freeze-thaw 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 2025-08-07. Numbers and descriptions here follow the published literature rather than marketing material.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
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.
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.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
=== French === Union Saint-Jean-Baptiste - Founded March 27, 1900 in Woonsocket, Rhode Island, as the Union Saint-Jean-Baptiste d'Amerique for Roman Catholic Franco-Americans. Activities include hospital volunteer work, comforting the bereaved, visiting shut-ins, and working in Catholic Action. The Saint-Jean-Baptiste Educational Foundation provides scholarships; the group also helps fund the Catholic Communications Foundation whose mission was to spread understanding of the Catholic faith and doctrine in the mass media. Headquarters was Woonsocket. The motto is "In Union there is strength". Lodges are called local councils, and the national convention is "National Congress". There was a ritual for initiation and the installation of officers. 62,000 members in 1968, 47,000 in January 1979. Merged with Catholic Family Life in 1991. Association Canado-Americaine - Founded in 1896 in Manchester, New Hampshire, which remained the organization's headquarters. Lodges were called Courts, regions District Courts, highest body "Supreme Court" which met quadrennially. A "High Court" administered the group in between sessions of the Supreme Court and determined district boundaries. Motto: "Religion, Patriotism, and Fraternity." The Association had rituals for initiation, installation, and other rites; the rituals reflected the Catholic values of the society whose patron was St. John the Baptist. The organization offered beneficiary and social membership; the former consisted of adult and infant divisions, the infants becoming adult members when they turned 18.
==== United Kingdom ==== In the United Kingdom, the three medical Royal Colleges (the Royal College of Physicians of London, the Royal College of Physicians of Edinburgh and the Royal College of Physicians and Surgeons of Glasgow) are responsible for setting curricula and training programmes through the Joint Royal Colleges Postgraduate Training Board (JRCPTB), although the process is monitored and accredited by the independent General Medical Council (which also maintains the specialist register). Doctors who have completed medical school spend two years in foundation training completing a basic postgraduate curriculum. After two years of Core Medical Training (CT1/CT2), or three years of Internal Medicine Training (IMT1/IMT2/IMT3) as of 2019, since and attaining the Membership of the Royal College of Physicians, physicians commit to one of the medical specialties:
In the 1950s, Har Gobind Khorana and co-workers developed a phosphodiester method where 3'-O-acetylnucleoside-5'-O-phosphate 2 (Scheme 3) was activated with N,N'-dicyclohexylcarbodiimide (DCC) or 4-toluenesulfonyl chloride (Ts-Cl). The activated species were reacted with a 5'-O-protected nucleoside 1 to give a protected dinucleoside monophosphate 3. Upon the removal of 3'-O-acetyl group using base-catalyzed hydrolysis, further chain elongation was carried out. Following this methodology, sets of tri- and tetradeoxyribonucleotides were synthesized and were enzymatically converted to longer oligonucleotides, which allowed elucidation of the genetic code. The major limitation of the phosphodiester method consisted in the formation of pyrophosphate oligomers and oligonucleotides branched at the internucleosidic phosphate. The method seems to be a step back from the more selective chemistry described earlier; however, at that time, most phosphate-protecting groups available now had not yet been introduced. The lack of the convenient protection strategy necessitated taking a retreat to a slower and less selective chemistry to achieve the ultimate goal of the study.
Inguinal hernias, in turn, belong to groin hernias, which also includes femoral hernias. A femoral hernia is not via the inguinal canal, but via the femoral canal, which normally allows passage of the common femoral artery and vein from the pelvis to the leg. In Amyand's hernia, the content of the hernial sac is the appendix.
==== α2-Adrenergic receptor ==== Antagonism of the α2-adrenergic receptors, which function largely as inhibitory autoreceptors and heteroreceptors, enhances adrenergic and serotonergic neurotransmission, notably central 5-HT1A receptor mediated transmission in the dorsal raphe nucleus and hippocampus; hence, mirtazapine's classification as a NaSSA. Indirect α1 adrenoceptor-mediated enhancement of serotonin cell firing and direct blockade of inhibitory α2 heteroreceptors located on serotonin terminals are held responsible for the increase in extracellular serotonin. Because of this, mirtazapine has been said to be a functional "indirect agonist" of the 5-HT1A receptor. Increased activation of the central 5-HT1A receptor is thought to be a major mediator of efficacy of most antidepressant drugs. Mirtazapine's antagonism of α2-adrenoreceptors is potentially functionally selective for presynaptic α2 receptors. Mirtazapine, at 25 μg/kg IV, in freely moving rats, enhanced the endogenous release of serotonin, specifically due to blockade of α2 heteroreceptors on serotonin neuron terminals, but required a dose of 500 μg/kg IV to block local norepinephrine mediated and postsynaptic α2 mediated inhibition of CA3 dorsal hippocampus pyramidal neurons in those rats. This is an approximate 20-fold functional selectivity for inhibiting presynaptic α2 over postsynaptic α2 (especially postsynaptic α2 in the rat hippocampus).
