鼻内给药 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-06-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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。
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。
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。
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
A substance that has been tested in a laboratory and has gotten approval from the U.S. Food and Drug Administration (FDA) to be tested in people. A drug may be approved by the FDA for use in one disease or condition but be considered investigational in other diseases or conditions. Also called experimental drug. (NCI) A pharmaceutical form of an active ingredient or placebo being tested or used as a reference in a clinical trial, including a product with a marketing authorization when used or assembled (formulated or packaged) in a way different from the approved form, or when used for an unapproved indication, or when used to gain further information about an approved use. (ICH E6) Investigational New Drug
The hull of the mature bean is hard, water-resistant, and protects the cotyledon and hypocotyl (or "germ") from damage. If the seed coat is cracked, the seed will not germinate. The scar, visible on the seed coat, is called the hilum (colors include black, brown, buff, gray and yellow) and at one end of the hilum is the micropyle, or small opening in the seed coat which can allow the absorption of water for sprouting. Some seeds such as soybeans containing very high levels of protein can undergo desiccation, yet survive and revive after water absorption. A. Carl Leopold began studying this capability at the Boyce Thompson Institute for Plant Research at Cornell University in the mid-1980s. He found soybeans and corn to have a range of soluble carbohydrates protecting the seed's cell viability. Patents were awarded to him in the early 1990s on techniques for protecting biological membranes and proteins in the dry state.
== Waste water produced by resin regeneration == Most ion-exchange systems use columns of ion-exchange resin that are operated on a cyclic basis. During the filtration process, water flows through the resin column until the resin is considered exhausted. That happens only when water leaving the column contains more than the maximal desired concentration of the ions being removed. Resin is then regenerated by sequentially backwashing the resin bed to remove accumulated suspended solids, flushing removed ions from the resin with a concentrated solution of replacement ions, and rinsing the flushing solution from the resin. Production of backwash, flushing, and rinsing wastewater during regeneration of ion-exchange media limits the usefulness of ion exchange for wastewater treatment. Water softeners are usually regenerated with brine containing 10% sodium chloride. Aside from the soluble chloride salts of divalent cations removed from the softened water, softener regeneration wastewater contains the unused 50–70% of the sodium chloride regeneration flushing brine required to reverse ion-exchange resin equilibria. Deionizing resin regeneration with sulfuric acid and sodium hydroxide is approximately 20–40% efficient. Neutralized deionizer regeneration wastewater contains all of the removed ions plus 2.5–5 times their equivalent concentration as sodium sulfate.
EosFP is a photoactivatable green to red fluorescent protein. Its green fluorescence (516 nm) switches to red (581 nm) upon UV irradiation of ~390 nm (violet/blue light) due to a photo-induced modification resulting from a break in the peptide backbone near the chromophore. Eos was first discovered as a tetrameric protein in the stony coral Lobophyllia hemprichii. Like other fluorescent proteins, Eos allows for applications such as the tracking of fusion proteins, multicolour labelling and tracking of cell movement. Several variants of Eos have been engineered for use in specific study systems including mEos2, mEos4 and CaMPARI.
Sources: en.wikipedia.org
Unlike physical disabilities, persons with mental illness are perceived by the public to be in control of their disabilities and responsible for causing them. Furthermore, research respondents are less likely to pity persons with mental illness, instead reacting to psychiatric disability with anger and believing that help is not deserved. The behavioral impact (or discrimination) that results from public stigma may take four forms: withholding help, avoidance, coercive treatment, and segregated institutions.
== Causes == The syndrome often occurs once children have moved away, and a partner has died or is dying. An elderly person with nobody left to cook for, or without the skills to cook, will revert to a diet of simple foods such as bread, cheese and crackers, and canned foods. While the sodium content is variable in such foods, they are among the top contributors of sodium in the average American's diet. However, if portion sizes are inadequate, a person may not be consuming enough protein and salt. When combined with excessive water intake, this results in insufficient solute concentration. Patients with poor kidney function, or low glomerular filtration rate, are at even higher risk of hyponatremia due to increased water retention. According to the New York Times, as many as 60% of seniors living at home are either malnourished or at risk of becoming malnourished. In addition to the problems that a lack of nutrients will cause, this state also means that the complications of other illnesses, even the common cold, can be much more severe. Factors that lead to the syndrome include poverty, social isolation, psychological issues such as depression, loss of taste and smell, chronic illnesses that cause a lack of appetite, dental problems that result in difficulty chewing and swallowing foods, a decline in cognitive functioning, alcoholism, and physical disabilities and limitations. Though less of a factor than psychological issues, the increased number of medications often taken by elderly people can also affect eating habits.
