The short version of lyophilization fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-09 and is reviewed periodically as new material appears.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
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 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.
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.
=== EC 1.3.1 With NAD+ or NADP+ as acceptor === EC 1.3.1.1: dihydrouracil dehydrogenase (NAD+) EC 1.3.1.2: dihydropyrimidine dehydrogenase (NADP+) EC 1.3.1.3: Δ4-3-oxosteroid 5β-reductase EC 1.3.1.4: transferred to EC 1.3.1.22, 3-oxo-5α-steroid 4-dehydrogenase (NADP+) EC 1.3.1.5: cucurbitacin Δ23-reductase EC 1.3.1.6: fumarate reductase (NADH) EC 1.3.1.7: meso-tartrate dehydrogenase EC 1.3.1.8: acyl-CoA dehydrogenase (NADP+) EC 1.3.1.9: enoyl-[acyl-carrier-protein] reductase (NADH) EC 1.3.1.10: enoyl-[acyl-carrier-protein] reductase (NADPH, Si-specific) EC 1.3.1.11: 2-coumarate reductase EC 1.3.1.12: prephenate dehydrogenase EC 1.3.1.13: prephenate dehydrogenase (NADP+) EC 1.3.1.14: dihydroorotate dehydrogenase (NAD+) EC 1.3.1.15: dihydroorotate dehydrogenase (NADP+) EC 1.3.1.16: β-nitroacrylate reductase EC 1.3.1.17: 3-methyleneoxindole reductase EC 1.3.1.18: kynurenate-7,8-dihydrodiol dehydrogenase EC 1.3.1.19: cis-1,2-dihydrobenzene-1,2-diol dehydrogenase EC 1.3.1.20: trans-1,2-dihydrobenzene-1,2-diol dehydrogenase EC 1.3.1.21: 7-dehydrocholesterol reductase EC 1.3.1.22: 3-oxo-5α-steroid 4-dehydrogenase (NADP+) EC 1.3.1.23: Identical to EC 1.3.1.3, Δ4-3-oxosteroid 5β-reductase EC 1.3.1.24: biliverdin reductase EC 1.3.1.25: 1,6-dihydroxycyclohexa-2,4-diene-1-carboxylate dehydrogenase EC 1.3.1.26: Now EC 1.17.1.8, 4-hydroxy-tetrahydrodipicolinate reductase EC 1.3.1.27: 2-hexadecenal reductase EC 1.3.1.28: 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase EC 1.3.1.29: cis-1,2-dihydro-1,2-dihydroxynaphthalene dehydrogenase EC 1.3.1.30: transferred to EC 1.3.1.22, 3-oxo-5α-steroid 4-dehydrogenase (NADP+) EC 1.3.1.31: 2-enoate reductase EC 1.3.1.32: maleylacetate reductase EC 1.3.1.33: protochlorophyllide reductase EC 1.3.1.34: 2,4 Dienoyl-CoA reductase (NADPH) EC 1.3.1.35: Now EC 1.14.19.22, microsomal oleoyl-lipid 12-desaturase EC 1.3.1.36: geissoschizine dehydrogenase EC 1.3.1.37: cis-2-enoyl-CoA reductase (NADPH) EC 1.3.1.38: trans-2-enoyl-CoA reductase (NADPH) EC 1.3.1.39: trans-2-enoyl-CoA reductase (NADPH) EC 1.3.1.40: 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate reductase EC 1.3.1.41: xanthommatin reductase EC 1.3.1.42: 12-oxophytodienoate reductase EC 1.3.1.43: arogenate dehydrogenase EC 1.3.1.44: trans-2-enoyl-CoA reductase (NAD+) EC 1.3.1.45: 2′-hydroxyisoflavone reductase EC 1.3.1.46: biochanin-A reductase EC 1.3.1.47: