melanocortin signalling is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
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.
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.
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
=== FastPP === In fast parallel proteolysis the researcher adds a thermostable protease (thermolysin) and takes out samples in parallel upon heating in a thermal gradient cycler. Optionally, for instance for proteins expressed at low levels, a western blot is then run to determine at what temperature a protein becomes degraded. For pure or highly enriched proteins, direct SDS-PAGE detection is possible facilitating Commassie-fluorescence based direct quantification. FastPP exploits that proteins become increasingly susceptible to proteolysis when unfolded and that thermolysin cleaves at hydrophobic residues which are typically found in the core of proteins. To reduce the workload, western blots could be replaced by SDS-PAGE gel polyhistidine-tag staining, provided that the protein has such a tag and is expressed in adequate amounts. FastPP can be used on unpurified, complex mixtures of proteins and proteins fused with other proteins, such as GST or GFP, as long as the sequence that is the target of the western blot, e.g., His-tag, is directly linked to the protein of interest. However, commercially available thermolysin is dependent on calcium ions for activity and denatures itself just above 85 degrees Celsius. So calcium must be present and calcium chelators absent in the buffer - other compounds that interfere with the function (such as high concentrations of detergents) of the protease could also be problematic. FASTpp has also been used to monitor binding-coupled folding of intrinsically disordered proteins (IDPs).
== Ecology == Like most Bacilli, the most common ecosystem of Bacillus cereus is the soil. In concert with arbuscular mycorrhiza (and Rhizobium leguminosarum in clover), they can up-regulate plant growth in heavy metal soils by decreasing heavy metal concentrations via bioaccumulation and biotransformation in addition to increasing phosphorus, nitrogen, and potassium uptake in certain plants. B. cereus was also shown to aid in survival of earthworms in heavy metal soils resulting from the use of metal-based fungicides, showing increases in biomass, reproduction and reproductive viability, and a decrease in metal content of tissues in those inoculated with the bacterium. These results suggest strong possibilities for its application in ecological bioremediation. Evidence of bioremediation potential by Bacillus cereus was also found in the aquatic ecosystem, where organic nitrogen and phosphorus wastes polluting a eutrophic lake were broken down in the presence of B. cereus. In a study measuring the ability of B. cereus to degrade keratin in chicken feathers, bacteria were found to sufficiently biodegrade keratin via hydrolytic mechanisms. These results indicate its potential to degrade keratinous waste from the poultry industry for potential recycling of the byproducts. B. cereus competes with Gram-negative bacteria species such as Salmonella and Campylobacter in the gut; its presence reduces the number of Gram-negative bacteria, specifically via antibiotic activity via enzymes such as cereins that impede their quorum sensing ability and exhibit bactericidal activity.
=== Liver damage === Naltrexone has been reported to cause liver damage when given at doses higher than recommended. Due to these reports, some physicians may check liver function tests before starting naltrexone, and periodically thereafter. Concerns for liver toxicity initially arose from a study of nonaddicted obese patients receiving 300 mg of naltrexone. Subsequent studies have suggested limited or no toxicity in other patient populations and at typical recommended doses such as 50 to 100 mg/day.
In June 2021, Biden took his first trip abroad as president, visiting Belgium, Switzerland, and the United Kingdom. He attended a G7 summit, a NATO summit, and an EU summit, and held one-on-one talks with Russian president Vladimir Putin. In September 2021, Biden announced AUKUS, a defense pact between Australia, the United Kingdom and the United States, to ensure "peace and stability in the Indo-Pacific". In February 2021, the Biden administration announced that the United States was ending its support for the Saudi-led bombing campaign in Yemen and revoked the designation of Yemen's Houthis as terrorists. In early February 2022, Biden ordered the counterterrorism raid in northern Syria that resulted in the death of Abu Ibrahim al-Hashimi al-Qurashi, the second leader of the Islamic State. In late July, Biden approved the drone strike that killed Ayman al-Zawahiri, the second leader of Al-Qaeda, and an integral member in the planning of the September 11 attacks. The 2022 OPEC+ oil production cut caused a diplomatic spat with Saudi Arabia, threatening a longstanding alliance. In August 2024, Biden negotiated and oversaw the 2024 Ankara prisoner exchange, the largest prisoner exchange since the end of the Cold War. It involved the release of 26 people, including journalist Evan Gershkovich and former Marine Paul Whelan. In November 2024, the Biden administration announced that it had helped broker a ceasefire agreement in the Israel–Hezbollah conflict.
