freeze-thaw cycle 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 2026-03-16. Numbers and descriptions here follow the published literature rather than marketing material.
Regulatory status varies by country and intended use. Major drug agencies have not granted marketing authorization for SR9009 as a medicine, and it is not listed as a controlled substance in many jurisdictions. It is often sold as a research chemical, a category that may fall outside pharmaceutical manufacturing rules. Buyers should verify local laws and supplier documentation, including certificates of analysis. The lack of standardized quality controls raises concerns about identity, purity, and actual content in products marketed online.
In laboratory settings, SR9009 is commonly identified by its molecular structure and its interaction with REV-ERB receptors. Vendors may list it under synonyms such as Stenabolic or REV-ERB agonist, but those names do not define purity or identity. Analytical confirmation typically uses high-performance liquid chromatography with ultraviolet detection or liquid chromatography–mass spectrometry. A reference standard is needed to compare retention time and mass spectrum, because the compound can be confused with related research chemicals.
Handling practices for SR9009 focus on minimizing degradation and contamination. The solid is generally stored desiccated at or below -20 °C, protected from light and moisture. Stock solutions are often prepared in dimethyl sulfoxide or ethanol, then aliquoted to avoid repeated freeze–thaw cycles. Aqueous solubility is low, so formulations for animal studies may require cosolvents or suspending agents. Personnel should follow institutional chemical safety procedures, because toxicological data for humans are incomplete.
At the molecular level, SR9009 binds the ligand-binding domain of REV-ERB and strengthens recruitment of corepressor proteins such as NCoR and HDAC3. This increases repression of target genes, including Bmal1 and other clock-controlled and metabolic genes. In rodent studies, such changes have been linked to altered lipid handling, glucose metabolism, and energy expenditure. The precise chain of events between receptor binding and whole-body effects remains an active area of research. Findings in animals do not automatically translate to humans.
Laboratory studies often administer SR9009 by injection because oral absorption appears poor in rodents. Reported pharmacokinetic properties include rapid metabolism and low systemic exposure after oral dosing. Human pharmacokinetic data are sparse, so absorption, distribution, metabolism, and excretion in people are not well defined. Some research explores related REV-ERB compounds with improved drug-like properties. Regulatory approval for any REV-ERB agonist as a human medicine has not been granted to date.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ, also called NR1D1 and NR1D2. These receptors help regulate circadian rhythms and metabolic gene programs. The compound was developed for laboratory research, not as an approved therapeutic. Its identity is distinct from steroid hormones and selective androgen receptor modulators. Scientific interest centers on how REV-ERB activation changes gene expression in cells and animal models.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white solid | Visual inspection is not sufficient for identity. |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water. |
| Typical storage | -20 °C, desiccated, dark | Protect from repeated temperature changes. |
| Common analytical method | LC-MS or HPLC-UV | Reference standard required for comparison. |
| Common synonyms | SR9009; Stenabolic; REV-ERB agonist | Vendor naming may vary. |
Quality control for research materials includes identity confirmation by nuclear magnetic resonance and purity assessment by high-performance liquid chromatography. Mass spectrometry provides molecular weight confirmation and can detect related impurities. Purchasers should request a certificate of analysis that lists lot-specific data. Online products advertised for human use often lack such documentation. Distinguishing legitimate research material from mislabeled or contaminated samples is a recurring challenge in independent testing, and independent laboratories may use orthogonal methods to verify identity.
Detection of SR9009 in biological samples usually relies on liquid chromatography coupled to tandem mass spectrometry. This approach separates the compound from matrix components and identifies it by mass transitions. Because SR9009 can undergo metabolism, laboratories often look for both parent drug and specific metabolites. Sample preparation may involve protein precipitation or solid-phase extraction. Method validation examines sensitivity, carryover, and interference from related substances, and reference standards are required for accurate calibration.
SR9009 binds REV-ERB receptors and alters their repressive activity on target genes. This action can change transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. In rodent studies, treated animals have shown changes in muscle oxidative capacity and exercise performance, though effects vary by dose, duration, and model. The precise molecular steps connecting receptor binding to whole-body outcomes are still an active area of investigation. Findings in animals do not automatically translate to humans.
