bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of Platinum Dispersed on Reduced Graphene Oxide‐supported Tungsten Carbide via Sacrificial Cu Adlayers for Methanol Oxidation
Authors: Shi Meiqin , Zhao Di , Liu Weiming , Chu Youqun , Ma Chun'an 
Published: March 2014

AbstractReduced graphene oxide‐supported tungsten carbide composite (WC/RGO) was prepared by program‐controlled reduction‐carburization technique. Scanning electron microscope (SEM) and transmission electron microscope (TEM) show that WC nanoparticles with a narrow distribution (10–20 nm) are highly dispersed both on the edge and between the layers of RGO. And then it was used as a support to load different low contents (no more than 0.4 wt%) of Pt via sacrificial Cu adlayers. The morphology and the electrocatalytic activity of the prepared catalysts were characterized by TEM and cyclic voltammograms (CV), respectively. The results indicate that a small amount of isolated Pt atoms show low or even no activity for methanol oxidation. With the increasing deposition cycles, the content of Pt and the ensembles of neighboring Pt atoms are increased, which makes the onset potential shift negatively and mass current density increase. The results demonstrate that controllable amount of Pt can be deposited on WC/RGO by galvanic displacement with Cu, and the extent and domain of Pt loading affect the electrochemical performance. Meanwhile, this research also provides another route to prepare a catalyst with ultra low noble metal on WC/RGO for solving the problem of high cost of the catalyst.
Status of Dye Solar Cell Technology as a Guideline for Further Research
Authors: Hinsch Andreas , Veurman Welmoed , Brandt Henning , Flarup Jensen Katrine , Mastroianni Simone 
Published: March 2014

AbstractRecently, the first commercial dye solar cell (DSC) products based on the mesoscopic principle were successfully launched. Introduction to the market has been accompanied by a strong increase in patent applications in the field during the last four years, which is a good indication of further commercialization activity. Materials and cell concepts have been developed to such extent that easy uptake by industrial manufacturers is possible. The critical phase for broad market acceptance has therefore been reached, which implies focusing on standardization‐related research topics. In parallel the number of scientific publications on DSC is growing further (>3500 since 2012), and the range of new or renewed fundamental topics is broadening. A recent example is the introduction of the perovskite mesoscopic cell, for which an efficiency of 14.1 % has been certified. Thus, a growing divergence between market introduction and research could be the consequence. Herein, an attempt is made to show that such an unwanted divergence can be prevented, for example, by developing suitable reference‐type cell and module concepts as well as manufacturing routes. An in situ cell manufacturing concept that can be applied to mesoscopic‐based solar cells in a broader sense is proposed. As a guideline for future module concepts, recent results for large‐area, glass‐frit‐sealed DSC modules from efficiency studies (6.6 % active‐area efficiency) and outdoor analysis are discussed. Electroluminescence measurements are introduced as a quality tool. Another important point that is addressed is sustainability, which affects both market introduction and the direction of fundamental research.
Mineralocorticoid receptor signaling reduces numbers of circulating human naïve T cells and increases their CD62L, CCR7, and CXCR4 expression
Authors: Besedovsky Luciana , Linz Barbara , Born Jan , Lange Tanja 
Published: March 2014

The role of mineralocorticoid receptors (MRs) in human T‐cell migration is not yet understood. We have recently shown that the MR antagonist spironolactone selectively increases the numbers of circulating naïve and central memory T cells during early sleep, which is the time period in the 24 h cycle hallmarked by predominant MR activation. To investigate whether this effect is specific to spironolactone's blockade of MRs and to study the underlying molecular mechanisms, healthy humans were given the selective MR‐agonist fludrocortisone or placebo and numbers of eight T‐cell subsets and their CD62L and CXCR4 expression were analyzed. Fludrocortisone selectively reduced counts of naïve CD4+, central memory CD4+, and naïve CD8+ T cells and increased CXCR4 expression on the naïve subsets. In complementing in vitro studies, fludrocortisone enhanced CXCR4 and CD62L expression, which was counteracted by spironolactone. Incubation of naïve T cells with spironolactone alone reduced CD62L and CCR7 expression. Our results indicate a regulatory influence of MR signaling on human T‐cell migration and suggest a role for endogenous aldosterone in the redistribution of T‐cell subsets to lymph nodes, involving CD62L, CCR7, and CXCR4. Facilitation of T‐cell homing following sleep‐dependent aldosterone release might thus essentially contribute to sleep's well‐known role in supporting adaptive immunity.
Color‐Tunable Luminescence of Y4Si2N2O7:Ce3+, Tb3+, Dy3+ Phosphors Prepared by the Soft‐Chemical Ammonolysis Method
Authors: Geng Dongling , Li Kai , Lian Hongzhou , Shang Mengmeng , Zhang Yang , Wu Zhijian , Lin Jun 
Published: March 2014

