bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile Deposition of Cu−SnOx Hybrid Nanostructures on Lightly Boron‐Doped Diamond Electrodes for CO2 Reduction
Authors: Roy Nitish , Suzuki Norihiro , Nakabayashi Yukihiro , Hirano Yuiri , Ikari Hiroshi , Katsumata Ken‐ichi , Nakata Kazuya , Fujishima Akira , Terashima Chiaki 
Published: June 2018

AbstractIn this work, we report a facile synthesis of Cu−SnOx hybrid nanostructures on lightly boron‐doped diamond (BDDL) electrodes by a potentiodynamic electrodeposition method. The deposition potential for Cu−SnOx hybrid nanostructures was cycled between 0 to −1.0 V vs Ag/AgCl for five consecutive runs at a scan rate of 50 mV/sec. The growth of the Cu−SnOx hybrid nanostructures on BDDL was optimized by varying the number of potentiodynamic deposition cycles and precursor concentration. A uniform particle size distribution of Cu−SnOx was obtained on BDDL using 10 mM CuSO4 and 5 mM SnCl2 in 50 mM aqueous NaNO3. Detail of surface morphology and surface elemental composition of the optimized Cu−SnOx hybrid nanostructures modified BDDL electrodes were characterized. The optimized Cu−SnOx hybrid nanostructures on BDDL were found to be in the size range of 50 to 100 nm with a 3 to 10 nm SnOx‐rich shell. This optimized Cu−SnOx modified BDDL electrode was tested for electrochemical CO2 reduction reaction in aqueous electrolyte and found to produce primarily CO with a Faradaic Efficiency of up to 82.5 % at −1.6 V vs Ag/AgCl.
Dynamic Nanoparticle‐Substrate Contacts Regulate Multi‐Peak Behavior of Single Silver Nanoparticle Collisions
Authors: Sun Linlin , Wang Wei , Chen Hong‐Yuan 
Published: June 2018

AbstractSingle nanoparticle collision (SNC) technology has attracted increasing attention to explore single nanoparticle electrochemistry. By improving the temporal resolution of electrochemical recording, several recent studies have uncovered the intermittent electron transfer processes during the SNC of single silver nanoparticles. The electrode current curve displayed multiple current peaks that were completely separated, instead of a single peak. In the present work, we employed surface plasmon resonance microscopy to monitor the collision and oxidation processes of single silver nanoparticles. Simultaneous optical and electrochemical recordings provided comprehensive capability to correlate the physical movement of nanoparticles (from optical signal) and the electron transfer activity (from electrochemical signal). While previous studies hypothesized the physical detachment of nanoparticles from the electrode due to electrostatic repulsion or Brownian motion, the optical imaging revealed that nanoparticles often remained in physical touch with the electrode even though no electron transfer was occurring. These results demonstrated that the electrical contact between nanoparticle and electrode, which could be rather stochastic due to thermal motion and micro‐convection, played critical roles in regulating the multi‐peak behavior of single silver nanoparticles.
Synthesis and Field‐Effect Transistor Application of π‐Extended Lactam‐Fused Conjugated Oligomers obtained by Tandem Direct Arylation
Authors: Takagi Koji , Yamamoto Shun‐ya , Tsukamoto Kenji , Hirano Yuto , Hara Mitsuo , Nagano Shusaku , Ie Yutaka , Takeuchi Daisuke 
Published: June 2018

AbstractFive π‐extended lactam‐fused conjugated oligomers (5FO, 5FS, 4FPO, 4FPS, and R‐4FPO) were synthesized by the tandem direct arylation. The intermolecular oxidative direct arylation was applied in the second step. These conjugated oligomers had fine‐tuned FMO energies predictable by the theoretical calculation and excellent thermal stabilities. 4FPO and 4FPS bearing tetrafluoropyridine exhibited lower LUMO energy levels (−3.20 eV and −3.39 eV, respectively) compared with others. Based on the X‐ray crystallography, 4FPO was found to have a herringbone crystal packing and a considerably large electron transfer integral value (137 meV). 4FPO‐based bottom‐gate, bottom‐contact FET device demonstrated an electron mobility of 5.2×10−3 cm2 V−1 s−1 as a result of an edge‐on alignment on the SiO2 substrate.
Sugar Acetonides are a Superior Motif for Addressing the Large, Solvent‐Exposed Ribose‐33 Pocket of tRNA‐Guanine Transglycosylase
Authors: Movsisyan Levon D. , Schäfer Elisabeth , Nguyen Andreas , Ehrmann Frederik R. , Schwab Anatol , Rossolini Thomas , Zimmerli Daniel , Wagner Björn , Daff Hamina , Heine Andreas , Klebe Gerhard , Diederich François 
Published: June 2018

