bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electronic properties and strain sensitivity of CVD-grown graphene with acetylene
Authors: Yang Meng , Sasaki Shinichirou , Ohnishi Masato , Suzuki Ken , Miura Hideo 
Published: March 2016

Abstract
Although many studies have shown that large-area monolayer graphene can be formed by chemical vapor deposition (CVD) using methane gas, the growth of monolayer graphene using highly reactive acetylene gas remains a big challenge. In this study, we synthesized a uniform monolayer graphene film by low-pressure CVD (LPCVD) with acetylene gas. On the base of Raman spectroscopy measurements, it was found that up to 95% of the as-grown graphene is monolayer. The electronic properties and strain sensitivity of the LPCVD-grown graphene with acetylene were also evaluated by testing the fabricated field-effect transistors (FETs) and strain sensors. The derived carrier mobility and gauge factor are 862–1150 cm2/(V·s) and 3.4, respectively, revealing the potential for high-speed FETs and strain sensor applications. We also investigated the relationship between the electronic properties and the graphene domain size.
Degradation mechanism for planar heterojunction perovskite solar cells
Authors: Yamamoto Kouhei , Furumoto Yoshikazu , Shahiduzzaman M. , Kuwabara Takayuki , Takahashi Kohshin , Taima Tetsuya 
Published: March 2016

Abstract
Organic–inorganic hybrid perovskite materials have recently emerged as a promising cost- and energy-efficient light absorber material for photovoltaic applications. Unfortunately, perovskite solar cells have a problem with decreasing power conversion efficiency owing to their degradation in air. To clarify the cause of the degradation of perovskite solar cells, we exposed deposited CH3NH3PbI3 and HC(NH2)2PbI3 films to an O2 or (H2O+N2) atmosphere condition. Analysis of these films revealed that a large energy band gap was observed as a result of the influence of the H2O molecule in CH3NH3PbI3 and HC(NH2)2PbI3. Under the (H2O+N2) atmosphere condition, the existence of CH3NH3I and HC(NH2)2I molecules was found to affect the morphology and as well as the crystalline diffraction peak. The resultant perovskite crystalline structure was degraded by H2O molecules under the air exposure condition.
AlGaN/GaN high electron mobility transistors with intentionally doped GaN buffer using propane as carbon precursor
Authors: Bergsten Johan , Li Xun , Nilsson Daniel , Danielsson Örjan , Pedersen Henrik , Janzén Erik , Forsberg Urban , Rorsman Niklas 
Published: March 2016

Abstract
AlGaN/GaN high electron mobility transistors (HEMTs) fabricated on a heterostructure grown by metalorganic chemical vapor deposition using an alternative method of carbon (C) doping the buffer are characterized. C-doping is achieved by using propane as precursor, as compared to tuning the growth process parameters to control C-incorporation from the gallium precursor. This approach allows for optimization of the GaN growth conditions without compromising material quality to achieve semi-insulating properties. The HEMTs are evaluated in terms of isolation and dispersion. Good isolation with OFF-state currents of 2 × 10−6 A/mm, breakdown fields of 70 V/µm, and low drain induced barrier lowering of 0.13 mV/V are found. Dispersive effects are examined using pulsed current–voltage measurements. Current collapse and knee walkout effects limit the maximum output power to 1.3 W/mm. With further optimization of the C-doping profile and GaN material quality this method should offer a versatile approach to decrease dispersive effects in GaN HEMTs.
The quasi 2 day wave activities during 2007 austral summer period as revealed by Whole Atmosphere Community Climate Model
Authors: Gu Sheng‐Yang , Liu Han‐Li , Pedatella N. M. , Dou Xiankang , Li Tao , Chen Tingdi 
Published: March 2016

