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1.
The demand for transparent conductors is expected to grow rapidly as electronic devices, such as touch screens, displays, solid state lighting and photovoltaics become ubiquitous in our lives. Doped metal oxides, especially indium tin oxide, are the commonly used materials for transparent conductors. As there are some drawbacks to this class of materials, exploration of alternative materials has been conducted. There is an interest in films of carbon nanomaterials such as, carbon nanotubes and graphene as they exhibit outstanding properties. This article reviews the synthesis and assembly of these films and their post-treatment. These processes determine the film performance and understanding of this platform will be useful for future work to improve the film performance. 相似文献
2.
Ask Vest Christiansen Anders Schmidt Vinther Dimitris Liokaftos 《Drugs (Abingdon, England)》2017,24(3):295-305
Recent research into the use of anabolic androgenic steroids (AAS) in fitness and strength training environments have revealed great variance in users’ approach to AAS use and more specifically their approach to health risks and desired objectives. However, there have only been few attempts to develop theoretical frameworks directed at conceptualising the variance in AAS use. In this paper, we propose a unified framework in the form of a typology, which concerns men’s general approach to AAS use. The typology is based on sociologist Max Weber’s method on the ideal typology. The work comes out of the authors’ own qualitative empirical research on male AAS users in fitness and strength training environments, but is also related to and draws on the international literature on the subject. The suggested typology consists of four ideal types: the Expert type, the Well-being type, the YOLO type and the Athlete type. The four types are developed around two overarching categories, namely users’ approach to risk and effectiveness. The typology outlines distinct and characteristic approaches to AAS use and can, thus, be employed by researchers as well as health professionals as a heuristic tool for investigation and explanation. 相似文献
3.
Young Beom Kwak Jundong Yu Eo Jin Im Bok Son Jeong Hye Hyun Yoo 《Drug testing and analysis》2022,14(4):718-723
Cobalt is a substance that has been abused for athletic performance enhancement and has thus been prohibited by human and animal sports doping control authorities. However, because cobalt is present in humans and animals as a trace element, a certain level of cobalt is naturally present in their excretions. In the racing industry, cobalt is a controlled substance with a threshold concentration specified by the International Agreement on Breeding, Racing and Wagering (IABRW) for international harmonization. Due to environmental and feed consumption differences among countries, regional cobalt concentration trends should be evaluated before cobalt testing is introduced. In this study, we conducted a preliminary evaluation of the urinary concentration of cobalt among a population of racehorses in Korea using inductively coupled plasma mass spectrometry (ICP-MS) analysis, followed by analysis of the urinary release of cobalt after the administration of cobalt chloride in various situations. The normal distribution for the Korea-based racehorses was used to determine a urine concentration limit (96.5 ng/ml, risk factor of 1 in 10,000). After the intravenous (IV) administration of CoCl2, the initial elimination of cobalt was rapid. A high concentration (over 2,000 ng/ml) and a slow excretion pattern were observed during the final 2 weeks of the 3-week observation period. When CoCl2 was administered orally, maximum concentration (Cmax, 92–992 ng/ml) was observed at 6–8 h. 相似文献
4.
《Drug testing and analysis》2017,9(1):75-86
In the present work, aqueous normal‐phase liquid chromatography coupled to tandem mass spectrometry (LC‐MS/MS), in different acquisition modes, was employed for the direct analysis and profiling of nine phospholipid classes (phosphatidic acids, phosphatidylserines, phosphatidylethanolamines, lysophosphatidylethanolamines, phosphatidylglycerols, phosphatidylinositols, phosphatidylcholines, lysophosphatidylcholines, and sphingomyelins) in biological and pharmaceutical matrices. After chromatographic separation by a diol column, detection and elucidation of phospholipid and sphingomyelin classes and molecular species were performed by different scan acquisition modes. For screening analysis, molecular ions [M + H]+ were detected in positive precursor ion scan of m /z 184 for the classes of phosphatidylcholines, lyso‐phosphatidylcholines and sphingomyelins; while phosphatidylethanolamines and lyso‐phosphatidylethanolamines were detected monitoring neutral loss scan of 141 Da; and phosphatidylserines detected using neutral loss scan of 184 Da. Molecular ions [M‐H]‐ were instead acquired in negative precursor ion scan of m /z 153 for the classes of phosphatidic acids and phosphatidylglycerols; and of m /z 241 for the phosphatidylinositols. For the identification of the single molecular species, product ion scan mass spectra of the [M + HCOO]‐ ions for phosphatidylcholines and [M + H]+ ions for the other phospholipids considered were determined for each class and compared with the fragmentation pattern of model phospholipid reference standard. By this approach, nearly 100 phospholipids and sphingomyelins were detected and identified. The optimized method was then used to characterize the phospholipid and sphingomyelin profiles in human plasma and urine samples and in two phospholipid‐based pharmaceutical formulations, proving that it also allows to discriminate compounds of endogenous origin from those resulting from the intake of pharmaceutical products containing phospholipidic liposomes. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
5.
