The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pe...The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pesticide residues in tea products exceed the maximum residue limits. However, the complex matrices present in tea samples comprise a major challenge in the analytical detection of pesticide residues. In this study, nine types of lateral flow immunochromatographic strips (LFICSs) were developed to detect the pesticides of interest (fenpropathrin, chlorpyrifos, imidacloprid, thiamethoxam, acetamiprid, carbendazim, chlorothalonil, pyraclostrobin, and iprodione). To reduce the interference of tea substrates on the assay sensitivity, the pretreatment conditions for tea samples, including the extraction solvent, extraction time, and purification agent, were optimized for the simultaneous detection of these pesticides. The entire testing procedure (including pretreatment and detection) could be completed within 30 min. The detected results of authentic tea samples were confirmed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), which suggest that the LFICS coupled with sample rapid pretreatment can be used for on-site rapid screening of the target pesticide in tea products prior to their market release.展开更多
Background:This study was planned to assess the accuracy and comparability of two commercially available,laboratory-based SARS-CoV-2(severe acute respiratory syndrome)antigen(Ag)immunoassays.Methods:We studied a cohor...Background:This study was planned to assess the accuracy and comparability of two commercially available,laboratory-based SARS-CoV-2(severe acute respiratory syndrome)antigen(Ag)immunoassays.Methods:We studied a cohort of subjects with acute SARS-CoV-2 infection,from whom a nasopharyngeal swab was taken and tested with a molecular assay(Altona Diagnostics RealStar SARS-CoV-2 RT-PCR Kit)and two laboratory-based,fully automated SARS-CoV-2 Ag immunoassays(Fujirebio Lumipulse G SARS-CoV-2 Ag and Roche Elecsys SARS-CoV-2 Ag).Results:The final population consisted in 93 subjects testing positive for SARS-CoV-2 RNA,34 with cycle threshold(Ct)values<29.5.The results of the two SARS-CoV-2 Ag immunoassays were significantly intercorrelated(r=0.77;P<0.001)in the entire cohort,though such correlation considerably improved in patients with high viral load(cycle threshold values<29.5:r=0.96;P<0.001).The accuracy for identifying samples with high viral load was excellent for both Lumipulse G SARS-CoV-2 Ag(AUC,0.99;P<0.001)and Elecsys SARS-CoV-2 Ag(AUC,0.99;P<0.001),with best cut-offs of 2.03 ng/mL for Lumipulse G SARS-CoV-2 Ag(1.00 sensitivity and 0.88 specificity)and 0.70 COI for Elecsys SARS-CoV-2 Ag(1.00 sensitivity and 0.80 specificity),respectively.Conclusion:The results of this study provide valuable support to usability of fully-automated,rapid,high throughput and accurate SARS-CoV-2 Ag immunoassays for complementing molecular assays.展开更多
基金supported by grants from Shanghai Agriculture Applied Technology Development Program,China(Grant No.:2020-02-08-00-08-F01456)the Key Research and Development Program of Zhejiang Province,China(Grant No.:2020C02024-2).
文摘The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pesticide residues in tea products exceed the maximum residue limits. However, the complex matrices present in tea samples comprise a major challenge in the analytical detection of pesticide residues. In this study, nine types of lateral flow immunochromatographic strips (LFICSs) were developed to detect the pesticides of interest (fenpropathrin, chlorpyrifos, imidacloprid, thiamethoxam, acetamiprid, carbendazim, chlorothalonil, pyraclostrobin, and iprodione). To reduce the interference of tea substrates on the assay sensitivity, the pretreatment conditions for tea samples, including the extraction solvent, extraction time, and purification agent, were optimized for the simultaneous detection of these pesticides. The entire testing procedure (including pretreatment and detection) could be completed within 30 min. The detected results of authentic tea samples were confirmed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), which suggest that the LFICS coupled with sample rapid pretreatment can be used for on-site rapid screening of the target pesticide in tea products prior to their market release.
文摘Background:This study was planned to assess the accuracy and comparability of two commercially available,laboratory-based SARS-CoV-2(severe acute respiratory syndrome)antigen(Ag)immunoassays.Methods:We studied a cohort of subjects with acute SARS-CoV-2 infection,from whom a nasopharyngeal swab was taken and tested with a molecular assay(Altona Diagnostics RealStar SARS-CoV-2 RT-PCR Kit)and two laboratory-based,fully automated SARS-CoV-2 Ag immunoassays(Fujirebio Lumipulse G SARS-CoV-2 Ag and Roche Elecsys SARS-CoV-2 Ag).Results:The final population consisted in 93 subjects testing positive for SARS-CoV-2 RNA,34 with cycle threshold(Ct)values<29.5.The results of the two SARS-CoV-2 Ag immunoassays were significantly intercorrelated(r=0.77;P<0.001)in the entire cohort,though such correlation considerably improved in patients with high viral load(cycle threshold values<29.5:r=0.96;P<0.001).The accuracy for identifying samples with high viral load was excellent for both Lumipulse G SARS-CoV-2 Ag(AUC,0.99;P<0.001)and Elecsys SARS-CoV-2 Ag(AUC,0.99;P<0.001),with best cut-offs of 2.03 ng/mL for Lumipulse G SARS-CoV-2 Ag(1.00 sensitivity and 0.88 specificity)and 0.70 COI for Elecsys SARS-CoV-2 Ag(1.00 sensitivity and 0.80 specificity),respectively.Conclusion:The results of this study provide valuable support to usability of fully-automated,rapid,high throughput and accurate SARS-CoV-2 Ag immunoassays for complementing molecular assays.