bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymmetric Bioreduction of β‐Acylaminonitroalkenes: Easy Access to Chiral Building Blocks with Two Vicinal Nitrogen‐Containing Functional Groups
Authors: Brenna Elisabetta , Crotti Michele , Gatti Francesco G. , Monti Daniela , Parmeggiani Fabio , Santangelo Sara 
Published: February 2017

AbstractThe reduction of (Z)‐β‐acylaminonitroalkenes catalyzed by ene‐reductases is described for the first time. The reaction occurs with a high conversion and excellent enantioselectivity and shows a wide substrate scope. The reduced products are valuable chiral synthons characterized by two vicinal nitrogen‐containing functional groups that can be further modified by functional group inter‐conversion thanks to the synthetic versatility of the nitro moiety. The chemo‐enzymatic synthesis of (R)‐N,N′‐(1‐phenylethane‐1,2‐diyl)diacetamide from easily accessible (Z)‐N‐(2‐nitro‐1‐phenylvinyl)acetamide is herein reported as a representative application of this synthetic procedure.
Facile Synthesis of Cu@CeO2 and Its Catalytic Behavior for the Hydrogenation of Methyl Acetate to Ethanol
Authors: Wang Yue , Zhao Yujun , Lv Jing , Ma Xinbin 
Published: February 2017

AbstractThe hydrogenation of methyl acetate (MA) is one of the key steps in the synthesis of ethanol from syngas. Given previous studies in this area, synergy of the Cu0 and Cu+ species is the crux to improving catalytic performance. However, neither Cu0 nor Cu+ is easy to maintain under reaction conditions comprising abundant H2 and high temperature. Here, a Cu@CeO2 core–shell catalyst was fabricated by using a facile sol–gel method, and this catalyst exhibited excellent activity and stability in the hydrogenation of MA. It was revealed that the Cu@CeO2 core–shell structure prevented the metallic copper particles from migrating and aggregating and also significantly increased the amount of Cu+ species by enlarging the intimate contact area of copper and ceria. Furthermore, the Cu0 and Cu+ species were found to be well distributed on the interface between the Cu core and the CeO2 shell. The close relative position of the two active sites is probably the main reason for the enhanced synergetic effect in the hydrogenation of MA. New insight into the core–shell structure–function relationship introduces new possibilities for the rational design of catalysts.
Recyclable Silica‐Supported Iridium Catalysts for Selective Reductive Transformation of Quinolines with Formic Acid in Water
Authors: Zhang Jing‐Fan , Zhong Rui , Zhou Quan , Hong Xi , Huang Shuang , Cui He‐Zhen , Hou Xiu‐Feng 
Published: February 2017

AbstractMesoporous silica (SBA‐15)‐supported iridium catalysts are prepared by grafting of the newly developed cyclometalated iridium 2‐aryl benzoxazole complexes with 3‐(triethoxysilyl)‐propyl‐isocyanate (TEPIC) as a linker. The supported catalysts are characterized by solid‐state NMR spectroscopy, small‐angle X‐ray scattering (SAXS), nitrogen physisorption, FTIR spectroscopy, and electron microscopy analysis, which indicate that the coordination environment of the iridium center as well as the two‐dimensional hexagonal pore structure of SBA‐15 is maintained after the immobilization. These supported catalysts have been successfully applied to the selective transfer hydrogenation of quinoline derivatives to 1,2,3,4‐tetrahydroquinolines (THQs) with formic acid in pure water. Moreover, by simply adapting the amount of formic acid used, N‐formyltetrahydroquinolines (FTHQs) could be selectively synthesized from quinolines in two‐step, one‐pot transfer hydrogenation/N‐formylation reactions with these supported catalysts. Notably, these supported catalysts showed better catalytic reactivity than their homogeneous analogs, and they can be easily reused 12 times in the transformation of quinoline to N‐formyltetrahydroquinoline (FTHQ) without significant loss of activity.
Study on the Catalytic Behavior of Bifunctional Hydrogen‐Bonding Catalysts Guided by Free Energy Relationship Analysis of Steric Parameters
Authors: Yang Chen , Wang Jie , Liu Yang , Ni Xiang , Li Xin , Cheng Jin‐Pei 
Published: February 2017

