nuclear receptor raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-07-30. Anything still debated is marked as such rather than presented as settled.
SR9009 is a synthetic small molecule studied as an agonist of REV-ERB nuclear receptors. REV-ERB alpha and REV-ERB beta help regulate circadian rhythms and metabolic gene expression. In laboratory research, SR9009 has been used to probe how these receptors affect skeletal muscle, liver, and adipose tissue. The compound was identified in academic drug-discovery work and is often described in scientific literature by its chemical name and research code. It is not an approved medicine, and human clinical data remain limited or absent.
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.
Research interest in SR9009 grew from studies of circadian biology and metabolic disease. Preclinical reports describe effects on exercise capacity, muscle metabolism, and blood lipid levels in rodents, but these findings come from controlled laboratory settings. The compound has low oral bioavailability in animals, which limits systemic exposure after swallowing. Investigators often use injected routes in experiments to achieve measurable plasma concentrations. Human clinical data are sparse, no approved therapeutic product exists, and whether animal effects translate to humans remains an open question.
Regulatory and sporting contexts treat SR9009 as a prohibited substance in many elite competitions. Its presence on banned lists reflects concerns about performance enhancement and unknown long-term safety. Analytical chemists have developed methods to detect the parent compound and its metabolites in urine and blood. Literature discussions distinguish between in vitro potency, animal pharmacology, and anecdotal human reports. The latter are difficult to verify because products sold online may lack purity or contain different compounds.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Small-molecule nuclear receptor ligand |
| Appearance | Off-white to pale yellow solid | Typical for research-grade powder |
| Solubility class | Soluble in DMSO; low water solubility | Common stock solutions use organic solvent |
| Typical stock solvent | Dimethyl sulfoxide | Used for laboratory assays |
| Common analytical method | HPLC with UV or mass detection | Used for identity and purity checks |
SR9009 is frequently discussed in fitness and research-chemical contexts, yet it has no approved medical indication. Regulatory agencies have not authorized it for human use, and it is not a standard prescription drug. Some sports organizations list it as a prohibited substance because of its potential performance-enhancing properties. Published human data are sparse, so claims about its effects in people often rely on animal models or anecdotal reports. Quality and identity of online materials can vary widely.
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.
REV-ERB proteins typically suppress gene expression by recruiting corepressor complexes to DNA response elements. SR9009 binds these receptors and strengthens that repressive action in cell-based assays. Studies in rodents have reported changes in lipid handling, mitochondrial function, and exercise capacity after treatment. Such findings are often cited as evidence for metabolic effects, but species differences and limited pharmacokinetic data make direct translation to humans uncertain. Researchers continue to examine which effects are robust and which depend on specific experimental conditions.
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.
Regulatory treatment of SR9009 varies by country and region. It is not approved as a pharmaceutical, and several jurisdictions restrict its sale for human consumption. Some authorities classify it as a research chemical, a prescription-only substance, or a prohibited performance-enhancing agent in sport. Purchasers may encounter certificates of analysis, but these documents do not guarantee identity, purity, or legality. In research settings, institutional safety reviews and controlled procurement help ensure that materials are handled under appropriate oversight. The absence of harmonized rules means that legal status can change and requires verification.
Analytical identification of SR9009 typically relies on liquid chromatography coupled with tandem mass spectrometry. In biological samples, researchers first separate the compound from matrix components using protein precipitation, liquid-liquid extraction, or solid-phase extraction. High-performance liquid chromatography with ultraviolet detection and nuclear magnetic resonance spectroscopy can support structural confirmation of reference materials. Because SR9009 is a small, relatively lipophilic molecule, reverse-phase columns and acidic mobile phases are common. Laboratories often include isotope-labeled internal standards to improve quantification and to correct for ion suppression.
=== 1949–1950 === Crick taught himself the mathematical theory of X-ray crystallography. During the period of Crick's study of X-ray diffraction, researchers in the Cambridge lab were attempting to determine the most stable helical conformation of amino acid chains in proteins (the alpha helix). Linus Pauling was the first to identify the 3.6 amino acids per helix turn ratio of the alpha helix. Crick was witness to the kinds of errors that his co-workers made in their failed attempts to make a correct molecular model of the alpha helix; these turned out to be important lessons that could be applied, in the future, to the helical structure of DNA. For example, he learned the importance of the structural rigidity that double bonds confer on molecular structures which is relevant both to peptide bonds in proteins and the structure of nucleotides in DNA.
