bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multicenter evaluation of transcatheter aortic valve replacement using either SAPIEN XT or CoreValve: Degree of device oversizing by computed‐tomography and clinical outcomes
Authors: Dvir Danny , Webb John G. , Piazza Nicolo , Blanke Philipp , Barbanti Marco , Bleiziffer Sabine , Wood David A. , Mylotte Darren , Wilson Alex B. , Tan John , Stub Dion , Tamburino Corrado , Lange Rudiger , Leipsic Jonathon 
Published: January 2015

ObjectiveTo analyze the association between computed‐tomography‐derived degrees of device oversizing and clinical outcomes during transcatheter aortic valve replacement (TAVR).BackgroundPrevious reports suggest that different devices reach optimal results with different degrees of device oversizing. Therefore, similar sized devices of different types (SAPIEN XT and CoreValve) may be favored in different annular ranges and a case considered borderline between two sizes of a specific device might be within a favorable range of another.Methods and ResultsA multicenter registry of 615 consecutive transfemoral TAVR procedures using either SAPIEN XT or CoreValve was analyzed. A first group of 190 patients had annular sizes for which only moderate oversizing degree was feasible (5–20% by area or 2.5–9.5% by perimeter). A second group included 178 patients that had annulus size for which only large oversizing degree was feasible (20.1–35% by area or 9.6–16.2% by perimeter). In the “only large oversizing feasible group” there were more annular rupture events in patients treated by SAPIEN XT valve as compared to those treated by CoreValve (3.4% vs. 0%, P = 0.04). In the “only moderate oversizing feasible group”, those treated by CoreValve had more post balloon dilatation and 30‐day major stroke in comparison with those treated by SAPIEN XT (16.1% vs. 7.7%, P = 0.04 and 8% vs. 1.3%, P = 0.02, respectively).ConclusionsOptimal clinical performance of CoreValve and SAPIEN XT appears to be reached with different degrees of oversizing. Certain annular sizes that allow for only moderate or large oversizing, but not both, appear to benefit from a device specific approach. © 2015 Wiley Periodicals, Inc.
Middle‐term results of trans‐catheter creation of atrial communication in patients receiving mechanical circulatory support
Authors: O'Byrne Michael L. , Glatz Andrew C. , Rossano Joseph W. , Schiavo Kellie L. , Dori Yoav , Rome Jonathan J. , Gillespie Matthew J. 
Published: January 2015

ObjectiveTo describe our center's middle‐term outcomes following trans‐catheter creation of atrial communication (ASD) in patients on mechanical circulatory support. Background: Trans‐catheter creation of an ASD in patients on mechanical circulatory support is an adjuvant therapy to reduce left atrial pressure and associated morbidity. Data on middle term outcomes following this procedure, specifically in regards to the fate of the ASD, are limited.MethodsRetrospective observational study of consecutive children and adults undergoing trans‐catheter creation of an atrial septal communication between 1/1/2006 and 5/1/2014, reviewing their baseline characteristics, procedural details, and data from follow‐up.ResultsOver the study period, 37/227 (16%) subjects undergoing veno‐arterial extra‐corporeal membrane oxygenation (VA‐ECMO) underwent trans‐catheter creation of an atrial communication. Mortality on VA‐ECMO support in this subgroup was 19%, with an additional 24% transitioning to ventricular assist device. Of the 57% who survived to separation from VA‐ECMO, 16/21 (76%) had residual atrial communications. 56% of these underwent closure procedures.ConclusionsFollowing trans‐catheter creation of ASD, a residual ASD is present in the majority of assessable survivors and represents a potential volume overload and/or right to left shunt that may need to be addressed. © 2015 Wiley Periodicals, Inc.
Palladium Nanoparticles Supported on Fibrous‐Structured Silica Nanospheres (KCC‐1): An Efficient and Selective Catalyst for the Transfer Hydrogenation of Alkenes
Authors: Qureshi Ziyauddin S. , Sarawade Pradip B. , Albert Matthias , D'Elia Valerio , Hedhili Mohamed N. , Köhler Klaus , Basset Jean‐Marie 
Published: January 2015

