bluuebunny/crossref_metadata_2025_split huggingface dataset:
The properties (rheological, dielectric, and mechanical) and microtopography of spherical fullerene‐filled poly(arylene ether nitrile) nanocomposites
Authors: Yang Wei , Yang Xulin , Pu Zejun , Xu Mingzhen , Liu Xiaobo 
Published: November 2013

AbstractPoly (arylene ether nitrile)/fullerene (PEN/fullerene) nanocomposites were prepared by a facile solution‐cast method and the rheological, dielectric, mechanical, and morphological properties of the resulted nanocomposites were systematically studied and compared. Rheological studies showed PEN/fullerene nanocomposites percolation network formed at fullerene containing of 1.50 wt %, when the shear frequency was fixed at 0.1 Hz, the fitted rheological percolation threshold was about 1.55 wt %, very close to the experimental observations. The dielectric transaction occurs when the fullerene loading reached 1.50 wt %, that is very close to its rheological percolation threshold. At this point, PEN/fullerene nanocomposites also showed the optimal mechanical properties with a tensile strength of 93.6 MPa and modulus of 1951.5 MPa, which is increased by 27% and 15% compared with the pure PEN. SEM and TEM images have manifested the separate fullerene aggregated to fullerene bundles in PEN/fullerene nanocomposites, and the dispersion of fullerene bundles begin to go bad when the containing above 1.50 wt %. The PEN/fullerene nanocomposites can be widely used due to its excellent dielectric and mechanical performance. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40100.
Tacrine–Flurbiprofen Hybrids as Multifunctional Drug Candidates for the Treatment of Alzheimer's Disease
Authors: Chen Yao , Sun Jianfei , Peng Sixun , Liao Hong , Zhang Yihua , Lehmann Jochen 
Published: November 2013

AbstractFive tacrine–flurbiprofen hybrid compounds (3a–e) were synthesized as multi‐target‐directed compounds for the treatment of Alzheimer's disease. Compared to tacrine, two compounds (3dand3e) showed better acetylcholinesterase (AChE) inhibitory activity and others (3b–e) better or the same butyrylcholinesterase (BuChE) inhibitory activity. Notably,3dshowed a mixed‐type inhibitory action for AChE, indicating a “dual‐binding site action” of both toward the catalytic active site (CAS) and the peripheral anionic site (PAS), whereas for BuChE, a competitive inhibitory action was observed. Furthermore, a cell‐based assay on amyloid‐β inhibition demonstrated that the selected target compound3deffectively inhibits the formation of amyloid‐βin vitro.
A Facile Access to Polyfunctional Oxygen‐containing Heterocycles via Intramolecularly Formed Protic Oxonium Ylide Trapping Processes
Authors: Guo Xin , Liu Wei , Hu Wenhao 
Published: November 2013

AbstractBased on the assumption that intramolecularly formed protic oxonium ylides could be trapped by electrophiles, transition‐metal‐catalyzed reactions of diazoesters bearing a primary hydroxy group with electron‐deficient aldehydes and isatins were examined. Good to high chemo‐ and diastereoselectivities were achieved with reactions catalyzed by Cu(hfacac)2. The reactions were assumed to occur via tandem intramolecular protic oxonium ylide formation and subsequent aldol‐type addition. They not only provided an efficient entry to 3‐substituted 1,4‐dioxan‐2‐one heterocycles with at least one quaternary carbon center but also provided experimental evidence for a stepwise pathway for the transition‐metal‐catalyzed intramolecular OH insertion of diazo compounds.
Carbon Nanotube‐Enhanced Polarization of Fluorescent Peptides: A Novel Amplification Strategy for Homogeneous Detection of Proteases
Authors: Huang Yong , Hu Kun , Zhao Shulin , Li Mei , Chen Zhen‐Feng , Lv Qiuju , Liang Hong 
Published: November 2013

