bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constructing an Atomic Layer Pt Electrocatalyst with a Concave Curved Surface for the Oxygen Reduction Reaction
Authors: Li Jian , Gao Yong‐Fu , Yin Hui‐Ming 
Published: June 2017

AbstractOne of the strategic objectives in fuel cell technologies is to develop oxygen reduction reaction (ORR) catalysts with high activity, stability and, moreover, a low Pt loading. Computational results have indicated that surfaces or nanostructures with concave defects exhibit higher ORR activity than convex ones. Here, atomic layers of Pt were epitaxially coated on nanoporous gold (NPG) for the unique surface structure, both with convex or concave curvatures of the NPG. Outstanding ORR activities were revealed on Pt overlayers who copied the substrate's surface features. Furthermore, ascribed to the adverse impacts of tensile Pt lattice on gold, an optimized specific activity has been found as a function of the increasing Pt atomic layers. Pt coating with three atomic layers on NPG (NPG−Pt3) shows the best specific activity with an approximate 9‐fold improvement with respect to commercial Pt/C, as well as a 10‐fold enhancement in mass activity at 0.9 V versus a reversible hydrogen electrode.
Linking ReI and PtII Chromophores with Aminopyridines: A Simple Route to Achieve a Complicated Photophysical Behavior
Authors: Kisel Kristina S. , Melnikov Alexei S. , Grachova Elena V. , Hirva Pipsa , Tunik Sergey P. , Koshevoy Igor O. 
Published: June 2017

AbstractThe bifunctional aminopyridine ligands H2N‐(CH2)n‐4‐C5H4N (n=0, L1; 1, L2; 2, L3) have been utilized for the preparation of the rhenium complexes [Re(phen)(CO)3(L1–L3)]+ (1–3; phen=phenanthroline). Complexes 2 and 3 with NH2‐coordinated L2 and L3, respectively, were coupled with cycloplatinated motifs {Pt(ppy)Cl} and {Pt(dpyb)}+ (ppy=2‐phenylpyridine, dpyb=dipyridylbenzene) to give the bimetallic species [Re(phen)(CO)3(μ‐L2/L3)Pt(ppy)Cl]+ (4, 6) and [Re(phen)(CO)3(μ‐L2/L3)Pt(dpyb)]2+ (5, 7). In solution, complexes 4 and 6 show 3MLCT {Re}‐based emission at 298 K, which changes to the 3IL(ppy) state at 77 K. The photophysical properties of compounds 5 and 7 display a pronounced concentration dependence, presumably due to the formation of bimolecular aggregates. Analysis of the spectroscopic data, combined with TD‐DFT simulations, suggest that unconventional heteroleptic {Re(phen)}⋅⋅⋅{Pt(dpyb)} π–π stacking operates as the driving force for ground‐state association. The latter, together with intra‐ and intermolecular energy‐transfer processes, determines the appearance of multiple emission bands and results in nonlinear relaxation kinetics of the excited states.
Preparation and evaluation of regioselectively substituted amylose derivatives for chiral separations
Authors: Tang Shouwan , Jin Zhaolei , Sun Baishen , Wang Fang , Tang Wenyuan 
Published: June 2017

AbstractSix novel regioselectively substituted amylose derivatives with a benzoate at 2‐position and two different phenylcarbamates at 3‐ and 6‐positions were synthesized and their structures were characterized by 1H nuclear magnetic resonance (NMR) spectroscopy. Their enantioseparation abilities were then examined as chiral stationary phases (CSPs) for high‐performance liquid chromatography (HPLC) after they were coated on 3‐aminopropyl silica gels. Investigations indicated that the substituents at the 3‐ and 6‐positions played an important role in chiral recognition of these amylose 2‐benzoate serial derivatives. The derivatives demonstrated characteristic enantioseparation and some racemates were better resolved on these derivatives than on Chiralpak AD, which is one of the most efficient CSPs, utilizing coated amylose tris(3,5‐dimethylphenylcarbamate) as the chiral selector. Among the derivatives prepared, amylose 2‐benzoate‐3‐(phenylcarbamate/4‐methylphenylcarbamate)‐6‐(3,5‐dimethylphenylcarbamate) exhibited chiral recognition abilities comparable to that of Chiralpak AD and may be useful CSPs in the future. The effect of mobile phase on chiral recognition was also studied. In general, with the decreased concentration of 2‐propanol, better resolutions were obtained with longer retention times. Moreover, when ethanol was used instead of 2‐propanol, poorer resolutions were often achieved. However, in some cases, improved enantioselectivity was achieved with ethanol rather than 2‐propanol as the mobile phase modifier.
Performance evaluation of GPU parallelization, space‐time adaptive algorithms, and their combination for simulating cardiac electrophysiology
Authors: Sachetto Oliveira Rafael , Martins Rocha Bernardo , Burgarelli Denise , Meira Wagner , Constantinides Christakis , Weber dos Santos Rodrigo 
Published: June 2017