AbstractThe quasi 2 day wave (QTDW) observed during 2007 austral summer period is well reproduced in an reanalysis produced by the data assimilation version of the Whole Atmosphere Community Climate Model (WACCM + Data Assimilation Research Testbed) developed at National Center for Atmospheric Research (NCAR). It is found that the QTDW peaked 3 times from January to February but with different zonal wave numbers. Diagnostic analysis shows that the mean flow instabilities, refractive index, and critical layers of QTDWs are fundamental for their propagation and amplification, and thus, the temporal variations of the background wind are responsible for the different wave number structures at different times. The westward propagating wave number 2 mode (W2) grew and maximized in the first half of January, when the mean flow instabilities related to the summer easterly jet were enclosed by the critical layers of the westward propagating wave number 3 (W3) and wave number 4 (W4) modes. This prevented W3 and W4 from approaching and extracting energy from the unstable region. The W2 decayed rapidly thereafter due to the recession of critical layer and thus the lack of additional amplification by the mean flow instability. The W3 peaked in late January, when the instabilities were still encircled by the critical layer of W4. The attenuation of W3 afterward was also due to the disappearance of critical layer and thus the lack of overreflection. Finally, the W4 peaked in late February when both the instability and critical layer were appropriate.
Long‐Range Electrostatics‐Induced Two‐Proton Transfer Captured by Neutron Crystallography in an Enzyme Catalytic Site
Authors: Gerlits Oksana , Wymore Troy , Das Amit , Shen Chen‐Hsiang , Parks Jerry M. , Smith Jeremy C. , Weiss Kevin L. , Keen David A. , Blakeley Matthew P. , Louis John M. , Langan Paul , Weber Irene T. , Kovalevsky Andrey 
Published: March 2016

AbstractNeutron crystallography was used to directly locate two protons before and after a pH‐induced two‐proton transfer between catalytic aspartic acid residues and the hydroxy group of the bound clinical drug darunavir, located in the catalytic site of enzyme HIV‐1 protease. The two‐proton transfer is triggered by electrostatic effects arising from protonation state changes of surface residues far from the active site. The mechanism and pH effect are supported by quantum mechanics/molecular mechanics (QM/MM) calculations. The low‐pH proton configuration in the catalytic site is deemed critical for the catalytic action of this enzyme and may apply more generally to other aspartic proteases. Neutrons therefore represent a superb probe to obtain structural details for proton transfer reactions in biological systems at a truly atomic level.
A Two‐Dimensional Zirconium Carbide by Selective Etching of Al3C3 from Nanolaminated Zr3Al3C5
Authors: Zhou Jie , Zha Xianhu , Chen Fan Y. , Ye Qun , Eklund Per , Du Shiyu , Huang Qing 
Published: March 2016

AbstractThe room‐temperature synthesis of a new two‐dimensional (2D) zirconium‐containing carbide, Zr3C2Tz MXene is presented. In contrast to traditional preparation of MXene, the layered ternary Zr3Al3C5 material instead of MAX phases is used as source under hydrofluoric acid treatment. The structural, mechanical, and electronic properties of the synthesized 2D carbide are investigated, combined with first‐principles density functional calculations. A comparative study on the structrual stability of our obtained 2D Zr3C2Tz and Ti3C2Tz MXenes at elevated temperatures is performed. The obtained 2D Zr3C2Tz exhibits relatively better ability to maintain 2D nature and strucural integrity compared to Ti‐based Mxene. The difference in structural stability under high temperature condition is explained by a theoretical investigation on binding energy.
Evolved Colloidosomes Undergoing Cell‐like Autonomous Shape Oscillations with Buckling
Authors: Tamate Ryota , Ueki Takeshi , Yoshida Ryo 
Published: March 2016

AbstractIn living systems, there are many autonomous and oscillatory phenomena to sustain life, such as heart contractions and breathing. At the microscopic level, oscillatory shape deformations of cells are often observed in dynamic behaviors during cell migration and morphogenesis. In many cases, oscillatory behaviors of cells are not simplistic but complex with diverse deformations. So far, we have succeeded in developing self‐oscillating polymers and gels, but complex oscillatory behaviors mimicking those of living cells have yet to be reproduced. Herein, we report a cell‐like hollow sphere composed of self‐oscillating microgels, that is, a colloidosome, that exhibits drastic shape oscillation in addition to swelling/deswelling oscillations driven by an oscillatory reaction. The resulting oscillatory profile waveform becomes markedly more complex than a conventional one. Especially for larger colloidosomes, multiple buckling and moving buckling points are observed to be analogous to cells.
Chemical Synthesis of Phosphorylated Histone H2A at Tyr57 Reveals Insight into the Inhibition Mode of the SAGA Deubiquitinating Module
Authors: Jbara Muhammad , Maity Suman Kumar , Morgan Michael , Wolberger Cynthia , Brik Ashraf 
Published: March 2016