AbstractFree energy relationship (FER) studies to correlate steric parameters with the enantiocatalytic performance of bifunctional tertiary‐amine hydrogen‐bonding catalysts, including (S,S)‐cyclohexane‐1,2‐diamine‐derived thioureas, Cinchona alkaloid derived thioureas, and (S,S)‐cyclohexane‐1,2‐diamine‐derived squaramides, in Michael reactions revealed that the reactions are much favored by catalysts with less bulky N‐substituents. The observed FERs are independent of the chiral scaffold and hydrogen‐bond donor, and deepen the understanding of current bifunctional hydrogen‐bonding catalysts. Moreover, DFT calculations were performed to interpret the observed high reactivities of thioureas with less bulky substituents. In particular, the computations demonstrated the advantage of a benzyl thiourea catalyst, in which an extra CH⋅⋅⋅π interaction between catalyst and substrate is the key factor.
A secure end‐to‐end SMS‐based mobile banking protocol
Authors: Bojjagani Sriramulu , Sastry V. N. 
Published: February 2017

SummaryShort message service (SMS) provides a wide channel of communication for banking in mobile commerce and mobile payment. The transmission of SMS is not secure in the network using global system for mobile communications or general packet radio service. Security threats in SMS restricted the use of SMS in mobile banking within certain limits. This paper proposed a model to address the security of SMS using elliptic curve cryptography. The proposed model provides end‐to‐end SMS communication between the customer and the bank through the mobile application. The main objective of the proposed model is to design and develop a security framework for SMS banking. Further, the protocol is verified for its correctness and security properties because most of the protocols are not having the facility to be verified by using the formal methods. Our proposed framework is experimentally validated by formal methods using model checking tool called automated validation of internet security protocols and Scyther tools. Security analysis shows that the proposed mechanism works better compared to existing SMS payment protocols for real‐world applications.
Drivers of tree species distribution across a tropical rainfall gradient
Authors: Gaviria Julian , Turner Benjamin L. , Engelbrecht Bettina M. J. 
Published: February 2017

AbstractUnderstanding the factors shaping species distribution patterns along tropical rainfall gradients is necessary to predict the consequences of climate change for tropical tree communities. Direct effects of water availability exclude wet forest species from dry forests, but the exclusion of dry forest species from wet forests remains unexplained. We tested the hypothesis that high light and nutrient requirements exclude dry forest species from dark, infertile, wet forests. We transplanted seedlings of 26 woody species to six sites along a pronounced regional rainfall gradient across the Isthmus of Panama. We examined the effects of soil moisture, phosphorus and light availability, and species' drought resistance on seedling performance, and linked the results directly to known species distribution patterns. Surprisingly, seedlings of wet forest species did not exhibit a home advantage: All species survived better under moister conditions, and the effects of phosphorus availability and light on seedling performance did not differ among species from dry or wet forests. Instead, dry forest species had intrinsically slower growth rates than wet forest species, which may lead to their exclusion from wet forests at later life history stages. High phosphorus exacerbated susceptibility to drought, although the mechanism remains unknown. Overall, our results demonstrate that seedling performance across tropical rainfall gradients is determined primarily by variation in soil water availability across space and time, while variation in nutrient and light availability plays a lesser role. Future changes in rainfall patterns will therefore have direct and pervasive consequences for forest composition and ecosystem function.
Two sides of the same coin: NEO‐PUFAs in Rett syndrome and post‐infarction cardiac arrhythmias
Authors: Demion Marie , Oger Camille , Vigor Claire , Thireau Jérôme , Guennec Jean‐Yves Le , Durand Thierry , Galano Jean‐Marie , Lee Jetty Chung‐Yung 
Published: February 2017

