This is a working overview of Certificate of analysis, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-05-19 and is reviewed periodically as new material appears.
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.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common route | Intranasal | Also injected in some animal work |
| Solubility class | Freely soluble in water | Solid form is hygroscopic |
| Typical storage | About -20 degrees Celsius | Keep desiccated and dark |
| Purity method | Reverse-phase HPLC | Reported as area percent |
| Confirmatory method | Mass spectrometry | Verifies expected molecular mass |
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.
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.
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.
In continuum mechanics, the generalized Lagrangian mean (GLM) is a formalism – developed by D.G. Andrews and M.E. McIntyre (1978a, 1978b) – to unambiguously split a motion into a mean part and an oscillatory part. The method gives a mixed Eulerian–Lagrangian description for the flow field, but appointed to fixed Eulerian coordinates.
A radioligand is a microscopic particle which consists of a therapeutic radioactive isotope and the cell-targeting compound — the ligand. The ligand is the target binding site; it may be on the surface of the targeted cancer cell for therapeutic purposes. Radioisotopes can occur naturally or be synthesized and produced in a cyclotron/nuclear reactor. Types of radioisotopes include Y-90, H-3, C-11, Lu-177, Ac-225, Ra-223, In-111, I-131, and I-125. Thus, radioligands must be produced in special nuclear reactors for the radioisotope to remain stable. Radioligands can be used to analyze/characterize receptors, to perform binding assays, to help in diagnostic imaging, and to provide targeted cancer therapy. Radiation is a novel method of treating cancer and is effective in short distances along with being unique/personalizable and causing minimal harm to normal surrounding cells. Furthermore, radioligand binding can provide information about receptor-ligand interactions in vitro and in vivo. Choosing the right radioligand for the desired application is important. The radioligand must be radiochemically pure, stable, and demonstrate a high degree of selectivity, and high affinity for their target.
Permission to examine, analyze, verify, and reproduce any records and reports that are important to evaluation of a clinical trial. Any party (e.g., domestic and foreign regulatory authorities, sponsors, monitors, and auditors) with direct access should take all reasonable precautions within the constraints of the applicable regulatory requirement(s) to maintain the confidentiality of subjects' identities and sponsor's proprietary information. (ICH E6) Documentation
Sources: en.wikipedia.org
=== Judith Mossman === Dr. Judith Mossman (voiced by Michelle Forbes) is introduced in Half-Life 2 as a physicist working with Eli Vance at the Black Mesa East Research Facility. Although she is apparently friendly with other scientists, her condescending attitude toward laypeople annoys Alyx. Over the course of the game, she is revealed as a triple agent who betrays the resistance in an attempt to form an alliance with Dr. Breen, then betrays him in turn. In the follow-on episodes, she is again working for the resistance in a remote location. According to writer Marc Laidlaw, Judith Mossman was based on the character Elena Hausmann from his novel The Third Force: A Novel of Gadget (1996), based on the computer game Gadget: Invention, Travel, & Adventure (1993). He originally named the character Elena Mossman, but because it sounded too similar to the Gadget character, he renamed her to Judith Mossman.
== Ligands == The AMYRs are bound by amylin with high affinity, and by calcitonin with relatively lower affinity. In humans, calcitonin gene-related peptide (CGRP) is a selective agonist with a greater affinity towards AMY1 than AMY3, while its affinity for AMY2 isn’t well understood. Drugs that mimic Amylin to activate amylin receptors (called Amylin receptor agonists) are being developed as therapies for diabetes and obesity, and one, pramlintide, has been FDA approved as a treatment for diabetes. CGRP receptor antagonists which are being developed for migraine, may also act as antagonists for AMY1, which could be playing a role in their effects. Dual agonists of the amylin and calcitonin receptors (DACRAs) are under development for obesity. Amylin and its receptors are believed to play a role in Alzheimer's disease.
