Everything below concerns peptide synthesis. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
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.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
acetylation The covalent attachment of an acetyl group (–COCH3) to a chemical compound, protein, or other biomolecule via an esterification reaction with acetic acid, either spontaneously or by enzymatic catalysis. Acetylation plays important roles in several metabolic pathways and in histone modification. Contrast deacetylation.
Similarly, in ships and yachts, marine sanitation devices use electricity to convert seawater into hypochlorous acid to disinfect macerated faecal waste before discharge into the sea. In deodorization, hypochlorous acid has been tested to remove up to 99% of foul odours, including garbage, rotten meat, toilet, stool, and urine odours.
=== Ion optics === Before mass separation, a beam of positive ions has to be extracted from the plasma and focused into the mass-analyzer. It is important to separate the ions from UV photons, energetic neutrals and from any solid particles that may have been carried into the instrument from the ICP. Traditionally, ICP-MS instruments have used transmitting ion lens arrangements for this purpose. Examples include the Einzel lens, the Barrel lens, Agilent's Omega Lens and Perkin-Elmer's Shadow Stop. Another approach is to use ion guides (quadrupoles, hexapoles, or octopoles) to guide the ions into mass analyzer along a path away from the trajectory of photons or neutral particles. Yet another approach is Varian patented used by Analytik Jena ICP-MS 90 degrees reflecting parabolic "Ion Mirror" optics, which are claimed to provide more efficient ion transport into the mass-analyzer, resulting in better sensitivity and reduced background. Analytik Jena ICP-MS PQMS is the most sensitive instrument on the market. A sector ICP-MS will commonly have four sections: an extraction acceleration region, steering lenses, an electrostatic sector and a magnetic sector. The first region takes ions from the plasma and accelerates them using a high voltage. The second uses may use a combination of parallel plates, rings, quadrupoles, hexapoles and octopoles to steer, shape and focus the beam so that the resulting peaks are symmetrical, flat topped and have high transmission.
He was a consistent performer in an inconsistent season for the Bombers, polling 16 Brownlow votes from a total of 43 received by Essendon players, including a three-vote game in his 100th AFL game, finishing equal-seventh in the 2010 Brownlow Medal count, and having the highest number of votes for a player from a team finishing outside the final eight. Watson was once again awarded the Crichton Medal, earning 291 points, which was 50 points clear of runner-up Heath Hocking. Watson had a relatively good season in 2011 despite missing six weeks with a hamstring injury, earning 15 Brownlow votes and finishing runner-up in the Crichton Medal, losing out to up-and-coming third-year midfielder David Zaharakis. Watson completed an outstanding 2012 season by winning the Brownlow Medal with 30 votes (though he was later ruled ineligible after being suspended during the Essendon Football Club supplements saga). Along with his third Crichton Medal, he also won a handful of other accolades, including the AFLPA best captain award, the Lou Richards Medal and selection in the 2012 All-Australian team as the centreman. Watson missed three weeks with a broken collarbone in 2013, but had another consistent season, earning 17 Brownlow votes, finishing runner-up in the Crichton Medal to former St Kilda utility (and later successor as captain) Brendon Goddard, and being named on the interchange in the 2013 All-Australian team. Between 2006 and 2013, Watson finished all but one season in the top two for votes for the Crichton Medal.
Sources: en.wikipedia.org
After rail services were extended to Dover in 1844, the Western Docks were used as a terminal for the Golden Arrow and other cross-channel train services with its own railway station, Dover Marine, later renamed Dover Western Docks. At Dover Marine station an estimated 5 million troops departed for the trenches of World War I and nearly 1.5 million wounded soldiers returned. In 1920 the remains of the Unknown Warrior were landed prior to transportation to London and a ceremonial interment at Westminster Abbey. Dover Marine railway station closed in 1994, later to be redeveloped into Cruise Terminal One. The Western Docks area was also used from 1968 to the early 2000s for a cross-channel hovercraft service run by Hoverspeed. Hoverspeed also ran catamaran services until being declared bankrupt in 2005. Another catamaran service was run from 2004 until November 2008 by the single ship of SpeedFerries, SpeedOne, with up to five services daily to Boulogne-sur-Mer. The hoverport has now been demolished and redeveloped as a cargo handling facility.
=== Early pumps === The predecessor to the vacuum pump was the suction pump. Dual-action suction pumps were found in the city of Pompeii. The Arab engineer Al-Jazari later described dual-action suction pumps as part of water-raising machines in the 13th century. He also said that a suction pump was used in siphons to discharge Greek fire. The suction pump later appeared in medieval Europe from the 15th century.
