bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strong, Conductive, Foldable Graphene Sheets by Sequential Ionic and π Bridging
Authors: Wan Sijie , Fang Shaoli , Jiang Lei , Cheng Qunfeng , Baughman Ray H. 
Published: July 2018

AbstractThe goal of this work is to develop an inexpensive low‐temperature process that provides polymer‐free, high‐strength, high‐toughness, electrically conducting sheets of reduced graphene oxide (rGO). To develop this process, we have evaluated the mechanical and electrical properties resulting from the application of an ionic bonding agent (Cr3+), a π–π bonding agent comprising pyrene end groups, and their combinations for enhancing the performance of rGO sheets. When only one bonding agent was used, the π–π bonding agent is much more effective than the ionic bonding agent for improving both the mechanical and electrical properties of rGO sheets. However, the successive application of ionic bonding and π–π bonding agents maximizes tensile strength, toughness, long‐term electrical stability in various corrosive solutions, and resistance to mechanical abuse and ultrasonic dissolution. Using a combination of ionic bonding and π–π bonding agents, high tensile strength (821 MPa), high toughness (20 MJ m−3), and electrical conductivity (416 S cm−1) were obtained, as well as remarkable retention of mechanical and electrical properties during ultrasonication and mechanical cycling by both sheet stretch and sheet folding, suggesting high potential for applications in aerospace and flexible electronics.
Hierarchically Porous Fe2CoSe4 Binary‐Metal Selenide for Extraordinary Rate Performance and Durable Anode of Sodium‐Ion Batteries
Authors: Ali Zeeshan , Asif Muhammad , Huang Xiaoxiao , Tang Tianyu , Hou Yanglong 
Published: July 2018

AbstractOwing to high energy capacities, transition metal chalcogenides have drawn significant research attention as the promising electrode materials for sodium‐ion batteries (SIBs). However, limited cycle life and inferior rate capabilities still hinder their practical application. Improvement of the intrinsic conductivity by smart choice of elemental combination along with carbon coupling of the nanostructures may result in excellence of rate capability and prolonged cycling stability. Herein, a hierarchically porous binary transition metal selenide (Fe2CoSe4, termed as FCSe) nanomaterial with improved intrinsic conductivity was prepared through an exclusive methodology. The hierarchically porous structure, intimate nanoparticle–carbon matrix contact, and better intrinsic conductivity result in extraordinary electrochemical performance through their synergistic effect. The synthesized FCSe exhibits excellent rate capability (816.3 mA h g−1 at 0.5 A g−1 and 400.2 mA h g−1 at 32 A g−1), extended cycle life (350 mA h g−1 even after 5000 cycles at 4 A g−1), and adequately high energy capacity (614.5 mA h g−1 at 1 A g−1 after 100 cycles) as anode material for SIBs. When further combined with lab‐made Na3V2(PO4)3/C cathode in Na‐ion full cells, FCSe presents reasonably high and stable specific capacity.
Heteroatom Donor‐Decorated Polymer‐Immobilized Ionic Liquid Stabilized Palladium Nanoparticles: Efficient Catalysts for Room‐Temperature Suzuki‐Miyaura Cross‐Coupling in Aqueous Media
Authors: Doherty Simon , Knight Julian G. , Backhouse Tom , Abood Einas , Al‐shaikh Hind , Clemmet Ashley R. , Ellison Jack R. , Bourne Richard A. , Chamberlain Thomas W. , Stones Rebecca , Warren Nicholas J. , Fairlamb Ian J. S. , Lovelock Kevin R. J. 
Published: July 2018

AbstractPalladium nanoparticles stabilized by heteroatom donor‐modified polystyrene‐based polymer immobilized ionic liquids (PdNP@HAD‐PIILP; HAD‐PPh2, OMe, NH2, CN, pyrrolidone) are highly efficient catalysts for the Suzuki‐Miyaura cross‐coupling in aqueous media under mild conditions. Catalyst modified with phosphine was consistently the most efficient as it gave high yields across a range of substrates under mild conditions at low catalyst loadings. Incorporation of polyethylene glycol into the phosphine modified immobilised ionic liquid support improved catalyst efficacy by improving dispersibility and facilitating access to the active site. Moreover, each of the heteroatom modified catalysts was more active than the corresponding unsubstituted imidazolium‐based polystyrene benchmark as well as commercial samples of Pd/C. Catalyst generated in situ from either [PdCl4]@PPh2‐PIILP or its PEGylated counterpart [PdCl4]@PPh2‐PEGPIILP, by reduction with phenylboronic acid, outperformed their pre‐formed counterparts for the vast majority of substrates examined. The turnover frequency of 16,300 h−1 obtained at room temperature is one of the highest to be reported for palladium nanoparticle‐catalysed Suzuki‐Miyaura cross‐coupling between 4‐bromoacetophenone and phenylboronic acid in aqueous media under such mild conditions.magnified image
Rhodium(II)‐Catalyzed Aryl C−H Carboxylation of 2‐Pyridylphenols with CO2
Authors: Cai Zhihua , Li Shangda , Gao Yuzhen , Li Gang 
Published: July 2018

