The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
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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.
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 |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
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.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
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.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
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.
15 June to 25 September Operation Iroquois Grove was a 1st Brigade, 5th Infantry Division (Mechanized) and 2nd Battalion, 5th Marines clear and search operation against PAVN Base Area 101 southeast of Quảng Trị City. the operation resulted in 134 PAVN and 13 U.S. killed.
NeoGenomics Laboratories, Inc., also known as NeoGenomics or Neo, is an American CLIA-certified clinical laboratory, pharma services and information services company that specializes in cancer genetics diagnostic testing. The company's testing services include cytogenetics, fluorescence in situ hybridization (FISH), flow cytometry, immunohistochemistry, anatomic pathology, and molecular genetics. Headquartered in Fort Myers, FL, NeoGenomics maintains a network of testing facilities across the US, with laboratories in Florida, California, Tennessee, and Texas.
or the coupling reagent COMU which is readily soluble as a dimethylmorpholine-uronium salt and which, like Oxyma, is superior to the standard additive HOBt for the suppression of racemization and acylation efficiency and is comparable to HOAt without presenting an explosion risk such as the benzotriazoles. With water-soluble derivatives of ethyl cyanohydroxyiminoacetate (glyceroacetonide-oxyma) as additive and DIC as coupling reagent even in weakly basic aqueous solutions the linking of protected amino acids to oligopeptides is possible with a yield of 95% and a diastereomeric excess of> 99% using the model substances Z-L-Phg-OH and L-H-Pro-NH2.
Diazepam is mainly used to treat anxiety, insomnia, panic attacks, and symptoms of acute alcohol withdrawal. It is also used as a premedication for inducing sedation, anxiolysis, or amnesia before certain medical procedures (e.g., endoscopy). In 2020, it was approved for use in the United States as a nasal spray to interrupt seizure activity in people with epilepsy. Diazepam is the most commonly used benzodiazepine for "tapering" benzodiazepine dependence due to diazepam's comparatively long half-life, allowing for more efficient dose reduction. Benzodiazepines have a relatively low toxicity in overdose. Diazepam has several uses, including:
Kay Mason Billig, the leader of Norfolk County Council, apologises "unreservedly" for posting a picture of a steak dinner on Facebook with the words: "Wonder what all the poor people are doing?" 21 June – An Ipsos poll gives Reform UK its highest poll rating so far, with 34%, nine points ahead of Labour on 25%, and 19 points ahead of the Conservatives on 15%. 22 June – Former Pembrokeshire councillor Andrew Edwards is disqualified from holding public office for four years over a racist voice note he posted on WhatsApp. 23 June – Reform UK announces that it would give people with non-domicile tax status the chance to avoid some UK taxes by paying a £250,000 fee, with the proceeds going to people on the lowest incomes. 25 June – Buckingham Palace confirms that US President Donald Trump will make a full state visit to the UK later in the year. Starmer says the government will press ahead with a parliamentary vote on welfare reform on 1 July, despite a growing rebellion among backbench Labour MPs that could see the proposed legislation defeated. Reform councillor Rob Howard resigns as leader of Warwickshire County Council citing his health, and leaving his 18-year-old deputy, George Finch, as interim leader. 29 June – Conservative MP George Freeman refers himself to the Parliamentary Commissioner for Standards after allegations a company he works for asked him to ask a question in Parliament. 30 June – Two Reform UK breakaway parties are formed by past Reform members. Advance UK is established by Ben Habib, and Restore Britain is started by Rupert Lowe.
Sources: en.wikipedia.org
The AGA does not recommend extensive pre-procedural testing, including repeated measurements of PT/INR or platelet count, before patients with stable cirrhosis undergo common gastrointestinal procedures. Nor do they suggest the routine use of blood products, such as platelets, for bleeding prevention. Cirrhosis is stable when there are no changes in baseline abnormalities of coagulation lab values. For patients with stable cirrhosis and low platelet count undergoing common low-risk procedures, the AGA does not recommend the routine use of thrombopoietin receptor agonists for bleeding prevention. In hospitalized patients who meet standard guidelines for clot prevention, the AGA suggests standard prevention. The AGA does not recommend routine screening for portal vein thrombosis. If there is a portal vein thrombosis, the AGA suggests treatment by anticoagulation. In the case of cirrhosis with atrial fibrillation, the AGA recommends using anticoagulation over no anticoagulation.
