NR1D2 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Physicochemical behavior influences handling. SR9009 is described as a solid with limited aqueous solubility, so organic solvents such as dimethyl sulfoxide or ethanol are common in research stock solutions. Aqueous dilution can produce precipitates if the organic content is too low. Light, heat, and repeated freeze-thaw cycles may affect stability. Storage recommendations usually specify a desiccated freezer environment protected from light, but exact stability data depend on the formulation and matrix.
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.
Handling recommendations for SR9009 in a laboratory setting include storing the solid at low temperature, protected from light and moisture. The compound is often dissolved in dimethyl sulfoxide or ethanol for experiments. Solutions should be prepared with appropriate personal protective equipment and disposed of according to local rules. Stability data for long-term storage are limited, so stock solutions are typically kept cold and used within defined periods. Records of preparation date and concentration support reproducibility.
SR9009 is not approved as a medicine by major regulatory agencies. It is commonly sold as a research chemical, a category that may fall outside customary drug approval and quality rules. In sports, the World Anti-Doping Agency lists SR9009 as a prohibited substance. Athletes who use it can face sanctions if it is detected in a sample. Legal status varies by country, and importation may be restricted. Enforcement practices differ across borders.
| Property | Value | Notes |
|---|---|---|
| Appearance | Off-white to pale yellow solid | Visual description varies with purity and source |
| Solubility | Soluble in DMSO and ethanol; poorly soluble in water | Organic stock solutions are common in research |
| Typical storage | -20 °C, desiccated, protected from light | Avoid repeated freeze-thaw cycles |
| Typical analytical method | LC-MS or HPLC-UV | Reference standards are needed for quantification |
| Molar mass | Approximately 437.9 g/mol | Calculated from the reported free-base formula |
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.
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.
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.
Accurate assessment and prediction of fish quality are of main importance to set prices, increase competitiveness, resolve conflicts of interest and prevent food wastage due to conservative product shelf-life estimations. In last years, research in food science and technology has focused on developing new methodologies to predict fish freshness.
=== Freeze drying === King's interest in hiking and camping reinforced his interests in freeze-dried foods to minimize the weight of his back-pack. He has done considerable research on dehydration of foods and beverages, and in particular those phenomena that influence the quality of the product. He started working with freeze drying, which removes water by direct vaporization from the frozen state. Although he started by measuring and explaining drying rates in terms of fundamental transport phenomena, he soon turned to learning how highly volatile substances such as taste and aroma components could best be retained despite their being much more volatile than the water which was itself being vaporized during evaporative drying. In 1971, King published a book, Freeze Drying of Foods. King also gave a fundamental understanding of the phenomenon of product collapse during freeze drying and how to avoid it. That research was also valuable to the pharmaceutical industry which also often uses freeze drying. He also worked with freeze concentration for beverages, such as fruit juices, wherein water is frozen as suspended ice crystals which are then filtered out. These lines of research were financed by the U. S. Dept. of Agriculture. Subsequent research supported by the U. S. Army dealt with limited freeze drying that would leave enough water to provide sufficient pliability of the product for compression to smaller size for military uses.
In contrast, the border with Canada is primarily maintained through joint border patrol and security camera programs, making it the world's longest undefended border. In remote areas along the border with Canada, where staffed border crossings are unavailable, there are hidden sensors on roads, trails, railways, and wooded areas near crossing points. Members of the Schengen Agreement are required to apply strict checks on travellers entering and exiting the area. These checks are coordinated by the European Union's Frontex agency, and subject to common rules. The details of border controls, surveillance and the conditions under which permission to enter into the Schengen Area may be granted are exhaustively detailed in the Schengen Borders Code. All persons crossing external borders are subject to a check by a border guard. The only exception is for regular cross-border commuters (both those with the right of free movement and third-country nationals) who are well known to the border guards: once an initial check has shown that there is no alert on record relating to them in the Schengen Information System or national databases, they can only be subject to occasional 'random' checks, rather than systematic checks every time they cross the border. Additionally, border security in Europe is increasingly being outsourced to private companies, with the border security market growing at a rate of 7% per year.
