bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalytic epoxidation of cis-stilbene and naphthalene by tetra-n-butylammonium hydrogen monopersulfate in the presence of manganese(III) tetraarylporphyrins and various anionic co-catalysts
Authors: Solati Zahra , Hashemi Majid , Keshavarzi Ahmad , Rafiee Ezzat
Published: January 2012

The epoxidation of cis-stilbene by n-Bu4NHSO5 was studied in the presence of two different manganese porphyrin complexes, [MnTPFPP(Cl) and MnTPP(Cl)], and various n-Bu4NX (X = OAc, F, Cl, Br, OCN, NO3, BF4). In general direct correlation was found between stereoselectivity of the epoxidation reaction and the nucleophilic properties of these anionic co-catalysts. Also epoxidation of naphthalene was carried out in high yield and good selectivity by n-Bu4NHSO5 in the presence of MnTPFPP(Cl) in association with n-Bu4NOAc or n-Bu4NF co-catalysts.
Towards the Realization of Higher Connectivity in MgB2Conductors: In-situ or Sintered Ex-situ?
Authors: Yamamoto Akiyasu , Tanaka Hiroya , Shimoyama Jun-ichi , Ogino Hiraku , Kishio Kohji , Matsushita Teruo
Published: January 2012

The two most common types of MgB2conductor fabrication technique –in-situandex-situ– show increasing conflicts concerning the connectivity, an effective current-carrying cross-sectional area. Anin-situreaction yields a strong intergrain coupling with a low packing factor, while anex-situprocess using pre-reacted MgB2yields tightly packed grains, however, their coupling is much weaker. We studied the normal-state resistivity and microstructure ofex-situMgB2bulks synthesized with varied heating conditions under ambient pressure. The samples heated at moderately high temperatures of ∼900 °C for a long period showed an increased packing factor, a larger intergrain contact area and a significantly decreased resistivity, all of which indicate the solid-state self-sintering of MgB2. Consequently the connectivity of the sinteredex-situsamples exceeded the typical connectivity range 5–15% of thein-situsamples. Our results show self-sintering develops the superior connectivity potential ofex-situMgB2, though its intergrain coupling is not yet fulfilled, to provide a strong possibility of twice or even much higher connectivity in optimally sinteredex-situMgB2than inin-situMgB2.
Review of Josephson Waveform Synthesis and Possibility of New Operation Method by Multibit Delta–Sigma Modulation and Thermometer Code for Its Further Advancement
Authors: Kaneko Nobu-hisa , Maruyama Michitaka , Urano Chiharu , Kiryu Shogo
Published: January 2012

A method of AC waveform synthesis with quantum–mechanical accuracy has been developed on the basis of the Josephson effect in national metrology institutes, not only for its scientific interest but its potential benefit to industries. In this paper, we review the development of Josephson arbitrary waveform synthesizers based on the two types of Josephson junction array and their distinctive driving methods. We also discuss a new operation technique with multibit delta–sigma modulation and a thermometer code, which possibly enables the generation of glitch-free waveforms with high voltage levels. A Josephson junction array for this method has equally weighted branches that are operated by thermometer-coded bias current sources with multibit delta–sigma conversion.
Complex Conductivity Using Wideband Spectroscopy for Yttria/Ytterbia-Stabilized Zirconia Ceramics
Authors: Teranishi Takashi , Shimizu Kosuke , Akiyama Naoki , Hayashi Hidetaka , Kishimoto Akira , Fujimori Kazuhiro
Published: January 2012

Complex conductivity wideband spectra from 10-1 to 1014 Hz (100 THz) were determined for 8 mol % yttria-stabilized zirconia (8YSZ) and 8 mol % ytterbia-stabilized zirconia (8YbSZ) ceramics. The contributions of electrolyte–electrode interfaces, grain boundaries, intragrain ion-hopping, and optical phonons were quantified to relate the microscopic conduction behavior to the overall conductivity. Intrinsic conductivity was mostly governed by ion-hopping. For both 8YSZ and 8YbSZ, ion-hopping followed the universal dielectric response (UDR) for broadband frequencies except for the phonon dispersion frequencies. The higher overall conductivities of the 8YbSZ ceramics compared to the 8YSZ ones were attributed to differences in the UDR contributions. The dominant factor determining the difference in the intrinsic conductivity in broadband frequencies from direct current (DC) to microwave between the 8YSZ and 8YbSZ ceramics was the DC conductivity due to UDR, σdc, where σdc(8YbSZ)>σdc(8YSZ). Other parameters in the UDR and the optical parameters did not greatly influence the intrinsic conductivities.
The Role of Rare Earth Metals on Effective Work Function Modulation of Nickel Fully-Silicided Gate/High-k Dielectric Stacks for n-Channel Metal Oxide Semiconductor Device Applications
Authors: Lee Bongmook , Novak Steven R. , Biswas Nivedita , Misra Veena
Published: January 2012

It was found that the structural properties with gadolinium (Gd) and europium (Eu) incorporation into nickel (Ni) fully silicided (FUSI) gate electrodes are markedly different and resulted in different degrees of effective work function modulation. It was found that Ni–Gd alloys tend to form stable compounds during silicidation and produced a Si-rich layer with amorphous/nanocystalline structure near the FUSI gate electrode/high-k dielectric interface. This compositional and structural change is the main mechanism responsible for effective work function modulation with Gd incorporation. However, in the case of Europium, Eu atoms tend to segregate outside the Ni-FUSI layer during silicidation and resulted in a uniform Ni
x
Si
y
layer with Eu pile-up layer at the FUSI gate electrode/high-k dielectric interface. This pile-up is believed to be the main cause of effective work function modulation with Eu incorporation. It was also found that the incorporation of Gd and Eu metals into Ni-FUSI gate can remotely scavenge the interfacial oxide layer resulting in lower equivalent oxide thickness (EOT) of the device.
Wide-Range Refractometric Sensor Using Differently Sensitive Y-Branched Waveguides
Authors: Son Geun-Sik , Kim Woo-Kyung , Lee Sang-Shin , Park Soon-Sup , Lee Daewon , Park Jun-Hee , Kwon Soon Woo , Sim Jae-Hwan , Lee Han-Young
Published: January 2012

