bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatially Distributed Current Oscillations with Electrochemical Reactions in Microfluidic Flow Cells
Authors: Bîrzu Adrian , Jia Yanxin , Sankuratri Varun , Liu Yifan , Kiss István Z. 
Published: January 2015

AbstractThe formation of spatiotemporal patterns is investigated by using a chemical reaction on the surface of a high‐aspect‐ratio metal electrode positioned in a flow channel. A partial differential equation model is formulated for nickel dissolution in sulfuric acid in a microfluidic flow channel. The model simulations predict oscillatory patterns that are spatially distributed on the electrode surface; the downstream portion of the metal surface exhibits large‐amplitude, nonlinear oscillations of dissolution rates, whereas the upstream portion displays small‐amplitude, harmonic oscillations with a phase delay. The features of the dynamical response can be interpreted by the dependence of local dynamics on the widely varying surface conditions and the presence of strong coupling. The patterns can be observed for both contiguous and segmented metal surfaces. The existence of spatially distributed current oscillations is confirmed in experiments with Ni electrodissolution in a microfluidic device. The results show the impact of a widely heterogeneous environment on the types of patterns of chemical reaction rates.
Efficient Exciton Harvesting through Long‐Range Energy Transfer
Authors: Wang Yanbin , Ohkita Hideo , Benten Hiroaki , Ito Shinzaburo 
Published: January 2015

AbstractEfficient exciton collection at charge‐generation sites is one of the key requirements for the improvement in power conversion efficiency (PCE) of organic solar cells, because only excitons arriving at a donor/acceptor interface can be dissociated into free charge carriers. We evaluated the effective diffusion length in poly(3‐hexylthiophene) (P3HT) by using donor/acceptor bilayers with two different exciton‐quenching acceptors. One is an insoluble fullerene polymer (p‐PCBVB), which is an efficient electron‐accepting material with negligible absorption in the visible region. The other is a low‐bandgap polymer, poly[(4,4‐bis(2‐ethylhexyl)‐dithieno[3,2‐b:2′,3′‐d]silole)‐2,6‐diyl‐alt‐(2,1,3‐benzothiadiazole)‐4,7‐diyl], (PSBTBT). This polymer has a large absorption band in the near‐IR region, which overlaps well with the emission band of P3HT. The effective diffusion length of P3HT excitons is evaluated to be 15 nm for P3HT/p‐PCBVB bilayers and improved to 30 nm for P3HT/PSBTBT bilayers. This improvement is ascribed to long‐range energy transfer from P3HT to PSBTBT. This finding suggests that the effective diffusion length of P3HT excitons can be increased through long‐range energy transfer by incorporating PSBTBT into P3HT/PCBM blends.
Modeling of Nanoplasmas Created from Finite Systems by Ultrafast Intense X‐ray Pulses
Authors: Ziaja B. , Jurek Z. , Saxena V. , Santra R. 
Published: January 2015

AbstractIn this review we discuss various simulation methods for modeling nanoplasmas created from finite‐size samples after their irradiation with femtosecond, intense X‐ray pulses. Depending on the sample composition and its size, either a particle method or a transport method can be applied. Also, the observables of interest influence the choice of the simulation method. The current status of dedicated methods developed by the CFEL Theory Division at DESY in Hamburg and their possible extensions are presented together with some application examples. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of Nonthermal Solid‐to‐Solid Phase Transition in Diamond Irradiated with Femtosecond x‐ray FEL Pulse
Authors: Medvedev N. , Tkachenko V. , Ziaja B. 
Published: January 2015

AbstractIn this contribution we review in detail our recently developed hybrid model able to trace simultaneously nonequilibrium electron kinetics, evolution of an electronic structure, and eventually nonthermal phase transition in solids irradiated with femtosecond free‐electron laser pulses. Diamond irradiated with an ultrashort intense x‐ray pulse serves as an example to show how an irradiated material undergoes an ultrafast phase transition on sub‐picosecond timescales. The transition of diamond into graphite is induced by an excitation of electrons from the valence band into the conduction band, which, in turn, induces a rapid change of the interatomic potential. Our theoretical model incorporates: a Monte‐Carlo method for tracing high‐energy electrons and K‐shell holes in diamond; a temperature equation for the valence‐band and low‐energy conduction‐band electrons; a tight binding method for calculation of the evolving electronic structure of the material and potential energy surfaces; and molecular dynamics propagating atomic trajectories. This unified approach predicts the damage threshold of diamond in a good agreement with experimentally measured values. It reveals a multi‐step nature of nonthermal phase transition being an interplay between electronic excitation, changes of the band structure, and atomic reordering. An effect of pulse parameters, such as photon energy and temporal pulse shape, on the phase transition is discussed in detail. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Production and Diagnostics of Dense Matter
Authors: Brambrink E. , Amadou N. , Benuzzi‐Mounaix A. , Geissel M. , Harmand M. , Pelka A. , Vinci T. , Koenig M. 
Published: January 2015

