bluuebunny/crossref_metadata_2025 huggingface dataset:
The Mechanism of Splenic Invariant NKT Cell Activation Dictates Localization In Vivo
Authors: King Irah L. , Amiel Eyal , Tighe Mike , Mohrs Katja , Veerapen Natacha , Besra Gurdyal , Mohrs Markus , Leadbetter Elizabeth A.
Published: June 2013

Invariant NKT (iNKT) cells are glycolipid-specific innate lymphocytes emerging as critical players in the immune response to diverse infections and disease. iNKT cells are activated through cognate interactions with lipid-loaded APCs, by Ag-independent cytokine-mediated signaling pathways, or a combination of both. Although each of these modes of iNKT cell activation plays an important role in directing the humoral and cell-mediated immune response, the spatio-temporal nature of these interactions and the cellular requirements for activation are largely undefined. Combining novel in situ confocal imaging of αGalactosylceramide-loaded CD1d tetramer labeling to localize the endogenous iNKT cell population with cytokine reporter mice, we reveal the choreography of early murine splenic iNKT cell activation across diverse settings of glycolipid immunization and systemic infection with Streptococcus pneumoniae. We find that iNKT cells consolidate in the marginal zone and require dendritic cells lining the splenic marginal zone for activation following administration of cognate glycolipids and during systemic infection but not following exogenous cytokine administration. Although further establishing the importance of cognate iNKT cell interactions with APCs, we also show that noncognate iNKT-dependent mechanisms are sufficient to mediate effector outcomes, such as STAT signaling and dendritic cell licensing throughout the splenic parenchyma. Collectively, these data provide new insight into how iNKT cells may serve as a natural adjuvant in facilitating adaptive immune responses, irrespective of their tissue localization.
Co-Complexes of MASP-1 and MASP-2 Associated with the Soluble Pattern-Recognition Molecules Drive Lectin Pathway Activation in a Manner Inhibitable by MAp44
Authors: Degn Søren E. , Jensen Lisbeth , Olszowski Tomasz , Jensenius Jens C. , Thiel Steffen
Published: June 2013

The lectin pathway of complement is an integral component of innate immunity. It is activated upon binding of mannan-binding lectin (MBL) or ficolins (H-, L-, and M-ficolin) to suitable ligand patterns on microorganisms. MBL and ficolins are polydisperse homo-oligomeric molecules, found in complexes with MBL-associated serine proteases (MASP-1, -2, and -3) and MBL-associated proteins (MAp19 and MAp44). This scenario is far more complex than the well-defined activation complex of the classical pathway, C1qC1r2C1s2, and the composition of the activating complexes of the lectin pathway is ill defined. We and other investigators recently demonstrated that both MASP-1 and MASP-2 are crucial to lectin pathway activation. MASP-1 transactivates MASP-2 and, although MASP-1 also cleaves C2, MASP-2 cleaves both C4 and C2, allowing formation of the C3 convertase, C4bC2a. Juxtaposition of MASP-1 and MASP-2 during activation must be required for transactivation. We previously presented a possible scenario, which parallels that of the classical pathway, in which MASP-1 and MASP-2 are found together in the same MBL or ficolin complex. In this study, we demonstrate that, although MASPs do not directly form heterodimers, the addition of MBL or ficolins allows the formation of MASP-1–MASP-2 co-complexes. We find that such co-complexes have a functional role in activating complement and are present in serum at varying levels, impacting on the degree of complement activation. This raises the novel possibility that MAp44 may inhibit complement, not simply by brute force displacement of MASP-2 from MBL or ficolins, but by disruption of co-complexes, hence impairing transactivation. We present support for this contention.
Tan spot - the most harmful wheat leaf disease in Latvia
Authors: Bankina Biruta
Published: June 2013

Tan spot (Pyrenophora tritici-repentis) is one of the most important wheat diseases in Latvia. Significant spreading of this disease was observed from 1998. Field experiments were carried out at the Research and Training Farm "Peterlauki" of the Latvia University of Agriculture, during 1998-2003. Development of diseases was observed on 14 winter wheat varieties, dynamics of development was investigated on 'Donskaja polukarlikovaja' and 'Stava'. Assessments of the disease severity were carried out on the upper three leaves each week from the start of stem elongation to full ripening. Tan spot was observed at the stage of stem elongation in 2003, and only after flowering in 1999. Increase of the disease severity was slow until stage of milk ripeness, and only in late stages of wheat development sharp increase of the disease was observed. Total rate of infection (through the session of vegetation) was very slow (0,01-0,19), but during ripening rate achieved 0,5-0,6. The main reason of so unequal development of the disease seems changes in amount of infection sources. Other possible reason of rapid increase of the disease development is the relationship between leaf age and susceptibility to the disease. Further research is necessary for better understanding of tan spot life cycle.
Reactions of winter wheat to Mycosphaerella graminicola (anamorph Septoria tritici)
Authors: Věchet Lubomir , Sychrová Eliška
Published: June 2013

Reaction of six winter wheat cultivars and lines (Vlasta, Šárka, Charger, 00ST022, SG-U8044C a SG-U2113B) to Mycosphaerella graminicola isolate BR-331 and UH-05 on leaf segments of the detached second seedling leaf of cultivars placed on water agar with bezimidazole in clear plastic box were tested. The isolate BR-331 produced high occurrence of the disease in the cultivar Šárka, middle occurrence (the percentage covered by lesions bearing pycnidia) in the cultivar Vlasta and SG-U8044C and low occurrence in the line 00ST0022. The isolate UH-105 produced high occurrence in the cultivar 00ST022 and middle occurrence in the cultivar Vlasta. The cultivar Charger was resistant. The cultivar Šárka was attacked at least. Results show on different virulence of M. graminicola isolates to wheat cultivars.
Fungi colonising the above-ground parts of fodder galega (Galega orientalis Lam.) cultivated in pure sowing and mixed with smooth brome-grass (Bromus inermis Leyss.)
Authors: Cwalina-Ambroziak Bożena , Koc Józef
Published: June 2013

