A practical reference on pharmacokinetics: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-16. Anything still debated is marked as such rather than presented as settled.
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
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.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by RP-HPLC | Area percentage of the main peak |
| Identity confirmation | Electrospray ionization mass spectrometry | Observed mass compared with the theoretical value near 751.9 Da |
| Recommended dry storage | -20 °C, desiccated | -80 °C for multi-year archival material |
| Solution handling | Prepare fresh; avoid long storage | Sterile filtration reduces microbial load |
| Common synonyms | TKPRPGP; TP-7 | Sequence code and laboratory designation used interchangeably |
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.
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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
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.
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.
== Overdose == Spironolactone is relatively safe in acute overdose. Symptoms following an acute overdose of spironolactone may include drowsiness, confusion, maculopapular or erythematous rash, nausea, vomiting, dizziness, and diarrhea. In rare cases, hyponatremia, hyperkalemia, or hepatic coma may occur in individuals with severe liver disease. These adverse reactions are unlikely, though, in the event of an acute overdose. Hyperkalemia can occur following an overdose of spironolactone, and this is especially so in people with decreased kidney function. Spironolactone has been studied at extremely high oral doses of up to 2,400 mg per day in clinical trials. Its oral median lethal dose (LD50) is more than 1,000 mg/kg in mice, rats, and rabbits. No specific antidote for overdose of spironolactone is known. Treatment may consist of induction of vomiting or stomach evacuation by gastric lavage. The treatment of spironolactone overdose is supportive, with the purpose of maintaining hydration, electrolyte balance, and vital functions. Spironolactone should be discontinued in people with impaired kidney function or hyperkalemia.
A 58-hour curfew was announced in Kherson. Oleksandr Prokudin, the Ukrainian governor of Kherson Oblast, said that during the curfew: "it is forbidden to move on the streets of the city. The city will also be closed for entry and exit". Twenty-four civilians were killed in Kherson city due to Russian shelling. Russia said it had shot down two drones over the Moscow Kremlin and accused Ukraine of sending them to assassinate President Vladimir Putin. The Institute for the Study of War commented that it was "extremely unlikely that two drones could have penetrated multiple layers of air defence and detonated or been shot down just over the heart of the Kremlin in a way that provided spectacular imagery caught nicely on camera". The Ukrainian government denied the accusations, calling them fabricated. The British Ministry of Defence reported that several unmanned aerial vehicles (UAVs) struck Russia's Seshcha Airbase in Bryansk Oblast, 150 km north of the Ukrainian border, adding that an An-124 heavy transport aircraft was likely damaged.
A poultice or cataplasm, also called a fomentation, is a soft moist mass, often heated and medicated, that is applied to the skin to reduce inflammation, soothe pain, promote healing, or otherwise treat wounds or ailments. Soft materials like cereals serve as a base for agents intended to affect the body transdermally. The preparation is usually spread on cloth, which is then applied to the area being treated. The cloth is used to keep the preparation in place, or additional bandaging to hold the poultice may be employed. Direct topical application (without cloths) is also used. The term "poultice" may also refer to a porous solid, filled with a solvent, and used to remove stains from porous stone such as marble or granite.
Sources: en.wikipedia.org
=== Pitching style === Mizell stood 6 feet 3 inches (1.91 m). A hard thrower, he had a loose and easy throwing motion. His delivery made it tricky to see the ball; Ken Boyer observed, "The guy shows you his glove, his rear, and somebody tells you it’s a strike." He was known for a high leg kick during his delivery, but this trait made it easier to steal bases against him, as Willie Mays observed. Earlier in his career, his fastball was his best pitch, but it had slowed by 1960, by which point his slow curveball was his strength. The fastball moved closer to left-handed hitters, and the curveball went low and farther away on them. Mizell also threw a slider. Control problems plagued him throughout his career, though these were not as bad in 1960.
spacer Also intergenic spacer (IGS) or non-transcribed spacer (NTS). Any sequence or region of non-coding DNA separating neighboring genes, whether transcribed or not. The term is used in particular to refer to the non-coding regions between the many repeated copies of the ribosomal RNA genes. See also intergenic region.
