bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling CME‐shock‐driven storms in 2012–2013: MHD test particle simulations
Authors: Hudson M. K. , Paral J. , Kress B. T. , Wiltberger M. , Baker D. N. , Foster J. C. , Turner D. L. , Wygant J. R.
Published: January 2015

The Van Allen Probes spacecraft have provided detailed observations of the energetic particles and fields environment for coronal mass ejection (CME)‐shock‐driven storms in 2012 to 2013 which have now been modeled with MHD test particle simulations. The Van Allen Probes orbital plane longitude moved from the dawn sector in 2012 to near midnight and prenoon for equinoctial storms of 2013, providing particularly good measurements of the inductive electric field response to magnetopause compression for the 8 October 2013 CME‐shock‐driven storm. An abrupt decrease in the outer boundary of outer zone electrons coincided with inward motion of the magnetopause for both 17 March and 8 October 2013 storms, as was the case for storms shortly after launch. Modeling magnetopause dropout events in 2013 with electric field diagnostics that were not available for storms immediately following launch have improved our understanding of the complex role that ULF waves play in radial transport during such events.
Evaluating the complementary relationship of evapotranspiration in the alpine steppe of the Tibetan Plateau
Authors: Ma Ning , Zhang Yinsheng , Szilagyi Jozsef , Guo Yanhong , Zhai Jianqing , Gao Haifeng
Published: January 2015

The complementary relationship (CR) of evapotranspiration allows the estimation of the actual evapotranspiration rate (ETa) of the land surface using only routine meteorological data, which is of great importance in the Tibetan Plateau (TP) due to its sparse observation network. With the highest in situ automatic climate observation system in a typical semiarid alpine steppe region of the TP, the wind function of Penman was replaced by one based on the Monin‐Obukhov Similarity theory for calculating the potential evapotranspiration rate (ETp); the Priestley‐Taylor coefficient, α, was estimated using observations in wet days; and the slope of the saturation vapor pressure curve was evaluated at an estimate of the wet surface temperature, provided the latter was smaller than the actual air temperature. A symmetric CR was obtained between the observed daily actual and potential evapotranspiration. Local calibration of the parameter value (in this order) is key to obtaining a symmetric CR: α, wet environment air temperature (Twea), and wind function. Also, present symmetric CR contradicts previous research that used default parameter values for claiming an asymmetric CR in arid and semiarid regions of the TP. The effectiveness of estimating the daily ETa via symmetric CR was greatly improved when local calibrations were implemented. At the same time, an asymmetric CR was found between the observed daily ETa and pan evaporation rates (Epan), both for D20 aboveground and E601B sunken pans. The daily ETa could also be estimated by coupling the Epan of D20 aboveground and/or E601B sunken pan through CR. The former provided good descriptors for observed ETa, while the latter still tended to overestimate it to some extent.
Functional error modeling for uncertainty quantification in hydrogeology
Authors: Josset L. , Ginsbourger D. , Lunati I.
Published: January 2015

Approximate models (proxies) can be employed to reduce the computational costs of estimating uncertainty. The price to pay is that the approximations introduced by the proxy model can lead to a biased estimation. To avoid this problem and ensure a reliable uncertainty quantification, we propose to combine functional data analysis and machine learning to build error models that allow us to obtain an accurate prediction of the exact response without solving the exact model for all realizations. We build the relationship between proxy and exact model on a learning set of geostatistical realizations for which both exact and approximate solvers are run. Functional principal components analysis (FPCA) is used to investigate the variability in the two sets of curves and reduce the dimensionality of the problem while maximizing the retained information. Once obtained, the error model can be used to predict the exact response of any realization on the basis of the sole proxy response. This methodology is purpose‐oriented as the error model is constructed directly for the quantity of interest, rather than for the state of the system. Also, the dimensionality reduction performed by FPCA allows a diagnostic of the quality of the error model to assess the informativeness of the learning set and the fidelity of the proxy to the exact model. The possibility of obtaining a prediction of the exact response for any newly generated realization suggests that the methodology can be effectively used beyond the context of uncertainty quantification, in particular for Bayesian inference and optimization.
Zero‐attracting variable‐step‐size least mean square algorithms for adaptive sparse channel estimation
Authors: Li Yingsong , Hamamura Masanori
Published: January 2015

Recently, sparsity‐aware least mean square (LMS) algorithms have been proposed to improve the performance of the standard LMS algorithm for various sparse signals, such as the well‐known zero‐attracting LMS (ZA‐LMS) algorithm and its reweighted ZA‐LMS (RZA‐LMS) algorithm. To utilize the sparsity of the channels in wireless communication and one of the inherent advantages of the RZA‐LMS algorithm, we propose an adaptive reweighted zero‐attracting sigmoid functioned variable‐step‐size LMS (ARZA‐SVSS‐LMS) algorithm by the use of variable‐step‐size techniques and parameter adjustment method. As a result, the proposed ARZA‐SVSS‐LMS algorithm can achieve faster convergence speed and better steady‐state performance, which are verified in a sparse channel and compared with those of other popular LMS algorithms. The simulation results show that the proposed ARZA‐SVSS‐LMS algorithm outperforms the standard LMS algorithm and the previously proposed sparsity‐aware algorithms for dealing with sparse signals. Copyright © 2015 John Wiley & Sons, Ltd.
Nd:YAG Near‐Infrared Luminescent Nanothermometers
Authors: Benayas Antonio , del Rosal Blanca , Pérez‐Delgado Alberto , Santacruz‐Gómez Karla , Jaque Daniel , Hirata Gustavo Alonso , Vetrone Fiorenzo
Published: January 2015

