bluuebunny/crossref_metadata_2025 huggingface dataset:
Cross‐shelf exchange in the shelf of the East China Sea
Authors: Zhou Feng , Xue Huijie , Huang Daji , Xuan Jiliang , Ni Xiaobo , Xiu Peng , Hao Qiang
Published: February 2015

A high‐resolution, 3‐dimensional primitive equation model is used to investigate the cross‐shelf exchange in the East China Sea (ECS). Favorable comparisons between field data and model simulations from both climatological run and hindcast run for 2006 indicate that the model has essential skills in capturing the key physics of the ECS. Temporal and spatial variations of the cross‐shelf exchanges are further analyzed. It was demonstrated from both observations and simulations that in 2006 high saline water could be delivered to the north of the Changjiang River mouth (near 32°N) as a result of stronger than typical cross‐shelf exchanges at the shelf break and flows through the Taiwan Strait with an annual mean rate of 2.59 and 1.83 Sv, respectively. A few new places at the shelf break were also identified where persistent and vigorous onshore or offshore exchanges occur throughout the year. Cross‐shelf exchange is largely determined by the along‐shelf geostrophic balance with weak seasonality, which is modulated in upper layers by northeasterly monsoon from early‐fall to late‐spring and at seabed by bottom friction during December–January, May, and August–September. Nonlinear effect, with strong spatial variations and intraseasonal variability, is a secondary but persistent contributor to the net seaward transport, except for northeast of Taiwan where the nonlinear effect becomes significant but more varied.
Multidecadal variations of the surface Kuroshio between 1950s and 2000s and its impacts on surrounding waters
Authors: Hsin Yi‐Chia
Published: February 2015

Based on the analyses of 59 year (1950–2008) surface geostrophic velocities, the multidecadal changes of Kuroshio from the eastern Luzon to the southern Japan are investigated. Result shows that the upstream Kuroshio from the east of Luzon to southern East China Sea suffers much more obvious multidecadal changes. Except for the decade of 1980, the Kuroshio east of Luzon possesses a multidecadal tendency opposite to that east of Taiwan. Besides 1980s, the multidecadal change of Kuroshio bordering Taiwan is mainly governed by the eddy activity off the eastern Taiwan, while the wind stress curl plays a major role in the Kuroshio in the east of Luzon and in the Luzon Strait. The wind‐stress‐induced Ekman transport plays a secondary role in regulating the Kuroshio east of Luzon. In addition, the multidecadal fluctuation of Kuroshio east of Luzon also modulates the westward intrusion in the Luzon Strait. Instead, the Ekman transport dominated the whole upstream Kuroshio area from the eastern Luzon to the vicinity of Taiwan during the exceptional decade of 1980. Associated changes of water properties in the northern South China Sea and southern East China Sea are also ascribed to the multidecadal changes of surface Kuroshio in the upstream area.
Turbulence in theEastChinaSea:The summertime stratification
Authors: Lozovatsky Iossif , Lee Jae‐Hak , Fernando H. J. S. , Kang Sok Kuh , Jinadasa S. U. P.
Published: February 2015

A series of 134 microstructure profiles were taken in the central East China Sea from a drifting ship, covering more than 12 miles over the sloping bottom. The water depthzvaried in the range 52–62 m; the tidal elevation of semidiurnal component was ±1 m. Prior to the onset of 25 h drift, a hydrographic section consisting of 9 stations, 15 miles apart, was taken in the area. A shallow mixed surface layer (SL) underlain by a diurnal pycnocline (z < 13 m), a sharp thermohalocline (13 < z < 30 m), and about 20 m tall bottom boundary layer (BBL) were the main features of summertime stratification. The splitting of upper pycnocline by a warmer, saltier intrusion led to the generation of turbulent patches at the lower, but not at the upper, density interface of this water body, suggesting asymmetry of mixing across the intrusion. In a limited range of the normalized squared buoyancy frequency,, the turbulent kinetic energy dissipation ratedecreased sharply as, whereW/kg ands−1. Measurements in the sharp pycnocline and in lesser‐stratified transitional layers between the pycnocline and the SL and BBL show that the cumulative distribution functionscan be modeled either by the generalized extreme value (GEV) distribution or the lognormal distribution.
An improved methodology for deriving high‐resolution surface shortwave radiative fluxes from MODIS in the Arctic region
Authors: Niu Xiaolei , Pinker Rachel T.
Published: February 2015

The Arctic is experiencing an unprecedented increase in surface air temperature and decrease in sea ice extent. The causes of these changes are still being debated; radiative fluxes are believed to play an important role in this warming. The primary motivation for this study is to advance the quality and resolution of currently available information on surface shortwave (solar) irradiance (SWR) for the Arctic. Such information is needed to meet the challenge for accurate estimates of heat input into the open waters. An inference scheme that utilizes the Moderate Resolution Imaging Spectroradiometer (MODIS) observations is optimized for high latitudes and implemented at 5 km for 2007 at an hourly time scale. Evaluation of the 5 km based SWR estimates against hourly ground observations at Barrow site shows a mean bias of 7.9 W m−2 (3% of mean values), a standard deviation of 58.2 W m−2 (23% of mean value), and a high correlation of 0.95. Evaluation of the SWR estimates against daily ground measurements at these latitudes shows good agreement with surface observations at three sites, with a mean bias of 1.9 W m−2 (1.1% of mean values), a standard deviation of 31.5 W m−2 (17.8% of mean value), and a high correlation of 0.96. Information at this high resolution and good quality can lead to improved estimates of heat input into the complex Arctic domain. For the Beaufort Sea domain (70°N–80°N, 120°E–50°E), the differences can amount to 116 MJ m−2 (~7%) of the total solar input of this region.
Atmospheric water vapor retrieval from Landsat 8 thermal infrared images
Authors: Ren Huazhong , Du Chen , Liu Rongyuan , Qin Qiming , Yan Guangjian , Li Zhao‐Liang , Meng Jinjie
Published: February 2015