Sources: en.wikipedia.org
Picking up where A Loner left off, Saddiction (2025) saw the band further explore the sonic aspects and the post-punk and cold wave facets of their influences. It spawned several singles, including "2 am Thoughts". Their lyrics generally explore dark and gloomy themes, set against the backdrop of urban landscapes, primarily in Paris and its suburbs. Their discography demonstrates a gradual transition towards a clean singing voice. Hangman's Chair suspended their activities in November 2025 for an indefinite period.
The introductions of Mia and Chloe helped further exploration of Ari's fictional backstory. It emerges that after their baby son died, Ari's grief caused him to self-destruct and he was later sent to prison for 10 years. Mia then chose to move away with Chloe, who lost the only father figure she had ever known. Ari is surprised when Chloe turns up in the Bay to see him, and he soon learns that Mia lied to Chloe about why he left them, saying that he did not want to be in their lives anymore. Kipa-Williams explained: "Just before her 10th birthday, Ari ended up getting arrested armed robbery and he went to jail. This left Chloe feeling very confused and hurt as to why he never came back home." The actor also said that Ari has mixed emotions about Chloe's arrival, as he knows that Mia will be close behind her and he is unsure about facing his past so soon. Mia turns up at Ari's door just as he is telling Mac about their history. Kipa Williams branded the exes "star-crossed lovers" and said they had a long history together. Ari knows that things were left unresolved between them and Kipa Williams believed that Ari never stopped loving Mia. After he breaks up with Mac, Ari has an awkward meeting with Mia in the gym. Kipa-Williams explained: "Ari doesn't actually tell Mia he's broken up with Mac, so Mia remains guarded and communicates with him like he's still in a relationship." While Kipa-Williams was disappointed about the end of Ari and Mac's relationship, he relished the opportunity to explore his character's background further with Mia and Chloe.
== History == In 2008 bitcoin was introduced as the first cryptocurrency following the principle outlined by Satoshi Nakamoto in the paper “Bitcoin: A Peer-to-Peer Electronic Cash System.” The project was described as an electronic payment system using cryptographic proof instead of trust. It also mentioned using cryptographic proof to verify and record transactions on a blockchain. The first wallet program, simply named Bitcoin, and sometimes referred to as the Satoshi client, was released in January 2009 by Satoshi Nakamoto as open-source software. In version 0.5 the client moved from the wxWidgets user interface toolkit to Qt, and the whole bundle was referred to as Bitcoin-Qt. After the release of version 0.9, the software bundle was renamed Bitcoin Core to distinguish itself from the underlying network. Bitcoin Core is, perhaps, the best known implementation or client. Forks of Bitcoin Core exist, such as Bitcoin XT, Bitcoin Unlimited, and Parity Bitcoin.
P-type calcium channels are voltage-dependent calcium channels that are classified under the high voltage activated class channel, along with L-, N-, Q- and R-type channels. These channels require a strong depolarization in order to be activated. They are found at axon terminals, as well as in somatodendritic areas of neurons within the central and peripheral nervous system. P-type calcium channels are also critical to vesicle release, specifically neurotransmitters and hormones at synaptic terminals of excitatory and inhibitory synapses. Voltage-gated P-type calcium channels consist of a main pore-forming α1 subunit (which is more specifically referred to as CaV2.1), an α2δ subunit and a β subunit. There can be γ subunits found in calcium channels of skeletal muscles. The α1 subunit is encoded specifically by the CACNA1A gene and is composed of four domains, each containing six transmembrane (S1-S6) spanning α helices. The S1-S2 loop and the S6 region are thought to be responsible for the channel's inactivation, the S4 region serves as the voltage sensor and S5-S6 loop forms the pore. There are seven subunits within the α1 subunit. The A subunit, called α1ACa2+, corresponds to what is functionally defined as the P-type and Q-type isoforms. P-type and Q-type calcium channels are closely related as they are produced from the same gene via alternative splicing. As a complication of the alternative splicing, P-type and Q-type channels may have different subunit compositions. The β subunit regulates the kinetics and expression of the channel, along with the α2δ subunit.
