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Probing the redox process of p-benzoquinone in dimethyl sulphoxide by using fluorescence spectroelectrochemistry

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Frontiers of Environmental Science & Engineering 2017年第1期11卷 137-143页

作者： Rui Lu Wei Chen wen-Wei Li guo-Ping Sheng Lian-jun Wang Han-Qing Yu Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological Engineering Nanjing University of Science and Technology Nanjing 210094 China CAS Key Laboratory of Urban Pollutant Conversion Department of Chemistry University of Science and Technology of China Hefei 230026 China

Quinones are common organic compounds frequently used as model dissolved organic matters in water, and their redox properties are usually characterized by either electrochemical or spectroscopic methods separately. In this work, electrochemical methodology was combined with two fluorescence spectroelectrochemical techniques, cyclic voltafluorescence spectrometry （CVF） and derivative cyclic voltafluorescence spectrometry （DCVF）, to determine the electrochemical properties of p-benzoQuinone in dimethvl sulfoxide, an aprotic solution. The CVF results show that the electrochemical reduction ofp-benzoquinone resulted in the formation of radical anion and dianion, which exhibited a lower fluorescence intensity and red-shift of the emission spectra compared to that of p-benzoauinone. The fluorescence intensity was found to vary along with the electrochemical oxidation and reduction ofp-benzoquinone. The CVF and DCVF results were in good consistence. Thus, the combined method offers a powerful tool to investigate the electrochemical process of p-benzoquinone and other natural organic compounds.

关键词： p-Benzoquinone Electrochemistry Fluorescence Spectroelectrochemistry Derivative cyclic volta fluorescence

Responses of the antioxidant system to fluroxypyr in foxtail millet (Setaria italica L.) at the seedling stage

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Journal of Integrative Agriculture 2018年第3期17卷 554-565页

作者： guo Mei-jun WANG Yu-guo YUAN Xiang-yang DONG Shu-qi wen Yin-yuan SONG Xi-e guo Ping-yi Key Laboratory of Crop Chemical Regulation and Chemical Weed Control of Shanxi Province/Agronomy College Shanxi Agricultural University

Foxtail millet （Setaria italica L.） is an important food and fodder crop in semi-arid areas. However, there are few herbicides suitable for use on weed control in field-grown foxtail millet during the post-emergence herbicides stage. The present study was conducted using four concentrations （0.5, 1, 2, and 4 L ai ha-1） of foliar-applied fluroxypyr, and the effect of fluroxypyr on selected metabolic and stress-related parameters in foxtail millet were assessed after 15 days. In this study, increasing concentrations decreased plant height and accumulation of chlorophylls. Our results also showed that malondialdehyde （MDA） accumulated in response to fluroxypyr application, demonstrating increased lipid peroxidation due to excessive reactive oxygen species production. In response to this oxidative stress, the activities of antioxidant enzymes were generally enhanced. Non-enzymatic antioxidant defense systems, which function in concert with antioxidant enzymes, can also protect plant cells from oxidative damage by scavenging reactive oxygen species （ROS）. In conclusion, the hybrid variety （Zhangzagu） exhibited a greater tolerance to fluroxypyr than did the conventional variety Jingu 21, which might be associated with the antioxidant mechanisms of Zhangzagu hybrid millet.

关键词： antioxidant defense system fluroxypyr reactive oxygen species Spring hybrid millet

Improving dehydrogenation properties of Mg/Nb composite films via tuning Nb distributions

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Rare Metals 2017年第7期36卷 574-580页

作者： wen-Cheng Huang jun Yuan Jin-guo Zhang Jiang-wen Liu Hui Wang Liu-Zhang Ouyang Mei-Qin Zeng Min Zhu Key Laboratory of Advanced Energy Storage Materials of Guangdong Province School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510640China

t To investigate the effect of Nb on the dehydro- genation properties of Mg-Nb composite films, Mg/Nb eight- layer film and Mg- 10 at% Nb alloy film with the similar Mg- to-Nb atomic ratio were prepared by magnetron sputtering. Results show that both Mg/Nb eight-layer film and Mg- 10 at% Nb alloy film exhibit excellent de/hydrogenation properties. Mg- 10 at% Nb alloy film starts to release hydrogen at 108 ℃, and its desorption peak temperature is lower to 146 ℃, which is much better than that of pure MgH2 under the same condi- tion. Scanning electron microscopy （SEM） results demon- strate that the dispersive Nb nanoparticles in Mg/Nb eight- layer film may serve as nucleation sites for Mg ←→ MgH2 reactions, which can provide channels for H diffusion. For Mg- 10 at% Nb alloy film, the uniform distributions of Nb can accelerate the hydrogen diffusion and effectively improve the dehydrogenation kinetics for MgH2. This study provides an enlightening way for designing and preparing Mg-based composite films with excellent dehydrogenation properties.