A virus may need to be inactivated, possibly with no further purification required. Recombinant proteins need many operations involving ultrafiltration and column chromatography. Finally, the vaccine is formulated by adding adjuvant, stabilizers, and preservatives as needed. The adjuvant enhances the immune response to the antigen, stabilizers increase the storage life, and preservatives allow the use of multidose vials. Combination vaccines are harder to develop and produce, because of potential incompatibilities and interactions among the antigens and other ingredients involved. The final stage in vaccine manufacture before distribution is fill and finish, which is the process of filling vials with vaccines and packaging them for distribution. Although this is a conceptually simple part of the vaccine manufacture process, it is often a bottleneck in the process of distributing and administering vaccines. Vaccine production techniques are evolving. Cultured mammalian cells are expected to become increasingly important, compared to conventional options such as chicken eggs, due to greater productivity and low incidence of problems with contamination. Recombination technology that produces genetically detoxified vaccines is expected to grow in popularity for the production of bacterial vaccines that use toxoids. Combination vaccines are expected to reduce the quantities of antigens they contain, and thereby decrease undesirable interactions, by using pathogen-associated molecular patterns.
The efficiency of removal can be optimized by treating the EPS sugars with different acids or bases before adding them to wastewater. Some contaminated soils contain high levels of polycyclic aromatic hydrocarbons (PAH); EPS from the bacterium Zoogloea sp. and the fungus Aspergillus niger, are efficient at removing these toxic compounds. EPS contain enzymes such as oxidoreductase and hydrolase, which are capable of degrading PAH. The amount of PAH degradation depends on the concentration of EPS added to the soil. This method proves to be low cost and highly efficient.
Sources: en.wikipedia.org
La Niña causes mostly the opposite effects of El Niño: above-average precipitation across the northern Midwest, the northern Rockies, Northern California, and the Pacific Northwest's southern and eastern regions. Meanwhile, precipitation in the southwestern and southeastern states, as well as southern California, is below average. This also allows for the development of many stronger-than-average hurricanes in the Atlantic and fewer in the Pacific. ENSO is linked to rainfall over Puerto Rico. During an El Niño, snowfall is greater than average across the southern Rockies and Sierra Nevada mountain range, and is well-below normal across the Upper Midwest and Great Lakes states. During a La Niña, snowfall is above normal across the Pacific Northwest and western Great Lakes. In Canada, La Niña will, in general, cause a cooler, snowier winter, such as the near-record-breaking amounts of snow recorded in the La Niña winter of 2007–2008 in eastern Canada. In the spring of 2022, La Niña caused above-average precipitation and below-average temperatures in the state of Oregon. April was one of the wettest months on record, and La Niña effects, while less severe, were expected to continue into the summer. Over North America, the main temperature and precipitation impacts of El Niño generally occur in the six months between October and March. In particular, the majority of Canada generally has milder than normal winters and springs, with the exception of eastern Canada where no significant impacts occur.
== Applications == Hafnium isomers (mainly 178m2Hf) have been considered as weapons that could be used to circumvent the Nuclear Non-Proliferation Treaty, since it is claimed that they can be induced to emit very strong gamma radiation. This claim is generally discounted. DARPA had a program to investigate this use of both nuclear isomers. The potential to trigger an abrupt release of energy from nuclear isotopes, a prerequisite to their use in such weapons, is disputed. Nonetheless a 12-member Hafnium Isomer Production Panel (HIPP) was created in 2003 to assess means of mass-producing the isotope. Technetium isomers 99m43Tc (with a half-life of 6.01 hours) and 95m43Tc (with a half-life of 61 days) are used in medical and industrial applications.
== Medical uses == Metformin is used to lower blood glucose in those with type 2 diabetes. It has also been used to help with metabolic abnormalities in polyendocrine metabolic ovarian syndrome (PMOS), and as a second-line agent for infertility in those with PMOS.
==== Adrenal medulla ==== By binding to ganglion type nicotinic receptors in the adrenal medulla, nicotine increases flow of adrenaline (epinephrine), a stimulating hormone and neurotransmitter. By binding to the receptors, it causes cell depolarization and an influx of calcium through voltage-gated calcium channels. Calcium triggers the exocytosis of chromaffin granules and thus the release of epinephrine (and norepinephrine) into the bloodstream. The release of epinephrine (adrenaline) causes an increase in heart rate, blood pressure and respiration, as well as higher blood glucose levels.
== Chemistry == Proanthocyanidins are the main constituent of the resin produced by Croton lechleri, constituting more than 90% of its dry weight. The remaining 10% is largely alkaloid taspine, as well as catechin, epigallocatechin, epicatechin, and low amounts of terpene compounds.