AbstractHigh energy lasers are a unique tool to create high pressure states above 10 Mbar at ns time scales, which allow to study material properties under these extreme conditions. These conditions are, for example, comparable with planetary cores, where material properties play an important role for the properties and evolution of a planet. The rapid compression allows also to study dynamic effects of phase transitions as compression times are comparable to relaxation times. We will present recent results of laser compression of iron reaching conditions of so called “super‐Earth” cores. A description of the compression schemes as well as present and future diagnostics is presented. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Equilibrium and Non‐Equilibrium Melting of Two‐Dimensional Plasma Crystals
Authors: Ivlev A.V. , Nosenko V. , Röcker T.B. 
Published: January 2015

AbstractRecent progress in experimental and theoretical studies of melting of two‐dimensional (2D) plasma crystals is summarized. Several generic, equilibrium and non‐equilibrium processes which can be observed and investigated in 2D complex plasmas are discussed, such as KTHNY, grain‐boundary‐induced, and shear‐induced melting. Furthermore, the key features of the dominant plasma‐specific mechanism of melting operating in 2D plasma crystals, the mode‐coupling instability, are presented. The onset of the instability, which is characterized by threshold values of the experimental parameters, identifies the “dividing line” between the regimes when 2D complex plasmas can be employed to study generic strong‐coupling phenomena, and the situations when the melting occurs due to specific processes peculiar to complex plasmas. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection of malignant mesothelioma using nuclear structure of mesothelial cells in effusion cytology specimens
Authors: Tosun Akif Burak , Yergiyev Oleksandr , Kolouri Soheil , Silverman Jan F. , Rohde Gustavo K. 
Published: January 2015

AbstractMesothelioma is a form of cancer generally caused from previous exposure to asbestos. Although it was considered a rare neoplasm in the past, its incidence is increasing worldwide due to extensive use of asbestos. In the current practice of medicine, the gold standard for diagnosing mesothelioma is through a pleural biopsy with subsequent histologic examination of the tissue. The diagnostic tissue should demonstrate the invasion by the tumor and is obtained through thoracoscopy or open thoracotomy, both being highly invasive surgical operations. On the other hand, thoracocentesis, which is removal of effusion fluid from the pleural space, is a far less invasive procedure that can provide material for cytological examination. In this study, we aim at detecting and classifying malignant mesothelioma based on the nuclear chromatin distribution from digital images of mesothelial cells in effusion cytology specimens. Accordingly, a computerized method is developed to determine whether a set of nuclei belonging to a patient is benign or malignant. The quantification of chromatin distribution is performed by using the optimal transport‐based linear embedding for segmented nuclei in combination with the modified Fisher discriminant analysis. Classification is then performed through a k‐nearest neighborhood approach and a basic voting strategy. Our experiments on 34 different human cases result in 100% accurate predictions computed with blind cross validation. Experimental comparisons also show that the new method can significantly outperform standard numerical feature‐type methods in terms of agreement with the clinical diagnosis gold standard. According to our results, we conclude that nuclear structure of mesothelial cells alone may contain enough information to separate malignant mesothelioma from benign mesothelial proliferations. © 2015 International Society for Advancement of Cytometry
Single‐cell mass cytometry reveals intracellular survival/proliferative signaling in FLT3‐ITD‐mutated AML stem/progenitor cells
Authors: Han Lina , Qiu Peng , Zeng Zhihong , Jorgensen Jeffrey L. , Mak Duncan H. , Burks Jared K. , Schober Wendy , McQueen Teresa J. , Cortes Jorge , Tanner Scott D. , Roboz Gail J. , Kantarjian Hagop M. , Kornblau Steven M. , Guzman Monica L. , Andreeff Michael , Konopleva Marina 
Published: January 2015

