The short version of tuftsin fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-08-01. 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.
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.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
| 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 |
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.
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.
This nascent activism was but one strand of a broader expansion of public expression that glasnost had unleashed across Soviet society. By the spring of 1989—in the wake of growing public disapproval of the Soviet–Afghan War—the USSR had not only experienced lively media debate, but had also held its first multi-candidate elections as liberalization spread from West to East.
Growing from a taproot like a carrot, dill grows up to 0.5–1.5 metres (1+1⁄2–5 feet) tall. Its stems are slender and hollow with finely divided, softly delicate leaves; the leaves are alternately arranged, 10–20 centimetres (4–8 inches) long with ultimate leaf divisions measuring 1–2 millimetres (1⁄32–3⁄32 in) broad, slightly wider than the similar leaves of fennel, which are less than 1 mm (1⁄16 in) across but harder in texture. In hot or dry weather, small white to yellow scented flowers form in small umbels 2.5–9 cm (1–3+1⁄2 in) in diameter from one long stalk. The seeds come from dried up fruit 4–5 mm (3⁄16–3⁄16 in) long and 1 mm (1⁄16 in) thick, and straight to slightly curved with a longitudinally ridged surface.
=== "New generation" Dexcom CGMs === In 2012, Dexcom received regulatory approval for the Dexcom G4 Platinum, commonly referred to as the Dexcom G4. This device introduced several aesthetic customization options, including various color choices for the G4 receiver; featured an expanded wireless transmission range of up to twenty feet without obstruction—an improvement over previous continuous glucose monitors; and had improved accuracy, especially during hypoglycemic episodes. In 2014, the G4 was approved for pediatric use, thereby extending its applicability to younger patients. In 2015, the Dexcom G5 was introduced. The G5 provided blood glucose readings at five‐minute intervals and was the first device in the Dexcom CGM series to offer direct compatibility with a mobile application. This advancement allowed users to view glucose data on their smartphones, share information via the Dexcom Share app, and track long‐term trends using the Dexcom Clarity app. Both the Dexcom G4 Platinum and the Dexcom G5 were discontinued at the end of 2020.
Architecture of the nucleus – Interaction of actin with alpha II-spectrin and other proteins are important for maintaining proper shape of the nucleus. Transcription – Actin is involved in chromatin reorganization, transcription initiation and interaction with the transcription complex. Actin takes part in the regulation of chromatin structure, interacting with RNA polymerase I, II and III. In Pol I transcription, actin and myosin (MYO1C, which binds DNA) act as a molecular motor. For Pol II transcription, β-actin is needed for the formation of the preinitiation complex. Pol III contains β-actin as a subunit. Actin can also be a component of chromatin remodelling complexes as well as pre-mRNP particles (that is, precursor messenger RNA bundled in proteins), and is involved in nuclear export of RNAs and proteins. Regulation of gene activity – Actin binds to the regulatory regions of different kinds of genes. Actin's ability to regulate gene activity is used in the molecular reprogramming method, which allows differentiated cells return to their embryonic state. Translocation of the activated chromosome fragment from under membrane region to euchromatin where transcription starts. This movement requires the interaction of actin and myosin. Integration of different cellular compartments. Actin is a molecule that integrates cytoplasmic and nuclear signal transduction pathways. An example is the activation of transcription in response to serum stimulation of cells in vitro.
Some genera of Gram-positive bacteria, such as Bacillus, Clostridium, Sporohalobacter, Anaerobacter, and Heliobacterium, can form highly resistant, dormant structures called endospores. Endospores develop within the cytoplasm of the cell; generally, a single endospore develops in each cell. Each endospore contains a core of DNA and ribosomes surrounded by a cortex layer and protected by a multilayer rigid coat composed of peptidoglycan and a variety of proteins. Endospores show no detectable metabolism and can survive extreme physical and chemical stresses, such as high levels of UV light, gamma radiation, detergents, disinfectants, heat, freezing, pressure, and desiccation. In this dormant state, these organisms may remain viable for millions of years. Endospores even allow bacteria to survive exposure to the vacuum and radiation of outer space, leading to the possibility that bacteria could be distributed throughout the universe by space dust, meteoroids, asteroids, comets, planetoids, or directed panspermia. Endospore-forming bacteria can cause disease; for example, anthrax can be contracted by the inhalation of Bacillus anthracis endospores, and contamination of deep puncture wounds with Clostridium tetani endospores causes tetanus, which, like botulism, is caused by a toxin released by the bacteria that grow from the spores. Clostridioides difficile infection, a common problem in healthcare settings, is caused by spore-forming bacteria.
