bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic detection and characterization of biogenic magnetic minerals: A comparison of ferromagnetic resonance and first‐order reversal curve diagrams
Authors: Chang Liao , Roberts Andrew P. , Winklhofer Michael , Heslop David , Dekkers Mark J. , Krijgsman Wout , Fitz Gerald John D. , Smith Paul 
Published: July 2014

AbstractBiogenic magnetic minerals produced by magnetotactic bacteria occur ubiquitously in natural aquatic environments. Their identification and characterization are important for interpretation of paleomagnetic and environmental magnetic records. We compare two magnetic methods for their identification and characterization in a diverse set of sedimentary environments: ferromagnetic resonance (FMR) spectroscopy and first‐order reversal curve (FORC) diagrams, constrained by transmission electron microscope observations. The advantages and limitations of each method are evaluated. FMR analysis provides a strong diagnostic indicator because of its ability to detect the strong shape anisotropy that arises from the biogenic chain architecture, but it can be obscured in mixed magnetic mineral assemblages. We develop a new FMR fitting approach that enables separation and characterization of biogenic components in natural samples. FMR spectral fitting on magnetofossil‐bearing samples does not always reveal a strong signature of biogenic magnetite with <111>‐aligned chains, in contrast to whole magnetotactic bacteria cells. This indicates that strictly <111>‐aligned chains are not as common in magnetofossil assemblages, due to either chain collapse or different crystallographic axis orientations. FORC analysis provides an excellent tool for isolating the biogenic component as a “central ridge” signature with peak switching field distribution between ~20 and 60 mT. We also analyzed tuff samples with similar FMR characteristics to biogenic magnetite chains, which can cause ambiguity. We propose a magnetic protocol to improve the robustness and efficiency of biogenic magnetite identification and past microbial activity in a wide range of environments.
Predictability of hydraulic head changes and characterization of aquifer‐system and fault properties from InSAR‐derived ground deformation
Authors: Chaussard E. , Bürgmann R. , Shirzaei M. , Fielding E. J. , Baker B. 
Published: July 2014

AbstractWe evaluate the benefits of space‐derived ground deformation measurements for basin‐wide characterization of aquifer‐system properties and groundwater levels. We use Interferometric Synthetic Aperture Radar (InSAR) time series analysis of ERS, Envisat, and ALOS SAR data to resolve 1992–2011 ground deformation in the Santa Clara Valley, California. T‐mode principal component analysis successfully isolates temporally variable deformation patterns embedded in the multidecadal time series. The data reveal uplift at 0.4 cm/yr between 1992 and 2000 and < 0.1 cm/yr during 2000–2011, illustrating the end of the aquifer‐system's poroelastic rebound following recovery of hydraulic heads after the 1960s low stand. In addition, seasonal elastic deformation with amplitude of up to 3 cm, in phase with head fluctuations, is observed over the confined aquifer sharply partitioned by the Quaternary Silver Creek Fault (SCF). Integration of this deformation with hydraulic head data enables characterization of the aquifer‐system storativity and elastic skeletal specific storage. Modeling of the deformation partitioning across the SCF constrains the fault's last tectonic activity, hydraulic conductivity, and material composition. The SCF likely cuts the shallow confining clays and was last active since ~140 ka, it has a horizontal hydraulic conductivity several orders of magnitude lower than the surrounding aquifer‐system, and is likely composed of clays, making it an effective barrier to across‐fault fluid flow. Finally, we show that after a period of calibration, InSAR can be used to characterize basin‐wide water level changes without well measurements with an accuracy of 70%, which demonstrates that it provides useful data for groundwater management.
Investigation of the causes of historical changes in the subsurface salinity minimum of the South Atlantic
Authors: Goes Marlos , Wainer Ilana , Signorelli Natalia 
Published: July 2014

