elevated plus maze 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 2025-10-14. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by RP-HPLC | Area percentage of the main peak |
| Identity confirmation | Electrospray ionization mass spectrometry | Observed mass compared with the theoretical value near 751.9 Da |
| Recommended dry storage | -20 °C, desiccated | -80 °C for multi-year archival material |
| Solution handling | Prepare fresh; avoid long storage | Sterile filtration reduces microbial load |
| Common synonyms | TKPRPGP; TP-7 | Sequence code and laboratory designation used interchangeably |
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
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.
== Genetic transformation == Of the 59 species listed in the table with their clinical characteristics, 11 species (or 19%) are known to be capable of natural genetic transformation. Natural transformation is a bacterial adaptation for transferring DNA from one cell to another. This process includes the uptake of exogenous DNA from a donor cell by a recipient cell and its incorporation into the recipient cell's genome by recombination. Transformation appears to be an adaptation for repairing damage in the recipient cell's DNA. Among pathogenic bacteria, transformation capability likely serves as an adaptation that facilitates survival and infectivity. The pathogenic bacteria able to carry out natural genetic transformation (of those listed in the table) are Campylobacter jejuni, Enterococcus faecalis, Haemophilus influenzae, Helicobacter pylori, Klebsiella pneumoniae, Legionella pneumophila, Neisseria gonorrhoeae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus pneumoniae and Vibrio cholerae.
=== Advantages in animals === Balanced anesthesia has various advantages in veterinary cases: In certain circumstances it is considerably cheaper than the usual anesthesia. Secondly, it can reduce the death rate. Furthermore, it offers more stable operating conditions for veterinarians. It also increase animal safety and comfort. Balanced anesthesia can make patients calm by using drugs such as: medetomidine, diazepam or midazolam, and acepromazine. Keeping patients calm prior to surgery can avoid the unpredictable consequences of stress, such as tachypnea, hypertension and tachycardia which may be harmful to the anesthetized patients. In addition, anxiety and stress may cause the nociceptive pain. The balanced anesthesia therefore may therefore decrease those possible complications. Another advantage of using balanced anesthesia is that it can decrease the chance of adverse effects. All medicines may have adverse effect on patients; some serious adverse effects of anesthesia may be caused by inhalational anesthetic, although in general these medicines are highly safe and useful. Using the correct amount of balanced anesthetic agents, the adverse effects can be reduced to some extent. Balanced anesthesia can also minimize the pain patients suffer. Pain may delay wound healing, decrease appetite, and even result in death. Using the proper amount of analgesics can reduce the amount of inhalant anesthetics required and help patients reduce the pain.
== Adverse effects == Lercanidipine is generally well tolerated; no single adverse effect has been observed in more than 1% of patients treated with this drug. Typical side effects are similar to those of other drugs of this class and include headache, dizziness, tachycardia (fast heartbeat), palpitations, flush, and oedema. Hypersensitivity reactions occur in less than one patient in 10,000. Oedemas are significantly less common under lercanidipine when compared to first-generation dihydropyridines such as nifedipine. For other side effects, data are inconclusive: A study comparing lercanidipine to first-generation drugs found no difference in the frequency of headache and flush, but switching from amlodipine, felodipine or nitrendipine (all at least second generation) to lercanidipine significantly decreased side effects in another study.
== Pathophysiology == Hemoglobin is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Hemoglobin in the blood carries oxygen from the lungs to the other tissues of the body, where it releases the oxygen to enable metabolism. A healthy level of hemoglobin for men is between 13.2 and 16.6 grams per deciliter, and in women between 11.6 and 15 g/dl. Normal adult hemoglobin (HbA) is composed of four protein chains, two α and two β-globin chains arranged into a heterotetramer. In thalassemia, patients have defects in the noncoding region of either the α or β-globin genes, causing ineffective production of normal alpha- or beta-globin chains, which can lead to ineffective erythropoiesis, premature red blood cell destruction, and anemia. The thalassemias are classified according to which chain of the hemoglobin molecule is affected. In α-thalassemias, production of the α-globin chain is affected, while in β-thalassemia, production of the β-globin chain is affected.
