Everything below concerns lyophilized powder. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-12. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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。
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。
| 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 |
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.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
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.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
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.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
== Pigments and polarity == Paper chromatography is one method for testing the purity of compounds and identifying substances. Paper chromatography is a useful technique because it is relatively quick and requires only small quantities of material. Separations in paper chromatography involve the principle of partition. In paper chromatography, substances are distributed between a stationary phase and a mobile phase. The stationary phase is the water trapped between the cellulose fibers of the paper. The mobile phase is a developing solution that travels up the stationary phase, carrying the samples with it. Components of the sample will separate readily according to how strongly they adsorb onto the stationary phase versus how readily they dissolve in the mobile phase. When a colored chemical sample is placed on a filter paper, the colors can be separated by placing one end of the paper in a solvent. The solvent diffuses up the paper, dissolving the various molecules in the sample according to the polarities of the molecules and the solvent. If the sample contains more than one color, that means it must have more than one kind of molecule. Because of the different chemical structures of each kind of molecule, each molecule will have at least a slightly different polarity, giving each molecule a different solubility in the solvent. The unequal solubility causes the various color molecules to travel at different rates as the solvent carries them up the paper. The more soluble a molecule is, the faster it will migrate up the paper.
Western academicians published various analyses of the post-Soviet states' development, claiming that the dissolution was followed by a severe drop in economic and social conditions in these countries, including a rapid increase in poverty, crime, corruption, unemployment, homelessness, rates of disease, infant mortality and domestic violence, as well as demographic losses, income inequality and the rise of an oligarchical class, along with decreases in calorie intake, life expectancy, adult literacy, and income. Between 1988–1989 and 1993–1995, the Gini ratio (a measure of inequality) increased by an average of 9 percentage points for all former Soviet republics. According to Western analysis, the economic shocks that accompanied wholesale privatization were associated with sharp increases in mortality, A 2026 Lancet preprint estimates 15.9 million deaths in former Soviet states through to 2019 occurred due to its dissolution, accounting for demographic shift and hampered development. Russia, Kazakhstan, Latvia, Lithuania, and Estonia saw a tripling of unemployment and a 42% increase in male death rates between 1991 and 1994, and in the following decades, only five or six of the post-communist states are on a path to joining the wealthy capitalist West while most are falling behind, some to such an extent that it will take over fifty years to catch up to where they were before the fall of the Soviet Bloc. As of 2011, the experience of the former Soviet republics was mixed, with some having recovered in terms of gross domestic product and others not.
Vulture bees are a small group of obligately necrophagous bees in the Trigona genus. Trigona worker bees play a similar role to worker bees in the Apis genus; however, along with collecting pollen, nectar, and plant resins, Trigona workers also collect carrion. Although pollen is associated with higher energy value, carrion is preferred by Trigona bees because it is biochemically easier to extract energy from. This dead animal tissue is used as a source of amino acids too. Cerumen pots are utilized by some Trigona species, such as T. necrophaga, as vesicles to store foodstuff. The foodstuff of T. necrophaga consists of both honey and carrion from vertebrate carcasses. Ultimately, the stored food is utilized by developing larvae and the worker bee itself as a source of nutrition and energy. Due to the rapid decomposition of carrion, especially in warm temperatures, the bees must efficiently metabolize the carrion to avoid rotten carrion in their cerumen pots. Trigona hypogea communicate the presence of a valuable carcass through olfactory signals. The bees create an odour trail between their nest and the prospective animal carcass; thus, the bees recruit the other nest members to respond and exploit the corpse's resources rapidly. Additionally, interspecific competition is observed in Trigona hypogea bees. The bees are observed to defend their colonized food item, including but not limited to a monkey, lizard, fish, or snake carcass, from competing necrophages, such as flies.
== History == Carbetocin was synthesized before 1971 at the Czechoslovak Institute of Organic Chemistry and Biochemistry and was first described by 1974. It was approved for medical use in Canada and the United Kingdom in 1997.
restrictions on the amount of exposed steel set by building codes. encasing structural steel in brick masonry or concrete to delay exposure to high temperatures. Historically, these masonry encasement methods use large amounts of heavy materials, thus greatly increasing the load to the steel frame. Newer materials and methods have been developed to resolve this issue. The following lists both older and newer methods of fireproofing steel beams (i-beams):
Sources: en.wikipedia.org
=== Ornithine decarboxylase === Ornithine decarboxylase (ODC), is a labile protein that is the first rate-limiting enzyme in polyamine biosynthesis. Its degradation is regulated by antizyme that is induced by polyamine production. NQO1 has been shown to stabilize the degradation of ODC by binding to it and protecting it from 20S proteasomal degradation.
