Clonal analysis of superficial depressed-type gastric carcinoma in humans

BACKGROUND: An important unanswered question concerning the histogenesis of superficial-type gastric carcinoma is whether it is monoclonal or multiclonal in origin. Therefore, the authors analyzed multiple areas of each cancer with a clonality assay based on trinucleotide repeat length polymorphism of the human androgen receptor gene (HUMARA) that was subject to random inactivation of X chromosomes. METHODS: The HUMARA assay was applied to 15 gastric carcinomas, early and advanced stage, manifested in superficial, depressed lesions of various sizes and at least some signet ring cells. DNA was extracted from fresh frozen and formalin fixed tumor tissues that were microdissected from the mucosal lesions, and the HUMARA locus was amplified by polymerase chain reaction with and without prior digestion of nonmethylated DNA with Hpa II. The amplified DNA samples were loaded on polyacrylamide gels, electrophoresed, and visualized by a silver-staining method. RESULTS: In the 15 cases examined, 9 cancers were informative (had features of the types sought in this study), and in these 9 cancers a total of 57 areas were analyzed. In 7 of the 9 cancers, the inactivated allele was common to all the informative areas of each tumor, irrespective of the macroscopic shape of the tumor or the degree of histologic heterogeneity within it. In one of the two remaining cancers, the inactivated allele of one of the areas examined was different from those in the other areas. CONCLUSIONS: Most of the superficial depressed-type gastric carcinomas in this study were demonstrated to be of monoclonal origin. This finding supports a notion expressed previously in the literature that superficial-type carcinoma has a long natural history, and it indicates that efforts to detect gastric carcinomas in early stages to improve patients' survival should be encouraged.     

Pattern modification of a neuronal network for individual-cell-based electrophysiological measurement using photothermal etching of an agarose architecture with a multielectrode array

A new type of individual-cell-based on-chip multielectrode array (MEA) cell-cultivation system with an agarose microchamber (AMC) array for topographical control of the network patterns of a living neuronal network has been developed. The advantages of this system are that it allows control of the cell positions and numbers for cultivation using AMCs, as well as easy and flexible control of the pattern of connections between the AMCs through photothermal etching where a portion of the agarose layer is melted with a 1480 nm infrared laser beam. With adequate laser power, narrow micrometer-order grooves (microchannels) can easily be fabricated that can be used to combine neighbouring AMCs to enable topographical control of the neural network pattern. Using this system, an individual-cell-based neural network pattern was formed of rat hippocampal cells within the AMC array without cells escaping from the electrode positions in the microchamber during an eight-day cultivation, and could record cell firing in response to 1.5 V, 500 kHz stimulation through an electrode. This demonstrated the potential of the on-chip AMCMEA cell cultivation system for long-term single-cell-based electrophysiological measurement of a neural network system.     

Microfabrication by hot embossing and injection molding at LASTI

LIGA process includes three processes as X-ray lithography, electroforming to fabricate metalic molds and replication, and can be fabricated nano and micro parts for various devices that it is difficult to product by conventional machining methods. A key technology which gathers mass-production efficiency in the LIGA process is micro-replication technology. We choiced hot embossing and injection molding methods for replication. For a demonstration, two kinds of Ni molds, a mesh pattern within a line width of 100 m, and an aspect ratio of 1.0 and a mesh pattern within a line width of 40 m, and an aspect ratio of 2.5, were prepared. These were produced with X-ray lithography and nickel electrofoming technique. In hot embossing, an experiment of micro-replication using polymethyl methacrylate (PMMA) and polycarbonate (PC) sheets succeeded. At injection molding, it could not transfer well with PMMA and PC, but injection temperature was set up highly, and it succeeded by cycloolefin polymer. Furthermore, we measured sidewalls surface roughness of microstructures produced at each steppes of the LIGA process, and it checked that the LIGA process had processing accuracy higher than a conventional machining method.We would like to thank Ms. A. Kitajima and Dr. R. Maeda at National Institute of Advanced Industrial Science and Technology (AIST), Mr. M. Ohtomo at Ikegami Mold Engineering Co., Ltd., and Mr. Noriaki Sato at Juken Kogyo Co., Ltd. for their valuable collaboration and contributions. This research was the contract research from the New Industry Research Organization (NIRO) supported financially by the New Energy and Industrial Technology Development Organization (NEDO).     

Fabrication of on-chip microcapillary using photosensitive glass

The on-chip microcapillary applying for electrophoresis analysis device has been fabricated on photosensitive glass. This process can make a high aspect-ratio channel structure. The channel-depth can be controlled by varying wet-etching time without widening the channel width because the substrate material has vertical high etch rate selectivity. This high aspect-ratio structure obtains a long optical path and appropriate sample volume resulting in high-sensitivity for various analyses. The fabrication process is simpler than a usual glass micromachining process because of photo-resistless lithography process. In order to smooth the channel surface and to attach a cover glass onto the substrate, a polysilazane coating process is proposed and revealed to be effective. We are indebted to Dr. N. Sawanobori (SUMITA OPTICAL GLASS, INC., Japan) for photosensitive glass and Dr. T. Ishikawa (TONEN CORPORATION, Japan) for polysilazane. They have given valuable advice for fabrication process in this study. This work was partially supported by the Grant-in-Aid for Science Research (No. 13450146) from the Japan Society for the Promotion of Science (JSPS).     