AbstractThe intestinal disease shigellosis caused by Shigella bacteria affects over 120 million people annually. There is an urgent demand for new drugs as resistance against common antibiotics emerges. Bacterial tRNA‐guanine transglycosylase (TGT) is a druggable target and controls the pathogenicity of Shigella flexneri. We report the synthesis of sugar‐functionalized lin‐benzoguanines addressing the ribose‐33 pocket of TGT from Zymomonas mobilis. Ligand binding was analyzed by isothermal titration calorimetry and X‐ray crystallography. Pocket occupancy was optimized by variation of size and protective groups of the sugars. The participation of a polycyclic water‐cluster in the recognition of the sugar moiety was revealed. Acetonide‐protected ribo‐ and psicofuranosyl derivatives are highly potent, benefiting from structural rigidity, good solubility, and metabolic stability. We conclude that sugar acetonides have a significant but not yet broadly recognized value in drug development.
Designing Metal‐Free Frustrated Lewis Pairs Catalyst for the Efficient Dehydrogenation of Ammonia Borane
Authors: Ma Gongli , Song Guoliang , Li Zhen Hua 
Published: June 2018

AbstractAmmonia borane (AB) has been in the spotlight for the chemical storage of hydrogen over the past decade. However, the development of methods for efficient and controlled hydrogen release from AB under mild conditions is still underway. Herein, using density functional theory (DFT) computations, we designed a metal‐free frustrated Lewis pair (FLP) catalyst o‐(BPh2)C6H4(NiPr2) (M1) that can efficiently dehydrogenate AB to release more than two equivalents of H2 under mild conditions. Catalyst M1 can dehydrogenate not only AB to H2N=BH2 (AOB) and H2, but also oligomers of AOB with rather low free‐energy barriers. The high dehydrogenation activity of M1 is the key of new oligomerization routes to the efficient dehydrogenation of AB to borazine (BZ) or H2B−(NH=BH)n−NH2 (PIB) and finally to polyborazylene (PBZ) so that more than two equivalents of H2 can be released. A first‐principle kinetic Monte Carlo (KMC) study reveals that the activity of our catalytic system can be tuned by varying the initial concentration of M1 and AB. This work can guide the design of catalyst for the highly efficient utilization of AB as a hydrogen storage material.
Waste to Chemicals for a Circular Economy
Authors: Iaquaniello Gaetano , Centi Gabriele , Salladini Annarita , Palo Emma , Perathoner Siglinda 
Published: June 2018

AbstractThe implementation of a circular economy is a fundamental step to create a greater and more sustainable future for a better use of resources and energy. Wastes and in particular municipal solid waste represent an untapped source of carbon (and hydrogen) to produce a large range of chemicals from methane to alcohols (as methanol or ethanol) or urea. The waste to chemical process and related economics are assessed in this concept article to show the validity of such solution both from an economic point of view and from an environmental perspective considering the sensible reduction in greenhouse gas emissions with respect to conventional production from fossil fuels.
Enantiomeric separation of β‐blockers and tryptophan using heparin as stationary and pseudostationary phases in capillary electrophoresis
Authors: Liu Yi , Sombra Lorena L. , Stege Patricia W. 
Published: June 2018

AbstractThe separation methods of the enantiomers of two β‐blockers and tryptophan were studied using capillary electrochromatography with heparin covalently as well as non‐covalently, bonded onto the capillary inner wall as stationary phase and electrokinetic chromatography with heparin as pseudostationary phase. In the case of heparin, used as a stationary phase, the method was unable to resolve enantiomers in both cases β‐blockers and tryptophan. On the other hand, when heparin was used as a pseudostationary phase, the resolution of the enantiomers was obtained only with 3‐aminopropyltriethoxysilane which were immobilised onto the inner phase of the capillary. The results of this study let us infer that the electrostatic, hydrophobic, and steric interactions were involved in the separation mechanisms. The separation was achieved in less than 10 minutes under the optimized conditions: 30 mM phosphate buffer (pH 2.5) with the adding of 15 mg/mL of heparin at 15°C and 10 kV. The usefulness of heparin as a chiral selector both in electrokinetic chromatography using 3‐aminopropyltriethoxysilane attached to the capillary was demonstrated for the first time. The developed method was powerful, sensitive, and fast, and it could be considered an important alternative to conventional methods used for chiral separation.
A three‐dimensional (3D) two‐way coupled fluid‐structure interaction (FSI) study of peristaltic flow in obstructed ureters
Authors: Takaddus Ahmed Tasnub , Chandy Abhilash J. 
Published: June 2018

