The short version of Preclinical research fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-06-18 and is reviewed periodically as new material appears.
Anti-doping laboratories identify GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the usual matrix, and detection can occur after the parent compound has cleared from blood. The exact detection window depends on dose, formulation, individual metabolism, and assay sensitivity. Because the compound is prohibited at all times, athletes are subject to testing in and out of competition. Analytical methods continue to improve as new metabolites and designer analogs are characterized.
GW501516 acts as a ligand for PPAR delta, a nuclear receptor that regulates transcription of genes involved in fatty acid oxidation and energy use. Activation of this receptor in skeletal muscle shifts metabolism toward fat burning in animal models. The compound does not burn fat directly; it changes gene expression over hours to days. Researchers study it to understand metabolic flexibility and exercise adaptation. Effects observed in rodents are not automatically expected in humans.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
Legal status varies by country. In some places, cardarine is controlled under medicines or psychoactive substances laws; in others, it may be sold with minimal oversight as a research chemical. Customs agencies have intercepted shipments, and several national health agencies have issued warnings about products marketed for bodybuilding or performance enhancement. The lack of a standardized pharmaceutical supply means identity, purity, and contamination levels can differ widely between samples. These factors make cardarine a regulatory and public health concern rather than a conventional prescription drug.
Cardarine is a common name for GW501516, a synthetic compound first described in the 1990s as a selective agonist of the peroxisome proliferator-activated receptor delta. It was studied in preclinical models for metabolic and cardiovascular conditions, but it has not been approved as a medicine in the United States, Europe, or other major jurisdictions. Retail products labeled as cardarine are generally research chemicals or supplements, not pharmaceutical formulations. Because human safety and efficacy data remain limited, regulatory agencies treat it as an unapproved substance rather than a therapeutic product.
Sporting authorities added GW501516 to prohibited lists after it appeared in athlete samples and online markets. The World Anti-Doping Agency classifies it as a hormone and metabolic modulator, and its use can lead to an anti-doping rule violation. Some early laboratory work suggested effects on fatty acid oxidation and endurance-related metabolism in animals, but those findings do not establish safe or effective use in people. Reports of adverse events in humans are scarce and often anecdotal, which complicates risk assessment.
| Property | Value | Notes |
|---|---|---|
| Molecular target | PPAR delta (NR1C2) | Ligand-activated nuclear receptor. |
| Primary tissues studied | Skeletal muscle, liver, adipose | Effects on fatty acid oxidation and energy use. |
| Typical detection matrix | Urine | Used in anti-doping analysis. |
| Common analytical method | LC-MS/MS | Detects parent compound and metabolites. |
| Sport regulatory class | Prohibited at all times | Listed as a metabolic modulator by WADA. |
Detection of GW501516 in biological samples generally relies on liquid chromatography coupled with tandem mass spectrometry. Urine is a common matrix in anti-doping analysis, while blood or plasma may be used in research settings. Sample preparation can involve enzymatic hydrolysis, protein precipitation, or solid-phase extraction before instrumental analysis. Because the compound undergoes metabolism, assays may target the parent molecule, one or more metabolites, or both. Detection windows are not fixed; they depend on factors such as dose, route, individual metabolism, and assay sensitivity. Reference standards are required for accurate identification and quantification.
Handling and quality assessment of cardarine reference material follow general laboratory practices for poorly characterized compounds. It typically appears as a white to off-white powder and is sparingly soluble in water but soluble in organic solvents such as dimethyl sulfoxide and ethanol. Storage recommendations usually specify a cool, dry, dark place, with long-term storage at low temperature and desiccation. Purity may be checked by high-performance liquid chromatography with ultraviolet detection, while identity is confirmed by mass spectrometry and nuclear magnetic resonance. No pharmacopeial monograph exists, so reported purity and stability depend on the supplier’s methods.
GW501516 acts as a selective agonist at PPARδ, a nuclear receptor that regulates transcription of genes involved in lipid handling and energy metabolism. Activation of PPARδ in preclinical models increases fatty acid oxidation, mitochondrial biogenesis, and exercise endurance in rodents. These effects have made the compound a subject of metabolic research and also a target for sport anti-doping rules. In humans, however, controlled studies are limited, and whether similar endurance or metabolic changes occur at tolerated exposures remains an open question. The receptor’s broad tissue distribution also means downstream effects may vary by organ and condition.