α-santonin 1,2-reductase EC 1.3.1.48: 13,14-dehydro-15-oxoprostaglandin 13-reductase EC 1.3.1.49: cis-3,4-dihydrophenanthrene-3,4-diol dehydrogenase EC 1.3.1.50: n Now EC 1.1.1.252 tetrahydroxynaphthalene reductase EC 1.3.1.51: 2′-hydroxydaidzein reductase EC 1.3.1.52: Now EC 1.3.8.5, 2-methyl-branched-chain-enoyl-CoA reductase EC 1.3.1.53: (3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate dehydrogenase EC 1.3.1.54: precorrin-6A reductase EC 1.3.1.55: identical to EC 1.3.1.25, 1,6-dihydroxycyclohexa-2,4-diene-1-carboxylate dehydrogenase EC 1.3.1.56: cis-2,3-dihydrobiphenyl-2,3-diol dehydrogenase EC 1.3.1.57: phloroglucinol reductase EC 1.3.1.58: 2,3-dihydroxy-2,3-dihydro-p-cumate dehydrogenase EC 1.3.1.59: There is no evidence that the enzyme exists EC 1.3.1.60: dibenzothiophene dihydrodiol dehydrogenase EC 1.3.1.61: identical to EC 1.3.1.53, (3S,4R)-3,4-dihydroxycyclohexa-1,5-diene-1,4-dicarboxylate dehydrogenase EC 1.3.1.62: pimeloyl-CoA dehydrogenase EC 1.3.1.63: Now EC 1.21.1.2, 2,4-dichlorobenzoyl-CoA reductase EC 1.3.1.64: phthalate 4,5-cis-dihydrodiol dehydrogenase EC 1.3.1.65: 5,6-dihydroxy-3-methyl-2-oxo-1,2,5,6-tetrahydroquinoline dehydrogenase EC 1.3.1.66: cis-dihydroethylcatechol dehydrogenase EC 1.3.1.67: cis-1,2-dihydroxy-4-methylcyclohexa-3,5-diene-1-carboxylate dehydrogenase EC 1.3.1.68: 1,2-dihydroxy-6-methylcyclohexa-3,5-dienecarboxylate dehydrogenase EC 1.3.1.69: zeatin reductase EC 1.3.1.70: Δ14-sterol reductase EC 1.3.1.71: Δ24(241)-sterol reductase EC 1.3.1.72: Δ24-sterol reductase EC 1.3.1.73: 1,2-dihydrovomilenine reductase EC 1.3.1.74: 2-alkenal reductase [NAD(P)+] EC 1.3.1.75: 3,8-divinyl protochlorophyllide a 8-vinyl-reductase (NADPH) EC 1.3.1.76: precorrin-2 dehydrogenase EC 1.3.1.77: anthocyanidin reductase [(2R,3R)-flavan-3-ol-forming] EC 1.3.1.78: arogenate dehydrogenase (NADP+) EC 1.3.1.79: arogenate dehydrogenase (NAD(P)+) EC 1.3.1.80: Now classified as EC 1.3.7.12, red chlorophyll catabolite reductase EC 1.3.1.81: (+)-pulegone reductase EC 1.3.1.82: (-)-isopiperitenone reductase EC 1.3.1.83: geranylgeranyl diphosphate reductase EC 1.3.1.84: acrylyl-CoA reductase (NADPH) EC 1.3.1.85: crotonyl-CoA carboxylase/reductase EC 1.3.1.86: crotonyl-CoA reductase EC 1.3.1.87: 3-(cis-5,6-dihydroxycyclohexa-1,3-dien-1-yl)propanoate dehydrogenase EC 1.3.1.88: tRNA-dihydrouridine16/17 synthase (NAD(P)+) EC 1.3.1.89: tRNA-dihydrouridine47 synthase (NAD(P)+) EC 1.3.1.90: tRNA-dihydrouridine20a/20b synthase (NAD(P)+) EC 1.3.1.91: tRNA-dihydrouridine20 synthase (NAD(P)+) EC 1.3.1.92: artemisinic aldehyde Δ11(13)-reductase EC 1.3.1.93: very-long-chain enoyl-CoA reductase EC 1.3.1.94: polyprenol reductase EC 1.3.1.95: acrylyl-CoA reductase (NADH) EC 1.3.1.96: Botryococcus squalene synthase