bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorination of Lithium‐Excess Transition Metal Oxide Cathode Materials
Authors: Richards William D. , Dacek Stephen T. , Kitchaev Daniil A. , Ceder Gerbrand 
Published: October 2017

AbstractFluorination of Li‐ion cathode materials is of significant interest as it is claimed to lead to significant improvements in long‐term reversible capacity. However, the mechanism by which LiF incorporates and improves performance remains uncertain. Indeed, recent evidence suggests that fluorine is often present as a coating layer rather than incorporated into the bulk of the material. In this work, first‐principles calculations are used to investigate the thermodynamics of fluorination in transition metal oxide cathodes to determine the conditions under which bulk fluorination is possible. It is found that unlike classic well‐ordered cathodes, which cannot incorporate fluorine, disordered rock salt‐structured materials achieve significant fluorination levels due to the presence of locally metal‐poor, lithium‐rich environments that are highly preferred for fluorine. As well as explaining the fluorination process in known materials, this finding is encouraging for the development of new disordered rock salt lithium‐excess transition metal oxides, a promising new class of Li‐ion battery cathode materials that offer superior practical capacity to traditional layered oxides. In particular, it is found that bulk fluorination may serve as an alternative source of Li‐excess in these compounds that can replace the conventional substitution of a heavy redox‐inactive element on the transition metal sublattice.
Toward High Efficiency Polymer Solar Cells: Rearranging the Backbone Units into a Readily Accessible Random Tetrapolymer
Authors: Zhou Cheng , Chen Zhiming , Zhang Guichuan , McDowell Caitlin , Luo Peng , Jia Xiaoe , Ford Michael J. , Wang Ming , Bazan Guillermo C. , Huang Fei , Cao Yong 
Published: October 2017

AbstractTwo donor–acceptor (D–A) conjugated polymers composed of the same ratio of 5‐fluorobenzothiadiazole and thiophene subunits are synthesized through different routes, providing a precisely regioregular (2TRR) and a random (2TRA) polymer structures. Detailed structural analyses indicate that the backbone of regioregular 2TRR has only one donor segment of bithiophene, while the backbone of random 2TRA consists of three different donor segments: thiophene, bithiophene, and terthiophene (in a ratio of 0.16:0.68:0.16). Synergetic contributions from these segments allow the “tetrapolymer” 2TRA to achieve more favorable film morphology and a higher hole‐mobility relative to 2TRR. Consequently, the random polymer 2TRA achieves a substantially higher power conversion efficiency (8.8%) than the regioregular polymer 2TRR (5.1%). Notably, the “tetrapolymer” 2TRA is readily synthesized from two monomers, rather than through complex conventional preparation required for similar multipolymers. These findings provide a novel route toward the design and synthesis of multipolymeric materials and demonstrate their potential advantages in high‐performance organic electronic applications.
A Facile and Very Effective Method to Enhance the Mechanical Strength and the Cyclability of Si‐Based Electrodes for Li‐Ion Batteries
Authors: Hernandez Cuauhtémoc Reale , Etiemble Aurélien , Douillard Thierry , Mazouzi Driss , Karkar Zouina , Maire Eric , Guyomard Dominique , Lestriez Bernard , Roué Lionel 
Published: October 2017

AbstractIt is well known that the mechanical properties of lithium‐ion battery electrodes impact their electrochemical performance. This is especially critical for Si‐based negative electrodes, which suffer from large volume changes of the active mass upon cycling. Here, this study presents a postprocessing treatment (called maturation) that improves the mechanical and electrochemical stabilities of silicon‐based anodes made with an acidic aqueous binder. It consists of storing the electrode in a humid atmosphere for a few days before drying and cell assembly. This results in a beneficial in situ reactive modification of the interfaces within the electrode. First, the binder tends to concentrate at the silicon interparticle contacts. As a result, the cohesion of the composite film is strengthened. Second, the corrosion of the copper current collector, inducing the formation of copper carboxylate bonds, improves the adhesion of the composite film. The great improvement of the mechanical stability of the matured electrode is confirmed by in‐operando optical microscopy showing the absence of film delamination. The result is a significant electrochemical performance gain, up to a factor 10, compared to a not‐matured electrode. This maturation procedure can be applied to other types of electrodes for improving their electrochemical performance and also their handling during cell manufacturing.
Palladium Nanoparticles Anchored on Anatase Titanium Dioxide‐Black Phosphorus Hybrids with Heterointerfaces: Highly Electroactive and Durable Catalysts for Ethanol Electrooxidation
Authors: Wu Tong , Fan Jinchen , Li Qiaoxia , Shi Penghui , Xu Qunjie , Min Yulin 
Published: October 2017

