An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai (cruciferous vegetable), chicken, fish, and po...An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai (cruciferous vegetable), chicken, fish, and pork] was developed using gas chromatography (GC-ECD) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Samples were extracted using acetone and n-hexane mixed solvent (1:2, v/v) and then purified using solid-phase extraction (SPE) columns. The extracts were analyzed using GC-ECD and LC-MS/MS. The multiple reaction monitoring (MRM) scheme used involved transitions of the precursor ions to selected two product ions in which one pair for identification was m/z 529 → 293 and another pair for quantification was m/z 529 → 249. The detection limits (LODs) of the method were 0.0015 and 0.0006 mg kg^-1, and the quantification limits (LOQs) were 0.005 and 0.002 mg kg^-1 for GC-ECD and LC-MS/MS, respectively. The relative standard deviations (RSDs) of recovery for indoxacarb were lower than 15% in 10 types of agro-products. Ten repetitive determinations of recovery achieved good reproducibility for indoxacarb and the recovery ranged from 72.08 to 113.74%. The proposed procedure was applied to the analysis of several real samples of different origin from Fujian Province, China, and 299 samples were screened for indoxacarb residue, of which 5 positive samples were found.展开更多
[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the...[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the differences of mitochondrial genes among different species.[Methods]The specificity,limit of detection and repeatability test were carried out by isolating somatic cells,extracting template DNA and determining the reaction conditions of real-time fluorescence-based PCR.[Results]The real-time fluorescence-based PCR method could be used to identify the bovine and ovine-derived materials of milk powder with high specificity,high sensitivity and good repeatability,and the limit of detection of milk components in goat milk powder could reach 0.01%.[Conclusions]The real-time fluorescence-based PCR method can be used to quickly and accurately detect the milk components in goat milk powder,and provide some technical support for the adulteration detection of dairy industry.展开更多
Scientists from China and the United States appear to make a breakthrough in determining the Earth’s earliest animals what organisms are the oldest animals on
The importance of the original artistic animation was discussed from the protection of region culture resources and the exploiture plan of the cultural resources in Hubei Province
The Middle East respiratory syndrome coronavirus (MERS-CoV) is a novel zoonotic pathogen. In 2012, the infectious outbreak caused by MERS-CoV in Saudi Arabia has spread to more than 1600 patients in 26 countries, re...The Middle East respiratory syndrome coronavirus (MERS-CoV) is a novel zoonotic pathogen. In 2012, the infectious outbreak caused by MERS-CoV in Saudi Arabia has spread to more than 1600 patients in 26 countries, resulting in over 600 deaths. Without a travel history, few clinical and radiological features can reliably differentiate MERS from SARS. But in real world, comparing with SARS, MERS presents more vaguely defined epidemiology, more severe symptoms, and higher case fatality rate. In this review, we summarize the recent findings in the field of MERS-CoV, especially its molecular virology, interspecies mechanisms, clinical features, antiviral therapies, and the further investigation into this disease. As a newly emerging virus, many questions are not fully answered, including the exact mode of transmission chain, geographical distribution, and animal origins. Furthermore, a new protocol needs to be launched to rapidly evaluate the effects of unproven antiviral drugs and vaccine to fasten the clinical application of new drugs.展开更多
基金grants from Fujian Pro- vincial Department of Science and Technology (2006F3002)Xiamen Science and Technology Bureau (3502Z20072003)China Postdoctoral Programme (20060390291)
文摘An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai (cruciferous vegetable), chicken, fish, and pork] was developed using gas chromatography (GC-ECD) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Samples were extracted using acetone and n-hexane mixed solvent (1:2, v/v) and then purified using solid-phase extraction (SPE) columns. The extracts were analyzed using GC-ECD and LC-MS/MS. The multiple reaction monitoring (MRM) scheme used involved transitions of the precursor ions to selected two product ions in which one pair for identification was m/z 529 → 293 and another pair for quantification was m/z 529 → 249. The detection limits (LODs) of the method were 0.0015 and 0.0006 mg kg^-1, and the quantification limits (LOQs) were 0.005 and 0.002 mg kg^-1 for GC-ECD and LC-MS/MS, respectively. The relative standard deviations (RSDs) of recovery for indoxacarb were lower than 15% in 10 types of agro-products. Ten repetitive determinations of recovery achieved good reproducibility for indoxacarb and the recovery ranged from 72.08 to 113.74%. The proposed procedure was applied to the analysis of several real samples of different origin from Fujian Province, China, and 299 samples were screened for indoxacarb residue, of which 5 positive samples were found.
文摘[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the differences of mitochondrial genes among different species.[Methods]The specificity,limit of detection and repeatability test were carried out by isolating somatic cells,extracting template DNA and determining the reaction conditions of real-time fluorescence-based PCR.[Results]The real-time fluorescence-based PCR method could be used to identify the bovine and ovine-derived materials of milk powder with high specificity,high sensitivity and good repeatability,and the limit of detection of milk components in goat milk powder could reach 0.01%.[Conclusions]The real-time fluorescence-based PCR method can be used to quickly and accurately detect the milk components in goat milk powder,and provide some technical support for the adulteration detection of dairy industry.
文摘Scientists from China and the United States appear to make a breakthrough in determining the Earth’s earliest animals what organisms are the oldest animals on
文摘The importance of the original artistic animation was discussed from the protection of region culture resources and the exploiture plan of the cultural resources in Hubei Province
基金This work was partially supported by the National Natural Science Foundation of China (No. 31500138) (to H.G.) and the Major Program of National Natural Science Foundation of China (No. 81590763) (to H.Y.)
文摘The Middle East respiratory syndrome coronavirus (MERS-CoV) is a novel zoonotic pathogen. In 2012, the infectious outbreak caused by MERS-CoV in Saudi Arabia has spread to more than 1600 patients in 26 countries, resulting in over 600 deaths. Without a travel history, few clinical and radiological features can reliably differentiate MERS from SARS. But in real world, comparing with SARS, MERS presents more vaguely defined epidemiology, more severe symptoms, and higher case fatality rate. In this review, we summarize the recent findings in the field of MERS-CoV, especially its molecular virology, interspecies mechanisms, clinical features, antiviral therapies, and the further investigation into this disease. As a newly emerging virus, many questions are not fully answered, including the exact mode of transmission chain, geographical distribution, and animal origins. Furthermore, a new protocol needs to be launched to rapidly evaluate the effects of unproven antiviral drugs and vaccine to fasten the clinical application of new drugs.