EC 1.3.1.97: botryococcene synthase EC 1.3.1.98: Now known to be catalyzed by two different enzymes, EC 1.3.1.122, (S)-8-oxocitronellyl enol synthase, and EC 5.5.1.34, (+)-cis,trans-nepetalactol synthase EC 1.3.1.100: chanoclavine-I aldehyde reductase EC 1.3.1.101: 2,3-bis-O-geranylgeranyl-sn-glycerol 1-phosphate reductase [NAD(P)H] EC 1.3.1.102: 2-alkenal reductase (NADP+) EC 1.3.1.103: 2-haloacrylate reductase EC 1.3.1.104: enoyl-[acyl-carrier-protein] reductase (NADPH) EC 1.3.1.105: 2-methylene-furan-3-one reductase EC 1.3.1.106: cobalt-precorrin-6A reductase EC 1.3.1.107: sanguinarine reductase EC 1.3.1.108: caffeoyl-CoA reductase EC 1.3.1.109: butanoyl-CoA dehydrogenase complex (NAD+, ferredoxin) EC 1.3.1.110: lactate dehydrogenase (NAD+,ferredoxin) EC 1.3.1.111: geranylgeranyl-bacteriochlorophyllide a reductase EC 1.3.1.112: anthocyanidin reductase [(2S)-flavan-3-ol-forming] EC 1.3.1.113: (4-alkanoyl-5-oxo-2,5-dihydrofuran-3-yl)methyl phosphate reductase EC 1.3.1.114: 3-dehydro-bile acid Δ4,6-reductase EC 1.3.1.115: 3-oxocholoyl-CoA 4-desaturase EC 1.3.1.116: 7β-hydroxy-3-oxochol-24-oyl-CoA 4-desaturase EC 1.3.1.117: hydroxycinnamoyl-CoA reductase EC 1.3.1.118: meromycolic acid enoyl-[acyl-carrier-protein] reductase EC 1.3.1.119: chlorobenzene dihydrodiol dehydrogenase EC 1.3.1.120: cyclohexane-1-carbonyl-CoA reductase NADP+) EC 1.3.1.121: 4-amino-4-deoxyprephenate dehydrogenase EC 1.3.1.122: (S)-8-oxocitronellyl enol synthase EC 1.3.1.123: 8-oxogeranial reductase EC 1.3.1.124: 2,4-dienoyl-CoA reductase [(3E)-enoyl-CoA-producing]
====== Alcohol-related programmes ====== A high amount of media coverage exists informing people of the dangers of driving drunk. Most people who recreationally consume alcohol are now aware of these dangers and safe ride techniques like 'designated drivers' and free taxicab programmes are reducing the number of drunk-driving crashes. Many cities have free-ride-home programmes during holidays involving high amounts of alcohol use, and some bars and clubs will provide a visibly drunk patron with a free cab ride. In New South Wales groups of licensees have formed local liquor accords and collectively developed, implemented and promoted a range of harm minimisation programmes including the aforementioned 'designated driver' and 'late night patron transport' schemes. Many of the transport schemes are free of charge to patrons, to encourage them to avoid drink-driving and at the same time reduce the impact of noisy patrons loitering around late night venues. Moderation Management is a programme which helps drinkers to cut back on their consumption of alcohol by encouraging safe drinking behaviour. Harm reduction in alcohol dependency could be instituted by use of naltrexone.