Sources: en.wikipedia.org
=== Qualitative analysis === Generally, chromatographic data is presented as a graph of detector response (y-axis) against retention time (x-axis), which is called a chromatogram. This provides a spectrum of peaks for a sample representing the analytes present in a sample eluting from the column at different times. Retention time can be used to identify analytes if the method conditions are constant. Also, the pattern of peaks will be constant for a sample under constant conditions and can identify complex mixtures of analytes. However, in most modern applications, the GC is connected to a mass spectrometer or similar detector that is capable of identifying the analytes represented by the peaks.
=== For China === As its counterpart as a powerful communist state, the Chinese Communist Party (CCP) has continually placed an emphasis on understanding the Soviet Union and its collapse as lessons for itself. In 2011, the CCP completed a study focusing on four reasons for the Soviet collapse. First, Gorbachev's rapid pursuit of democracy which undermined the centrality of the Communist Party. Second, rapid privatization of state-owned enterprises. Third, the end of the ideological monopoly of the Communist Party, leading to historical nihilism and attacks on socialism. Fourth, the West's promotion of a peaceful evolution, cultivating a pro-West "fifth column" in Soviet society. A 2023 Center for Strategic and International Studies report argued modern Chinese scholarship's attributes the Soviet collapse primarily to its concept of historical nihilism, equated to the penetration of Western ideas into society. In December 1989, then-leader Jiang Zemin first attributed both the fall of communism in Eastern Europe and the Tiananmen Square protests to historical nihilism. A second current in Chinese writing are from Sovietologists who argue the Communist Party of the Soviet Union's institutions and policies was more responsible for collapse than its ideology. Despite Xi Jinping's focus on the historical nihilism current, he stated in 2021 "the Soviet Communist Party separated itself from the people and became a privileged bureaucratic group".
Aspartic, glutamic, and metallo-proteases activate a water molecule, which performs a nucleophilic attack on the peptide bond to hydrolyze it. Serine, threonine, and cysteine proteases use a nucleophilic residue (usually in a catalytic triad). That residue performs a nucleophilic attack to covalently link the protease to the substrate protein, releasing the first half of the product. This covalent acyl-enzyme intermediate is then hydrolyzed by activated water to complete catalysis by releasing the second half of the product and regenerating the free enzyme
Ottoman anti slavery laws where not enforced in the late 19th-century, particularly not in Hejaz; the first attempt to ban the Red Sea slave trade in 1857, the firman of 1857, resulted in a rebellion in the Hejaz Province, the Hejaz rebellion, which resulted in Hejaz being exempted from the ban. The Anglo-Ottoman Convention of 1880 formally banned the Red Sea slave trade, but it was not enforced in the Ottoman Provinces in the Arabian Peninsula. In the late 19th century, the Sultan of Morocco stated to Western diplomats that it was impossible for him to ban slavery because such a ban would not be enforceable, but the British asked him to ensure that the slave trade in Morocco would at least be handled discreet and away from the eyes of foreign witnesses. Chattel slavery lasted in most of the Middle East until the 20th century. The Red Sea slave trade still provided enslaved people from Africa to the Arabian Peninsula after World War II. As recently as the 1960s, Saudi Arabia's slave population was estimated at 300,000. Along with Yemen, the Saudis abolished slavery in 1962.
