bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrathin Polymeric Coatings Based on Hydrogen‐Bonded Polyphenol for Protection of Pancreatic Islet Cells
Authors: Kozlovskaya Veronika , Zavgorodnya Oleksandra , Chen Yi , Ellis Kristin , Tse Hubert M. , Cui Wanxing , Thompson J. Anthony , Kharlampieva Eugenia 
Published: April 2012

AbstractThough transplantation of pancreatic islet cells has emerged as a promising treatment for Type 1 diabetes its clinical application remains limited due to a number of limitations including both pathogenic innate and adaptive immune responses. This paper reports on a novel type of multifunctional cytoprotective material applied to coat living pancreatic islets. The coating utilizes hydrogen‐bonded interactions of a natural polyphenol (tannic acid) with poly(N‐vinylpyrrolidone) deposited on the islet surface via non‐ionic layer‐by‐layer assembly. It is demonstrated that the coating is conformal over the surface of mammalian islets including those derived from rat, non‐human primate (NHP), and human. In contrast to unmodified controls, the coated islets maintain their viability and β‐cell functionality for at least 96 hours in vitro. It is also determined that the coating demonstrates immunomodulatory cytoprotective properties suppressing pro‐inflammatory cytokine synthesis in stimulated bone marrow‐derived macrophages and diabetogenic BDC‐2.5 T cells. The coating material combines high chemical stability under physiologically relevant conditions with capability of suppressing cytokine synthesis, crucial parameters for prolonged islet integrity, viability, and function in vivo. This study offers new opportunities in the area of advanced multifunctional materials to be used for a cell‐based transplantation therapy
Growth of Transparent and Conductive Polycrystalline (0001)‐ZnO Films on Glass Substrates Under Low‐Temperature Hydrothermal Conditions
Authors: Podlogar Matejka , Richardson Jacob J. , Vengust Damjan , Daneu Nina , Samardžija Zoran , Bernik Slavko , Rečnik Aleksander 
Published: April 2012

AbstractFlat panel display technology seems to be an ever‐expanding field developing into a multibillion dollar market. A set of technical solutions involve a transparent conducting film (TCF) that is today still dominated by indium‐tin‐oxide (ITO). In a race to find alternatives that would avoid the indium pitfalls, mainly due to its increasing price and limited natural availablity, replacement materials have been extensively investigated. This work demonstrates that by exploiting basic principles of crystal growth in geometrically constrained conditions, zinc oxide (ZnO) could easily be utilized for this purpose. ZnO layers were grown on inexpensive glass substrates via low‐temperature citrate‐assisted hydrothermal (HT) method. It was shown that in the nucleation stage the crystal growth can be efficiently controlled by spatially confined oriented growth (SCOG) mechanism to produce smooth and dense (0001) oriented polycrystalline ZnO films with superb optical properties. Our products show optical transparency of 82% and surprisingly low sheet resistance for undoped ZnO, only in the order of few 100 Ω sq−1. We believe that a very high degree of self‐organization between the ZnO crystals in our polycrystalline films grown under controlled SCOG conditions is main reason for the highest so far reported transparency to conductivity ratio for undoped ZnO thin film ceramics.
Sonochemical Activation of Al/Ni Hydrogenation Catalyst
Authors: Dulle Jana , Nemeth Silke , Skorb Ekaterina V. , Irrgang Torsten , Senker Jürgen , Kempe Rhett , Fery Andreas , Andreeva Daria V. 
Published: April 2012

