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介绍瞬态闪光光强测量中的一种调整数据采集电路的设计方法、工作原理、与单片机的接口及其应用。  相似文献   
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学习能力是学生从事学习活动、获取新知和应用知识所必需的能力,它对促进学生学习能力的发展和在教学工作中“因材施教”具有重要的意义,所以寻求一种有效的测量工具来了解学生的学习能力就成为一个基本的问题了.“少年儿童学习能力测验”(简称测验)是林传鼎、张厚粲等根据澳大利亚教育学会制定的学习能力测验改编而成的.它由三个多项选择式的分测验组成:1,找同义词,有31题,属于智力结构中的V因素;2,  相似文献   
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The diagnosis of Duchenne muscular dystrophy (DMD) has historically utilized either PCR or requires Southern blot analysis, a southern blot analysis, however, is not amenable to incorporation in a microdevice format. A PCR amplification-based method has been developed, and we have previously coupled this amplification with microchip separation of the PCR fragments for DMD diagnosis. Diagnoses of affected patients were performed by comparing exon concentrations to those of control samples amplified at the same time. To accurately identify mutations in patient samples, this work established normal ranges for the concentration of each amplified exon fragment using control samples amplified over successive days. Our studies show that the number of cycles used in the amplification process affects this range. Affected patient samples were analyzed using these normal ranges and the mutations detected by Southern blot analysis were also diagnosed using the microchip separation method.

Employing the microchip separation method decreases the time required for the analysis, but the time required for DNA purification and PCR amplification must also be decreased for faster total analysis of patient samples. Development of microchip methods for these processing steps is one approach for reducing the individual times, while also providing the possibility of integrating these steps in a single device. Here we report on the microchip extraction of genomic DNA from whole blood using a novel sol–gel matrix that is easily formed in microdevices. IR-mediated PCR amplification of a β-globin fragment from genomic DNA followed by electrophoretic analysis on a single integrated microdevice is presented for the first time. Work towards the development of a micro-total analysis device for DMD diagnosis, through integration of all processing steps on a single device, is also discussed.  相似文献   

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Multistage mass spectrometry experiments reveal a sequence of gas phase reactions for the oxidation of methanol to formaldehyde with a mononuclear oxo vanadate anion as the catalyst and dioxygen as the terminal oxidant.  相似文献   
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We demonstrate a new and sensitive amplification technique (referred to as Nested Polymerase Chain Reaction; nPCR). It based on a magnetically actuated circular closed-loop PCR microchip system. nPCR involves the use of two sets of primers in two successive PCR runs, and allows the amplification of a single locus from a minute quantity of template DNA. Two sets of primers are specially designed to a target 500-bp region of the bacteriophage lambda template DNA in the first PCR run, and a 247-bp region of the targeted 500-bp first PCR product in the second PCR run. PCR is run on the microchip system and concurrently in regular thermocycler for comparison. The products are analyzed by conventional agarose gel electrophoresis. The detection limit for the initial template DNA is 1.63?×?105 copies per μL (or 8.67?pg) for the first PCR run, and 1.63 copies per μL (or 0.0867?fg) for the second run. The results are comparable to a regular thermocycler. This preliminary study opens a new gateway to future development of specialized nPCR on chip.
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Nested polymerase chain reaction (nPCR) was first demonstrated on the magnetically actuated circular closed-loop PCR microchip system, using DNA amplification on bacteriophage lambda template DNA as a chemical model.  相似文献   
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