The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-18. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Principal proposed target | GABA-A receptor complex | Hypothesis derived mainly from animal pharmacology |
| Common behavioral assay | Elevated plus maze | Rodent test for anxiety-like behavior |
| Reported molecular marker | Hippocampal BDNF expression | Measured by immunoassay or mRNA quantification |
| Typical dosing route | Intranasal | Chosen to reduce first-pass metabolism |
| Reported plasma half-life | Minutes | Based on limited peptide stability data |
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
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.
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.
=== Congregation for the Causes of Saints === On 8 May 1969, Pope Paul VI issued the apostolic constitution Sacra Rituum Congregatio, separating the Congregation into two parts: The Congregation for the Divine Worship and the renamed Sacred Congregation for the Causes of Saints, which was given three offices, those of the judiciary, the Promoter General of the Faith, and the historical-juridical. With the changes in the canonization process introduced by Pope John Paul II in 1983, a College of Relators, with five relators (priests appointed to oversee the canonisation process), was added to prepare the cases of those declared as Servants of God. In January 2014, the Prefect of the Congregation announced that at the direction of Pope Francis those working on canonizations must adhere to financial guidelines to eliminate unfairness in the treatment of cases based on the financial resources provided. According to L'Osservatore Romano, Pope Francis hoped to promote the causes of those less well-known, those from poorer regions, and those who were victims of 20th-century totalitarian persecutions.
Paracetamol is available in oral, suppository, and intravenous forms. Intravenous paracetamol is sold under the brand name Ofirmev in the United States. In some formulations, paracetamol is combined with the opiate codeine, sometimes referred to as co-codamol (BAN) and Panadeine in Australia. In the U.S., this combination is available only by prescription. As of 1 February 2018, medications containing codeine also became prescription-only in Australia. Paracetamol is also combined with other opioids such as dihydrocodeine, referred to as co-dydramol (British Approved Name (BAN)), oxycodone or hydrocodone. Another very commonly used analgesic combination includes paracetamol in combination with propoxyphene napsylate. A combination of paracetamol, codeine, and the doxylamine succinate is also available. Paracetamol is also available combined with butalbital and caffeine as a treatment for tension and migraine headaches. Paracetamol is sometimes combined with phenylephrine hydrochloride. Sometimes a third active ingredient, such as ascorbic acid, caffeine, chlorpheniramine maleate, or guaifenesin is added to this combination.
A cryoEM structure of the 50S subunit from the archaeon Methanothermobacter thermautotrophicus has been determined. It shares the 50S size/sedimentation rate and the two rRNA count, but its 23S expansion segments have more in common with eukaryotes. A cryoEM reconstruction of the native 50S subunit of the extremely halophilic Archaean Halococcus morrhuae (classified under Euryarchaeota; Stenosarchaea group) is available. The 50S subunit contains a 108‐nucleotide insertion in its 5S rRNA, which at subnanometer resolution, is observed to emerge from a four‐way junction without affecting the parental canonical 5S rRNA structure. Due to the differences, archaeal 50S are less sensitive to some antibiotics that target bacterial 50S.
The trade particularly picked up after the Viking invasions, with major markets at Chester and Bristol supplied by Danish, Mercian, and Welsh raiding of one another's borderlands. At the time of the Domesday Book, nearly 10% of the English population were slaves. William the Conqueror introduced a law preventing the sale of slaves overseas. According to historian John Gillingham, by 1200 slavery in the British Isles was non-existent. Slavery had never been authorized by statute within England and Wales, and in 1772, in the case Somerset v Stewart, Lord Mansfield declared that it was also unsupported within England by the common law. The slave trade was abolished by the Slave Trade Act 1807, although slavery remained legal in possessions outside Europe until the passage of the Slavery Abolition Act 1833 and the Indian Slavery Act, 1843. However, when England began to have colonies in the Americas, and particularly from the 1640s, African slaves began to make their appearance in England and remained a presence until the eighteenth century. In Scotland, slaves continued to be sold as chattels until late in the eighteenth century (on the second May 1722, an advertisement appeared in the Edinburgh Evening Courant, announcing that a stolen slave had been found, who would be sold to pay expenses, unless claimed within two weeks).
