HE Ran,who was born and raised in Hejiayan Village in Youyang,a Tujia and Miao autonomous county in Chongqing Municipality,was once reluctant to stay in her hometown.“It was a bit dirty and disorganized,and the...HE Ran,who was born and raised in Hejiayan Village in Youyang,a Tujia and Miao autonomous county in Chongqing Municipality,was once reluctant to stay in her hometown.“It was a bit dirty and disorganized,and there weren’t many good jobs for me,”the 24-year-old told the reporter.But now,as the manager of a local cafe and guesthouse in Hejiayan,she has decided to settle down there and work for the betterment of the village.展开更多
Low temperature is one of the most important abiotic factors inhibiting growth, productivity, and distribution of rapeseed(Brassica napus L.). Therefore, it is important to identify and cultivate cold-tolerant germpla...Low temperature is one of the most important abiotic factors inhibiting growth, productivity, and distribution of rapeseed(Brassica napus L.). Therefore, it is important to identify and cultivate cold-tolerant germplasm. The objective of this study was to figure out the mechanism of chilling(4 and 2°C) and freezing(–2 and –4°C) stresses along with a control(22°C) in B. napus cultivars(1801 and C20) under controlled environment(growth chamber). The experiment was arranged in a complete randomized design with three replications. Our results exhibited that under chilling and freezing stresses, the increment of proline accumulation, soluble sugar and protein contents, and antioxidant enzyme activity were enhanced more in 1801 cultivar compared with C20 cultivar. At –2 and –4°C, the seedlings of C20 cultivar died completely compared with 1801 cultivar. Hydrogen peroxide(H2 O2) and malondialdehyde contents(MDA) increased in both cultivars, but when the temperature was decreased up to –2 and –4°C, the MDA and H2 O2 contents continuously dropped in 1801 cultivar. Moreover, we found that leaf abscisic acid(ABA) was enhanced in 1801 cultivar under chilling and freezing stresses. Additionally, the transcriptional regulations of cold-tolerant genes(COLD1, CBF4, COR6.6, COR15, and COR25) were also determined using real-time quantitative PCR(RT-q PCR). RT-q PCR showed that higher expression of these genes were found in 1801 as compared to C20 under cold stress(chilling and freezing stresses). Therefore, it is concluded from this experiment that 1801 cultivar has a higher ability to respond to cold stress(chilling and freezing stresses) by maintaining hormonal, antioxidative, and osmotic activity along with gene transcription process than C20. The result of this study will provide a solid foundation for understanding physiological and molecular mechanisms of cold stress signaling in rapeseed(B. napus).展开更多
A real-time RT-PCR assay using Taq Man-MGB probes was developed to detect and type the bovine viral diarrhea virus（BVDV） in cattle.Universal primers and Taq Man-MGB probes were designed from the 5′-untranslated reg...A real-time RT-PCR assay using Taq Man-MGB probes was developed to detect and type the bovine viral diarrhea virus（BVDV） in cattle.Universal primers and Taq Man-MGB probes were designed from the 5′-untranslated region of known pestiviral sequences.Prior to optimizing the assay, c RNAs were transcribed in vitro from the BVDV 1 and BVDV 2 RTPCR products to make standard curves.The detection limit of the assay was 1.72×102 copies for BVDV 1 and 2.14×102copies for BVDV 2.The specificity of the assay evaluated on several BVDV strains including bovine herpesvirus 1（BHV 1）, foot and mouth disease virus（FMDV） and several classical swine fever virus（CSFV） strains showed specific detection of the positive virus over 40 cycles.The assay was highly reproducible with the coefficient of variance ranging from 1.04 to 1.33% for BVDV 1 and from 0.83 to 1.48% for BVDV 2, respectively.Using this method, we tested a total of 2 327 cattle from three dairy farms for the presence of BVDV persistently infected（PI） animals.In this assay, each RT-PCR template contained a mixture of ten samples from different animals.The occurrence rate of PI cattle in three farms ranging from 0.9 to 2.54% could represent partly the PI rates in cattle farm in China.In conclusion, using our real-time PCR assay, we could effectively detect and type BVDV and identify PI cattle in a rapid and cost-effective manner.展开更多
