bluuebunny/crossref_metadata_2025 huggingface dataset:
Borehole Volumetric Strainmeter Calibration From a Nearby Seismic Broadband Array at Etna Volcano
Authors: Currenti G. , Zuccarello L. , Bonaccorso A. , Sicali A.
Published: October 2017

Strainmeter and broadband seismic signals have been analyzed jointly with the aim of calibrating a borehole strainmeter at Etna volcano by using a seismo‐geodetic technique. Our results reveal a good coherence between the dynamic strains estimated from seismometer data and strains recorded by a dilatometer in a low‐frequency range [0.03–0.06 Hz] at the arrival of teleseismic waves. This significant coherence enabled estimating the calibration coefficient and making a comparison with calibration results derived from other methods. In particular, we verified that the proposed approach provides a calibration coefficient that matches the results obtained from the comparison of the recorded strain both with theoretical strain tides and with normal‐mode synthetic straingrams. The approach presented here has the advantage of exploiting recorded seismic data, avoiding the use of computed strain from theoretical models.
The 2016 Southeastern U.S. Drought: An Extreme Departure From Centennial Wetting and Cooling
Authors: Park Williams A. , Cook Benjamin I. , Smerdon Jason E. , Bishop Daniel A. , Seager Richard , Mankin Justin S.
Published: October 2017

The fall 2016 drought in the southeastern United States (SE U.S.) appeared exceptional based on its widespread impacts, but the current monitoring framework that only extends from 1979 to present does not readily facilitate evaluation of soil‐moisture anomalies in a centennial context. A new method to extend monthly gridded soil‐moisture estimates back to 1895 is developed, indicating that since 1895, October–November 2016 soil moisture (0–200 cm) in the SE U.S. was likely the second lowest on record, behind 1954. This severe drought developed rapidly and was brought on by low September–November precipitation and record‐high September–November daily maximum temperatures (Tmax). Record‐high Tmax drove record‐high atmospheric moisture demand, accounting for 28% of the October–November 2016 soil‐moisture anomaly. Drought and heat in fall 2016 contrasted with 20th century wetting and cooling in the region but resembled conditions more common from 1895–1956. Dynamically, the exceptional drying in fall 2016 was driven by anomalous ridging over the central United States that reduced south‐southwesterly moisture transports into the SE U.S. by approximately 75%. These circulation anomalies were partly promoted by a moderate La Niña and warmth in the tropical Atlantic, but these processes accounted for very little of the SE U.S. drying in fall 2016, implying a large role for internal atmospheric variability. The extended analysis back to 1895 indicates that SE U.S. droughts as strong as the 2016 event are more likely than indicated from a shorter 60 year perspective and continued multidecadal swings in precipitation may combine with future warming to further enhance the likelihood of such events.
Neoproterozoic‐Early Paleozoic Peri‐Pacific Accretionary Evolution of the Mongolian Collage System: Insights From Geochemical and U‐Pb Zircon Data From the Ordovician Sedimentary Wedge in the Mongolian Altai
Authors: Jiang Y. D. , Schulmann K. , Kröner A. , Sun M. , Lexa O. , Janoušek V. , Buriánek D. , Yuan C. , Hanžl P.
Published: October 2017

Neoproterozoic to early Paleozoic accretionary processes of the Central Asian Orogenic Belt have been evaluated so far mainly using the geology of ophiolites and/or magmatic arcs. Thus, the knowledge of the nature and evolution of associated sedimentary prisms remains fragmentary. We carried out an integrated geological, geochemical, and zircon U‐Pb geochronological study on a giant Ordovician metasedimentary succession of the Mongolian Altai Mountains. This succession is characterized by dominant terrigenous components mixed with volcanogenic material. It is chemically immature, compositionally analogous to graywacke, and marked by significant input of felsic to intermediate arc components, pointing to an active continental margin depositional setting. Detrital zircon U‐Pb ages suggest a source dominated by products of early Paleozoic magmatism prevailing during the Cambrian‐Ordovician and culminating at circa 500 Ma. We propose that the Ordovician succession forms an “Altai sedimentary wedge,” the evolution of which can be linked to the geodynamics of the margins of the Mongolian Precambrian Zavhan‐Baydrag blocks. This involved subduction reversal from southward subduction of a passive continental margin (Early Cambrian) to the development of the “Ikh‐Mongol Magmatic Arc System” and the giant Altai sedimentary wedge above a north dipping subduction zone (Late Cambrian‐Ordovician). Such a dynamic process resembles the tectonic evolution of the peri‐Pacific accretionary Terra Australis Orogen. A new model reconciling the Baikalian metamorphic belt along the southern Siberian Craton with peri‐Pacific Altai accretionary systems fringing the Mongolian microcontinents is proposed to explain the Cambro‐Ordovician geodynamic evolution of the Mongolian collage system.
Rapid Evolution of Subduction‐Related Continental Intraarc Rifts: The Taupo Rift, New Zealand
Authors: Villamor P. , Berryman K. R. , Ellis S. M. , Schreurs G. , Wallace L. M. , Leonard G. S. , Langridge R. M. , Ries W. F.
Published: October 2017

