bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anticancer Gold(III) Porphyrins Target Mitochondrial Chaperone Hsp60
Authors: Hu Di , Liu Yungen , Lai Yau‐Tsz , Tong Ka‐Chung , Fung Yi‐Man , Lok Chun‐Nam , Che Chi‐Ming 
Published: December 2015

AbstractIdentification of the molecular target(s) of anticancer metal complexes is a formidable challenge since most of them are unstable toward ligand exchange reaction(s) or biological reduction under physiological conditions. Gold(III) meso‐tetraphenylporphyrin (gold‐1 a) is notable for its high stability in biological milieux and potent in vitro and in vivo anticancer activities. Herein, extensive chemical biology approaches employing photo‐affinity labeling, click chemistry, chemical proteomics, cellular thermal shift, saturation‐transfer difference NMR, protein fluorescence quenching, and protein chaperone assays were used to provide compelling evidence that heat‐shock protein 60 (Hsp60), a mitochondrial chaperone and potential anticancer target, is a direct target of gold‐1 a in vitro and in cells. Structure–activity studies with a panel of non‐porphyrin gold(III) complexes and other metalloporphyrins revealed that Hsp60 inhibition is specifically dependent on both the gold(III) ion and the porphyrin ligand.
Ruthenium(0)‐Catalyzed [4+2] Cycloaddition of Acetylenic Aldehydes with α‐Ketols: Convergent Construction of Angucycline Ring Systems
Authors: Saxena Aakarsh , Perez Felix , Krische Michael J. 
Published: December 2015

AbstractRuthenium(0) complexes modified by CyJohnPhos or RuPhos catalyze the successive C−C coupling of acetylenic aldehydes with α‐ketols to form [4+2] cycloadducts as single diastereomers. This method enables convergent construction of type II polyketide ring systems of the angucycline class.
Flow‐Assisted Synthesis of [10]Cycloparaphenylene through Serial Microreactions under Mild Conditions
Authors: Kim Heejin , Lee Hyune‐Jea , Kim Dong‐Pyo 
Published: December 2015

AbstractCycloparaphenylene (CPP) has been recognized as an attractive template for the bottom‐up synthesis of carbon nanotubes with uniform diameter, and is important for the chemistry of graphitic as well as ring‐shaped macromolecules. However, the reported routes from halogenated benzenes have suffered from low yields even under time‐ and labor‐consuming multistep conditions. Herein we report a flow‐assisted synthesis of [10]CPP in four steps under mild conditions. For the synthesis, a selective nucleophilic addition of the unprotected diketone without the double‐added byproduct was achieved within 3 s in high yield. Subsequently, the obtained compound was reacted with dilithiated benzene at 25 °C to form a U‐shaped precursor for CPP in a separate microreactor, which was finally dimerized and aromatized to obtain [10]CPP by a two‐step in‐flask reaction. Precise control of time and flow facilitated by the flow‐assisted system enabled the development of an efficient synthetic route for [10]CPP.
Nanowire Chemical/Biological Sensors: Status and a Roadmap for the Future
Authors: Fennell John F. , Liu Sophie F. , Azzarelli Joseph M. , Weis Jonathan G. , Rochat Sébastien , Mirica Katherine A. , Ravnsbæk Jens B. , Swager Timothy M. 
Published: December 2015

AbstractChemiresistive sensors are becoming increasingly important as they offer an inexpensive option to conventional analytical instrumentation, they can be readily integrated into electronic devices, and they have low power requirements. Nanowires (NWs) are a major theme in chemosensor development. High surface area, interwire junctions, and restricted conduction pathways give intrinsically high sensitivity and new mechanisms to transduce the binding or action of analytes. This Review details the status of NW chemosensors with selected examples from the literature. We begin by proposing a principle for understanding electrical transport and transduction mechanisms in NW sensors. Next, we offer the reader a review of device performance parameters. Then, we consider the different NW types followed by a summary of NW assembly and different device platform architectures. Subsequently, we discuss NW functionalization strategies. Finally, we propose future developments in NW sensing to address selectivity, sensor drift, sensitivity, response analysis, and emerging applications.
Chemoselective Switch in the Asymmetric Organocatalysis of 5H‐Oxazol‐4‐ones and N‐Itaconimides: Addition–Protonation or [4+2] Cycloaddition
Authors: Zhu Bo , Lee Richmond , Li Jiangtao , Ye Xinyi , Hong San‐Ni , Qiu Shuai , Coote Michelle L. , Jiang Zhiyong 
Published: December 2015