A surface sensor rendering an extended detection range was proposed and demonstrated, taking advantage of a Y-branch structure. The sensing and reference waveguides, comprising the Y-branch structure, were overlaid with TiO2 films of different thicknesses; thus, they show unequal sensitivities. The phase change experienced by the two waveguides was in situ monitored through a birefringence analyzer. The interference number for the sensing waveguide was derived from the response of the reference waveguide. The implemented sensor was evaluated by varying the concentration of glucose solution, confirming that the proposed sensing scheme is useful for efficiently extending the detection range.
Analysis of Ion Behavior Affecting Voltage Holding Property of Liquid Crystal Displays
Authors: Mizusaki Masanobu , Yoshimura Yohji , Yamada Yuichiro , Okamoto Kenji
Published: January 2012

A mechanism for the decay of charged voltage, which leads to the lowering of the voltage holding ratio of liquid crystal displays (LCDs), was proposed using a model for the behavior of ions in an LC layer. The proposed model was verified by experimental results using two LC cells of different LC materials. The decay of the charged voltage occurs with two decay components; one originates from the ions arriving at the surface of an alignment layer due to the application of pulsed voltage diffusing toward the LC layer, and the other originates from the ions in the LC layer moving toward the opposite surface and canceling the dielectric polarization of LC molecules during an open-circuit period. We found that the decay of the charged voltage increases with increasing density of ions arriving at the surface before the open-circuit period.
Temperature Dependence of Oxygen Diffusion and Crystal Structure for Thermally Oxidized Titanium Thin Films
Authors: Horio Yoshimi , Hara Yuichiro , Yamamoto Yoshitaka , Morimoto Yuuki , Naitoh Tatsuya
Published: January 2012

The thermal oxidation of titanium (Ti) thin films has been investigated, focusing on the depth profile of oxygen and crystallinity. Ti thin films were epitaxially grown on Si(001) substrates, even at room temperature, by electron bombardment. The thermal oxidations of the Ti films were carried out in an oxygen environment of 0.1 Torr at temperatures ranging from 200 to 1000 °C for a fixed oxidation time of 30 min. It was found that the Ti film was insufficiently oxidized at a temperature lower than 600 °C, and crystalline TiO and Ti2O3 were formed. Above 600 °C, the Ti film was sufficiently oxidized and its crystal structure became completely rutile-type TiO2. No anatase crystal structure appeared at any oxidation temperature. A thermal diffusion model of oxygen in a Ti film is presented for each oxidation temperature. The volume expansion of the Ti film due to oxidation was also examined and obtained to be 1.77.
Investigation of Cu-Deficient Copper Gallium Selenide Thin Film as a Photocathode for Photoelectrochemical Water Splitting
Authors: Kim Jaehong , Minegishi Tsutomu , Kobota Jun , Domen Kazunari
Published: January 2012

Polycrystalline thin films of CuGaSe2-related Cu-deficient materials were prepared by vacuum co-evaporation. The composition was adjusted in order to prepare copper gallium selenide, abbreviated as CGSe, with an optimal band gap and valence band maximum position for photoelectrochemical water splitting. The effect of the Ga/Cu ratio on the photoelectrochemical properties of CGSe was also studied. With increasing Ga/Cu ratio, the band gap of CGSe became larger, and the valence band maximum position became deeper against the vacuum level. However, an analysis of the photocurrent and onset potential indicated that the Ga/Cu ratio should be less than 3.5 for optimal performance. A Pt-deposited CGSe electrode with a Ga/Cu ratio of 3 showed an onset potential of about 1.1 V vs RHE and an energy conversion efficiency of 0.35% under AM 1.5G light illumination in a 0.1 M Na2SO4solution with pH 9.5.
Feature Profiles on Plasma Etch of Organic Films by a Temporal Control of Radical Densities and Real-Time Monitoring of Substrate Temperature
Authors: Yamamoto Hiroshi , Kuroda Hiroki , Ito Masafumi , Ohta Takayuki , Takeda Keigo , Ishikawa Kenji , Kondo Hiroki , Sekine Makoto , Hori Masaru
Published: January 2012

The precise etching of organic films with a low dielectric constant (low-k) in a dual-frequency capacitively coupled plasma etching reactor with a plasma generation of 100 MHz and an applied bias of 2 MHz employing a gas mixture of hydrogen and nitrogen was performed by real-time control of the densities of hydrogen (H) and nitrogen (N) radicals based on real-time measurement of the Si substrate temperature. H and N radical densities were monitored near the sidewall of the reactor by vacuum ultraviolet absorption spectroscopy, and temperature was monitored by an optical fiber-type low-coherence interferometer. On the basis of the results of surface analysis by X-ray photoelectron spectroscopy, etched profiles were effectively determined from the chemical component of protection layers on the sidewall of the etched pattern affected by the ratio of H/(H+N) and substrate temperature. As the etching feature evolves, the ratio of radical density should be controlled temporally to maintain vertical profiles according to the change in substrate temperature. As a result, we have successfully realized an organic film with a vertical feature. These results indicate the need for autonomous control of the etch process based on real-time information on the plasma process for the next-generation ultrafine etching.
Reduction of Bowing in GaN-on-Sapphire and GaN-on-Silicon Substrates by Stress Implantation by Internally Focused Laser Processing
Authors: Aida Hideo , Takeda Hidetoshi , Aota Natsuko , Koyama Koji
Published: January 2012

