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Size distribution and chemical characteristics of particles from crop residue open burning in North China

Journal of Environmental Sciences 2021年第11期33卷 66-76页

作者： Tingkun Li Qili Dai Xiaohui BI Jianhui Wu Yufen Zhang Yinchang Feng State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin300350China.

Crop residue open burning is an important emission source of ambient particles in China.This study analyzed the particle emission characteristics of crop residue open burning through combustion experiments with a novel open combustion simulation device using three typical crop straws in north China(corn,wheat,and rice).Particle samples size ranging from 0.006–9.890μm were collected by an Electrical Low Pressure Impactor plus,a high size-resolution instrument capable of dividing particles into 14 size stages.The size distributions of organic carbon(OC),elemental carbon(EC),water-soluble ions,and elements were analyzed,and source chemical profiles were constructed for PM0.1,PM1,PM2.5,and PM10.The number concentration of particles was concentrated in the Aiken nuclei mode(0.006–0.054μm),accounting for 75%of the total number,whereas the mass concentration was concentrated in the accumulation mode(0.054–0.949μm),accounting for 85.43%of the mass loading.OC,EC,Cl−,and K(include total K and water-soluble K)were the major chemical components of the particles,whose mass percentage distributions differed from those of other components.These fivemain components exhibited a bell-shaped size distribution in the 0.006–9.890μm range,whereas the other components exhibited a U-shaped distribution.Among the chemical profiles for PM0.1–PM10,OC was the most important component at 10–30%,followed by EC at 2%–8%.The proportions of K^(+),Cl^(−),and K varied substantially in different experimental groups,ranging from 0–15%,and K+and Cl−were significantly correlated(r=0.878,α=0.000).

关键词： Crop residue Open burning Size distribution Source profile Electrical Low Pressure Impactor plus(ELPI+)

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Assessment of heavy metal pollution characteristics and human health risk of exposure to ambient PM_(2.5) in Tianjin,China

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Particuology 2015年第3期13卷 104-109页

作者： Peifei Chen Xiaohui BI Jiaqi Zhang Jianhui Wu Yinchang Feng College of Environmental Science and Safety Engineering Tianjin University of Technology College of Environmental Science and Engineering Nankai University

To examine the features of heavy metal pollution of PM2.5 （particulate matter less than 2.5 μm） in Tianjin, China, as well as the exposure risk of PM2.5 to human health, we analyzed ambient PM2.5samples collected from a campus of Nankai University in June, August, and October 2012. The concentrations of PM2.5 and heavy metals （Ni, Cu, Pb, Zn, Cr, Cd, Hg, As and Mn） in PM2.5 were analyzed by gravimetric analysis and inductively coupled plasma-mass spectrometry, respectively. The results show that the heavy metals contained in PM2.5 were, in descending order, Cu, Zn, Pb, Mn, Cr, Ni, Cd, As, and Hg. The proportion of Cd exceeded the secondary level of National Ambient Air Quality Standard of China （GB 3095-2012） by 1.3 times, while others were within the limit. Enrichment factor analysis indicated that Cu, Zn, Cd, Pb, and Hg are mainly from anthropogenic sources. Principal component analysis indicated that the main sources of the heavy metals are vehicle exhaust, chemical waste, and coal-burning activities. The nine heavy metals which may cause health issues by exposure through the human respiratory system and should be further examined are Cr, Cd, As, Ni, Cu, Pb, Mn, Zn, and Hg, in the order of decreasing risk levels. With reference to the U.S. EPA standard the risk levels of all nine metals were below the acceptable level （10 6/year）.