AbstractCe3+‐, Tb3+‐, and Dy3+‐activated Y4Si2N2O7 phosphors have been prepared by the Pechini‐type sol–gel method followed by ammonolysis of the precursors. The phase purity, morphology, crystallization condition, chemical composition, and thermal stability of the products have been studied carefully by X‐ray diffraction (XRD), energy‐dispersive X‐ray (EDX), scanning electron microscopy (SEM), high‐resolution transmission electron microscopy (HRTEM), fourier‐transform infrared (FTIR), and thermogravimetry analysis (TGA) techniques. The photoluminescence (PL) and cathodoluminescence (CL) properties of Ce3+‐, Tb3+‐, and Dy3+‐doped Y4Si2N2O7 phosphors were also investigated. The electronic structure of Y4Si2N2O7 has been investigated by density‐functional theory methods. The calculations revealed that the nitrogen atom contributes more excited electrons than the O atom. The band gap has been calculated through the reflection spectrum of the Y4Si2N2O7 host. For Ce3+/Tb3+/Dy3+ singly doped Y4Si2N2O7 products, the phosphors give the typical emissions of the activators. The energy transfers from Ce3+ to Tb3+ and Dy3+ ions have been found and demonstrated through the PL spectra and luminescence decay times. The emission color of Y4Si2N2O7:Ce3+, Tb3+ and Y4Si2N2O7:Ce3+, Dy3+ samples can be tuned by energy transfer processes. Additionally, the temperature‐dependent PL properties and the degradation property of CL under continuous electron bombardment of the as‐synthesized phosphors prove that the Y4Si2N2O7 host has good stability. Therefore, the Y4Si2N2O7:Ce3+, Tb3+, Dy3+ phosphors could serve as a promising candidate for UV W‐LEDs and FEDs.
High‐Speed Lithium‐Ion Transfer inside Mesoporous Core–Shell LiFePO4/Carbon‐Sphere Cathodes
Authors: Hsu Chun‐Han , Liao Hsin‐Yi , Kuo Ping‐Lin 
Published: March 2014

AbstractA thin layer of LiFePO4 was coated onto a mesoporous carbon sphere to obtain a mesoporous core–shell LiFePO4/carbon sphere (LFP/MCS) composite, for which the thickness of the nanoscale LiFePO4 thin shell was approximately 30–50 nm. Meanwhile, pristine LFP and MCS mixed with LFP samples (MCS‐m‐LFP) were prepared for comparison. The significantly larger surface area of LFP/MCS (43–151 m2 g−1) compared with pristine LFP (12 m2 g−1) is derived from the mesoporous carbon framework and thin nanoscale LFP shell. The large surface area of LFP/MCS provides greater surface content between the LiFePO4 shell and electrolytes, which results in a high charge–discharge rate. Also, this remarkably thin LiFePO4 cathode shell shortens the diffusion length of lithium ions thereby achieving a high charge–discharge rate for electrode materials. Consequently, under all charge–discharge rates (0.1–20 C), the specific capacities of LFP/MCS are higher than those of both the pristine LFP and MCS‐m‐LFP. More specifically, at 10 C, LFP/MCS exhibited the excellent rate performance of 82 mAh g−1, compared to 25 and 41 mAh g−1 for LFP and MCS‐m‐LFP, respectively. Furthermore, the discharge capacity for LFP/MCS at the high discharge rate of 20 C remains stable whereas that for LFP does not. This demonstrates the efficient transport capability of Li ions into the nanoscale LFP shell in the core–shell structure of LFP/MCS, which is essential for the improvement of the electrochemical performance.
Endocrine disruption and reproduction impairment in zebrafish after long-term exposure to DE-71
Authors: Yu Liqin , Liu Chunsheng , Chen Qi , Zhou Bingsheng 
Published: March 2014

