bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thioether‐Functionalized Corn Oil Biosorbents for the Removal of Mercury and Silver Ions from Aqueous Solutions
Authors: Dunn Robert O. , Bantchev Grigor B. , Doll Kenneth M. , Ascherl Kim L. , Lansing James C. , Murray Rex E. 
Published: July 2018

AbstractHeavy‐metal contamination is one of the most important environmental problems faced in the world, particularly in developing countries. Metals such as silver and mercury from drinking water, food, and air sources can accumulate in living organisms and present significant health concerns. Meanwhile, the demand for these metals in many industries continues to increase. In the present study, thioether‐functionalized corn oil (TFCO) from a photoinitiated thiol‐ene synthesis was utilized to remove Ag+ and Hg2+ ions from an aqueous solution. An aqueous solution containing AgNO3 and Hg[NO3]2 was prepared and contacted directly with TFCO. After vortex mixing for 60 s, the experiment ran for 351 min with the aqueous phase being periodically sampled for the analysis of metal ions (M
n+). Results showed that 88.9% of Ag+ and 99.6% of Hg2+ ions were removed from the aqueous phase by the TFCO. Mass balances indicated that the total M
n+ concentration in the oil phase was 13.890 g kg−1 under the conditions studied. TFCO exhibited higher selectivity for removing Hg2+ than for Ag+ ions. Analysis of the adsorption kinetics showed that a pseudosecond‐order model may be used to determine the rate of Ag+ ion sorption by the oil phase. The presence of the Hg2+ ions interfered with the adsorption of Ag+ ions from the aqueous solution.
Hydrolytic and thermal degradation of polyethylene glycol compatibilized poly(lactic acid)‐nanocrystalline cellulose bionanocomposites
Authors: Zhang Ping , He Yi‐Yao , Gao De , Cai Yingfeng , Liu Bingren 
Published: July 2018

ABSTRACTThis study investigates the effect of nanocrystalline cellulose (NCC) and polyethylene glycol (PEG) on the hydrolytic degradation behavior of poly(lactic acid) (PLA) bio‐nanocomposites compared with that of neat PLA, under specific environmental condition, namely at 37°C in a pH 7.4 phosphate buffer medium for a time period up to 60 days. The water absorption, mass loss, molecular weight, and the morphologies of nanocomposites before and after degradation were explored. Thermogravimetric analysis (TGA) was used to study the thermal decomposition of the PLA/NCC/PEG nanocomposites before and after degradation. The results showed that the presence of hydrophilic NCC and PEG significantly accelerated the hydrolytic degradation of PLA, which was related to the rapid dissolution of PEG causing easy access of water molecules to the composites and initiating fast hydrolytic chain scission of PLA. The thermal degradation temperatures of the nanocomposites slightly decreased due to the poor thermal stability of NCC in comparison with that of the neat PLA. After degradation, the thermal stability of the separated PLA from nanocomposites significantly decreased because the molecular decreased during the hydrolytic process. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 46933.
Mitochondrial DNA analyses of Donax trunculus (Mollusca: Bivalvia) population structure in the Iberian Peninsula, a bivalve with high commercial importance
Authors: Fernández‐Pérez Jenyfer , Nantón Ana , Arias‐Pérez Alberto , Freire Ruth , Martínez‐Patiño Dorotea , Méndez Josefina 
Published: July 2018

