Everything below concerns synthetic heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-06-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
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.
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.
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.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
== Culture == Most of the district's news media has been either weekly or monthly publications. The earliest newspaper was the Scarborough News and Advertiser which was published weekly starting in September 1921, which lasted until the 1930s. Other short-lived papers and magazines included The Enterprise (1945–1966), Scarborough Mail (1946–1955) and The News (1952–1996) and 54east magazine (2005–2009). The last remaining English-language local newspaper was the Scarborough Mirror, which started publication in 1962 and was later acquired by the Toronto Star's community news division, Metroland. In 2023, it became an online-only publication as part of Toronto.com. A Scarborough edition of the Toronto-wide photography publication SNAP Scarborough was launched in 2009. Ming Pao Daily News is a Chinese-language newspaper whose headquarters is in the district. They started publication in 1993. In 1961, the CTV Toronto (CFTO) television channel began operating from the 9 Channel Nine Court studios at the intersection of McCowan Road and Highway 401. Today, the studio also is the headquarters of The Sports Network (TSN). Both companies produce programming at the studio. In 1970, Trillium Cable started to provide cable TV service to Scarborough. It was purchased by Shaw Cable in 1995; but later swapped with Rogers Cable in 2001. During the early days of the company, they produced several local shows for their own cable channel. These shows were produced by volunteers and showed a wide variation in quality. These shows were satirized by Mike Myers in his comedy film Wayne's World.
The basement membrane is visible under light microscopy. Electron microscopy shows that the basement membrane consists of three layers: the lamina lucida (electron-lucent), lamina densa (electron-dense), and lamina fibro-reticularis (electron-lucent). The lamina densa was formerly called the “basal lamina”. The terms “basal lamina” and “basement membrane” were often used interchangeably, until it was realised that all three layers seen with the electron microscope constituted the single layer seen with the light microscope. This has led to considerable terminological confusion; if used, the term “basal lamina” should be confined to its meaning as lamina densa. Some theorize that the lamina lucida is an artifact created when preparing the tissue, and that the lamina lucida is therefore equal to the lamina densa in vivo. The term "basal lamina" is usually used with electron microscopy, while the term "basement membrane" is usually used with light microscopy. Examples of basement membranes include:
== Life and work == Magati was born in Scandiano, Reggio Emilia, in the landed family of Giorgio and Laura Mattacoda. A brother, Giovanni Battista, became a physician while a sister became the grandmother of Antonio Vallisneri. He studied at Pauda and from 1596, medicine at the University of Bologna. Graduating in 1597 he worked at the Hospital of Santa Maria della Consolazione in Rome. He was influenced by the teachings of Flaminio Rota, Giulio Cesare Claudini, and Giovanni Battista Cortese. He then took the exam of the College of Physicians and became a surgeon at the Hospital of Santa Anna. He then returned to Scandiano and around 1612, through the influence of Marquis Enzio Bentivoglio, he became a lecturer in surgery at Ferrara. In 1618 he became very ill and gave up teaching. He joined the Capuchin order as a lay brother in 1618 and took his vows in Ravenna the next year, and going by the name of Padre Liberato da Scandiano. He continued to practice medicine for the House of Este. In 1647 Magati was operated on for gall-stones at Bologna but he died three days after the surgery. Magati's major contribution was in wound hygiene and healing. He went against the contemporary practice of frequent change in dressing and the use of ointments. He instead suggested that natural processed played a key role in healing and that these processes needed to be aided. For this he is remembered as a fundamental reformer of surgery.
Although many natural toxins are secondary metabolites, these poisons also include peptides and proteins. An example of a toxic peptide is alpha-amanitin, which is found in relatives of the death cap mushroom. This is a potent enzyme inhibitor, in this case preventing the RNA polymerase II enzyme from transcribing DNA. The algal toxin microcystin is also a peptide and is an inhibitor of protein phosphatases. This toxin can contaminate water supplies after algal blooms and is a known carcinogen that can also cause acute liver haemorrhage and death at higher doses. Proteins can also be natural poisons or antinutrients, such as the trypsin inhibitors (discussed in the "metabolic regulation" section above) that are found in some legumes. A less common class of toxins are toxic enzymes: these act as irreversible inhibitors of their target enzymes and work by chemically modifying their substrate enzymes. An example is ricin, an extremely potent protein toxin found in castor oil beans. This enzyme is a glycosidase that inactivates ribosomes. Since ricin is a catalytic irreversible inhibitor, this allows just a single molecule of ricin to kill a cell.
