The short version of lyophilized powder fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-10-25 and is reviewed periodically as new material appears.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
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.
which means that the divergence of the velocity field is zero everywhere. Physically, this is equivalent to saying that the local volume dilation rate is zero, hence a flow of water through a converging pipe will adjust solely by increasing its velocity as water is largely incompressible.
Essendon Hall of Fame Legends (year inducted): Bill Brew (2013), Bill Busbridge (1996), Jack Clarke (1996), John Coleman (1996), Bill Cookson (1996), Wally Crichton (2010), Terry Daniher (1996), Barry Davis (2006), Ron Evans (2012), Tom Fitzmaurice (1996), Ken Fraser (1996), Allan Hird Sr (1996), James Hird (2011), Harry Hunter (2015), Bill Hutchison (1996), Matthew Lloyd (2013), Simon Madden (1996), Alex McCracken (1996), Michael Long (2010), Howard Okey (2012), Frank Reid (1996), Dick Reynolds (1996), Greg Sewell (2009), Kevin Sheedy (2008), Albert Thurgood (1996), Tim Watson (1998), Neale Daniher* (2018), Dustin Fletcher*, Dr Bruce Reid* (2014), Gavin Wanganeen* *denotes recent elevation to Legend status Essendon Hall of Fame members (year inducted): Noel Allanson (2015), Fred Baring (2013), John Birt (2010), Reg Burgess (2015), Wally Buttsworth (2010), Barry Capuano (2014), Kevin Egan (2015), Alec Epis (2014), Ken Fletcher (2011), Keith Forbes (2010), Garry Foulds (2010), Darryl Gerlach (2013), Mark Harvey (2014), Bruce Heymanson (2013), Jack Jones (2012), Ron Kirwan (2016), Harold Lambert (2018), Scott Lucas (2013), Roy McConnell (2013), Don McKenzie (2010), Roger Merrett (2018), Joe Misiti (2012), Hugh Mitchell (2012), Graham Moss (2012), Gary O'Donnell (2014), Dr Ian Reynolds (2018), Paul Salmon (2012), David Shaw (2011), Arthur Showers (2010), George Stuckey (2010), Hugh Torney (2011), Paul Vander Haar (2015)
Rather, in the 10 years from 1980 to 1990, it grew 10-fold." According to a report commissioned by the Drug Policy Alliance, and released in March 2006 by the Justice Policy Institute, harsher sentences for drug offenses committed in drug-free school zones are ineffective at keeping youths away from drugs and instead create strong racial disparities in the judicial system. According to data collected by the Federal Bureau of Prisons 45.3% of all criminal charges were drug related and 25.5% of sentences for all charges last 5–10 years. Furthermore, non-whites make up 41.4% of the federal prison system's population and over half are under the age of 40. The Bureau of Justice Statistics states that over 80% of all drug related charges are for mere possession rather than the sale or manufacture of drugs.
SIMS is a mass spectrometry method to measure small-scale elemental and isotopic variations of samples. Its ability to measure in spots with a narrow diameter (10–40 μm) makes it a useful tool to date small (<100 μm) mineral grains and individual domains within a single crystal. SIMS can achieve a precision of ~3%. Sensitive high-resolution ion microprobe (SHRIMP) is widely regarded as a powerful tool among SIMS. SIMS analyzes the mineral surface (a few μm) composition by sputtering the surface with a focused primary ion beam under vacuum. The secondary ions liberated from the mineral are accelerated, measured and analyzed in the mass spectrometer. Sample are analysed in rotation with a standard of known elemental or isotopic ratios in order to determine the ratios in the sample for dating.
The Soviet Union's alternative to the Marshall Plan, which was purported to involve Soviet subsidies and trade with central and eastern Europe, became known as the Molotov Plan (later institutionalized in January 1949 as the Council for Mutual Economic Assistance). Stalin was also fearful of a reconstituted Germany; his vision of a post-war Germany did not include the ability to rearm or pose any kind of threat to the Soviet Union. In early 1948, Czech Communists executed a coup d'état in Czechoslovakia (resulting in the formation of the Czechoslovak Socialist Republic), the only Eastern Bloc state that the Soviets had permitted to retain democratic structures. The public brutality of the coup shocked Western powers more than any event up to that point and swept away the last vestiges of opposition to the Marshall Plan in the United States Congress. In an immediate aftermath of the crisis, the London Six-Power Conference was held, resulting in the Soviet boycott of the Allied Control Council and its incapacitation, an event marking the beginning of the full-blown Cold War, as well as ending any hopes at the time for a single German government and leading to formation in 1949 of the Federal Republic of Germany and German Democratic Republic. The twin policies of the Truman Doctrine and the Marshall Plan led to billions in economic and military aid for Western Europe, Greece, and Turkey. With the US assistance, the Greek military won its civil war.