Field experiments were carried out in 1999-2001 in the experimental field in Knopin near Dobre Miasto to determine the intensity of fodder galega diseases cultivated in pure sowing and mixed with smooth brome-grass (the Hillstrand and Auld' s modified scale, 1982). The fungi colonising the phyllosphere of fodder galega were analysed in a laboratory (Chruoeciak , 1974). The following symptoms were observed in fodder galega: ascochyta blight (Ascochyta sp.), gray mould (Botrytis cinerea) and plant wilting (Fusarium oxysporum.). The climatic conditions had an effect on the development of diseases. The greatest intensity of gray mould (Ii = 24.3%) and plant wilting (17.9% of plants with the disease symptoms) were observed in 2001. Ascochyta blight occurred with the lowest intensity and the highest infection index in 1999 in the cultivation of fodder galega mixed with smooth brome-grass was only 12.1%. The type of cultivation also modified fodder galega disease intensity. Gray mould and plant wilting developed better in pure sowing than in mixed sowing with smooth brome-grass. Throughout the entire experiment period the average infection index was 22.8% and 15.9% of plants with the wilt symptoms. Ascochyta blight found better conditions for development in plants cultivated in a mix with smooth brome-grass (average infection index - 10.0%). The fodder galega phyllosphere provided 4149 fungal isolates represented by 17 species and yeast-like fungi. Yeast-like fungi dominated (75.6% of the total isolates). The following species were less numerous: Botrytis cinerea, Humicola brevis, Acremonium strictum and Cladosporium cladosporioides. From the leaves of fodder galega cultivated in pure sowing, 3.8% more fungi were obtained than from the leaves of plants cultivated with a mix of smooth brome-grass, including more frequently isolated pathogenic fungi representing the genera of Fusarium and the species of Botrytis cinerea.
The use of PCR assay for quality testing of grain of winter wheat cultivated in organic, integrated, conventional system and monoculture in phytopathological aspect
Authors: Łukanowski Aleksander , Sadowski Czesław
Published: June 2013

The aim of experiments was to evaluate the occurrence of fungi on grain of winter wheat cv. Roma cultivated in four systems on the experimental fields owned by the Institute of Soil Science and Plant Cultivation. Among pathogenic species, fungi from genus Fusarium dominated. Their number was the lowest on grain harvested in organic system and the highest in integrated one. Saprotrophic species were represented mainly by Alternaria alternata, which occurred the most often in organic system. Determination of F. avenaceum, F. culmorum and F. poae with microscope was confirmed with a PCR assay. All isolates of F. culmorum and F. poae gave an amplification product of Tri 5 gene coding the possibility of trichocene production, while none of isolates of F. avenaceum.
Immunodiagnosis of eyespot disease in winter wheat cultivated in different production systems
Authors: Solarska Ewa , Skomra Urszula
Published: June 2013

The aim of the study carried out in the years 2001-2003 was to determine the occurrence of Pseudocercosporella herpotrichoides in winter wheat cultivated in different production systems using traditional visible disease assessment and ELISA technique. Pathogen was detected by ELISA test in all years of the study and attained highest level in 2003. The greatest quantities of Pseudocercosporella herpotrichoides were observed in integrated system and monoculture and significantly lower in conventional production system.
Graphene Based Nanogenerator for Energy Harvesting
Authors: Kwon Junggou , Sharma Bhupendra K. , Ahn Jong-Hyun
Published: June 2013

Development of energy harvesting system becomes one of the most important necessities of today. In this context, nanogenerators (NGs) have attracted considerable attentions in recent years due to their potential applications such as self-powered portable devices. This review article addresses the significant development of NGs systems based on semiconducting and insulating piezoelectric materials. Further, the need of mechanical flexibility and optical transparency on the demand of various electronic applications has been highlighted. In addition, we discussed some recent studies on graphene-based NGs which have been explored for stable performance of NGs.
130 kV High-Resolution Electron Beam Lithography System for Sub-10-nm Nanofabrication
Authors: Okino Teruaki , Kuba Yukio , Shibata Masahiro , Ohyi Hideyuki
Published: June 2013

An electron beam lithography (EBL) system, CABL-UH, with a 130 kV high acceleration voltage has been developed that succeeded in minimizing beam size by minimizing Coulomb blur. This system has a short single-stage electron beam (EB) gun with an alignment function of two extractor centers to minimize Coulomb blur. This gun has also succeeded in thoroughly avoiding microdischarges. By adopting this EB gun and many other techniques, high resolution and long-term high stability have been achieved and an extremely fine pattern (4 nm line) has been delineated.
Interfacial Nanostructure of the Polymer Electrolyte Fuel Cell Catalyst Layer Constructed with Different Ionomer Contents
Authors: Baba Koki , Iwasawa Kenta , Eguchi Mika , Kobayashi Yoshio , Kobori Maya , Nishitani-Gamo Mikka , Ando Toshihiro
Published: June 2013