关键词： Hydrogen storage Mg-Nb Sputtering Thinfilm Kinetics

Molecular cloning and characterization of a putative proline dehydrogenase gene in the Colorado potato beetle, Leptinotarsa decemlineata

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Insect Science 2014年第2期21卷 147-158页

作者： Pin-jun Wan Dong Lu wen-Chao guo Tursun Ahmat Lu Yang Li-Li Mu guo-Qing Li Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests College of Plant Protection Nanjing Agricultural University Nanjing Department of Plant Protection Xinjiang Academy of Agricultural Sciences Urumqi China

Leptinotarsa decemlineata adults exhibit a season-dependent activity. In spring, post-diapause beetles often fly a long distance from overwintering sites to potato fields. In summer and autumn, the flight ability is sharply reduced. Proline is the main energy substrate ofL. decemlineata during flight and proline dehydrogenase （ProDH） catalyzes the first step in proline catabolism. Here we identified a putative LdProDHgene; it had three cDNA isoforms which shared the same 5＇UTR and coding region, but differed in the lengths of 3＇UTRs （515, 1 092 and 1 242 bp for isoforms-1, -2 and -3, respectively）. LdProDH encoded a 616 amino acid protein that showed high sequence similarity to ProDH-like proteins from other insect species. LdProDHwas expressed in the third and fourth instars larvae and adults, but not in pupae. Dietary ingestion of bacterially expressed LdProDH- dsRNA by adults significantly decreased its messenger RNA （mRNA） level, and caused an elevation of free proline content in the hemolymph. Further observation revealed that three canonical polyadenylation signals （AATAAA） were tandemly located in the 3＇UTR of isoform-3. The first, second and third polyadenylation sites gave rise to isoforms-1, -2 and -3, respectively. Analysis of the genomic DNA uncovered that the three isoforms resulted from alternative polyadenylation. The mRNA level of isoform-1, which expressed at low levels in pre-diapause adults, became abundant in post-diapause beetles. It is indicated that the LdProDH expression is fine-tuned through 3＇UTR to control proline catabolism for the season-dependent activity ofL. decemlineata adults.

关键词： alternative polyadenylation isoform RNA interference temporal expres-sion 3~UTR

Characterization of the chemosensory protein EforCSP3 and its potential involvement in host location by Encarsia formosa

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Journal of Integrative Agriculture 2023年第2期22卷 514-525页

作者： WANG Ke HE Yan-yan ZHANG You-jun guo Zhao-jiang XIE wen WU Qing-jun WANG Shao-li Institute of Vegetables and Flowers Chinese Academy of Agricultural SciencesBeijing 100081P.R.China

Chemosensory proteins(CSPs) perform several functions in *** study performed the gene expression,ligand-binding,and molecular docking assays on the EforCSP3 identified in the parasitoid wasp Encarsia formosa,to determine whether EforCSP3 functions in olfaction,especially in host location and host *** results showed that EforCSP3 was highly expressed in the female head,and its relative expression was much higher in adults than in other developmental *** fluorescence binding assays suggested that the EforCSP3 exhibited high binding affinities to a wide range of host-related volatiles,among which dibutyl phthalate,1-octene,β-elemene,and tridecane had the strongest binding affinity with EforCSP3,besides α-humulene and β-myrcene,and should be assessed as potential *** structure modeling and molecular docking predicted the amino acid residues of EforCSP3possibly involved in volatile binding.α-Humulene and β-myrcene attracted *** in a previous study and exhibited strong binding affinities with EforCSP3 in the current *** conclusion,EforCSP3 may be involved in semiochemical reception by ***.

关键词： Encarsia formosa chemosensory protein expression profiles fluorescence binding assay molecular docking

Selection of PCEs' location in multi-domain optical networks

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The Journal of China Universities of Posts and Telecommunications 2013年第6期20卷 62-68页

作者： XIE wen-jun HUANG Shan-guo ZHAO Yong-li LIU Xin GU Wan-yi State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Huawei Technologies Co. Ltd

Path computation elements （PCEs） are employed to compute end-to-end paths across multi-domain optical networks due to the advantages of powerful computation capability. However, PCEs＇ location selection is still an open problem which is closely related to the communication overhead. This paper mainly focuses on the problem of PCEs＇ location selection to minimize the overall communication overhead in the control plane. The problem is formulated as a quadratic integer programming （QIP） model, and an optimal decision rule is gained from the solution of the QIP model. Then based on the decision rule, a distributed heuristic algorithm is proposed for dynamic network scenario. Simulation results demonstrate the benefit and the effectiveness of our proposed approach by comparing it with random selection policy.

