mass spectrometry raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-03-08. 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.
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.
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.
| 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 |
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
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.
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.
=== Post-Streich years === In March 2024, it was announced that Streich's assistant coach, Julian Schuster, would take over as head coach of the club. During the 2024–25 season, Freiburg reached the Champions League spots, climbing to fourth place after a crucial away win against Wolfsburg on matchday 31. However, a 3–1 home defeat to Eintracht Frankfurt on the final matchday saw them drop to fifth place and Europa League qualification, narrowly missing out on the Champions League for the fifth time following 2001, 2013, 2022, and 2023. In Schuster's second season, the club reached the Europa League final, the first European final in the club's history. In the final in Istanbul, they however lost 3-0 to English Aston Villa.
=== Background === The name CosMc originated as a McDonaldland character, appearing in McDonald's advertisements from 1986 to 1992. CosMc is an extraterrestrial who "craves McDonald's food." The character occasionally came to steal food for his planet, CosMcland. It also spoke in a mixture of robot-esque sounds and normal speech. In 2023, McDonald's started focusing more on its classic mascots and the Grimace Birthday Meal became a viral Internet phenomenon. The specialty coffee-selling business had been growing, which McDonald's CEO Chris Kempczinski described as an "attractive and fast growing category". CNN described CosMc's as McDonald's "answer to Starbucks."
=== Blockade for diseases with a chronic immunological component === As increasingly documented, the SP-NK1R system induces or modulates many aspects of the immune response, including WBC production and activation, and cytokine expression, Reciprocally, cytokines may induce expression of SP and its NK1R. In this sense, for diseases in which a pro-inflammatory component has been identified or strongly suspected, and for which current treatments are absent or in need of improvement, abrogation of the SP-NK1 system continues to receive focus as a treatment strategy. Currently, the only completely developed method available in that regard is antagonism (blockade, inhibition) of the SP preferring receptor, i.e., by drugs known as neurokinin type 1 antagonists (also termed: SP antagonists, or tachykinin antagonists.) One such drug is aprepitant to prevent the nausea and vomiting that accompanies chemotherapy, typically for cancer. With the exception of chemotherapy-induced nausea and vomiting, the patho-physiological basis of many of the disease groups listed below, for which NK1RAs have been studied as a therapeutic intervention, are to varying extents hypothesized to be initiated or advanced by a chronic non-homeostatic inflammatory response.
It has to be appreciated that at the time the menace of doping for the health of athletes or of the purity of competition had yet to enter the morals because, after this marathon, the official race report said: The marathon has shown from a medical point of view how drugs can be very useful to athletes in long-distance races. Hicks was, in the phrase of the time, "between life and death" but recovered, collected his gold medal a few days later, and lived until 1952. Nonetheless, he never again took part in athletics.
=== Autism spectrum disorder === Unlike ADHD, which significantly increases the risk of substance use disorder, autism spectrum disorder has the opposite effect of significantly reducing the risk of substance use. This is because introversion, inhibition and lack of sensation seeking personality traits, which are typical of autism spectrum disorder, protect against substance use and thus substance use levels are low in individuals who are on the autism spectrum. However, certain forms of substance use disorders, especially alcohol use disorder, can cause or worsen certain neuropsychological symptoms which are common to autism spectrum disorder. This includes impaired social skills due to the neurotoxic effects of alcohol on the brain, especially in the prefrontal cortex area of the brain. The social skills that are impaired by alcohol use disorder include impairments in perceiving facial emotions, prosody perception problems and theory of mind deficits; the ability to understand humour is also impaired in people who consume excessive amounts of alcohol.
Sources: en.wikipedia.org
=== Relationship Testing === BRT's Relationship Testing division offers services in Paternity Testing and Family reunification Immigration Testing. DNA testing can identify relationships between parent and child, full or half siblings, grandparent and grandchild, uncles or aunts and nieces or nephews, as well as identical and non-identical twins. The Laboratory is accredited by the AABB (formerly, American Association of Blood Banks). Testing can be performed for submission in legal proceedings (court admissible) or for personal knowledge. Application for immigration to the United States and Canada often requires documentation of biological relationship between a petitioner and his or her beneficiary. DNA testing can be used to prove a relationship if documents are absent or challenged. The US Immigration and Naturalization Service (INS) and United States Citizenship and Immigration Services (USCIS) offices accept DNA testing results from AABB accredited laboratories only.
Nalbuphine in the 15 to 60 mg range had similar analgesic effects to immediate release codeine in the 30 to 60 mg range (Kantor et al. 1984; Sunshine et al. 1983). Schmidt et al. (1985) reviewed the preclinical pharmacology of nalbuphine and reported comparative data relative to other types of opioid compounds. The authors point out that the nalbuphine moiety is approximately ten times more pharmacologically potent than the mixed opioid agonist/antagonist butorphanol on an "antagonist index" scale which quantitates the drug's ability to act both as an analgesic (via opioid KOR agonism) as well as a MOR antagonist. The opioid antagonist activity of nalbuphine is one-fourth as potent as nalorphine and 10 times that of pentazocine.
=== International freight forwarding services === Kerry Logistics (00636.HK) focuses on international logistics services, including full container shipping and international air freight forwarding, providing enterprises with convenient cross-border services. The supply chain service provides end-to-end logistics services, including supply chain consulting, warehouse management, transportation management, supply chain optimization, logistics partnership and other services. Amazon Web Services has announced that SF Supply Chain has partnered with them to develop the intelligent integrated management platform Shuzhi Gate, designed to meet the logistics needs of multi-scenario parks and provide end-to-end supply chain visibility. SF Supply Chain has optimized its logistics solutions to cover inbound logistics, manufacturing logistics, distribution logistics, and service logistics.