AbstractAn efficient palladium catalyst supported on fibrous silica nanospheres (KCC‐1) has been developed for the hydrogenation of alkenes and α,β‐unsaturated carbonyl compounds, providing excellent yields of the corresponding products with remarkable chemoselectivity. Comparison (high‐resolution TEM, chemisorption) with analogous mesoporous (MCM‐41, SBA‐15) silica‐supported Pd nanocatalysts prepared under identical conditions, demonstrates the advantage of employing the fibrous KCC‐1 morphology versus traditional supports because it ensures superior accessibility of the catalytically active cores along with excellent Pd dispersion at high metal loading. This morphology ultimately leads to higher catalytic activity for the KCC‐1‐supported nanoparticles. The protocol developed for hydrogenation is advantageous and environmentally benign owing to the use of HCOOH as a source of hydrogen, water as a solvent, and because of efficient catalyst recyclability and durability. The recycled catalyst has been analyzed by XPS spectroscopy and TEM showing only minor changes in the oxidation state of Pd and in the morphology after the reaction, thus confirming the robustness of the catalyst.
Rhodium versus Iridium Catalysts in the Controlled Tandem Hydroformylation–Isomerization of Functionalized Unsaturated Fatty Substrates
Authors: Ternel Jérémy , Couturier Jean‐Luc , Dubois Jean‐Luc , Carpentier Jean‐François 
Published: January 2015

AbstractThe hydroformylation of 10‐undecenitrile (1) and related unsaturated fatty substrates (H2CCH(CH2)7CH2R; R=CO2Me, CH2Br, CHO) has been studied with rhodium, iridium, ruthenium, and palladium biphephos catalysts. The reactions proceeded effectively with all four systems, with high selectivities for the linear aldehyde (ratio of linear/branched aldehydes=99:1). The biphephos‐bis[chloro(cyclooctadiene)iridium] system showed a non‐optimized hydroformylation turnover frequency (TOFHF) of 770 h−1 that was only approximately 5 times lower than that of the rhodium‐based system (TOFHF=3320 h−1); the palladium and ruthenium biphephos systems were less active (TOFHF=210 and 310 h−1, respectively). Upon recycling, remarkable productivities were achieved in both cases (TON≈58 000 mol(1/1‐int) mol(Ir)−1 and 250 000 mol(1/1‐int) mol(Rh)−1, in which int=internal olefin). Competitive isomerization of terminal to internal olefins occurred with these catalysts. Iridium biphephos systems allowed slightly better control of the distribution of the internal isomers than the rhodium biphephos catalyst, with higher ratios of 9‐/8‐undecenitrile (1‐int).
Glucose Biochip Based on Flexible Carbon Fiber Electrodes: In Vivo Diabetes Evaluation in Rats
Authors: Iost Rodrigo M. , Sales Fernanda C. P. F. , Martins Marccus V. A. , Almeida Maria C. , Crespilho Frank N. 
Published: January 2015

AbstractThis paper reports an implantable biochip for intravenous glucose monitoring in rat blood. A key feature of this device is the combination of the flexibility of the flexible carbon fiber (FCF) electrodes for the micromanipulation of the biosensor in the implant. FCF, modified with a neutral red electrochemical mediator and an enzyme glucose oxidase, enables the biochip to be manipulated conveniently during insertion in the rat veins. For in vivo experiments, the biochip is inserted into the jugular vein of a living rat (Rattus novergicus) using a poly(propylene) catheter. The capability for in vivo glucose detection is evaluated with a normal concentration of glucose (30 mg dL−1) and with a diabetic simulation (200 mg dL−1). Through electrochemical data, this type of biochip can distinguish different concentration of glucose in the blood of the animal. The biochip showed promise performance for future applications of implantable bioelectronics devices.
Asymmetric Supercapacitors Based on Activated‐Carbon‐Coated Carbon Nanotubes
Authors: Shi Kaiyuan , Zhitomirsky Igor 
Published: January 2015

