The short version of 鼻内给药 fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-11-06. Anything still debated is marked as such rather than presented as settled.
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.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid from research suppliers |
| Solubility | Freely soluble in water | Also dissolves in aqueous buffers; solutions are used fresh |
| Typical storage temperature | -20 °C for lyophilized powder | Short-term transport at 2-8 °C is common |
| Common analytical method | Reverse-phase HPLC | Paired with mass spectrometry for identity confirmation |
| Common synonyms | ACTH(4-10) analogue; MEHFPGP | N-terminal methionine retained in the chain |
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
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。
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。
== Legal perspective == NIST, a cybersecurity framework, was published in 2014 in the US. The Tallinn Manual, published in 2013, is an academic, non-binding study on how international law, in particular the jus ad bellum and international humanitarian law, apply to cyber conflicts and cyber warfare. It was written at the invitation of the Tallinn-based NATO Cooperative Cyber Defence Centre of Excellence by an international group of approximately twenty experts between 2009 and 2012. The Shanghai Cooperation Organisation (members of which include China and Russia) defines cyberwar to include dissemination of information "harmful to the spiritual, moral and cultural spheres of other states". In September 2011, these countries proposed to the UN Secretary General a document called "International code of conduct for information security". In contrast, the United approach focuses on physical and economic damage and injury, putting political concerns under freedom of speech. This difference of opinion has led to reluctance in the West to pursue global cyber arms control agreements. However, American General Keith B. Alexander did endorse talks with Russia over a proposal to limit military attacks in cyberspace. In June 2013, Barack Obama and Vladimir Putin agreed to install a secure Cyberwar-Hotline providing "a direct secure voice communications line between the US cybersecurity coordinator and the Russian deputy secretary of the security council, should there be a need to directly manage a crisis situation arising from an ICT security incident" (White House quote).
=== Cor–Cz === Robert Corey (1897–1971). American protein chemist at Caltech, known for work with Linus Pauling on the α-helix and β-sheet. Member Natl. Acad. Sci. USA. Carl Ferdinand Cori (1896–1984). American biochemist at Washington University and Albert Einstein College of Medicine, who worked on glycogen. Nobel Prize in Physiology or Medicine (1947). Member Natl. Acad. Sci. USA. Gerty Cori (1896–1957). Czech-American biochemist at Washington University, known for glycogen research. Nobel Prize in Physiology or Medicine (1947). Athel Cornish-Bowden (b. 1943). British enzymologist at the CNRS, Marseille. He has contributed to the development of metabolic control analysis, and is the author of Fundamentals of Enzyme Kinetics. Suzanne Cory (b. 1942). Australian molecular biologist known fotr work on the genetics of the immune system, at the Walter and Eliza Hall Institute of Medical Research, Melbourne. Peter Coveney (b. 1958). British Computational molecular biology specialist at University College London, University of Amsterdam and Yale. Nicholas R. Cozzarelli (1938–2006). American biochemist at UC Berkeley, and former editor-in-chief of the Proceedings of the National Academy of Sciences. Member Natl. Acad. Sci. USA. Gerald Crabtree (b. 1946). American biochemist at Stanford, known for defining the Ca2+-calcineurin-NFAT signalling pathway, pioneering the development of synthetic ligands for regulation of biological processes. Robert K. Crane (1919–2010).
==== Harris lines ==== Harris lines form before adulthood, when bone growth is temporarily halted or slowed down due to some sort of stress (typically disease or malnutrition). During this time, bone mineralization continues, but growth does not, or does so at reduced levels. If and when the stressor is overcome, bone growth resumes, resulting in a line of increased mineral density visible in a radiograph. Absent removal of the stressor, no line forms. Particularly, deficiencies in protein and vitamins, which lead to delayed longitudinal bone growth, can result in the formation of Harris lines. During the process of endochondral bone growth, the cessation of osteoblastic activity results in the deposition of a thin layer of bone beneath the cartilage cap, potentially forming Harris lines. Subsequent recovery, necessary for the restoration of osteoblastic activity, is also implicated in Harris line formation. When matured cartilage cells reactivate, bone growth resumes, thickening the bony stratum. Therefore, complete recovery from periods of chronic illness or malnutrition manifests as transverse lines on radiographs. Lines tend to be thicker with prolonged and severe malnutrition. Harris line formation typically peaks in long bones around 2–3 years after birth and becomes rare after the age of 5 until adulthood. Harris lines occur more frequently in boys than in girls.