《Drug testing and analysis》2018,10(2):350-356
Consumption of Ephedra alkaloids is prohibited in‐competition by the World Anti‐Doping Agency (WADA). In Taiwan, colds are often treated with Chinese herbal formulae containing Herba Ephedrae. We screened products sold in Taiwan and preliminarily assessed their relationships with WADA threshold violations. Fifty‐six concentrated powder products, including 19 Chinese herbal formulae that contained Herba Ephedrae, were collected. The content of Ephedra alkaloids, namely ephedrine (E), methylephedrine (ME), norpseudoephedrine (NPE; cathine), pseudoephedrine (PE), and norephedrine (NE; phenylpropanolamine), was determined using a validated high‐performance liquid chromatography method. The results revealed that the phenotypic indicators of the collected products, E/PE and E/total ratios, were 1.52–4.70 and 0.49–0.72, respectively, indicating that the Herba Ephedrae species in these products was probably E. sinica or E. equisetina, but not E. intermedia. The contents of E, ME, NPE, PE, and NE and the total alkaloid contents in the daily doses of the products were 0.45–34.97, 0.05–4.87, 0.04–3.61, 0.15–12.09, and 0.01–2.00 mg and 0.68–53.64 mg, respectively. The alkaloid contents followed a relatively consistent order (E > PE > ME ≈ NPE > NE), even for products from different manufacturers. We calculated that single doses of 50.0% and 3.6% of the products would result in the WADA thresholds of E and NPE being exceeded, respectively. Our data provide critical information for athletes and medical personnel, who should be wary of using complex Chinese herbal formulae in addition to over‐the‐counter products. 相似文献
6.
《Drug testing and analysis》2018,10(3):460-473
The doping of greyhound dogs with testosterone is done in an attempt to improve their athletic performance, but such doping cannot easily be confirmed, especially in male dogs owing to the natural presence of endogenous testosterone. As testosterone is usually administered as its esters, their direct detection in hair would provide confirmatory evidence of the administration of a pharmaceutical product. This article demonstrates that the use of a liquid chromatography–high resolution mass spectrometry method with heated electrospray ionisation (HESI) combined with the use of amino solid‐phase extraction (SPE) cartridges for sample clean‐up, is suitable for the sensitive determination of propionate, phenyl propionate, isocaproate, decanoate, and enanthate esters of testosterone in greyhound hair. The method is linear over the range, 0.1 μg/kg–10 μg/kg, for all the testosterone esters analysed. The limits of detection (LOD) are 0.05 μg/kg for testosterone phenyl propionate, isocaproate, and decanoate, 0.025 μg/kg for testosterone propionate, and 0.25 μg/kg for testosterone enanthate. This method was applied to hair samples collected from male greyhounds before and after a single administration of a product containing several testosterone esters, each of which could be detected up to 100 days post‐administration. The study also demonstrates that tail hair is the specimen of choice for the analysis of testosterone in dog hair and that washing of dogs does not impact the analysis of testosterone esters in hair. This method may be useful in racing regulation for the detection of illegitimate use of testosterone in all species. 相似文献
7.
《Drug testing and analysis》2017,9(7):1093-1097
The concentration of hepcidin, a key regulator of iron metabolism, is suppressed during periods of increased erythropoietic activity. The present study obtained blood samples from 109 elite athletes and examined the correlations between hepcidin and markers of erythropoiesis and iron metabolism (i.e., haemoglobin, erythropoietin (EPO), ferritin, erythroferrone (ERFE), and iron concentration). Furthermore, an administration study was undertaken to examine the effect of recombinant human EPO (rhEPO) delta (Dynepo™) on hepcidin concentrations in healthy male volunteers. The effects on hepcidin were then compared with those on reticulocyte percentage (Ret%) and ferritin concentration. There was a significant positive correlation between hepcidin and ferritin, iron, and haemoglobin levels in athletes, whereas hepcidin showed an inverse correlation with ERFE. Administration of rhEPO delta reduced hepcidin levels, suggesting that monitoring hepcidin may increase the sensitivity of the Athlete Biological Passport (ABP) for detecting rhEPO abuse. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
8.
9.
《Drug testing and analysis》2017,9(4):545-552
Sport supplements containing steroids never approved for therapeutic use have the potential for abuse by athletes. Most are marketed online and may contain undisclosed steroids yet are readily available despite lacking toxicological or pharmacological evaluation. In this study, 18 supplements purchased online underwent organic solvent extraction to isolate any steroids they contained. From the 18 supplements, 19 steroids were identified and for each, its intrinsic androgenic potency was determined by a yeast cell (Saccharomyces cerevisiae ) androgen bioassay and its potential androgenic potency was determined by a liver (HuH7) cell androgen bioassay. The yeast bioassay showed that of the 19 steroids tested, 6 demonstrated strong intrinsic bioactivity, with 4 metabolically activated to even stronger androgens. Moreover, 4 steroids with moderate and 1 with intrinsically weak androgenic bioactivity were activated to more potent androgens. Finally, 8 steroids were metabolically inactivated or deactivated into weaker androgens. Our results show that Internet‐sourced sport supplements may contain intrinsically strong androgens, or precursors that can be metabolized to them. These potentially potent pharmacologically active steroids are being used without regulatory control or consumer awareness of their potential adverse effects. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
10.
Background: The sanction that an athlete receives when an anti-doping rule violation has been committed depends on the specific circumstances of the case. Anti-doping tribunals decide on the final sanction, following the rules of the World Anti-Doping Code. Objectives: To assess the athletes’ degree of fault based on the length of sanctions imposed on them to feed policy-related discussions. Methods: Analysing data from the results management database of the World Anti-Doping Agency for anonymous information of anti-doping rule violations in eight selected sports covering the years 2010-2012. Results: Four out of ten athletes who committed an anti-doping rule violation received a suspension that was lower than the standard. This is an indication that tribunals in many instances are not convinced that the athletes concerned were completely at fault, that mitigating circumstances were applicable, or that full responsibility of the suspected violation should not be held against them. Anabolic agents, peptide hormones, and hormone modulators lead to higher sanctions, as do combinations of several anti-doping rule violations. Conclusions: This first analysis of information from the World Anti-Doping Agency's results management database indicates that a large proportion of the athletes who commit anti-doping rule violations may have done this unintentionally. Anti-doping professionals should strive to improve this situation in various ways. 相似文献