bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced Efficiency of TaON and BiOI-based Solar Cells by Au Nanoparticles
Authors: Ahmmad B. , Kurawaki J. , Leonard K. , Kusumoto Y. 
Published: September 2010

Au nanoparticles were prepared by a chemical reduction method and were deposited on TaON nanoparticle or BiOI microsphere to prepare the composites of Au/TaON or Au/BiOI, respectively. The composites of Au/TaON and Au/BiOI were analyzed by UV-visible spectroscopy, XRD, and EDX. The films of these nanocomposites were prepared by a squeeze method and were applied to solar cell where Pt film was used as counter electrode. A water based solution of Ce3+/Ce4+ was used as an electrolyte. It was found that Au deposited TaON or BiOI film shows higher current (I)-voltage (V) curve under UV-visible light irradiation. Key words: Au; TaON; BiOI; Composite; Solar cell. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v2i3.5000 J. Sci. Res. 2 (3), 413-417 (2010)
Cutting Edge: Hematopoietic-Derived APCs Select Regulatory T Cells in Thymus
Authors: Román Eulogia , Shino Hanabuchi , Qin F. Xiao-Feng , Liu Yong Jun 
Published: August 2010

Abstract
Recognition of self-peptide–MHC complexes by high-affinity TCRs and CD28 signaling are critical for the development of forkhead-winged helix box transcription factor 3+ regulatory T cells (Tregs) in thymus. However, the type of APCs that are responsible for selecting Tregs has remained unclear. To dissect the role of hematopoietic-derived APCs (HCs) and thymic epithelial cells (TECs) in Treg selection, we constructed bone marrow chimeras with disrupted CD28/B7 signaling in the HC or TEC compartment and analyzed the generation of Tregs in the thymus. We found that both HCs and TECs were independently able to fully reconstitute the Treg population in the thymus of bone marrow chimeras. In addition, Treg selection requires the TCR signal and CD28 costimulation presented in cis on the same APC type in vivo. This study demonstrates a new role, to our knowledge, for HCs in the development of Tregs in thymus.
Secreted Immunodominant Mycobacterium tuberculosis Antigens Are Processed by the Cytosolic Pathway
Authors: Grotzke Jeff E. , Siler Anne C. , Lewinsohn Deborah A. , Lewinsohn David M. 
Published: August 2010

Abstract
Exposure to Mycobacterium tuberculosis can result in lifelong but asymptomatic infection in most individuals. Although CD8+ T cells are elicited at high frequencies over the course of infection in both humans and mice, how phagosomal M. tuberculosis Ags are processed and presented by MHC class I molecules is poorly understood. Broadly, both cytosolic and noncytosolic pathways have been described. We have previously characterized the presentation of three HLA-I epitopes from M. tuberculosis and shown that these Ags are processed in the cytosol, whereas others have demonstrated noncytosolic presentation of the 19-kDa lipoprotein as well as apoptotic bodies from M. tuberculosis-infected cells. In this paper, we now characterize the processing pathway in an additional six M. tuberculosis epitopes from four proteins in human dendritic cells. Addition of the endoplasmic reticulum-Golgi trafficking inhibitor, brefeldin A, resulted in complete abrogation of Ag processing consistent with cytosolic presentation. However, although addition of the proteasome inhibitor epoxomicin blocked the presentation of two epitopes, presentation of four epitopes was enhanced. To further examine the requirement for proteasomal processing of an epoxomicin-enhanced epitope, an in vitro proteasome digestion assay was established. We find that the proteasome does indeed generate the epitope and that epitope generation is enhanced in the presence of epoxomicin. To further confirm that both the epoxomicin-inhibited and epoxomicin-enhanced epitopes are processed cytosolically, we demonstrate that TAP transport and new protein synthesis are required for presentation. Taken together, these data demonstrate that immunodominant M. tuberculosis CD8+ Ags are processed and presented using a cytosolic pathway.
Capacitors with an Equivalent Oxide Thickness of <0.5 nm for Nanoscale Electronic Semiconductor Memory
Authors: Kim Seong Keun , Lee Sang Woon , Han Jeong Hwan , Lee Bora , Han Seungwu , Hwang Cheol Seong 
Published: August 2010

