Lyophilisation 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.
Last reviewed on 2026-01-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid form |
| Solubility class | Freely soluble in water | Hydrophilic heptapeptide |
| Dry storage temperature | -20 degrees Celsius or lower | Sealed, desiccated, protected from light |
| Solution storage | 2 to 8 degrees Celsius short term | Avoid repeated freeze-thaw cycles |
| Common identification method | Reversed-phase HPLC with mass spectrometry | Confirms purity and molecular mass |
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
== Extracellular NAMPT == Extracellular NAMPT (eNAMPT) is functionally different from intracellular NAMPT (iNAMPT), and less well understood (which is why the enzyme has been given so many names: NAMPT, PBEF and visfatin). iNAMPT is secreted by many cell types (nobably adipocytes) to become eNAMPT. The sirtuin 1 (SIRT1) enzyme is required for eNAMPT secretion from adipose tissue. eNAMPT may act more as a cytokine, although its receptor (possibly TLR4) has not been proven. It has been demonstrated that eNAMPT could bind to and activate TLR4. eNAMPT can exist as a dimer or as a monomer, but is normally a circulating dimer. As a monomer, eNAMPT has pro-inflammatory effects that are independent of NAD+, whereas the dimeric form of eNAMPT protects against these effects. eNAMPT/PBEF/visfatin was originally cloned as a putative cytokine shown to enhance the maturation of B cell precursors in the presence of Interleukin-7 (IL-7) and stem cell factor, it was therefore named "pre-B cell colony-enhancing factor" (PBEF). When the gene encoding the bacterial nicotinamide phosphoribosyltransferase (nadV) was first isolated in Haemophilus ducreyi, it was found to exhibit significant homology to the mammalian PBEF gene. Rongvaux et al. demonstrated genetically that the mouse PBEF gene conferred Nampt enzymatic activity and NAD-independent growth to bacteria lacking nadV. Revollo et al. determined biochemically that the mouse PBEF gene product encodes an eNAMPT enzyme, capable of modulating intracellular NAD levels. Others have since confirmed these findings.
=== Dairy and eggs === One of the main differences between a vegan and a lacto-ovo vegetarian diet is the avoidance of both eggs and dairy products such as milk, cheese, butter and yogurt. Ethical vegans do not consume dairy or eggs because they state that their production causes the animal suffering or a premature death. To produce milk from dairy cattle, farmers separate calves from their mothers soon after birth to retain cow milk for human consumption.
A few months before [Daniel Ellsberg died in June 2023], he and I spent several hours talking at his home in Kensington, California ... not far from San Francisco. ... He reflected on his life's effort to rid the world of nuclear weapons and bluntly acknowledged his failure. Then, without a trace of irony or exaggeration, he compared our current course to that of the Titanic, speeding through the dark despite numerous ice warnings. His message was clear: we are not merely drifting toward Armageddon, we are racing there." (p.21.)
=== Cancer immunotherapy === Garcia has conducted several studies targeting cellular receptors for applications in cancer immunotherapy. In 2013, Garcia's group developed high affinity antagonists of the receptor CD47 that potently enhance the antitumor effects of established therapeutic antibodies. Garcia later determined that the therapeutic effects of CD47 blockade require combination therapy with checkpoint blockade antibodies in immunocompetent hosts, thus proving that CD47-based therapy relies upon stimulation of the adaptive immune system. Garcia's lab published the creation of an "orthogonal" IL-2 receptor complex to enable the selective delivery of IL-2 signals to engineered T cells during adoptive cell therapy. They also reported a new technology using yeast-displayed peptide-MHC molecules to identify tumor antigens recognized by Tumor Infiltrating Lymphocytes.
Sources: en.wikipedia.org
== Religion == At the New York Public Library in May 2007, Hitchens debated Al Sharpton on the issue of theism and anti-theism, giving rise to a memorable exchange about Mormonism in particular. In God is Not Great, Hitchens contended that,
== Origin and foundations == Dora Kunz, a theosophy promoter and one-time president (1975–1987) of the Theosophical Society in America, and Dolores Krieger, now Professor Emerita of Nursing Science, New York University, developed therapeutic touch in the 1970s. According to Krieger, therapeutic touch has roots in ancient healing practices, such as the laying on of hands, although it has no connection with religion or with faith healing. Krieger states that, "in the final analysis, it is the healee (client) who heals himself. The healer or therapist, in this view, acts as a human energy support system until the healee's own immunological system is robust enough to take over." Justification for TT has been sought in two fields: Martha E. Rogers' contemporal "Science of Unitary Human Beings", and quantum mechanics, in particular Fritjof Capra's mystical interpretation of the latter. A 2002 review found that neither justification was tenable: Rogers's theories were found to be inconsistent with the tenets of TT, while the overlap in terminology between the two could be ascribed to a lack of precision in Rogers's works, making them multi-interpretable. The quantum physics justification holds that the possibility to heal at a distance is made possible by a "global interconnectivity" of the universe, which TT adherents ascribe to an interpretation of Bell's theorem and the possibility of quantum nonlocality; this interpretation is not supported by experimental evidence.
Sugar cane accounted for around 21% of the global crop production over the 2000–2021 period. The Americas was the leading region in the production of sugar cane (52% of the world total). Global production of sugarcane in 2022 was 1.9 billion tonnes, with Brazil producing 38% of the world total and India 23% (table). Sugarcane is any of several species, or their hybrids, of giant grasses in the genus Saccharum in the family Poaceae. They have been cultivated in tropical climates in the Indian subcontinent and Southeast Asia over centuries for the sucrose found in their stems.
Sources: en.wikipedia.org
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.
Reversed-phase HPLC establishes purity, while mass spectrometry confirms the expected molecular mass. Sequence confirmation may use tandem mass spectrometry or peptide mapping. A certificate of analysis typically reports these results alongside the analytical method applied.
In Russia it is a registered medicine available by prescription. In many other countries it is not approved for human use and is supplied only as a research chemical. Import and possession rules differ by jurisdiction, and buyers are responsible for checking local requirements.
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.