bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved Optical Degradation Characteristics of Eu Complex Encapsulated by High-Pressure Annealing
Authors: Kato Sayaka , Fukuda Takeshi , Akiyama Shinnosuke , Honda Zentaro , Kamata Norihiko , Kijima Naoto
Published: January 2011

The instability of Eu complexes against ultraviolet (UV) light irradiation is an important problem to solve before they can be practically applied in white light-emitting diodes. A novel technique of encapsulating tris(2-thenoyltrifluoroacetonato)(1,10-phenanthroline)europium(III) [Eu(TTA)3phen] was investigated using high-pressure annealing (solvothermal process) as a final process in the sol–gel synthesis. The photoluminescence and excitation spectra of encapsulated Eu(TTA)3phen samples synthesized by solvothermal and conventional annealing processes were almost the same. A half brightness time of 589 min was achieved while irradiating with UV light of 360 nm and 5 mW/cm2 by optimization of ammonia concentration and annealing temperature. The longest half brightness time was longer than that of encapsulated Eu(TTA)3phen synthesized by conventional thermal treatment. One possible reason for this result is that the chemical reaction of the sol–gel based glass network occurs more efficiently with high-pressure annealing. As a result, a high encapsulating efficiency was achieved owing to the small amount of organic component in the sol–gel derived glass network.
Influence of Cation Dopants in the A-Site on the Crystal Structure, Microstructure, and Electrical Conductivity of Ba0.5Sr0.5Co0.8Fe0.2O3-δ as a New Solid-Oxide-Fuel-Cell Cathode
Authors: Deehasing Suwichar , Sato Kazunori , Saguanruang Oravan , Chaianansutcharit Soamwadee
Published: January 2011

(Ba0.5Sr0.5)1-x
Ca
x
Co0.8Fe0.2O3-δ (BSCCF), (Ba0.5Sr0.5)0.8La0.2Co0.8Fe0.2O3-δ (BSLCF), and (Ba0.5Sr0.5)0.8La0.2-x
Ca
x
Co0.8Fe0.2O3-δ (BSLCCF) perovskite oxides were synthesized by the modified citrate method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). These oxides showed primarily a cubic phase with their dense bodies after sintering. The lattice parameter was decreased with increasing Ca2+-ion content in BSCCF. Conversely, the substitution of Ca2+ ions for La3+ ions in BSLCCF increased the lattice parameter. The maximum electrical conductivities were 96 S·cm-1 at 650 °C for the 30 mol % Ca2+-substituted BSCCF and 353 S·cm-1 at 350 °C for BSLCF. The thermal expansion coefficient (TEC) of BSCCF was almost constant regardless of the Ca2+-ion contents, whereas that of BSLCCF decreased with decreasing Ca2+-ion content.
Photoluminescence Properties of Eu3+ Activated CaMoSiO4 Red Phosphor by Combustion Method
Authors: Kim Jong Min , Kim Kyung Hwan , Jang Kyung Uk , Park Sang Joon , Choi Hyung Wook
Published: January 2011

The luminescent properties of Eu3+ doped CaMoSiO4 red phosphor were investigated. The aim of this work is to investigate the effect of an activator on the luminescent properties of red-emitting CaMoSiO4:Eu3+ phosphor. CaMoSiO4:Eu3+ phosphors were synthesized using a combustion method to obtain small spherical particles that have smooth and round surfaces. Using urea as a fuel and ammonium nitrate as an oxidizer, CaMoSiO4:Eu3+ was successfully synthesized using this combustion method. The Eu3+ influenced the photoluminescence (PL) spectra of the produced CaMoSiO4:Eu3+ phosphors. The experiment results showed that the strongest emissions occurred with an optimal concentration of the Eu3+; it exhibited a red emission spectrum for near-ultraviolet (UV) excitation. The material would be suited for the fluorescent material used in UV light-emitting diodes (UV-LEDs). The characteristics of the synthesized CaMoSiO4:Eu3+ phosphor were investigated by means of X-ray diffraction (XRD), a scanning electron microscope (SEM), and PL detection.
Equivalent Circuit Model of Triple-Barrier Resonant Tunneling Diodes Monolithically Integrated with Bow-Tie Antennas and Analysis of Rectification Properties towards Ultra Wideband Terahertz Detections
Authors: Takahagi Satoshi , Shin-ya Hideaki , Asakawa Kiyoto , Saito Mitsufumi , Suhara Michihiko
Published: January 2011

Towards an application for terahertz detector, a monolithic integrated device structure of a triple-barrier resonant tunneling diodes (TBRTDs) with a bow-tie antenna is proposed and its terahertz rectification properties are investigated on the basis of a physics-based equivalent circuit model. A possibility of zero-bias detection is examined owing to nonlinear asymmetric current–voltage characteristics. A possibility of broadband zero-bias detection in terahertz range is suggested for a tentatively designed device structure. A method to analyze rectified signal is established taking the self-bias effect into account.
Characterization of Unpassivated-Solution-Processed Zinc–Tin Oxide Thin Film Transistors
Authors: Avis Christophe , Jang Jin
Published: January 2011

We have studied the bias stress and environment stability effects of transparent bottom-gate, bottom contact spin-coated zinc–tin oxide (ZTO) thin-film transistors (TFT). Various ratios of zinc to tin (Zn:Sn= 2:1, 1:1, and 1:2) were used for TFT fabrication. The linear mobilities of the TFTs with Zn:Sn= 2:1, 1:1, and 1:2 are 2.27, 6.77, and 0.44 cm2V-1s-1respectively. The on/off drain current ratio is 108for Zn:Sn= 2:1. However, the off-current increases by more than 5 orders in 7 days, which appears to be due to the adsorption of oxygen and water molecules. The TFTs are stable under negative bias stress for more than 10,000 s, but they show a large threshold shift under positive bias stress.
Fabrication of ZnO Thin-Film Transistors by Chemical Vapor Deposition Method using Zinc Acetate Solution
Authors: Alias Afishah , Hazawa Kouta , Kawashima Nobuaki , Fukuda Hisashi , Uesugi Katsuhiro
Published: January 2011