Abstract

The objective of the present study was to investigate the impact of polybrominated diphenyl ethers (PBDEs) on fish reproduction over 2 generations. Zebrafish (Danio rerio) embryos (F0) were exposed to low concentrations (3 µg/L, 10 µg/L, and 30 µg/L) of the PBDE mixture DE-71 until they were sexually mature, and steroid hormone production, expression of genes involved in steroidogenesis, gonadal development, and gamete characteristics were examined. Exposure of female zebrafish to DE-71 resulted in lower estradiol production and downregulation of cytochrome P450 aromatase mRNA. In males, exposure to DE-71 resulted in greater testosterone production and greater cytochrome P450 c17 α-hydroxylase,17,20-lase mRNA expression. Moreover, hepatic vitellogenin mRNA and estrogenic receptor β gene transcription were downregulated in females and males. Expression of the follicle-stimulating hormone β gene in the pituitary was upregulated, and the expression of luteinizing hormone β was downregulated in both sexes. Histological examination showed inhibition of oocyte maturation in females and retarded spermiation in males. The average number of eggs (F1) produced was also reduced. Additionally, exposure of F0 embryos to DE-71 did not result in developmental toxicity, whereas delayed hatching, reduced survival, and decreased growth were observed in the F1 embryos derived from parent fish exposed to DE-71. Therefore, long-term exposure to low concentrations of PBDEs in zebrafish could cause reproductive impairment, suggesting that PBDEs might have significant adverse effects on fish population in the highly PBDEs-contaminated aquatic environment. Environ Toxicol Chem 2014;33:1354–1362. © 2014 SETAC
Lymph node ratio influence on risk of head and neck cancer locoregional recurrence after initial surgical resection: Implications for adjuvant therapy
Authors: Prabhu Roshan S. , Hanasoge Sheela , Magliocca Kelly R. , Hall William A. , Chen Susie A. , Higgins Kristin A. , Saba Nabil F. , El‐Deiry Mark , Grist William , Wadsworth J. Trad , Chen Amy Y. , Beitler Jonathan J. 
Published: March 2014

AbstractBackgroundThe purpose of this study was to determine if lymph node ratio is associated with locoregional recurrence for patients with oral cavity or laryngeal cancer treated with initial surgical management.MethodsThe study included 350 patients with oral cavity (73%) or laryngeal cancer (27%) who underwent initial surgery. All analyses were multivariable, adjusting for primary site, pathologic prognostic factors, and adjuvant therapy.ResultsLymph node ratio was significantly associated with locoregional recurrence, in which each 1% increase in lymph node ratio had an adjusted hazard ratio (HR) for locoregional recurrence of 1.02 (95% confidence interval [CI], 1.002–1.042; p = .05). Lymph node ratio was also associated with OS, in which each 1% increase in lymph node ratio had an adjusted HR for death of 1.028 (95% CI, 1.012–1.045; p = .001).ConclusionAdjusting for pathologic factors and adjuvant therapy, lymph node ratio was found to be an independent prognostic factor for locoregional recurrence and overall survival (OS). Patients with lymph node ratio ≥20% are at high risk of locoregional recurrence and death, and may be considered for adjuvant chemoradiation. © 2014 Wiley Periodicals, Inc. Head Neck 37: 777–782, 2015
Controls on carbon and nitrogen export in an eroding catchment of south‐eastern Queensland, Australia
Authors: Garzon‐Garcia Alexandra , Olley Jon M. , Bunn Stuart E. 
Published: March 2014

AbstractEffects of gully and channel erosion on the export of sediments are in general well understood, but the effects on carbon (C) and nitrogen (N) export remain an open question. We examined these effects and the role of flow magnitude, total wet season rainfall, catchment size and the C and N content and solubility of most probable sediment sources in a subtropical catchment. We sampled the baseflow and the rising stage of high‐flow events for one wet season and analysed 5 years of water quality data from event sampling stations. Total suspended sediment was the main variable explaining N export followed by rainfall, flow and catchment size. N was exported mainly in particulate organic form and C in dissolved form. The quality of most probable sediment source fractions explains these results and points to fractionation during transport into C and N richer and C and N poorer fractions, with travel distance ultimately determining the average quality of transported sediment for different flow magnitudes. Erosion would have caused a lower C and N concentration in sediments, a lower proportion of mineralized N, a larger proportion of dissolved organic C and a larger C : N ratios of the soluble fraction as compared with unincised grassed valleys. This would alter the rates of nutrient cycling and energy flow within and across ecosystem compartments in streams receiving this export. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis and evaluation of novel dental monomer with branched carboxyl acid group
Authors: Song Linyong , Ye Qiang , Ge Xueping , Misra Anil , Laurence Jennifer S. , Berrie Cynthia L. , Spencer Paulette 
Published: March 2014