Sources: en.wikipedia.org
Chlorpheniramine is an antihistamine that helps to relieve allergic disorders due to cold, hay fever, itchy skin, insect bites and stings. Chlorpromazine is a tranquilizer that sedates without inducing sleep. It is used to relieve anxiety, excitement, restlessness or even mental disorder. Ephedrine and phenylephrine, as amine hydrochlorides, are used as decongestants. Amphetamine, methamphetamine, and methcathinone are psychostimulant amines that are listed as controlled substances by the US DEA. Thioridazine, an antipsychotic drug, is an amine which is believed to exhibit its antipsychotic effects, in part, due to its effects on other amines. Amitriptyline, imipramine, lofepramine and clomipramine are tricyclic antidepressants and tertiary amines. Nortriptyline, desipramine, and amoxapine are tricyclic antidepressants and secondary amines. (The tricyclics are grouped by the nature of the final amino group on the side chain.) Substituted tryptamines and phenethylamines are key basic structures for a large variety of psychedelic drugs. Opiate analgesics such as morphine, codeine, and heroin are tertiary amines.
The British government took these defeats badly and with the sieges continuing was compelled to send two more divisions plus large numbers of colonial volunteers. By January 1900 this would become the largest force Britain had ever sent overseas, amounting to 180,000 men with further reinforcements being sought. While watching for these reinforcements, Buller made another bid to relieve Ladysmith by crossing the Tugela west of Colenso. Buller's subordinate, Major General Charles Warren, successfully crossed the river, but was faced with a fresh defensive position centred on a prominent hill known as Spion Kop. In the resulting Battle of Spion Kop, British troops captured the summit by surprise during the early hours of 24 January 1900, but as the fog lifted, they realised too late that they were overlooked by Boer gun emplacements on the surrounding hills. The rest of the day resulted in a disaster caused by poor communication between Buller and his commanders. Between them they issued contradictory orders, on the one hand ordering men off the hill, while other officers ordered fresh reinforcements to defend it. The result was 350 men killed and nearly 1,000 wounded and a retreat across the Tugela River into British territory. There were nearly 300 Boer casualties. Buller attacked Louis Botha again on 5 February at Vaal Krantz and was again defeated. Buller withdrew early when it appeared that the British would be isolated in an exposed bridgehead across the Tugela, for which he was nicknamed "Sir Reverse" by some of his officers.
The Gravity Gun is first given to Gordon Freeman by his ally in the anti-Combine resistance, Alyx Vance, after which he uses it as both a weapon and tool. Certain objects in the game world, such as saw blades, can be used as de facto "ammunition", and the Zombie Chopper achievement rewards the player for beating the Ravenholm segment - an abandoned town infested by headcrab zombies - using only the Gravity Gun. Late in the game, Freeman is captured by the Combine and forced to relinquish all his weapons. However, in a sudden plot twist, the Gravity Gun is accidentally supercharged by the energy field meant to destroy it, turning blue and becoming capable of grabbing and throwing living objects, including the Combine themselves. This allows Freeman to escape and defeat the malevolent Doctor Breen.
and new varieties are being developed continually to improve frost tolerance, disease resistance, machine harvesting, fruit quality, nutritional content and fruit flavour. Varieties producing green fruit, less strongly flavoured and sweeter than typical blackcurrants, are cultivated in Finland, where they are called "greencurrants" (viherherukka). In Poland, the Research Institute of Horticulture has done work on improving the blackcurrant with regard to disease and pest resistance, fruit quality, adaptations to local conditions and mechanical harvesting. Researchers have crossed various varieties and introduced inter-specific genetic material from the gooseberry (Ribes grossularia), the redcurrant (Ribes rubrum) and the flowering currant (Ribes sanguineum). The resulting offspring were further back-crossed to R. nigrum. Cultivars produced include 'Tisel' and 'Tiben' in 2000 and 'Ores', 'Ruben' and 'Tines' in 2005. Further cultivars 'Polares' and 'Tihope' are being tested. Since 1991, New Zealand has become an important centre for research and development, as its temperate climate is particularly suitable for cultivation of the crop. Breeding programmes are concentrating on yield, large fruit size, consistency of cropping and upright habit. In North America, there is a need for this fruit to have resistance to white pine blister rust. New cultivars such as 'Crusader', 'Coronet' and 'Consort' have been developed there by crossing R. nigrum with R. ussuriense and these show resistance to the disease.
== Early life == Cam McCormick was born to father Corey and mother Debra McCormick in Mesa, Arizona on April 2, 1998. His parents met in Arizona, and Corey had been a college baseball player at Arizona State University. Two years after McCormick's birth, his parents were divorced. Debra suffered a bout of melanoma—diagnosed at one point as stage 4—when McCormick was five years old. McCormick and his mother remained in the Phoenix metropolitan area until shortly before McCormick began the second grade in 2006 when his mother moved with him to Pennsylvania. McCormick and his mother returned to the Western United States in 2012, settling down in Bend, Oregon.
Sources: en.wikipedia.org
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
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.