Sources: en.wikipedia.org
== Function == Lactoferrin belongs to the innate immune system. Apart from its main biological function, namely binding and transport of iron ions, lactoferrin also has antibacterial, antiviral, antiparasitic, catalytic, anti-cancer, and anti-allergic functions and properties.
=== Biofuel production === One the most widely known biobased chemicals produced through fermentation, the process of fermenting sugars from plants into ethanol and CO2 uses Saccharomyces cerevisiae. Biobased ethanol is used as a popular renewable transportation fuel and also holds value in the chemical industry as the precursor for ethylene, which can be converted into polyethylene. Commercial bioethanol production via fermentation is dominant in Brazil and the USA and employs sugarcane and starch from corn as feedstocks. The process involves starch enzymatic hydrolysis to glucose, followed by fermentation and distillation. There were around 200 ethanol plants operating in the U.S. as of 2021, with capacities of production varying from 6 kilotonnes to over one million tonnes annually.
The Mustang was a good fighter and the best escort due to its incredible range, make no mistake about it. It was also the best American dogfighter. But the laminar-flow wing fitted to the Mustang could be a little tricky. It could not by any means out-turn a Spitfire. No way. It had a good rate-of-roll, better than the Spitfire, so I would say the plusses to the Spitfire and the Mustang just about equate. If I were in a dogfight, I'd prefer to be flying the Spitfire. The problem was I wouldn't like to be in a dogfight near Berlin, because I could never get home to Britain in a Spitfire! The US Air Forces, Flight Test Engineering, assessed the Mustang B on 24 April 1944 thus:
== Early life and education == Alessio Ciulli was born in Florence on 22 July 1977. He attended University of Florence in his hometown with an undergraduate laurea in chemistry and graduated magna cum laude. Under the late Prof Ivano Bertini, his final year laurea project was in computational drug design and NMR spectroscopy of matrix metalloproteases. Awarded with a Gates Cambridge Scholarship, he did his PhD under the supervision of the late Professor Chris Abell at the University of Cambridge and in collaboration with Astex Technology (now Astex Pharmaceuticals) produced a thesis concerned with studying weak protein-ligand interactions using biophysical and structural methods.
Sources: en.wikipedia.org
===== Transgenic plants ===== Transgenic crops have been made to express dsRNA, carefully chosen to silence crucial genes in target pests. These dsRNAs are designed to affect only insects that express specific gene sequences. As a proof of principle, in 2009 a study showed RNAs that could kill any one of four fruit fly species while not harming the other three.
), as shown by the equations. The distribution coefficient is calculated as the ratio between the concentration of the metal cations in the organic and aqueous phase, whereas the separation factor is calculated as the ratio between the two distribution coefficients.
=== Glucose transporter (GLUTs) === The glucose transporter (GLUTs) is a type of uniporter responsible for the facilitated diffusion of glucose molecules across cell membranes.Glucose is a vital energy source for most living cells, however, due to its large size, it cannot freely move through the cell membrane. The glucose transporter is specialized in transporting glucose specifically across the membrane. The GLUT proteins have several types of isoforms, each distributed in different tissues and exhibiting different kinetic properties.
Sources: en.wikipedia.org
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.
A fraction of an intranasal dose is thought to reach the central nervous system, and this route is favoured partly for that reason. The proportion is not well characterized. Direct measurement in humans remains difficult with current methods.
Raised BDNF and NGF expression has been reported across several animal studies, which makes the signal fairly consistent. Whether the same change occurs in humans at usable doses is not established. It is best treated as a working hypothesis rather than a confirmed clinical mechanism.
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.