AbstractThis paper proposes a sonochemical approach to the nanostructuring of Al/Ni catalyst with high content of accessible Ni centers and a high reusability. The surface and bulk composition as well as pore size distribution of this catalyst are controlled synergistically by adjusting the ultrasound intensity in aqueous solution. Sonochemical activation of Al/Ni alloy leads to formation of mesoporous Al/Ni metallic based frameworks with surface area up to 125 m2 g−1, and regular distribution of nickel active center in the porous matrix. One of the opportunities of porous Al/Ni catalyst is that due to a time‐resolved controllable formation of protective oxide layer it can be stored and handled under air in comparison to traditional Raney catalysts which need inert conditions. The Al/Ni catalyst is characterized by scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), X‐ray photoelectron spectroscopy (XPS), confocal scanning fluorescence microscopy (CSFM), solid‐state NMR experiments, and powder X‐ray diffraction analysis (PXRD). The catalytic activity was investigated for the hydrogenation of acetophenone.
Strained Interface Defects in Silicon Nanocrystals
Authors: Lee Benjamin G. , Hiller Daniel , Luo Jun‐Wei , Semonin Octavi E. , Beard Matthew C. , Zacharias Margit , Stradins Paul 
Published: April 2012

AbstractThe surface of silicon nanocrystals embedded in an oxide matrix can contain numerous interface defects. These defects strongly affect the nanocrystals’ photoluminescence efficiency and optical absorption. Dangling‐bond defects are nearly eliminated by H2 passivation, thus decreasing absorption below the quantum‐confined bandgap and enhancing PL efficiency by an order of magnitude. However, there remain numerous other defects seen in absorption by photothermal deflection spectroscopy; these defects cause non‐radiative recombination that limits the PL efficiency to <15%. Using atomistic pseudopotential simulations, we attribute these defects to two specific types of distorted bonds: Si‐Si and bridging Si‐O‐Si bonds between two Si atoms at the nanocrystal surface.
Triblock‐Terpolymer‐Directed Self‐Assembly of Mesoporous TiO2: High‐Performance Photoanodes for Solid‐State Dye‐Sensitized Solar Cells
Authors: Docampo Pablo , Stefik Morgan , Guldin Stefan , Gunning Robert , Yufa Nataliya A. , Cai Ning , Wang Peng , Steiner Ullrich , Wiesner Ulrich , Snaith Henry J. 
Published: April 2012

AbstractA new self‐assembly platform for the fast and straightforward synthesis of bicontinuous, mesoporous TiO2 films is presented, based on the triblock terpolymer poly(isoprene‐b‐styrene‐b‐ethylene oxide). This new materials route allows the co‐assembly of the metal oxide as a fully interconnected minority phase, which results in a highly porous photoanode with strong advantages over the state‐of‐the‐art nanoparticle‐based photoanodes employed in solid‐state dye‐sensitized solar cells. Devices fabricated through this triblock terpolymer route exhibit a high availability of sub‐bandgap states distributed in a narrow and low enough energy band, which maximizes photoinduced charge generation from a state‐of‐the‐art organic dye, C220. As a consequence, the co‐assembled mesoporous metal oxide system outperformed the conventional nanoparticle‐based electrodes fabricated and tested under the same conditions, exhibiting solar power‐conversion efficiencies of over 5%.
Rapid removal of cobalt (II) from aqueous solution using cuttlefish bones; equilibrium, kinetics, and thermodynamic study
Authors: Sandesh K. , Suresh Kumar R. , JagadeeshBabu P. E. 
Published: April 2012

ABSTRACTThe objective of this study is to assess the adsorption potential of cobalt (II) using cuttlefish bones. The bones were treated with 0.01 N HCl to enhance the heavy metal uptake. The adsorbent was characterized using scanning electron microscope and energy dispersive X‐ray spectrometer. An adsorption study was conducted in a batch system to optimize process variables such as initial concentration of cobalt (II), pH, sorbent loading, particle size, process temperature, and contact time. The optimal pH was found to be 9. The kinetic data followed the pseudosecond‐order kinetic model, and the equilibrium time was found to be 20 min. In the first minute of the adsorption process, 50% of the cobalt (II) was adsorbed by the cuttle bones. Adsorption isotherms were expressed by the Langmuir and Freundlich adsorption models. The Langmuir adsorption model fits the experimental data reasonably well compared with the Freundlich model. The maximum adsorption capacity of this new sorbent was found to be 76.6 mg g−1 at 40 °C. Thermodynamic parameters, including the Gibbs free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo), indicated that the adsorption of cobalt (II) by cuttlefish bones was feasible and endothermic at a temperature range of 20–40 °C. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Protein‐grafted carboxylic poly(ether sulfone) membranes: Preparation and characterization
Authors: Wang Dongsheng , Li Beijia , Zhao Weifeng , Lu Yi , Sun Shudong , Zhao Changsheng 
Published: April 2012

