bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stepwise Methane‐to‐Methanol Conversion on CuO/SBA‐15
Authors: Le Ha V. , Parishan Samira , Sagaltchik Anton , Ahi Hamideh , Trunschke Annette , Schomäcker Reinhard , Thomas Arne 
Published: May 2018

AbstractThe direct partial oxidation of methane to methanol is a challenging scientific and economical objective to expand the application of this abundant fuel gas as a major resource for one‐step production of value‐added chemicals. Despite substantial efforts to commercialize this synthetic route, to date no heterogeneous catalyst can selectively oxidize methane to methanol by O2 with an economically acceptable conversion. Cu‐exchanged zeolites have been recently highlighted as one of the most promising bioinspired catalysts toward the direct production of methanol from methane under mild conditions. In this work, Cu‐based catalysts were prepared using mesoporous silica SBA‐15 as an alternative support and their activity for this conversion was investigated. The results demonstrate that highly dispersed CuO species on SBA‐15 are able to react with methane and subsequently produce methanol with high selectivity (>84 %) through water‐assisted extraction. Furthermore, it was confirmed that the main intermediate formed after interaction of the catalyst with methane is a methoxyl species, which can be further converted to methanol or dimethyl ether on extraction with water or methanol, respectively.
Si@C Microsphere Composite with Multiple Buffer Structures for High‐Performance Lithium‐Ion Battery Anodes
Authors: Li Yankai , Liu Wenbo , Long Zhi , Xu Pengyuan , Sun Yang , Zhang Xiaokang , Ma Shuhua , Jiang Ning 
Published: May 2018

AbstractIn this work, a Si@C microsphere composite with multiple buffer structures is prepared by hydrothermal treatment to solve the fatal drawbacks of serious pulverization and low electronic conductivity of Si anodes. By virtue of ferric citrate being the carefully chosen coating carbon source, the silicon nanoparticles with a SiOx layer are encapsulated by the homogeneous mesoporous carbon layer. The SiOx layer with appropriate toughness can primarily suppress the volume expansion of silicon. The plentiful mesopores in the carbon layer and the framework formed by carbon nanotubes with good mechanical strength can effectively buffer and accommodate the volume change of silicon, and greatly improve the infiltration of the electrolyte to the anode. Meanwhile, the mesoporous carbon and carbon nanotube network also enhance the conductivity of the composite. Therefore, the Si@C electrodes exhibit a high initial charge/discharge capacity of 2956/4197 mAh g−1 at a current density of 0.42 A g−1, excellent rate capability, and outstanding cycle performance up to 800 cycles by virtue of the multiple buffer structures.
A Dipyrrin Programmed for Covalent Loading with Fullerenes
Authors: Li Chengjie , Wurst Klaus , Kräutler Bernhard 
Published: May 2018

AbstractWe describe here a di‐(β,β′‐sulfoleno)pyrrin programmed for efficient and specific β,β′‐functionalization via [4+2] cycloaddition reactions. At 120 °C and in the presence of an excess of C60‐fullerene the di‐(β,β′‐sulfoleno)pyrrin decomposed cleanly, furnishing a di‐(β,β′‐fullereno)pyrrin and the corresponding monofullereno‐dipyrrin in an overall yield of 96 %. Hence, relatively mild thermolysis of the di‐(β,β′‐sulfoleno)pyrrin induced stepwise extrusion of two equivalents of SO2, producing highly reactive dipyrrin‐β,β′‐diene intermediates readily, providing a very effective path to [4+2]‐cycloadducts. As presented here by the example of the covalent attachment of C60‐fullerene units, a convenient general methodology for the efficient synthesis of covalent dipyrrin β,β′‐cycloadducts is made available.
Using the Relative Energy Gradient Method with Interacting Quantum Atoms to Determine the Reaction Mechanism and Catalytic Effects in the Peptide Hydrolysis in HIV‐1 Protease
Authors: Thacker Joseph C. R. , Vincent Mark A. , Popelier Paul L. A. 
Published: May 2018

