Hitachi (United States)

We examined the effects of the thickness of the Pt shell, lattice mismatch, and particle size on specific and mass activities from the changes in effective surface area and activity for oxygen reduction induced by stepwise Pt-monolayer depositions on Pd and Pd(3)Co nanoparticles. The core-shell structure was characterized at the atomic level using Z-contrast scanning transmission electron microscopy coupled with element-sensitive electron energy loss spectroscopy. The enhancements in specific activity are largely attributed to the compressive strain effect based on the density functional theory calculations using a nanoparticle model, revealing the effect of nanosize-induced surface contraction on facet-dependent oxygen binding energy. The results suggest that moderately compressed (111) facets are most conducive to oxygen reduction reaction on small nanoparticles and indicate the importance of concerted structure and component optimization for enhancing core-shell nanocatalysts' activity and durability.

Association-rule mining has heretofore relied on the condition of high support to do its work efficiently. In particular, the well-known a priori algorithm is only effective when the only rules of interest are relationships that occur very frequently. However, there are a number of applications, such as data mining, identification of similar Web documents, clustering, and collaborative filtering, where the rules of interest have comparatively few instances in the data. In these cases, we must look for highly correlated items, or possibly even causal relationships between infrequent items. We develop a family of algorithms for solving this problem, employing a combination of random sampling and hashing techniques. We provide analysis of the algorithms developed and conduct experiments on real and synthetic data to obtain a comparative performance analysis.

Tumor cell-derived exosomes (TEX) suppress functions of immune cells. Here, changes in the gene profiles of primary human T lymphocytes exposed in vitro to exosomes were evaluated. CD4(+) Tconv, CD8(+) T or CD4(+) CD39(+) Treg were isolated from normal donors' peripheral blood and co-incubated with TEX or exosomes isolated from supernatants of cultured dendritic cells (DEX). Expression levels of 24-27 immune response-related genes in these T cells were quantified by qRT-PCR. In activated T cells, TEX and DEX up-regulated mRNA expression levels of multiple genes. Multifactorial data analysis of ΔCt values identified T cell activation and the immune cell type, but not exosome source, as factors regulating gene expression by exosomes. Treg were more sensitive to TEX-mediated effects than other T cell subsets. In Treg, TEX-mediated down-regulation of genes regulating the adenosine pathway translated into high expression of CD39 and increased adenosine production. TEX also induced up-regulation of inhibitory genes in CD4(+) Tconv, which translated into a loss of CD69 on their surface and a functional decline. Exosomes are not internalized by T cells, but signals they carry and deliver to cell surface receptors modulate gene expression and functions of human T lymphocytes.

Magnetic nanoparticles have potential applications in high-density memory devices, but their complicated synthesis often requires high temperatures, expensive reagents, and postsynthesis annealing to achieve the desired magnetic properties. Current synthetic methods for magnetic nanoparticles often require post-synthetic modifications, suggesting that the practical application of magnetic nanoparticles will depend on the development of alternative synthetic strategies. We report a biological template to directly grow magnetic nanoparticles of desired material composition and phase under ambient conditions. A phage display methodology was adapted to identify peptide sequences that both specifically bind to the ferromagnetic L10 phase of FePt and control the crystallization of FePt nanoparticles using a modified arrested precipitation technique. TEM, electron diffraction, STEM, and X-ray diffraction all indicate these nanoparticles are composed of an FePt alloy with some degree of chemical ordering, and SQUID analysis shows these nanostructures are ferromagnetic at room temperature, possessing coercivities up to 1000 Oe.