Zinc oxide (ZnO) thin-film transistors (TFTs) were fabricated by thermal chemical vapor deposition (CVD) using aqueous solutions of zinc acetate (ZnAc2) dihydrate as a source. The precursor was supplied to the substrate by the nitrogen bubbling method through a plate with numerous orifices in the ZnAc2 solution. The ZnO thin films were grown on silicon substrates in the growth temperature (T
G) range from 280 to 700 °C. The growth rate of ZnO thin films were linearly proportional to the growth temperature, which suggested that the growth rate is limited by the decomposition of ZnAc2. Depletion-mode TFTs with the ZnO film grown at T
G = 350 °C was found to exhibit a relatively low saturation mobility (µsat). However, µsat increased from 1 to 14 cm2·V-1·s-1 and the operational mode was changed from the depletion mode to the enhancement mode by annealing treatment at 200 °C for 2 h under N2 ambient.
Development of ZnO Based Charged Particle Monitor for Processing Facility
Authors: Yanagida Takayuki , Kawaguchi Noriaki , Fujimoto Yutaka , Yokota Yuui , Tokutake Taichi , Miyamoto Miyuki , Sekiwa Hideyuki , Kobayashi Jun , Chani Valery , Yoshikawa Akira
Published: January 2011

In the present paper, we describe the development of an α-ray imaging detector based on a ZnO single crystalline scintillator and a position-sensitive photomultiplier tube (PSPMT). The ZnO crystal was grown by the hydrothermal synthesis method with 2-in.-φ in diameter. The ZnO specimen was polished out to be 0.5 mm in thickness. After optically coupling with PSPMT, the crystal was irradiated with 241Am α-ray for evaluation of both spatial resolution and pulse height spectrum. Using the charge center of the gravity method, two-dimensional α-ray images were successfully obtained. The efficiency of the energy window in terms of imaging quality was also examined.
Fabrication and Characteristics of Through Silicon Vias Interconnection by Electroplating
Authors: Jang Jae-Gwon , Lim Seung-Kyu , Kim Teak-You , Kim Nam-Jeong , Suh Su-Jeong
Published: January 2011

The electroplating method was improved using double anodes and a penetrated jig to fill high-aspect-ratio through silicon vias (TSVs) with copper. In this study, the double anodes were used to limit the formation of voids that degrade the electrical properties when the device is working. In addition, in this study we examined how the V-shaped electroplated copper is formed in the first electroplating step to seal openings. After establishing the conditions for electroplating using the double anodes and current wave, a void-free interconnection was fabricated, which consisted of TSVs with a diameter of 40 µm and an aspect ratios of 6.25:1 and 10:1 for silicon interposers.
Density Functional Theory Study of the Interaction of Magnesium Ions with Graphene Chip
Authors: Kato Koichi , Iyama Tetsuji , Tachikawa Hiroto
Published: January 2011

The interaction of magnesium atom (Mg) and ionic species (Mg+ and Mg2+) with graphene chip (finite sized graphene) have been investigated by means of density functional theory (DFT) method. The B3LYP/6-31G(d) calculation showed that the Mg atom does not make a chemical bind to the graphene chip. On the other hand, the ionic species can bind srongly to a hexagonal site of graphene chip. Time-dependent (TD)-DFT calculation of Mg+ doped graphene showed that the first excitation band is assigned to a charge transfer band from a π-orbital of graphene chip (HOMO: highest occupied molecular orbital) to a singly occupied molecular orbital (SOMO) composed of Mg+(3s) orbital, whereas the second excitation band is composed of a π–π* transition corresponding to the HOMO–lowest unoccupied molecular orbital (LUMO) excitation of free graphene chip. The nature of the interaction between the Mg ions and the graphene chip was discussed on the basis of theoretical results.
Density Functional Theory Study on the Water Clusters on Graphene Chip
Authors: Abe Shigeaki , Nagoya Yoshinori , Watari Fumio , Tachikawa Hiroto
Published: January 2011

The structures and electronic states of graphene–water interaction systems have been investigated by means of density functional theory (DFT) method to elucidate the effects of water clusters on the electronic states of graphene chip. Solvation caused by five to eight water molecules (n = 5–8) was examined as the interaction systems. A graphene chip composed of 14 benzene rings was used as a model of finite-sized graphene (C42H16). The water clusters interact with the graphene chip with hydrogen bonds. The band gap of graphene was slightly red-shifted by the solvation and the first excitation energy was saturated around n = 5. The electronic states of graphene–water systems were discussed on the basis of theoretical results.
Density Functional Theory Study of Boron- and Nitrogen-Atom-Doped Graphene Chips
Authors: Tachikawa Hiroto , Iyama Tetsuji , Azumi Kazuhisa
Published: January 2011

The structures and electronic states of boron- and nitrogen-substituted graphene chips (B-, N-, and BN-doped graphene chips) have been investigated by means of the density functional theory (DFT) method in order to shed light on the mechanism of change in the electronic properties of graphene chips caused by heteroatoms. The atomic charge of nitrogen atoms in N-graphene was a negative value, whereas that of boron atoms in B-graphene was positive. In the case of the BN-doped graphene chip, a charge polarization such as Bδ+–Nδ- was found. It was also found that the B–N bond pair is preferentially formed because of the large heat of formation of the B–N bond. The BN-doped graphene chips showed a large red shift of the band gap compared with that of normal graphene. The electric states of BN-graphenes were discussed on the basis of theoretical results.
Phase Control of Ti–Fe Nanoparticles Prepared by Pulsed Wire Discharge
Authors: Tokoi Yoshinori , Orikawa Takuya , Suzuki Tsuneo , Nakayama Tadachika , Suematsu Hisayuki , Niihara Koichi
Published: January 2011