AbstractWe report a synthetic strategy for a chemoselective switch and a diastereo‐divergent approach for the asymmetric reaction of 5H‐oxazol‐4‐ones and N‐itaconimides catalyzed by l‐tert‐leucine‐derived tertiary amine–urea compounds. The reaction was modulated to harness either tandem conjugate addition–protonation or [4+2] cycloaddition as major product with excellent enantio‐ and diastereoselectivities. Subjecting the enantio‐enriched cycloaddition products to a basic silica gel reagent yields the diastereomer vis‐à‐vis the product directly obtained under conditions for addition–protonation, thus opening a diastereo‐divergent route for creating 1,3‐tertiary‐hetero‐quaternary stereocenters. Quantum chemical studies further provide stereochemical analysis for the [4+2] process and a plausible mechanism for this chemoselective switch is proposed.
Synthesis of Chiral Tertiary Boronic Esters by Oxime‐Directed Catalytic Asymmetric Hydroboration
Authors: Shoba Veronika M. , Thacker Nathan C. , Bochat Andrew J. , Takacs James M. 
Published: December 2015

AbstractChiral boronic esters are useful intermediates in asymmetric synthesis. We have previously shown that carbonyl‐directed catalytic asymmetric hydroboration (CAHB) is an efficient approach to the synthesis of functionalized primary and secondary chiral boronic esters. We now report that the oxime‐directed CAHB of alkyl‐substituted methylidene and trisubstituted alkene substrates by pinacolborane (pinBH) affords oxime‐containing chiral tertiary boronic esters with yields up to 87 % and enantiomeric ratios up to 96:4 e.r. The utility of the method is demonstrated by the formation of chiral diols and O‐substituted hydroxylamines, the generation of quaternary carbon stereocenters through carbon–carbon coupling reactions, and the preparation of chiral 3,4,4‐trisubstituted isoxazolines.
Study of sparger location on solid suspension in a triple‐impeller stirred vessel
Authors: See Tiam You , Abdul Raman Abdul Aziz , Raja Ehsan Shah Raja Shazrin Shah , Ibrahim Shaliza , Mohamad Nor Mohamad Iskandr 
Published: December 2015

AbstractSeveral advantages such as good gas and solids dispersion have been associated with triple‐impeller system for three phase mixing processes. In this work, minimum impeller speed required for achieving just suspended condition was studied with gassing using three Rushton turbines as agitators. The effects of sparger location and gas flow rate on the just suspension speed, gas hold‐up, gas–liquid mass transfer coefficient and power consumption were discussed. Sparger placed above the bottom impeller showed the highest gas hold‐up at just suspended condition with the same total power consumption as the other two sparger locations. The highest gas hold‐up value achieved was 12% at total power consumption of 370 W. The data obtained fitted well into ∆Njs = kQg with k = 3.67 when the sparger is located below the bottom impeller. Significantly lower k values can be obtained when the sparger is shifted above the bottom impeller. The sparger location above the bottom‐most impeller is proposed to be superior for industrial application of aerated solid suspensions where at least 8% saving on power consumption can be achieved. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Influence of chloroacetate group on physical properties of natural rubber and its interaction with fillers
Authors: Boochathum Ploenpit , Rongtongaram Natee 
Published: December 2015