Though its absolute bioavailability in humans is unknown, bicalutamide is known to be extensively and well-absorbed. Its absorption is not affected by food. The absorption of bicalutamide is linear at doses up to 150 mg/day and is saturable at doses above this, with no further increases in steady-state levels of bicalutamide occurring at doses above 300 mg/day. Whereas absorption of (R)-bicalutamide is slow, with levels peaking at 31 to 39 hours after a dose, (S)-bicalutamide is much more rapidly absorbed. Steady-state concentrations of the drug are reached after 4 to 12 weeks of treatment independently of dosage, with a 10- to 20-fold progressive accumulation in levels of (R)-bicalutamide. The long time to steady-state levels is the result of bicalutamide's very long elimination half-life. There is wide interindividual variability in (R)-bicalutamide levels (up to 16-fold) with bicalutamide regardless of dosage. The tissue distribution of bicalutamide is not well-characterized. The amount of bicalutamide in semen that could potentially be transferred to a female partner during sexual intercourse is low and is not thought to be important. Based on animal studies with rats and dogs it was thought that bicalutamide could not cross the blood–brain barrier and hence could not enter the brain. As such, it was initially thought to be a peripherally selective antiandrogen.
Sources: en.wikipedia.org
=== Reduction === Like esters, most carboxylic acids can be reduced to alcohols by hydrogenation, or using hydride transferring agents such as lithium aluminium hydride. Strong alkyl transferring agents, such as organolithium compounds but not Grignard reagents, will reduce carboxylic acids to ketones along with transfer of the alkyl group. The Vilsmaier reagent (N,N-Dimethyl(chloromethylene)ammonium chloride; [ClHC=N+(CH3)2]Cl−) is a highly chemoselective agent for carboxylic acid reduction. It selectively activates the carboxylic acid to give the carboxymethyleneammonium salt, which can be reduced by a mild reductant like lithium tris(t-butoxy)aluminum hydride to afford an aldehyde in a one pot procedure. This procedure is known to tolerate reactive carbonyl functionalities such as ketone as well as moderately reactive ester, olefin, nitrile, and halide moieties.
And the question in my mind is, how many additional American casualties is Saddam [Hussein] worth? And the answer is, not that damned many. So, I think we got it right, both when we decided to expel him from Kuwait, but also when the President made the decision that we'd achieved our objectives and we were not going to go get bogged down in the problems of trying to take over and govern Iraq. On 15 March 1991, Sheikh Jaber al-Ahmad al-Sabah returned to Kuwait, staying at the private home of a wealthy Kuwaiti as his own palace had been destroyed. He was met with a symbolic arrival with several dozen cars filled with people honking their horns and waving Kuwaiti flags who tried to follow the emir's convoy. According to The New York Times, he faced a population divided between those who stayed and those who fled, a government straining to reassert control and a rejuvenated opposition pressing for greater democracy and other postwar changes, including voting rights for women. Democracy advocates had been calling for restoration of Parliament that the emir had suspended in 1986.
== History == In 1992, Professor John T. Isaacs of The Johns Hopkins School of Medicine in Baltimore, Maryland, was investigating ways to approach the treatment of slow-growing tumors and discovered they could be efficiently destroyed if intracellular calcium levels were raised significantly. He determined that the ideal agent for upsetting intracellular calcium levels was the novel chemical thapsigargin. He began collaborating with Dr. Soren Christensen, a natural products chemist, at the University of Copenhagen in Denmark, and the first scientist to isolate thapsigargin from the plant Thapsia garganica, a poisonous weed that grows wild in areas of the Mediterranean. The objective of the collaboration was to chemically alter thapsigargin to a derivative that could be linked to peptides, thus forming prodrugs to treat certain tumors. Drs. Isaacs and Christensen were joined in their research by Dr. Hans Lilja, now at the Memorial Sloan-Kettering Cancer Center in New York, and Dr. Samuel Denmeade, of the Johns Hopkins School of Medicine. Together the four co-inventors developed a technology platform in which the therapeutic component of all the compounds would remain the same, but the targeting peptide would change. Peptides would be selected that could only be "cut off" or cleaved by enzymes specific for certain tumors. In March 2016, CEO and CFO, Craig A. Dionne resigned and Peter E. Grebow was announced as interim CEO. On August 1, 2016 the company changed its name to Inspyr Therapeutics and began trading under NSPX.
Ronald Dickson Woodroof (February 3, 1950 – September 12, 1992) was an American man who created what would become known as the Dallas Buyers Club in March 1988, one of several such AIDS buyers clubs that sprang up at the time. After learning he had contracted the human immunodeficiency virus (HIV) in 1985 and being diagnosed with AIDS, he created the group as part of his efforts to find and distribute drugs to treat AIDS at a time when the disease was poorly understood. He sued the United States Food and Drug Administration (FDA) over a ban on peptide T, a drug he was using. Woodroof's final years became the basis of the 2013 film Dallas Buyers Club, in which he was portrayed by Matthew McConaughey.