Atmospheric water vapor (wv) is required for the accurate retrieval of the land surface temperature from remote sensing data and other applications. This work aims to estimate wv from Landsat 8 Thermal InfraRed Sensor (TIRS) images using a new modified split‐window covariance‐variance ratio (MSWCVR) method on the basis of the brightness temperatures of two thermal infrared bands. Results show that the MSWCVR method can theoretically retrieve wv with an accuracy better than 0.3 g/cm2 for dry atmosphere (wv <2 g/cm2) conditions and better than 0.5 g/cm2 for wet atmosphere conditions. The method was applied at different locations with dry and moist atmospheres and was validated at 42 ground sites using AERONET (Aerosol Robotic Network) ground‐measured data and MODIS (Moderate Resolution Imaging Spectroradiometer) products. The results show that the retrieved wv from the TIRS data is highly correlated with the wv of AERONET and MODIS but is generally larger. This difference was probably attributed to the uncertainty of radiometric calibration and stray light coming outside from field of view of TIRS instrument in the current images. Consequently, the data quality and radiometric calibration of the TIRS data should be improved in the future.
Chemical variations in Yellowknife Bay formation sedimentary rocks analyzed by ChemCam on board the Curiosity rover on Mars
Authors: Mangold N. , Forni O. , Dromart G. , Stack K. , Wiens R. C. , Gasnault O. , Sumner D. Y. , Nachon M. , Meslin P.‐Y. , Anderson R. B. , Barraclough B. , Bell J. F. , Berger G. , Blaney D. L. , Bridges J. C. , Calef F. , Clark B. , Clegg S. M. , Cousin A. , Edgar L. , Edgett K. , Ehlmann B. , Fabre C. , Fisk M. , Grotzinger J. , Gupta S. , Herkenhoff K. E. , Hurowitz J. , Johnson J. R. , Kah L. C. , Lanza N. , Lasue J. , Le Mouélic S. , Léveillé R. , Lewin E. , Malin M. , McLennan S. , Maurice S. , Melikechi N. , Mezzacappa A. , Milliken R. , Newsom H. , Ollila A. , Rowland S. K. , Sautter V. , Schmidt M. , Schröder S. , d'Uston C. , Vaniman D. , Williams R.
Published: February 2015

The Yellowknife Bay formation represents a ~5 m thick stratigraphic section of lithified fluvial and lacustrine sediments analyzed by the Curiosity rover in Gale crater, Mars. Previous works have mainly focused on the mudstones that were drilled by the rover at two locations. The present study focuses on the sedimentary rocks stratigraphically above the mudstones by studying their chemical variations in parallel with rock textures. Results show that differences in composition correlate with textures and both manifest subtle but significant variations through the stratigraphic column. Though the chemistry of the sediments does not vary much in the lower part of the stratigraphy, the variations in alkali elements indicate variations in the source material and/or physical sorting, as shown by the identification of alkali feldspars. The sandstones contain similar relative proportions of hydrogen to the mudstones below, suggesting the presence of hydrous minerals that may have contributed to their cementation. Slight variations in magnesium correlate with changes in textures suggesting that diagenesis through cementation and dissolution modified the initial rock composition and texture simultaneously. The upper part of the stratigraphy (~1 m thick) displays rocks with different compositions suggesting a strong change in the depositional system. The presence of float rocks with similar compositions found along the rover traverse suggests that some of these outcrops extend further away in the nearby hummocky plains.
Uncertainty quantification for a climatology of the frequency and spatial distribution of North Atlantic tropical cyclone landfalls
Authors: Tolwinski‐Ward S. E.
Published: February 2015

A spatially resolved climatology for the annual frequency of tropical cyclone (TC) landfalls along the Atlantic coast of North America is developed, and its uncertainty deriving from multiple sources is quantified. Historical landfall counts in piecewise‐linear segments approximating the coastline are modeled using Poisson regression with spatial random effects. Predictors include index representations of the mean hurricane‐season phases of the Southern Oscillation, the Atlantic Multidecadal Oscillation, and the North Atlantic Oscillation, with the effect of the latter also modeled spatially. This spatial generalized linear model for landfall frequency is used in conjunction with a data level accounting explicitly for the time‐dependent uncertainty in the recorded landfall positions. The model performs skillfully in cross‐validation exercises. The inferred effects of the climatic predictors are also consistent with current scientific understanding of the mechanisms through which related large‐scale climatic variability affects the development and motion of Atlantic tropical cyclones. Sampling variability in the data over the short length of the observational record and observational error in the historical data are found to contribute substantially to the overall climatological uncertainty. The contribution from uncertainty in the underlying model parameters is negligible compared to these other sources. The model presented here could be used for applications in insurance and risk management, and adaptations could also be used to investigate changes in TC landfall climatology under an uncertain and changing climate.
The tilt of mean sea level along the east coast of North America
Authors: Higginson S. , Thompson K. R. , Woodworth P. L. , Hughes C. W.
Published: February 2015