ABSTRACTFiller–rubber composites were prepared by mixing chloroacetated natural rubber (CNR) with silica, carbon black (CB), or calcium carbonate using a two‐roll mill. The interactions between the CNR and fillers, including silica, carbon black, and calcium carbonate, were characterized based on glass transition temperature (Tg) and shear storage modulus (G′). The results showed that both the Tg and G′ values of the CNR‐Si composite were found to be higher than those of the CNR–CB and CNR–CaCO3 composites, indicating the existence of the CNR and silica interaction. The outstanding direct interaction between the CNR rubber matrix and silica without using a coupling agent was believed to be due to hydrogen bonds that formed between the hydroxyls of the silanol groups of silica and the carbonyls in the chloroacetate groups of CNR molecules. Moreover, it was also found that silica dispersed and distributed in the CNR matrix much better than in the natural rubber matrix. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43076.
Influence of melt processing on biodegradable nisin‐PBAT films intended for active food packaging applications
Authors: Zehetmeyer Gislene , Meira Stela Maris Meister , Scheibel Jóice Maria , de Oliveira Ricardo Vinicius Bof , Brandelli Adriano , Soares Rosane Michele Duarte 
Published: December 2015

ABSTRACTBiodegradable poly(butylene adipate‐co‐terephthalate) (PBAT) films incorporated with different levels of the antimicrobial peptide nisin were developed by melt processing. Structural, morphological, thermal, mechanical, and antimicrobial properties of the films were determined. The X‐ray diffraction patterns exhibited decreasing levels of intensity at 2θ values as the concentration of nisin increased. Scanning electron microscopy showed a heterogeneous morphology when higher amounts of nisin were incorporated. The antimicrobial films tested presented no significant differences in the melting temperature (123–125°C), and the crystallization temperature ranged from 69 to 75°C. The addition of nisin caused no significant modification in tensile strength values. However, results of Young's modulus and deformation at break differed significantly among samples. Active films demonstrated inhibition against the Gram‐positive bacterium Listeria monocytogenes. These results demonstrated that PBAT/nisin films produced by melt processing present a great potential for use as active food packaging materials aiming enhanced food safety. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43212.
Synthesis and characterization of a ferrocene‐modified, polyaniline‐like conducting polymer
Authors: Li Yunlong , Zheng Yuying 
Published: December 2015

ABSTRACTA novel monomer called 1,1′‐ferrocenediacyl anilide (FcA) was synthesized from ferrocene (Fc). Copolymerization was carried out between FcA and aniline (ANI) by an electrochemical method. The novel monomer and copolymer were characterized with 1H‐NMR, Fourier transform infrared (FTIR) spectroscopy, and ultraviolet–visible (UV–vis) spectroscopy. The hydrogen protons of the benzene ring were moved to a low field in 1H‐NMR, and the absorption band of NQN (where Q is the quinoid ring) appeared in the FTIR spectrum of the polymer. The peaks of both Fc and the π–π* electronic transition in the UV–vis spectra were redshifted. The results indicate that the copolymer mainly existed as a highly delocalized conjugated system. X‐ray diffraction analysis established further proof, and the process of electrochemical deposition was observed by scanning electron microscopy. The optimal synthesis conditions of the copolymer were determined through changes in the monomer molar ratios and the scan rate. The ideal performance of the copolymer was gained when the monomer molar ratio between FcA and ANI was 1:4 and the scan rate was 50 mV/s. Furthermore, the electrochemical performances were tested in detail by cyclic voltammetry, galvanostatic charge–discharge testing, and electrochemical impedance spectroscopy. The results show that the specific capacitance of poly(1,1′‐ferrocenediacyl anilide‐co‐aniline) increased up to 433.1 F/g at 0.5 A/g, the diffusion resistance was very small, and the durability was good enough. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43217.
Efficient Benzodioxole‐based unimolecular photoinitiators: From synthesis to photopolymerization under UV‐A and visible LED light irradiation
Authors: Dong Xiaoqing , Shen Weizhen , Hu Peng , Li Zhiquan , Liu Ren , Liu Xiaoya 
Published: December 2015

ABSTRACTThe narrow emission spectra of light emitting diodides (LED) as irradiation source has brought great challenge for the development of efficient photoinitiators sensitive to LED light. This paper described a series of novel unimolecular type II photoinitiators, containing thioxanthones as chromophores and benzodioxoles as coinitiators. The structures of the photoinitiators were characterized by 1H NMR, 13C NMR and high‐resolution mass spectrometer. Study on the photophysical properties of the photoinitiators indicated that electron donors/acceptors as spacers between thioxanthone and benzodioxole affected both the UV–Vis absorption and the fluorescence emission. The long wavelength absorptions from 385 nm to 402 nm as well as low fluorescence quantum yields make the investigated benzodioxole derivatives quite attractive as efficient photoinitiators under UV‐A and visible LED light irradiation. With a proper molecular design, the unimolecular photoinitiator exhibited higher initiation efficiency than the thioxanthone derivatives from the literature. Possible initiation mechanism was also proposed based on the photolysis study. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43239.
Carbon‐fiber‐reinforced acrylonitrile–styrene–acrylate composites: Mechanical and rheological properties and electrical resistivity
Authors: Song Jianbin , Liu Xueshen , Zhang Yanhua , Huang Biao , Yang Wenbin 
Published: December 2015