Sources: en.wikipedia.org
=== Pharmacokinetics === Desloratadine is well absorbed from the gut and reaches highest blood plasma concentrations after about three hours. In the bloodstream, 83 to 87% of the substance are bound to plasma proteins. Desloratadine is metabolized to 3-hydroxydesloratadine in a three-step sequence in normal metabolizers. First, N-glucuronidation of desloratadine by UGT2B10; then, 3-hydroxylation of desloratadine N-glucuronide by CYP2C8; and finally, a non-enzymatic deconjugation of 3-hydroxydesloratadine N-glucuronide. Both desloratadine and 3-hydroxydesloratadine are eliminated via urine and feces with a half-life of 27 hours in normal metabolizers.
In nuclear physics, the Geiger–Nuttall law or Geiger–Nuttall rule relates the decay constant of a radioactive isotope with the energy of the alpha particles emitted. Roughly speaking, it states that short-lived isotopes emit more energetic alpha particles than long-lived ones. The relationship also shows that half-lives are exponentially dependent on decay energy, so that very large changes in half-life make comparatively small differences in decay energy, and thus alpha particle energy. In practice, this means that alpha particles from all alpha-emitting isotopes across many orders of magnitude of difference in half-life, all nevertheless have about the same decay energy. Formulated in 1911 by Hans Geiger and John Mitchell Nuttall as a relation between the decay constant and the range of alpha particles in air, in its modern form the Geiger–Nuttall law is
14-3-3 proteins play an isoform-specific role in class switch recombination. They are believed to interact with the protein activation-induced cytidine deaminase in mediating class switch recombination. Phosphorylation of Cdc25C by CDS1 and CHEK1 creates a binding site for the 14-3-3 family of phosphoserine binding proteins. Binding of 14-3-3 has little effect on Cdc25C activity, and it is believed that 14-3-3 regulates Cdc25C by sequestering it to the cytoplasm, thereby preventing the interactions with CycB-Cdk1 that are localized to the nucleus at the G2/M transition. The eta isoform, YWHAH, is reported to be a biomarker (in synovial fluid) for rheumatoid arthritis. In a systematic review, 14-3-3η has been described as a welcome addition to the rheumatology field. The authors indicate that the serum based 14-3-3η marker is additive to the armamentarium of existing tools available to clinicians, and that there is adequate clinical evidence to support its clinical benefits in the management of patients diagnosed with rheumatoid arthritis (RA). 14-3-3 proteins bind to and sequester the transcriptional coregulators YAP/TAZ to the cytoplasm, inhibiting their function.
Due to its high fission yield, relatively long half-life, and mobility in the environment, technetium-99 is one of the more significant components of nuclear waste. Measured in becquerels per amount of spent fuel, it is the dominant producer of radiation in the period from about 104 to 106 years after the creation of the nuclear waste. The next shortest-lived fission product is samarium-151 with a half-life of 94.6 years, though a number of actinides produced by neutron capture have half-lives in the intermediate range.
Novo Nordisk has also developed a genetically engineered insulin independently using a yeast process. According to a survey that the International Diabetes Federation conducted in 2002 on the access to and availability of insulin in its member countries, approximately 70% of the insulin that is currently sold in the world is recombinant, biosynthetic 'human' insulin. A majority of insulin used clinically today is produced this way, although clinical experience has provided conflicting evidence on whether these insulins are any less likely to produce an allergic reaction. Adverse reactions have been reported; these include loss of warning signs that patients may slip into a coma through hypoglycemia, convulsions, memory lapse and loss of concentration. However, the International Diabetes Federation's position statement from 2005 is very clear in stating that "there is NO overwhelming evidence to prefer one species of insulin over another" and "[modern, highly purified] animal insulins remain a perfectly acceptable alternative." Since January 2006, all insulins distributed in the US and some other countries are synthetic "human" insulins or their analogues. A special FDA importation process is required to obtain bovine or porcine derived insulin for use in the US, although there may be some remaining stocks of porcine insulin made by Lilly in 2005 or earlier, and porcine lente insulin is also sold and marketed under the brand name Vetsulin(SM) in the US for veterinary usage in the treatment of companion animals with diabetes.