Sorenson, MD, from the Mayo Clinic in Rochester, Minnesota "While this is very disappointing, at least it was definitive and gives, I think, a pretty definitive answer, at least for this strategy for this drug," Dr. Sorenson said. However, he added, "there is still a great deal of evidence that the IGF-1 pathway can be beneficial to people who have ALS, but just not the way we administered it." Novel methods of delivering IGF-1 in a more selected fashion are now under way, including the use of viral mediators or stem cells. Two previous phase 3 trials of IGF-1 in ALS showed inconsistent results: 1 trial, carried out in North America, did find a benefit, whereas the other, a European trial, did not confirm the earlier findings. "The results of our study most resemble those of the previous European study, with no benefit in either survival or functional scales", De Sorenson concludes. "It is disappointing that we were unable to confirm the benefit that was noted in the previous North American study." Conclusive evidence points, what Iplex (and any form of IGF-1) can't slow progression in human ALS. Lot of sites that have published articles about the link between Lyme disease and ALS are sponsored by clinics specializing in the treatment of chronic Lyme disease, or by the sellers of products for treating this, or both.
junk RNA Any RNA-encoded sequence, especially a transcript, that appears to have no known biological function, or whose function has no positive or a net negative effect on the fitness of the genome from which it is transcribed. Despite remaining untranslated, many non-coding RNAs still serve important functions, whereas junk RNAs are truly useless: often they are the product of accidental transcription of a junk DNA sequence, or they may result from post-transcriptional processing of primary transcripts, as with spliced-out introns. Junk RNA is usually quickly degraded by ribonucleases and other cytoplasmic enzymes.
=== Congress calls for total withdrawal === On 24 July 1972, Congress passed an act calling for the total withdrawal of all American forces from Vietnam once all of the American POWs in North Vietnam were released, causing Kissinger to say that the North Vietnamese only had to wait until "Congress voted us out of the war". However, the sight of Nixon and Kissinger posing for photographs with Brezhnev and Mao deeply worried the North Vietnamese, who were afraid of being "sold out" by either China or the Soviet Union, causing some flexibility in their negotiating tactics. The Eastern Offensive had not caused the collapse of the South Vietnamese government, but it increased the amount of territory under Communist control. The North Vietnamese were moving towards taking up the "standstill ceasefire" offer and ordered the Viet Cong to seize as much territory as possible in preparation for a "leopard's spot" ceasefire (so called because the patchwork of territories controlled by the Viet Cong and the Saigon government resembled the spots on a leopard's fur). On 1 August 1972, Kissinger met Tho again in Paris, and for the first time, he seemed willing to compromise, saying that the political and military terms of an armistice could be treated separately and hinted that his government was no longer willing to make the overthrow of Thiệu a precondition. Kissinger, for his part, seemed keen to make a deal before the elections, saying that if an agreement was signed by 1 September, all American forces would be out of Vietnam by the end of 1972.
Sources: en.wikipedia.org
perform both visual and digital oral health examinations. prescribe oral prosthetics to dental technicians. prescribe radiography. Supervise auxiliary personnel in the performance of their delegated duties. Create impressions of peoples' teeth, in order to make customized partial or complete dentures and mouthguards. Refer patients with more complex issues to a dentist or specialist dentist when appropriate. Treat bruxism and sleep apnea by using night guard and anti snoring device. Treat teeth whitening by using custom bleach tray. Maintain and repair existing dental prostheses. Educate patients on oral health hygiene techniques.
The Heidelberg University Archives has, in its possession, a photo album from 1907 marking the 25th anniversary of Theodor Curtius receiving his Doctorate. It shows pictures of science scholars, buildings, and labs such as the physio-chemical, pharmaceutical, and organics labs, and much more.
=== Impact of pregnancy === During pregnancy, the ovaries and the placenta produce estrogen and progesterone. These hormones stimulate the 15 to 20 lobes of the milk-secreting glands in the breasts to develop. Women who experience multiple pregnancies repeatedly stretch the skin envelope during engorgement while lactating. As a woman's breasts change in size during repeated pregnancies, the size of her breasts change as her mammary glands are engorged with milk and as she gains and loses weight with each pregnancy. In addition, when milk production stops (usually as a child is weaned), the voluminous mammary glands diminish in volume, but they still add bulk and firmness to the breast. A 2010 review found that weight gain during pregnancy and breastfeeding were not significant risk factors for ptosis.