Describes circuit techniques for fabricating a high-speed adder using pass-transistor logic. Double pass-transistor logic (DPL) is shown to improve circuit performance at reduced supply voltage. Its symmetrical arrangement and double-transmission characteristics improve the gate speed without increasing the input capacitance. A carry propagation circuit technique called conditional carry selection (CCS) is shown to resolve the problem of series-connected pass transistors in the carry propagation path. By combining these techniques, the addition time of a 32-b ALU can be reduced by 30% from that of an ordinary CMOS ALU. A 32-b ALU test chip is fabricated in 0.25- mu m CMOS technology using these circuit techniques and is capable of an addition time of 1.5 ns at a supply voltage of 2.5 V.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Because of their distribution and known ability to promote neuronal adhesion, it has been proposed that N-CAM and N-cadherin are involved in the formation of the nervous system. Here, we examine the expression of these molecules during the initiation and cessation of trunk neural crest cell migration during the formation of the peripheral nervous system. Whereas other neural tube cells express N-cadherin, the dorsal neural tube containing neural crest precursors has little or no N-cadherin immunoreactivity. In contrast, N-CAM is expressed in the dorsal neural tube and on early migrating neural crest cells, from which it gradually disappears during migration. Both N-CAM and N-cadherin are absent from neural crest cells at advanced stages of migration. As neural crest cells cease migration and condense to form dorsal root and sympathetic ganglia, N-cadherin but not N-CAM is observed on the forming ganglia, identified by neurofilament expression and the aggregation of HNK-1 reactive cells. The results demonstrate that the absence of N-cadherin correlates with the onset of neural crest migration and its reappearance correlates with cessation of migration and precedes gangliogenesis.

AIM: To develop antibody-aptamer functionalized fibre-optic biosensor for specific detection of Listeria monocytogenes from food products. METHODS AND RESULTS: Aptamer, a single-stranded oligonucleotide ligand that displays affinity for the target molecule, was used in the assay to provide sensor specificity. Aptamer-A8, specific for internalin A, an invasive protein of L. monocytogenes, was used in the fibre-optic sensor together with antibody in a sandwich format for detection of L. monocytogenes from food. Biotinylated polyclonal anti-Listeria antibody, P66, was immobilized on streptavidin-coated optical waveguide surface for capturing bacteria, and Alexa Fluor 647-conjugated A8 was used as a reporter. The biosensor was able to selectively detect pathogenic Listeria in pure culture and in mixture with other bacteria at a concentration of approx. 10(3) CFU ml(-1). This sensor also successfully detected L. monocytogenes cells from artificially contaminated (initial inoculation of 10(2) CFU 25 g(-1) ) ready-to-eat meat products such as sliced beef, chicken and turkey after 18 h of enrichment. CONCLUSION: Based on the data presented in this study, the antibody-aptamer functionalized fibre-optic biosensor could be used as a detection tool for sensitive and specific detection of L. monocytogenes from foods. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrates feasibility and novel application of aptamer on fibre-optic biosensor platform for the sensitive detection of L. monocytogenes from food products.

Near-infrared spectroscopy is discussed from the viewpoint of human higher-order brain function analysis. Pioneering work in this field is reviewed; then we describe our concept of noninvasive trans-cranial dynamic optical topography and its instrumentation. Also, the validity of its functional images is assessed from both physical and physiological viewpoints. After confirming the validity of this method, we have applied it to a wide variety of fields such as clinical medicine, cognitive science, and linguistics in collaboration with researchers at several other institutes. Further application possibilities and the future of trans-cranial dynamic optical topography are also discussed. © 1999 Society of Photo-Optical Instrumentation Engineers.

Endothelial cells (ECs) line the mammalian vascular system and respond to the hemodynamic stimulus of fluid shear stress, the frictional force produced by blood flow. When ECs are exposed to shear stress, one of the fastest responses is an increase of K(+) conductance, which suggests that ion channels are involved in the early shear stress response. Here we show that an applied shear stress induces a K(+) ion current in cells expressing the endothelial Kir2.1 channel. This ion current shares the properties of the shear-induced current found in ECs. In addition, the shear current induction can be specifically prevented by tyrosine kinase inhibition. Our findings identify the Kir2.1 channel as an early component of the endothelial shear response mechanism.

