bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Generic Synthetic Approach to Large‐Scale Pristine‐Graphene/Metal‐Nanoparticles Hybrids
Authors: Wang Xiujuan , Meng Guowen , Zhu Chuhong , Huang Zhulin , Qian Yiwu , Sun Kexi , Zhu Xiaoguang 
Published: June 2013

AbstractThe homogeneous attachment of metal‐nanoparticles (metal‐NPs) on pristine‐graphene surface to construct pristine‐graphene/metal‐NPs hybrids is highly expected for application in many fields such as transparent electrodes and conductive composites. However, it remains a great challenge since the pristine‐graphene is highly hydrophobic. Here, an environmentally friendly generic synthetic approach to large‐scale pristine‐graphene/metal‐NPs hybrids is presented, by a combinatorial process of exfoliating expanded graphite in N‐methyl pyrrolidone via sonication and centrifugation to achieve the pristine‐graphene, and attaching pre‐synthesized metal‐NPs on the pristine‐graphene in ethanol via van der Waals interactions between the metal‐NPs and the pristine‐graphene. Nanoparticles of different metals (such as Ag, Au, and Pd) with various morphologies (such as sphere, cube, plate, multi‐angle, and spherical‐particle assembling) can be homogeneously attached on the defect‐free pristine‐graphene with controlled packing densities. Both the pristine‐graphene and the metal‐NPs preserve their original intrinsic structures. The as‐synthesized pristine‐graphene/Ag‐NPs hybrids show very high surface‐enhanced Raman scattering activity due to the combined effects of large surface area of the pristine‐graphene to adsorb more target molecules and the electromagnetic enhancement of the Ag‐NPs. This large‐scale synthesis of the pristine‐graphene/metal‐NPs hybrids with tunable shape and packing density of metal‐NPs opens up opportunities for fundamental research and potential applications ranging from devices to transparent electrodes and conductive composites.
Mortality from solid tumors among workers in formaldehyde industries: An update of the NCI cohort
Authors: Beane Freeman Laura E. , Blair Aaron , Lubin Jay H. , Stewart Patricia A. , Hayes Richard B. , Hoover Robert N. , Hauptmann Michael 
Published: June 2013

AbstractBackgroundFormaldehyde, a widely used chemical, is considered a human carcinogen.MethodsWe extended follow‐up of the largest industrial cohort of workers in formaldehyde industries (n = 25,619) by 10 years through 2004. Standardized mortality ratios (SMRs) and rate ratios (RRs) were calculated for deaths from solid tumors using quantitative formaldehyde exposure estimates.ResultsDuring 998,239 person‐years, 13,951 deaths occurred. With one additional death, previously observed excesses for nasopharyngeal cancer (n = 10) persisted for peak, average intensity and cumulative exposure; RRs in the highest exposure categories were 7.66 (95% CI: 0.94, 62.34), P‐trend = 0.005, 11.54 (95% CI: 1.38, 96.81), P‐trend = 0.09, and 2.94 (95% CI: 0.65, 13.28), P‐trend = 0.06, respectively. For all cancer, solid tumors and lung cancer, SMRs among exposed workers were elevated, but internal analyses revealed no positive associations with formaldehyde exposure.ConclusionsConsistent with previous analyses of this cohort, this update continues to suggest a link between formaldehyde exposure and nasopharyngeal cancer. Am. J. Ind. Med. 56:1015–1026, 2013. © 2013 Wiley Periodicals, Inc.
Luminescent Cyclometalated Alkynylplatinum(II) Complexes with a Tridentate Pyridine‐Based N‐Heterocyclic Carbene Ligand: Synthesis, Characterization, Electrochemistry, Photophysics, and Computational Studies
Authors: Leung Sammual Yu‐Lut , Lam Elizabeth Suk‐Hang , Lam Wai Han , Wong Keith Man‐Chung , Wong Wing‐Tak , Yam Vivian Wing‐Wah 
Published: June 2013

AbstractA new class of luminescent alkynylplatinum(II) complexes with a tridentate pyridine‐based N‐heterocyclic carbene (2,6‐bis(1‐butylimidazol‐2‐ylidenyl)pyridine) ligand, [PtII(C^N^C)(CCR)][PF6], and their chloroplatinum(II) precursor complex, [PtII(C^N^C)Cl][PF6], have been synthesized and characterized. One of the alkynylplatinum(II) complexes has also been structurally characterized by X‐ray crystallography. The electrochemistry, electronic absorption and luminescence properties of the complexes have been studied. Nanosecond transient absorption (TA) spectroscopy has also been performed to probe the nature of the excited state. The origin of the absorption and emission properties has been supported by computational studies.
Mechanistic Insight into the Catalytic Oxidation of Cyclohexane over Carbon Nanotubes: Kinetic and In Situ Spectroscopic Evidence
Authors: Yang Xixian , Wang Hongjuan , Li Jing , Zheng Wenxu , Xiang Rong , Tang Zikang , Yu Hao , Peng Feng 
Published: June 2013