Abstract

The wedge clam, Donax trunculus (Linnaeus, 1758), is an ecologically and economically important species found in the warm waters of the Atlantic and Mediterranean areas. Donax trunculus has been suffering from a severe population decline in some wild stocks of the Iberian Peninsula, and genetic monitoring of wild populations can provide valuable information to support conservation measures and management policies.
In this study, mitochondrial 16S rDNA (16S) and cytochrome b (Cytb) gene variation was examined at 18 localities across the Iberian Peninsula to test whether the patterns of genetic diversity, population structure, and demographic inferences previously deduced by using microsatellites are supported by these molecular markers.
Samples (N = 557) were collected from 18 localities of the Iberian Peninsula and attention was paid to the north‐western Atlantic area, where wild stocks have diminished greatly. Analysis of molecular variance, fixation index (FST), and demographic inferences were estimated based on mitochondrial DNA. Since D. trunculus shows doubly uniparental inheritance, both types of mitochondrial DNA (F and M) were analysed.
A high level of genetic diversity was detected using the haplotype diversity dataset, showing different geographic patterns.
FST values for the M type revealed significant differentiation between populations on both sides of the Almeria–Oran front, and between the locality from the Alboran Sea (FU) and localities from the Atlantic Ocean. However, the F type did not detect the differentiation of FU. This makes the M genome sequences more suitable for investigating genetic structure of D. trunculus populations.
Management and recovering strategies of this important resource should consider the genetic structure observed.
Several strategies for conservation and management of this commercial and ecologically important bivalve are proposed.
Age‐related changes in hepatic expression and activity of drug metabolizing enzymes in male wild‐type and breast cancer resistance protein knockout mice
Authors: Zheng Haihui , Wang Liping , Zeng Sijing , Chen Jiamei , Wang Haojia , Yu Jia , Gong Xia , Jiang Huangyu , Yang Xia , Qi Xiaoxiao , Wang Ying , Lu Linlin , Hu Ming , Zhu Lijun , Liu Zhongqiu 
Published: July 2018

AbstractThis study aimed to reveal age‐related changes in the expression and activity of seven hepatic drug metabolizing enzymes (DMEs) in male wild‐type and breast cancer resistance protein knockout (Bcrp1−/−) FVB mice. The protein expression of four cytochrome P450 (Cyps) (Cyp3a11, 2d22, 2e1, and 1a2), and three UDP‐glucuronosyltransferases (Ugts) (Ugt1a1, 1a6a, and 1a9) in liver microsomes of wild‐type and Bcrp1−/− FVB mice at different ages were determined using a validated ultra high performance liquid chromatography with tandem mass spectrometry (UHPLC–MS/MS) method. The activities and mRNA levels of these DMEs were measured using the probe substrates method and real‐time PCR, respectively. In the liver of wild‐type FVB mice, Cyp3a11, 2d22, 2e1, 1a2, Ugt1a1, and 1a6a displayed maximum protein levels at 6–9 weeks of age. Cyp1a2, Ugt1a1, 1a6a, and 1a9 showed maximum activities at 6–9 weeks of age, whereas Cyp3a11, 2d22, and 2e1 showed maximum activities in 1–3‐week‐old mice. Additionally, most of the DMEs showed maximum mRNA levels in 17‐week‐old mice liver. Compared with wild‐type FVB mice, the protein levels of these DMEs showed no significant changes in Bcrp1−/− FVB mice liver. However, the activity of Cyp2e1 was increased and that of Cyp2d22 was decreased. In conclusion, the seven hepatic DMEs in FVB mice liver showed significant alterations in an isoform‐specific manner with increased age. Although the protein levels of these DMEs showed no significant changes, the activities of Cyp2e1 and 2d22 were changed in Bcrp1−/− mice.
Selective C−C Hydrogenolysis of Alkylbenzenes to Methylbenzenes with Suppression of Ring Hydrogenation
Authors: Yanatake Shin , Nakaji Yosuke , Betchaku Mii , Nakagawa Yoshinao , Tamura Masazumi , Tomishige Keiichi 
Published: July 2018

