A practical reference on nasal drops: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-12-29. Anything still debated is marked as such rather than presented as settled.
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.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
| 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 |
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
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.
The main building of the Institute is located at the intersection of Kremlyovskaya and Lobachevskaya streets. This four-story building built in 1953 in the style of Soviet neoclassicism under the guidance of architect A.G. Bikchentaev. The building of the museum of Kazan chemical school is located in the campus of the main university building, built in the 1830s in a classical style under the guidance of architect M.P. Corinfskiy. In 2015 construction of a large laboratory building in the campus of Alexander Butlerov Institute of Chemistry was finished. The 7-storey building housed classrooms and laboratories of departments of Alexander Butlerov Institute of Chemistry, Institute of Geology and Petroleum Technologies, Institute of Physics. The building was constructed with the support of the President of Tatarstan R.N. Minnikhanov and PSC "TAIF".
Hox genes play a massive role in some amphibians and reptiles in their ability to regenerate lost limbs, especially HoxA and HoxD genes. If the processes involved in forming new tissue can be reverse-engineered into humans, it may be possible to heal injuries of the spinal cord or brain, repair damaged organs and reduce scarring and fibrosis after surgery. Despite the large conservation of the Hox genes through evolution, mammals and humans specifically cannot regenerate any of their limbs. This raises a question as to why humans which also possess an analog to these genes cannot regrow and regenerate limbs. Beside the lack of specific growth factor, studies have shown that something as small as base pair differences between amphibian and human Hox analogs play a crucial role in human inability to reproduce limbs. Undifferentiated stem cells and the ability to have polarity in tissues is vital to this process.
A throat culture is a laboratory diagnostic test that evaluates for the presence of a bacterial or fungal infection in the throat. A sample from the throat is collected by swabbing the throat and placing the sample into a special cup (culture) that allows infections to grow. If an organism grows, the culture is positive and the presence of an infection is confirmed. The type of infection is found using a microscope, chemical tests, or both. If no infection grows, the culture is negative. Common infectious organisms tested for by a throat culture include Candida albicans, known for causing thrush, and Group A streptococcus, known for causing strep throat, scarlet fever, and rheumatic fever. Throat cultures are more sensitive (81% sensitive) than the rapid strep test (70%) for diagnosing strep throat, but are nearly equal in terms of specificity.
Romanowsky was the first to realise the differences in the staining abilities of eosin and methylene blue. The individual stains (monochromatic staining) were good only for general colouring of tissue or cell, but not for contrasting the different components. By mixing specific amount of eosin and methylene blue, Romanowsky found that the mixture gave images of contrasting clarity that helped to visualise different parts and components of cells. This mixture method, polychromatic staining or polychromy, with various modifications became the most efficient way of staining cells for identifying cellular components. The chemical phenomenon by which a mixture of stains produces vibrant cell images is known as "Romanowsky effect". In December 1890, Romanowsky published his invention as a preliminary report of his major work for his doctoral thesis in the journal Vrach as "On the question of the structure of malaria parasites" (as translated in English). Incorrectly, it is more often recorded in books and journals that Romanowsky published his findings in 1891, which led to a controversy on priority that Ernst Malachowsky independently developed the technique as the latter published his research in August 1891.
58. Dermatol Online J. 2018 May 15;24(5):13030/qt2gz9f9jk. A glimpse into the underground market of melanotan. Callaghan Iii DJ(1). Author information: (1)Department of Dermatology, Boston Medical Center, Boston, Massachusetts. danieljcallaghan3@gmail.com. Melanotan-I and melanotan-II are alpha-melanocyte stimulating hormone (a-MSH) analogues that can be purchased illicitly online with relative ease and are injected subcutaneously to stimulate a tan. Little is known about the use of these unregulated substances. An observational survey was posted to an online forum in which participants share their experiences using melanotan-I or melanotan-II. Users were asked to complete this voluntary, anonymous survey, which had questions focusing on motivation and hesitation for and against using melanotan, difficulty in acquiring it, and plans for continuing to use melanotan in the future.
