This is a working overview of freeze-thaw, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-10-19. Anything still debated is marked as such rather than presented as settled.
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.
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.
| 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.
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.
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.
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 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.
For long-term storage, SR9009 is typically kept as a solid at low temperature, protected from moisture and light. Desiccated conditions limit hydrolysis, while opaque containers reduce photochemical breakdown. Solutions are less stable than solids and are often stored frozen in aliquots to avoid repeated freeze-thaw cycles. Stability data are not standardized across all suppliers, so users should rely on certificate-of-analysis information when available. Degradation may appear as color change, precipitate, or decreased chromatographic purity.
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.
Drawing on existing heroin and cannabis smuggling networks, the Guadalajara Cartel, led by Miguel Ángel Félix Gallardo, emerged as intermediaries, transporting Colombian cocaine across the Mexico–United States border. By the mid-1980s, the Guadalajara Cartel had firmly established itself as a reliable transporter, initially paid in cash but shifting by the late 1980s to a payment-in-kind arrangement. While many factors contributed to the escalation of drug trafficking violence, security analysts trace the origins of cartel power to the unraveling of an implicit arrangement between traffickers and then-ruling Institutional Revolutionary Party (PRI), which began to lose its grip on power in the 1980s. The fighting between rival drug cartels began in earnest after the 1989 arrest of Félix Gallardo, with cartel infighting escalating in the 1990s.
In most modern ("boosted") thermonuclear weapons, fusion directly provides only a small fraction of the total energy. Fission of a natural uranium-238 tamper by fast neutrons produced from D–T fusion accounts for a much larger (i.e. boosted) energy release than the fusion reaction itself.
=== Example: Omalizumab Therapy === Omalizumab is a humanized monoclonal antibody for the treatment of various allergic diseases, including asthma, urticaria, and allergic rhinitis. It targets the immunoglobulin E (IgE) in human body, which plays an important role in allergic reactions. The efficacy of omalizumab may vary among patients. To identify responders to omalizumab, the level of several biomarkers can be measured, including serum eosinophils, fractional exhaled nitric oxide, and serum IgE. For instance, patients with higher baseline eosinophil counts are likely to respond better to omalizumab therapy.
=== Age of onset === Feline hypersomatotropism is usually diagnosed in elderly cats. The average age of diagnosis is between 10 and 11 years with a range of 4–17 years. The age range of dogs reported with growth hormone secreting tumours is between 7 and 10 years. The age range of bitches with progestone induced hypersomatotropism is 4–11 years, for bitches with hypersomatotropism resulting from the estrous cycle the age range is between 6 and 13 years.
Sources: en.wikipedia.org
Replacing labile ligands such as H2O, H−, or CO directly by nitrogen: these are often reversible reactions that proceed at mild conditions. Reducing metal complexes in the presence of a suitable co-ligand in excess under nitrogen gas. A common choice includes replacing chloride ligands with dimethylphenylphosphine (PMe2Ph) to make up for the smaller number of nitrogen ligands attached to the original chlorine ligands. Converting a ligand with N–N bonds, such as hydrazine or azide, directly into a dinitrogen ligand. Occasionally the N≡N bond may be formed directly within a metal complex, for example by directly reacting coordinated ammonia (NH3) with nitrous acid (HNO2), but this is not generally applicable. Most dinitrogen complexes have colours within the range white-yellow-orange-red-brown; a few exceptions are known, such as the blue [{Ti(η5-C5H5)2}2-(N2)].
=== Start and stop codons === Translation starts with a chain-initiation codon or start codon. The start codon alone is not sufficient to begin the process. Nearby sequences such as the Shine-Dalgarno sequence in E. coli and initiation factors are also required to start translation. The most common start codon is AUG, which is read as methionine or as formylmethionine (in bacteria, mitochondria, and plastids). Alternative start codons depending on the organism include "GUG" or "UUG"; these codons normally represent valine and leucine, respectively, but as start codons they are translated as methionine or formylmethionine. The three stop codons have names: UAG is amber, UGA is opal (sometimes also called umber), and UAA is ochre. Stop codons are also called "termination" or "nonsense" codons. They signal release of the nascent polypeptide from the ribosome because no cognate tRNA has anticodons complementary to these stop signals, allowing a release factor to bind to the ribosome instead.
Due to competition, the early 1980s recession, the early 1990s recession, and lost focus, the company's growth stalled in the 1980s and early 1990s. D’Arbeloff, the chairman of the company, died of cancer and the COO and CTO died in a helicopter crash while commuting between facilities. The anticipated synergies never materialized. In 1994, an investor group led by management purchased the company for $360 million. That year, the company introduced Symmetry HPLC columns. It had a renewed focus for growth under CEO Douglas A. Berthiaume. Pharmaceutical spending also increased after the failure of the Clinton health care plan of 1993. In November 1995, the company once again became a public company via an initial public offering. In 1996, in addition to acquiring TA Instruments, it introduced the Alliance HPLC system. The following year, Waters acquired Micromass for $176 million, entering the mass spectrometry market. In 2004, the company introduced the Acquity UPLC system, which brought greater speed, resolution, and sensitivity to chromatographic separations and was considered a breakthrough technology. In 2006, Waters acquired Vicam, provider of bio-separation and rapid detection products for improving food safety and quality. In January 2020, it acquired Andrew Alliance, a producer of software and robotics for laboratory automation, for $77.4 million. In September, Udit Batra was named President and Chief Executive Officer of the company. In May 2023, Waters acquired Wyatt Technology for $1.36 billion in cash.