Ti–Fe nanoparticles were prepared by pulsed wire discharge (PWD) using iron (Fe) and titanium (Ti) twisted wire in Ar gas at a pressure of 100 kPa. The content of Fe (C
Fe), which was changed from 0 to 100 wt %, was controlled by adjusting the number of Ti and Fe wires in the twisted wire. From the X-ray diffraction, the phase of the prepared nanoparticles changed from α-Ti to β-Ti, FeTi, Fe2Ti, Fe(Ti), and Fe with increasing C
Fe. FeTi nanoparticles were obtained at approximately C
Fe = 30 wt %. From these results, the phases of the prepared Ti–Fe nanoparticles were controlled by adjusting the content of Fe in the twisted wire.
Preparation and Process Clarification of Metal Nanoplate by Pulse Wire Discharged Method in Liquid Media
Authors: Izuari Yahya M. , Josho Keisuke , Tokoi Yoshinori , Suzuki Tsuneo , Nakayama Tadachika , Suematsu Hisayuki , Niihara Koichi
Published: January 2011

The synthesis of triangular silver nanoplates on various substrates was studied in this work. A silver nanocolloid/solution was prepared by a pulsed wire discharged (PWD) method in deionized water with various wire diameters and relative energies (K), where K is defined as the ratio of the charged energy of the capacitor to the vaporization energy of the wire. The effect of the substrate dipping time in the silver colloid/solution on silver nanoplate growth was investigated. The formation of the silver nanoplate has been analyzed using X-ray diffraction (XRD) with Cu Kα radiation and scanning electron microscopy (SEM). The results indicated that silver nanoplates were formed on Cu, W, Ni, and Si substrates but not on SiO2 substrates with increasing K. The size or number of silver nanoplates increased rapidly on Si(100) substrates. With increasing substrate dipping time, the size or the number of triangular silver nanoplates linearly increased. It was concluded that the ionization of silver atoms in the discharge and the reduction of silver ions on the substrates are possible mechanisms behind the formation of silver nanoplates on substrates.
Study of Carbon-Nanotube Web Thermoacoustic Loud Speakers
Authors: Suzuki Katsunori , Sakakibara Shingo , Okada Morihiro , Neo Yoichiro , Mimura Hidenori , Inoue Yoku , Murata Toshihiro
Published: January 2011

Thermoacoustic carbon nanotube (CNT) speakers were fabricated using CNT webs spun from a multiwalled carbon nanotube (MWNT) array of 0.8–1.6 mm height. The generated sound pressure level (SPL) showed a linear relationship with frequency over a wide range from 10 Hz to 40 kHz with a slope of 6 dB/octave. In addition to this, significantly broad and flat SPLs were obtained in the ultrasonic region, ranging from 40 to 100 kHz. The distance from the speaker to the microphone was 0.5 m. The high SPL is due to the good heat radiation property of the MWNT web. Herein, we showed an acoustical property for the MWNT web thermoacoustic speaker from the viewpoint of the structural web morphology. The role of heat radiation behavior and the effects of the length of individual MWNTs are discussed.
Novel Synthesis of CaF2 Nanocrystals and the Effect of Pyridine Addition on Their Crystal Size
Authors: Rungrodnimitchai Supitcha
Published: January 2011

Various types of calcium fluoride nanocrystals were prepared by the reactions between calcium metal and ammonium fluoride in liquid ammonia. The obtained nanocrystals were observed by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), absorption spectroscopy, and fluorescent spectroscopy. The particle size of pure CaF2 nanocrystals was about 14 nm. The addition of pyridine and the selection of the period of pyridine removal gave two particle size ranges, which were 8–10 and 13–15 nm. The nanocrystals were successfully doped with Mn2+ and Eu2+. The optical properties of the nanocrystals were investigated. The results implied that Eu2+ was stable in the CaF2 nanocrystals.
A Micrograting Sensor for DNA Hybridization and Antibody Human Serum Albumin–Antigen Human Serum Albumin Interaction Experiments
Authors: Chathirat Naphat , Atthi Nithi , Hruanun Charndet , Poyai Amporn , Leasen Suthisa , Osotchan Tanakorn , Hodak Jose H.
Published: January 2011

A biosensor structure comprising silicon nitride (Si3N4) micrograting arrays coated with a spin-on-glass (SOG) material was investigated. This grating structure was located on a silicon groove, which was etched by a deep reactive ion etching (DRIE) process. The biosensor was used as a specific detector of DNA molecules and antibody–antigen interactions. In our DNA sensing experiments, the first step was the activation of the grating surface with amine functional groups, followed by attachment of a 23-base oligonucleotide probe layer for hybridization with a complementary target DNA. The sensing device was tested for detecting specific antigen/antibody interactions for human serum albumin (HSA) and antigen bovine serum albumin (BSA). The readout system consisted of a white light lamp that illuminated a small spot on the grating surface at normal incidence through a fiber optic probe with a spectrometer used to collect the reflected light through a second fiber. We show that these sensing devices have the capability to detect DNA as well as antigen–antibody binding for HSA. The detection sensitivity for HSA was better than that for DNA mainly owing to the larger size and concomitant refractive index changes upon binding to the sensor. We show that it is possible to quantify the amount of biomolecules bound to the grating surface by measuring the wavelength shift of the reflectance spectra upon exposure to the samples.
Detection of Human IgG on Poly(pyrrole-3-carboxylic acid) Thin Film by Electrochemical-Surface Plasmon Resonance Spectroscopy
Authors: Janmanee Rapiphun , Baba Akira , Phanichphant Sukon , Sriwichai Saengrawee , Shinbo Kazunari , Kato Keizo , Kaneko Futao
Published: January 2011

