The short version of mass spectrometry fits in a sentence. The long version — which is the one that helps — is below.
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The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
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.
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.
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.
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.
Perhaps the most serious oral condition caused by smoking (including pipe smoking) is oral cancer. However, smoking also increases the risk for various other oral diseases, some almost completely exclusive to tobacco users. Roughly half of periodontitis or inflammation around the teeth cases are attributed to current or former smoking. Smokeless tobacco causes gingival recession and white mucosal lesions. Up to 90% of periodontitis patients who are not helped by common modes of treatment are smokers. Smokers have significantly greater loss of bone height than non-smokers, and the trend can be extended to pipe smokers to have more bone loss than non-smokers. Smoking traditional cigarettes, e-cigarettes, and heat-not-burn products also affects the salivary cytokine levels needed in immune responses. Traditional cigarettes slightly intensify the immune response in long-term smokers compared to non-smokers, with long-term smokers showing higher levels of IFN-γ than non-smokers. E-cigarettes and heat-not-burn products, while marketed as a healthier alternative, have been shown to inhibit immune response function. Users of these products show lower levels of salivary cytokines, chemokines, and growth factors that function to keep the immune response strong and active in the mouth. Smoking has been proven to be an important factor in teeth staining. Halitosis or bad breath is common among tobacco smokers. Tooth loss is 2 to 3 times higher in smokers than in non-smokers.
Russian launched around 81 missiles, including 6 kinzhal missiles and 8 drones at Ukrainian cities. Ukraine's Military stated it shot down 34 missiles and 4 Shahed drones. Around nine people were killed and blackouts were reported. The Zaporizhzhia Nuclear Power Plant was briefly cut off from the Ukrainian electrical grid, leaving it running on backup diesel generators for the sixth time since Russian forces seized control of it 12 months ago. Russia stated that the attack was response to the 2023 Bryansk Oblast attack. The Head of Lithuanian military intelligence Elegijus Paulavicius, said in an interview that Russia had the resources to continue the war in Ukraine for at least two years at the "current intensity". He also dismissed the effect of sanctions as Russia had "long chains of intermediaries" to obtain Western technology. Western officials estimated between 20,000 and 30,000 Russian soldiers had been killed or wounded in the fighting around Bakhmut, while Ukrainian forces have lost about one fifth as many. These numbers could not be verified.
Molecular diagnostics uses in vitro biological assays such as PCR-ELISA or Fluorescence in situ hybridization. The assay detects a molecule, often in low concentrations, that is a marker of disease or risk in a sample taken from a patient. Preservation of the sample before analysis is critical. Manual handling should be minimised. The fragile RNA molecule poses certain challenges. As part of the cellular process of expressing genes as proteins, it offers a measure of gene expression but it is vulnerable to hydrolysis and breakdown by ever-present RNAse enzymes. Samples can be snap-frozen in liquid nitrogen or incubated in preservation agents. Because molecular diagnostics methods can detect sensitive markers, these tests are less intrusive than a traditional biopsy. For example, because cell-free nucleic acids exist in human plasma, a simple blood sample can be enough to sample genetic information from tumours, transplants or an unborn fetus. Many, but not all, molecular diagnostics methods based on nucleic acids detection use polymerase chain reaction (PCR) to vastly increase the number of nucleic acid molecules, thereby amplifying the target sequence(s) in the patient sample. PCR is a method that a template DNA is amplified using synthetic primers, a DNA polymerase, and dNTPs. The mixture is cycled between at least 2 temperatures: a high temperature for denaturing double-stranded DNA into single-stranded molecules and a low temperature for the primer to hybridize to the template and for the polymerase to extend the primer.
RCOCl + R'OH → RCO2R' + HCl (RCO)2O + R'OH → RCO2R' + RCO2H The reactions are irreversible simplifying work-up. Since acyl chlorides and acid anhydrides also react with water, anhydrous conditions are preferred. The analogous acylations of amines to give amides are less sensitive because amines are stronger nucleophiles and react more rapidly than does water. This method is employed only for laboratory-scale procedures, as it is expensive.
Since breasts are an external organ and do not contain muscle, exercise cannot improve their shape. They are not protected from external forces and are subject to gravity. Many women mistakenly believe that breasts cannot anatomically support themselves and that wearing a brassiere will prevent their breasts from sagging later in life. Researchers, bra manufacturers, and health professionals have not found any evidence to support the idea that wearing a bra for any amount of time slows breast ptosis. Bra manufacturers are careful to claim that bras only affect the shape of breasts while they are being worn. There is some evidence that bra use reduces the development of Cooper's ligaments, connective tissue that supports breast shape. That atrophy from bra-wearing may therefore lead to more breast sag in the long run, much as the connective tissue in a limb weakens while it is in a cast and must be re-strengthened afterward. Studies have actually documented that, after an initial period of adjustment, women experienced a significant increase in comfort and breast firmness after forgoing bras.
