lyophilized powder 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.
Updated 2026-05-24. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
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.
== Methods == Prohibited methods include manipulation of blood components (e.g. autologous red blood cell transfer, "blood doping"), manipulation of samples, and gene doping. These are prohibited at all times.
The Portuguese Republican Party (Portuguese: Partido Republicano Português, pronounced [pɐɾˈtiðu ʁɛpuβliˈkɐnu puɾtuˈɣeʃ]) was a Portuguese political party formed during the late years of the constitutional monarchy that proposed and later brought about the replacement of the monarchy with the Portuguese First Republic. When the Republic was established on the 5 October 1910 Revolution, the members of the party initially stood together, but soon began splitting into different parties, including the Democratic Party, Republican Union, and Evolutionist Party, some of which themselves later merged or split to form the Democratic Leftwing Republican Party, Reformist Party, Centrist Republican Party, Popular Party, Radical Party, Republican Liberal Party, Liberal Republican Union, Reconstitution Party and Nationalist Republican Party.
According to a 2017 Cochrane review, vitamin A deficiency, using serum retinol less than 0.70 μmol/L as a criterion, is a major public health problem affecting an estimated 190 million children under five years of age in low- and middle-income countries, primarily in Sub-Saharan Africa and Southeast Asia. In lieu of or in combination with food fortification programs, many countries have implemented public health programs in which children are periodically given very large oral doses of synthetic vitamin A, usually retinyl palmitate, as a means of preventing and treating vitamin A deficiency. Doses were 50,000 to 100,000 IU (International units) for children aged 6 to 11 months and 100,000 to 200,000 IU for children aged 12 months to five years, the latter typically every four to six months. In addition to a 24% reduction in all-cause mortality, eye-related results were reported. Prevalence of Bitot's spots at follow-up were reduced by 58%, night blindness by 68%, xerophthalmia by 69%.
The chancellor of Germany is the political leader of Germany and the head of the federal government. The office holder is responsible for selecting all other members of the government and chairing cabinet meetings. The office was created in the North German Confederation in 1867, when Otto von Bismarck became the first chancellor. With the unification of Germany and establishment of the German Empire in 1871, the Confederation evolved into a German nation-state and its leader became known as the chancellor of Germany. Originally, the chancellor was only responsible to the emperor. This changed with the constitutional reform in 1918, when the Parliament was given the right to dismiss the chancellor. Under the 1919 Weimar Constitution the chancellors were appointed by the directly elected president, but were responsible to the Reichstag (parliament). The constitution was set aside during the 1933–1945 Nazi regime. During the Allied occupation, no independent German government and no chancellor existed; and the office was not reconstituted in East Germany, thus the head of government of East Germany was chairman of the Council of Ministers. The 1949 Basic Law made the chancellor the most important office in West Germany, while diminishing the role of the president.
Sources: en.wikipedia.org
==== Lactic acid ==== It was once believed that lactic acid build-up was the cause of muscle fatigue. The assumption was lactic acid had a "pickling" effect on muscles, inhibiting their ability to contract. Though the impact of lactic acid on performance is now uncertain, it may assist or hinder muscle fatigue. Produced as a by-product of fermentation, lactic acid can increase intracellular acidity of muscles. This can lower the sensitivity of contractile apparatus to Ca2+ but also has the effect of increasing cytoplasmic Ca2+ concentration through an inhibition of the chemical pump that actively transports calcium out of the cell. This counters inhibiting effects of potassium on muscular action potentials. Lactic acid also has a negating effect on the chloride ions in the muscles, reducing their inhibition of contraction and leaving potassium ions as the only restricting influence on muscle contractions, though the effects of potassium are much less than if there were no lactic acid to remove the chloride ions. Ultimately, it is uncertain if lactic acid reduces fatigue through increased intracellular calcium or increases fatigue through reduced sensitivity of contractile proteins to Ca2+. Lactic acid is now used as a measure of endurance training effectiveness and VO2 max.
Each of the Malay Sultanates created their own literary tradition, influenced by pre-existing oral stories and by the stories that came with Islam. The first Malay literature was in the Arabic script. The earliest known Malay writing is on the Terengganu Stone, made in 1303. Chinese and Indian literature became common as the number of speakers increased in Malaysia, and locally produced works based on languages from those areas began to be produced in the 19th century. English has also become a common literary language. In 1971, the government took the step of defining the literature of different languages. Literature written in Malay was called "the national literature of Malaysia", literature in other bumiputera languages was called "regional literature", while literature in other languages was called "sectional literature". Malay poetry is highly developed, and uses many forms. The Hikayat form is popular, and the pantun has spread from Malay to other languages.
