Nervous necrosis virus （NNV） is the causative agent of fulminant infectious diseases in marine fishes such as grouper. Specific primers were designed based on the conserved sequence of capsid protein （CP） gene of ...Nervous necrosis virus （NNV） is the causative agent of fulminant infectious diseases in marine fishes such as grouper. Specific primers were designed based on the conserved sequence of capsid protein （CP） gene of red-spotted grouper nervous necrosis virus （NNV）. By optimizing the reaction conditions, a rapid and simple reverse transcription loop-mediated isothermal amplification （RT-LAMP） method was established for NNV detection. After adding SYTO-9 fluorescent dye in the reaction system, the amplification curve was monitored in real time using a fluorescence detector, and the result was obviously easy to assess. Moreover, the specificity and sensitivity of the established method was analyzed. The results showed that the established RT-LAMP method has good specificity with a detection limit of 1.3 pg/μl. The detection sensitivity of the established RT-LAMP method is 100 times that of the conventional RT-PCR method, and the detection duration is only 40 min. The established RT-LAMP method is suitable for quarantine and rapid detection of grouper nervous necrosis virus.展开更多
PSPICE model driven by an electric equivalent circuit of a piezoelectric circuit is presented. In order to confirm this model to be effective, an independent model of cold cathode fluorescent lamp(CCFL) driving circui...PSPICE model driven by an electric equivalent circuit of a piezoelectric circuit is presented. In order to confirm this model to be effective, an independent model of cold cathode fluorescent lamp(CCFL) driving circuit is used to conduct simulations, leading to a precise modeling. A library is configured through modeling and its accuracy is verified through simulations for widely used and representative lamps such as CCFL, fluorescent lamps, HID lamps, and electrodeless fluorescent lamps. On the basis of experiments, a lamp simulation is also performed using PSPICE, which allows us to take advantage of the lamp library easily. Also, PSPICE model driven by an electric equivalent circuit of a piezoelectric transformer is presented. In order to confirm this model to be effective, an independent model of CCFL driving circuit is used to conduct simulations, leading to a precise modeling. In addition, a new type of electronic ballast is proposed, which allows 35 W-class(T5-class) fluorescent lamp to work. This system is built by a rectifier which has improved power factor and half-bridge series resonant inverter. Also, with size of 27.5 mm high, 27.5 mm wide and 2.5 mm thick, the produced piezoelectric transformer has a high step-up ratio, through which it is possible for the electric ballast circuit to be lighter, smaller and more efficient. After the produced ballast is used to drive the fluorescent lamp for 25 min, it yields 0.95 in power factor correction, 86% in efficiency, 35.07 W in output voltage and 20.5 °C in temperature increase while meeting the characteristics of the 35 W-class fluorescent lamp.展开更多