AbstractThe use of computer models as a tool for the study and understanding of the complex phenomena of cardiac electrophysiology has attained increased importance nowadays. At the same time, the increased complexity of the biophysical processes translates into complex computational and mathematical models. To speed up cardiac simulations and to allow more precise and realistic uses, 2 different techniques have been traditionally exploited: parallel computing and sophisticated numerical methods. In this work, we combine a modern parallel computing technique based on multicore and graphics processing units (GPUs) and a sophisticated numerical method based on a new space‐time adaptive algorithm. We evaluate each technique alone and in different combinations: multicore and GPU, multicore and GPU and space adaptivity, multicore and GPU and space adaptivity and time adaptivity. All the techniques and combinations were evaluated under different scenarios: 3D simulations on slabs, 3D simulations on a ventricular mouse mesh, ie, complex geometry, sinus‐rhythm, and arrhythmic conditions. Our results suggest that multicore and GPU accelerate the simulations by an approximate factor of 33×, whereas the speedups attained by the space‐time adaptive algorithms were approximately 48. Nevertheless, by combining all the techniques, we obtained speedups that ranged between 165 and 498. The tested methods were able to reduce the execution time of a simulation by more than 498× for a complex cellular model in a slab geometry and by 165× in a realistic heart geometry simulating spiral waves. The proposed methods will allow faster and more realistic simulations in a feasible time with no significant loss of accuracy.
Factors contributing to the accumulation of reproductive isolation: A mixed model approach
Authors: Castillo Dean M. 
Published: June 2017

AbstractThe analysis of large datasets describing reproductive isolation between species has been extremely influential in the study of speciation. However, the statistical methods currently used for these data limit the ability to make direct inferences about the factors predicting the evolution of reproductive isolation. As a result, our understanding of iconic patterns and rules of speciation rely on indirect analyses that have clear statistical limitations. Phylogenetic mixed models are commonly used in ecology and evolution, but have not been applied to studies of reproductive isolation. Here I describe a flexible framework using phylogenetic mixed models to analyze data collected at different evolutionary scales, to test both categorical and continuous predictor variables, and to test the effect of multiple predictors on rates and patterns of reproductive isolation simultaneously. I demonstrate the utility of this framework by re‐analyzing four classic datasets, from both animals and plants, and evaluating several hypotheses that could not be tested in the original studies: In theDrosophilaand Bufonidae datasets, I found support for more rapid accumulation of reproductive isolation in sympatric species pairs compared to allopatric species pairs. UsingSileneandNolana, I found no evidence supporting the hypothesis that floral differentiation elevates postzygotic reproductive isolation. The faster accumulation of postzygotic isolation in sympatry is likely the result of species coexistence determined by the level of postzygotic isolation between species. In addition, floral trait divergence does not appear to translate into pleiotropic effects on postzygotic reproductive isolation. Overall, these methods can allow researchers to test new hypotheses using a single statistical method, while remedying the statistical limitations of several previous methods.
Evolutionary responses to a changing climate: Implications for reindeer population viability
Authors: Bårdsen Bård‐Jørgen 
Published: June 2017