AbstractObstruction in the ureter flow path is one of the most common problems in urinary‐related diseases. As the ureter transports the urine using the expansion bolus created by the peristaltic pulses, an obstruction in its path can cause unwanted backflow and can also result in damage to the wall. But in order to understand this further, and specifically to quantify and parametrize the effect of the obstruction in the ureter, a detailed study investigating various level of obstructions in peristaltic ureter flow is necessary. In the current study, full 3D numerical simulations of peristalsis in an obstructed ureter are carried out using a finite element solver along with a two‐way coupling between the fluid and structural domain with the arbitrary Eulerian‐Lagrangian method. Analysis of the results shows that the larger the obstruction, the higher the wall shear stress and pressure gradient in the fluid. In addition, the amount of backflow increases with increase in the obstruction.
Precision Switching in a Discrete Supramolecular Assembly: Alkali Metal Ion‐Carboxylate Selectivities and the Cationic Hofmeister Effect
Authors: Hillyer Matthew B. , Gan Haiying , Gibb Bruce C. 
Published: June 2018

AbstractA cavitand host has been shown to switch from a dimeric assembly to a tetrameric assembly in the presence of cations. Induced by pseudo‐specific cation binding attenuating the net negative charge of each host, switching was shown to be highly cation selective. Thus, the concentration of cation required to induce assembly switching ranged from 2 mM in the case of N(n‐Bu)4+ to ∼80 mM in the case of Na+. Overall cation affinity was found to be essentially the reverse of Collins’ law of matching water affinities, which predicts Na+ to have the strongest affinity for carboxylate groups. Combined with previous data, these results highlight the point that cation affinity for carboxylates are in large part dictated by context.
Intrinsic Triple Order in A‐site Columnar‐Ordered Quadruple Perovskites: Proof of Concept
Authors: Belik Alexei A. , Khalyavin Dmitry D. , Zhang Lei , Matsushita Yoshitaka , Katsuya Yoshio , Tanaka Masahiko , Johnson Roger D. , Yamaura Kazunari 
Published: June 2018

AbstractThere is an emerging topic in the science of perovskite materials: A‐site columnar‐ordered A2A′A′′B4O12 quadruple perovskites, which have an intrinsic triple order at the A sites. However, in many examples reported so far, A′ and A′′ cations are the same, and the intrinsic triple order is hidden. Here, we investigate structural properties of Dy2CuMnMn4O12 (1) and Ho2MnGaMn4O12 (2) by neutron and X‐ray powder diffraction and prove the triple order at the A sites. The cation distributions determined are [Ho2]A[Mn]A′[Ga0.66Mn0.34]A′′[Mn3.66Ga0.34]BO12 and [Dy2]A[Cu0.73Mn0.27]A′[Mn0.80Dy0.20]A′′[Mn1.89Cu0.11]B1[Mn2]B2O12. There are clear signatures of Jahn‐Teller distortions in 1 and 2, and the orbital pattern is combined with an original type of charge ordering in 1. Columnar‐ordered quadruple perovskites represent a new playground to study complex interactions between different electronic degrees of freedom. No long‐range magnetic order was found in 2 by neutron diffraction, and its magnetic properties in low fields are dominated by an impurity with negative magnetization or magnetization reversal. On the other hand, 1 shows three magnetic transitions at 21, 125, and 160 K.
Improvement in estimation accuracy of impedance with electrical and ultrasonic multiimaging systems
Authors: Hamatsu Fumiya , Kimoto Akira , Hamagami Tomoki 
Published: June 2018

AbstractElectrical impedance imaging is an emerging medical imaging technique which can produce tomographic images of impedance properties. Many fusion systems with impedance imaging combined with other modalities are developed, but no technique currently exists of the multiimaging system that could simultaneously produce imaging of the same region. To realize the multiimaging systems, an improved fusion impedance imaging technique with electrical and ultrasonic multiimaging system is developed. Especially, this paper investigates the accuracy effects against the increasing sensor number and proposes an improved parameter adjustment method. The numerical simulation and the practical experiment are conducted on the assumption of breast cancer. The imaging result shows that the accuracy of estimating impedance can be improved by increasing the sensor number and modifying the parameter setting.
Good neighbors make good defenses: associational refuges reduce defense investment in African savanna plants
Authors: Coverdale Tyler C. , Goheen Jacob R. , Palmer Todd M. , Pringle Robert M. 
Published: June 2018