The formation mechanism of the discharge spot at a bottom of a lead wire in a fluorescent lamp at end-of-life is investigated. When the lamp at end-of life is ignited by applying high voltage, glow-like discharge is f...The formation mechanism of the discharge spot at a bottom of a lead wire in a fluorescent lamp at end-of-life is investigated. When the lamp at end-of life is ignited by applying high voltage, glow-like discharge is formed on the surface of the lead wire. A few seconds later, a bright spot is formed at the bottom 0fthe lead-wire. Then the stem glass on which the lead-wires are mounted begins to melt. High electric field is formed between the surface of the lead-wire and the stem glass surrounding the lead wire. Then discharge spot will be formed at the contact portion of the lead wire to the stem glass by this high electric field. To prevent discharge spot formation at the bottom of the lead wire, the metal ring is set to encircle the lead wire and is connected to the lead wire potential through a resistor. By this configuration, discharge spot formation is effectively suppressed. The mechanism for preventing hot discharge spot formation by the metal ring is discussed.展开更多
【目的】建立基于荧光显色的可视化禽传染性支气管炎病毒(IBV)环介导等温扩增(LAMP)检测体系,为IBV的快速临床检测提供有力的技术支持。【方法】根据NCBI中收录的IBV 5a+5b基因的8个区域设计了3对LAMP引物,通过对反应体系各组分和条件...【目的】建立基于荧光显色的可视化禽传染性支气管炎病毒(IBV)环介导等温扩增(LAMP)检测体系,为IBV的快速临床检测提供有力的技术支持。【方法】根据NCBI中收录的IBV 5a+5b基因的8个区域设计了3对LAMP引物,通过对反应体系各组分和条件的优化,建立IBV LAMP检测方法,并对该方法的特异性和敏感性进行验证。分别用SYBR Green I和一定浓度比的钙黄绿素/锰离子混合物作为显色剂,对IBV LAMP检测结果进行可视化判定。应用该检测体系和PCR方法对临床送检的60份样品同时进行检测,比较2种方法的阳性检出率。【结果】成功建立了IBV LAMP检测方法,该方法能够在等温(63℃)条件下1h内完成反应,具有良好的敏感性和特异性,最低可以检出1拷贝/μL的阳性重组质粒,比普通PCR方法敏感100倍,而对其他病毒检测结果均为阴性。应用SYBR Green I和钙黄绿素/锰离子显色时,阴阳性样品均有强烈的颜色对比,其中0.05mmol/L钙黄绿素与0.6mmol/L锰离子混合液可以用于LAMP扩增产物的判断,其结果与琼脂糖凝胶电泳结果一致。在对60份临床样本的检测中,LAMP和PCR方法检测出的阳性样本数量分别为49份和42份。【结论】建立了基于荧光显色的IBVLAMP检测方法,该方法具有在科研机构、基层实验室特别是检测现场推广和应用的潜力。展开更多
建立调味粉中罂粟碱LAMP(loop-mediated isothermal amplification of DNA,LAMP)检测方法,并研制出配套试剂盒。根据罂粟碱的特异性基因序列设计引物,对12种罂粟、11种香辛料和1种虞美人核酸样品进行特异性、最佳温度筛选及敏感性实验,...建立调味粉中罂粟碱LAMP(loop-mediated isothermal amplification of DNA,LAMP)检测方法,并研制出配套试剂盒。根据罂粟碱的特异性基因序列设计引物,对12种罂粟、11种香辛料和1种虞美人核酸样品进行特异性、最佳温度筛选及敏感性实验,根据优化后的反应条件,组装试剂盒,并采用试剂盒对市售的8种调味粉进行检测。结果表明:12种罂粟和虞美人发生了特异性反应,最佳反应温度为65℃,LAMP检测最低浓度达70pg/μL,敏感性是PCR检测的10倍。市售8种调味粉中,有1种含有罂粟碱成分。实验所建立的检测方法及研制的试剂盒对调味粉中掺加罂粟粉检测具有重要意义。展开更多
基金Supported by Application Technology R&D and Demonstration Project of Hainan Province(ZDXM2015025)
文摘Nervous necrosis virus （NNV） is the causative agent of fulminant infectious diseases in marine fishes such as grouper. Specific primers were designed based on the conserved sequence of capsid protein （CP） gene of red-spotted grouper nervous necrosis virus （NNV）. By optimizing the reaction conditions, a rapid and simple reverse transcription loop-mediated isothermal amplification （RT-LAMP） method was established for NNV detection. After adding SYTO-9 fluorescent dye in the reaction system, the amplification curve was monitored in real time using a fluorescence detector, and the result was obviously easy to assess. Moreover, the specificity and sensitivity of the established method was analyzed. The results showed that the established RT-LAMP method has good specificity with a detection limit of 1.3 pg/μl. The detection sensitivity of the established RT-LAMP method is 100 times that of the conventional RT-PCR method, and the detection duration is only 40 min. The established RT-LAMP method is suitable for quarantine and rapid detection of grouper nervous necrosis virus.
