The short version of lyophilization fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-10-20. Anything still debated is marked as such rather than presented as settled.
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.
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.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
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.
| Property | Value | Notes |
|---|---|---|
| Solubility | Freely soluble in water | Also in aqueous buffers |
| Typical purity (HPLC) | 95 percent or higher | Lot-dependent |
| Dry powder storage | Minus 20 degrees Celsius | Sealed, dry, protected from light |
| Solution storage | 2 to 8 degrees Celsius | Short-term use |
| Identity confirmation | Mass spectrometry | ESI or MALDI-TOF |
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
The Maluku Islands, historically known as the "Spice Islands", are a region in Indonesia known for producing nutmeg, mace, cloves, and pepper, and were a major source of these spices in the world. The presence of these spices in the Maluku Islands sparked European interest to buy them directly in the 16th century. Black pepper was a well-known and widespread, if expensive, seasoning in the Roman Empire. Apicius' De re coquinaria, a third-century cookbook probably based at least partly on one from the first century CE, includes pepper in a majority of its recipes. In the 18th century, Edward Gibbon wrote that pepper was "a favorite ingredient of the most expensive Roman cookery". In the third century CE, black pepper made its first definite appearance in Chinese texts, as hujiao or "foreign pepper". It does not appear to have been widely known at the time, failing to appear in a fourth-century work describing a wide variety of spices from beyond China's southern border, including long pepper. By the 12th century, however, black pepper had become a popular ingredient in the cuisine of the wealthy and powerful, sometimes taking the place of China's native Sichuan pepper (the tongue-numbing dried fruit of an unrelated plant).
The defence submitted that there was no case to answer on the air‑embolism allegations, arguing that the prosecution's experts lacked sufficient clinical experience, that the research basis for air embolism was inconsistent, and that expert descriptions of the condition varied. Goss ruled that there was "a sufficient body of accepted medical opinion" to allow the allegation to be considered by the jury.
== Function == The melanocortin system is one of the mammalian body's tools to regulate food intake in a push-pull fashion. The only neurons known to release melanocortins are located in the arcuate nucleus of the hypothalamus. However, melanocortins are also produced by keratinocytes in response to UV exposure. Accordingly, there is a subpopulation called POMC neurons and one called AgRP neurons. When POMC neurons release α-MSH, appetite is decreased. On the other hand, when AgRP neurons release AgRP, appetite is stimulated. Leptin, the energy surfeit hormone, and Ghrelin, the hunger hormone, are upstream regulators of the melanocortin system in the brain. These hormones also regulate the release of peptides other than the melanocortins. Disturbance of the leptin-melanocortin pathway can lead to early onset obesity as well as various metabolic disorders and suppressed immune function.
=== US rationale === The Trump administration did not initially announce any specific legal authority for the first strike. Secretary of Defense Pete Hegseth declared, "We have the absolute and complete authority", citing "... the defense of the American people alone. 100,000 Americans were killed each year under the previous administration because of an open border and open drug traffic flow. That is an assault on the American people." Regarding the initial strike, the Trump administration did not provide evidence about the vessel's cargo, nor did it establish that the vessel's crew were threatening to attack. Trump was questioned on 5 September about the legality of the first strike, to which he responded: "We don't want drugs killing our people. I believe we lost 300,000 ... last year"—a number he repeated days later in an Oval Office meeting. Drug overdose deaths in the US in 2024 were about 80,000 according to the US Centers for Disease Control and Prevention, representing a 25 percent decline from the previous year deaths of 112,910. When speaking impromptu to reporters prior to boarding Air Force One on 14 September, Trump inflated that number to 300 million. CNN states that "allegations involving [Venezuela's] presidential palace in cocaine trafficking have existed for at least a decade." Former US Attorney General William Barr first accused Maduro of supporting drug trafficking in 2020, stating that 250 tons of cocaine are smuggled through Venezuela annually, facilitated by the government, although no evidence was presented.
== Self-replication == "Molecular assemblers" have been confused with self-replicating machines. To produce a practical quantity of a desired product, the nanoscale size of a typical science fiction universal molecular assembler requires an extremely large number of such devices. However, a single such theoretical molecular assembler might be programmed to self-replicate, constructing many copies of itself. This would allow an exponential rate of production. Then, after sufficient quantities of the molecular assemblers were available, they would then be re-programmed for production of the desired product. However, if self-replication of molecular assemblers were not restrained then it might lead to competition with naturally occurring organisms. This has been called ecophagy or the grey goo problem. One method of building molecular assemblers is to mimic evolutionary processes employed by biological systems. Biological evolution proceeds by random variation combined with culling of the less-successful variants and reproduction of the more-successful variants. Production of complex molecular assemblers might be evolved from simpler systems since "A complex system that works is invariably found to have evolved from a simple system that worked. . . . A complex system designed from scratch never works and can not be patched up to make it work. You have to start over, beginning with a system that works." However, most published safety guidelines include "recommendations against developing ... replicator designs which permit surviving mutation or undergoing evolution".
