neurotrophic factor 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 2026-01-06 and is reviewed periodically as new material appears.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
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.
| Property | Value | Notes |
|---|---|---|
| Primary research models | Rodent studies | Largest share of published data |
| Reported markers | BDNF and NGF expression | Measured mainly in animal tissue |
| Common administration | Intranasal | Matches the registered formulation |
| Blood residence time | Minutes | Rapid enzymatic degradation |
| Evidence quality | Small trials, limited replication | Noted repeatedly in reviews |
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
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.
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.
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.
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。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
The poly-Pro I helix is much denser than the PPII helix due to the cis isomers of its peptide bonds. It is also rarer than the PPII conformation because the cis isomer is higher in energy than the trans. Its typical dihedral angles (-75°, 160°) are close, but not identical to, those of the PPII helix. However, the PPI helix is a right-handed helix and more tightly wound, with roughly 3.3 residues per turn (rather than 3). The rise per residue in the PPI helix is also much smaller, roughly 1.9 Å. Again, there is no internal hydrogen bonding in the poly-Pro I helix, both because an H-bond donor atom is lacking and because the amide nitrogen and oxygen atoms are too distant (roughly 3.8 Å again) and oriented incorrectly.
Evidence for the important role antithrombin plays in regulating normal blood coagulation is demonstrated by the correlation between inherited or acquired antithrombin deficiencies and an increased risk of any affected individual developing thrombotic disease. Antithrombin deficiency generally comes to light when a patient suffers recurrent venous thrombosis and pulmonary embolism.
aureus, it is suggested by many public health institutions, including the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), to treat first with empirical therapies for S. aureus, with an emphasis on evaluating the response to initial treatment and laboratory diagnostic techniques to isolate cases of drug resistance. Due to the possibility of potential severe or fatal consequences of resistant strains, initial treatment often includes concomitant administration of multiple antimicrobial agents that are not known to show cross-resistance, so as to reduce the possibility of a resistant strain remaining inadequately treated by a single agent during the evaluation of drug response. Once a specific resistance profile has been isolated via clinical laboratory findings, treatment is often modified as indicated. Vancomycin has long been considered a drug of last resort, due to its efficiency in treating multiple drug-resistant infectious agents and the requirement for intravenous administration. Recently, resistance to even vancomycin has been shown in some strains of S. aureus (sometimes referred to as vancomycin resistant S. aureus (VRSA) or vancomycin intermediate-resistance S. aureus (VISA)), often coinciding with methicillin/penicillin resistance, prompting the inclusion of newer antibiotics, such as linezolid, that have shown efficacy in highly drug-resistant strains. There are also strains of enterococci that have developed resistance to vancomycin, referred to as vancomycin resistant enterococcus (VRE).
== Structure == Convulxin is a heterodimer made up of α-(13.9 kDa) and β- (12.6 kDa) subunits, with 38% sequence identity and homologous structures. The subunits are connected by disulfide bridges to form a cyclic, ring-like α4β4 structure . Its function arises from its ability to bind with high affinity to the platelet receptor for collagen, glycoprotein (GP) VI. It is, therefore, an important task to determine the binding site on the heterodimer to the GPVI. The heterodimer structure presents a concave surface, predicted to be the ligand binding site. Furthermore, general research into the C-type lectin family describes the binding site as being formed by loop regions, falling between the second α-helix and the second β-strand on both the α- and β-subunits. Investigating the particular sequences of these structures showed high variability, suggesting that it is indeed these variable, concave loops that offer specificity in ligand binding. Analysis on the specific Cvx structure has revealed 3 possible sites of interaction with GPVI. Firstly, two adjacent patches of positive and negative charge on the α-subunit; secondly, a cavity in the same subunit lines with the following residues:Trp23, Ser67, Leu104, Ala117, Gly121 and Ile123; finally, a negatively charged patch on the β-subunit.
