Simplified 20-µm pitch vertical interconnection process for 3D chip stacking

This paper describes a simplified vertical interconnection process for three-dimensional (3D) chip stacking. The unique feature of this new process is that the conductive filling material in the through-silicon-vias (TSVs), the microbumps, and the interconnection materials are all fabricated in one processing stage. All of the steps can be performed with the same piece of equipment. Prototype chips with 20-µm-pitch vertical interconnections have been demonstrated successfully. By using this technique, 75-µm deep high-aspect-ratio vias can be completely filled without voids using Ni electroplating and uniform 20-µm-pitch microbumps that are 4-µm tall have been fabricated using Sn-Cu electroplating. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Designed construction of recombinant DNA at the ura3Δ0 locus in the yeast Saccharomyces cerevisiae

Recombinant DNAs are traditionally constructed using Escherichia coli plasmids. In the yeast Saccharomyces cerevisiae, chromosomal gene targeting is a common technique, implying that the yeast homologous recombination system could be applied for recombinant DNA construction. In an attempt to use a S. cerevisiae chromosome for recombinant DNA construction, we selected the single ura3Δ0 locus as a gene targeting site. By selecting this single locus, repeated recombination using the surrounding URA3 sequences can be performed. The recombination system described here has several advantages over the conventional plasmid system, as it provides a method to confirm the selection of correct recombinants because transformation of the same locus replaces the pre‐existing selection marker, resulting in the loss of the marker in successful recombinations. In addition, the constructed strains can serve as both PCR templates and hosts for preparing subsequent recombinant strains. Using this method, several yeast strains that contained selection markers, promoters, terminators and target genes at the ura3Δ0 locus were successfully generated. The system described here can potentially be applied for the construction of any recombinant DNA without the requirement for manipulations in E. coli. Interestingly, we unexpectedly found that several G/C‐rich sequences used for fusion PCR lowered gene expression when located adjacent to the start codon. Copyright © 2013 John Wiley & Sons, Ltd.     

关于溶菌酶过滤器的验证报告——过滤器内微生物的二次污染验证和对策

酶过滤器的主要功能就是杀灭被过滤器表面所捕获的悬浮细菌,以保护过滤器系统不受二次污染。溶解酶均匀地固化在过滤介质的横截面上,保护过滤系统不受二次污染。对高效过滤器和ASHRAE级过滤器微生物二次污染的认定方法,报导“杀菌酶过滤器”的现场数据,证明了预防性措施的实际效果。     

Conformational behaviour of (styrene-p-chlorostyrene) triblock copolymers in dilute solutions. 2. Temperature dependence of conformational behaviour in a selective solvent

Intrinsic viscosity, osmotic second virial coefficient and light scattering of the B_mA_nB_m and A_mB_nA_m copolymers (A, styrene monomeric unit; B, p-chlorostyrene monomeric unit, m and n denote the number of units) in cumene which is a good solvent for polystyrene but a θ solvent for poly(p-chlorostyrene) at 59.0°C, were studied over the temperature range 65° to 15°C. The results suggested that conformational transition from a random coil form to a segregated form occurs at a critical temperature which appears to be in the range 40° to 30°C, depending on the composition, molecular weight and structure of the block copolymers; the θ condition could not be attained by cooling the block copolymer solutions, and micelle formations due to intermolecular associations were found in some cases below the transition temperature.     

Characterization of embryoid bodies of mouse embryonic stem cells formed under various culture conditions and estimation of differentiation status of such bodies

Various types of embryoid body (EB) that were formed from mouse embryonic stem (ES) cells under various culture conditions were characterized in terms of gene expression pattern to estimate the differentiation status of the bodies. The gene expression of typical markers (i.e., GATA-4, GATA-6, transthyretin [TTR], alpha-fetoprotein [AFP], Nkx2.5, and alpha-myosin heavy chain [alpha-MHC]) was quantitatively analyzed in various types of EB, and the gene expression pattern of those marker genes was graphically shown for each EB. The gene expression pattern accurately represented the differentiation status of the EBs. The gene expression pattern indicated that the Nkx2.5 and alpha-MHC genes were highly expressed in the EBs formed from 1000 ES cells in a low-adherence 96-well plate. By transferring the EBs into an attachment culture, cardiomyocytes were more efficiently generated in the outgrowth of the EBs. When we increased the seeding cell number from 1000 to 4000 ES cells, the gene expression pattern changed, that is, the expression levels of the TTR and AFP genes increased, whereas those of the Nkx2.5 and alpha-MHC genes decreased, and the trend of differentiation changed from cardiomyogenesis to visceral yolk-sac-like structure formation.     

关于通高大堂的空间认知的研究

通过两个通高大堂进行现场草图实验,围绕着比较参加实验者的草图和实际图纸的差别进行结果的分析,得出结论为∶第一、当距离较短时容易被认知得比实际长。相反,当距离较长时容易被认知得比实际短;第二、细长的空间趋向被认知为接近正方体的空间;第三、空间认知在三维坐标系中具有方向性,其原因可以推测为视野在三维方向的范围不同。