AbstractCarboxylic poly(ether sulfone) membranes were prepared by a controlled acetylating and surface‐oxidating reaction followed by the grafting of bovine serum albumin (BSA) and bovine serum fibrinogen (BFG) onto the surfaces. Attenuated total reflection–Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and Micro BCA Protein Assay Kits confirmed that the proteins were successfully grafted onto the surfaces of the membranes. The protein grafting degrees were measured at different time intervals and under different conditions. The modified membranes showed higher hydrophilicity, lower protein (BSA and BFG) adsorption, and suppressed platelet adhesion values. Because of the binding of calcium ions in blood, the modified membranes showed longer plasma recalcification times, activated partial thromboplastin times, prothrombin times, and whole blood clotting times. The results indicate that the blood compatibility of the poly (ether sulfone) membranes could be improved after surface carboxylic modification and protein immobilization and that the modified membranes could be used in the blood purification field. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Structure and drug release of superabsorbent sponge prepared by polyelectrolyte complexation and freezing‐induced phase separation
Authors: Yu Chhen , Yu Liang , Yiguli Are , Yanwei Zhang , Yi Ding , Yanwen Guo , Yanchun Ye , Huimin Tan 
Published: April 2012

AbstractSuperabsorbent sponge with uniform porous structure was prepared by polyelectrolyte complex (PEC) of polyacrylic acid (PAA) with inorganic polymers, high polymer state polyaluminum chloride (HPSPAC), in combination with freezing‐induced phase separation (FIPS). The above superabsorbent sponge was prepared under mild conditions, without strong heat, oxidation, or corrosion, which is an ideal superabsorbent material for drug embedding. Structure analysis and swelling kinetics of the superabsorbent sponge as well as kinetics of the release of the model drug, 4‐acetaminophen (AMP), from the sponge were investigated. In addition, effects of the crosslinker HPSPAC, the pH of the solution, and the concentration of NaCl solution on the structure and the swelling property of the sponge and sustained‐release kinetics were explored. Further, the relationship between the structure of the superabsorbent sponge and its swelling property as well as sustained drug‐release characteristics was investigated. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The Stonehenge Hidden Landscapes Project
Authors: Gaffney Chris , Gaffney Vince , Neubauer Wolfgang , Baldwin Eamonn , Chapman Henry , Garwood Paul , Moulden Helen , Sparrow Tom , Bates Richard , Löcker Klaus , Hinterleitner Alois , Trinks Immo , Nau Erich , Zitz Thomas , Floery Sebastian , Verhoeven Geert , Doneus Michael 
Published: April 2012

ABSTRACTOver the centuries many archaeologists have investigated the site of Stonehenge and we now know a great deal about the phasing and nature of the site. However, the area around the henge, while containing many symbolic and ritual elements, is curiously ‘blank’. The Stonehenge Hidden Landscapes Project aims to place the site and its development through time within a landscape context using fast and accurate ground‐based geophysical techniques. The project has developed a rapid strategy to map, visualize and interpret landscape‐scale data and is applying the strategy to the area known as the Stonehenge ‘envelope’. The data are interpreted within a data rich three‐dimensional data cube that has provided new insights regarding the apparent blank areas surrounding Stonehenge. It is an aim of the project to discover more about Stonehenge by looking out from the site rather than looking at it. Copyright © 2012 John Wiley & Sons, Ltd.
Use of Edge Delineating Methods in Interpreting Magnetic Archaeological Prospection Data
Authors: Stampolidis Alexandros , Tsokas Grigorios N. 
Published: April 2012

