A practical reference on blood-brain barrier: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
| Property | Value | Notes |
|---|---|---|
| Primary route studied | Intranasal | Also examined parenterally in animal work |
| Reported plasma half-life | Minutes to tens of minutes | Values vary widely between reports |
| Main model systems | Rodent behavioural and cell assays | Human trials are few and small |
| Principal proposed targets | GABA-A receptor, GABA transaminase | Monoamine and neurotrophic pathways also reported |
| Evidence grade | Preliminary | Limited independent replication |
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
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.
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.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
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.
Kwashiorkor is primarily caused by inadequate protein intake. Its symptoms include edema, wasting, liver enlargement, hypoalbuminaemia, and steatosis; the condition may also cause depigmentation of skin and hair. The disorder is further identified by a characteristic swelling of the belly, and extremities which disguises the patient's undernourished condition. 'Kwashiorkor' means 'displaced child' and is derived from the Ga language of coastal Ghana in West Africa. It means "the sickness the baby gets when the next baby is born," as it often occurs when the older child is deprived of breastfeeding and weaned to a diet composed largely of carbohydrates. Marasmus (meaning 'to waste away') can result from a sustained diet that is deficient in both protein and energy. This causes their metabolism to adapt to prolong survival. The primary symptoms are severe wasting, leaving little or no edema; minimal subcutaneous fat; and abnormal serum albumin levels. It is traditionally seen in cases of famine, significant food restriction, or severe anorexia. Conditions are characterized by extreme wasting of the muscles and a gaunt expression.
=== EC 1.11.1 Peroxidases === EC 1.11.1.1: NADH peroxidase EC 1.11.1.2: NADPH peroxidase EC 1.11.1.3: fatty-acid peroxidase EC 1.11.1.4: Now EC 1.13.11.11 EC 1.13.11.11 tryptophan 2,3-dioxygenase EC 1.11.1.5: cytochrome-c peroxidase EC 1.11.1.6: catalase EC 1.11.1.7: peroxidase EC 1.11.1.8: iodide peroxidase EC 1.11.1.9: glutathione peroxidase EC 1.11.1.10: chloride peroxidase EC 1.11.1.11: L-ascorbate peroxidase EC 1.11.1.12: phospholipid-hydroperoxide glutathione peroxidase EC 1.11.1.13: manganese peroxidase EC 1.11.1.14: lignin peroxidase EC 1.11.1.15: Now described by EC 1.11.1.24, thioredoxin-dependent peroxiredoxin; EC 1.11.1.25, glutaredoxin-dependent peroxiredoxin; EC 1.11.1.26, NADH-dependent peroxiredoxin; EC 1.11.1.27, glutathione-dependent peroxiredoxin; EC 1.11.1.28, lipoyl-dependent peroxiredoxin; and EC 1.11.1.29, mycoredoxin-dependent peroxiredoxin EC 1.11.1.16: versatile peroxidase EC 1.11.1.17: glutathione amide-dependent peroxidase EC 1.11.1.18: bromide peroxidase EC 1.11.1.19: dye decolorizing peroxidase EC 1.11.1.20: prostamide/prostaglandin F2α synthase EC 1.11.1.21: catalase-peroxidase EC 1.11.1.22: hydroperoxy fatty acid reductase EC 1.11.1.23: (S)-2-hydroxypropylphosphonic acid epoxidase EC 1.11.1.24: thioredoxin-dependent peroxiredoxin EC 1.11.1.25: glutaredoxin-dependent peroxiredoxin EC 1.11.1.26: NADH-dependent peroxiredoxin EC 1.11.1.27: glutathione-dependent peroxiredoxin EC 1.11.1.28: lipoyl-dependent peroxiredoxin EC 1.11.1.29: mycoredoxin-dependent peroxiredoxin
== Drug liberalization == Drug liberalization as a harm-reduction strategy gives the ability to treat substance use disorder solely as a public health issue rather than a criminal activity. This enables other harm-reduction strategies to be employed, which results in a lower incidence of HIV infection.
