bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using Aqueous Ammonia in Hydroaminomethylation Reactions: Ruthenium‐Catalyzed Synthesis of Tertiary Amines
Authors: Wu Lipeng , Fleischer Ivana , Zhang Min , Liu Qiang , Franke Robert , Jackstell Ralf , Beller Matthias 
Published: September 2014

AbstractThe direct synthesis of tertiary amines from ammonia and olefins is presented. Using a combination of Ru3(CO)12 and 2‐phosphino‐substituted imidazole ligand as catalyst system allows for hydroaminomethylation reactions of bulk aliphatic and functionalized olefins. Tertiary amines are obtained in an atom‐efficient domino process in moderate to good isolated yields (45–76 %) with excellent regioselectivities (n/iso up to 99:1).
Comparison of volatile compounds of hot‐pressed, cold‐pressed and solvent‐extracted flaxseed oils analyzed by SPME‐GC/MS combined with electronic nose: Major volatiles can be used as markers to distinguish differently processed oils
Authors: Wei Chang Q. , Liu Wen Y. , Xi Wan P. , Cao Dong , Zhang Hui J. , Ding Ming , Chen Lu , Xu Ya Y. , Huang Ke X. 
Published: September 2014

AbstractAnalysis of volatile profiles from differently processed flaxseed oils (FSO) was performed by SPME‐GC‐MS, electronic nose (E‐nose) and descriptive sensory analysis. A total of 61 volatiles were tentatively identified and then quantified. Among these components, 51 volatiles were obtained from the hot‐pressed FSO, 47 from cold‐pressed FSO, and 40 by solvent extraction. Principal component analysis (PCA) demonstrated that three FSO samples tested resulted in significant differences of three treatments (p<0.05) and the marker compounds that contributed to discrimination of different processed FSO were hexanal, (E, E)‐2, 4‐pentadienal, (E, E)‐2, 4‐heptadienal, 6‐hydroxy‐2‐hexanone, 1‐hexanol, methyl‐pyrazine, nonanal, 2,3‐pentanedione, 1‐butanol, acetic acid, hexanoic acid, and ethyl acetate. In addition, there was good consistency among GS‐MS, sensory evaluation and E‐nose analysis results. These results indicated that the process method has a significant effect on the aroma quality of FSO and may be helpful in evaluating aroma quality and the detection of frauds.Practical applications: The results showed that the major volatile components could be used as chemical markers to distinguish differently processed FSOs by the chemometric method. There was good consistency among GS‐MS, sensory evaluation and E‐nose analysis results, suggesting that E‐nose technique combined with a PCA of the data provided by the sensor arrays has the good potential to evaluate FSO quality and the detection of frauds.Sixty‐one volatiles were identified and significant differences were found in different processed flaxseed oils. Twelve major volatile compounds contributed to discrimination of different processed flaxseed oils. Flaxseed oil samples were distinguished from each other through PCA of E‐nose data, suggesting that the E‐nose can successfully discriminate different processed flaxseed oils.
Addition–Elimination versus Direct Substitution Mechanisms for Arene Chlorination
Authors: Galabov Boris , Koleva Gergana , Kong Jing , Schaefer Henry F. , v. R. Schleyer Paul 
Published: September 2014

AbstractTheoretical modelling of the chlorination of arenes (benzene, toluene and naphthalene) in a nonpolar solvent (CCl4) at the B3LYP‐D3/6‐311+G(2d,2p) level reveals two alternative reaction pathways, namely, direct substitution and addition–elimination, both of which lead to the same substitution products. The closeness of their barriers indicates competition between these alternative routes. Neither of these mechanistic pathways includes a σ‐complex intermediate, which is traditionally believed to be a key feature of electrophilic aromatic substitution (SEAr) mechanisms. Instead, the direct substitution pathway involves a single concerted transition state following the barrierless formation of a π‐complex between the reactants. The reported catalytic effect of HCl catalysis on the reaction product is modelled systematically and considerably decreases the transition‐state energies. The computed reaction barriers are in excellent accord with the experimentally established reactivity trends for the arenes investigated.
Determination of α‐Lipoic acid on a Pyrolytic Graphite Electrode Modified with Cobalt Phthalocyanine
Authors: Ferreira Ana Paula M. , dos Santos Pereira Laise N. , da Silva Iranaldo Santos , Tanaka Sônia M. C. N. , Tanaka Auro A. , Angnes Lúcio 
Published: September 2014