AbstractA new fluorescence polarization (FP) amplification strategy based on the use of multiwalled carbon nanotubes (MWCNTs) as the FP enhancer was developed for the simple, sensitive, and universal monitoring of protease activity in homogeneous solution. A fluorophore‐labeled peptide that includes a protease‐cleavable element and ten histidine residues for binding MWCNTs is adsorbed on MWCNTs through strong π–π stacking and electrostatic interactions. When the fluorophore‐labeled peptide/MWCNT complexes are exposed to a protease target, specific peptide cleavage by the protease target occurs, thus releasing fragments carrying the fluorophore from the surface of MWCNTs, which in turn results in a significant decrease in the FP value. The detection limits of this assay for two proteases, thrombin and chymotrypsin (CTP), were estimated to be 0.5 pM and 0.3 pM, respectively. In addition, it is also demonstrated that this MWCNT‐enhanced FP assay is suitable for protease inhibitor screening.
Optimization of pedestrian phase patterns at signalized intersections: a multi‐objective approach
Authors: Ma Wanjing , Liu Yue , Head K. Larry 
Published: November 2013

SUMMARYThis paper presents a multi‐objective optimization model and its solution algorithm for optimization of pedestrian phase patterns, including the exclusive pedestrian phase (EPP) and the conventional two‐way crossing (TWC) at an intersection. The proposed model will determine the optimal pedestrian phase pattern and the corresponding signal timings at an intersection to best accommodate both vehicular traffic and pedestrian movements. The proposed model is unique with respect to the following three critical features: (1) proposing an unbiased performance index for comparison of EPP and TWC by explicitly modeling the pedestrian delay under the control of TWC and EPP; (2) developing a multi‐objective model to maximize the utilization of the available green time by vehicular traffic and pedestrian under both EPP or TWC; and (3) designing a genetic algorithm based heuristic algorithm to solve the model. Case study and sensitivity analysis results have shown the promising property of the proposed model to assist traffic practitioners, researchers, and authorities in properly selecting pedestrian phase patterns at signalized intersections. Copyright © 2013 John Wiley & Sons, Ltd.
Prenatal ultrasound findings observed in the Wolf‐hirschhorn syndrome: Data from the registry of congenital malformations in auvergne
Authors: Debost‐Legrand Anne , Goumy Carole , Laurichesse‐Delmas Hélène , Déchelotte Pierre , Beaufrère Anne‐Marie , Lémery Didier , Francannet Christine , Gallot Denis 
Published: November 2013

BACKGROUNDWolf‐Hirschhorn syndrome (WHS) is associated with facial dysmorphism including high forehead, high nasal bridge, hypertelorism and severe mental retardation. WHS results from a 4p16.3 deletion. Only a small number of reports have been made on the prenatal ultrasound findings observed in WHS.CASESHere we report our experience on 10 cases of WHS ascertained prenatally between 1983 and 2009 through the CEMC‐Auvergne registry of congenital malformations.CONCLUSIONThe assumption that a “Greek warrior helmet” facies is pathognomonic of WHS could lead to misdiagnosis. Other clinical findings such as severe and early onset intrauterine growth retardation, facial dysmorphism (high forehead, high nasal bridge, low‐set ears, micrognathia, hypertelorism), atrial or ventricular septal defect, and renal dysplasia should help obstetricians to suspect the diagnosis of WHS prenatally. Birth Defects Research (Part A), 97:806–811, 2013. © 2013 Wiley Periodicals, Inc.
Carbimazole/methimazole embryopathy in siblings: A possible genetic susceptibility
Authors: Goel Himanshu , Dudding Tracy 
Published: November 2013

