bluuebunny/crossref_metadata_2025_split huggingface dataset:
One‐Step Synthesis of Silver Nanoparticle‐Decorated Hydroxyapatite Nanowires for the Construction of Highly Flexible Free‐Standing Paper with High Antibacterial Activity
Authors: Xiong Zhi‐Chao , Zhu Ying‐Jie , Chen Fei‐Fei , Sun Tuan‐Wei , Shen Yue‐Qin 
Published: June 2016

AbstractA highly flexible and free‐standing paper with high antibacterial activity made from silver nanoparticle (AgNP)‐decorated ultralong hydroxyapatite nanowires (HAPNWs) is reported. The HAPNWs@AgNPs nanocomposites were obtained from a facile one‐step solvothermal process and utilized for the construction of highly flexible and free‐standing inorganic paper through a simple vacuum‐filtration procedure. The structure and properties of the HAPNWs@AgNPs paper were characterized in detail. Scanning electron microscope (SEM) and transmission electron microscope (TEM) micrographs show that AgNPs are highly dispersed and stabilized in the nanocomposite and exhibit a narrow particle size distribution. The effects of the concentration of silver nitrate, solvothermal temperature and time on the product were systematically investigated. This method is simple, convenient and reproducible. The as‐prepared HAPNWs@AgNPs paper shows long‐time sustained silver‐ion release, high antibacterial activity against both Gram‐negative and Gram‐positive bacteria, and good biocompatibility. Overall, this work provides a novel pathway for the preparation of a new type of highly flexible, free‐standing and antibacterial inorganic paper made from silver nanoparticle‐decorated hydroxyapatite nanowires for various applications, as a promising functional biomaterial.
Ascorbic Acid‐Assisted Synthesis of Mesoporous Sodium Vanadium Phosphate Nanoparticles with Highly sp2‐Coordinated Carbon Coatings as Efficient Cathode Materials for Rechargeable Sodium‐Ion Batteries
Authors: Hung Tai‐Feng , Cheng Wei‐Jen , Chang Wen‐Sheng , Yang Chang‐Chung , Shen Chin‐Chang , Kuo Yu‐Lin 
Published: June 2016

AbstractHerein, mesoporous sodium vanadium phosphate nanoparticles with highly sp2‐coordinated carbon coatings (meso‐Na3V2(PO4)3/C) were successfully synthesized as efficient cathode material for rechargeable sodium‐ion batteries by using ascorbic acid as both the reductant and carbon source, followed by calcination at 750 °C in an argon atmosphere. Their crystalline structure, morphology, surface area, chemical composition, carbon nature and amount were systematically explored. Following electrochemical measurements, the resultant meso‐Na3V2(PO4)3/C not only delivered good reversible capacity (98 mAh g−1 at 0.1 A g−1) and superior rate capability (63 mAh g−1 at 1 A g−1) but also exhibited comparable cycling performance (capacity retention: ≈74 % at 450 cycles at 0.4 A g−1). Moreover, the symmetrical sodium‐ion full cell with excellent reversibility and cycling stability was also achieved (capacity retention: 92.2 % at 0.1 A g−1 with 99.5 % coulombic efficiency after 100 cycles). These attributes are ascribed to the distinctive mesostructure for facile sodium‐ion insertion/extraction and their continuous sp2‐coordinated carbon coatings, which facilitate electronic conduction.
A Mechanistic Investigation of the Visible‐Light Photocatalytic Trifluoromethylation of Heterocycles Using CF3I in Flow
Authors: Su Yuanhai , Kuijpers Koen P. L. , König Niels , Shang Minjing , Hessel Volker , Noël Timothy 
Published: June 2016