AbstractIn this work voltammetric techniques were explored for quantification of α‐Lipoic acid (ALA) using a pyrolytic graphite electrode modified with cobalt phthalocyanine. Cyclic voltammograms recorded in phosphate buffer solution containing 1×10−3 mol L−1 of ALA presented an oxidation peak located at +0.8 V vs. SCE. The modification of the electrode produced a 100 mV shift of the onset oxidation potential to less positive value and a substantial increase in the ALA oxidation current. Among the voltammetric techniques explored, differential pulse voltammetry showed the best performance for quantifications of the analyte in low concentrations. Limits of detection and quantification of ALA obtained corresponds to 3.4×10−9 mol L−1 and 1.2×10−8 mol L−1, respectively.
Experimental studies on the effect of fire accelerants during living room fires and detection of ignitable liquids in fire debris
Authors: Krüger Simone , Deubel Jan H. , Werrel Martin , Fettig Ina , Raspe Tina 
Published: September 2014

SummaryReconstructing the course of a fire and performing chemical analysis of ignitable liquids in fire debris is an important tool to conduct fire investigations in suspected arson cases. Here, a total of five fire tests has been performed to investigate the effect of fire accelerants on the fire development of a room fire and to prove the capability of analytical methods. Different experimental scenarios have been realized (no accelerant, accelerant applied at different positions, and different amounts of fire accelerant). Each test room was equipped with an identical set of living room furnishing. The location and amount of the fire accelerant applied löschen varied in four of five tests. One experiment was carried out without fire accelerant. Fire quantities such as mass loss (of the entire room), gas temperatures (at several locations in the room), and heat release were determined during the experiments, and chemical‐analytical studies were carried out. A headspace solid phase micro extraction procedure, using gas chromatography–mass spectrometry, was used to analyze fire debris samples to potentially detect ignitable liquids. Beside the analysis of fire debris samples, swipe soot samples were analyzed and the detectability of the fire accelerant used was demonstrated. Results show that it is possible to provide evidence of ignitable liquids in soot samples collected from walls. This allows an additional sampling strategy at potential crime scenes, besides taking fire debris samples. Copyright © 2014 John Wiley & Sons, Ltd.
Forecasting Death Rates Using Exogenous Determinants
Authors: French Declan , O'Hare Colin 
Published: September 2014

ABSTRACTMortality models used for forecasting are predominantly based on the statistical properties of time series and do not generally incorporate an understanding of the forces driving secular trends. This paper addresses three research questions: Can the factors found in stochastic mortality‐forecasting models be associated with real‐world trends in health‐related variables? Does inclusion of health‐related factors in models improve forecasts? Do resulting models give better forecasts than existing stochastic mortality models? We consider whether the space spanned by the latent factor structure in mortality data can be adequately described by developments in gross domestic product, health expenditure and lifestyle‐related risk factors using statistical techniques developed in macroeconomics and finance. These covariates are then shown to improve forecasts when incorporated into a Bayesian hierarchical model. Results are comparable or better than benchmark stochastic mortality models. Copyright © 2014 John Wiley & Sons, Ltd.
Proton Exchange Membrane Fuel Cell Operation and Degradation in Short‐Circuit
Authors: Silva R. E. , Harel F. , Jemeï S. , Gouriveau R. , Hissel D. , Boulon L. , Agbossou K. 
Published: September 2014

AbstractHybridization of proton exchange membrane fuel cells (PEMFC) and ultra capacitors (UC) are considered as an alternative way to implement high autonomy, high dynamic, and reversible energy sources. PEMFC allow high efficiency and high autonomy, however their dynamic response is limited and this source does not allow recovering energy. UC appears to be a complementary source to fuel cell systems (FCS) due to their high power density, fast dynamics, and reversibility. A direct hybridization of these sources could allow reducing the number of power converters and then the total cost of the hybridized system. Simulations show the behavior of the hybrid source when the fuel cell and ultra capacitors are interconnected and the natural energy management when a charge is connected. The results show that the magnitude of the transient current supplied by the fuel cell to charge the UC can be much higher than its nominal value. An experimental setup is implemented to study the effects of these high currents in a PEMFC. This is done by imposing a controlled short‐circuit between the electrodes. The PEMFC degradation is quantified by using electrochemical impedance spectroscopy.
SAXS Analysis of Catalyst Degradation in High Temperature PEM Fuel Cells Subjected to Accelerated Ageing Tests
Authors: Valle F. , Zuliani N. , Marmiroli B. , Amenitsch H. , Taccani R. 
Published: September 2014