关键词： PM2.5 Heavy metalEnrichment factorPrincipal component analysisHealth risk assessment

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Insight into the critical factors determining the particle number concentrations during summer at a megacity in China

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Journal of Environmental Sciences 2019年第1期31卷 169-180页

作者： Baoshuang Liu Xiaohui BI Jiaying Zhang Jie Yuan Zhimei Xiao Qili Dai Yinchang Feng Yufen Zhang State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control & Center for Urban Transport Emission Research College of Environmental Science and EngineeringNankai University Tianjin Environmental Monitoring Center

To identify the critical factors impacting the number concentration of particles with the aerodynamic diameters less than 2.5 μm(PNC_(2.5)), the continuous measurement of PNC_(2.5),chemical components in PM_(2.5), gaseous pollutants and meteorological conditions were conducted at an urban site in Tianjin in June 2015. Results indicated that the average PNC_(2.5) was 2839 ± 2430 d N/dlog Dp 1/cm^3 during the campaign. Compared to other meteorological parameters, the relative humidity(RH) had the strongest relationship with PNC_(2.5), with a Pearson's correlation coefficient of 0.53, and RH larger than 30% influenced strongly PNC_(2.5).The important influence of secondary reactions on PNC_(2.5) was inferred due to higher correlation coefficients between PNC_(2.5) and SO_4^(2-), NO_3^-, NH_4^+(r = 0.78–0.89; p < 0.01) and between PNC_(2.5) and ratios that represent the conversion of nitrogen and sulfur oxides to particulate matter(r = 0.42–0.49; p < 0.01). Under specific RH conditions, there were even stronger correlations between PNC_(2.5) and NO_3^-, SO_4^(2-), NH_4^+, while those between PNC_(2.5) and EC, OC were relatively weak, especially when RH exceeded 50%. Principal component analysis(PCA) and Pearson's correlation analysis indicated that secondary sources, vehicle emission and coal combustion might be major contributors to PNC_(2.5). Backward trajectory and potential source contribution function(PSCF) analysis suggested that the transport of air masses originated from these regions around Tianjin(Liaoning, Hebei, Shandong and Jiangsu) influenced critically PNC_(2.5). The north of Jiangsu, the west of Shandong, and the east of Hebei were distinguished as major potential source-areas of PNC_(2.5) by PSCF model.

关键词： Particle number concentration Correlation analysis Emission sources PSCF

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Diagnostic value of 3D-FLAIR MRI in children with sudden deafness caused by inner ear hemorrhage

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World Journal of Pediatric Surgery 2021年第4期4卷 16-20页

作者： Fu Sheng Gao Xuan Jia xiaohui Ma Jing bi Qiang Shu Department of Radiology Children's Hospital Zhejiang University School of MedicineNational Clinical Research Center For Child HealthHangzhouZhejiangChina Department of Otorhinolaryngology Children's Hospital Zhejiang University School of MedicineNational Clinical Research Center For Child HealthHangzhouZhejiangChina Department of Cardio-Thoracic Surgery Children's Hospital Zhejiang University School of MedicineNational Clinical Research Center For Child HealthHangzhouZhejiangChina

Objective To investigate the diagnostic value of three-dimensional fluid-attenuated inversion recovery(3D-FLAIR)MRI in children with sudden deafness caused by inner ear hemorrhage.Methods The diagnostic efficacies of three different MRI sequences in the examination of the inner ear for 32 children with sudden deafness were compared.Hearing examination results and 3-month follow-up outcomes were analyzed.Results The age of 32 children with sudden deafness ranged from 5 to 18 years.MRI was performed from 1 to 18 days after onset.Six cases of sudden deafness caused by inner ear hemorrhage were finally diagnosed clinically.For different MRI sequences,the 3D-FLAIR sequence detected five positive cases;the conventional T1-weighted image sequence also detected five positive cases;but the conventional T2-weighted image sequence only detected three positive cases.The sensitivity and specificity of the 3D-FLAIR sequence in the diagnosis of inner ear hemorrhage were 83.3%(5/6)and 96.2%(25/26),respectively,and the area under the curve value of the receiver operating characteristic curve was 0.897.In the hemorrhage group,all six cases had extremely severe sensorineural hearing loss,and the hearing recovery was ineffective after 3 months of follow-up.The degree of hearing impairment,3-month short-term treatment efficacy,and 3D-FLAIR MRI in the diagnosis of inner ear hemorrhage between hemorrhage group and non-hemorrhage group were statistically significant(p=0.043,p=0.000,p=0.000).Conclusions 3D-FLAIR MRI is helpful for the diagnosis of inner ear hemorrhage in children with sudden deafness.Besides,short-term treatment indicates poor effects on children with severe hearing impairment.