== Structure == The non-fluid parts of the interstitium are predominantly collagen types I, III, and V; elastin; and glycosaminoglycans, such as hyaluronan and proteoglycans, that are cross-linked to form a honeycomb-like reticulum. Collagen bundles of the extracellular matrix form scaffolding with a high tensile strength. Interstitial cells (e.g., fibroblasts, dendritic cells, adipocytes, interstitial cells of Cajal and inflammatory cells, such as macrophages and mast cells), serve a variety of structural and immune functions. Fibroblasts synthesize the production of structural molecules as well as enzymes that break down polymeric molecules. Such structural components exist both for the general interstitium of the body, and within individual organs, such as the myocardial interstitium of the heart, the renal interstitium of the kidneys, and the pulmonary interstitium of the lungs. The interstitium in the submucosae of visceral organs, the dermis, superficial fascia, and perivascular adventitia are fluid-filled spaces supported by a collagen bundle lattice. Blind end, highly permeable, lymphatic capillaries extend into the interstitium. The fluid spaces communicate with draining lymph nodes, although they do not have lining cells or structures of lymphatic channels. Interstitial fluid entering the lymphatic system becomes lymph, which is transported through lymphatic vessels until it empties into the microcirculation and the venous system.
Sources: en.wikipedia.org
=== Aryl cyclooctynes === Fusion of a cyclooctyne to two aryl rings increases the reaction rate, and the cyclooctyne reagents of the Bertozzi group proceeded through a series of fusions that sought to increase the ring strain even further. DIBO (dibenzo cyclooctyne) was developed as a precursor to BARAC (biarylazacyclooctynone), although calculations had predicted that a single fused aryl ring would be optimal. Attempts to make a difluoro benzo cyclooctyne (DIFBO) were unsuccessful due to the instability of the compound. The reason for the instability of DIFBO is that it is so reactive that it spontaneously trimerizes to form two asymmetric products that can be characterized by X-ray crystallography. To stabilize the DIFBO, it is trapped by forming a stable inclusion complex with β-cyclodextrin in aqueous media. This complex, formed with the β-cyclodextrin, can then be stored as a lyophilized powder. To obtain the free DIFBO, the lyophilized powder is dissociated with organic solvents to produce the free DIFBO for in situ kinetic and spectroscopic analysis. Problems with DIFO with in vivo mouse studies illustrate the difficulty of producing bioorthogonal reactions.
The enormous number of published literature makes it virtually impossible for individuals to read every paper, resulting in disjointed sub-fields of research. Literature analysis aims to employ computational and statistical linguistics to mine this growing library of text resources. For example:
Funerals of activists killed in the intensifying violence became an important focal point for political activity and for further violence. Widely attended, culturally important, and highly emotional, they often attracted rosters of guest speakers drawn from among the top rung of the internal anti-apartheid movement and were closely monitored by state security forces. In 1985, funerals were the site of massacres by police in Uitenhage and in Queenstown. Thula Simpson writes:As the journalist Allister Sparks observed, during the uprising there was a funeral almost every weekend for people who had been killed in clashes with the authorities. At those funerals, police would open fire on demonstrators, thus creating the next week’s funeral – feeding an unending cycle of rage and mourning.On 20 July 1985, Botha's announcement of the state of emergency was immediately followed by news broadcasts of events of two separate funerals, both held earlier that day: footage of Maki Skosana's execution in Duduza was juxtaposed with footage of the funeral of the Cradock Four in the Cape, at which activists brazenly unfurled South African Communist Party flags and chanted the name of Umkhonto we Sizwe (MK). The state of emergency regulations themselves included restrictions on the conduct and attendance of funerals, which in turn were protested and defied, leading to further confrontation, notably in townships north of Durban after the funeral of Victoria Mxenge on 1 August 1985.
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
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.