AbstractPhotocatalytic radical trifluoromethylation strategies have impacted the synthesis of trifluoromethyl‐containing molecules. However, mechanistic aspects concerning such transformations remain poorly understood. Here, we describe in detail the mechanism of the visible‐light photocatalytic trifluoromethylation of N‐methylpyrrole with gaseous CF3I in flow. The use of continuous‐flow microreactor technology allowed for the determination of different important parameters with high precision (e.g., photon flux, quantum yield, reaction rate constants) and for the handling of CF3I in a convenient manner. Our data indicates that the reaction occurs through a reductive quenching mechanism and that there is no radical chain process present.
Exploiting the Distal Reactivity of Indolyl Methylenemalononitriles: An Asymmetric Organocatalyzed [4+2] Cycloaddition with Enals Enables the Assembly of Elusive Dihydrocarbazoles
Authors: Rassu Gloria , Curti Claudio , Zambrano Vincenzo , Pinna Luigi , Brindani Nicoletta , Pelosi Giorgio , Zanardi Franca 
Published: June 2016

AbstractAn unprecedented technique for the in situ generation of indolyl ortho‐quinodimethanes from 2‐methylindole‐based methylenemalononitriles by amine‐mediated remote C(sp3)−H deprotonation was developed. These intermediates were efficiently trapped by diverse enals to provide a rapid entry to 2,9‐dihydro‐1H‐carbazole‐3‐carboxyaldehyde structures through a formal asymmetric [4+2] eliminative cycloaddition governed by a α,α‐diphenylprolinol trimethylsilyl ether catalyst.
Flexible association modelling and prediction with semi‐competing risks data
Authors: Li Ruosha , Cheng Yu 
Published: June 2016

AbstractSemi‐competing risks data involve a non‐terminal event time, such as time to disease progression, and a terminal event time such as time to death. Existing methods for handling semi‐competing risks data often assume that the underlying association between the two event times follows a pre‐specified copula with unknown association parameters, which often correspond to the strength of association. In this article we propose a flexible association model that does not require pre‐specifying a copula. Therefore our methods facilitate a convenient and robust evaluation of the underlying association pattern, as well as the association strength. Furthermore the proposed association model leads to a robust estimator for the conditional survival probability of the terminal event given the non‐terminal event. The methods were also extended to handle left‐truncation. Both the association and survival estimators were shown to feature desirable asymptotic properties and satisfactory numerical performance. Our methods were successfully applied to a diabetes data set to study the association between time to diabetic nephropathy and time to death, and to predict the mortality rate given the onset time of nephropathy. The Canadian Journal of Statistics 44: 361–374; 2016 © 2016 Statistical Society of Canada
Guidelines for the Synthesis of Small‐Molecule Irreversible Probes Targeting G Protein‐Coupled Receptors
Authors: Jörg Manuela , Scammells Peter J. 
Published: June 2016

AbstractIrreversible probes have been proven to be useful pharmacological tools in the study of structural and functional features in drug receptor pharmacology. They have been demonstrated to be particularly valuable for the isolation and purification of receptors. Furthermore, irreversible probes are helpful tools for the identification and characterization of binding sites, thereby supporting the advancement of rational drug design. In this Minireview, we provide insight into universal strategies and guidelines to successfully synthesize irreversible probes that target G protein‐coupled receptors (GPCRs). We provide an overview of commonly used chemoreactive and photoreactive groups, and make a comparison of their properties and potential applications. Furthermore, there is a particular focus on synthetic approaches to introduce these reactive groups based on commercially available reagents.
A Comprehensive Discussion of HMBC Pulse Sequences: 4. Establishing Two‐Bond Correlations from HMBC and Related Experiments
Authors: Saurí Josep , Martin Gary E. , Furrer Julien 
Published: June 2016