Reduction of the bowing of GaN-on-sapphire and GaN-on-silicon substrates was demonstrated with an internally focused laser processing. Stress implantation was successfully achieved inside the sapphire and silicon substrates by the internally focused laser process to compensate for the strain generated by the GaN/sapphire and GaN/Si systems which resulted in substrate bow reduction. This new approach gives us a larger flexibility in the design engineering of epitaxial and device fabrication processes and thus accelerates the realization of a larger diameter device process with GaN-on-sapphire and GaN-on silicon.
Resolvin D1 prevents TNF-α-mediated disruption of salivary epithelial formation
Authors: Odusanwo Olutayo , Chinthamani Sreedevi , McCall Andrew , Duffey Michael E. , Baker Olga J.
Published: January 2012

Sjögren's syndrome is a chronic autoimmune disorder characterized by inflammation of salivary glands resulting in impaired secretory function. Our present studies indicate that chronic exposure of salivary epithelium to TNF-α and/or IFN-γ alters tight junction integrity, leading to secretory dysfunction. Resolvins of the D-series (RvDs) are endogenous lipid mediators derived from DHA that regulate excessive inflammatory responses leading to resolution and tissue homeostasis. In this study, we addressed the hypothesis that activation of the RvD1 receptor ALX/FPR2 in salivary epithelium prevents and/or resolves the TNF-α-mediated disruption of acinar organization and enhances monolayer formation. Our results indicate that 1) the RvD1 receptor ALX/FPR2 is present in fresh, isolated cells from mouse salivary glands and in cell lines of salivary origin; and 2) the agonist RvD1 (100 ng/ml) abolished tight junction and cytoskeletal disruption caused by TNF-α and enhanced cell migration and polarity in salivary epithelium. These effects were blocked by the ALX/FPR2 antagonist butyloxycarbonyl-Phe-Leu-Phe-Leu-Phe. The ALX/FPR2 receptor signals via modulation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways since, in our study, blocking PI3K activation with LY294002, a potent and selective PI3K inhibitor, prevented RvD1-induced cell migration. Furthermore, Akt gene silencing with the corresponding siRNA almost completely blocked the ability of Par-C10 cells to migrate. Our findings suggest that RvD1 receptor activation promotes resolution of inflammation and tissue repair in salivary epithelium, which may have relevance in the restoration of salivary gland dysfunction associated with Sjögren's syndrome.
Lactic acid restores skeletal muscle force in an in vitro fatigue model: are voltage-gated chloride channels involved?
Authors: Bandschapp Oliver , Soule Charles L. , Iaizzo Paul A.
Published: January 2012

High interstitial K+ concentration ([K+]) has been reported to impede normal propagation of electrical impulses along the muscle cell membrane (sarcolemma) and then also into the transverse tubule system; this is one considered underlying mechanism associated with the development of muscle fatigue. Interestingly, the extracellular buildup of lactic acid, once considered an additional cause for muscle fatigue, was recently shown to have force-restoring effects in such conditions. Specifically, it was proposed that elevated lactic acid (and intracellular acidosis) may lead to inhibition of voltage-gated chloride channels, thereby reestablishing better excitability of the muscle cell sarcolemma. In the present study, using an in vitro muscle contractile experimental setup to study functionally viable rectus abdominis muscle preparations obtained from normal swine, we examined the effects of 20 mM lactic acid and 512 μM 9-anthracenecarboxylic acid (9-AC; a voltage-gated chloride channel blocker) on the force recovery of K+-depressed (10 mM K+) twitch forces. We observed a similar muscle contractile restoration after both treatments. Interestingly, at elevated [K+], myotonia (i.e., hyperexcitability or afterdepolarizations), usually present in skeletal muscle with inherent or induced chloride channel dysfunctions, was not observed in the presence of either lactic acid or 9-AC. In part, these data confirm previous studies showing a force-restoring effect of lactic acid in high-[K+] conditions. In addition, we observed similar restorative effects of lactic acid and 9-AC, implicating a beneficial mechanism via voltage-gated chloride channel modulation.
The role of calcium-independent phospholipase A2γ in modulation of aqueous humor drainage and Ca2+ sensitization of trabecular meshwork contraction
Authors: Pattabiraman Padmanabhan P. , Lih Fred B. , Tomer Kenneth B. , Rao Ponugoti Vasantha
Published: January 2012