Sources: en.wikipedia.org
=== Further investigations and arrests === Following the verdict, police continued to investigate whether Letby had harmed other infants. Detectives reviewed around 30 cases at the Countess of Chester Hospital that had been identified as "suspicious". Neonatologists examined approximately 4,000 admissions at that hospital, where Letby had worked from 2012, and at Liverpool Women's Hospital, where she had completed two placements in 2012 and 2015, and were asked to refer any "unexpected and unexplained" deteriorations to police. At least one family was informed that their child's case at Liverpool Women's Hospital formed part of the inquiry. Cheshire Police interviewed Letby under caution in relation to deaths at both hospitals. On 2 July 2025, the Crown Prosecution Service confirmed that it was considering further charges based on new evidence provided by the police. On 20 January 2026, after reviewing evidence relating to allegations of murder involving two children and attempted murder involving seven others, the Crown Prosecution Service announced that no further charges would be brought against Letby. On 4 October 2023, Cheshire Constabulary announced an investigation into potential corporate manslaughter at the Countess of Chester Hospital. On 1 July 2025, three members of the hospital's former senior leadership team were arrested on suspicion of gross negligence manslaughter. On 22 April 2026 one of the three was arrested and bailed for perverting the course of justice.
=== Interactions === alcohol - may lower the antidiuretic effect carbamazepine, chloropropamide, clofibrate, tricyclic antidepressants and fludrocortisone may raise the antidiuretic effect lithium, demeclocycline, heparin or norepinephrine may lower the antidiuretic effect vasopressor effect may be higher with the concurrent use of ganglionic blocking medications
Addressing the United Nations General Assembly, Lula compared "using lethal force in situations that do not constitute armed conflict" to "executing people without trial." Mexican President Claudia Sheinbaum stated in October: "We do not agree with these attacks, with the way they are being carried out." Mexico and the US agreed in November 2025 on a protocol whereby "Mexico's Navy will be responsible for intercepting these vessels in international waters near the country's coasts in order to prevent further bombings", according to El País. Foreign Policy magazine described Latin America's reaction to the strikes as "disjointed" and fragmented in November 2025, "explained, in part, by ideological divisions across the region", with "left-wing leaders of Colombia, Mexico, and Brazil [as] the most vocal critics of the strikes", while "countries with right-wing leaders—such as Paraguay, Argentina, and Ecuador—have generally aligned themselves with the Trump administration's approach to drug trafficking and Maduro.
== Ion and atom sources == Sources can be adapted in many ways, but the lists below give the general uses of a number of sources. Of these, flames are the most common due to their low cost and their simplicity. Although significantly less common, inductively-coupled plasmas, especially when used with mass spectrometers, are recognized for their outstanding analytical performance and their versatility. For all atomic spectroscopy, a sample must be vaporized and atomized. For atomic mass spectrometry, a sample must also be ionized. Vaporization, atomization, and ionization are often, but not always, accomplished with a single source. Alternatively, one source may be used to vaporize a sample while another is used to atomize (and possibly ionize). An example of this is laser ablation inductively-coupled plasma atomic emission spectrometry, where a laser is used to vaporize a solid sample and an inductively-coupled plasma is used to atomize the vapor. With the exception of flames and graphite furnaces, which are most commonly used for atomic absorption spectroscopy, most sources are used for atomic emission spectroscopy. Liquid-sampling sources include flames and sparks (atom source), inductively-coupled plasma (atom and ion source), graphite furnace (atom source), microwave plasma (atom and ion source), and direct-current plasma (atom and ion source). Solid-sampling sources include lasers (atom and vapor source), glow discharge (atom and ion source), arc (atom and ion source), spark (atom and ion source), and graphite furnace (atom and vapor source).