AbstractA protocol for C−H carboxylation of electron‐deficient 2‐pyridylphenols with CO2through a Rh(II)‐catalyzed C−H bond activation under redox‐neutral conditions has been developed. A suitable phosphine ligand was crucial for this reaction. This method provided, in generally high yields, an access to a class of pyrido‐coumarins that are key structural motifs in biologically important molecules. Facile product derivatizations were also exemplified.magnified image
Copper‐Catalyzed Synthesis of 3‐NO2 Quinolines from o‐Azidobenzaldehyde and Nitro‐olefins and its Application in the Concise Synthesis of Quindolines
Authors: Zheng Lei , Zeng Zhigang , Yan Qiong , Jia Fengcheng , Jia Lihui , Chen Yunfeng 
Published: July 2018

AbstractAn efficient copper‐catalyzed cyclization of o‐azidobenzaldehyde and nitro‐olefins was developed. This reaction proceeds under solvent‐free conditions and displays broad functional group compatibility and affords 3‐nitroquinolines in good to excellent yields. The synthetic utility of this strategy is illustrated by the concise construction of quindolines in only three steps, which renders the reaction more practical.magnified image
Surgical resection of ripple onset predicts outcome in pediatric epilepsy
Authors: Tamilia Eleonora , Park Eun‐Hyoung , Percivati Stefania , Bolton Jeffrey , Taffoni Fabrizio , Peters Jurriaan M. , Grant P. Ellen , Pearl Phillip L. , Madsen Joseph R. , Papadelis Christos 
Published: July 2018

ObjectiveIn patients with medically refractory epilepsy (MRE), interictal ripples (80–250Hz) are observed in large brain areas whose resection may be unnecessary for seizure freedom. This limits their utility as epilepsy biomarkers for surgery. We assessed the spatiotemporal propagation of interictal ripples on intracranial electroencephalography (iEEG) in children with MRE, compared it with the propagation of spikes, identified ripples that initiated propagation (onset‐ripples), and evaluated their clinical value as epilepsy biomarkers.MethodsTwenty‐seven children who underwent epilepsy surgery were studied. We identified propagation sequences of ripples and spikes across multiple iEEG contacts and calculated each ripple or spike latency from the propagation onset. We classified ripples and spikes into categories (ie, onset, spread, and isolated) based on their spatiotemporal characteristics and correlated their mean rate inside and outside resection with outcome (good outcome, Engel 1 versus poor outcome, Engel≥2). We determined, as onset‐zone, spread‐zone, and isolated‐zone, the areas generating the corresponding ripple or spike category and evaluated the predictive value of their resection.ResultsWe observed ripple propagation in all patients and spike propagation in 25 patients. Mean rate of onset‐ripples inside resection predicted the outcome (odds ratio = 5.37; p = 0.02) and correlated with Engel class (rho = −0.55; p = 0.003). Resection of the onset‐ripple‐zone was associated with good outcome (p = 0.047). No association was found for the spread‐ripple‐zone, isolated‐ripple‐zone, or any spike‐zone.InterpretationInterictal ripples propagate across iEEG contacts in children with MRE. The association between the onset‐ripple‐zone resection and good outcome indicates that onset‐ripples are promising epilepsy biomarkers, which estimate the epileptogenic tissue better than spread‐ripples or onset‐spikes. Ann Neurol 2018;84:331–346
Chiral N,N Ligands Enabling Palladium‐Catalyzed Enantioselective Intramolecular Heck–Matsuda Carbonylation Reactions by Sequential Migratory and CO Insertions
Authors: Carmona Rafaela C. , Köster Otto D. , Correia Carlos Roque Duarte 
Published: July 2018

AbstractUnprecedented enantioselective intramolecular Heck carbonylation reactions of arenediazonium salts were enabled by a chiral N,N ligand. This reaction constitutes the first enantioselective Heck carbonylation that proceeds through migratory insertion followed by CO insertion. The enantioenriched functionalized dihydrobenzofurans were obtained in good to high yields and enantiomeric ratios of up to 98:2 under mild and operationally simple reaction conditions.
Tailored Cobalt‐Catalysts for Reductive Alkylation of Anilines with Carboxylic Acids under Mild Conditions
Authors: Liu Weiping , Sahoo Basudev , Spannenberg Anke , Junge Kathrin , Beller Matthias 
Published: July 2018