=== Various === As an enolate, avobenzone forms with heavy metal ions (such as Fe3+) colored complexes, and chelating agents can be added to suppress them. Stearates, aluminum, magnesium and zinc salts can lead to poorly soluble precipitates. Manufacturers also recommend to avoid the inclusion of iron and ferric salts, heavy metals, formaldehyde donors and PABA and PABA esters. Avobenzone in sunscreen may stain clothes yellow-orange and make them sticky if washed in iron-rich water, as it reacts with iron to produce rust. The damage can be undone with a rust remover or stain remover. The staining properties of sunblock made with avobenzone are particularly noticeable on fiberglass boats with white gelcoat. Avobenzone also reacts with boron trifluoride to form a stable crystalline complex that is highly fluorescent under UV irradiation. The emission color of the crystals depends on the molecular packing of the boron avobenzone complex. The photoluminescence may also be altered by mechanical force in the solid state, resulting in a phenomenon called "mechanochromic luminescence". The altered emission color recovers itself slowly at room temperature or more swiftly at higher temperatures.
=== Definitions and general characteristics === In a hydrogen bond, the electronegative atom not covalently attached to the hydrogen is named the proton acceptor, whereas the one covalently bound to the hydrogen is named the proton donor. This nomenclature is recommended by the IUPAC. The hydrogen of the donor is protic and therefore can act as a Lewis acid and the acceptor is the Lewis base. Hydrogen bonds are represented as H···Y system, where the dots represent the hydrogen bond. Liquids that display hydrogen bonding (such as water) are called associated liquids.
TMA-2's affinity (Ki) for the serotonin 5-HT2A receptor has been found to be 1,300 nM. Its EC50Tooltip half-maximal effective concentration at the receptor was 190 nM and its EmaxTooltip maximal efficacy was 84%. The drug was also active at the serotonin 5-HT2B receptor and, to a much lesser extent, at the serotonin 5-HT2C receptor. In an earlier study, its affinities (Ki) were 1,650 nM at the serotonin 5-HT2 receptor and 46,400 nM at the serotonin 5-HT1 receptor. TMA-2 is inactive at the monoamine transporters. It was inactive at the mouse trace amine-associated receptor 1 (TAAR1), whereas it bound to the rat TAAR1 with an affinity (Ki) of 3,100 nM and was not assessed at the human TAAR1.
Sources: en.wikipedia.org
Apples grown for consumption are suitable for cider making, though some regional cider-makers prefer to use a mix of eating and cider apples (as in Kent, England), or exclusively cider apples (as in the West Country, England and West of England). There are many hundreds of varieties of cultivars developed specifically for cider making.
=== Multiwell plate === Multiwell plates are multiple petri dishes incorporated into one container, with the number of individual wells ranging from 6 to over 1536. Multiwell Plate Assays are convenient for handling necessary dosages and replicates. There are a wide range of plate types that have a standardized footprint, supporting equipment, and measurement systems. Electrodes can be integrated into the bottom of the plates to capture information as a result of the binding assays. The binding reagents become immobilized on the electrode surface and then can be analyzed. The multiwell plates are manufactured to allow researchers to create and manipulate different types of assays (i.e., bioassays, immunoassays, etc.) within each multiwell plate. Due to the variability in multiwell plate formatting, it is not uncommon for artifacts to arise. Artifacts are due to the different environments found within the different wells on the plate, especially near the edges and center of the wells. Such effects are known as well effects, edge effects, and plate effects. Thus, emphasizing the necessity to position assay designs in the correct manner both within, and between, each plate. The use of multiwell plates are common when measuring in vitro biological assay activity, or measuring immunoreactivity through immunoassays. Artifacts can be avoided by maintaining plate uniformity by applying the same dose of the specific medium in each well, in addition to maintaining atmospheric pressure and temperature rates in order to reduce humidity.
Kittens require a high-calorie diet that contains more protein than the diet of adult cats. Young orphaned kittens require cat milk every two to four hours, and they need physical stimulation to defecate and urinate. Cat milk replacer is manufactured to feed young kittens because cow's milk does not provide all the necessary nutrients. Human-reared kittens tend to be very affectionate with humans as adults and sometimes more dependent on them than kittens reared by their mothers, but they can also show volatile mood swings and aggression. Depending on the age at which they were orphaned and how long they were without their mothers, these kittens may be severely underweight and can have health problems later in life, such as heart conditions. The compromised immune system of orphaned kittens — due to the absence of antibodies normally found in the mother's milk — can make them especially susceptible to infections, often necessitating antibiotics.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
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.