An electrochemically controlled surface plasmon resonance (SPR) immunosensor for the detection of human immunoglobulin G (IgG) has been developed using poly(pyrrole-3-carboxylic acid) (PP3C) film. In this work, a pyrrole-3-carboxylic acid monomer was used for electropolymerization of a PP3C film on a gold-coated high-refractive-index glass slide. In situ electrochemical (EC)-SPR spectroscopy was performed to study the kinetic property and electroactivity property of the PP3C film. Moreover, ultraviolet–visible (UV–vis) spectroscopy was performed to characterize the PP3C film. Finally, the immunosensor-based PP3C film was constructed. The carboxylic acid surface of the PP3C film was activated for the immobilization of anti-human IgG. The immunosensor electrode was used for probing the binding reaction of anti-human IgG/human IgG with several concentrations of human IgG at different constant applied potentials. The probe immobilization and immunosensing process were in situ monitored by EC-SPR technique. The sensitivity of the sensor was improved by controlling the morphology of the PP3C film by applying the potential.
Innate immunity in alcoholic liver disease
Authors: Gao Bin , Seki Ekihiro , Brenner David A. , Friedman Scott , Cohen Jessica I. , Nagy Laura , Szabo Gyongyi , Zakhari Samir
Published: January 2011

Excessive alcohol consumption is a leading cause of chronic liver disease in the Western world. Alcohol-induced hepatotoxicity and oxidative stress are important mechanisms contributing to the pathogenesis of alcoholic liver disease. However, emerging evidence suggests that activation of innate immunity involving TLR4 and complement also plays an important role in initiating alcoholic steatohepatitis and fibrosis, but the role of adaptive immunity in the pathogenesis of alcoholic liver disease remains obscure. Activation of a TLR4-mediated MyD88-independent (TRIF/IRF-3) signaling pathway in Kupffer cells contributes to alcoholic steatohepatitis, whereas activation of TLR4 signaling in hepatic stellate cells promotes liver fibrosis. Alcohol consumption activates the complement system in the liver by yet unidentified mechanisms, leading to alcoholic steatohepatitis. In contrast to activation of TLR4 and complement, alcohol consumption can inhibit natural killer cells, another important innate immunity component, contributing to alcohol-mediated acceleration of viral infection and liver fibrosis in patients with chronic viral hepatitis. Understanding of the role of innate immunity in the pathogenesis of alcoholic liver disease may help us identify novel therapeutic targets to treat this disease.
Interactive effects ofAPOEhaplotype, sex, and exercise on postheparin plasma lipase activities
Authors: Seip Richard L. , Zoeller Robert F. , Angelopoulos Theodore J. , Salonia James , Bilbie Cherie , Moyna Niall M. , Miles Mary P. , Visich Paul S. , Pescatello Linda S. , Gordon Paul M. , Tsongalis Gregory J. , Bausserman Linda , Thompson Paul D.
Published: January 2011

Hepatic lipase (HL) and lipoprotein lipase (LPL) activities (HLA, LPLA) modify lipoproteins and facilitate their binding to hepatic receptors. Apolipoprotein E (APOE) physically interacts with the lipases, and the three common haplotypes of the APOE gene (ε2, ε3, and ε4) yield protein isoforms (E2, E3, and E4, respectively) that are functionally different. Lipase activities themselves differ by sex and exercise training status. The interaction of APOE genotype, exercise training, and sex effects on lipase activities has not been studied. We measured postheparin plasma lipase activities in normolipidemic men and women with the three most common APOE genotypes, which are the haplotype combinations ε2/ε3 ( n = 53 ), ε3/ε3 ( n = 62), and ε4/ε3 ( n = 52), enrolled in 6 mo of aerobic exercise training. These haplotype combinations comprise an estimated 11.6, 62.3, and 21.3% of the population, respectively. Baseline HLA was 35% lower in women than in men ( P < 0.0001). In men but not women, HLA was higher in ε2/ε3 group compared with ε4/ε3 ( P = 0.01) and ε3/ε3 ( P = 0.05). Neither sex nor APOE genotype affected baseline LPLA. Training decreased HLA by 5.2% ( P = 0.018) with no APOE effect. The apparent increase in LPLA following exercise was significant and APOE dependent only when corrected for baseline insulin ( P < 0.05). Exercise decreased LPLA by 0.8 μmol free fatty acid (FFA)·ml−1·h−1(−6%) in ε3/ε3 compared with the combined increases of 6.6% in ε2/ε3 and 12% in ε4/ε3 ( P = 0.018 vs. ε3/ε3). However, these differences were statistically significant only after correcting for baseline insulin. We conclude that common APOE genotypes interact with 1) sex to modulate HLA regardless of training status, with ε2/ε3 men demonstrating higher HLA than ε3/ε3 or ε4/ε3 men, and 2) aerobic training to modulate LPLA, regardless of sex, with ε3/ε3 subjects showing a significant decrease compared with an increase in ε2/ε3 and ε3/ε4 after controlling for baseline insulin.
The occurrence of refractoriness and mast cell mediator release following mannitol-induced bronchoconstriction
Authors: Larsson Johan , Perry Clare P. , Anderson Sandra D. , Brannan John D. , Dahlén Sven-Erik , Dahlén Barbro
Published: January 2011

