A practical reference on intranasal delivery: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-01-12 and is reviewed periodically as new material appears.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Dry storage temperature | -20 C or below | Sealed, desiccated, protected from light |
| Solution stability | Hours to days at 2-8 C | Depends on buffer and microbial load |
| Preferred pH range | Near neutral to slightly acidic | Alkaline pH accelerates hydrolysis |
| Main degradation routes | Hydrolysis and deamidation | No cysteine or methionine in sequence |
| Identity confirmation | Electrospray mass spectrometry | Observed mass compared with 751.9 Da |
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
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.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Byzantine literature concerns all Greek literature from the Middle Ages. Although the empire was linguistically diverse, the vast majority of extant texts are in medieval Greek, in two diglossic variants: a scholarly form based on Attic Greek, and a vernacular based on Koine Greek. Most contemporary scholars consider all medieval Greek texts to be literature, but some offer varying constraints. The literature's early period (c. 330–650) was dominated by the competing cultures of Hellenism, Christianity and Paganism. The Greek Church Fathers—educated in an Ancient Greek rhetoric tradition—sought to synthesise these influences. Important early writers include John Chrysostom, Pseudo-Dionysius the Areopagite and Procopius, all of whom aimed to reinvent older forms to fit the empire. Theological miracle stories were particularly innovative and popular; the Sayings of the Desert Fathers (Apophthegmata Patrum) were copied in nearly every Byzantine monastery. During the Byzantine Dark Ages (c. 650–800), production of literature mostly stopped, though some important theologians were active, such as Maximus the Confessor, Germanus I of Constantinople and John of Damascus. The subsequent cultural Macedonian Renaissance (c. 800–1000; the "Encyclopedism period") saw a renewed proliferation of literature and revived the earlier Hellenic-Christian synthesis. Works by Homer, Ancient Greek philosophers and tragedians were translated, and hagiography was heavily reorganised.
=== Fruit and seed === The fruit develops from the ovary of the plant after fertilization, its flesh comprising the pericarp walls. The fruit contains locules, hollow spaces full of seeds. These vary among cultivated varieties. Some smaller varieties have two locules; globe-shaped varieties typically have three to five; beefsteak tomatoes have a great number of small locules; and plum tomatoes have very few, very small locules. The fruit contains lycopene that produces a red colour when ripe to attract animals that eat and disperse them elsewhere. However, not all tomatoes have same levels of lycopene; so not all of them have the same red colour when they ripe. Yellow tomatoes have levels of delta-carotene and lutein higher than lycopene, orange tomatoes have higher levels of beta-carotene and prolycopene. For propagation, the seeds need to come from a mature fruit, and must be lightly fermented to remove the gelatinous outer coating and then dried before use. The tomato has a mutualistic relationship with arbuscular mycorrhizal fungi such as Rhizophagus irregularis. Scientists use the tomato as a model species for investigating such symbioses.
The avian circulatory system is driven by a four-chambered, myogenic heart contained in a fibrous pericardial sac. This pericardial sac is filled with a serous fluid for lubrication. The heart itself is divided into a right and left half, each with an atrium and ventricle. The atrium and ventricles of each side are separated by atrioventricular valves which prevent back flow from one chamber to the next during contraction. Being myogenic, the heart's pace is maintained by pacemaker cells found in the sinoatrial node, located on the right atrium. The sinoatrial node uses calcium to cause depolarisation of the signal transduction pathway from the atrium through right and left atrioventricular bundle which communicates contraction to the ventricles. The avian heart also consists of muscular arches that are made up of thick bundles of muscular layers. Much like a mammalian heart, the avian heart is composed of endocardial, myocardial and epicardial layers. The atrium walls tend to be thinner than the ventricle walls, due to the intense ventricular contraction used to pump oxygenated blood throughout the body. Avian hearts are generally larger than mammalian hearts when compared to body mass. This adaptation allows more blood to be pumped to meet the high metabolic need associated with flight.
== DNA storage == DNA storage is an important aspect of DNA extraction projects as it ensures the integrity and stability of the extracted DNA for downstream applications. One common method of DNA storage is ethanol precipitation, which involves adding ethanol and a salt, such as sodium chloride or potassium acetate, to the extracted DNA to precipitate it out of solution. The DNA is then pelleted by centrifugation and washed with 70% ethanol to remove any remaining contaminants. The DNA pellet is then air-dried and resuspended in a buffer, such as Tris-EDTA (TE) buffer, for storage. Another method is freezing the DNA in a buffer such as TE buffer, or in a cryoprotectant such as glycerol or DMSO, at -20 or -80 degrees Celsius. This method preserves the integrity of the DNA and slows down the activity of any enzymes that may degrade it. It's important to note that the choice of storage buffer and conditions will depend on the downstream application for which the DNA is intended. For example, if the DNA is to be used for PCR, it may be stored in TE buffer at 4 degrees Celsius, while if it is to be used for long-term storage or shipping, it may be stored in ethanol at -20 degrees Celsius. The extracted DNA should be regularly checked for its quality and integrity, such as by running a gel electrophoresis or spectrophotometry. The storage conditions should be also noted and controlled, such as the temperature and humidity. It's also important to consider the long-term stability of the DNA and the potential for degradation over time.