Sources: en.wikipedia.org
As of 2005, India was the only country producing licit opium (opium gum) for both domestic use and export. Licit opium was produced also in Democratic People's Republic of Korea for domestic use, and in Japan for maintenance of the pertinent technology (small quantities). Opium poppies were grown principally for extraction of alkaloids (from poppy straw) in nine other countries: Australia, China, France, Hungary, Slovakia, Spain, the Republic of Macedonia, Turkey, and the United Kingdom. China ceased producing licit opium after 2001. Opium poppies grown principally for the seed crop, with licit poppy straw as a by-product, were produced in the Czech Republic, Serbia and Montenegro. Another six countries cultivated opium poppies solely for the poppy seed or horticultural purposes, without extraction of alkaloids from poppy straw: Austria, Estonia, Germany, Netherlands, Poland, and Ukraine. Illicit production of Polish heroin and other products derived from poppy straw is an ongoing problem in Poland, although it isn't as serious as in the 1980s, after poppies containing high levels of opioid alkaloids were banned in 1990s. The production of licit opium in India was in accord with terms of the 1961 Single Convention on Narcotic Drugs. After the opium was harvested, the plants were allowed to mature and harvested for poppy seeds. The sale of poppy seeds delivered a significant proportion of the income from the licit opium crop. Unknown fractions of both the opium harvest and the poppy straw residue from the poppy seed harvest were diverted to illicit uses.
Trabectedin, sold under the brand name Yondelis, is an antitumor chemotherapy medication for the treatment of advanced soft-tissue sarcoma and ovarian cancer. The most common adverse reactions include nausea, fatigue, vomiting, constipation, decreased appetite, diarrhea, peripheral edema, dyspnea, and headache. It is sold by Pharma Mar S.A. and Johnson and Johnson. It is approved for use in the European Union, Russia, South Korea and the United States. The European Commission and the U.S. Food and Drug Administration (FDA) granted orphan drug status to trabectedin for soft-tissue sarcomas and ovarian cancer. It was originally discovered in the sea squirt Ecteinascidia turbinata. Because natural yields are extremely low, its supply is based on a semisynthetic process starting from a chemical obtained from the bacterium Pseudomonas fluorescens.
=== Korean Culture and coffee consumption === The most popular coffee among Koreans is Iced Americano, regardless of weather. Even in the cold winter, Koreans like to drink Iced Americano. AFP has mentioned, in winter the consumption of Iced Americano is greater than warm drinks. For this particular coffee consumption, there's a new phrase created called 'Eoljukah' which means 'iced coffee even if I freeze to death'. The reason that particular drink is popular is because of Korea's fast paced culture. Iced Americano comes out in a short amount of time compared to the other drinks so in fast-paced culture in Korea, most people prefer that drink. In 2019, Hyundai Research Lab found out that the individuals' average yearly consumption of coffee is 353 cups, which is the rate that is twice higher than worldwide average.
== Treatment and prognosis == Treatment is symptomatic and includes the administration of non-steroidal anti-inflammatory agents or the application of heat to the affected muscles. Intercostal 2% xylocaine injections with normal saline have been used to relieve symptoms in certain cases. Relapses during the weeks following the initial episode are a characteristic feature of this disease. Bornholm disease typically lasts between one day and one week with an average illness duration of four days. In 20% of cases studied, the illness lasted between one and two weeks. The illness in children was found to be shorter than the illness in adults. Patients typically make a complete recovery with supportive care. Although recovering from Bornholm disease is expected, some rare complications include myocarditis, respiratory failure, hepatic necrosis with coagulopathy, and disseminated intravascular coagulopathy (DIC). Aseptic meningitis, pericarditis and pleurisy are also known potential complications of Bornholm disease. Another uncommon complication is orchitis that manifests as unilateral testicular pain and swelling in the days or weeks following the expected symptoms of Bornholm disease.
The second presidency of Luiz Inácio Lula da Silva, also known as Lula's third government, began on 1 January 2023, when Luiz Inácio Lula da Silva returned to office for a third term as President of Brazil. A member of the Workers' Party (PT), Lula was elected in the second round of the 2022 presidential election, defeating incumbent president Jair Bolsonaro. He became the first Brazilian president to be elected to three terms and the first since Getúlio Vargas to return to the presidency after an interval between terms. The administration took office amid deep political polarization and the aftermath of the 2022–2023 Brazilian coup attempt, with the 8 January attacks on Brazil's government institutions constituting one of its first major political crises. The administration has been characterized by the restoration and expansion of social and public policies, changes to Brazil's fiscal and tax framework, and efforts to strengthen the role of the federal government. Major economic measures included the approval of a consumption tax reform and the replacement of the previous spending cap with a new fiscal framework. The government recorded periods of economic growth and declining unemployment, while facing concerns over public debt, fiscal sustainability, interest rates, household indebtedness, corporate financial difficulties, and the rising cost of living, particularly food prices.
Sources: en.wikipedia.org
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.