Proliferation of human lymphocytes in response to various stimuli has traditionally been assessed by measuring uptake of radiolabeled nucleotides such as 3H-thymidine. We have evaluated a fluorometric assay, which uses the commercially available reagent, alamarBlue, as a potential substitute for the 3H-thymidine assay in measuring proliferation of human lymphocytes. In this assay, alamarBlue is added to a population of cells where it is reduced by mitochondrial enzyme activity. The reduced form of the reagent is fluorescent and can be quantitatively detected. The safety and convenience of the alamarBlue assay make it very attractive for use in the clinical laboratory. In this study peripheral blood mononuclear cells (PBMC) from healthy donors were stimulated using the mitogen Concanavalin A, and proliferation was assessed using either the 3H-thymidine or the alamarBlue assay. The alamarBlue assay reliably detects human PBMC and we found that the linear range of detection was 10(4) cells/well (96-well plate) to 5 x 10(5) cells/well. Detection of human PBMC is highly reproducible and the alamarBlue assay may be suitable in a number of applications where detection or relative quantitation of human PBMC is required. The alamarBlue assay also detected mitogen induced proliferation of PBMC although with a significantly lower level of sensitivity than the standard 3H-thymidine assay.

In the clinical photoacoustic (PA) imaging, ultrasound (US) array transducers are typically used to provide B-mode images in real-time. To form a B-mode image, delay-and-sum (DAS) beamforming algorithm is the most commonly used algorithm because of its ease of implementation. However, this algorithm suffers from low image resolution and low contrast drawbacks. To address this issue, delay-multiply-and-sum (DMAS) beamforming algorithm has been developed to provide enhanced image quality with higher contrast, and narrower main lobe compared but has limitations on the imaging speed for clinical applications. In this paper, we present an enhanced real-time DMAS algorithm with modified coherence factor (CF) for clinical PA imaging of humans in vivo. Our algorithm improves the lateral resolution and signal-to-noise ratio (SNR) of original DMAS beamformer by suppressing the background noise and side lobes using the coherence of received signals. We optimized the computations of the proposed DMAS with CF (DMAS-CF) to achieve real-time frame rate imaging on a graphics processing unit (GPU). To evaluate the proposed algorithm, we implemented DAS and DMAS with/without CF on a clinical US/PA imaging system and quantitatively assessed their processing speed and image quality. The processing time to reconstruct one B-mode image using DAS, DAS with CF (DAS-CF), DMAS, and DMAS-CF algorithms was 7.5, 7.6, 11.1, and 11.3 ms, respectively, all achieving the real-time imaging frame rate. In terms of the image quality, the proposed DMAS-CF algorithm improved the lateral resolution and SNR by 55.4% and 93.6 dB, respectively, compared to the DAS algorithm in the phantom imaging experiments. We believe the proposed DMAS-CF algorithm and its real-time implementation contributes significantly to the improvement of imaging quality of clinical US/PA imaging system.

Hitachi's SH series microprocessors feature 32-bit RISC architecture with a 16-bit, fixed-length instruction set. We describe SH3, a pipelined implementation of the SH architecture with on-chip cache, MMU, and software-programmable power management. Its higher code density and corresponding improvement in instruction-fetch latency lead to higher performance than typical 32-bit RISC architectures achieve. These features, small die size, and low power consumption make SH3 an ideal microprocessor for portable computing systems or multimedia systems.