=== Criticism === Examples are the use of mercenaries to perform the work that the Culture does not want to get their hands dirty with, and even outright threats of invasion (the Culture has issued ultimatums to other civilisations before). Some commentators have also argued that those Special Circumstances agents tasked with civilising foreign cultures (and thus potentially also changing them into a blander, more Culture-like state) are also those most likely to regret these changes, with parallels drawn to real-world special forces trained to operate within the cultural mindsets of foreign nations. The events of Use of Weapons are an example of just how dirty Special Circumstances will play in order to get their way and the conspiracy at the heart of the plot of Excession demonstrates how at least some Minds are prepared to risk killing sentient beings when they conclude that these actions are beneficial for the long term good. Special Circumstances represents a very small fraction of Contact, which itself is only a small fraction of the entire Culture, making it comparable again to size and influence of modern intelligence agencies.
==== Sustainable biotextiles ==== Biotextiles are used as an alternative to synthetic textiles to prevent and combat the excess amounts of water and waste pollution from the textile industry. Large brands such as Nike, Adidas, Hermes and Stella McCartney are starting to use biotextiles for some of their fashion collections. One solution created by sustainable textile companies such as Pangaia and Agraloop is denim made out of nettle and hemp plants. Nettle plants are a renewable, biodegradable resource that can be used to design nettle denim by mixing organic cotton and Himalayan nettle. Hemp is another plant that is being looked into as an alternative denim material by these two companies since it is more durable and only consumes about a tenth of the water needed for cotton. The company Collina Strada is developing another biotextile solution called rose sylk. Rose sylk is an organic, biodegradable cellulose fiber that is derived from the natural waste of rose stems and bushes. Collina Strada promotes upcycling and reuse of old textiles by using factories to turn Ghana's textile waste materials into insulation for coats and houses. A third solution involves clothing made from a pineapple based leather alternative, which is currently being used by major brands such as Nike, Hugo Boss and H&M. This pineapple leather alternative is made from cellulose fibers extracted from pineapple leaves and stalks.
Sources: en.wikipedia.org
== Awards == Twin Peaks won a 2010 Hot Concept award from Nation's Restaurant News. In 2011, Twin Peaks was named "Franchisee of the Year" by the International Franchise Association at their annual conference in Washington, D.C. Twin Peaks was named number 1 in Knapp Track for comp sales in 2017 among all casual dining brands. In 2017, Twin Peaks was named a winner in the Enterprise Innovator category at the 2017 MURTEC (Multi-Unit Restaurant Technology Conference). In 2018, Twin Peaks was ranked number 196 on the Franchise Times top 200 list.
=== Other === Progesterone is a notable example. Because progesterone is poorly water-soluble and has limited absorption from the gastrointestinal tract in its native crystalline form, micronization to particle diameters of approximately 5–10 μm substantially increases its oral bioavailability. Micronized progesterone is the active ingredient in the U.S. Food and Drug Administration–approved product Prometrium, indicated for use in hormone replacement therapy in postmenopausal women receiving conjugated estrogens and for the treatment of secondary amenorrhea.
===== MeSH D08.811.682.732 – peroxidases ===== MeSH D08.811.682.732.332 – catalase MeSH D08.811.682.732.360 – chloride peroxidase MeSH D08.811.682.732.380 – cytochrome-c peroxidase MeSH D08.811.682.732.440 – eosinophil peroxidase MeSH D08.811.682.732.500 – glutathione peroxidase MeSH D08.811.682.732.512 – horseradish peroxidase MeSH D08.811.682.732.512.900 – wheat germ agglutinin-horseradish peroxidase conjugate MeSH D08.811.682.732.525 – iodide peroxidase MeSH D08.811.682.732.550 – lactoperoxidase MeSH D08.811.682.732.700 – peroxidase
We Happy Few is Compulsion Games' second game following its 2013 game Contrast. The game, powered by Unreal Engine 4, has tripled the development staff from Contrast. Some inspiration for We Happy Few came at the end of Contrast's development, as studio founder and producer Guillaume Provost had to struggle with the death of his father three weeks before Contrast shipped. During this time, he had reflected on his state of life, and came up with ideas for We Happy Few in his emotional distress, particularly the idea of a society fixated on drugs and masks. Provost presented this to his creative team, who saw the possibilities of expanding on this. Narrative director Alex Epstein considered the idea similar to Prozac Nation, and where in current times, there is a prescription drug for every conceivable malady. The title of the game comes from the St Crispin's Day Speech from Henry V:
=== Mantle === A hyphal sheath known as the mantle, which often has more biomass than the Hartig net interface, envelops the root. The structure of the mantle is variable, ranging from a loose network of hyphae to a structured and stratified arrangement of tissue. Often, these layers resemble plant parenchyma tissue and are referred to as pseudoparenchymatous. Because the root is enveloped by the mantle it is often affected developmentally. EcM fungal partners characteristically suppress root hair development of their plant symbiont. They can also increase root branching by inducing cytokinins in the plant. These branching patterns can become so extensive that a single consolidated mantle can envelop many root tips at a time. Structures like this are called tuberculate or coralloid ectomycorrhizas. The mantles of different EcM pairs often display characteristic traits such as color, extent of branching, and degree of complexity which are used to help identify the fungus, often in tandem with molecular analyses. Fruiting bodies are also useful but are not always available.
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 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.