heptapeptide 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 2026-03-10. Where a claim depends on a specific study, the study is described rather than over-claimed.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity | ≥95% by HPLC | Research-grade material |
| Detection wavelength | 214 nm | Peptide bond absorbance |
| Reconstitution medium | Sterile water or saline | Prepare fresh or aliquot immediately |
| Storage (solution) | -80 °C, single-use aliquots | Avoid repeated freeze-thaw cycles |
| Common salt form | Acetate or trifluoroacetate | Affects mass and solubility |
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
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.
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.
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.
18 And she revealed her whorings, and she revealed her nakedness, and so I turned from her just as I turned from her sister. 19 Yet she increased her whorings, recalling the days of her childhood when she was prostituted in the land of Egypt. 20 And she lusted after her male lovers whose genitalia were the genitalia of male donkeys and their seminal emission was the seminal emission of horses. Ezekiel 23:18–20 Lexham English Bible
Only two divisions (43rd and 53rd), two armoured brigades, and a parachute brigade were to remain allocated for NATO and the defence of Western Europe; the other eight divisions were placed on a lower establishment for home defence only. The territorial units of the Royal Armoured Corps were also reduced in number to nine armoured regiments and eleven reconnaissance regiments. This was effected by the amalgamation of pairs of regiments, and the conversion of four RAC units to an infantry role. The new parachute brigade group become the 44th Independent Parachute Brigade Group. British forces contracted dramatically as the end of conscription in 1960 came in sight as announced in the 1957 Defence White Paper. On 20 July 1960, a reorganisation of the TA was announced in the House of Commons. The territorials were to be reduced from 266 fighting units to 195. There was to be a reduction of 46 regiments of the Royal Artillery, 18 battalions of infantry, 12 regiments of the Royal Engineers and two regiments of the Royal Corps of Signals. The reductions were carried out in 1961, mainly by amalgamating units. Thus, on 1 May 1961, the TA divisional headquarters were merged with regular army districts, which were matched with Civil Defence Regions to aid mobilisation for war. The Army Reserve Act of April 1962 made provision for a new TA Emergency Reserve (TAER), within existing TA units, who could be called out without Royal Proclamation as individuals to reinforce regular units around the world, for up to six months in every twelve.
== Philosophical background == Traditional Chinese medicine includes a broad range of practices sharing common concepts that developed in China for more than 2,000 years, including various forms of herbal medicine, acupuncture, massage (tui na), exercise (qigong), and dietary therapy. It is primarily used as a complementary alternative medicine approach. Traditional practices are widely used in China and, in an adapted form, also in the West. Its philosophy is based on School of Yin Yang, which incorporates Five Phases theory and Yin–Yang theory, and elements of which were absorbed by Daoism. Philosophical texts influenced medical thought and practice, mostly by being grounded in the same theories of qi, yin-yang and wuxing and microcosm-macrocosm analogies.
In 1998, Andrew Fire at Carnegie Institution for Science in Washington DC and Craig Mello at University of Massachusetts in Worcester discovered the RNAi mechanism while working on gene expression in the nematode, Caenorhabditis elegans. The two won the Nobel prize for their research with RNAi in 2006. siRNA and its role in post-transcriptional gene silencing (PTGS) was discovered in plants by David Baulcombe's group at the Sainsbury Laboratory in Norwich, England, a discovery reported in Science in 1999. Thomas Tuschl and colleagues soon reported in Nature that synthetic siRNAs could induce RNAi in mammalian cells. These discoveries led to a surge in interest in harnessing RNAi for biomedical research and drug development. As of 2017, human applications of siRNA had faced significant roadblocks to their success, one of these being "off-targeting". As that decade came to a close, the possibility that these therapies could trigger innate immunity had been discussed. As of 2019, animal models had not been successful in accurately representing the extent of this response in humans; hence, studying the effects of siRNA therapies has been a challenge. As of 2025, seven siRNA-based drugs have received approval from the U.S. Food and Drug Administration (FDA), spanning indications including hypercholesterolaemia, acute hepatic porphyria, primary hyperoxaluria, transthyretin amyloidosis, and haemophilia A and B.