As for second-hand smoke, the NIH study points to the large amount of smoke generated by one cigar, saying "cigars can contribute substantial amounts of tobacco smoke to the indoor environment; and, when large numbers of cigar smokers congregate in a cigar smoking event, the amount of passive smoke produced is sufficient to be a health concern for those regularly required to work in those environments". Smoking also tends to increase blood cholesterol levels. Furthermore, the ratio of high-density lipoprotein (HDL, commonly referred to as "good" cholesterol) to low-density lipoprotein (LDL, "bad" cholesterol) tends to be lower in smokers compared to non-smokers. Smoking also raises the levels of fibrinogen and increases platelet production (both involved in blood clotting), which makes the blood thicker and more likely to clot. Carbon monoxide binds to hemoglobin (the component carrying the oxygen in red blood cells), resulting in a much more stable complex than hemoglobin bound with oxygen or carbon dioxide and therefore permanent loss of blood cell functionality. Blood cells are naturally recycled after a certain period, allowing for the creation of new, functional red blood cells. However, if carbon monoxide exposure reaches a certain point before it can be recycled, hypoxia (and later death) occurs. All these factors make smokers more at risk of developing various forms of arteriosclerosis (hardening of the arteries).
Sources: en.wikipedia.org
=== Mechanism === RIP causes G:C to A:T transition mutations within repeats, however, the mechanism that detects the repeated sequences is unknown. RID is the only known protein essential for RIP. It is a DNA methyltransferease-like protein, that when mutated or knocked out results in loss of RIP. Deletion of the rid homolog in Aspergillus nidulans, dmtA, results in loss of fertility while deletion of the rid homolog in Ascobolus immersens, masc1, results in fertility defects and loss of methylation induced premeiotically (MIP).
From 1899 to 1901 the six separate self-governing colonies in Australia sent contingents to serve in the war. That much of the population had originated from Britain explains a desire to support it. After the colonies formed the Commonwealth of Australia in 1901, the new Government of Australia sent "Commonwealth" contingents to the war. The Boer War was thus the first war in which the Commonwealth of Australia fought. A few Australians fought on the Boer side. The most famous and colourful character was Colonel Arthur Alfred Lynch, formerly of Ballarat, Victoria, who raised the Second Irish Brigade. The Australian climate and geography were far closer to that of South Africa than most other parts of the empire, so Australians adapted quickly, with troops serving mostly among the army's "mounted rifles". Enlistment in official Australian contingents totalled 16,463. Another five to seven thousand Australians served in "irregular" regiments raised in South Africa. Perhaps 500 Australian irregulars were killed. In total about 20,000 Australians served and about 1,000 were killed. 267 died from disease, 251 were killed in action or from wounds sustained in battle; 43 men were reported missing. When the war began some Australians, like some Britons, opposed it. As the war dragged on some Australians became disenchanted, in part because of the sufferings of Boer civilians reported in the press.
Cultivation of microorganisms does not require fertile soil and therefore does not compete with agriculture. Thanks to the low water requirements, SCP cultivation can even be done in dry climates with infertile soil and may provide a means of fail-safe food supply in arid countries. Photosynthetic microorganisms can reach a higher solar-energy-conversion efficiency than plants, because in photobioreactors supply of water, CO2 and a balanced light distribution can be tightly controlled. Unlike agricultural products which are processed towards a desired quality, it is easier with microorganisms to direct production towards a desired quality. Instead of extracting amino acids from soy beans and throwing away half of the plant body in the process, microorganisms can be genetically modified to overproduce or even secrete a particular amino acid. However, in order to keep a good consumer acceptance, it is usually easier to obtain similar results by screening for microorganisms which already have the desired trait or train them via selective adaptation. Although SCP shows very attractive features as a nutrient for humans, however there are some problems that deter its adoption on global basis:
The Goths were expanding towards the Lower Danube from the 230s, forcing the native peoples to flee to the Roman Empire or to accept their suzerainty. The Goths' rule ended abruptly when the Huns invaded their territory in 376, causing new waves of migrations. The Huns forced the remnants of the local population into submission, but their empire collapsed in 454. The Gepids took possession of the former Dacia province. Place names that are of Slavic origin abound in Romania, indicating that a significant Slavic-speaking population lived in the territory. The first Slavic groups settled in Moldavia and Wallachia in the 6th century, in Transylvania around 600. The nomadic Avars defeated the Gepids and established a powerful empire around 570. The Bulgars, who also came from the European Pontic steppe, occupied the Lower Danube region in 680.
Sources: en.wikipedia.org
== Causes == The cause of biliary atresia in most infants is not fully understood and it is well possible that a number of factors may play a role, but especially maternal rotavirus infection during pregnancy and subsequent transmission of the virus to the child resulting in infection of the biliary epithelium and subsequent occluding fibrosis may be important in this respect. Some cases may relate to infection with other viruses such as SARS-CoV-2, hepatotropic virus reovirus 3, or congenital cytomegalovirus. In addition, autoimmune processes may contribute to pathogenesis in some cases as well. However, with regard to these alternative causation the experimental evidence remains rather weak.
== External links == Processing Radioactive Materials - large set of images by the IAEA showing automated package labelling and tracking for shipment of hazardous radioactive pharmaceuticals. FDA Compliance Policy Guides - CPG Sec. 450.500 Tamper-Resistant Packaging Requirements for Certain Over-the-Counter Human Drug Products
With the exception of biopharmaceuticals, which are manufactured by only a few selected fine chemical companies, the technology toolboxes of all these companies are similar. This means that they can carry out practically all types of chemical reactions. They differentiate on the basis of the breadth and quality of the service offering.
Sources: en.wikipedia.org
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.