All nanotubes are expected to be very good thermal conductors along the tube, exhibiting a property known as "ballistic conduction", but good insulators lateral to the tube axis. Measurements show that an individual SWNT has a room-temperature thermal conductivity along its axis of about 3500 W·m−1·K−1; compare this to copper, a metal well known for its good thermal conductivity, which transmits 385 W·m−1·K−1. An individual SWNT has a room-temperature thermal conductivity lateral to its axis (in the radial direction) of about 1.52 W·m−1·K−1, which is about as thermally conductive as soil. Macroscopic assemblies of nanotubes such as films or fibres have reached up to 1500 W·m−1·K−1 so far. Networks composed of nanotubes demonstrate different values of thermal conductivity, from the level of thermal insulation with the thermal conductivity of 0.1 W·m−1·K−1 to such high values. That is dependent on the amount of contribution to the thermal resistance of the system caused by the presence of impurities, misalignments and other factors. The temperature stability of carbon nanotubes is estimated to be up to 2800 °C in vacuum and about 750 °C in air. Crystallographic defects strongly affect the tube's thermal properties. Such defects lead to phonon scattering, which in turn increases the relaxation rate of the phonons. This reduces the mean free path and reduces the thermal conductivity of nanotube structures. Phonon transport simulations indicate that substitutional defects such as nitrogen or boron will primarily lead to the scattering of high-frequency optical phonons.
The 2024 New Year Honours are appointments by some of the 15 Commonwealth realms to various orders and honours to recognise and reward good works by citizens of those countries. The New Year Honours are awarded as part of the New Year celebrations at the start of January and those for 2024 were announced on 29 December 2023, on the same day as the 2022 Prime Minister's Resignation Honours. The recipients of honours are displayed as they were styled before their new honour and arranged by the country whose ministers advised Charles III on the appointments, then by the honour and by the honour's grade (i.e. Knight/Dame Grand Cross, Knight/Dame Commander, etc.), and then by divisions (i.e. Civil, Diplomatic, and Military), as appropriate. The BBC reported that it had already received press releases from some recipients before the honours list was published, contrary to the "longstanding practice of modest secrecy ahead of the announcement, even though award winners will have known for weeks".
Sources: en.wikipedia.org
==== Response and fallout ==== Although the experimental protocol had not been published, physicists in several countries attempted, and failed, to replicate the excess heat phenomenon. The first paper submitted to Nature reproducing excess heat, although it passed peer review, was rejected because most similar experiments were negative and there were no theories that could explain a positive result; this paper was later accepted for publication by the journal Fusion Technology. Nathan Lewis, professor of chemistry at the California Institute of Technology, led one of the most ambitious validation efforts, trying many variations on the experiment without success, while CERN physicist Douglas R. O. Morrison said that "essentially all" attempts in Western Europe had failed. Even those reporting success had difficulty reproducing Fleischmann and Pons' results. On 10 April 1989, a group at Texas A&M University published results of excess heat and later that day a group at the Georgia Institute of Technology announced neutron production—the strongest replication announced up to that point due to the detection of neutrons and the reputation of the lab. On 12 April Pons was acclaimed at an ACS meeting. But Georgia Tech retracted their announcement on 13 April, explaining that their neutron detectors gave false positives when exposed to heat. Another attempt at independent replication, headed by Robert Huggins at Stanford University, which also reported early success with a light water control, became the only scientific support for cold fusion in 26 April US Congress hearings.