The contractile and relaxation characteristics of trabecular meshwork (TM) are presumed to influence aqueous humor (AH) drainage and intraocular pressure. The mechanisms underlying regulation of TM cell contractile properties, however, are not well understood. This study investigates the role of calcium-independent phospholipase A2 (iPLA2), which controls eicosanoid synthesis, in regulation of TM cell contraction and AH outflow using mechanism-based isoform specific inhibitors (R)-bromoenol lactone (R-BEL, iPLA2γ specific) and (S)-bromoenol lactone (S-BEL, iPLA2β specific). Immunohistochemical analysis revealed intense staining for both iPLA2β and γ isoforms throughout the TM, juxtacanalicular tissue, and Schlemm's canal of human eye. Inhibition of iPLA2γ by R-BEL or small interfering RNA-mediated silencing of iPLA2γ expression induced dramatic changes in TM cell morphology, and decreased actin stress fibers, focal adhesions, and myosin light-chain (MLC) phosphorylation. AH outflow facility increased progressively and significantly in enucleated porcine eyes perfused with R-BEL. This response was associated with a significant decrease in TM tissue MLC phosphorylation and alterations in the morphology of aqueous plexi in R-BEL-perfused eyes. In contrast, S-BEL did not affect either of these parameters. Additionally, R-BEL-induced cellular relaxation of the TM was associated with a significant decrease in the levels of active Rho GTPase, phospho-MLC phosphatase, phospho-CPI-17, and arachidonic acid. Taken together, these observations demonstrate that iPLA2γ plays a significant and isoform-specific role in regulation of AH outflow facility by altering the contractile characteristics of the TM. The effects of iPLA2γ on TM contractile status appear to involve arachidonic acid and Rho GTPase signaling pathways.
Differential role of opioid receptors in tibial nerve inhibition of nociceptive and nonnociceptive bladder reflexes in cats
Authors: Tai Changfeng , Larson Jeffrey A. , Ogagan P. Dafe , Chen Guoqing , Shen Bing , Wang Jicheng , Roppolo James R. , de Groat William C.
Published: January 2012

Naloxone (an opioid receptor antagonist) was used to examine the role of opioid mechanisms in bladder reflexes and in somatic afferent inhibition of these reflexes by tibial nerve stimulation (TNS). Experiments were conducted in α-chloralose-anesthetized cats when the bladder was infused with saline or 0.25% acetic acid (AA). The bladder volume was measured at the first large-amplitude (>30 cmH2O) contraction during a cystometrogram and termed “estimated bladder capacity” (EBC). AA irritated the bladder, induced bladder overactivity, and significantly ( P < 0.0001) reduced EBC to 14.3 ± 1.9% of the saline control. TNS (5 Hz, 0.2 ms) at 4 and 8 times the threshold (T) intensity for inducing an observable toe movement suppressed AA-induced bladder overactivity and significantly increased EBC to 41.5 ± 9.9% (4T, P < 0.05) and 46.1 ± 7.9% (8T, P < 0.01) of the saline control. Naloxone (1 mg/kg iv) completely eliminated TNS inhibition of bladder overactivity. Naloxone (0.001–1 mg/kg iv) did not change EBC during AA irritation. However, during saline infusion naloxone (1 mg/kg iv) significantly ( P < 0.01) reduced EBC to 66.5 ± 8.1% of the control EBC. During saline infusion, TNS induced an acute increase in EBC and an increase that persisted following the stimulation. Naloxone (1 mg/kg) did not alter either type of inhibition. However, naloxone administered during the poststimulation inhibition decreased EBC. These results indicate that opioid receptors have different roles in modulation of nociceptive and nonnociceptive bladder reflexes and in somatic afferent inhibition of these reflexes, raising the possibility that opioid receptors may be a target for pharmacological treatment of lower urinary tract disorders.
The Study of Resource Allocation among Software Development Phases: An Economics-Based Approach
Authors: Yiftachel Peleg , Hadar Irit , Peled Dan , Farchi Eitan , Goldwasser Dan
Published: January 2012

This paper presents an economics-based approach for studying the problem of resource allocation among software development phases. Our approach is structured along two parallel axes: theoretical and empirical. We developed a general economic model for analyzing the allocation problem as a constrained profit maximization problem. The model, based on a novel concept of software production function, considers the effects of different allocations of development resources on output measures of the resulting software product. An empirical environment for evaluating and refining the model is presented, and a first exploratory study for characterizing the model's components and developers' resource allocation decisions is described. The findings illustrate how the model can be applied and validate its underlying assumptions and usability. Future quantitative empirical studies can refine and substantiate various aspects of the proposed model and ultimately improve the productivity of software development processes.
N‐TiO2: Chemical Synthesis and Photocatalysis
Authors: Factorovich Matias , Guz Lucas , Candal Roberto
Published: January 2012

The chemical synthesis of nitrogen‐doped titanium dioxide (N‐TiO2) is explored in an attempt to understand the mechanisms of doping. Urea is used as precursor in a sol gel synthesis of N‐TiO2. Chemical and structural changes during thermal treatment of the precursors were followed by several techniques. The effect of doping on band gap, morphology, and microstructure was also determined. The byproducts produced during firing correspond to those obtained during urea thermal decomposition. Polynitrogenated colored compounds produced at temperatures below 400°C may act as sensitizer. Incorporation of N in the TiO2 structure is possible at higher temperatures. Degradation experiments of salicylic acid under UVA and visible light (λ > 400 nm) in the presence of TiO2 or N‐TiO2 indicate that doping decreases the activity under UVA light, while stable byproducts are produced under visible light.
A Self-Organized and Smart-Adaptive Clustering and Routing Approach for Wireless Sensor Networks
Authors: Lee Kyuhong , Lee Heesang
Published: January 2012

Efficient energy consumption is a critical factor for the deployment and operation of wireless sensor networks (WSNs). In general, WSNs perform clustering and routing using localized neighbor information only. Therefore, some studies have used self-organized systems and smart mechanisms as research methods. In this paper, we propose a self-organized and smart-adaptive clustering (SOSAC) and routing method, which performs clustering in WSNs, operates the formed clusters in a smart-adaptive way, and performs cluster-based routing. SOSAC is comprised of three mechanisms, which are used to change the fitness value over time, to back up routing information in preparation for any potential breakdown in WSNs, and to adapt to the changes of the number of sensor nodes for a WSN. We compared the performance of the proposed SOSAC with that of a well-known clustering and routing protocol for WSNs. Our computational experiments demonstrate that the network lifetime, energy consumption, and scalability of SOSAC are better than those of the compared method.
A Novel Method for Bacterial UTI Diagnosis Using Raman Spectroscopy
Authors: Kastanos Evdokia , Kyriakides Alexandros , Hadjigeorgiou Katerina , Pitris Costas
Published: January 2012