AbstractA new method is developed for the fabrication of asymmetric supercapacitor devices containing fibrous electrode materials. The approach is based on the synthesis of uniform polypyrrole (PPy) coatings on multiwalled carbon nanotubes (MWCNT), which were used for the fabrication of MWCNTs coated with N‐doped activated carbon (N‐AC). The N‐AC‐MWCNT electrodes show good electrochemical performance in positive and negative potential windows. The electrochemical performance of positive electrodes is further enhanced by the development of MnO2‐coated N‐AC‐MWCNT. In this approach, the problem of MWCNT degradation in the reaction with KMnO4 is avoided by the use of a sacrificial N‐AC layer, which allows a relatively high mass content of MnO2 in the final material. The approach offers the advantages of small size of MnO2 nanoparticles, good electrical contact of MnO2 and MWCNT and fibrous microstructure of the material. Testing results show a remarkably high specific capacitance of 6.29 F cm−2 (311.7 F g−1) at a mass loading of 20 mg cm−2. The important finding is the possibility to fabricate asymmetric devices, which show a specific capacitance of 2.19 F cm−2 (62.7 F g−1) in a voltage window of 1.9 V in aqueous Na2SO4 electrolyte, an energy density of 26.4 mWh g−1 and a power density of 1.7 W g−1. The electrodes and devices show good capacitance retention at high charge–discharge rates and good cycling stability. The asymmetric capacitors developed herein are promising for practical energy‐storage applications.
Probing Structure Modification of Palladium Nanomaterials during Chemical Synthesis by using In Situ X‐ray Diffraction: Electrochemical Properties
Authors: Holade Yaovi , Napporn Teko W. , Morais Claudia , Servat Karine , Kokoh K. Boniface 
Published: January 2015

AbstractExperimental evidence for Pd‐based structure modification of electrocatalysts with hydrogen during their chemical synthesis is still missing. Therefore, in situ X‐ray diffraction (XRD) techniques were as used to investigate hydrogen insertion into the lattice of Pd nanomaterials during their preparation. It was shown that the use of NaBH4as reducing agent led to PdHxwhereasL‐ascorbic acid gave Pd nanoparticles. The subsequent influence of hydrogen insertion on the catalytic properties of Pd nanostructures was demonstrated by using carbon monoxide and glucose as probing molecules. High active surface areas and catalytic activities were found for the unmodified Pd nanostructures through electrochemical studies. Notably, the reducing agent has a significant effect on the size distribution of the nanoparticles. Its use can precisely and effectively tune their catalytic properties. Consequently, the remarkable behavior uncovered herein provides new strategic routes that can be used for the preparation of Pd‐based nanomaterials.
Facile Synthesis of Mesoporous MoS2‐TiO2 Nanofibers for Ultrastable Lithium Ion Battery Anodes
Authors: Zhuang Wei , Li Licheng , Zhu Jiahua , An Rong , Lu Linghong , Lu Xiaohua , Wu Xinbing , Ying Hanjie 
Published: January 2015

AbstractTiO2 hybrid nanocomposites are promising electrode materials for lithium‐ion batteries because of the large specific capacity, excellent rate capability, and high cycling stability. We have developed an effective facile incipient wetness impregnation method that can be used to fabricate novel mesoporous MoS2–TiO2 fibrous nanocomposites. The MoS2–TiO2 nanocomposites exhibited notable electrochemical performance with a high capacity of 120 mA h g−1 at a rate of 40 C and long‐term, stable capacity of 124 mA h g−1 with a capacity retention of 75.2 % after 1000 cycles. These results suggest that the structure of mesoporous TiO2 nanofibers composited with a thin, uniform, well‐dispersed MoS2 layer improve the rate performance and cycling stability. Such good performance may be derived from the dispersed MoS2 layer, which accelerates the surface electrochemical reactions and offers a stable structure.
Controlled Synthesis of Nanoporous Nickel Oxide with Two‐Dimensional Shapes through Thermal Decomposition of Metal–Cyanide Hybrid Coordination Polymers
Authors: Zakaria Mohamed B. , Hu Ming , Salunkhe Rahul R. , Pramanik Malay , Takai Kimiko , Malgras Victor , Choi Seyong , Dou Shi Xue , Kim Jung Ho , Imura Masataka , Ishihara Shinsuke , Yamauchi Yusuke 
Published: January 2015