In this work, the thermal sensing capability of Nd3+‐doped Y3Al5O12 nanoparticles fabricated by combustion synthesis is reported. Under excitation at 808 nm, the relative intensity of the two spectrally isolated luminescence peaks located at around 940 nm (corresponding to a 4F3/2 →4I9/2 transition of the Nd3+ ions) is found to be markedly temperature‐dependent allowing for ratiometric luminescence nanothermometry. The potential use of neodymium‐doped yttrium aluminum garnet nanoparticles in nanothermometry has been successfully tested in a variety of systems including integrated microelectronics, optofluidic devices, and subtissue ex vivo experiments.
Enantioselective Preparation of 3‐Arylcycloalkylamines by Rhodium‐Catalyzed 1,4‐Addition and Subsequent Stereodivergent Reduction
Authors: Gebhardt Sandra , Müller Christian H. , Westmeier Johannes , Harms Klaus , von Zezschwitz Paultheo
Published: January 2015

N‐Sulfonylimines of cycloalk‐2‐enones are well‐suited for the enantioselective rhodium(I)/binap‐catalyzed 1,4‐additions of arylzinc halides. The cyclic enamides, obtained after quenching, are sensitive towards chromatography, but can undergo diastereoselective reductions to furnish cis‐ or trans‐3‐arylcycloalkylamines with five‐ to seven‐membered rings. The 1,4‐addition is not influenced by a methyl group at C‐5 of six‐membered rings, providing further configurational options. 3‐Arylcycloalkylamines are subunits in a number of bioactive substances and can also be oxidatively transformed into cyclic γ‐amino acids.

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Thermal Behavior and Ion Conductivity of Polyethylene Oxide/Polyhedral Oligomeric Silsesquioxane Nanocomposite Electrolytes
Authors: Jung Gyu‐Yeon , Choi Jung Hwa , Lee Jong Keun
Published: January 2015

We prepared and characterized nanocomposites of polyethylene oxide (PEO)/polyethylene glycol‐polyhedral oligomeric silsesquioxane (PEG‐POSS), all of which incorporated a KI/I2 salt system, as electrolytes. Differential scanning calorimetry was used to investigate their melting and crystallization behaviors and to measure their respective degrees of crystallinity over mixing wide range of compositions. The degree of crystallinity reduced with POSS content, indicating restricted segmental motion of the polymer chains. Morphological observations were made using a polarized microscope, and the spherulite patterns observed in PEO/KI/I2 collapsed with added POSS. A decrease in storage modulus was also observed by dynamic mechanical analysis. The ion conductivity measured by electrochemical impedance spectroscopy was enhanced from 1.19 × 10−5 to 1.27 × 10−4 S·cm−1 at 70 wt% POSS; presumably, this was due to the combined effects of lower crystallinity, lower glass transition, and lower modulus as POSS content increases.
Cardiorespiratory fitness and cognitive function in midlife: Neuroprotection or neuroselection?
Authors: Belsky Daniel W. , Caspi Avshalom , Israel Salomon , Blumenthal James A. , Poulton Richie , Moffitt Terrie E.
Published: January 2015

Objective

A study was undertaken to determine whether better cognitive functioning at midlife among more physically fit individuals reflects neuroprotection, by which fitness protects against age‐related cognitive decline, or neuroselection, by which children with higher cognitive functioning select more active lifestyles.

Methods

Children in the Dunedin Longitudinal Study (N = 1,037) completed the Wechsler Intelligence Scales and the Trail Making, Rey Delayed Recall, and Grooved Pegboard tasks as children and again at midlife (age = 38 years). Adult cardiorespiratory fitness was assessed using a submaximal exercise test to estimate maximum oxygen consumption adjusted for body weight in milliliters/minute/kilogram. We tested whether more fit individuals had better cognitive functioning than their less fit counterparts (which could be consistent with neuroprotection), and whether better childhood cognitive functioning predisposed to better adult cardiorespiratory fitness (neuroselection). Finally, we examined possible mechanisms of neuroselection.

Results

Participants with better cardiorespiratory fitness had higher cognitive test scores at midlife. However, fitness‐associated advantages in cognitive functioning were already present in childhood. After accounting for childhood baseline performance on the same cognitive tests, there was no association between cardiorespiratory fitness and midlife cognitive functioning. Socioeconomic and health advantages in childhood and healthier lifestyles during young adulthood explained most of the association between childhood cognitive functioning and adult cardiorespiratory fitness.

Interpretation

We found no evidence for a neuroprotective effect of cardiorespiratory fitness as of midlife. Instead, children with better cognitive functioning are selecting healthier lives. Fitness interventions may enhance cognitive functioning. However, observational and experimental studies testing neuroprotective effects of physical fitness should consider confounding by neuroselection. Ann Neurol 2015;77:607–617
Mammalian target of rapamycin pathway mutations cause hemimegalencephaly and focal cortical dysplasia
Authors: D'Gama Alissa M. , Geng Ying , Couto Javier A. , Martin Beth , Boyle Evan A. , LaCoursiere Christopher M. , Hossain Amer , Hatem Nicole E. , Barry Brenda J. , Kwiatkowski David J. , Vinters Harry V. , Barkovich A. James , Shendure Jay , Mathern Gary W. , Walsh Christopher A. , Poduri Annapurna
Published: January 2015