2,5-DMA has been encountered as a novel designer drug, with capsules of 200 mg of the hydrobromide salt, equivalent to 170 mg of the hydrochloride salt. It was initially misrepresented as mescaline or MDA before being named DMA. According to Shulgin, this might be an effective dose level that has not been formally clinically explored.
Sources: en.wikipedia.org
TikTok content is able to influence the food choices of its users. A 2023 study of teenagers found that TikTok content influences both short-term food decisions, such as trying a new food item or recipe, and long-term food decisions, like dietary adjustments. TikTok has also led to an increase in custom orders at restaurants, known on the platform as menu hacks. In 2021, some Starbucks baristas complained of an increase in complicated, custom drinks being ordered that were not on its menu after videos of the custom drinks went viral on TikTok. In 2023, Chipotle Mexican Grill added a viral TikTok custom order created by two influencers as a permanent item to its menu after receiving an influx of orders for the item. The same year, several videos of different Waffle House branches refusing to serve custom orders from TikTok went viral on the platform.
=== Characteristics of elution mode === In elution mode, solutes are applied to the column as narrow bands and, at low concentration, move down the column as approximately Gaussian peaks. These peaks continue to broaden as they travel, in proportion to the square root of the distance traveled. For two substances to be resolved, they must migrate down the column at sufficiently different rates to overcome the effects of band spreading. Operating at high concentration, where the isotherm is curved, is disadvantageous in elution chromatography because the rate of travel then depends on concentration, causing the peaks to spread and distort. Retention in elution chromatography is usually controlled by adjusting the composition of the mobile phase (in terms of solvent composition, pH, ionic strength, and so forth) according to the type of stationary phase employed and the particular solutes to be separated. The mobile phase components generally have lower affinity for the stationary phase than do the solutes being separated, but are present at higher concentration and achieve their effects due to mass action. Resolution in elution chromatography is generally better when peaks are strongly retained, but conditions that give good resolution of early peaks lead to long run-times and excessive broadening of later peaks unless gradient elution is employed. Gradient equipment adds complexity and expense, particularly at large scale.
Dutch investigators believe a criminal organisation from the port city of Rotterdam was involved in this hit. In June 2018, the Dutch government evicted two diplomats from the Iranian embassy and deported them from the country. The two men were members of Iran's intelligence agencies. This case eventually created more tension between the 2 countries.
2000: Feodor Lynen Fellowship of the Alexander von Humboldt Foundation 2002: Emmy Noether Fellowship of the German Research Foundation (DFG) 2002: Friedrich Weygand Prize of the Max Bergmann Circle e.V. 2003: Young Scientist Award for Natural Product Research of DECHEMA e.V. 2003: Eli Lilly Lecture Award 2006: Lecturer Fellowship from the German Chemical Industry Association (VCI) 2010: Sigma Aldrich Lecture, Lunteren, Netherlands 2013: Visiting Professorship at Ben Gurion University of the Negev, Israel 2014: Van Arkel Chair at Leiden University, Netherlands 2020: Recipient of the Max Bergmann Medal for outstanding achievements in the field of peptide natural products
In a meta-analysis of various trials involving fluoxetine (Prozac), fluvoxamine (Faverin/Luvox), and sertraline (Zoloft) to test their relative efficacies in treating OCD, clomipramine was found to be significantly more effective. Other studies have borne similar results even when risk of bias is eliminated. A potentially significantly greater inherent side-effect profile, however, makes it a second-line choice in the treatment of OCD. SSRIs are generally better-tolerated but appear to be inferior in terms of actual clinical efficacy.
Sources: en.wikipedia.org
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.
Behavioral endpoints include time spent in open arms of the elevated plus maze and avoidance latencies. Biochemical endpoints include BDNF concentration, cytokine levels, and monoamine metabolite ratios in brain tissue.
Most published studies are small, originate from a limited number of laboratories, and lack independent replication. Dose-response relationships, measured brain exposure, and long-term outcomes are not well characterized.
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.