Laboratory handling focuses on identity, purity, and stability. Reference standards are typically stored cold and dry, protected from light, because solutions can degrade over time. Analytical checks may use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Impurities and related substances can be separated chromatographically and compared with a known standard. Because cardarine is not an approved drug, compendial monographs are absent, and laboratories often rely on in-house methods. Reported purity varies among unregulated products and should not be assumed from a label.
GW501516 binds and activates PPARδ, a nuclear receptor that influences transcription of genes involved in fatty acid oxidation and energy use. Activation shifts some metabolic pathways in preclinical models, which is why the compound has been studied for lipid disorders and exercise-related endpoints. The exact downstream effects in humans are incompletely mapped. PPARδ is expressed in many tissues, including skeletal muscle, liver, and adipose tissue, so broad activation may have varied consequences. Researchers continue to examine how selective or partial activation might alter the balance between benefits and risks.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
== History == In the early 1920s, several groups noted that pancreatic extracts injected into diabetic animals would result in a brief increase in blood sugar prior to the insulin-driven decrease in blood sugar. In 1922, C. Kimball and John R. Murlin identified a component of pancreatic extracts responsible for this blood sugar increase, terming it "glucagon", a portmanteau of "glucose agonist". In the 1950s, scientists at Eli Lilly isolated pure glucagon, crystallized it, and determined its amino acid sequence. This led to the development of the first radioimmunoassay for detecting glucagon, described by Roger Unger's group in 1959. A more complete understanding of its role in physiology and disease was not established until the 1970s, when a specific radioimmunoassay was developed. In 1979, while working in Joel Habener's laboratory at Massachusetts General Hospital, Richard Goodman collected islet cells from Brockman bodies of American anglerfish in order to investigate somatostatin. By splicing DNA from anglerfish islet cells into bacteria, Goodman was able to identify the gene which codes for somatostatin. P. Kay Lund joined the Habener lab and used Goodman's bacteria to search for the gene for glucagon. In 1982, Lund and Goodman published their discovery that the proglucagon gene codes for three distinct peptides: glucagon and two novel peptides. Graeme Bell at Chiron Corporation led a team which isolated the two latter peptides, which are now known as glucagon-like peptide-1 and glucagon-like peptide-2.
One of the first adoptions of the trope is Rachel Pollack's Tree House (1984). The titular megaflora in Larry Niven's 1984 novel The Integral Trees exist within an orbiting gaseous torus full of life adapted to free-fall. The concept is discussed in Carl Sagan and Ann Druyan's 1985 non-fiction book Comet, and several paintings of Dyson trees around Saturn and in interstellar space are provided in the book by Jon Lomberg. In Michael Swanwick's 1987 transhumanist novel Vacuum Flowers, "dysonsworlders" have established tree settlements in the Oort Cloud. Under the name of "Space Poplars", Dyson trees are described in Donald Moffitt's two science fiction novels, The Genesis Quest and Second Genesis. Here they are used as both habitats and spacecraft, propelled by reflective outer leaves used as organic solar sails. Dan Simmons, in Endymion (1996) and the Rise of Endymion (1997) – both part of his Hyperion Cantos – refers to Dyson trees, and in the latter novel to a huge tree system that surrounds an entire star (reminiscent of a Dyson sphere). In Stephen Baxter's Manifold: Space (2001), Baxter's protagonist Reid Malenfant at one point finds himself inside a Dyson tree. In the Orion's Arm shared universe (established 2000), Dyson trees and Dyson tree "forests" are called orwoods; these have been established in a number of star systems throughout terragen space. The word "Orwood" in this context was originally coined by Anders Sandberg. The Transhuman Space roleplaying game includes the beginning of a Dyson tree endeavour on Yggdrasil Station.
