Everything below concerns tuftsin. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-22. Numbers and descriptions here follow the published literature rather than marketing material.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
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.
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.
| 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 |
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
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.
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.
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.
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.
== Legal issues == There have been allegations by independent franchises that Cold Stone's business practices have put them at a competitive disadvantage. These former franchises claim that the parent company opens locations too close to each other, requires expensive remodeling and overstates potential revenues and income. Other franchises have contended that is not the case and that they are experiencing growth amid financial uncertainties and higher costs associated with fuel and energy prices. In June 2008, The Wall Street Journal examined the issue. The article stated that a large number of locations, approximately 16–20%, of Cold Stone Creamery franchises have closed or were put up for sale by their owners, many of whom had suffered significant financial losses due to their investment. The article included claims by franchisees that the company had misrepresented the average revenues of Cold Stone stores and acted in ways that reduced stores' profit margins. A company spokeswoman said that the number of stores for sale was "at par with industry expectations" in light of "the economically challenging times."
== Fungi foods == Dried mushrooms – typically prepared by sun-drying, hot-air drying or freeze-drying. Some types of mushrooms that are prepared dried include shiitake, straw and morel mushrooms. Mushroom extract – a paste-like, concentrated extract made from dried edible mushrooms. Mushroom extract is used to add flavor to soups, sauces, soy sauce and other foods.
Overexposure to UVB radiation not only can cause sunburn but also some forms of skin cancer. However, the degree of redness and eye irritation (which are largely not caused by UVA) do not predict the long-term effects of UV, although they do mirror the direct damage of DNA by ultraviolet. All bands of UV radiation damage collagen fibers and accelerate aging of the skin, but the two bands reaching the ground act differently: UVB is largely absorbed in the epidermis and is the main cause of sunburn, while UVA penetrates deeper into the skin and is the main driver of photoaging, causing little redness, which makes exposure easy to underestimate. Both UVA and UVB destroy vitamin A in skin, which may cause further damage. UVB radiation can cause direct DNA damage. This cancer connection is one reason for concern about ozone depletion and the ozone hole. The most deadly form of skin cancer, melanoma, is mostly caused by DNA damage independent from UVA radiation. This can be seen from the absence of a direct UV signature mutation in 92% of all melanoma. Occasional overexposure and sunburn are probably greater risk factors for melanoma than long-term moderate exposure. UVC is the highest-energy, most-dangerous type of ultraviolet radiation, and causes adverse effects that can variously be mutagenic or carcinogenic. In the past, UVA was considered not harmful or less harmful than UVB, but today it is known to contribute to skin cancer via indirect DNA damage (free radicals such as reactive oxygen species).
Sources: en.wikipedia.org
peptide-C(O)NHCH2CO2− + O2 + 2 [H] → peptide-C(O)NHCH(OH)CO2− + H2O This process shown above is the hydroxylation of a methylene group (-CH2-) by O2, and this process relies on a copper ion cofactor. Dopamine beta-hydroxylase, also a copper-containing enzyme, effects a similar transformation. The PAL subunit then completes the conversion, by catalyzing elimination from the hydroxylated glycine:
== Technology == Digital agriculture encompasses a wide range of technologies, most of which have multiple applications along the agricultural value chain. These technologies include, but are not limited to:
Preclinical and early clinical studies have been started to examine bortezomib's effectiveness in treating other B-cell-related cancers, particularly some types of non-Hodgkin's lymphoma. Clinical results also seem to justify use of proteasome inhibitor combined with chemotherapy, for B-cell acute lymphoblastic leukemia Proteasome inhibitors can kill some types of cultured leukemia cells that are resistant to glucocorticoids. The molecule ritonavir, marketed as Norvir, was developed as a protease inhibitor and used to target HIV infection. However, it has been shown to inhibit proteasomes as well as free proteases; to be specific, the chymotrypsin-like activity of the proteasome is inhibited by ritonavir, while the trypsin-like activity is somewhat enhanced. Studies in animal models suggest that ritonavir may have inhibitory effects on the growth of glioma cells. Proteasome inhibitors have also shown promise in treating autoimmune diseases in animal models. For example, studies in mice bearing human skin grafts found a reduction in the size of lesions from psoriasis after treatment with a proteasome inhibitor. Inhibitors also show positive effects in rodent models of asthma. Labeling and inhibition of the proteasome is also of interest in laboratory settings for both in vitro and in vivo study of proteasomal activity in cells. The most commonly used laboratory inhibitors are lactacystin and the peptide aldehyde MG132 initially developed by Goldberg lab. Fluorescent inhibitors have also been developed to specifically label the active sites of the assembled proteasome.