The evolution of the continental intraarc Taupo Rift in the North Island, New Zealand, is rapid, significantly faster than comparative intracontinental rifts such as the African Rifts. Based on our faulting data and published geological, geophysical, and borehole data, we show that activity in the ~2 Ma Taupo Rift has rapidly and asymmetrically narrowed via inward and eastward migration of faulting (at rates of approximately 30 km Myr−1 and 15 km Myr−1, respectively) and has propagated southward along its axis ~70 km in 350 kyr. The loci of voluminous volcanic eruptions and active faulting are correlated in time and space, suggesting that a controlling factor in the rapid rift narrowing is the presence of large shallow heterogeneities in the crust, such as large rhyolitic magma bodies generated by subduction processes, which weaken the crust and localize deformation. Eastward migration of faulting also follows the eastward migration of the volcanic arc which may be related to rollback of the Pacific crust slab at the Hikurangi subduction zone. Southward propagation of the rift is linked with southward migration of the Hikurangi Plateau/Chatham Rise subduction point and occurs episodically aided by stress changes associated with voluminous local volcanism. The large magma supply during early continental intraarc rift stages explains faster evolution (from tectonic to magmatic) than intracontinental rifts. However, the fast changes in magma supply from the subduction zone can also lead to evolution reversals (more evolved magmatic stages reverting to less evolved tectonic stages), rift cessation, and thus failed continental breakup.
Thermoelectric Polymer Aerogels for Pressure–Temperature Sensing Applications
Authors: Han Shaobo , Jiao Fei , Khan Zia Ullah , Edberg Jesper , Fabiano Simone , Crispin Xavier
Published: October 2017

The evolution of the society is characterized by an increasing flow of information from things to the internet. Sensors have become the cornerstone of the internet‐of‐everything as they track various parameters in the society and send them to the cloud for analysis, forecast, or learning. With the many parameters to sense, sensors are becoming complex and difficult to manufacture. To reduce the complexity of manufacturing, one can instead create advanced functional materials that react to multiple stimuli. To this end, conducting polymer aerogels are promising materials as they combine elasticity and sensitivity to pressure and temperature. However, the challenge is to read independently pressure and temperature output signals without cross‐talk. Here, a strategy to fully decouple temperature and pressure reading in a dual‐parameter sensor based on thermoelectric polymer aerogels is demonstrated. It is found that aerogels made of poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) can display properties of semiconductors lying at the transition between insulator and semimetal upon exposure to high boiling point polar solvents, such as dimethylsulfoxide (DMSO). Importantly, because of the temperature‐independent charge transport observed for DMSO‐treated PEDOT‐based aerogel, a decoupled pressure and temperature sensing can be achieved without cross‐talk in the dual‐parameter sensor devices.
A Physicochemically Optimized and Neuroconductive Biphasic Nerve Guidance Conduit for Peripheral Nerve Repair
Authors: Ryan Alan J. , Lackington William A. , Hibbitts Alan J. , Matheson Austyn , Alekseeva Tijna , Stejskalova Anna , Roche Phoebe , O'Brien Fergal J.
Published: October 2017

Clinically available hollow nerve guidance conduits (NGCs) have had limited success in treating large peripheral nerve injuries. This study aims to develop a biphasic NGC combining a physicochemically optimized collagen outer conduit to bridge the transected nerve, and a neuroconductive hyaluronic acid‐based luminal filler to support regeneration. The outer conduit is mechanically optimized by manipulating crosslinking and collagen density, allowing the engineering of a high wall permeability to mitigate the risk of neuroma formation, while also maintaining physiologically relevant stiffness and enzymatic degradation tuned to coincide with regeneration rates. Freeze‐drying is used to seamlessly integrate the luminal filler into the conduit, creating a longitudinally aligned pore microarchitecture. The luminal stiffness is modulated to support Schwann cells, with laminin incorporation further enhancing bioactivity by improving cell attachment and metabolic activity. Additionally, this biphasic NGC is shown to support neurogenesis and gliogenesis of neural progenitor cells and axonal outgrowth from dorsal root ganglia. These findings highlight the paradigm that a successful NGC requires the concerted optimization of both a mechanical support phase capable of bridging a nerve defect and a neuroconductive phase with an architecture capable of supporting both Schwann cells and neurons in order to achieve functional regenerative outcome.
Photonic Microhand with Autonomous Action
Authors: Martella Daniele , Nocentini Sara , Nuzhdin Dmitry , Parmeggiani Camilla , Wiersma Diederik S.
Published: October 2017