AbstractDesigning high‐performance palladium (Pd) supports with enhanced ethanol oxidation reaction (EOR) activity has consistently been a challenge. Here, a novel anatase titanium dioxide nanosheets‐black phosphorus (ATN‐BP) hybrid is fabricated as a support for Pd nanoparticles used in the EOR. The direct ball‐milling of BP nanoflakes and ATN under argon protection lead to the formation of ATN‐BP hybrids with BP nanoflakes interconnected by cataclastic ATN with POTi bonds. The structure of ATN‐BP not only is beneficial for improving the electrolyte penetration and electron transportation but also has a strong influence on the stripping of reactive intermediates through the synergistic interaction between Pd and ATN‐BP. The results demonstrate that the Pd/ATN‐BP hybrids with heterointerfaces of Pd, BP, and ATN exhibit ultrahigh electroactivity and durability. In the EOR, the Pd/ATN‐BP catalyst can achieve an electrochemically active surface area of ≈462.1 m2 gPd−1 and a mass peak current density of 5023.8 mA mgPd−1, which are 11.67 and 6.87 times greater, respectively, than those of commercial Pd/C. The Pd/ATN‐BP catalysts also show remarkable stability with a retention rate of the peak current density of ≈30.6% after a durability test of 3600 s.
Selective Reduction of CO2 to a Formate Equivalent with Heterobimetallic Gold‐ ‐ ‐Copper Hydride Complexes
Authors: Hicken Alexandra , White Andrew J. P. , Crimmin Mark R. 
Published: October 2017

AbstractA series of heterobimetallic complexes containing three‐center, two‐electron Au−H−Cu bonds have been prepared from addition of a parent gold hydride to a bent d10 copper(I) fragment. These highly unusual heterobimetallic complexes represent a missing link in the widely investigated series of neutral and cationic coinage metal hydride complexes containing Cu−H−Cu and M−H−M+ moieties (M=Cu, Ag). The well‐defined heterobimetallic hydride complexes act as precatalysts for the conversion of CO2 into HCO2Bpin with HBpin as the reductant. The selectivity of the heterobimetallic complexes for the catalytic production of a formate equivalent surpasses that of the parent monomeric Group 11 complexes.
Three‐Dimensional Printing with Biomass‐Derived PEF for Carbon‐Neutral Manufacturing
Authors: Kucherov Fedor A. , Gordeev Evgeny G. , Kashin Alexey S. , Ananikov Valentine P. 
Published: October 2017

AbstractBiomass‐derived poly(ethylene‐2,5‐furandicarboxylate) (PEF) has been used for fused deposition modeling (FDM) 3D printing. A complete cycle from cellulose to the printed object has been performed. The printed PEF objects created in the present study show higher chemical resistance than objects printed with commonly available materials (acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), glycol‐modified poly(ethylene terephthalate) (PETG)). The studied PEF polymer has shown key advantages for 3D printing: optimal adhesion, thermoplasticity, lack of delamination and low heat shrinkage. The high thermal stability of PEF and relatively low temperature that is necessary for extrusion are optimal for recycling printed objects and minimizing waste. Several successive cycles of 3D printing and recycling were successfully shown. The suggested approach for extending additive manufacturing to carbon‐neutral materials opens a new direction in the field of sustainable development.
Catalytic Reduction of Alkyl and Aryl Bromides Using Propan‐2‐ol
Authors: Haibach Michael C. , Stoltz Brian M. , Grubbs Robert H. 
Published: October 2017

AbstractMilstein's complex, (PNN)RuHCl(CO), catalyzes the efficient reduction of aryl and alkyl halides under relatively mild conditions by using propan‐2‐ol and a base. Sterically hindered tertiary and neopentyl substrates are reduced efficiently, as well as more functionalized aryl and alkyl bromides. The reduction process is proposed to occur by radical abstraction/hydrodehalogenation steps at ruthenium. Our research represents a safer and more sustainable alternative to typical silane, lithium aluminium hydride, and tin‐based conditions for these reductions.
Efficient and recyclable novel Ni‐based metal–organic framework nanostructure as catalyst for the cascade reaction of alcohol oxidation–Knoevenagel condensation
Authors: Aryanejad Sima , Bagherzade Ghodsieh , Farrokhi Alireza 
Published: October 2017