== Pathophysiology == Acanthosis nigricans results from activation of growth factor receptor pathways, most commonly insulin-mediated stimulation of insulin-like growth factor receptor on keratinocytes and fibroblasts. Hyperinsulinaemia may also displace IGF-1 from its binding proteins, amplifying epidermal proliferation. Contributing mechanisms include:
On 9 July, Thom took Florey and Heatley to Washington, D.C., to meet Percy Wells, the acting assistant chief of the USDA Bureau of Agricultural and Industrial Chemistry and as such the head of the USDA's four laboratories. Wells sent an introductory telegram to Orville May, the director of the UDSA's Northern Regional Research Laboratory (NRRL) in Peoria, Illinois. They met with May on 14 July, and he arranged for them to meet Robert D. Coghill, the chief of the NRRL's fermentation division, who raised the possibility that fermentation in large vessels might be the key to large-scale production. On 17 August, Florey met with Alfred Newton Richards, the chairman of the Committee for Medical Research (CMR) of the Office of Scientific Research and Development (OSRD), who promised his support. On 8 October, Richards held a meeting with representatives of four major pharmaceutical companies: Squibb, Merck, Pfizer and Lederle. Vannevar Bush, the director of OSRD was present, as was Thom, who represented the NRRL. Richards told them that antitrust laws would be suspended, allowing them to share information about penicillin. This was not legalized until 7 December 1943, and it covered only penicillin and no other drug. OSRD arranged with the War Production Board (WPB) for them to have priority for equipment for laboratories and pilot plants.
== Introduction == Unlike epithelial cells – which are stationary and characterized by an apico-basal polarity with binding by a basal lamina, tight junctions, gap junctions, adherent junctions and expression of cell-cell adhesion markers such as E-cadherin, mesenchymal cells do not make mature cell-cell contacts, can invade through the extracellular matrix, and express markers such as vimentin, fibronectin, N-cadherin, Twist, and Snail. MET plays also a critical role in metabolic switching and epigenetic modifications. In general, epithelium-associated genes are upregulated and mesenchyme-associated genes are downregulated in the process of MET.
Sources: en.wikipedia.org
For both existing and new customers, these costs of meeting AML/CFT obligations regularly outweigh the potential benefits for the financial institutions. Debanking affects commercial and personal users of financial institutions. A report by the FATF pointed out that access to financial services is essential for full participation in modern societies as well being a critical pre-condition for a well-functioning economy. If debanked, companies or individuals lose access to the financial system, making trade, investment, asset management and day-to-day activities difficult. The report noted that there had also been a growth in financial exclusion, due to debanking, amongst the poor, deprived groups, minorities, the elderly, the disabled and NPOs. There is no precise measurement of the full extent of the complex economic and social costs of regulation, including debanking, balanced against the scale of harms associated with money laundering, and given the evaluation problems involved in assessing such an issue, it is unlikely that the effectiveness of terror finance and money laundering laws could be determined with any degree of accuracy. Because of the intrinsic uncertainties of the amount of money laundered, changes in the amount of money laundered, and the cost of anti–money laundering systems, it is almost impossible to tell which anti–money laundering systems work and which are more or less cost effective.
Colin Pitchfork was arrested in 1987 and it was found that his DNA profile matched the semen samples from the murder. Because of this case, DNA databases were developed. There is the national (FBI) and international databases as well as the European countries (ENFSI: European Network of Forensic Science Institutes). These searchable databases are used to match crime scene DNA profiles to those already in a database.
=== Source 2, virtual reality and Half-Life: Alyx (2015–present) === Valve announced the Source 2 engine in March 2015, and ported Dota 2 to Source 2 in September. That year, Valve collaborated with the electronics company HTC to develop the HTC Vive, a VR headset released in 2016. Valve experimented with VR games, and in 2016 released The Lab, a collection of VR minigames. Valve recognized that many players wanted a more ambitious VR AAA game, and began exploring the development of a major VR game. They developed several prototypes, with three further VR projects under development by 2017. Finding that the portal systems of its puzzle series Portal were disorienting in VR, it settled on Half-Life. Walker said that Half-Life 3 had been a "terrifyingly daunting prospect", and the team saw VR as a way to return to the series. Full development of a VR Half-Life game started around late 2016, with the largest team in Valve's history. Valve acquired the 3D audio software developer Impulsonic in January 2017. In April 2018, Valve acquired the independent developer Campo Santo, known for the 2016 adventure game Firewatch. Campo Santo planned to develop its own games under Valve, though it initially helped develop Half-Life: Alyx. In November 2018, Valve released Artifact, a digital collectible card game based on Dota 2, with design by Richard Garfield, the creator of Magic: The Gathering. Artifact had unusual pay-for mechanics to acquire new cards, and did not draw a large playerbase, losing 95% of players months after release.
=== Treatment approach === Any interventions done are matched with the needs of each individual in an ethical and respected manner. Health belief model encourages increasing individuals' perceived susceptibility to negative health outcomes and making individuals aware of the severity of such negative health behavior outcomes. E.g. through health promotion messages. In addition, the health belief model suggests the need to focus on the benefits of health behaviors and the fact that barriers to action are easily overcome. The theory of planned behavior suggests using persuasive messages for tackling behavioral beliefs to increase the readiness to perform a behavior, called intentions. The theory of planned behavior advocates the need to tackle normative beliefs and control beliefs in any attempt to change behavior. Challenging the normative beliefs is not enough but to follow through the intention with self-efficacy from individual's mastery in problem solving and task completion is important to bring about a positive change. Self efficacy is often cemented through standard persuasive techniques.
Sources: en.wikipedia.org
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.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.