Abstract A thermoresponsive hydrogel, poly( N ‐isopropylacrylamide) (poly(NIPAM)), is synthesized in situ within an oxidized porous Si template, and the nanocomposite material is characterized. Infiltration of the hydrogel into the interconnecting nanoscale pores of the porous SiO 2 host is confirmed by scanning electron microscopy. The optical reflectivity spectrum of the nanocomposite hybrid displays Fabry–Pérot fringes characteristic of thin film interference, enabling direct, real‐time observation of the volume phase transition of the confined poly(NIPAM) hydrogel. Reversible optical reflectivity changes are observed to correlate with the temperature‐dependent volume phase transition of the hydrogel, providing a new means of studying nanoscale confinement of responsive hydrogels. The confined hydrogel displays a swelling and shrinking response to changes in temperature that is significantly faster than that of the bulk hydrogel. The porosity and pore size of the SiO 2 template, which are precisely controlled by the electrochemical synthesis parameters, strongly influence the extent and rate of changes in the reflectivity spectrum of the nanocomposite. The observed optical response is ascribed to changes in both the mechanical and the dielectric properties of the nanocomposite.

Exosomes in plasma of glioma patients hold promise as biomarkers of prognosis. We aimed to determine whether changes in total exosomal protein and mRNA expression levels could serve as surrogate markers of immunological and clinical responses in glioma patients receiving antitumor vaccines. Exosomes were isolated from pre/post-vaccine plasma specimens in 20/22 patients enrolled in a phase I/II trial with the antitumor vaccine. Exosomal protein content was analyzed and mRNA expression levels for 24 genes were simultaneously assessed by qRT-PCR. Pre- to post-vaccination changes in exosomal protein and ΔCt values were correlated with immunological and clinical responses and survival using Spearman rank statistics and hazard ratios (HR). Exosomal protein levels positively correlated (p < 0.0043) with the WHO tumor grade at diagnosis. Protein levels were lower in post- vs. pre-vaccination exosome fractions. Post-therapy increases in tumor size were associated with elevations in exosome proteins in glioblastoma but not always in anaplastic astrocytoma (AA). Only exosomal ΔCt values for IL-8, TIMP-1, TGF-β and ZAP70 were significant (p < 0.04 to p < 0.001). The ΔCt for IL-8 and TGF-β mRNA positively correlated with post-vaccine immunologic responses to glioma antigens, while ΔCt for TIMP-1 mRNA was negatively correlated to ΔCt for IL-8 and TGF-β. Only ΔCt for IL-8 weakly correlated with OS and time to progression (TTP). In post-vaccine exosomes of the longest surviving patient with AA, mRNA for PD-1 was persistently elevated. Protein and mRNA expression levels for immune-related genes in plasma exosomes were useful in evaluating glioma patients' response to vaccination therapy.

We first report a multi-level-cell (MLC) spin-transfer torque memory (SPRAM) with series-connected magnetotunnel junctions (MTJs). The series MTJs (with different areas) show multi-level resistances by a combination of their magnetization directions. A four-level operation by spin-transfer-torque writing was experimentally demonstrated. A scheme for the write/read operation of the MLC SPRAM was also presented.

Visualizing ocular vasculature is important in clinical ophthalmology because ocular circulation abnormalities are early signs of ocular diseases. Photoacoustic microscopy (PAM) images the ocular vasculature without using exogenous contrast agents, avoiding associated side effects. Moreover, 3D PAM images can be useful in understanding vessel-related eye disease. However, the complex structure of the multi-layered vessels still present challenges in evaluating ocular vasculature. In this study, we demonstrate a new method to evaluate blood circulation in the eye by combining in vivo PAM imaging and an ocular surface estimation method based on a machine learning algorithm: a random sample consensus algorithm. By using the developed estimation method, we were able to visualize the PA ocular vascular image intuitively and demonstrate layer-by-layer analysis of injured ocular vasculature. We believe that our method can provide more accurate evaluations of the eye circulation in ophthalmic applications.

