If you have been reading about aliquot 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.
Updated 2026-05-10. Numbers and descriptions here follow the published literature rather than marketing material.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
| Property | Value | Notes |
|---|---|---|
| Typical purity | ≥95% by HPLC | Research-grade material |
| Detection wavelength | 214 nm | Peptide bond absorbance |
| Reconstitution medium | Sterile water or saline | Prepare fresh or aliquot immediately |
| Storage (solution) | -80 °C, single-use aliquots | Avoid repeated freeze-thaw cycles |
| Common salt form | Acetate or trifluoroacetate | Affects mass and solubility |
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.
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.
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.
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.
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.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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。
== Ideology == SWAPO was founded with the aim of attaining the independence of Namibia and therefore is part of the African nationalist movement. Pre-independence it had a socialist, Marxist–Leninist ideology, which was not immediately abandoned when independence was achieved in 1990 and SWAPO became the ruling party. Officially, however, it adopted a social democratic ideology, until the electoral congress in 2017 approved the official change to socialism with a "Namibian character", although some Namibians have labelled the change as lacking a "grass-roots" nature. Various commentators have characterised the politics of SWAPO in different ways. Gerhard Tötemeyer, himself a party member, considered its post-independence politics neoliberal and social democratic. Henny Seibeb, an opposition politician from the Landless People's Movement, describes the current party ideology as liberal nationalism with traces of "dogmatism, authoritarianism, and statism".
=== Immune function === Vitamin A plays an important role in the body's immune function, both the adaptive response, and to help the body fight off infection. The anti-inflammatory effects of vitamin A also contribute to repairing mucosal cells that can be damaged by an infection. For these reasons, there have been quite a few studies looking at the potential role that Vitamin A supplementation may play in improving an immune response or to helping the body fight off an infection. The evidence supporting vitamin A supplementation for children under the age of 7 years to prevent upper respiratory tract infections is weak, and the weak evidence from low-quality clinical trials does not support vitamin A as being effective or having a benefit. More research is needed to consider different doses, the ages and populations of people who may potentially benefit, and the length of treatment.
The resulting campaign was costly for both sides, but ultimately ended in disaster for France and the near-destruction of Napoleon's Grande Armée. French forces retreated from Russia by December 1812 and began reconstituting their lost strength. Encouraged by the defeat, Austria, Prussia, and several minor powers joined Russia, Britain, and Spain in a Sixth Coalition and began a campaign against France. The Sixth Coalition defeated Napoleon at Leipzig in October 1813. The allies then invaded France on two fronts: the Russians, Austrians, and Prussians invaded France from the east, while the British, Spanish, and Portuguese invaded France from the west. Coalition troops captured Paris in March 1814, forced Napoleon to abdicate in April, exiled him to the island of Elba, and restored power to the Bourbons. Napoleon escaped exile in February 1815 and reassumed control of France for around one hundred days, igniting the eponymous conflict. The allies formed the Seventh Coalition, which defeated him at Waterloo in June 1815 and exiled him to Saint Helena, where he died in 1821. The wars had profound consequences on history. New methods of warfare were introduced, including mass conscription and guerrilla warfare. Politically, the wars greatly influenced Europe through the advancements in civil law brought about by the Napoleonic Code, which was largely retained where it was adopted, and the spread of nationalism and liberalism. Independence movements emerged in Spanish America as a direct consequence of the wars, leading to the decline of the Spanish and Portuguese Empires.
==== MeSH D06.472.910 – thymus hormones ==== MeSH D06.472.910.750 – thymic factor, circulating MeSH D06.472.910.800 – thymopoietins MeSH D06.472.910.800.850 – thymopentin MeSH D06.472.910.850 – thymosin
== Effect on investment, sales and profit == According to Thomson Reuters in their 2012 publication "The Economic Power of Orphan Drugs", there has been increased investment in orphan drug research and development, partly due to the U.S. Orphan Drug Act of 1983 (ODA) and similar acts in other regions of the world driven by "high-profile philanthropic funding". According to a 2012 article in Drug Discovery Today, the years 2001 to 2011 were the "most productive period in the history of orphan drug development, in terms of average annual orphan drug designations and orphan drug approvals". For the same decade the compound annual growth rate (CAGR) of the orphan drugs was an "impressive 25.8%, compared to only 20.1% for a matched control group of non-orphan drugs". By 2012, the market for orphan drugs was worth US$637 million, compared with US$638 million for a control group of non-orphan drugs. By 2012,
Sources: en.wikipedia.org
Intensity-fading MALDI is a term coined to rename an existing method originally reported in 1999 to indirectly study a Protein–protein interaction or other protein complex and was the same year applied to a biological mixture to study the antigenicity of the influenza virus. It involves treating a protein and a potential binding partner with a site-specific endoproteinase with the binding sites identified by their reduced area (or intensity) in a MALDI mass spectrum compared to that of non-bound protein control. It was falsely reported as new and novel in a later application by a Spanish group. The true origins of the approach and a range of applications including those employing gel based separations, drug-protein interactions and the relative affinity of such interactions, are described in a review article.
