This is a working overview of shelf life, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-02-28. Anything still debated is marked as such rather than presented as settled.
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.
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.
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 |
|---|---|---|
| Purity assay | RP-HPLC, UV 214 nm | Typical research grade 95 percent or higher |
| Mass confirmation | ESI-MS or MALDI-TOF | Compared with theoretical value |
| Main degradation route | Methionine oxidation | Sulfoxide formation in solution |
| Powder storage | -20 °C, desiccated | Amber vial, minimal headspace |
| Working solution | Sterile water or saline | Prepare fresh; avoid repeated thawing |
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.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
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.
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.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
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。
A connective tissue nevus is a skin lesion which may be present at birth or appear within the first few years of life. It is elevated, soft to firm in consistency, varying in size from 0.5 to several centimeters in diameter, and may manifest as grouped, linear, or irregularly-distributed lesions.
CB2 receptors are predominantly found in the immune system or immune-derived cells, with varying expression patterns. A subpopulation of microglia in the human cerebellum expresses CB2. CB2 receptors are linked to immunomodulatory effects and potential therapeutic benefits in animal models.
In May 2023, Ajinomoto signed a letter of intent for a strategic alliance with Solar Foods, a company that developed Solein, a microbial protein feeding on CO2 as a nutrient source, and obtained a marketing license in Singapore. In November 2023, Ajinomoto acquired US-based Forge Biologics for $620 million. In September 2024, Ajinomoto entered into a global strategic partnership with Danone to reduce greenhouse gas emissions from Danone’s raw milk supply chain. In the same year, through joint research with Professor Chinatsu Kasamatsu (Project Professor) of the Institute for SDGs Promotion at Ochanomizu University in Japan, Ajinomoto became the first in the world to develop a new concept of 'electric seasoning,' which adjusts the taste of food using transdermal electrical stimulation. In March 2025, Ajinomoto decided to participate as a partner in the 'Demonstration Survey for the Restoration Model of Degraded Agricultural Land in Brazil,' a project under the Japan-Brazil Green Partnership Initiative promoted by the governments of Japan and Brazil. In April 2025, Ajinomoto was selected by CDP, an international environmental not-for-profit charity, for its "Climate Change A-List" for fiscal 2024. This is the fifth consecutive year that Ajinomoto has been selected for the A-list.
=== For diagnostics === The original goal for paper-based microfluidics (μPAD) was to make low-cost and user-friendly point-of-care (POC) devices that can be operated without the assistance of medical personnel or any other qualified specialist in resource-limited and rural areas. To achieve this goal, μPAD should fit the "Affordable, Sensitive, Specific, User-friendly, Rapid and robust, Equipment-free, Deliver" criteria, provided by the World Health Organization (WHO), which are the requirements for diagnostic testing for resource-constrained settings. However, in POC's official "Guide to aid the selection of diagnostic tests", it is stated that these criteria are generic and can be modified according to test application. The main problem of paper-based microfluidic diagnostics is that research in this field is directed on providing new concepts and ideas rather than on improving user acceptance and as a result, most μPAD devices are still unable to be interpreted by non-professional users. However, POC is not the only application of paper-based microfluidics for diagnostics. Recently, a paper was employed in the production of more complicated microfluidic analytical devices, called lab-on-a-chip (LOC) devices, which are also used in diagnostics. Using paper to make LOC devices instead of polydimethylsiloxane (PDMS) and glass can decrease cost and size while increasing portability. This allows LOC devices to become more accessible in resource-limited conditions.
The territory of the Viceroyalty of New Granada became the Republic of Colombia, organized as a union of the current territories of Colombia, Panama, Ecuador, Venezuela, parts of Guyana and Brazil and north of Marañón River. The Congress of Cúcuta in 1821 adopted a constitution for the new Republic. Simón Bolívar became the first President of Colombia, and Francisco de Paula Santander was made Vice President. However, the new republic was unstable and the Gran Colombia ultimately collapsed. Modern Colombia comes from one of the countries that emerged after the dissolution of Gran Colombia, the other two being Ecuador and Venezuela. Colombia was the first constitutional government in South America, and the Liberal and Conservative parties, founded in 1848 and 1849, respectively, are two of the oldest surviving political parties in the Americas. Slavery was abolished in the country in 1851. Internal political and territorial divisions led to the dissolution of Gran Colombia in 1830. The so-called "Department of Cundinamarca" adopted the name "New Granada", which it kept until 1858 when it became the "Confederación Granadina" (Granadine Confederation). After a two-year civil war in 1863, the United States of Colombia was created, which became known as the Republic of Colombia in 1886.