AbstractThe utility of the HMBC experiment for structure elucidation is unquestionable, but the nature of the coupling pathways leading to correlations in an HMBC experiment creates the potential for misinterpretation. This misinterpretation potential is intimately linked to the size of the long‐range heteronuclear couplings involved, and may become troublesome in those cases of a particularly strong 2JCH correlation that might be mistaken for a 3JCH correlation or a 4JCH correlation of appreciable strength that could be mistaken for a weaker 3JCH correlation. To address these potential avenues of confusion, work from several laboratories has been focused on the development of what might be considered “coupling pathway edited” long‐range heteronuclear correlation experiments that are derived from or related to the HMBC experiment. The first example of an effort to address the problems associated with correlation path length was seen in the heteronucleus‐detected XCORFE experiment described by Reynolds and co‐workers that predated the development of the HMBC experiment. Proton‐detected analogs of the HMBC experiment intended to differentiate 2JCH correlations from nJCH correlations where n = 3, 4, include the 2J,3J‐HMBC, HMBC‐RELAY, H2BC, edited‐HMBC, and HAT H2BC experiments. The principles underlying the critical components of each of these experiments are discussed and experimental verification of the results that can be obtained using model compounds are shown. This contribution concludes with a brief discussion of the 1,1‐ADEQUATE experiments that provide an alternative means of identifying adjacent protonated and non‐protonated carbon correlations by exploiting 1JCC correlations at natural abundance.
Quantifying the spatiotemporal dynamics in a chorus frog (Pseudacris) hybrid zone over 30 years
Authors: Engebretsen Kristin N. , Barrow Lisa N. , Rittmeyer Eric N. , Brown Jeremy M. , Moriarty Lemmon Emily 
Published: June 2016

AbstractAlthough theory suggests that hybrid zones can move or change structure over time, studies supported by direct empirical evidence for these changes are relatively limited. We present a spatiotemporal genetic study of a hybrid zone between Pseudacris nigrita and P. fouquettei across the Pearl River between Louisiana and Mississippi. This hybrid zone was initially characterized in 1980 as a narrow and steep “tension zone,” in which hybrid populations were inferior to parentals and were maintained through a balance between selection and dispersal. We reanalyzed historical tissue samples and compared them to samples of recently collected individuals using microsatellites. Clinal analyses indicate that the cline has not shifted in roughly 30 years but has widened significantly. Anthropogenic and natural changes may have affected selective pressure or dispersal, and our results suggest that the zone may no longer best be described as a tension zone. To the best of our knowledge, this study provides the first evidence of significant widening of a hybrid cline but stasis of its center. Continued empirical study of dynamic hybrid zones will provide insight into the forces shaping their structure and the evolutionary potential they possess for the elimination or generation of species.
Habitat‐mediated timing of migration in polar bears: an individual perspective
Authors: Cherry Seth G. , Derocher Andrew E. , Lunn Nicholas J. 
Published: June 2016

AbstractMigration phenology is largely determined by how animals respond to seasonal changes in environmental conditions. Our perception of the relationship between migratory behavior and environmental cues can vary depending on the spatial scale at which these interactions are measured. Understanding the behavioral mechanisms behind population‐scale movements requires knowledge of how individuals respond to local cues. We show how time‐to‐event models can be used to predict what factors are associated with the timing of an individual's migratory behavior using data from GPS collared polar bears (Ursus maritimus) that move seasonally between sea ice and terrestrial habitats. We found the concentration of sea ice that bears experience at a local level, along with the duration of exposure to these conditions, was most associated with individual migration timing. Our results corroborate studies that assume thresholds of >50% sea ice concentration are necessary for suitable polar bear habitat; however, continued periods (e.g., days to weeks) of exposure to suboptimal ice concentrations during seasonal melting were required before the proportion of bears migrating to land increased substantially. Time‐to‐event models are advantageous for examining individual movement patterns because they account for the idea that animals make decisions based on an accumulation of knowledge from the landscapes they move through and not simply the environment they are exposed to at the time of a decision. Understanding the migration behavior of polar bears moving between terrestrial and marine habitat, at multiple spatiotemporal scales, will be a major aspect of quantifying observed and potential demographic responses to climate‐induced environmental changes.
Corolla chirality does not contribute to directed pollen movement in Hypericum perforatum (Hypericaceae): mirror image pinwheel flowers function as radially symmetric flowers in pollination
Authors: Diller Carolina , Fenster Charles B. 
Published: June 2016

