neurotrophic factor comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-06-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
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。
== Further reading == Biot, René. (1962). The Enigma of the Stigmata. Hawthorn Books. Carroll, Robert Todd. (2003). Stigmata. In The Skeptic's Dictionary. Wiley. ISBN 978-0-471-27242-7 Harrison, Ted. (1994). Stigmata: A Medieval Phenomenon in a Modern Age. St Martins Press. ISBN 0-312-11372-2 Mazzoni, Cristina. (1996). Saint Hysteria: Neurosis, Mysticism, and Gender in European Culture. Cornell University Press. ISBN 0-8014-3229-4 Nickell, Joe. (1993). Looking for a Miracle: Weeping Icons, Relics, Stigmata, Visions & Healing Cures. Prometheus Books. ISBN 1-57392-680-9 Radford, Benjamin. (2014). What is Stigmata?. LiveScience. Retrieved 12 May 2016. Wilson, Ian. (1988). The Bleeding Mind: An Investigation into the Mysterious Phenomena of Stigmata. Weidenfeld & Nicolson. ISBN 0-297-79099-4 Yarom, Nitza. (1992). Body, Blood, and Sexuality: A Psychoanalytic Study of St. Francis' Stigmata and Their Historical Context. Peter Lang Publisher. Van Osselaer, Tina; Graus, Andrea; Rossi, Leonardo; Smeyers, Kristof (12 October 2020). The Devotion and Promotion of Stigmatics in Europe c. 1800–1950, between Saints and Celebrities (PDF). Numen Book Series-Studies in the History of Religions. Vol. 167. Leiden, Boston: Brill. p. 487. ISBN 978-90-04-43935-1. ISSN 0169-8834. LCCN 2020031449. Archived (PDF) from the original on September 9, 2021.
In electron capture, some proton-rich nuclides were found to capture their own atomic electrons instead of emitting positrons, and subsequently, these nuclides emit only a neutrino and a gamma ray from the excited nucleus (and often also Auger electrons and characteristic X-rays, as a result of the re-ordering of electrons to fill the place of the missing captured electron). These types of decay involve the nuclear capture of electrons or emission of electrons or positrons, and thus acts to move a nucleus toward the ratio of neutrons to protons that has the least energy for a given total number of nucleons. This consequently produces a more stable (lower energy) nucleus. A hypothetical process of positron capture, analogous to electron capture, is theoretically possible in antimatter atoms, but has not been observed, as complex antimatter atoms beyond antihelium are not experimentally available. Such a decay would require antimatter atoms at least as complex as beryllium-7, which is the lightest known isotope of normal matter to undergo decay by electron capture.
=== Skeleton === Sex hormones play an important role in bone growth and maintenance. The effects of hormone therapy on bone health are not fully understood, and may depend on whether hormone therapy is started before or after puberty. Bone density continue to grow and change over time. Significant changes to bone structure have been observed, and transgender women have statistically poorer bone health even before beginning the transition process, possibly due to a lack of physical exercise or other risk factors such as low vitamin D, eating disorders, and substance abuse. Approximately 14% of transgender women suffer from osteoporosis. Transgender women below the age of 50 show increased fracture risk compared to age-matched cisgender women, equal to the risk to cisgender men of equivalent age. Transgender women above the age of 50 have a similar fracture risk to post-menopausal women — higher than that of age-matched cis men. In both cases, trans women's fracture patterns follow that of cis women, suffering long-term stress fractures concentrated in the hip, spine, and arms, typical of chronic low bone mineral density, rather than the fracture patterns typical of external injury suffered by cis men. Current clinical guidelines are for bone health to be monitored regularly throughout the transition process, particularly if risk factors are present. Transgender individuals are encouraged to ingest at least 1g of Calcium and 1000 IU of Vitamin D daily, engage regularly in weight-bearing physical activity, and reduce alcohol and smoking consumption.
=== Civic Society === Bromley Civic Society is a civic society for the historic centre of Bromley. It is a founder member of Civic Voice. It seeks to educate the public about the community's history and to preserve historical sites.
Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold. The color has also led to the nicknames brass, brazzle, and brazil, primarily used to refer to pyrite found in coal.
