counterion 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 2026-04-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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 |
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.
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.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
=== Novel experimental treatments === Though medications and behavioral treatments are effective forms for treating OUD, relapse remains a common problem. The medical community has looked to novel technologies and traditional alternative medicines for new ways to approach the issues of continued cravings and impaired executive functioning. While consensus on their efficacy has not been reached, a number of reviews have shown promising results for the use of non-invasive brain stimulation (NIBS) for reducing cravings in OUD. These results are consistent with the use of NIBS for reducing cravings of other substances. Investigations into the anecdotal evidence of psychedelics like ibogaine have also shown the possibility of decreased cravings and withdrawal symptoms. Emerging research includes the noribogaine analogue GM-3009, a next-generation neuroplastogen engineered to eliminate the cardiotoxicity of traditional ibogaine, with clinical Phase 1 trials commencing in 2026. Ibogaine is illegal in the U.S. but is unregulated in Mexico, Costa Rica, and New Zealand, where many clinics use it for addiction treatment. Research has shown a minor mortality risk due to its cardiotoxic and neurotoxic effects. In 2024 the FDA approved the NET (NeuroElectric Therapy) device, which reduces withdrawal symptoms by neurostimulation. Used for three to five days of continuous treatment, NET delivers alternating current via surface electrodes placed trans-cranially at the base of the skull on each side of the head.
Aticaprant, also known by its developmental codes JNJ-67953964, CERC-501, and LY-2456302, is a κ-opioid receptor (KOR) antagonist which was under development for the treatment of major depressive disorder and other conditions. Aticaprant is taken orally. Side effects of aticaprant include itching, among others. Aticaprant acts as a selective antagonist of the KOR, the biological target of the endogenous opioid peptide dynorphin. The medication has decent selectivity for the KOR over the μ-opioid receptor (MOR) and other targets, a relatively long half-life of 30 to 40 hours, and readily crosses the blood–brain barrier to produce central effects. Aticaprant was originally developed by Eli Lilly, was under development by Cerecor for a time, and is now under development by Janssen Pharmaceuticals. In July 2022, it was in phase III clinical trials for major depressive disorder. In March 2025, Johnson & Johnson discontinued development of aticaprant for major depressive disorder due to lack of effectiveness in phase III trials. Aticaprant was also under development for the treatment of alcoholism, cocaine use disorder, and nicotine withdrawal, but development for these indications was discontinued as well.
=== Types === There are seven types of synovial joints. Some are relatively immobile, therefore more stable. Others have multiple degrees of freedom, but at the expense of greater risk of injury. In ascending order of mobility, they are:
...dependent arising is a phenomenon that lasts an instant; it is impermanent. Therefore, Birth and Death must be explained as phenomena within the process of dependent arising in everyday life of ordinary people. Right Mindfulness is lost during contacts of the Roots and surroundings. Thereafter, when vexation due to greed, anger, and ignorance is experienced, the ego has already been born. It is considered as one 'birth'".Ñāṇavīra Thera is another modern Theravada Bhikkhu known for rejecting the traditional interpretation and instead explaining the 12 links as a structural schema which does not happen in successive moments in time, but is instead a timeless structure of experience.
Norleucine (abbreviated as Nle) is an amino acid with the formula CH3(CH2)3CH(NH2)CO2H. A systematic name for this compound is 2-aminohexanoic acid. The compound is an isomer of the more common amino acid leucine. Like most other α-amino acids, norleucine is chiral. It is a white, water-soluble solid.
Sources: en.wikipedia.org
Autosomal-dominant mutations in APP cause hereditary early-onset Alzheimer's disease (familial AD, fAD). This form of AD accounts for no more than 10% of all cases, and the vast majority of AD is not accompanied by such mutations. However, familial Alzheimer's disease is likely to result from altered proteolytic processing. This is evidenced by the fact that many mutations that lead to fAD occur near γ-secretase cleavage sites on APP. One of the most common mutations causing fAD, London Mutation, occurs at codon 717 of the APP gene, and results in a valine to isoleucine amino acid substitution. Histochemical analysis of the APP V717I mutation has revealed extensive Aβ pathology throughout neuroaxis as well as widespread cerebral amyloid angiopathy (CAA). The gene for the amyloid precursor protein is located on chromosome 21, and accordingly people with Down syndrome have a very high incidence of Alzheimer's disease.
