The short version of neurotrophic signaling fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-06-14. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| 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 |
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.
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.
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.
"Alsos Digital Library for Nuclear Issues – Plutonium". Washington and Lee University. Archived from the original on February 3, 2009. Retrieved February 15, 2009. Sutcliffe, W. G.; et al. (1995). "A Perspective on the Dangers of Plutonium". Lawrence Livermore National Laboratory. Archived from the original on September 29, 2006. "Physical, Nuclear, and Chemical, Properties of Plutonium". IEER. 2005. Retrieved February 15, 2009. "A History of Plutonium". Los Alamos National Laboratory. Retrieved July 8, 2023. Bhadeshia, H. "Plutonium crystallography". Samuels, D. (2005). "End of the Plutonium Age". Discover Magazine. 26 (11). Pike, J.; Sherman, R. (2000). "Plutonium production". Federation of American Scientists. Archived from the original on February 3, 2009. Retrieved February 15, 2009. "Plutonium Manufacture and Fabrication". Ong, C. (1999). "World Plutonium Inventories". Nuclear Files.org. Archived from the original on August 5, 2014. Retrieved February 15, 2009. "Challenges in Plutonium Science". Los Alamos Science. I & II (26). 2000. Retrieved February 15, 2009. "Plutonium". Royal Society of Chemistry. Retrieved February 6, 2015. "Plutonium". The Periodic Table of Videos. University of Nottingham. Retrieved February 6, 2015. Plutonium Fuel Fabrication by Argonne National Laboratory on YouTube
The European Renaissance brought expanded interest in both empirical natural history and physiology. In 1543, Andreas Vesalius inaugurated the modern era of Western medicine with his seminal human anatomy treatise De humani corporis fabrica, which was based on dissection of corpses. Vesalius was the first in a series of anatomists who gradually replaced scholasticism with empiricism in physiology and medicine, relying on first-hand experience rather than authority and abstract reasoning. Via herbalism, medicine was also indirectly the source of renewed empiricism in the study of plants. Otto Brunfels, Hieronymus Bock and Leonhart Fuchs wrote extensively on wild plants, the beginning of a nature-based approach to the full range of plant life. Bestiaries—a genre that combines both the natural and figurative knowledge of animals—also became more sophisticated, especially with the work of William Turner, Pierre Belon, Guillaume Rondelet, Conrad Gessner, and Ulisse Aldrovandi. Artists such as Albrecht Dürer and Leonardo da Vinci, often working with naturalists, were also interested in the bodies of animals and humans, studying physiology in detail and contributing to the growth of anatomical knowledge. The traditions of alchemy and natural magic, especially in the work of Paracelsus, also laid claim to knowledge of the living world. Alchemists subjected organic matter to chemical analysis and experimented liberally with both biological and mineral pharmacology.
==== 5α-DHP subpathway ==== The pathway from progesterone (P4) to DHT is similar to that described above from 17OHP to DHT, but the initial substrate for 5α-reductase is P4 rather than 17OHP. Placental P4 in the male fetus is the feedstock, that is, a starting point, the initial substrate, for the backdoor pathway found operating in multiple non-gonadal tissues. The first step in this pathway is 5α-reduction of P4 toward 5α-dihydroprogesterone (5α-DHP) by SRD5A1. 5α-DHP is then converted to allopregnanolone (AlloP5) via 3α-reduction by AKR1C2 or AKR1C4. AlloP5 is then converted to 5α-Pdiol by the 17α-hydroxylase activity of CYP17A1. 5α-Pdiol is also known as 17α-hydroxyallopregnanolone or 17OH-allopregnanolone. 5α-Pdiol is then converted to 5α-androstan-3α-ol-17-one, also known as androsterone (AST) by 17,20-lyase activity of CYP17A1 which cleaves a side-chain (C17-C20 bond) from the steroid nucleus, converting a C21 steroid (a pregnane) to a C19 steroid (an androstane or androgen). AST is 17β-reduced to 5α-androstane-3α,17β-diol (3α-diol) by HSD17B3 or AKR1C3. The final step is 3α-oxidation of 3α-diol in target tissues to DHT by an enzyme that has 3α-hydroxysteroid oxidase activity, such as AKR1C2, HSD17B6, HSD17B10, RDH16, RDH5, and DHRS9. This oxidation is not required in the classical androgen pathway. The pathway can be summarized as: P4 → 5α-DHP → AlloP5 → 5α-Pdiol → AST → 3α-diol → DHT.
Plants respond to injury by signalling that damage has occurred, by secreting materials to seal off the damaged area, by producing antimicrobials to limit the spread of pathogens, and in some woody plants by regrowing over the wound.
=== 2018–present === On January 9, 2018, construction workers broke ground on a new 5,100 square foot (470 m2) wound healing center at the hospital, it would be double the size of the old facility. The wound healing center was completed at the end of 2018 and included six treatment rooms, three hyperbaric chambers, waiting area and a lobby. On May 22, 2019, AdventHealth signed a definitive agreement to purchase Lake Wales Medical Center from Community Health Systems. On September 1, AdventHealth took over the management of Lake Wales Medical Center, it had purchased the hospital for $10,146,000 and renamed it AdventHealth Lake Wales. On January 1, 2021, all hospitals were required to have their chargemaster on its website by the Centers for Medicare & Medicaid Services. In early February, 2023, almost all of the AdventHealth hospitals had their chargemaster on their website, including AdventHealth Lake Wales.