Focal malformations of cortical development, including focal cortical dysplasia (FCD) and hemimegalencephaly (HME), are important causes of intractable childhood epilepsy. Using targeted and exome sequencing on DNA from resected brain samples and nonbrain samples from 53 patients with FCD or HME, we identified pathogenic germline and mosaic mutations in multiple PI3K/AKT pathway genes in 9 patients, and a likely pathogenic variant in 1 additional patient. Our data confirm the association of DEPDC5 with sporadic FCD but also implicate this gene for the first time in HME. Our findings suggest that modulation of the mammalian target of rapamycin pathway may hold promise for malformation‐associated epilepsy. Ann Neurol 2015;77:720–725
Growth and Origami Folding of DNA on Nanoparticles for High‐Efficiency Molecular Transport in Cellular Imaging and Drug Delivery
Authors: Yan Juan , Hu Chongya , Wang Ping , Zhao Bin , Ouyang Xiangyuan , Zhou Juan , Liu Rui , He Dannong , Fan Chunhai , Song Shiping
Published: January 2015

A novel three‐dimensional (3D) superstructure based on the growth and origami folding of DNA on gold nanoparticles (AuNPs) was developed. The 3D superstructure contains a nanoparticle core and dozens of two‐dimensional DNA belts folded from long single‐stranded DNAs grown in situ on the nanoparticle by rolling circle amplification (RCA). We designed two mechanisms to achieve the loading of molecules onto the 3D superstructures. In one mechanism, ligands bound to target molecules are merged into the growing DNA during the RCA process (merging mechanism). In the other mechanism, target molecules are intercalated into the double‐stranded DNAs produced by origami folding (intercalating mechanism). We demonstrated that the as‐fabricated 3D superstructures have a high molecule‐loading capacity and that they enable the high‐efficiency transport of signal reporters and drugs for cellular imaging and drug delivery, respectively.
Die Elektronentunnelraten im Atmungskettenkomplex I sind auf eine effiziente Energiewandlung abgestimmt
Authors: de Vries Simon , Dörner Katerina , Strampraad Marc J. F. , Friedrich Thorsten
Published: January 2015

Der Atmungskettenkomplex I wandelt die freie Energie, die bei der Reduktion von Ubichinon durch NADH frei wird, in einen Protonengradienten über die Membran um. Die biologische Redoxreaktion wird von einem Flavinmononukleotid und einer Kette von sieben Eisen‐Schwefel‐Zentren katalysiert. Die Elektronentransfergeschwindigkeiten zwischen den Zentren wurden über eine schnelle “Freeze‐Quench”‐Methode und Analyse der Proben mittels EPR‐ und UV/Vis‐Spektroskopie bestimmt. Der Komplex I oxidiert sehr schnell drei Moleküle NADH; dabei hängt die Elektronentunnelrate zwischen den beiden Zentren der Kette mit dem größten Abstand zueinander vom Redoxzustand des distalen Zentrums N2 ab. Diese Geschwindigkeit ist sechsmal geringer, wenn N2 im reduzierten Zustand vorliegt. Die konformativen Änderungen, die mit der Reduktion des Zentrums N2 einhergehen, verlangsamen die elektronische Kopplung des längsten Transferschritts. Die Kette der Eisen‐Schwefel‐Zentren ist somit nicht einfach ein Draht für den Elektronentransfer, sondern sie passt die Elektronentunnelraten der Zeitskala der konformativen Bewegungen an, die für die Protonentranslokation benötigt werden. Die Synchronisierung von Geschwindigkeiten ist ein generelles Prinzip, um die Spezifität enzymatischer Reaktionen zu erhöhen.
Synergistic Interplay of a Non‐Heme Iron Catalyst and Amino Acid Coligands in H2O2 Activation for Asymmetric Epoxidation of α‐Alkyl‐Substituted Styrenes
Authors: Cussó Olaf , Ribas Xavi , Lloret‐Fillol Julio , Costas Miquel
Published: January 2015

Highly enantioselective epoxidation of α‐substituted styrenes with aqueous H2O2 is described by using a chiral iron complex as the catalyst and N‐protected amino acids (AAs) as coligands. The amino acids synergistically cooperate with the iron center in promoting an efficient activation of H2O2 to catalyze epoxidation of this challenging class of substrates with good yields and stereoselectivities (up to 97 % ee) in short reaction times.
Induction of a Proton Gradient across a Gold‐Supported Biomimetic Membrane by Electroenzymatic H2 Oxidation
Authors: Gutiérrez‐Sanz Óscar , Tapia Cristina , Marques Marta C. , Zacarias Sonia , Vélez Marisela , Pereira Inês A. C. , De Lacey Antonio L.
Published: January 2015

Energy‐transduction mechanisms in living organisms, such as photosynthesis and respiration, store light and chemical energy in the form of an electrochemical gradient created across a lipid bilayer. Herein we show that the proton concentration at an electrode/phospholipid‐bilayer interface can be controlled and monitored electrochemically by immobilizing a membrane‐bound hydrogenase. Thus, the energy derived from the electroenzymatic oxidation of H2 can be used to generate a proton gradient across the supported biomimetic membrane.
Pd‐Nanoparticle‐Supported, PDDA‐Functionalized Graphene as a Promising Catalyst for Alcohol Oxidation
Authors: Bin Duan , Ren Fangfang , Wang Ying , Zhai Chunyang , Wang Caiqin , Guo Jun , Yang Ping , Du Yukou
Published: January 2015

Poly(diallyldimethylammonium chloride) (PDDA) has been employed as a modifying material for the development of new functional materials; then, the functionalized graphene was employed as a support for Pd nanoparticles through a facile method. The structures and morphologies of the as‐synthesized Pd/PDDA–graphene composites were extensively characterized by Raman spectroscopy, XRD, XPS, and TEM. Morphological observation showed that Pd NPs with average diameters of 4.4 nm were evenly deposited over the functionalized graphene sheets. Moreover, the electrochemical experiments indicated that the Pd/PDDA–graphene catalyst showed improved electrocatalytic activity toward alcohol‐oxidation reactions compared to the Pd/graphene and commercial Pd/C systems, as well as previously reported Pd‐based catalysts. This study demonstrates the great potential of PDDA‐functionalized graphene as a support for the development of metal–graphene nanocomposites for important applications in fuel cells.
Metal‐immobilized magnetic nanoparticles for cytochrome C purification from rat liver
Authors: Perçin Işık , Karakoç Veyis , Ergün Bahar , Denizli Adil
Published: January 2015

