The short version of Neurotrophic signalling fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | ≥ 95 % of peak area by HPLC | Some suppliers quote 98 % or higher |
| Identity confirmation | Mass spectrometry (electrospray or MALDI) | Observed mass is compared with the calculated mass |
| Common analytical method | Reversed-phase HPLC on a C18 column | Acetonitrile and water gradients with trifluoroacetic acid |
| Primary degradation route | Oxidation of the methionine residue | Yields a sulfoxide that separates cleanly on chromatography |
| Storage of dissolved material | Aliquoted and frozen at −20 °C or below | Single-use aliquots avoid repeated temperature cycling |
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.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
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.
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.
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.
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.
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.
=== Microneedle vaccines === A microneedle approach, which is still in stages of development, uses "pointed projections fabricated into arrays that can create vaccine delivery pathways through the skin".
== Awards == 2023 Tung-Ho Outstanding Research Award, THS Foundation 2023 16th Taiwan Outstanding Women in Science Awards, Wu Chien Shiung Education Foundation & L'ORÉAL Taiwan 2022 Outstanding Research Award, National Science and Technology Council 2022 Outstanding Research Award, National Science and Technology Council 2021 National Innovation Award 2020 Taiwan Society for Mass Spectrometry Medal 2011 Taiwan Society for Mass Spectrometry Outstanding Scholar Award 2007 Federation of Asian Chemical Societies Distinguished Young Chemists Award 2006 Chinese Chemical Society Outstanding Young Investigator Award
Gearbox went on to develop Blue Shift, Half-Life's second expansion pack. Like Opposing Force, Blue Shift was published by Sierra Entertainment. Announced in 2000, the game was initially developed as a bonus campaign for the Dreamcast port of Half-Life; however, the port was cancelled and Blue Shift was instead released for Windows on June 12, 2001. Blue Shift puts the player in the position of Barney Calhoun, a security guard working at Black Mesa. The game takes place within the early parts of Half-Life, with Calhoun attempting to escape the facility with a small group of scientists. Blue Shift also includes a High Definition pack, which upgrades the quality of the models and textures in Blue Shift as well as Half-Life, Opposing Force, and Team Fortress. Critics praised the atmosphere and new graphics, but noticed the lack of new content and short length.
Sources: en.wikipedia.org
=== Load carrying equipment === 1937 pattern web equipment - Used until the early 1960s, in limited use with Territorial Army and other second-line troops until the mid to late 1970s. 1944 pattern web equipment - Used in tropical conditions 1958 pattern web equipment - Used from the late 1950s until the early 1990s Personal Load Carrying Equipment - Trialled from the mid-1980s to the late 1980s, adopted by the (very) late 1980s
Colin Ayton Greenhalgh, Principal, Hills Road Sixth Form College, Cambridge. For services to Education. Ian Gregg, Chairman, River Tweed Commissioners and Tweed Foundation. For services to Salmon and Trout Fishing. Vernon Charles Grove, Administrator, Wales and Chester Circuit, Lord Chancellor's Department. Rex Farrow Gyngell, . For political and public service. Arthur Barry Haines, Chair, Aerodynamics Group, Royal Aeronautical Society. For services to Aerodynamics. Eunice Hanna. For political service. Lieutenant Colonel Grattan Herbert Hart, . For services to the Royal British Legion in Sussex. Robert James Hasson, Assistant Controller (Collection and Personnel), Board of Inland Revenue. Anthony Roger Heath. For services to the Administration of Justice. Jennifer Mary Toresen, Lady Hemingford. For services to the community in Hemingford Abbots, Cambridgeshire and to the British Red Cross Society. Desmond Charles Henley, Embalmer. For services in the Aftermath of Disasters. Damon Graham Hill. For services to Motor Racing. John William Hoaen, Grade 7, Department of Trade and Industry. Margaret Edith Hobrough, Principal and Chief Executive, Godalming Sixth Form College, Surrey. For services to Education. Brigadier David Hendry Hodge, . For services to the Territorial Auxiliary and Volunteer Reserve Association in the North of England. The Reverend Roger Graham Holloway. For services to Export. John Hood. For services to Industry. John Trevor Hopkins, Headmaster, Bishop Stopford School, Kettering, Northamptonshire. For services to Education.