A novel Ni‐based metal–organic framework (Ni‐MOF) with a Schiff base ligand as an organic linker, Ni3(bdda)2(OAc)2⋅6H2O (H2bdda = 4,4′‐[benzene‐1,4‐diylbis(methylylidenenitrilo)]dibenzoic acid), was synthesized and characterized using powder X‐ray powder diffraction, thermogravimetric analysis, Brunauer–Emmett–Teller measurements, inductively coupled plasma atomic emission spectroscopy, transmission electron microscopy, elemental analysis and Fourier transform infrared spectroscopy. The synthesized Ni‐MOF exhibited a high catalytic activity in benzyl alcohol oxidation using tert‐butyl hydroperoxide under solvent‐free conditions. Also, the efficiency of the catalyst was investigated in the cascade reaction of oxidation–Knoevanagel condensation under mild conditions. The Ni‐MOF catalyst could be recovered and reused four times without significant reduction in its catalytic activity.
Synthesis, characterization and solid‐phase extraction properties of novel bis(diazo‐azomethine) ligands supported on mesoporous silica
Authors: Uruş Serhan , Karabörk Muharrem , Köksal Hüseyin 
Published: October 2017

AbstractThe novel mesoporous silica‐supported bis(diazo‐azomethine) compounds have been synthesized and characterized successively. In the first step, 1,3‐phenylenedimethanamine and 4,4′‐diaminodiphenylmethane were diazotized, and the obtained bis(diazonium) cations were coupled with 2,4‐dihydroxybenzaldehyde. The synthesized bis(diazo‐carbonyl) compounds, 5,5′‐((1,3‐phenylenebis(methylene))bis(diazene‐2,1‐diyl))bis(2,4‐dihydroxybenzaldehyde) (A1) and 5,5′‐((methylenebis(4,1‐phenylene))bis(diazene‐2,1‐diyl))bis(2,4‐dihydroxybenzaldehyde) (A2) were chemically supported on amino‐modified silica‐gel (as L1 and L2). Elemental analysis, liquid chromatography‐mass spectroscopy, liquid‐phase NMR (1H and 13C) and solid‐phase NMR (CP‐MAS 29Si and 13C), FT‐IR, TG/DTA, scanning electron microscopy and energy‐dispersive X‐ray spectroscopy techniques were used for characterizations of all the synthesized compounds. The syringe and batch techniques were applied for the solid‐phase extraction properties of Pb(II), Cu(II), Cd(II) and Cr(III) ions using an inductively coupled plasma‐atomic emission spectroscopy instrument. The recoveries of Pb(II), Cu(II), Cd(II) and Cr(III) ions have been achieved to 95–99% with the (RSDs) of ± 2–3% in optimum conditions.
Surface properties, thermal, and mechanical characteristics of poly(vinyl alcohol)–starch‐bacterial cellulose composite films
Authors: Chiulan Ioana , Frone Adriana Nicoleta , Panaitescu Denis Mihaela , Nicolae Cristian Andi , Trusca Roxana 
Published: October 2017

ABSTRACTNanocomposite films for food packaging applications were developed using bacterial cellulose (BC) nanofibers in different amount in a poly(vinyl alcohol)/starch (PVA/St) matrix. In search of a better method to reduce the harmful ingredients in food packaging, the cellulose nanofibers were obtained by the mechanical defibrillation of BC pellicles thus avoiding the addition of chemicals in the final packaging material. Improved mechanical performances were obtained starting from just 1% BC nanofibers in PVA/St. Atomic force microscopy images showed a uniform dispersion of BC nanofibers on the surface of nanocomposites. A twofold increase of both tensile strength and modulus was obtained for 2 wt % BC in the composite. BC nanofibers have greatly improved the barrier properties of PVA/St matrix, a twofold increase of water vapor permeability being obtained for only 2 wt % BC nanofibers in the composite film. PVA/St/2BC was proposed as a high potential material for food packaging applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45800.
HPLC–MS/MS analysis of peramivir in rat plasma: Elimination of matrix effect using the phospholipid‐removal solid‐phase extraction method
Authors: Lei Mingdao , Gan Wei , Sun Yongbing 
Published: October 2017