Cu2+‐immobilized magnetic poly(hydroxyethylmethacrylate‐N‐methacryloyl‐(l)‐histidinemethylester) (mPHEMAH) nanoparticles were prepared by surfactant‐free emulsion polymerization for cytochrome C (cyt C) purification from rat liver. Elemental analysis, atomic force microscopy, zeta sizer, and vibrating sample magnetometer were used to characterize mPHEMAH nanoparticles. In addition to these characterization steps, surface area, average particle size, and size distribution of mPHEMAH nanoparticles were determined. Quantity of immobilized Cu2+ was measured using atomic absorption spectrophotometry. N‐Methacryloyl‐(l)‐histidinemethylester and Cu2+ content of mPHEMAH nanoparticles were 0.18 mmol/g polymer and 0.11 mmol/g polymer, respectively. Specific surface area of Cu2+‐immobilized mPHEMAH nanoparticles was 1180 m2/g. Effect of initial cyt C concentration, pH, temperature, and ionic strength on cyt C adsorption onto Cu2+‐immobilized mPHEMAH nanoparticles was investigated. Maximum cyt C adsorption capacity of Cu2+‐immobilized mPHEMAH nanoparticles was 311.9 mg/g polymer. Maximum adsorption was obtained at pH 8.0 and 4 °C. Cu2+‐immobilized mPHEMAH nanoparticles were used ten times with 4.1% decrease in adsorption capacity. In the last stage, Cu2+‐immobilized mPHEMAH nanoparticles were used to purify cyt C from rat liver tissue, and the purity of desorbed fractions was controlled by SDS‐PAGE.
Successful versus unsuccessful antegrade recanalization of single chronic coronary occlusion: Eight‐year experience and outcomes by a propensity score ascertainment
Authors: Jaguszewski Milosz , Ciecwierz Dariusz , Gilis‐Malinowska Natasza , Fijalkowski Marcin , Targonski Radoslaw , Masiewicz Emilia , Strozyk Aneta , Duda Maciej , Chmielecki Michal , Lewicki Lukasz , Dubaniewicz Witold , Burakowski Slawomir , Drewla Piotr , Skarzynski Pawel , Rynkiewicz Andrzej , Alibegovic Jasmina , Landmesser Ulf , Gruchala Marcin
Published: January 2015

Aims

The effectiveness of revascularization of chronic total occlusion (CTO) remains intriguing. Thus, we sought to investigate whether a successful PCI for single CTO improves outcomes in a setting of stable angina and chronic occlusion of single coronary artery.

Methods and Results

Of 11 957 consecutive patients referred for nonurgent PCI between 2003 and 2010, 1110 displayed single CTO and were enrolled to the central CTO‐registry database. The primary end‐point included all‐cause mortality, the secondary end‐point a composite of safety outcome measure of all‐cause death, nonfatal‐MI, the need for urgent revascularization and stroke. The major adverse cardiovascular event (MACE) records were extracted from the national administrative database and all patients were linked to the long‐term follow‐up. Since the patient assignment was not random, we performed the propensity scoring to minimize selection bias; 734 patients (66%) had a successful PCI‐CTO. Compared with successful procedures, unsuccessful procedures had similar rates of all‐cause death both in crude (HR, 0.78; 95%CI, 0.49–1.25; P = 0.30) and adjusted analysis (HR, 0.80; 95%CI, 0.50‐1.28; P = 0.34). A similar, significant reduction in overall MACE was noted with successful PCI‐CTO compared with unsuccessful procedure in unadjusted (HR, 0.74; 95%CI, 0.56–0.96; P = 0.020) and adjusted calculation (HR, 0.73; 95%CI, 0.56–0.96; P = 0.019). Patients after successful PCI‐CTO as compared with failed recanalization less frequently underwent surgical revascularization. The benefit was sustained at 3 years follow‐up.

Conclusions

Successful PCI for single CTO does not improve long‐term survival, nonetheless, is associated with reduced overall MACE and the need for surgical revascularization. © 2015 Wiley Periodicals, Inc.
An Enhanced Anode based on Polymer‐Coated Carbon Black for use as a Direct Methanol Fuel Cell Electrocatalyst
Authors: Yang Zehui , Hafez Inas H. , Berber Mohamed R. , Nakashima Naotoshi
Published: January 2015

Sluggish methanol oxidation reaction and low durability are the main obstacles for commercialization of direct methanol fuel cells (DMFCs). In this study, we describe the fabrication of 4 different carbon black (CB)‐based electrocatalysts for the DMFC by changing the weight ratio between the Pt feed and polymer wrapped carbon support. In all the fabricated electrocatalysts, CB was coated with poly[2,2′‐(2,6‐pyridine)‐5,5′‐bibenzimidazole] on which the Pt nanoparticles were deposited, which were further coated with poly(vinylphosphonic acid). We found that a decrease in the Pt particle size produced higher catalytic activity. The electrochemical surface area (ECSA) of the electrocatalyst with the smallest Pt particle size was 120.8±12.0 m2 gPt−1. The mass activity of the methanol oxidation reaction reached 1860 mA mgPt−1, which is, to the best of our knowledge, the highest value among the recorded catalytic activities of the CB‐based electrocatalysts. Moreover, after 100 000 cycles the electrocatalyst displayed only 38 % and 10.7 % decrease in ECSA and methanol oxidation activity, respectively. Such an obtained durability was ≈10 times higher than that of the commercial CB/Pt electrocatalyst.
Polyaniline‐Coated Hollow Fe2O3 Nanoellipsoids as an Anode Material for High‐Performance Lithium‐Ion Batteries
Authors: Ma Ruguang , Wang Man , Dam Duc Tai , Yoon Yong‐Jin , Chen Yu , Lee Jong‐Min
Published: January 2015

