In this article, fluid control methods for nanofluidic chemical and biochemical analytical systems are reviewed. The fluid control methods realize stable pressure-driven flow in a fluidic channel having a sub-micrometer width (nanometer-sized channel). Two fluid control methods, back-pressure regulation and air-pressure regulation methods, and their application.

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   The pp interaction between phthalocyanines (Pcs) in the solid state induces useful conductivity that is applicable to photoconductors, but it also has disadvantages in terms of reducing the monomeric photochemical properties, i.e., the sharp Q absorption band, intense fluorescence, and ability of singlet oxygen (1Dg) generation. Here, I describe recent methods for preparing silica gel-supported Pcs having both monomeric photochemical properties and high ability of singlet oxygen generation. In particular, magnetic silica gel-supported Pcs can act as the singlet oxygen generator, which can be collected by using magnets.

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   It is known that epileptic discharges on the electrocorticography, which cause seizures, are terminated by focal cooling of the cortical surface. In the previous study, the authors devised a focal cooling device with a thermoelectric chip and examined its performance to cool the cortex and to suppress the epileptic discharges through the animal studies. However, for the efficient development, it is needed to estimate the cooling performance through numerical simulations. Then the authors carry out a numerical simulations to analyze the heat conduction in the cortex when its surface is cooled by the thermoelectric chip. By comparing with the result of the animal study, the validity of the simulation is shown.

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    Promoted by the rapid advance in the bioimaging technologies, the frontier in life science shifts its next target to understainding the dynamical aspects of microscopic biological phenomena by using quantitative measurement and analysis. In this review, by employing my research work as an example, I will demonstrate that engineering, informatics, and mathematics play the pivotal roles in this field, and show its future directions.

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    Silicon neuron is electrical circuit that mimics the electrophysiological functions of a neuronal cell. One of the goals of researches on silicon neuron is to construct some functional silicon neural networks by connecting silicon neurons each other via silicon synapses that mimics the electrophysiological function of synapse. It is expected to realize an intelligent artificial system that operates based on novel principles similar to brain and nerve systems. To construct such systems, a silicon neuron circuit has to be simple and consumes low power. Some researchers are designing silicon neuron by analog electrical circuit that solves differential equations of ionic-conductance models of a neuronal cell. Such circuits are proved to reproduce various behaviors of the neuron model quite precisely in real time. However, because the ionic-conductance models describe the behavior of lipid and protein, they are not quite compatible to the characteristics of electrical circuit, which restricts the simplification of circuitry and reduction of power consumption. To solve this problem, we proposed a new designing method that is based on mathematical knowledge on ionic-conductance models and designed and implemented a new type of silicon neuron circuit.

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   A long-range electrostatic interaction is one of the extremely important forces in analyzing the structure and the function of proteins. Recently, the exact electrostatic potential (ESP) can be estimated based on the all-electron wave function of protein. However, because the post-processing cost is very expensive, it also requires the heavy computational resources and consumes long CPU time. In this research, it succeeded in the new development of the processing program by GPU, and the great speed-up of ESP estimation based on the quantum chemical calculation. For 51 residues insulin, it was 12 minutes using GPU (Tesla C870) whereas it took 16 hours in CPU, which showed the 79 times acceleration. This corresponds to the 63% of the peak performance of GPU.

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   The amber suppression system is the system to incorporate amino acids to the location indicated by the amber codon. The system is practically used for incorporation of non-natural amino acids into proteins. However, mischarging occurs due to insufficient orthogonality between the amber suppression and the translation system of the host cell. It would deteriorate the quality of synthesized non-natural proteins due to contamination of mischarged amino acids. In order to improve the orthogonality, we performed mutation of tRNA in the amber suppression systems not to be recognized by the aminoacyl-tRNA synthetases in the host cell.

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   Tissue Engineering is an interdisciplinary field that integrates the principles of medicine, life science and engineering toward the development of biological substitutes that restore, maintain, or improve tissue function or a whole organ. It is based on a fundamental methodology as follows (1) to attach stem/progenitor cells possessing growth ability and pluripotency to a scaffold material, (2) to apply signals which stimulate those cells to grow and differentiate to a targeted lineage, and (3) to organize them to a tissue or organ. Among them, controlling differentiation and growth of pluripotent cells plays a crucial role in the reconstruction of tissues. In this short review, we focus on the “signals to cells” and introduce latest achievements in hepatic differentiation from ES cells as an example of induction of specific differentiation.