AbstractThe reaction mechanism in an active site is of the utmost importance when trying to understand the role that an enzyme plays in biological processes. In a recently published paper [Theor. Chem. Acc. 2017, 136, 86], we formalised the Relative Energy Gradient (REG) method for automating an Interacting Quantum Atoms (IQA) analysis. Here, the REG method is utilised to determine the mechanism of peptide hydrolysis in the aspartic active site of the enzyme HIV‐1 Protease. Using the REG method along with the IQA approach we determine the mechanism of peptide hydrolysis without employing any arbitrary parameters and with remarkable ease (albeit at large computational cost: the system contains 133 atoms, which means that there are 17 689 individual IQA terms to be calculated). When REG and IQA work together it is possible to determine a reaction mechanism at atomistic resolution from data directly derived from quantum calculations, without arbitrary parameters. Moreover, the mechanism determined by this novel method gives concrete insight into how the active site residues catalyse peptide hydrolysis.
Synthesis of 1‐Aminoindenes through Aza‐Prins‐Type Cyclization
Authors: Bai Jian‐Fei , Yasumoto Kento , Kano Taichi , Maruoka Keiji 
Published: May 2018

AbstractAn acid‐catalyzed aza‐Prins‐type endo cyclization of 2‐alkenylbenzaldehydes with BocNH2 or aniline derivatives through in situ generation of iminium intermediates has been developed, and various 1‐aminoindene derivatives were readily obtained. The first catalytic asymmetric variant of the present reaction has also been demonstrated.
A Highly Stable Framework of Crystalline Zinc Phosphite with Selective Removal, Recovery, and Turn‐On Sensing Abilities for Mercury Cations in Aqueous Solutions
Authors: Wang Chih‐Min , Lin Yong‐Jie , Pan Ming‐Feng , Su Cheng‐Kuan , Lin Tai‐Yuan 
Published: May 2018

AbstractA highly stable framework of organic‐inorganic hybrid zinc phosphite (NTOU‐4) and its cobalt analogue (NTOU‐4a) were synthesized under the hydro(solvo)thermal conditions and structurally characterized by single‐crystal X‐ray diffraction. Their frameworks consisted of inorganic metallophosphite chains, in which the metal atoms were interlinked through 1H‐1,2,4‐triazole‐3,5‐diamine and 1,4‐benzenedicarboxylate linkers to form new crystalline materials. It is extremely difficult to achieve the consolidation of three distinct coordinations of metal‐carboxylate, metal‐triazolate, and metal‐phosphite bonds into one crystal, resulting in the synthesis of the first mixed‐ligand terephthalate‐metallophosphite solids in the absence of organic molecules as templates or space‐filling counters in their structures. Interestingly, the zinc compound not only exhibits high thermal stability (up to 400 °C in air) and chemical resistance to seawater, aqueous solutions (pH 3–11), and organic solvents at boiling conditions, but also shows selective removal, recovery, and “turn‐on” sensing abilities of toxic mercury ions in aqueous solutions. Furthermore, the synthesis, characterization, and the difference of the framework stabilities between isostructural zinc and cobalt compounds are also reported.
Phosphine‐Relayed Aldehyde‐Olefination and Aza‐Wittig Reaction with 2,2,2‐Trifluorodiazoethane
Authors: Zhang Fa‐Guang , Lv Ning , Zheng Yan , Ma Jun‐An 
Published: May 2018

AbstractPhosphine‐relayed olefination and aza‐Wittig reactions of readily available aldehydes with 2,2,2‐trifluorodiazoethane (CF3CHN2) have been realized. This protocol enables the facile construction of a series of trifluoromethylated alkenes and hydrazones in good to high yield under mild conditions.
Bioactive Alkaloids from Indole‐3‐carbinol Exposed Culture of Daldiniaeschscholzii
Authors: Lin Li Ping , Tan Ren Xiang 
Published: May 2018