AbstractIntraspecific variation in plant defense phenotype is common and has wide‐ranging ecological consequences. Yet prevailing theories of plant defense allocation, which primarily account for interspecific differences in defense phenotype, often fail to predict intraspecific patterns. Furthermore, although individual variation in defense phenotype is often attributed to ecological interactions, few general mechanisms have been proposed to explain the ubiquity of variable defense phenotype within species. Here, we show experimentally that associational refuges and induced resistance interact to create predictable intraspecific variation in defense phenotype in African savanna plants. Physically defended species from four families (Acanthaceae, Asparagaceae, Cactaceae, and Solanaceae) growing in close association with spinescent Acacia trees had 39–78% fewer spines and thorns than did isolated conspecifics. For a subset of these species, we used a series of manipulative experiments to show that this variability is maintained primarily by a reduction in induced responses among individuals that seldom experience mammalian herbivory, whether due to association with Acacia trees or to experimental herbivore exclusion. Unassociated plants incurred 4‐ to 16‐fold more browsing damage than did associated individuals and increased spine density by 16–38% within one month following simulated browsing. In contrast, experimental clipping induced no net change in spine density among plants growing beneath Acacia canopies or inside long‐term herbivore exclosures. Associated and unassociated individuals produced similar numbers of flowers and seeds, but seedling recruitment and survival were vastly greater in refuge habitats, suggesting a net fitness benefit of association. We conclude that plant‐plant associations consistently decrease defense investment in this system by reducing both the frequency of herbivory and the intensity of induced responses, and that inducible responses enable plants to capitalize on such associations in heterogeneous environments. Given the prevalence of associational and induced defenses in plant communities worldwide, our results suggest a potentially general mechanism by which biotic interactions might predictably shape intraspecific variation in plant defense phenotype.
Eligibility for cardiac resynchronization therapy in patients hospitalized with heart failure
Authors: Osmanska Joanna , Hawkins Nathaniel M. , Toma Mustafa , Ignaszewski Andrew , Virani Sean A. 
Published: June 2018

AbstractAimsRecent guidelines recommend cardiac resynchronization therapy (CRT) in mildly symptomatic heart failure (HF) but favour left bundle branch block (LBBB) morphology in patients with moderate QRS prolongation (120–150 ms). We defined how many patients hospitalized with HF fulfil these criteria.Methods and resultsA single‐centre retrospective cohort study of 363 consecutive patients hospitalized with HF (438 admissions) was performed. Electronic imaging, electrocardiograms, and records were reviewed. Overall, 153 patients (42%) had left ventricular ejection fraction (LVEF) ≤ 35%, and 34% of patients had QRS prolongation. Eighty patients (22%) were potentially eligible with LVEF ≤ 35% and QRS ≥ 120 ms or existing CRT. The majority (68 of 80) had a Class I or IIa recommendation according to international guidelines (LBBB or non‐LBBB QRS ≥ 150 ms or right ventricular pacing). Only a minority (12 of 80) had moderate QRS prolongation of non‐LBBB morphology. One‐quarter (n = 22) of patients fulfilling criteria were ineligible for reasons including dementia, co‐morbidities, or palliative care. A further eight patients required optimization of medical therapy. CRT was therefore immediately indicated in 50 patients. Of these, 29 were implanted or had existing CRT systems. Twenty‐one of the 80 patients eligible for CRT were not identified or treated (6% of the total hospitalized cohort).ConclusionsTwenty‐two per cent of elderly real‐life patients hospitalized with HF fulfil LVEF and QRS criteria for CRT, most having a Class I or IIa indication. However, a large proportion is ineligible owing to co‐morbidities or requires medical optimization. Although uptake of CRT was reasonable, there remain opportunities for improvement.
Long-term effects and recovery of streams from acid mine drainage and evaluation of toxic metal threshold ranges for macroinvertebrate community reassembly
Authors: Herbst David B. , Medhurst R. Bruce , Black Ned J.P. 
Published: June 2018