Fibrous carbon materials such as carbon nanotubes (CNTs) and carbon nanofilaments (CNFs) have attracted attention for use in the polymer electrolyte fuel cells (PEFCs). We have applied one type of fibrous carbon materials named Marimo carbon (MC) as the catalyst support. The modified nanocolloidal method was used preparing the Marimo carbon supported Pt catalyst (Pt/MC). And then, ionomer/carbon ratio in the cathode catalyst layer of the PEFC has been investigated for its effect on performance and structure of the membrane electrode assembly (MEA). The morphologies and cell performance of cathode catalyst layer using Marimo carbon changed dramatically with ionomer content. In case of excess ionomer, the air volume between CNFs was plugged up by ionomer, and blocked supply fuel gas diffusion caused decrease cell performance. PEFC cell performance was increase with decreasing ionomer content.
Electrical Resistivity Measurements of Layer Number Determined Multilayer Graphene Wiring for Future Large Scale Integrated Circuit Interconnects
Authors: Ito Kazuyuki , Katagiri Masayuki , Sakai Tadashi , Awano Yuji
Published: June 2013

To investigate the feasibility of nanocarbon interconnects for future LSIs, the electrical resistance of exfoliated multilayer graphene (MLG) wirings has been studied with accurate measurements of the number of layers. We employed transmission electron microscopy (TEM) as an exact number determination method, atomic force microscopy (AFM) as a simple method, and an extended optical contrast method as an easy distinction method, which we proposed for determining the number of layers. The sheet resistance of MLG wirings, including TEM determined 3-, 54-, and 341-layer MLGs, has been measured using the four-probe method and the layer number dependence of sheet resistance was discussed on the basis of a ladder circuit model simulation. It is shown that the dependence agrees well with the simulations, suggesting parallel conduction in MLG wirings, even if the probe electrodes are deposited just on the top layer of MLG.
Improvement of the Reproducibility of the Switching Voltage of Resistance Change Random Access Memory by Restricting Formation of Conductive Filaments
Authors: Furuya Saeko , Otsuka Shintaro , Shimizu Tomohiro , Shingubara Shouso , Watanabe Tadataka , Takano Yoshiki , Takase Kouichi
Published: June 2013

Resistance change random access memory (ReRAM) has been expected to be a next generation non-volatile memory. However, poor reproducibility of threshold voltage at which the dramatic change of the resistivity occurs hinders the practical application. We have attempted to improve the reproducibility of switching voltages using anodic porous alumina whose nanoholes are quite useful to restrict the filament forming area on the basis of the filament model. In this study, we have reported the pore size and film properties dependences of the variation width of the switching voltages. Two kinds of oxide films prepared by oxalic and sulfuric acids with two different anodic times were used as the insulating layer. Contrary to our expectation, just the sulfuric samples indicate good improvement about the switching voltages. Considering that the size of the effective contact area is not enough small against the filament size, the changing the film properties seems to be important for the suppressing the variation of switching voltages.
Temperature-Controlled Symmetry of Linear Polarization of Photoluminescence from InGaAs-Buried InAs/GaAs Quantum Dots
Authors: Mukai Kohki , Kikushima Kousuke , Tanaka Tomoya , Nakashima Seisuke
Published: June 2013

We have succeeded in adjusting the symmetry of the linear polarization of exciton emission from self-assembled InAs/GaAs quantum dots by controlling the combination of temperature and composition of the InGaAs burying layer. The anisotropic shape of the Stranski–Krastanow-type quantum dot is a drawback to the generation of a polarization-entangled photon pair. We found that the polarization symmetry of the intensity and wavelength of photon emission depends on the sample temperature and the composition of the burying layer. The ground-state emission peaks in two linear polarization directions were tuned to overlap by lowering the temperature and using a high indium composition of the burying layer. Our results will aid in the development of an entangled-photon generator using the emission of exciton molecule in self-assembled quantum dots.
Preparation and Characteristic of Relative-Humidity Sensors Based on Laterally Grown ZnO Nanowires
Authors: Tsai Fu-Shou , Wang Shui-Jinn , Tu Yung-Chun , Lin Tseng-Hsing
Published: June 2013

The use of laterally oriented zinc oxide nanowires (ZnO NWs) grown by a hydrothermal growth (HTG) method for relative-humidity (RH) sensing devices at room temperature (RT) is demonstrated. Sensing response under various RH conditions (12–96%) at RT is presented and discussed. A humidity sensor based on laterally oriented ZnO NWs with a sensing response (R12%/R96%) as high as 2.2 was obtained at RT. The RT-operable humidity-sensing characteristics with comparably good sensitivity of the proposed humidity sensors is attributed to the full utilization of the entire NW surface, because the current path is aligned with the orientation of the bridged lateral ZnO NWs during the humidity sensing application, thus making possible.
Visible Electroluminescence of a n+-Indium–Tin-Oxide/Sm-Doped i-TiO2/p-NiO/p+-Si Light-Emitting Diode
Authors: Ohtsuki Takuya , Harako Susumu , Komuro Syuji , Zhao Xinwei
Published: June 2013

A n+-indium–tin-oxide (ITO)/Sm-doped i-TiO2/p-NiO/p+-Si light-emitting diode (LED) was fabricated via laser ablation and post annealing treatment. The LED emitted red light at room temperature under a relatively low threshold voltage of 12 V. The electroluminescence and photoluminescence spectra of the LED were compared, and a stable and single-type Sm3+luminescent center was observed to give rise to red emission under different excitation conditions. These results suggest that there is a strong possibility of realizing LEDs based on rare-earth-doped metal oxide semiconductors.
Temperature-Shift Speed Dependence of Nonspecific Amplification of Polymerase Chain Reaction Examined by 1480 nm Photothermal Transition Speed Controllable High-Speed Polymerase Chain Reaction System
Authors: Terazono Hideyuki , Hattori Akihiro , Kim Hyonchol , Takei Hiroyuki , Nomura Fumimasa , Kaneko Tomoyuki , Yasuda Kenji
Published: June 2013