AbstractThe recent progress in the metal‐insulator‐metal (MIM) capacitor technology is reviewed in terms of the materials and processes mostly for dynamic random access memory (DRAM) applications. As TiN/ZrO2‐Al2O3‐ZrO2/TiN (ZAZ) type DRAM capacitors approach their technical limits, there has been renewed interest in the perovskite SrTiO3, which has a dielectric constant of >100, even at a thickness ∼10 nm. However, there are many technical challenges to overcome before this type of MIM capacitor can be used in mass‐production compatible processes despite the large advancements in atomic layer deposition (ALD) technology over the past decade. In the mean time, rutile structure TiO2 and Al‐doped TiO2 films might find space to fill the gap between ZAZ and SrTiO3 MIM capacitors due to their exceptionally high dielectric constant among binary oxides. Achieving a uniform and dense rutile structure is the key technology for the TiO2‐based dielectrics, which depends on having a dense, uniform and smooth RuO2 layer as bottom electrode. Although the Ru (and RuO2) layers grown by ALD using metal‐organic precursors are promising, recent technological breakthroughs using the RuO4 precursor made a thin, uniform, and denser Ru and RuO2 layer on a TiN electrode. A minimum equivalent oxide thickness as small as 0.45 nm with a low enough leakage current was confirmed, even in laboratory scale experiments. The bulk dielectric constant of ALD SrTiO3 films, grown at 370 °C, was ∼150 even with thicknesses ≤15 nm. The recent development of novel group II precursors made it possible to increase the growth rate largely while leaving the electrical properties of the ALD SrTiO3 film intact. This is an important advancement toward the commercial applications of these MIM capacitors to DRAM as well as to other fields, where an extremely high capacitor density and three‐dimensional structures are necessary.
Architecture of Supramolecular Soft Functional Materials: From Understanding to Micro‐/Nanoscale Engineering
Authors: Li Jing‐Liang , Liu Xiang‐Yang 
Published: August 2010

AbstractThis article gives an overview of the current progress of a class of supramolecular soft materials consisting of fiber networks and the trapped liquid. After discussing the up‐to‐date knowledge on the types of fiber networks and the correlation to the rheological properties, the gelation mechanism turns out to be one of the key subjects for this review. In this concern, the following two aspects will be focused upon: the single fiber network formation and the multi‐domain fiber network formation of this type of material. Concerning the fiber network formation, taking place via nucleation, and the nucleation‐mediated growth and branching mechanism, the theoretical basis of crystallographic mismatch nucleation that governs fiber branching and formation of three‐dimensional fiber networks is presented. In connection to the multi‐domain fiber network formation, which is governed by the primary nucleation and the subsequent formation of single fiber networks from nucleation centers, the control of the primary nucleation rate will be considered. Based on the understanding on the the gelation mechanism, the engineering strategies of soft functional materials of this type will be systematically discussed. These include the control of the nucleation and branching‐controlled fiber network formation in terms of tuning the thermodynamic driving force of the gelling system and introducing suitable additives, as well as introducing ultrasound. Finally, a summary and the outlook of future research on the basis of the nucleation‐growth‐controlled fiber network formation are given.
Solution‐Processed Zinc Oxide as High‐Performance Air‐Stable Electron Injector in Organic Ambipolar Light‐Emitting Field‐Effect Transistors
Authors: Gwinner Michael C. , Vaynzof Yana , Banger Kulbinder K. , Ho Peter K. H. , Friend Richard H. , Sirringhaus Henning 
Published: August 2010

AbstractElectron injection from the source–drain electrodes limits the performance of many n‐type organic field‐effect transistors (OFETs), particularly those based on organic semiconductors with electron affinities less than 3.5 eV. Here, it is shown that modification of gold source–drain electrodes with an overlying solution‐deposited, patterned layer of an n‐type metal oxide such as zinc oxide (ZnO) provides an efficient electron‐injecting contact, which avoids the use of unstable low‐work‐function metals and is compatible with high‐resolution patterning techniques such as photolithography. Ambipolar light‐emitting field‐effect transistors (LEFETs) based on green‐light‐emitting poly(9,9‐dioctylfluorene‐alt‐benzothiadiazole) (F8BT) and blue‐light‐emitting poly(9,9‐dioctylfluorene) (F8) with electron‐injecting gold/ZnO and hole‐injecting gold electrodes show significantly lower electron threshold voltages and several orders of magnitude higher ambipolar currents, and hence light emission intensities, than devices with bare gold electrodes. Moreover, different solution‐deposited metal oxide injection layers are compared. By spin‐coating ZnO from a low‐temperature precursor, processing temperatures could be reduced to 150 °C. Ultraviolet photoemission spectroscopy (UPS) shows that the improvement in transistor performance is due to reduction of the electron injection barrier at the interface between the organic semiconductor and ZnO/Au compared to bare gold electrodes.
Silica‐Gelatin Hybrids with Tailorable Degradation and Mechanical Properties for Tissue Regeneration
Authors: Mahony Oliver , Tsigkou Olga , Ionescu Claudia , Minelli Caterina , Ling Lowell , Hanly Ruth , Smith Mark E. , Stevens Molly M. , Jones Julian R. 
Published: August 2010