AbstractThe first cobalt‐catalyzed hydrogenative N‐methylation and alkylation of amines with readily available carboxylic acid feedstocks as alkylating agents and H2 as ideal reductant is described. Combination of tailor‐made triphos ligands with cobalt(II) tetrafluoroborate significantly improved the efficiency, thus promoting the reaction under milder conditions. This novel protocol allows for a broad substrate scope with good functional group tolerance, even in the presence of reducible alkenes, esters, and amides.
Direct N‐Alkylation and Kemp Elimination Reactions of 1‐Sulfonyl‐1H‐Indazoles
Authors: Tang Meng , Chu Bingjie , Chang Xiaowei 
Published: July 2018

AbstractThe reactions of 1‐sulfonyl‐1H‐indazoles under basic conditions are discussed, and the direct N‐alkylation and Kemp elimination reactions of these compounds are reported. A series of 2‐(p‐tosylamino)benzonitriles and N‐alkyl indazoles were prepared in good yields. Moreover, the 2‐(p‐tosylamino)benzonitriles could be transformed into a diverse range of important derivatives in a one‐pot reaction. This method was successfully applied to the total syntheses of quindolinone and cryptolepinone; quindolinone was prepared in a one‐pot reaction from 1‐sulfonyl‐1H‐indazole.
Self‐Assembly of Water‐Soluble Platinum(II)‐Based Metallacalixarenes and Tuning Their Conformational Interconversion via Synergistic Effects between Solvents and Anions
Authors: Deng Wei , Yu Zheng‐Su , Ma Hong‐Wei , Yu Shu‐Yan 
Published: July 2018

AbstractThe aqueous self‐assembly of the flexible ligand L bis(1H‐benz[d]imidazole‐1‐yl)methane and cis‐coordinated PtII precursors [(en)Pt2+, (tmeda)Pt2+, en=ethylenediamine, tmeda=N,N,N′,N′‐tetramethylethylenediamine)] led to the formation of the metallacalixarenes with full alternative conformations (e.g., two novel water‐soluble metallacalixarenes [M2L2]4+ and [M3L3]6+ with D2 and D3 symmetry, respectively). Their molecular structures were determined by single crystal X‐ray analyses in solid state. The two metallacalixarenes present different cavity sizes and the [M3L3]6+ cavity encapsulates one NO3−. NOESY NMR revealed that the conformational interconversion between 1,3‐alternate conformer in methanol and cone conformer in DMSO was tuned via the synergistic effect between solvent and anion. Guest encapsulation is also discussed.
Desymmetrization of Achiral Heterobicyclic Alkenes through Catalytic Asymmetric Hydrophosphination
Authors: Sadeer Abdul , Ong Yew Jin , Kojima Tadayuki , Foo Ce Qing , Li Yongxin , Pullarkat Sumod A. , Leung Pak‐Hing 
Published: July 2018

AbstractAsymmetric addition of diarylphosphines to oxa‐ and azabicyclic alkenes proceeded in the presence of a chiral phosphapalladacycle catalyst and a mild acid at room temperature to give exclusively the enantioenriched addition products in excellent yields and good selectivities. Three new chiral carbon centers were generated stereoselectively by the catalytic hydrophosphination reaction.
Integrating theoretical and experimental permeability estimations for provisional biopharmaceutical classification: Application to the WHO essential medicines
Authors: Cabrera‐Pérez Miguel Ángel , Pham‐The Hai , Cervera Mirna Fernández , Hernández‐Armengol Rosario , Miranda‐Pérez de Alejo Claudia , Brito‐Ferrer Yudileidy 
Published: July 2018