We have examined the contribution of temperature shift speed from denaturation to extension for the reduction of nonspecific amplification caused by the mismatched primer-target attachment. We have newly developed the photothermal quantitative polymerase chain reaction (qPCR) system, in which the direct absorption of a 1480 nm infrared laser beam was controlled by a rotating gradient neutral density (ND) filter to acquire the precise control of the desired speed of temperature shift between 60 and 95 °C up to 1 s. The results showed that a quick shift of the temperature during the qPCR procedure reduced nonspecific amplicons with a significant reduction of qPCR time when we have chosen proper primer sets, whereas the non-proper primer set amplified nonspecific amplicons in the fast qPCR. The results indicate that the potential of quick qPCR using proper primers can reduce nonspecific amplification and the required time for qPCR measurement, and the necessity of more precise check of the matching of the primer template adequate for the fast temperature shift and for quick qPCR analysis.
Physiological Sample Uniformity and Time–Course Stability in Lined-Up Structure of Human Cardiomyocyte Network for In vitro Predictive Drug-Induced Cardiotoxicity
Authors: Hamada Tomoyo , Kaneko Tomoyuki , Nomura Fumimasa , Yasuda Kenji
Published: June 2013

We have evaluated the electrophysiological characteristics of a line-shaped network of a three-dimensionally controlled in vitro human cardiomyocyte assay (hCM line) against conventional cell clusters as the standard model (hCM cluster) from the viewpoint of quality control of sample variety and time–course stability. The beating intervals of the hCM line demonstrated a more stable uniformity of samples (846 ±130 ms, 15.3% fluctuation) and better time–course stability, whereas those of the hCM cluster showed a much larger variety of samples (2001 ±1127 ms, 56.3% fluctuation) and weaker time–course stability. The field potential amplitude of the hCM line also showed better uniformity of samples (629 ±428 µV, 68.0% fluctuation) against those of the hCM cluster (1984 ±2288 µV, 115.3% fluctuation). The results suggested the importance of the cell-network shape control for the uniformity and stability of the beating interval and the field potential amplitude. They also suggest that the hCM line can improve the reproducibility and accuracy of the samples, which is important for a functional human cardiotoxicity model.
On-Chip Single-Cell-Shape Control Technology for Understanding Contractile Motion of Cardiomyocytes Measured Using Optical Image Analysis System
Authors: Kaneko Tomoyuki , Takizawa Eikei , Nomura Fumimasa , Hamada Tomoyo , Hattori Akihiro , Yasuda Kenji
Published: June 2013

Quantitative evaluation of mechanophysiological responses of cardiomyocytes has become more important for more precise prediction of cardiotoxicity. For the accurate detection of cardiomyocyte contraction, we have developed an on-chip single-cell-shape control technology on the basis of an agarose microchamber system and an on-chip optical image analysis system that records the contractile motions of cardiomyocytes with noninvasive/nondestructive measurement for long-term experiments. Using this on-chip single-cell-shape control technology, the shape of single cardiomyocytes was controlled by seeding the cells in 21-µm-radius (circular) or 20×70 µm2 (rectangular) agarose microchambers. To detect the contractility of cardiomyocytes, the cells were labeled with microbeads attached onto the surface of target cells and the motion of beads was acquired and analyzed using a newly developed wider-depth-of-field optics equipped with a 1/100 s high-speed digital camera. Mechanophysiological properties such as displacement and direction of movement were obtained using a real-time processing system module at spatial and temporal resolutions of 0.15 µm and 10 ms, respectively. Comparisons of displacement and direction of contraction between circular and rectangular cardiomyocytes indicated that the rectangular cardiomyocytes tended to contract along the longitudinal direction as in a real heart. This result suggests that the shape of cells affected the function of cells. The on-chip single-cell-shape control technology and optical image analysis system enable the detection of the motion of contraction of single-shape-controlled cardiomyocytes, and are expected to be applicable to the more precise prediction of cardiotoxicity.
Advanced Ring-Shaped Microelectrode Assay Combined with Small Rectangular Electrode for Quasi-In vivo Measurement of Cell-to-Cell Conductance in Cardiomyocyte Network
Authors: Nomura Fumimasa , Kaneko Tomoyuki , Hamada Tomoyo , Hattori Akihiro , Yasuda Kenji
Published: June 2013