AbstractTo enhance the water miscibility and increase the mechanical properties of dentin adhesives, a new glycerol‐based monomer with vinyl and carboxylic acid, 4‐((1,3‐bis(methacryloyloxy)propan‐2‐yl)oxy)‐2‐methylene‐4‐oxobutanoic acid (BMPMOB), was synthesized and characterized. Dentin adhesive formulations containing 2‐hydroxyethyl methacrylate (HEMA), 2,2‐bis[4‐(2‐hydroxy‐3‐methacryloxypropoxy) phenyl]propane (BisGMA), and BMPMOB were characterized with regard to real‐time photopolymerization behavior, water sorption, dynamic mechanical analysis, and microscale three‐dimensional internal morphologies and compared with HEMA/BisGMA controls. The experimental adhesive copolymers showed higher glass transition temperature and rubbery moduli, as well as improved water miscibility compared to the controls. The enhanced properties of the adhesive copolymers indicated that BMPMOB is a promising comonomer for dental restorative materials. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1473–1484, 2014.
Unattended sleep studies in pediatric OSA: A systematic review and meta‐analysis
Authors: Certal Victor , Camacho Macario , Winck João C. , Capasso Robson , Azevedo Inês , Costa‐Pereira Altamiro 
Published: March 2014

The objective of this study was to systematically assess the evidence for the diagnostic accuracy of unattended type 2 or type 3 multichannel studies for predicting and monitoring pediatric obstructive sleep apnea (OSA). Four medical databases were searched for eligible studies. Only studies that evaluated the ability of unattended multichannel devices to accurately diagnose or monitor OSA in children were included. Those with appropriate data were selected for meta‐analysis. Study quality was assessed by using the Quality Assessment Tool for Diagnostic Accuracy Studies tool. Summary estimates of diagnostic accuracy were determined by using sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio, summary receiver operating characteristics, and the area under the curve (AUC). Ten diagnostic studies with 724 patients were included in the systematic review, which was followed by a meta‐analysis using studies that provided sufficient information for the calculation of diagnostic parameters. The overall analysis revealed a moderate sensitivity of 76% (95% confidence interval [CI]: 64%‐85%), a moderate specificity of 76% (95% CI: 60%–88%), and a pooled diagnostic odds ratio of 15.18 (95% CI: 3.52–65.43). The AUC (0.88) indicated that unattended multichannel devices showed good diagnostic performance for predicting pediatric OSA. Using a cutoff of AHI >1 for the diagnosis of OSA, the results appeared to be more useful, with a higher sensitivity (88%) while maintaining a moderate specificity (71%). These findings suggest that unattended sleep studies are a good tool for predicting both the presence and severity of OSA in children, especially in those with mild‐to‐moderate disease.Level of EvidenceNA Laryngoscope, 125:255–262, 2015
Synthesis and Properties of Polyethylene‐Bound Antioxidants
Authors: Zhang Yongjie , Li Huayi , Zhang Yu , Li Qian , Ma Zhi , Dong Jin‐Yong , Hu Youliang 
Published: March 2014

Four novel well‐defined polyethylene‐bound antioxidants (PE‐bound antioxidants) with distinct secondary structures are synthesized via transesterification reactions between methyl 3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propionate and hydroxyl‐terminated polyethylenes. The results of thermal gravimetric analysis under an air atmosphere demonstrate that the thermal stabilities of PE‐bound antioxidants are higher than that of commercial antioxidant Irganox1076 and are strongly related to their chemical structures. Particularly, the most thermally stable PE‐bound antioxidant is the one bearing both primary and secondary antioxidant moieties. The antioxidant activities of the PE‐bound antioxidants are evaluated in polypropylene by their melt flow index.
image
Synthesis of poly(4‐hydroxystyrene)‐based block copolymers containing acid‐sensitive blocks by living anionic polymerization
Authors: Sweat Daniel P. , Yu Xiang , Kim Myungwoong , Gopalan Padma 
Published: March 2014

