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 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
SR9009 is a synthetic small molecule studied as a REV-ERB agonist. REV-ERBα and REV-ERBβ are nuclear receptors that help regulate circadian rhythms and metabolic gene expression. The compound was identified in academic screening efforts to find synthetic ligands for these receptors. In cell and animal studies, SR9009 alters transcription of genes involved in lipid and glucose metabolism, and it can shift circadian behavior. It is not an approved therapeutic agent.
Mechanistically, SR9009 binds the ligand-binding domain of REV-ERBα/β and enhances recruitment of corepressor complexes. This represses target genes rather than activating them. Because REV-ERB proteins normally compete with ROR proteins at shared response elements, the net effect depends on tissue and timing. Researchers use SR9009 to probe how nuclear receptor signaling links the clock to metabolism, inflammation, and muscle biology. Findings are largely preclinical, and the precise contribution of each receptor subtype remains under study.
Research interest in SR9009 grew from studies showing improved running endurance in mice after short treatment periods. Those experiments linked the compound to increased mitochondrial content and fatty acid oxidation in muscle, but the findings come from animal models and specific dosing schedules. Independent replication has been limited, and the pathways connecting REV-ERB activation to exercise performance are still being mapped. Whether similar responses occur in humans is an open question.
SR9009 is often grouped with compounds studied for circadian and metabolic regulation rather than with classical anabolic steroids. Its interactions with nuclear receptors differ from those of androgen receptor ligands, and its proposed mechanisms involve transcriptional control rather than direct hormone signaling. Some sources classify it as a metabolic modulator because of observed effects on energy utilization. The distinction matters for regulation and for interpreting research results across different compound classes.
SR9009 is a synthetic small molecule developed as a REV-ERB agonist. It binds to REV-ERBα and REV-ERBβ, nuclear receptors that help regulate circadian rhythms and metabolic gene expression. In cell and animal studies, the compound alters lipid and glucose handling and influences skeletal muscle oxidative capacity. Its exact effects in humans remain largely uncharacterized because controlled clinical trials have not been reported. The molecule is frequently described in preclinical literature as a metabolic modulator.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Small-molecule ligand; not a hormone or peptide |
| Molecular formula | C20H24ClN3O4S | Reported for the free base |
| CAS Registry Number | 1379686-30-2 | Unique chemical identifier |
| Common synonyms | SR9009; stenabolic | Stenabolic is informal and not an official name |
| Reported targets | REV-ERBα and REV-ERBβ | Nuclear receptors linked to circadian and metabolic regulation |
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.
Preclinical reports have linked SR9009 to improved endurance and altered energy expenditure in rodents. Such findings have prompted interest in whether REV-ERB activation can influence skeletal muscle metabolism. However, the reported effects depend on dose, route, and experimental model, and replication across laboratories is limited. Human trials have not established comparable outcomes, so claims about exercise performance remain speculative. The absence of controlled human data is a central limitation in interpreting these observations.
SR9009 is frequently discussed alongside other REV-ERB ligands, including synthetic agonists and natural heme-related molecules. Its selectivity for REV-ERB over related nuclear receptors has been measured in binding and reporter assays, though off-target activity at higher concentrations is possible. The compound is prohibited in sport by the World Anti-Doping Agency, and it is not approved for any medical use in major jurisdictions. Products sold online may be labeled as research chemicals, and their identity and purity are not guaranteed by regulatory review.
SR9009 is a synthetic small molecule that acts on the nuclear receptors REV-ERBα and REV-ERBβ. These receptors are part of the circadian clock machinery and normally repress transcription of certain target genes. In laboratory research, SR9009 is used as a chemical tool to study how REV-ERB activity influences metabolism, inflammation, and daily biological rhythms. The compound is not an approved medicine, and its effects in humans remain largely uncharacterized. It is often described as an investigational agent rather than a therapeutic product.