==== 10 Man Operational Ration Pack ==== The UK also fields a larger pack of rations intended to feed ten soldiers for 24 hours from centralised but basic preparation; generally similar in content to the single issue ORP but tending to contain larger quantities of food in cylindrical tin cans to be divided up on preparation, rather than individual retort pouches or packets. Even dry materials like sugar or biscuits are often packed in these cans. They contain ingredients for baking bread and tinned food, including vegetables, corned beef and sausages in lard. Also included are chocolate, pre-cooked chicken or beef in gravy and soya mince. Ten boxed one-man ORPs are supplied in larger boxes identical in shape to the single ten-man pack.
They suggest that people actively create it and make their lives meaningful by dedicating themselves to what they love. Objectivists contend that meaning does not depend on subjective preferences but is grounded in objective features of reality. Some people seek meaning by promoting concrete general values, like truth, moral goodness, and beauty. Others pursue it in religious practice by trying to realize a supernatural purpose. Further suggested sources of meaning include altruism, creativity, and self-actualization. The inability to find meaning in life can lead to an existential crisis, associated with anxiety and spiritual confusion.
=== Saxon era === A minster was founded in the 8th century at Westbury on Trym and is mentioned in a charter of 804. In 946 an outlaw named Leof killed Edmund I in a brawl at a feast in the royal palace at Pucklechurch, which lies about six miles from Bristol. The town of Bristol was founded on a low hill between the rivers Frome and Avon at some time before the early 11th century. The main evidence for this is a coin of Aethelred issued c. 1010. This shows that the settlement must have been a market town and the name Brycg stowe indicates "place by the bridge". It is believed that the Bristol L (the tendency for the local accent to add a letter L to the end of some words) is what changed the name Brycg stowe to the current name Bristol. It appears that St Peter's church, the remains of which stand in modern Castle Park, may have been another minster, possibly with 8th-century origins. By the time of Domesday the church held three hides of land, which was a sizeable holding for a mere parish church. The Anglo-Saxon Chronicle records that in 1052 Harold Godwinson took ship to Brycgstow and later in 1062 he took ships from the town to subdue the forces of Gruffydd ap Llywelyn of Wales, indicating the status of the town as a port. Brycg stowe was a major centre for the Anglo-Saxon slave trade. Men, women and children captured in Wales or northern England were traded through Bristol to Dublin as slaves. From there the Viking rulers of Dublin would sell them on throughout the known world.
==== LL Cool J ==== Ice-T had a feud with LL Cool J in the late 1980s and early 1990s. Apparently, this was instigated by LL's claim to be "the baddest rapper in the history of rap itself". Ice-T recorded disses against LL on his 1988 album Power. On the album was the track, "I'm Your Pusher", in which a rap music addict declines to buy an LL Cool J record. In the book Check the Technique: Liner Notes for Hip-Hop Junkies, Ice-T said that the song "Girls L.G.B.N.A.F." was also intended as a diss to LL Cool J, by making a crude song to contrast with the love songs that LL was making at the time. On LL's response, "To da Break of Dawn" in 1990, he dissed Kool Moe Dee (whose feud with LL was far more publicized) as well as MC Hammer. He then devoted the third verse of the song to dissing Ice-T, mocking his rap ability ("take your rhymes around the corner to rap rehab"), his background ("before you rapped, you was a downtown car thief"), and his style ("a brother with a perm deserves to get burned"). He also suggested that the success of Power was due to the appearance of Ice-T's girlfriend Darlene on the album cover. Ice-T appeared to have ignored the insults and he had also defended LL Cool J after his arrest in the song "Freedom of Speech". In August 2012, Ice-T said that the rivalry was "never serious" and that he needed a nemesis to create "an exciting dispute".
Sources: en.wikipedia.org
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.
A reported purity value reflects the share of the main peak in one chromatographic run and says nothing about identity. Confirming that the expected sequence is present requires a separate measurement such as mass spectrometry. Purity and identity are distinct questions.
A mass spectrum reports the molecular masses present in a sample and shows whether they match the value expected for selank, near 751.9 Da. It also flags common artifacts such as truncation or adduct formation. It does not establish correct stereochemistry or complete sequence order on its own.
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.