(WINNER) The contestant won the whole competition. ‡ The contestant won the Pre-Heat challenge. (WIN) The contestant won the Main Heat challenge. (HIGH) The contestant had one of the best dishes for that week. (IN) The contestant performed well enough to move on to the next week. (LOW) The contestant had one of the bottom dishes for that week, but was not eliminated. (OUT) The contestant was eliminated for worst dish.
Sources: en.wikipedia.org
== Prognosis == Diabulimia appears to lower life expectancy compared to other patients with type 1 diabetes, with the mean age of death around 45 (13 years lower than that for type 1 diabetes without an eating disorder). This reduced life expectancy is correlated with the severity of eating disorder behaviors.
Henry Slattery (born 22 January 1986) is a former professional Australian rules footballer who played for the Essendon Football Club in the Australian Football League (AFL). Henry Slattery attended Rostrevor College in Adelaide, South Australia. Slattery was recruited by Essendon with selection 46 in the 2004 AFL draft. He had previously played for West Adelaide in the SANFL. He made his debut in 2005 against St Kilda, kicking a goal in what was Matthew Lloyd's 200th AFL game. His first three seasons were limited by hip and knee injuries before he cemented his place in the Essendon starting team, often as a small, lock-down defender or defensive midfielder. At the end of the 2012 AFL season, Slattery decided to leave Essendon in search of greater opportunities at AFL level, after playing in only 2 games for the year, nominating South Australia as his preferred destination. He was not selected in the 2012 AFL draft, but was recruited by the Port Adelaide Magpies in the South Australian National Football League (SANFL). Slattery, along with 33 other Essendon players, was found guilty of using a banned performance-enhancing substance, thymosin beta-4, as part of Essendon's sports supplements program during the 2012 season. He and his team-mates were initially found not guilty in March 2015 by the AFL Anti-Doping Tribunal, but a guilty verdict was returned in January 2016 after an appeal by the World Anti-Doping Agency.
== Side effects == There is considerable variability in a patient's response to propofol, at times showing profound sedation with small doses. One of propofol's most common side effects is pain on injection, especially in smaller veins, due to activation of the sensory nerve pain receptor, TRPA1,. This can be mitigated by pretreatment with lidocaine or slower infusion in a large vein (antecubital fossa). Propofol may lead to low blood pressure related to vasodilation. Reports of blood pressure drops of 30% or more are thought to be at least partially due to inhibition of sympathetic nerve activity. This effect is related to the dose and rate of propofol administration. It may also be potentiated by opioid analgesics. Transient apnea and cerebrovascular effects have followed induction doses. Propofol has more pronounced hemodynamic effects relative to many intravenous anesthetic agents. Propofol can also decrease systemic vascular resistance, myocardial blood flow, and oxygen consumption, possibly through direct vasodilation. There are also reports that it may cause green discoloration of the urine. Although propofol is widely used in the adult ICU setting, the side effects associated with the medication seem to be more concerning in children. In the 1990s, multiple reported deaths of children in ICUs associated with propofol sedation prompted the FDA to issue a warning. As a respiratory depressant, propofol frequently produces apnea.
It is the process where new blood vessels form from pre-existing ones. This happens naturally when the body needs to repair tissue or when a wound needs to heal. It is driven by signals from growth factors, such as Vascular Endothelial Growth Factor (VEGF), which prompts the formation of new vessels. However, this process can occasionally go wrong in tumour formation where it allows the tumours to create their own blood supply and grow larger, which can contribute to diseases like cancer. Angiogenesis is the most common type of neovascularization seen in development and growth, and is important to both physiological and pathological processes. Angiogenesis occurs through the formation of new vessels from pre-existing vessels. This occurs through the sprouting of new capillaries from post-capillary venules, requiring precise coordination of multiple steps and the participation and communication of multiple cell types. The complex process is initiated in response to local tissue ischemia or hypoxia, leading to the release of angiogenic factors such as VEGF and HIF-1. This leads to vasodilatation and an increase in vascular permeability, leading to sprouting angiogenesis or intussusceptive angiogenesis.
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.
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.