Sources: en.wikipedia.org
One interview in 2015 with the then Director of the White House Office of National Drug Control Policy under the Obama administration, Michael Botticelli, where he states that because opioid users are predominantly 'white and middle class', they "know how to call a legislator, [and] fight with their insurance company." In October 2017, Marino withdrew his nomination after it was reported that his relationship with the drug industry might be a conflict of interest. In July 2017, FDA commissioner Scott Gottlieb stated that for the first time, pharmacists, nurses, and physicians would have training made available on appropriate prescribing of opioid medicines, because opioid addiction had become the "FDA's biggest crisis". Trump nominated his then deputy chief-of-staff, James Carroll as the acting director of the Office of National Drug Control Policy in 2018. In January 2019, Carroll was approved by the Senate. In April 2017, the Department of Health and Human Services announced their "Opioid Strategy" consisting of five aims:
== Treatment == Gilbert's syndrome is a benign condition that typically requires no medical treatment. The primary approach involves patient education and reassurance about the harmless nature of the syndrome. Episodes of jaundice, when they occur, are usually mild and resolve on their own without intervention. To minimize the frequency of these episodes, individuals are advised to avoid known triggers such as fasting, dehydration, stress, and strenuous physical exertion. Maintaining a healthy lifestyle, including regular meals and adequate hydration, can help manage the condition effectively. If jaundice is significant, phenobarbital may be used.
As the environments of most organisms are constantly changing, the reactions of metabolism must be finely regulated to maintain a constant set of conditions within cells, a condition called homeostasis. Metabolic regulation also allows organisms to respond to signals and interact actively with their environments. Two closely linked concepts are important for understanding how metabolic pathways are controlled. Firstly, the regulation of an enzyme in a pathway is how its activity is increased and decreased in response to signals. Secondly, the control exerted by this enzyme is the effect that these changes in its activity have on the overall rate of the pathway (the flux through the pathway). For example, an enzyme may show large changes in activity (i.e. it is highly regulated) but if these changes have little effect on the flux of a metabolic pathway, then this enzyme is not involved in the control of the pathway.
=== Controversy and conservation issues === The use and trade of elephant ivory have become controversial because they have contributed to seriously declining elephant populations in many countries. It is estimated that consumption in Great Britain alone in 1831 amounted to the deaths of nearly 4,000 elephants. In 1975, the Asian elephant was placed on Appendix I of the Convention on International Trade in Endangered Species (CITES), which prevents international trade between member states of species that are threatened by trade. The African elephant was placed on Appendix I in January 1990. Since then, some southern African countries have had their populations of elephants "downlisted" to Appendix II, allowing the domestic trade of non-ivory items; there have also been two "one off" sales of ivory stockpiles. In June 2015, more than a ton of confiscated ivory was crushed in New York City's Times Square by the Wildlife Conservation Society to send a message that the illegal trade will not be tolerated. The ivory, confiscated in New York and Philadelphia, was sent up a conveyor belt into a rock crusher. The Wildlife Conservation Society has pointed out that the global ivory trade leads to the slaughter of up to 35,000 elephants a year in Africa. In June 2018, Conservative MEPs' Deputy Leader Jacqueline Foster MEP urged the EU to follow the UK's lead and introduce a tougher ivory ban across Europe. China was the biggest market for poached ivory but announced they would phase out the legal domestic manufacture and sale of ivory products in May 2015.