BACKGROUNDThe teratogenic effects of antenatal exposure of antithyroid drugs, carbimazole and methimazole have been well reported in the literature. These comprise of typical facial features and a wide variety of malformations such as choanal atresia, tracheo‐esophageal anomalies, congenital heart disease and ectodermal defects. However, the longitudinal studies have failed to establish the consistent teratogenicity of these drugs.CASESwe report here two siblings with physical features consistent with carbimazole/methimazole embryopathy. We also describe previously unreported minor dental anomalies in these siblings with antenatal exposure of carbimazole.CONCLUSIONGenerally, only a small proportion of prenatally exposed children have the typical manifestations, and the presence in siblings supports a possible hereditary susceptibility to carbimazole/ methimazole embryopathy. This highlights the importance of recognizing this diagnosis before a subsequent pregnancy. Birth Defects Research (Part A) 97:755–758, 2013. © 2013 Wiley Periodicals, Inc.
Influence of extremely low frequency, low energy electromagnetic fields and combined mechanical stimulation on chondrocytes in 3‐D constructs for cartilage tissue engineering
Authors: Hilz Florian M. , Ahrens Philipp , Grad Sibylle , Stoddart Martin J. , Dahmani Chiheb , Wilken Frauke L. , Sauerschnig Martin , Niemeyer Philipp , Zwingmann Jörn , Burgkart Rainer , von Eisenhart‐Rothe Rüdiger , Südkamp Norbert P. , Weyh Thomas , Imhoff Andreas B. , Alini Mauro , Salzmann Gian M. 
Published: November 2013

AbstractArticular cartilage, once damaged, has very low regenerative potential. Various experimental approaches have been conducted to enhance chondrogenesis and cartilage maturation. Among those, non‐invasive electromagnetic fields have shown their beneficial influence for cartilage regeneration and are widely used for the treatment of non‐unions, fractures, avascular necrosis and osteoarthritis. One very well accepted way to promote cartilage maturation is physical stimulation through bioreactors. The aim of this study was the investigation of combined mechanical and electromagnetic stress affecting cartilage cells in vitro. Primary articular chondrocytes from bovine fetlock joints were seeded into three‐dimensional (3‐D) polyurethane scaffolds and distributed into seven stimulated experimental groups. They either underwent mechanical or electromagnetic stimulation (sinusoidal electromagnetic field of 1 mT, 2 mT, or 3 mT; 60 Hz) or both within a joint‐specific bioreactor and a coil system. The scaffold‐cell constructs were analyzed for glycosaminoglycan (GAG) and DNA content, histology, and gene expression of collagen‐1, collagen‐2, aggrecan, cartilage oligomeric matrix protein (COMP), Sox9, proteoglycan‐4 (PRG‐4), and matrix metalloproteinases (MMP‐3 and ‐13). There were statistically significant differences in GAG/DNA content between the stimulated versus the control group with highest levels in the combined stimulation group. Gene expression was significantly higher for combined stimulation groups versus static control for collagen 2/collagen 1 ratio and lower for MMP‐13. Amongst other genes, a more chondrogenic phenotype was noticed in expression patterns for the stimulated groups. To conclude, there is an effect of electromagnetic and mechanical stimulation on chondrocytes seeded in a 3‐D scaffold, resulting in improved extracellular matrix production. Bioelectromagnetics. 35:116–128, 2014. © 2013 Wiley Periodicals, Inc.
Simulation study of delivery of subnanosecond pulses to biological tissues with an impulse radiating antenna
Authors: Guo Fei , Yao Chenguo , Bajracharya Chandra , Polisetty Swetha , Schoenbach Karl H. , Xiao Shu 
Published: November 2013