As such, it is far more suitable for men for whom long-term medication is being chosen. Mineralcortocoid receptor antagonists (MRA) as a class (including spironolactone, canerenone, eplerenone and finerenone) are cornerstones of heart failure with reduced ejection fraction (HFrEF EF≤40%) management, however, the comparative magnitude of effect on mortality between agents remains uncertain. Primarily, evidence explores spironolactone and eplerenone, with limited comparative data available for canerenone. Furthermore, there is limited evidence for benefit of finerenone in a HFrEF patient cohort, a newer agent recently licensed for the treatment of chronic kidney disease (CKD) in type 2 diabetes mellitus.
=== Risk in adding too much === Nitrogen supplements, particularly DAP, stimulates yeast reproduction and can greatly increase the biomass. This could have the consequence of speeding up the fermentation rate faster than what a winemaker may desire and will also increase the fermentation temperature due to the heat being generated by the yeast. The excess biomass can also create a scarcity of other yeast nutrients, such a vitamins and sterols, due to increase competition and may lead to the production of off-odors (such as hydrogen sulfide) and even stuck fermentations. Excessive levels of the amino acid arginine (greater than 400 mg/L), especially near the end of fermentation, can pose the risk increase the production of ethyl carbamate. This is because arginine gets broken down into urea which can be reabsorbed and utilized by yeast or metabolized into ammonia. However, urea also reacts with ethanol if it is not completely metabolized which coupled with long term exposure (as well as high temperatures) can lead to the production of the ester ethyl carbamate.
Sources: en.wikipedia.org
== Types == Originally, seven such proteins were discovered. Of these, six (BMP2 through BMP7) belong to the Transforming growth factor beta superfamily of proteins. BMP1 is a metalloprotease. Since then, thirteen more BMPs, all of which are in the TGF-beta family, have been discovered, bringing the total to twenty. The current nomenclature only recognizes 13, as many others are put under the growth differentiation factor naming instead.
Concept had a remake by Felix Wankel, a self-taught tightness specialist, never had an engineer diploma, neither a driver's license, for the Torpedo engine Jumo KM-8. Itala (company) succeeded in a different type of Rotary Valve. In Britain, the National Engine Company Ltd advertised its rotary valve engine for use in early aircraft, at a time when poppet valves were prone to failure by sticking or burning. In the end of 1930s, Frank Aspin developed a design with a rotary valve that rotated on the same axis as the cylinder bore, but with limited success. US company Coates International Ltd has developed a spherical rotary valve for internal combustion engines which replaces the poppet valve system. This particular design is four-stroke, with the rotary valves operated by overhead shafts in lieu of overhead camshafts (i.e. in line with a bank of cylinders). The first sale of such an engine was part of a natural gas engine-generator. Rotary valves are potentially highly suitable for high-revving engines, such as those used in racing sportscars and F1 racing cars, on which traditional poppet valves with springs can fail due to valve float and spring resonance and where the desmodromic valve gear is too heavy, large in size and too complex to time and design properly. Rotary valves could allow for a more compact and lightweight cylinder head design. They rotate at half engine speed (or one quarter) and lack the inertia forces of reciprocating valve mechanisms. This allows for higher engine speeds, offering approximately perhaps 10% more power.
=== 10 April === Three people, including a 14-year-old child, were killed in a Russian airstrike in Lyptsi, Kharkiv Oblast. Six people, including a 10-year-old child, were killed in a Russian airstrike in Odesa. In Russia, the governor of Kursk Oblast claimed that three people, including two children were killed in a Ukrainian drone strike on a car in Korenevsky District. The Ukrainian military claimed that a Russian Ka-27 helicopter was destroyed in disputed circumstances over Chornomorske, Crimea. On the same day, the Russian Defence Ministry said that an Mi-24 helicopter crashed due to possible equipment failure off the Crimean coast. The SBU arrested a former city councilor of Bakhmut on suspicion of collaboration with Russia. The US Department of Defense sold Ukraine $138 million in spare parts to maintain and upgrade its HAWK missile systems. Germany announced a new aid package to Ukraine that included 6,000 rounds of 155 mm shells, a mine clearing tank, small arms and some one million bullets.
Sources: en.wikipedia.org
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.
The methionine residue at the start of the chain is vulnerable to oxidation, producing a sulfoxide variant. Amide bonds can also hydrolyze, though more slowly under neutral conditions. Cold storage, oxygen exclusion and minimization of freeze-thaw cycles slow both processes but do not stop them.
A purity number on a certificate does not establish that a powder is the same product as a registered nasal medicine. Counter-ion content, residual solvents and peptide-related impurities may differ between the two. Independent verification is the only way to narrow that gap.
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.