To predict the risk of fatal arrhythmia induced by cardiotoxicity in the highly complex human heart system, we have developed a novel quasi-in vivo electrophysiological measurement assay, which combines a ring-shaped human cardiomyocyte network and a set of two electrodes that form a large single ring-shaped electrode for the direct measurement of irregular cell-to-cell conductance occurrence in a cardiomyocyte network, and a small rectangular microelectrode for forced pacing of cardiomyocyte beating and for acquiring the field potential waveforms of cardiomyocytes. The advantages of this assay are as follows. The electrophysiological signals of cardiomyocytes in the ring-shaped network are superimposed directly on a single loop-shaped electrode, in which the information of asynchronous behavior of cell-to-cell conductance are included, without requiring a set of huge numbers of microelectrode arrays, a set of fast data conversion circuits, or a complex analysis in a computer. Another advantage is that the small rectangular electrode can control the position and timing of forced beating in a ring-shaped human induced pluripotent stem cell (hiPS)-derived cardiomyocyte network and can also acquire the field potentials of cardiomyocytes. First, we constructed the human iPS-derived cardiomyocyte ring-shaped network on the set of two electrodes, and acquired the field potential signals of particular cardiomyocytes in the ring-shaped cardiomyocyte network during simultaneous acquisition of the superimposed signals of whole-cardiomyocyte networks representing cell-to-cell conduction. Using the small rectangular electrode, we have also evaluated the response of the cell network to electrical stimulation. The mean and SD of the minimum stimulation voltage required for pacing (V
Min) at the small rectangular electrode was 166±74 mV, which is the same as the magnitude of amplitude for the pacing using the ring-shaped electrode (179±33 mV). The results showed that the addition of a small rectangular electrode into the ring-shaped electrode was effective for the simultaneous measurement of whole-cell-network signals and single-cell/small-cluster signals on a local site in the cell network, and for the pacing by electrical stimulation of cardiomyocyte networks.
Electrokinetic Evaluation of Individual Exosomes by On-Chip Microcapillary Electrophoresis with Laser Dark-Field Microscopy
Authors: Kato Kei , Kobayashi Masashi , Hanamura Nami , Akagi Takanori , Kosaka Nobuyoshi , Ochiya Takahiro , Ichiki Takanori
Published: June 2013

Cell-secreted nanovesicles called exosomes are expected as a promising candidate biomarker of various diseases. Toward the future application of exosomes as a disease biomarker for low-invasive diagnostics, challenges remain in the development of sensitive and precise analysis methods for exosomes. In this study, we performed the electrokinetic evaluation of individual exosomes by the combined use of on-chip microcapillary electrophoresis and laser dark-field microscopy. We extracted exosomes from six types of human cell cultured in a serum-free medium by differential ultracentrifugation and their zeta potential (electrophoretic mobility) were evaluated. We demonstrated that the proposed electrophoresis apparatus is particularly suitable for the tracking analysis of the electrophoretic migration of individual exosomes and enables the accurate evaluation of the zeta potential distribution of exosomes, for the first time. From the experimental results, we found that there is a strong correlation between the average zeta potentials of exosomes and their cells of origin.
Novel Sensor Structure and Its Evaluation for Integrated Complementary Metal Oxide Semiconductor Microelectromechanical Systems Accelerometer
Authors: Konishi Toshifumi , Yamane Daisuke , Matsushima Takaaki , Motohashi Ghou , Kagaya Ken , Ito Hiroyuki , Ishihara Noboru , Toshiyoshi Hiroshi , Machida Katsuyuki , Masu Kazuya
Published: June 2013

This paper reports a novel sensor structure and its evaluation results for an integrated complementary metal oxide semiconductor (CMOS) microelectromechanical systems (MEMS) accelerometer with a wide detection range on a chip. The proposed sensor structure has the following features: i) a layer separation technique between the proof mass and the mechanical suspensions, ii) mechanical stoppers for the proof mass to avoid destruction, and iii) a SiO2 film underneath the proof mass to prevent stiction and electrical short. Gold was used as the MEMS structure material to reduce the proof mass size and to lower the Brownian noise to below 100 µg/√Hz. Furthermore, the micro fabrication was carried out below 310 °C for the CMOS devices to remain intact. The evaluation results indicate that the Brownian noise was 90.6 µg/√Hz. Thus, we have confirmed that the proposed MEMS structure has the potential for use in future integrated CMOS-MEMS accelerometers.
Microfabrication of Super Absorbent Polymer Structure Using Nanoimprinting and Swelling Process
Authors: Inaba Tomomi , Kano Tomonori , Miki Norihisa
Published: June 2013

Micro-fabrication technologies have been extensively studied to achieve smaller sizes and higher aspect ratios. When the features have sizes of a couple of micrometers or below, nano-imprinting can be an effective method for micro-fabrication at low cost. However, it is difficult to achieve aspect ratio greater than 1. In this research, we propose micro fabrication of super absorbent polymer (SAP) as a new material for micro devices. SAP swells by adding deionized water, which can be used as a post patterning process to enhance the aspect ratio of micro structures. Micropatterning of SAP must be conducted under thoroughly dry conditions and we used nano-imprinting processes. We successfully augmented an aspect ratio of the nano-imprinted micro holes of SAP from 0.65 to 1.2 by the swelling process. The proposed patterning and swelling process of SAP can be applicable to micro-fabricate high-aspect-ratio structures at low cost for high performance lab-on-a-chip.
Infrared Detector Array with an Incident-Ray Concentrator
Authors: Choi Ju Chan , Lee June Kyoo , Choi Young Chan , Jung Dong Geun , Kong Seong Ho
Published: June 2013

In this paper, we report an infrared (IR) detector array combined with an incident-ray concentrator for improving performance characteristics, such as optical responsivity and fill factor. To achieve an improved optical responsivity, the use of an IR concentrating structure for collecting incident IR rays is proposed in this paper. This structure is combined with an IR detector by epoxy bonding. Compared with a conventional IR detector without an IR concentrator, the responsivity of the proposed IR detector with an IR concentrator increased approximately 17.5%. By applying the IR concentrator, the fill factor of the fabricated IR detector array was also increased owing to the increased input IR light in the sensing area.
Relationship between Diffusion and Adhesion Properties of Ferroelectric Thin-Film Structure on Releasable Substrate
Authors: Honda Fumiaki , Hosono Toshifumi , Fujino Masahisa , Suga Tadatomo , Ichiki Masaaki , Itoh Toshihiro
Published: June 2013