{\displaystyle {\frac {\partial W^{*}}{\partial t^{*}}}+U^{*}{\frac {\partial W^{*}}{\partial X^{*}}}+W^{*}{\frac {\partial W^{*}}{\partial Z^{*}}}\ =-{\frac {\partial p_{d}}{\partial Z^{*}}}+Pr\left({\frac {\partial ^{2}W^{*}}{\partial X^{*2}}}+{\frac {\partial ^{2}W^{*}}{\partial Z^{*2}}}\right)\ -{Ra_{s}Pr_{s}S}+{Ra_{T}Pr_{T}T}}
Sources: en.wikipedia.org
== History == Golodirsen was developed by collaborative research led by Prof. Steve Wilton and Prof. Sue Fletcher in the Perron Institute and licensed to Sarepta Therapeutics by the University of Western Australia. In the clinical trial of golodirsen, dystrophin levels increased, on average, from 0.10% of normal at baseline to 1.02% of normal after 48 weeks of treatment with the drug or longer. The change was a surrogate endpoint and the trial did not establish clinical benefit of the drug, including changes to the subject's motor function. The pharmacological assessment of golodirsen did not include special population groups, e.g., pregnant and lactating women, the elderly, and people with concurrent disease states. As DMD predominantly affects male children and young adults, and golodirsen is indicated for the treatment of children, but primarily not for adult women, the elderly, and people with comorbidity, it was not evaluated on them. The US Food and Drug Administration (FDA) approved golodirsen in December 2019, under the accelerated approval pathway. The application for golodirsen was granted fast track, priority review, and orphan drug designations, and a rare pediatric disease priority review voucher.
The Orange Box was met with universal acclaim from reviewers. The averaging website GameRankings cites both the Xbox 360 version and the PC version as the highest-rated game of their respective platforms. AllGame editor Mark Hoogland called The Orange Box "the gold standard for bundled (video) games". IGN described The Orange Box as "the best deal in video game history," and awarded both the Windows and Xbox 360 versions with an Editors' Choice Award. All three versions won GameSpot's Editors' Choice Award. Approximately 3 million copies of The Orange Box were sold by the end of November 2008.
The largest amounts of estradiol are produced by the granulosa cells of the ovaries, but lesser amounts are derived from testicular and adrenal testosterone. Adrenal androgens are steroids produced by the zona reticulosa of the adrenal cortex in both sexes. The major adrenal androgens are dehydroepiandrosterone, androstenedione (which are precursors of testosterone), and dehydroepiandrosterone sulfate which is present in large amounts in the blood. Adrenal androgens contribute to the androgenic events of early puberty in females. IGF1 (insulin-like growth factor 1) rises substantially during puberty in response to rising levels of growth hormone and may be the principal mediator of the pubertal growth spurt. Leptin is a protein hormone produced by adipose tissue. Its primary target organ is the hypothalamus. The leptin level seems to provide the brain a rough indicator of adipose mass for purposes of regulation of appetite and energy metabolism. It also plays a permissive role in female puberty, which usually will not proceed until an adequate body mass has been achieved.
Temperature in the anus (rectum/rectal) is at or over 37.5–38.3 °C (99.5–100.9 °F). An ear (tympanic) or forehead (temporal) temperature may also be used. Temperature in the mouth (oral) is at or over 37.2 °C (99.0 °F) in the morning or over 37.7 °C (99.9 °F) in the afternoon Temperature under the arm (axillary) is usually about 0.6 °C (1.1 °F) below core body temperature. In adults, the normal range of temperatures in healthy individuals is 36.32–37.76 °C (97.4–100.0 °F) (rectal), 35.76–37.52 °C (96.4–99.5 °F) (ear), 35.61–37.61 °C (96.1–99.7 °F) (urine), 35.73–37.41 °C (96.3–99.3 °F) (oral), and 35.01–36.93 °C (95.0–98.5 °F) (axillary), with no significant gender differences. Normal body temperatures vary depending on many factors, including age, sex, time of day, ambient temperature, activity level, and more. Normal daily temperature variation has been described as 0.5 °C (0.9 °F). A raised temperature is not always a fever. For example, the temperature rises in healthy people when they exercise, but this is not considered a fever, as the set point is normal. On the other hand, a "normal" temperature may be a fever, if it is unusually high for that person; for example, medically frail elderly people have a decreased ability to generate body heat, so a "normal" temperature of 37.3 °C (99.1 °F) may represent a clinically significant fever.
== Efforts to characterize all human cell types == Several efforts have been made to make a list or a map of all human cells. One of the largest and most recent is the HuBMAP (Human BioMolecular Atlas Program). The HuBMAP project has organized 1551 different samples in 17 collections, each dedicated to a different system. However, this project still only mapped about 31 of the human body's 70 organs. Their datasets and visualisations place great emphasis on biomarkers and location in the body, but less on cell development and how cells can change over time. Usually specific surface proteins are used to identify cells, and based on this they are put into different categories. Another major effort to make an overview of these proteins that allows us to observe cell types is the Human Protein Atlas. A similar project, the Human Brain Project has also attempted to map the human brain, although much of the publicly accessible model does not have cellular resolution.