AbstractSelective reduction of alkylbenzenes, which are supplied by refining heavy hydrocarbons, to methylbenzenes by selective C−C hydrogenolysis was accomplished by Ru/CeO2 catalyst. Hydrogenolysis of ethylbenzene was carried out with gas‐phase fixed‐bed flow reactor and various noble metal catalysts. The catalyst with high Ru loading (4 wt%) on CeO2 support pre‐calcined at high temperature (1073 K; Ru(4)/CeO21073 catalyst) showed both good activity and selectivity to toluene. The yield of toluene reached 65 %‐C in the conditions of 533 K and H2 partial pressure of 0.075 MPa. Hydrogenolysis of other alkylbenzenes including p‐ethyltoluene, propylbenzene and cumene was also carried out. Hydrogenolysis of Caryl‐Calkyl bond and hydrogenation of benzene ring was slow in all substrate cases. Hydrogenolysis of p‐ethyltoluene can give p‐xylene as the main product (highest yield: 53 %‐C). These high yields of methylbenzenes make a marked contrast to the traditional bifunctional hydrocracking systems which preferably dissociate Caryl‐Calkyl bond in alkylbenzenes. Characterization of Ru catalysts suggests that the block‐shaped Ru particles with small size (<2 nm) in Ru(4)/CeO21073 give good catalytic performance. Too strong interaction between Ru species and CeO2 support induced by decreasing the loading amount rather gives ring‐hydrogenation activity and decreases methylbenzenes selectivity.
Cycloaddition versus Cleavage of the C=S Bond of Isothiocyanates Promoted by Digallane Compounds with Noninnocent α‐Diimine Ligands
Authors: Zhang Wei , Dodonov Vladimir A. , Chen Weixing , Zhao Yanxia , Skatova Alexandra A. , Fedushkin Igor L. , Roesky Peter W. , Wu Biao , Yang Xiao‐Juan 
Published: July 2018

AbstractWhereas the chemistry of single‐bond activation by compounds of the main group elements has undergone some development in recent years, the cleavage of multiple bonds remains underexplored. Herein, the reactions of two digallanes bearing α‐diimine ligands, namely, [L1Ga−GaL1] (1, L1=dpp‐dad=[(2,6‐iPr2C6H3)NC(CH3)]2) and [L2Ga−GaL2] (2, L2=dpp‐bian=1,2‐[(2,6‐iPr2C6H3)NC]2C10H6), with isothiocyanates are reported. Reactions of 1 or 2 with isothiocyanates in 1:2 molar ratio proceeded with [2+4] cycloaddition of the C=S bond across the C2N2Ga metallacycle with formation of C−C and S−Ga single bonds to afford [L1(RN=C−S)Ga−Ga(S−C=NR)L1] (3, R=Me; 4, R=Ph) and [L2(RN=C−S)Ga−Ga(S−C=NR)L2] (8, R=allyl; 9, R=Ph). In the cases of 8 and 9, this cycloaddition is reversible. The digallanes reacted with 2 equiv of PhNCS in the presence of Na metal or at high temperatures through a unique reductive cleavage of the C=S bond to yield the disulfide‐bridged digallium species [Na(THF)3]2[L1Ga(μ‐S)2GaL1] (5), [L2Ga(μ‐S)2GaL2] (10), and [Na(DME)3][L2Ga(μ‐S)2GaL2] (11). Moreover, products 4 and 5 can further react with an excess of isothiocyanate, through cleavage of the C=S bond or cycloaddition, to give the bis‐ or mono‐S‐bridged complexes [Na(THF)2]2[L1(PhN=C−S)Ga(μ‐S)2Ga(S−C=NPh)L1] (6) and [L1(PhN=C−S)Ga(μ‐S)Ga(S−C=NPh)L1] (7). All the newly prepared compounds were characterized by elemental analysis, single‐crystal X‐ray diffraction, IR spectroscopy, NMR (3–9) or ESR spectroscopy (11), and DFT calculations.
Pressure‐Induced Spin‐Crossover Features at Variable Temperature Revealed by In Situ Synchrotron Powder X‐ray Diffraction
Authors: Tailleur Elodie , Marchivie Mathieu , Itié Jean‐Paul , Rosa Patrick , Daro Nathalie , Guionneau Phillippe 
Published: July 2018