For several hours after exercise-induced bronchoconstriction, there is diminished responsiveness to repeated challenge. The mechanism causing this refractoriness is unclear. Inhalation of dry powder mannitol is a new bronchial provocation test that has been suggested as a surrogate for an exercise challenge. Refractoriness to repeated mannitol challenge has however not been established. Our objective was to investigate if repeated challenge with mannitol is associated with refractoriness and diminished release of mast cell mediators of bronchoconstriction. Sixteen subjects with asthma underwent repeated inhalation of mannitol 90 min apart. Lung function was assessed by forced expiratory volume in 1 s (FEV1). The urinary excretion (ng/mmol creatinine) of the mediators 9α,11β-prostaglandin (PG) F2and leukotriene (LT) E4were measured. The group mean fall in FEV1after the second challenge was 48.5 ± 5.8% of the first ( P < 0.001). The protection afforded by the initial challenge, however, varied considerably between subjects (range 88–0%). Furthermore, the urinary excretion of the two mediators was increased after both challenges. The average excretion of mediators after the challenges was significantly higher for the six most refractory subjects. This was observed both for LTE4(95.6 ± 5.2 vs. 58.0 ± 2.4 for the 6 least refractory) ( P < 0.001) and for 9α,11β-PGF2(137.6 ± 6.7 vs. 50.1 ± 1.1 for the 6 least refractory) ( P = 0.002). As occurs with exercise-induced bronchoconstriction, repeated inhalation of mannitol induced refractoriness. We propose that refractoriness is due to tachyphylaxis at the level of the airway smooth muscle responsiveness to mediators of bronchoconstriction rather than due to fatigue of their release from mast cells.
Effects of polycythemia on systemic endothelial function in chronic hypoxic lung disease
Authors: Boyer Laurent , Chaar Vicky , Pelle Gabriel , Maitre Bernard , Chouaid Christos , Covali-Noroc Ala , Zerah Françoise , Bucherer Catherine , Lacombe Catherine , Housset Bruno , Dubois-Randé Jean-Luc , Boczkowski Jorge , Adnot Serge
Published: January 2011

Chronic obstructive pulmonary disease (COPD) is a major risk factor for cardiovascular disease. Polycythemia, a common complication of hypoxic COPD, may affect systemic vascular function by altering blood viscosity, vessel wall shear stress (WSS), and endothelium-derived nitric oxide (NO) release. Here, we evaluated the effects of hypoxia-related polycythemia on systemic endothelial function in patients with COPD. We investigated blood viscosity, WSS, and endothelial function in 15 polycythemic and 13 normocythemic patients with COPD of equal severity, by recording brachial artery diameter variations in response to hyperemia and by using venous occlusion plethysmography (VOP) to measure forearm blood flow (FBF) responses to a brachial artery infusion of acetylcholine (ACh), bradykinin (BK), sodium nitroprusside (SNP), substance P (SP), isoptin, and N-monomethyl-l-arginine (l-NMMA). At baseline, polycythemic patients had higher blood viscosity and larger brachial artery diameter than normocythemic patients but similar calculated WSS. Flow-mediated brachial artery vasodilation was increased in the polycythemic patients, in proportion to the hemoglobin levels. ACh-induced vasodilation was markedly impaired in the polycythemic patients and negatively correlated with hemoglobin levels. FBF responses to endothelium- (BK, SP) and non-endothelium-dependent (SNP, isoptin) vasodilators were not significantly different between the two groups. l-NMMA infusion induced a similar vasoconstrictor response in both groups, in accordance with their similar baseline WSS. In conclusion, systemic arteries in polycythemic patients adjust appropriately to chronic or acute WSS elevations by appropriate basal and stimulated NO release. Overall, our results suggest that moderate polycythemia has no adverse effect on vascular function in COPD.
Studies on Mechanism of Action of Anticancer Peptides by Modulation of Hydrophobicity Within a Defined Structural Framework
Authors: Huang Yi-bing , Wang Xiao-fei , Wang Hong-ye , Liu Yu , Chen Yuxin
Published: January 2011

In the present study, the hydrophobicity of a 26-residue α-helical peptide (peptide P) was altered to study the effects of peptide hydrophobicity on the mechanism of action of cationic anticancer peptides. Hydrophobicity of the nonpolar face of the peptides was shown to correlate with peptide helicity. The self-association ability of peptides in aqueous environment, determined by the reversed-phase high performance liquid chromatography temperature profiling, showed strong influence on anticancer activity. The peptide analogues with greater hydrophobicity showed stronger anticancer activity determined by IC50 values with a necrotic-like membrane disruption mechanism. Peptide analogues exhibited high specificity against cancer cells and much higher anticancer activity than widely-used anticancer chemical drugs. The mechanism of action of anticancer peptides was also investigated. The hydrophobicity of peptides plays a crucial role in the mechanism of action against cancer cells, which could present a way, using a de novo design approach, to create anticancer peptides as potential therapeutics in clinical practices. Mol Cancer Ther; 10(3); 416–26. ©2011 AACR.
Comprehensive Evaluation of the Contribution of X Chromosome Genes to Platinum Sensitivity
Authors: Gamazon Eric R. , Im Hae Kyung , O'Donnell Peter H. , Ziliak Dana , Stark Amy L. , Cox Nancy J. , Dolan M. Eileen , Huang Rong Stephanie
Published: January 2011

