If you have been reading about intranasal delivery 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 2026-04-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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.
| 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.
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.
== Treatment == Smallpox vaccination within three days of exposure will prevent or significantly lessen the severity of smallpox symptoms in the vast majority of people. Vaccination four to seven days after exposure can offer some protection from disease or may modify the severity of the disease. Other than vaccination, treatment of smallpox is primarily supportive, such as wound care and infection control, fluid therapy, and possible ventilator assistance. Flat and hemorrhagic types of smallpox are treated with the same therapies used to treat shock, such as fluid resuscitation. People with semi-confluent and confluent types of smallpox may have therapeutic issues similar to patients with extensive skin burns. Antiviral treatments have improved since the last large smallpox epidemics, and as of 2004, studies suggested that the antiviral drug cidofovir might be useful as a therapeutic agent. The drug must be administered intravenously, and may cause serious kidney toxicity. In July 2018, the Food and Drug Administration approved tecovirimat, the first drug approved for treatment of smallpox. However, during treatment viral mutations causing resistance have been known to occur, especially since its use in the 2022–2023 mpox outbreak which jeopardize its effectiveness for smallpox biothreat preparedness. In June 2021, Brincidofovir was approved for medical use in the United States for the treatment of human smallpox disease caused by variola virus.
The jalapeño is variously named huachinango, for the ripe red jalapeño, and chile gordo (meaning "fat chili pepper") also known as cuaresmeño. The name jalapeño is Spanish for "from Xalapa", the capital city of Veracruz, Mexico. Contrary to popular belief, the jalapeño pepper is not grown in or around Xalapa, but Vicente Jiménez invented the process of pickling and canning the peppers in Xalapa. Genetic analysis of Capsicum annuum places jalapeños as a distinct genetic clade with no close sisters that are not directly derived from jalapeños. Jalapeños were in use by the Aztecs prior to the Spanish conquest; Bernardino de Sahagún in the Florentine Codex writes of Aztec markets selling chipotles (smoked jalapeños) and mole made from chipotles, besides the sale of fresh chilies. The use of peppers in the Americas dates back thousands of years, including the practice of smoking some varieties of peppers in order to preserve them; further well preserved samples and genetic testing would be needed to determine the usage and existence of the jalapeño clade and pod type in the past.
The low levels of progesterone with oral progesterone may also explain its differences in risk of breast cancer and venous thromboembolism relative to progestogens when added to estrogen therapy in postmenopausal women. Such risks are increased by progestins, which are PR agonists similar to progesterone, but have been found to be increased less or not at all by oral progesterone. Since typical clinical doses of oral progesterone achieve very low levels of progesterone, and progesterone therapy with luteal-phase progesterone levels has never been properly evaluated in sufficiently large clinical studies, it has been said that notion that progesterone somehow differs from progestins and does not increase the risk of breast cancer or venous thromboembolism is unsubstantiated. Moreover, in the absence of adequate data to the contrary, it would be reasonable to consider progesterone at least equivalent to progestins as a potential risk factor for such complications. Indeed, preclinical research suggests a carcinogenic role for progesterone in the breast, and the French E3N study observed a significantly higher risk of breast cancer with estrogen and oral progesterone therapy in postmenopausal women after long-term (>5-year) administration. This is potentially consistent with a weak proliferative effect of oral progesterone on the breasts such that a longer duration of exposure may be necessary for an increase in breast cancer risk to manifest.
=== 21 March === The SAF retook the Republican Palace in Khartoum from the RSF. An RSF drone strike on the palace that same day killed six journalists including two military reporters and four members of a Sudan TV crew.
Sources: en.wikipedia.org
However, as the United States maintained global power, its role in many regime changes during the Cold War went mostly officially unacknowledged, even when some, such as El Salvador, Argentina and Indonesia, resulted in extensive human rights violations.
=== Liquid crystals, colloidal glasses, and hydrogels === Owed to their anisotropic shape and surface charge, nanocelluloses (mostly rigid CNCs) have a high excluded volume and self-assemble into cholesteric liquid crystals beyond a critical volume fraction. Nanocellulose liquid crystals are left-handed due to the right-handed twist on particle level. Nanocellulose phase behavior is susceptible to ionic charge screening. An increase in ionic strength induces the arrest of nanocellulose dispersions into attractive glasses. At further increasing ionic strength, nanocelluloses aggregate into hydrogels. The interactions within nanocelluloses are weak and reversible, wherefore nanocellulose suspensions and hydrogels are self-healing and may be applied as injectable materials or 3D printing inks.
=== Inscribed triangle === If three points D, E, F on the respective sides AB, BC, and CA of a reference triangle ABC are the vertices of an inscribed triangle, which thereby partitions the reference triangle into four triangles, then the area of the inscribed triangle is greater than the area of at least one of the other interior triangles, unless the vertices of the inscribed triangle are at the midpoints of the sides of the reference triangle (in which case the inscribed triangle is the medial triangle and all four interior triangles have equal areas):
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.