The tilt of mean sea level along the North American east coast has been a subject of debate for many decades. Improvements in geoid and ocean circulation models, and GPS positioning of tide gauge benchmarks, provide an opportunity to produce new tilt estimates. Tilts estimated using tide gauge measurements referenced to high‐resolution geoid models (the geodetic approach) and ocean circulation models (the ocean approach) are compared. The geodetic estimates are broadly similar, with tilts downward to the north through the Florida Straits and at Cape Hatteras. Estimates from the ocean approach show good agreement with the geodetic estimates, indicating a convergence of the two approaches and resolving the long standing debate as to the sign of the tilt. These tilts differ from those used by Yin and Goddard (2013) to support a link between changing ocean circulation and coastal sea level rise.
Hypervelocity Impact Testing of a Metallic Glass‐Stuffed Whipple Shield
Authors: Hofmann Douglas C. , Hamill Lee , Christiansen Eric , Nutt Steve
Published: February 2015

In this work, hypervelocity impact tests up to 7 km · s−1are used to compare the performance of Whipple shields integrated with layers of metallic glasses with a baseline target analogue of one of the shields similar to what is used on the International Space Station. The baseline target failed under the impact while the target utilizing metallic glass as a replacement for the fabric layers in the baseline passed the test. The paper postulates on the prospects of future implementation of metallic glasses as spacecraft debris shields.
Alignment of Rod‐Shaped Single‐Photon Emitters Driven by Line Defects in Liquid Crystals
Authors: Pelliser Laurent , Manceau Mathieu , Lethiec Clotilde , Coursault Delphine , Vezzoli Stefano , Leménager Godefroy , Coolen Laurent , DeVittorio Massimo , Pisanello Ferruccio , Carbone Luigi , Maitre Agnes , Bramati Alberto , Lacaze Emmanuelle
Published: February 2015

Arrays of liquid crystal defects—linear smectic dislocations—are used to trap semiconductor CdSe/CdS dot‐in‐rods which behave as single‐photon emitters. Measurements of the emission diagram are combined together with measurements of the emitted polarization of the single emitters. It is shown that the dot‐in‐rods are confined parallel to the linear defects to allow for a minimization of the disorder energy associated with the dislocation cores. It is demonstrated that the electric dipoles associated with the dot‐in‐rods, tilted with respect to the rods, remain oriented in the plane including the smectic linear defects and perpendicular to the substrate, most likely due to dipole/dipole interactions between the dipoles of the liquid crystal molecules and those of the dot‐in‐rods. Using smectic dislocations, nanorods can consequently be oriented along a unique direction for a given substrate, independently of the ligands' nature, without any induced aggregation, leading as well to a fixed azimuthal orientation for the dot‐in‐rods' dipoles. These results open the way for the fine control of nanoparticle anisotropic optical properties, in particular, fine control of single‐photon emission polarization.
Coupling Freshly Isolated CD44+Infrapatellar Fat Pad‐Derived Stromal Cells with a TGF‐β3 Eluting Cartilage ECM‐Derived Scaffold as a Single‐Stage Strategy for Promoting Chondrogenesis
Authors: Almeida Henrique V. , Cunniffe Gráinne M. , Vinardell Tatiana , Buckley Conor T. , O'Brien Fergal J. , Kelly Daniel J.
Published: February 2015

An alternative strategy to the use of in vitro expanded cells in regenerative medicine is the use of freshly isolated stromal cells, where a bioactive scaffold is used to provide an environment conducive to proliferation and tissue‐specific differentiation in vivo. The objective of this study is to develop a cartilage extracellular matrix (ECM)‐derived scaffold that could facilitate the rapid proliferation and chondrogenic differentiation of freshly isolated stromal cells. By freeze‐drying cryomilled cartilage ECM of differing concentrations, it is possible to produce scaffolds with a range of pore sizes. The migration, proliferation, and chondrogenic differentiation of infrapatellar fat pad‐derived stem cells (FPSCs) depend on the concentration/porosity of these scaffolds, with greater sulphated glycosaminoglycan (sGAG) accumulation observed in scaffolds with larger‐sized pores. It is then sought to determine if freshly isolated fat pad‐derived stromal cells, seeded onto a transforming growth factor (TGF)‐β3 eluting ECM‐derived scaffold, could promote chondrogenesis in vivo. While a more cartilage‐like tissue could be generated using culture expanded FPSCs compared to nonenriched freshly isolated cells, fresh CD44+stromal cells are capable of producing a tissue in vivo that stained strongly for sGAGs and type II collagen. These findings open up new possibilities for in‐theatre cell‐based therapies for joint regeneration.
Heterogeneous Gold‐Catalyzed Selective Reductive Transformation of Quinolines with Formic Acid
Authors: Tao Lei , Zhang Qi , Li Shu‐Shuang , Liu Xiang , Liu Yong‐Mei , Cao Yong
Published: February 2015

Single phase rutile titania supported gold nanoparticles (Au/TiO2‐R) are found to be efficient and versatile catalysts for chemo‐ and regioselective transfer hydrogenation of quinoline derivatives to 1,2,3,4‐tetrahydroquinolines (THQs) using formic acid (FA) as a safe and convenient hydrogen source under mild conditions. The activity and chemoselectivity of the Au/TiO2‐R catalyst towards THQs is excellent, with a substrate to catalyst ratio (S/C) of 1000 being feasible. Furthermore, a straightforward and selective route to N‐formyltetrahydroquinolines (FTHQ) directly from quinoline compounds and FA by one‐pot, gold‐catalyzed reductive N‐formylation protocol is also established.