Two different solvents had been used to separate benzene from 1-hexene under atmosphere pressure by employing one of the following two solvents, viz.: dimethyl sulfoxide (DMSO) at 298.15 K and 318.15 K, and furfural a...Two different solvents had been used to separate benzene from 1-hexene under atmosphere pressure by employing one of the following two solvents, viz.: dimethyl sulfoxide (DMSO) at 298.15 K and 318.15 K, and furfural at 298.15 K. A series of liquid-liquid equilibrium (LLE) data had been obtained and the distribution coefficient together with the separation factor were calculated from them. Both the NRTL and the UNIQUAC models could fit in with the experimental data quite well.展开更多
In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate （LZT） film are studied by X-ray diffraction （XRD） and scanning eletron microscope （SEM）. The ratio of PbTi...In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate （LZT） film are studied by X-ray diffraction （XRD） and scanning eletron microscope （SEM）. The ratio of PbTiOJPbZrO3 in LZT is 53/47, which is around morphotropic phase boundary （MPB）. LZT film is composed of cubic particles with the average size of 5 ~ma. Density of thin film is figured out through the datum measured in experiments. The displacement model used to analyze the driving ability of bimorph is set up, and the effect of elastic intermediate layer is taken into account. Piezoelectric coefficient of LZT film is worked out by using the displacement model. Experiments of driving ability show that deformation of bimorph free end does not increase with times of crystal growth processes and the maximum deformation is obtained after two times crystal growth processes. Finally, the ferroelectric property of the bimorph is investigated and coercive voltage of the bimorph is obtained.展开更多
为了研究基于矩形贴片天线的应变测量技术,根据传输线模型,分析了矩形贴片天线与应变间的作用机理,明确了天线辐射单元尺寸受应变影响,可导致贴片天线中心频率发生偏移,且获得了频率偏移量与应变间的线性关系理论表达式.设计3种不同中...为了研究基于矩形贴片天线的应变测量技术,根据传输线模型,分析了矩形贴片天线与应变间的作用机理,明确了天线辐射单元尺寸受应变影响,可导致贴片天线中心频率发生偏移,且获得了频率偏移量与应变间的线性关系理论表达式.设计3种不同中心频率的矩形贴片天线,利用高频结构模拟器(high frequency structure simulator,HFSS)电磁仿真软件和拉伸应变检测系统,对不同应变状态下,贴片天线中心频率随应变的变化趋势进行了仿真与实验测试.仿真和实验结果表明:贴片天线的中心频率的偏移量与应变之间线性关系明显,且贴片天线的中心频率越高,应变灵敏度越大.利用矩形贴片天线作为应变传感器,可满足结构应变测量要求,为结构健康无线监测研究奠定了基础.展开更多
本研究采用罗氏、天隆、赛默飞世尔等公司生产的5种核酸提取试剂盒,对新城疫病毒RNA的提取效率进行比较,以优选出提取效率高、耗时短、成本低的核酸提取方法,为各级实验室开展新城疫病毒核酸检测提供技术参考。采用5种商品化核酸提取试...本研究采用罗氏、天隆、赛默飞世尔等公司生产的5种核酸提取试剂盒,对新城疫病毒RNA的提取效率进行比较,以优选出提取效率高、耗时短、成本低的核酸提取方法,为各级实验室开展新城疫病毒核酸检测提供技术参考。采用5种商品化核酸提取试剂盒,对不同浓度(稀释度10~0~10^(-8)/EID50 10^(8.3))的新城疫病毒标准样品进行RNA提取,通过实时定量荧光RT-PCR进行检测,以Ct值评价5种试剂盒的RNA提取效率,并对试剂盒的RNA提取时间和价格等进行综合比较分析。结果显示:High Pure Viral RNA Kit(罗氏)、动物疫病病毒RNA核酸提取试剂盒(天隆)和Lab Serv Viral Total NA Kit(赛默飞世尔)的RNA提取效率较高。其中,Lab Serv Viral Total NA Kit对低浓度样本的RNA提取效率最高,价格最便宜;Tian Long的RNA提取所需时间也较短,但操作最为简便。综合提取效率、时间及成本等因素,分析认为Lab Serv Viral Total NA Kit(赛默飞世尔)性价比最高,适用于大批量临床样品的集中检测。展开更多
目的研究急性前循环梗死合并中重度脑白质疏松患者超早期静脉应用重组组织型纤溶酶原激活剂(recombinant tissue plasminogen activator,rt-PA)静脉溶栓治疗的预后及相关因素,为患者的临床诊断及预后评估提供指导。方法回顾性分析2015年...目的研究急性前循环梗死合并中重度脑白质疏松患者超早期静脉应用重组组织型纤溶酶原激活剂(recombinant tissue plasminogen activator,rt-PA)静脉溶栓治疗的预后及相关因素,为患者的临床诊断及预后评估提供指导。方法回顾性分析2015年1月-2018年6月上海市第一人民医院宝山分院接诊的88例急性前循环梗死患者。按照治疗方法的不同,将所有患者分为研究组与对照组,研究组48例给予rt-PA溶栓治疗。对照组36例患者未给予溶栓处理。观察对比两组患者的肢体运动功能、神经功能、脑白质疏松情况、梗死面积以及预后情况。结果研究组患者基线NIHSS评分(National Institute of Health stroke scale)、24 h NIHSS评分、7 d NIHSS评分明显高于对照组患者,差异有统计学意义。两组患者入院FMS评分(Functional Movement Screen)无明显差异。研究组患者的90 d FMS评分明显低于对照组患者。logistic回归分析结果提示,中重度脑白质疏松是影响静脉溶栓患者90 d预后的危险因素(OR=4.565 2,95%CI=1.200 1~67.725 1,P=0.032 7)。结论急性前循环梗死合并中重度脑白质疏松患者给予rt-PA静脉溶栓治疗后出血转化发生率提高,中重度脑白质疏松可作为预后不良的独立因素。展开更多
文摘HE Ran,who was born and raised in Hejiayan Village in Youyang,a Tujia and Miao autonomous county in Chongqing Municipality,was once reluctant to stay in her hometown.“It was a bit dirty and disorganized,and there weren’t many good jobs for me,”the 24-year-old told the reporter.But now,as the manager of a local cafe and guesthouse in Hejiayan,she has decided to settle down there and work for the betterment of the village.