AbstractWe have numerically studied the delivery of subnanosecond pulsed radiation to biological tissues for bioelectric applications. The antenna fed by 200 ps pulses uses an elliptical reflector in conjunction with a dielectric lens. Two numerical targets were studied: one was a hemispherical tissue with a resistivity of 0.3–1 S/m and a relative permittivity of 9–70 and the other was a realistic human head model (HUGO). The electromagnetic simulation shows that despite tissue heterogeneity of the human head, the electric field converges to a spot 8 cm in depth and the spot volume is approximately 1 cm × 2 cm × 1 cm in both cases when using only the reflector and a lens as an addition. Rather than increasing as it approaches the converging point, the electric field decreases strongly with distance from the skin to the converging point due to tissue resistive loss. The electric field distribution, however, can be reversed by making the dielectric lens lossy with the two innermost layers being partially resistive. The lossy lens causes an attenuation of the electric field near the axis, but the electric field generated by the waves which pass the lens at a wider angles compensate for this loss. A local maximum electric field in a deeper region of the tissue may form with the lossy lens. The study shows that it is possible to generate the desired electric field distribution in the complex biological target by modifying the dielectric properties of the lens used in conjunction with the reflector antenna. Bioelectromagnetics. 35:145–159, 2014. © 2013 Wiley Periodicals, Inc.
Molecular modeling of ErbB4/HER4 kinase in the context of the HER4 signaling network helps rationalize the effects of clinically identified HER4 somatic mutations on the cell phenotype
Authors: Telesco Shannon E. , Vadigepalli Rajanikanth , Radhakrishnan Ravi 
Published: November 2013

AbstractIn the ErbB/HER family of receptor tyrosine kinases, the deregulation of the EGFR/ErbB1/HER1, HER2/ErbB2, and HER3/ErbB3 kinases is associated with several cancers, while the HER4/ErbB4 kinase has been shown to play an anti‐carcinogenic role in certain tumors. We present molecular and network models of HER4/ErbB4 activation and signaling in order to elucidate molecular mechanisms of activation and rationalize the effects of the clinically identified HER4 somatic mutants. Our molecular‐scale simulations identify the important role played by the interactions within the juxtamembrane region during the activation process. Our results also support the hypothesis that the HER4 mutants may heterodimerize but not activate, resulting in blockage of the HER4‐STAT5 differentiation pathway, in favor of the proliferative PI3K/AKT pathway. Translating our molecular simulation results into a cellular pathway model of wild type versus mutant HER4 signaling, we are able to recapitulate the major features of the PI3K/AKT and JAK/STAT activation downstream of HER4. Our model predicts that the signaling downstream of the wild type HER4 is enriched for the JAK‐STAT pathway, whereas downstream of the mutant HER4 is enriched for the PI3K/AKT pathway. HER4 mutations may hence constitute a cellular shift from a program of differentiation to that of proliferation.
Flocculating Zymomonas mobilis is a promising host to be engineered for fuel ethanol production from lignocellulosic biomass
Authors: Zhao Ning , Bai Yun , Liu Chen‐Guang , Zhao Xin‐Qing , Xu Jian‐Feng , Bai Feng‐Wu 
Published: November 2013

AbstractWhereas Saccharomyces cerevisiae uses the Embden‐Meyerhof‐Parnas pathway to metabolize glucose, Zymomonas mobilis uses the Entner‐Doudoroff (ED) pathway. Employing the ED pathway, 50% less ATP is produced, which could lead to less biomass being accumulated during fermentation and an improved yield of ethanol. Moreover, Z. mobilis cells, which have a high specific surface area, consume glucose faster than S. cerevisiae, which could improve ethanol productivity. We performed ethanol fermentations using these two species under comparable conditions to validate these speculations. Increases of 3.5 and 3.3% in ethanol yield, and 58.1 and 77.8% in ethanol productivity, were observed in ethanol fermentations using Z. mobilis ZM4 in media containing ∼100 and 200 g/L glucose, respectively. Furthermore, ethanol fermentation bythe flocculating Z. mobilis ZM401 was explored. Although no significant difference was observed in ethanol yield and productivity, the flocculation of the bacterial species enabled biomass recovery by cost‐effective sedimentation, instead of centrifugation with intensive capital investment and energy consumption. In addition, tolerance to inhibitory byproducts released during biomass pretreatment, particularly acetic acid and vanillin, was improved. These experimental results indicate that Z. mobilis, particularly its flocculating strain, is superior to S. cerevisiae as a host to be engineered for fuel ethanol production from lignocellulosic biomass.
Retrograde approach to coronary chronic total occlusion via an occluded saphenous bypass graft: a case report
Authors: Alhejily Wesam A. , Kong David F. , Magnus Ohman E. 
Published: November 2013