The current state of the art on bacterial classification using Raman and Surface Enhanced Raman Spectroscopy (SERS) for the purpose of developing a rapid and more accurate method for urinary tract infection (UTI) diagnosis is presented. SERS, an enhanced version of Raman offering much increased sensitivity, provides complex biochemical information which, in conjunction with advanced analysis and classification techniques, can become a valuable diagnostic tool. The variety of metal substrates used for SERS, including silver and gold colloids, as well as nanostructured metal surfaces, is reviewed. The challenges in preprocessing noisy and complicated spectra and the various methods used for feature creation as well as a novel method using spectral band ratios are described. The various unsupervised and supervised classification methods commonly used for SERS spectra of bacteria are evaluated. Current research on transforming SERS into a valuable clinical tool for the diagnosis of UTIs is presented. Specifically, the classification of bacterial spectra (a) as positive or negative for an infection, (b) as belonging to a particular species of bacteria, and (c) as sensitive or resistant to an antibiotic are described. This work can lead to the development of novel technology with extremely important benefits for public health.
New ab Initio Potential Energy Surfaces for the Renner-Teller Coupled 11A′
and 11A′′
States of CH2
Authors: Ma Haitao , Zhang Chunfang , Zhang Zhijun , Liu Xiaojun , Bian Wensheng
Published: January 2012

New ab initio potential energy surfaces (PESs) for the two lowest-lying singlet 11A′ and 11A′′ electronic states of CH2, coupled by the Renner-Teller (RT) effect and meant for the spectroscopic study, are presented. The surfaces are constructed using a dual-level strategy. The internally contracted multireference
configuration interaction calculations with the Davidson correction, using the aug-cc-pVQZ basis set, are
employed to obtain 3042 points at the lower level. The core and core-valence correlation effects are taken
into account in the ab initio calculations with a modified optimized aug-cc-pCVQZ basis set for the higher-level points. The analytical representations of these PESs, with the inclusion of the nonadiabatic RT terms,
are obtained by the nonlinear least-squares fit of the calculated points to three-body expansion. Quantum
dynamical calculations are performed on these PESs, and the computed vibronic energy levels for the two
singlet electronic states are in excellent agreement with experiment.
Cortical Auditory Evoked Potentials in Children with a Hearing Loss: A Pilot Study
Authors: Koravand Amineh , Jutras Benoît , Lassonde Maryse
Published: January 2012

Objective. This study examined the patterns of neural activity in the central auditory system in children with hearing loss.Methods. Cortical potentials and mismatch responses (MMRs) were recorded from ten children aged between 9 and 10 years: five with hearing loss and five with normal hearing in passive oddball paradigms using verbal and nonverbal stimuli.Results. Results indicate a trend toward larger P1 amplitude, a significant reduction in amplitude, and latency of N2 in children with hearing loss compared to control. No significant group differences were observed for the majority of the MMRs conditions.Conclusions. Data suggest that the reduced auditory input affects the pattern of cortical-auditory-evoked potentials in children with a mild to moderately severe hearing loss. Results suggest maturational delays and/or deficits in central auditory processing in children with hearing loss, as indicated by the neurophysiological markers P1 and N2. In contrast, negative MMR data suggest that the amplification provided by the hearing aids could have allowed children with hearing loss to develop adequate discriminative abilities.
Simulated Optical Properties of Gold Nanocubes and Nanobars by Discrete Dipole Approximation
Authors: Alsawafta Mohammed , Wahbeh Mamoun , Truong Vo-Van
Published: January 2012

The absorption spectra for a gold nanocube and for a gold nanobar are calculated by using the Discrete Dipole Approximation (DDA). The results show the excitation of a single albeit broad surface plasmon (SP) band of the gold nanocube. The extinction cross section of the gold nanocube is dominated by the absorption cross section that gains importance as the width increases. Further increasing the nanocube size beyond 80 nm will result in an optical response mainly characterized by scattering properties. The absorption spectrum of the nanobar shows the excitation of both the longitudinal mode (LM) and the transverse mode (TM). The nanobar is also compared to a cylinder, a spherically capped cylinder, and a spheroid of the same aspect ratio. The band position of the TM of the nanobar is red‐shifted as compared to the ones calculated for other morphologies, while the LM is either blue‐shifted or red‐shifted depending on the morphologies considered.
Cardiovascular Risk Factors in Bulgarian Patients with Polycystic Ovary Syndrome and/or Obesity
Authors: Gateva Antoaneta , Kamenov Zdravko
Published: January 2012

Polycystic ovarian syndrome (PCOS) is one of the most common endocrine disturbances in women of reproductive age. Besides its well-known effects on reproductive health, it is also linked to increased cardiovascular risk in later life. The aim of this study is to investigate some classical cardiovascular risk factors in a crossectional study of Bulgarian women with PCOS and/or obesity. We performed a retrospective medical chart review of 375 women from an university endocrine clinic. We found significant differences in the indices of carbohydrate metabolism, blood pressure, lipid profile, rate of liver steatosis, and the levels liver enzymes and hematological results between the lean and obese PCOS women. Obese women without PCOS did not show significantly different results in their OGGT form obese PCOS women. Waist-to-stature-ratio (WSR) correlated better with the baseline IRI levels and lipid profile than waist-to-hip-ratio (WHR) that makes it a better marker for unfavorable metabolic profile.
Topographical Choroidal Thickness Change Following PDT for CSC: An OCT Case Report
Authors: Wirostko William J. , Nordgren Rick N. , Dubis Adam M.
Published: January 2012

