Publications by authors named "Xiangwen Luo"

11 Publications

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Residue changes and processing factors of eighteen field-applied pesticides during the production of Chinese Baijiu from rice.

Food Chem 2021 Oct 29;359:129983. Epub 2021 Apr 29.

Longping Branch, Graduate School of Hunan University, Changsha 410125, China; Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha 410125, China. Electronic address:

The fate of eighteen pesticides in field-collected rice samples during Chinese Baijiu production was systematically studied. The results indicated that steeping decreased flonicamid residue by 73.2% due to its high water-solubility and low octanol/water partition coefficient. The steaming step reduced pesticide residues by 32.0%-75.3% through evaporation or thermal degradation. After steaming, the pesticide residues were further reduced by 39.8-74.2% in fermentation which might be caused by biological degradation. In addition, distillation was shown to be most effective, responsible for greater than 90% losses of the remaining pesticide residues. The processing factors (PFs) were generally lower than 1 for different processes and the whole procedure. These results revealed that the procedure of Chinese Baijiu production could dramatically decrease residues of all the eighteen pesticides. Overall, this study provide important references for monitoring pesticide residue levels during the production of Chinese Baijiu from rice, and ensuring proper risk assessment from pesticide contamination.
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http://dx.doi.org/10.1016/j.foodchem.2021.129983DOI Listing
October 2021

Residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and its metabolites during tea growing and tea brewing.

J Sci Food Agric 2021 Apr 13. Epub 2021 Apr 13.

Longping Branch, Graduate School of Hunan University, Changsha, China.

Background: Tolfenpyrad and dinotefuran are two representative pesticides used for pest control in tea gardens. Their application may bring about a potential risk to the health of consumers. Therefore, it is essential to investigate the residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and metabolites from tea garden to teacup.

Results: An effective analytical method was established and validated to simultaneously determine tolfenpyrad, dinotefuran and its metabolites (DN and UF) in tea. The average recoveries of tolfenpyrad, dinotefuran, DN and UF were in the range 72.1-106.3%, with relative standard deviations lower than 11.8%. On the basis of the proposed method, the dissipation of tolfenpyrad and dinotefuran in fresh tea leaves followed first-order kinetics models with half-lives of 4.30-7.33 days and 4.65-5.50 days, respectively. With application amounts of 112.5-168.75 g a.i. ha once or twice, the terminal residues of tolfenpyrad and total dinotefuran in green tea were lower than 19.6 and 7.13 mg kg , respectively, and below their corresponding maximum residue limits . The leaching rates of tolfenpyrad and total dinotefuran during the tea brewing were in the ranges 1.4-2.3% and 93.7-98.1%, respectively.

Conclusion: Tolfenpyrad and dinotefuran in tea were easily degraded. The RQ and RQ values for tolfenpyrad were 37.6% and 5.4%, which were much higher than for dinotefuran at 24.7% and 0.84%, respectively. The data indicated that there was no significant health risk in tea for consumers at the recommended dosages. The results provide scientific data regarding the reasonable use of tolfenpyrad and dinotefuran aiming to ensure safe tea consuption. © 2021 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.11253DOI Listing
April 2021

Study on degradation behaviour, residue distribution, and dietary risk assessment of propiconazole in celery and onion under field application.

J Sci Food Agric 2021 Mar 5;101(5):1998-2005. Epub 2020 Oct 5.

Longping Branch, Graduate School of Hunan University, Changsha, 410125, China.

Background: Propiconazole is widely used to control fungal diseases in field crops, including celery and onion. The potential risk to the environment and human health has aroused much public concern. Therefore, it is significant to investigate the degradation behaviour, residue distribution, and dietary risk assessment of propiconazole in celery and onion.

Results: A sensitive analytical method for determination of propiconazole residue in celery and onion was established and validated through high-performance liquid chromatography tandem mass spectrometry. The average recovery rate of propiconazole ranged from 85.7% to 101.8%, with a relative standard deviation of 2.1-6.3%. For the dissipation kinetics, the data showed that propiconazole in celery and onion was degraded, with half-lives of 6.1-6.2 days and 8.7-8.8 days respectively. In the terminal residue experiments, the residues of propiconazole were below 4.66 mg kg in celery after application two or three times and were below 0.029 mg kg in onion after application of three or four times with an interval of 14 days under the designed dosages. The chronic and acute dietary exposure assessments for propiconazole were valued by risk quotient, with all values being lower than 100%.

