Everything below concerns freeze-thaw. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Dry storage temperature | -20 C or below | Sealed, desiccated, protected from light |
| Solution stability | Hours to days at 2-8 C | Depends on buffer and microbial load |
| Preferred pH range | Near neutral to slightly acidic | Alkaline pH accelerates hydrolysis |
| Main degradation routes | Hydrolysis and deamidation | No cysteine or methionine in sequence |
| Identity confirmation | Electrospray mass spectrometry | Observed mass compared with 751.9 Da |
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.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
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.
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.
The fourth round of negotiations, originally scheduled for May 3, 2025, in Rome, was postponed amid rising tensions. Iranian officials cited US sanctions, military action against the Houthis, and what they described as "contradictory behaviour and provocative statements" by Washington as contributing factors, while stating that a new date would depend on the US approach. Oman, which mediated previous rounds, referred to logistical reasons for the delay. A source familiar with the matter indicated that the United States had not confirmed its participation, and that the timing and venue for the next round remained unconfirmed. The negotiations were taking place amid daily rolling blackouts across Iran due to ongoing electricity shortages. Supporters of Iran's nuclear program argue that the country requires nuclear energy for electricity generation. On May 7, 2025, ahead of the 2025 visit by Donald Trump to the Middle East, US officials reported that president Donald Trump had decided that United States federal agencies would refer to the Persian Gulf as the "Arabian Gulf" or the "Gulf of Arabia" and had plans to make it official during a planned visit to Saudi Arabia later in May. This plan received outrage and condemnation from Iranians and the Iranian government. The proposed change was opposed by Iranians across the political spectrum, who displayed rare unity in rejecting the possible American move.
The greatest omission in our 106-year history is undoubtedly that Mahatma Gandhi never received the Nobel Peace Prize. Gandhi could do without the Nobel Peace Prize. Whether the Nobel committee can do without Gandhi, is the question. Other high-profile individuals with widely recognised contributions to peace have been overlooked. In 2009, an article in Foreign Policy magazine identified seven people who "never won the prize, but should have". The list consisted of Gandhi, Eleanor Roosevelt, Václav Havel, Ken Saro-Wiwa, Sari Nusseibeh, Corazon Aquino, and Liu Xiaobo. Liu Xiaobo would go on to win the 2010 Nobel Peace Prize while imprisoned. In 1965, UN Secretary General U Thant was informed by the Norwegian Permanent Representative to the UN that he would be awarded that year's prize and asked whether or not he would accept. He consulted staff and later replied that he would. At the same time, Chairman Gunnar Jahn of the Nobel Peace Prize committee lobbied heavily against giving U Thant the prize and the prize was at the last minute awarded to UNICEF. The rest of the committee all wanted the prize to go to U Thant, for his work in defusing the Cuban Missile Crisis, ending the war in the Congo, and his ongoing work to mediate an end to the Vietnam War. The disagreement lasted three years and in 1966 and 1967 no prize was given, with Gunnar Jahn effectively vetoing an award to U Thant. The Literature Prize also has controversial omissions. Adam Kirsch has suggested that many notable writers have missed out on the award for political or extra-literary reasons.
5-Oxo-ETE and 5-oxo-15(S)-hydroxy-ETE but not 5-hydroxy members of the 5-HETE family such as 5-(S)-HETE activate peroxisome proliferator-activated receptor gamma (PPARγ). This activation does not proceed through OXER1; rather, it involves the direct binding of the oxo analog to PPARγ with 5-oxo-15-(S)-hydroxy-ETE being more potent than 5-oxo-ETE in binding and activating PPARγ. The Activation of OXER1 receptor and PPARγ by the oxo analogs can have opposing effects on cell function. For example, 5-oxo-ETE-bound OXER1 stimulates whereas 5-oxo-ETE-bound PPARγ inhibits the proliferation of various types of human cancer cell lines; this results in 5-oxo-ETE and 5-oxo-15-(S)-HETE having considerably less potency than anticipated in stimulating these cancer cells to proliferate relative to the potency of 5-(S)-HETE, a relationship not closely following the potencies of these three compounds in activating OXER1. 5-Oxo-ETE relaxes pre-contracted human bronchi by a mechanism that does not appear to involve OXER1 but is otherwise undefined.
Due to the heat and expanse of the Houston area residents spent long drives in their cars, "the music that most appropriately complements that has always been the music of DJ Screw, it's slowed down—and when I say slowed down I mean he would record sessions in his apartment with rappers freestyling over beats and he would make these big mixtapes and then he would actually slow them down even further on his cassette recorder." DJ Screw's invoking lean in his lyrics and his use of slow tempos had caused his style to be characterized "[a]s if the song itself has taken too much codeine promethazine". Rappers far beyond Houston would come to adopt aspects of DJ Screw's unique style, but not before he died of a codeine overdose in 2000.