AbstractNature has evolved mechanisms to create a diversity of specialized materials through nanoscale organization. Inspired by nature, hybrid materials are designed with highly tailorable properties, which are achieved through careful control of their nanoscale interactions. These novel materials, based on a silica‐gelatin hybrid system, have the potential to serve as a platform technology for human tissue regeneration. Covalent interactions between the inorganic and organic constituents of the hybrid are essential to enable the precise control of mechanical and dissolution properties. Furthermore, hybrid scaffold porosity is found to highly influence mechanical properties, to the extent where scaffolds of particular strength could be specified based on their porosity. The hybrids also demonstrate a non‐cytotoxic effect when mesenchymal stem cells are cultured on the material. Cytoskeletal proteins of the cells are imaged using actin and vimentin staining. It is envisaged these hybrid materials will find a diverse application in both hard and soft tissue regenerating scaffolds.
Ferritin–Polymer Conjugates: Grafting Chemistry and Integration into Nanoscale Assemblies
Authors: Hu Yunxia , Samanta Debasis , Parelkar Sangram S. , Hong Sung Woo , Wang Qian , Russell Thomas P. , Emrick Todd 
Published: August 2010

AbstractControlled free radical polymerization chemistry is used to graft polymer chains to the corona of horse spleen ferritin (HSF) nanocages. Specifically, poly(methacryloyloxyethyl phosphorylcholine) (polyMPC) and poly(PEG methacrylate) (polyPEGMA) chains are grafted onto the nanocages by atom transfer radical polymerization (ATRP), in which the molecular weight of the polymer grafts is controlled by the monomer‐to‐initiator feed ratio. PolyMPC and polyPEGMA‐grafted ferritin show a generally suppressed inclusion into diblock copolymer films relative to native ferritin, and the polymer coating is seen to mask the ferritin nanocages from antibody recognition. The solubility of polyPEGMA‐coated ferritin in organic solvents enables its processing with polystyrene‐block‐poly(ethylene oxide) copolymers, and selective integration into the PEO domains of microphase‐separated copolymer structures.
Anchoring Hydrous RuO2 on Graphene Sheets for High‐Performance Electrochemical Capacitors
Authors: Wu Zhong‐Shuai , Wang Da‐Wei , Ren Wencai , Zhao Jinping , Zhou Guangmin , Li Feng , Cheng Hui‐Ming 
Published: August 2010

AbstractHydrous ruthenium oxide (RuO2)/graphene sheet composites (ROGSCs) with different loadings of Ru are prepared by combining sol–gel and low‐temperature annealing processes. The graphene sheets (GSs) are well‐separated by fine RuO2 particles (5–20 nm) and, simultaneously, the RuO2 particles are anchored by the richly oxygen‐containing functional groups of reduced, chemically exfoliated GSs onto their surface. Benefits from the combined advantages of GSs and RuO2 in such a unique structure are that the ROGSC‐based supercapacitors exhibit high specific capacitance (∼570 F g−1 for 38.3 wt% Ru loading), enhanced rate capability, excellent electrochemical stability (∼97.9% retention after 1000 cycles), and high energy density (20.1 Wh kg−1) at low operation rate (100 mA g−1) or high power density (10000 W kg−1) at a reasonable energy density (4.3 Wh kg−1). Interestingly, the total specific capacitance of ROGSCs is higher than the sum of specific capacitances of pure GSs and pure RuO2 in their relative ratios, which is indicative of a positive synergistic effect of GSs and RuO2 on the improvement of electrochemical performance. These findings demonstrate the importance and great potential of graphene‐based composites in the development of high‐performance energy‐storage systems.
Heteroepitaxial Patterned Growth of Vertically Aligned and Periodically Distributed ZnO Nanowires on GaN Using Laser Interference Ablation
Authors: Yuan Dajun , Guo Rui , Wei Yaguang , Wu Wenzhuo , Ding Yong , Wang Zhong Lin , Das Suman 
Published: August 2010