ABSTRACTThe aim of this study was to improve the mechanical properties of an acrylonitrile–styrene–acrylate copolymer (ASA) with the help of carbon fibers (CFs). Additionally, the effects of the CFs on the morphology, rheological properties, dynamical mechanical properties, electrical resistivity, and heat resistance of the ASA composites were studied with scanning electron microscopy, rotational rheometry, and dynamic thermomechanical analysis (DMA). The mechanical properties of the ASA composites were enhanced largely by the CFs. The maximum tensile strength of the ASA/CF composites reached 107.2 MPa. The flexural strength and flexural modulus also reached 162.7 MPa and 12.4 GPa, respectively. These findings were better than those of neat ASA; this was attributed to the excellent interfacial adhesion between the CFs and ASA resin. Rheological experiments proved that the viscosity and storage modulus (G′) values of the ASA/CF composites did not increase until the CF content reached 20%. The DMA outcomes confirmed that the glass‐transition temperature of the ASA composites was elevated from 120.6 to 125°C. Importantly, the G′ values of the composites with 20 and 30% CFs showed a large increase during heating. In addition, the ASA/CF composites exhibited excellent conductivity and heat resistance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43252.
Design and in vitro investigation of nanocomposite hydrogel based in situ spray dressing for chronic wounds and synthesis of silver nanoparticles using green chemistry
Authors: Kumar Arun , Jaiswal Maneesh 
Published: December 2015

ABSTRACTAn innovative concept of spontaneous film dressing has been designed as sprayed hydrogel dressings (SHD) using a blend of polyvinyl alcohol (PVA) and sodium alginate (SA) as synthetic and natural polymeric components and, were crosslinked with boric acid and calcium chloride, respectively. Silver nanoparticles (AgNPs) are synthesized by green chemistry using Ficus benghalensis extract (FB) and were characterized by SEM and zeta sizer. FTIR spectra show polymeric interaction with AgNPs, while SEM images show outer surface of the SHD film. Equilibrium swelling and degradation in aqueous media (distilled water and buffers) are found to be dependent upon PVA/SA ratio. Polymeric combination exhibit pseudoplastic behavior with Farrow's constant >1. Uniformly distributed AgNPs (particle size ∼27.55 ± 2.01 nm), high water retention (∼13 fold), and biodegradable (∼5 days) nature of dressing along with sustained release profile of both AgNPs and extract with concentration‐dependent antimicrobial activity have been observed for 24 h. Self shaped, biodegradable, aseptic, prolong anti‐oxidative, non‐hemolytic, blood compatible, and hemostatic properties of SHD film appears as promising dressing for superficial wounds. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43260.
Influence of the Tensor Product Model Representation Of QLPV Models on The Feasibility of Linear Matrix Inequality
Authors: Szollosi Alexandra , Baranyi Peter 
Published: December 2015

AbstractThe present paper proves that the vertexes of the tensor product (TP) model type polytopic representation of a given quasi linear parameter varying (qLPV) state‐space model strongly interfere with the feasibility regions of linear matrix inequality (LMI)‐based control design methods. Furthermore this is valid both for the LMI‐based feasibility of the controller and the observer design, but the influence differs for the controller and the observer system components. More specifically, the factors influencing the feasibility regions of the LMI‐based control design include: (i) the manipulation of the vertexes' position; and (ii) the size and complexity of the TP model type polytopic representation, i.e. the number of the vertexes contained in the TP model representation. The proof is based on a complex control design example, where the influence of these factors stated above can be easily and clearly indicated. Furthermore the paper shows via the example that the maximal parameter space of the controller and observer also depends on these factors. The example model consists of the complex Nonlinear Aeroelastic Test Apparatus (NATA) model of the three degree of freedom aeroelastic wing section model including Stribeck friction and the control design method is based on the relaxed TP model transformation‐based control design framework that supports the flexible manipulation of these factors.
Effects of turbulent viscosity on a rotating gas ring around a black hole: Results of numerical simulations
Authors: Giri K. , Chang H.‐K. 
Published: December 2015