2024 – David Perlman Memorial Award, American Chemical Society, Biochemical Technology. 2024 – Founder Award, Kendall Square Association. 2024 – American Association for Cancer Research Academy, Fellow. 2023 – Australian Academy of Technological Science & Engineering, Fellow. 2021 – Outstanding Scientist Award, AAISCR Cancer Research Annual Meeting. 2019 – Honorary Degree, DSc (Medicine) University of London – Institute Cancer Research. 2017 – Catalyst Award, Science Club for Girls. 2017 – Innovation at the Intersection Award, Xconomy Awards, Biotech Week Boston. 2017 – Honorary Degree, Doctorate Utrecht University, the Netherlands. 2017 – AIMBE STEM Award, American Institute for Medical and Biological Engineering. 2015 – 20th Heinz Award for Technology, Heinz Family Foundation. 2015 – American Academy of Arts and Sciences, Fellow. 2014 – Lemelson-MIT Prize, Lemelson-MIT Program. 2014 – Pioneers of Miniaturization Prize, Lab on a Chip Lectureship at MicroTAS. 2011 – Massachusetts Academy of Sciences, Fellow. 2011 – Biomedical Engineering Society, Fellow. 2011 – Brown Engineering Alumni Medal, Brown University School of Engineering. 2011 – Thomas A. McMahon Mentoring Award, MIT, Health Sciences & Technology. 2010 – John J. and Dorothy Wilson Professor, MIT, HST & EECS, Endowed Chair. 2010 – Young Investigator Award, American College of Clinical Pharmacology. 2009 – American Society for Clinical Investigation, Fellow. 2005 – American Institute for Medical and Biological Engineering, Fellow. 2003 – Y.C. Fung Young Investigator Award, American Society of Mechanical Engineers.
Sources: en.wikipedia.org
== Drawbacks == Acromegaly patients, who suffer from natural growth hormone levels of up to 100 times higher than normal, have lower stamina towards physical activity than people with regular levels. When the patients are treated and their growth hormone levels decrease, their stamina improves. This knowledge is part of the evidence behind the new belief that athletes who use supplemental HGH to raise their levels far above average could actually decrease their exercise tolerance, and thus hurt their athletic performance. Further backing was provided in a study done by the Danish Institute of Sports Medicine. They found cyclists of good health and endurance "were unable to complete accustomed cycling tasks after administration of exogenous hGH" and concluded that HGH can inhibit recuperation from exercise. Participants have also been found to have lower stamina after HGH treatment along with higher rates of fatigue. Although adverse side effects can result from excessive doses, typical GH therapy has few side effects and those have likely been overstated due to the excessive amounts administered in earlier studies.
Hahn remained modest and informal all his life. His disarming frankness, unfailing kindness, good common sense, and impish humour will be remembered by his many friends all over the world. The Royal Society in London wrote in an obituary:
=== Bitcoin's theoretical roots and ideology === According to the European Central Bank, the decentralization of money offered by bitcoin has its theoretical roots in the Austrian school of economics, especially with Friedrich Hayek's The Denationalisation of Money, in which he advocates a complete free market in the production, distribution and management of money to end the monopoly of central banks. Sociologist Nigel Dodd argues that the essence of the bitcoin ideology is to remove money from social, as well as governmental, control. The Economist describes bitcoin as "a techno-anarchist project to create an online version of cash, a way for people to transact without the possibility of interference from malicious governments or banks". These philosophical ideas initially attracted libertarians and anarchists.
For services to Library and Information Services in Wales. George Norman Wilson, Vice-Chairman, Peak Park Joint Planning Board, Peak District National Park. For services to Local Government. Monica Wilson. For services to disabled people. Primrose Eileen Wilson. For services to Conservation. Anthony Webbe Winkle. For services to the Construction Industry in Scotland. Samuel Derek Woods. For public service. Diplomatic Service and Overseas List Norma Alice Cox Astwood, Vice-President, The Senate, Bermuda. David John Franklin Burton, Director, British Council, Jordan. The Honourable William McKeeva Bush, , Minister of Community Development, Sports, Women's and Youth Affairs and Culture, Cayman Islands. Alfred Chappory, . For services to sport in Gibraltar. Chen Din-hwa. For charitable and community services in Hong Kong. Joan Collins. For services to drama. Michael John Cooper, Principal, British School in the Netherlands. William Montgomerie Courtauld. For services to British commercial interests in Hong Kong. Thomas Eddie Cowin, lately Director, British Council, Ghana. Anthony Campbell Crombie, Deputy Head of Mission, Belgrade. Christopher Tom Franklin. For services to British musical interests in France. Robert John Gladwell. For services to British commercial and aerospace interests in the United States of America. Stuart Wreford Harbinson, , Permanent Hong Kong Representative to the World Trade Organization, Geneva. Peter Anthony Jenner, lately Editor, NATO Review. Sarah Caroline Rowland Jones, , lately First Secretary, HM Embassy, Budapest. Masood Husain Khan.