基金supported by the National Key Research and Development Program of China (2017YFD0101700)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciencesthe Hubei Agricultural Science and Technology Innovation Center, China
文摘Low temperature is one of the most important abiotic factors inhibiting growth, productivity, and distribution of rapeseed(Brassica napus L.). Therefore, it is important to identify and cultivate cold-tolerant germplasm. The objective of this study was to figure out the mechanism of chilling(4 and 2°C) and freezing(–2 and –4°C) stresses along with a control(22°C) in B. napus cultivars(1801 and C20) under controlled environment(growth chamber). The experiment was arranged in a complete randomized design with three replications. Our results exhibited that under chilling and freezing stresses, the increment of proline accumulation, soluble sugar and protein contents, and antioxidant enzyme activity were enhanced more in 1801 cultivar compared with C20 cultivar. At –2 and –4°C, the seedlings of C20 cultivar died completely compared with 1801 cultivar. Hydrogen peroxide(H2 O2) and malondialdehyde contents(MDA) increased in both cultivars, but when the temperature was decreased up to –2 and –4°C, the MDA and H2 O2 contents continuously dropped in 1801 cultivar. Moreover, we found that leaf abscisic acid(ABA) was enhanced in 1801 cultivar under chilling and freezing stresses. Additionally, the transcriptional regulations of cold-tolerant genes(COLD1, CBF4, COR6.6, COR15, and COR25) were also determined using real-time quantitative PCR(RT-q PCR). RT-q PCR showed that higher expression of these genes were found in 1801 as compared to C20 under cold stress(chilling and freezing stresses). Therefore, it is concluded from this experiment that 1801 cultivar has a higher ability to respond to cold stress(chilling and freezing stresses) by maintaining hormonal, antioxidative, and osmotic activity along with gene transcription process than C20. The result of this study will provide a solid foundation for understanding physiological and molecular mechanisms of cold stress signaling in rapeseed(B. napus).
基金supported by the China Agriculture Research System(CARS-37)
文摘A real-time RT-PCR assay using Taq Man-MGB probes was developed to detect and type the bovine viral diarrhea virus（BVDV） in cattle.Universal primers and Taq Man-MGB probes were designed from the 5′-untranslated region of known pestiviral sequences.Prior to optimizing the assay, c RNAs were transcribed in vitro from the BVDV 1 and BVDV 2 RTPCR products to make standard curves.The detection limit of the assay was 1.72×102 copies for BVDV 1 and 2.14×102copies for BVDV 2.The specificity of the assay evaluated on several BVDV strains including bovine herpesvirus 1（BHV 1）, foot and mouth disease virus（FMDV） and several classical swine fever virus（CSFV） strains showed specific detection of the positive virus over 40 cycles.The assay was highly reproducible with the coefficient of variance ranging from 1.04 to 1.33% for BVDV 1 and from 0.83 to 1.48% for BVDV 2, respectively.Using this method, we tested a total of 2 327 cattle from three dairy farms for the presence of BVDV persistently infected（PI） animals.In this assay, each RT-PCR template contained a mixture of ten samples from different animals.The occurrence rate of PI cattle in three farms ranging from 0.9 to 2.54% could represent partly the PI rates in cattle farm in China.In conclusion, using our real-time PCR assay, we could effectively detect and type BVDV and identify PI cattle in a rapid and cost-effective manner.
基金the financial supports provided by the National Natural Science Foundation of China (No.21177038)
文摘Two different solvents had been used to separate benzene from 1-hexene under atmosphere pressure by employing one of the following two solvents, viz.: dimethyl sulfoxide (DMSO) at 298.15 K and 318.15 K, and furfural at 298.15 K. A series of liquid-liquid equilibrium (LLE) data had been obtained and the distribution coefficient together with the separation factor were calculated from them. Both the NRTL and the UNIQUAC models could fit in with the experimental data quite well.