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Examining the Influence of Production Scale on the Volume Expansion Behavior of Polyethylene Foams in Rotational Foam Molding
Authors: Emami Maryam , Vlachopoulos John , Thompson Michael R. , Maziers Eric
Published: February 2015

In the present study, an evaluation of the “scale of production” on rotational foam molding was conducted and experimental observations from microscopic, lab‐ and pilot‐scale foam systems were used to investigate the impact of the rheology on the process. A systematic comparison looking at the influence of rheological properties of the polymer matrix on the expansion behavior of polyethylene foams indicated that the size of the foam system does not affect the fundamental mechanisms of the foaming process and that the effects of system size on foam techniques could be suppressed by tailoring the processing conditions. It was demonstrated that the impact of rheology on bubble development observed in microscopic studies can be practically extended to higher scales of foaming, and the results can provide guidelines for the selection of the polymer materials for customized foam applications.
Is cardiac rhabdomyoma a feature of Birt Hogg Dubé syndrome?
Authors: Bondavalli Davide , White Susan M , Steer Andrew , Pflaumer Andreas , Winship Ingrid
Published: February 2015

We report on a child with two cardiac rhabdomyomas. Initially, a diagnosis of Tuberous Sclerosis Complex (TSC) syndrome was suspected, although this could neither be confirmed clinically nor genetically. Coincidentally, Birt Hogg Dubé syndrome (BHD) had been previously diagnosed in members of the extended family; this prompted a diagnostic re‐evaluation of the child who was found to have the known family FLCN mutation. We recommend consideration of cardiac rhabdomyomas as part of the clinical BHD spectrum. © 2015 Wiley Periodicals, Inc.
Clinical comparison of 10q26 overlapping deletions: Delineating the critical region for urogenital anomalies
Authors: Vera‐Carbonell Ascensión , López‐González Vanesa , Bafalliu Juan Antonio , Ballesta‐Martínez María J , Fernández Asunción , Guillén‐Navarro Encarna , López‐Expósito Isabel
Published: February 2015

The 10q26 deletion syndrome is a clinically heterogeneous disorder. The most common phenotypic characteristics include pre‐ and/or postnatal growth retardation, microcephaly, developmental delay/intellectual disability and a facial appearance consisting of a broad nasal bridge with a prominent nose, low‐set malformed ears, strabismus, and a thin vermilion of the upper lip. In addition, limb and cardiac anomalies as well as urogenital anomalies are occasionally observed. In this report, we describe three unrelated females with 10q26 terminal deletions who shared clinical features of the syndrome, including urogenital defects. Cytogenetic studies showed an apparently de novo isolated deletion of the long arm of chromosome 10, with breakpoints in 10q26.1, and subsequent oligo array‐CGH analysis confirmed the terminal location and defined the size of the overlapping deletions as ∼13.46, ∼9.31 and ∼9.17 Mb. We compared the phenotypic characteristics of the present patients with others reported to have isolated deletions and we suggest that small 10q26.2 terminal deletions may be associated with growth retardation, developmental delay/intellectual disability, craniofacial features and external genital anomalies whereas longer terminal deletions affecting the 10q26.12 and/or 10q26.13 regions may be responsible for renal/urinary tract anomalies. We propose that the haploinsufficiency of one or several genes located in the 10q26.12‐q26.13 region may contribute to the renal or urinary tract pathogenesis and we highlight the importance of FGFR2 and probably of CTBP2 as candidate genes.
Alpha‐synuclein (SNCA) polymorphisms and susceptibility to Parkinson's disease: A meta‐analysis
Authors: Han Wei , Liu Yingli , Mi Yingjun , Zhao Jing , Liu Dianwu , Tian Qing‐Bao
Published: February 2015

It has been reported that single nucleotide polymorphisms (SNPs) of Alpha‐synuclein (SNCA) are associated with Parkinson's disease (PD). Some researchers have attempted to validate this finding in various ethnic populations. The results of studies concerning SNCA polymorphisms and PD susceptibility remain conflicting. To evaluate the association between these SNPs and PD, the authors conducted a series of meta‐analyses using a predefined protocol. Databases including PubMed, MEDLINE and PD gene were searched to identify relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. All analyses were calculated using STATA11.0. A total of 19 studies on the SNPS rs181489, rs356186, rs356219, rs894278, rs2583988, rs2619363, rs2619364, rs2737029, rs10005233 and rs11931074 were included. This meta‐analysis showed that eight out of these 10 candidate SNPs may be associated with PD risk. Significant association was found between PD and the following SNPs: rs181489, rs356186, rs356219, rs894278 rs2583988, rs2619364, rs10005233 and rs11931074. Among these SNPs, rs356186 was found to be the only SNP that may play a protective role in Parkinson's disease. These results suggest that the SNCA gene may be associated with PD. © 2015 Wiley Periodicals, Inc.
A Metal–Ligand Cooperative Pathway for Intermolecular Oxa‐Michael Additions to Unsaturated Nitriles
Authors: Perdriau Sébastien , Zijlstra Douwe S. , Heeres Hero J. , de Vries Johannes G. , Otten Edwin
Published: February 2015

An unprecedented catalytic pathway for oxa‐Michael addition reactions of alcohols to unsaturated nitriles has been revealed using a PNN pincer ruthenium catalyst with a dearomatized pyridine backbone. The isolation of a catalytically competent Ru–dieneamido complex from the reaction between the Ru catalyst and pentenenitrile in combination with DFT calculations supports a mechanism in which activation of the nitrile through metal–ligand cooperativity is a key step. The nitrile‐derived Ru‐N moiety is sufficiently Brønsted basic to activate the alcohol and initiate conjugate addition of the alkoxide to the α,β‐unsaturated fragment. This reaction proceeds in a concerted manner and involves a six‐membered transition state. These features allow the reaction to proceed at ambient temperature in the absence of external base.
Electron Transfer in Peptides: On the Formation of Silver Nanoparticles
Authors: Kracht Sonja , Messerer Matthias , Lang Matthieu , Eckhardt Sonja , Lauz Miriam , Grobéty Bernard , Fromm Katharina M. , Giese Bernd
Published: February 2015