Identity and purity of SR9009 samples are usually checked with chromatographic and spectrometric methods. High-performance liquid chromatography can separate the compound from related impurities, while mass spectrometry provides molecular mass confirmation. Nuclear magnetic resonance spectroscopy may be used for structural verification in research settings. No single method proves biological activity, and certificates of analysis should be reviewed alongside raw data. Independent testing is often needed because online products vary widely.
SR9009 stability depends on temperature, moisture, light, and solvent. Solid material is generally kept cool and dry, while solutions may require protection from repeated warming and cooling. Degradation can appear as color changes, precipitate, or new chromatographic peaks. Researchers should follow supplier instructions and their own stability data. Long-term storage conditions for human use have not been established because the compound lacks approved clinical formulation.
SR9009 is supplied as a solid research chemical, often in milligram quantities. Laboratories typically weigh it in a controlled environment because fine powders can disperse. Stock solutions are commonly prepared in dimethyl sulfoxide and stored in small aliquots to reduce freeze-thaw cycles. Personal protective equipment and chemical fume hoods are standard when handling unknown or potent compounds. These practices address laboratory safety rather than human use.
Laboratory identification of SR9009 typically relies on chromatographic separation coupled to mass spectrometry, often with ultraviolet detection as a secondary check. Nuclear magnetic resonance spectroscopy can confirm molecular structure when a reference standard is available. Because many suppliers sell the compound as a research chemical, independent identity testing is important for experimental reproducibility. A single retention time is not sufficient proof of identity, especially when related compounds may be present. Purity assessments usually report a percentage based on area normalization.
SR9009 is generally described as poorly soluble in water and more soluble in organic solvents such as dimethyl sulfoxide and ethanol. Stock solutions are commonly prepared in an organic solvent before dilution into an aqueous buffer or vehicle. Precipitation can occur if the organic fraction is reduced too quickly or if the final concentration exceeds the compound's solubility limit. Sonication or gentle warming may aid dissolution in some protocols, but excessive heat can promote degradation. Container material and pH can also influence observed solubility.
Tho shouted at Kissinger for over an hour, and despite Kissinger's requests not to speak so loudly because the reporters outside the room could hear what he was saying, he did not relent. Tho concluded: "For more than ten years, America has used violence to beat down the Vietnamese people-napalm, B-52s. But you don't draw any lessons from your failures. You continue the same policy. Ngu xuan! Ngu xuan! Ngu xuan!". When Kissinger asked what ngu xuan meant in Vietnamese, the translator refused to translate, as ngu xuan roughly meant that a person is grossly stupid. When Kissinger was finally able to speak, he argued that it was Tho who, by being unreasonable, had forced Nixon to order the Christmas bombings, a claim that led Tho to snap in fury: "You've spent billions of dollars and many tons of bombs when we had a text ready to sign". Kissinger replied: "I have heard many adjectives in your comments. I propose that you should not use them". Tho answered: "I have used those adjectives with a great deal of restraint already. World opinion, the U.S. press and U.S. political personalities have used harsher words". After the tirade, negotiations proceeded well. Kissinger inserted a vaguely written paragraph calling for the withdrawal of all foreign forces from South Vietnam, which Tho accepted while at the same time saying the PAVN forces were not foreign. On the night of 9 January 1973, Kissinger phoned Nixon in Washington to say that a peace agreement would be signed very soon.
=== Test strip process === The niacin test strip is typically composed of potassium thiocyanate, chloramine-T, citric acid, and 4-Aminosalicylic acid. In the presence of citric acid, chloramine-T and potassium thiocyanate will react to form cyanogen chloride. This chemical will break apart the pyridine ring of niacin to produce y-carboxy glutaconic aldehyde and joins an aromatic amine to form a yellow color.