Zipline originated from Romotive, a company founded in 2011 by Keller Rinaudo Cliffton that produced an iPhone-controlled robot. Romotive ceased operations in 2014, after which Rinaudo, Ryan Oksenhorn, William Hetzler, and Keenan Wyrobek began developing a fixed-wing drone platform intended for medical delivery. This effort became the basis for Zipline. The company began operations in Rwanda in October 2016 following a government agreement to deliver blood and medical supplies to rural clinics from a centralized distribution center. A second Rwandan center opened in 2018 as the scope of deliveries expanded to include routine vaccines and essential medicines. Zipline launched operations in Ghana on April 24, 2019 under a government contract that provided drone delivery services to public-sector health facilities. The program later expanded to multiple distribution centers serving additional regions. Beginning in 2020, the company participated in regulatory programs, including the FAA type-certification process for delivery drones in the United States. It also deployed temperature-controlled payload systems to support delivery of vaccines requiring cold-chain conditions, including during COVID-19 vaccination campaigns in parts of Africa. From 2022 onward, Zipline initiated operations outside Africa, including a partner-operated distribution center in Japan and limited pilot projects in the United States. It also introduced a new platform aimed at home deliveries in denser urban and suburban environments.
==== Alkene and tetrazole photoclick reaction ==== The tetrazole-alkene "photoclick" reaction is another dipolar addition that Huisgen first introduced in the late 1960s (ChemBioChem 2007, 8, 1504. (68) Clovis, J. S.; Eckell, A.; Huisgen, R.; Sustmann, R. Chem. Ber. 1967, 100, 60). Tetrazoles with amino or styryl groups that may be activated by UV light at 365 nm react quickly, so that the UV light does not have to be on for a long time (usually approximately 1–4 minutes) to make fluorogenic pyrazoline products. This reaction scheme is well suited for the purpose of labeling in live cells, because UV light at 365 nm damages cells minimally. Quantum yields for short wavelength UV light may be higher than 0.5, allowing tetrazoles to be used selectively in combination with another photoligation reactions, where at the short wavelength the tetrazole ligation reaction proceeds nearly exclusively and at longer wavelength other reactions (e.g. ligation via o-quinodimethanes) proceeds preferably. Finally, the non-fluorogenic reactants give rise to a fluorogenic product, equipping the reaction with a built-in spectrometric handle. Both tetrazoles and the alkene groups have been incorporated as protein handles as unnatural amino acids, but this benefit is not unique. Instead, the photoinducibility of the reaction makes it a prime candidate for spatiotemporal specificity in living systems. Challenges include the presence of endogenous alkenes, although usually cis (as in fatty acids) they can still react with the activated tetrazole.
=== Opposition to COVID-19 vaccine requirements (2021) === In October 2021, the In-N-Out location in San Francisco was ordered closed by the San Francisco Department of Public Health (SFDPH), for failure to enforce the public health order requiring that all dine-in patrons of restaurants present proof that they are fully vaccinated for COVID-19. The location had posted signage warning of the mandate, but the SFDPH received complaints that it was not actually enforced. The company's chief legal officer Arnie Wensinger stated that the company "fiercely disagree[s] with any government dictate that forces a private company to discriminate against customers who choose to patronize their business". The location was allowed to re-open for takeout service only until it demonstrates "an adequate process and procedure for complying with the health order". Later that month, after an In-N-Out location in Contra Costa County was similarly ordered closed by public health for not complying with its vaccine mandate, all In-N-Out locations in the region closed their dining rooms and began operating with takeout service only. The locations attracted anti-mandate demonstrations in support of the company.
Sources: en.wikipedia.org
== SD == sd – (s) Sindhi language (ISO 639-1 code) SD (i) Secure Digital (memory card format) Sheriff's department Smoke/Decontamination (s) South Dakota (postal symbol) Sudan (ISO 3166 digram) SDC (i) Shaft Driven Compressor U.S. Army Strategic Defense Command (1985–1992) SDG – (s) Sudanese pound (ISO 4217 currency code) SDG – (i) Sum Dum Goy - greasy spoon chinese restaurant SDH – (i) Synchronous Digital Hierarchy SDHC – (i) Secure Digital High Capacity SDHL - (i/p) Svenska damhockeyligan (Swedish, "Swedish Women's Hockey League") SDI – see entry SDN – (s) Sudan (ISO 3166 trigram) SDO – (i) Scattered Disc Object SDP – (i) Social Democratic Party (European politics) SDR – (i) Strategic Defence Review SDRAM – (i) Synchronous Dynamic Random-Access Memory ("ess-dee-ram") SDS – (i) Students for a Democratic Society SDSS – (i) Sloan Digital Sky Survey SDXC – (p) Secure Digital eXtended Capacity
=== Buses === Wilmslow's main bus interchange is at Bank Square; it is served by D&G Bus, which provides services to Altrincham, Macclesfield, Manchester Airport and Handforth Dean. There is also a free bus service, between Knutsford and Handforth Dean retail park.