AbstractAn accurate high‐pressure X‐ray diffraction investigation, at various temperatures, on a powder of a spin‐crossover (SCO) complex has allowed the rare deconvolution of the structural features of the high‐spin and low‐spin phases. As a result, the pressure dependence of the structural parameters of the high‐spin and low‐spin phases can be discussed independently in the pressure domain where both phases co‐exist within the powder. Consequently, crucial unprecedented information is given, such as the variation of bulk moduli with temperature, similar here in amplitude for both spin phases, the temperature‐dependence of the pressure‐induced SCO abruptness, the temperature dependence of the pressure at which SCO occurs, and arguments for a possible piezo‐hysteresis. Performed on the molecular complex [Fe(PM‐PeA)2(NCSe)2] (PM‐PeA=N‐(2′‐pyridylmethylene)‐4‐(phenylethynyl) aniline), this study reveals a pressure‐induced SCO at 0.16 GPa and demonstrates that, when increasing temperature, the pressure of transition increases linearly, the abruptness of the pressure‐induced SCO strongly increases, and the bulk moduli decrease.
Involvement of sonic hedgehog and notch signaling in regenerative neurogenesis in adult zebrafish optic tectum after stab injury
Authors: Ueda Yuto , Shimizu Yuki , Shimizu Nobuyuki , Ishitani Tohru , Ohshima Toshio 
Published: July 2018

AbstractUnlike humans and other mammals, adult zebrafish have the superior capability to recover from central nervous system (CNS) injury. We previously found that proliferation of radial glia (RG) is induced in response to stab injury in optic tectum and that new neurons are generated from RG after stab injury. However, molecular mechanisms which regulate proliferation and differentiation of RG are not well known. In the present study, we investigated Shh and Notch signaling as potential mechanisms regulating regeneration in the optic tectum of adult zebrafish. We used Shh reporter fish and confirmed that canonical Shh signaling is activated specifically in RG after stab injury. Moreover, we have shown that Shh signaling promotes RG proliferation and suppresses their differentiation into neurons after stab injury. In contrast, Notch signaling was down‐regulated after stab injury, indicated by the decrease in the expression level of her4 and her6, a target gene of Notch signaling. We also found that inhibition of Notch signaling after stab injury induced more proliferative RG, but that inhibition of Notch signaling inhibited generation of newborn neurons from RG after stab injury. These results suggest that high level of Notch signaling keeps RG quiescent and that appropriate level of Notch signaling is required for generation of newborn neurons from RG. Under physiological condition, activation of Shh signaling or inhibition of Notch signaling also induced RG proliferation. In adult optic tectum of zebrafish, canonical Shh signaling and Notch signaling play important roles in proliferation and differentiation of RG in physiological and regenerative conditions.
A Unified Integral Equation Scheme for Doubly Periodic Laplace and Stokes Boundary Value Problems in Two Dimensions
Authors: Barnett Alex H. , Marple Gary R. , Veerapaneni Shravan , Zhao Lin 
Published: July 2018

AbstractWe present a spectrally accurate scheme to turn a boundary integral formulation for an elliptic PDE on a single unit cell geometry into one for the fully periodic problem. The basic idea is to use a small least squares solve to enforce periodic boundary conditions without ever handling periodic Green's functions. We describe fast solvers for the two‐dimensional (2D) doubly periodic conduction problem and Stokes nonslip fluid flow problem, where the unit cell contains many inclusions with smooth boundaries. Applications include computing the effective bulk properties of composite media (homogenization) and microfluidic chip design.We split the infinite sum over the lattice of images into a directly summed “near” part plus a small number of auxiliary sources that represent the (smooth) remaining “far” contribution. Applying physical boundary conditions on the unit cell walls gives an expanded linear system, which, after a rank‐1 or rank‐3 correction and a Schur complement, leaves awell‐conditionedsquare system that can be solved iteratively using fast multipole acceleration plus a low‐rank term. We are rather explicit about the consistency and nullspaces of both the continuous and discretized problems. The scheme is simple (no lattice sums, Ewald methods, or particle meshes are required), allows adaptivity, and is essentially dimension‐ and PDE‐independent, so it generalizes without fuss to 3D and to other elliptic problems. In order to handle close‐to‐touching geometries accurately we incorporate recently developed spectral quadratures. We include eight numerical examples and a software implementation. We validate against high‐accuracy results for the square array of discs in Laplace and Stokes cases (improving upon the latter), and show linear scaling for up to 104randomly located inclusions per unit cell. © 2018 Wiley Periodicals, Inc.
The Equilibrium Measure for a Nonlocal Dislocation Energy
Authors: Mora Maria Giovanna , Rondi Luca , Scardia Lucia 
Published: July 2018