She cuts ties with Otto and brings Eric out of retirement to launch SternTao, targeting fintech company Tender. After a one-night stand with Tender CFO Whitney Halberstram, Harper is tipped off by journalist James Dycker that Tender is concealing misconduct. She hires Sweetpea and Kwabena Bannerman—her former colleague and casual partner—and sends them to Accra to investigate Tender’s acquisitions, where they uncover falsified profits and recycled revenue. Harper presents the findings at an investment conference, causing Tender’s stock to fall 28%. During this period, she learns her estranged mother has died and struggles to grieve amid her work. Eric later transfers his ownership stake in SternTao to her and withdraws from the partnership without explanation, having been blackmailed, leaving Harper devastated. She reconciles with Yasmin after helping circulate claims that the Labour government suppressed concerns about Tender, prompting investigations and a new audit. The Tender short ultimately earns SternTao £110 million, and Harper, Sweetpea, and Kwabena scout a new office. In Paris, Harper attends a fundraiser hosted by Yasmin for Reform MP Sebastian Stefanowicz and is disturbed by the guests (including the Nazi-sympathizing Bauer family) and Yasmin's use of escorts; Yasmin shows her a compromising recording of Eric with an underage prostitute, leaving Harper shaken. She later reflects on the Tender short in an interview with journalist Patrick Radden Keefe and ponders her future.
Significant increases in central MP levels were also observed after just two weeks of supplementation. Furthermore, in patients who had an atypical MP distribution in the eye (i.e., they did not have a high concentration of pigment in the centre of the macula), when supplemented with a meso-zeaxanthin-dominant supplement for 8 weeks, the normal pigment profile was reinstated, whereas this was not the case when patients were supplemented with a formulation lacking meso-zeaxanthin. The main findings from the MOST trials in patients with AMD were published in 2013 and 2015. The series of publications from these trials concluded, "Augmentation of the MP optical density across its spatial profile and enhancements in contrast sensitivity were best achieved after supplementation with a formulation containing high doses of meso-zeaxanthin in combination with lutein and zeaxanthin". Also, the final publication from this work, published in 2015, concluded that, "The inclusion of meso-zeaxanthin in a supplement formulation seems to confer benefits in terms of MP augmentation and in terms of enhanced contrast sensitivity in subjects with early AMD.". In 2016 and 2017, the results of two small clinical trials were published. The first trial, the CREST (Central Retinal Enrichment Supplementation Trials) study involved 105 normal healthy volunteers who underwent a series of complex tests of vision and were supplemented over 12 months.
=== Wet symptoms === Circulatory shock Diarrhea (feces which resemble more liquid than solid) Hemorrhage (bleeding) and sometimes bleeding diathesis (a person loses more blood than usual from an injury – for example, getting only a little cut, and losing a lot of blood) Petechiae (small red or purple spots) Swelling caused by edema The severity of symptoms varies with both individual immune competence and the type of virus. The "VHF syndrome" causes bleeding diathesis, capillary leak, and circulatory shock. It happens to most people who have Filoviridae infections (such as Ebola virus or Marburg virus), Crimean–Congo hemorrhagic fever (CCHF), or the South American hemorrhagic fevers (which are caused by Arenaviridae). VHF syndrome only happens to a small minority of people who have dengue fever or Rift Valley fever.
== Contraindications == The two contraindications to taking ezetimibe are a previous allergic reaction to it, including symptoms of rash, angioedema, anaphylaxis, and severe liver disease, especially when taken with a statin. Ezetimibe may have significant medication interactions with ciclosporin and with fibrates other than fenofibrate.
Sources: en.wikipedia.org
==== Metabolic acidosis and potassium ==== The bicarbonate content should ideally be between 17 and 22 mEq/L. Sodium bicarbonate or potassium citrate is administered for buffering, whereby the latter also compensates for any existing potassium deficiency. A diet rich in potassium and magnesium is recommended and is already used in most commercial kidney diets. Potassium gluconate can also be used to compensate for a potassium deficiency, but potassium chloride is usually poorly accepted by cats and often causes gastrointestinal disorders. The restriction of renal excretion in stage IV, ACE inhibitors or aldosterone deficiency due to renin deficiency can also lead to hyperkalemia, which is why potassium levels must be checked regularly and a low-potassium diet may also need to be used.
PyMOL – introduce a set of common PTM's into protein models AWESOME – Interactive tool to see the role of single nucleotide polymorphisms to PTM's Chimera – Interactive Database to visualize molecules
A Jarisch–Herxheimer reaction is a sudden and typically transient reaction that may occur within 24 hours of being administered antibiotics for an infection by a spirochete, including syphilis, leptospirosis, Lyme disease, and relapsing fever. Signs and symptoms include fever, chills, shivers, feeling sick, headache, fast heart beat, low blood pressure, breathing fast, flushing of skin, muscle aches, and worsening of skin lesions. It may sometimes be mistaken as an allergy to the antibiotic. Jarisch–Herxheimer reactions are usually self-limiting but severe presentations can be life-threatening if they cause a significant drop in blood pressure and cause acute end-organ injury, eventually leading to multi-organ failure.
West Yorkshire contains 22 constituencies of the Parliament of the United Kingdom, and parts of the two constituencies of Selby and Weatherby and Easingwold. As of the 2024 United Kingdom general election, 19 of the constituencies are held by Members of Parliament from the Labour Party, two by members of the Conservative Party, and one by an Independent politician.
=== Safety === Vitamin A toxicity (hypervitaminosis A) occurs when too much vitamin A accumulates in the body. It comes from consumption of preformed vitamin A but not of carotenoids, as conversion of the latter to retinol is suppressed by the presence of adequate retinol.
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.
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。