An imbalance between oxidants and antioxidants that favors the oxidants leads to a disruption of the redox signaling control and/or molecular damage. The action of the oxidants in a non‐enzymatic process generates isoprostanoids from polyunsaturated fatty acids. In this review, we will focus on the effects of ω3‐polyunsaturated fatty acids in two different pathogeneses related to chronic and acute oxidative stress, one in neurodevelopmental, also known as the Rett syndrome, and the second in myocardial infarction and cardiac arrhythmias, respectively. We hypothesize that ω3‐polyunsaturated fatty acid supplementation displays antioxidant properties under a high oxidative stress situation, as in the Rett Syndrome, as well as protective properties of isoprostanoids from polyunsaturated fatty acids in pro‐arrhythmic conditions.Practical applications: In this review, we highlighted the role of omega 3‐ polyunsaturated fatty acids in 2 distinct pathologies where oxidative stress is elevated (in the Rett syndrome as an anti‐oxidant molecule and in cardiac arrhythmias as messenger with biologic properties). The physiological relevance of these data open new unexplored pathways in integrative mechanism and thus potential new “non‐drug” applications.In this review, we highlight the role of ω3‐polyunsaturated fatty acids in 2 distinct pathologies where oxidative stress is elevated as in the Rett syndrome and as an antioxidant in cardiac arrhythmias acting as a messenger with biological properties. The physiological relevance of these data open new and unexplored pathways in integrative mechanisms, and thus potential new “natural drug” applications. (Adapted with Servier Medical Art, https://creativecommons.org/licenses/by/3.0/fr/).
A critical evaluation of the utility of eggshells for estimating mercury concentrations in avian eggs
Authors: Peterson Sarah H. , Ackerman Joshua T. , Eagles-Smith Collin A. , Hartman C. Alex , Herzog Mark P. 
Published: February 2017

Abstract

Eggshells are a potential tool for nonlethally sampling contaminant concentrations in bird eggs, yet few studies have examined their utility to represent mercury exposure. We assessed mercury concentrations in eggshell components for 23 bird species and determined whether they correlated with total mercury (THg) in egg contents. We designed a multi-experiment analysis to examine how THg is partitioned into eggshell components, specifically hardened eggshells, material adhered to the eggshells, and inner eggshell membranes. The THg concentrations in eggshells were much lower than in egg contents, and almost all of the THg within the eggshell was contained within material adhered to eggshells and inner eggshell membranes, and specifically not within calcium-rich hardened eggshells. Despite very little mercury in hardened eggshells, THg concentrations in hardened eggshells had the strongest correlation with egg contents among all eggshell components. However, species with the same THg concentrations in eggshells had different THg concentrations in egg contents, indicating that there is no global predictive equation among species for the relationship between eggshell and egg content THg concentrations. Furthermore, for all species, THg concentrations in eggshells decreased with relative embryo age. Although the majority of mercury in eggshells was contained within other eggshell components and not within hardened eggshells, THg in hardened eggshells can be used to estimate THg concentrations in egg contents, if embryo age and species are addressed. Environ Toxicol Chem 2017;36:2417–2427. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Fluid dynamics of an idealized left ventricle: the extended Nitsche's method for the treatment of heart valves as mixed time varying boundary conditions
Authors: Tagliabue A. , Dedè L. , Quarteroni A. 
Published: February 2017

SummaryIn this work, we study the blood flow dynamics in idealized left ventricles (LV) of the human heart modelled by the Navier–Stokes equations with mixed time varying boundary conditions. The latter are introduced for simulating the functioning of the aortic and mitral valves. On the basis of the extended Nitsche's method firstly presented in [Juntunen and Stenberg, Mathematics of Computation, 2009], we propose a formulation allowing an efficient and straightforward numerical treatment of the opening and closing phases of the heart valves that are associated with different kind of boundary conditions, namely, natural and essential, switching during each heartbeat. Moreover, our formulation already includes terms preventing the numerical instabilities associated to backflow divergence, that is, nonphysical reinflow at the valves. We present and discuss numerical results for the LV obtained by means of isogeometric analysis for the spatial approximation with the aim of both analysing the formulation and showing the effectiveness of the approach. In particular, we show that the formulation allows to reproduce meaningful results even in idealized LV. Copyright © 2017 John Wiley & Sons, Ltd.
Damage to right medial temporal structures disrupts the capacity for scene construction—a case study
Authors: Irish Muireann , Mothakunnel Annu , Dermody Nadene , Wilson Nikki‐Anne , Hodges John R , Piguet Olivier 
Published: February 2017