Sources: en.wikipedia.org
tRNAs with modified anticodons and/or acceptor stems can be used to modify the genetic code. Scientists have successfully repurposed codons (sense and stop) to accept amino acids (natural and novel), for both initiation (see: start codon) and elongation. In 1990, tRNAfMet2CUA (modified from the tRNAfMet2CAU gene metY) was inserted into E. coli, causing it to initiate protein synthesis at the UAG stop codon, as long as it is preceded by a strong Shine-Dalgarno sequence. At initiation it not only inserts the traditional formylmethionine, but also formylglutamine, as glutamyl-tRNA synthase also recognizes the new tRNA. The experiment was repeated in 1993, now with an elongator tRNA modified to be recognized by the methionyl-tRNA formyltransferase. A similar result was obtained in Mycobacterium. Later experiments showed that the new tRNA was orthogonal to the regular AUG start codon showing no detectable off-target translation initiation events in a genomically recoded E. coli strain.
=== Aftermath === An informal memorial was held for Staley on the night of April 20, 2002, at the Seattle Center, which was attended by at least 100 fans and friends, including Alice in Chains bandmates Cantrell, Starr, Inez and Kinney, and Soundgarden frontman Chris Cornell. Staley's body was cremated and a private memorial service was held for him on April 28, 2002 at Kiana Lodge in Poulsbo, Washington. During her appearance on Celebrity Rehab in 2010, Staley's mother said she has kept his ashes in a box. Staley's private memorial was attended by his family and friends, along with his Alice in Chains bandmates, the band's manager Susan Silver and her then-husband Chris Cornell, as well as other music personalities. Chris Cornell, joined by Heart's Ann and Nancy Wilson, sang a rendition of The Rolling Stones' "Wild Horses" at the funeral. They also performed The Lovemongers' song "Sand". Jerry Cantrell dedicated his solo album, Degradation Trip, released two months after Staley's death, to his memory. Cantrell also took in Staley's cat, Sadie, who he and the family took care of until Sadie's death in 2010, at the age of 18. Shortly after Staley's death, his parents Nancy McCallum and Phil Staley started receiving donations from fans all over the world. Nancy and Phil worked with Seattle's Therapeutic Health Services clinic to create the Layne Staley Memorial Fund to help other heroin addicts and their families in the Seattle music community. Alice in Chains remained inactive following Staley's death.
== Early life == Brian Rafat Awadis was born on November 19, 1996 in San Diego, California, to immigrant Chaldo-Assyrian parents from Tel Keppe, Iraq. His father owns two stores. He graduated from Mira Mesa Senior High School and attended San Diego Miramar College before dropping out during his freshman year to pursue his YouTube career full-time. He can speak the Suret language, although not fluently.
In liquid chromatography-mass spectrometry (LC-MS), the GC is replaced with a liquid chromatograph. The main difference is that chemical derivatization is not necessary. Applications of LC-MS to MFA, however, are rare. In each case, MS instruments divide a particular isotopomer distribution by its molecular weight. All isotopomers of a particular metabolite that contain the same number of labeled carbon atoms are collected in one peak signal. Because every isotopomer contributes to exactly one peak in the MS spectrum, the percentage value can then be calculated for each peak, yielding the mass isotopomer fraction. For a metabolite with n carbon atoms, n+1 measurements are produced. After normalization, exactly n informative mass isotopomer quantities remain. The drawback to using MS techniques is that for gas chromatography, the sample must be prepared by chemical derivatization in order to obtain molecules with charge. There are numerous compounds used to derivatize samples. N,N-Dimethylformamide dimethyl acetal (DMFDMA) and N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) are two examples of compounds that have been used to derivatize amino acids. In addition, strong isotope effects observed affect the retention time of differently labeled isotopomers in the GC column. Overloading of the GC column also must be prevented. Lastly, the natural abundance of other atoms than carbon also leads to a disturbance in the mass isotopomer spectrum. For example, each oxygen atom in the molecule might also be present as a 17O isotope and as a 18O isotope.
Sporting leagues in Hong Kong include Hong Kong Premier League, Hong Kong Premiership (rugby union), Hong Kong A1 Division Championship, and the Hong Kong Ice Hockey League. Famous local sporting clubs include Hong Kong Football Club, South China Athletic Association, Kitchee SC, and Hong Kong Eastern. Hong Kong sports have been described as "Club Life". Some clubs have documented their history thoroughly, while others have disappeared along with their past.
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.