Polyaniline‐coated hollow Fe2O3 nanoellipsoids were successfully synthesized by using a solvothermal method followed by a post‐coating step. The as‐fabricated hollow Fe2O3@PANi nanoellipsoids deliver charge capacities of 366, 223.4, and 105.8 mAh g−1 at 0.5, 1.0, and 2.0 C, respectively, and retain a charge capacity of 412.1 mAh g−1 for 150 cycles at 0.2 C, demonstrating improved rate capability as well as extended cycling lifespan.
Covalent Modification of Graphene Oxide with Carbazole Groups for Laser Protection
Authors: Bai Ting , Li Cong‐Qi , Sun Jie , Song Yi , Wang Jun , Blau Werner J. , Zhang Bin , Chen Yu
Published: January 2015

In the past decades, significant effort has been invested into the research and development of optical limiting materials and processes in order to develop practical solutions for the protection from laser beams. In this study, a new soluble graphene oxide based material (GO–Cz) has been synthesized through the covalent modification of graphene oxide (GO) with a carbazole derivative (Cz). The formation of an amido bond between the Cz group and GO has been confirmed by X‐ray photoelectron and Fourier transform infrared spectroscopy. At the same concentration, both the nonlinear extinction coefficient and the imaginary third‐order susceptibility were increased by a factor of ≈6.93 at 532 nm and ≈6.07 at 1064 nm relative to those of GO, as a result of the covalent grafting of the Cz moieties onto the GO surface. The GO–Cz dispersions exhibit a much better optical limiting performance than GO and GO/Cz blends at both 532 and 1064 nm due to the possible intramolecular electron‐transfer between the GO and Cz moieties and the effective combination of the different nonlinear optical mechanisms.
Mild and Selective Activation and Substitution of Strong Aliphatic CF Bonds
Authors: Janjetovic Mario , Träff Annika M. , Hilmersson Göran
Published: January 2015

A procedure for chemoselectively manipulating the strong aliphatic CF bond with direct transformation into a CN bond under mild conditions is reported. The activation and subsequent substitution of primary alkyl fluorides is mediated by La[N(SiMe3)2]3, and results in high to excellent yields of tertiary amines. The methodology displays high selectivity towards the C(sp3)F bond, and a variety of secondary amines are applicable as nucleophiles. Mechanistic investigations reveal a reaction that is first order with respect to [La[N(SiMe3)2]3], [R1R2NH], and [alkyl fluoride], and a 6‐membered cyclic transition state is proposed. In addition, 1H NMR spectroscopy shows that La[N(SiMe3)2]3 is the active species involved in the substitution and that protonolysis of the amine, yielding La[NR1R2]3, lowers the reactivity.
Sonochemical Synthesis of Gold Nanoparticles by Using High Intensity Focused Ultrasound
Authors: Yusof Nor Saadah Mohd , Ashokkumar Muthupandian
Published: January 2015

The sonochemical synthesis of gold nanoparticles (GNPs) with different shapes and size distributions by using high‐intensity focused ultrasound (HIFU) operating at 463 kHz is reported. GNP formation proceeds through the reduction of Au3+ to Au0 by radicals generated by acoustic cavitation. TEM images reveal that GNPs show irregular shapes at 30 W, are primarily icosahedral at 50 W and form a significant amount of nanorods at 70 W. The size of GNPs decreases with increasing acoustic power with a narrower size distribution. Sonochemiluminescence images help in the understanding of the effect of HIFU in controlling the size and shapes of GNPs. The number of radicals that form and the mechanical forces that are generated control the shape and size of the GNPs. UV/Vis spectra and TEM images are used to propose a possible mechanism for the observed effects. The results presented demonstrate, for the first time, that the HIFU system can be used to synthesise size‐ and shape‐controlled metal nanoparticles.
Multichromophoric Organic Molecules Encapsulated in Polymer Nanoparticles for Artificial Light Harvesting
Authors: Bhattacharyya Santanu , Jana Bikash , Patra Amitava
Published: January 2015

We designed a self‐assembled multichromophoric organic molecular arrangement inside polymer nanoparticles for light‐harvesting antenna materials. The self‐assembled molecular arrangement of quaterthiophene molecules was found to be an efficient light‐absorbing antenna material, followed by energy transfer to Nile red (NR) dye molecules, which was confined in polymer nanoparticles. The efficiency of the antenna effect was found to be 3.2 and the effective molar extinction coefficient of acceptor dye molecules was found to be enhanced, which indicates an efficient light‐harvesting system. Based on this energy‐transfer process, tunable photo emission and white light emission has been generated with 14 % quantum yield. Such self‐assembled oligothiophene–NR systems encapsulated in polymer nanoparticles may open up new possibilities for fabrication of artificial light harvesting system.
The Thermodynamic Driving Force for Kinetics in General and Enzyme Kinetics in Particular
Authors: Pekař Miloslav
Published: January 2015

The thermodynamic driving force of a reaction is usually taken as the chemical potential difference between products and reactants. The forward and backward reaction rates are then related to this force. This procedure is of very limited validity, as the resulting expression contains no kinetic factor and gives little information on reaction kinetics. The transformation of the reaction rate as a function of concentration (and temperature) into a function of chemical potential should be more properly performed, as illustrated by a simple example of an enzymatic reaction. The proper thermodynamic driving force is the difference between the exponentials of the totaled chemical potentials of reactants and products.
Tips and traps on crystal twinning: how to fully describe your twin
Authors: Nespolo Massimo
Published: January 2015