AbstractThe medial temporal lobes (MTLs) are widely held to support a range of constructive endeavors including remembering the past, envisaging the future, and imagining hypothetical scenarios. While right MTL structures have been ascribed a prominent role in the construction of spatial contexts, lesion evidence to directly test this hypothesis is lacking. To this end, we assessed scene construction performance in two cases, GC and DF, who presented with left‐ and right‐lateralized presentations of semantic dementia, respectively. GC displayed characteristic semantic processing difficulties in the context of marked left anterior and medial temporal lobe atrophy. Despite significant volume loss across the entire length of the left hippocampus, GC was capable of generating richly detailed, spatially coherent scenes, most likely reflecting the preservation of his right anterior MTL. In contrast, DF's cognitive profile was one of dense prosopagnosia, with subjectively reported gaps in autobiographical memory and wayfinding difficulties. Formal testing on the scene construction task revealed striking deficits, with DF producing impoverished descriptions of spatially fragmented scenes. We attribute DF's inability to construct spatially contiguous scenes to the degeneration of right‐sided MTL structures, most prominently the right anterior hippocampus (19% volume loss) and right parahippocampal cortex (23% volume loss). Our findings complement the extant fMRI literature to suggest a fundamental role for right medial temporal regions in the construction of rich detailed spatial arrays.
The relationship between children's executive functioning, theory of mind, and verbal skills with their own and others' behaviour in a cooperative context: Changes in relations from early to middle school‐age
Authors: Huyder Vanessa , Nilsen Elizabeth S. , Bacso Sarah A. 
Published: February 2017

AbstractLearning to behave in socially competent ways is an essential component of children's development. This study examined the relations between children's social, communicative, and cognitive skills and their behaviours during a cooperative task, as well as how these relationships change at different ages. Early school‐age (5–8 years old) and middle school‐age (9–12 years old) children completed tasks to assess their executive functioning (i.e., inhibitory control, working memory, and planning), theory of mind, and verbal skills and participated in an interactive cooperative task. Because children participated in pairs, dyadic data analysis was used to examine the effect of individual characteristics on children's own and their partners' social behaviour. Results indicated that better theory of mind was related to lower levels of the competitive behaviours demonstrated by younger children, as well as by partners. In contrast, for older children, planning and verbal skills related to lower levels of competitive behaviour. The associations of theory of mind and planning skills with behaviour were significantly different between the early and middle school‐age groups. Findings suggest that children may utilize different skills at various developmental stages to guide their social behaviours. Findings have implications for theories of children's social development, as well as for interventions aimed at enhancing social skills.Highlights

Children's theory of mind, executive functioning, and verbal skills were assessed in relation to their own and a peer's social behaviour
Dyadic analyses were used to examine children's cooperative and competitive behaviour during an interactive task with a peer
Findings reveal that the impact specific skills have on their own and a peer's behaviour depends on developmental stage
The Translocation of Na+ Ion Inside Human Thrombin Accounts for the Activation of the Enzyme
Authors: Gdalya Hagit , Nachliel Esther , Gutman Menachem , Einav Yulia , Tsfadia Yossi 
Published: February 2017

AbstractThrombin is a member of the chymotrypsin family that splits the peptide bond next to arginine. The catalytic activity of thrombin is accelerated by Na+. Inspection of the crystal structure reveals an ion binding site 17 Å from the active‐site, leading to ambiguous definition of its mode of rate‐enhancement. During unbiased Molecular Dynamics simulations in the presence of Na+ ions, the Na+ ion was noticed to alternate between two locations: the crystal‐structure site (adjacent to R221a and K224) and another site next to D189, very close to the binding and the active sites. There is a free passage between the two locations, and both sites can exchange ions with the bulk. When the ion is close to D189 it can assume position between the guanidino moiety of the product and the carboxylate of D189, thus weakening the protein‐product interaction. This transient structure either ejects the Na+ ion out of the protein or releases the product from the enzyme. We propose that the enhancement of the catalysis by the ion is a reflection of its ability to destabilize the product‐enzyme complex.
A Highly Efficient Gene Expression Programming Model for Predicting the Discharge Coefficient in a Side Weir along a Trapezoidal Canal
Authors: Azimi Hamed , Bonakdari Hossein , Ebtehaj Isa 
Published: February 2017

