旋转孔径白光散斑照相法的研究

本文报道利用旋转孔径法进行白光散斑照相,研测动态问题.其不仅具有旋转孔径激光散斑照相的优点,而且最突出的优点是能走出实验室,到现场进行动态测量研究.     

Microarrays by structured substrate swelling

A technique is presented for manufacturing surface microstructures on polymer substrates. It is based on the uptake of solvent vapors by a prestructured polymer, selective swelling, and the flow of the softened polymer. Prestructuring is done by evaporating material, UV illumination, or ion bombardment through a mask. As an application we describe the fabrication of two-dimensional ordered arrays of microvessels which can be of different shape, size, and material. The bottom of the microvessels can be functionalized by several means and it can be transparent to allow for optical analysis. Applications of the microvessel array are seen in combinatorial chemistry, as microreactors, and as confined spaces for controlling crystal growth.     

DNA microarray scanner with a DVD pick-up head

A low-cost highly sensitive DNA microarray scanner for fluorescent detection is developed based on the pick-up head of a commercially available optical storage device, DVD. A laser beam of 650 nm, generated by a DVD laser diode, is used for dynamic auto-focusing as well as the excitation of Cy5 fluorescent dye. The fluorescence intensity emitted from Cy5 dye is measured by a photomultiplier tube (PMT). In contrast to other microarray scanners, the DVD-based scanner offers the auto-focusing function using the focus error signal (FES) and a voice coil motor (VCM), and this enables fast response, high accuracy and compact size. The fluorescence-detecting performance of the scanner is inspected by using a commercial BAC (bacterial artificial chromosome) oligonucleotide chip and a scanner evaluation microarray (DS01). Experiments have shown that the DVD-based scanner meets the limit of detection, ensuring the feasibility of a low-cost, highly sensitive DNA microarray scanner.     

激光显示中光学系统研究

为了满足机械转镜扫描要求(转镜转速每分钟不少于3万转)及光束与水平信号的行场同步要求，提出采用面阵空间光调制器及多像素并行扫描方式。采用“面阵空间光调制器”对激光束进行选通和光强调制，使覆盖多像素的激光束在高速扫过面阵空间光调制器时，光强按视频图像的强弱进行调制，从而形成激光视频图像。由于采用了多像素并行扫描、新型二维扫描转镜和积分器光路，扫描速度大大降低，由每分钟几万转降低到3000转，解决了扫描式激光显示的技术瓶颈和激光干涉条纹问题，获得了很好的显示效果。     

Development of peptide-based patterns by laser transfer

Peptide-based arrays and patterns have provided a powerful tool in the study of protein recognition and function. A variety of applications have been identified, including the interactions between peptides-enzymes, peptides-proteins, peptides-DNA, peptides-small molecules and peptides-cells. One of the main and most critical unresolved issues is the generation of high-density arrays which maintain the biological function of the peptides. In this study, we employ nanosecond laser-induced forward transfer for the generation of high-density peptide arrays and patterns on modified glass surfaces. We show that peptide-based microarrays can be fabricated on solid surfaces and specifically recognized by appropriate fluorescent tags, with the transfer not affecting the ability of the peptides to form fibrils. These initial results are poised to the construction of larger peptide patterns as scaffolds for the incorporation and display of ligands critical for cell attachment and growth, or for the templating of inorganic materials.     

Improved Halbach sensor for NMR scanning of drill cores

A lightweight Halbach magnet system for use in nuclear magnetic resonance (NMR) studies on drill cores was designed and built. It features an improved homogeneous magnetic field with a strength of 0.22 T and a maximum accessible sensitive volume. Additionally, it is furnished with a sliding table for automatic scans of cylindrical samples. This device is optimized for nondestructive online measurements of porosity and pore size distributions of water-saturated full cylindrical and split semicylindrical drill cores of different diameters. The porosity of core plugs with diameters from 20 to 80 mm can be measured routinely using exchangeable radiofrequency coils. Advanced NMR techniques that provide 2D T(1)-T(2) correlations with an average measurement time of 30 min and permeability estimates can be performed with a special insert suitable for small core plugs with diameter and length of 20 mm.     

A cam-based laser-induced fluorescence scanner for capillary array electrophoresis

Capillary array electrophoresis (CAE) is an important high throughput analytical technique. Laser-induced fluorescence (LIF) has been the dominant detection method for CAE owing to its low limit of detection (LOD) and wide linear dynamic range (LDR). Linear LIF scanners were first used in CAE because linear motions of an objective match well with a common planar array of capillaries. A problem with linear scanners is that the motor is required accelerating/decelerating so that all capillaries can be properly scanned, which makes motion control complicated and reduces the duty cycle. Rotary scanners were developed to overcome this problem. While rotary scanners have been successfully applied in CAE, the capillaries have to be arranged in a circular format, which can be inconvenient in some cases. In this report, we describe a cam-based LIF scanner as an alternative technique for CAE detection. In this system, a rotary motor is mechanically linked with a capillary holder via a cam. During operation, the motor carries the cam in a rotary motion that drives an array of capillaries on the holder to move back and forth across the objective for fluorescence detection. Using this design, the capillaries can be parallel-arranged in a plane while the motor acceleration/deceleration is avoided. To demonstrate the feasibility of this approach, we constructed a prototype instrument with a constant-velocity scanning distance of ∼10 mm, a scanning frequency of 3 Hz and a duty cycle of ∼70%. The scanner exhibited a LOD of 69 pM of fluorescein and a LDR of 3.5 orders of magnitude. Multiplexed capillary SDS-PAGE was performed on this scanner for protein separations.     

Consensus analysis of multiple classifiers using non-repetitive variables: diagnostic application to microarray gene expression data

Class prediction based on DNA microarray data has been emerged as one of the most important application of bioinformatics for diagnostics/prognostics. Robust classifiers are needed that use most biologically relevant genes embedded in the data. A consensus approach that combines multiple classifiers has attributes that mitigate this difficulty compared to a single classifier. A new classification method named as consensus analysis of multiple classifiers using non-repetitive variables (CAMCUN) was proposed for the analysis of hyper-dimensional gene expression data. The CAMCUN method combined multiple classifiers, each of which was built from distinct, non-repeated genes that were selected for effectiveness in class differentiation. Thus, the CAMCUN utilized most biologically relevant genes in the final classifier. The CAMCUN algorithm was demonstrated to give consistently more accurate predictions for two well-known datasets for prostate cancer and leukemia. Importantly, the CAMCUN algorithm employed an integrated 10-fold cross-validation and randomization test to assess the degree of confidence of the predictions for unknown samples.     

激光扫描实时共聚焦显微成像系统设计

共聚焦扫描显微镜已成为生物医学和材料科学领域研究中非常有价值的一种工具.本文给出了一种反射型激光扫描共聚焦显微成像系统的系统结构和具体设计.采用多面体转镜进行水平扫描,摆镜进行垂直扫描.利用商品透镜设计了光学扫描中继系统,采用光电倍增管作为激发出的荧光探测器,同时给出了数据采集和扫描同步控制系统的组成与设计.利用COD...