Pb(Zr0.52,Ti0.48)O3 thin-films with various thicknesses were prepared on releasable Pt/SiO2/Si substrates. The adhesion force between Pt and SiO2 was estimated, mainly in the viewpoint of the diffusion of Pb, in X-ray photoelectron spectroscopy (XPS) and tensile test for the clarification of the bonding properties of the nano-transfer method. The adhesion strength of Pt to SiO2 has an inverse linear relationship with the thickness of Pt. On the other hand the adhesion strength of the samples, that were crystallized with different number of layers, were shown to be in the same region of 2–4 MPa as in case of PZT with over 250 nm in thickness. These results indicate that the origin of the bonding is the diffusion of Pb in the film and that the bonding strength is connected with the earlier stage of crystallization.
Reduction of Transverse Surface Acoustic Wave Leakage in Resonator on Al/42° YX-LiTaO3 Substrate for High-Frequency Applications
Authors: Komatsu Tomoya , Nakamura Hiroyuki , Nakanishi Hidekazu , Turunari Tetsuya , Fujiwara Joji
Published: June 2013

In this paper, we propose a new structure for reducing the extent of transverse surface acoustic wave (SAW) leakage for the SAW resonator on a 42° YX-LiTaO3 substrate. Such leakage occurs from the interdigital region toward the busbar region in the SAW resonators. The new structure has a Ta2O5 film outside the interdigital region. This structure can make the SAW velocity in the busbar region lower than the velocity in the interdigital region. Therefore, the new structure could reduce the extent of leakage, and contribute to confine the SAW energy in the interdigital region. This structure was applied in SAW resonators and ladder-type SAW filters fabricated on a 42° YX-LiTaO3 substrate. The insertion loss could be improved by suppressing transverse SAW leakage. This technique could be applied to the fabrication of the filters and duplexers using leaky SAW on a 42° YX-LiTaO3 substrate, and the SAW devices could exhibit excellent performance.
Longitudinal-Type Leaky Surface Acoustic Wave on LiNbO3 with High-Velocity Thin Film
Authors: Matsukura Fumiya , Uematsu Masato , Hosaka Keiko , Kakio Shoji
Published: June 2013

The loss reduction of a longitudinal-type leaky surface acoustic wave (LLSAW) by loading with a dielectric thin film with a higher velocity than the substrate is proposed. An aluminum nitride (AlN) thin film was adopted as a high-velocity thin film, and the propagation properties of an LLSAW on an X36°Y-LiNbO3 (LN) substrate were investigated. First, the elastic constants c
11 and c
44 of an amorphous AlN (a-AlN) thin film deposited by RF magnetron sputtering were determined from the measured phase velocities of two SAW modes with mutually perpendicular particle motion, and they were 78 and 96% of those of a single-crystal AlN thin film. Next, from the theoretical calculation for the LLSAW on X36°Y-LN using the determined constants, it was found that the LLSAW attenuation can be reduced to zero by loading with an a-AlN thin film. Then, the propagation properties of the LLSAW on X36°Y-LN were measured by using an interdigital transducer pair. It was found that the losses due to bulk wave radiation can be reduced by loading with an a-AlN thin film.
Influence of Liquid Height on Mechanical and Chemical Effects in 20 kHz Sonication
Authors: Tran Khuyen Viet Bao , Asakura Yoshiyuki , Koda Shinobu
Published: June 2013

We examined the influence of liquid height on mechanical and chemical effects in 20 kHz sonication with a new Langevin-type transducer. Mechanical effects were evaluated from the degradation of polyethylene oxide in aqueous solution and chemical effects were measured with potassium iodide solution. Standing waves or reactive zones were observed using sonochemical luminescence and aluminum foil erosion. The observed wavelength was reduced by coupled vibration, compared with the wavelength calculated by dividing velocity by irradiation frequency. As liquid height increased, mechanical effects were suppressed. In the case of chemical effects, the stable sonochemical efficiency gained at a height of over 120 mm, and the sonochemical efficiency were also markedly higher than those of a conventional horn-type one.
Focus Control Aided by Numerical Simulation in Heterogeneous Media for High-Intensity Focused Ultrasound Treatment
Authors: Narumi Ryuta , Matsuki Kosuke , Mitarai Shigeru , Azuma Takashi , Okita Kohei , Sasaki Akira , Yoshinaka Kiyoshi , Takagi Shu , Matsumoto Yoichiro
Published: June 2013

A focus control method based on time reversal aided by numerical simulation was implemented to correct focal errors in heterogeneous media by using a 56-element phased array transducer at a frequency of 2 MHz. Two types of acrylic phantom were employed to mimic the acoustic heterogeneities in the human body. Focal errors were significantly reduced by applying the phase correction. Moreover, the effects of amplitude correction, array configuration of the transducer, and transverse wave propagation in an elastic body were examined to improve the focal quality. The results suggested that the ultrasound was effectively converged on the target by correcting the amplitude of the ultrasound, and the accuracy of the focus control was enhanced by changing the array configuration and taking into account the shear elasticity of the elastic body in the simulation.
Development of a Bone-Conducted Ultrasonic Hearing Aid for the Profoundly Deaf: Evaluation of Sound Quality Using a Semantic Differential Method
Authors: Nakagawa Seiji , Fujiyuki Chika , Kagomiya Takayuki
Published: June 2013