AbstractThe urgent need for nanoporous metal oxides with highly crystallized frameworks is motivating scientists to try to discover new preparation methods, because of their wide use in practical applications. Recent work has demonstrated that two‐dimensional (2D) cyanide‐bridged coordination polymers (CPs) are promising materials and appropriate for this purpose (Angew. Chem. Int. Ed.­ 2013, 52, 1235). After calcination, 2D CPs can be transformed into nanoporous metal oxides with a highly accessible surface area. Here, this strategy is adopted in order to form 2D nanoporous nickel oxide (NiO) with tunable porosity and crystallinity, using trisodium citrate dihydrate as a controlling agent. The presence of trisodium citrate dihydrate plays a key role in the formation of 2D nanoflakes by controlling the nucleation rate and the crystal growth. The size of the nanoflakes gradually increases by augmenting the amount of trisodium citrate dihydrate in the reaction. After heating the as‐prepared CPs in air at different temperatures, nanoporous NiO can be obtained. During this thermal treatment, organic units (carbon and nitrogen) are completely removed and only the metal content remains to take part in the formation of nanoporous NiO. In the case of large‐sized 2D CP nanoflakes, the original 2D flake‐shapes are almost retained, even after thermal treatment at low temperature, but they are completely destroyed at high temperature because of further crystallization in the framework. Nanoporous NiO with high surface area shows significant efficiency and interesting results for supercapacitor application.
Experimental and Computational Studies on the CH Amination Mechanism of Tetrahydrocarbazoles via Hydroperoxides
Authors: Gulzar Naeem , Jones Kevin Mark , Konnerth Hannelore , Breugst Martin , Klussmann Martin 
Published: January 2015

AbstractThe acid‐catalyzed reactions of photochemically generated tetrahydrocarbazole peroxides with anilines have been studied experimentally and computationally to identify the underlying reaction mechanism. The kinetic data indicate a reaction order of one in the hydroperoxide and zero in the aniline. Computational investigations using density functional theory support the experimental findings and predict an initial tautomerization between an imine and enamine substructure of the primarily generated tetrahydrocarbazole peroxide to be the rate controlling step. The enamine tautomer then loses hydrogen peroxide upon protonation, generating a stabilized allylic carbocation that is reversibly trapped by solvent or aniline to form the isolated products.
Micro‐/Nanostructured Multicomponent Molecular Materials: Design, Assembly, and Functionality
Authors: Yan Dongpeng 
Published: January 2015

AbstractMolecule‐based micro‐/nanomaterials have attracted considerable attention because their properties can vary greatly from the corresponding macro‐sized bulk systems. Recently, the construction of multicomponent molecular solids based on crystal engineering principles has emerged as a promising alternative way to develop micro‐/nanomaterials. Unlike single‐component materials, the resulting multicomponent systems offer the advantages of tunable composition, and adjustable molecular arrangement, and intermolecular interactions within their solid states. The study of these materials also supplies insight into how the crystal structure, molecular components, and micro‐/nanoscale effects can influence the performance of molecular materials. In this review, we describe recent advances and current directions in the assembly and applications of crystalline multicomponent micro‐/nanostructures. Firstly, the design strategies for multicomponent systems based on molecular recognition and crystal engineering principles are introduced. Attention is then focused on the methods of fabrication of low‐dimensional multicomponent micro‐/nanostructures. Their new applications are also outlined. Finally, we briefly discuss perspectives for the further development of these molecular crystalline micro‐/nanomaterials.
Regulation of Charge Delocalization in a Heteronuclear Fe2Ru System by a Stepwise Photochromic Process
Authors: Xu Guang‐Tao , Li Bin , Wang Jin‐Yun , Zhang Dao‐Bin , Chen Zhong‐Ning 
Published: January 2015