AbstractThe loss in performance during fuel cell operation is one of the critical factors that hamper fuel cells commercialization. This paper presents a research activity related to high temperature polymer electrode membrane fuel cell (HT‐PEMFC) degradation. The aim of the study is to investigate catalyst degradation of membrane electrode assemblies (MEAs) subjected to load cycles. Two HT‐PEM MEAs have been subjected to accelerated ageing tests based on load cycling. The cycles profile has been chosen in order to enhance catalyst degradation. Both the tests show a fuel cell performance loss lower than 30 mV after 100,000 cycles at 600 mA cm−2. In order to analyze the catalyst evolution, synchrotron small angle X‐ray scattering (SAXS) has been employed. The catalyst degradation of the two conditioned samples has been compared with the data obtained from a new MEA that has been used as reference sample. The SAXS results showed a mean size increase of the platinum nanoparticles up to the 100%.
Effects of PH3 and CH3Cl Contaminants on the Performance of Solid Oxide Fuel Cells
Authors: Li T. S. , Gao C. , Xu M. , Li B. , Wu M. , Wang W. G. 
Published: September 2014

AbstractSolid oxide fuel cells (SOFCs) have been considered as one of the most efficient power generators that can directly convert chemical energy in the natural gas, biomass, or coal‐derived gas to electrical energy. Various contaminants in syngas are capable to cause catalyst malfunction and cell performance drop, limiting fuel cell to a wide application. The effects of PH3 and CH3Cl fuel impurities on the electrochemical performance of SOFCs are investigated at various testing conditions. Performance drop caused by the addition of 10 ppm PH3 remains identical in pure hydrogen and simulated coal‐derived syngas at 750 °C, but a slight increase is observed when the cells are fueled syngas at 850 °C. The presence of CH3Cl in syngas causes cell degradation to a larger extent at 850 °C. Moreover, the cooperative influences of PH3 and CH3Cl impurities in hydrogen are also studied at 750, 800, and 850 °C. The addition of CH3Cl can stop and remove PH3 poisoning behavior, which is associated with each contaminant concentrations and operational temperatures. The related mechanism has been deeply analyzed and diagnosed.
Co‐synthesis of Sm0.5Sr0.5CoO3‐Sm0.2Ce0.8O1.9 Composite Cathode with Enhanced Electrochemical Property for Intermediate Temperature SOFCs
Authors: Jiang W. , Wei B. , Lü Z. , Wang Z. H. , Zhu X. B. , Zhu L. 
Published: September 2014

AbstractA 70 wt.% Sm0.5Sr0.5CoO3 – 30 wt.% Sm0.2Ce0.8O1.9 (SSC–SDC73) composite cathode was co‐synthesized by a facile one‐step sol–gel method, which showed lower polarization resistance and overpotential than those of physically mixed SSC–SDC73 cathode. The polarization resistance of co‐synthesized SSC–SDC73 cathode at 800 °C was as low as 0.03 Ω cm2 in air. Scanning electron microscopy (SEM) images showed that the enhanced electrochemical property was mainly attributed to the smaller grains and good dispersion of SSC and SDC phases within the composite cathode, leading to an increase in three‐phase boundary length. The dependence of polarization resistance with oxygen partial pressure indicated that the rate‐limiting step for oxygen reduction reaction was the dissociation of molecular oxygen to atomic oxygen process. An anode supported fuel cell with a co‐synthesized SSC–SDC73 cathode exhibited a peak power density of 924 mW cm−2 at 800 °C. Our results suggested that co‐synthesized composite was a promising cathode for intermediate temperature solid oxide fuel cells (IT‐SOFCs).
Interfacial Stability between Air Electrode and Ceria‐Based Electrolyte under Cathodic Polarization in Solid Oxide Fuel Cells
Authors: Matsui T. , Komoto M. , Muroyama H. , Eguchi K. 
Published: September 2014