==== Phycobilins ==== Phycobilins are a third group of pigments found in cyanobacteria, and glaucophyte, red algal, and cryptophyte chloroplasts. Phycobilins come in all colors, though phycoerytherin is one of the pigments that makes many red algae red. Phycobilins often organize into relatively large protein complexes about 40 nanometers across called phycobilisomes. Like photosystem I and ATP synthase, phycobilisomes jut into the stroma, preventing thylakoid stacking in red algal chloroplasts. Cryptophyte chloroplasts and some cyanobacteria don't have their phycobilin pigments organized into phycobilisomes, and keep them in their thylakoid space instead.
== Physiology == Amino acids, e.g. from ingested food, can be oxidized by the body as an alternative source of energy, yielding urea and carbon dioxide. The oxidation pathway starts with the removal of the amino group by a transaminase; the amino group is then fed into the urea cycle. The first step in the conversion of amino acids into metabolic waste in the liver is removal of the alpha-amino nitrogen, which produces ammonia. Because ammonia is toxic, it is excreted immediately by fish, converted into uric acid by birds, and converted into urea by mammals. Ammonia (NH3) is a common byproduct of the metabolism of nitrogenous compounds. Ammonia is smaller, more volatile, and more mobile than urea. If allowed to accumulate, ammonia would raise the pH in cells to toxic levels. Therefore, many organisms convert ammonia to urea, even though this synthesis has a net energy cost. Being practically neutral and highly soluble in water, urea is a safe vehicle for the body to transport and excrete excess nitrogen. Urea is synthesized in the body of many organisms as part of the urea cycle, either from the oxidation of amino acids or from ammonia. In this cycle, amino groups donated by ammonia and L-aspartate are converted to urea, while L-ornithine, citrulline, L-argininosuccinate, and L-arginine act as intermediates. Urea production occurs in the liver and is regulated by N-acetylglutamate. Urea is then dissolved into the blood (in the reference range of 2.5 to 6.7 mmol/L) and further transported and excreted by the kidney as a component of urine.
According to Pahnke, these categories "describe the core of a universal psychological experience, free from culturally determined philosophical or theological interpretations", and allow researchers to assess mystical experiences on a qualitative, numerical scale. In the 1962 Marsh Chapel Experiment, run by Pahnke at the Harvard Divinity School under Leary's supervision, almost all the graduate degree divinity student volunteers who received psilocybin reported profound religious experiences. One of the participants was religious scholar Huston Smith, author of several textbooks on comparative religion; he called his experience "the most powerful cosmic homecoming I have ever experienced." In a 25-year followup to the experiment, all the subjects given psilocybin said their experience had elements of "a genuine mystical nature and characterized it as one of the high points of their spiritual life". Psychedelic researcher Rick Doblin considered the study partially flawed due to incorrect implementation of the double-blind procedure and several imprecise questions in the mystical experience questionnaire. Nevertheless, he said that the study cast "considerable doubt on the assertion that mystical experiences catalyzed by drugs are in any way inferior to non-drug mystical experiences in both their immediate content and long-term effects". Psychiatrist William A.
Sources: en.wikipedia.org
Angiotensinogen is an α-2-globulin synthesized in the liver and is a precursor for angiotensin, but has also been indicated as having many other roles not related to angiotensin peptides. It is a member of the serpin family of proteins, leading to another name: Serpin A8, although it is not known to inhibit other enzymes like most serpins. In addition, a generalized crystal structure can be estimated by examining other proteins of the serpin family, but angiotensinogen has an elongated N-terminus compared to other serpin family proteins. Obtaining actual crystals for X-ray diffractometric analysis is difficult in part due to the variability of glycosylation that angiotensinogen exhibits. The non-glycosylated and fully glycosylated states of angiotensinogen also vary in molecular weight, the former weighing 53 kDa and the latter weighing 75 kDa, with a plethora of partially glycosylated states weighing in between these two values. Angiotensinogen is also known as renin substrate. It is cleaved at the N-terminus by renin to result in angiotensin I, which will later be modified to become angiotensin II. This peptide is 485 amino acids long, and 10 N-terminus amino acids are cleaved when renin acts on it. The first 12 amino acids are the most important for activity.
