http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Protective effect of resveratrol on arsenic trioxide-induced nephrotoxicity in rats
Weiqian Zhang,Yan Liu,Ming Ge,Jiang Jing,Yan Chen,Huijie Jiang,Hongxiang Yu,Ning Li,Zhigang Zhang 한국영양학회 2014 Nutrition Research and Practice Vol.8 No.2
BACKGROUND/OBJECTIVES: Arsenic, which causes human carcinogenicity, is ubiquitous in the environment. This study was designed to evaluate modulation of arsenic induced cancer by resveratrol, a phytoalexin found in vegetal dietary sources that has antioxidant and chemopreventive properties, in arsenic trioxide (As₂O₃)-induced Male Wistar rats. MATERIALS/METHODS: Adult rats received 3 mg/kg As₂O3 (intravenous injection, iv.) on alternate days for 4 days. Resveratrol(8 mg/kg) was administered (iv.) 1 h before As₂O₃ treatment. The plasma and homogenization enzymes associated with oxidative stress of rat kidneys were measured, the kidneys were examined histologically and trace element contents were assessed. RESULTS: Rats treated with As₂O₃ had significantly higher oxidative stress and kidney arsenic accumulation; however, pretreatment with resveratrol reversed these changes. In addition, prior to treatment with resveratrol resulted in lower blood urea nitrogen, creatinine and insignificant renal tubular epithelial cell necrosis. Furthermore, the presence of resveratrol preserved the selenium content (0.805 ± 0.059 μg/g) of kidneys in rats treated with As₂O₃. However, resveratrol had no effect on zinc level in the kidney relative to As₂O₃-treated groups. CONCLUSIONS: Our data show that supplementation with resveratrol alleviated nephrotoxicity by improving antioxidant capacity and arsenic efflux. These findings suggest that resveratrol has the potential to protect against kidney damage in populations exposed to arsenic.
Xiaona Wang,Haiyuan Zhao,Yilan Shao,Pei Wang,Yanru Wei,Weiqian Zhang,Jing Jiang,Yan Chen,Zhigang Zhang 한국영양학회 2014 Nutrition Research and Practice Vol.8 No.1
Inorganic arsenic (iAs) is a toxic metalloid found ubiquitously in the environment. In humans, exposure to iAs can result in toxicity and cause toxicological manifestations. Arsenic trioxide (As2O3) has been used in the treatment for acute promyelocytic leukemia. The kidney is the critical target organ of trivalent inorganic As (iAs<SUP>Ⅲ</SUP>) toxicity. We examine if oral administration of astaxanthin (AST) has protective effects on nephrotoxicity and oxidative stress induced by As2O3 exposure (via intraperitoneal injection) in rats. Markers of renal function, histopathological changes, Na<SUP>+</SUP>-K<SUP>+</SUP> ATPase, sulfydryl, oxidative stress, and As accumulation in kidneys were evaluated as indicators of As2O3 exposure. AST showed a significant protective effect against As2O3-induced nephrotoxicity. These results suggest that the mechanisms of action, by which AST reduces nephrotoxicity, may include antioxidant protection against oxidative injury and reduction of As accumulation. These findings might be of therapeutic benefit in humans or animals suffering from exposure to iAs<SUP>Ⅲ</SUP> from natural sources or cancer therapy.
New ZVZCT Bidirectional DC-DC Converter Using Coupled Inductors
Wei Qian,Xi Zhang,Zhe Liu,Wenqiang Jin,Jochen Wiedemann 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1
In this study, a novel zero voltage zero current transition (ZVZCT) bidirectional DC-DC converter is proposed by employingcoupled inductors. This converter can turn the main switch on at ZVZCT and it can turn it off with zero voltage switching (ZVS)for both the boost and buck modes. These characteristics are obtained by using a simple auxiliary sub-circuit regardless of thepower flow direction. In the boost mode, the auxiliary switch achieves zero current switching (ZCS) turn-on and ZVS turn off. Due to the coupling inductors, this converter can make further efficiency improvements because the resonant energy in thecapacitor or inductor can be transferred to the load. The main diode operates with ZVT turn-on and ZCS turn-off in the boostmode. For the buck mode, there is a releasing circuit to conduct the currents generated by the magnetic flux leakage to the output. The auxiliary switch turns on with ZCS and it turns off with ZVT. The main diode also turns on with ZVT and turns off withZCS. The design method and operation principles of the converter are discussed. A 500 W experimental prototype has been builtand verified by experimental results.