nasal drops raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-12-16 and is reviewed periodically as new material appears.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Typical purity | 95% or higher | By reversed-phase HPLC area |
| Identity method | Electrospray mass spectrometry | Confirms molecular mass |
| Purity method | Reversed-phase HPLC | Detection near 214 nm |
| Primary degradation | Methionine oxidation | Sulfoxide product, +16 Da |
| Solution storage | 2-8 °C, short term | Aliquot to avoid freeze-thaw |
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.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
== Adverse effects == The most common side effects include nausea (feeling sick), vomiting, constipation, loss of appetite, alopecia (hair loss), headache, fatigue (tiredness), convulsions (fits), rash, neutropenia or lymphopenia (low white-blood-cell counts), and thrombocytopenia (low blood platelet counts). People receiving the solution for infusion may also have injection-site reactions, such as pain, irritation, itching, warmth, swelling and redness, as well as bruising.
Pyruvate + NADH + H+ → Lactate + NAD+ This process occurs in the bacteria involved in making yogurt (the lactic acid causes the milk to curdle). This process also occurs in animals under hypoxic (or partially anaerobic) conditions, found, for example, in overworked muscles that are starved of oxygen. In many tissues, this is a cellular last resort for energy; most animal tissue cannot tolerate anaerobic conditions for an extended period of time. Some organisms, such as yeast, convert NADH back to NAD+ in a process called ethanol fermentation. In this process, the pyruvate is converted first to acetaldehyde and carbon dioxide, and then to ethanol. Lactic acid fermentation and ethanol fermentation can occur in the absence of oxygen. This anaerobic fermentation allows many single-cell organisms to use glycolysis as their only energy source. Anoxic regeneration of NAD+ is only an effective means of energy production during short, intense exercise in vertebrates, for a period ranging from 10 seconds to 2 minutes during a maximal effort in humans. (At lower exercise intensities it can sustain muscle activity in diving animals, such as seals, whales and other aquatic vertebrates, for very much longer periods of time.) Under these conditions NAD+ is replenished by NADH donating its electrons to pyruvate to form lactate. This produces 2 ATP molecules per glucose molecule, or about 5% of glucose's energy potential (38 ATP molecules in bacteria). But the speed at which ATP is produced in this manner is about 100 times that of oxidative phosphorylation.
In March 1946, the government of Kimon Georgiev was reorganized—two ministries were added, the number of sub-chairmen was reduced, and there were personnel changes and changes in the proportions of the coalition parties. This was on the orders of Joseph Stalin, who criticised the Bulgarian communists for the slow imposition of the totalitarian regime in the country. He demanded the strengthening of the presence of the BPC and BZNS in the cabinet, the removal of the foreign minister Petko Staynov and a purge of the foreign ministry staff, and the replacement of the finance minister Stancho Cholakov. Despite the pressure against Zveno, Georgiev himself retained the confidence of Stalin and Georgi Dimitrov and remained at the head of the cabinet. Apart from being prime minister, he remained a minister without portfolio. On Joseph Stalin's direct instructions to Georgi Dimitrov, a purge in the army began in the summer of 1946, accompanied by public show trials against alleged officer organizations - "Tsar Krum", "Neutral Officer" and others, as well as opposition leaders such as G. M. Dimitrov and Krustyo Pastukhov. These were coordinated with the parallel mounted trial in Yugoslavia against Draža Mihailović, during which Mihailović's links with Bulgarian public figures such as G. М. Dimitrov, Asen Stamboliyski and the war minister Damyan Velchev. In this setting, Kimon Georgiev publicly spoke out in support of the Military Union and personally of Damyan Velchev, whom he called his "closest and most inseparable personal friend, political associate and comrade in the cabinet".