Sources: en.wikipedia.org
According to data from 2024, the 250 seats in the People's Council are distributed as follows: Sunni Muslims (171 seats), reflecting their majority status in Syria's population, Alawites (39 seats), corresponding to their demographic proportion, Christians (23 seats), allocated across various provinces, Druze (9 seats), with a significant number from the Suwayda Governorate, Shia Muslims (5 seats), Ismailis (2 seats) and Murshidites (1 seat). Out of a 210-member People's Assembly formed after the fall of the Ba'athist government in 2024, 140 seats were allocated through a transitional electoral process. Of those elected, six were women and 10 were minority representatives (Kurds, Christians, and two Alawites). The 70 appointed members included 15 women, with officials stating the appointments were intended to address limited representation in the elected portion of the assembly.
A scavenger in chemistry is a chemical substance added to a mixture in order to remove or de-activate impurities and unwanted reaction products, for example oxygen, to make sure that they will not cause any unfavorable reactions. Their use is wide-ranged:
==== Injection ==== Subjective effects not commonly shared with other methods of administration include a ringing in the ears moments after injection (usually when over 120 milligrams) lasting 2 to 5 minutes including tinnitus and audio distortion. This is colloquially referred to as a "bell ringer". In a study of cocaine users, the average time taken to reach peak subjective effects was 3.1 minutes. The euphoria passes quickly. Aside from the toxic effects of cocaine, there is also the danger of circulatory emboli from the insoluble substances that may be used to cut the drug. As with all injected illicit substances, there is a risk of the user contracting blood-borne infections if sterile injecting equipment is not available or used.
Magnetic nanoparticles (MNPs) are a class of nanoparticle that can be manipulated using magnetic fields. Such particles commonly consist of two components, a magnetic material, often iron, nickel and cobalt, and a chemical component that has functionality. While nanoparticles are smaller than 1 micrometer in diameter (typically 1–100 nanometers), the larger microbeads are 0.5–500 micrometer in diameter. Magnetic nanoparticle clusters that are composed of a number of individual magnetic nanoparticles are known as magnetic nanobeads with a diameter of 50–200 nanometers. Magnetic nanoparticle clusters are a basis for their further magnetic assembly into magnetic nanochains. The magnetic nanoparticles have been the focus of much research recently because they possess attractive properties which could see potential use in catalysis including nanomaterial-based catalysts, biomedicine and tissue specific targeting, magnetically tunable colloidal photonic crystals, microfluidics, magnetic resonance imaging, magnetic particle imaging, data storage, environmental remediation, nanofluids, optical filters, defect sensor, magnetic cooling and cation sensors.
Sources: en.wikipedia.org
The progenitor of the Samoyeds was the Nenets Herding Laika, a reindeer herding spitz commonly used throughout the Arctic, especially the Nenets people, who were pejoratively referred to as Samoyeds at that time. DNA evidence confirms that Samoyeds are a basal breed that predates the emergence of the modern breeds in the 19th century. A genomic study of two dog specimens nearly 100 years old obtained from the Nenets people on the Yamal Peninsula found that these are related to two specimens dated 2,000 years old and 850 years old, which suggests continuity of the lineage in this region. The two 100-year-old dogs were closely related with the Samoyed breed, which indicates that the ancient Arctic lineage lives on in the modern Samoyed dog.
Translocase is a general term for a protein that assists in moving another molecule, usually across a cell membrane. These enzymes catalyze the movement of ions or molecules across membranes or their separation within membranes. The reaction is designated as a transfer from “side 1” to “side 2” because the designations “in” and “out”, which had previously been used, can be ambiguous. Translocases are the most common secretion system in Gram positive bacteria. It is also a historical term for the protein now called elongation factor G, due to its function in moving the transfer RNA (tRNA) and messenger RNA (mRNA) through the ribosome.
