intranasal delivery comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-07-14. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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 |
|---|---|---|
| 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 |
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.
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。
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。
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
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.
==== Indonesia ==== In Indonesia, Mister Donut is operated under management of Indomaret, a subsidiary of Salim Group. The first store was opened in 2015, with 7 standalone outlets and 1,350 stands inside Indomaret outlets, mostly located in the city center, malls, airports, rail stations, or shop-in-shops at every Indomaret outlet.
== Life == Biolik's parents emigrated to Canada from Poland after World War 2. Her roots in Poland are reflected in her coat of arms which was granted to her in 2003. Biolik was Canada's Consul General to Saint Petersburg, Russian Federation from 2001 to 2004. She is fluent in Russian and she encouraged sustainable development as a likely area for cooperation between Canada and Russia as they share a similar interest in the frozen north. Biolik was Ambassador Extraordinary and Plenipotentiary to Kazakhstan from 2004 to 2006, with concurrent accreditation to the Republic of Kyrgyzstan and the Republic of Tajikistan. In 2006 she outlined Canada's concerns about drug smuggling. She was briefed by Tajikistan ’s Drug Control Agency about their work. She wanted to ensure that Afghanistan's neighbours were aware as she saw that country's stability as key to the region. She was replaced in 2006 by Margaret Skok. Biolik was Canada's first Ambassador to Mongolia in 2008. Canada is the second largest investor in Mongolia after Russia - where she had previously been head of mission. She was thanked by Prime Minister Sükhbaataryn Batbold when she left. She was succeeded by J. Gregory Goldhawk. In 2011, she was appointed as the Regional Director of the Department of Foreign Affairs and International Trade's Vancouver Regional Office.
Naturally occurring iodine (53I) consists of one stable isotope, 127I, and is a mononuclidic element for atomic weight. Radioisotopes of iodine are known from 108I to 147I. The longest-lived of those, 129I, has a half-life of 16.14 million years, which is too short for it to exist as a primordial nuclide. It is, however, found in nature as a trace isotope and universally distributed, produced naturally by cosmogenic sources in the atmosphere and by natural fission of the actinides. Today, however, most is artificial as fission product; like krypton-85 the contribution of past nuclear testing and of operating reactors are dwarfed by release from nuclear reprocessing. All other iodine radioisotopes have half-lives less than 60 days, and four of these are used as tracers and therapeutic agents in medicine – 123I, 124I, 125I, and 131I. All industrial use of radioactive iodine isotopes involves these four. In addition, one other isotope has a half-life in the same range – 126I (12.93 days; decays almost equally to tellurium or to xenon). The isotope 135I has a half-life less than seven hours, which is inconveniently short for those purposes. However, the unavoidable in situ production of this isotope is important in nuclear reactor control, as it decays to 135Xe, the most powerful known neutron absorber, and the nuclide responsible for the so-called iodine pit phenomenon. In addition to commercial production, 131I (half-life 8 days) is one of the common radioactive fission products of nuclear fission, and thus occurs in large amounts inside nuclear reactors.
Similarly, ethylene oxide is detected by the bright pink color of the indicator when passing air through aqueous solutions of some salts of sodium or potassium (chlorides, iodides, thiosulfates, etc.) with the addition of phenolphthalein:
Sources: en.wikipedia.org
=== Cancer === After finding that Ras proteins are mutated in 30% of human cancers, it was suspected that mutated Rho proteins might also be involved in cancer reproduction. However, as of August 2007, no oncogenic mutations have been found in Rho proteins, and only one has been found to be genetically altered. To explain the role of Rho pathways without mutation, researchers have now turned to the regulators of rho activity and the levels of expression of the Rho proteins for answers. One way to explain altered signaling in the absence of mutation is through increased expression. Overexpression of RhoA, RhoB, RhoC, Rac1, Rac2, Rac3, RhoE, RhoG, RhoH, and Cdc42 has been shown in multiple types of cancer. This increased presence of so many signaling molecules implies that these proteins promote the cellular functions that become overly active in cancerous cells. A second target to explain the role of the Rho proteins in cancer is their regulatory proteins. Rho proteins are very tightly controlled by a wide variety of sources, and over 60 activators and 70 inactivators have been identified. Multiple GAPs, GDIs, and GEFs have been shown to undergo overexpression, downregulation, or mutation in different types of cancer. Once an upstream signal is changed, the activity of its targets downstream—i.e., the Rho proteins—will change in activity. Ellenbroek et al. outlined a number of different effects of Rho activation in cancerous cells. First, in the initiation of the tumor modification of Rho activity can suppress apoptosis and therefore contribute to artificial cell longevity.
Natural food freezing (using winter frosts) had been in use by people in cold climates for centuries. In 1861 Thomas Sutcliffe Mort established at Darling Harbour in Sydney, Australia, the world's first freezing works, which later became the New South Wales Fresh Food and Ice Company. Mort financed experiments by Eugene Dominic Nicolle, a French born engineer who had arrived in Sydney in 1853 and registered his first ice-making patent in 1861. The first trial shipment of frozen meat to London was in 1868. Although their machinery was never used in the frozen meat trade, Mort and Nicolle developed commercially viable systems for domestic trade. The financial return on that investment was minimal for Mort. Regular shipments of frozen meat from Australia and New Zealand to Europe began in 1881, with a consignment of frozen New Zealand sheep exported to London on board the Dunedin. By 1885 a small number of chickens and geese were being shipped from Russia to London in insulated cases using this technique. By March 1899, the "British Refrigeration and Allied Interests" reported that a food importing business, "Baerselman Bros", was shipping some 200,000 frozen geese and chickens per week from three Russian depots to New Star Wharf, Lower Shadwell, London over three or four winter months. This trade in frozen food was enabled by the introduction of Linde cold air freezing plants in three Russian depots and the London warehouse. The Shadwell warehouse stored the frozen goods until they were shipped to markets in London, Birmingham, Liverpool and Manchester.
It is usually served either with a sweet ginger syrup, or a mushroom gravy called da lu (打卤). It is normally coagulated at the restaurant into a serving container. Douhua is not always considered a type of tofu, but rather a type of food in its own right. Some variation exists among soft tofus. Black douhua (黑豆花, hēidòuhuā) is a type of silken tofu made from black soybeans, which is usually made into dòuhuā (豆花) rather than firm or dry tofu. The texture of black bean tofu is slightly more gelatinous than regular douhua and the color is greyish in tone. This type of tofu is eaten for its earthy "black bean taste". Edamame tofu is a Japanese variety of kinugoshi tōfu made from edamame (fresh green soybeans); it is pale green in color and often studded with whole edamame.
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。
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.