文摘PSPICE model driven by an electric equivalent circuit of a piezoelectric circuit is presented. In order to confirm this model to be effective, an independent model of cold cathode fluorescent lamp(CCFL) driving circuit is used to conduct simulations, leading to a precise modeling. A library is configured through modeling and its accuracy is verified through simulations for widely used and representative lamps such as CCFL, fluorescent lamps, HID lamps, and electrodeless fluorescent lamps. On the basis of experiments, a lamp simulation is also performed using PSPICE, which allows us to take advantage of the lamp library easily. Also, PSPICE model driven by an electric equivalent circuit of a piezoelectric transformer is presented. In order to confirm this model to be effective, an independent model of CCFL driving circuit is used to conduct simulations, leading to a precise modeling. In addition, a new type of electronic ballast is proposed, which allows 35 W-class(T5-class) fluorescent lamp to work. This system is built by a rectifier which has improved power factor and half-bridge series resonant inverter. Also, with size of 27.5 mm high, 27.5 mm wide and 2.5 mm thick, the produced piezoelectric transformer has a high step-up ratio, through which it is possible for the electric ballast circuit to be lighter, smaller and more efficient. After the produced ballast is used to drive the fluorescent lamp for 25 min, it yields 0.95 in power factor correction, 86% in efficiency, 35.07 W in output voltage and 20.5 °C in temperature increase while meeting the characteristics of the 35 W-class fluorescent lamp.
文摘The formation mechanism of the discharge spot at a bottom of a lead wire in a fluorescent lamp at end-of-life is investigated. When the lamp at end-of life is ignited by applying high voltage, glow-like discharge is formed on the surface of the lead wire. A few seconds later, a bright spot is formed at the bottom 0fthe lead-wire. Then the stem glass on which the lead-wires are mounted begins to melt. High electric field is formed between the surface of the lead-wire and the stem glass surrounding the lead wire. Then discharge spot will be formed at the contact portion of the lead wire to the stem glass by this high electric field. To prevent discharge spot formation at the bottom of the lead wire, the metal ring is set to encircle the lead wire and is connected to the lead wire potential through a resistor. By this configuration, discharge spot formation is effectively suppressed. The mechanism for preventing hot discharge spot formation by the metal ring is discussed.
文摘【目的】建立基于荧光显色的可视化禽传染性支气管炎病毒(IBV)环介导等温扩增(LAMP)检测体系,为IBV的快速临床检测提供有力的技术支持。【方法】根据NCBI中收录的IBV 5a+5b基因的8个区域设计了3对LAMP引物,通过对反应体系各组分和条件的优化,建立IBV LAMP检测方法,并对该方法的特异性和敏感性进行验证。分别用SYBR Green I和一定浓度比的钙黄绿素/锰离子混合物作为显色剂,对IBV LAMP检测结果进行可视化判定。应用该检测体系和PCR方法对临床送检的60份样品同时进行检测,比较2种方法的阳性检出率。【结果】成功建立了IBV LAMP检测方法,该方法能够在等温(63℃)条件下1h内完成反应,具有良好的敏感性和特异性,最低可以检出1拷贝/μL的阳性重组质粒,比普通PCR方法敏感100倍,而对其他病毒检测结果均为阴性。应用SYBR Green I和钙黄绿素/锰离子显色时,阴阳性样品均有强烈的颜色对比,其中0.05mmol/L钙黄绿素与0.6mmol/L锰离子混合液可以用于LAMP扩增产物的判断,其结果与琼脂糖凝胶电泳结果一致。在对60份临床样本的检测中,LAMP和PCR方法检测出的阳性样本数量分别为49份和42份。【结论】建立了基于荧光显色的IBVLAMP检测方法,该方法具有在科研机构、基层实验室特别是检测现场推广和应用的潜力。
文摘建立调味粉中罂粟碱LAMP(loop-mediated isothermal amplification of DNA,LAMP)检测方法,并研制出配套试剂盒。根据罂粟碱的特异性基因序列设计引物,对12种罂粟、11种香辛料和1种虞美人核酸样品进行特异性、最佳温度筛选及敏感性实验,根据优化后的反应条件,组装试剂盒,并采用试剂盒对市售的8种调味粉进行检测。结果表明:12种罂粟和虞美人发生了特异性反应,最佳反应温度为65℃,LAMP检测最低浓度达70pg/μL,敏感性是PCR检测的10倍。市售8种调味粉中,有1种含有罂粟碱成分。实验所建立的检测方法及研制的试剂盒对调味粉中掺加罂粟粉检测具有重要意义。