Helmholtz coils can be used for the measurement of open-circuit magnetization of most permanent magnet materials. The author describes the physics of the measurement, lists the materials that can be measured, derives the coil constant, and derives a correction factor for the measurement of arc magnets. A measurement is made by placing the magnet at the center of the coils, and zeroing the integrating voltmeter or fluxmeter. The magnet is then removed from the coil, parallel to the coil axis, to a distance such that the sample has no influence on the reading, typically 75 to 100 cm. The open-circuit magnetization of the sample is related to the time-integrated voltage.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Human colon cancer frequently develops liver metastasis. Matrilysin (MMP-7), the smallest member of the matrix metalloproteinase (MMP) family, is commonly produced by human colon carcinoma cells and has been suggested to be involved in the progression and metastasis of this type of cancer. In the present study, we tested the effect of a matrilysin-specific antisense phosphorothioate oligonucleotide on liver metastasis of the human colon carcinoma cell line WiDr in nude mice. In culture, the antisense oligonucleotide moderately inhibited the secretion of matrilysin by WiDr cells. Injection of WiDr cells into the spleen of nude mice produced many metastatic tumor nodules in the liver. When the antisense oligonucleotide was injected daily into the mice for 11 days, the formation of the metastatic tumor nodules was strongly inhibited in a dose-dependent manner. An inhibition of liver metastasis of over 70% was obtained at a dose of 120 micrograms of the oligonucleotide per mouse. The antisense oligonucleotide did not inhibit tumor growth in spleen and in liver. A scrambled control oligonucleotide had no effect on liver metastasis of WiDr cells. Our results demonstrate an important role of matrilysin in liver metastasis of human colon cancer and the therapeutic potential of matrilysin antisense oligonucleotides for the prevention of metastasis.

The use of metal nanoparticles as seed layers for controlling the microstructures of tin oxide (SnO2) films on temperature controllable micromachined platforms has been investigated. The study is focused on SnO2 due to its importance in the field of chemical microsensors. Nanoparticle seeds of iron, cobalt, nickel, copper and silver were formed by vapour deposition on the microhotplates followed by annealing at 500 °C prior to self-aligned SnO2 deposition. Significant control of SnO2 grain sizes, ranging between 20 and 121 nm, was achieved depending on the seed-layer type. A correlation was found between decreasing the SnO2 grain size and increasing the melting temperature of the seed-layer metals, suggesting the use of high temperature metals as being appropriate choices as seed layers for obtaining a smaller SnO2 grain structure. Smaller grain diameters resulted in high sensitivity in 90 ppm ethanol illustrating the benefits of nanoparticle seeding for chemical sensing. The initial morphology, particle size and distribution of the seed layers was found to dictate the final SnO2 morphology and grain size. This paper not only demonstrates the possibility of depositing nanostructured oxide materials for chemical microsensor applications, but also demonstrates the feasibility of conducting combinatorial research into nanoparticle growth using temperature controllable microhotplate platforms. This paper also demonstrates the possibility of using multi-element arrays to form a range of different types of devices that could be used with suitable olfactory signal processing techniques in order to identify a variety of gases.

The Power Reactor Innovative Small Module (PRISM) designed by GE Hitachi Nuclear Energy is a small, modular, sodium-cooled fast reactor. The PRISM core is located in a pool-type containment vessel and is fueled with metallic fuel. Each PRISM produces 311 MW of electricity. The PRISM is inherently safe due to its negative power reactivity feedback, large in-vessel coolant inventory, passive heat removal systems, below-grade siting, and atmospheric reactor vessel operating pressure. In NUREG-1368, “Preapplication Safety Evaluation Report for the Power Reactor Innovative Small Module (PRISM) Liquid-Metal Reactor,” the U.S. Nuclear Regulatory Commission stated that “On the basis of the review performed, the staff, with the ACRS [Advisory Committee on Reactor Safeguards] in agreement, concludes that no obvious impediments to licensing the PRISM design have been identified.” PRISM is able to fission electrometallurgically recycled used nuclear fuel (UNF) from light water reactors as well as weapons-grade materials. PRISM, with the associated Nuclear Fuel Recycling Center, represents a safe, diversion resistant, commercially viable technology for recycling UNF with a small modular reactor.