isomers Ions or molecules with identical chemical formulas but distinct structures or spatial arrangements. Isomers do not necessarily share similar properties. The two main types of isomers are structural isomers and stereoisomers.
Sources: en.wikipedia.org
In April 1955, Eisenhower proposed a special economic fund for Asia. To implement Congress's August 1954 decision that technical assistance for developing countries should be put back under the State Department, Eisenhower abolished FOA in May 1955 and created the new International Cooperation Administration (ICA) in the State Department. This separated development assistance from military assistance.
== Side effects == In studies, the most serious side effects of the combination olaratumab/doxorubicin were neutropenia (low count of neutrophil white blood cells) with a severity of grade 3 or 4 in 55% of patients, and musculoskeletal pain grade 3 or 4 in 8% of patients. Common milder side effects were lymphopenia, headache, diarrhoea, nausea and vomiting, mucositis, and reactions at the infusion site; all typical effects of cancer therapies.
Starting to breastfeed may be challenging for mothers of preterm infants, especially those born before 34 weeks, because their breasts may still be developing (in Lactogenesis I, see Breastfeeding Physiology). Additionally, mother–infant separation and the stressful environment of the NICU are also barriers to breastfeeding. Availability of a lactation specialist in the NICU can be helpful for mothers trying to establish their milk supply. Additionally, skin-to-skin (Kangaroo Care) is safe and beneficial to both mother and baby. Kangaroo Care stabilizes newborn premature infants' vital signs, such as their heart rate, providing a naturally warm environment that helps them regulate their temperature. It is also beneficial to the mother, as it may improve the development of milk supply and be beneficial for mental health.
There are several variations of the MALDI technology and comparable instruments are today produced for very different purposes, from more academic and analytical, to more industrial and high throughput. The mass spectrometry field has expanded into requiring ultrahigh resolution mass spectrometry such as the FT-ICR instruments as well as more high-throughput instruments. As many MALDI MS instruments can be bought with an interchangeable ionization source (electrospray ionization, MALDI, atmospheric pressure ionization, etc.) the technologies often overlap and many times any soft ionization method could potentially be used. For more variations of soft ionization methods see: Soft laser desorption or Ion source.
During the 2025 legislative session, Moore introduced the Expungement Reform Act, a bill that would expand criminal record expungement options for violations of parole and probation. He also expressed support for state efforts aimed at "supporting an elevating our men and boys" by removing barriers that keep men out of the workforce, including those returning from incarceration. In April 2025, Moore signed the Expungement Reform Act and the Second Look Act—which allows people incarcerated for at least 20 years for crimes they committed between the ages of 18 and 25 to petition for a reduced sentence—into law. In September 2025, Moore announced that his administration would close the Maryland Correctional Institution - Jessup and transfer prisoners held there to other prisons in the state, saying that the facility would've needed $200 million in renovations to continue operations. In January 2026, he proposed a pause on funding for the construction of the Baltimore Therapeutic Treatment Center, a new jail in Baltimore designed for people who have substance use issues and are facing criminal charges. In May 2026, Moore signed into law the Youth Charging Reform Act, which removes first-degree assault and several handgun offenses from the list of offenses that result in minors being automatically charged as adults.
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.
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.