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Development of a novel conductance-based technology for environmental bacterial sensing

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Chinese Science Bulletin 2013年第4期58卷 440-448页

作者： SHEN FangXia TAN MiaoMiao xu Hong xu zhencheng YAO MaoSheng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University College of Mechanical and Electrical Engineering Beijing Union University Department of Reproductive Health Guangdong Women and Children Hospital South China Institute of Environmental Science Ministry of Environmental Protection

In this study, a simple impedance based technology for measuring bacterial concentrations was developed. The measurement system includes the signal amplification, copper probes and a sample loader. During the experiments, the conductance of Bacillus subtilis var niger, Pseudomonas fluorescens, and Escherichia coli were measured using the combination of a pre-amplifier and a lock-in amplifier. The conductance data were modeled verses the bacterial concentrations. Results indicated that the relationship between the conductance of bacterial suspensions and their concentrations follows a generic model: Y=C1+C2×e ( X/C3 ) , where Y is the conductance (S), X is the bacterial concentration (Number/mL: abbreviated to N/mL) for all species tested, and C1 3 are constants. Gram negative P. fluorescens and E. coli assumed similar conductance curves, which were flatter than that of gram positive B. subtilis var niger. For P. fluorescens and E. coli the culturing technique resulted in higher concentration levels (statistically significant) from 2 to 4 times that measured by the impedance based technology. For B. subtilis var niger, both methods resulted in similar concentration levels. These differences might be due to membrane types, initial culturability and the obtained conductance curves. The impedance based technology here was shown to obtain the bacterial concentration instantly, holding broad promise in realtime monitoring biological agents.

关键词：技术开发细菌检测电导数基础 Bacillus 细菌浓度阻抗测量环境

Development of Disposable Amperometric Cholesterol Biosensor

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稀有金属材料与工程 2006年第A3期35卷 321-323页

作者： Xiaohao Wang Fei Tang Xiaowen xu zhencheng Chen State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua University Beijing 100084 China

A novel disposable cholesterol biosensor based on electrochemical process is developed adopting screen printing *** system consists of a graphite reference electrode and a working *** mixture of cholesterol oxidase and K_4Fe (CN)_6 is printed on the *** biosensor determines total cholesterol content through indirect determination of free cholesterol in the whole human *** 0.3V voltage is applied to the electrodes,the range of detection is from 250 mg/L to 2000 mg/L,with the correlation coefficient of *** total detective duration is less than 200s,and the sample volume is only 4μL.

关键词： cholesterol biosensor carbon electrode screen printing

TaMYB72 directly activates the expression of TaFT to promote heading and enhance grain yield traits in wheat(Triticum aestivum L.)

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Journal of Integrative Plant Biology 2024年第7期66卷 1266-1269页

作者： Lifen Wu zhencheng Xie Danping Li Yaoyu Chen Chuan Xia Xiuying Kong xu Liu Lichao Zhang State Key Laboratory of Crop Gene Resources and Breeding Institute of Crop Sciencesthe Chinese Academy of Agricultural SciencesBeijing 100081China State Key Laboratory of North China Crop Improvement and Regulation Hebei Sub‐Center for National Maize Improvement CenterCollege of AgronomyHebei Agricultural UniversityBaoding 071001China

Wheat(Triticum aestivum L.)is a staple food for approximately half the global *** the population continues to grow,the demand for high-yielding varieties is increasing(Zorb et al.,2018).Higher yields can be achieved by increasing the number and weight of grains produced and by optimizing heading dates to maximize production in local environments(Sakuma and Schnurbusch,2020).

关键词： heading Wheat yielding

Distribution of polybrominated diphenyl ethers and decabromodiphenylethane in surface sediments from Fuhe River and Baiyangdian Lake,North China

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Journal of Environmental Sciences 2010年第12期22卷 1833-1839页

作者： Guocheng Hu zhencheng xu Jiayin Dai Bixian Mai Hong Cao Jianshe Wang Zhimin Shi Muqi xu Metropolitan Environment Center South China Institute of Environmental Sciences Ministry of Environmental Protection Guangzhou 510655 China Key Laboratory of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China State Key Laboratory of Organic Chemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