Some microorganisms perform anaerobic mineral respiration by reducing metal ions to metal nanoparticles, using peptide aggregates as medium for electron transfer (ET). Such a reaction type is investigated here with model peptides and silver as the metal. Surprisingly, Ag+ ions bound by peptides with histidine as the Ag+‐binding amino acid and tyrosine as photoinducible electron donor cannot be reduced to Ag nanoparticles (AgNPs) under ET conditions because the peptide prevents the aggregation of Ag atoms to form AgNPs. Only in the presence of chloride ions, which generate AgCl microcrystals in the peptide matrix, does the synthesis of AgNPs occur. The reaction starts with the formation of 100 nm Ag@AgCl/peptide nanocomposites which are cleaved into 15 nm AgNPs. This defined transformation from large nanoparticles into small ones is in contrast to the usually observed Ostwald ripening processes and can be followed in detail by studying time‐resolved UV/Vis spectra which exhibit an isosbestic point.
Organic Donor Materials Based on Bis(arylene ethynylene)s for Bulk Heterojunction Organic Solar Cells with High Voc Values
Authors: Zhan Hongmei , Liu Qian , Dai Fengrong , Ho Cheuk‐Lam , Fu Yingying , Li Leijiao , Zhao Li , Li Hua , Xie Zhiyuan , Wong Wai‐Yeung
Published: February 2015

A series of purely organic small molecules 1–4 based on bis(arylene ethynylene)s with various electron‐rich aromatic bridges, such as benzene, cyclopentadithiophene (CDT), and diphenyl(p‐tolyl)amine, were synthesized by a Sonogashira coupling reaction. Their optical, electronic, and electrochemical properties were fully characterized. The photovoltaic properties of these molecules as donor materials and [6,6]‐phenyl‐C71‐butyric acid methyl ester as an acceptor material in solution‐processed bulk heterojunction devices were studied. Among them, CDT‐bridged molecule 2 exhibited the best photovoltaic performance and achieved a power conversion efficiency of 3.28 %. In addition, the photovoltaic efficiencies of these molecules are higher than their corresponding platinum‐containing counterparts, probably owing to their stronger light absorption and improved open‐circuit voltage.
A H+/Ag+ Dual‐Target Responsive Label‐Free Light‐Up Probe Based on a DNA Triplex
Authors: Xu Lijun , Guo Yahui , Wang Jine , Zhou Lu , Zhang Yuanyuan , Hong Shanni , Wang Zhili , Zhang Jianye , Pei Renjun
Published: February 2015

We developed a dual‐target responsive sensor for label‐free light‐up fluorescent detection of protons (H+) and silver ions (Ag+) using an “OR′′ logic gate. Berberine, a cost‐effective and non‐toxic indicator, partially intercalates the formed triplex DNA in the presence of H+ or Ag+, generating enhanced fluorescence. The designed Ag+ probe has high selectivity and desirable sensitivity, which is necessary for practical use. The robust ”OR“ logic gate is capable of a rapid and reversible response to the H+ and/or Ag+ inputs.
Maternal risk for down syndrome and polymorphisms in the promoter region of the DNMT3B gene: A case–control study
Authors: Jaiswal Sushil Kumar , Sukla Krishna Kishore , Kumari Neha , Lakhotia Anjali Rani , Kumar Ashok , Rai Amit Kumar
Published: February 2015

Background

Epigenetic changes leading to improper methylation of the pericentromeric region of chromosome 21 may contribute to the nondisjunction of this chromosome. Polymorphisms in the DNA Methyltransferase 3B (DNMT3B) gene, one of the crucial gene of the folate metabolism, affects the activity of the enzyme and increases the susceptibility of nondisjunction in mothers of Down syndrome children (MDS).

Methods

Considering this hypothesis we investigated the association of single nucleotide polymorphisms in the promoter region of the DNMT3B gene (rs1569686 ‐579G>T; rs2424913 ‐149C>T) with a predisposition of mothers to deliver a Down syndrome (DS) child. The study was performed on DNA samples from 150 MDS and 172 control mothers. Transmission disequilibrium tests were performed on 103 DS trio families. Genotyping was done using a polymerase chain reaction‐restriction fragment length polymorphism method.

Results

With respect to the single nucleotide polymorphisms studied, no significant difference was observed in the genotypes and alleles frequency distributions between MDS and control mothers. The frequency of the DNMT3B‐579G allele was, respectively, 0.34 in MDS and 0.33 in control mothers whereas the frequency of the DNMT3B‐149C allele was respectively 0.31 in MDS and 0.26 in control mothers. No significant deviation in genotypic combinations as well as in transmission disequilibrium tests analysis was observed. However, a strong linkage disequilibrium was observed with significant differences in the distribution of G‐T and G‐C haplotypes among case and control mothers.