Bone-conducted ultrasound (BCU) is perceived even by the profoundly sensorineural deaf. A novel hearing aid using the perception of amplitude-modulated BCU (BCU hearing aid: BCUHA) has been developed. However, there is room for improvement particularly in terms of sound quality. BCU speech is accompanied by a strong high-pitched tone and contain some distortion. In this study, the sound quality of BCU speech with several types of amplitude modulation [double-sideband with transmitted carrier (DSB-TC), double-sideband with suppressed carrier (DSB-SC), and transposed modulations] and air-conducted (AC) speech was quantitatively evaluated using semantic differential and factor analysis. The results showed that all the types of BCU speech had higher metallic and lower esthetic factor scores than AC speech. On the other hand, transposed speech was closer than the other types of BCU speech to AC speech generally; the transposed speech showed a higher powerfulness factor score than the other types of BCU speech and a higher esthetic factor score than DSB-SC speech. These results provide useful information for further development of the BCUHA.
Enhancement of Light Extraction Efficiency in GaN-Based Blue Light-Emitting Diodes by Doping TiO2 Nanoparticles in Specific Region of Encapsulation Silicone
Authors: Wang Pin-Chao , Lin Chun-Liang , Su Yan-Kuin
Published: June 2013

TiO2 nanoparticles (NPs) are doped in silicone for encapsulation of GaN-based blue light-emitting diodes (LEDs). The average refractive index of silicone is increased by doping TiO2 NPs with an average diameter of 21 nm, and the light extraction efficiency of GaN-based blue LEDs is also increased. Four different TiO2 NPs doping profiles are evaluated including without TiO2 NPs doping, uniform doping, doping around the LED chip only, and doping in the region far from the LED chip. LED, with TiO2 NPs (weight percentage of 0.01%) doping around the LED chip only, has the highest luminous flux of 0.98 lm at 20 mA. The conventional blue LED without TiO2 doping has the luminous flux of 0.94 lm at 20 mA. According to our calculations based on the experimental results, the enhancement of the luminous flux is 3 and 5% higher than that without TiO2 doping packages at 20 and 80 mA, respectively. TiO2 doped in silicone can not only increase the luminous flux but also inhibit the lumen degradation under the stress test for 1500 h.
Wet‐Spun Stimuli‐Responsive Composite Fibers with Tunable Electrical Conductivity
Authors: Grigoryev Anton , Sa Vijoya , Gopishetty Venkateshwarlu , Tokarev Ihor , Kornev Konstantin G. , Minko Sergiy
Published: June 2013

Wet‐spun stimuli‐responsive composite fibers made of covalently crosslinked alginate with a high concentration of single‐walled carbon nanotubes (SWCNTs) are electroconductive and sensitive to humidity, pH, and ionic strength, due to pH‐tunable water absorbing properties of the covalently crosslinked alginate. The conductivity depends on the material swelling in humid atmosphere and aqueous solutions: the greater the swelling, the smaller is the electrical conductivity. The covalently crosslinked fibers reversibly deform during the swelling/shrinking. In the swollen state, the fibers are less conductive, while they return to the same level of conductivity after shrinking. This unique reversible change of electroconductivity of the SWCNT‐alginate fibers is due to the elastic deformation of the alginate network in the area of electrical contacts between SWCNT bundles arrested in the alginate matrix. Fibers of this kind can be used as a simple, robust, disposable, and biocompatible platform for electrotextiles, biosensors, and flexible electronics in biomedical and biotechnological applications.
1‐Arylsulfonyl‐5‐(N‐hydroxyacrylamide)indolines Histone Deacetylase Inhibitors Are Potent Cytokine Release Suppressors
Authors: Lee Hsueh‐Yun , Yang Chia‐Ron , Lai Mei‐Jung , Huang Han‐Li , Hsieh Yi‐Ling , Liu Yi‐Min , Yeh Teng‐Kuang , Li Yu‐Hsuan , Mehndiratta Samir , Teng Che‐Ming , Liou Jing‐Ping
Published: June 2013

A series of 1‐arylsulfonyl‐5‐(N‐hydroxyacrylamide)indolines (7–15) has been developed; the compounds exhibited potent histone deacetylase (HDAC) inhibitory activities. Notably, almost all of this series exhibited better HDAC‐inhibitory and antiproliferative activities than 3‐(1‐benzenesulfonyl‐1H‐indol‐5‐yl)‐N‐hydroxyacrylamide (6), as reported in a previous study. Among these compounds, 3‐[1‐(4‐methoxybenzenesulfonyl)‐2,3‐dihydro‐1H‐indol‐5‐yl]‐N‐hydroxyacrylamide (9) showed a two‐ to tenfold increase in activity compared to SAHA (1) in the suppression of lipopolysaccharide‐induced cytokine production. Compound 9 also caused a marked reduction in carrageenan‐induced acute inflammation in a rat model. Taken together, these data indicated that 1‐arylsulfonyl‐5‐(N‐hydroxyacrylamide)indolines HDAC inhibitors exhibit potent anti‐inflammatory activity.
Sequential Norrish Type II Photoelimination and Intramolecular Aldol Cyclization of α‐Diketones: Synthesis of Polyhydroxylated Cyclopentitols by Ring Contraction of Hexopyranose Carbohydrate Derivatives
Authors: Alvarez‐Dorta Dimitri , León Elisa I. , Kennedy Alan R. , Martín Angeles , Pérez‐Martín Inés , Riesco‐Fagundo Concepción , Suárez Ernesto
Published: June 2013

