mass spectrometry comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-01-09. 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.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
| 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 |
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
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.
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.
=== Physical properties === Technetium is a silvery-gray radioactive metal with an appearance similar to platinum, commonly obtained as a gray powder. The crystal structure of the bulk pure metal is hexagonal close-packed. Atomic technetium has characteristic emission lines at wavelengths of 363.3 nm, 403.1 nm, 426.2 nm, 429.7 nm, and 485.3 nm. The unit cell parameters of the orthorhombic Tc metal were reported when Tc is contaminated with carbon (a = 0.2805(4), b = 0.4958(8), c = 0.4474(5)·nm for Tc-C with 1.38 wt% C and a = 0.2815(4), b = 0.4963(8), c = 0.4482(5)·nm for Tc-C with 1.96 wt% C ). The metal form is slightly paramagnetic, meaning its magnetic dipoles align with external magnetic fields, but will assume random orientations once the field is removed. Pure, metallic, single-crystal technetium becomes a type-II superconductor at temperatures below 7.46 K (−265.69 °C; −446.24 °F). Below this temperature, technetium has a very high magnetic penetration depth, greater than any other element except niobium.
The findings were published after President Trump and Kennedy both claimed that paracetamol use during pregnancy was contributing to rising autism rates, urging women to avoid the common painkiller. Health experts and the World Health Organization rejected those claims, emphasizing that paracetamol remains the safest recommended medication for fever and pain relief during pregnancy, as untreated fever can pose serious risks to fetal development. Acetaminophen and paracetamol are the identical chemical drug compound. The name acetaminophen (brand name Tylenol) is commonly used in the United States while the name paracetamol (brand name Panadol) is commonly used in Europe and world wide.
Southern Rhodesia's main contribution to the Burma Campaign in terms of manpower was made by the Rhodesian African Rifles (RAR), a regiment of black troops led by white officers that joined the front at the end of 1944. The colony also made a significant contribution to the Commonwealth forces' command element in Burma, providing white officers and NCOs to the 81st (West Africa), 82nd (West Africa) and 11th (East Africa) Divisions, made up of units from Nigeria, the Gold Coast, the Gambia, Sierra Leone, Kenya, Uganda, Tanganyika, Nyasaland, Northern Rhodesia and the Congo. Almost every African battalion in Burma had white Rhodesian officers and NCOs attached; some were over 70% Rhodesian-led. Modelled on the Rhodesia Native Regiment of World War I, the RAR was formed in May 1940 under the command of Lieutenant-Colonel F J Wane, who the black soldiers nicknamed msoro-we-gomo ("top of the mountain"). Most volunteers for the regiment came from Mashonaland, much to the surprise of the white recruiters, who had expected Matabeleland, with stronger martial traditions, to provide more men. Originally comprising one battalion, the RAR expanded to two battalions in late 1943 to accommodate a rush of new recruits following the news that the 1st Battalion was being deployed overseas.
As of 2018, the overwhelming majority of bitcoin transactions took place on cryptocurrency exchanges. Since 2014, regulated bitcoin funds also allow exposure to the asset or to futures as an investment. Bitcoin is used as a store of value: individuals and companies such as the Winklevoss twins and Elon Musk's companies SpaceX and Tesla have each bought and sold hundreds of millions of dollars worth of bitcoin. Bitcoin wealth is highly concentrated, with 0.01% holding 27% of in-circulation currency, as of 2021. As of March 2025, El Salvador had $550 million worth of bitcoin in its international reserves, about 6,102 coins. Bitcoin, along with other cryptocurrencies, has been described as an economic bubble by several economists, including Nobel Prize in Economics laureates, such as Joseph Stiglitz, James Heckman, and Paul Krugman. Another recipient of the prize, Robert Shiller, argues that bitcoin is rather a fad that may become an asset class. He describes its price growth as an "epidemic", driven by contagious narratives. In 2024, Jean Tirole, also Nobel laureate, described bitcoin as a "pure bubble" as its intrinsic value is zero. According to him, some bubbles are long-lasting such as gold and fiat currencies, and it is impossible to predict whether bitcoin would implode like other financial bubbles or become an alternative to gold. The same year, Federal Reserve Chair Jerome Powell described bitcoin as a digital competitor to gold but not to the dollar as he argued it is a highly volatile speculative asset not used as a form of payment.
