Direct Toner Printing: A Versatile Technology for Easy Fabrication of Flexible Miniaturized Electrodes

We reported here three simple, low cost and easy to accomplish strategies for the fabrication of microelectrodes and other conductive patterns using ordinary office laser‐printers. In this work, toner patterns were directly printed onto the flexible substrate, acting as a mask to create the intended conductive design. To highlight the versatility of such technology, toner‐printed patterns were employed in two diverse ways: one in which the patterned toner had the exact design of the electrode and other employing a reverse toner‐printed pattern. The first one was used for the adaptation of the well‐known printed circuit board (PCB) fabrication technique, but using direct toner printing (DTP) in an already conductive flexible substrate. The second was employed for the two remaining strategies: one based on the deposition of conductive film, followed by lift‐off process; and another based on drop‐casting of a conductive ink into the formed toner cavities, followed by thermal cure. As proof‐of‐concept, all three DTP strategies were used for the fabrication of miniaturized gold electrodes in polyimide substrate, and electrochemical performance of each obtained electrode was evaluated by cyclic voltammetry. Insights about DTP technology, alignment issues, advantages, limitations and resolution of each presented approach were provided. Finally, direct toner printing showed to be a simple, affordable and quite promising technology for the fabrication of low cost point‐of‐care electrochemical devices using flexible platforms.     

光敏热显成像材料概述

本文综述了近十多年来国际感光界关注热点之一的光敏热显成像材料(Photothermographic materials,简称PTG)的研究情况.重点介绍了羧酸银、卤化银、调色剂、防灰雾剂与稳定剂、光谱增感剂以及粘合剂等PTG材料的主要组分,并对PTG材料成像机理的研究情况进行了评述.     

Copy number variants calling for single cell sequencing data by multi-constrained optimization

Variations in DNA copy number carry important information on genome evolution and regulation of DNA replication in cancer cells. The rapid development of single-cell sequencing technology allows one to explore gene expression heterogeneity among single-cells, thus providing important cancer cell evolution information. Single-cell DNA/RNA sequencing data usually have low genome coverage, which requires an extra step of amplification to accumulate enough samples. However, such amplification will introduce large bias and makes bioinformatics analysis challenging. Accurately modeling the distribution of sequencing data and effectively suppressing the bias influence is the key to success variations analysis.Recent advances demonstrate the technical noises by amplification are more likely to follow negative binomial distribution, a special case of Poisson distribution. Thus, we tackle the problem CNV detection by formulating it into a quadratic optimization problem involving two constraints, in which the underling signals are corrupted by Poisson distributed noises. By imposing the constraints of sparsity and smoothness, the reconstructed read depth signals from single-cell sequencing data are anticipated to fit the CNVs patterns more accurately. An efficient numerical solution based on the classical alternating direction minimization method (ADMM) is tailored to solve the proposed model. We demonstrate the advantages of the proposed method using both synthetic and empirical single-cell sequencing data. Our experimental results demonstrate that the proposed method achieves excellent performance and high promise of success with single-cell sequencing data.     

激光共聚焦扫描显微镜对激光打印文件墨粉厚度的分析研究

使用激光共聚焦扫描显微镜,对六种品牌和型号的激光打印机分别在打印纸和高光相纸上打印的图文墨粉厚度进行测量。结果表明,测量普通打印纸张上激光打印形成墨粉厚度时,测量数据因纸张纤维凹凸不平的影响有一定波动,相纸上激光打印形成的墨粉厚度测量数据相对稳定,并总结出随着打印文件图文线条宽度与墨粉厚度的变化规律。实验表明激光打印文件墨粉厚度的数据测量具有可行性,同一台激光打印机的打印文件墨粉厚度相对稳定,该指标作为一种重要参数可以为激光打印文件检验提供量化依据,并为打印机的同一认定提供依据。     

烟酸在热敏成像材料中的调色作用

本文将烟酸引入以硬脂酸银为银源的热敏成像材料中,可以明显提高显影密度,并使影像颜色由金黄色变成黑色;同时显影银粒子的尺寸变大、形貌也会发生改变,并且显影银粒子像链珠一样排成一条线,而线与线之间基本上是平行排列的.进一步实验结果表明,烟酸的引入会降低材料的pH、pAg值和银盐的相变温度,硬脂酸银与烟酸一起加热可能反应生成了新的化合物.     