Because REV-ERB receptors are core clock components, SR9009 has been examined for effects on daily rhythms as well as metabolism. Research has explored whether the compound can shift or reinforce circadian gene expression in tissues such as liver and muscle. Some studies report improved metabolic markers in obese or diabetic mice, while others show context-dependent responses. Questions remain about which effects are direct, which are secondary to timing, and how they might differ across species.
The mechanism of action involves binding to REV-ERB receptors and recruiting corepressor complexes, which represses target gene transcription. This contrasts with many nuclear receptor agonists that activate transcription. Downstream effects may include changes in autophagy, mitochondrial biogenesis, and lipid handling, but the precise pathways remain an active area of study. Whether these molecular events translate into meaningful physiological effects in humans is unresolved. Most evidence comes from cultured cells and rodent models rather than human participants.
SR9009 is a synthetic small molecule developed as an agonist of the nuclear receptors REV-ERBα (NR1D1) and REV-ERBβ (NR1D2). These receptors help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, SR9009 alters transcription of genes involved in lipid metabolism, inflammation, and mitochondrial function. It is not an approved medicine, and its pharmacological profile in humans remains largely uncharacterized. The compound is frequently discussed in the context of circadian biology and metabolic research rather than clinical use.
Detection in biological samples can be complicated by rapid metabolism and low circulating concentrations. Some studies report phase I and phase II metabolites, and analytical methods may need to target those species in addition to the parent compound. Immunoassays are not broadly available, so mass spectrometry remains the main confirmatory approach. For anti-doping testing, laboratories look for SR9009 and its metabolites using validated LC-MS methods. Open questions include how long metabolites remain detectable and how different routes of administration alter detection windows.
In laboratory settings, SR9009 is typically characterized by liquid chromatography–mass spectrometry (LC-MS) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These methods can confirm identity and estimate purity, but they require reference standards for accurate quantification. Because SR9009 is not a licensed pharmaceutical, no harmonized pharmacopeial monograph exists. Laboratories often validate in-house methods for matrices such as plasma, urine, or cell culture media. Sample preparation may involve protein precipitation or liquid-liquid extraction before analysis.
=== Tracking === The headset and controllers both use lighthouse tracking systems, while retaining full compatibility with all previous HTC Vive base stations, using SteamVR. The Valve Index utilizes Valve's Lighthouse 2.0 tracking system, which involves external base stations to establish a 3D tracking environment. These base stations are small, rectangular units placed around the room that emit non-visible infrared light and laser patterns. The headset and controllers, equipped with sensors, detect these signals to determine their position and orientation. Each base station includes two rapidly spinning laser emitters that project a sweeping pattern of lasers across the room. Unlike the Lighthouse 1.0, which used an infrared Sync Blinker for synchronization, Lighthouse 2.0 employs a more refined synchronization mechanism integrated into the laser system itself. The sensors on the headset and controllers detect the laser beams to determine their exact positions relative to the base stations. Typically, two base stations are used to ensure comprehensive coverage and minimize occlusion, though additional base stations can be added to extend the tracking range. Although the Valve Index uses external base stations, the tracking system is considered inside-out because the tracking sensors are mounted on the tracked devices themselves—the headset and controllers. These sensors process the tracking information internally, which differentiates it from traditional outside-in systems that use fixed cameras or sensors to monitor the tracked objects from outside.
== External links == Biological Products at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Debbie Strickland (2007). "Guide to Biotechnology" (PDF). Biotechnology Industry Organization (BIO). Archived from the original (PDF) on 2007-09-27. Retrieved 2007-12-17. Timothy B. Coan; Ron Ellis (2001-06-01). "Report for USA Specialty Pharmaceuticals: Generic Biologics: The Next Frontier" (PDF). Consumer Project on Technology. Retrieved 2007-12-17. "About biologics". National Psoriasis Foundation. 2006-11-01. Archived from the original on 2006-01-01. Retrieved 2007-12-17.