Sources: en.wikipedia.org
Nike, Inc announces it will sell "limited quantities" of a replica goalkeeper shirt worn by England goalkeeper Mary Earps during the 2023 Women's World Cup after around 150,000 people signed an online petition calling for them to be made available. A police officer is taken to hospital with critical injuries after being hit by a train while trying to help a distressed man on the railway track in Nottinghamshire. 25 August – Hartwig Fischer announces he will step down as director of the British Museum after treasures were stolen from the London institution. 26 August – Two people are killed after driving a car into a flooded road in the Mossley Hill area of Liverpool. 27 August – The Metropolitan Police launch an investigation into a possible data breach involving details about thousands of their officers after "unauthorised access" was gained to the system of one of its suppliers. 29 August – Nottinghamshire Police officer Sgt Graham Saville, 46, who was struck by a train while trying to help a distressed man on the railway track, dies in hospital from injuries sustained in the incident. London's Ultra Low Emission Zone is expanded to include the whole of Greater London. 30 August – England's Autumn 2023 flu vaccination and COVID-19 booster programme is brought forward by a month, from October to September, as scientists from the UK Health Security Agency monitor the BA.2.86 variant. Although it is not a variant of concern, it is being monitored due to its high number of mutations.
== The Chemical Basis of Growth and Senescence (1923) == In between 1916 and 1920 Robertson published a series of 16 papers in the Journal of Biological Chemistry under the title Experimental Studies on Growth. The papers became the foundation of his (1923) textbook, The Chemical Basis of Growth and Senescence (BR.39): a work that examined the "self-accelerated" natural processes of growth and aging in plants, animals, and humans (as they were understood at that time). Using mathematical principles, Robertson employed an S-Curve (a.k.a. 'sigmoid curve') (p.5) to demonstrate both the "autokinetic phase" of a "self-accelerated" growth process, "during which the rate of growth is continuously increasing" (p.4), and its "autostatic phase", "during which the rate of growth is decreasing" (p.4). Drawing an analogy to the autocatalyzed chemical reactions of Wilhelm Ostwald (father of his Berkeley colleague Wolfgang Ostwald), Robertson referred to these "self-accelerated" processes as being "autocatalyzed" (p.6). As Lee and Hanson observed (in 1947), "[Robertson's] theory of autocatalytic control over growth ... has been variously rejected, acknowledged and accepted by investigators" (RL.1, p.53).
=== Municipal politics (2025–2026) === On September 17, 2025, Findlay became the advisory board chair of the Conservative Electors Association, a newly formed municipal party in British Columbia. Her role was to help with candidate recruitment and policy development. In February 2026, Findlay was involved in a launch event for the Conservative Electors Association, where they announced the slate of candidates for the 2026 Surrey municipal election.
Media related to Bananas and plantains as food at Wikimedia Commons Musapedia: "The banana knowledge compendium", maintained by ProMusa CGIAR's RTB Research Program Banana Page Banana and Plantain at the International Institute of Tropical Agriculture (IITA)
The classic triad of EDMD consists of early contractures, muscle weakness, and heart involvement, typically manifesting in adolescence. Contractures often manifest before weakness, and they can be more disabling. They tend to fix the elbow into flexion and ankle into plantarflexion via Achilles tendon shortening. The spine is also affected, with limited neck flexion initially, and eventually the entire spine can become fixed into extension, referred to as a rigid spine. Elbow and neck contractures seldom occur in other diseases. Eventually, orthopedics (walker, cane) may be needed. The weakness is slowly progressive and preferentially involves the muscles that overlie the humerus bone (biceps and triceps muscles) and those situated on the outside of the lower leg (peroneal). Later, the muscles that position the scapula can be weakened, completing a pattern that is termed 'scapulohumeroperoneal'. Weakness of the scapular fixators can cause a winged scapula, which can impair the ability to lift the arms over the head and can be painful. Weakness of the peroneal muscles can result in toe walking, which can present in the first decade of life. Facial, hand, and thigh muscles can be affected, although less often. Calf hypertrophy can occur. Involvement of the heart occurs in almost all cases, presenting as syncope in the second or third decades, or as sudden cardiac death. A multitude of cardiac arrhythmias can result, requiring a pacemaker often by age 30 years.