AbstractIf we want to understand how climate change affects long‐lived organisms, we must know how individuals allocate resources between current reproduction and survival. This trade‐off is affected by expected environmental conditions, but the extent to which density independent (DI) and density dependent (DD) processes interact in shaping individual life histories is less clear. Female reindeer (or caribou: Rangifer tarandus) are a monotocous large herbivore with a circumpolar distribution. Individuals that experience unpredictable and potentially harsh winters typically adopt risk averse strategies where they allocate more resources to building own body reserves during summer and less to reproduction. Such a strategy implies that the females do not reproduce or that they produce fewer or smaller offspring. A risk averse strategy thus results in females with large autumn body reserves, which is known to increase their survival probabilities if the coming winter is harsh. In contrast, females experiencing predictable winters may adopt a more risk prone strategy in which they allocate more resources to reproduction as they do not need as many resources to buffer potentially adverse winter conditions. This study uses a seasonal state‐dependent model showing that DD and DI processes interact to affect the evolution of reproductive strategies and population dynamics for reindeer. The model was run across a wide range of different winter climatic scenarios: One set of simulations where the average and variability of the environment was manipulated and one set where the frequency of good and poor winters increased. Both reproductive allocation and population dynamics of reindeer were affected by a combination of DI and DD processes even though they were confounded (harsh climates resulted in lowered density). Individual strategies responded, in line with a risk sensitive reproductive allocation, to climatic conditions and in a similar fashion across the two climatic manipulations.
Fluorescent Polypyrrole Nanospheres – Synthesis and Properties of “Wireless” Redox Probes
Authors: Kłucińska Katarzyna , Jaworska Ewa , Maksymiuk Krzysztof , Michalska Agata 
Published: June 2017

AbstractIn this work a novel concept of monitoring of occurrence of redox reactions between conducting polymer nanospheres and redox species in a solution is proposed. The redox process is monitored in the emission mode (without wiring of the probe to an electrochemical measuring set‐up) as a change in emission spectrum of a dye (not participating in the redox process itself) but reporting the alteration of properties of highly sensitive conducting polymer nanoparticles. This approach is possible due to applied unique method of synthesis of conducting polymers nanospheres of highly active, unblocked surface. Thus the nanospheres redox state is affected by the solution redox potential, leading to change of their properties. If solvatochromic probe of sufficiently high brightness (pyrene) is present in nanospheres, a redox reaction between the conducting polymer and solution can be observed as change of emission spectrum of the probe. Thus a localized redox potential optical probe can be obtained. The emission properties of the dye incorporated were preserved in the nanospheres, moreover, the emission spectrum of the probe was affected by the change in redox potential of the solution, thus influencing the redox state and ultimately the properties of the conducting polymer. The emission changes observed were dependent on ion‐exchange properties of polypyrrole, i.e. depending on the dopant ions present in the polymer, the sensitivity of the optical probe can be tuned.
A Phos‐tag‐based micropipette‐tip method for rapid and selective enrichment of phosphopeptides
Authors: Yuan Elena Tianfei , Ino Yoko , Kawaguchi Maho , Kimura Yayoi , Hirano Hisashi , Kinoshita‐Kikuta Emiko , Kinoshita Eiji , Koike Tohru 
Published: June 2017

AbstractPhosphorylated peptides are attractive targets in the study of the phosphoproteome. Here, we introduce a simple and convenient micropipette‐tip method for the separation of phosphorylated and nonphosphorylated peptides by using a phosphate‐binding zinc(II) complex of 1,3‐bis(pyridin‐2‐ylmethylamino)propan‐2‐olate (Phos‐tag). A 200‐μL micropipette tip containing 10 μL of swollen agarose beads functionalized with Phos‐tag moieties was prepared. All steps in the phosphate‐affinity separation (binding, washing, and elution) were conducted by using aqueous buffers at neutral pH values. The entire separation protocol required less than 30 min per sample. By means of three independent separation experiments, followed by mass spectrometric (MS) analyses, we identified 1,649 non‐redundant phosphopeptides from the lysates of human embryonic kidney cells (the peptides sample derived from 25 μg proteins per an MS analysis). The average ratio of identified phosphopeptides to total peptides in the respective experiments was >90%, showing a high selectivity. Furthermore, the high correlation between the triplicate analyses was confirmed by scatter plots based on the normalized abundance of each peptide, as calculated by a label‐free peptide relative quantification analysis in Progenesis QI. This micropipette‐tip method would be thus used preferentially as an alternative to existing tools for the reliable enrichment of phosphopeptides.
Development of biotic ligand model–based freshwater aquatic life criteria for lead following US Environmental Protection Agency guidelines
Authors: DeForest David K. , Santore Robert C. , Ryan Adam C. , Church Brian G. , Chowdhury M. Jasim , Brix Kevin V. 
Published: June 2017