关键词： hemorrhage diagnosis treatment

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Degradation kinetics of larotaxel and identification of its degradation products in alkaline condition

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Journal of Pharmaceutical Analysis 2017年第2期7卷 118-122页

作者： Xiaoming Liang Zhenzhen Liu Huiyan Shi Yuanyuan Zhang Shixiao Wang Kaishun bi xiaohui Chen Department of Pharmaceutical Analysis School of PharmacyShenyang Pharmaceutical University Department of Functional Science School of MedicineYangtze University

Larotaxel, a new taxane compound prepared by partial synthesis from 10-deacetyl baccatin III, is active against tumors. In this research, a selective LC–MS method was developed and validated for the study of degradation kinetics of larotaxel, which was carried out in aqueous solutions with different pH（1.5, 3.0, 5.0, 6.5, 7.4, 9.0, 10 and 11.0） and temperature（0, 25, 37 and 45 °C）. The linear range was 0.5–25 μg/mL, the intra-and inter-day precisions were less than 7.0%, and accuracy ranged from 97.4–104.5% for each analyte. The observed rate obtained by measuring the remaining intact larotaxel was shown to follow first-order kinetics. The activation energies for degradation were 126.7 and 87.01 k J/mol at pH 1.5 and 11, respectively. Although larotaxel was stable in pH 5, 6.5 and 7.4 buffers at 37 °C for 24 h during our study, increasing or decreasing the pH of the solutions would decrease its stabilities. Moreover, three main degradation products in alkaline condition were separated by HPLC and identified by Q–TOF–MS. The three degradation products were confirmed as 10-deacetyl larotaxel, 7, 8-cyclopropyl baccatin Ⅲ and 10-deacetyl-7, 8-cyclopropyl baccatin Ⅲ.

关键词： Larotaxel Degradation kinetics pH Temperature Degradation products

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Source apportionment of ambient PM_(10) in urban areas of Wuxi,China

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Frontiers of Environmental Science & Engineering 2011年第4期5卷 552-563页

作者： Bo HAN Xiaohui BI Yonghua XUE Jianhui WU Tan ZHU Baogui ZHANG Jianqing DING Yuanxin DU College of Environmental Science and Engineering Nankai UniversityTianjin 300071China Wuxi Environmental Monitoring Center Jiangsu 214023China

A total of 168 PM_(10)samples were collected during the year of 2005 at eight sites in the city of Wuxi in China.Fifteen chemical elements,three water-soluble ions,total carbon and organic carbon were analyzed.Six source categories were identified and their contributions to ambient PM_(10)in Wuxi were estimated using a nested chemical mass balance method that reduces the effects of colinearity on the chemical mass balance model.In addition,the concentrations of secondary aerosols,such as secondary organic carbon,sulfate and nitrate,were quantified.The spatially averaged PM_(10)was high in the spring and winter(123μg·m^(-3)and low in the summer-fall(90μg·m^(-3)).According to the result of source apportionment,resuspended dust was the largest contributor to ambient PM_(10),accounting for more than 50%of the PM_(10)mass.Coal combustion(14.6%)and vehicle exhaust(9.4%)were also significant source categories of ambient PM_(10).Construction and cement dust,sulfates,secondary organic carbon,and nitrates made contributions ranging between 4.1%and 4.9%.Other source categories such as steel manufacturing dust and soil dust made low contributions to ambient PM_(10).