== Function == This gene encodes a precursor protein that is processed to produce oxytocin and neurophysin I. Oxytocin is a posterior pituitary hormone that is synthesized as an inactive precursor in the hypothalamus along with its carrier protein neurophysin I. Together with neurophysin, it is packaged into neurosecretory vesicles and transported axonally to the nerve endings in the neurohypophysis, where it is either stored or secreted into the bloodstream. The precursor seems to be activated while it is being transported along the axon to the posterior pituitary. This hormone contracts smooth muscle during parturition and lactation. It is also involved in cognition, tolerance, adaptation, and complex sexual and maternal behavior, as well as in the regulation of water excretion and cardiovascular functions. [provided by RefSeq, Dec 2013].
Sources: en.wikipedia.org
==== Pregnancy ==== The placenta produces leptin. Leptin levels rise during pregnancy and fall after childbirth. Leptin is also expressed in fetal membranes and the uterine tissue. Uterine contractions are inhibited by leptin. Leptin plays a role in hyperemesis gravidarum (severe morning sickness of pregnancy), in polycystic ovary syndrome, and hypothalamic leptin is implicated in bone growth in mice.
, the Darcy friction factor (also called flow coefficient λ). For laminar flow in a circular pipe of diameter Dc, the friction factor is inversely proportional to the Reynolds number alone (fD = 64/Re) which itself can be expressed in terms of easily measured or published physical quantities (see section below). Making this substitution the Darcy–Weisbach equation is rewritten as
By total area (including its waters), Canada is the second-largest country. By land area alone, Canada ranks fourth, due to having the world's largest area of fresh water lakes. Stretching from the Atlantic Ocean in the east, along the Arctic Ocean to the north, and to the Pacific Ocean in the west, the country encompasses 9,984,670 square kilometres (3,855,100 sq mi) of territory. Canada also has vast maritime terrain, with the world's longest coastline of 243,042 kilometres (151,019 mi) In addition to sharing the world's largest land border with the United States—spanning 8,891 kilometres (5,525 mi)—Canada shares a short (1,280 metres (4,200 ft)) land border with Greenland (and hence the Kingdom of Denmark) to the northeast, on Hans Island, and a maritime boundary with France's overseas collectivity of Saint Pierre and Miquelon to the southeast. Canada is also home to the world's northernmost settlement, Canadian Forces Station Alert, on the northern tip of Ellesmere Island—latitude 82.5°N—which lies 817 kilometres (508 mi) from the North Pole. In latitude, Canada's most northerly point of land is Cape Columbia in Nunavut at 83°6′41″N, with its southern extreme at Middle Island in Lake Erie at 41°40′53″N. In longitude, Canada's land extends from Cape Spear, Newfoundland, at 52°37′W, to Mount St. Elias, Yukon Territory, at 141°W. Canada can be divided into seven physiographic regions: the Canadian Shield, the Interior Plains, the Great Lakes–St. Lawrence Lowlands, the Appalachian region, the Western Cordillera, Hudson Bay Lowlands, and the Arctic Archipelago.
"Cid", "Lucy", "Sidney", "Blotters", "Droppers", "Sugar Cubes") O-Acetylpsilocin (believed to be a prodrug of psilocin) psilocin (found in psilocybin mushrooms) psilocybin (also found in psilocybin mushrooms; prodrug to psilocin) ibogaine (found in Tabernanthe iboga ("Iboga")) Atypicals salvinorin A (found in Salvia divinorum, a trans-neoclerodane diterpenoid ("Diviner's Sage", "Lady Salvia", "Salvinorin")) tetrahydrocannabinol (found in cannabis)
Sources: en.wikipedia.org
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.
Reported human trials are few, brief and originate mainly from one country. They describe effects on anxiety-related measures, but sample sizes are small and reporting is limited. The results are widely regarded as preliminary rather than confirmed.
Reverse-phase liquid chromatography is used to assess purity and separation of related impurities. Mass spectrometry confirms that the observed molecular mass matches the expected peptide. A certificate of analysis from the supplier is the usual document of record.
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.