The protein component of AGPs is rich in the amino acids Proline (P), Alanine (A), Serine (S) and Threonine (T), also known as 'PAST', and this amino acid bias is one of the features used to identify them. AGPs are intrinsically disordered proteins as they contain a high proportion of disordering amino acids such as Proline that disrupt the formation of stable folded structures. Characteristic of intrinsically disordered proteins, AGPs also contain repeat motifs and post-translational modifications. Proline residues in the protein backbone can be hydroxylated to Hydroxyproline (O) depending on the surrounding amino acids. The 'Hyp contiguity hypothesis' predicts that when O occurs in a non-contiguous manner, for example the sequence 'SOTO', such as occurs in AGPs, this acts as a signal for O-linked glycosylation of large branched type II arabinogalactan (AG) polysaccharides. Sequences that direct AG glycosylation (SO, TO, AO, VO) are called AGP glycomotifs. All AGP protein backbones contain a minimum of 3 clustered AGP glycomotifs and an N-terminal signal peptide that directs the protein into the endoplasmic reticulum (ER) where post-translational modifications begin. Prolyl hydroxylation of P to O is fulfilled by prolyl 4-hydroxylases (P4Hs) belonging to the 2-oxoglutarate dependant dioxygenase family. P4H has been identified in both the ER and Golgi apparatus. The addition of the glycosylphosphatidylinositol (GPI)-anchor occurs in most but not all AGPs.
Insulin (e.g. intravenous injection of 10 units of regular insulin along with 50 mL of 50% dextrose to prevent the blood sugar from dropping too low) leads to a shift of potassium ions into cells, secondary to increased activity of the sodium-potassium ATPase. Its effects last a few hours, so it sometimes must be repeated while other measures are taken to suppress potassium levels more permanently. The insulin is usually given with an appropriate amount of glucose to help prevent hypoglycemia following the insulin administration, though hypoglycaemia remains common especially in the context of acute or chronic renal impairment and capillary blood glucose measurements should be taken regularly after administration to identify this. Salbutamol (albuterol), a β2-selective catecholamine, is administered by nebuliser (e.g. 10–20 mg). This medication also lowers blood levels of K+ by promoting its movement into cells, and will work within 30 minutes. It is recommended to use 20 mg for maximum potassium lowering effect, but to use lower doses if the patient is tachycardic or has ischaemic heart disease. Note that 12-40% of patients do not respond to salbutamol therapy for reasons unknown, especially if on beta-blockers, so it should not be used as monotherapy Sodium bicarbonate may be used with the above measures if it is believed the person has metabolic acidosis, though time to effectiveness is longer and its use is controversial.
Sources: en.wikipedia.org
=== Reform and further enlargement === East Germany joined on 3 October 1990 through reunification with West Germany. In the 1990s, several European countries, now members of the European Union, expressed their willingness to join the Organisation. In 1995, Cyprus applied for membership, but according to the Cypriot government, it was vetoed by Turkey. In 1996, Estonia, Latvia, and Lithuania signed a Joint Declaration expressing willingness to become members of the OECD, and Slovenia also applied for membership that same year. In 2005, Malta applied to join the Organisation. The EU is lobbying for the admission of all EU member states. Romania reaffirmed in 2012 its intention to become a member of the Organisation through the letter addressed by Romanian Prime Minister Victor Ponta to OECD Secretary-General José Ángel Gurría. In September 2012, the government of Bulgaria confirmed it would apply for membership before the OECD Secretariat. The OECD established a working group headed by ambassador Seiichiro Noboru to work out a plan for the enlargement with non-members.
=== Colony division === Whole colonies can reproduce asexually, forming two colonies with the same genotype. The possible mechanisms include fission, bailout and fragmentation. Fission occurs in some corals, especially among the family Fungiidae, where the colony splits into two or more colonies during early developmental stages. Bailout occurs when a single polyp abandons the colony and settles on a different substrate to create a new colony. Fragmentation involves individuals broken from the colony during storms or other disruptions. The separated individuals can start new colonies.
London theorized that attractive forces between molecules that cannot be explained by ionic or covalent interaction can be caused by polar moments within molecules. Multipoles could account for attraction between molecules having permanent multipole moments that participate in electrostatic interaction. However, experimental data showed that many of the compounds observed to experience van der Waals forces had no multipoles at all. London suggested that momentary dipoles are induced purely by virtue of molecules being in proximity to one another. By solving the quantum mechanical system of two electrons as harmonic oscillators at some finite distance from one another, being displaced about their respective rest positions and interacting with each other's fields, London showed that the energy of this system is given by:
Stimulates parietal cell maturation and fundal growth. Causes chief cells to secrete pepsinogen, the zymogen (inactive) form of the digestive enzyme pepsin. Increases antral muscle mobility and promotes stomach contractions. Strengthens antral contractions against the pylorus, and relaxes the pyloric sphincter, which increases the rate of gastric emptying. Plays a role in the relaxation of the ileocecal valve. Induces pancreatic secretions and gallbladder emptying. May impact lower esophageal sphincter (LES) tone, causing it to contract, - although pentagastrin, rather than endogenous gastrin, may be the cause. Gastrin contributes to the gastrocolic reflex.