AbstractA simple two‐step method of fabricating vertically aligned and periodically distributed ZnO nanowires on gallium nitride (GaN) substrates is described. The method combines laser interference ablation (LIA) and low temperature hydrothermal decomposition. The ZnO nanowires grow heteroepitaxially on unablated regions of GaN over areas spanning 1 cm2, with a high degree of control over size, orientation, uniformity, and periodicity. High resolution transmission electron microscopy and scanning electron microscopy are utilized to study the structural characteristics of the LIA‐patterned GaN substrate in detail. These studies reveal the possible mechanism for the preferential, site‐selective growth of the ZnO nanowires. The method demonstrates high application potential for wafer‐scale integration into sensor arrays, piezoelectric devices, and optoelectronic devices.
Photoinduced Degradation of Polymer and Polymer–Fullerene Active Layers: Experiment and Theory
Authors: Reese Matthew O. , Nardes Alexandre M. , Rupert Benjamin L. , Larsen Ross E. , Olson Dana C. , Lloyd Matthew T. , Shaheen Sean E. , Ginley David S. , Rumbles Garry , Kopidakis Nikos 
Published: August 2010

AbstractAs organic photovoltaic efficiencies steadily improve, understanding degradation pathways becomes increasingly important. In this paper, the stability under prolonged illumination of a prototypical polymer:fullerene active layer is studied without the complications introduced by additional layers and interfaces in complete devices. Combining contactless photoconductivity with spectroscopy, structural characterization at the molecular and film level, and quantum chemical calculations, the mechanism of photoinduced degradation in bulk heterojunctions of poly (3‐hexylthiophene) (P3HT) and [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) is studied. Bare films are subjected to four conditions for 1000 h with either constant illumination or dark and either ambient or inert atmosphere. All samples are found to be intrinsically stable for 1000+ h under inert conditions, in contrast to complete devices. While PCBM stabilizes P3HT films exposed to air, its fullerene cage is found to undergo a series of oxidations that are responsible for the deterioration of the photoconductivity of the material. Quantum chemical calculations show that PCBM oxides have deeper LUMO levels than pristine PCBM and therefore act as traps for electrons in the PCBM domains.
Electrospinning Derived One‐Dimensional LaOCl: Ln3+ (Ln = Eu/Sm, Tb, Tm) Nanofibers, Nanotubes and Microbelts with Multicolor‐Tunable Emission Properties
Authors: Li Guogang , Hou Zhiyao , Peng Chong , Wang Wenxin , Cheng Ziyong , Li Chunxia , Lian Hongzhou , Lin Jun 
Published: August 2010

AbstractOne‐dimensional LaOCl: Ln3+ (Ln3+ = Eu3+/Sm3+, Tb3+, Tm3+) nanofibers, nanotubes, and quasi‐1D microbelts are successfully prepared by a sol–gel/electrospinning process. XRD, FT‐IR, SEM, TEM, as well as photoluminescence (PL) and cathodoluminescecne (CL) spectra are used to characterize the resulting samples. Through a heat treatment process at high temperature, the as‐prepared samples are well‐crystallized with the tetragonal structure of LaOCl. Under ultraviolet radiation and low‐voltage electron beam excitation, the LaOCl: Eu3+, LaOCl:Sm3+, LaOCl: Tb3+, and LaOCl: Tm3+ samples give the characteristic transitions of Eu3+ (5D0, 1, 2 → 7F0, 1, 2, 3, 4), Sm3+ (4G5/2 → 6H5/2, 7/2, 9/2), Tb3+ (5D3, 4 → 7F2, 3, 4, 5, 6), and Tm3+ (1D2, 1G4 → 3F4, 3H6), respectively. Moreover, there exists simultaneous luminescence of Tb3+, Tm3+, Eu3+, or Sm3+ individually when codoping them in the single‐phase LaOCl host (for example, LaOCl: Tb3+, Eu3+/Sm3+; LaOCl: Tm3+, Eu3+/Sm3+; LaOCl: Tb3+, Tm3+, Eu3+/Sm3+ systems), which is beneficial to tune the emission colors. Under low‐voltage electron beam excitation (1–5 kV), a variety of colors can be efficiently adjusted in a wide triangle region enveloped by three CIE chromaticity coordinate points [LaOCl:Eu3+, (x = 0.6039, y = 0.3796); LaOCl: Tb3+, (x = 0.2452, y = 0.5236); LaOCl: Tm3+, (x = 0.1456, y = 0.0702)] for mono‐ and co‐doped LaOCl: Ln3+ (Eu3+, Sm3+, Tb3+, Tm3+) samples, making these materials have potential applications in field‐emission display devices.
Steady flow of a Williamson fluid past a porous plate
Authors: Hayat T. , Khalid Umbreen , Qasim M. 
Published: August 2010