AbstractAs some of the most interesting metal‐free catalysts, carbon nanotubes (CNTs) and other carbon‐based nanomaterials show great promise for some important chemical reactions, such as the selective oxidation of cyclohexane (C6H12). Due to the lack of fundamental understanding of carbon catalysis in liquid‐phase reactions, we have sought to unravel the role of CNTs in the catalytic oxidation of C6H12through a combination of kinetic analysis, in situ spectroscopy, and density functional theory. The catalytic effect of CNTs originates from a weak interaction between radicals and their graphene skeletons, which confines the radicals around their surfaces. This, in turn, enhances the electron‐transfer catalysis of peroxides to yield the corresponding alcohol and ketone.
Arylation with Unsymmetrical Diaryliodonium Salts: A Chemoselectivity Study
Authors: Malmgren Joel , Santoro Stefano , Jalalian Nazli , Himo Fahmi , Olofsson Berit 
Published: June 2013

AbstractPhenols, anilines, and malonates have been arylated under metal‐free conditions with twelve aryl(phenyl)iodonium salts in a systematic chemoselectivity study. A new “anti‐ortho effect” has been identified in the arylation of malonates. Several “dummy groups” have been found that give complete chemoselectivity in the transfer of the phenyl moiety, irrespective of the nucleophile. An aryl exchange in the diaryliodonium salts has been observed under certain arylation conditions. DFT calculations have been performed to investigate the reaction mechanism and to elucidate the origins of the observed selectivities. These results are expected to facilitate the design of chiral diaryliodonium salts and the development of catalytic arylation reactions that are based on these sustainable and metal‐free reagents.
The role of person and organizational variables in the three component model of occupational commitment
Authors: Lin Shu‐Huei , Huang Liang‐Chih , Chang Chiung‐Chuan , Lin Chiou‐Shiu , Chang Po‐Chien , Chen Pei‐Fan 
Published: June 2013

AbstractWe add to the small number of studies that have used the Meyer, Allen, and Smith (1993) three component model to better understand occupational commitment. A series of demographic (age, education), dispositional (emotional intelligence), and organizational variables (human resources practices and perceived organizational support) were examined for their relationship to occupational commitment. Our relatively small set of variables, from 431 debt‐collection employees and their supervisors at 34 banks in Taiwan, accounted for substantial variance in each of the commitment facets. In the context of the entire set of variables, perceived organizational support was the strongest predictor across all three forms of occupational commitment. Other variables (e.g., age, emotional intelligence) were of predictive value for a subset of the components only. Copyright © 2013 ASAC. Published by John Wiley & Sons, Ltd.
Beyond clusters: How regional geographic signature affects firm value and risk
Authors: Bell Geoffrey G. , Deng Saiying 
Published: June 2013

AbstractExisting studies examining how geography affects firm outcomes primarily consider how clusters affect performance. We examine how regional geographic signature—industry clusters, regional economic diversity, region size, and regional innovativeness—affects firm value and systematic and unsystematic risk using a sample of publicly traded American bank holding companies. After controlling for endogeneity of clusters, we find that locating in large and innovative regions enhances firm value, while locating in clusters and diversifying into many regions reduces value. Clusters reduce systematic risk and increase unsystematic risk, while economic diversity and innovativeness increase systematic risk. Thus, geographic locales exert multifaceted influences on value and risk, and we need to consider more than industry clusters and geographic diversification when considering geographic influence. Copyright © 2013 ASAC. Published by John Wiley & Sons, Ltd.
Recent Developments of 19‐Nor‐1,25‐dihydroxyvitamin D3 Analogues
Authors: Zhang Can‐Fei , Wan Ren‐Zhong , Liu Zhao‐Peng 
Published: June 2013