Sources: en.wikipedia.org
Foodborne illness (also known as foodborne disease and food poisoning) is any illness resulting from the contamination of food by pathogenic bacteria, viruses, or parasites, as well as prions (the agents of mad cow disease), and toxins such as aflatoxins in peanuts, poisonous mushrooms, and various species of beans that have not been boiled for at least 10 minutes. While contaminants directly cause some symptoms, many effects of foodborne illness result from the body's immune response to these agents, which can vary significantly between individuals and populations based on prior exposure. Symptoms vary depending on the cause. They often include vomiting, fever, aches, and diarrhea and dehydration. Bouts of vomiting can be repeated with an extended delay in between. This is because even if infected food was eliminated from the stomach in the first bout, microbes, like bacteria (if applicable), can pass through the stomach into the intestine and begin to multiply. Some types of microbes stay in the intestine. For contaminants requiring an incubation period, symptoms may not manifest for hours to days, depending on the cause and on the quantity of consumption. Longer incubation periods tend to cause those affected to not associate the symptoms with the item consumed, so they may misattribute the symptoms to gastroenteritis, for example. In low- and middle-income countries in 2010, foodborne disease were responsible for approximately 600 million illnesses and 420,000 deaths, along with an economic loss estimated at US$110 billion annually.
This scenario usually occurs at very low solidification velocities (< 1 μm s−1) or with extremely fine particles because they can move by Brownian motion away from the front. The resultant structure contains no macroporosity. If one were to increase the solidification speed, the size of the particles or solid loading moderately, the particles begin to interact in a meaningful way with the approaching ice front. The result is typically a lamellar or cellular templated structure whose exact morphology depends on the particular conditions of the system. It is this type of solidification that is targeted for porous materials made by freeze-casting. The third possibility for a freeze-cast structure occurs when particles are given insufficient time to segregate from the suspension, resulting in complete encapsulation of the particles within the ice front. This occurs when the freezing rates are rapid, particle size becomes sufficiently large, or when the solids loading is high enough to hinder particle motion. To ensure templating, the particles must be ejected from the oncoming front. Energetically speaking, this will occur if there is an overall increase in free energy if the particle were to be engulfed (Δσ > 0).
== June 6, 1915 (Sunday) == Third Battle of Krithia — British general Aylmer Hunter-Weston managed to reorganize the Allied forces into an effective defense on the coast of Gallipoli and beat back the Ottoman defense, inflicting 3,000 casualties and forcing a stalemate. Second Battle of Artois — The French captured the main road leading to Neuville-Saint-Vaast, France. British carrier SS Immingham was lost in the Mediterranean Sea. Switzerland held a referendum on a war tax with most voters, over 450,000 (94 percent of electorate), in favor on implementing the one-off tax and over 27,000 against (about 6 percent). It was the first time a referendum has passed in every Swiss canton. The BHP Newcastle Steelworks opened in Newcastle, New South Wales, Australia. The London Underground extended the Bakerloo line with a new tube station at Maida Vale. The Icelandic sports club Þór Akureyri was established, and now encompasses teams for association football, basketball, handball and taekwondo.
transcript A product of transcription; that is, any RNA molecule which has been synthesized by RNA polymerase using a complementary DNA molecule as a template. When transcription is completed, transcripts separate from the DNA and become independent primary transcripts. Particularly in eukaryotes, multiple post-transcriptional modifications are usually necessary for raw transcripts to be converted into stable and persistent molecules, which are then described as mature, though not all transcribed RNAs undergo maturation. Many transcripts are accidental, spurious, incomplete, or defective; others are able to perform their functions immediately and without modification, such as certain non-coding RNAs.
Sources: en.wikipedia.org
It is usually detected by LC-MS or HPLC-UV against a reference standard. In biological matrices, metabolite targeting can improve detection. No universal immunoassay is widely available.
The compound is generally handled as light-sensitive and stored cold and dry. Stability in solution depends on solvent, concentration, and storage time. Specific degradation rates are not fully standardized.
Limited water solubility affects formulation for cell and animal studies. Organic co-solvents are often used to dissolve it. Precipitation can confound assay results if not controlled.
Its legal status depends on the country and intended use. It is not an approved medicine in major jurisdictions. In sport, it is prohibited by anti-doping rules.