AbstractTwo new and rare bioactive indoles named dalesindoloids A (1) and B (3), along with 3‐(1H‐indole‐3ylmethyl)‐2‐oxindole (2), were characterized from the indole‐3‐carbinol (I3C)‐exposed culture of Daldinia eschscholzii. The absolute configuration of 2 was determined by quantum chemical calculations of the electronic circular dichroism (ECD) spectrum. Dalesindoloids A and B were cytotoxic against the leukemia HL‐60 cell line with the IC50 values of 1.0 and 7.4 μmol/L, respectively, with the former being inhibitory on Staphylococcus aureus (MIC: 9.1 μmol/L). The simultaneous characterization of the alkaloids from the I3C‐exposed fungal culture highlighted that the 2,3‐epoxyindoline motif can be transformed into both lactam and indolin‐3‐one moieties. This is the first‐time description of the 2,3‐epoxyindoline chemical versatility and Wagner‐Meerwein rearrangement (WMR) reaction in the microbial culture.
Advances in DNA Origami Nanopores: Fabrication, Characterization and Applications
Authors: Ren Yong‐An , Gao Han , Ouyang Xiangyuan 
Published: May 2018

AbstractIn recent years, bio‐nanopore and solid‐state nanopore have been greatly improved for molecule bio‐sensing. Whereas, the development of this scientific field seems to have encountered a bottleneck due to their respective limitations. The small pore size of the former impedes the detection of large single molecule, and the latter is difficult to achieve similar accuracy and functional control. DNA origami plays a novel role to bring more opportunities for the development of nanopore technology since it is relatively easy to synthesize and modify. This review mainly focuses on introducing the DNA origami nanopore fabrication methods, characterization and application. Meanwhile, the challenges in the present DNA origami nanopore research are also discussed.
Prevalence and outcome of patients referred for chest pain with high‐sensitivity troponin elevation and no diagnosis at discharge
Authors: Lordet Vincent , Lesbordes Matthieu , Garcia Rodrigue , Varroud‐Vial Nicolas , Ingrand Pierre , Christiaens Luc , Levesque Sébastien 
Published: May 2018

IntroductionSpecialized chest pain units appear to increase the proportion of patients with acute chest pain who are properly evaluated, but some of them remain doubtful.HypothesisThe aim of this study was to evaluate the survival and occurrence of cardiovascular events in patients without diagnosis at the end of management of chest pain with high‐sensitivity troponin (Tn) elevation.MethodAll consecutive patients who came to the cardiac emergency room of Poitiers University Hospital between January 1, 2014, and August 7, 2015, for chest pain and Tn elevation were included. The primary endpoint was the number of undiagnosed patients; secondary endpoints included survival and major adverse cardiac events.ResultsA total of 1001 patients (695 male; mean age, 68 ±16 years) who had chest pain and Tn elevation were included. Median follow‐up was 24.5 (IQR, 14.7–29.5) months. Forty‐seven (4.7%) patients remained without diagnosis. Compared with patients with diagnosis, these patients were younger (53.6 ±19.7 years; P < 0.0001) and had less hypertension (29.8%; P < 0.0001), diabetes (4.3%; P = 0.0016), and history of coronary artery disease (6.4%; P < 0.0001). No patients died or experienced MACE in 6‐month follow‐up. Survival curves showed the probability of survival was excellent, not only at 6 months, but also at 36 months (P = 0.0025).ConclusionsLess than 5% of patients referred for chest pain and with high‐sensitivity Tn elevation remained without diagnosis after adapted care in the chest pain unit. Their 6‐month prognosis was excellent.
Optimal timing for cardioversion in patients with atrial fibrillation
Authors: Hellman Tapio , Kiviniemi Tuomas , Nuotio Ilpo , Biancari Fausto , Vasankari Tuija , Hartikainen Juha , Lehto Mika , Airaksinen K.E. ,   for the FinCV Investigators
Published: May 2018

