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Stable germline transformation of the malaria mosquito Anopheles stephensi   总被引:8,自引:0,他引:8  
Anopheline mosquito species are obligatory vectors for human malaria, an infectious disease that affects hundreds of millions of people living in tropical and subtropical countries. The lack of a suitable gene transfer technology for these mosquitoes has hampered the molecular genetic analysis of their physiology, including the molecular interactions between the vector and the malaria parasite. Here we show that a transposon, based on the Minos element and bearing exogenous DNA, can integrate efficiently and stably into the germ line of the human malaria vector Anopheles stephensi, through a transposase-mediated process.  相似文献   

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汽车尾气催化转化器内流动均匀性对起燃特性的影响   总被引:1,自引:0,他引:1  
为了优化汽车尾气催化转化器设计,研究其中流动均匀性与催化剂起燃特性的关系。建立了冷启动过程催化剂载体温度场变化的数学模型。使用计算流体力学软件分析流动均匀性对载体温度场和催化剂转化效率的影响。实验中,通过改变载体端面形状,改变催化器内流动均匀性,并在发动机实验台上测试流动均匀性对起燃特性和催化剂转化效率的影响。计算和实验结果都显示:提高催化器内流动均匀性将明显延缓催化剂的起燃过程,从而增加起燃过程中尾气中污染物的排放。  相似文献   

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针对核辐射事故现场对辐射泄漏点监测、辐射分布情况分析等应急处理需求,并结合国内外现有的研究成果以及相关产品的发展技术,设计出面向核辐射领域的具有飞行、监测能力的仪器。该仪器的飞行动力单元设计采用四旋翼飞行器,利用其适应环境能力强、可移动的特点,飞入到人不可能到达的地方进行辐射剂量监测,从而保证实时传回监测中心的数据更加准确与可靠。  相似文献   

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S Singer 《Nature》1973,244(5411):110-111
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O Van Reeth  F W Turek 《Nature》1989,339(6219):49-51
A number of environmental and pharmacological stimuli capable of inducing phase shifts and/or period changes in the circadian clock of mammals have now been identified. Agents that can alter circadian clocks provide a means for investigating the cellular and neural mechanisms responsible for their generation, regulation and entrainment. Two stimuli that have been used to probe the basis of circadian rhythmicity are pulses of darkness on a background of constant light and injections of short-acting benzodiazepines, such as triazolam. Surprisingly, these two very different stimuli have remarkably similar phase-shifting effects on the circadian clock of hamsters. The observation that a short-term increase in locomotor activity occurs when the circadian activity rhythm of hamsters is shifted by dark pulses or triazolam injections, coupled with the finding that activity bouts themselves are capable of shifting this rhythm, raises the possibility that dark pulses or triazolam alter the circadian clock by inducing acute hyperactivity. Here we demonstrate that the phase-advancing and phase-delaying effects of dark pulses or triazolam on the circadian activity rhythm can be totally suppressed by immobilization of the animals during treatment. These results indicate that behavioural events mediate the phase-shifting effects of both dark pulses and triazolam on the circadian activity rhythm and question present hypotheses regarding the pathways by which light-dark information and pharmacological agents influence circadian pacemakers.  相似文献   

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高宏 《科技资讯》2013,(15):214-214,216
失速可以发生在飞行的任何一个阶段,而且飞机失速对飞行安全会带来难以估计的影响。本文介绍了飞机失速的原因,飞行过程中对失速的预防以及飞机失速的判断与处置。  相似文献   

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