== History == On August 10, 1863, the Napa Valley Register first published. It was founded by J.I. Horrell as a pro-Union paper, in contrast to the pro-Succession Napa Echo. By 1864, the newspaper had dropped “Valley” from its name, becoming simply the Napa Register, until returning to the original name over a century later. Editor R.T. Montgomery retired from the paper in January 1866. He returned that May and sold it to N.E. White in January 1868. White left after six months and Montgomery returned again, only to later sell the Register a second time in November 1869 to R.D. Hopkins, formerly editor of the Vallejo Recorder. Hopkins sold to Rev. George W. Henning and George M. Francis in February 1872. The Register moved to daily publication in December 1872. Henning sold out to Charles A. Gardner in May 1873. Gardner left after a few years to run the St. Helena Star. George M. Francis became sole owner of the Register in 1878, upon the death of his business partner. Francis was succeeded in ownership by his son George H. Francis in 1932. The paper remained with Francis and various partners until 1958, when it was sold to Scripps League Newspapers. Scripps was acquired by Pulitzer in 1996, and Pulitzer was acquired by Lee Enterprises in 2005. Dan Evans became the paper's editor in March 2022, and he soon unveiled a newly reconstituted editorial board that October. The board was made up of three members of the newspaper's staff and seven community members. It aimed to assist in driving the official opinion of the paper. In April 2023, the paper laid off two employees.
== Chemical properties == Bromo(I) fluorosulfonate is a blackish-red, viscous, hydrolysis-sensitive liquid that reacts violently with water. Upon cooling, it solidifies into a glassy state. Bromo(I) fluorosulfonate reacts with iodine(I) fluorosulfonate at temperatures above 50 °C to form dibromoiodofluorosulfonate:
Sources: en.wikipedia.org
Glucogenic, with the products having the ability to form glucose by gluconeogenesis Ketogenic, with the products not having the ability to form glucose: These products may still be used for ketogenesis or lipid synthesis. Amino acids catabolized into both glucogenic and ketogenic products
== Veterinary uses == In the US, clomipramine is only licensed to treat separation anxiety in dogs for which it is sold under the brand name Clomicalm. It has proven effective in the treatment of obsessive–compulsive disorders in cats and dogs. In dogs, it has also demonstrated similar efficacy to fluoxetine in treating tail chasing. In dogs some evidence suggests its efficacy in treating noise phobia. Clomipramine has also demonstrated efficacy in treating urine spraying in cats. Various studies have been done on the effects of clomipramine on cats to reduce urine spraying/marking behavior. It has been shown to be able to reduce this behavior by up to 75% in a trial period of four weeks. Clomipramine has the side effect of inhibiting thyroid peroxidase and inhibiting the uptake of iodide.
== History == Avalglucosidase alfa's safety data was obtained from four clinical trials (trial 1/NCT02782741, trial 2/NCT01898364, trial 3/NCT02032524, trial 4/NCT03019406). These trials enrolled 124 participants with late-onset Pompe disease and 22 participants with infantile-onset Pompe disease. The participants were from 22 countries around the world, including the United States. Avalglucosidase alfa was evaluated in four trials of 146 participants with Pompe disease. Trial 1 evaluated the benefits and side effects of avalglucosidase alfa, and all four trials evaluated the side effects of avalglucosidase alfa. In trial 1, participants received either avalglucosidase alfa or another drug (called the active comparator) intravenously once every two weeks for 49 weeks. Neither the participants nor the healthcare providers knew which treatment was being given until after week 49. Participants in this trial were followed for up to five years. The benefit of avalglucosidase alfa was evaluated by comparing the change in lung function and distance walked between participants who received avalglucosidase alfa to the change in participants who were treated with the active comparator.
Relative humidity The relative humidity of air is defined as the partial pressure of water vapour divided by the saturated vapour pressure at the same temperature and total pressure. If the temperature is kept constant, lower relative humidities result in higher drying rates due to the increased moisture gradient in wood, resulting from the reduction of the moisture content in the surface layers when the relative humidity of air is reduced. The relative humidity is usually expressed on a percentage basis. For drying, the other essential parameter related to relative humidity is the absolute humidity, which is the mass of water vapour per unit mass of dry air (kg of water per kg of dry air). However, its influenced by the amount of water in the heated air. Air circulation rate Drying time and timber quality depend on the air velocity and its uniform circulation. At a constant temperature and relative humidity, the highest possible drying rate is obtained by rapid circulation of air across the surface of wood, giving rapid removal of moisture evaporating from the wood. However, a higher drying rate is not always desirable, particularly for impermeable hardwoods, because higher drying rates develop greater stresses that may cause the timber to crack or distort. At very low fan speeds, less than 1 m/s, the air flow through the stack is often laminar flow, and the heat transfer between the timber surface and the moving air stream is not particularly effective.