A series of guidelines (tips) to provide a satisfactory characterization of a twinned sample is provided, and a series of traps to avoid is pointed out. The fundamental concepts and definitions are summarized, which represent the minimal theoretical background behind these guidelines.
Unexpected Tackifiers from Isosorbide
Authors: Zenner Michael D. , Madbouly Samy A. , Chen Jason S. , Kessler Michael R.
Published: January 2015

Molecularly well‐defined tackifiers with up to 100 % bio‐content were prepared from isosorbide and various cyclic anhydrides. These tackifiers are tacky over a broad temperature range and exhibit high maximum tack (ca. 2000 kPa). Structural modifications shift the temperature at which maximum tack is observed and change the viscosity of the tackifiers.
Physiological response and ion accumulation in two grasses, one legume, and one saltbush under soil water and salinity stress
Authors: Bhuiyan Mohammad , Raman Anantanarayanan , Hodgkins Dennis , Mitchell David , Nicol Helen
Published: January 2015

A glasshouse–pot trial using four levels of soil moisture (>100%, 90%, 75%, and 60% field capacity) and three levels of salinity (1.0 dSm–1, 3.5 dSm–1, and 6.0 dSm–1) was done to evaluate Na+, K+, and Cl− accumulation capacity and the physiological responses (net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, quantum efficiency of PSII, and non‐photochemical quenching) in Melilotus siculus, Tecticornia pergranulata, Cynodon dactylon , and Thinopyrum ponticum. Results reveal that the combined effects of soil water and salinity had a significant effect on Na+ and Cl− accumulation and not on that of K+. Concentrations of Na+ and Cl− and non‐photochemical quenching increased significantly whereas, the net photosynthetic rate (Pn), stomatal conductance (gs), and intercellular CO2 concentration decreased significantly in the tested plants, because of salinity. Salinity had no significant effect on the maximum quantum yield and relative water contents in shoots. Soil moisture had a significant effect on Na+, K+, and Cl− accumulation and the physiological responses in tested plants. T. pregranulata accumulated the highest concentrations of Na+ and Cl− and had the lowest Pn. C. dactylon accumulated the lowest concentrations of Na+ and Cl−, whereas Pn was the highest. No strong positive correlation between Pn and gs was evident in tested plants. We indicate that the reduced physiological performance was because of non‐stomatal activities. Na+ and Cl− accumulation capacity in the tested plants was in the following order: T. pergranulata>M. siculus>T. ponticum>C. dactylon. C. dactylon, a C4 plant, accumulated lower salt ions than the other three C3 plants. Copyright © 2015 John Wiley & Sons, Ltd.
Homoleptic and Heteroleptic Bismuth(III) Thiazole–Thiolates and the Influence of Ring Substitution on Their Antibacterial and Antileishmanial Activity
Authors: Luqman Ahmad , Blair Victoria L. , Brammananth Rajini , Crellin Paul K. , Coppel Ross L. , Kedzierski Lukasz , Andrews Philip C.
Published: January 2015

Two new homo‐ and heteroleptic bismuth thiazole‐thiolato complexes derived from 4‐phenylthiazole‐2‐thiol MBT(H) have been synthesised and structurally characterised, [BiPh(MBT)2]2 and [Bi(MBT)3]2. Syntheses were achieved using BiPh3 or Bi(OtBu)3 in protolysis reactions with MBT(H), or by salt metathesis with BiCl3 or BiPhCl2 and the sodium thiolate, [NaMBT]. The complexes were obtained under both standard solvent‐free and solvent‐mediated conditions, and by microwave irradiation. The solid‐state structures of [BiPh(MBT)2]2 and [Bi(MBT)3]2, were determined using single‐crystal X‐ray diffraction, showing them to be dimeric. The bactericidal properties of the complexes against Mycobacterium smegmatis, Staphylococcus aureus, methicillin‐resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, vancomycin‐resistant Enterococcus (VRE) and Escherichia coli revealed [BiPh(MBT)2]2 to be the most effective against all the bacteria with MIC values of 0.6 μg/mL (0.25 μM) against S. aureus and 0.9 μg/mL (0.27 μM) against E. faecalis. [Bi(MBT)3]2 was less active overall. However, comparisons with the analogous complex [Bi(4‐BrMTD)3], revealed a significant hundred‐fold enhanced activity against S. aureus, MRSA, VRE, and E. faecalis. Both complexes showed little or no toxicity towards mammalian COS‐7 cells at 20 μg/mL. [BiPh(MBT)2]2 also was found to display good antileishmanial activity with an IC50 value of 0.11 μg/mL (0.17 μM), at which concentration the complex was non‐toxic to human fibroblast cells.
Formation of Different Isomers of Phosphine–Imidazolyl and –Pyridyl Ruthenium(II) Complexes Affecting the Catalyst Activity in the Acceptorless Dehydrogenation of Alcohols
Authors: Langer Robert , Gese Alexander , Gesevičius Donatas , Jost Maximilian , Langer Bastian R. , Schneck Felix , Venker Alexander , Xu Weiqin
Published: January 2015

