Everything below concerns Tuftsin analog. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-06-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
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.
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.
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.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
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.
=== Limosilactobacillus fermentum ME-3 === The strain L. fermentum ME-3 has recently been discovered and identified as an antimicrobial and antioxidative probiotic. This strain of L. fermentum was discovered from the analysis of human fecal samples in 1994. One of the important characteristics of a probiotic microbe is the tolerance to conditions in the digestive tract. Tests conducted on the ME-3 strain in different bile concentrations found that it was able to survive without large loss in numbers. It has also been found that L. fermentum ME-3 has a tolerance to survive drops of pH levels. It can withstand a drop in values from 4.0 to 2.5 without decreasing in numbers. These characteristics of tolerance to bile concentrations and pH levels serve to classify ME-3 as a probiotic. Limosilactobacillus fermentum ME-3 has also been found to have the capability to suppress mainly gram-negative bacteria. To a lesser extent, ME-3 has also been observed to be able to suppress enterococci and Staphylococcus aureus. This would serve a beneficial purpose to the host. ME-3 has several antimicrobial characteristics. These include acetic, lactic and succinic acids. Research on the antioxidant properties of strain ME-3 in soft cheese products revealed that it prevented spoilage. Experimentation has also been conducted on the consumption of the ME-3 strain. The consumption had a positive influence on the microbiota of the gut. Volunteers were given goat milk fermented by strain ME-3 and capsulated ME-3.
It is not significantly produced in nuclear reactors because 243Pu has a short half-life, but some is produced in nuclear explosions. 244Pu has been found in interstellar space and has the second longest half-life of any non-primordial radioisotope.
What is behavior? Baby don't ask me, don't ask me, no more at Earthling Nature. behaviorinformatics.org Links to review articles by Eric Turkheimer and co-authors on behavior research Links to IJCAI2013 tutorial on behavior informatics and computing
Sources: en.wikipedia.org
After a few attempts, he produced a model with physically plausible hydrogen bonds. Pauling then worked with Corey and Branson to confirm his model before publication. In 1954, Pauling was awarded his first Nobel Prize "for his research into the nature of the chemical bond and its application to the elucidation of the structure of complex substances" (such as proteins), prominently including the structure of the α-helix.
=== Produce === Preservation and processing of fresh produce poses many biological engineering challenges. Understanding of biology is particularly important to processing produce because most fruits and vegetables are living organisms from the time of harvest to the time of consumption. Before harvesting, understanding of plant ontogeny, or origin and development, and the manipulation of these developmental processes are key components of the industrial agriculture process. Understanding of plant developmental cycles governs how and when plants are harvested, impacts storage environments, and contributes to creating intervention processes. Even after harvesting, fruits and vegetables undergo the biological processes of respiration, transpiration, and ripening. Control over these natural plant processes should be achieved to prevent food spoilage, sprouting or growth of produce during storage, and reduction in quality or desirability, such as through wilting or loss of desirable texture.
== Tourism == The World Economic Forum's Travel & Tourism Competitiveness Index 2017 Report, ranked Thailand 34 of 136 nations (1=most competitive, 136=least competitive). Other ASEAN nations ranked were: Singapore, 6; Malaysia, 26; Indonesia, 42; Vietnam, 67; Philippines, 79; Laos, 94; Cambodia, 101. International Tourist Arrivals and Receipts: Thailand ranked number nine in 2016, with 32.5 million arrivals. It ranked third in international tourism receipts, US$49.9 billion. Global Destinations Cities Index 2016: In this seventh annual survey published by MasterCard, Bangkok ranked number one of 100 cities worldwide as the top global destination city as determined by number of visitors. It displaced London, the previous number one. Other ASEAN cities ranked in the survey were Singapore, 6; Ho Chi Minh City, 42; Hanoi, 52; Jakarta, 66; and Manila, 74. Travel and Tourism Competitiveness Report 2015: Thailand ranked 35 of 141 nations. Among ASEAN nations, Singapore was ranked 11; Malaysia, 25: Indonesia, 50; Philippines, 74; Vietnam, 75; Laos, 96; Cambodia, 105; and Myanmar, 134. International Tourist Arrivals: Thailand ranked number ten in 2013, up five places from 2012 with 26.5 million arrivals. International Tourist Receipts: Ranked number seven in the world in 2013, up two places from 2012, with receipts estimated at US$42.1 billion. Total tourism contribution to GDP: Thailand ranked 18 of 184 nations in 2014, with travel and tourism income totalling 2,345 billion baht or 19.3 percent of GDP.
Sources: en.wikipedia.org
Skittles, a brand name of candy products produced by the Wm. Wrigley Jr. Company, come in a wide variety of flavors. Most of the varieties are available only in particular regions of the world. The first flavor was Original Fruit Skittles, first released in Europe in 1974, and then in the United States in 1979. Earlier Skittles products tended to focus on fruit flavors; more recent products have branched out to include flavors such as chocolate, bubble gum, popcorn, mint, and sours. The original Skittles flavors in the United States (and other countries except for Europe) are orange, lemon, lime, grape and strawberry. In 2013, Skittles changed its original flavor line-up to include green apple, causing a consumer backlash. Green apple also replaced lime in the sour packets. It was rumored that the reason behind this is the green apple flavor outperforming lime in taste tests. A "Long Lost Lime" variation of Skittles was released in summer 2017 and 2018, bringing the lime flavor back to the original mix of Skittles for a limited time only. In September 2021, it was announced that lime would be permanently returning to the original Skittles flavor in October 2021, replacing green apple for the first time since 2013.
Other potentially important mechanisms associated with type 2 diabetes and insulin resistance include: increased breakdown of lipids within fat cells, resistance to and lack of incretin, high glucagon levels in the blood, increased retention of salt and water by the kidneys, and inappropriate regulation of metabolism by the central nervous system. However, not all people with insulin resistance develop diabetes since an impairment of insulin secretion by pancreatic beta cells is also required. In the early stages of insulin resistance, the mass of beta cells expands, increasing the output of insulin to compensate for the insulin insensitivity, so that the disposition index remains constant. But when type 2 diabetes has become manifest, the person will have lost about half of their beta cells. The causes of the aging-related insulin resistance seen in obesity and in type 2 diabetes are uncertain. Effects of intracellular lipid metabolism and ATP production in liver and muscle cells may contribute to insulin resistance.
By applying Menon's idea of creating a meal based on a single food, as this culinary writer had indicated in 1755, in Les Soupers de la cour ou l'art de travailler toutes sortes d'aliments pour servir les meilleures tables, suivant les quatre saisons with his Menu d'un repas servi tout en mouton, Menu d'un repas servi tout en cochon and Menu d'un repas servi tout en œufs, Parmentier demonstrates to a group of influential people in good society, including Nicolas François de Neufchâteau, that the potato can be used, in different forms, at different times of the meal. He thus succeeded in promoting the vegetable on the culinary level, which still leaves its mark on people's minds for a long time to come: "The guests, who were all distinguished men, people in credit or people of spirit, went to the fashionable salons to tell the news of their dinner where the potato reigned without rival", wrote the Semaine des familles, nearly a century later. Parmentier took every opportunity to promote the tuber: when he received Arthur Young on October 24, 1787, the menu was based on potatoes and, for the first time, his sister Marie-Suzanne Houzeau served, among other dishes, steamed potatoes. However, the use of this tuber did not become widespread in France until the end of the 19th century, when Alexandre Dumas felt the need to affirm its healthiness:
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.