Sources: en.wikipedia.org
Fermentation is less efficient at using the energy from glucose: only 2 ATP are produced per glucose, compared to the 38 ATP per glucose nominally produced by aerobic respiration. Glycolytic ATP, however, is produced more quickly. For prokaryotes to continue a rapid growth rate when they are shifted from an aerobic environment to an anaerobic environment, they must increase the rate of the glycolytic reactions. For multicellular organisms, during short bursts of strenuous activity, muscle cells use fermentation to supplement the ATP production from the slower aerobic respiration, so fermentation may be used by a cell even before the oxygen levels are depleted, as is the case in sports that do not require athletes to pace themselves, such as sprinting.
doi:10.1021/acs.jproteome.5b00827. ISSN 1535-3893. PMC 5706558. PMID 26435392. Omenn, Gilbert S.; Lane, Lydie; Lundberg, Emma K.; Beavis, Ronald C.; Nesvizhskii, Alexey I.; Deutsch, Eric W. (2015). "Metrics for the Human Proteome Project 2015: Progress on the Human Proteome and Guidelines for High-Confidence Protein Identification". Journal of Proteome Research. 14 (9): 3452–3460. doi:10.1021/acs.jproteome.5b00499. ISSN 1535-3893. PMC 4755311. PMID 26155816. Fenyö, David; Beavis, Ronald C. (2015). "The GPMDB REST interface". Bioinformatics. 31 (12): 2056–2058. doi:10.1093/bioinformatics/btv107. ISSN 1367-4803. PMID 25697819.
== Welfare considerations during farmed insect rearing == As with other livestock animals, a variety of welfare concerns can manifest during the rearing and slaughter of insects. The 5 Domains framework can be used to broadly categorize these areas of possible concern into four functional domains (nutrition, environment, behavior, and physical health) which then influence the mental domain of the animal's welfare state. As the insect industry is very new, and there are few animal welfare scientists dedicated to studying its livestock, there is little guidance or infrastructure dedicated to improving farmed insect welfare. Further, just as with farmed vertebrates, species-specific guidance is needed to maintain high welfare for each species of insects that is farmed. Recently, several comprehensive and open access review papers have been published that cover the likely welfare concerns for black soldier flies (Hermetia illucens), yellow mealworms (Tenebrio molitor), and three species of farmed crickets (Acheta domesticus, Gryllus bimaculatus, Gryllodes sigillatus), as well as some work on the housefly (Musca domestica). The major, currently known areas of welfare concern during rearing are organized below by functional domain and largely focus on the most farmed insects: black soldier flies, yellow mealworms, and farmed crickets.
The branch of medical science that deals with the study of incidence and distribution and control of a disease in a population. (NLM) The study of the patterns, causes, and control of disease in groups of people. (NCI) Equivalence trial
In her autobiography, Out of the Shadows, Anne Marie reflects on how when she asked why her mother had collected Charmaine — who was part-Pakistani, while Anne Marie was fully white — but not her, Fred callously replied: "She wouldn't want you, love. You're the wrong colour." Charmaine's body was initially stowed in the coal cellar of Midland Road until Fred was released from prison. He later buried her naked body in the yard close to the back door of the flat, and remained adamant that he had not dismembered her. A subsequent post-mortem suggested the body had been severed at the hip, but that this damage may have been caused by building work Fred conducted at the property in 1976. Several bones—particularly patellae, finger, wrist, toe and ankle bones—were missing from Charmaine's skeleton, leading to speculation that the missing parts had been retained as keepsakes. This trait would prove to be a distinctive finding in all the autopsies of the Wests' victims when they were exhumed in 1994.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.