AbstractThe vitamin D hormone, 1α,25‐dihydroxyvitamin D3 [1,25‐(OH)2D3], exerts its hormonal effects predominantly on intestine, bone, and kidney, where it plays a crucial role in calcium and phosphorus homeostasis and bone mineralization. In addition to its classical actions, 1,25(OH)2D3 exerts pleiotropic effects in a wide variety of target tissues and cell types, often in an autocrine/paracrine fashion. These biological activities of 1,25(OH)2D3 have suggested a multitude of potential therapeutic applications for the vitamin D hormone in the treatment of hyperproliferative disorders (e.g. cancer and psoriasis), immune dysfunction (autoimmune diseases), and endocrine disorders (e.g. hyperparathyroidism). However, the calcemic effects induced by 1,25(OH)2D3—hypercalcemia, increased bone resorption, and soft tissue calcification—limit the use of the natural ligand in these clinical applications. Therefore, numerous 1,25(OH)2D3 analogues have been synthesized with the intent of producing therapeutic agents devoid of hypercalcemic and hyperphosphatemic side effects. To this aim, much attention has been focused on the development of 19‐nor‐vitamin D3 derivatives that lack the ring‐A exocyclic methylene group (C19). In this review, the 19‐nor‐1,25(OH)2D3 analogues are classified according to modifications made at the A‐ring, the side chain, or both the A‐ring and side chain, as well as other positions. The biological activities of these 19‐nor‐1,25(OH)2D3 analogues are summarized and their structure–activity relationships and binding features with the vitamin D receptor (VDR) are discussed.
Accelerating virtual high‐throughput ligand docking: current technology and case study on a petascale supercomputer
Authors: Ellingson Sally R. , Dakshanamurthy Sivanesan , Brown Milton , Smith Jeremy C. , Baudry Jerome 
Published: June 2013

SUMMARYIn this paper, we give the current state of high‐throughput virtual screening. We describe a case study of using a task‐parallel Message Passing Interface version of AutoDock4 to run a virtual high‐throughput screen of one million compounds on the Jaguar Cray XK6 Supercomputer at Oak Ridge National Laboratory. We include a description of scripts developed to increase the efficiency of the predocking file preparation and postdocking analysis. A detailed tutorial, scripts, and source code for this Message Passing Interface version of AutoDock4 are available online at http://www.bio.utk.edu/baudrylab/autodockmpi.htm. Copyright © 2013 John Wiley & Sons, Ltd.
Electrochemistry of Single Metalloprotein and DNA‐Based Molecules at Au(111) Electrode Surfaces
Authors: Salvatore Princia , Zeng Dongdong , Karlsen Kasper K. , Chi Qijin , Wengel Jesper , Ulstrup Jens 
Published: June 2013

AbstractWe have briefly overviewed recent efforts in the electrochemistry of single transition metal complex, redox metalloprotein, and redox‐marked oligonucleotide (ON) molecules. We have particularly studied self‐assembled molecular monolayers (SAMs) of several 5′‐C6‐SH single‐ (ss) and double‐strand (ds) ONs immobilized on Au(111) electrode surfaces via AuS bond formation, using a combination of nucleic acid chemistry, electrochemistry and electrochemically controlled scanning tunnelling microscopy (in situ STM). Ds ONs stabilized by multiply charged cations and locked nucleic acid (LNA) monomers have been primary targets, with a view on stabilizing the ds‐ONs and improving voltammetric signals of intercalating electrochemical redox probes. Voltammetric signals of the intercalator anthraquinone monosulfonate (AQMS) at ds‐DNA/Au(111) surfaces diluted by mercaptohexanol are significantly sharpened and more robust in the presence than in the absence of [Co(NH3)6]3+. AQMS also displays robust Faradaic voltammetric signals specific to the ds form on binding to similar LNA/Au(111) surfaces, but this signal only evolves after successive voltammetric scanning into negative potential ranges. Triply charged spermidine (Spd) invokes itself a strong voltammetric signal, which is specific to the ds form and fully matched sequences. This signal is of non‐Faradaic, capacitive origin but appears in the same potential range as the Faradaic AQMS signal. In situ STM shows that molecular scale structures of the size of Spd‐stabilized ds‐ONs are densely packed over the Au(111) surface in potential ranges around the capacitive peak potential.
Testing potential selective agents acting on leaf shape inIpomoea hederacea: predictions based on an adaptive leaf shape cline
Authors: Campitelli Brandon E. , Stinchcombe John R. 
Published: June 2013