=== Immigration Act of 1924 === Anti-miscegenation laws, along with the Immigration Act of 1924, contributed to the anti-immigrant sentiment that existed during the development of United States history. At this point in time, the United States was concerned with foreigners coming into the country in higher numbers and therefore enforced its first border patrol and regulated the number of foreign immigrants from south and eastern Europe, as well as permitting people from the southern people specialized in agriculture and work from the southern border. In the forgotten narrative of Latin American History, U.S., Mexican immigrants and citizens were labeled and seen as a problem in society because they were seen as hyper-fertile and supported theories that Mexicans were of a lower racial level. By the first half of the 20th century, almost 60,000 people had been sterilized under the different U.S. Eugenics Programs implemented.
== Applications in biochemistry == Coomassie brilliant blue R-250 was first used to visualise proteins in 1963 by Fazekas de St. Groth and colleagues. Protein samples were separated electrophoretically on a cellulose acetate sheet. The sheet was then soaked in sulfosalicylic acid to fix the protein bands and transferred to a solution of the dye. Two years later in 1965 Meyer and Lambert used Coomassie brilliant blue R-250 to stain protein samples after electrophoretic separation in a polyacrylamide gel. They soaked the gel in a dye solution containing methanol, acetic acid and water. As the dye stained the polyacrylamide gel as well as the protein, in order to visualise the protein bands they needed to destain the gel, which they did electrophoretically. Subsequent publications reported that polyacrylamide gels could be successfully destained using an acetic acid solution. The first report of the use of the G form of the dye to visualise protein bands in polyacrylamide gels came in 1967, where the dye was dissolved in an acetic acid solution containing methanol. It was subsequently discovered that the protein bands could be stained without staining the polyacrylamide by using a colloid of the G form of the dye in a trichloroacetic acid solution containing no methanol. With this procedure it was no longer necessary to destain the gel. Modern formulations typically use a colloid of the G form of dye in a solution containing phosphoric acid, ethanol (or methanol) and ammonium sulfate (or aluminium sulfate).
Nucleolus Nuclear speckle Cajal body Paraspeckle Synaptonemal complex Other nuclear structures including heterochromatin form by mechanisms similar to phase separation, so can also be classified as biomolecular condensates. RNAs with triplet expansion that produce neurodegenerative disorders can also independently form RNA foci in vitro or in mammalian nuclei. This phenomenon is further reconsituted in bacteria E. coli, by expressing engineered CAG repeats, providing strong evidence that these RNA repeats phase separate without the need of additional proteins.
Narrated by Roger Allam, produced by Richard Melman, written, produced and directed by Chris Haws, made by InCA Productions 22 August The Emperor's New Mind, about artificial intelligence, with mathematician Roger Penrose, a play on words of the phrase Emperor's new clothes; Canadian Hans Moravec of the Robotics Institute; a scene from the edition Figure it out of the Look at Life (film series); the Mathematical Institute, University of Oxford; children of Westfields Junior School in Yateley, Hampshire, and a middle school in Oxford; crudely-operating computers were not intuitive in forming or deducing algorithms - computers could not truly understand such general rules; Euclidean tilings by convex regular polygons, and whether computers could calculate such possibilities; Gödel's incompleteness theorems; in 1974 the Arecibo Ionospheric Observatory found the Hulse–Taylor binary, the first binary pulsar found, which confirmed general relativity; wave function collapse; the cytoskeleton, microtubules and noncomputability; computers would only be able to simulate the computable parts of reasoning, and not any more.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
Dry powder is normally held at -20 °C or lower, away from light and moisture. Sealed vials can also be kept at 2-8 °C for shorter intervals. Warming to room temperature before opening prevents condensation.