Key Clinical MessageRetrograde coronary intervention of chronic total coronary occlusion remains challenging. We describe a successful retrograde intervention of chronically occluded right coronary artery ostium via an occluded vein graft. An occluded saphenous vein graft can be a useful means to access the distal coronary bed, enabling delivery of retrograde percutaneous coronary intervention (PCI) equipment.
Effect of Cation–π Interactions and Steric Bulk on the Catalytic Action of Oxidosqualene Cyclase: A Case Study of Phe728 of β‐Amyrin Synthase from Euphorbia tirucalli L
Authors: Ito Ryousuke , Hashimoto Ippei , Masukawa Yukari , Hoshino Tsutomu 
Published: November 2013

AbstractThe function of the active‐site residues of oxidosqualene cyclases (OSCs) has been presumed mainly in light of the product distribution; however, not much research has been performed into the enzymatic activity of mutated OSCs. β‐Amyrin, which is widely found in the plant kingdom, is classified as an OSC; mutational studies on β‐amyrin cyclase are very limited. Six site‐specific mutations targeted at the Phe728 residue of Euphorbia tirucalli β‐amyrin synthase (EtAS) were constructed to inspect the function of this aromatic residue. We developed a simple method to evaluate the in vivo enzymatic activity; the expression levels of EtASs and the quantities of the cyclic triterpenes produced were determined by use of western blot and GC analyses, respectively. Measurement of the relative in vivo activity of the mutants versus that of the wild‐type enzyme showed that the Ala, Met, His, and Trp variants had significantly decreased activity, but that the Tyr mutant had a high activity, which was nearly the same as that of the wild‐type enzyme. In contrast to Tyr, Ala and Met possess no π‐electrons; thus, the role of Phe728 is to stabilize the cationic intermediates, resulting in facilitation of the ring‐expansion processes, especially by stabilizing the secondary cations. The decreased activity of the Trp mutant is ascribed to the introduction of a large steric bulk, leading to looser binding of oxidosqualene in the Trp variant. The His mutant afforded germanicol as the main product, indicating that the Phe residue is located near the D/E‐ring‐formation site. Changes in the steric bulk gave some cationic intermediates, resulting in the formation of 13 cyclic triterpenes, including an unnatural triterpene, (17E)‐dammara‐17(20),24‐dien‐3β‐ol, and isoursenol, which has rarely been found in nature. In this study, we provide the first experimental evidence that cation–π interactions play a key role in the catalytic action of OSCs.
La2@Cs(17 490)‐C76: A New Non‐IPR Dimetallic Metallofullerene Featuring Unexpectedly Weak Metal–Pentalene Interactions
Authors: Suzuki Mitsuaki , Mizorogi Naomi , Yang Tao , Uhlik Filip , Slanina Zdenek , Zhao Xiang , Yamada Michio , Maeda Yutaka , Hasegawa Tadashi , Nagase Shigeru , Lu Xing , Akasaka Takeshi 
Published: November 2013