AbstractUnderstanding the unique phenotypes and complex signaling pathways of leukemia stem cells (LSCs) will provide insights and druggable targets that can be used to eradicate acute myeloid leukemia (AML). Current work on AML LSCs is limited by the number of parameters that conventional flow cytometry (FCM) can analyze because of cell autofluorescence and fluorescent dye spectral overlap. Single‐cell mass cytometry (CyTOF) substitutes rare earth elements for fluorophores to label antibodies, which allows measurements of up to 120 parameters in single cells without correction for spectral overlap. The aim of this study was the evaluation of intracellular signaling in antigen‐defined stem/progenitor cell subsets in primary AML. CyTOF and conventional FCM yielded comparable results on LSC phenotypes defined by CD45, CD34, CD38, CD123, and CD99. Intracellular phosphoprotein responses to ex vivo cell signaling inhibitors and cytokine stimulation were assessed in myeloid leukemia cell lines and one primary AML sample. CyTOF and conventional FCM results were confirmed by western blotting. In the primary AML sample, we investigated the cell responses to ex vivo stimulation with stem cell factor and BEZ235‐induced inhibition of PI3K and identified activation patterns in multiple PI3K downstream signaling pathways including p‐4EBP1, p‐AKT, and p‐S6, particularly in CD34+ subsets. We evaluated multiple signaling pathways in antigen‐defined subpopulations in primary AML cells with FLT3‐ITD mutations. The data demonstrated the heterogeneity of cell phenotype distribution and distinct patterns of signaling activation across AML samples and between AML and normal samples. The mTOR targets p‐4EBP1 and p‐S6 were exclusively found in FLT3‐ITD stem/progenitor cells, but not in their normal counterparts, suggesting both as novel targets in FLT3 mutated AML. Our data suggest that CyTOF can identify functional signaling pathways in antigen‐defined subpopulations in primary AML, which may provide a rationale for designing therapeutics targeting LSC‐enriched cell populations. © 2015 International Society for Advancement of Cytometry
Diagnosis of Short‐Circuit Faults in Stator Winding Inside Low‐Voltage Induction Motor Using Impulse Voltage Test
Authors: Nakamura Hisahide 
Published: January 2015

SUMMARYShort‐circuit faults in windings due to the deterioration of insulation is among the most common faults in motor drive systems. An easy and effective fault diagnosis method is urgently required to ensure highly reliable operation. This paper proposes a novel method for the diagnosis of short‐circuit faults in stator winding inside a low‐voltage induction motor without removing the rotor, by performing an impulse voltage test. As the rotor does not need to be removed from the motor in this novel diagnosis method, the method can be put to practical use. In this study, first, several impulse voltage tests are carried out on the stator windings of motors. Second, the values of two features that represent the characteristics corresponding to the condition of the motor are calculated, and it is found that the shape of the feature distribution does not depend on the rotor position but on the condition of the winding. Third, the distance between the feature distribution for the healthy motor and features obtained from a target motor is calculated. On the basis of this distance, the condition of the stator winding inside the induction motor is determined. The effectiveness of the proposed diagnosis method is verified by performing experiments that involve several motors with healthy and faulty windings.
Assisted Control of Step Passage Motion and Its Comfort Evaluation in Two‐Wheel Wheelchair Systems
Authors: Hirata Kazuya , Murakami Toshiyuki 
Published: January 2015

SUMMARYTwo‐wheel wheelchair systems have been attracting attention because their mobility is better than that of conventional four‐wheel wheelchair systems. However, two‐wheel wheelchair systems must achieve stabilization control in the presence of disturbances caused by modeling error or the road situation, since these systems are underactuated systems similar to the inverted pendulum. In this investigation, step passage motion in two‐wheel wheelchair systems is considered. A reaction torque observer was employed to estimate the pitch angular interaction torque and the pure external wheel disturbance. Repulsive compliance control was employed to determine the optimal pitch angle command to compensate for the center of gravity of the user and to assist the whole step passage motion. Experimental results are evaluated in terms of user comfort by utilizing the ISO 2631‐1 generalized index.
Experimental Study on Dependence of Bow‐Tie Trees on Nuclei
Authors: Kumazawa Takao , Morinaga Seiji 
Published: January 2015