5-MAPB, also known as 5-(N-methyl-2-aminopropyl)benzofuran, as well as by nicknames such as "MDMA 2.0" and "Gas Station Molly", is an entactogen of the phenethylamine, amphetamine, and benzofuran families related to MDMA ("Ecstasy"). It is an analogue of MDMA in which one of the oxygen atoms of the benzodioxole ring has been replaced with a carbon atom. The drug is said to have the closest-known effects to MDMA of any other MDMA analogue, but is said to be less stimulating in comparison and to have less comedown and hangover. In addition, it is more potent than MDMA and has a longer duration. The drug acts as a serotonin–norepinephrine–dopamine releasing agent (SNDRA) similarly to MDMA. It is also an agonist of several serotonin receptors, including the serotonin 5-HT1B, 5-HT2A, 5-HT2B, and 5-HT2C receptors. Some notable analogues of 5-MAPB besides MDMA include other benzofurans like 5-APB, 5-MAPDB, and 6-MAPB. 5-MAPB was first encountered as a novel designer drug in 2013 and was described in the scientific literature in 2014. It is said to have been first synthesized in 2009. The drug has been patented by Tactogen for potential use as a medicine to treat psychiatric disorders. It is openly sold as a legal recreational drug in the United States. In addition to its use by itself, 5-MAPB is used as a component of the more closely MDMA-mimicking Borax combo.
Obesity is a chronic health problem. It is one of the biggest factors for type II diabetes and cardiovascular disease. It is also associated with cancer (e.g., colorectal cancer), osteoarthritis, liver disease, sleep apnea, depression, and other medical conditions that affect mortality and morbidity. According to NHANES data, African American and Mexican American adolescents between 12 and 19 years old are more likely to be overweight than non-Hispanic White adolescents. The prevalence is 21%, 23% and 14% respectively. Also, in a national survey of American Indian children 5–18 years old, 39 percent were found to be overweight or at risk for being overweight. As per national survey data, these trends indicate that by 2030, 86.3% of adults will be overweight or obese and 51.1% obese. A 2007 study found that long-term participation in the Supplemental Nutrition Assistance Program was associated with a 50% increased obesity rate among female adults. Looking at the long-term consequences, overweight adolescents have a 70 percent chance of becoming overweight or obese adults, which increases to 80 percent if one or both parents are overweight or obese. In 2000, the total cost of obesity for children and adults in the United States was estimated to be US$117 billion (US$61 billion in direct medical costs). Given existing trends, this amount is projected to range from US$860.7–956.9 billion in healthcare costs by 2030. Food consumption has increased over time.
=== Two-dimensional chromatography === Two-dimensional chromatography represents the most thorough and rigorous approach to evaluation of the proteome. While previously accepted approaches have utilized elution mode chromatographic approaches such as cation exchange to reversed phase HPLC, yields are typically very low requiring analytical sensitivities in the picomolar to femtomolar range. As displacement chromatography offers the advantage of concentration of trace components, two dimensional chromatography utilizing displacement rather than elution mode in the upstream chromatography step represents a potentially powerful tool for analysis of trace components, modifications, and identification of minor expressed components of the proteome.