Grabbing and holding objects at the microscale is a complex function, even for microscopic living animals. Inspired by the hominid‐type hand, a microscopic equivalent able to catch microelements is engineered. This microhand is light sensitive and can be either remotely controlled by optical illumination or can act autonomously and grab small particles on the basis of their optical properties. Since the energy is delivered optically, without the need for wires or batteries, the artificial hand can be shrunk down to the micrometer scale. Soft material is used, in particular, a custom‐made liquid‐crystal network that is patterned by a photolithographic technique. The elastic reshaping properties of this material allow finger movement, using environmental light as the only energy source. The hand can be either controlled externally (via the light field), or else the conditions in which it autonomously grabs a particle in its vicinity can be created. This microrobot has the unique feature that it can distinguish between particles of different colors and gray levels. The realization of this autonomous hand constitutes a crucial element in the development of microscopic creatures that can perform tasks without human intervention and self‐organized automation at the micrometer scale.
Photogating in Low Dimensional Photodetectors
Authors: Fang Hehai , Hu Weida
Published: October 2017

Low dimensional materials including quantum dots, nanowires, 2D materials, and so forth have attracted increasing research interests for electronic and optoelectronic devices in recent years. Photogating, which is usually observed in photodetectors based on low dimensional materials and their hybrid structures, is demonstrated to play an important role. Photogating is considered as a way of conductance modulation through photoinduced gate voltage instead of simply and totally attributing it to trap states. This review first focuses on the gain of photogating and reveals the distinction from conventional photoconductive effect. The trap‐ and hybrid‐induced photogating including their origins, formations, and characteristics are subsequently discussed. Then, the recent progress on trap‐ and hybrid‐induced photogating in low dimensional photodetectors is elaborated. Though a high gain bandwidth product as high as 109 Hz is reported in several cases, a trade‐off between gain and bandwidth has to be made for this type of photogating. The general photogating is put forward according to another three reported studies very recently. General photogating may enable simultaneous high gain and high bandwidth, paving the way to explore novel high‐performance photodetectors.
Fluorination of Lithium‐Excess Transition Metal Oxide Cathode Materials
Authors: Richards William D. , Dacek Stephen T. , Kitchaev Daniil A. , Ceder Gerbrand
Published: October 2017

Fluorination 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

Two 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

It 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

Designing 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.
Enhanced solubility of hydrogen and carbon monoxide in propane‐ and propylene‐expanded liquids
Authors: Liu Dupeng , Chaudhari Raghunath V. , Subramaniam Bala
Published: October 2017

Conventional propylene hydroformylation occurs in a gas‐expanded liquid phase. Reliable knowledge of the phase equilibria of such systems, including the solubilities of CO and H2 in propylene‐expanded solvents, is essential for rational process design and development. Herein, we report the vapor–liquid equilibrium (VLE) data of the following ternary systems involving CO, H2, propane, propylene, toluene and NX‐795 at temperatures from 70 to 90°C and pressures up to 1.5 MPa: propane/H2/toluene, propane/CO/toluene, propylene/H2/toluene, propylene/CO/toluene, propane/H2/NX‐795, propane/CO/NX‐795, propylene/H2/NX‐795 and propylene/CO/NX‐795. The solubilities of H2 and CO in either propane‐expanded or propylene‐expanded phases are observed to be greater than those in the neat organic solvents, by as high as 78% at 70°C and 1.5 MPa. By modeling the vapor and the liquid phases as pseudo‐binary systems, the Peng‐Robinson equation of state (PR‐EoS) with van der Waals’ mixing rules and binary interaction parameters is shown to satisfactorily predict the experimental VLE data. © 2017 American Institute of Chemical Engineers AIChE J, 64: 970–980, 2018
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

A 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

Biomass‐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

Milstein'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

The 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

Nanocomposite 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

A 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

The 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

Mobile 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

Triphenylene 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

A 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

Sulfur‐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

BACKGROUND

Prostate 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.

METHODS

In 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.

RESULTS

Benign 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.