Sources: en.wikipedia.org
A later investigation by the aircraft manufacturer stated it was an accident; Noriega's authority over the government investigation led to speculation about his involvement. Florencio Flores Aguilar had inherited Torrijos's position, but true power lay with the trio of Noriega, Díaz Herrera, and Rubén Darío Paredes, who ranked just below him. Flores was removed in a quiet coup on March 3, 1982. By general agreement, Paredes was made leader until 1983, after which the military would work together to ensure his election as the president in the election scheduled for 1984. During this period Noriega became a full colonel and the National Guard's chief of staff, effectively the second-highest rank in the country. He reformed the National Guard as the Panama Defense Forces (PDF), and with the financial assistance of the U.S., expanded and modernized it. The quick promotions they received earned him the officer corps' loyalty. Among the steps he took to consolidate his control was to bring the various factions of the army together into the PDF. On August 12, 1983, in keeping with Noriega's earlier deal with Paredes, Paredes handed over his position to Noriega, newly appointed a general, with the understanding that Noriega would allow him to stand for president. However, Paredes never received the political support he expected, and after assuming his new position Noriega reneged on the deal, telling Paredes he could not contest the election. Noriega, now head of the PDF, thus became the de facto ruler of Panama.
== Further reading == Bishop, Michael; Duben-Engelkirk, Janet L., and Fody, Edward P. (1992). "Chapter 19, Liver Function, Clinical Chemistry Principles, Procedures, Correlations, 2nd Ed." Philadelphia, J.B. Lippincott Company. Miyabara, Yuichi; Tabata, Masako; Suzuki, Junzo; Suzuki, Shizuo (1992). "Separation and sensitive determination of i-urobilin and 1-stercobilin by high-performance liquid chromatography with fluorimetric detection". Journal of Chromatography B: Biomedical Sciences and Applications. 574 (2): 261–265. doi:10.1016/0378-4347(92)80038-R. PMID 1618958. Miyabara, Y.; Sakata, Y.; Suzuki, J.; Suzuki, S. (1994). "Estimation of faecal pollution based on the amounts of urobilins in urban rivers". Environmental Pollution. 84 (2): 117–122. doi:10.1016/0269-7491(94)90093-0. PMID 15091706. Munson-Ringsrud, Karen and Jorgenson-Linné, Jean (1995). "Urinalysis and Body Fluids, a ColorText and Atlas." St. Louis, Mosby. Nelson, L.; David, Cox M.M. (2005). “Chapter 22 – Biosynthesis of Amino Acids, Nucleotides, and Related Molecules”, pp. 856, In Lehninger Principles of Biochemistry. Freeman, New York. pp. 856. Voet, Donald; Voet, Judith G.; Pratt, Charlotte W. (2018-01-23). Voet's Principles of Biochemistry, Global Edition, 5th Edition. Wiley. p. 1200. ISBN 978-1-119-45166-2. Retrieved 2024-02-01.
=== Train of four ratio test === The train of four ratio (i.e., ToFr) is a neuromuscular test for monitoring neuromuscular function (see monitoring neuromuscular blockade). In this test, a peripheral nerve (most commonly the ulnar nerve) is stimulated by an electrical impulse 4 times (i.e., T1, T2, T3, T4) and the strength of contraction is measured in a muscle(s) (i.e., the abductor pollicis longus and brevis muscles for the ulnar nerve). The ratio of the amplitude of muscle contraction in response to the fourth impulse (T4) divided by the amplitude of muscle contraction in response to the first impulse is calculated. The ratio of these two contractions should be 1.0. Values less than this are regarded as abnormal. ToFr is used to determine when the effects of an administered neuromuscular-blocking drug have worn off (see postoperative residual curarization) or as the most objective, accurate, and sensitive test for determining the presence and severity of myasthenia gravis: myasthenia gravis is considered to afflict the tested muscle if its ToFr ratio (i.e., T4/T1) is less than 0.9.
1993/1130) Dundee Teaching Hospitals National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1131) Caithness and Sutherland National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1132) Southern General Hospital National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1133) Stirling Royal Infirmary National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1134) Victoria Infirmary National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1135) West Lothian National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1136) Yorkhill National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1137) North Ayrshire and Arran National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1138) Monklands and Bellshill Hospitals National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1139) Ayrshire and Arran Community Health Care National Health Service Trust (Appointment of Trustees) Order 1993 (S.I. 1993/1140) Essex and Greater London (County and London Borough Boundaries) Order 1993 (S.I. 1993/1141) Croydon, Lambeth and Southwark (London Borough Boundaries) Order 1993 (S.I. 1993/1147) Greater London and Surrey (County and London Borough Boundaries) Order 1993 (S.I. 1993/1148) Coast Protection (Variation of Excluded Waters) Regulations 1993 (S.I. 1993/1149) Income-related Benefits Schemes (Miscellaneous Amendments) (No. 2) Regulations 1993 (S.I.
Kendall was elected to the United States National Academy of Sciences in 1950, and both the American Academy of Arts and Sciences and the American Philosophical Society in 1951. Kendall's career at Mayo ended in 1951, when he reached mandatory retirement age. He moved on to Princeton University, where he was a visiting professor in the Department of Biochemistry. He remained affiliated with Princeton until his death in 1972. In addition to the Nobel Prize, Kendall received other major awards including the Lasker Award, the Passano Foundation Award and the Cameron Prize for Therapeutics of the University of Edinburgh. Kendall received the Golden Plate Award of the American Academy of Achievement in 1966. He was awarded honorary doctorates from the University of Cincinnati, Western Reserve University, Williams College, Yale University, Columbia University, National University of Ireland, and Gustavus Adolphus College.
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.
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.