AbstractIn this paper we characterize the equilibrium measure for a nonlocal and anisotropic weighted energy describing the interaction of positive dislocations in the plane. We prove that the minimum value of the energy is attained by a measure supported on the vertical axis and distributed according to the semicircle law, a well‐known measure that also arises as the minimizer of purely logarithmic interactions in one dimension. In this way we give a positive answer to the conjecture that positive dislocations tend to form vertical walls. This result is one of the few examples where the minimizer of a nonlocal energy is explicitly computed and the only one in the case of anisotropic kernels. © 2018 Wiley Periodicals, Inc.
Heat Flow on Time‐Dependent Metric Measure Spaces and Super‐Ricci Flows
Authors: Kopfer Eva , Sturm Karl‐Theodor 
Published: July 2018

We study the heat equation on time‐dependent metric measure spaces (as well as the dual and the adjoint heat equation) and prove existence, uniqueness, and regularity. Of particular interest are properties that characterize the underlying space as a super‐Ricci flow as previously introduced by the second author [51]. Our main result yields the equivalence of

dynamic convexity of the Boltzmann entropy on the (time‐dependent) L2‐Wasserstein space,
monotonicity of L2‐Kantorovich‐Wasserstein distances under the dual heat flow acting on probability measures (backward in time),
gradient estimates for the heat flow acting on functions (forward in time), and
a Bochner inequality involving the time‐derivative of the metric.
Moreover, we characterize the heat flow on functions as the unique forward EVI flow for the (time‐dependent) energy in L2‐Hilbert space and the dual heat flow on probability measures as the unique backward EVI~flow for the (time‐dependent) Boltzmann entropy in L2‐Wasserstein space.© 2018 Wiley Periodicals, Inc.
On the effects of allocation strategies for exascale computing systems with distributed storage and unified interconnects
Authors: Pascual Jose A. , Lant Joshua , Concatto Caroline , Attwood Andrew , Navaridas Javier , Luján Mikel , Goodacre John 
Published: July 2018

SummaryThe convergence between computing‐ and data‐centric workloads and platforms is imposing new challenges on how to best use the resources of modern computing systems. In this paper, we investigate alternatives for the storage subsystem of a novel exascale‐capable system with special emphasis on how allocation strategies would affect the overall performance. We consider several aspects of data‐aware allocation such as the effect of spatial and temporal locality, the affinity of data to storage sources, and the network‐level traffic prioritization for different types of flows. In our experimental set‐up, temporal locality can have a substantial effect on application runtime (up to a 10% reduction), whereas spatial locality can be even more significant (up to one order of magnitude faster with perfect locality). The use of structured access patterns to the data and the allocation of bandwidth at the network level can also have a significant impact (up to 20% and 17% reduction of runtime, respectively). These results suggest that scheduling policies exposing data‐locality information can be essential for the appropriate utilization of future large‐scale systems. Finally, we found that the distributed storage system we are implementing can outperform traditional SAN architectures, even with a much smaller (in terms of I/O servers) back‐end.
Density Functional Characterization of the 4f‐Relevant Electronic Transitions of Lanthanide‐Doped Lu2O3 Luminescence Materials
Authors: Meng Junling , Zhang Lifang , Yao Fen , Liu Xiaojuan , Meng Jian , Zhang Hongjie 
Published: July 2018