== Characteristics == Limosilactobacillus fermentum belongs to the genus Limosilactobacillus. Species in this genus are heterofermentative and adapted to the intestinal tract of vertebrates but also used for a wide variety of applications including food and feed fermentation. L. fermentum differs from most or all other species in the genus as it has a nomadic lifestyle and is not a stable member of human or animal intestinal microbiota. It has been found that some strains for L. fermentum have natural resistances to certain antibiotics and chemotherapeutics. They are considered potential vectors of antibiotic resistance genes from the environment to humans or animals to humans. Some strains of L. fermentum have been associated with cholesterol metabolism.
Sources: en.wikipedia.org
== Further reading == Walker, John (November 21, 2007). "RPS Exclusive: Gabe Newell Interview". Rock, Paper, Shotgun. Bramwell, Tom (August 29, 2007). "Valve's Gabe Newell". Eurogamer. Gamer Network. Keighley, Geoff (November 12, 2004). "The Final Hours of Half-Life 2". GameSpot. CBS Interactive. Psycho_byte (June 26, 2003). "An interview with Gabe Newell". HL2Central. Game Central Network. Archived from the original on August 11, 2018. Retrieved February 9, 2016. Peterson, Andrea (January 3, 2014). "Gabe Newell on what makes Valve tick". The Washington Post.
Dorian Andrew Mientjez Yates (born 19 April 1962) is an English retired professional bodybuilder and a six-time Mr. Olympia champion. He won the title consecutively from 1992 to 1997 and became known by the nickname "The Shadow" for his discreet approach to competition, often appearing at major events without prior public confirmation. Between contests, Yates maintained a low public profile. This also contributed to his distinctive reputation within bodybuilding. Known for his impressive conditioning and wide and thick back, he is regarded as one of the greatest professional bodybuilders of all time. Influenced by the concepts of Mike Mentzer, Yates is credited with popularising high-intensity training (HIT) in the 1990s. He was inducted into the IFBB Hall of Fame in 2003.
==== Kanon Sainouchi ==== Sainouchi appears in Ultimate X-Men. Kanon is the Ultimate counterpart of Kwannon. She is a senior at Idori High School, an expert fencer, and younger sister of a police officer named Tatsuya.
Formation of Compound I: APX reacts with H2O2 to form Compound I - where the heme is oxidized to Fe4+ = O (oxyferryl). This produces a porphyrin pi-organic cation radical. APX + H2O2 → Compound I + H2O [1] Formation of Compound II: Through a one electron reduction, Compound I is reduced by substrate (HS) to form Compound II; Compound II accepts a second electron from ascorbate to regenerate the ferric resting state. This is s sequential single-electron transfer steps. Compound I + HS → Compound II + S• [2] Compound II + HS → APX + S• + H2O [3] In ascorbate peroxidase, Compound I is a transient (green) species and contains a high-valent iron species (known as ferryl heme, FeIV) and a porphyrin pi-cation radical, as found in horseradish peroxidase. Compound II contains only the ferryl heme. Spectroscopic and kinetic work on plant APXs supports these intermediates and sequential one electron transfers.