Abstract

The US Environmental Protection Agency's (USEPA's) current ambient water quality criteria (AWQC) for lead (Pb) in freshwater were developed in 1984. The criteria are adjusted for hardness, but more recent studies have demonstrated that other parameters, especially dissolved organic carbon (DOC) and pH, have a much stronger influence on Pb bioavailability. These recent studies have been used to support development of a biotic ligand model (BLM) for Pb in freshwater, such that acute and chronic Pb toxicity can be predicted over a wide range of water chemistry conditions. Following USEPA guidelines for AWQC development and using a methodology consistent with that used by the USEPA in developing its recommended BLM-based criteria for copper in 2007, we propose acute and chronic BLM-based AWQC for Pb in freshwater. In addition to the application of the BLM approach that can better account for site-specific Pb bioavailability, the toxicity data sets presented are much more robust than in 1984, and there are now sufficient chronic Pb toxicity data available that use of an acute-to-chronic ratio is no longer necessary. Over a range of North American surface waters with representative water chemistry conditions, proposed acute BLM-based Pb criteria ranged from approximately 20 to 1000 μg/L and chronic BLM-based Pb criteria ranged from approximately 0.3 to 40 μg/L. The lowest criteria were for water with low DOC (1.2 mg/L), pH (6.7), and hardness (4.3 mg/L as CaCO3), whereas the highest criteria were for water with high DOC (9.8 mg/L), pH (8.2), and hardness (288 mg/L as CaCO3). Environ Toxicol Chem 2017;36:2965–2973. © 2017 SETAC
Widespread occurrence and potential for biodegradation of bioactive contaminants in Congaree National Park, USA
Authors: Bradley Paul M. , Battaglin William A. , Clark Jimmy M. , Henning Frank P. , Hladik Michelle L. , Iwanowicz Luke R. , Journey Celeste A. , Riley Jeffrey W. , Romanok Kristin M. 
Published: June 2017

Abstract

Organic contaminants with designed molecular bioactivity, such as pesticides and pharmaceuticals, originate from human and agricultural sources, occur frequently in surface waters, and threaten the structure and function of aquatic and terrestrial ecosystems. Congaree National Park in South Carolina (USA) is a vulnerable park unit due to its location downstream of multiple urban and agricultural contaminant sources and its hydrologic setting, being composed almost entirely of floodplain and aquatic environments. Seventy-two water and sediment samples were collected from 16 sites in Congaree National Park during 2013 to 2015, and analyzed for 199 and 81 targeted organic contaminants, respectively. More than half of these water and sediment analytes were not detected or potentially had natural sources. Pharmaceutical contaminants were detected (49 total) frequently in water throughout Congaree National Park, with higher detection frequencies and concentrations at Congaree and Wateree River sites, downstream from major urban areas. Forty-seven organic wastewater indicator chemicals were detected in water, and 36 were detected in sediment, of which approximately half are distinctly anthropogenic. Endogenous sterols and hormones, which may originate from humans or wildlife, were detected in water and sediment samples throughout Congaree National Park, but synthetic hormones were detected only once, suggesting a comparatively low risk of adverse impacts. Assessment of the biodegradation potentials of 8 14C-radiolabeled model contaminants indicated poor potentials for some contaminants, particularly under anaerobic sediments conditions. Environ Toxicol Chem 2017;36:3045–3056. 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.
Discovery of Mesoproterozoic kimberlite from Dörbed Banner, Inner Mongolia and its tectonic significance
Authors: Zhou Zhiguang , Wang Guosheng , Di Yong‐jun , Gu Yong‐chang , Zhang Da , Zhu Wei‐ping , Liu Changfeng , Wu Chen , Li Hongying , Chen Li‐zhen 
Published: June 2017