关键词： multi-domain optical networks path computation element PCE location selection QIP model

Flow of Steel in Mold Region During Continuous Casting

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Journal of Iron and Steel Research International 2007年第2期14卷 30-35,41页

作者： ZHANG Xing-guo ZHANG wen-xiao JIN jun-ze J. W. Evans Research Center of Foundry Engineering Dalian University of Technology Dalian 116023 Liaoning China Department of Material Science and Engineering University of California at Berkeley Berkeley CA94720 USA

The particle image velocimetry （PIV） technique was used to study the fluid flow phenomena that occurred during continuous casting, using a water model with dimensions of 1 840mm× 280 mm. Two types of solidified shells, i. e. , the smooth type and the coarse type, were used to characterize the dendrite in order to simulate different liquid-solid interfacial conditions. The influence of the nozzle angle and the immersion depth of nozzle, as well as the casting speed on the flow behavior was investigated quantitatively. The results were as follows：（1） There are two large recirculations above and below the fluid jet in the mold, respectively, under the smooth interface condition. However, in the case of the dendrite solidified shell, it was found that the flow velocity of the fluid decreased and more smaller vortices appeared in the upper region of the mold. （2） The angle and the immersion depth of nozzle are two important factors affecting the flow pattern, and they are also capable of bringing about the change in the flow direction. （3） The higher the casting speed, the higher are the jet stream and the impacting point on the narrow face. However, the high casting speed causes serious fluctuation of the meniscus, and correspondingly leads to various defects.

关键词： particle image velocimetry continuous casting steel fluid flow

Achievable rate region for the multiple-access channel with multiple cognitive transmitters

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The Journal of China Universities of Posts and Telecommunications 2013年第3期20卷 20-25,24-25页

作者： guo Yu-chen NIU Kai XU wen-jun HE Zhi-qiang LIN Jia-ru Key Lab of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications

A scenario where one ＇dumb＇ radio and multiple cognitive radios communicating simultaneously with a common receiver is considered. In this paper, we derive an achievable rate region of the multiple-user cognitive multiple-access channel （MUCMAC） under both additive white Gaussian noise （AWGN） channel and rayleigh fading channel, by using a combination of multiple user dirty paper coding （DPC） and superposition coding. Through cognition, it is assumed that the secondary users （SUs） are able to obtain the message of the primary user （PU） non-causally beforehand. Using this side information, the SUs can perform multiple user DPC to avoid the interference from the SU. Besides, the SUs can also allocate part of their transmit power to aid the PU, using superposition coding. Therefore, the capacity region of traditional multiple-access channel （MAC） can be enlarged. Moreover, some asymptotic results are shown as the number of SUs increases. In the AWGN case, it is illustrated that the maximum achievable rate of the PU grows logarithmically with the increase of the number of SUs, whereas in the Rayleigh case, we show that the cognitive gain will increase with the decreasing of the channel signal to noise ratio （SNR）.

关键词： cognitive radios MAC superposition coding DPC

In depth understanding of retinitis pigmentosa pathogenesis through optical coherence tomography angiography analysis:a narrative review

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International Journal of Ophthalmology(English edition) 2021年第12期14卷 1979-1985页

作者： Bing-wen Lu guo-jun Chao Gai-Ping Wu Li-Ke Xie Department of Ophthalmology Ophthalmology Hospital of China Academy of Traditional Chinese MedicineBeijing 100040China

Retinitis pigmentosa(RP)is the most recognized inherited retinal disorder involving progressive photoreceptors degeneration which eventually causes ***,the pathogenesis of RP is still unclear,making it difficult to establish satisfying *** have been found to support the theory that vascular dysfunction is associated with the progression of *** coherence tomography angiography(OCTA)is a newly developed technology that enables visualization as well as quantitative assessment of retinal and choroidal vasculature *** in OCTA have opened a window for indepth understanding of RP ***,we propose a hypothesis of RP pathogenesis based on the current OCTA findings in RP,which includes four stages and two important key factors,vascular dysfunction and microglia ***,we discuss the future animal experiments needed and how advanced OCTA technology can help to further verity the *** final goal is to explore potential treatment options with enhanced understanding of RP pathogenesis.

关键词： retinitis pigmentosa optical coherence tomography angiography vascular dysfunction microglia activation