Aprepitant, sold under the brand name Emend among others, is a medication used to prevent chemotherapy-induced nausea and vomiting and to prevent postoperative nausea and vomiting. It may be used together with ondansetron and dexamethasone. It is taken by mouth or administered by intravenous injection. A prodrug, fosaprepitant, is also available for intravenous administration. Common side effects include tiredness, loss of appetite, diarrhea, abdominal pain, hiccups, itchiness, pneumonia, and blood pressure changes. Other severe side effects may include anaphylaxis. While use in pregnancy does not appear to be harmful, such use has not been well studied. Aprepitant belongs to the class of neurokinin-1 receptor antagonists. It works by blocking substance P from attaching to the NK1 receptors. Aprepitant was approved for medical use in the European Union and the United States in 2003. It is made by Merck & Co. It is on the World Health Organization's List of Essential Medicines.
=== Mechanism of action === In the setting of HLH, over-secretion of IFN-γ is thought to contribute to the pathogenesis of the disease. Emapalumab binds and neutralizes IFN-γ, preventing it from inducing pathological effects.
Sources: en.wikipedia.org
=== Linker === Between the reactive group and the tag, ABPs often include a linker / spacer / biorecognition element, which can tune probe solubility, steric accessibility, and substrate mimicry. Simple linkers may consist of alkyl chains or polyethylene glycol (PEG) spacers which adjust hydrophobicity and improve labeling across diverse proteomes. More complex designs incorporate biorecognition elements which can impart enzyme family or subfamily selectivity. For example, substrate-mimetic phosphonates have been used to target specific serine proteases and optimized peptide sequences can discriminate caspase isoforms. Binding or targeting motifs within the linker can further enhance interactions with enzymes whose active sites impose structural constraints, thereby improving probe specificity. In addition, linker length and composition can modulate probe permeability and distribution in cellular or in vivo contexts. This component allows probe designers to balance breadth (profiling an entire enzyme class) versus specificity (targeting individual members).
And, another study reported that the level of FFAR2 messenger RNA in circulating blood monocytes was elevated in humans with gout compared to those who did not have gout and rose further during flare-ups of their disease; the study suggested that FFAR2 is involved in triggering gout flare-ups. Notably, a study based on the premise that FFAR2 promotes inflammation examined the effect of GLPG0974, a potent allosteric antagonist inhibitor of FFAR2, on patients with the inflammatory disease ulcerative colitis. The study progressed through phase I and II clinical studies that found the drug to be safe (i.e., non-toxic) but ineffective in reducing mild to moderate ulcerative colitis (further development of GLPG609 was terminated). While most studies suggest that FFAR2 suppresses human and mouse inflammation, further studies are needed to determine if and why FFAR2 promotes some types of inflammation.
== Terminology == There exists some controversy about what structures are considered "fascia" and how they should be classified. The current version of the International Federation of Associations of Anatomists divides into:
Psilocybe semilanceata fruits solitarily or in groups on rich and acidic soil, typically in grasslands, such as meadows, pastures, or lawns. It is often found in pastures that have been fertilized with sheep or cow dung, although it does not typically grow directly on the dung. P. semilanceata, like all others species of the genus Psilocybe, is a saprobic fungus, meaning it obtains nutrients by breaking down organic matter. The mushroom is also associated with sedges in moist areas of fields, and it is thought to live on the decaying root remains. At least one study has demonstrated an association of P. semilanceata with the roots of the grasses Agrosiis tenuis, Poa annua, and the dicot Lolium perenne. Like some other grassland psilocybin mushroom species such as P. mexicana, P. tampanensis and Conocybe cyanopus, P. semilanceata may form sclerotia, a dormant form of the fungus, which affords it some protection from wildfires and other natural disasters. Laboratory tests have shown P. semilanceata to suppress the growth of the soil-borne water mold Phytophthora cinnamomi, a virulent plant pathogen that causes the disease root rot. When grown in dual culture with other saprobic fungi isolated from the rhizosphere of grasses from its habitat, P. semilanceata significantly suppresses their growth. This antifungal activity, which can be traced at least partly to two phenolic compounds it secretes, helps it compete successfully with other fungal species in the intense competition for nutrients provided by decaying plant matter.