AbstractA simple HPLC–MS/MS method has been developed for the determination of peramivir in rat plasma in the present study. The analytes were separated on a C18 column (50 × 2.1 mm, 1.7 μm) and a triple‐quadrupole mass spectrometer equipped with an electrospray ionization source was applied for the detection. A phospholipid‐free cartridge solid‐phase extraction was used to pretreat the plasma and eliminate the endogenous phospholipid. The in‐source collision‐induced dissociation approach showed that this pretreatment could result in negligible ion suppression from the extracted sample and could produce cleaner samples when compared with the protein precipitation. The method was linear over the concentration range of 0.12–1200.0 ng/mL for peramivir. The method was validated and successfully applied to a pharmacokinetic study after peramivir was orally and intravenously administered to Sprague–Dawley rats.
Effect of metformin and celecoxib on cytotoxicity and release of GDF‐15 from human mesenchymal stem cells in high glucose condition
Authors: Zafarvahedian Elaheh , Roohi Azam , Sepand Mohammad Reza , Ostad Seyed Nasser , Ghahremani Mohammad Hossein 
Published: October 2017

Mesenchymal stem cells (MSCs) have therapeutic potential for treatment of diabetes. However, in vitro behavior of MSCs in high glucose condition as well as presence of glucose lowering agents is not fully understood. Because MSCs have an important role in tissue repair, we examined the effects of metformin and celecoxib on viability of MSCs in different glucose conditions. MSCs, from umbilical cord blood, were cultured in normoglycemic (glucose 5.5 mM), midglycemic (glucose 10 mM), and hyperglycemic (glucose 25 mM) conditions, and the cell viability was evaluated by MTT assay. The cytotoxicity and secretion of GDF‐15 were further tested in MSCs treated with metformin and celecoxib in various glucose concentrations. Our results showed that high glucose condition lowered viability of MSCs. Metformin treatment also inhibited proliferation of MSCs, but its toxicity was not changed in high glucose condition. Celecoxib induced cytotoxicity in MSCs, and the toxicity was increased in high glucose condition. Metformin and celecoxib induced release from MSCs; however, high glucose inhibited the metformin‐induced GDF‐15 release. These findings suggested that metformin did not increase the cytotoxicity of high glucose condition in MSCs. Moreover, celecoxib treatment in diabetic condition can reduce the viability of MSCs to proliferate and regenerate perhaps via change in release of GDF‐15.
Efficient Mukaiyama–Aldol Reaction with Aqueous Formaldehyde on a Hydrophobic Mesoporous Lewis Acid Polymer
Authors: Zhang Fang , Liang Chao , Wang Zhen , Li Hexing 
Published: October 2017

AbstractThe design of robust water‐compatible solid Lewis acid catalysts in the efficient utilization of aqueous formaldehyde is a challenging task. Herein, we describe an ytterbium triflate containing ordered mesoporous polymer (Yb(OTf)2‐MP) that acts as a highly active and selective Lewis acid catalyst for the Mukaiyama–aldol reaction with aqueous formaldehyde. The unique capacity of hydrophobic surface and ordered mesoporosity was able to stabilize the hydrophilic and hydrophobic reactants simultaneously and catalyze the reaction selectively by minimizing water interference at active sites. Accordingly, it enabled a broad range of silyl enol ethers to be used to create structurally diverse β‐hydroxy carbonyl molecules efficiently. Notably, the process can be scaled up easily to achieve the gram‐scale production of the key intermediate of natural product sarkomycin. Additionally, it is stable under aqueous conditions and can be recovered easily and used repeatedly at least six times.
Performance of New and Artificially Aged Electret Filters in Indoor Air Cleaners
Authors: Schumacher Stefan , Spiegelhoff Daniel , Schneiderwind Ute , Finger Hartmut , Asbach Christof 
Published: October 2017

AbstractMobile air cleaners, in particular such with fibrous electret filters, are widely used to improve the indoor air quality. The particle size dependence of the air cleaning efficiency was investigated and concluded that recent testing standards overestimate the cleaning performance with respect to relevant indoor aerosols if considering only particles larger than 0.3 µm. Furthermore, the filters were artificially aged with cigarette smoke to evaluate their long‐term stability. Finally, the results were compared to an aging method proposed by a recent testing standard and a very distinct aging behavior was found.
Dibenzohexacene: Stabilization Through Additional Clar Sextets
Authors: Rüdiger Elias C. , Müller Matthias , Koser Silke , Rominger Frank , Freudenberg Jan , Bunz Uwe H. F. 
Published: October 2017

