RÉSUMÉ
This paper describes the detections of nonsteroidal and steroidal selective androgen receptor modulators (SARMs), namely, RAD140 and YK-11, in mane hair collected from horses having been orally administered with the respective drugs. SARMs are potent anabolic agents with a high potential of misuse in horseracing and equestrian sports, and the misuses of RAD140 and YK-11 in human sports have been reported. To better control the misuse of RAD140 and YK-11 in horses, two separate oral administration studies of RAD140 (0.3 mg/kg daily for 3 days) and YK-11 (0.2 mg/kg daily for 3 days) were previously conducted to investigate their metabolism and to identify target analyte(s) with the longest detection time in urine and plasma for doping control. In this work, segmental analyses of post-administration hair samples have revealed that (i) RAD140 and YK-11 could be detected in horse mane after oral administration and (ii) internal incorporation of RAD140 into hair via bloodstream and external incorporation through sweat or sebum were both observed, whereas YK-11 was primarily incorporated into hair via sweat or sebum.
RÉSUMÉ
We have synthesized a series of binuclear rare-earth metal complexes bearing the newly designed enamino-oxazolinate ligands that feature bridging para-phenyl, meta-phenyl, 1,5-naphthalenyl, and 1,5-anthracenyl moieties. NMR and X-ray diffraction analyses confirmed the binuclear structures of the obtained complexes with two enamino-oxazolinate-metal units located at a trans position against the bridged aryl plane. After activation by [Ph3C][B(C6F5)4], all the rare-earth metal complexes served as efficient catalysts for isoprene polymerization, producing polymers with high cis-1,4 regularity (up to 96.1%) and high molecular weight. The steric and electronic effects exerted on the active metal centers, as well as the radius of metal centers, were the major contributing factors for determining both the catalytic activity and cis-1,4-selectivity of the binuclear catalytic systems. Compared to its mononuclear analogue, the binuclear yttrium catalytic system with a para-phenyl bridge exhibited a higher thermostability and catalytic efficiency during polymerization, revealing a special binuclear effect in this binuclear catalytic system.
RÉSUMÉ
Bisphosphonates and myo-inositol trispyrophosphate (ITPP) are two classes of difficult-to-detect polar drugs that are prohibited under the rules of racing. ITPP is a drug capable of increasing the amount of oxygen in hypoxic tissues, and studies have shown that administration of ITPP increases the maximal exercise capacity in mice. The properties of ITPP make it an ideal candidate as a doping agent to enhance performance in racehorses. In recent years, ITPP had indeed been detected in racehorses and confiscated items. As for bisphosphonates, it is especially critical to control their use as since February 2019, the International Agreement on Breeding, Racing and Wagering (IABRW) by the International Federation of Horseracing Authorities (IFHA) had identified specific conditions on which bisphosphonates should not be administered to a racehorse. A recent review of literature shows that there is yet a simultaneous screening method for detecting ITPP and bisphosphonates in equine samples. This paper describes an efficient ion chromatography high-resolution mass spectrometry (IC-HRMS) method for the simultaneous detection of ITPP and 10 bisphosphonates at sub-parts-per-billion (ppb) to low-ppb levels in equine plasma after solid-phase extraction (SPE) and its application to an administration study of clodronic acid in horses.
RÉSUMÉ
As one of the most important sources for green hydrogen, anion exchange membrane water electrolyzers (AEMWEs) have been developing rapidly in recent decades. Among these components, anion exchange membranes (AEMs) with high ionic conductivity and good stability play an important role in the performance of AEMWEs. In this study, we have developed a simple blending method to fabricate the blended membrane ImPSF-PEGx via the introduction of a hydrophilic PEG into the PSF-based ionic polymer. Given their hydrophilicity and coordination properties, the introduced PEGs are beneficial in assembling the ionic groups to form the ion-conducting channels. Moreover, an asymmetric structure is observed in ImPSF-PEGx membranes with a layer of finger-like cracks at the upper surface because PEGs can act as pore-forming agents. During the study, the ImPSF-PEGx membranes exhibited higher water uptake and ionic conductivity with lower swelling ratios and much better mechanical properties in comparison to the pristine ImPSF membrane. The ImPSF-PEG1000 membrane showed the best overall performance among the membranes with higher ionic conductivity (82.6 mS cm-1 at 80 °C), which was approximately two times higher than the conductivity of ImPSF, and demonstrated better mechanical and alkaline stability. The alkaline water electrolyzer assembled by ImPSF-PEG1000 achieved a current density of 606 mA cm-2 at 80 °C under conditions of 1 M KOH and 2.06 V, and maintained an essentially unchanged performance after 48 h running.
RÉSUMÉ
Gene doping involves the misuse of genetic materials to alter an athlete's performance, which is banned at all times in both human and equine sports. Quantitative polymerase chain reaction (qPCR) assays have been used to control the misuse of transgenes in equine sports. Our laboratory recently developed and implemented duplex as well as multiplex qPCR assays for transgenes detection. To further advance gene doping control, we have developed for the first time a sensitive and definitive PCR-liquid chromatography high-resolution tandem mass spectrometry (PCR-LC-HRMS/MS) method for transgene detection with an estimated limit of detection of below 100 copies/mL for the human erythropoietin (hEPO) transgene in equine plasma. The method involved magnetic-glass-particle-based extraction of DNA from equine plasma prior to PCR amplification with 2'-deoxyuridine 5'-triphosphate (dUTP) followed by treatments with uracil DNA glycosylase and hot piperidine for selective cleavage to give small oligonucleotide fragments. The resulting DNA fragments were then analyzed by LC-HRMS/MS. The applicability of this method has been demonstrated by the successful detection of hEPO transgene in a blood sample collected from a gelding (castrated male horse) that had been administered the transgene. This novel approach not only serves as a complementary method for transgene detection but also paves the way for developing a generic PCR-LC-HRMS/MS method for the detection of multiple transgenes.