AbstractHeteronuclear complexes FeCp2DTECCRu(dppe)2Cl (1 o; dppe=1,2‐bis(diphenylphosphino)ethane, Cp=cyclopentadienyl, DTE=dithienylethene) and FeCp2DTECCRu(dppe)2CCDTEFeCp2 (2 oo), with redox‐active ferrocenyl and ruthenium centers separated by a photochromic DTE moiety, were prepared to achieve photoswitchable charge delocalization and Fe⋅⋅⋅Ru electronic communication. Upon UV‐light irradiation of 2 oo, the Fe⋅⋅⋅Ru heterometallic electronic interaction is increasingly facilitated with stepwise photocyclization, 2 oo→2 co→2 cc; this is ascribed to the gradual increase in π‐conjugated systems. The near‐infrared absorptions in mixed‐valence species [2 oo]+/[2 co]+/[2 cc]+ are gradually intensified following the conversion of [2 oo]+→[2 co]+→[2 cc]+, which demonstrates that the extent of charge delocalization shows progressive enhancement with stepwise photocyclization. As revealed by electrochemical, spectroscopic, and theoretical studies, complex 2 exhibits nine switchable states through stepwise photochromic and reversible redox processes.
Masked Unsaturated Esters/Amides in Asymmetric Organocatalysis
Authors: Monge David , Jiang Hao , Alvarez‐Casao Yolanda 
Published: January 2015

AbstractThis Concept article summarizes strategies and developments regarding the use of masked unsaturated esters/amides in asymmetric organocatalysis. Useful substrates are categorized by the design of their inherent carboxylate template. This template group not only enables their functionality as ester surrogates, but also define their accessibilities, modes of interactions with catalysts and the simplicity with which they transform back to the parent carboxylates. Both covalent and noncovalent catalytic systems are discussed and examples showing the entire process (from substrates‐to‐functionalized ester/amides) are given.
Three‐Dimensional Fe2N@C Microspheres Grown on Reduced Graphite Oxide for Lithium‐Ion Batteries and the Li Storage Mechanism
Authors: Yu Peng , Wang Lei , Sun Fanfei , Zhao Dongdong , Tian Chungui , Zhao Lu , Liu Xu , Wang Jianqiang , Fu Honggang 
Published: January 2015

AbstractNanostructured iron compounds as lithium‐ion‐battery anode material have attracted considerable attention with respect to improved electrochemical energy storage and excellent specific capacity, so lots of iron‐based composites have been developed. Herein, a novel composite composed of three‐dimensional Fe2N@C microspheres grown on reduced graphite oxide (denoted as Fe2N@C‐RGO) has been synthesized through a simple and effective technique assisted by a hydrothermal and subsequent heating treatment process. As the anode material for lithium‐ion batteries, the synthetic Fe2N@C‐RGO displayed excellent Li+‐ion storage performance with a considerable initial capacity of 847 mAh g−1, a superior cycle stability (a specific discharge capacity of 760 mAh g−1 remained after the 100th cycle), and an improved rate‐capability performance compared with those of the pure Fe2N and Fe2N‐RGO nanostructures. The good performance should be attributed to the existence of RGO layers that can facilitate to enhance the conductivity and shorten the lithium‐ion diffusion path; in addition, the carbon layer on the surface of Fe2N can avert the structure decay caused by the volume change during the lithiation/delithiation process. Moreover, in situ X‐ray absorption fine‐structure analysis demonstrated that the excellent performance can be attributed to the lack of any obvious change in the coordination geometry of Fe2N@C‐RGO during the charge/discharge processes.
The Influence of the Capping Agent on the Oxidation of Silver Nanoparticles: Nano‐impacts versus Stripping Voltammetry
Authors: Toh Her Shuang , Jurkschat Kerstin , Compton Richard G. 
Published: January 2015