==== PowerPlay ==== PowerPlay was a technological initiative headed by Valve and Cisco Systems to decrease the latency for online games, announced in January 2000. It was described as a set of protocols and deployment standards at the router level to improve performance. It was claimed that a player with 1000 ms ping was able to play against another player on a LAN connection with no noticeable disadvantage. Initially the protocol was to be released with PowerPlay 1.0 focusing on quality of service (QoS) and later a revision, PowerPlay 2.0 that would focus on functionality. Cisco and Valve intended to deliver a single dial-up service in Q1 2000 in the United States with a 30-day free trial with a bundled copy of Team Fortress modified to support PowerPlay. The standard was to involve purchasing PowerPlay approved Cisco hardware and infrastructure that had adequate bandwidth and QoS standards that prioritize PowerPlay gaming packets at all others' expense. Newell conceded that Internet service providers (ISPs) would bear the brunt of this expense: "The ISPs are going to need to spend a fair amount of money to be compliant with PowerPlay. But how they get that back is up to them. Some will have a tiered service, and some will just try to recoup their investment through reduced customer churn and customer acquisition." Despite never deploying the dial-up plan featuring PowerPlay 1.0, Valve announced in January 2001 that the standard had indeed been finalized. 12 months after its announcement, PowerPlay was abandoned.
The mouth is the first part of the upper gastrointestinal tract and is equipped with several structures that begin the first processes of digestion. These include salivary glands, teeth and the tongue. The mouth consists of two regions; the vestibule and the oral cavity proper. The vestibule is the area between the teeth, lips and cheeks, and the rest is the oral cavity proper. Most of the oral cavity is lined with oral mucosa, a mucous membrane that produces a lubricating mucus, of which only a small amount is needed. Mucous membranes vary in structure in the different regions of the body but they all produce a lubricating mucus, which is either secreted by surface cells or more usually by underlying glands. The mucous membrane in the mouth continues as the thin mucosa which lines the bases of the teeth. The main component of mucus is a glycoprotein called mucin and the type secreted varies according to the region involved. Mucin is viscous, clear, and clinging. Underlying the mucous membrane in the mouth is a thin layer of smooth muscle tissue and the loose connection to the membrane gives it its great elasticity. It covers the cheeks, inner surfaces of the lips, and floor of the mouth, and the mucin produced is highly protective against tooth decay. The roof of the mouth is termed the palate and it separates the oral cavity from the nasal cavity.
A chipotle ( chih-PO(H)T-lay, Spanish: [tʃiˈpotle]), or chilpotle, is a smoke-dried ripe jalapeño chili pepper used for seasoning. It is used primarily in Mexican and Mexican-inspired cuisines, such as Tex-Mex and Southwestern United States dishes. It comes in different forms, such as chipotles en adobo (stewed in adobo sauce).
Sources: en.wikipedia.org
=== CNS === Axons that react to URP are primarily found in organum vasculosum laminae terminalis (OVLT) and in the median eminence (ME). These axons are located near the hypothalamus and almost always contain the hormone Gondotropin- releasing hormone (GnRH) which was found through in situ hybridization which provides information of the anatomical location URP mRNA. This means that URP might have an effect on reproduction which has not been discovered .
Mahathir's political views have shifted during his lengthy career. During the 1980s and 1990s, he was a supporter of third-worldism, while during other periods he has been a proponent of "Asian values" and globalisation. A Muslim thinker, he holds Islamic political views. In 2002, he characterised himself as an Islamic fundamentalist. Mahathir is generally respected in developing and Islamic countries, particularly due to his oversight of Malaysia's economic growth and his support of liberal Muslim values. Mahathir has been described as a proponent of Malay nationalism. In The Malay Dilemma, he argued that the Malay race had been marginalised, and voiced his support for affirmative action policies for them. Upon his first resignation, he expressed his disappointment at the progress made towards his "principle task" of supporting the Malay race. In 2021, Mahathir said he did not believe in Ketuanan Melayu, calling it a "fantasy", and said instead that he believed in the concept of "Bangsa Malaysia". He has been described as anti-royalist by the left-wing French newspaper Libération, owing to his efforts to oppose immunity for members of Malaysia's monarchies. Mahathir is a vocal critic of neoliberalism and the Western world. In 2011, Mahathir suggested that the September 11 attacks might have been staged by the United States government. Mahathir condemned the Universal Declaration of Human Rights in 1997, suggesting it be revised to place greater importance on economic growth over civil liberties.