The induced fit concept cannot be used to rationalize catalysis. That is, the chemical catalysis is defined as the reduction of Ea‡ (when the system is already in the ES‡) relative to Ea‡ in the uncatalyzed reaction in water (without the enzyme). The induced fit only suggests that the barrier is lower in the closed form of the enzyme but does not tell us what the reason for the barrier reduction is. Induced fit may be beneficial to the fidelity of molecular recognition in the presence of competition and noise via the conformational proofreading mechanism. However, the role of induced fit in controlling replication fidelity has been questioned and remains poorly defined. Experimental and theoretical analyses have suggested that induced fit alone does not provide a sufficient explanation for high replication fidelity.
Sources: en.wikipedia.org
In ion chromatography, the interaction of the solute ions and the stationary phase based on their charges determines which ions will bind and to what degree. When the stationary phase features positive groups which attracts anions, it is called an anion exchanger; when there are negative groups on the stationary phase, cations are attracted and it is a cation exchanger. The attraction between ions and stationary phase also depends on the resin, organic particles used as ion exchangers. Each resin features relative selectivity which varies based on the solute ions present who will compete to bind to the resin group on the stationary phase. The selectivity coefficient, the equivalent to the equilibrium constant, is determined via a ratio of the concentrations between the resin and each ion, however, the general trend is that ion exchangers prefer binding to the ion with a higher charge, smaller hydrated radius, and higher polarizability, or the ability for the electron cloud of an ion to be disrupted by other charges. Despite this selectivity, excess amounts of an ion with a lower selectivity introduced to the column would cause the lesser ion to bind more to the stationary phase as the selectivity coefficient allows fluctuations in the binding reaction that takes place during ion exchange chromatography. Following table shows the commonly used ion exchangers.
=== Antiquity === Ancient Babylonian texts describe symptoms resembling migraine, which were believed to be caused by supernatural forces and were treated using spiritual or religious practices. A description consistent with migraine is contained in the Ebers Papyrus, written around 1500 BCE in ancient Egypt. Trepanation, a surgical procedure involving drilling or scraping an opening into the skull, has been practiced since the Neolithic period, although there is little evidence that it was specifically used to treat headaches or migraine. During the Greco-Roman era, explanations for migraine shifted from supernatural beliefs to the theory of the four humors. Writings from the Hippocratic school of medicine described the visual aura that can precede headache and noted that vomiting could provide partial relief. Headaches were thought to result from an imbalance of these bodily fluids. A description by Aretaeus of Cappadocia classified headaches into cephalalgia, cephalea, and heterocrania, while Galen of Pergamon adapted this latter term to produce "hemicrania", from which the modern word migraine is derived. He proposed that the pain arose from the meninges and blood vessels of the head. The mystical visions described by Hildegard von Bingen as "reflections of the living light", have been interpreted by some scholars as being consistent with the visual aura experienced during migraine attacks.
In some countries, the black soldier fly, Hermetia illucens, is used to process food industry by-products and food waste. Hermetia illucens is a facultative necrophage and can grow on a wide range of decomposing organic substrates including those of animal origin (e.g. abattoir waste), plant origin (e.g. almond hulls), and a mix of both (e.g. meat, fish and vegetable food waste). Fly larvae are grown on this organic waste and then used as livestock feed or fish feed. The frass generated by the larvae can be used as soil fertilizer too. This waste conversion process, known as bioconversion, has several advantages. It reduces the greenhouse gas emissions caused by microbial decomposition of food waste in landfills (e.g. methane), it generates high-quality protein for feeding livestock, and it generates low-cost fertilizer for crop cultivation.
The AI Cold War heralds a new world order in geopolitics, according to Hemant Taneja and Fareed Zakaria. This new world order is a departure from the unipolar system dominated by the US. It is characterized by existence of two parallel digital ecosystems, ran by China and the US. In order to succeed countries that consider themselves as democracies are to align their technological ecosystems to that of the US, in a process labelled re-globalization. As of July 2026, the world is now divided into two camps on the Artificial Intelligence (AI) alliance viz., the Pax Silica led by the USA and the World Artificial Intelligence Cooperation Organization (WAICO) led by China.
Sources: en.wikipedia.org
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase liquid chromatography establishes purity, while mass spectrometry confirms molecular mass. The two techniques are normally used together. Retention time alone is not sufficient evidence of identity.
Different counterions change the mass per unit of peptide and can shift chromatographic behavior. Two samples of equal stated purity may therefore not be directly comparable. Reports should specify the counterion whenever quantitative comparisons are made.
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.