DNA‐Forensik

Forensics deals with the scientific methods to gather information at a crime scene for solving criminal actions. DNA forensics uses genetic material for these purposes. DNA fingerprinting is established as an important method for police detective work since the end of the 1980s. Currently, DNA forensics faces completely new possibilities through the application of more efficient high‐throughput sequencing methods, summarized as Next Generation Sequencing (NGS). Using NGS it could be possible to predict numerous externally visible characteristics including the complete facial shape of an unknown perpetrator. This article aims at presenting practices of forensic DNA analyses used to date and extending the picture for future possibilities and challenges.     

一种用于核酸高灵敏检测的液滴式数字聚合酶链式反应芯片

为了实现对核酸的高灵敏度检测,构建了一种新型的液滴式数字聚合酶链式反应(dd PCR)芯片.该芯片由产生液滴的聚二甲基硅氧烷(PDMS)模块和储存液滴的玻璃腔室构成.实验结果表明,该芯片可以在25 min内产生2×106个直径为20μm的微液滴(体积4.187 p L).利用该芯片定量检测了表皮生长因子受体(EGFR)基因第19号外显子,在DNA浓度为106~101copies/μL范围内呈现良好的线性关系(R2=0.9998);在浓度为106copies/μL的19号外显子野生型DNA中检测105~100copies/μL的突变型DNA,其检测敏感度可达到0.0001%.该方法在同一芯片上实现了液滴产生、核酸扩增和荧光信号读取的功能,在核酸绝对定量及痕量突变基因的检测中具有潜在应用前景.     

High-throughput multiplex microsatellite marker assay for detection and quantification of adulteration in Basmati rice (Oryza sativa)

Basmati rice is a very special type of aromatic rice known world-wide for its extra long grains and pleasant and distinct aroma. Traditional Basmati rice cultivars, confined to Indo-Gangetic regions of the Indian subcontinent, are often reported to be adulterated with crossbred Basmati varieties and long-grain non-Basmati varieties in the export market. At present, there is no commercial scale technology to reliably detect adulteration. We report here a CE-based multiplex microsatellite marker assay for detection as well as quantification of adulteration in Basmati rice samples. The single-tube assay multiplexes eight microsatellite loci to generate variety-specific allele profiles that can detect adulteration from 1% upwards. The protocol also incorporates a quantitative-competitive PCR-based analysis for quantification of adulteration. Accuracy of quantification has been shown to be +/-1.5%. The experiments used to develop and validate the methodology are described.     

Genetic analysis of human complement factor H polymorphisms

Human complement factor H (factor H) is polymorphic, with five previously reported FH alleles and three previously reported HF alleles (HF*A, HF*B, and HF*Q0). The relationship between the FH and HF alleles is not clear, and the genetic basis of factor H phenotypes has not yet been identified. In this study, nucleotide sequence analysis of complementary DNA (cDNA) from individuals with each HF phenotype identified seven mutated sites in the factor H gene. However, in four cases, the same cDNA sequence was observed in individuals with two different HF phenotypes. Western blotting and 2-DE also showed that a 160 kDa protein corresponding to factor H was expressed in individuals with HF phenotypes. In addition, factor H cross-reacting 45 and 42 kDa polypeptides were detected in individuals with HF A, HF B, or HF AB phenotypes, but not in individuals with the HF Q0 (a null allele) phenotype. Thus, HF phenotype did not correlate well with factor H gene or protein structural variation. Evidence is provided to support the hypothesis that the HF phenotypes do not correspond to polymorphism in factor H, but instead correspond to polymorphism in factor H-related protein 1. A novel PCR-RFLP method was developed and used to detect four polymorphisms (G257A, G1492A, A2089G, and G2881T) in the factor H gene in 54 unrelated Japanese individuals. This method could be useful for studies on genetic disease associated with these mutations.     

复合式蝎形引物实时定量检测端粒酶延伸产物

针对端粒酶延伸产物中靶基因序列的特殊性,开发了一种可产生荧光的复合式蝎形引物,该引物的5'端带有可特异性检测靶基因的探针序列,PCR阻断剂将其与引物序列连接.当复合式蝎形引物延伸,探针序列与同一分子内的靶基因杂交,荧光信号产生.运用该技术,建立了定量检测端粒酶延伸产物的实时荧光PCR方法.该法可在快速PCR循环条件下,对0.15～1.50×10³ amol/μL范围内的样品进行定量检测,线性相关系数R²=0.9992.该法操作简便,无需PCR后额外的检测步骤.     

Detection of BCR- ABL Gene Rearrangement by RT/PCR Technology and Its Mechanism in the Generation and Development of Chronic Myeloid Leukemia

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Finding Y‐relevant part of X by use of PCR and PLSR model reduction methods

The paper is considering the following question: using principal component regression (PCR) or partial least squares regression (PLSR), how much data can be removed from X while retaining the original ability to predict Y ? Two model reduction methods using similarity transformations are discussed, one giving projections of original loadings onto the column space of the fitted response matrix (essentially the orthogonal signal correction (OSC) methods), and one giving projections of original scores onto the column space of the coefficient matrix (essentially the net analyte signal (NAS) methods). The loading projection method gives model residuals that are orthogonal to Y and , which is valuable in certain applications. The score projection method, on the other hand, gives model residuals that are orthogonal to , which is essential in other applications. It is shown that the reduced matrix X from the score projection method is a subset of the reduced matrix X from the loading projection method. It therefore has the smallest Frobenius norm, and thus the smallest total column variance, assuming centered data. Copyright © 2007 John Wiley & Sons, Ltd.     

耦合角度对平面波导叠加型光栅解波分复用性能的影响

利用玻璃材料的光敏性可在平面波导中制作出具有解波分复用功能的叠加型光栅,根据耦合模理论对这种平面波导叠加型光栅的解波分复用特性进行研究,发现了入射角度通过改变耦合系数会对光栅的反射率和带宽产生影响：当入射角度较大时,单个光栅的反射率虽稍有增大,但带宽变宽;而在入射角度较小时尽管其反射率稍有下降,但带宽却显著变窄.因此在光栅设计时必须综合考虑反射率和带宽的要求以获得更好的解波分复用性能.     

采用WDM技术的光纤Bragg光栅传感网络

采用绝对测量原理的波长调制技术,光纤Bragg光栅可组成并行、串行和阵列WDM拓扑结构.分析表明,光纤Bragg光栅网络的工作原理类似于一个多宽带平面镜.利用光谱仪可测量上述光纤Bragg光栅网络的反射谱,其中,光源是宽带为～40nm的掺饵光纤放大器.当网络中的光纤Bragg光栅受扰动后,受扰光栅的反射谱发生相应的变化,即Bragg波长发生相应的偏移.结果表明,当事先确定了光纤光栅的波长调制范围,反射的峰值波长能反应光纤光栅传感网络的信息.值得注意的是～3nm的波长调制范围可满足～100℃和～2000με的参量测量.     

根据时分复用机制优化多路FIR滤波器实现结构

针对多路有限长单脉冲响应(Finite Impulse Response,FIR)滤波器实现结构的资源需求量有待降低的问题,本文根据多路采样数据的时分多路复用传输机制,通过使多路采样数据复用同一单路FIR滤波器,对多路FIR滤波器的FPGA实现结构进行优化。分析证明,该优化实现结构由不同类型的单路FIR滤波器实现结构构成时,与典型多路FIR滤波器实现结构相比,其寄存器需求量大幅降低,同时可以保证乘法器和加法器需求量大幅降低或大致相同。