AbstractLeaf shape is a highly variable phenotype, and is likely influenced by many sources of selection.Ipomoea hederaceaexhibits an adaptive latitudinal cline in leaf shape, which is controlled by a singleMendelian locus: lobed individuals dominate the north with entire‐shaped individuals mostly in the south. We test if the following candidate selective agents, suggested by the literature, are responsible for the cline: differential insect herbivory, genetic correlations with other clinal traits like flowering time and growth rate, and thermoregulatory differences. We planted 1680 F3individuals, segregating for leaf shape, in the north ofI. hederacea'srange, where we expected lobed genotypes to have higher fitness. Individuals were assigned to insect removal or control treatments, and we scored herbivory, flowering time, growth rate, leaf temperature, and fitness (seed number). Herbivory, flowering, and growth rate had significant fitness effects, but none differed between leaf shapes. Lobed leaves were consistently warmer at night, but no performance advantage was detected. Finally, we detected no overall fitness differences between leaf shape genotypes, whether we controlled for other traits under selection or not. Our data suggest these candidate selective agents may not be important contributors to the cline, and alternative approaches to understanding the mechanisms maintaining the leaf shape cline inI. hederaceamay be necessary.
Mechanism of Shaft End‐to‐End Voltage Generation by Asymmetry in an Inverter‐Driven Motor
Authors: Asakura Yusuke , Akagi Hirofumi 
Published: June 2013

SummaryThis paper deals with the shaft end‐to‐end voltage resulting from asymmetric stray capacitances in an inverter‐driven motor. The origin of the voltage can be any of the following: a ground leakage current, dielectric breakdown in the bearings, and asymmetric stray capacitances on the stator windings. The third origin seems to be related to the differential‐mode current, but the details of the relationship have not been clarified. In this study, differential‐mode tests are carried out on an ungrounded motor rated at 400 V and 15 kW, and shaft end‐to‐end voltage generation by the asymmetric stray capacitances is theoretically discussed. Finally, a winding model is presented for the purpose of understanding the mechanism responsible for the shaft end‐to‐end voltage. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 185(1): 48–56, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22415
Disposable on‐chip microfluidic system for buccal cell lysis, DNA purification, and polymerase chain reaction
Authors: Cho Woong , Maeng Joon‐Ho , Ahn Yoomin , Hwang Seung Yong 
Published: June 2013

This paper reports the development of a disposable, integrated biochip for DNA sample preparation and PCR. The hybrid biochip (25 × 45 mm) is composed of a disposable PDMS layer with a microchannel chamber and reusable glass substrate integrated with a microheater and thermal microsensor. Lysis, purification, and PCR can be performed sequentially on this microfluidic device. Cell lysis is achieved by heat and purification is performed by mechanical filtration. Passive check valves are integrated to enable sample preparation and PCR in a fixed sequence. Reactor temperature is needed to lysis and PCR reaction is controlled within ±1°C by PID controller of LabVIEW software. Buccal epithelial cell lysis, DNA purification, and SY158 gene PCR amplification were successfully performed on this novel chip. Our experiments confirm that the entire process, except the off‐chip gel electrophoresis, requires only approximately 1 h for completion. This disposable microfluidic chip for sample preparation and PCR can be easily united with other technologies to realize a fully integrated DNA chip.
Thermophysical properties of polyurethane foams and their melts
Authors: Pau D. S. W. , Fleischmann C. M. , Spearpoint M. J. , Li K. Y. 
Published: June 2013

AbstractThe thermal conductivity (λ) and the specific heat (cp) of seven polyurethane foam formulations and their melts are obtained using a transient plane source technique called the Hot Disk experiment. In the experiment, the Hot Disk sensor is sandwiched by the samples and acts as both a heat source and a temperature sensor. The fundamental assumption is that throughout the experiment, the heat from the sensor does not penetrate beyond the boundaries of the sample. The suitable sample dimensions and sensor radius are determined from the preliminary calculations. Through sensitivity analysis, the appropriate measuring time and output power for the experiments are established. For polyurethane foams, λ ranges from 0.048 to 0.050 W/m K, and cp ranges from 2359 to 2996 J/kg K. For melts, λ ranges from 0.186 to 0.200 W/m K, and cp ranges from 1958 to 2076 J/kg K. When foam decomposes into melts, the changes in thermophysical properties shows λ increases by approximately 300%, whereas cp decreases by approximately 20%. On the basis of these changes, the collapse of the foam structure into melt appears to improve the heat transfer through the material. Copyright © 2013 John Wiley & Sons, Ltd.
Successful single‐session endosonography‐based endoscopic retrograde cholangiopancreatography without fluoroscopy in pregnant patients with suspected choledocholithiasis: a case series
Authors: Vohra Sheba , Holt Edward W. , Bhat Yasser M. , Kane Steve , Shah Janak N. , Binmoeller Kenneth F. 
Published: June 2013