=== Phase 3 === Benzoyl peroxide/tretinoin (IDP-120) – combination of benzoyl peroxide (undefined mechanism of action) and tretinoin (retinoid) Berdazimer sodium (SB-204; MAP3-NONOate; NVN1000) – nitric oxide releasing agent Denifanstat (ASC–40; TVB-2640) – fatty acid synthetase complex inhibitor GED 0507-34-Levo (GED-0507; GED-0507-34; N-acetyl-GED-0507-34; NAC-GED-0507) – peroxisome proliferator-activated receptor gamma (PPARγ) modulator
Sources: en.wikipedia.org
=== Hosting === In addition to acting, Hart has also hosted various ceremonies. Hart first hosted the 2011 BET Awards. Hart then hosted the 2012 MTV Video Music Awards, after his longtime friend Judd Apatow, the director who gave him his first big on-screen break in the TV series Undeclared, recommended him for the position. Hart hoped this would project him into a side career as an emcee, stating: "Hopefully after MTV, of course we're talking Emmys, Oscars, whatever." From 2013–2015, he hosted three episodes of Saturday Night Live. In 2015, Hart hosted the Comedy Central Roast of Justin Bieber. In 2016, Hart co-hosted the 2016 MTV Movie Awards with Dwayne Johnson. In September 2018 Hart hosted HQ Trivia with Scott Rogowsky and gave away $100,000 to one person. On December 4, 2018, Hart was announced as the host of the 2019 Academy Awards. Two days later, however, he withdrew from hosting duties in the wake of backlash against him over several homophobic tweets he had posted between 2010 and 2011. He characterized the protest as unconstructive and argued: "If you don't believe people change, grow as they get older, I don't know what to tell you." On December 7, he tweeted an apology to the LGBTQ community following criticism for not issuing one the previous day.
HCO−3 is known as the bicarbonate ion. Calcium bicarbonate is many times more soluble in water than calcium carbonate—indeed it exists only in solution. Some of the HCO−3 combines with H+ in solution according to
This case demonstrated the rare association between Natural Killer cell lymphoma and PNP, suggesting that Natural Killer cells could be involved in the pathogenesis of PNP. The article warned clinicians to be alert to the possibility that paraneoplastic pemphigus in lymphomas not of B-cell lineage. This added to the already complex, not fully understood pathogenesis of PNP. A study in 2013 outlined the effectiveness of plasma exchange in PNP patients with benign tumors. The University of Toronto has been working to develop a form of treatment that improves the patient's overall quality of life while remaining economically achievable. They believe they have achieved this through fixed-dose rituximab. It has proven to be effective among auto-immune diseases, but the correct administration process for treating PNP is yet to be defined. The results of the study demonstrated varying levels of remission.
Jennings was also appointed as a pitchman for Wisconsin even outside the specialized burger promotion, in a contract signed on October 1, 2009; in exchange, A&W donated $10,000 to The Greg Jennings Foundation. In January 2013, A&W Restaurants appointed Lexington-based advertising agency Cornett Integrated Marketing as its new agency of record. The contract was renewed in January 2024. In January 2019, ahead of its hundredth anniversary, A&W removed the ampersand from its logo as part of a tongue-in-cheek campaign to bring back the ampersand to the alphabet as its 27th letter. Beginning in October 2020, in order to recoup economic losses from the closure of several of its restaurants, A&W set up a series of quizzes on its website. For Halloween that year, it released a web stunt called The Onion Ring, a parody of The Ring. A&W unveiled a new campaign in 2024, capitalizing on the ampersand of its logo and the tagline Burgers, Floats & Then Some. Packaging was also changed accordingly.
Sources: en.wikipedia.org
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.
In solution, hydrolysis of peptide bonds and oxidation of the methionine residue are the principal concerns. Oxidation converts methionine to its sulfoxide form, shifting the mass by sixteen daltons. Both processes are slowed by cold storage and by avoiding alkaline conditions.
A certificate documents what the supplier measured on a specific lot, not how a laboratory will use the material. Independent verification of identity and purity is common practice. Acceptance criteria should be defined before a batch is ordered.
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。