Using a genome-wide gene expression data set generated from Affymetrix GeneChip Human Exon 1.0ST array, we comprehensively surveyed the role of 322 X chromosome gene expression traits on cellular sensitivity to cisplatin and carboplatin. We identified 31 and 17 X chromosome genes whose expression levels are significantly correlated (after multiple testing correction) with sensitivity to carboplatin and cisplatin, respectively, in the combined HapMap CEU (Utah residents with ancestry from northern and western Europe) and YRI (Yoruba in Ibahan, Nigeria) populations (false discovery rate, FDR < 0.05). Of those, 14 overlap for both cisplatin and carboplatin. Using an independent gene expression quantification method, the Illumina Sentrix Human-6 Expression BeadChip, measured on the same HapMap cell lines, we found that 4 and 2 of these genes are significantly associated with carboplatin and cisplatin sensitivity, respectively, in both analyses. Two genes, CTPS2 and DLG3, were identified by both genome-wide gene expression analyses as correlated with cellular sensitivity to both platinating agents. The expression of DLG3 gene was also found to correlate with cellular sensitivity to platinating agents in NCI-60 cancer cell lines. In addition, we evaluated whether the expression of X chromosome genes contributed to the observed differences in sensitivity to the platinums between CEU and YRI-derived cell lines. Of the 34 distinct genes significantly correlated with either carboplatin or cisplatin sensitivity, 14 are differentially expressed (defined as P < 0.05) between CEU and YRI. Thus, sex chromosome genes play a role in cellular sensitivity to platinating agents and differences in the expression level of these genes are an important source of variation that should be included in comprehensive pharmacogenomic studies. Mol Cancer Ther; 10(3); 472–80. ©2011 AACR.
Effectiveness of the Passive Lingual Arch for E Space Maintenance in Subjects with Anterior or Posterior Rotation of the Mandible: A Retrospective Study
Authors: Fichera Grazia , Greco Mariagrazia , Leonardi Rosalia
Published: January 2011

Objective: The aim of this study was to determine whether or not lingual arches in subjects with anterior or posterior mandible rotation can produce different effects in the prevention of first permanent molar mesial migration. Subjects and Methods: Forty-two patients with a mean age of 9 ± 0.8 years were selected from the Department of Orthodontics, University of Catania, Italy. These subjects were treated with a passive mandibular fixed lingual arch. The sample was divided into 3 groups according to the gonial angle in order to establish the pattern of mandible growth: mandibular posterior rotation (MPR), mandibular growth in straight-downward direction (MSD) and mandibular anterior rotation (MAR). Lateral cephalograms and study models of the patients before and after treatment were examined to determine any positional changes of the mandibular first molars and incisors. Results: Statistically significant differences between the MPR group and the other 2 (MSD and MAR) were found as regards mandibular first molar and incisor positional changes. No significant differences were found between the MSD and MAR groups. Conclusion: The results indicate that the effect of lingual arch is influenced by mandibular growth patterns. In patients with MPR, the lingual arch preserves arch length but the mesial migration of first permanent molars is not completely blocked.
A Comparison of the Antifungal Activity of Herbal Toothpastes against Other Brands of Toothpastes on Clinical Isolates of Candida albicans and Candida dubliniensis
Authors: Ellepola Arjuna N.B. , Khan Zia U. , Chandy Rachel , Philip Leeba
Published: January 2011

Objectives: To evaluate the anti-Candida activity on Candida albicans and Candida dubliniensis species of 2 herbal and 7 other brands of toothpastes commonly used in Kuwait. Materials and Methods: Antifungal activity was determined by agar diffusion test on 65 isolates of C. albicans and 21 isolates of C. dubliniensis for each toothpaste. A uniform quantity of toothpaste was filled into wells punched into Sabouraud dextrose agar medium plates inoculated with the test isolates, incubated at 37°C; inhibition zone diameters were read after 24 h. Results: The mean inhibition zone diameters ranged between 12 and 23 mm for C. albicans and between 12 and 27 mm for C. dubliniensis. A herbal toothpaste brand manufactured in the Middle Eastern region (United Arab Emirates) consisting of many herbal ingredients compared to other brands was found to be the most active (p < 0.001) against both Candida species tested, which also demonstrated higher inhibitory activity against C. dubliniensis isolates compared to C. albicans.Conclusions: The herbal toothpaste brand presented significant anticandidal activity over conventional toothpastes and may be useful in reducing the pathogenic potential of Candida species.
TP53 Codon 72 Polymorphism Is Associated with Coronary Artery Disease in Chilean Subjects
Authors: Caamaño José , Saavedra Nicolás , Jaramillo Priscilla C. , Lanas Cecilia , Lanas Fernando , Salazar Luis A.
Published: January 2011

Objective: To investigate the possible association between the codon 72 polymorphism (Pro72Arg, rs1042522) of the tumor suppressor gene (TP53) and the presence of coronary artery disease (CAD) in Chilean subjects. Subjects andMethods: A total of 209 unrelated patients with a diagnosis of CAD confirmed by angiography (33–74 years old) and 216 healthy controls (30–68 years old) were included in this study. The Pro72Arg polymorphism of the TP53 gene was evaluated by PCR-RFLP. Results: The genotype distribution for the Pro72Arg variant of the TP53 gene in CAD patients (PP: n = 13, 6.2%; PR: n = 61, 29.4%; RR: n = 135, 64.6%) and controls (PP: n = 18, 8.3%; PR: n = 94, 43.5%; RR: n = 104, 48.1%) was significantly different (p = 0.003). Similarly, the allelic frequency was also different (p = 0.003). The odds ratio for CAD related to the 72Arg allele was 2.0 (95% CI = 1.33–2.90), confirming the presence of an association. Conclusion: These findings suggest that the Pro72Arg polymorphism of the TP53 gene is associated with CAD in Chilean individuals.
Implication of Umbilical Cord in Preeclampsia
Authors: Salama Ragaa H.M. , Fathalla Mohamed M.F. , Mekki Abdel-Raheim M. , Elsadek Bakheet El-Kot M.
Published: January 2011