Sources: en.wikipedia.org
As a potential weapon material, pure uranium-233 is more similar to plutonium-239 than uranium-235 in terms of source (bred vs natural), half-life and critical mass (both 4–5 kg in beryllium-reflected sphere). Unlike reactor-bred plutonium, it has a very low spontaneous fission rate, which combined with its low critical mass made it initially attractive for compact gun-type weapons, such as small-diameter artillery shells. A declassified 1966 memo from the US nuclear program stated that uranium-233 has been shown to be highly satisfactory as a weapons material, though it was only superior to plutonium in rare circumstances. It was claimed that if the existing weapons were based on uranium-233 instead of plutonium-239, Livermore would not be interested in switching to plutonium. The co-presence of uranium-232 can complicate the manufacture and use of uranium-233, though the Livermore memo indicates a likelihood that this complication can be worked around. Chuck Hansen wrote in Swords of Armageddon that 233U was evaluated by the United States for its ability to substitute for supergrade plutonium in nuclear weapons. As it was deemed equivalent to plutonium rather than superior to it, military interest in 233U-based weapons waned in the late 1960s. However, several 233U-based nuclear weapons were tested by the US between 1955 and 1968. The Rocky Flats Plant, which refined fissile materials for weapons production, was refining 233U until the early 1980s.
===== Czech Republic ===== As of May 2023, the State Agricultural and Food Inspection of the Czech Republic is putting together broad regulations regarding a ban on CBD products. They will make it illegal to sell products containing cannabidiol and other cannabinoids derived from hemp, as a result of EU Novel Food Regulation. In case of Czech Republic, European Industrial Hemp Association has submitted an official request to the Czech Republic to recognize natural hemp extracts with cannabinoids as traditional food.
. Stress intensity replaced strain energy release rate and a term called fracture toughness replaced surface weakness energy. Both of these terms are simply related to the energy terms that Griffith used:
== Society and culture == Fibromyalgia causes substantial economic and societal strain due to disability, reduced work hours, informal care, early retirement, and healthcare utilization. According to a 2014 review indirect costs, such as those due to disability and lost productivity, accounted for most of the costs, and the cost to society amounted to "tens of thousands of dollars each year" per patient. A 2022 review of 36 studies found that fibromyalgia causes a significant economic strain on healthcare systems. Annual costs per patient were estimated to be $1,750 to $35,920 in the US, and $1,250 to $8,504 in Europe. People with fibromyalgia can be subjected to significant stigma in society generally, and within the medical system. They may face disbelief in the legitimacy of their pain, moralizing attitudes, and suspicions of malingering, which relate to the invisible nature of the pain and prejudices relating to the historic predominance of women amongst people with the condition. Health professionals may hold negative attitudes towards patients with fibromyalgia, considering them "demanding" or their symptoms to be exaggerated or fake, and they may lack knowledge about the condition, which can also contribute to delays in diagnosis. Many people with fibromyalgia feel that healthcare providers believe they are faking or exaggerating. This stigma can have a considerable impact on the social interactions, trust in healthcare, and mental health of people with fibromyalgia.
which reasonably match experimental data, the collisional integrals may be computed numerically or from correlations. In some cases, the collision integrals are regarded as fitting parameters, and are fitted directly to experimental data. This is a common approach in the development of reference equations for gas-phase viscosities. An example of such a procedure is the Sutherland approach for the single-component gas, discussed above. For gas mixtures consisting of simple molecules, Revised Enskog Theory has been shown to accurately represent both the density- and temperature dependence of the viscosity over a wide range of conditions.