AbstractTriphenylene units stabilize hexacenes as dibenzohexacenes. The hexacenes formed by a statistical Yamamoto coupling of dibromobenzene with dibromo‐TIPS‐pentacene or, alternatively, Stille coupling with dimethyldibenzostannole. UV/Vis spectroscopy and quantum chemical calculations show that despite the double benzannulation, the species have hexacene‐type character, as evidenced by their redshifted absorption characteristics. The charge carrier mobility of dibenzohexacene 1 a was determined up to 0.2 cm2/(Vs).
Efficient Solar‐Assisted O2 Reduction Using a Cofacial Iron Porphyrin Dimer Catalyst Integrated into a p‐CuBi2O4 Photocathode
Authors: Zahran Zaki N. , Mohamed Eman A. , Haleem Ashraf Abdel , Naruta Yoshinori 
Published: October 2017

AbstractA cofacial iron porphyrin heterodimer, Fe2TPFPP‐TMP showed high electrocatalytic activity, selectivity, and stability for O2 reduction to H2O both in homogeneous non‐aqueous and heterogeneous neutral aqueous solutions. When it is integrated to FTO/p‐CuBi2O4 (FTO=fluorine doped tin oxide) photocathode prepared by a simple novel method, a remarkable efficient solar‐assisted O2 reduction is achieved in neutral potassium phosphate (KPi) or basic NaOH solutions saturated with O2.
Mechanistic Aspects of Redox‐Induced Assembly and Disassembly of S‐Bridged [2M‐2S] Structures
Authors: Koch Felix , Berkefeld Andreas , Speiser Bernd , Schubert Hartmut 
Published: October 2017

AbstractSulfur‐bridged binuclear structures [2M‐2S] play a pivotal role in a variety of chemical processes such as bond breaking and formation and electron transfer. In general, structural persistence is deemed essential to the respective function but owing to the lack of a suitable molecular model system, the current understanding of the factors that control the thermodynamic and kinetic stability of [2M‐2S] cores clearly is limited. This work reports a series of binuclear complexes of nickel derived from a 1,4‐terphenyldithiophenol ligand platform that is ideally suited for mechanistic work to overcome this limitation. Redox‐induced assembly and disassembly of S‐bridged [2M‐2S] fragments have been investigated at the molecular level. As part of an extended square scheme, metastable binuclear structures that are significant mechanistically have been identified, characterized, and their reactivity studied quantitatively. Electronic properties that are inherent to [2M‐2S] structures and determine thermodynamic and kinetic stability are differentiated from steric effects imposed by co‐ligands.
Multi‐institutional nomogram predicting benign prostate pathology on magnetic resonance/ultrasound fusion biopsy in men with a prior negative 12‐core systematic biopsy
Authors: Truong Matthew , Wang Bokai , Gordetsky Jennifer B. , Nix Jeffrey W. , Frye Thomas P. , Messing Edward M. , Thomas John V. , Feng Changyong , Rais‐Bahrami Soroush 
Published: October 2017

BACKGROUNDProstate multiparametric magnetic resonance imaging (mpMRI) may be recommended for patients with a prior negative systematic biopsy (SB). However, a proportion of these patients will continue to have no prostate cancer (PCa) identified on magnetic resonance/ultrasound fusion biopsy (FB) despite abnormal mpMRI findings.METHODSIn this multi‐institutional, retrospective study, clinical and mpMRI parameters were assessed for 285 consecutive patients with at least 1 prior negative biopsy who underwent FB for a Prostate Imaging Reporting and Data System (PI‐RADS) score of 3 to 5 at the University of Rochester Medical Center from December 2014 to December 2016, or at the University of Alabama at Birmingham from February 2014 to February 2017. Nomograms were generated for predicting benign prostate pathology on both the targeted biopsy and the concurrent SB.RESULTSBenign pathology was found in 132 of 285 patients (46.3%). In a multivariate analysis, the predictors of benign prostate pathology on FB were age, prostate‐specific antigen, prostate volume, and PI‐RADS score. The predicted probabilities were plotted on a receiver operating characteristic curve, and the area under the curve was 0.825. The nomogram demonstrated excellent calibration and a high net benefit in a decision curve analysis. With a theoretical cutoff probability of ≥0.7 used to recommend deferment of FB, 61 of 285 patients (21.4%) would have avoided an unnecessary biopsy, and only 4 of 285 patients (1.4%) with PCa with a Gleason score ≥ 3 + 4 would have been missed.CONCLUSIONSFalse‐positive mpMRI examinations may occur in up to 46.3% of patients with a prior negative biopsy. Thus, a multi‐institutional nomogram has been developed and validated for predicting benign pathology after FB in patients with a prior negative biopsy, and this may help to reduce the number of unnecessary biopsies in the setting of abnormal mpMRI findings. Cancer 2018;124:278‐85. © 2017 American Cancer Society.