SUMMARYBow‐tie trees (BTTs) generated by contaminants, for example, metal, amber (overcured resin), carbon, and voids in the insulators of XLPE (cross‐linked polyethylene) cables still remain a factor contributing to deterioration. In order to examine the influence of contaminants on the behavior of BTT generation, we performed several experiments using XLPE samples containing copper powder, finely divided overcured resin, or micro voids as BTT nuclei. As a result of the experiments, in spite of the great difference in the distribution of particle diameter, and the shape and permittivity of the nuclei, all samples containing copper powder or overcured resin showed a common dependence of the number of BTTs on the mean size of the BTT nuclei. Consequently, there is no fundamental difference in these nuclei. We consider that the lower limit of the nucleus size suitable for BTT generation is determined by the local electric field at the tip of the nuclei and its upper limit is determined by the extent of stagnation of ions around the nuclei. Moreover, we consider that the increase in the mean size of BTTs with the initial water content was caused by relaxation of the local electric field due to absorbed water in XLPE samples.
A Fast Outage Planning Method Focusing on Circuit Breakers Near Outage Facilities
Authors: Murakami Chihaya , Fujiwara Aya , Iwamoto Shinichi 
Published: January 2015

SUMMARYJapanese electric power utilities installed many electric power facilities to respond to increasing power demand in the era of high economic growth. However, these facilities have aged about 40 years and should be replaced in the near future. The utilities will now have to replace larger numbers of facilities at the same time because of the increase in the number of power facilities to be replaced. Therefore, outage planning should be made more efficient. However, creating an outage plan requires time and labor, because the plan must specify (1) the outage schedule, (2) the power system configuration during outage operations, and (3) the system switching of the power system in order to conduct the outage operations. To solve these problems, a fast outage planning method focusing on circuit breakers near the outage facilities is proposed in this paper. Simulations run on IEEJ subtransmission system model I confirm the validity of the proposed method.
Clinical profile and prognostic significance of natriuretic peptide trajectory following hospitalization for worsening chronic heart failure: findings from the ASTRONAUT trial
Authors: Greene Stephen J. , Maggioni Aldo P. , Fonarow Gregg C. , Solomon Scott D. , Böhm Michael , Kandra Albert , Prescott Margaret F. , Reimund Bernard , Hua Tsushung A. , Lesogor Anastasia , Zannad Faiez , Gheorghiade Mihai ,   for the ASTRONAUT Investigators and Coordinators
Published: January 2015

AimsThe purpose of this study was to determine the prognostic significance and associated clinical profile of early post‐discharge N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) trajectory among patients hospitalized for worsening chronic heart failure (HHF).Methods and resultsThis post‐hoc analysis of the Aliskiren Trial in Acute Heart Failure Outcomes (ASTRONAUT) included 1351 HHF patients with ejection fraction (EF) ≤40%, elevated B‐type natriuretic peptide ≥400 pg/mL or NT‐proBNP ≥1600 pg/mL at admission, and available NT‐proBNP measurements (from a central core laboratory) at baseline (median 5 days after admission) and 1‐month follow‐up. The co‐primary endpoints were all‐cause mortality and cardiovascular mortality or HHF within 12 months. Median follow‐up was 11.3 months. Patients with decreasing post‐discharge NT‐proBNP trajectory tended to be younger and have non‐ischaemic HF aetiology. The presence of baseline atrial fibrillation was associated with high NT‐proBNP at 1 month (i.e. above the median), regardless of the baseline value. After adjustment for patient characteristics and 1‐month NT‐proBNP level, every twofold increase in continuous NT‐proBNP change from baseline to 1 month was predictive of increased cardiovascular mortality or HHF (hazard ratio 1.14; 95% confidence interval 1.02–1.26), but not all‐cause mortality (hazard ratio 0.95; 95% confidence interval 0.81–1.11).ConclusionIn this cohort of HHF patients with reduced EF, early post‐discharge NT‐proBNP trajectory was associated with a distinct clinical profile and carried independent prognostic value after adjustment for patient characteristics and absolute NT‐proBNP level. Future prospective study of serial NT‐proBNP measurement during the hospital and early post‐discharge periods is warranted to validate these findings and evaluate post‐discharge NT‐proBNP trajectory as a therapeutic target.
Hydrolytic Stability and Hydrogen Peroxide Activation of Zirconium‐Based Oxoclusters
Authors: Faccioli Francesco , Bauer Matthias , Pedron Danilo , Sorarù Antonio , Carraro Mauro , Gross Silvia 
Published: January 2015