Effect of Composition on Surface Properties of Polydimethylsiloxane-based Inorganic/Organic Hybrid Films

Surface properties of the polydimethylsiloxane (PDMS)-based inorganic/organic hybrids films prepared from silanol-terminated PDMS and titanium tetra-isopropoxide (TIP) were investigated with an aim at the application to the thermal-fixation roll for electro-photographic printers. The 300°C-treated hybrid film with the PDMS/TIP molar ratio of 0.5 exerted a relatively high contact angle of water as 115°C. It was found by using Tapping-Mode Atomic Force Microscopy (AFM) that the hybrid film surface changed from lamella structure to sea-island structure with the increase of PDMS content when heat-treated at 150°C, and became homogenous surface over 300°C. The phase-shift detected by AFM was negative shift, showing that hybrid surface became more hydrophobic as the PDMS/TIP molar ratios of 0.35 and 4.0 exhibited excellent toner-offset property of showing no adhesion of toners, suggesting their practical use in the photographic printers.     

Stuffer‐free multiplex ligation‐dependent probe amplification based on conformation‐sensitive capillary electrophoresis: A novel technology for robust multiplex determination of copy number variation

Developing diagnostic tools based on the application of known disease/phenotype‐associated copy number variations (CNVs) requires the capacity to measure CNVs in a multiplex format with sufficient reliability and methodological simplicity. In this study, we developed a reliable and user‐friendly multiplex CNV detection method, termed stuffer‐free MLPA‐CE‐SSCP, that combines a variation of multiplex ligation‐dependent probe amplification (MLPA) with CE‐SSCP. In this variation, MLPA probes were designed without the conventionally required stuffer sequences. To separate the similar‐sized stuffer‐free MLPA products, we adopted CE‐SSCP rather than length‐dependent conventional CE analysis. An examination of the genomic DNA from five cell lines known to vary in X‐chromosome copy number (1–5) revealed that copy number determinations using stuffer‐free MLPA‐CE‐SSCP were more accurate than those of conventional MLPA, and the CV of the measured copy numbers was significantly lower. Applying our system to measure the CNVs on autosomes between two HapMap individuals, we found that all peaks for CNV targets showed the expected copy number changes. Taken together, our results indicate that this new strategy can overcome the limitations of conventional MLPA, which are mainly related to long probe length and difficulties of probe preparation.     

Simultaneous detection of single nucleotide polymorphisms and copy number variations in the CYP2D6 gene by multiplex polymerase chain reaction combined with capillary electrophoresis

CYP2D6 (cytochrome P450 2D6) is one of the most important enzymes involved in drug metabolism, and CYP2D6 gene variants may cause toxic effects of therapeutic drugs or treatment failure. In this research, a rapid and simple method for genotyping the most common mutant alleles in the Asian population (CYP2D6*1/*1, CYP2D6*1/*10, CYP2D6*10/*10, CYP2D6*1/*5, CYP2D6*5/*10, and CYP2D6*5/*5) was developed by allele-specific polymerase chain reaction (AS-PCR) combined with capillary electrophoresis (CE). We designed a second mismatch nucleotide next to the single nucleotide polymorphism (SNP) site in allele-specific primers to increase the difference in PCR amplification. Besides, we established simulation equations to predict the CYP2D6 genotypes by analyzing the DNA patterns in the CE chromatograms. The multiplex PCR combined with CE method was applied to test 50 patients, and all of the test results were compared with the DNA sequencing method, long-PCR method and real-time PCR method. The correlation of the analytical results between the proposed method and other methods were higher than 90%, and the proposed method is superior to other methods for being able to simultaneous detection of SNPs and copy number variations (CNV). Furthermore, we compared the plasma concentration of aripiprazole (a CYP2D6 substrate) and its major metabolites with the genotype of 25 patients. The results demonstrate the proposed genotyping method is effective for estimating the activity of the CYP2D6 enzyme and shows potential for application in personalized medicine. Similar approach can be applied to simultaneous detection of SNPs and CNVs of other genes.     

The index of merit of kth-copy integration lattices

r2d2lri   is an automatic two-dimensional cubature algorithm that demonstrates the practical value of using an augmentation sequence consisting of (2^k)²$(2^k{)}^2$-copy lattices as a basis for numerical integration. This paper investigates use of similar embedded augmentation sequences in higher dimensions by developing theoretical results relating to the index of merit of s  -dimensional (2^k)^s$(2^k{)}^s$-copy lattices generated from rank-1 simple lattices. The theoretical results can be used to guide the search for good augmentation sequences in s dimensions in the sense of high index of merit.