== See also == 2026 deaths in the US 2026 in American music 2026 in American television List of American films of 2026 List of animated feature films of 2026 2026 NFL season 2026–27 NHL season 2026–27 NBA season 2026 Major League Baseball season
Radioactive waste comes from a number of sources. In countries with nuclear power plants, nuclear armament, or nuclear fuel treatment plants, the majority of waste originates from the nuclear fuel cycle and nuclear weapons reprocessing. Other sources include medical and industrial wastes, as well as naturally occurring radioactive materials (NORM) that can be concentrated as a result of the processing or consumption of coal, oil, and gas, and some minerals, as discussed below.
Sources: en.wikipedia.org
Visualizing bacterial cell wall structures. Studying bacterial cell wall growth. Monitoring bacterial cell wall turnover. Quantifying bacterial cell wall growth activity. Assaying the anti-cell wall ability of antibiotics. Screening new anti-cell wall antibiotics. Tracking transpeptidase activity in vitro.
nj are the stoichiometric coefficients of the reactants in the equilibrium equation, and mj are the coefficients of the products. The value of δGr for these reactions is a function of the chemical potentials of all the species.
== Commercial release == "Valley Girl" was picked up by KROQ-FM, who obtained an acetate disc before release. Zappa praised the station's original programming but feared it would lead to others copying it, adding, "I would hate for it to become another service, freeze-dried to other stations." Moon was a regular KROQ listener and persuaded the station to play the track during an interview. There was an immediate response from the public, and the song began receiving regular airplay. The song was Zappa's only Top 40 single in North America, peaking at #32 on the U.S. Billboard Hot 100 chart and at #18 on the Canadian RPM Top Singles chart in September 1982, although he had charted hits in other parts of the world. The song was also included on the compilation album Strictly Commercial (1995). In the U.S. the B-side was "You Are What You Is", but in other territories it was "Teen-Age Prostitute." Promotional copies contained the album and single versions of the song.
=== t:slim X2 === The t:slim X2 is a rechargeable, touchscreen insulin pump with a 300-unit cartridge. It delivers programmed basal and bolus insulin through an infusion set and can receive software updates without replacement of the pump hardware. When used with a compatible CGM and Control-IQ technology, it can automatically adjust insulin delivery. The platform has supported integrations with Dexcom and FreeStyle Libre sensors in different markets. The t:slim line replaced Tandem's earlier t:flex and t:slim G4 models. The t:slim G4, approved in 2015, combined a Tandem pump with the Dexcom G4 Platinum CGM display.
=== As an androgen === DHEA and other adrenal androgens such as androstenedione, although relatively weak androgens, are responsible for the androgenic effects of adrenarche, such as early pubic and axillary hair growth, adult-type body odor, increased oiliness of hair and skin, and mild acne. DHEA is potentiated locally via conversion into testosterone and dihydrotestosterone (DHT) in the skin and hair follicles. Women with complete androgen insensitivity syndrome (CAIS), who have a non-functional androgen receptor (AR) and are immune to the androgenic effects of DHEA and other androgens, have absent or only sparse/scanty pubic and axillary hair and body hair in general, demonstrating the role of DHEA and other androgens in body hair development at both adrenarche and pubarche.
Sources: en.wikipedia.org
It binds to and activates PPAR delta, a nuclear receptor that controls expression of genes related to fatty acid oxidation. This mechanism can alter energy metabolism in animal models. It is not a direct stimulant or fat-burning enzyme.
Early-stage trials examined lipid and glucose markers, but the development program was discontinued. Published human results are limited and do not support approved use for any indication. Claims of performance or health benefits remain unproven.
Yes. Laboratories use LC-MS/MS to detect GW501516 and its metabolites in urine. Detection depends on timing and sensitivity, but the substance is banned at all times.
No. Major drug regulators have not approved GW501516 for treating any medical condition. Products sold as cardarine are typically unapproved research chemicals or supplements, so their contents and safety are not assured.