AbstractIn this study, we investigate the subsurface salinity changes on decadal timescales across the subtropical South Atlantic Ocean using two ocean reanalysis products, the latest version of the Simple Ocean Data Assimilation and the Estimating the Circulation and Climate of the Ocean, Phase II, as well as using additional climate model experiments. Results show that there is a recent significant salinity increase at the core of the salinity minimum at intermediate levels. The main underlying mechanism for this subsurface salinity increase is the lateral advective (gyre) changes due to the Southern Annular Mode variability, which conditions an increased contribution from the Indian Ocean high salinity waters into the Atlantic. The global warming signal has a secondary but complementary contribution. Latitudinal differences at intermediate depth in response to large‐scale forcing are in part caused by local variation of westward propagation features, and by compensating contributions of salinity and temperature to density changes.
Predicting hygroscopic growth using single particle chemical composition estimates
Authors: Healy Robert M. , Evans Greg J. , Murphy Michael , Jurányi Zsófia , Tritscher Torsten , Laborde Marie , Weingartner Ernest , Gysel Martin , Poulain Laurent , Kamilli Katharina A. , Wiedensohler Alfred , O'Connor Ian P. , McGillicuddy Eoin , Sodeau John R. , Wenger John C. 
Published: July 2014

AbstractSingle particle mass spectral data, collected in Paris, France, have been used to predict hygroscopic growth at the single particle level. The mass fractions of black carbon, organic aerosol, ammonium, nitrate, and sulphate present in each particle were estimated using a combination of single particle mass spectrometer and bulk aerosol chemical composition measurements. The Zdanovskii‐Stokes‐Robinson (ZSR) approach was then applied to predict hygroscopic growth factors based on these mass fraction estimates. Smaller particles with high black carbon mass fractions and low inorganic ion mass fractions exhibited the lowest predicted growth factors, while larger particles with high inorganic ion mass fractions exhibited the highest growth factors. Growth factors were calculated for subsaturated relative humidity (90%) to enable comparison with hygroscopic tandem differential mobility analyzer measurements. Mean predicted and measured hygroscopic growth factors for 110, 165, and 265 nm particles were found to agree within 6%. Single particle‐based ZSR hygroscopicity estimates offer an advantage over bulk aerosol composition‐based hygroscopicity estimates by providing additional chemical mixing state information. External mixing can be determined for particles of a given diameter through examination of the predicted hygroscopic growth factor distributions. Using this approach, 110 nm and 265 nm particles were found to be predominantly internally mixed; however, external mixing of 165 nm particles was observed periodically when thinly coated and thickly coated black carbon particles were simultaneously detected. Single particle‐resolved chemical information will be useful for modeling efforts aimed at constraining cloud condensation nuclei activity and hygroscopic growth.
Thermal and Mechanical Properties of Natural Rubber Composites Reinforced with Cellulose Nanocrystals from Southern Pine
Authors: Zhang Chunmei , Dan Yi , Peng Jun , Turng Lih‐Sheng , Sabo Ronald , Clemons Craig 
Published: July 2014

ABSTRACTThere is currently a considerable interest in developing bio‐based and green nanocomposites in industrial and technological areas owing to their biodegradability, biocompatibility, and environmental friendliness. In this study, a bio‐based nanosized material, cellulose nanocrystals (CNC), extracted from southern pine pulp was employed as a reinforcing agent in a natural rubber (NR) matrix. NR/CNC nanocomposites were prepared by a solution mixing and casting method. The morphology, thermal, and mechanical properties of the nanocomposites were investigated using scanning electron microscopy, Fourier transform‐infrared spectroscopy, tensile tests, dynamic mechanical analysis, thermal gravimetric analysis, and differential scanning calorimetry. The CNC displayed a gradient dispersion in the nanocomposites, and no microscaled aggregates were observed. Both the tensile strength and modulus of the nanocomposites increased with the addition of CNC, accompanied by a slight decrease in elongation at break. The storage modulus also improved with the addition of CNC, which served as good evidence of the reinforcing tendency of CNC in the NR matrix. The thermal stability of the nanocomposites showed an insignificant decrease in CNC addition. The glass transition temperature of the nanocomposites was not influenced by CNC.
Function of CH2 Addends on 54π Fullerene Acceptors
Authors: Chen Shan , Xiao Zuo , He Dan , Ma Lina , Ding Liming 
Published: July 2014

AbstractThree structurally analogous 54π fullerene acceptors, tris‐o‐quinodimethane‐C60 (tris‐OQC), bis‐o‐quinodimethanemethano[60]fullerene (bis‐OQMF), and o‐quinodimethane‐bis‐methano[60]fullerene (OQBMF), were systematically investigated. As o‐quinodimethane addends on C60 are replaced stepwise by methylene groups (CH2), the electron mobility of fullerene, the crystallinity of poly(3‐hexylthiophene), and the morphology of the active layer of solar cells were simultaneously improved while bimolecular recombination in the active layer was reduced, leading to a remarkable enhancement in power conversion efficiency.
Periostin and receptor activator of nuclear factor κ‐B ligand expression in allergic fungal rhinosinusitis
Authors: Laury Adrienne M. , Hilgarth Roland , Nusrat Asma , Wise Sarah K. 
Published: July 2014