AbstractMonoubiquitination of histone H2B plays a central role in transcription activation and is required for downstream histone‐methylation events. Deubiquitination of H2B by the Spt‐Ada‐Gcn5 acetyltransferase (SAGA) coactivator complex is regulated by a recently discovered histone mark, phosphorylated H2AY57 (H2AY57p), which inhibits deubiquitination of H2B by the SAGA complex as well as restricting demethylation of H3 and increasing its acetylation. Evidence for the effect of H2AY57p, however, was indirect and was investigated in vivo by monitoring the effects of chemical inhibition of Tyr kinase CK2 or by mutating the phosphorylation site. We applied the total chemical synthesis of proteins to prepare H2AY57p efficiently and study the molecular details of this regulation. This analogue, together with semisynthetically prepared ubiquitinated H2B, enabled us to provide direct evidence for the cross‐talk between those two marks and the inhibition of SAGA activity by H2AY57p.
Exchange of Coordinated Solvent During Crystallization of a Metal–Organic Framework Observed by In Situ High‐Energy X‐ray Diffraction
Authors: Wu Yue , Breeze Matthew I. , Clarkson Guy J. , Millange Franck , O'Hare Dermot , Walton Richard I. 
Published: March 2016

AbstractUsing time‐resolved monochromatic high energy X‐ray diffraction, we present an in situ study of the solvothermal crystallisation of a new MOF [Yb2(BDC)3(DMF)2]⋅H2O (BDC=benzene‐1,4‐dicarboxylate and DMF=N,N‐dimethylformamide) under solvothermal conditions, from mixed water/DMF solvent. Analysis of high resolution powder patterns obtained reveals an evolution of lattice parameters and electron density during the crystallisation process and Rietveld analysis shows that this is due to a gradual topochemical replacement of coordinated solvent molecules. The water initially coordinated to Yb3+ is replaced by DMF as the reaction progresses.
Desilylation‐Activated Propargylic Transformation: Enantioselective Copper‐Catalyzed [3+2] Cycloaddition of Propargylic Esters with β‐Naphthol or Phenol Derivatives
Authors: Shao Long , Wang Ya‐Hui , Zhang De‐Yang , Xu Jie , Hu Xiang‐Ping 
Published: March 2016

AbstractA copper‐catalyzed asymmetric [3+2] cycloaddition of 3‐trimethylsilylpropargylic esters with either β‐naphthols or electron‐rich phenols has been realized and proceeds by a desilylation‐activated process. Under the catalysis of Cu(OAc)2⋅H2O in combination with a structurally optimized ketimine P,N,N‐ligand, a wide range of optically active 1,2‐dihydronaphtho[2,1‐b]furans or 2,3‐dihydrobenzofurans were obtained in good yields and with high enantioselectivities (up to 96 % ee). This represents the first desilylation‐activated catalytic asymmetric propargylic transformation.
A Bio‐Inspired, Heavy‐Metal‐Free, Dual‐Electrolyte Liquid Battery towards Sustainable Energy Storage
Authors: Ding Yu , Yu Guihua 
Published: March 2016

AbstractWide‐scale exploitation of renewable energy requires low‐cost efficient energy storage devices. The use of metal‐free, inexpensive redox‐active organic materials represents a promising direction for environmental‐friendly, cost‐effective sustainable energy storage. To this end, a liquid battery is designed using hydroquinone (H2BQ) aqueous solution as catholyte and graphite in aprotic electrolyte as anode. The working potential can reach 3.4 V, with specific capacity of 395 mA h g−1 and stable capacity retention about 99.7 % per cycle. Such high potential and capacity is achieved using only C, H and O atoms as building blocks for redox species, and the replacement of Li metal with graphite anode can circumvent potential safety issues. As H2BQ can be extracted from biomass directly and its redox reaction mimics the bio‐electrochemical process of quinones in nature, using such a bio‐inspired organic compound in batteries enables access to greener and more sustainable energy‐storage technology.
Nanomechanical study of polymer‐polymer thin film interface under applied service conditions
Authors: Mallikarjunachari G. , Pijush Ghosh 
Published: March 2016

ABSTRACTSingle layer and multilayer polymer thin film coating on polymer substrate are gaining significant importance in different industries. The quantitative and qualitative estimation of interface response for thin film coating under different service conditions is significantly important from the perspective of modeling and designing novel materials. However, to characterize an interface between the soft polymer layer and soft polymer substrate is challenging because of the confinement effect, surface roughness, the viscoelastic nature of the polymers involved, and most importantly, the comparable mechanical properties of soft polymeric film and polymer substrate. Nanoindentation technique was applied in this work to find out the mechanical response of thin film PMMA (100–200 nm) and Epoxy interfaces of different interfacial strengths. Interfaces of different strengths were obtained by exposing the film‐substrate system to different service conditions. It has been observed from this study that pile‐up plays a major role in finding out the mechanical response of the interfaces of different strengths. The hardness was observed to increase as the interfacial strength reduces. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43532.
Facile preparation and separation performances of cellulose nanofibrous membranes
Authors: Soyekwo Faizal , Zhang Qiu Gen , Lin Xiao Chen , Wu Xin Mei , Zhu Ai Mei , Liu Qing Lin 
Published: March 2016