Properly speaking, BaP is a procarcinogen, meaning that its mechanism of carcinogenesis depends on its enzymatic metabolism to BaP diol epoxide It intercalates in DNA, and the electrophilic epoxide is attacked by nucleophilic guanine bases, forming a bulky guanine adduct.
generation 1. In any given organism, a single reproductive cycle, or the phase between two consecutive reproductive events, i.e. between an individual organism's reproduction and that of the progeny of that reproduction; or the actual or average length of time required to complete a single reproductive cycle, either for a particular lineage or for a population or species as a whole. 2. In a given population, those individuals (often but not necessarily living contemporaneously) who are equally removed from a given common ancestor by virtue of the same number of reproductive events having occurred between them and the ancestor.
However, in low-confidence regions, the RMSD can exceed 2 Å, indicating greater deviations. In proteins with multiple domains connected by flexible linkers, AlphaFold2 predicts individual domain structures accurately but may assign random relative positions to these domains. Additionally, AlphaFold2 does not account for structural constraints such as the membrane plane, sometimes placing protein domains in positions that would physically clash with the membrane.
Sources: en.wikipedia.org
is constant), the relation Qp = Q1p1 = Q2p2 can be obtained. Over a short section of the pipe, the gas flowing through the pipe can be assumed to be incompressible so that Poiseuille law can be used locally,
Homology - the structure is similar between the two species because of shared ancestry and common genetics. Convergence - the structure is similar between the two species because of independent adaptation to common environmental pressures. Understanding which characteristics and structures belong to each type is an important part of understanding plant evolution. The evolutionary biologist relies on the plant morphologist to interpret structures, and in turn provides phylogenies of plant relationships that may lead to new morphological insights.
An unexpected medical problem that happens during treatment with a drug or other therapy. Adverse events do not have to be caused by the drug or therapy, and they may be mild, moderate, or severe. (NCI) An AE is any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product (see the ICH guidance for Clinical Safety Data Management: Definitions and Standards for Expedited Reporting). (ICH E6) Adverse reaction
===== PI 88788 ===== The vast majority of cultivars in the US have soybean cyst nematode resistance (SCN resistance), but rely on only one breeding line (PI 88788) as their sole source of resistance. (The resistance genes provided by PI 88788, Peking, and PI 90763 were characterized in 1997.) As a result, for example, in 2012 only 18 cultivars out of 807 recommended by the Iowa State University Extension had any ancestry outside of PI 88788. By 2020 the situation was still about the same: Of 849 there were 810 with some ancestry from PI 88788, 35 from Peking, and only 2 from PI 89772. (On the question of exclusively PI 88788 ancestry, that number was not available for 2020.) That was speculated to be in 2012—and was clearly by 2020—producing SCN populations that are virulent on PI 88788.
Sources: en.wikipedia.org
SR9009 is a synthetic research compound that acts on REV-ERB nuclear receptors. It is not approved for human use and is sold only as a research chemical. Its effects have been studied mainly in cells and rodents.
It binds REV-ERB alpha and REV-ERB beta and changes the expression of genes tied to metabolism and circadian rhythm. These changes can affect mitochondria and energy use in animal models. The exact chain from receptor binding to physiological outcome is still being mapped.
No reliable human trials show that SR9009 improves athletic performance. Some rodent studies report endurance changes, but these results are not proof of human benefit. Its use in sport is prohibited, and quality and safety data are lacking.
SR9009 is a synthetic small molecule studied as an agonist of the REV-ERB nuclear receptors. It is not an approved medicine, and its effects in humans are not well characterized.