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       Measurement of neuronal firing rates has been a standard methodology for characterizing properties of neural activities during experiments. On the other hand, modulation of other statistics, such as ones derived from distributions and patterns of inter-spike intervals, can be an important index for analysis of neuronal response and may provide insights into the neuronal codes. In this study, we propose an analysis method for measuring variabilities in multiple-trial spike data with a high time resolution. [This abstract is not included in the PDF]

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       The rotating cutting tool on the tip of a catheter is required to to remove hard cemented deposits in heart blood vessals without damaging soft vessel walls. The requirements were evaluated through a cutting experiment using a boiled egg; that is, the tool can cut the hard shell, not the soft white. The authors introduce a rotating "grater-like" cutting tool, preventing tool-tips from dropping out, while conventional tool is in danger of dropping diamond particles which block blood flow eventually. The anodized aluminium tool of 2 mm in diameter with less than 20 microns height tool-tip, rotated at 200,000 rpm in the water, could realize the cutting requirements without any tool wear. The coolant film around the tool-tip was hydrodynamically pressured, and made the soft wookpiece deform elastically, protecting it from cutting off. [This abstract is not included in the PDF]

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       When DNA is confined in a structure with dimension below the polymer’s free solution radius of gyration, the confining geometry will alter the DNA molecule’s conformation. Nanochannel structures are used to stretch out single DNA molecules, creating a linear extension of the genome along the channel for analysis. We have developed a novel nanochannel fabrication technique by using simple processes, including general MEMS operations and deformation of thin PDMS film. With these devices, we present measurements of DNA extended in nanochannels via fluorescence microscopy, and show that there are two different regimes with varying the device dimensions, which were previously predicted through the theories in polymer physics. [This abstract is not included in the PDF]

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       The number of the esophagus cancer incidence is about sixteen thousand people per year in Japan. Since the cancer metastasize around the esophagus, it’s usual to remove the whole esophagus surgically and substitute it with a part of stomach or colon. The only and the most important function of the esophagus is to convey foods or saliva by peristalsis. Hence, the mechanical device will work as its substitute and reduce surgery infection. This paper proposes the mechatronic esophagus using thin straight fibers type artificial muscle. The experiments were performed to investigate the performance of artificial muscles. [This abstract is not included in the PDF]

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       Through the recent progress in atomic force microscopy in liquids, we can foresee the investigation of biological samples in their natural environment with resolution down to the atomic scale. A new atomic force microscope has been built and tested with this aim. This AFM use a phase-modulation technique which allow to image large features in liquids with a good stability and a temperature control system has been developed to image biological samples in the best conditions. To date, this AFM achieved high resolution imaging of gold in water and show promising qualities for the imaging of biological samples. [This abstract is not included in the PDF]

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       To investigate the behavior of the driver, EEG of a subject manipulating the driving simulator is analyzed with Parallel Factor Analysis, called PARAFAC. This is a method to decompose a multichannel time-varying spectrum into space/frequency/time atoms and expected to be an effective and efficient tool to analyze EEG, since we can easily obtain topographic time/frequency data. Although the driving simulator is not a good place to record EEG, the results clearly exhibited alpha and beta activities of the brain of the subject, who was manipulating the driving simulator. [This abstract is not included in the PDF]

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       Increasing awareness of environmental needs is driving changes in the way the concrete industry operates. Demand for cement and concrete products is increasing in response to economic development, and yet the industry must somehow reduce its environmental impact while meeting supply needs. Research into sustainable development in the concrete industry has, until now, been fairly limited. Some areas have potential for promoting sustainable ideas, such as the utilization of waste material from other industries as cementitious replacement products and the recycling of waste products both within and from beyond the concrete industry as filler material in new concrete construction. This paper reviews the challenges faced by the concrete industry and the research work which has been performed to meet this challenge. [This abstract is not included in the PDF]

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