ABSTRACTUltrafiltration (UF) is a size selective pressure‐driven membrane separation process increasingly required for high efficient water treatment and suspended solids removal in many industrial applications. This study examined the morphology of as‐prepared cellulose nanofibers and then utilized the nanofibers dispersion to fabricate nanofibrous nanoporous membranes with potential wide applications in various fields including water treatment. The nanofibers were prepared using a simple and powerful mechanical high intensity ultrasonication following a pre‐chemical treatment of α‐cellulose. The cellulose nanofibers’ morphology, crystallinity, and yield were found to be influenced by pre‐chemical treatment. Cellulose nanofibrous membranes were fabricated from cellulose nanofibers dispersion on a porous support. A nanoporous structure with an extensive interconnected network of fine cellulose nanofibers was formed on the support substrate. The resulting membranes exhibited typical and high‐efficient UF performances with high water fluxes of up to 2.75 103 L/m2/h/bar. The membranes also displayed high rejections for ferritin and 10 nm gold nanoparticles with a reactive surface area capable of rapidly decolorizing methylene blue from its aqueous solution. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43544.
Nitrogen‐Doped Graphene Quantum Dots Anchored on Thermally Reduced Graphene Oxide as an Electrocatalyst for the Oxygen Reduction Reaction
Authors: Zhang Bo , Xiao Chunhui , Xiang Yang , Dong Bitao , Ding Shujiang , Tang Yuhai 
Published: March 2016

AbstractNitrogen‐doped graphene quantum dots (N‐GQDs) with a size of 2.5–8.5 nm are ultra‐uniformly grown in situ on thermally reduced graphene oxide (rGO) and are different from those catalysts fabricated by adding pre‐prepared GQDs artificially. N‐GQD/rGO shows catalytic activity for the oxygen reduction reaction, which is comparable to that of the Pt/C catalyst, but with better durability and a higher tolerance to the methanol crossover effect. This method might extend the application of N‐GQDs in electrocatalysis.
Detection of Sulfatase Enzyme Activity with a CatalyCEST MRI Contrast Agent
Authors: Sinharay Sanhita , Fernández‐Cuervo Gabriela , Acfalle Jasmine P. , Pagel Mark D. 
Published: March 2016

AbstractA chemical exchange saturation transfer (CEST) MRI contrast agent has been developed that detects sulfatase enzyme activity. The agent produces a CEST signal at δ=5.0 ppm before enzyme activity, and a second CEST signal appears at δ=9.0 ppm after the enzyme cleaves a sulfate group from the agent. The comparison of the two signals improved detection of sulfatase activity.
Alkaline Earth–Olefin Complexes with Secondary Interactions
Authors: Roşca Sorin‐Claudiu , Dinoi Chiara , Caytan Elsa , Dorcet Vincent , Etienne Michel , Carpentier Jean‐François , Sarazin Yann 
Published: March 2016

AbstractStrontium and calcium (alkaline earth: Ae) olefin complexes stabilised by secondary Ae⋅⋅⋅F−C and β‐agostic Ae⋅⋅⋅H−Si interactions are presented. Olefin coordination onto the alkaline earths is plain in the solid state, and it is thermodynamically favoured over the coordination of THF. The existence of the Ae⋅⋅⋅olefin interactions is corroborated by solution NMR data and DFT computations. The coordination mode of the olefin varies with steric effects and, if enforced, olefin dissociation can be compensated by the other non‐covalent interactions, as supported by DFT computations.
Reservoir impairment by asphaltenes: A critical review
Authors: Eskin Dmitry , Mohammadzadeh Omid , Akbarzadeh Kamran , Taylor Shawn David , Ratulowski John 
Published: March 2016