CONCLUSIONS

False‐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.
Distrust in health care and cultural factors are associated with uptake of colorectal cancer screening in Hispanic and Asian Americans
Authors: Hong Young‐Rock , Tauscher Justin , Cardel Michelle
Published: October 2017

BACKGROUND

There are racial/ethnic disparities in colorectal cancer (CRC) screening, including lower uptake rates among Hispanic Americans (HAs) and Asian Americans (AAs) relative to non‐Hispanic white Americans. The objective of this study was to explore pathways associated with the use of health services and to characterize multifaceted associations with the uptake of CRC screening among HAs and AAs.

METHODS

Data were obtained from the Medical Expenditure Panel Survey (2012‐2013). Participants included HA (n = 3731) and AA (n = 1345) respondents ages 50 to 75 years who met CRC screening recommendations. A modified Andersen behavioral model was used to examine pathways that lead to CRC screening uptake, including predisposing characteristics (education, economic, and cultural factors), health insurance, health needs (perceived health status and several comorbidities), and health provider contextual factors (access to care, perceived quality of health services, and distrust in health care). Structural equation modeling was used to examine the models for HAs and AAs.

RESULTS

In the HA model, cultural factors (standardized regression coefficient [β] = −0.04; P = .013) and distrust in health care (β = −0.05; P = .007) directly and negatively affected CRC screening. Similarly, cultural factors (β = −0.11; P = .002) negatively affected CRC screening in the AA model, but distrust in health care was not significant (P = .103). In both models, perceived quality of health services was positively associated with CRC screening uptake and mediated the negative association between cultural factors and CRC screening. Access to care was not associated with CRC screening.

CONCLUSIONS

Correlations between CRC screening and associated factors differ among HAs and AAs, suggesting a need for multilevel interventions tailored to race/ethnicity. The current findings suggest that facilitating access to care without improving perceived quality of health services may be ineffective for increasing the uptake of CRC screening among HAs and AAs. Cancer 2018;124:335‐45. © 2017 American Cancer Society.
Dynamic formation of service communities in the cloud under distribution and incomplete information settings
Authors: Khosrowshahi‐Asl Ehsan , Bentahar Jamal , Estrada Rebeca , Otrok Hadi , Mizouni Rabeb , Khosravifar Babak
Published: October 2017

Communities that gather functionally identical or complementary cloud services aim to provide better visibility, efficiency, and market share. This paper investigates the issue of forming these communities in distributed decision‐making settings under incomplete information. By incomplete information, we mean only partial information about the individual performance of cloud services within communities and about how they will behave within these communities is available. Forming communities in these particular settings is still an open problem. Most of the existing models require real‐time global knowledge about the services and high computational complexity, which makes the community formation extremely hard and time‐consuming. In this paper, we propose a strategic Distributed Decision‐making Mechanism (DDM) that regulates the cloud services decision‐making process. DDM first generates an initial set of data based on information obtained from existing cloud services regarding their single and cooperative efficiency. By analyzing this set and on the basis of a distance function, the decision‐making mechanism with regard to which community to form is implemented as a decision profile of strategies and their expected utility computed in terms of computational efficiency. DDM efficiently and systematically helps 1) communities find appropriate cloud services to invite as new members and 2) single services find suitable communities to join. To evaluate the proposed mechanism, we performed experiments using real data including 142 users and 4,000 cloud services obtained from the CloudArmor, CloudHarmony, and WS‐DREAM datasets. The experimental results show that our algorithms outperform the existing solutions.
Untangling cell tracks: Quantifying cell migration by time lapse image data analysis
Authors: Svensson Carl‐Magnus , Medyukhina Anna , Belyaev Ivan , Al‐Zaben Naim , Figge Marc Thilo
Published: October 2017

Automated microscopy has given researchers access to great amounts of live cell imaging data from in vitro and in vivo experiments. Much focus has been put on extracting cell tracks from such data using a plethora of segmentation and tracking algorithms, but further analysis is normally required to draw biologically relevant conclusions. Such relevant conclusions may be whether the migration is directed or not, whether the population has homogeneous or heterogeneous migration patterns. This review focuses on the analysis of cell migration data that are extracted from time lapse images. We discuss a range of measures and models used to analyze cell tracks independent of the biological system or the way the tracks were obtained. For single‐cell migration, we focus on measures and models giving examples of biological systems where they have been applied, for example, migration of bacteria, fibroblasts, and immune cells. For collective migration, we describe the model systems wound healing, neural crest migration, and Drosophila gastrulation and discuss methods for cell migration within these systems. We also discuss the role of the extracellular matrix and subsequent differences between track analysis in vitro and in vivo. Besides methods and measures, we are putting special focus on the need for openly available data and code, as well as a lack of common vocabulary in cell track analysis. © 2017 International Society for Advancement of Cytometry
Highly contrasted population genetic structures in a host–parasite pair in the Caribbean Sea
Authors: Jossart Quentin , De Ridder Chantal , Lessios Harilaos A. , Bauwens Mathieu , Motreuil Sébastien , Rigaud Thierry , Wattier Rémi A. , David Bruno
Published: October 2017