The Australian National University Act received royal assent on 1 August 1946. The act created the Australian National University (ANU), and gave the medical research institute the name "John Curtin School of Medical Research". H. C. "Nugget" Coombs, an economist and head of the Department of Post-War Reconstruction, accompanied the Prime Minister, Ben Chifley, on an official visit to the UK as his principal advisor. Coombs met with Florey in Oxford in May 1946. They agreed that the success of the new university would depend on the quality of faculty they could attract, and he wanted four eminent scholars to lead the four research schools: Florey for medicine, Mark Oliphant for physics, Keith Hancock for history, and Raymond William Firth for Pacific studies. Each received an official invitation in April 1947, and they were invited to come to Canberra for consultation in December 1947 and January 1948. They would constitute an academic advisory committee, for which they would be paid £250 (equivalent to A$20,242 in 2022) plus £200 (equivalent to A$16,193 in 2022) expenses per annum. Since they were all located in the UK, a London office of the university was opened to provide liaison. Florey never moved to Canberra, but he did accept the position of acting director of the John Curtin School of Medical Research for a five-year term commencing in May 1948 in order to establish it. Brian Lewis had been appointed university architect, but Florey hired Stephen Welsh, the professor of architecture at Sheffield University.
Sources: en.wikipedia.org
== Protactinium-230 == Protactinium-230 has 139 neutrons and a half-life of 17.4 days. Most of the time (92%), it undergoes beta plus decay to 230Th, with a smaller (8%) beta-minus decay branch leading to 230U. It also has a very rare (0.0032%) alpha decay mode leading to 226Ac. It is not found in nature because its half-life is short and it is not found in the decay chains of 235U, 238U, or 232Th. Protactinium-230 is of interest as a progenitor of uranium-230, an isotope that has been considered for use in targeted alpha-particle therapy (TAT). It can be produced through proton or deuteron irradiation of natural thorium.
== Prohormone convertases == The two proprotein convertases that specialize in the processing of the precursors of peptide hormones and neuropeptides are also known in the field as "prohormone convertases". Both "prohormone convertase" and "proprotein convertase" are interchangeably abbreviated as "PC". PC1 (also known as PC3 and commonly referred to as PC1/3) and PC2 are the primary enzymes involved in the processing of the bioactive peptides precursors at paired basic residues. PC1/3 and PC2 do not directly produce most neuropeptides and peptide hormones, but instead generate intermediates that contain C-terminal extensions of lysine and/or arginine residues; these are subsequently removed by carboxypeptidase E.
Neurological manifestations can include tremors, chorea, myopathy, and in some susceptible individuals (in particular of Asian descent) periodic paralysis. An association between thyroid disease and myasthenia gravis has been recognized. Thyroid disease, in this condition, is autoimmune in nature, and approximately 5% of people with myasthenia gravis also have hyperthyroidism. Myasthenia gravis rarely improves after thyroid treatment and the relationship between the two entities is becoming better understood over the past 15 years.In Graves' disease, ophthalmopathy may cause the eyes to look enlarged because the eye muscles swell and push the eye forward. Sometimes, one or both eyes may bulge. Some have swelling of the front of the neck from an enlarged thyroid gland (a goiter). Minor ocular (eye) signs, which may be present in any type of hyperthyroidism, are eyelid retraction ("stare"), extraocular muscle weakness, and lid-lag. In hyperthyroid stare (Dalrymple sign) the eyelids are retracted upward more than normal (the normal position is at the superior corneoscleral limbus, where the "white" of the eye begins at the upper border of the iris). Extraocular muscle weakness may present with double vision. In lid-lag (von Graefe's sign), when the person tracks an object downward with their eyes, the eyelid fails to follow the downward-moving iris, and the same type of upper globe exposure which is seen with lid retraction occurs, temporarily. These signs disappear with treatment of the hyperthyroidism.
In enzymology, L-threonine 3-dehydrogenase (EC 1.1.1.103), or just threonine dehydrogenase, is an enzyme that participates in the process of breaking down threonine in certain non-human organisms like mice. In particular, it catalyzes the chemical reaction
Sources: en.wikipedia.org
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.
A reported purity value reflects the share of the main peak in one chromatographic run and says nothing about identity. Confirming that the expected sequence is present requires a separate measurement such as mass spectrometry. Purity and identity are distinct questions.
A mass spectrum reports the molecular masses present in a sample and shows whether they match the value expected for selank, near 751.9 Da. It also flags common artifacts such as truncation or adduct formation. It does not establish correct stereochemistry or complete sequence order on its own.
The most common approach combines reverse-phase liquid chromatography with mass spectrometry. Chromatography separates the components while mass spectrometry confirms the molecular mass. Peptide sequencing or tandem mass analysis can further verify the amino acid order.