Sources: en.wikipedia.org
== Air Force career == John Chain had a wide and varied military career, serving in a number of powerful positions. He accrued over 5,000 flying hours (including 400 combat hours) in more than 45 different military aircraft. He is a master parachutist with 66 jumps, and has been awarded the Air Force Distinguished Service Medal, the Legion of Merit, the Distinguished Flying Cross, and the Bronze Star. Chain was commissioned as a second lieutenant through the Air Force Reserve Officer Training Corps program. He received his pilot wings in 1957 and then entered combat crew training. From 1958 to 1959 the general was an F-100 Super Sabre pilot at Toul-Rosières Air Base in France, and from 1959 to 1962 at Ramstein Air Base in West Germany. General Chain then served as a flight examiner at Cannon Air Force Base, New Mexico. In 1964 he was assigned as a forward air controller in Fort Campbell, Kentucky. While there he became a master parachutist and flew Army O-1s and Air National Guard F-84 Thunderjets. In 1966 Chain flew combat missions while assigned to Tan Son Nhut Air Base in South Vietnam. He then transferred to Washington, D.C. From 1969 to 1970, Chain was an exchange officer with the U.S. Department of State. He entered the National War College in 1970 and upon graduation was assigned to Davis-Monthan Air Force Base in Arizona as deputy commander for operations. In 1972 he became deputy commander for logistics. In 1972 and 1973, Chain flew combat missions in F-4 Phantoms from Korat Royal Thai Air Force Base in Thailand.
=== Scientific research === Liquid argon is used as the target for neutrino experiments and direct dark matter searches. The interaction between the hypothetical WIMPs and an argon nucleus produces scintillation light that is detected by photomultiplier tubes. Two-phase detectors containing argon gas are used to detect the ionized electrons produced during the WIMP–nucleus scattering. As with most other liquefied noble gases, argon has a high scintillation light yield (about 51 photons/keV), is transparent to its own scintillation light, and is relatively easy to purify. Compared to xenon, argon is cheaper and has a distinct scintillation time profile, which allows the separation of electronic recoils from nuclear recoils. On the other hand, its intrinsic beta-ray background is larger due to 39Ar contamination, unless one uses argon from underground sources, which has much less 39Ar contamination. Most of the argon in Earth's atmosphere was produced by electron capture of long-lived 40K (40K + e− → 40Ar + ν) present in natural potassium within Earth. The 39Ar activity in the atmosphere is maintained by cosmogenic production through the knockout reaction 40Ar(n,2n)39Ar and similar reactions. The half-life of 39Ar is only 269 years. As a result, the underground Ar, shielded by rock and water, has much less 39Ar contamination. Dark-matter detectors currently operating with liquid argon include DarkSide, WArP, ArDM, microCLEAN and DEAP.
Similarly, the vast majority of Brazilian electricity is derived from renewable sources: 83% compared to 25% worldwide. The leading sources are hydraulic energy at 64.9%; biomass, 8.4%; wind, 8.6%; solar, 1%; natural gas, 9.3%; oil products, 2%; nuclear, 2.5%; and coal and derivatives, 3.3%. Brazil has the largest electricity sector in Latin America; its capacity at the end of 2021 was 181,532 MW. The Brazilian government has embarked on a program over the decades to reduce dependence on imported oil, which previously accounted for more than 70% of the country's oil needs. Brazil became self-sufficient in oil in 2006–2007. By the end of 2021, the country was the seventh largest oil producer in the world, with an average of nearly three million barrels per day, and became an exporter of the product.
An appeal was issued to the workers of the other East European countries, urging them to follow in the footsteps of Solidarity. To the Soviets, the gathering was an "anti-socialist and anti-Soviet orgy" and the Polish communist leaders, increasingly led by Jaruzelski and General Czesław Kiszczak, were ready to apply force. In October 1981, Jaruzelski was named first secretary of the PZPR. The Plenum's vote was 180 to 4, and he kept his government posts. Jaruzelski asked parliament to ban strikes and allow him to exercise extraordinary powers, but when neither request was granted, he decided to proceed with his plans anyway.
Glucose is a sugar with the molecular formula C6H12O6. It is the most abundant monosaccharide, a subcategory of carbohydrates. It is made from water and carbon dioxide during photosynthesis by plants and most algae. It is used by plants to make cellulose, the most abundant carbohydrate in the world, for use in cell walls, and by all living organisms to make adenosine triphosphate (ATP), which is used by the cell as energy. Glucose is often abbreviated as Glc. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as amylose and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form is d-glucose, while its stereoisomer l-glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Glucose is naturally occurring and is found in its free state in fruits and other parts of plants. In animals, it is released from the breakdown of glycogen in a process known as glycogenolysis. Glucose, as intravenous sugar solution, is on the World Health Organization's List of Essential Medicines. It is also on the list in combination with sodium chloride (table salt). The name glucose is derived from Ancient Greek γλεῦκος (gleûkos) 'wine, must', from γλυκύς (glykýs) 'sweet'.
Sources: en.wikipedia.org
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.
The main chemical risks are methionine oxidation and backbone hydrolysis in solution. Moisture and repeated temperature cycling accelerate both processes. Dry powder held cold and desiccated is considerably more stable than any reconstituted preparation.
It holds a medicine registration in Russia, where it has been used clinically for decades. In most other countries it is treated as a research chemical. That split explains the uneven distribution of clinical literature.
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.