Conclusion: Propiconazole in celery and onion was rapidly degraded following first-order kinetics models. The dietary risk of propiconazole through celery or onion was negligible to consumers. The study not only offers a valuable reference for reasonable usage of propiconazole on celery and onion, but also facilitates the establishment of maximum residue limits in China. © 2020 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.10817DOI Listing
March 2021

First evidence showing that Pepper vein yellows virus P4 protein is a movement protein.

BMC Microbiol 2020 03 30;20(1):72. Epub 2020 Mar 30.

Longping Branch, Hunan University, Changsha, 410125, China.

Background: Plant viruses move through plasmodesmata (PD) to infect new cells. To overcome the PD barrier, plant viruses have developed specific protein(s) to guide their genomic RNAs or DNAs to path through the PD.

Results: In the present study, we analyzed the function of Pepper vein yellows virus P4 protein. Our bioinformatic analysis using five commonly used algorithms showed that the P4 protein contains an transmembrane domain, encompassing the amino acid residue 117-138. The subcellular localization of P4 protein was found to target PD and form small punctates near walls. The P4 deletion mutant or the substitution mutant constructed by overlap PCR lost their function to produce punctates near the walls inside the fluorescent loci. The P4-YFP fusion was found to move from cell to cell in infiltrated leaves, and P4 could complement Cucumber mosaic virus movement protein deficiency mutant to move between cells.

Conclusion: Taking together, we consider that the P4 protein is a movement protein of Pepper vein yellows virus.
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http://dx.doi.org/10.1186/s12866-020-01758-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7106754PMC
March 2020

Knowledge and behavior regarding pesticide use: a survey among caregivers of children aged 1-6 years from rural China.

Environ Sci Pollut Res Int 2019 Aug 10;26(22):23037-23043. Epub 2019 Jun 10.

Department of Paediatrics, Third Xiangya Hospital of Central South University, Changsha, China.

Little is known about pesticide exposure risks for children in rural areas in China, many of whom have been left behind by migrant workers. To survey caregivers of children in rural China and assess their pesticide use and disposal methods, the measures were used to protect the children and their perceptions of the adverse effects of pesticides on children's health. Three or four villages in each of Xinhua, Gongan and Sansui Counties in China were selected by random cluster sampling. The main caregivers of children aged 1-6 years were surveyed in face-to-face interviews. The questionnaire used was adapted from the World Health Organization "Exposure to Pesticides: Standard Protocol" survey and similar studies. The study included 464 caregivers (mean age, 46.4 years), who were most commonly the children's grandparents (65.3%). Among the caregivers, 41.9% were educated to middle school level or higher, 45.4% had a household income < 297 USD, and 29.7% had received education/training about pesticide use/adverse health effects in children. The score for caregivers' knowledge of the adverse effects of pesticides on children's health was higher in those who had received education/training (5.1 ± 2.6 vs. 3.4 ± 2.5, P < 0.001). Factors associated with unsafe behaviors during pesticide use included grandparent as the caregiver (odds ratio [OR] 0.551; 95% confidence interval [95% CI] 0.368-0.824; P = 0.004), annual income < 297 USD (OR 0.580; 95% CI 0.395-0.853; P = 0.006), and insufficient health-related education/training (OR 0.436; 95% CI 0.286-0.665; P < 0.001). Improved education and training are needed to promote the safe use of pesticides by caregivers of children in rural China.
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http://dx.doi.org/10.1007/s11356-019-05560-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6658672PMC
August 2019

Biodegradation of fenpropathrin by Rhodopseudomonas sp. strain PSB07-21 cultured under three different growth modes.

J Basic Microbiol 2019 Jun 23;59(6):591-598. Epub 2019 Apr 23.

Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, Hunan, People's Republic of China.

This study aimed at the biodegradation of fenpropathrin by Rhodopseudomonas sp. strain PSB07-21 cultured under different growth modes. The biomass production, cell surface hydrophobicity and fenpropathrin biodegradation efficiency of the strain PSB07-21 cultured under the photoheterotrophic growth mode were better than that shown by the strain PSB07-21 cultured under the photoautotrophic or the chemotrophic growth mode. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis using cell-free protein extracts showed several distinct protein bands in the gels representing the strain PSB07-21 cultured under the photoheterotrophic growth mode. The fenpropathrin enzymatic degradation was clearly affected the bacterial growth mode. Results obtained from this study should improve our knowledge regarding fenpropathrin biodegradation under field conditions. Our findings can also be used to optimize the usage of Rhodopseudomonas sp. PSB07-21 in field applications.
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http://dx.doi.org/10.1002/jobm.201800490DOI Listing
June 2019

Cloning and characterization of a pyrethroid pesticide decomposing esterase gene, Est3385, from Rhodopseudomonas palustris PSB-S.