Sources: en.wikipedia.org
== Publishers == George Haven Putnam* (1864), publisher of G. P. Putnam's Sons, son of publisher George Palmer Putnam Henry S. Harper (1888), director of Harper and Brothers, Titanic survivor Bernard H. Ridder (1903), publisher of The St. Paul Dispatch and The Pioneer Press, chairman emeritus of Ridder Publications Alfred Harcourt (1904) and Donald Brace (1904), founders of Harcourt Brace Joseph E. Ridder (1907), publisher of The Journal of Commerce and chairman of Ridder Publications John Neville Wheeler (1908), founder and owner of the North American Newspaper Alliance and Bell Syndicate Harold Latham (1909), editor-in-chief of Macmillan Inc., known for discovering Margaret Mitchell Alfred A. Knopf (1912), founder and chairman of Alfred A. Knopf George T. Delacorte Jr. (1913), founder of Dell Publishing Arthur Hays Sulzberger (1913), publisher of The New York Times Douglas Black (1916), president of Doubleday and Company Bennett Cerf (1920), founder of Random House Donald S. Klopfer* (1922), founder of Random House Richard L. Simon (1920) and Max Lincoln Schuster (1919), co-founders of Simon & Schuster Elliott V. Bell (1925), former editor and publisher of Businessweek David A. Boehm (1934), founder of Sterling Publishing Robert Giroux (1936), chairman of Farrar, Straus and Giroux Ian Ballantine (1938), founder of Ballantine Books Walter B. Pitkin Jr. (1938), editor-in-chief and executive vice president of Bantam Books William D.
=== Ischemia === Ischemia is an important factor in the formation and persistence of wounds, especially when it occurs repetitively (as it usually does) or when combined with a patient's old age. Ischemia causes tissue to become inflamed and cells to release factors that attract neutrophils such as interleukins, chemokines, leukotrienes, and complement factors. While they fight pathogens, neutrophils also release inflammatory cytokines and enzymes that damage cells. One of their important jobs is to produce Reactive Oxygen Species (ROS) to kill bacteria, for which they use an enzyme called myeloperoxidase. The enzymes and ROS produced by neutrophils and other leukocytes damage cells and prevent cell proliferation and wound closure by damaging DNA, lipids, proteins, the extracellular matrix (ECM), and cytokines that speed healing. Neutrophils remain in chronic wounds for longer than they do in acute wounds, and contribute to the fact that chronic wounds have higher levels of inflammatory cytokines and ROS. Since wound fluid from chronic wounds has an excess of proteases and ROS, the fluid itself can inhibit healing by inhibiting cell growth and breaking down growth factors and proteins in the ECM. This impaired healing response is considered uncoordinated. However, soluble mediators of the immune system (growth factors), cell-based therapies and therapeutic chemicals can propagate coordinated healing.
== Research progress == Cannabinoids have multiple therapeutic potentials, including pain, nausea and vomiting, feeding disorder, glaucoma, neurodegeneration, multiple sclerosis, schizophrenia, cancer, epilepsy, stress and anxiety. There are ongoing investigations on the currently marketed drugs, exploring their therapeutic potentials on top of the existing medical uses. For instance, some recent studies have illustrated the antitumor effects of CBD, with the underlying mechanisms being the induction of cell cycle arrest and autophagy, promotion of apoptosis, modulation of angiogenesis, and inhibition of tumor cell migration and invasion. Several clinical reports also showed that CBD can be used to treat cancer. The use of other cannabinoid receptor modulators are also under investigations. Olorinab, Ajulemic acid, NTRX-07 and CNTX-6016 are examples of the new cannabinoid receptors modulators undergoing different stages of clinical trials for their respective therapeutic uses, such as treating Alzheimer's disease and diabetic neuropathy.
Steven Eugene Wilson (born 1951) is an American ophthalmologist and professor at Cleveland Clinic, where he is a surgeon and directs corneal research. He has also received honors for several published historical fiction novels. His research has focused on corneal cellular responses to injury and surgery, with his most-cited work being about keratocyte apoptosis, as well as cellular and molecular interactions involved in homeostasis, wound healing, and diseases of the cornea. He holds two United States patents related to corneal healing. He previously served as a professor and chair of the Department of Ophthalmology at the University of Washington in Seattle from 1998 to 2003, and was named Grace E. Hill Endowed Chair in Vision Research.
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.
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.