Sources: en.wikipedia.org
A 2023 systematic review found that paroxetine was among the SSRIs most frequently reported in PSSD case reports, alongside escitalopram, citalopram, sertraline, and fluoxetine. Paroxetine's high rate of on-treatment sexual dysfunction relative to other SSRIs, combined with its severe withdrawal profile, may make persistent post-discontinuation sexual effects particularly difficult for patients and clinicians to distinguish from withdrawal symptoms. In 2019, the European Medicines Agency's Pharmacovigilance Risk Assessment Committee (PRAC) recommended that product labels for all SSRIs and SNRIs, including paroxetine, be updated to state that sexual dysfunction may be long-lasting even after treatment is stopped. Health Canada followed with similar label updates in 2021. In 2024, Australia's Therapeutic Goods Administration aligned all SSRI and SNRI product information to reflect this risk.
==== European Union ==== In February 2016, orphan designation (EU/3/16/1615) was granted by the European Commission to Gilead Sciences International Ltd, United Kingdom, for remdesivir for the treatment of Ebola virus disease. In April 2020, the European Medicines Agency (EMA) provided recommendations on compassionate use of remdesivir for COVID‑19 in the EU. In May 2020, the Committee for Medicinal Products for Human Use (CHMP) of the EMA recommended expanding the compassionate use of remdesivir to those not on mechanical ventilation. In addition to those undergoing invasive mechanical ventilation, the compassionate use recommendations cover the treatment of hospitalized individuals requiring supplemental oxygen, non-invasive ventilation, high-flow oxygen devices or ECMO (extracorporeal membrane oxygenation). The updated recommendations were based on preliminary results from the NIAID-ACTT study, which suggested a beneficial effect of remdesivir in the treatment of hospitalized individuals with severe COVID‑19. In addition, a treatment duration of five days was introduced alongside the longer ten-day course, based on preliminary results from another study (GS-US-540-5773) suggesting that for those not requiring mechanical ventilation or ECMO, the treatment course may be shortened from ten to five days without any loss of efficacy. Individuals who receive a five-day treatment course but do not show clinical improvement will be eligible to continue receiving remdesivir for an additional five days.
As of 2025, the artificial intelligence (AI) market in the United Kingdom is worth over £21 billion, and is expected to exceed £1 trillion by 2035. It is the world's third-largest AI market and consistently ranked 3rd in private AI funding between 2013 and 2024, both behind the United States and China. The country ranked fifth globally in a 2024 report on AI development by Stanford University. In the first (2024) edition of GIRAI, the United Kingdom was ranked 4th out of 138 countries assessed and in the second (2026) edition, the country rank fell to 7th out of 135 countries. The UK AI market is valued at over £21 billion in 2025 and projected to exceed £1 trillion by 2035. The UK's prominence is rooted in a strong historical foundation, beginning with Alan Turing's theoretical work in the 1930s and 1940s, and the establishment of early AI research centres in the 1960s, such as those at the University of Edinburgh. Despite periods of reduced funding known as "AI winters", modern UK AI research has seen significant breakthroughs, most notably through London-based DeepMind's achievements in deep reinforcement learning and protein structure prediction. The UK AI sector has experienced rapid growth. The number of AI companies increased by 85% between 2022 and 2024, reaching 5,862 firms. In 2024, the sector generated an estimated £23.9 billion in revenue and £11.8 billion in Gross Value Added (GVA), employing over 86,000 people.
=== UK === In the UK, clinical psychologists undertake a Doctor of Clinical Psychology (DClinPsych), which is a practitioner doctorate with both clinical and research components. This is a three-year full-time salaried program sponsored by the National Health Service (NHS) and based in universities and the NHS. Entry into these programs is highly competitive and requires at least a three-year undergraduate degree in psychology plus some form of experience, usually in either the NHS as an assistant psychologist or in academia as a research assistant. It is not unusual for applicants to apply several times before being accepted onto a training course as only about one-fifth of applicants are accepted each year. These clinical psychology doctoral degrees are accredited by the British Psychological Society and the Health and Care Professions Council (HCPC). The HCPC is the statutory regulator for practitioner psychologists in the UK. Those who successfully complete clinical psychology doctoral degrees are eligible to apply for registration with the HPC as a clinical psychologist. In the UK, registration as a clinical psychologist with the Health and Care Professions Council (HCPC) is necessary. The HCPC is the statutory regulator for practitioner psychologists in the UK. In the UK the following titles are restricted by law "registered psychologist" and "practitioner psychologist"; in addition, the specialist title "clinical psychologist" is also restricted by law.