BackgroundAllergic fungal rhinosinusitis (AFRS) is a disease demonstrating substantial eosinophilic inflammation and characteristic radiographic bony erosion/expansion. Periostin is an extracellular matrix protein associated with eosinophil accumulation in eosinophilic esophagitis, allergic asthma mucus production, and chronic rhinosinusitis (CRS) polyp formation. Receptor activator of nuclear factor κ‐B ligand (RANKL) is an osteoclast activator present in osteoporosis and periodontal disease. We sought to evaluate periostin and RANKL expression in AFRS and correlate these levels with radiographic scales of disease severity.MethodsThirty sinus tissue specimens were intraoperatively collected from 3 patient groups: AFRS; CRS without nasal polyps (CRSsNP); and controls (n = 10 per group). Specimens were analyzed by semiquantitative reverse‐transcription polymerase chain reaction (sq‐RT‐PCR) and immunofluorescence (IF) labeling/confocal microscopy for the presence of both periostin and RANKL. Immunofluorescence staining intensity was quantified by pixel density analysis. Preoperative computed tomography (CT) scans from each patient were scored using both the Lund‐Mackay and CT bone erosion scoring systems.ResultsPeriostin was significantly elevated in AFRS sinus tissue compared to CRSsNP and controls, as demonstrated by IF (p < 0.001) and PCR (p = 0.011). RANKL was not detected in sinus tissue by IF or PCR. Periostin levels positively correlated with radiographic indices of disease severity for both soft tissue and bone, using Lund‐Mackay (r = 0.926 [PCR] and r = 0.581 [IF]) and CT bone erosion (r = 0.672 [PCR] and r = 0.616 [IF]) scoring systems, respectively.ConclusionPeriostin is increased in AFRS tissue compared to CRSsNP and controls. Periostin levels positively correlate with radiologic disease severity scores. The increased levels of periostin in AFRS are possibly tied to its intense eosinophilic inflammatory etiology.
Perturbation of Spin Crossover Behavior by Covalent Post‐Synthetic Modification of a Porous Metal–Organic Framework
Authors: Clements John E. , Price Jason R. , Neville Suzanne M. , Kepert Cameron J. 
Published: July 2014

AbstractCovalent post‐synthetic modification is a versatile method for gaining high‐level synthetic control over functionality within porous metal–organic frameworks and for generating new materials not accessible through one‐step framework syntheses. Here we apply this topotactic synthetic approach to a porous spin crossover framework and show through detailed comparison of the structures and properties of the as‐synthesised and covalently modified phases that the modification reaction proceeds quantitatively by a thermally activated single‐crystal‐to‐single‐crystal transformation to yield a material with lowered spin‐switching temperature, decreased lattice cooperativity, and altered color. Structure–function relationships to emerge from this comparison show that the approach provides a new route for tuning spin crossover through control over both outer‐sphere and steric interactions.
Durch ein N‐heterocyclisches Carben koordinierte neutrale und kationische schwere Cyclopropylidenanaloga
Authors: Jana Anukul , Omlor Isabell , Huch Volker , Rzepa Henry S. , Scheschkewitz David 
Published: July 2014

AbstractCyclopropyliden ist ein kurzlebiges Zwischenprodukt der Allen‐Propin‐Cyclopropen‐Isomerisierung. Der Einbau schwerer Gruppe‐14‐Elemente in das Cyclopropyliden‐Grundgerüst war bisher auf den formalen Austausch des Carbenkohlenstoffatoms durch ein einzelnes basenstabilisiertes Silicium(II)‐Zentrum beschränkt. Hier berichten wir über die Synthese und Charakterisierung von NHC‐koordinierten schweren Cyclopropylidenanaloga (Si2GeR3X und Si3R3Br; X=Cl, Mesityl; R=Tip=2,4,6‐iPr3C6H2), bei denen der Dreiring ausschließlich aus Silicium und Germanium besteht. Im Falle des chlorsubstituierten Si2Ge‐Analogons wird durch eine NHC‐induzierte Chloridabspaltung ein stabiles, schweres, kationisches Cycloprop‐1‐yl‐2‐ylidenanalogon erhalten.
Silicone membranes to inhibit water uptake into thermoset polyurethane shape‐memory polymer conductive composites
Authors: Yu Ya‐Jen , Infanger Stephen , Grunlan Melissa A. , Maitland Duncan J. 
Published: July 2014

ABSTRACTElectroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature (Tg) resulting in shape recovery in vivo. While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo. In this study, a silicone membrane was used to inhibit water uptake into a thermoset SMP composite containing conductive filler. Thermoset polyurethane SMPs were loaded with either 5 wt % carbon black or 5 wt % carbon nanotubes, and subsequently coated with either an Al2O3‐ or silica‐filled silicone membrane. It was observed that the silicone membranes, particularly the silica‐filled membrane, reduced the rate of water absorption (37°C) and subsequent Tg depression versus uncoated composites. In turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41226.
Ferroelectric nanodot formation from spin‐coated poly(vinylidene fluoride‐co‐trifluoroethylene) films and their application to organic solar cells
Authors: Choi Yoon‐Young , Kwak Kyungwon , Seo Ji‐Won , Park Moonkyu , Paik Haemin , Lee Jung‐Yong , Hong Jongin , No Kwangsoo 
Published: July 2014

ABSTRACTWe demonstrated a facile route to the preparation of self‐assembled poly(vinylidene fluoride‐co‐trifluoroethylene) [P(VDF‐TrFE)] nanodots from spin‐coated thin films. We found that the initial film thickness would play an important role in the formation of such P(VDF‐TrFE) nanodots. Interestingly, the electric dipoles of such nanodots were self‐aligned toward the bottom electrode and their ferroelectric properties were determined by using piezoresponse force microscopy. In addition, the self‐polarized ferroelectric nanostructures were introduced to small molecular organic photovoltaic devices and allowed for enhancing the short circuit current density (Jsc) from 9.4 mA/cm2 to 10.2 mA/cm2 and the power conversion efficiency from 2.37% to 2.65%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41230.
Particle Swarm Optimization for Vehicle Positioning Based on Robust Cubature Kalman Filter
Authors: Liu Jiang , Cai Baigen , Wang Yunpeng 
Published: July 2014

AbstractThis paper is concerned with the particle swarm optimization (PSO) based adaptive solution of a robust cubature Kalman filter (RCKF) for data fusion in land vehicle positioning. The cubature rule applied in the cubature Kalman filter is employed to solve the nonlinearity in system and measurement models. With the principle of bounded error covariance, a robust filtering solution is derived to provide tolerance to model uncertainties and the nonlinear approximation errors. On this basis, particle swarm optimization is adopted to assist the original RCKF algorithm and improve the estimation performance by adjusting the restraint coefficient, which is designed as a key parameter. Thus, a novel PSO‐assisted robust Kalman filtering scheme is proposed for both the adaption and robustness performance. Simulation analysis and discussions are given to illustrate capabilities and advantages of the proposed filtering solution.
Changes to radiosonde reports and their processing for numerical weather prediction
Authors: Ingleby Bruce , Edwards David 
Published: July 2014

AbstractIn the biggest change to radiosonde reporting for many years binary BUFR reports are replacing alphanumeric TEMP code. The binary reports can provide much higher vertical resolution and the time and position of each level, but changes to observation processing at forecast centres are needed to use the new reports and in particular the level dependent positions. Using data vertically averaged over model layers, observation minus background (O − B) statistics from both formats compare closely (with a temperature offset of about 0.1°C due to rounding in the older format). Correct treatment of balloon drift improves the O − B statistics at upper‐levels.
Effect of telaprevir on the metabolism and hepatic uptake of tacrolimus (FK506)
Authors: Oda Kazuo , Yamano Katsuhiro 
Published: July 2014