Conclusion

Although the above studied polymorphisms of DNMT3B may not be an independent risk factor it might be possible that certain allelic combinations (G‐T) are. This finding suggests that DNMT3B might be a maternal risk factor for DS in our Indian cohort. Replication studies are required to confirm these findings. Birth Defects Research (Part A) 103:299–305, 2015. © 2015 Wiley Periodicals, Inc.
Photoluminescence properties of LiBaPO4:M3+ phosphor for near‐UV light‐emitting diode (M = Eu and Dy)
Authors: Puppalwar S. P. , Dhoble S. J.
Published: February 2015

A novel phosphor LiBaPO4 doped with rare earths Eu and Dy prepared by high temperature solid‐state reaction method is reported. The phosphors were characterized by X‐ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL). The emission and excitation spectra of these materials were measured at room temperature with a spectrofluorophotometer. The excitation spectra of LiBaPO4:Eu3+ phosphor can be efficiently excited by 394 nm, which is matched well with the emission wavelength of near‐UV light‐emitting diode (LED) chip. PL properties of Eu3+‐doped LiBaPO4 exhibited the characteristic red emission coming from 5D0 → 7 F1 (593 nm) and 5D0 → 7 F2 (617 nm) electronic transitions with color co‐ordinations of (0.680, 0.315). The results demonstrated that LiBaPO4:Eu3+ is a potential red‐emitting phosphor for near‐UV LEDs. Emission spectra of LiBaPO4:Dy3+ phosphors showed efficient blue (481 nm) and yellow (574 nm) bands, which originated from 4 F9/2 → 6H15/2 and 4 F9/2 → 6H13/2 transitions of the Dy3+ ion, respectively. The 574 nm line is more intense than the 481 nm lines, which indicates that the site Dy3+ is located with low symmetry. This article summarizes fundamentals and possible applications of optically useful inorganic phosphates with visible photoluminescence of Eu3+ and Dy3+ ions. Copyright © 2015 John Wiley & Sons, Ltd.
The role of proline‐containing peptide triads in β‐sheet formation: A kinetic study
Authors: Takor Gaius A. , Higashiya Seiichiro , Sikirzhytski Vitali K. , Seeley Jason P. , Lednev Igor K. , Welch John T.
Published: February 2015

The design of biomimetic materials through molecular self‐assembly is a growing area of modern nanotechnology. With problems of protein folding, self‐assembly, and sequence–structure relationships as essential in nanotechnology as in biology, the effect of the nucleation of β‐hairpin formation by proline on the folding process has been investigated in model studies. Previously such studies were limited to investigations of the influence of proline on the formation of turns in short peptide sequences. The effect of proline‐based triads on the folding of an 11‐kDa amyloidogenic peptide GH6[(GA)3GY(GA)3GE]8GAH6 (YE8) was investigated by selective substitution of the proline‐substituted triads at the γ‐turn sites. The folding and fibrillation of the singly proline‐substituted polypeptides, e.g., GH6[(GA)3GY(GA)3GE]7(GA)3GY(GA)3PDGAH6 (8PD), and doubly proline‐substituted polypeptides, e.g., GH6[(GA)3GY(GA)3GE]3(GA)3GY(GA)3PD[(GA)3GY(GA)3GE]3(GA)3GY(GA)3PDGAH6 (4,8PD), were directly monitored by circular dichroism and deep UV resonance Raman and fluorescence spectroscopies. These findings were used to identify the essential folding domains, i.e., the minimum number of β‐strands necessary for stable folding. These experimental findings may be especially useful in the design and construction of peptidic materials for a wide range of applications as well as in understanding the mechanisms of folding critical to fibril formation. © 2015 Wiley Periodicals, Inc. Biopolymers 103: 339–350, 2015.
Exploring students' learning attitude and achievement in flipped learning supported computer aided design curriculum: A study in high school engineering education
Authors: Chao Chih‐Yang , Chen Yuan‐Tai , Chuang Kuei‐Yu
Published: February 2015

This research aims to explore the benefits of a flipped learning approach for students who are taking an introductory‐level curriculum on bridge computer aided design in terms of learning attitude and achievement within the curriculum. In this study, collaborative problem based learning (CPBL) supported by flipped learning, a blended learning design, was integrated into a high school bridge computer aided design curriculum. Ninety‐one 17‐year‐old students from two K11 classes were assigned randomly to an experimental group and a control group for the study, respectively. To assess the students' achievements and learning attitudes in the different groups, an 8‐week (16 h in total) pre‐ and post‐test quasi‐experimental study was designed. The results confirmed the effectiveness of the flipped learning approach. Significant differences were found between the experimental and control group in terms of students' achievements. In the experimental group, students' learning attitudes, motivation and self‐evaluation were enhanced. In conclusion, the results show that the flipped learning approach has a positive effect on the transfer of learning. Based on the findings obtained, recommendations for the improvement of future K12 engineering education instruction using the flipped learning approach are provided. © 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:514–526, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21622
AMP promotes oxygen consumption and ATP synthesis in heart mitochondria through the adenylate kinase reaction: an NMR spectroscopy and polarography study
Authors: Doliba Nicolai M. , Babsky Andriy M. , Doliba Nataliya M. , Wehrli Suzanne L. , Osbakken Mary D.
Published: February 2015

Adenylate kinase plays an important role in cellular energy homeostasis by catalysing the interconversion of adenine nucleotides. The goal of present study was to evaluate the contribution of the adenylate kinase reaction to oxidative ATP synthesis by direct measurements of ATP using 31P NMR spectroscopy. Results show that AMP can stimulate ATP synthesis in the presence or absence of ADP. In particular, addition of 1 mM AMP to the 0.6 mM ADP superfusion system of isolated superfused mitochondria (contained and maintained in agarose beads) led to a 25% increase in ATP synthesis as measured by the increase in βATP signal. More importantly, we show that AMP can support ATP synthesis in the absence of ADP, demonstrated as follows. Superfusion of mitochondria without ADP led to the disappearance of ATP γ, α and β signals and the increase of Pi. Addition of AMP to the medium restored the production of ATP, as demonstrated by the reappearance of γ, α and β ATP signals, in conjunction with a decrease in Pi, which is being used for ATP synthesis. Polarographic studies showed Mg2+ dependence of this process, confirming the specificity of the adenylate kinase reaction. Furthermore, data obtained from this study demonstrate, for the first time, that different aspects of the adenylate kinase reaction can be evaluated with 31P NMR spectroscopy. Copyright © 2015 John Wiley & Sons, Ltd.