Evolution and population genetic structure of marine species across the Caribbean Sea are shaped by two complex factors: the geological history and the present pattern of marine currents. Characterizing and comparing the genetic structures of codistributed species, such as host–parasite associations, allow discriminating the relative importance of environmental factors and life history traits that influenced gene flow and demographic events. Using microsatellite and Cytochrome Oxidase I markers, we investigated if a host–parasite pair (the heart urchin Meoma ventricosa and its parasitic pea crab Dissodactylus primitivus) exhibits comparable population genetic structures in the Caribbean Sea and how the observed patterns match connectivity regions from predictive models and other taxa. Highly contrasting patterns were found: the host showed genetic homogeneity across the whole studied area, whereas the parasite displayed significant differentiation at regional and local scales. The genetic diversity of the parasitic crabs (both in microsatellites and COI) was distributed in two main groups, Panama–Jamaica–St Croix on the one hand, and the South‐Eastern Caribbean on the other. At a smaller geographical scale, Panamanian and Jamaican parasite populations were genetically more similar, while more genetic differentiation was found within the Lesser Antilles. Both species showed a signature of population expansion during the Quaternary. Some results match predictive models or data from previous studies (e.g., the Western‐Eastern dichotomy in the parasite) while others do not (e.g., genetic differentiation within the Lesser Antilles). The sharp dissimilarity of genetic structure of these codistributed species outlines the importance of population expansion events and/or contrasted patterns of gene flow. This might be linked to differences in several life history traits such as fecundity (higher for the host), swimming capacity of larval stages (higher for the parasite), and habitat availability (higher for the host).
Modification and Restacking of Layered Terbium Hydroxide 2D Crystals
Authors: Feng Pingping , Shao Baiyi , Wang Xinying , Yang Xiaojing
Published: October 2017

We report that 2D crystals, prepared by delamination of layered terbium hydroxide (LTbH) intercalated with dodecyl sulfate ions (DS–) in formamide, can be modified by DS– ions and further restacked to a new layer‐structured compound. The modification proceeds in situ in formamide through the substitution of DS– for the hydroxyl groups, which coordinate to Tb3+ upon the delamination of the LTbH layer. With the supplementary addition of DS–, the substitution reaction progresses to a large degree of substitution, m > 2 in the chemical formula Tb2(OH)6–mDSm·nH2O. Since the negatively charged SO42– heads of DS– anchor to Tb3+, the alkyl chains protruding outwards convert the 2D crystal from hydrophilic to hydrophobic. The modified 2D crystals aggregate in aqueous media, restacking to the layered rare‐earth compound characteristic of m greater than 2. The restacked crystals are ready to delaminate in some organic solvents owning to their structural and hydrophobic features.
Synthesis of Layered LiMn1/3Ni1/3Co1/3O2 Oxides for Lithium‐Ion Batteries using Biomass‐Derived Glycerol as Solvent
Authors: Hamad Khaleel I. , Liao Jin‐Yun , Smith Taylor W. , Xing Yangchuan
Published: October 2017

In an attempt to exploit biomass‐derived glycerol as a solvent, a sol–gel method was used to synthesize LiMn1/3Ni1/3Co1/3O2 (LMNC) layered oxide cathode materials for Li‐ion batteries. The effects of particle size and structure of the layered oxide materials at different annealing temperatures have been studied. The chemical compositions, cation ordering, and particle morphology were obtained by various advanced techniques. Electrochemical performance of the layered oxides was analyzed by cycling testing, cyclic voltammograms, and electrochemical impedance spectroscopy. A comparison of four LMNC samples in this study shows that LMNC annealed at 900 °C exhibits the most promising electrochemical properties. In particular, an initial discharge capacity of 177.1 mAh g−1 has been achieved, with a retention of the discharge capacity of more than 83.7 % after 100 cycles. Furthermore, the sample shows good rate capability up to 5 C, making it well qualified for lithium‐ion battery applications. This study demonstrated the possibility of using glycerol, a byproduct in biodiesel production, as a solvent instead of water in the sol–gel method to synthesize layered structure cathode materials.