BackgroundElectrical cardioversion (CV) is essential in rhythm management of atrial fibrillation (AF). However, optimal timing of CV remains unknown.HypothesisTiming of CV in AF is associated with risk of adverse events.MethodsWe analyzed the effect of AF episode duration on safety and efficacy of electrical CV in a multicenter, multicohort study exploring 4356 CVs in 2530 patients on oral anticoagulation. The composite adverse outcome included unsuccessful CV, acute arrhythmic complications, thromboembolic events, mortality, and AF recurrence within 30‐day follow‐up.ResultsStudy groups were stratified according to duration of index AF episode (<24 h, 24–48 h, 48 h–30d, and > 30d), consisting of 1767, 516, 632, and 1441 CVs, respectively. CVs were unsuccessful in 8.5% (<24 h), 5.4% (24–48 h), 11.1% (48 h–30d), and 13.9% (>30d), respectively (P < 0.01). Occurrence of thromboembolic events (0.1%), mortality (0.1%), and asystole >5 seconds (0.7%) within 30‐day follow‐up was infrequent and comparable in the study groups. AF recurrence within 30 days after initially successful CVs was 29.8% (<24 h), 26.5% (24–48 h), 37.3% (48 h–30d), and 30.3% (>30d), respectively (P < 0.01). Composite adverse outcome occurred in 1669 (38.4%) CVs, and index AF episode >48 hours was an independent predictor for the composite endpoint (OR: 1.49, 95% CI: 1.28–1.74, P < 0.01) in multivariate analysis.ConclusionsOptimal timing of CV for AF showed a J‐shaped curve, with fewest adverse outcomes in patients with CV performed 24 to 48 hours after onset of AF. In patients with rhythm‐control strategy, delaying CV >48 hours is associated with increased risk for adverse outcomes.
Electrocardiographic diagnosis of atrial infarction in patients with acute inferior ST‐segment elevation myocardial infarction
Authors: Yıldız Suleyman Sezai , Keskin Kudret , Avsar Murat , Cetinkal Gokhan , Sigirci Serhat , Aksan Gokhan , Cetin Sukru , Okuyan Ertugrul , Kilickesmez Kadriye Orta 
Published: May 2018

BackgroundPatients with atrial myocardial infarction (ATMI) have frequent cardiac and noncardiac complications. However, ATMI is uncommonly diagnosed because of its nonspecific ECG changes. Our objective was to analyze the ECG characteristics of ATMI in patients with inferior STEMI.HypothesisElectrocardiographic P wave parameters can help in diagnosis of ATMI.MethodsWe evaluated 932 patients who underwent coronary angiography and recruited 39 patients with ATMI and 33 patients without ATMI with inferior STEMI for a retrospective study. Twelve‐lead ECGs were obtained to measure P‐wave parameters in diagnosis of ATMI. P‐wave parameters and PR‐segment displacement were compared in patients with and without ATMI.ResultsIn inferior leads, PWD and PWDisp were significantly longer in the ATMI group than in the non‐ATMI group (limb lead II, 109.79 ±15.51 ms and 86.65 ±5.02 ms, respectively; P < 0.001; limb lead III, 108.31 ±12.51 ms and 85.27 ±7.47 ms, P < 0.001; aVF, 106.49 ±13.68 ms and 83.01 ±7.89 ms, P < 0.001; PWDisp, 41.67 ±10.72 ms and 25.18 ±5.17 ms, P < 0.001). By contrast, PWA was significantly lower in the ATMI group than in the non‐ATMI group (limb lead II, 0.96 ±0.18 mV and 1.39 ±0.22 mV, respectively; P < 0.001; limb lead III, 0.90 ±0.11 and 1.21 ±0.23, P < 0.001; aVF, 0.88 ±0.17 and 1.26 ±0.28, P < 0.001). PR‐segment displacement was found in 8 (20.5%) patients with ATMI. A PWD ≥95.5 ms in lead DII diagnosed ATMI with a higher sensitivity and specificity (90%, 94%) than did PWA or PWDisp.ConclusionsThis study suggests P‐wave parameters might be considered ECG findings in diagnosis of ATMI in patients with inferior STEMI.
A New Class of 1‐Aryl‐5,6‐dihydropyrrolo[2,1‐a]isoquinoline Derivatives as Reversers of P‐Glycoprotein‐Mediated Multidrug Resistance in Tumor Cells
Authors: Nevskaya Alisa A. , Matveeva Maria D. , Borisova Tatiana N. , Niso Mauro , Colabufo Nicola A. , Boccarelli Angelina , Purgatorio Rosa , de Candia Modesto , Cellamare Saverio , Voskressensky Leonid G. , Altomare Cosimo D. 
Published: May 2018