==== Production of "Instant" 99mTc ==== The feasibility of 99mTc production with the 22-MeV-proton bombardment of a 100Mo target in medical cyclotrons was demonstrated in 1971. The recent shortages of 99mTc reignited the interest in the production of "instant" 99mTc by proton bombardment of isotopically enriched 100Mo targets (>99.5%) following the reaction 100Mo(p,2n)99mTc. Canada is commissioning such cyclotrons, designed by Advanced Cyclotron Systems, for 99mTc production at the University of Alberta and the Université de Sherbrooke, and is planning others at the University of British Columbia, TRIUMF, University of Saskatchewan and Lakehead University. A particular drawback of cyclotron production via (p,2n) on 100Mo is the significant co-production of 99gTc. The preferential in-growth of this nuclide occurs due to the larger reaction cross-section pathway leading to the ground state, which is almost five times higher at the cross-section maximum in comparison with the metastable one at the same energy. Depending on the time required to process the target material and recovery of 99mTc, the amount of 99mTc relative to 99gTc will continue to decrease, in turn reducing the specific activity of 99mTc available. It has been reported that ingrowth of 99gTc as well as the presence of other Tc isotopes can negatively affect subsequent labelling and/or imaging; however, the use of high purity 100Mo targets, specified proton beam energies, and appropriate time of use have shown to be sufficient for yielding 99mTc from a cyclotron comparable to that from a commercial generator.
=== Simplifications === In case of conservative body forces, ∇ × B = 0. For a barotropic fluid, ∇ρ × ∇p = 0. This is also true for a constant density fluid (including incompressible fluid) where ∇ρ = 0. Note that this is not the same as an incompressible flow, for which the barotropic term cannot be neglected. This note seems to be talking about the fact that conservation of momentum says
Along with most of the Commonwealth and Allied nations, Southern Rhodesia sent a delegation of soldiers, airmen and seamen to London to take part in the grand Victory Parade of 8 June 1946. The colony's contingent, led by Colonel R E B Long, marched after South Africa and before Newfoundland. The Southern Rhodesian colour guard comprised a white officer and two black sergeants of the Rhodesian African Rifles. During the royal visit to Southern Rhodesia in April 1947, King George VI accorded the prefix "Royal" to the Rhodesia Regiment in recognition of its contributions to the two World Wars, and agreed to be its Colonel-in-Chief.
Fibromyalgia can be viewed as a condition defined by nociplastic pain. Nociplastic pain is caused by altered function of pain-related sensory pathways in the periphery and the central nervous system, resulting in hypersensitivity. As of 2023, the underlying processes of nociplastic pain remain poorly understood. Nociplastic pain may be caused by either (1) increased processing of pain stimuli or (2) decreased suppression of pain stimuli at several levels in the nervous system, or both. Nociplastic pain has been referred to as "Nociplastic pain syndrome" because it is coupled with other symptoms including fatigue, sleep disturbance, cognitive disturbance, hypersensitivity to environmental stimuli, anxiety, and depression. Nociplastic pain states can be triggered by a variety of stressors such as trauma, infections, and chronic stressors. A 2024 review reported that symptoms such as fatigue, sleep, memory, and mood problems, and sensitivity to non-painful sensory stimuli were also CNS-driven symptoms that were inherent to nociplastic pain. In 2023, the "Fibromyalgia: Imbalance of Threat and Soothing Systems" (FITSS) model was suggested as a working hypothesis. According to the FITSS model, the salience network (also known as the midcingulo-insular network) may remain continuously hyperactive due to an imbalance in emotional self-regulation, which is reflected by an overactive "threat" system and an underactive "soothing" system. This hyperactivation, along with other mechanisms, may contribute to fibromyalgia.
