneficial since it is less pricey than other methods, easy to use, and has high sensitivity of the dye for protein. After 5 minutes of incubation, the absorbance can be read at 595 nm using a spectrophotometer or a mobile smartphone camera (RGBradford method). This assay is one of the fastest assays performed on proteins. The total time it takes to set up and complete the assay is under 30 minutes. The entire experiment is done at room temperature. The Bradford protein assay can measure protein quantities as little as 1 to 20 μg. It is an extremely sensitive technique. The dye reagent is a stable ready to use product prepared in phosphoric acid. It can remain at room temperature for up to 2 weeks before it starts to degrade. Protein samples usually contain salts, solvents, buffers, preservatives, reducing agents and metal chelating agents. These molecules are frequently used for solubilizing and stabilizing proteins.
==== Type 2 ==== Type 2 VWD (15-50% of cases) is a qualitative defect and the bleeding tendency can vary between individuals. Four subtypes exist: 2A, 2B, 2M, and 2N. These subtypes depend on the presence and behavior of the underlying multimers. Type 2 VWD (other than 2N) features an activity-to-antigen ratio of less than 0.7. This ratio is obtained by dividing the VWF activity by the VWF antigen.
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.
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。