Sources: en.wikipedia.org
"Cooks in the early Navy were left to their own imaginations when it came to preparing meals. In the main, this resulted in whatever was on the official ration for that day of the week being tossed in a ship's coppers and boiled until meal time. The first official Navy cook book was produced by Paymaster F. T. Arms and published by the Bureau of Supplies and Accounts in 1902. It contained five recipes for soup, six for fish, thirty-four for meats, fowl, and eggs, and several for desserts, including "plum duff"."
==== Education ==== Family, friends, and co-workers of a person with diabetes may provide life-saving treatment in the case of a hypoglycemic episode. It is important for these people to receive training on how to recognize hypoglycemia, what foods to help the hypoglycemic eat, how to administer injectable or intra-nasal glucagon, and how to use a glucose meter.
=== Musculoskeletal system === Estrogens increase muscle mass and strength, as well as the speed of muscle regeneration. They protect against damage to muscles and increase their sensitivity to exercise. In mice, estrogen supplementation has been shown to restore the proportion of type IIX muscle fibers to over 40% following an ovariectomy. Estrogens promote stronger collagen synthesis, increasing the collagen content of connective tissues, tendons, and ligaments. This decreases the stiffness of tendons and ligaments, especially during menstruation. Women have a lower predisposition to muscle strains, but soft ligaments are more prone to injuries. ACL tears are two to eight times more common among women than men. Estrogens are responsible for both the pubertal growth spurt, which causes an acceleration in linear growth, and epiphyseal closure, which limits height and limb length, in both females and males. In addition, estrogens are responsible for bone maturation and maintenance of bone mineral density throughout life. They reduce bone resorption and promote bone formation. Due to hypoestrogenism, the risk of osteoporosis increases during menopause.
Sources: en.wikipedia.org
== Discoveries made using egg extracts == Purification of M-phase promoting factor (MPF) Elucidation of the role of synthesis and degradation of cyclin B in cell cycle progression Discovery that degradation of a protein(s) other than cyclin B is necessary for initiating chromosome segregation Discovery of a mechanism of spindle assembly that depends on chromatin, but not centrosomes Proposal of a DNA replication licensing system and identification of its responsible factor Identification of importin α/β responsible for nuclear transport Discovery of the condensin complex essential for mitotic chromosome assembly Identification of the cohesin complex essential for sister chromatid cohesion More recently, the egg extracts have been used to study reprogramming of differentiated nuclei, physical properties of spindles and nuclei, and theoretical understanding of cell cycle control.
=== Mitigation measures === Several strategies have been proposed as a way to protect people at the greatest risk of occupational exposure to PFAS, including exposure monitoring, regular blood testing, and the use of PFAS-free alternatives such as fluorine-free firefighting foam and plant-based ski wax.
=== Aromatic amines === In aromatic amines ("anilines"), nitrogen is often nearly planar owing to conjugation of the lone pair with the aryl substituent. The C-N distance is correspondingly shorter. In aniline, the C–N distance is the same as the C–C distances.
(1996), the MatrixFillmore Bar (1998), PlumpJack Wines shop Noe Valley branch (1999), PlumpJackSport retail clothing (2000), and a second Balboa Café at Squaw Valley (2000). Newsom's investments included five restaurants and two retail clothing stores. Newsom's annual income was greater than $429,000 from 1996 to 2001. In 2002, his business holdings were valued at more than $6.9 million. Newsom gave a monthly $50 gift certificate to PlumpJack employees whose business ideas failed, because in his view, "There can be no success without failure." Newsom sold his share of his San Francisco businesses when he became mayor in 2004. He maintained his ownership in the PlumpJack companies outside San Francisco, including the PlumpJack Winery in Oakville, California, new PlumpJack-owned Cade Winery in Angwin, California, and the PlumpJack Squaw Valley Inn. He is the president in absentia of Airelle Wines Inc., which is connected to the PlumpJack Winery in Napa County. Newsom earned between $141,000 and $251,000 in 2007 from his business interests. In February 2006, he paid $2,350,000 for his residence in the Russian Hill neighborhood, which he put on the market in April 2009 for $3,000,000. At the time of the Silicon Valley Bank collapse in March 2023, it was acknowledged that at least three of Newsom's wine companies—PlumpJack, Cade, and Odette—were Silicon Valley Bank clients.
Sources: en.wikipedia.org
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.
Hydrolysis of peptide bonds and deamidation of arginine and proline residues are the main degradation routes. Alkaline pH and higher temperatures accelerate both processes. Buffered, near-neutral solutions stored cold generally degrade more slowly than unbuffered ones.
Reverse-phase chromatography gives the clearest single view of related impurities and truncated sequences. Mass spectrometry then confirms that the main peak carries the expected mass. Neither test detects enantiomeric impurities, which require a separate chiral assay.
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.