Purpose. To describe topographical changes in choroidal thickness as measured by optical coherence tomography following photodynamic therapy (PDT) for central serous chorioretinopathy (CSC).Methods. Case report.Results. By 1 month following PDT, mean (SD) choroidal thickness decreased from 562 microns (24) to 424 microns (27) (P<0.01) at 3 mm temporal to fovea, 483 microns (9) to 341 microns (21) (P<0.01) at 1.5 mm temporal to fovea, 576 microns (52) to 370 microns (81) (P<0.01) under the fovea, 442 microns (30) to 331 microns (54) (P<0.04) at 1.5 mm nasal to fovea, and 274 microns (39) to 171 microns (17) (P<0.01) at 3 mm nasal to fovea. The Location of greatest choroidal thickness (648 microns) prior to treatment was at point of leakage on fluorescein angiogram (FA). This region decreased to 504 microns following treatment.Conclusion. A decrease in choroidal thickness can be seen following PDT for CSC as far as 3 mm temporal and 3 mm nasal to fovea. The Location of greatest choroidal thickness may be at point of leakage on FA.
Genetic Variations of Glutathione S-Transferase Influence on Blood Cadmium Concentration
Authors: Khansakorn Nitchaphat , Wongwit Waranya , Tharnpoophasiam Prapin , Hengprasith Bunlue , Suwannathon Lerson , Chanprasertyothin Suwannee , Sura Thunyachai , Kaojarern Sming , Sritara Piyamit , Sirivarasai Jintana
Published: January 2012

The glutathione S-transferases (GSTs) are involved in biotransformation and detoxification of cadmium (Cd). Genetic polymorphisms in these genes may lead to interindividual variation in Cd susceptibility. The objective of this study was to assess the association ofGSTs (GSTT1, GSTM1, andGSTP1Val105Ile) polymorphisms with blood Cd concentrations in a nonoccupationally exposed population. The 370 blood samples were analyzed for Cd concentration and polymorphisms in GSTs genes. Geometric mean of blood Cd among this population was0.46±0.02 μg/L (with 95% CI; 0.43–0.49 μg/L). Blood Cd concentrations in subjects carryingGSTP1Val/Val genotype were significantly higher than those with Ile/Ile and Ile/Val genotypes. No significant differences in blood Cd concentrations among individual with gene deletions ofGSTT1andGSTM1were observed.GSTP1/GSTT1andGSTP1/GSTM1combinations showed significantly associated with increase in blood Cd levels. This study indicated that polymorphisms ofGSTP1combined withGSTT1and/orGSTM1deletion are likely to influence on individual susceptibility to cadmium toxicity.
A Determination of an Abrupt Motion of the Sea Bottom by Using Snapshot Data of Water Waves
Authors: Jang T. S. , Sung Hong Gun , Park Jinsoo
Published: January 2012

This paper presents an inverse problem and its solution procedure, which are aimed at identifying a sudden underwater movement of the sea bottom. The identification is mathematically shown to work with a known snapshot data of generated water wave configurations. It is also proved that the problem has a unique solution. However, the inverse problem is involved in an integral equation of the first kind, resulting in an ill‐posed problem in the sense of stability. That is, the problem lacks solution stability properties. To overcome the difficulty of solution instability, in this paper, a stabilization technique, called regularization, is incorporated in the present solution procedure for the identification of the sea bottom movement. A numerical experiment is presented to demonstrate that the proposed (numerical) solution procedure operates.
Preliminary Assessment of the Chemical Stability of Dried Extracts fromGuazuma ulmifoliaLam. (Sterculiaceae)
Authors: Lopes Gisely C. , Longhini Renata , dos Santos Paulo Victor P. , Araújo Adriano A. S. , Bruschi Marcos Luciano , de Mello João Carlos P.
Published: January 2012

We report the results of a preliminary estimation of the stability of the dried extract from bark ofGuazuma ulmifoliaLam. (“Mutamba”), with and without added colloidal silicon dioxide (CSD). The physical and chemical properties and the compatibility of CSD in the extract were evaluated for 21 days of storage under stress conditions of temperature (45±2°C) and humidity (75±5%). Thermogravimetry (TG) was supplemented using selective high-performance liquid chromatography (HPLC) for determination of stability of the characteristic constituents (chemical markers), namely, procyanidin B2 (PB2) and epicatechin (EP). The results showed that PB2 is an appropriate compound to be used as a chemical marker in the quality control of dried extracts ofG. ulmifolia. The stress study showed that there was no significant difference between the two formulations. However, considering the TG data and the high temperatures involved, the results suggest that CSD increases the stability of the dried extract ofG. ulmifolia.
A Comparison of Methodical Approaches to Fingerprinting of the Volatile Fraction from Winter Savory (Satureja montana)
Authors: Rzepa Józef , Sajewicz Mieczysław , Baj Tomasz , Gorczyca Patrycja , Włodarek Magdalena , Głowniak Kazimierz , Waksmundzka-Hajnos Monika , Kowalska Teresa
Published: January 2012

It was the aim of this study to compare the efficiency of the different essential oil extraction methods upon the two winter savory (Satureja montana) samples of different origin. The compared techniques were the headspace gas chromatography with mass spectrometric detection (HS-GC/MS) run at the two different headspace temperatures (i.e., at 80 and 100°C) and the three different steam distillation techniques preceding the GC/MS analysis. HS-GC/MS is considered as the technique of the first choice, and the compared steam distillation techniques are recommended, respectively, by Polish Pharmacopoeia, European Pharmacopoeia, and the Polish Patent. Adequate conclusions were drawn as to the advantage of HS-GC/MS (not having the pharmacopoeial recommendation) over the different steam distillation techniques and the drawbacks of each individual analytical procedure were discussed.
Self-Assembly of Cholesterol-Containing Water-Soluble Polymers
Authors: Yusa Shin-ichi
Published: January 2012