Porphyritic olivine kimberlitic breccia, discovered in the Dörbed Banner of Inner Mongolia, Western China, is referred to as Longtou Shan Kimberlite in our study. This kimberlite occurs as a pipe in the Halahuogete Formation of Bayan Obo Group. Zircon U–Pb ages of Longtou Shan Kimberlite reveals a Mesoproterozoic age of ~1,552 Ma, constraining the deposition age of Halahuogete Formation to the Mesoproterozoic. Compared with Mesoproterozoic kimberlite of the ancient landmass, it can be inferred that the North China Craton is a member of the Ur ancient continent of the Columbia supercontinent. Furthermore, according to the tectonic background of the Bayan Obo Group, we raise this possibility that “Bayan Obo Aulacogen” should be renamed the “Bayan Obo Continental Rift.”
The role of child temperament on low‐income preschool children's relationships with their parents and teachers
Authors: Acar Ibrahim H. , Torquati Julia C. , Encinger Amy , Colgrove Amy 
Published: June 2017

The current study examined the associations between low‐income preschool children's temperament (reactive and regulatory) and their relationships with parents and teachers. In particular, we focused on the moderating role of regulatory temperament on reactive temperament in the prediction of closeness and conflict with parents and teachers. Two hundred ninety‐one children (M = 53.88 months, SD = 6.44 months), their parents, and teachers from 3 different preschools serving low‐income children in 2 midwestern cities in the United States participated. Parents reported on temperament and parent–child relationships, and teachers reported on teacher–child relationships. Hierarchical regression models using SAS PROC MIXED were employed to allow for nesting of children within classrooms. After controlling for child age, gender, ethnicity, and parent education, children's reactive temperament was negatively associated with parent–child closeness and positively associated with parent–child conflict and teacher–child conflict. Children's regulatory temperament was positively related to teacher–child closeness and negatively associated with teacher–child conflict. Regulatory temperament moderated the association between reactive temperament and teacher–child closeness. These findings suggest that although reactive temperament potentially undermines closeness in relationships with teachers, regulatory temperament can buffer the influence of reactive temperament on teacher–child closeness.Highlights

This study examined the association between children's temperament and their relationships with parents and teachers.
Reactive temperament was positively associated with parent/teacher–child conflict and negatively associated with parent–child closeness. Regulatory temperament was a moderator for the association between reactive temperament and teacher–child closeness.
Improving children's regulatory temperament may be helpful for children with the reactive temperament to have better social relationships with their teachers.
Patterns of emotional availability between mothers and young children: Associations with risk factors for borderline personality disorder
Authors: Trupe Rebecca D. , Macfie Jenny , Skadberg Rebecca M. , Kurdziel Gretchen 
Published: June 2017

AbstractEmotional availability (EA) characterizes a warm, close relationship between caregiver and child. We compared patterns (clusters) of EA on risk factors, including those for borderline personality disorder (BPD). We sampled 70 children aged 4 to 7 years from low socio‐economic backgrounds: 51% of whose mothers had BPD. We coded filmed interactions for EA: mothers' sensitivity, structuring, non‐intrusiveness, non‐hostility, and children's responsiveness to, and involvement of, mothers. We additionally coded children's over‐responsiveness and over‐involvement. Using person‐centred analyses, we identified four clusters: high functioning, low functioning, asynchronous (mothers above average on two of four dimensions and children below), and below average. Mothers in the low‐functioning cluster had lower income, less social support, more of the borderline feature of negative relationships, and more depression than did mothers in the high‐functioning cluster. The children in the low‐functioning group had more risk factors for BPD (physical abuse, neglect, and separation from, or loss of caregivers, and negative narrative representations of the mother–child relationship in their stories) than did children in the high‐functioning group. The asynchronous group included older girls who were over‐responsive and over‐involving with their mothers in an apparent role reversal. Interventions targeting emotional availability may provide a buffer for children facing cumulative risks and help prevent psychopathology.Highlights

This paper investigated how mother‐child emotional availability (warmth and closeness) relates to risk factors for borderline personality disorder, including mother‐child role reversal.
In filmed mother‐child interactions, low emotional availability was associated with risk for borderline personality disorder and role reversal was more likely for older girls.
Findings support the cumulative risk hypothesis and may inform interventions to improve mother‐child emotional availability to prevent the development of psychopathology.