关键词： source apportionment inhalable particulate matter nested chemical mass balance method

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Development of a UPLC–MS/MS method for determination of pimavanserin tartrate in rat plasma: Application to a pharmacokinetic study

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Journal of Pharmaceutical Analysis 2017年第6期7卷 406-410页

作者： Shixiao Wang Yang Wang Shuang Gao Yuanyuan Zhang Hanpei Wang Longshan Zhao Kaishun bi Shaojie Wang xiaohui Chen School of Pharmacy Shenyang Pharmaceutical University Shenyang 110016 China Key Laboratory of Structure-Based Drugs Design&Discovery of Ministry of Education Shenyang Pharmaceutical University Shenyang 110016 China

A simple, rapid and sensitive method based on an ultra-performance liquid chromatography tandem mass spectrometry （UPLC-MS/MS） has been developed and validated for the determination of pimavanserin in rat plasma. The analyte was extracted by protein precipitation with methanol and separated on an ACQUITY BEH C18 column （100 mm × 2.1 mm, 1.7μm; Waters, USA）, with an isocratic elution of acetonitrile-water containing 10 mM ammonium acetate （70：30, v/v）, at a flow rate of 0.2 mL/min for 2.5 rain. The analyte and clarithromyein （the internal standard） were detected and quantified in positive ion mode using multiple reaction monitoring transitions at m/z 428.2 - 223.0 for pimavanserin and m/z 748.5 - 589.5 for clarithromycin. Relative coefficient （r） for the calibration curve was more than 0.9980. The intra-day and inter-day precisions （relative standard deviation, RSD%） were less than 13.3% and 10.5%, respectively, and the accuracy （relative error, RE%） was within ± 11.5%. The analytical method was successfully applied to a routine pharmacokinetic study of pimavanserin in rats after oral administration at the dose of 10 mg/kg.

关键词： UPLC-MS/MS Pimavanserin Pharmacokinetics Rat plasma

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Discrimination of aqueous and vinegary extracts of Shixiao San using metabolomics coupled with multivariate data analysis and evaluation of antihyperlipidemic effect

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Asian Journal of Pharmaceutical Sciences 2014年第1期9卷 17-26页

作者： Xiaofan Wang Xu Zhao Liqiang Gu Yuanyuan Zhang Kaishun bi xiaohui Chen School of Pharmacy Shenyang Pharmaceutical UniversityNo.103Wenhua RoadShenyang 110016China School of Traditional Chinese Material Medica Shenyang Pharmaceutical UniversityShenyang 110016China

A novel study using LCeMS(Liquid chromatography tandem mass spectrometry)coupled with multivariate data analysis and bioactivity evaluation was established for discrimination of aqueous extract and vinegar extract of Shixiao San.Batches of these two kinds of samples were subjected to analysis,and the datasets of sample codes,tR-m/z pairs and ion intensities were processed with principal component analysis(PCA).The result of score plot showed a clear classification of the aqueous and vinegar groups.And the chemical markers having great contributions to the differentiation were screened out on the loading plot.The identities of the chemical markers were performed by comparing the mass fragments and retention times with those of reference compounds and/or the known compounds published in the literatures.Based on the proposed strategy,quercetin-3-Oneohesperidoside,isorhamnetin-3-O-neohespeeridoside,kaempferol-3-O-neohesperidoside,isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-(2G-a-l-rhamnosyl)-rutinoside were explored as representative markers in distinguishing the vinegar extract from the aqueous extract.The anti-hyperlipidemic activities of two processed extracts of Shixiao San were examined on serum levels of lipids,lipoprotein and blood antioxidant enzymes in a rat hyperlipidemia model,and the vinegary extract,exerting strong lipid-lowering and antioxidative effects,was superior to the aqueous extract.Therefore,boiling with vinegary was predicted as the greatest processing procedure for anti-hyperlipidemic effect of Shixiao San.Furthermore,combining the changes in the metabolic profiling and bioactivity evaluation,the five representative markers may be related to the observed antihyperlipidemic effect.