=== Second House passage === The House of Representatives needed to pass the Senate version of the OBBBA for the bill to reach the President's desk. On July 1, 2025, President Trump and Senate majority leader Thune expressed confidence that the bill would pass in the House. House Republican moderates such as David Valadao and Young Kim of California, and Jeff Van Drew of New Jersey, who are against Medicaid cuts, Nick LaLota of New York, who is against SALT changes, and fiscal conservatives such as Chip Roy and Keith Self of Texas, who oppose federal deficit increases, had expressed opposition by June 30 to the bill in its then-current form. The House Rules Committee voted 7–6 on July 1, 2025, to advance the bill to the floor. Fiscal conservative Republicans Chip Roy and Ralph Norman voted against advancing the bill. Usually, the members of the majority party on the Rules Committee always vote to advance the bill to the floor. A procedural vote on July 2, 2025, while negotiations were ongoing off the House floor, was the longest vote in House history. In the early morning of July 3, 2025, the House approved the final procedural rule vote 219–213. The vote, which began on the evening of July 2, was initially opposed by five Republicans: moderate Brian Fitzpatrick of Pennsylvania and fiscal conservatives Victoria Spartz of Indiana, Andrew Clyde of Georgia, Keith Self of Texas, and Thomas Massie of Kentucky. Eight other fiscal conservative Republicans, including Tim Burchett of Tennessee and Chip Roy of Texas, withheld their votes.
Aging in dogs varies widely depending on the breed; certain breeds, such as giant dog breeds and English Bulldogs, have much shorter lifespans than average. Most dogs reach adolescence by one year old; smaller and medium-sized breeds begin to age more slowly in adulthood. Old elephants near death do not leave their herd to go to an "elephants' graveyard" to die. The hippopotamus does not produce pink milk, nor does it sweat blood. The skin secretions of the hippopotamus are red due to the presence of hipposudoric acid, a red pigment which acts as a natural sunscreen, and is neither sweat nor blood. It does not affect the color of their milk, which is white or beige. Lemmings do not engage in mass suicide by diving off cliffs. The idea was popularized by the 1958 Disney documentary film White Wilderness, in which the lemmings were repeatedly shoved off a cliff by the filmmakers to create the illusion of a mass suicide. The misconception itself is much older, dating back to at least the late 19th century, though its exact origins are uncertain. Mice do not have a special appetite for cheese, and will eat it only for lack of better options; they actually favor sweet sugary foods. The myth may have come from the fact that before the advent of refrigeration, cheese was usually stored outside and was therefore a food easy for mice to reach. Porcupines do not shoot their quills. They can detach, and porcupines will deliberately back into attackers to impale them, but their quills do not project. Rabbits are not especially partial to carrots.
(1999), "Conditioned Arising Evolves: Variation and Change in Textual Accounts of the Paticca-samupadda Doctrine", Journal of the International Association of Buddhist Studies, 22 (2) Jurewicz, Joanna (2000), "Playing with Fire: The pratityasamutpada from the perspective of Vedic thought", Journal of the Pali Text Society, 26: 77–103 Shulman, Eviatar (2008), "Early Meanings of Dependent-Origination" (PDF), Journal of Indian Philosophy, 36 (2): 297–317, doi:10.1007/s10781-007-9030-8, S2CID 59132368, archived from the original (PDF) on 10 October 2016 Gombrich, Richard (2009), "Chaper 9. Causation and non-random process", What the Buddha Thought, Equinox Jones, Dhivan Thomas (2009), "New Light on the Twelve Nidanas", Contemporary Buddhism, 10 (2): 241–259, doi:10.1080/14639940903239793, S2CID 145413087
Sources: en.wikipedia.org
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.
The peptide enters plasma rapidly and is broken down by ordinary proteases into amino acids and shorter fragments. Reported half-lives are short. Whether meaningful amounts of the intact molecule reach the brain is an open question.
Most clinical reports are small, published in Russian and not independently replicated. English-language reviews highlight the absence of large randomised trials. Conclusions about efficacy should be treated as provisional.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.