The discovery of the ultraviolet radiation with wavelengths below 200 nm, named "vacuum ultraviolet" because it is strongly absorbed by the oxygen in air, was made in 1893 by German physicist Victor Schumann. The division of UV into UVA, UVB, and UVC was decided "unanimously" by a committee of the Second International Congress on Light on 17 August 1932, at the Castle of Christiansborg in Copenhagen.
Sources: en.wikipedia.org
Extracts of the adrenal gland were first obtained by Polish physiologist Napoleon Cybulski in 1895. These extracts, which he called nadnerczyna ("adrenalin"), contained adrenaline and other catecholamines. American ophthalmologist William H. Bates discovered adrenaline's usage for eye surgeries prior to 20 April 1896. In 1897, John Jacob Abel (1857–1938), the father of modern pharmacology, found a natural substance produced by the adrenal glands that he named epinephrine. The first hormone to be identified, it remains a crucial, first-line treatment for cardiac arrests, severe allergic reactions, and other conditions. In 1901, Jokichi Takamine successfully isolated and purified the hormone from the adrenal glands of sheep and oxen. Adrenaline was first synthesized in the laboratory by Friedrich Stolz and Henry Drysdale Dakin, independently, in 1904. Although secretin is mentioned as the first hormone, adrenaline is the first hormone since the discovery of the activity of adrenal extract on blood pressure was observed in 1895 before that of secretin in 1902. In 1895, George Oliver (1841–1915), a general practitioner in North Yorkshire, and Edward Albert Schäfer (1850–1935), a physiologist at University College of London published a paper about the active component of adrenal gland extract causing the increase in blood pressure and heart rate was from the medulla, but not the cortex of the adrenal gland.
== External links == http://www.apsciences.com http://www.invitroadmet.com "Scientist shows the way to take guinea pigs off lab," Karthika Gopalakrishnan. The Times of India. 17 February 2011. Retrieved 19 August 2015.
=== Carbonyl compounds === There are five types of carbonyl compounds, including aldehydes, ketones, carboxylic acids and esters. The principal fragmentation modes are described as follows: Alpha-cleavage can occur on either side of the carbonyl functional group since an oxygen lone pair can stabilize the positive charge.
Lamivudine/zidovudine, sold under the brand name Combivir among others, is a fixed-dose combination antiretroviral medication used to treat HIV/AIDS. It contains two antiretroviral medications, lamivudine and zidovudine. It is used together with other antiretrovirals. It is taken by mouth twice a day. Common side effects include headache, feeling tired, nausea, diarrhea, and fever. Severe side effects may include bone marrow suppression, muscle damage, worsening of hepatitis B if previously infected, high blood lactate and liver enlargement. It may be part of a recommended treatment during pregnancy. The medications are both of the nucleoside reverse transcriptase inhibitor (NRTI) class. They work by blocking the action of the enzyme, reverse transcriptase, that the virus requires to reproduce. Lamivudine/zidovudine was approved for medical use in the United States in 1997, and in the European Union in 1998. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication.
Sources: en.wikipedia.org
Liquid chromatography–mass spectrometry is common for identity and purity checks. High-performance liquid chromatography with ultraviolet detection can also be used. Both methods require a suitable reference standard.
The solid is usually kept desiccated at -20 °C or lower and protected from light. Stock solutions are aliquoted to limit freeze–thaw cycles. Aqueous solutions are not generally recommended for long-term storage.
Laws differ by country and by intended use. It is not an approved medicine, and many vendors sell it as a research chemical. Purchasers are responsible for confirming local restrictions.
SR9009 is a synthetic research compound that activates the REV-ERBα and REV-ERBβ nuclear receptors. It is not an approved drug and has no established human therapeutic use. Most published biological data come from cell and rodent studies.