They study the effects of foods, drugs, allergens and other substances on living tissues; they research molecular biology, the study of life at the molecular level and the study of genes and gene expression; and they study chemical reactions in metabolism, growth, reproduction, and heredity, and apply techniques drawn from biotechnology and genetic engineering to help them in their research. About 75% work in either basic or applied research; those in applied research take basic research and employ it for the benefit of medicine, agriculture, veterinary science, environmental science, and manufacturing. Each of these fields allows specialization; for example, clinical biochemists can work in hospital laboratories to understand and treat diseases, and industrial biochemists can be involved in analytical research work, such as checking the purity of food and beverages. Biochemists in the field of agriculture research the interactions between herbicides with plants. They examine the relationships of compounds, determining their ability to inhibit growth, and evaluate the toxicological effects surrounding life. Biochemists also prepare pharmaceutical compounds for commercial distribution. Modern biochemistry is considered a sub-discipline of the biological sciences, due to its increased reliance on, and training, in accord with modern molecular biology. Historically, even before the term biochemist was formally recognized, initial studies were performed by those trained in basic chemistry, but also by those trained as physicians.
Sources: en.wikipedia.org
Although all known members of the class possess relevant enzyme induction capabilities, the degree of induction overall as well as the impact on each specific enzyme span a broad range, with phenobarbital and secobarbital being the most potent enzyme inducers and butalbital and talbutal being among the weakest enzyme inducers in the class. People who are known to have killed themselves by barbiturate overdose include Stefan Zweig, Charles Boyer, Ruan Lingyu, Dalida, Jeannine Deckers, Felix Hausdorff, Abbie Hoffman, Phyllis Hyman, Carole Landis, C. P. Ramanujam, George Sanders, Jean Seberg, Lupe Vélez and the members of Heaven's Gate cult. Others who have died as a result of barbiturate overdose include Pier Angeli, Brian Epstein, Judy Garland, Jimi Hendrix, Inger Stevens, Dinah Washington, Ellen Wilkinson, and Alan Wilson; in some cases these have been speculated to be suicides as well. Those who died of a combination of barbiturates and other drugs include Rainer Werner Fassbinder, Dorothy Kilgallen, Malcolm Lowry, Edie Sedgwick, Marilyn Monroe, and Kenneth Williams. Dorothy Dandridge died of either an overdose or an unrelated embolism. Ingeborg Bachmann may have died of the consequences of barbiturate withdrawal (she was hospitalized with burns, the doctors treating her were not aware of her barbiturate addiction).
Azacitidine, sold under the brand name Vidaza among others, is a medication used for the treatment of myelodysplastic syndrome, myeloid leukemia, and juvenile myelomonocytic leukemia. It is a chemical analog of cytidine, a nucleoside in DNA and RNA. Azacitidine and its deoxy derivative, decitabine (also known as 5-aza-2′-deoxycytidine) were first synthesized in Czechoslovakia as potential chemotherapeutic agents for cancer. The most common adverse reactions in children with juvenile myelomonocytic leukemia include pyrexia, rash, upper respiratory tract infection, and anemia.
Fatty acids are also synthesized de novo within tissues with high metabolic demands, such as mammary glands (i.e., for milk fat production during lactation), immune cells (i.e., macrophages, B cells, T cells), and even within the brain (i.e., during neurogenesis). Notably, although saturated and monounsaturated fatty acids are considered non-essential, both saturated and monounsaturated fatty acids can be synthesized de novo alongside polyunsaturated fatty acids. De novo fatty acid synthesis is separated into two groups based on the compartment wherein fatty acid synthesis takes place: cytosolic fatty acid synthesis (FAS/FASI) and mitochondrial fatty acid synthesis (mtFAS/mtFASII).
== Etymology == The term "botany" comes from the Ancient Greek word botanē (βοτάνη) meaning "pasture", "herbs" "grass", or "fodder"; Botanē is in turn derived from boskein (Greek: βόσκειν), "to feed" or "to graze". Traditionally, botany has also included the study of fungi and algae by mycologists and phycologists respectively, with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress.
Sources: en.wikipedia.org
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.
Freeze-dried material is kept frozen, often at minus 20 degrees Celsius, and protected from light and moisture. Dissolved peptide is refrigerated for short-term use. Repeated freeze-thaw cycles are avoided.
A certificate of analysis typically lists purity by HPLC, the confirmed mass, appearance, and sometimes water or counter-ion content. It documents results for a specific batch. Details vary by supplier.
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.