Themes of nature, pioneers, trappers, and traders played an important part in the early development of Canadian symbolism. Modern symbols emphasize the country's geography, northern climate, lifestyles, and the Canadianization of traditional European and Indigenous symbols. The use of the maple leaf as a symbol dates to the early 18th century in New France. The maple leaf is depicted on Canada's current and previous flags and on the arms of Canada. Canada's official tartan, known as the "maple leaf tartan", reflects the colours of the maple leaf through the seasons—green in the spring, gold in the early autumn, red at the first frost, and brown after falling. The arms of Canada are closely modelled after those of the United Kingdom, with French and distinctive Canadian elements replacing or added to those derived from the British version. Other prominent symbols include the national motto, "A mari usque ad mare" ("from sea to sea"), the sports of ice hockey and lacrosse, the beaver, Canada goose, common loon, Canadian horse, the Royal Canadian Mounted Police, the Canadian Rockies, and, more recently, the Indigenous totem pole and Inuksuk. Canadian cuisine items such as Canadian beer, maple syrup, Nanaimo bars, butter tarts, and the Quebec dishes of poutine and tourtière, alongside material items such as tuques, canoes and Hudson's Bay point blanket are considered as uniquely Canadian. Canadian coins feature many of these symbols: the loon on the $1 coin, the coat of arms on the 50¢ piece, and the beaver on the nickel.
Many herbs are applied topically to the skin in a variety of forms. Essential oil extracts can be applied to the skin, usually diluted in a carrier oil. Many essential oils can burn the skin or are simply too high dose used straight; diluting them in olive oil or another food grade oil such as almond oil can allow these to be used safely as a topical. Salves, oils, balms, creams, and lotions are other forms of topical delivery mechanisms. Most topical applications are oil extractions of herbs. Taking a food-grade oil and soaking herbs in it for anywhere from weeks to months allows certain phytochemicals to be extracted into the oil. This oil can then be made into salves, creams, lotions, or simply used as an oil for topical application. Many massage oils, antibacterial salves, and wound healing compounds are made this way. Inhalation, as in aromatherapy, can be used as a treatment.
Sources: en.wikipedia.org
1894–1917 Sir Joseph Lyons 1917–1922 Montague Gluckstein 1923–1928 Alfred Salmon 1928–1941 Sir Isidore Salmon MP 1941–1950 Harry Salmon JP 1950–1956 Major Montague Isidore Gluckstein 1956–1960 Isidore Montague Gluckstein 1960–1965 Barnett Alfred Salmon 1965–1968 Sir Samuel Isidore Salmon JP (Mayor of Hammersmith 1968/69) 1968–1972 Geoffrey Salmon 1972–1977 Brian Lawson Salmon 1977–1981 Neil Lawson Salmon
Class 350: 350 °F (176.7 °C) at 100% relative humidity for paper records, which keeps the contents below the charring point of 420 °F (215.6 °C); Class 150: 150 °F (65.6 °C) at 85% relative humidity for photographic, magnetic, or similar non-paper records; Class 125: 125 °F (51.7 °C) at 80% relative humidity for the more heat-sensitive floppy disks. A safe rated UL Class 150 or UL Class 125 and intended to hold only computer media is sometimes called a media safe, and Class 125 units are also known as data safes. NFPA 232 requires that the vault door be a listed vault door with a fire-resistive rating that meets or exceeds that of the vault walls. Wall penetrations must be sealed to prevent the intrusion of smoke, heat, flame, or water, with a listed fire-rated through-penetration assembly for general penetrations and listed fire-rated material for penetrations for sprinkler piping, electric lighting, conduit, and power-limited circuits, in each case with a rating that meets or exceeds that of the vault. Ventilation openings must be as small as possible, protected to maintain the required rating of the wall, and fitted with smoke dampers activated by automatic sensing devices. Paper water-damaged in a fire can be remediated by vacuum freeze-drying, in which water is sublimed from the liquid state to a vapor, causing less ink bleeding and planar distortion than air or desiccant drying.
glutamate (reduced nicotinamide adenine dinucleotide) synthase, glutamate synthase (NADH), L-glutamate synthetase(NADH), NADH-dependent glutamate synthase, NADH-glutamate synthase, and NADH-Glutamine oxoglutarate aminotransferase (NADH-GOGAT).
== Data collection == Protein NMR utilizes multidimensional nuclear magnetic resonance experiments to obtain information about the protein. Ideally, each distinct nucleus in the molecule experiences a distinct electronic environment and thus has a distinct chemical shift by which it can be recognized. However, in large molecules such as proteins the number of resonances can typically be several thousand and a one-dimensional spectrum inevitably has incidental overlaps. Therefore, multidimensional experiments that correlate the frequencies of distinct nuclei are performed. The additional dimensions decrease the chance of overlap and have a larger information content, since they correlate signals from nuclei within a specific part of the molecule. Magnetization is transferred into the sample using pulses of electromagnetic (radiofrequency) energy and between nuclei using delays; the process is described with so-called pulse sequences. Pulse sequences allow the experimenter to investigate and select specific types of connections between nuclei. The array of nuclear magnetic resonance experiments used on proteins fall in two main categories — one where magnetization is transferred through the chemical bonds, and one where the transfer is through space, irrespective of the bonding structure. The first category is used to assign the different chemical shifts to a specific nucleus, and the second is primarily used to generate the distance restraints used in the structure calculation, and in the assignment with unlabelled protein.
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.