The short version of Lyophilisation fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-05. Anything still debated is marked as such rather than presented as settled.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
=== Pharmacodynamics === Methocinnamox is an opioid receptor antagonist, it works at the μ-opioid receptor. By acting as an antagonist, it binds to the receptor but does not activate it, thus blocking the action of agonists such as heroin and fentanyl. It is a pseudo-irreversible non-competitive antagonist of the μ-opioid receptor and a competitive antagonist of the κ- and δ-opioid receptors. Methocinnamox has affinity values for the opioid receptors of 0.6 nM for the μ-opioid receptor, 2.2 nM for the δ-opioid receptor, and 4.9 nM for the κ-opioid receptor. Hence, it has about 3.7-fold preferential affinity for the μ-opioid receptor over the δ-opioid receptor and about 8.2-fold higher affinity for the μ-opioid receptor over the κ-opioid receptor. The antagonism of the μ-opioid receptor by methocinnamox is not irreversible as the drug does not form a covalent bond with the receptor. This is in contrast to prototypical μ-opioid receptor alkylating agents like β-funaltrexamine and β-chlornaltrexamine. However, in spite of its lack of covalent binding to the μ-opioid receptor, methocinnamox appears to not dissociate from the μ-opioid receptor or dissociates from it extremely slowly. Hence, methocinnamox has been described as a pseudo-irreversible antagonist of the μ-opioid receptor or as a "functionally irreversible" antagonist. The mechanism underlying the pseudo-irreversible antagonism of methocinnamox hasn't been fully elucidated.
For example, enteric coatings only dissolve in the basic environment of the intestines. Drugs held in solution do not need to be dissolved before being absorbed. Lipid-soluble drugs are absorbed more rapidly than water-soluble drugs.
Bariatric surgery ("weight loss surgery") is the use of surgical intervention in the treatment of obesity. As every operation may have complications, surgery is only recommended for severely obese people (BMI > 40) who have failed to lose weight following dietary modification and pharmacological treatment. Weight loss surgery relies on various principles: the two most common approaches are reducing the volume of the stomach (e.g. by adjustable gastric banding and vertical banded gastroplasty), which produces an earlier sense of satiation, and reducing the length of bowel that comes into contact with food (e.g. by gastric bypass surgery or endoscopic duodenal-jejunal bypass surgery), which directly reduces absorption. Band surgery is reversible, while bowel shortening operations are not. Some procedures can be performed laparoscopically. Complications from weight loss surgery are frequent. Surgery for severe obesity is associated with long-term weight loss and decreased overall mortality. One study found a weight loss of between 14% and 25% (depending on the type of procedure performed) at 10 years, and a 29% reduction in all cause mortality when compared to standard weight loss measures. A marked decrease in the risk of diabetes mellitus, cardiovascular disease and cancer has also been found after bariatric surgery. Marked weight loss occurs during the first few months after surgery, and the loss is sustained in the long term.
These attempts were unsuccessful, but presaged the use of hydroxyurea as a treatment modality. In addition, Beutler designed the first artificial storage media for red blood cells, introduced the use of mannitol (still a mainstay in red cell preservation), and devised a variety of approaches to maintaining red cell ATP and 2,3-DPG levels and determined the viability of the cells in human volunteers. He also played a major role in pioneering new therapies for leukemia: bone marrow transplantation in acute leukemia, and 2-chorodeoxyadenosine in chronic leukemias and lymphomas. Beginning in the mid-1990s, Beutler attempted to positionally clone the mutation responsible for the common adult-onset form of hereditary hemochromatosis. He failed to identify the mutation before it was found by others to affect HFE, a member of the major histocompatibility complex family of proteins. However, in contrast to the reports of others, he found that only about 2% of males and no females homozygous for the mutation showed severe clinical manifestations of the disease. This study depended upon genotypic and phenotypic analysis of more than 43,000 subjects. Beutler served as an editor of Williams Hematology, a widely used text in this medical specialty, for more than 20 years: from its inception until the last year of his life. In keeping with his editorial interests and his requirements as a publishing scientist, Beutler also wrote the software for the first comprehensive bibliographic retrieval system used by publishing scientists.
Sources: en.wikipedia.org
== Contaminant == A contaminant is a substance present in nature at a level higher than fixed levels or that would not otherwise be there. This may be due to human activity and bioactivity. The term contaminant is often used interchangeably with pollutant, which is a substance that detrimentally impacts the surrounding environment. While a contaminant is sometimes a substance in the environment as a result of human activity, but without harmful effects, it is sometimes the case that toxic or harmful effects from contamination only become apparent at a later date. The "medium" such as soil or organism such as fish affected by the pollutant or contaminant is called a receptor, whilst a sink is a chemical medium or species that retains and interacts with the pollutant such as carbon sink and its effects by microbes.
== Products and services == Railway freight: Rolling stock, components (bogies, couplers, locomotive shells, gears); Railway transit: Rolling stock (electric locomotives, EMU trainsets, DEMU trainsets, metros, body shells, bogies, propulsion & electrical equipment); Automobile: Commercial electric vehicles, commercial vehicle load bodies; Containers: Marine container, refrigerated container, truck mounted container & cold chain transport container
This is a list of dried foods. Food drying is a method of food preservation that works by removing water from the food, which inhibits the growth of bacteria and has been practiced worldwide since ancient times to preserve food. Where or when dehydration as a food preservation technique was invented has been lost to time, but the earliest known practice of food drying is 12000 BC by inhabitants of the modern Middle East and Asia.
Sources: en.wikipedia.org
==== Dol ==== The dol (from the Latin word for pain, dolor) is a unit of measurement for pain. James D. Hardy, Herbert G. Wolff, and Helen Goodell of Cornell University proposed the unit based on their studies of pain during the 1940s and 1950s. They defined one dol to equal a just-noticeable difference in pain. The unit never came into widespread use and other methods are now used to assess the level of pain experienced by patients.
Original – Classic brewed hard tea. Tea + Lemonade – A combination of sweet tea and citrus. Peach – A bold, juicy peach twist. Green Tea – A smooth and earthy green tea blend. Packaging includes 12 U.S. fl oz (350 mL) variety packs and 24 US fl oz (710 mL) singles, as well as 16 US fl oz (473 mL) depending on the flavor.
== Founding of Novo Terapeutisk Laboratorium == In 1924 a dispute occurred at Nordisk: Thorvald was fired by Hans Christian Hagedorn, co-founder of Nordisk, and Harald resigned in solidarity. In February 1925 the brothers formally founded Novo Terapeutisk Laboratorium. The company developed a dedicated insulin production facility and a specialty injection device (the "Novo Syringe").
=== Age-related changes === Aging affects multiple layers of the eyelid, leading to skin laxity, weakening of the orbital septum, fat herniation, and volume loss. These changes contribute to upper eyelid hooding and lower eyelid contour irregularities.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.