建立了一步式QuEChERS自动提取和净化技术结合气相色谱-串联质谱同时测定风干牦牛肉中15种N-亚硝胺的分析方法。样品水化后,经乙腈提取,加入4.0 g MgSO_(4)和1.0 g NaCl除水,经十八烷基硅烷(C_(18))和N-丙基乙二胺(PSA)填料净化,采用DB-...建立了一步式QuEChERS自动提取和净化技术结合气相色谱-串联质谱同时测定风干牦牛肉中15种N-亚硝胺的分析方法。样品水化后,经乙腈提取,加入4.0 g MgSO_(4)和1.0 g NaCl除水,经十八烷基硅烷(C_(18))和N-丙基乙二胺(PSA)填料净化,采用DB-HeavyWAX色谱柱(30 m×0.25 mm×0.25μm)分离15种N-亚硝胺,在多重反应监测(MRM)模式下进行测定,外标法定量。结果表明,15种N-亚硝胺分离性能良好,在0.1~200μg/L范围内线性关系良好,相关系数(r^(2))≥0.999 0;检出限(LOD)为0.05~0.20μg/kg,定量限(LOQ)为0.10~0.50μg/kg;在1倍、2倍和10倍LOQ 3个添加水平下的平均回收率分别为79.4%~102.1%、80.6%~109.5%、83.0%~110.6%,相对标准偏差(RSD)为0.8%~16.0%。应用建立的方法检测2种不同加工工艺的市售样品,其中7种N-亚硝胺类化合物(N-亚硝基二甲胺、N-亚硝基二异丁胺、N-亚硝基二正丁胺、N-亚硝基甲基苯胺、N-亚硝基乙基苯胺、N-亚硝基吡咯烷、N-亚硝基二苯胺)均有不同程度检出,平均含量为0.08~20.18μg/kg,且熟制风干牦牛肉中N-亚硝胺的检出率和平均含量均高于传统生制风干牦牛肉。该方法实现了前处理的自动化,相较于其他传统方法,操作简单,实验效率高,人为影响因素小,检测灵敏度高,适用于风干牦牛肉中15种N-亚硝胺的快速测定,为研究肉制品中N-亚硝胺的测定提供了方法支持。展开更多
扩张型心肌病(dilated cardiomyopathy,DCM)是一类以左心室扩张和左心室收缩功能障碍为主要特征的心脏病,可最终引起心力衰竭、心律失常和猝死,也是目前心脏移植的最主要病因。准确评估DCM患者心脏受累程度,对疾病进行危险分层,识别需...扩张型心肌病(dilated cardiomyopathy,DCM)是一类以左心室扩张和左心室收缩功能障碍为主要特征的心脏病,可最终引起心力衰竭、心律失常和猝死,也是目前心脏移植的最主要病因。准确评估DCM患者心脏受累程度,对疾病进行危险分层,识别需密切随访及强化治疗的高危患者尤为重要。心脏磁共振(cardiovascular magnetic resonance,CMR)多模态、多参数成像,常规CMR电影序列能准确评估心脏的形态及功能异常,而基于CMR的组织学与微观结构成像还能为DCM患者的预后提供更多有价值的信息。作者对CMR在DCM的危险分层及预后评估中的应用进展予以综述。展开更多
淀粉样变性是一类系统性疾病,其特征是不同来源的错误折叠蛋白片段在器官内沉积。淀粉样变性可累及心脏,称为心肌淀粉样变,且病变的严重程度是决定患者预后的主要因素。目前临床最常见的心肌淀粉样变类型主要为原发性免疫球蛋白轻链型(l...淀粉样变性是一类系统性疾病,其特征是不同来源的错误折叠蛋白片段在器官内沉积。淀粉样变性可累及心脏,称为心肌淀粉样变,且病变的严重程度是决定患者预后的主要因素。目前临床最常见的心肌淀粉样变类型主要为原发性免疫球蛋白轻链型(light-chain amyloidosis,AL)和遗传性甲状腺素转载蛋白型淀粉样变(transthyretinrelated amyloidosis,ATTR),而不同类型的淀粉样变的治疗手段及预后也不相同。因此,早期、准确诊断心肌淀粉样变尤为重要。心脏磁共振(cardiovascular magnetic resonance,CMR)具有多模态、多参数成像特点,不仅能早期发现心肌淀粉样变的形态及功能异常,还能准确评判心肌组织学特征及微循环改变,为疾病的诊断、危险分层及预后评估提供重要信息。笔者将对心肌淀粉样变性的CMR应用进展进行综述。展开更多
肥厚型心肌病(hypertrophic cardiomyopathy,HCM)是最常见的遗传性原发型心肌病,也是青年人猝死的最常见原因。心脏磁共振(cardiovascular magnetic resonance,CMR)多参数、多模态成像,能从多个方面综合评估患者心脏受累程度,从而为HCM...肥厚型心肌病(hypertrophic cardiomyopathy,HCM)是最常见的遗传性原发型心肌病,也是青年人猝死的最常见原因。心脏磁共振(cardiovascular magnetic resonance,CMR)多参数、多模态成像,能从多个方面综合评估患者心脏受累程度,从而为HCM患者危险分层及预后评估提供重要信息。本文就CMR成像,尤其是组织学成像在HCM患者危险分层及预后评估中的应用进展予以综述。展开更多
At present,the understanding of the dynamics of denitrifiers at different dissolved oxygen(DO)layers under organic carbon consumption within the surface sediments remains inadequate.In this study,high-throughput seque...At present,the understanding of the dynamics of denitrifiers at different dissolved oxygen(DO)layers under organic carbon consumption within the surface sediments remains inadequate.In this study,high-throughput sequencing and quantitative PCR targeting nirS gene were used to analyze the denitrifier abundance dynamics,community composition,and structure for aerobic(DO 0.5-6.9 mg/L),hypoxic-anoxic(DO 0-0.5 mg/L),and anoxic(DO 0 mg/L)layers in surface sediments under