Sources: en.wikipedia.org
=== Drug interactions === Drug interactions may be the result of altered pharmacokinetics or pharmacodynamics due to one of the drugs involved. Cisplatin, dexamethasone, doxorubicin, etoposide, and vinblastine are all potentially co-administered with docetaxel and did not modify docetaxel plasma binding in phase II studies. Cisplatin is known to have a complex interaction with some CYPs and has in some events been shown to reduce docetaxel clearance by up to 25%. Anticonvulsants induce some metabolic pathways relevant to docetaxel. CYP450 and CYP3A show increased expression in response to the use of anticonvulsants and the metabolism of docetaxel metabolite M4 is processed by these CYPs. A corresponding increase in clearance of M4 by 25% is observed in patients taking phenytoin and phenobarbital, common anticonvulsants.
== Actions and psychopharmacology == CRH is produced in response to stress, predominantly by parvocellular neurosecretory cells within the paraventricular nucleus of the hypothalamus and is released at the median eminence from neurosecretory terminals of these neurons into the primary capillary plexus of the hypothalamo-hypophyseal portal system. The portal system carries the CRH to the anterior lobe of the pituitary, where it stimulates corticotropes to secrete adrenocorticotropic hormone (ACTH) and other biologically-active substances (β-endorphin). ACTH stimulates the synthesis of cortisol, glucocorticoids, mineralocorticoids and DHEA. In the short term, CRH can suppress appetite, increase subjective feelings of anxiety, and perform other functions like boosting attention. During chronic stress conditions such as post-traumatic stress disorder (PTSD), blood serum levels of CRH are decreased in combat veterans with PTSD compared to healthy individuals. It is believed that chronic stress enhances the negative feedback inhibition of the HPA axis, resulting in lower CRH levels and HPA function. Abnormally high levels of CRH have been found in people with major depression, and in the cerebrospinal fluid of people who have committed suicide. Corticotropin-releasing hormone has been shown to interact with its receptors, corticotropin-releasing hormone receptor 1 (CRFR1) and corticotropin-releasing hormone receptor 2 (CRFR2), in order to induce its effects.
Most charts or tables indicate the type of friction factor, or at least provide the formula for the friction factor with laminar flow. If the formula for laminar flow is f = 16/Re, it is the Fanning factor f, and if the formula for laminar flow is fD = 64/Re, it is the Darcy–Weisbach factor fD. Which friction factor is plotted in a Moody diagram may be determined by inspection if the publisher did not include the formula described above:
The 2021 Canadian census enumerated a total population of 36,991,981, an increase of around 5.2 percent over the 2016 figure. It is estimated that Canada's population surpassed 40,000,000 in 2023. The main drivers of population growth are immigration and, to a lesser extent, natural growth. Canada has one of the highest per-capita immigration rates in the world, driven mainly by economic policy and family reunification. A record 483,390 immigrants were admitted in 2024. Canada leads the world in refugee resettlement; it resettled more than 47,600 in 2022. New immigrants settle mostly in major urban areas, such as Toronto, Montreal, and Vancouver. Canada's population density, at 4.2 inhabitants per square kilometre (11/sq mi), is among the lowest in the world, with approximately 95 percent of the population residing south of the 55th parallel north. About 80 percent of the population lives within 150 kilometres (93 mi) of the border with the contiguous United States. Canada is highly urbanized, with over 80 percent of the population living in urban centres. The majority of Canadians (over 70%) live south of the 49th parallel, with 50 percent of Canadians living south of 45°42′ (45.7 degrees) north. The most densely populated part of the country is the Quebec City–Windsor Corridor in Southern Quebec and Southern Ontario along the Great Lakes and the St. Lawrence River. The majority of Canadians (81.1%) live in family households, 12.1 percent report living alone, and 6.8 percent live with other relatives or unrelated persons.
Sources: en.wikipedia.org
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase liquid chromatography establishes purity, while mass spectrometry confirms molecular mass. The two techniques are normally used together. Retention time alone is not sufficient evidence of identity.
Different counterions change the mass per unit of peptide and can shift chromatographic behavior. Two samples of equal stated purity may therefore not be directly comparable. Reports should specify the counterion whenever quantitative comparisons are made.
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.