Self-assembly of amphiphilic polymers containing cholesteryl groups has proved to be attractive in the field of nanotechnology research. Some cholesterol derivatives are known to form ordered structures which indicate thermotropic and lyotropic liquid-crystalline, monolayers, multilayers, micelles, and liposomes. This paper involves the synthesis and characterization of various kinds of amphiphilic polymers bearing cholesteryl moieties.
Some Generalizations of Ulam‐Hyers Stability Functional Equations to Riesz Algebras
Authors: Polat Faruk
Published: January 2012

Badora (2002) proved the following stability result. Let ε and δ be nonnegative real numbers, then for every mapping f of a ring ℛ onto a Banach algebra ℬ satisfying | | f(x + y) − f(x) − f(y)|| ≤ ε and | | f(x · y) − f(x)f(y)|| ≤ δ for all x, y ∈ ℛ, there exists a unique ring homomorphism h : ℛ → ℬ such that | | f(x) − h(x)|| ≤ ε, x ∈ ℛ. Moreover, b · (f(x) − h(x)) = 0, (f(x) − h(x)) · b = 0, for all x ∈ ℛ and all b from the algebra generated by h(ℛ). In this paper, we generalize Badora′s stability result above on ring homomorphisms for Riesz algebras with extended norms.
Electrochemically Deposited Polypyrrole for Dye-Sensitized Solar Cell Counter Electrodes
Authors: Keothongkham Khamsone , Pimanpang Samuk , Maiaugree Wasan , Saekow Saman , Jarernboon Wirat , Amornkitbamrung Vittaya
Published: January 2012

Polypyrrole films were coated on conductive glass by electrochemical deposition (alternative current or direct current process). They were then used as the dye-sensitized solar cell counter electrodes. Scanning electron microscopy revealed that polypyrrole forms a nanoparticle-like structure on the conductive glass. The amount of deposited polypyrrole (or film thickness) increased with the deposition duration, and the performance of polypyrrole based-dye-sensitized solar cells is dependant upon polymer thickness. The highest efficiency of alternative current and direct current polypyrrole based-dye-sensitized solar cells (DSSCs) is 4.72% and 4.02%, respectively. Electrochemical impedance spectroscopy suggests that the superior performance of alternative current polypyrrole solar cells is due to their lower charge-transfer resistance between counter electrode and electrolyte. The large charge-transfer resistance of direct current solar cells is attributed to the formation of unbounded polypyrrole chains minimizing theI3 −reduction rate.
The Ethical, Legal, and Social Issues Impacted by Modern Assisted Reproductive Technologies
Authors: Brezina Paul R. , Zhao Yulian
Published: January 2012

Background. While assisted reproductive technology (ART), includingin vitrofertilization has given hope to millions of couples suffering from infertility, it has also introduced countless ethical, legal, and social challenges. The objective of this paper is to identify the aspects of ART that are most relevant to present-day society and discuss the multiple ethical, legal, and social challenges inherent to this technology.Scope of Review. This paper evaluates some of the most visible and challenging topics in the field of ART and outlines the ethical, legal, and social challenges they introduce.Major Conclusions. ART has resulted in a tectonic shift in the way physicians and the general population perceive infertility and ethics. In the coming years, advancing technology is likely to exacerbate ethical, legal, and social concerns associated with ART. ART is directly challenging society to reevaluate the way in which human life, social justice and equality, and claims to genetic offspring are viewed. Furthermore, these issues will force legal systems to modify existing laws to accommodate the unique challenges created by ART. Society has a responsibility to ensure that the advances achieved through ART are implemented in a socially responsible manner.
A Comparison of Epithelial Cells, Fibroblasts, and Osteoblasts in Dental Implant Titanium Topographies
Authors: Teng Fu-Yuan , Ko Chia-Ling , Kuo Hsien-Nan , Hu Jin-Jia , Lin Jia-Horng , Lou Ching-Wen , Hung Chun-Cheng , Wang Yin-Lai , Cheng Cheng-Yi , Chen Wen-Cheng
Published: January 2012

The major challenge for dental implants is achieving optimal esthetic appearance and a concept to fulfill this criterion is evaluated. The key to an esthetically pleasing appearance lies in the properly manage the soft tissue profile around dental implants. A novel implant restoration technique on the surface was proposed as a way to augment both soft- and hard-tissue profiles at potential implant sites. Different levels of roughness can be attained by sandblasting and acid etching, and a tetracalcium phosphate was used to supply the ions. In particular, the early stage attaching and repopulating abilities of bone cell osteoblasts (MC3T3-E1), fibroblasts (NIH 3T3), and epithelial cells (XB-2) were evaluated. The results showed that XB-2 cell adhesive qualities of a smooth surface were better than those of the roughened surfaces, the proliferative properties were reversed. The effects of roughness on the characteristics of 3T3 cells were opposite to the result for XB-2 cells. E1 proliferative ability did not differ with any statistical significance. These results suggest that a rougher surface which provided calcium and phosphate ions have the ability to enhance the proliferation of osteoblast and the inhibition of fibroblast growth that enhance implant success ratios.
Hip Fracture Mortality: Is It Affected by Anesthesia Techniques?
Authors: Karaca Saffet , Ayhan Egemen , Kesmezacar Hayrettin , Uysal Omer
Published: January 2012