Nineteen surface sediment samples collected from Baiyangdian Lake and its inflowing river （Fuhe River） in North China were analyzed for polybrominated diphenyl ethers （PBDEs） and decabromodiphenylethane （DBDPE）. The concentrations of PBDEs and DBDPE in sediments ranged from 5.5 to 300.7 ng/g dry weight （dw） and 1.1 to 68.2 ng/g dw, respectively. Their levels in sediments in Fuhe River were significantly higher than those in Balyandian Lake. Compared to data from other regions, the PBDE levels in surface sediments from Baiyangdian Lake and Fuhe River were in the medium to lower range. Among the PBDE congeners, BDE209 was predominant, with contributions to the total PBDEs ranging from 79.4% to 97.3% in sediment samples. For the lowly brominated congeners （tri- to hepta-BDE）, BDE47 and BDE99 were the most abundant, which contributed 52.1% and 44.1% to the sum of tri- to hepta-BDEs in the sediments from Baiyangdian Lake and Fuhe River, respectively. The compositional patterns of PBDEs in Baiyangdian Lake sediments indicated that technical deca-BDE mixture was the major pollutant sources with a minor contribution of penta-BDE mixture. The present study suggested that the importance of Fuhe River as a possibly potential sources of PBDEs contamination in Baiyangdian Lake.

关键词： polybrominated diphenyl ethers decabromodiphenylethane contamination profile Baiyangdian Lake Fuhe River

Effect of chemical composition of PM_(2.5) on visibility in Guangzhou,China,2007 spring

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Particuology 2009年第1期7卷 68-75页

作者： Jun Tao Kin-Fai Ho Laiguo Chen Lihua Zhu Jinglei Han zhencheng xu South China Institute of Environmental Sciences SEPA Guangzhou 510655 China The Hong Kong Polytechnic University Hong Kong China

The object of this study was to investigate the correlation of visibility with chemical composition of PM2.5 in Guangzhou. In April 2007, 28 PM2.5 samples were collected daily at the monitoring station of the South China Institute of Environmental Sciences （SCIES）, in urban Guangzhou. Water-soluble ionic species （CI^-, NO3^-, SO4^2-, NH4^＋, K^＋, Na^＋, Ca^2＋, and Mg^2＋） and carbonaceous contents （OC and EC） of the PM2.5 samples were determined to characterize their impact on visibility impairment. The results showed that sulfate was the dominant species that affected both light scattering and visibility. The average percentage contributions of the visibility-degrading species to light scattering coefficient were 40% for sulfate, 16% for nitrate, 22% for organics, and 22% for elemental carbon. Because of its foremost effect on visibility, sulfate reduction in PM2.5 would effectively improve the visibility of Guangzhou.

关键词： Visibility PM2.5 Carbonaceous aerosols Water-soluble ions

Airborne PCDD/Fs in two e-waste recycling regions after stricter environmental regulations

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Journal of Environmental Sciences 2017年第12期29卷 3-10页

作者： Manwen Zhang Guixian Feng Wenhua Yin Bing Xie Mingzhong Ren zhencheng xu Sukun Zhang Zongwei Cai Partner State Key Laboratory of Environmental and Biological Analysis Department of Chemistry Hong Kong Baptist University South China Institute of Environmental Science Ministry of Environmental Protection

Since the 2010 s, the authorities of Guangdong province and local governments have enhanced law enforcement and environmental regulations to abolish open burning, acid washing, and other uncontrolled e-waste recycling activities. In this study, ambient air and indoor dust near different kinds of e-waste recycling processes were collected in Guiyu and Qingyuan to investigate the pollution status of particles and polychlorinated dibenzo-pdioxins and furans（PCDD/Fs） after stricter environmental regulations. PM_（2.5） and PCDD/Fs both showed significantly reduced levels in the two regions compared with the documented data. The congener distribution and principal component analysis results also confirmed the significant differences between the current PCDD/Fs pollution characterizations and the historical ones. The estimated total intake doses via air inhalation and dust ingestion of children in the recycling region of Guiyu ranged from 10 to 32 pg TEQ/（kg·day）, which far exceeded the tolerable daily intake（TDI） limit（1–4 pg TEQ/（kg·day）. Although the measurements showed a significant reduction of the release of PCDD/Fs, the pollution status was still considered severe in Guiyu town after stricter regulations were implemented.