The synthesis, reactivity, and catalytic activity of RuII complexes with different pyridine‐ and imidazole‐based P,N ligands are reported. The investigations reveal a strong influence of the N‐heterocycle and the steric demand of the phosphine groups on the stability of different isomers of [L2RuX2] (L = P,N ligand; X = Cl, H). The imidazole‐based complex 5 with dicyclohexylphosphine groups was found to be the most active precatalyst for the acceptorless dehydrogenation of primary alcohols, whereas different phosphine groups at the imidazole ligand as well as pyridine‐based ligands caused a drop in catalytic activity. In the presence of a primary amine, imines are preferentially formed under these conditions. In summary, the investigations show that comparably small changes in the ligand moiety have a strong effect on the relative stability of stereoisomers for both hydride and chloride complexes, whereas isomerization of the kinetic reaction products was observed in some cases. The described changes in the ligand moiety most probably have a strong impact on the relative stabilities of isomeric intermediates as well and thus affect the catalytic activity of these complexes.
A study of the effect of step excrescences and free‐stream disturbances on boundary layer stability
Authors: Sescu Adrian , Visbal Miguel , Rizzetta Donald
Published: January 2015

In this work, a study of the mechanism by which free‐stream acoustic and vorticity disturbances interact with a boundary layer flow developing over a flat plate featuring a step excrescence located at a certain distance from a blunt leading edge is included. The numerical tool is a high‐fidelity implicit numerical algorithm solving for the unsteady, compressible form of the Navier–Stokes equations in a body‐fitted curvilinear coordinates and employing high‐accurate compact differencing schemes with Pade‐type filters. Acoustic and vorticity waves are generated using a source term in the momentum and energy equations, as opposed to using inflow boundary conditions, to avoid spurious waves that may propagate from boundaries. The results show that the receptivity to surface step excrescences is largely the result of an overall adverse pressure gradient posed by the step, and that the free‐stream disturbances accelerate the generation of instabilities in the downstream. As expected, it is found that the acoustic disturbance interacting with the surface imperfection is more efficient in exciting the Tollmien–Schlichting waves than the vorticity disturbance. The latter generates Tollmien–Schlichting waves that are grouped in wave packets consistent with the wavelength of the free‐stream disturbance. Copyright © 2015 John Wiley & Sons, Ltd.
An approach to control the spurious currents in a multiphase lattice Boltzmann method and to improve the implementation of initial condition
Authors: Leclaire Sébastien , Pellerin Nicolas , Reggio Marcelo , Trépanier Jean‐Yves
Published: January 2015

Multiphase lattice Boltzmann methods are known to generate spurious or parasitic currents at the fluid–fluid interfaces. This nonphysical phenomenon has to be avoided, or at least controlled, in order to achieve reliable solutions. In this article, a method to control these fictitious velocities via lattice refinement is proposed, which is based on interface thickness control for which both the spurious currents and the physical fluid–fluid interface thickness vanishes as the spatial resolution increases. It has been found that a proper interface thickness adjustment is required as the lattice refinement is applied, or an increase in spurious currents, instead of a reduction, can occur. By combining the new method with an appropriate multiphase flow initialization, the overall stability for high density O(1000) and viscosity O(100) ratios is greatly improved. Although this research has been conducted with a Rothman and Keller type lattice Boltzmann model, it is believed that other types of multiphase lattice Boltzmann models could benefit from the basic ideas underlying this research. Copyright © 2015 John Wiley & Sons, Ltd.
A Genome‐Wide Association Study of Early Spontaneous Preterm Delivery
Authors: Zhang Heping , Baldwin Don A. , Bukowski Radek K. , Parry Samuel , Xu Yaji , Song Chi , Andrews William W. , Saade George R. , Esplin M. Sean , Sadovsky Yoel , Reddy Uma M. , Ilekis John , Varner Michael , Biggio Joseph R. ,   for the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Genomic and Proteomic Network for Preterm Birth Research (GPN‐PBR)
Published: January 2015

Preterm birth is the leading cause of infant morbidity and mortality. Despite extensive research, the genetic contributions to spontaneous preterm birth (SPTB) are not well understood. Term controls were matched with cases by race/ethnicity, maternal age, and parity prior to recruitment. Genotyping was performed using Affymetrix SNP Array 6.0 assays. Statistical analyses utilized PLINK to compare allele occurrence rates between case and control groups, and incorporated quality control and multiple‐testing adjustments. We analyzed DNA samples from mother–infant pairs from early SPTB cases (200/7–336/7 weeks, 959 women and 979 neonates) and term delivery controls (390/7–416/7 weeks, 960 women and 985 neonates). For validation purposes, we included an independent validation cohort consisting of early SPTB cases (293 mothers and 243 infants) and term controls (200 mothers and 149 infants). Clustering analysis revealed no population stratification. Multiple maternal SNPs were identified with association P‐values between 10 × 10–5 and 10 × 10–6. The most significant maternal SNP was rs17053026 on chromosome 3 with an odds ratio (OR) 0.44 with a P‐value of 1.0 × 10–6. Two neonatal SNPs reached the genome‐wide significance threshold, including rs17527054 on chromosome 6p22 with a P‐value of 2.7 × 10–12 and rs3777722 on chromosome 6q27 with a P‐value of 1.4 × 10–10. However, we could not replicate these findings after adjusting for multiple comparisons in a validation cohort. This is the first report of a genome‐wide case‐control study to identify single nucleotide polymorphisms (SNPs) that correlate with SPTB.
Elemental geochemistry of the early Jurassic black shales in the Qiangtang Basin, eastern Tethys: constraints for palaeoenvironment conditions
Authors: Fu Xiugen , Wang Jian , Chen Wenbin , Feng Xinglei , Wang Dong , Song Chunyan , Zeng Shengqiang
Published: January 2015