ABSTRACTThis article presents the series solution for the steady magnetohydrodynamic (MHD) flow of a Williamson fluid past a porous plate. Both suction and injection cases are analyzed. The resulting nonlinear problem is solved by employing the homotopy analysis method (HAM). The influence of various parameters of interest on the velocity is discussed by displaying graphs. A comparison with the case of Newtonian fluid is given. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Adsorptive separation of emulsified oil in wastewater using biosorbents
Authors: Ibrahim Shariff , Ang Ha‐Ming , Wang Shaobin 
Published: August 2010

ABSTRACTAn agricultural waste, barley straw, was chemically modified using a cationic surfactant hexadecylpyridinium chloride monohydrate (CPC) to obtain a biosorbent for removal of emulsified mineral oil from aqueous solution. The physical and chemical properties of the raw and surfactant‐modified barley straw (SMBS) were characterized by N2 adsorption, bulk density, Fourier transforms infrared spectra and the composition of cellulose, hemicellulose and lignin. The adsorption tests were performed using a standard mineral oily wastewater in a batch adsorption system. The effects of contact time and pH of solution on the emulsified oil uptake were investigated and discussed. It was found that the removal efficiency of emulsified oil increased with the increase in contact time. Biosorption was found to be less favorable at high acidic condition and a maximum removal was obtained at about neutrality. The isotherm study indicated that emulsified oil adsorption on SMBS was fitted well with the Langmuir model rather than the Freundlich model. The maximum adsorption capacity determined from the Langmuir isotherm was 518.6 mg g−1 at 25 °C. The kinetic study revealed that equilibrium time was achieved in less than 40 min and the kinetic data were fitted well to the pseudo‐first‐order model. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Statistical optimization of palm oil hydrolysis by Pseudomonas aeruginosa PseA lipase
Authors: Gaur Ruchi , Khare Sunil Kumar 
Published: August 2010

AbstractContinuous hydrolysis of palm oil by Pseudomonas aeruginosa PseA lipase has been investigated in isooctane‐aqueous biphasic system using statistical approach. PseA lipase could hydrolyze all the oils tested, palm oil being best hydrolyzed. Factors influencing palm oil hydrolysis were screened by Plackett–Burman screening and their optimal values were determined by response surface methodology (RSM). Under optimized conditions, 89% palm oil hydrolysis was achieved within 2 h at 30 °C. Due to its broad substrate specificity, the present lipase may find potential applications in bioconversion and bioremediation of oil rich industrial waste. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Determination of paeoniflorin, calycosin‐7‐O‐β‐d‐glucoside, ononin, calycosin and formononetin in rat plasma after oral administration of Buyang Huanwu decoction for their pharmacokinetic study by liquid chromatography–mass spectrometry
Authors: Zhang Jiye , Yang Guangde , Lin Rong , Hu Zheng 
Published: August 2010

AbstractThe purpose of this study was to simultaneously investigate the pharmacokinetics of five bioactive compounds in rat plasma after oral administration of Buyang Huanwu decoction (BYHWD) using high‐performance liquid chromatography coupled with mass spectrometry (HPLC‐MS). The separations were performed on a Thermo Hypersil Gold C18 analytical column (50 × 2.1 mm, 3 µm) with the column temperature kept at 30°C. The quantitative analysis was performed using a quadrupole mass spectrometer detector operated under selected ion monitoring mode. A linear gradient elution of A (0.1% formic acid solution) and B (100% acetonitrile) was used at a flow rate of 0.2 mL/min. The method was validated within the concentration ranges 1.8–450, 6.0–1500, 2.0–500, 1.2–300 and 1.2–150 ng/mL for paeoniflorin, calycosin‐7‐O‐β‐d‐glucoside, ononin, calycosin and formononetin, respectively. The calibration curves were linear with correlation coefficients > 0.99. The lower limits of quantitations were < 6.0 ng/mL. The method was further applied to assess the pharmacokinetics of the five bioactive constituents of BYHWD in rat plasma. Copyright © 2010 John Wiley & Sons, Ltd.