SIGNIFICANCE OF RESEARCH PARAGRAPH

The data generated in the present study indicate that 31P NMR spectroscopy can effectively be used to study the adenylate kinase reaction under a variety of conditions. This is important because understanding of adenylate kinase function and/or malfunction is essential to understanding its role in health and disease. The data obtained with 31P NMR were confirmed by polarographic studies, which further strengthens the robustness of the NMR findings. In summary, 31P NMR spectroscopy provides a sensitive tool to study adenylate kinase activity in different physiological and pathophysiological conditions, including but not exclusive of, cancer, ischemic injury, hemolytic anemia and neurological problems such as sensorineural deafness.
Structure, Activity, and Deactivation Mechanisms in Double Metal Cyanide Catalysts for the Production of Polyols
Authors: Almora‐Barrios Neyvis , Pogodin Sergey , Bellarosa Luca , García‐Melchor Max , Revilla‐López Guillem , García‐Ratés Miquel , Vázquez‐García Ana Belén , Hernández‐Ariznavarreta Pedro , López Núria
Published: February 2015

Polyether polyols are used widely in the plastic and coating industries in the form of polyurethanes. The polymerization of epoxides can be catalyzed by double metal cyanides (DMCs), Zn3[Co(CN)6]2. These catalysts were first reported in the 1960s by General Tire Inc. and provide products with excellent technical features, which are better than those that result from traditional alkaline polymerization as side reactions are alleviated. However, DMC‐catalyzed polymerization is not free of drawbacks as high‐molecular‐weight side products (1–3 wt %) can form in the propylene process. These tails are detrimental to the subsequent use of these polymers, in particular to foam stability. Despite the wide industrial interest in DMCs, there are only a few experimental studies and a complete lack of theoretical research of their structure, activity, and performance. The present work is thus the first attempt to describe the nature of the active site, the main polymerization mechanism, and two potential origins for the high‐weight tails from a theoretical standpoint by analyzing three crucial steps in the polymerization process.
Iron(II) Pincer‐Catalyzed Synthesis of Lactones and Lactams through a Versatile Dehydrogenative Domino Sequence
Authors: Peña‐López Miguel , Neumann Helfried , Beller Matthias
Published: February 2015

The synthesis of lactones and lactams by using iron(II) pincer‐catalyzed dehydrogenative methodology was developed. Starting from 1,n‐diols or 1,n‐amino alcohols, this domino transformation takes place through initial dehydrogenation of the substrates, subsequent intramolecular cyclization, and final oxidation to afford the desired products in good yields. The ability to access heterocycles of different sizes makes this protocol especially versatile, in which two consecutive oxidation reactions are performed without requiring an external oxidant. In this paper, we report the application of the Fe‐MACHO‐BH complex [carbonylhydrido(tetrahydroborato)[bis(2‐diisopropylphosphinoethyl)amino]iron(II)] in this atom‐efficient and environmentally benign process, for which molecular hydrogen is formed as the only stoichiometric side product.
In Situ Electrochemical Generation of Hydrogen Peroxide in Alkaline Aqueous Solution by using an Unmodified Gas Diffusion Electrode
Authors: Barros Willyam R. P. , Ereno Thaís , Tavares Ana C. , Lanza Marcos R. V.
Published: February 2015

Hydrogen peroxide (H2O2) is an oxidizing agent commonly used for various applications and is available in aqueous solution in a wide range of concentrations. This work describes the H2O2 electrogeneration process in alkaline medium (KOH 1.0 mol L−1), using an unmodified gas diffusion electrode (GDE) manufactured with Printex 6L carbon. The experiments were performed in a single‐compartment electrochemical cell equipped with a GDE as the working electrode, which was fed with N2 or O2 at a pressure of 0.2 bar. Electrolysis experiments were performed at a constant potential (−0.5≤E≤−1.4 V) for 90 min. The H2O2 concentration reached a maximum value of 3370 mg L−1 at −1.1 V (vs. Ag/AgCl), and H2O2 electrogeneration followed pseudo‐zero‐order kinetics with an apparent rate constant kapp=59.7 mg L−1 min−1. A low energy consumption of 8.0 kWh kg−1 was calculated for these electrogeneration conditions.
Matrix‐Free DNP‐Enhanced NMR Spectroscopy of Liposomes Using a Lipid‐Anchored Biradical
Authors: Fernández‐de‐Alba Carlos , Takahashi Hiroki , Richard Alexandre , Chenavier Yves , Dubois Lionel , Maurel Vincent , Lee Daniel , Hediger Sabine , De Paëpe Gaël
Published: February 2015

Magic‐angle spinning dynamic nuclear polarization (MAS‐DNP) has been proven to be a powerful technique to enhance the sensitivity of solid‐state NMR (SSNMR) in a wide range of systems. Here, we show that DNP can be used to polarize lipids using a lipid‐anchored polarizing agent. More specifically, we introduce a C16‐functionalized biradical, which allows localization of the polarizing agents in the lipid bilayer and DNP experiments to be performed in the absence of excess cryo‐protectant molecules (glycerol, dimethyl sulfoxide, etc.). This constitutes another original example of the matrix‐free DNP approach that we recently introduced.
Synthesis of Four Diastereomers of Sclerophytin F and Structural Reassignment of Several Sclerophytin Natural Products
Authors: Clark J. Stephen , Delion Laëtitia , Farrugia Louis J.
Published: February 2015