关键词： Polychlorinated dibenzo-p-dioxins and furans E-waste recycling China Environmental regulation

Heavy metal concentrations of agricultural soils and vegetables from Dongguan, Guangdong

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Journal of Geographical Sciences 2010年第1期20卷 121-134页

作者： CAI Limei HUANG Lanchun ZHOU Yongzhang xu zhencheng PENG Xiaochun YAO Ling＇ai ZHOU Yang PENG Ping＇an State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry CAS Guangzhou 510640 China Research Center of the Pearl River Delta Environmental Pollution and Control Guangzhou 510640 China South China Institute of Environmental Sciences Ministry of Environmental Protection Guangzhou 510655 China Center for Earth Environment and Resources Sun Yat-sen University Guangzhou 510275 China

A total of 118 of agricultural soil and 43 of vegetable samples were collected from Dongguan City, Guangdong, China. The spatial distribution, sources, accumulation characteristics and potential risk of heavy metals in the agricultural soils and vegetables were depicted in details by three different approaches, including total contents of eight metal elements in soils and vegetables, GIS maps and multivariate analysis of heavy metals in soils in the study. The results show that there are higher accumulation of heavy metals such as Cu, Zn, Ni, Pb, Cd and Hg in agricultural soils, and the contents of Pb （65.38 mg kg^-1） and Hg （0.24 mg kg^-1） are 1.82 and 2.82 times of the background contents of the corresponding heavy metals in soils of Guangdong Province, respectively. There are about 3.4% of Cu, 5.9% of Ni, 1.7% of Cd and 28% of Hg in all collected soil samples from all investigated sites which have overran the contents for heavy metals of the China Environmental Quality Standard for Soils （GB15618-1995, Grade Ⅱ）. The pollution characteristics of multi-metals in soils are mainly reflected by Hg. There are different sources to eight metal elements in soils, Cu, Zn, Ni Cr and As are predominantly derived from parent materials, and Pb, Hg and Cd are affected by anthropogenic activities. The spatial distribution shows that the Cu, Zn, Ni, Cr, Pb, As and Hg contents of agricultural soils are high in the west and low in the east, and Cd contents are high in the northwest, southeast and low in the southwest in Dongguan. The ratios of vegetable samples which Ni, Pb and As concentrations higher than the Maximum Levels of Contaminants in Foods （GB2762-2005） are 4.7%, 16.3% and 48.8%, respectively. The order of bio-concentration factors （BCF） of heavy metals in vegetables is Cd 〉 Zn 〉 Cu 〉 As 〉 Ni 〉 Hg 〉 Cr 〉 Pb. It is necessary to focus on potential risk of heavy metals for food safety and human＇s health from agricultural soils and vegetables in Dongguan City, Guangdong Prov

关键词： agricultural soil vegetable heavy metal pollution spatial distribution Dongguan

Synthesis of surface sulfated BiWO with enhanced photocatalytic performance

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Journal of Environmental Sciences 2012年第12期24卷 2180-2190页

作者： Yongming Ju Jianming Hong Xiuyu Zhang zhencheng xu Dongyang Wei Yanhong Sang Xiaohang Fang Jiande Fang Zhenxing Wang South China Institute of Environmental Science Ministry of Environmental ProtectionGuangzhou 510655China Center of Material Analysis Nanjing UniversityNanjing 210093China

Sulfated BiWO （SBiWO） was synthesized by an impregnation method to enhance the visible-light-driven photoactivities of BiWO （BiWO）. The characterization results verified that sulfate anion mainly anchored on the catalyst surface greatly extended the visible- light-responsive range without destroying the crystal lattice. Moreover, the SBiWO-based photoactivities were evaluated with the removal of Malachite Green （MG） under UV-Vis irradiation emitted from two microwave-powered electrodeless discharge lamps （MPEDL_2） and under visible light （L 〉 420 nm）. The results demonstrated that the kinetic constant was increased 2.25 times, varying from 0.1478 （BiWO） to 0.3328 rain-1 （SBiWO- 1 ）. Similar results were also obtained for the visible light-driven reaction. Furthermore, radical scavengers such as t-butanol restricted the visible-light induced degradation of MG over BiWO and SBiWO-1. This indicated that the sulfating process increased the generation of reactive oxygen species, which was further verified by molecular probe with salicylic acid. Thus, more blue-shifting at k = 618 nm was observed over SBiWO. On the basis of the above results, the photocatalytic mechanism over the sulfated catalyst was also discussed.

关键词： sulfated BiWO photocatalytic Malachite Green visible light microwave

Development of a novel conductance-based technology for environmental bacterial sensing

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Science Bulletin 2013年第Z1期 440-449页

关键词： bacterial impedance conductance bioaerosol bacterial concentrations