Alas! The bride had died in horrible agony; for no sooner had she put on Medea's gifts than a devouring poison consumed her limbs as with fire, and in his endeavor to save his daughter the old father died too. While Medea is pleased with her current success she decides to take it one step further. Since Jason brought shame upon her by trying to start a new family, Medea resolves to destroy the family he was willing to give up by killing their sons. Medea does have a moment of hesitation when she considers the pain that her children's deaths will put her through. However, she steels her resolve to cause Jason the most pain possible and rushes offstage with a knife to kill her children. Determined to stop Medea, the chorus runs after her only to hear the children scream. Jason then rushes onto the scene to confront Medea about murdering Creon and Glauce, and he quickly discovers that his children have been killed as well. Medea then appears above the stage with the bodies of her children in a chariot given to her by the sun god Helios. When this play was put on, this scene was accomplished using the mechane device usually reserved for the appearance of a god or goddess. She confronts Jason, reveling in his pain at being unable to ever hold his children again:
The IDF said that it killed a senior commander of the elite Redwan Force unit along with a deputy and another fighter in Nabatieh which was confirmed by Hezbollah the next day. A total of seven Hezbollah members were announced dead from the attacks. In response to the launch of a UAV toward the Lower Galilee from Lebanese territory on 19 February, Israeli jets targeted Hezbollah militants in Marwahin, two weapons storage facilities near the city of Sidon, and Hezbollah infrastructure in the Meiss El Jabal and al-Adisa areas of Lebanon. On 21 February, an Israeli airstrike on a residential area of Damascus near a fortified compound used by Syrian security forces killed two civilians. On the same day, an Israeli airstrike on the village of Majdal Zoun killed two more civilians, a mother and her child. In addition, Israeli forces struck a Hezbollah observation post in Ramyeh and shelled an area near Aitaroun with artillery to "remove threats." Later on Israeli jets attacked an observation post in Khaim, a military post in Zibqin—from which a missile was fired at Shlomi—and other Hezbollah infrastructure. On 22 February, after a projectile from Lebanon hit a home in the border town of Yuval, an Israeli drone struck an apartment building in Kfar Remen, killing at least two Hezbollah fighters and wounding three others. The next day, on 23 February, an Israeli strike on a Hezbollah-linked clinic in Blida killed two civilian paramedics and one Hezbollah fighter and injured an unknown number of people.
There are several national and international bioanalytical organisations active throughout the world. Often they are part of a bigger organisation, e.g. Bioanalytical Focus Group and Ligand Binding Assay Bioanalytical Focus Group, which are both within the American Association of Pharmaceutical Scientists (AAPS) and FABIAN, a working group of the Analytical Chemistry Section of the Royal Netherlands Chemical Society. The European Bioanalysis Forum (EBF), on the other hand, is independent of any larger society or association.
Sources: en.wikipedia.org
Early measurements of coaxial stacking were performed using biochemical assays that studies the relative migration of different nucleic acid molecules based on their conformation and the kind of interactions present. Short DNA molecules containing nicks that could still stack coaxially migrated faster than DNA molecules containing gaps and thus had no coaxial stacking. This could be explained by polymeric properties of DNA where are more rigid rod like molecule will migrate faster along an electrical gradient in a matrix compared to a more flexible molecule. Development of newer techniques such as optical tweezers and the ability to fold DNA nanostructures led to measurement so of DNA bundles and their ability to stack with each other. The force needed to pull these bundles apart using optical tweezers could then be analyzed to measure the base-pair stacking energies. These measurements were performed mainly under non-equilibrium conditions and various extrapolations were made to arrive at the exact values of coaxial stacking between bases. Recent single-molecule studies using DNA nanostructures and DNA-PAINT super-resolution microscopy has allowed for measurement of these interaction between dinucleotides using in-depth kinetic analysis of binding times of short DNA molecules to their complimentary sequences in the presence or absence of DNA-stacking interactions.