AbstractThe stability of interfacial structure between air electrode and ceria‐based electrolyte (Sm2O3–CeO2, SDC) was evaluated under various polarization conditions at 1,000 °C. This is because the structural change at the interface is strongly related to the diffusion of constituent elements and has the potential to affect the long‐term stability. In this study, (La,Sr)MnO3 (LSM) and (La,Sr)(Co,Fe)O3 (LSCF) were applied as air electrodes. The cell with LSM/SDC interface showed the performance enhancement after cathodic polarization for 5 h, accompanied with the change in interfacial structure. The magnitude of the microstructural change as well as activation was dependent on the current density and the oxygen partial pressure. However, the active triple phase boundary (TPB)‐length decreased at every condition studied. On the other hand, no appreciable change in interfacial structure was confirmed for the LSCF/SDC system regardless of polarization conditions. In response to this phenomenon, the total TPB‐length was almost identical to the active one. The difference in morphological evolution at the interface depending on the electrode material was discussed.
Curvature Reversal and Residual Stress in Solid Oxide Fuel Cell Induced by Chemical Shrinkage and Expansion
Authors: Xiang Z. , Haibo S. , Fenghui W. , Kang L. , Jianye H. 
Published: September 2014

AbstractStructural stability of layered functional ceramic composites is challenged by curvature effects and residual stresses caused by the thermal mismatch and chemical strains. In this study, a phenomenon of curvature reversal is found in the half‐cell structure of solid oxide fuel cell (SOFC) during the reduction of the half‐cell from NiO‐YSZ to Ni‐YSZ. An analytical model is derived to study the curvature and residual stress caused by the chemical shrinkage and expansion of anode. With reducing to Ni‐YSZ, the curvature of the half‐cell changes from the initial direction to an opposite direction, then back to the initial direction. This curvature reversal is inevitable during reduction while the thickness ratio of electrolyte to anode is between 0 and 0.102. The residual stress in electrolyte, calculated by the analytical model, is well agreement with the experiment result using X‐ray stress analysis. The YSZ layer is always subjected to compressive stress in despite of curvature reversal existing in half‐cell. It is impossible to get the residual stress by measuring the curvature unless the half‐cell was reduced completely.
The Research and Design of A Land Reclamation Supervisory Information System in A Mining Area
Authors: Guo Xiaozhong , Pan Jian , Wu Ganguo , Xue Fanxiu , Lu Yuanqing 
Published: September 2014

AbstractUsing an overall document data comprehensive analysis system and a structure analysis, this study preliminarily classified technical indicators, structured the regulatory index database on construction of land reclamation, and explicated the information operation process and main content of land reclamation. From the perspective of module design, this article describes the most significant details about information query and release process, engineering construction quality monitoring and control, the land reclamation engineering acceptance process, and post‐project evaluation. From the perspective of user management, this article details the most significant features of the operation flow for the department of land and resources management, land reclamation obligations, and system management supervisors. Using the technology of Struts, Spring, and Hibernate, this article develops and designs the Land Reclamation Supervision Information System Alpha (LRSIS Alpha Version) and tests the interface and path, function, and performance of the system. Copyright © 2014 John Wiley & Sons, Ltd.
Optimized demineralization of human cancellous bone by application of a vacuum
Authors: Eagle Mark J. , Rooney Paul , Kearney John N. 
Published: September 2014

AbstractHuman demineralized bone matrix derived from cortical bone is used by surgeons due to its ability to promote bone formation. There is also a need for shaped demineralized bone matrices made from cancellous bone, where the properties of the material allow its insertion into defects, therefore acting as a void filler and scaffold onto which new bone can form. In this study, we report that demineralized bone sponges were prepared by dissecting and cutting knee bone into cancellous bone cubes of 1 cm3. These cubes were then taken through a series of warm water washes, some with sonication, centrifugation, and two decontamination chemical washes. The cubes were optimally demineralized into sponges with 0.5N hydrochloric acid under vacuum with constant pH measurement. Demineralization was confirmed by quantitative measurement of calcium and qualitatively by compression. The sponges were freeze dried before terminal sterilisation with a target dose of 25 kGy gamma radiation whilst frozen. Samples of the sponges were histologically examined for calcium and collagen and also tested for osteoinductivity. Data showed well defined collagen staining in the sponges, with little residual calcium. Sponges from two out of three donors demonstrated osteoinductivity when implanted into the muscle of an athymic mouse. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1023–1029, 2015.
WNT5A Has Anti-Prostate Cancer Effects In Vitro and Reduces Tumor Growth in the Skeleton In Vivo
Authors: Thiele Stefanie , Göbel Andy , Rachner Tilman D , Fuessel Susanne , Froehner Michael , Muders Michael H , Baretton Gustavo B , Bernhardt Ricardo , Jakob Franz , Glüer Claus C , Bornhäuser Martin , Rauner Martina , Hofbauer Lorenz C 
Published: September 2014