organic carbon consumption.Based on the analysis of nirS gene abundance,the values of denitrifying bacteria decreased with organic carbon consumption at different DO layers.When the bacterial species abundance at the genus level were compared between the high-carbon and low-carbon sediments,there was significant increase in 6 out of 36,7 out of 36 and 6 out of 36 genera respectively for the aerobic,hypoxic-anoxic and anoxic layers.On the other hand,14 out of 36,9 out of 36 and 15 out of 36 genera showed significant decrease in bacterial species abundance respectively for the aerobic,hypoxic-anoxic and anoxic layers.Additionally,14 out of 36,20 out of 36,and 15 out of 36 genera had no change in bacterial species abundance respectively for the aerobic,hypoxic-anoxic,and anoxic layers.This indicates that the carbon utilization ability of different denitrifiers on each DO layers was generally different from each other.Diversity of denitrifying bacteria also presented significant differences in different DO layers between the high-and low-carbon content sediment layers.Moreover,under the high-carbon and low-carbon content,the abundance of nirS gene showed a high peak within the hypoxic-anoxic regions,suggesting that this region might be the main distribution area for the denitrifying bacteria within the surface sediments.Furthermore,community of unique denitrifiers occurred in different DO layers and the adaptive changes of the denitrifier community followed the organic carbon consumption.展开更多
文摘建立了一步式QuEChERS自动提取和净化技术结合气相色谱-串联质谱同时测定风干牦牛肉中15种N-亚硝胺的分析方法。样品水化后,经乙腈提取,加入4.0 g MgSO_(4)和1.0 g NaCl除水,经十八烷基硅烷(C_(18))和N-丙基乙二胺(PSA)填料净化,采用DB-HeavyWAX色谱柱(30 m×0.25 mm×0.25μm)分离15种N-亚硝胺,在多重反应监测(MRM)模式下进行测定,外标法定量。结果表明,15种N-亚硝胺分离性能良好,在0.1~200μg/L范围内线性关系良好,相关系数(r^(2))≥0.999 0;检出限(LOD)为0.05~0.20μg/kg,定量限(LOQ)为0.10~0.50μg/kg;在1倍、2倍和10倍LOQ 3个添加水平下的平均回收率分别为79.4%~102.1%、80.6%~109.5%、83.0%~110.6%,相对标准偏差(RSD)为0.8%~16.0%。应用建立的方法检测2种不同加工工艺的市售样品,其中7种N-亚硝胺类化合物(N-亚硝基二甲胺、N-亚硝基二异丁胺、N-亚硝基二正丁胺、N-亚硝基甲基苯胺、N-亚硝基乙基苯胺、N-亚硝基吡咯烷、N-亚硝基二苯胺)均有不同程度检出,平均含量为0.08~20.18μg/kg,且熟制风干牦牛肉中N-亚硝胺的检出率和平均含量均高于传统生制风干牦牛肉。该方法实现了前处理的自动化,相较于其他传统方法,操作简单,实验效率高,人为影响因素小,检测灵敏度高,适用于风干牦牛肉中15种N-亚硝胺的快速测定,为研究肉制品中N-亚硝胺的测定提供了方法支持。
文摘扩张型心肌病(dilated cardiomyopathy,DCM)是一类以左心室扩张和左心室收缩功能障碍为主要特征的心脏病,可最终引起心力衰竭、心律失常和猝死,也是目前心脏移植的最主要病因。准确评估DCM患者心脏受累程度,对疾病进行危险分层,识别需密切随访及强化治疗的高危患者尤为重要。心脏磁共振(cardiovascular magnetic resonance,CMR)多模态、多参数成像,常规CMR电影序列能准确评估心脏的形态及功能异常,而基于CMR的组织学与微观结构成像还能为DCM患者的预后提供更多有价值的信息。作者对CMR在DCM的危险分层及预后评估中的应用进展予以综述。
文摘淀粉样变性是一类系统性疾病,其特征是不同来源的错误折叠蛋白片段在器官内沉积。淀粉样变性可累及心脏,称为心肌淀粉样变,且病变的严重程度是决定患者预后的主要因素。目前临床最常见的心肌淀粉样变类型主要为原发性免疫球蛋白轻链型(light-chain amyloidosis,AL)和遗传性甲状腺素转载蛋白型淀粉样变(transthyretinrelated amyloidosis,ATTR),而不同类型的淀粉样变的治疗手段及预后也不相同。因此,早期、准确诊断心肌淀粉样变尤为重要。心脏磁共振(cardiovascular magnetic resonance,CMR)具有多模态、多参数成像特点,不仅能早期发现心肌淀粉样变的形态及功能异常,还能准确评判心肌组织学特征及微循环改变,为疾病的诊断、危险分层及预后评估提供重要信息。笔者将对心肌淀粉样变性的CMR应用进展进行综述。