Sources: en.wikipedia.org
=== Countercurrent exchange in sea and desert birds to conserve water === Sea and desert birds have been found to have a salt gland near the nostrils which concentrates brine, later to be "sneezed" out to the sea, in effect allowing these birds to drink seawater without the need to find freshwater resources. It also enables the seabirds to remove the excess salt entering the body when eating, swimming or diving in the sea for food. The kidney cannot remove these quantities and concentrations of salt. The salt secreting gland has been found in seabirds like pelicans, petrels, albatrosses, gulls, and terns. It has also been found in Namibian ostriches and other desert birds, where a buildup of salt concentration is due to dehydration and scarcity of drinking water. In seabirds the salt gland is above the beak, leading to a main canal above the beak, and water is blown from two small nostrils on the beak, to empty it. The salt gland has two countercurrent mechanisms working in it: a. A salt extraction system with a countercurrent multiplication mechanism, where salt is actively pumped from the blood 'venules' (small veins) into the gland tubules. Although the fluid in the tubules is with a higher concentration of salt than the blood, the flow is arranged in a countercurrent exchange, so that the blood with a high concentration of salt enters the system close to where the gland tubules exit and connect to the main canal.
Carey (1940), executive officer of the American Association for the Advancement of Science and publisher of Science 1975–1987 Robert Bleiberg (1943), former publisher and managing editor of Barron's Gilman Kraft (1947), former owner and publisher of Playbill Jason Epstein (1949), editorial director of Random House and co-founder of the New York Review of Books Bernard Shir-Cliff (1949), editor of Ballantine Books and Warner Books Arthur Ochs Sulzberger (1951), publisher of The New York Times Lee Guittar (1953), former publisher of the San Francisco Examiner, The Denver Post, Dallas Times Herald, and president of USA Today Richard Goodwin Capen, Jr. (1956), former publisher of the Miami Herald; U.S. ambassador to Spain 1992–1993 Peter Mayer (1956), publisher of Overlook Press and former CEO of Penguin Books Daniel Leab (1957), historian, antiquarian and publisher book catalogues, former editor of Labor History Donald Welsh (1965), founding publisher of outdoors magazine Outside Albert Scardino (1970), publisher of The Georgia Gazette and Pulitzer Prize winner in 1984 Louis Rossetto (1971), founder and publisher of Wired magazine David Rothkopf (1977), CEO and editor of Foreign Policy magazine John R. MacArthur (1978), president and publisher of Harper's magazine, grandson of billionaire John D. MacArthur, benefactor of the MacArthur Fellows Program Jake Dobkin (1998), co-founder and publisher of Gothamist franchise
=== Antibody identification === Antibodies to blood group system antigens and their characteristics must be identified when such antibodies are detected in a potential recipient's serum or plasma. The specificity of the antibody aids the medical laboratory scientist in determining if the antibody is clinically significant. Antibody identification is a very laborious process. Characteristics of clinically significant antibodies include: reactive at body temperature (37°C), immunoglobulin (Ig) class G, IgM that reacts at body temperature, ability to cross the placenta, ability to cause red blood cell destruction, and/or antibodies directed against commonly known clinically significant red cell antigens. For example, if an individual is exposed to a red cell antigen (via blood transfusion, pregnancy, stem-cell transplant) that they do not inherently possess, they may form a clinically significant antibody directed against that antigen. If a patient receives a transfusion of packed red blood cells possessing the Kell antigen (big K or simply K), they may form an antibody called anti-K (anti big K). Subsequent transfusions with K-positive packed red blood cells would cause an immediate hemolytic transfusion reaction. The K antibody reacts at 37°C, is IgG, capable of crossing the placenta, and known to cause immediate red blood cell destruction. The presence of autoantibodies directed against self red blood cell antigens can complicate the antibody identification process.
=== Strain Release === Strain-release amination (2016) Stereospecific strain-release cyclopentylation of amines, alcohols, thiols, carboxylic acids, and other heteroatoms (2017) Enantiocontrolled Azetidine Library Synthesis via Strain Release Functionalization of 1-Azabicyclobutanes (2024)
genetic abnormalities in the metabolism of ethanol, which can cause the ethanol metabolite, acetaldehyde, to accumulate in tissues and trigger the release of histamine, or true allergy reactions to allergens occurring naturally in, or contaminating, alcoholic beverages (particularly wine and beer), and other unknown causes.
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.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.