AbstractAlthough all the pure‐carbon fullerene isomers above C60 reported to date comply with the isolated pentagon rule (IPR), non‐IPR structures, which are expected to have different properties from those of IPR species, are obtainable either by exohedral modification or by endohedral atom doping. This report describes the isolation and characterization of a new endohedral metallofullerene (EMF), La2@C76, which has a non‐IPR fullerene cage. The X‐ray crystallographic result for the La2@C76/[NiII(OEP)] (OEP=octaethylporphyrin) cocrystal unambiguously elucidated the Cs(17 490)‐C76 cage structure, which contains two adjacent pentagon pairs. Surprisingly, multiple metal sites were distinguished from the X‐ray data, which implies dynamic behavior for the two La3+ cations inside the cage. This dynamic behavior was also corroborated by variable‐temperature 139 La NMR spectroscopy. This phenomenon conflicts with the widely accepted idea that the metal cations in non‐IPR EMFs invariably coordinate strongly with the negatively charged fused‐pentagon carbons, thereby providing new insights into modern coordination chemistry. Furthermore, our electrochemical and computational studies reveal that La2@Cs(17 490)‐C76 has a larger HOMO–LUMO gap than other dilanthanum‐EMFs with IPR cage structures, such as La2@D3h(5)‐C78 and La2@Ih(7)‐C80, which implies that IPR is no longer a strict rule for EMFs.
Mixed Oligoureas Based on Constrained Bicyclic and Acyclic β‐Amino Acids Derivatives: On the Significance of the Subunit Configuration for Folding
Authors: André Christophe , Legrand Baptiste , Moulat Laure , Wenger Emmanuel , Didierjean Claude , Aubert Emmanuel , Averlant‐Petit Marie Christine , Martinez Jean , Amblard Muriel , Calmes Monique 
Published: November 2013

AbstractThe combination of a non‐functionalized constrained bicyclo[2.2.2]octane motif along with urea linkages allowed the formation of a highly rigid 2.512/14 helical system both in solution and the solid state. In this work, we aimed at developing stable and functionalized systems as promising materials for biological applications in investigating the impact of this constrained motif and its configuration on homo and heterochiral mixed‐oligourea helix formation. Di‐, tetra‐, hexa‐, and octa‐oligoureas alternating the highly constrained bicyclic motif of (R) or (S) configuration with acyclic (S)‐β3‐amino acid derivatives were constructed. Circular dichroism (CD), NMR experiments, and the X‐ray crystal structure of the octamer unequivocally proved that the alternating heterochiral R/S sequences form a stable left‐handed 2.5‐helix in contrast to the mixed (S/S)‐oligoureas, which did not adopt any defined secondary structure. We observed that the (−)‐synclinal conformation around the CαCβ bond of the acyclic residues, although sterically less favorable than the (+)‐synclinal conformation, was imposed by the (R)‐bicyclic amino carbamoyl (BAC) residue. This highlighted the strong ability of the BAC residue to drive helical folding in heterochiral compounds. The role of the stereochemistry of the BAC unit was assessed and a model was proposed to explain the misfolding of the S/S sequences.
A Self‐Assembled Nanohybrid Composed of Fluorophore–Phenylamine Nanorods and Ag Nanocrystals: Energy Transfer, Wavelength Shift of Fluorescence and TPEF Applications for Live‐Cell Imaging
Authors: Kong Lin , Yang Jia‐xiang , Li Sheng‐li , Zhang Qiong , Xue Zhao‐ming , Zhou Hong‐ping , Wu Jie‐ying , Jin Bao‐kang , Tian Yu‐peng 
Published: November 2013

AbstractA fluorophore–phenylamine derivative (L) has been coupled with silver nanocrystals (NCs) to construct an L–Ag nanohybrid. Owing to synergic effects of the L and Ag components, the exciton–plasmon interactions between L and Ag increase the strength of the donor–acceptor interaction within the nanohybrid, a fact that results in an energy‐transfer process and further brings about a dramatic redshift of single‐photon absorption and fluorescence, and a decreased fluorescence FL lifetime. The coupling effect also leads to enhancement of a series of nonlinear optical properties, including two‐photon‐excited fluorescence (TPEF), two‐photon‐absorption (TPA) cross section (δ), two‐photon‐absorption coefficient (β), nonlinear refractive index (γ), and third order nonlinear optical susceptibility (χ(3)). The enhanced two‐photon fluorescence of the nanohybrid is proven to be potentially useful for two‐photon microscopy of live cells, such as HepG2. Moreover, cytotoxicity tests show that the low‐micromolar concentrations of the nanohybrid do not cause significant reduction in cell viability over a period of at least 24 h and should be safe for further biological studies.