关键词： Anti-hyperlipidemic effect Herb processing Multivariate data analysis Shixiao San Liquid chromatography tandem mass spectrometry

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Determination of 6258-70,a new semi-synthetic taxane,in rat plasma and tissues:Application to the pharmacokinetics and tissue distribution study

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Journal of Pharmaceutical Analysis 2016年第4期6卷 219-225页

作者： Simin Zhao Yuanyuan Zhang Ping Ju Liqiang Gu Rui Zhuang Longshan Zhao Xing Tang Kaishun bi xiaohui Chen School of Pharmacy Shenyang Pharmaceutical University

Cancer is the leading cause of death all over the world.Among the chemotherapy drugs,taxanes play an important role in cancer treatment.6258-70 is a new semi-synthetic taxane which has a broad spectrum of antitumor activity.A fast and reliable high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） method was developed for quantification of 6258-70 in rat plasma and tissues in this paper.After extraction by liquid-liquid extraction method with methyl tert-butyl ether,the samples were separated on a Kinetex C_（18） column（50 mm × 2.1 mm,2.6 μm,Phenomenex,USA） within3 min.The method was fully validated with the matrix effect between 87.7%and 99.5%and the recovery ranging from 80.3%to 90.1%.The intra- and inter-day precisions were less than 9.5%and the accuracy ranged from-3.8%to 6.5%.The reliable method was successfully applied to the pharmacokinetics and tissue distribution studies of 6258-70 after intravenous administration in rats.The pharmacokinetic results indicated that the pharmacokinetic behavior of 6258-70 in rats was in accordance with linear features within tested dosage of 1 to 4 mg/kg,and there was no significant difference between the two genders.The tissue distribution study showed that 6258-70 had an effective penetration,spread widely and rapidly and could cross blood-brain barrier.The results of pharmacokinetics and tissue distribution may provide a guide for future study.

关键词： 6258-70 HPLC-MS/MS Pharmacokinetics Tissue distribution

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Full-spectrum responsive photocatalytic activity via non-noble metal bi decorated mulberry-like biVO_(4)

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Journal of Materials Science & Technology 2021年第24期83卷 102-112页

作者： Yaxin bi Yanling Yang Xiao-Lei Shi Lei Feng Xiaojiang Hou xiaohui Ye Li Zhang Guoquan Suo Siyu Lu Zhi-Gang Chen School of Materials Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science and TechnologyXi'an710021China Centre for Future Materials University of Southern QueenslandSpringfieldQLD4300Australia School of Mechanical and Mining Engineering The University of QueenslandBrisbaneQLD4072Australia College of Chemistry and Molecular Engineering Zhengzhou UniversityZhengzhou 450001China

Due to its appropriate bandgap(~2.4 e V)and efficient light absorption,bismuth vanadate(bi VO_(4))shows promising photocatalysis activity.However,the charge carrier recombination and poor electron transmission often induce poor photocatalytic performance.Herein,we report a new method to in-situ synthesize non-noble metal bi decorated mulberry-like bi VO_(4)by a two-step calcination process.Comprehensive characterizations reveal that non-noble metal bi nanoparticles grown in-situ on bi VO_(4)result in the red-shift of the absorbance edge,greatly extending the light absorption from the ultraviolet into the near-infrared region.The surface plasmon resonance excitation of bi nanoparticles and synergetic effects between bi and bi VO_(4)effectively improve the photocatalytic efficiency and promote the separation of photoinduced electron-hole pairs in mulberry-like bi VO_(4).Density functional theory(DFT)calculation results further verify that the electrons are transferred from bi to bi VO_(4)and the formation of·OH radical in bi/bi VO_(4)is attributed to the lower simulated free energy,which supports our experimental outcomes.This work provides a novel strategy to enhance light absorption and promote efficient solar utilization of photocatalysts for practical applications.

关键词： bi biVO_(4) Photocatalysis Full-spectrum Density functional theory

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