Ibogaine is a psychoactive indole alkaloid derived from plants such as Tabernanthe iboga, characterized by hallucinogenic and oneirogenic effects. Ibogaine exhibits complex pharmacology by interacting with multiple neurotransmitter systems, notably affecting opioid, serotonin, sigma, NMDA, and nicotinic acetylcholine receptors; its metabolite noribogaine primarily acts as a serotonin reuptake inhibitor and κ-opioid receptor agonist. The psychoactivity of the root bark of the iboga tree, T. iboga, one of the plants from which ibogaine is extracted, was first discovered by forager tribes in Central Africa, who passed the knowledge to the Bwiti tribe of Gabon. It was first documented in the 19th century for its spiritual use, later isolated and synthesized for its psychoactive properties, briefly marketed in Europe as a stimulant, and ultimately controversially researched for its potential in treating addiction despite being classified as a controlled substance. Ibogaine can be semisynthetically produced from voacangine, with its total synthesis achieved in 1956 and its structure confirmed by X-ray crystallography in 1960. Its clinical use and development have been limited due to regulatory barriers and serious safety risks, such as toxicity to the heart. Ibogaine produces a two-phase experience—initially visionary and dream-like with vivid imagery and altered perception, followed by an introspective period marked by lingering side effects, such as nausea and mood disturbances, which may persist for days.
Sources: en.wikipedia.org
The members of Es La Guerilla wanted to move in a different musical direction, but had rehearsed very little with Kévone, the band's singer, before entering the recording studio. Kévone was less interested in the band's new direction. After a while, Nackphouminh tried his hand at singing.
In response to the potential ban, many users signed up for the Chinese app Xiaohongshu (Chinese: 小红书), known internationally as REDnote. On 18 January 2025, hours before the bill went into effect, TikTok became unavailable across the country. The next day, TikTok restored access to their service after re-elected US President Donald Trump assured TikTok he would not enforce the law. President Trump signed an executive order on 20 January 2025, delaying the enforcement of the TikTok ban by 75 days. In April 2025, President Trump signed another executive order further delaying the enforcement of the TikTok ban by 75 days, and did so again in June 2025 with a 90-day extension. The Department of Justice's Office of Legal Counsel determined that TikTok USDS, the version of TikTok operated by the TikTok U.S. Data Security Joint Venture, was not subject to the No TikTok on Government Devices Act, thereby permitting employees to use TikTok on government devices, subject to agency discretion and workplace policies.
The concentration of erbium in the Earth’s crust is about 2.8 mg/kg and in seawater 0.9 ng/L. (Concentration of less abundant elements may vary with location by several orders of magnitude making the relative abundance unreliable). Like other rare earths, this element is never found as a free element in nature but is found in monazite and bastnäsite ores. It has historically been very difficult and expensive to separate rare earths from each other in their ores but ion-exchange chromatography methods developed in the late 20th century have greatly reduced the cost of production of all rare-earth metals and their chemical compounds. The principal commercial sources of erbium are from the minerals xenotime and euxenite, and most recently, the ion adsorption clays of southern China. Consequently, China has now become the principal global supplier of this element. In the high-yttrium versions of these ore concentrates, yttrium is about two-thirds of the total by weight, and erbia is about 4–5%. When the concentrate is dissolved in acid, the erbia liberates enough erbium ion to impart a distinct and characteristic pink color to the solution. This color behavior is similar to what Mosander and the other early workers in the lanthanides saw in their extracts from the gadolinite minerals of Ytterby.
=== Condiments === Hot dogs are commonly served with one or more condiments. In 2005, the US-based National Hot Dog & Sausage Council (part of the American Meat Institute) found mustard to be the most popular, preferred by 32% of respondents; 23% favored ketchup; 17% chili; 9% pickle relish, and 7% onions. Other toppings include sauerkraut, mayonnaise, lettuce, tomato, cheese, and chili peppers.
In addition, acetylcysteine in aqueous solution can undergo hydrolysis, leading to the breakdown of the amide bond in the molecule. Still, aqueous solutions of acetylcysteine are generally stable when stored properly: the solutions should be kept in tightly sealed containers and stored at controlled room temperature to prolong the stability. Acetylcysteine has been reported to have a pH of 2.2 when administered through inhalation.
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
Identity is confirmed by matching the retention time in reversed-phase chromatography against a reference standard and by measuring the molecular mass with mass spectrometry. Tandem mass spectrometry or amino acid analysis can verify the sequence of the seven residues. Because the peptide contains no aromatic amino acids, detection at 280 nm is not useful.