AbstractA number of aza‐heterocyclic compounds, which share the 5,6‐dihydropyrrolo[2,1‐a]isoquinoline (DHPIQ) scaffold with members of the lamellarin alkaloid family, were synthesized and evaluated for their ability to reverse in vitro multidrug resistance in cancer cells through inhibition of P‐glycoprotein (P‐gp) and/or multidrug‐resistance‐associated protein 1. Most of the investigated DHPIQ compounds proved to be selective P‐gp modulators, and the most potent modulator, 8,9‐diethoxy‐1‐(3,4‐diethoxyphenyl)‐3‐(furan‐2‐yl)‐5,6‐dihydropyrrolo[2,1‐a]isoquinoline‐2‐carbaldehyde, attained sub‐micromolar inhibitory potency (IC50: 0.19 μm). Schiff bases prepared by the condensation of some 1‐aryl‐DHPIQ aldehydes with p‐aminophenol also proved to be of some interest, and one of them, 4‐((1‐(4‐fluorophenyl)‐5,6‐dihydro‐8,9‐dimethoxypyrrolo[2,1‐a]isoquinolin‐2‐yl)methyleneamino)phenol, had an IC50 value of 1.01 μm. In drug combination assays in multidrug‐resistant cells, some DHPIQ compounds, at nontoxic concentrations, significantly increased the cytotoxicity of doxorubicin in a concentration‐dependent manner. Studies of structure–activity relationships and investigation of the chemical stability of Schiff bases provided physicochemical information useful for molecular optimization of lamellarin‐like cytotoxic drugs active toward chemoresistant tumors as well as nontoxic reversers of P‐gp‐mediated multidrug resistance in tumor cells.
Design of Active Sites on Nickel in the Anode of Intermediate‐Temperature Solid Oxide Fuel Cells using Trace Amount of Platinum Oxides
Authors: Rednyk Andrii , Mori Toshiyuki , Yamamoto Shunya , Suzuki Akira , Yamamoto Yuta , Tanji Takayoshi , Isaka Noriko , Kúš Peter , Ito Shigeharu , Ye Fei 
Published: May 2018

AbstractIn recent years, the lowering of the operation temperature of solid oxide fuel cells (SOFCs) has attracted much attention owing to the trade‐off between the best performance and the life span of SOFCs. For this challenge, new active sites on the Ni surfaces in a Nickel–Yttria‐Stabilized Zirconia (Ni‐YSZ) cermet anode of SOFCs have been created by deposition of trace amounts of platinum oxide (PtOx) followed by an activation step of the anode at 1073 K in a hydrogen flow. The internal resistance (IR) free value (185 mA cm−2 at 0.8 V) observed for the single cell with an anode sputtered with a trace amount of PtOx (Pt content in anode: from 9 to 91 ppm) at 973 K is conspicuously higher than that of a similar single cell with a nonsputtered cermet anode (85 mA cm−2) at 0.8 V and 1073 K. Transmission electron microscopy microanalysis shows that the defect structure is formed on a partially oxidized Ni surface by active Pt species. Also, surface atomistic simulation on NiO (111) predicts the formation of Frenkel defect clusters with Pt cations, which partially cover the Ni surface. The formation of Frenkel defect clusters on the partially oxidized Ni surface (i.e., creation of new active sites for formation of water molecules) promotes the anode reaction, resulting in improvements in the anode performance of SOFC single cells at 973 K. Design of the aforementioned new active sites on Ni through sputtering of trace amounts of PtOx provides a great opportunity for “radical innovation” in the design of intermediate‐temperature SOFCs.
Occupancy modeling species–environment relationships with non‐ignorable survey designs
Authors: Irvine Kathryn M. , Rodhouse Thomas J. , Wright Wilson J. , Olsen Anthony R. 
Published: May 2018