We hypothesized that combined peripheral nerve block (CPNB) technique might reduce mortality in hip fracture patients with the advantage of preserved cardiovascular stability. We retrospectively analyzed 257 hip fracture patients for mortality rates and affecting factors according to general anesthesia (GA), neuraxial block (NB), and CPNB techniques. Patients’ gender, age at admission, trauma date, ASA status, delay in surgery, followup period, and Barthel Activities of Daily Living Index were determined. There were no differences between three anesthesia groups regarding to sex, followup, delay in surgery, and Barthel score. NB patients was significantly younger and CPNB patients’ ASA status were significantly worse than other groups. Mortality was lower for regional group (NB + CPNB) than GA group. Mortality was increased with age, delay in surgery, and ASA and decreased with CPNB choice; however, it was not correlated with NB choice. Since the patients’ age and ASA status cannot be changed, they must be operated immediately. We recommend CPNB technique in high-risk patients to operate them earlier.
Mathematical Models of Multiserver Queuing System for Dynamic Performance Evaluation in Port
Authors: Dragović Branislav , Park Nam-Kyu , Zrnić Nenad Đ. , Meštrović Romeo
Published: January 2012

We discuss dynamic system performance evaluation in the river port utilizing queuing models with batch arrivals. The general models of the system are developed. This system is modelled by MX/M/n/m queue with finite waiting areas and identical and independent cargo‐handling capacities. The models are considered with whole and part batch acceptance (or whole and part batch rejections) and the interarrival and service times are exponentially distributed. Results related to the batch blocking probability and the blocking probability of an arbitrary vessel in nonstationary and stationary states have been obtained. Numerical results and computational experiments are reported to evaluate the efficiency of the models for the real system.
A Subspace-Based Compensation Method for the Mutual Coupling in Concentric Circular Ring Arrays for Near-Field Source Localisation
Authors: Abedin Mohammed Jainul , Mohan Ananda Sanagavarapu
Published: January 2012

We propose a technique for compensating the effect of mutual coupling on parameter estimation that is suitable with any subspace-based super-resolution algorithms. A Concentric circular ring array (CCRA) formed using thin dipole antennas in the receiving mode is employed to estimate the parameters of electromagnetic sources located in the radiating near field of the array. A CCRA geometry that obtains a lowest Cramer-Rao lower bound (CRLB) in the presence of array mutual coupling is chosen for investigation. The mutual coupling among antenna elements of the array would affect the orthogonality of subspaces when MUSIC or ESPRIT algorithms are used for parameter estimation. The proposed method obtains a compensation matrix that restores the orthogonality between the subspaces there by improving the accuracy of estimation. To avoid three-dimensional searches, the range parameter is estimated using a cross-correlation-based method. Numerical simulation using a full-wave electromagnetic (EM) solver is employed to demonstrate the effectiveness of the proposed compensation approach.
Double-Layer Low-Density Parity-Check Codes over Multiple-Input Multiple-Output Channels
Authors: Mao Yun , Guo Ying , Peng Jun , Jiang Xueqin , Ho Lee Moon
Published: January 2012

We introduce a double-layer code based on the combination of a low-density parity-check (LDPC) code with the multiple-input multiple-output (MIMO) system, where the decoding can be done in both inner-iteration and outer-iteration manners. The present code, called low-density MIMO code (LDMC), has a double-layer structure, that is, one layer defines subcodes that are embedded in each transmission vector and another glues these subcodes together. It supports inner iterations inside the LDPC decoder and outeriterations between detectors and decoders, simultaneously. It can also achieve the desired design rates due to the full rank of the deployed parity-check matrix. Simulations show that the LDMC performs favorably over the MIMO systems.
Schwann Cell Metabolic Activity in Various Short-Term Holding Conditions: Implications for Improved Nerve Graft Viability
Authors: Janssen Insa , Reimers Kerstin , Allmeling Christina , Matthes Stella , Vogt Peter M. , Radtke Christine
Published: January 2012

Strategies for improvement of nerve regeneration and optimal conditions to prevent Schwann cell (SC) loss within a nerve transplant procedure are critical. The purpose of this study was to examine SC viability, which plays an important role in peripheral nerve regeneration, under various incubation conditions up to three hours. To address this issue, Schwann cell metabolic activity was determined using different independent test methods. The following experimental conditions were compared: SCs prepared from nerves were incubated in (1) isotonic saline solution (2) Dulbecco's modified Eagles medium as used for cell culturing, (3) Hannover bioreactor medium, and (4) Leibovitz's medium. SC metabolic activity of excised rat sciatic nerve was determined at 4°C, 18°C, and 37°C over 3 hrs. The results indicate that SC activity was optimized by the usage of Leibovitz's medium or HBRM at 37°C. Greater SC viability at the time of surgical nerve grafting could contribute to improved axonal regeneration and remyelination after nerve transplantation, and thus more successful functional recovery.
A Comparison between Fixed‐Basis and Variable‐Basis Schemes forFunction Approximation and Functional Optimization
Authors: Gnecco Giorgio
Published: January 2012

Fixed‐basis and variable‐basis approximation schemes are compared for the problems of function
approximation and functional optimization (also known as infinite programming). Classes
of problems are investigated for which variable‐basis schemes with sigmoidal computational
units perform better than fixed‐basis ones, in terms of the minimum number of computational
units needed to achieve a desired error in function approximation or approximate optimization.
Previously known bounds on the accuracy are extended, with better rates, to families of d‐variable functions whose actual dependence is on a subset of d′ ≪ d variables, where the indices
of these d′ variables are not known a priori.