The excitation of the innermost carbonyl of nono‐2,3‐diulose derivatives by irradiation with visible‐light initiates a sequential Norrish type II photoelimination and aldol cyclization process that finally gives polyfunctionalized cyclopentitols. The rearrangement has been confirmed by the isolation of stable acyclic photoenol intermediates that can be independently cyclized by a thermal 5‐(enolexo)‐exo‐trig uncatalyzed aldol reaction with high diastereoselectivity. In this last step, the large deuterium kinetic isotope effect found for the 1,5‐hydrogen atom transfer seems to indicate that the aldol reaction runs through a concerted pericyclic mechanism. Owing to the ready availability of pyranose sugars of various configurations, this protocol has been used to study the influence of pyranose ring‐substituents on the diastereoselectivity of the aldol cyclization reaction. In contrast with other pyranose ring contraction methodologies no transition‐metal reagents are needed and the sequential rearrangement occurs simply by using visible light and moderate heating (0 to 60 °C).
Manufacturer Support for a Partially Integrated Channel in South Korea: Power‐dependence vs. Marketing Effectiveness Perspective
Authors: Yi Ho‐taek , Dubinsky Alan J. , Lim Chae Un
Published: June 2013

This article introduces the unique context of a partially‐integrated channel (PIC) that incorporates both market and hierarchical governance forms. In so doing, it examines determinants of the manufacturer's support for a PIC. Using power‐dependence and marketing effectiveness theories, we collected data from 172 marketing managers in charge of PICs in 15 companies in South Korea. The results showed that from the power‐dependence perspective, demand volatility, manufacturer's competitive intensity, and channel concentration are positively related to a manufacturer's dependence on the retailer, which is positively related to the manufacturer's support for the PIC with a retailer. From a marketing effectiveness perspective, channel bonding and customer linking are positively associated with manufacturer marketing effectiveness, which is an antecedent to PIC support for a retailer. Copyright © 2013 ASAC. Published by John Wiley & Sons, Ltd.
A blind modulation identification algorithm for STBC systems using multidimensional ICA
Authors: Luo Minggang , Li Liping , Qian Guobing , Lu Jianqi
Published: June 2013

Blind parameter identification is a research topic of high importance for both military and civilian communication systems. To our knowledge, there is no report in literature on blindly recognizing the modulation of noncooperative MIMO systems in association with space–time block code where channel state information and coding matrix are unavailable. In this paper, we first present a classifier based on maximum likelihood on the condition of virtual channel matrix; second, the modulations are classified into two classes according to the independence of the source signals: independent and groupwise independent constellations. In the next step, a multidimensional independent component analysis algorithm is proposed by utilizing the block‐diagonal structure of the cumulant matrices to estimate the virtual channel matrix for these two cases, respectively. Last, the ambiguities are removed partly, and the classifier is proven to be insensitive to the remaining indeterminacy. Parallel computation technique is adopted to accelerate the computation of the logarithm likelihood function. Simulations show that our algorithm can work with high recognition probabilities in noncooperative space–time block code communication systems. Copyright © 2013 John Wiley & Sons, Ltd.
Power analysis based reverse engineering on the secret round function of block ciphers
Authors: Tang Ming , Qiu Zhenlong , Li Weijie , Sun Weijin , Hu Xiaobo , Zhang Huanguo
Published: June 2013

The recent cryptanalysis on block ciphers has two major trends. Side channel analysis (SCA) has become a new threat to the hardware implementations of encryption algorithms. On the other hand, reverse engineering has been adopted to explore the unknown part of the encryption algorithms, which has become a new target of the cryptanalysis. Some drawbacks have been found in the existing methods of reverse engineering, which target on the special structures or utilize the flaws in the unknown parts. The major disadvantage is that the number of rounds to be analyzed is limited, and the complexity is high. The existing SCAs for reverse engineering depend on the leakage models in a large extent and mainly focus on the single component of the algorithms, whereas the other parts of the target algorithm are known. In this paper, we present a more general and feasible reverse analysis by combining the mathematical methods and the SCA methods. We use the strict avalanche criterion for the non‐linear operations of block ciphers and apply the power analysis to reverse the structure parameters. We propose a new reverse analysis method to reduce the dependency on the leakage models, which can be combined with the structural cryptanalysis to reverse the internal parameters of the linear and non‐linear operations. We finally achieve the reverse analysis on the unknown round function of block ciphers. Copyright © 2013 John Wiley & Sons, Ltd.
Spectral and conductivity features of novel ternary Tl1–xIn1–xSnxS2 crystals
Authors: Myronchuk G. , Danylchuk S. , Parasyuk O. V. , Piskach L. V. , Fedorchuk A. O.
Published: June 2013

Complex studies of novel Tl1–xIn1–xSnxS2 single crystalline alloys (x = 0.1; 0.2; 0.3; 0.4; 0.5) were performed. Here we present the study of the effect of the partial cation substitution of Sn ions by In ions on their optical absorption and photoconductivity characteristics. The dependences of optical and electric properties of the crystals of the crystalline solid solutions on temperature and composition are discussed within a framework of intrinsic defect states forming then fundamental absorption. The calculations of the charged defects responsible for the experimentally determined values of Δ0 were done. Some increase of the concentration for charged defects with the sample temperature is probably related to the thermal ionization of some of the defects that were neutral at lower temperature. The results obtained will be analyzed within the framework of the intrinsic defect's model.