Abstract

Monitoring of benthic invertebrates in streams receiving acidic metal-contaminated water over an 18-yr period revealed both degraded conditions and recovery along a network of downstream locations. Compared with reference streams, and over the course of clean-up remediation efforts below an abandoned open-pit sulfur mine in the central Sierra Nevada of California, improving water quality was accompanied by recovery of benthic communities at some sites. Years of high flow resulted in degraded biological status when acid mine drainage capture was incomplete and metal loading had increased with runoff. Seasonal patterns of recovery evident in the fall after the summer treatment season reverted in the next spring after overwinter periods when sources were not captured. As the metal load has been reduced, phased recovery of community structure, function, and similarity progressed toward that of reference assemblage taxonomic composition. From impacted communities dominated by relatively tolerant midges, reassembly involved an increase in density, return of long-lived taxa, an increased ratio of sensitive-to-tolerant forms, then overall diversity and community composition, and eventually large predators and grazers reappearing along with mayfly, stonefly, and caddisfly richness. Threshold effect levels defined using several analysis methods showed that the response range of biological indicators corresponds to US Environmental Protection Agency guidelines of predicted effects utilizing cumulative criterion units (CCUs) of metal toxicity (i.e., CCU ∼ 1). All sites have shown improved function with increased density of some or all trophic groups over time. Although recovery is progressing, year-around treatment may be necessary to fully restore biological integrity in streams nearest the mine. Environ Toxicol Chem 2018;37:2575–2592. © 2018 SETAC
Abstract
Progression of community reassembly responses with acid mine drainage recovery. These frame the predicted metal criterion sum CCUs = 1, showing mean and range of responses of threshold detection methods. First, midges as the dominant group decrease as densities of others increase, with long-lived taxa and the ratio of sensitive-to-tolerant taxa escalating; then overall diversity and community similarity rise, and finally the sensitive Ephemeroptera, Plecoptera, and Tricoptera (EPTs)—including large predators and grazers—recover.
Systematic review of prostaglandin analogues for retained placenta
Authors: Grillo‐Ardila Carlos F. , Amaya‐Guio Jairo , Ruíz‐Parra Ariel I. , Amaya‐Restrepo Juan C. 
Published: June 2018

AbstractBackgroundMedical management of retained placenta could be a safe alternative to manual removal.ObjectiveTo evaluate the efficacy of prostaglandin analogues for retained placenta.Search strategyMEDLINE, EMBASE, CENTRAL, ICTRP, LILACS, and OpenSIGLE were searched without language restrictions from inception to January 31, 2017, by combining terms for retained placenta and prostaglandin analogues.Selection criteriaRandomized controlled trials comparing prostaglandin analogues with any other intervention.Data collection and analysisTrials were independently assessed for inclusion, data extraction, and risk of bias. Data were extracted for meta‐analyses. GRADE was used to evaluate the quality of data.Main resultsSeven randomized controlled trials (851 patients) were included. Prostaglandins did not increase the placenta expulsion rate (relative risk [RR] 1.40, 95% confidence interval [CI] 0.83–2.36) or decrease maternal transfusion (RR 0.72, 95% CI 0.43–1.22). In comparison with oxytocin, prostaglandins did not modify the expulsion rate (RR 1.26, 95% CI 0.90–1.78), maternal transfusion (RR 1.05, 95% CI 0.27–4.09), or time for delivery of placenta (mean difference −1.56 minutes, 95% CI, −9.25–6.13). Three trials comparing prostaglandins with oxytocin agonists, ergometrine, and manual removal reported similar results.ConclusionsProstaglandin analogues do not offer an effective alternative for management of retained placenta.
Phase‐Locked Lasing in 1D and 2D Patterned Metal–Organic Microcavities
Authors: Mischok Andreas , Kliem Mona , Brückner Robert , Meister Stefan , Fröb Hartmut , Gather Malte C. , Leo Karl 
Published: June 2018

AbstractOrganic microcavities provide unique properties that are highly advantageous for designing microlasers, but lack in efficient ways to directly integrate electrodes able to drive high currents. The introduction of thin, patterned metal films, leading to the formation of local Tamm plasmon polariton states, has been recently demonstrated as a possible route to preserving coherence in the presence of significant optical loss. Here, periodic micron‐scale gratings of silver are embedded into a high‐quality organic microcavity, creating a crystal‐like photonic potential structure. Despite strong absorption of metallic layers, these structures readily lase upon optical excitation. In that case, the above threshold emission originates not from isolate metal‐free areas but instead from phase‐locked supermodes spreading over several grating periods. Remarkably, in‐plane coherence can spread even further when decreasing the grating period, covering distances of more than 50 m and more than ten metal stripes. 1D and 2D gratings with varying periods are investigated using tomographic scanning of the k‐space emission fine structure, which exhibits a strong dependence on the grating geometry. These results support the fabrication of highly customizable organic microlasers with tailored in‐plane coherence, and demonstrate the coexistence of extended coherence and optical loss.