Sources: en.wikipedia.org
== Prevalence == In the United States, approximately 40,000 people were lobotomized, and in England, 17,000 lobotomies were performed. According to one estimate, in the three Nordic countries of Denmark, Norway, and Sweden, a combined figure of approximately 9,300 lobotomies was performed. Scandinavian hospitals lobotomized 2.5 times as many people per capita as hospitals in the US. According to another estimate, Sweden lobotomized at least 4,500 people between 1944 and 1966, mainly women. This figure includes young children. And in Norway, there were 2,005 known lobotomies. In Denmark, there were 4,500 known lobotomies. The Soviet Union banned the practice in 1950 on moral grounds. In Germany, it was performed only a few times. By the late 1970s, the practice of lobotomy had generally ceased, although it continued as late as the 1980s in France. As of 2019, legality of the procedure in the United States varies according to state law, with some states restricting it heavily, while others effectively leave its regulation to laws of general applicability.
The prostate is an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found in all male mammals. It differs between species anatomically, chemically, and physiologically. Anatomically, the prostate is found below the bladder, with the urethra passing through it. It is described in gross anatomy as consisting of lobes and in microanatomy by zone. It is surrounded by an elastic, fibromuscular capsule and contains glandular and connective tissue. The prostate produces and contains fluid that forms part of semen, the substance emitted during ejaculation as part of the male sexual response. This prostatic fluid is slightly alkaline, and milky or white in appearance. The alkalinity of semen helps neutralize the acidity of the vaginal tract, prolonging the lifespan of sperm. The prostatic fluid is expelled in the first part of ejaculate, together with most of the sperm, because of the action of smooth muscle tissue within the prostate. In comparison with the few spermatozoa expelled together with mainly seminal vesicular fluid, those in prostatic fluid have better motility, longer survival, and better protection of genetic material. Disorders of the prostate include enlargement, inflammation, infection, and cancer. The word prostate is derived from Ancient Greek prostátēs (προστάτης), meaning "one who stands before", "protector", "guardian", with the term originally used to describe the seminal vesicles.
The United States Congress established the Anti-Drug Abuse Act of 1988 to criminalize the distribution and possession of non-medical anabolic steroids. In 1999, WADA was formed to address the escalating use of substances in sports, particularly after the 1998 doping scandal in cycling.
=== 1978 reconstitution - the GRA === Following a number of episodes, the three 1962 representative bodies were replaced by four new associations, including the Garda Representative Association. Unlike the previous body, the GRA is constituted as an independent unincorporated association, albeit it is required to comply with the provisions of the establishing regulations. The new association began with 26 divisions and 110 districts, and a much-expanded structure of delegates to the central committee. It held its first annual general meeting in May 1979, and in addition to annual delegate conferences thereafter, it sometimes convened special conferences, such as one of policing reform in May 1983. 1988 saw the first female delegate to the annual conference of the association, which also received a report on a challenge by Garda detectives to the GRA's exclusive right of representation, lost in court; this later led to the formation of a breakaway Garda Federation. After the Federation merged back into the GRA in 1997, the association took a strong line in negotiations with Garda management, culminating, in May 1998, in a coordinated "blue flu" campaign. This involved Garda members making themselves unavailable for duty by calling in sick en masse, and was described by one national newspaper as "“the first major industrial action in the force's 75 year history." In July 2023, the GRA announced that rank-and-file Gardaí would be balloted on a motion of no-confidence in the Garda Commissioner over roster disputes.
==== Other pain ==== Paracetamol fails to relieve procedural pain in newborn babies. For perineal pain postpartum paracetamol appears to be less effective than nonsteroidal anti-inflammatory drugs (NSAIDs). The studies to support or refute the use of paracetamol for cancer pain and neuropathic pain are lacking. There is limited evidence in favor of the use of the intravenous form of paracetamol for acute pain control in the emergency department. The combination of paracetamol with caffeine is superior to paracetamol alone for the treatment of acute pain.