AbstractThe influence of capping agents on the oxidation of silver nanoparticles was studied by using the electrochemical techniques of anodic stripping voltammetry and anodic particle coulometry (“nano‐impacts”). Five spherical silver nanoparticles each with a different capping agent (branched polyethylenimine (BPEI), citrate, lipoic acid, polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP)) were used to perform comparative experiments. In all cases, regardless of the capping agent, complete oxidation of the single nanoparticles was seen in anodic particle coulometry. The successful quantitative detection of the silver nanoparticle size displays the potential application of anodic particle coulometry for nanoparticle characterisation. In contrast, for anodic stripping voltammetry using nanoparticles drop casting, it was observed that the capping agent has a very significant effect on the extent of silver oxidation. All five samples gave a low oxidative charge corresponding to partial oxidation. It is concluded that the use of anodic stripping voltammetry to quantify nanoparticles is unreliable, and this is attributed to nanoparticle aggregation.
Gold‐Catalyzed Multiple Cascade Reaction of 2‐Alkynylphenylazides with Propargyl Alcohols
Authors: Li Nan , Wang Tian‐Yi , Gong Liu‐Zhu , Zhang Liming 
Published: January 2015

AbstractAn unprecedented gold‐catalyzed multiple cascade reaction between 2‐alkynyl arylazides and alkynols has been developed, allowing for the step‐economical synthesis of pyrroloindolone derivatives with a wide range of structural diversity. In this reaction, the gold complex participates in triple catalysis in tandem fashion. Moreover, the efficient chirality transfer from optically pure alkynol substrates enables facile access to chiral pyrroloindolone derivatives with two stereogenic centers, including a quaternary one, with excellent levels of optical purity.
Enzymatic Resolution of α‐Methyleneparaconic Acids and Evaluation of their Biological Activity
Authors: Chakrabarty Kuheli , Defrenza Ivana , Denora Nunzio , Drioli Sara , Forzato Cristina , Franco Massimo , Lentini Giovanni , Nitti Patrizia , Pitacco Giuliana 
Published: January 2015

ABSTRACTBoth enantiomers of three biologically relevant paraconic acids—MB‐3, methylenolactocin, and C75—were obtained with enantioselectivities up to 99% by kinetic enzymatic resolutions. Good enantiomeric excesses were obtained for MB‐3 and methylenolactocin, using α‐chymotrypsin and aminoacylase as enantiocomplementary enzymes, while C75 was resolved with aminoacylase. They all were evaluated for their antiproliferative, antibacterial, and antifungal activities, showing weak effects and practically no difference between enantiomers in each case. At high concentrations (16–64 µg/mL), (–)‐ C75 acted as an antimicrobial agent against Gram‐positive bacteria. Chirality 27:239–246, 2015. © 2015 Wiley Periodicals, Inc.
Entmischungsvorgänge bei Schüttgütern und ihre Simulation mit der Diskrete‐Element‐Methode
Authors: Dau Günter , Ripperger Siegfried 
Published: January 2015

AbstractEin typischer Vorgang bei der Handhabung von Schüttgütern ist das Aufhäufen eines Schüttkegels, wobei unterschiedliche Eigenschaften der Partikel zu einer Entmischung führen. Dieser Vorgang wurde an binären Kugelmischungen experimentell untersucht. Der Entmischungsgrad wurde durch eine Entmischungskennzahl charakterisiert und die Abhängigkeit von verschiedenen experimentellen Parametern dargestellt. Die Simulation des Versuches durch die Diskrete‐Elemente‐Methode gab eine gute Übereinstimmung, wenn die zugrunde gelegten Rechenparameter sinnvoll angepasst wurden.