文摘肥厚型心肌病(hypertrophic cardiomyopathy,HCM)是最常见的遗传性原发型心肌病,也是青年人猝死的最常见原因。心脏磁共振(cardiovascular magnetic resonance,CMR)多参数、多模态成像,能从多个方面综合评估患者心脏受累程度,从而为HCM患者危险分层及预后评估提供重要信息。本文就CMR成像,尤其是组织学成像在HCM患者危险分层及预后评估中的应用进展予以综述。
基金Supported by the National Natural Science Foundation of China(Nos.31800112,31800390,31870450,31670465)。
文摘At present,the understanding of the dynamics of denitrifiers at different dissolved oxygen(DO)layers under organic carbon consumption within the surface sediments remains inadequate.In this study,high-throughput sequencing and quantitative PCR targeting nirS gene were used to analyze the denitrifier abundance dynamics,community composition,and structure for aerobic(DO 0.5-6.9 mg/L),hypoxic-anoxic(DO 0-0.5 mg/L),and anoxic(DO 0 mg/L)layers in surface sediments under organic carbon consumption.Based on the analysis of nirS gene abundance,the values of denitrifying bacteria decreased with organic carbon consumption at different DO layers.When the bacterial species abundance at the genus level were compared between the high-carbon and low-carbon sediments,there was significant increase in 6 out of 36,7 out of 36 and 6 out of 36 genera respectively for the aerobic,hypoxic-anoxic and anoxic layers.On the other hand,14 out of 36,9 out of 36 and 15 out of 36 genera showed significant decrease in bacterial species abundance respectively for the aerobic,hypoxic-anoxic and anoxic layers.Additionally,14 out of 36,20 out of 36,and 15 out of 36 genera had no change in bacterial species abundance respectively for the aerobic,hypoxic-anoxic,and anoxic layers.This indicates that the carbon utilization ability of different denitrifiers on each DO layers was generally different from each other.Diversity of denitrifying bacteria also presented significant differences in different DO layers between the high-and low-carbon content sediment layers.Moreover,under the high-carbon and low-carbon content,the abundance of nirS gene showed a high peak within the hypoxic-anoxic regions,suggesting that this region might be the main distribution area for the denitrifying bacteria within the surface sediments.Furthermore,community of unique denitrifiers occurred in different DO layers and the adaptive changes of the denitrifier community followed the organic carbon consumption.
文摘应用液相色谱-四极杆/静电场轨道阱质谱(LC-Q-Orbitrap/MS)建立了畜禽肉及水产品中磺胺类、喹诺酮类、四环素类等14类160种兽药残留快速筛查方法。均浆后的样品(猪、鸡、鱼)中加入80%(V/V)乙腈-水溶液(含0.2%(V/V)甲酸)振荡提取,Oasis PRiME HLB固相萃取柱净化,在全扫描/数据依赖二级质谱扫描(Full MS/dd-MS2)模式下采集,基质匹配外标法定量。结果表明,160种兽药在0.25~100μg/L范围内线性关系良好,线性相关系数(R2)≥0.99,方法筛查限(SDL)和定量限(LOQ)均为0.5~20μg/kg。除敌敌畏、卡巴氧和二嗪磷回收率低于60%外,其余兽药在猪肉、鸡肉和鱼肉中1倍、 2倍和10倍定量限3个加标水平下的总体回收率为65.0%~119.6%,相对标准偏差(RSD)为0.73%~20%。方法应用于75批市售畜禽肉及水产品检测,共筛查出6类8种兽药。本方法可同时筛查畜禽肉及水产品中多种兽药残留。