ABSTRACTLiving anionic polymerization of an acetal protected 4‐hydroxystyrene monomer, (4‐(2‐tetrahydropyranyloxy)styrene) (OTHPSt), and the chain extension of the poly(OTHPSt) anion with a variety of monomers including styrene, 4‐tert‐butylstyrene, methacryloyl polyhedral oligomeric silsesquioxane (MAPOSS) and hexamethylcyclotrisiloxane is demonstrated. The P(OTHPSt) homopolymer has a glass transition temperature well above room temperature, which facilitates handling and purification of the protected poly(4‐hydroxystyrene) (PHS). The resulting diblock copolymers have narrow dispersities <1.05. Chemoselective mild deprotection conditions for the P(OTHPSt) block were identified to prevent simultaneous degradation of the MAPOSS or dimethylsiloxane (DMS) block, thus allowing for the first reported synthesis of P(HS‐b‐DMS) and P(HS‐b‐MAPOSS). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1458–1468
Functional aramids: Aromatic polyamides with reactive azido and amino groups in the pendant structure
Authors: Trigo‐López Miriam , Pablos Jesús Luis , García Félix Clemente , Serna Felipe , García José Miguel 
Published: March 2014

ABSTRACTThe structure of the high‐performance aromatic polyamides, also known as aramids, was modified to render functional polymers by the introduction of primary amine and azide functional groups in the main polymer chain. These materials were prepared as parent polymers for future use in the simple and inexpensive preparation of other high‐performance materials by the chemical derivatization of the primary amine and azide groups using their well‐known and broad reactivity. The potential of the parent aramids was exemplified with the preparation of four novel functional aramids containing the fluorescent dansyl group, the anion and cation receptors urea and triazole with free primary alcohol functional groups, and the iminophosphorane ligand for forthcoming synthetic processes. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1469–1477
MIT virtual source GaNFET‐high voltage (MVSG‐HV) model: A physics based compact model for HV‐GaN HEMTs
Authors: Radhakrishna Ujwal , Imada Tadahiro , Palacios Tomás , Antoniadis Dimitri 
Published: March 2014

AbstractA new physics based transport and charge model for long channel GaN HEMTs is proposed. The model is based on the concept of virtual source (VS) carrier transport (A. Khakifirooz et al., IEEE‐TED 56(8), 1674 (2009) [1]) and is extended to drift diffusion regime. The model is fully scalable from non‐velocity saturation to velocity saturation regime. In addition, non‐linear access regions are modeled as implicit‐gated transistors. Self‐heating effects and self‐consistent charge models are included. The model is validated against state of the art industry devices. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of HVPE‐grown UV LED heterostructures
Authors: Kurin Sergey , Antipov Andrey , Barash Iosif , Roenkov Alexander , Usikov Alexander , Helava Heikki , Ratnikov Valentin , Shmidt Natalia , Sakharov Alexey , Tarasov Sergey , Menkovich Ekaterina , Lamkin Ivan , Papchenko Boris , Makarov Yuri 
Published: March 2014

AbstractIn this paper, we report on growth of ultraviolet light‐emitting diode (UV LED) heterostructures by hydride vapour phase epitaxy (HVPE) on sapphire substrates and results of the heterostructures characterization by X‐ray diffractometry, scanning electron microscopy, photo‐ and electroluminescence, micro‐photoluminescence, collected from the cleaved edges and the surface of the heterostructure with lateral resolution of about 1 µm. The heterostructures demonstrate efficient hole injection and low droop of the external quantum efficiency. Packaged 360 nm UV LED chips have wall‐plug efficiency of 1‐1.5%. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Embedding nano‐pillar arrays into InGaN light‐emitting diodes
Authors: Li K. H. , Zang K. Y. , Chua S. J. , Choi H. W. 
Published: March 2014

AbstractThe embedded nano‐pillar light‐emitting diodes are fabricated via nanosphere lithography in combination with epitaxial lateral overgrowth method, followed by standard micro‐fabrication process. Apart from output power enhancement due to diffraction and scattering effect from the embedded nano‐pillars, the device is demonstrated to have insignificant spectral blue shift with increasing injection currents, which is dependent on the built‐in piezoelectric field that is partially suppressed by strain relaxation of nanostructured quantum wells. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evidence of lateral electric fields in c ‐plane III‐V nitrides via terahertz emission
Authors: Woodward Nathaniel , Enck Ryan , Gallinat Chad S. , Rodak Lee E. , Metcalfe Grace D. , Speck James S. , Shen Hongen , Wraback Michael 
Published: March 2014

AbstractWe observe terahertz (THz) emission from c ‐plane InN and In0.15Ga0.85N films on GaN templates due to surface‐normal transport with a strong anomalous in‐plane transport component. Analysis of the rotational dependence of the THz emission associated with this in‐plane transport indicates that an electric field exists along the [1‐100] m‐axis correlated with the underlying template miscut. Calculations show that the field is correlated with strain‐induced polarization fields at the heterointerface related to step‐like charges at interfaces of the epilayers and the miscut templates. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)