The early Jurassic black shales are the most important source rocks in the Qiangtang Basin, Tibet. These black shales may provide a useful example for understanding the sedimentary conditions during the early Jurassic in the eastern Tethys. Thirty‐two black‐shale samples were collected from the Qiangtang Basin to reconstruct the depositional environments during the early Jurassic in the eastern Tethys. The palaeoclimate index Σ(Fe + Mn + Cr + Ni + V + Co)/Σ(Ca + Mg + Sr + Ba + K + Na) varies between 0.58 and 1.14, together with low Sr/Ba (0.20–0.60) and Sr/Cu (1.68–7.88) ratios, indicating a warm humid to semi‐humid climatic condition during black‐shale deposition. The early Jurassic black shales exhibit slight Ce anomalies (0.89–0.94) and Mn enrichment (EF = 1.2), suggesting a slightly oxic depositional environment. The conditions of the sedimentary water system during black‐shale deposition were apparently brackish as evidenced by middle B/Ga (3.96–5.73) and Th/U (3.96–6.51) ratios. Copyright © 2015 John Wiley & Sons, Ltd.
Structural, metamorphic and geochronological record in the Goszów quartzites of the Orlica–Śnieżnik Dome (SW Poland): implications for the polyphase Variscan tectonometamorphism of the Saxothuringian terrane
Authors: Jastrzębski Mirosław , Budzyń Bartosz , Stawikowski Wojciech
Published: January 2015

This integrated study on the pressure–temperature–deformation‐time record of the Goszów light quartzites from the Młynowiec–Stronie Group (Sudety Mts., SW Poland) provides new data that improve our understanding of the structure and geodynamic development of the Orlica–Śnieżnik Dome (OSD) as a Gondwana‐derived unit involved in the formation of the Variscan orogen. The structural and metamorphic record of the Goszów light quartzites, when compared to the under‐ and overlying rock formations, indicates that the whole Młynowiec–Stronie Group in the eastern part of the Saxothuringian terrane functioned as a single, integral lithotectonic unit with no visible structural or metamorphic discontinuities. The sequence of structures and thermodynamic modelling indicate that the light quartzites underwent the same polyphase tectonometamorphic evolution as the adjacent rocks belonging to the Młynowiec–Stronie Group. The development of tight, N–S‐trending folds and axial penetrative metamorphic foliation was related to metamorphic progression from 500 °C to 640 °C at 6–7 kbar. Subsequently, under the retrogressive conditions below 540 °C, the foliation was reactivated as a result of subsequent N–S‐directed ductile shearing and extension. Therefore, the study of the light quartzites exemplifies the penetrative structures in the OSD, and the metamorphic foliation and N–S‐trending lineation are composite structures. The monazite metamorphic ages ofca. 364 Ma and 335 Ma may be related to the approximately E–W‐ and N–S‐oriented tectonic movements, respectively, which occurred during the amalgamation of the Saxothuringian terrane with Brunovistulia. In contrast, the previously unknown early Palaeozoic monazite age ofca. 494 Ma is interpreted as the protolith age of the light quartzites. Copyright © 2015 John Wiley & Sons, Ltd.
Neotectonics and seismicity in southern Patagonia
Authors: Perucca Laura , Alvarado Patricia , Saez Mauro
Published: January 2015

Research for evaluation of geologic hazards involving earthquakes and volcanic eruptions in southern Argentina seems to have historically received little attention. Nevertheless, the relatively small work done indicates a Neogene tectonic architecture in the area with capability of generating potential hazardous earthquakes in a growing population region. Seismicity and some morphotectonic evidences of Quaternary activity of the Magallanes–Fagnano left‐lateral fault system in the transform boundary between South America and Scotia plates, are analysed in this paper. This fault system is considered to be an important seismogenic source, responsible for large earthquakes that have occurred in southern Argentina. Some examples from the South and Austral Andean Volcanic Zones are also examined in order to show recent volcanic activity which also generated crustal seismicity. Preliminary hazard estimation clearly shows the presence of both potentially active volcanic centres in southern Patagonia that may also trigger seismicity and the high probability for large crustal earthquake generation. Copyright © 2015 John Wiley & Sons, Ltd.
Genetic contribution of catechol‐O‐methyltransferase in hippocampal structural and functional changes of female migraine sufferers
Authors: Liu Jixin , Lan Lei , Mu Junya , Zhao Ling , Yuan Kai , Zhang Yi , Huang Liyu , Liang Fanrong , Tian Jie
Published: January 2015

Physiological and emotional stressors are associated with or provoke each migraine attack and cause structural and functional changes in the central nervous system. The hippocampus, a limbic structure important in anxiety‐related behavior, is vulnerable to long‐term stress. Given that catechol‐O‐methyltransferase (COMT) is widely distributed in the hippocampus and its genetic variation is thought to contribute to the interindividual variability in pain perception and anxiety regulation, whether or not migraine and COMT val158met genotype have an interactive effect in the key brain area related to maladaptive stress, the hippocampus, is still poorly understood. Using T1‐weighted and resting functional MRI, we evaluated the effect of COMT genetic variations on migraine and possible interactions between COMT and the disease in brain structure and function in 135 females with migraine without aura (MWoA) and 111 matched health controls (HC). Optimized voxel‐based morphometry (VBM) and functional connectivity (FC) analyses were applied. From the whole brain VBM analysis, we found a significant disease × genotype interaction in the hippocampus, which overlapped with disease‐related increase of gray matter (GM) in val homozygote migraineurs. In our results, increased GM in the hippocampus was only found in val homozygote MWoA compared to val homozygote HC. Moreover, FC between the hippocampus and the medial prefrontal cortex was significantly decreased in val homozygotes, and it was negatively correlated with self‐rating anxiety scale values.Our results indicated that brain structure and function of the hippocampus are differentially affected by migraine in val homozygotes compared with met carriers. Hum Brain Mapp 36:1782–1795, 2015. © 2015 Wiley Periodicals, Inc.