Analysis of organic solvent tolerance in Escherichia coli using gene expression profiles from DNA microarrays

To investigate the biological mechanism of organic solvent tolerance (OST), DNA microarrays were used to collect and compare the gene expression profiles of normal and organic solvent-tolerant Escherichia coli strains. First, we compared the tolerant-strain OST3410 to its sensitive parent strain JA300 in the absence of organic solvents. Numerous genes showed higher expression levels in OST3410, and Northern analysis was used to confirm the higher expression level of some genes. Next, the gene expression profiles of JA300 and OST3410 exposed to hexane as an organic solvent were investigated and compared with JA300 before exposure to organic solvent. In OST3410 and JA300, 115 and 47 hexane-induced genes were found, respectively. As candidates for genes related to OST, we focused on six genes: cysD, marA, mg1B, tnaA, tnaB and yihM, which were upregulated by hexane in both strains. When these genes were over-expressed on plasmids, only the marA plasmid increased OST activity. It should be noted that we succeeded in finding a gene related to OST activity using only DNA microarray data, without any biochemical or biological knowledge.     

Shuffle up and deal: accelerating GPGPU Monte Carlo simulation with application to option pricing

In this paper, we demonstrate some speedup opportunity regarding Monte Carlo simulation on graphic processing unit architecture, with financial application. We leverage on the possibility of reducing the volume of actually generated random numbers, by replacing the generation phase with some shuffling using Compute Unified Device Architecture's built‐in shuffle instructions. We will study various shuffling patterns and duration, elect the best among them with regard to induced correlation, using Granger causality test. We will then study the accuracy and variance of results actually achieved by our general‐purpose computing on graphic processing unit shuffled Monte‐Carlo, exhibiting a computational time reduced by half while error remains marginal. Copyright © 2015 John Wiley & Sons, Ltd.     

The application of image processing technology to industrial automation

Some typical applications of image processing technology in Japanese industry are introduced in this paper. A steady growth of application has been seen in a number of industrial fields over the past decade. The motivation for such applications has always been the demand for more efficient production systems and product quality improvement by eliminating human error. Results so far are promising, though the barriers presented by existing limitations to binary image processing remain to be overcome.     

Hyper-miniaturization of monodisperse alginate–TiO2 composite particles with densely packed TiO2 nanoparticles

We report a novel technique to fabricate alginate–TiO₂ composite particles with densely packed TiO₂ nanoparticles. Using a microfluidic device, monodisperse sodium alginate droplets containing low-density TiO₂ nanoparticles (1 or 5 w/v%) were formed in the oil phase. The sodium alginate droplets formed in the oil phase were subsequently placed on a Ca²⁺-loaded agarose-gel plate to induce shrinkage by water removal (from the droplets to the Ca²⁺-loaded agarose-gel plate) and gelation by Ca²⁺ transport (from the Ca²⁺-loaded agarose-gel plate to the droplets). Thus, the produced alginate–TiO₂ composite particles containing densely packed TiO₂ nanoparticles were significantly smaller than the microchannel. We also investigated the optimal conditions to successfully produce spherical composite particles by varying the oil phases, surfactants, calcium concentrations and gel strength of the agarose-gel plate. Moreover, our method could decrease the probability of channel clogging that often occurs when a colloidal suspension (e.g., nanoparticles) is used as the dispersed phase. This method facilitates the stable production of monodisperse alginate–inorganic composite particles for a wide range of applications.     

Electron paramagnetic resonance-based pH mapping using spectral-spatial imaging of sequentially scanned spectra

The development of electron paramagnetic resonance (EPR)-based mapping of pH is an important advancement for the field of diagnostic imaging. The ability to accurately quantify pH change in vivo and monitor spatial distribution is desirable for the assessment of a number of pathological conditions in the human body as well as the monitoring of treatment response. In this work we introduce a method for EPR-based pH mapping utilizing a method of spectral-spatial imaging of sequentially scanned spectra to decrease the missing gradient rotation angle, without increasing the spatial field of view. Repeated in vitro measurements of pH phantom tubes demonstrated higher precision measurements of the hyperfine coupling constant (HFC) compared to previous EPR-based methods, resulting in mean pH values accurate to less than 0.1 pH across a range of physiologically observed values.     

Risk assessment for liquid hydrogen fueling stations

In recent years, consumers calling for the protection of the environment on a regional and global scale are demanding the use of vehicles that do not emit harmful exhaust. It is anticipated that one response to this demand is the widespread use of fuel cell vehicles (FCVs). In order to achieve this, it is necessary to provide hydrogen fueling stations where FCVs can refuel.     

Surface modification of a glass microchannel for the formation of multiple emulsion droplets

We herein report a method for the preparation of a glass microchannel capable of forming multiple emulsion droplets (i.e., water-in-oil-in-water and oil-in-water-in-oil) by locally controlling the wettability of the glass microchannel. Production of multiple emulsion droplets using a glass microchannel requires partial control of its wettability using a method that consists of two steps: (1) hydrophobization of a whole glass microchannel by filling the microchannel with octadecyltrichlorosilane (OTS) solution, and (2) local hydrophilization of the OTS-treated glass microchannel by exposure to ultraviolet light through a mask. However, conditions for the preparation of OTS-SAMs for controlling microchannel wettability and subsequent multiple emulsion droplet formation have not yet been reported. In this study, we investigated the conditions required to form multiple emulsion droplets and demonstrated formation of multiple emulsion droplets using a treated glass microchannel with multiple junctions. The glass microchannel prepared according to this method was able to form various aqueous and organic droplets due to its resistance to swelling.