AbstractThe accuracy of the provisional estimation of the Biopharmaceutics Classification System (BCS) is heavily influenced by the permeability measurement. In this study, several theoretical and experimental models currently employed for BCS permeability classification have been analysed. The experimental models included the in situ rat intestinal perfusion, the ex vivo rat intestinal tissue in an Ussing chamber, the MDCK and Caco‐2 cell monolayers, and the parallel artificial membrane (PAMPA). The theoretical models included the octanol–water partition coefficient and the QSPeR (Quantitative Structure‐Permeability Relationship) model recently developed. For model validation, a dataset of 43 compounds has been recompiled and analysed for the suitability for BCS permeability classification in comparison with the use of human intestinal absorption and oral bioavailability values. The application of the final model, based on a majority voting system showed a 95.3% accuracy for predicting human permeability. Finally, the present approach was applied to the 186 orally administered drugs in immediate‐release dosage forms of the WHO Model List of Essential Medicines. The percentages of the drugs that were provisionally classified as BCS Class I and Class III was 62.4%, suggesting that in vivo bioequivalence (BE) may potentially be assured with a less expensive and more easily implemented in vitro dissolution test, ensuring the efficiency and quality of pharmaceutical products. The results of the current study improve the accuracy of provisional BCS classification by combining different permeability models.
Chiral ligand‐induced photoluminescence intermittence difference of CdTe quantum dots
Authors: Yang Jie , Dong Chaoqing , Ren Jicun 
Published: July 2018

AbstractSemiconductor quantum dots (QDs) are a new nano‐material, and their unique optical properties have become a focal point of research in both academia and industry. In this study, we studied photoluminescence (PL) intermittence (or ‘blinking’) behaviors of individual QDs prepared with different chiral ligands by using single molecule microscopy and single molecule fluorescence correlation spectroscopy (FCS). We found that the chirality of N‐isobutyryl‐d/l‐cysteine (D/L‐NIC) as surface stabilizers significantly influences PL blinking behaviors of cadmium telluride (CdTe) QDs synthesized in aqueous solution. The ‘on time’ distribution and the power‐law exponent analyses show that the D‐NIC more efficiently suppresses the blinking of QDs over L‐NIC. Ensemble spectroscopies verfied that the remarkably‐different blinking behaviors of QDs induced by ligand chirality were attributed to the different number of chiral ligands bound in the surface of QDs.
Virtual and augmented reality: Applications for the learning of technical historical heritage
Authors: Rojas‐Sola José I. , Aguilera‐García Ángel 
Published: July 2018

AbstractThis manuscript presents two applications developed for learning about the details and operation of Agustín de Betancourt́s machine for cutting cane and other aquatic plants in navigable channels and rivers, drawing on virtual reality for personal computers under Windows, and augmented reality for mobile devices based on Android, along with a 3D printing of the 3D model. Similarly, in the case of augmented reality, an algorithm for the selection of parts or systems has been developed that shows the technical information of each piece or system of this historical invention. Finally, the evaluation of these applications has been satisfactory according to the results of an anonymous survey with seven questions given to a group of 10 people because the values obtained from statistical variables such as the mean, median and standard deviation prove it.
Photosensitised Multiheme Cytochromes as Light‐Driven Molecular Wires and Resistors
Authors: van Wonderen Jessica H. , Li Daobo , Piper Samuel E. H. , Lau Cheuk Y. , Jenner Leon P. , Hall Christopher R. , Clarke Thomas A. , Watmough Nicholas J. , Butt Julea N. 
Published: July 2018

AbstractMultiheme cytochromes possess closely packed redox‐active hemes arranged as chains spanning the tertiary structure. Here we describe five variants of a representative multiheme cytochrome engineered as biohybrid phototransducers for converting light into electricity. Each variant possesses a single Cys sulfhydryl group near a terminus of the heme chain, and this was efficiently labelled with a RuII(2,2′‐bipyridine)3 photosensitiser. When irradiated in the presence of a sacrificial electron donor (SED) the proteins exhibited different types of behaviour. Certain proteins were rapidly and fully reduced. Other proteins were rapidly semi‐reduced but resisted complete photoreduction. These findings reveal that photosensitised multiheme cytochromes can be engineered to act as resistors, with intrinsic regulation of light‐driven electron accumulation, and also as molecular wires with essentially unhindered photoreduction. It is proposed that the observed behaviour arises from interplay between the site of electron injection and the distribution of heme reduction potentials along the heme chain.
Impact and trends of intravascular imaging in diagnostic coronary angiography and percutaneous coronary intervention in inpatients in the United States
Authors: Smilowitz Nathaniel R. , Mohananey Divyanshu , Razzouk Louai , Weisz Giora , Slater James N. 
Published: July 2018