ABSTRACT

Prostate cancer is the most frequent malignancy in men, and a major cause of prostate cancer–related death is attributable to bone metastases. WNT5A is known to influence the clinical outcome of various cancer types, including prostate cancer, but the exact mechanisms remain unknown. The goal of this study was to assess the relevance of WNT5A for the development and progression of prostate cancer. WNT5A expression was determined in a cDNA and tissue microarray of primary tumor samples in well-defined cohorts of patients with prostate cancer. Compared with benign prostate tissue, the expression of WNT5A and its receptor Frizzled-5 was higher in prostate cancer, and patients with a WNT5A expression above the median had a higher probability of survival after 10 years. Using different osteotropic human prostate cancer cell lines, the influence of WNT5A overexpression and knock-down on proliferation, migration, and apoptosis was assessed. In vitro, WNT5A overexpression induced prostate cancer cell apoptosis and reduced proliferation and migration, whereas WNT5A knock-down showed opposite effects. In vivo, different xenograft models were used to determine the effects of WNT5A on tumor growth. Local tumor growth and tumor growth in the bone microenvironment was considerably diminished after WNT5A overexpression in PC3 cells. WNT5A exhibits antitumor effects in prostate cancer cells and may be suitable as a prognostic marker and therapeutic target for prostate cancer and associated skeletal metastases. © 2014 American Society for Bone and Mineral Research.
Iodine vapor staining for atomic number contrast in backscattered electron and X‐ray imaging
Authors: Boyde Alan , Mccorkell Fergus A. , Taylor Graham K. , Bomphrey Richard J. , Doube Michael 
Published: September 2014

ABSTRACTIodine imparts strong contrast to objects imaged with electrons and X‐rays due to its high atomic number (53), and is widely used in liquid form as a microscopic stain and clinical contrast agent. We have developed a simple technique which exploits elemental iodine's sublimation‐deposition state‐change equilibrium to vapor stain specimens with iodine gas. Specimens are enclosed in a gas‐tight container along with a small mass of solid I2. The bottle is left at ambient laboratory conditions while staining proceeds until empirically determined completion (typically days to weeks). We demonstrate the utility of iodine vapor staining by applying it to resin‐embedded tissue blocks and whole locusts and imaging them with backscattered electron scanning electron microscopy (BSE SEM) or X‐ray microtomography (XMT). Contrast is comparable to that achieved with liquid staining but without the consequent tissue shrinkage, stain pooling, or uneven coverage artefacts associated with immersing the specimen in iodine solutions. Unmineralized tissue histology can be read in BSE SEM images with good discrimination between tissue components. Organs within the locust head are readily distinguished in XMT images with particularly useful contrast in the chitin exoskeleton, muscle and nerves. Here, we have used iodine vapor staining for two imaging modalities in frequent use in our laboratories and on the specimen types with which we work. It is likely to be equally convenient for a wide range of specimens, and for other modalities which generate contrast from electron‐ and photon‐sample interactions, such as transmission electron microscopy and light microscopy. Microsc. Res. Tech. 77:1044–1051, 2014. © 2014 The Authors. Microscopy Research Technique published by Wiley Periodocals, Inc.
Determination of sedative hypnotics in sewage sludge by pressurized liquid extraction with high‐performance liquid chromatography and tandem mass spectrometry
Authors: Arbeláez Paula , Granados Judith , Borrull Francesc , Marcé Rosa Maria , Pocurull Eva 
Published: September 2014

This paper describes a method for the determination of eight sedative hypnotics (benzodiazepines and barbiturates) in sewage sludge using pressurized liquid extraction and liquid chromatography with tandem mass spectrometry. Pressurized liquid extraction operating conditions were optimized and maximum recoveries were reached using methanol under the following operational conditions: 100ºC, 1500 psi, extraction time of 5 min, one extraction cycle, flush volume of 60% and purge time of 120 s. Pressurized liquid extraction recoveries were higher than 88% for all the compounds except for carbamazepine (55%). The repeatability and reproducibility between days, expressed as relative standard deviation (n = 5), were lower than 6 and 10%, respectively. The detection limits for all compounds were lower than 12.5 μg/kg of dry weight. The method was applied to determine benzodiazepines and barbiturates in sewage sludge from urban sewage treatment plants, and carbamazepine showed the highest concentration (7.9–18.9 μg/kg dry weight).