Gastrointestinal side-effects (nausea, vomiting, diarrhoea) are common; the delayed-release formulation is meant to help overcome this problem. It is also a cause of drug-induced hepatitis. Patients with glucose-6-phosphate dehydrogenase deficiency should avoid taking aminosalicylic acid as it causes haemolysis. Thyroid goitre is also a side-effect because aminosalicylic acid inhibits the synthesis of thyroid hormones. Drug interactions include elevated phenytoin levels. When taken with rifampicin, the levels of rifampicin in the blood fall by about half. It is not known whether it will harm an unborn baby. With heat, 4-aminosalicylic acid is decarboxylated to produce CO2 and 3-aminophenol.
77. Tirzepatide. Farzam K(1), Patel P. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. 2026 Sep 14. Author information: (1)McMaster University Tirzepatide is a medication approved by the US Food and Drug Administration (FDA) for the treatment of type 2 diabetes, obesity, and obstructive sleep apnea. As a dual agonist of the glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide receptors, it improves glycemic control and reduces body weight in patients with type 2 diabetes. Administered once weekly via subcutaneous injection with incremental dose adjustments, tirzepatide is used as a second-line diabetes medication. Tirzepatide is not approved for the treatment of type 1 diabetes and has not been adequately studied in patients with pancreatitis. Common adverse effects are gastrointestinal, including nausea, vomiting, and diarrhea. This activity provides an overview of the indications, mechanism of action, administration, adverse effects, contraindications, drug interactions, and considerations for specific patient populations. The activity also enhances clinicians’ competence in administering tirzepatide, monitoring treatment response and adverse effects, and managing patients with type 2 diabetes to improve patient outcomes and safety. Copyright © 2026, StatPearls Publishing LLC.
Gelatin in American English or gelatine in British English (gelatus, 'stiff, frozen') is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry, and rubbery when moist. It may also be referred to as hydrolyzed collagen, collagen hydrolysate, gelatine hydrolysate, hydrolyzed gelatine, and collagen peptides after it has undergone hydrolysis. It is commonly used as a gelling agent in food, beverages, medications, drug or vitamin capsules, photographic films, papers, and cosmetics. Substances containing gelatin or functioning in a similar way are called gelatinous substances. Gelatin is an irreversibly hydrolyzed form of collagen, wherein the hydrolysis reduces protein fibrils into smaller peptides; depending on the physical and chemical methods of denaturation, the molecular weight of the peptides falls within a broad range. Gelatin is present in jelly, most gummy candy and marshmallows, ice creams, dips, and yogurts. Gelatin for cooking comes as powder, granules, and sheets. Instant types can be added to the food as they are; others must soak in water beforehand. Gelatin is a natural polymer derived from collagen through hydrolysis. Its chemical structure is primarily composed of amino acids, including glycine, proline, and hydroxyproline. These amino acid chains form a three-dimensional network through hydrogen bonding and hydrophobic interactions giving gelatin its gelling properties. Gelatin dissolves well in water and can form reversible gel-like substances.
Although americium was likely produced in previous nuclear experiments, it was first intentionally synthesized, isolated and identified in late autumn 1944, at the University of California, Berkeley, by Glenn T. Seaborg, Leon O. Morgan, Ralph A. James, and Albert Ghiorso. They used a 60-inch cyclotron at the University of California, Berkeley. The element was chemically identified at the Metallurgical Laboratory (now Argonne National Laboratory) of the University of Chicago. Following the lighter neptunium, plutonium, and heavier curium, americium was the fourth transuranium element to be discovered. At the time, the periodic table had been restructured by Seaborg to its present layout, containing the actinide row below the lanthanide one. This led to americium being located right below its twin lanthanide element europium; it was thus by analogy named after the Americas: "The name americium (after the Americas) and the symbol Am are suggested for the element on the basis of its position as the sixth member of the actinide rare-earth series, analogous to europium, Eu, of the lanthanide series." The new element was isolated from its oxides in a complex, multi-step process. First plutonium-239 nitrate solution was coated on a platinum foil of about 0.5 cm2 area, the solution was evaporated and the residue was converted into plutonium dioxide (PuO2) by calcining. After cyclotron irradiation, the coating was dissolved with nitric acid, and then precipitated as the hydroxide using concentrated aqueous ammonia solution. The residue was dissolved in perchloric acid.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
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.