AbstractSide weirs in trapezoidal canals are used to regulate and measure flow in drainage networks and irrigation systems. In this study, the discharge coefficient of a side weir in a trapezoidal canal is predicted using gene expression programming (GEP). The effects of Froude number (Fr), ratio of side weir length to trapezoidal canal bottom width (L/b), ratio of side weir length to flow depth upstream of the side weir (L/y1), trapezoidal canal side wall slope (m) and ratio of flow depth upstream of the side weir to main canal bottom width (y1/b) are studied on the side weir discharge capacity in a trapezoidal canal. A superior model is introduced as a function of parameters Fr, L/b, L/y1, m and y1/b. In testing the superior model, the calculated RMSE and MARE were 0.011 and 0.024, while the scatter index and BIAS values obtained for this model were 0.030 and 0.009, respectively. Also in model testing, 18.8% of data showed 5–10% error and 81.3% of data had less than 5% error. The correlation coefficient value and average discrepancy ratio calculated for the optimal model selected were 0.916 and 0.995, respectively. Copyright © 2017 John Wiley & Sons, Ltd.
Directed PBDs with Block Sizes from K Where K
Authors: Wei Hengjia , Ge Gennian 
Published: February 2017

AbstractThe research on directed PBDs is motivated by the construction of t‐deletion/insertion‐correcting codes. Fuji‐Hara, Miao, Wang, and Yin have determined the existence of directed PBDs with block sizes from the set and the set completely. In this paper, we consider the cases of . We settle almost completely for these cases, leaving finite values undetermined.
Effects of ammonia on propionate degradation and microbial community in digesters using propionate as a sole carbon source
Authors: Li Ying , Zhang Yue , Kong Xiaoying , Li Lianhua , Yuan Zhenhong , Dong Renjie , Sun Yongming 
Published: February 2017

AbstractBACKGROUNDPropionate accumulation may lead to digester failure. This study aimed to investigate the effect of ammonia, a metabolic product of protein, on propionate degradation. The shift of microbial community was also investigated.RESULTSPropionate accumulated over the experimental period in the reactor with a total ammonia nitrogen (TAN) concentration of 2.5 g N L−1, as a result the digester failed after 4 hydraulic retention times (HRT) at an organic load rate (OLR) of 0.8 g propionic acid (HPr) L−1 d−1. The average HPr degradation rate was below 54% during the fourth HRT, while >97% of the degraded HPr was converted to methane. The reactor without ammonia stress did not experience HPr accumulation and OLR was increased stepwise to 1.2 g L−1 d−1 at the 8th HRT. The average HPr degradation rate and methane recovery rate of this reactor in the last HRT was 99% and 74%, respectively. According to the shifts of microbial community, acetoclastic methanogen was more vulnerable to ammonia than hydrogenotrophic methanogenCONCLUSIONTAN concentration of 2.5 g N L−1 inhibited propionate degradation more severely than methanogenesis. The loss of abundance of Clostridiaceae and Syntrophobacter might be the main reason for the poor performance under ammonia stress. © 2017 Society of Chemical Industry
Differences in the nanoscale electrical properties of GaN films grown on sapphire and ZnO substrates by molecular beam epitaxy
Authors: Chen Sy‐Hann , Su Chiung‐Wu , Chang Li‐Hsin , Tsai Tzung‐Han 
Published: February 2017

AbstractGallium nitride (GaN) films were grown on sapphire and zinc oxide (ZnO) single crystal substrates using plasma‐assisted molecular beam epitaxy. As ZnO for GaN have a better lattice match, the coverage ratio of the GaN (002) plane on the ZnO substrate was significantly higher by about 45%. According to conducting atomic force microscopy and scanning surface potential microscopy measurements, the surface of GaN films grown on the ZnO substrate had two excellent physical characteristics: (a) an 18% reduction of the high contact current region, and (b) a highly uniform work function distribution. Therefore, for future applications in GaN‐based light‐emitting diodes, the use of ZnO as a substrate will prolong the luminescence lifetime and enhance the luminescent monochromaticity.