Synthesis of the triol that has been proposed to be the marine natural product sclerophytin F has been completed along with the syntheses of three diastereomers. Comparison of the NMR spectroscopic data for all four compounds to the data reported for the natural product reveals that sclerophytin F is not the 3S diastereomer of sclerophytin A as proposed by Friedrich and Paquette. Re‐analysis of the NMR spectroscopic data for known sclerophytin natural products and synthetic analogues leads to the conclusion that sclerophytins E and F are the same compound. This finding has allowed structural reassignment of several other cladiellin natural products.
Azobenzene‐Functionalized Cage Silsesquioxanes as Inorganic–Organic Hybrid, Photoresponsive, Nanoscale, Building Blocks
Authors: Liu Yun , Yang Wenyan , Liu Hongzhi
Published: February 2015

Mono‐ and octa‐azobenzene‐functionalized cage silsesquioxanes were easily synthesized by the reaction of 4‐bromoazobenzene with monovinyl‐substituted octasilsesquioxane and cubic octavinylsilsesquioxane through the Heck coupling reaction. Excited‐state energies obtained from time‐dependent density functional theory (TDDFT) and the CAM‐B3LYP functional correlate very well with experimental trans–cis photoisomerization results from UV/Vis spectroscopy. These azobenzene‐functionalized cages exhibit good thermal stability and are fluorescent with maximum emission at approximately 400 nm, making them potential materials for blue‐light emission.
Pd‐Catalyzed Csp2H Functionalization of Heteroarenes via Isocyanide Insertion: Concise Synthesis of Di‐(Hetero)Aryl Ketones and Di‐(Hetero)Aryl Alkylamines
Authors: Sharma Upendra K. , Sharma Nandini , Xu Jun , Song Gonghua , Van der Eycken Erik V.
Published: February 2015

We report herein an efficient Pd‐catalyzed direct CH bond functionalization of heteroarenes via an isocyanide insertion strategy for the synthesis of di‐(hetero)aryl ketones and di‐(hetero)aryl alkylamines. The methodology involves a three component reaction between an azole, a haloarene and an isocyanide resulting in the formation of an imine, which in turn is either hydrolyzed or reduced to get the desired product.
Iridium‐Catalyzed Hydrogen Production from Monosaccharides, Disaccharide, Cellulose, and Lignocellulose
Authors: Li Yang , Sponholz Peter , Nielsen Martin , Junge Henrik , Beller Matthias
Published: February 2015

Hydrogen constitutes an important feedstock for clean‐energy technologies as well as for production of bulk and fine chemicals. Hence, the development of novel processes to convert easily available biomass into H2 is of general interest. Herein, we demonstrate a one‐pot protocol hydrogen generation from monosaccharides, disaccharide, and extremely demanding cellulose and lignocellulose substrates by using a pincer‐type iridium catalyst. Applying ppm amounts of this catalyst, hydrogen is produced at temperatures lower than 120 °C. More specifically, catalyst turnover numbers (TONs) for lignocellulose from bamboo reached up to about 3000. Interestingly, even (used) cigarette filters, which are composed of cellulose acetate, produce hydrogen under optimized conditions.
Lack of association of apolipoprotein E (Apo E) polymorphism with the prevalence of metabolic syndrome: the National Heart, Lung and Blood Institute Family Heart Study
Authors: Lai Lana Y. H. , Petrone Andrew B. , Pankow James S. , Arnett Donna K. , North Kari E. , Ellison R. Curtis , Hunt Steven C. , Rosenzweig James L. , Djoussé Luc
Published: February 2015

Objective

Metabolic syndrome (MetS), characterized by abdominal obesity, atherogenic dyslipidaemia, elevated blood pressure and insulin resistance, is a major public health concern in the United States. The effects of apolipoprotein E (Apo E) polymorphism on MetS are not well established.

Methods

We conducted a cross‐sectional study consisting of 1551 participants from the National Heart, Lung and Blood Institute Family Heart Study to assess the relation of Apo E polymorphism with the prevalence of MetS. MetS was defined according to the American Heart Association–National Heart, Lung and Blood Institute–International Diabetes Federation–World Health Organization harmonized criteria. We used generalized estimating equations to estimate adjusted odds ratios (ORs) for prevalent MetS and the Bonferroni correction to account for multiple testing in the secondary analysis.

Results

Our study population had a mean age (standard deviation) of 56.5 (11.0) years, and 49.7% had MetS. There was no association between the Apo E genotypes and the MetS. The multivariable adjusted ORs (95% confidence interval) were 1.00 (reference), 1.26 (0.31–5.21), 0.89 (0.62–1.29), 1.13 (0.61–2.10), 1.13 (0.88–1.47) and 1.87 (0.91–3.85) for the Ɛ3/Ɛ3, Ɛ2/Ɛ2, Ɛ2/Ɛ3, Ɛ2/Ɛ4, Ɛ3/Ɛ4 and Ɛ4/Ɛ4 genotypes, respectively. In a secondary analysis, Ɛ2/Ɛ3 genotype was associated with 41% lower prevalence odds of low high‐density lipoprotein [multivariable adjusted ORs (95% confidence interval) = 0.59 (0.36–0.95)] compared with Ɛ3/Ɛ3 genotype.

Conclusions

Our findings do not support an association between Apo E polymorphism and MetS in a multicentre population‐based study of predominantly White US men and women. Copyright © 2015 John Wiley & Sons, Ltd.