Sci Rep 2018 05 9;8(1):7384. Epub 2018 May 9.

Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, 410125, China.

Full length open reading frame of pyrethroid detoxification gene, Est3385, contains 963 nucleotides. This gene was identified and cloned based on the genome sequence of Rhodopseudomonas palustris PSB-S available at the GneBank. The predicted amino acid sequence of Est3385 shared moderate identities (30-46%) with the known homologous esterases. Phylogenetic analysis revealed that Est3385 was a member in the esterase family I. Recombinant Est3385 was heterologous expressed in E. coli, purified and characterized for its substrate specificity, kinetics and stability under various conditions. The optimal temperature and pH for Est3385 were 35 °C and 6.0, respectively. This enzyme could detoxify various pyrethroid pesticides and degrade the optimal substrate fenpropathrin with a Km and Vmax value of 0.734 ± 0.013 mmol·l and 0.918 ± 0.025 U·µg, respectively. No cofactor was found to affect Est3385 activity but substantial reduction of enzymatic activity was observed when metal ions were applied. Taken together, a new pyrethroid degradation esterase was identified and characterized. Modification of Est3385 with protein engineering toolsets should enhance its potential for field application to reduce the pesticide residue from agroecosystems.
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http://dx.doi.org/10.1038/s41598-018-25734-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5943319PMC
May 2018

Tiotropium in Early-Stage Chronic Obstructive Pulmonary Disease.

N Engl J Med 2017 09;377(10):923-935

From the National Center for Respiratory Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Diseases, the First Affiliated Hospital (Y.Z., N.Z., Xiaochen Li, S.C., J. Zheng, D.Z., W.G., P.R.), the Third Affiliated Hospital (L.W., G.H.), and Liwan Hospital (F.L., Y.C.), Guangzhou Medical University, Guangzhou Panyu Center Hospital (R.Z., Yinhuan Li), the First Affiliated Hospital, Sun Yat-sen University (C.X.), and the First Affiliated Hospital of Jinan University (S.L.), Guangzhou, Chenzhou No. 1 People's Hospital, Chenzhou (B. He, H.T.), Guizhou Provincial People's Hospital, Guizhou (X. Zhang, X.Y.), Wengyuan County People's Hospital (C. Yang, Lizhen Zeng, C. Ye) and Shaoguan Iron and Steel Group Company Limited Hospital (T.C.), Shaoguan, Henan Provincial People's Hospital, Zhengzhou (Ying Li, X.M.), the Affiliated Hospital of GuiYang Medical College, GuiYang (J.D., X.H.), the Second People's Hospital of Hunan Province, Changsha (J.G., J.T.), Huizhou First Hospital, Huizhou (B. Hu, Z.S.), Affiliated Zhongshan Hospital of Fudan University (C.B., X. Zhu) and Shanghai Xuhui Central Hospital (R.Y.), Shanghai, Shenzhen Sixth People's Hospital, Shenzhen (P.H., X.D.), the First People's Hospital of Foshan, Foshan (G.C., M.L.), Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan (Y.X., J. Zhao), Xinqiao Hospital, Chongqing (C.W., Q.M.), the Affiliated Hospital, Guangdong Medical University (W. Yao, B.L.), and the Second People's Hospital of Zhanjiang (Xiongbin Li), Zhanjiang, Beijing Chao-Yang Hospital, Beijing (Y. Lin), and Lianping County People's Hospital, Heyuan (W. Ye, X. Luo, Lingshan Zeng, S.Y.) - all in China.

Background: Patients with mild or moderate chronic obstructive pulmonary disease (COPD) rarely receive medications, because they have few symptoms. We hypothesized that long-term use of tiotropium would improve lung function and ameliorate the decline in lung function in patients with mild or moderate COPD.

Methods: In a multicenter, randomized, double-blind, placebo-controlled trial that was conducted in China, we randomly assigned 841 patients with COPD of Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 1 (mild) or 2 (moderate) severity to receive a once-daily inhaled dose (18 μg) of tiotropium (419 patients) or matching placebo (422) for 2 years. The primary end point was the between-group difference in the change from baseline to 24 months in the forced expiratory volume in 1 second (FEV) before bronchodilator use. Secondary end points included the between-group difference in the change from baseline to 24 months in the FEV after bronchodilator use and the between-group difference in the annual decline in the FEV before and after bronchodilator use from day 30 to month 24.