Sources: en.wikipedia.org
On February 26, 1997, Staley and the other members of Alice in Chains attended the Grammy Awards after the song "Again" was nominated for Best Hard Rock Performance. In April of that same year, Staley purchased a 1,500 sq ft (140 m2), three-bedroom condominium in Seattle's University District via the "John LaRusta" trust, an alias used by Staley. Toby Wright, the producer of Alice in Chains' third album, set up a home recording system for him there. In 1998, amid rumors that Staley rarely left his apartment, had contracted gangrene, and had lost the ability to ingest food and was living on a diet of Ensure, Jerry Cantrell told Kerrang! that the members of Alice in Chains regularly hung out at Staley's house. On June 22, 1998, Staley made a phone call to radio program Rockline and gave a rare interview while Cantrell was promoting his first solo album, Boggy Depot. Staley called the show to talk to Cantrell and stated that he had loved the album. In October 1998, Staley re-emerged to record two tracks with Alice in Chains, "Get Born Again" and "Died", which were released on the Music Bank box set in 1999. Additional reports of Staley's deteriorating condition persisted in the midst of the sessions. Dirt producer Dave Jerden—originally chosen by the band for the production—said, "Staley weighed 80 pounds...and was white as a ghost." Studio engineer Elan Trujillo commented that Layne "definitely didn't look like how he used to look" and noticed Staley had, in addition to no teeth, atrophy in his legs.
The USSR also included most of the world's largest lakes; the Caspian Sea (shared with Iran), and Lake Baikal, the world's largest (by volume) and deepest freshwater lake that is also an internal body of water in Russia.
Although flightless, emus have vestigial wings, the wing chord measuring around 20 cm (8 in), and each wing having a small claw at the tip. Emus flap their wings when running, perhaps as a means of stabilising themselves when moving fast. They have long necks and legs, and can run at speeds of 48 km/h (30 mph) due to their highly specialised pelvic limb musculature. Their feet have only three toes and a similarly reduced number of bones and associated foot muscles; emus are unique among birds in that their gastrocnemius muscles in the back of the lower legs have four bellies instead of the usual three. The pelvic limb muscles of emus contribute a similar proportion of the total body mass as do the flight muscles of flying birds. When walking, the emu takes strides of about 100 cm (3.3 ft), but at full gallop, a stride can be as long as 275 cm (9 ft). Its legs are devoid of feathers and underneath its feet are thick, cushioned pads. Like the cassowary, the emu has sharp claws on its toes which are its major defensive attribute, and are used in combat to inflict wounds on opponents by kicking. The toe and claw total 15 cm (6 in) in length. The bill is quite small, measuring 5.6 to 6.7 cm (2.2 to 2.6 in), and is soft, being adapted for grazing. Emus have good eyesight and hearing, which allows them to detect threats at some distance.
== Areas of application == This technique can be utilized in the aviation industry. As in principle, prepreg has the potential to be processed batch sizes. Despite fiber glass having high applicability in aircraft specifically small aircraft motors, carbon fiber is employed in this type of industry at a higher rate, and the demand for it is increasing. For example, the characterization of Airbus A380 is handled by means of a mass fraction. This mass fraction is about 20%, and the Airbus A350XWB by a mass fraction of about 50% of carbon fiber prepregs. Carbon fiber prepregs have been used in the airfoils of the Airbus fleet for more than 20 years. The usage of prepreg in automotive industry is used at relatively limited quantities in comparison with other techniques like automated tape lay-up and automated fiber placement. The main reason behind this is the relative high cost of prepreg fibers as well as the compounds used in molds. Example of such materials are bulk moulding compound (BMC) or sheet moulding compound (SMC). This material is used to make the cockpit doors on the Airbus A320. This material provides bulletproofness.
organizations as rational systems: Highly formalized structures in terms of bureaucracy's and hierarchy, with formal systems of rules regarding authority and highly specific goals; organizations as natural systems: Participants may regard the organization as an end in itself, not merely a means to some other end. Promoting group values to maintain solidarity is high on the agenda. They do not rely on profit maximization. Their perversity and violence in respect of relationships is often remarkable, but they are characterized by their focus on the connections between their members, their associates and their victims; and, organizations open systems: High levels of interdependence between themselves and the environment in which they operate. There is no one way in which they are organized or how they operate. They are adaptable and change to meet the demands of their changing environments and circumstances. Organized crime groups may be a combination of all three.
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.
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.