AbstractPrecipitation and deposition of asphaltenes and other organic substances in formation rock causes formation damage and reduces effective hydrocarbon mobility, which can result in significant production losses. The development of reliable experimental, analytical, and modelling methods improves the understanding of asphaltene‐induced formation damage and provides tools for preventing and/or controlling formation damage due to asphaltenes in oil‐bearing formations. To make further advancements in understanding asphaltene impairment, it is important to analyze the current state of technology and research in this area. In addition to analyses of known experimental data and models of reservoir impairment by asphaltenes, prospective directions of future research in this area are also suggested.
Rigid, Bistable Molecular Shuttles Combining T‐shaped Benzimidazolium and Y‐shaped Imidazolium Recognition Sites
Authors: Farahani Nasim , Zhu Kelong , Loeb Stephen J. 
Published: March 2016

AbstractTwo different recognition sites, one a T‐shaped 2,4,7‐triphenylbenzimidazolium and the other a Y‐shaped 2,4,5‐triphenylimidazolium are combined to construct a rigid bistable [2]rotaxane molecular shuttle on which the position of a 24‐membered crown ether macrocycle can be controlled by acid–base chemistry. Molecular shuttling in both the neutral and dicationic versions were studied.
Phthalocyanine–Gold Nanoparticle Hybrids: Modulating Quenching with a Silica Matrix Shell.
Authors: Baldovi Herme G. , Blas‐Ferrando Vicente M. , Ortiz Javier , Garcia Hermenegildo , Fernández‐Lázaro Fernando , Sastre‐Santos Ángela 
Published: March 2016

AbstractAn asymmetrically substituted zinc phthalocyanine (ZnPc) with a terminal dithiolane group is anchored to Au nanoparticles (NPs) directly or through an interposed silica matrix. Transient absorption spectroscopy shows that the quenching of the ZnPc excited state by AuNPs occurs through a photoinduced electron transfer, the efficiency of which is modulated by the presence of the insulating silica matrix.
Utilization of G‐Quadruplex‐Forming Aptamers for the Construction of Luminescence Sensing Platforms
Authors: Ma Dik‐Lung , Wang Wanhe , Mao Zhifeng , Kang Tian‐Shu , Han Quan‐Bin , Chan Philip Wai Hong , Leung Chung‐Hang 
Published: March 2016

AbstractAptamers are nucleic acid sequences that can recognize and bind to analytes with high affinity and selectivity. Intriguingly, a number of aptamers undergo a conformational change within the G‐quadruplex motif upon ligand binding. This Minireview aims to highlight interesting examples of luminescent G‐quadruplex aptamer‐based probes that have been developed in recent years. Various mechanisms and sensing modes are described, and the outlook and future directions of this field are also discussed.
Fine needle aspiration cytology of cystic primary adult granulosa cell tumor of the ovary: Potential diagnostic pitfalls with other cystic ovarian lesions
Authors: Harbhajanka Aparna , lamzabi Ihab , Jain Richa , Syed Sahr , Murro Diana , Gattuso Paolo 
Published: March 2016

IntroductionFine needle aspiration(FNA) of cystic adult granulosa cell tumors(CAGCT) has been sporadically reported in the literature. We undertook a retrospective study to further elucidate the cytologic features on FNA material in order to avoid possible misinterpretation with other primary tumors of ovary.Materials and MethodsDuring 1992 and 2014, FNA of five cases of CAGCT were recorded.ResultsThe patient's age ranged from 28 to 62 years. One was bilateral and all cases involved right side of ovary. The size of tumor was 5.5 to 10 cm. FNA of the five CAGCT show similar cytologic features except one case. Four cases contained a background composed of histiocytic cells and debris material. The tumor cells were small with round to oval nuclei and fine chromatin pattern, inconspicuous nucleoli, scanty cytoplasm with rare intranuclear longitudinal grooves. Tumor cells were arranged in small groups as well as single cells were appreciated some of which were deprived of cytoplasm. Microfollicular or rosette pattern were vague, some of which contain amorphous material resembling Call‐Exner bodies. In addition, two cases also showed prominent papillary component and one of which was misdiagnosed for serous papillary carcinoma. All five cases were surgically resected and CAGCT was confirmed.ConclusionsFNA of CAGCT of ovary can be a challenging diagnosis as classic cytologic features may not be present and can be confused with benign follicular cyst especially when the ultrasound study favor benign cystic lesion. Rarely this tumor may show prominent papillary component and can be confused for a more clinically aggressive tumor such as papillary serous carcinoma. Diagn. Cytopathol. 2016;44:461–465. © 2016 Wiley Periodicals, Inc.