AbstractHerein, we present a theoretical study on trivalent‐lanthanide‐substituted luminescence materials (Lu2O3 : Ln; with Ln=Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) by using first‐principles calculations based on the Coulomb‐corrected density functional theory (DFT+U). Large‐scale calculations of electronic the structure are carried out with the goal of pinpointing the 4f‐relevant electronic transition rule and optical features of Lu2O3 : Ln systems. A characteristic double “zigzag” pattern for Ln3+ and Ln2+ energy levels is observed. Accordingly, four types of electric‐dipole allowed transition modes are predicted in the lanthanide‐doped Lu2O3 family, with Lu2O3 : Eu and Lu2O3 : Yb showing superior absorption features. Finally, this 4f‐controlled electronic transition image provides useful guidance for designing new luminescence materials with desired properties.
Building a Thermostable Metabolon for Facilitating Coenzyme Transport and In Vitro Hydrogen Production at Elevated Temperature
Authors: Chen Hui , Huang Rui , Kim Eui‐Jin , Zhang Yi‐Heng P. Job 
Published: July 2018

AbstractTo facilitate coenzyme transport and in vitro enzymatic hydrogen production, a multi‐enzyme metabolon comprising a miniscaffoldin containing three cohesins, a dockerin‐containing mutant dehydrogenase, a dockerin‐containing diaphorase, and a Histidine‐tagged (His‐tagged) NiFe hydrogenase was constructed. As the NiFe hydrogenase has very complicated structure and cannot be fused directly with a dockerin, a bifunctional peptide was designed. The bifunctional peptide, in which one terminus contains a modified dockerin binding the cohesin of the miniscaffoldin and the other, after chemical modification, binds the His‐tag of NiFe hydrogenase, enabled His‐tagged proteins to be integrated into the cohesin–dockerin‐based metabolon. The metabolon exhibited an initial reaction rate 4.5 times that of the enzyme cocktail at the same enzyme loading, which indicated enhanced coenzyme transport of the metabolon. However, this metabolon was unstable owing to the degradation of the miniscaffoldin at elevated temperature. Glutaraldehyde was used to cross‐link the metabolon for locking its spatial organization. The cross‐linked metabolon not only exhibited 2.5 times the reaction rate of the enzyme cocktail, but also retained its stability at 70 °C. The amount of hydrogen production catalyzed by the cross‐linked metabolon was nearly twice that of the metabolon without glutaraldehyde cross‐linking and four times that of the enzyme cocktail at 70 °C after 22 h of reaction.
Low‐Weight 3D Al2O3 Network as an Artificial Layer to Stabilize Lithium Deposition
Authors: Tian Ran , Feng Xiaoqian , Duan Huanan , Zhang Peng , Li Hua , Liu Hezhou , Gao Lian 
Published: July 2018

AbstractLithium metal has been regarded as an ideal anode for high‐energy‐density batteries. However, safety and efficiency concerns still linger due to dendrite formation, reactions between the liquid electrolyte and lithium, high resistance with lithium metal, and the weight of interface layer. A new nanometer‐thick, hollow, Al2O3 fiber network with an elastic and porous 3D structure has been prepared through an atomic‐layer deposition process by using cotton sacrificial templates. Through a comparison study of the lithium deposition behavior by employing artificial layers with different structures, the low‐weight 3D layer with lithiophilic properties overcomes the issues resulting from the 2D rigid Al2O3 layer and provides a low overpotential and dendrite‐free growth of lithium metal. Moreover, stable lithium deposition enables Li–Li symmetric cells with a 3D artificial layer to be stably cycled 300 times in carbonate‐based electrolyte, with superior rate capability, and with a LiNi1/3Co1/3Mn1/3O2 cathode.