AbstractCorolla chirality, the pinwheel arrangement of petals within a flower, is found throughout the core eudicots. In 15 families, different chiral type flowers (i.e., right or left rotated corolla) exist on the same plant, and this condition is referred to as unfixed/enantiomorphic corolla chirality. There are no investigations on the significance of unfixed floral chirality on directed pollen movement even though analogous mirror image floral designs, for example, enantiostyly, has evolved in response to selection to direct pollinator and pollen movement. Here, we examine the role of corolla chirality on directing pollen transfer, pollinator behavior, and its potential influence on disassortative mating. We quantified pollen transfer and pollinator behavior and movement for both right and left rotated flowers in two populations of Hypericum perforatum. In addition, we quantified the number of right and left rotated flowers at the individual level. Pollinators were indifferent to corolla chirality resulting in no difference in pollen deposition between right and left flowers. Corolla chirality had no effect on pollinator and pollen movement between and within chiral morphs. Unlike other mirror image floral designs, corolla chirality appears to play no role in promoting disassortative mating in this species.
Precocious reproduction increases at the leading edge of a mangrove range expansion
Authors: Dangremond Emily M. , Feller Ilka C. 
Published: June 2016

AbstractClimate change‐driven shifts in species ranges are ongoing and expected to increase. However, life‐history traits may interact with climate to influence species ranges, potentially accelerating or slowing range shifts in response to climate change. Tropical mangroves have expanded their ranges poleward in the last three decades. Here, we report on a shift at the range edge in life‐history traits related to reproduction and dispersal. With a common garden experiment and field observations, we show that Rhizophora mangle individuals from northern populations reproduce at a younger age than those from southern populations. In a common garden at the northern range limit, 38% of individuals from the northernmost population were reproductive by age 2, but less than 10% of individuals from the southernmost population were reproductive by the same age, with intermediate amounts of reproduction from intermediate latitudes. Field observations show a similar pattern of younger reproductive individuals toward the northern range limit. We also demonstrate a shift toward larger propagule size in populations at the leading range edge, which may aid seedling growth. The substantial increase in precocious reproduction at the leading edge of the R. mangle range could accelerate population growth and hasten the expansion of mangroves into salt marshes.
Variation of life‐history traits of the Asian corn borer, Ostrinia furnacalis in relation to temperature and geographical latitude
Authors: Xiao Liang , He Hai‐Min , Huang Li‐Li , Geng Ting , Fu Shu , Xue Fang‐Sen 
Published: June 2016

AbstractLife‐history traits from four geographical populations (tropical Ledong population [LD], subtropical Guangzhou [GZ] and Yongxiu populations, and temperate Langfang population [LF]) of the Asian corn borer, Ostrinia furnacalis were investigated at a wide range of temperatures (20–32°C). The larval and pupal times were significantly decreased with increasing rearing temperature, and growth rate was positively correlated with temperature. The relationship between body weight and rearing temperature in O. furnacalis did not follow the temperature–size rule (TSR); all populations exhibited the highest pupal and adult weights at high temperatures or intermediate temperatures. However, development time, growth rate, and body weight did not show a constant latitudinal gradient. Across all populations at each temperature, female were significantly bigger than males, showing a female‐biased sexual size dimorphism (SSD). Contrary to Rensch's rule, the SSD tended to increase with rising temperature. The subtropical GZ population exhibited the largest degree of dimorphism while the temperate LF exhibited the smallest. Male pupae lose significantly more weight at metamorphosis compared to females. The proportionate weight losses of different populations were significantly different. Adult longevity was significantly decreased with increasing temperature. Between sexes, all populations exhibit a rather female‐biased adult longevity. Finally, we discuss the adaptive significance of higher temperature‐inducing high body weight in the moth's life history and why the moth exhibits the reverse TSR.
Nanoporous Gold Electrodes with Tuneable Pore Sizes for Bioelectrochemical Applications
Authors: Siepenkoetter Till , Salaj‐Kosla Urszula , Xiao Xinxin , Belochapkine Serguei , Magner Edmond 
Published: June 2016