AbstractIn this paper, we present the time evolution of a rotationally axisymmetric gas ring around a non rotating black hole using two dimensional grid‐based hydrodynamics simulations. We show the way in which angular momentum transport is included in simulations of non‐selfgravitating accretion of matter towards a black hole. We use the Shakura‐Sunyaev α viscosity prescription to estimate the turbulent viscosity for all major viscous stress tensors. We investigate how a gas ring which is initially assumed to rotate with Keplerian angular velocity is accreted onto a black hole and hence forms an accretion disc in the presence of turbulent viscosity. We show that a centrifugally pressure supported sub‐Keplerian flow with shocks forms when the ring starts to disperse with inclusion of relatively small amount of viscosity. But, if the viscosity is above the critical value, the shock disappears altogether and the whole disc becomes Keplerian which is subsonic everywhere except in a region close to the horizon, where it supersonically enters to the black hole. We discovered a multiple valued Mach number solution and the corresponding density distributions that connect matter (a) from the initial Keplerian gas ring to a sub‐Keplerian disc with shocks in presence of small amount of viscosity and (b) from the sub‐Keplerian flow to a Keplerian disc in presence of huge amount of viscosity. We calculate the temporal variations of the magnitude of various time scales which ensure us about the stability of the flow. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New orbits for comets C/1843 J1 (Mauvais) and C/1853 W1 (van Arsdale)
Authors: Branham R. L. 
Published: December 2015

AbstractNew orbits for comet C/1843 J1 (Mauvais) and comet C/1853 W1 (van Arsdale) are calculated. Both orbits are hyperbolic, with e = 1.001145 and semi‐major axis a = –1412.18 AU for Mauvais and e = 1.000700 and a = –2919.24 AU for van Arsdale. Integrating the orbits backwards indicate that both comets were born in the far Oort cloud. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cell death and cell proliferation in human spina bifida
Authors: Avagliano Laura , Doi Patrizia , Tosi Delfina , Scagliotti Valeria , Gualtieri Angelica , Gaston‐Massuet Carles , Pistocchi Anna , Gallina Andrea , Marconi Anna Maria , Bulfamante Gaetano , Massa Valentina 
Published: December 2015

BackgroundSpina bifida is a multifactorial congenital malformation of the central nervous system. The aim of this study was to ascertain the relevance of cell death/proliferation balance in human spina bifida and to assess autophagy distribution and levels during embryo‐fetal development in neural tissue.MethodsFive human cases with myelomeningocoele were compared with 10 healthy human controls and LC3 protein expression was also analyzed in mouse embryos. Cell death was evaluated using TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridinetriphosphate nick end‐labeling) assay; cell proliferation was studied by counting Ki67‐positive cells, and autophagy was assessed by observing the presence of LC3 punctuate dots.ResultsComparing human cases and controls (13 to 21 weeks of gestation), we observed a significant increase in TUNEL‐positive cells in human spina bifida associated with a significantly decreased proliferation rate, indicating an alteration of the physiological cell rate homeostasis. LC3 distribution was found to be spatiotemporally regulated in both human and murine embryo‐fetuses: in early pregnancy a diffuse and ubiquitous LC3 signal was detected. After neural tube closure, an intense LC3‐positive signal, normally associated to extra energy requirement, was confined to the Lissauer's tract, the dorsolateral spinal zone containing centrally projecting axons from dorsal root ganglia, at any medullar levels. LC3 signal disappeared from 12 weeks of gestation.ConclusionIn conclusion, this study confirms the fundamental role of cell death/proliferation balance during central nervous system development and reports the changing expression of LC3 protein in mouse and human neural tube. Birth Defects Research (Part A) 106:104–113, 2016. © 2015 Wiley Periodicals, Inc.