AbstractPurposeSame session endosonography (EUS) immediately prior to scheduled endoscopic retrograde cholangiopancreatography (ERCP) may eliminate the need for ERCP and its associated risks in pregnant patients with no evidence of choledocholithiasis on EUS. In patients with choledocholithiasis, EUS provides information regarding the location, size and number of stones present, which helps guide biliary interventions and confirm stone clearance without the use of fluoroscopy.MethodsWe retrospectively identified 10 pregnant patients referred to our tertiary endoscopy center for suspected choledocholithiasis between June 2008 and January 2012. All patients underwent same‐session EUS‐based ERCP.ResultsOf 10 pregnant patients managed with EUS‐guided ERCP, six were found to have common bile duct stones and went on to ERCP. Four patients with no evidence of choledocholithiasis on EUS did not undergo ERCP. Patients with confirmed choledocholithiasis underwent ERCP without the use of fluoroscopy using the additional information provided by EUS.ConclusionsSame‐session EUS immediately prior to scheduled ERCP may eliminate the need for ERCP and its risks in pregnant patients with no evidence of choledocholithiasis on EUS. In patients with confirmed choledocholithiasis, EUS provided additional information regarding the location, number and size of bile duct stones, which enabled the successful clearance of the bile duct without the use of fluoroscopy.
On the cyclic material stability of shape memory polymer
Authors: Mogharebi S. , Kazakeviciute‐Makovska R. , Steeb H. , Eggeler G. , Neuking K. 
Published: June 2013

AbstractThis paper presents the experimental study of a Thermoplastic Polyurethane (TPU) based Shape Memory Polymer (SMP) produced from granulates of commercially available EstaneTM ETE75DT3 NAT022 (Oevel Westerlo, Belgium). This polymer is characterized by Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Thermal Analysis (DMTA). The experimental procedure was designed to study the functional properties (shape fixity and shape recovery) of this shape memory polymer in multiple programming/shape‐recovery cycles at three different programming temperatures. The results are displayed in the temperature‐stress‐strain space with focus on parameters which characterize the functional fatigue and material stability of the tested polymer during consecutive cycles. These results give a better understanding of this material class that has a potential for actuator applications in engineering.
Experimental testing of wood‐concrete and steel‐concrete composite elements in comparison with numerical testing
Authors: Smilovic M. , Cubela D. , Radnic J. , Harapin A. 
Published: June 2013

AbstractThe paper presents the results of experimental tests with a numerical comparison of some typical composite element systems. Two different kinds of elements were tested: composite steel‐concrete and composite wood‐concrete elements. Deflections at midspan under monotonously increasing static load on simply supported beams were measured. The affects of different types of composite connections on the results were researched. In numerical tests the structure was modeled with two‐dimensional plane elements. The composite surface was modeled with two‐dimensional contact (interface) elements for the continuous connection simulation and modified beam elements for the discrete connection simulation. The applied material models include the most important nonlinear effects of concrete, steel and wood behavior, as well as the nonlinear behavior of the composite surface at the connection. The achieved results of the developed numerical model were compared with the results obtained through the experimental test.
Biodegradable and thermosensitive micelles of amphiphilic polyaspartamide derivatives containing aromatic groups for drug delivery
Authors: Ma Yingying , Jiang Xulin , Zhuo Renxi 
Published: June 2013

ABSTRACTThe preparation, characterization, release, and in vitro cytotoxicity of a biodegradable polymeric micellar formulation of paclictaxel (PTX) were investigated. The micelles based on thermosensitive and degradable amphiphilic polyaspartamide derivatives containing pendant aromatic structures (phe‐g‐PHPA‐g‐mPEG) were prepared by a quick heating method without using toxic organic solvent. Dynamic light‐scattering results show that the micelles are stable upon dilution under physiological conditions and the destabilization of the micelles is pH‐dependent and the phe‐g‐PHPA‐g‐mPEG polymers are biodegradable. PTX was loaded into the phe‐g‐PHPAs‐g‐mPEG micelles with encapsulation efficiency of >90%, resulting in a high drug loading content (up to 29%). PTX‐loaded micelles had a mean size around 70 nm with narrow size distribution (polydispersity index, <0.1). The PTX‐loaded micelles showed sustained drug release and obvious anticancer activity similar to Taxol against HepG2 cells, whereas blank micelles were nontoxic. The present results suggest that the thermosensitive and biodegradable phe‐g‐PHPA‐g‐mPEG micelles are a promising delivery system for the hydrophobic drugs. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3917–3924