AbstractNanoporous gold (NPG) fabricated by sputtering is a material of versatile morphology with pores whose size can be tailored to accommodate enzymes. The process of pore formation and the size of the pores in NPG are influenced by the composition of Au and Ag in the alloy used to prepare the electrodes together with the temperature and time period of the dealloying process. On increasing the time from 1 to 60 min and the temperature from 0.5 °C to 60.5 °C in concentrated HNO3, significant increases in the average pore diameters from 4.4 to 78 nm were observed with simultaneous decreases in the roughness factor (Rf). The pores of NPG were fully addressable regardless of the diameter, with Rf increasing linearly up to an alloy thickness of 500 nm. The influence of the pore size on the bioelectrochemical response of redox proteins was evaluated using cytochrome c as a model system. The highest current densities of ca. 30 µA cm−2 were observed at cytochrome c modified NPG electrodes with an average pore size of ca. 10 nm. The pores in NPG were also tuned for the mediatorless immobilization of Myrothecium verrucaria bilirubin oxidase. High current densities of ca. 65 µA cm−2 were observed at MvBOD modified NPG electrodes prepared by dealloying at 0.5 °C for 5 min with an average pore size of 8 nm, which is too small to accommodate the enzyme into the pores, indicating that the response was from enzyme adsorbed on the electrode surface.
Trace element storage capacity of sediments in dead Posidonia oceanica mat from a chronically contaminated marine ecosystem
Authors: Di Leonardo Rossella , Mazzola Antonio , Cundy Andrew B. , Tramati Cecilia Doriana , Vizzini Salvatrice 
Published: June 2016

Abstract

Posidonia oceanica mat is considered a long-term bioindicator of contamination. Storage and sequestration of trace elements and organic carbon (Corg) were assessed in dead P. oceanica mat and bare sediments from a highly polluted coastal marine area (Augusta Bay, central Mediterranean). Sediment elemental composition and sources of organic matter have been altered since the 1950s. Dead P. oceanica mat displayed a greater ability to bury and store trace elements and Corg than nearby bare sediments, acting as a long-term contaminant sink over the past 120 yr. Trace elements, probably associated with the mineral fraction, were stabilized and trapped despite die-off of the overlying P. oceanica meadow. Mat deposits registered historic contamination phases well, confirming their role as natural archives for recording trace element trends in marine coastal environments. This sediment typology is enriched with seagrass-derived refractory organic matter, which acts mainly as a diluent of trace elements. Bare sediments showed evidence of inwash of contaminated sediments via reworking; more rapid and irregular sediment accumulation; and, because of the high proportions of labile organic matter, a greater capacity to store trace elements. Through different processes, both sediment typologies represent a repository for chemicals and may pose a risk to the marine ecosystem as a secondary source of contaminants in the case of sediment dredging or erosion. Environ Toxicol Chem 2017;36:49–58. © 2016 SETAC
Discharge estimation under uncertainty using variational methods with application to the full Saint‐Venant hydraulic network model
Authors: Gejadze Igor , Malaterre Pierre‐Olivier 
Published: June 2016

SummaryEstimating river discharge from in situ and/or remote sensing data is a key issue for evaluation of water balance at local and global scales and for water management. Variational data assimilation (DA) is a powerful approach used in operational weather and ocean forecasting, which can also be used in this context. A distinctive feature of the river discharge estimation problem is the likely presence of significant uncertainty in principal parameters of a hydraulic model, such as bathymetry and friction, which have to be included into the control vector alongside the discharge. However, the conventional variational DA method being used for solving such extended problems often fails. This happens because the control vector iterates (i.e., approximations arising in the course of minimization) result into hydraulic states not supported by the model. In this paper, we suggest a novel version of the variational DA method specially designed for solving estimation‐under‐uncertainty problems, which is based on the ideas of iterative regularization.The method is implemented with SIC2, which is a full Saint‐Venant based 1D‐network model. The SIC2 software is widely used by research, consultant and industrial communities for modeling river, irrigation canal, and drainage network behavior. The adjoint model required for variational DA is obtained by means of automatic differentiation. This is likely to be the first stable consistent adjoint of the 1D‐network model of a commercial status in existence.The DA problems considered in this paper are offtake/tributary estimation under uncertainty in the cross‐device parameters and inflow discharge estimation under uncertainty in the bathymetry defining parameters and the friction coefficient. Numerical tests have been designed to understand identifiability of discharge given uncertainty in bathymetry and friction. The developed methodology, and software seems useful in the context of the future Surface Water and Ocean Topography satellite mission. Copyright © 2016 John Wiley & Sons, Ltd.