Oxidative Stress and Non-enzymatic Antioxidants in Leaves of Three Edible Canna Cultivars under Drought Stress

Wene Zhang,Zhiguo Tian,Xuejun Pan,Xiuming Zhao,Fei Wang 한국원예학회 2013 Horticulture, Environment, and Biotechnology Vol.54 No.1

The physiological responses of three edible canna cultivars (Canna edulis ker. cv. ‘PLRF’, ‘Xingyu-1’, and ‘Xingyu-2’) to continuous drought stress for 35 days were investigated by characterizing the water saturation deficit (WSD), relative electrical conductivity (REC), superoxidative radical content (SRC), ascorbic acid (AsA) content,glutathione (GSH) content and protein content. It was observed that WSD, REC, SRC progressively increased in the upper leaves of three cultivars under both control and drought treatments. The content changes of AsA, GSH and water soluble protein were lower in ‘Xingyu-2’ than in ‘Xingyu-1’ and ‘PLRF’, in upper leaves than in lower leaves. Compared with control, drought stress aggravated these physiological changes in all three cultivars. The correlation analysis showed that there were significant correlations between indexes except for protein content, which significantly correlated only with SRC. These indicated that drought stress directly led to water loss, and then the REC increased, while the GSH and AsA played major roles in removing the SRC. These results revealed that ‘Xingyu-2’ was more tolerant to drought stress than ‘PLRF’ and ‘Xingyu-1’,and the lower leaves were more sensitive than the upper leaves. The present study not only provides new insights into mechanisms of acclimation and tolerance to drought stress in edible canna but also provides clues for improving drought tolerance of edible canna through breeding or genetic engineering.

The Development of Clinical Document Standards for Semantic Interoperability in China

Peng Yang,Feng Pan,Danhong Liu,Yongyong Xu,Yi Wan,Haibo Tu,Xuejun Tang,Jianping Hu 대한의료정보학회 2011 Healthcare Informatics Research Vol.17 No.4

Objectives: This study is aimed at developing a set of data groups (DGs) to be employed as reusable building blocks for the construction of the eight most common clinical documents used in China’s general hospitals in order to achieve their structural and semantic standardization. Methods: The Diagnostics knowledge framework, the related approaches taken from the Health Level Seven (HL7), the Integrating the Healthcare Enterprise (IHE), and the Healthcare Information Technology Standards Panel (HITSP) and 1,487 original clinical records were considered together to form the DG architecture and data sets. The internal structure, content, and semantics of each DG were then defined by mapping each DG data set to a corresponding Clinical Document Architecture data element and matching each DG data set to the metadata in the Chinese National Health Data Dictionary. By using the DGs as reusable building blocks, standardized structures and semantics regarding the clinical documents for semantic interoperability were able to be constructed. Results: Altogether, 5 header DGs, 48 section DGs, and 17 entry DGs were developed. Several issues regarding the DGs, including their internal structure, identifiers,data set names, definitions, length and format, data types, and value sets, were further defined. Standardized structures and semantics regarding the eight clinical documents were structured by the DGs. Conclusions: This approach of constructing clinical document standards using DGs is a feasible standard-driven solution useful in preparing documents possessing semantic interoperability among the disparate information systems in China. These standards need to be validated and refined through further study.

IGCT Self-Protection Strategy for IGCT Converters

Hong Zeng,Xiulin Chen,Yongmin Chen,Xuejun Pan,Shunbiao Zhang,Fanglin Chen,Wenbin Zeng 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

The high-power semiconductor IGCT is widely used in two-level or three-level IGCT converters and for these converters a comprehensive system-protection strategy may be used to protect the IGCT. But there are still some problems resulted from signal transmission delays, such as incorrect timing, low response speeds, second breakdown and those problems can result in IGCT overload failure, bridge-arm shoot-through and other consequences. In this paper, the anode voltage and current parameters gained from the IGCT device are studied as protection reference in a new GCT gate drive unit. The gate drive unit can control and process the signal logic, and execute safe and reliable switching action. The signal is simultaneously feed back to the host computer in IGCT converters to perform the switching control of other devices. This new gate unit can effectively reduce device failure rates and improve the reliability of IGCT converters systems, while reducing operating costs.

Spatiotemporal Variations and Possible Sources of Ambient PM10 from 2003 to 2012 in Luzhou, China

Dong Ren,Youping Li,Hong Zhou,Xiaoxia Yang,Xiaoman Li,Xuejun Pan,Bin Huang 대한환경공학회 2014 Environmental Engineering Research Vol.19 No.4

Descriptive statistics methods were used to study the spatiotemporal variations and sources of ambient particulate matter (PM10) in Luzhou, China. The analyzed datasets were collected from four national air quality monitoring stations: Jiushi (S1), Xiaoshi (S2), Zhongshan (S3), Lantian (S4) over the period of 2003-2012. This city was subjected serious PM10 pollution, and the long-term annual average PM10 concentrations varied from 76 to 136 μg/m3. The maximum concentration was more than 3-fold of the annual average (40 μg/m3) issued by EPA-China for the ambient air quality. General temporal pattern was characterized by high concentrations in winter and low concentrations in summer, and general spatial gradient was in the reduction order of S2 > S4 > S3 > S1, which were both due to different particulate contributors and special meteorological conditions. The source apportionment indicated that vehicular emissions, road dusts, coal burning and chemical dusts were the major contributors of the identified PM10 pollution, and the vehicular emissions and the road wear re-suspended particles dominated the heavy PM10 pollution in recent years. Two other potential sources, agricultural and celebration activities could decrease the air quality in a short term. Finally, some corresponding suggestions and measures were provided to improve the air quality.

Photodegradation of 17α-ethynylestradiol in nitrate aqueous solutions

Dong Ren,Tingting Bi,Shumei Gao,Xukun Li,Bin Huang,Xuejun Pan 대한환경공학회 2016 Environmental Engineering Research Vol.21 No.2

17α-Ethynylestradiol (Ee₂) has gotten growing concerns due to its widely detected in the environment and high estrogenic potency. However, the knowledge on the photochemical behaviors of Ee₂ in natural waters is still limited. Herein, the photodegradation and estrogenic potency variation of Ee₂ induced by nitrate were studied using a sunlight simulator consisted by a 300 W medium pressure mercury lamp and 290 nm cut-off filters. It was found that Ee₂ could be photodegraded at a rate of 0.0193 h-1 in pure aqueous solutions, and the photodegradation of Ee₂ could be significantly promoted by nitrate. The photodegradation removal rate of Ee₂ was increased from 9% in Milli-Q water to 85% in 2.0 mM nitrate solutions. Reactive species scavenging experiments demonstrated that the photogenerated HO? contributed about 55% to Ee₂ degradation. Fe(III), Cl- and dissolved humic acid (DHA) could inhibit the photodegradation of Ee₂ by competing the incident light and photogenerated HO?, while HCO₃ - had no influence on Ee₂ photodegradation. Ee₂ was determined to be phototransformed into organic chemicals without estrogenic potency by GC-MS and MCF-7 cell proliferation toxicity tests. These findings could extend our knowledge on the photochemical behaviors of steroid estrogens and provide information for ecological risk assessment.