Fossils of one major deuterostome group, the echinoderms (whose modern members include starfish, sea urchins and crinoids), are quite common from the start of the Cambrian, 542 million years ago. The Mid Cambrian fossil Rhabdotubus johanssoni has been interpreted as a pterobranch hemichordate. Opinions differ about whether the Chengjiang fauna fossil Yunnanozoon, from the earlier Cambrian, was a hemichordate or chordate. Another fossil, Haikouella lanceolata, also from the Chengjiang fauna, is interpreted as a chordate and possibly a craniate, as it shows signs of a heart, arteries, gill filaments, a tail, a neural chord with a brain at the front end, and possibly eyes—although it also had short tentacles round its mouth. Haikouichthys and Myllokunmingia, also from the Chengjiang fauna, are regarded as fish. Pikaia, discovered much earlier (1911) but from the Mid Cambrian Burgess Shale (505 Mya), is also regarded as a primitive chordate. On the other hand, fossils of early chordates are very rare, since invertebrate chordates have no bones or teeth, and only one has been reported for the rest of the Cambrian. The best known and earliest unequivocally identified Tunicate is Shankouclava shankouense from the Lower Cambrian Maotianshan Shale at Shankou village, Anning, near Kunming (South China). The evolutionary relationships between the chordate groups and between chordates as a whole and their closest deuterostome relatives have been debated since 1890. Studies based on anatomical, embryological, and paleontological data have produced different "family trees".
Sources: en.wikipedia.org
During FY2018, the federal government spent $4.11 trillion, up $127 billion or 3.2% vs. FY2017 spending of $3.99 trillion. Spending increased for all major categories and was mainly driven by higher spending for Social Security, net interest on the debt, and defense. Spending as % GDP fell from 20.7% GDP to 20.3% GDP, equal to the 50-year average. During FY2017, the federal government spent $3.98 trillion, up $128 billion or 3.3% vs. FY2016 spending of $3.85 trillion. Major categories of FY 2017 spending included: Healthcare such as Medicare and Medicaid ($1,077B or 27% of spending), Social Security ($939B or 24%), non-defense discretionary spending used to run federal Departments and Agencies ($610B or 15%), Defense Department ($590B or 15%), and interest ($263B or 7%). Expenditures are classified as "mandatory", with payments required by specific laws to those meeting eligibility criteria (e.g., Social Security and Medicare), or "discretionary", with payment amounts renewed annually as part of the budget process. Around two thirds of federal spending is for "mandatory" programs. CBO projects that mandatory program spending and interest costs will rise relative to GDP over the 2016–2026 period, while defense and other discretionary spending will decline relative to GDP.
=== Subclinical === Subclinical hypothyroidism is a biochemical diagnosis characterized by an elevated serum TSH level, but with a normal serum free thyroxine level. The incidence of subclinical hypothyroidism is estimated to be 3-15% and a higher incidence is seen in elderly people, females and those with lower iodine levels. Subclinical hypothyroidism is most commonly caused by autoimmune thyroid diseases, especially Hashimoto's thyroiditis. The presentation of subclinical hypothyroidism is variable and classic signs and symptoms of hypothyroidism may not be observed. Of people with subclinical hypothyroidism, a proportion will develop overt hypothyroidism each year. In those with detectable antibodies against thyroid peroxidase (TPO), this occurs in 4.3%, while in those with no detectable antibodies, this occurs in 2.6%. In addition to detectable anti-TPO antibodies, other risk factors for conversion from subclinical hypothyroidism to overt hypothyroidism include female sex or in those with higher TSH levels or lower level of normal free T4 levels. Those with subclinical hypothyroidism and detectable anti-TPO antibodies who do not require treatment should have repeat thyroid function tested more frequently (e.g. every 6 months) compared with those who do not have antibodies.