ABSTRACTTelaprevir, a chronic hepatitis C virus (HCV) protease inhibitor, is known to be a cytochrome P450 (CYP) 3A4/5 substrate and inhibitor. In the present study, the in vitro inhibitory effect of telaprevir on the metabolism of tacrolimus in human liver microsomes was investigated using 13‐O‐demethyltacrolimus (M‐I) as a monitor metabolite. Telaprevir inhibited M‐I formation in a time‐dependent fashion with rate of enzyme inactivation (kinact) and concentration to reach 50% of kinact (KI) values of 0.113 min‐1 and 0.511 µm, respectively. Using the inhibition parameters generated, in vitro–in vivo extrapolations were performed to evaluate the clinical relevance of the effect of telaprevir on the area under the curve versus time (AUC) of tacrolimus. When 750 mg of telaprevir was administered orally, the intestinal wall availability (Fg) of tacrolimus was estimated to be increased 3.7‐ to 7.0‐fold. The hepatic intrinsic clearance (CLint) of tacrolimus was also estimated to be decreased 4.4‐ to 19‐fold. These results suggest that the increased AUC of tacrolimus in the presence of telaprevir was caused by intestinal and hepatic metabolism inhibition. In addition, the inhibitory effect of telaprevir on the hepatic uptake of tacrolimus was also examined using human cryopreserved hepatocytes. However, no significant inhibitory effect was noted, suggesting that the effect of telaprevir on hepatic transporters did not contribute to the increase in tacrolimus exposure. Copyright © 2014 John Wiley & Sons, Ltd.
Development of a flow‐injection analysis system with fluorescence detection for gatifloxacin determination in organized medium
Authors: Lima Vaz Monica F. , de Oliveira João Vitor F. , Cassella Ricardo J. , Pacheco Wagner F. 
Published: July 2014

AbstractThis work reports the development and optimization of a flow injection analysis system with fluorescence detection (FIA–FLUO) for gatifloxacin (GFX) determination in organized medium. The analytical system was based on the enhanced fluorescence of gatifloxacin in micellar medium containing sodium dodecyl sulfate (SDS) at pH 6.0. The influence of physical (carrier flow rate, sample volume and volume of reaction coil) and chemical (pH, concentration of buffer and concentration of SDS) parameters that could affect the performance of the FIA system was evaluated in order to reach optimum conditions in terms of sensitivity and analytical throughput. Under optimized conditions, the FIA–FLUO system allowed the injection of 40 samples per hour with a limit of quantification of 72 µg/L and a RSD of 3.5% at 0.20 mg/L. Real samples of commercial pharmaceutical formulations containing GFX were analyzed, and no statistical difference was observed between the results obtained using the developed system and those obtained using the reference method based on high‐performance liquid chromatography with UV detection. Copyright © 2014 John Wiley & Sons, Ltd.
Enhanced spectrofluorimetric determination of esomeprazole and pantoprazole in dosage forms and spiked human plasma using organized media
Authors: Belal Fathalla , Sharaf EL‐Din Mohie , Tolba Manar M. , Alaa Heba 
Published: July 2014

AbstractA simple, sensitive and rapid spectrofluorimetric method was developed for the determination of esomeprazole (EMZ) and pantoprazole (PRZ) in their pharmaceutical formulations and human plasma. The proposed method is based on the fluorescence spectral behavior of EMZ in methanol in the presence of 0.1 m NaOH containing 0.5% methyl cellulose (MC) at 306/345 nm. The fluorescence intensity of EMZ was enhanced about 1.3‐fold and good linearity in the range 0.4–4.0 µg/mL with a lower detection limit of 0.04 µg/mL and lower quantification limit of 0.14 µg/mL. For PRZ, its methanolic solution exhibited marked native fluorescence at 290/325 nm after enhancement (about 2.1‐ or 1.4‐fold) using either 0.025% sodium dodecyl sulfate (SDS) or 0.05% MC in the presence of 0.2 m borate buffer of pH 9.5. The fluorescence–concentration plots of PRZ were rectilinear over the ranges 0.2–2.0 and 0.3–3.0 µg/mL with lower detection limits of 0.02 and 0.03 µg/mL and lower quantification limits of 0.07 and 0.09 µg/mL using sodium dodecyl sulfate and MC, respectively. The method was successfully applied to the analysis of EMZ and PRZ in their commercial dosage forms and the results were in good agreement with those obtained with the comparison method. Furthermore, in a preliminary investigation, the proposed method was extended to the in vitro determination of the two drugs in spiked human plasma and the results were satisfactory. Copyright © 2014 John Wiley & Sons, Ltd.