Objectives: To investigate the role of biochemical changes in the umbilical cord and placenta in developing preeclampsia (PE). Subjects and Methods: Thirty women with PE and 15 healthy pregnant women as controls were enrolled in this study. Vascular endothelial growth factor (VEGF), soluble vascular endothelial growth factor receptor 1 (sVEGFR-1), platelet-derived endothelial cell growth factor (PD-ECGF), neutrophil elastase and nitric oxide (NO) were measured. Results: Both serum (maternal and fetal) and tissue (placenta and umbilical cord) levels of VEGF, sVEGFR-1, PD-ECGF and neutrophil elastase were significantly increased, whereas NO was significantly decreased (except placental tissue showed no changes) in preeclamptic patients. The cord serum level of PD-ECGF was significantly higher in severe PE compared to mild PE and normal pregnant women. The placental and cord tissue levels of PD-ECGF and neutrophil elastase were significantly higher in severe PE, while the cord tissue level of NO was significantly lower in severe PE. Conclusion: Our data showed that umbilical cord vessels and stroma can serve as an additional source of vasoactive and angiogenic substances that contribute to the biochemical changes occurring in PE.
Blood Culture Contamination in a Neonatal Intensive Care Unit in Shiraz, Southwest-Central Iran
Authors: Hashemizadeh Zahra , Bazargani Abdollah , Davarpanah Mohammad Ali
Published: January 2011

Objective: To measure bacterial contamination rates in blood culture specimens and distinguish sepsis from blood culture contamination in newborn hospitalized patients in a neonatal intensive care unit and to recognize the most commonly isolated bacteria. Materials and Methods: Blood samples of 578 neonates were collected and cultured throughout the year of study (March 2006 to February 2007). Isolated bacteria were identified by traditional biochemical tests. Clinical criteria combined with laboratory data were used to differentiate the contaminated cultures from clinically significant cultures. Results: Of the 578 neonatal blood culture samples, 78 (13.49%) were positive for bacteria, and 49 isolates (8.47%) were classified as contaminants. Pseudomonas aeruginosa and Staphylococcus aureus were the most common isolates from true bacteremia, and Staphylococcus epidermidis and diphtheroids were the most common contaminants. Conclusion: The blood culture contamination rate in our studied neonatal intensive care unit was high. A variety of measures are recommended for reducing the rate of blood culture contamination to avoid undesirable outcomes associated with blood culture contamination.
Angiotensin-Converting Enzyme 2 Deficiency in Whole Body or Bone Marrow–Derived Cells Increases Atherosclerosis in Low-Density Lipoprotein Receptor
−/−
Mice
Authors: Thatcher Sean E. , Zhang Xuan , Howatt Deborah A. , Lu Hong , Gurley Susan B. , Daugherty Alan , Cassis Lisa A.
Published: January 2011

Objective—

The renin-angiotensin system contributes to atherosclerotic lesion formation. Angiotensin-converting enzyme 2 (ACE2) catabolizes angiotensin II (Ang II) to angiotensin 1–7 (Ang-(1–7)) to limit effects of the renin-angiotensin system. The purpose of this study was to define the role of ACE2 in atherosclerosis.

Methods and Results—

Male
Ace2

−/
y

mice in an low-density lipoprotein receptor–deficient background were fed a high-fat diet for 3 months. ACE2 deficiency increased atherosclerotic area (
Ace2

+/
y

, 17±1;
Ace2

−/
y

, 23±2 mm
2
,
P
<0.002). This increase was blunted by losartan. To determine whether leukocytic ACE2 influenced atherosclerosis, irradiated low-density lipoprotein receptor–deficient male mice were repopulated with bone marrow–derived cells from
Ace2

+/
y

or
Ace2

−/
y

mice and fed a high-fat diet for 3 months. ACE2 deficiency in bone marrow–derived cells increased atherosclerotic area (
Ace2

+/
y

, 1.6±0.3;
Ace2

−/
y

, 2.8±0.3 mm
2
;
P
<0.05). Macrophages from
Ace2

−/
y

mice exhibited increased Ang II secretion and elevated expression of inflammatory cytokines. Conditioned media from mouse peritoneal macrophages of
Ace2

−/
y

mice increased monocyte adhesion to human umbilical vein endothelial cells. Incubation of human umbilical vein endothelial cells with Ang II promoted monocyte adhesion, which was blocked by Ang-(1–7). Coinfusion of Ang-(1–7) with Ang II reduced atherosclerosis.

Conclusion—

These results demonstrate that ACE2 deficiency in bone marrow–derived cells promotes atherosclerosis through regulation of Ang II/Ang-(1–7) peptides.
Towards Modular Development of Typed Unification Grammars
Authors: Sygal Yael , Wintner Shuly
Published: January 2011

Development of large-scale grammars for natural languages is a complicated endeavor: Grammars are developed collaboratively by teams of linguists, computational linguists, and computer scientists, in a process very similar to the development of large-scale software. Grammars are written in grammatical formalisms that resemble very-high-level programming languages, and are thus very similar to computer programs. Yet grammar engineering is still in its infancy: Few grammar development environments support sophisticated modularized grammar development, in the form of distribution of the grammar development effort, combination of sub-grammars, separate compilation and automatic linkage, information encapsulation, and so forth.