=== Recombinant human CNTF (Axokine) === A recombinant version of human CNTF (rhCNTF), trade name Axokine, is a modified version with a 15 amino acid truncation of the C-terminus and two amino acid substitutions. It is three to five times more potent than CNTF in in vitro and in vivo assays and has improved stability properties. Like CNTF it is a neurotrophic factor, and may stimulate nerve cells to survive. It was tested in the 1990s as a treatment for amyotrophic lateral sclerosis. It did not improve muscle control as much as expected, but trial participants did report a loss of appetite. Phase III clinical trials for the drug against obesity were conducted in 2003 by Axokine's maker, Regeneron Pharmaceuticals, demonstrating a small positive effect in some patients, but the drug was not commercialized. A major problem with the treatment was that in nearly 70% of the subjects tested, antibodies against Axokine were produced after approximately three months of treatment. In the minority of subjects who did not develop the antibodies, weight loss averaged 12.5 pounds in one year, versus 4.5 pounds for placebo-treated subjects. In order to obtain this benefit, subjects needed to receive daily subcutaneous injections of one microgram Axokine per kilogram body weight. Xencor patent application raises the disturbing idea that subjects producing antibodies against CNTF analogues may eventually suffer severe adverse effects, as these antibodies could potentially interfere with the neuroprotective functions of endogenous CNTF.
Trump tells reporters that US forces shot down seven Iranian "fast boats". May 5 Iran War: U.S. Secretary of State Marco Rubio announces that Operation Epic Fury has concluded. President Trump announces that Operation Project Freedom has been paused, citing progress in negotiations. CNN hosts the California gubernatorial primary debate. Vivek Ramaswamy wins the Republican nomination for the governor of Ohio. Tanner Horner is sentenced to death after pleading guilty to the murder of Athena Strand, a 7-year-old girl he took from her Texas home while delivering a Christmas gift. May 6 Iran war: Amid negotiations over the Strait of Hormuz crisis, President Trump says that the U.S. and Israeli war against Iran could end if Iran accepts a U.S. proposal, but warns that bombing would resume at "a much higher level and intensity" if it rejects the terms. Iran says it is reviewing the proposal. Former collegiate American football quarterback Stephen Garcia, who played for the University of South Carolina, announces he has been diagnosed with stage IV colorectal cancer. May 7 – The U.S. Department of State along with other federal agencies orders an investigation of all 53 Mexican consulates throughout the country. The Trump administration accuses former Mexican President Andrés Manuel López Obrador of utilizing Mexican consulates in the U.S. to monitor political activities. May 8 Tariffs in the second Trump administration: The U.S. Court of International Trade rules that the 10% global tariffs imposed by Trump are illegal.
Their half-lives range from years to millions of years and as alpha emitters they are particularly radiotoxic. While there are proposed – and to a much lesser extent current – uses of all those elements, commercial-scale reprocessing using the PUREX-process disposes of them as waste together with the fission products. The waste is subsequently converted into a glass-like ceramic for storage in a deep geological repository. The duration that radioactive waste must be stored depends on the type of waste and radioactive isotopes it contains. Short-term approaches to radioactive waste storage have been segregation and storage on the surface or near-surface of the earth. Burial in a deep geological repository is a favored solution for long-term storage of high-level waste, while re-use and transmutation are favored solutions for reducing the HLW inventory. Boundaries to recycling of spent nuclear fuel are regulatory and economic as well as the problem of radioactive contamination if chemical separation processes cannot achieve a very high purity. Furthermore, elements may be present in both useful and troublesome isotopes, which would require costly and energy intensive isotope separation for their use – a currently uneconomic prospect. A summary of the amounts of radioactive waste and management approaches for most developed countries are presented and reviewed periodically as part of a joint convention of the International Atomic Energy Agency (IAEA).
Sources: en.wikipedia.org
SR9009 is a synthetic compound investigated as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is used in preclinical research on circadian rhythm and metabolism. It is not an approved drug.
No. It has no approved medical indication, and human safety and efficacy data are limited. It appears in research chemical markets and is banned by some sports authorities.
Natural ligands include heme and certain metabolites; SR9009 is a synthetic small molecule with higher potency and selectivity in some assays. Its effects depend on cell type and timing. It is not a naturally occurring compound.
It is a synthetic REV-ERB agonist used mainly in preclinical research. It is not an approved medicine for human use.