Sources: en.wikipedia.org
At 2:40 pm on September 11, Secretary of Defense Donald Rumsfeld was issuing orders to his aides to look for evidence of Iraqi involvement. According to notes taken by senior policy official Stephen Cambone, Rumsfeld asked for, "Best info fast. Judge whether they are good enough to hit S.H. at the same time. Not only OBL." Hours after the attacks, New York Governor George Pataki mobilized elements of the New York National Guard and ordered them to lower Manhattan. By nightfall, soldiers from the 42nd Infantry Division arrived at the WTC site and established a security perimeter around the piles of rubble that had once been the WTC complex. The 42nd Division later assumed command of the New York National Guard joint task force for response and recovery in lower Manhattan. The District of Columbia Air National Guard's 113th Wing at Andrews Air Force Base was not part of the North American Aerospace Defense Command (NORAD) network tasked with domestic airspace monitoring. Following a direct inquiry to the Secret Service regarding airspace restrictions, the Secret Service bypassed the standard military chain of command to request an immediate fighter scramble from the White House. Lt. Col. Marc Sasseville and 1st Lt. Heather Penney scrambled their F-16s without ammunition or live missiles, operating under ad-hoc orders to protect the capital using whatever force necessary—including intentional mid-air ramming maneuvers if United Airlines Flight 93 threatened the U.S. Capitol or White House.
Antibody responses elicited by DNA vaccinations are influenced by multiple variables, including antigen type; antigen location (i.e. intracellular vs. secreted); number, frequency and immunization dose; site and method of antigen delivery.
Lysine (symbol Lys or K; also L-lysine) is an α-amino acid that is a precursor to many proteins. Lysine contains an α-amino group (which is in the protonated −NH+3 form when the lysine is dissolved in water at physiological pH), an α-carboxylic acid group (which is in the deprotonated −COO− form when the lysine is dissolved in water at physiological pH), and a side chain (CH2)4NH2 (which is partially protonated when the lysine is dissolved in water at physiological pH), and so it is classified as a basic, charged (in water at physiological pH), aliphatic amino acid. It is encoded by the codons AAA and AAG. Like almost all other amino acids, the α-carbon is chiral and lysine may refer to either enantiomer or a racemic mixture of both. For the purpose of this article, lysine will refer to the biologically active enantiomer L-lysine, where the α-carbon is in the S configuration. The human body cannot synthesize lysine. It is essential in humans and must therefore be obtained from the diet. In organisms that synthesize lysine, two main biosynthetic pathways exist, the diaminopimelate and α-aminoadipate pathways, which employ distinct enzymes and substrates and are found in diverse organisms. Lysine catabolism occurs through one of several pathways, the most common of which is the saccharopine pathway. Lysine plays several roles in humans, most importantly proteinogenesis, but also in the crosslinking of collagen polypeptides, uptake of essential mineral nutrients, and in the production of carnitine, which is key in fatty acid metabolism.
The Samoyed tail is one of the breed's distinguishing features. Like the Alaskan Malamute, the tail is carried curled over the back; however, unlike the Alaskan Malamute, the Samoyed tail is held actually touching the back. It is not usually held in a tight curl, or held flag-like; it is usually carried lying over the back and to one side. In cold weather, Samoyeds may sleep with their tails over their noses to provide additional warmth. Almost all Samoyeds will allow their tails to fall when they are relaxed and at ease, as when being stroked or while eating, but will return their tails to a curl when more alert. Samoyeds have a dense, double layer coat. The topcoat contains long, coarse, and straight guard hairs, which appear white but have a hint of silver coloring. This top layer keeps the undercoat relatively clean and free of debris. The under layer, or undercoat, consists of a dense, soft, and short fur that keeps the dog warm. The undercoat typically sheds heavily once or twice a year, and this seasonal process is sometimes referred to as "blowing coat". This does not mean the Samoyed will shed only during that time however; fine hairs (versus the dense clumps shed during seasonal shedding) will be shed all year round, and have a tendency to stick to cloth and float in the air. The standard Samoyed may come in a mixture of biscuit and white coloring, although pure white and all biscuit dogs are common. Males typically have larger ruffs than females. While this breed is touted as "hypoallergenic", it does shed a fair amount and needs frequent grooming.
Sources: en.wikipedia.org
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.
Hydrolysis of peptide bonds and deamidation of arginine and proline residues are the main degradation routes. Alkaline pH and higher temperatures accelerate both processes. Buffered, near-neutral solutions stored cold generally degrade more slowly than unbuffered ones.
Reverse-phase chromatography gives the clearest single view of related impurities and truncated sequences. Mass spectrometry then confirms that the main peak carries the expected mass. Neither test detects enantiomeric impurities, which require a separate chiral assay.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.