== Early life and education == In 1974, Eaton graduated from Montana State University with a Bachelor of Science in Pre-Medical Sciences. Under the guidance of Curtis Klaassen and John Doull, he earned a Ph.D. in pharmacology and toxicology at the University of Kansas Medical Center in 1978. In 1979, he joined the faculty at the University of Washington after completing a postdoctoral fellowship in toxicology at the same institution after earning his Ph.D.
Sources: en.wikipedia.org
=== Class III: Cys-based PTPs === The third class of PTPs contains three cell cycle regulators, CDC25A, CDC25B and CDC25C, which dephosphorylate CDKs at their N-terminal, a reaction required to drive progression of the cell cycle. They are themselves regulated by phosphorylation and are degraded in response to DNA damage to prevent chromosomal abnormalities.
=== Legal status === Levomethadone is listed under the Single Convention On Narcotic Drugs 1961 and is a Schedule II Narcotic controlled substance in the US as an isomer of methadone (ACSCN 9250) and is not listed separately, nor is dextromethadone. It is similarly controlled under the German Betäubungsmittelgesetz and similar laws in practically every other country.
==== Lieutenant of the Royal Victorian Order (LVO) ==== Hamish Blair, Senior Executive Officer, Scottish Office. Captain Robert Neil Blair, Royal Navy, Private Secretary to The Duke of York and to Princess Alexandra, the Honourable Lady Ogilvy. Laurence Albert Brown. For services to the Royal Collection. Donald Reeve Buttress, Surveyor of the Fabric, Westminster Abbey. Bernard Joseph Frahm, . For services to the Crown on Royal Visits to New Zealand. Commander Thomas Dixon Laidlaw, , Metropolitan Police. Leonora Mary, The Countess of Lichfield, Extra Lady in Waiting to The Princess Royal. Allan Arthur Percival, lately Press Secretary to The Prince of Wales. Alexander Hay Sutherland, Chief Publicity Officer, Scottish Office.
Larger doses do not appear to increase risks in this population. A broader retrospective study found that the rate of hyperkalemia in gender-diverse individuals is correlated with age, with those above 45 years old being more at risk. The finding suggests that patients below or at 45 years old without other conditions that affect potassium handling can be spared from routine monitoring.
A coffee bean is a seed from the Coffea plant and the source for coffee. This fruit is often referred to as a coffee cherry, but unlike the cherry, which usually contains a single pit, it most commonly contains two seeds with their flat sides together. The seeds are referred to as beans because of their appearance, though they are not true beans. A few coffee cherries, referred to as "peaberries" contain a single seed; they make up around 10% to 15% of all coffee beans. It is often claimed that peaberries are superior to normal beans, but there is little hard evidence to support this. Like Brazil nuts (a seed) and white rice, coffee beans consist mostly of endosperm. The two most economically important varieties of coffee plants are the arabica and the robusta, accounting for approximately 60% and 40% of the coffee produced worldwide, respectively. Arabica beans contain 0.8–1.4% caffeine and robusta beans contain 1.7–4.0% caffeine. As coffee is one of the world's most widely consumed beverages, coffee beans are a major cash crop and an important export product, accounting for over 50% of some developing nations' foreign exchange earnings. In 2023 the largest producer of coffee and coffee beans was Brazil. Other main exporters of coffee beans are Colombia, Vietnam, and Ethiopia.
Sources: en.wikipedia.org
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.
The compound is registered as a medicine in Russia, so clinical work has concentrated there. Trials elsewhere are few and generally small. This geographic concentration is a recognized limitation in evidence reviews.
Some fraction may reach the central nervous system through olfactory pathways, and this is often cited as the rationale for the nasal route. The size of that fraction in humans is not well quantified. Blood concentrations after nasal dosing are low, which complicates measurement.
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.