AbstractStatistical models supporting inferences about species occurrence patterns in relation to environmental gradients are fundamental to ecology and conservation biology. A common implicit assumption is that the sampling design is ignorable and does not need to be formally accounted for in analyses. The analyst assumes data are representative of the desired population and statistical modeling proceeds. However, if data sets from probability and non‐probability surveys are combined or unequal selection probabilities are used, the design may be non‐ignorable. We outline the use of pseudo‐maximum likelihood estimation for site‐occupancy models to account for such non‐ignorable survey designs. This estimation method accounts for the survey design by properly weighting the pseudo‐likelihood equation. In our empirical example, legacy and newer randomly selected locations were surveyed for bats to bridge a historic statewide effort with an ongoing nationwide program. We provide a worked example using bat acoustic detection/non‐detection data and show how analysts can diagnose whether their design is ignorable. Using simulations we assessed whether our approach is viable for modeling data sets composed of sites contributed outside of a probability design. Pseudo‐maximum likelihood estimates differed from the usual maximum likelihood occupancy estimates for some bat species. Using simulations we show the maximum likelihood estimator of species–environment relationships with non‐ignorable sampling designs was biased, whereas the pseudo‐likelihood estimator was design unbiased. However, in our simulation study the designs composed of a large proportion of legacy or non‐probability sites resulted in estimation issues for standard errors. These issues were likely a result of highly variable weights confounded by small sample sizes (5% or 10% sampling intensity and four revisits). Aggregating data sets from multiple sources logically supports larger sample sizes and potentially increases spatial extents for statistical inferences. Our results suggest that ignoring the mechanism for how locations were selected for data collection (e.g., the sampling design) could result in erroneous model‐based conclusions. Therefore, in order to ensure robust and defensible recommendations for evidence‐based conservation decision‐making, the survey design information in addition to the data themselves must be available for analysts. Details for constructing the weights used in estimation and code for implementation are provided.
The prevalence and impact of transient species in ecological communities
Authors: Snell Taylor Sara J. , Evans Brian S. , White Ethan P. , Hurlbert Allen H. 
Published: May 2018

AbstractTransient species occur infrequently in a community over time and do not maintain viable local populations. Because transient species interact differently than non‐transients with their biotic and abiotic environment, it is important to characterize the prevalence of these species and how they impact our understanding of ecological systems. We quantified the prevalence and impact of transient species in communities using data on over 19,000 community time series spanning an array of ecosystems, taxonomic groups, and spatial scales. We found that transient species are a general feature of communities regardless of taxa or ecosystem. The proportion of these species decreases with increasing spatial scale leading to a need to control for scale in comparative work. Removing transient species from analyses influences the form of a suite of commonly studied ecological patterns including species–abundance distributions, species–energy relationships, species–area relationships, and temporal turnover. Careful consideration should be given to whether transient species are included in analyses depending on the theoretical and practical relevance of these species for the question being studied.
Need for closure and compensatory rule‐based perception: The role of information consistency
Authors: Dragon Piotr , Kossowska Małgorzata 
Published: May 2018

AbstractWhen making comparisons, people tend to use routinized standards, rules, and knowledge structures. Compensatory rules (e.g., “if competent, then cold”, “if incompetent, then warm”) allow for the quick and easy evaluation of groups when they are compared. We claim that the application of these rules is especially attractive for people who are motivated to seek quick and firm answers (people high in the need for closure—NFC). However, we assume that when people are confronted with expectancy‐inconsistent information, higher levels of NFC lead to a lower reliance on these rules. This is because the inconsistency may serve as a signal that the rules no longer provide guidance on how to act. We demonstrated these effects in three studies set in different group contexts, where we manipulated expectancy‐consistent and expectancy‐inconsistent information. These findings allow for a more comprehensive view of the dynamic and diverse effects of NFC.