AbstractBackgroundIntravascular imaging with intravascular ultrasound (IVUS) and optical coherence tomography (OCT) is an important adjunct to invasive coronary angiography.ObjectivesThe primary objective was to examine the frequency of intravascular coronary imaging, trends in imaging use, and outcomes of patients undergoing angiography and/or percutaneous coronary intervention (PCI) in the United States.MethodsAdult patients ≥18 years of age undergoing in‐hospital cardiac catheterization from January 2004 to December 2014 were identified from the National Inpatient Sample (NIS). International Classification of Diseases, Ninth Revision (ICD‐9) diagnosis and procedure codes were used to identify IVUS and OCT use during diagnostic angiography and PCI.ResultsAmong 3,211,872 hospitalizations with coronary angiography, intracoronary imaging was performed in 88,775 cases (4.8% of PCI and 1.0% of diagnostic procedures), with IVUS in 98.9% and OCT in 1.1% of cases. Among patients undergoing PCI, the rate of intravascular coronary imaging increased from 2.1% in 2004–2005 to 6.6% in 2013–2014 (P < 0.001 for trend). Use of intravascular coronary imaging was associated with lower in‐hospital mortality in patients undergoing PCI (adjusted OR 0.77; 95% CI 0.71–0.83). There was marked variability in intravascular imaging by hospital, with 63% and 13% of facilities using intravascular imaging in <5% and >15% of PCIs, respectively.ConclusionsIn a large administrative database from the United States, intravascular imaging use was low, increased over time, and imaging was associated with reduced in‐hospital mortality. Substantial variation in the frequency of intravascular imaging by hospital was observed. Additional investigation to determine clinical benefits of IVUS and OCT are warranted.
Initial clinical experience with the FlexPoint Steerable Transseptal Needle in left‐sided structural heart procedures
Authors: Rogers Jason H. , Stripe Benjamin R. , Singh Gagan D. , Boyd Walter D. , Fan Dali , Smith Thomas W.R. 
Published: July 2018

AbstractObjectivesThe purpose of this study is to describe the initial clinical experience with a steerable transseptal needle (STSN) for left‐sided structural heart procedures.BackgroundTargeted transseptal (TS) puncture is required for many structural heart procedures, and the use of a steerable needle has not previously been described.MethodsConsecutive patients undergoing structural heart interventions with targeted TS puncture under transesophageal echocardiographic (TEE) and fluoroscopic guidance were studied. The STSN was used in all patients with a standard commercial TS sheath. Deflection of the needle was performed “real time” to achieve localization of the TS puncture site.ResultsTwenty‐seven patients underwent STSN puncture of the interatrial septum. In all cases, the needle could be deflected in vivo to achieve optimal tenting and localization of the puncture site without having to remove or reshape the needle. The needle was deflected to match a wide range of right atrial diameters (width 4.3 ± 0.9 cm and length 6.0 ± 0.9 cm in the 4‐chamber view). In two patients with prior mitral valve surgery and a fibrotic septum, assisted crossing was achieved using the piercing stylet in one patient, and Bovie energy in the other. There were no procedural complications, and all patients had successful completion of the intended structural heart procedure.ConclusionsThe STSN needle can be used to target the intended puncture location on the interatrial septum with real‐time adjustable deflection without the need to remove and reshape the needle. In all cases crossing was successful and there were no complications.
Enzymatic Synthesis of Therapeutic Nucleosides using a Highly Versatile Purine Nucleoside 2’‐DeoxyribosylTransferase from Trypanosoma brucei
Authors: Pérez Elena , Sánchez‐Murcia Pedro A. , Jordaan Justin , Blanco María Dolores , Mancheño José Miguel , Gago Federico , Fernández‐Lucas Jesús 
Published: July 2018

AbstractThe use of enzymes for the synthesis of nucleoside analogues offers several advantages over multistep chemical methods, including chemo‐, regio‐ and stereoselectivity as well as milder reaction conditions. Herein, the production, characterization and utilization of a purine nucleoside 2’‐deoxyribosyltransferase (PDT) from Trypanosoma brucei are reported. TbPDT is a dimer which displays not only excellent activity and stability over a broad range of temperatures (50–70 °C), pH (4–7) and ionic strength (0–500 mM NaCl) but also an unusual high stability under alkaline conditions (pH 8–10). TbPDT is shown to be proficient in the biosynthesis of numerous therapeutic nucleosides, including didanosine, vidarabine, cladribine, fludarabine and nelarabine. The structure‐guided replacement of Val11 with either Ala or Ser resulted in variants with 2.8‐fold greater activity. TbPDT was also covalently immobilized on glutaraldehyde‐activated magnetic microspheres. MTbPDT3 was selected as the best derivative (4200 IU/g, activity recovery of 22 %), and could be easily recaptured and recycled for >25 reactions with negligible loss of activity. Finally, MTbPDT3 was successfully employed in the expedient synthesis of several nucleoside analogues. Taken together, our results support the notion that TbPDT has good potential as an industrial biocatalyst for the synthesis of a wide range of therapeutic nucleosides through an efficient and environmentally friendly methodology.