This work provides preliminary foundations for modular construction of (typed) unification grammars for natural languages. Much of the information in such formalisms is encoded by the type signature, and we subsequently address the problem through the distribution of the signature among the different modules. We define signature modules and provide operators of module combination. Modules may specify only partial information about the components of the signature and may communicate through parameters, similarly to function calls in programming languages. Our definitions are inspired by methods and techniques of programming language theory and software engineering and are motivated by the actual needs of grammar developers, obtained through a careful examination of existing grammars. We show that our definitions meet these needs by conforming to a detailed set of desiderata. We demonstrate the utility of our definitions by providing a modular design of the HPSG grammar of Pollard and Sag.
Learning and Evaluation of Dialogue Strategies for New Applications: Empirical Methods for Optimization from Small Data Sets
Authors: Rieser Verena , Lemon Oliver
Published: January 2011

We present a new data-driven methodology for simulation-based dialogue strategy learning, which allows us to address several problems in the field of automatic optimization of dialogue strategies: learning effective dialogue strategies when no initial data or system exists, and determining a data-driven reward function. In addition, we evaluate the result with real users, and explore how results transfer between simulated and real interactions. We use Reinforcement Learning (RL) to learn multimodal dialogue strategies by interaction with a simulated environment which is “bootstrapped” from small amounts of Wizard-of-Oz (WOZ) data. This use of WOZ data allows data-driven development of optimal strategies for domains where no working prototype is available. Using simulation-based RL allows us to find optimal policies which are not (necessarily) present in the original data. Our results show that simulation-based RL significantly outperforms the average (human wizard) strategy as learned from the data by using Supervised Learning. The bootstrapped RL-based policy gains on average 50 times more reward when tested in simulation, and almost 18 times more reward when interacting with real users. Users also subjectively rate the RL-based policy on average 10% higher. We also show that results from simulated interaction do transfer to interaction with real users, and we explicitly evaluate the stability of the data-driven reward function.
Analyzing and Integrating Dependency Parsers
Authors: McDonald Ryan , Nivre Joakim
Published: January 2011

There has been a rapid increase in the volume of research on data-driven dependency parsers in the past five years. This increase has been driven by the availability of treebanks in a wide variety of languages—due in large part to the CoNLL shared tasks—as well as the straightforward mechanisms by which dependency theories of syntax can encode complex phenomena in free word order languages. In this article, our aim is to take a step back and analyze the progress that has been made through an analysis of the two predominant paradigms for data-driven dependency parsing, which are often called graph-based and transition-based dependency parsing. Our analysis covers both theoretical and empirical aspects and sheds light on the kinds of errors each type of parser makes and how they relate to theoretical expectations. Using these observations, we present an integrated system based on a stacking learning framework and show that such a system can learn to overcome the shortcomings of each non-integrated system.
Modulatory Effects of Levodopa on Cognitive Control in Young but not in Older Subjects: A Pharmacological fMRI Study
Authors: Onur Özgür A. , Piefke Martina , Lie Chuh-Hyoun , Thiel Christiane M. , Fink Gereon R.
Published: January 2011

Older individuals show decline of prefrontal cortex (PFC) functions which may be related to altered dopaminergic neurotransmission. We investigated the effects of aging and dopaminergic stimulation in 15 young and 13 older healthy subjects on the neural correlates of interference control using fMRI. In a double-blind, placebo-controlled within-subject design, subjects were measured after levodopa (100 mg) or placebo administration. In each session, subjects performed a visual–spatial interference task based on a Stroop/Simon-like paradigm. Across age groups, interference (incongruent relative to congruent trials) was associated with activations in the presupplementary motor area, ACC, and intraparietal cortex. Increased interference was found behaviorally in older volunteers. Differential activation in left dorsolateral PFC in young subjects and bilateral PFC activity in older subjects was observed to be associated with interference control. Performance deteriorated under levodopa only in young subjects. This was accompanied by an increase of neural activity in ACC (p < .05; small-volume correction for multiple comparisons). Worsening of performance under levodopa in young subjects and the associated effect on ACC may indicate that overstimulation of the dopaminergic system compromises interference control. This supports the inverted-U-shaped model of neurotransmitter action.
Lessons from EU Peace Operations
Authors: Keohane Daniel
Published: January 2011

In 1999, few people would have predicted that the EU would send ships to Somalia, police to Afghanistan, judges to Kosovo and soldiers to Chad. Yet, that is exactly what the EU has been doing. The European Security and Defence policy (ESDP) –since renamed the Common Security and Defence Policy (CSDP) – was launched shortly after NATO’s war in Kosovo in June 1999, to ensure that Europeans could respond to international crises, including launching operations, without depending on the US (via NATO). Since 2003 the EU has initiated some 24 peace-support operations in Europe, Africa and Asia, using both civil and military resources, and some of these missions have had impressive results. However, at times there have been some real difficulties with CSDP operations, ranging from resource shortages, intermittent political support from Member States, and a lack of coordination between EU actors. Lessons already identified in the crisis management debate point to two fundamental factors of success. First, a comprehensive approach that brings together the different actors deployed in the field. Second, the resilience of the political and material commitment of crisis management actors, possibly over many years. Both these factors pose important questions for the future of EU peace operations.
Probabilistic multi-level maps from LIDAR data
Authors: Rivadeneyra César , Campbell Mark
Published: January 2011

Recent research has shown that robots can model their world with Multi-Level (ML) maps, which utilize patches in a two-dimensional grid space to represent various environment elevations within a given grid cell. Although these maps are able to produce three-dimensional models of the environment while exploiting the computational feasibility of single elevation maps, they do not take into account in-plane uncertainty when matching measurements to grid cells or when grouping those measurements into patches. To respond to these drawbacks, this paper proposes to extend these ML maps into Probabilistic Multi-Level (PML) maps, which use formal probability theory to incorporate estimation and modeling errors due to uncertainty. Measurements are probabilistically associated with cells near the nominal location, and are categorized through hypothesis testing into patches via classification methods that incorporate uncertainty. Experimental results on representative objects found in both indoor and outdoor environments show that PML generally outperforms ML, including in noisy and sparse data environments, by producing more consistent, informative and conservative maps. In addition, PML provides the framework to heterogeneous, cooperative mapping and a way to probabilistically discriminate between conflicting maps.