AbstractInvited for the cover of this issue are the groups of Silvia Gross (IENI‐CNR and University of Padova) and Mauro Carraro (University of Padova) in collaboration with Matthias Bauer (Paderborn University) and Danilo Pedron (University of Padova). The cover image shows the oxidation of organic sulfides by Zr‐based peroxides, obtained from the reaction of Zr oxoclusters with hydrogen peroxide
High Performance Liquid Chromatography/Electrochemistry/High Resolution Electrospray Ionization‐Mass Spectrometry (HPLC/EC/HR ESI‐MS) Characterization of Selected Cytokinins Oxidation Products
Authors: Karady Michal , Novák Ondřej , Horna Aleš , Strnad Miroslav , Doležal Karel 
Published: January 2015

AbstractElectrochemistry combined with mass spectrometry represents an emerging analytical technique used to study the oxidation pathway of various drugs and in vivo occurring compounds, continuously showing a capability to generate many known metabolites or new oxidation products. An on‐line HPLC/EC/HR ESI‐MS method had been used to investigate the oxidation of selected cytokinin compounds. This setup allowed rapid identification and general structure elucidation of the obtained products. An electrochemical oxidation of isopentenyladenine resulted in five products, including hydroxylated and dehydrogenated products, which correlates very well with its in vivo metabolism. Electrochemical conversion of trans‐zeatin revealed six products, with two dehydrogenation products corresponding to its in vivo occurring metabolites. cis‐Zeatin oxidation in the electrochemical cell gave rise to eight products, resembling similarity to trans‐zeatin oxidation. All three compounds underwent a complete turnover mainly through two oxidation reactions occurring in the electrochemical celldehydrogenation and a less typical aliphatic hydroxylation. The resulting products are in correlation with their known in vivo metabolism.
Coating on Zinc Surface to Improve the Electrochemical Behavior of Zinc Anodes for Zinc‐Air Fuel Cells
Authors: Kim Hong Shin , Jo Yong Nam , Lee Won Jong , Kim Ki Jae , Lee Chang Woo 
Published: January 2015

AbstractThe corrosion of Zn anode, associated with corrosion current and hydrogen evolution reaction, is a major reason for capacity loss and safety problems. As a way of improving the current issue, a newly coating method using difference of melting points has been attempted to synthesize anode materials and found to be highly effective. Effects of corrosion inhibitors are also investigated by diverse electrochemical techniques. The Tafel extrapolation shows the reduced corrosion current compared with that of pure Zn. ZnNi‐2 (Zn:Ni, 95 : 5 wt.%) demonstrates the hydrogen overpotential is shifted to the most negative value as −1.7 V vs. Hg/HgO.
A Novel Label‐Free Immunosensor Based on Activated Graphene Oxide for Acetaminophen Detection
Authors: Tertiş Mihaela , Hosu Oana , Fritea Luminiţa , Farcau Cosmin , Cernat Andreea , Săndulescu Robert , Cristea Cecilia 
Published: January 2015

AbstractA simple label‐free immunosensor for the selective detection of acetaminophen was developed by modifying a graphite based screen‐printed electrode with graphene oxide after the functionalization with N‐hydroxysuccinimide in the presence of 1‐ethyl‐3‐(3‐dimethyl aminopropyl) carbodiimide hydrochloride. The template made by layer‐by‐layer technique provides activated carboxylic groups, which form amidic covalent bonds with the terminal amine groups from the antiacetaminophen antibody. The optimization of antibody immobilization and the blocking of the free active groups from graphene template with bovine serum albumin was performed by using electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry. The electrochemical quartz crystal microbalance technique was used to determine the quantity of different components deposited onto the electrode surface during the optimization steps. The above described immunosensor was applied with good results for the determination of acetaminophen in synthetic and real samples by using square wave voltammetry. A limit of detection of 0.17 µM (S/N=3) was obtained with no or minimal interference of dosage forms excipients and serum components.