Secure optical data storage with random phase key codes by use of a configuration of a joint transform correlator

A secure optical storage based on a configuration of a joint transform correlator by use of a photorefractive material is presented. A key code designed through the use of an optimized algorithm so that its Fourier transform has a uniform amplitude distribution and a uniformly random phase distribution is introduced. Original two-dimensional data and the key code are placed side-by-side at the input plane. Both of them are stored in a photorefractive material as a joint power spectrum. The retrieval of the original data can be achieved with the same key code. We can record multiple two-dimensional data in the same crystal by angular multiplexing and/or key code multiplexing.     

Chemiluminescence detection for a microchip capillary electrophoresis system fabricated in poly(dimethylsiloxane)

Chemiluminescence (CL) detection integrated with a microchip capillary electrophoresis (MCE) system that was fabricated in poly(dimethylsiloxane) was demonstrated for chemical and biochemical analyses. Two model CL systems were involved here: metal ion-catalyzed luminol-peroxide reaction and dansyl species conjugated peroxalate-peroxide reaction. Different strategies based on three chip patterns (cross, cross combining with Y, and cross combining with V) to perform on-line CL detection for MCE were evaluated and compared in terms of sensitivity, reproducibility, and peak symmetry. The chip pattern of cross combining with Y proved to be promising for the luminol-peroxide CL system, while the chip pattern of cross combining with V was preferred for the peroxalate-peroxide system where CL reagent could not be effectively transported by electroosmotic flow. A detection limit down to submicromolar concentrations (midattomole) was achieved with good reproducibility and symmetric peak shape. Successful separation of three metal cations such as Cr(III), Co(II), and Cu(II) and chiral recognition of dansyl phenylalanine enantiomers within 1 min revealed distinct advantages of combining MCE with CL detection for rapid and sensitive analyses.     

Morphology and Mechanical Properties in Polymer Blends of Photocurable Polymer and Polycarbonate

Relationships between the morphologies and mechanical properties of binary blends of a photocurable polymer (2‐propenoic acid, (octahydro‐4,7‐methano‐1H‐indenediyl) bis(methylene)ester; DCA) and a linear polymer (poly(4,4′‐cyclohexylidene bisphenol carbonate); PCz) have been investigated. The blend films are prepared by in situ photopolymerization of homogeneous mixtures of a DCA‐monomer and PCz. The phase structure has been converted from a semi‐interpenetrating polymer networks (semi‐IPN) structure to a bicontinuous structure by controlling the cure temperature. Bicontinuous phase‐separated structures can be obtained by curing a wide range of compositions of 17–50 wt.‐% PCz at high temperatures. Miscible semi‐IPN structures are attained by means of photopolymerization below the glass transition temperature of the homogenous mixture before performing photoirradiation, such that magnetic relaxation measurements showed the blend to be miscible in the 10 nm order. The tensile strength and modulus reached a maximum in those blends having an intermediate vague phase structure between semi‐IPN and bicontinuous structures that have a strong interfacial interaction, which leads to incomplete phase decomposition in the PCz‐rich matrix phase. The maximum strength and modulus prepared under optimum condition are inferior to those of the individual components. In contrast, the elongation and break energy are greatly improved in those blends with bicontinuous structures having a diffused phase boundary.

DCA‐rich domain size in bicontinuous structure for DCA/PCz system, as a function of cure temperature; (□) 17 wt.‐% PCz, (○) 30 wt.‐% PCz, and (?) 50 wt.‐% PCz.     

Bidirectional Data Injection Operation of Hybrid Integrated SOA–MZI All-Optical Wavelength Converter

A bidirectional data signal input scheme of a semiconductor optical amplifier--Mach-Zehnder interferometer (SOA-MZI) wavelength converter was proposed and experimentally verified for a nonreturn-to-zero (NRZ)-format signal. Theoretical analyses reveal that it is possible to mitigate the patterning effect induced by cross-gain modulation (XGM) by utilizing the difference of the ratio between the XGM and cross-phase modulation on the injection directions of data signals. A hybrid integrated SOA-MZI all-optical wavelength converter, in which the coupling loss between the SOA and the silica waveguide was as small as 1 dB owing to a unique active alignment technique, was used for the experiment. We have verified the superior characteristics of the proposed operation scheme for the first time. Error-free wavelength-conversion operation for an NRZ signal at 40 Gb/s was confirmed     

In-Plane Coupling of Light From InP-Based Photonic Crystal Band-Edge Lasers Into Single-Mode Waveguides

In this paper, we analyze the coupling of light from photonic-crystal band-edge lasers into single-mode waveguides. Both active and passive devices lie in the same plane and coupling of light is achieved by using parabolic and nanotapers in InP based epitaxial structures. Two- and three-dimensional finite-difference time-domain methods are employed to analyze these devices. Coupling efficiencies higher than 80% can be obtained with parabolic couplers. We also present laser configurations that can reduce multiwavelength coupling of light into single-mode waveguides, using structures that are similar to coupled cavity Fabry-Peacuterot lasers     

Color displays and flexible displays using quick‐response liquid‐powder technology for electronic paper

Abstract— Color displays and flexible displays that use electronic liquid powder have been developed. Novel types of color displays using either a colored powder or a color filter are discussed. We have also developed a flexible display with low‐cost substrate films with a high‐throughput roll‐to‐roll manufacturing method. These technologies enable a QR‐LPD to be widely used as an electronic‐paper display.