Results: Of 841 patients who underwent randomization, 388 patients in the tiotropium group and 383 in the placebo group were included in the full analysis set. The FEV in patients who received tiotropium was higher than in those who received placebo throughout the trial (ranges of mean differences, 127 to 169 ml before bronchodilator use and 71 to 133 ml after bronchodilator use; P<0.001 for all comparisons). There was no significant amelioration of the mean (±SE) annual decline in the FEV before bronchodilator use: the decline was 38±6 ml per year in the tiotropium group and 53±6 ml per year in the placebo group (difference, 15 ml per year; 95% confidence interval [CI], -1 to 31; P=0.06). In contrast, the annual decline in the FEV after bronchodilator use was significantly less in the tiotropium group than in the placebo group (29±5 ml per year vs. 51±6 ml per year; difference, 22 ml per year [95% CI, 6 to 37]; P=0.006). The incidence of adverse events was generally similar in the two groups.

Conclusions: Tiotropium resulted in a higher FEV than placebo at 24 months and ameliorated the annual decline in the FEV after bronchodilator use in patients with COPD of GOLD stage 1 or 2. (Funded by Boehringer Ingelheim and others; Tie-COPD ClinicalTrials.gov number, NCT01455129 .).
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http://dx.doi.org/10.1056/NEJMoa1700228DOI Listing
September 2017

Genome Sequence of Pyrethroid-Degrading Bacterium Rhodopseudomonas palustris Strain JSC-3b.

Genome Announc 2014 Jan 23;2(1). Epub 2014 Jan 23.

Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Changsha, China.

Rhodopseudomonas palustris strain JSC-3b is a facultative, thermophilic bacterium, which was isolated from water in a canal adjacent to a vegetable field. Strain JSC-3b biodegrades several varieties of pyrethroid residues effectively through cometabolic pathways. Here, we present the genome sequence of this biodegrader.
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http://dx.doi.org/10.1128/genomeA.01228-13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3900912PMC
January 2014

Cometabolic biotransformation of fenpropathrin by Clostridium species strain ZP3.

Biodegradation 2011 Sep 23;22(5):869-75. Epub 2010 Dec 23.

Longping branch, Graduate College, Central South University, Changsha, People's Republic of China.

A novel bacterial strain capable of degrading the pyrethroid pesticide fenpropathrin was isolated from mixed wastewater and sludge samples. Phylogenetic analysis of the 16S rDNA sequence revealed that the organism belongs to the genus Clostridium. The organism can co-metabolically transform fenpropathrin at 100 mg l(-1) at 35°C and pH 7.5 in 12 days. Metabolic products of fenpropathrin from strain ZP3 were examined by gas chromatography/mass spectrometry, and the results showed that the organism degraded fenpropathrin with an oxidization process to yield benzyl alcohol, benzenemethanol, 3,5-dimethylamphetamine. Analyses of cell-free extracts from this strain showed that the optimal degrading conditions for degrading fenpropathrin were 35°C and pH 7.5, and degradation efficiency was 20.0 mg l(-1) day(-1), and it might be potential using for rapid treating fenpropathrin, for example, on the surface of fruits and vegetables.
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http://dx.doi.org/10.1007/s10532-010-9444-yDOI Listing
September 2011

[Isolation, identification and degrading gene cloning of a pyrethroids-degrading bacterium].

Wei Sheng Wu Xue Bao 2009 Nov;49(11):1520-6

Branch of Longping, Graduate College, Central South University, Changsha 410125, China.

Objective: This study aimed to isolate, identify and clone degrading gene of a synthetic pyrethroids degrading bacterium.

Methods: A photosynthetic bacterial strain PSB07-21 capable of degrading several synthetic pyrethroids efficiently was isolated by an enrichment culture. PSB07-21 was identified based on its morphology, physiology and phylogenetic analysis of 16S rDNA sequence. The degradation ability of this strain was evaluated with gas chromatography.The degrading gene was cloned with PCR.

Results: PSB07-21 was closely related to Rhodopseudomonas sp. The optimum condition of degrading synthetic pyrethroidss was at 35 degrees C, pH 7 and 3000 lx. PSB07-21 could degrade fenpropathrin, cypermethrin and bipthenthrin by 66.63%, 43.25% and 50.18% in a concentration of 600 mg/L at day 15, respectively. We cloned a putative gene which was 326bp long with 37.0% identical to 20G-Fe (II) oxygenase gene. When compensating low concentration Fe (II) in PSB medium with synthetic pyrethroids, the degradation efficiency of PSB07-21 was enhanced.

Conclusion: The strain has the potential application to synthetic pyrethroids bioremediation.
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November 2009