基金This project is supported by National Natural Science Foundation of China (No.50675025)Scientific Research Foundation of Ministry of Education,Dalian City for the Returned Overseas Chinese ScholarsDoctoral Startup Fund of Liaoning Province of China (No.20051080).
文摘In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate （LZT） film are studied by X-ray diffraction （XRD） and scanning eletron microscope （SEM）. The ratio of PbTiOJPbZrO3 in LZT is 53/47, which is around morphotropic phase boundary （MPB）. LZT film is composed of cubic particles with the average size of 5 ~ma. Density of thin film is figured out through the datum measured in experiments. The displacement model used to analyze the driving ability of bimorph is set up, and the effect of elastic intermediate layer is taken into account. Piezoelectric coefficient of LZT film is worked out by using the displacement model. Experiments of driving ability show that deformation of bimorph free end does not increase with times of crystal growth processes and the maximum deformation is obtained after two times crystal growth processes. Finally, the ferroelectric property of the bimorph is investigated and coercive voltage of the bimorph is obtained.
文摘为了研究基于矩形贴片天线的应变测量技术,根据传输线模型,分析了矩形贴片天线与应变间的作用机理,明确了天线辐射单元尺寸受应变影响,可导致贴片天线中心频率发生偏移,且获得了频率偏移量与应变间的线性关系理论表达式.设计3种不同中心频率的矩形贴片天线,利用高频结构模拟器(high frequency structure simulator,HFSS)电磁仿真软件和拉伸应变检测系统,对不同应变状态下,贴片天线中心频率随应变的变化趋势进行了仿真与实验测试.仿真和实验结果表明:贴片天线的中心频率的偏移量与应变之间线性关系明显,且贴片天线的中心频率越高,应变灵敏度越大.利用矩形贴片天线作为应变传感器,可满足结构应变测量要求,为结构健康无线监测研究奠定了基础.
文摘本研究采用罗氏、天隆、赛默飞世尔等公司生产的5种核酸提取试剂盒,对新城疫病毒RNA的提取效率进行比较,以优选出提取效率高、耗时短、成本低的核酸提取方法,为各级实验室开展新城疫病毒核酸检测提供技术参考。采用5种商品化核酸提取试剂盒,对不同浓度(稀释度10~0~10^(-8)/EID50 10^(8.3))的新城疫病毒标准样品进行RNA提取,通过实时定量荧光RT-PCR进行检测,以Ct值评价5种试剂盒的RNA提取效率,并对试剂盒的RNA提取时间和价格等进行综合比较分析。结果显示:High Pure Viral RNA Kit(罗氏)、动物疫病病毒RNA核酸提取试剂盒(天隆)和Lab Serv Viral Total NA Kit(赛默飞世尔)的RNA提取效率较高。其中,Lab Serv Viral Total NA Kit对低浓度样本的RNA提取效率最高,价格最便宜;Tian Long的RNA提取所需时间也较短,但操作最为简便。综合提取效率、时间及成本等因素,分析认为Lab Serv Viral Total NA Kit(赛默飞世尔)性价比最高,适用于大批量临床样品的集中检测。
文摘目的研究急性前循环梗死合并中重度脑白质疏松患者超早期静脉应用重组组织型纤溶酶原激活剂(recombinant tissue plasminogen activator,rt-PA)静脉溶栓治疗的预后及相关因素,为患者的临床诊断及预后评估提供指导。方法回顾性分析2015年1月-2018年6月上海市第一人民医院宝山分院接诊的88例急性前循环梗死患者。按照治疗方法的不同,将所有患者分为研究组与对照组,研究组48例给予rt-PA溶栓治疗。对照组36例患者未给予溶栓处理。观察对比两组患者的肢体运动功能、神经功能、脑白质疏松情况、梗死面积以及预后情况。结果研究组患者基线NIHSS评分(National Institute of Health stroke scale)、24 h NIHSS评分、7 d NIHSS评分明显高于对照组患者,差异有统计学意义。两组患者入院FMS评分(Functional Movement Screen)无明显差异。研究组患者的90 d FMS评分明显低于对照组患者。logistic回归分析结果提示,中重度脑白质疏松是影响静脉溶栓患者90 d预后的危险因素(OR=4.565 2,95%CI=1.200 1~67.725 1,P=0.032 7)。结论急性前循环梗死合并中重度脑白质疏松患者给予rt-PA静脉溶栓治疗后出血转化发生率提高,中重度脑白质疏松可作为预后不良的独立因素。