ABSTRACTVarious edge delineating methods (edge mappers) are tested on different types of synthetic data produced by calculating the response of a model of buried ancient ruins. The model was constructed to resemble a commonly occurring situation with ruins of two historical phases buried one beneath the other. These weak signals of relatively small wavelengths of the archaeological prospection comprise tough tests for the mappers considered. Additionally, a particular mapper, the balanced horizontal gradient magnitude scaled by the analytic signal is introduced in this study. An example of applying the mappers to real data is also presented. All the mappers proved capable of locating the lateral limits of the subsurface targets but with varying success. Also some of them are very sensitive to noise, rendering them useless for practical application. Some others proved robust in the presence of noise. For a number of them, the varying strength of the aligned maximum values proves an indicator of the variation of the burial depth of the targets. Their merits and drawbacks are demonstrated and discussed with respect to their application on the various types of magnetic archaeological prospection data. Also, relative comparisons are presented. Copyright © 2012 John Wiley & Sons, Ltd.
Intense photon emission induced by fracture of γ–irradiated Dy‐, Tm‐, Sm‐ and Mn‐doped CaSO4 single crystals
Authors: Chandra BP , Tiwari CS , Sharma R 
Published: April 2012

ABSTRACTWhen an γ‐irradiated Dy‐, Tm‐, Sm‐ or Mn‐doped CaSO4 crystal is impulsively deformed, two peaks appear in the ML intensity versus time curve, whereby the first ML peak is found in the deformation region and the second in the post‐deformation region of the crystals. In this study, intensities Im1 and Im2 corresponding to first and second ML peaks, respectively, increased linearly with an impact velocity v0 of the piston used to deform the crystals, and times tm1 and tm2 corresponding to the first and second ML peaks, respectively, decreased with impact velocity. Total ML intensity initially increased with impact velocity and then reached a saturation value for higher values of impact velocity. ML intensity increased with increasing γ‐doses and size of crystals. Results showed that the electric field produced as a result of charging of newly‐created surfaces caused tunneling of electrons to the valence band of the hole‐trapping centres. The free holes generated moved in the valence band and their subsequent recombination with electron trapping centres released energy, thereby resulting in excitation of luminescent centres. Copyright © 2012 John Wiley & Sons, Ltd.
Phospholipid profiling of 57 soybean (Glycine max) varieties by high‐performance liquid chromatography–tandem mass spectrometry and principal component analysis to classify Korean soybean germplasm
Authors: Park Semin , Kim Soo Taek , Kim Chi Yeon , Kim Yun Hi , Jeong Sung Woo , Kim Gon‐Sup , Chung Jong Il , Lee Soo Jung , Shim Jae‐Han , Shin Sung Chul 
Published: April 2012

ABSTRACTPhospholipids (PLs) in 57 varieties of soybeans were profiled by high‐performance liquid chromatography–electrospray ionization‐tandem mass spectrometry and principal component analysis (PCA) to discriminate PL‐rich soybeans. The PL calibration curves showed linearity with correlation coefficients >0.9964. The recoveries at 5 mg/L spiked level ranged from 72.8 to 86.7% and those at 12.5 mg/L from 78.2 to 85.1%. The repeatability at a 5 mg/L spiked level ranged from 2.5 to 7.0% and those at 12.5 mg/L from 1.2 to 3.9%. The average total PL content in the 57 soybean varieties was about 35.3 mg/kg. The total PL content was the highest in Aodaiz (35, 48.7 ± 1.4 mg/kg) and the lowest in Poongsannamul (56, 16.0 ± 0.7 mg/kg). The PCA showed that RS‐78sun (42), Gyeongsang #1 (3) and Aodaiz (35) are the most improved varieties of the investigated 57 varieties from the viewpoint of PL content. Copyright © 2012 John Wiley & Sons, Ltd.
Investigation of the metabolic biotransformation of substance P in liver microsomes by liquid chromatography quadrupole ion trap mass spectrometry
Authors: Pailleux Floriane , Lemoine Jérôme , Beaudry Francis 
Published: April 2012

ABSTRACTSubstance P (SP) belongs to the tachykinin family and plays an essential role in pain transmission and in neurogenic inflammation. It can be detected in the central and peripheral nervous systems. The objectives of this study were to establish SP metabolic stability in liver microsomes in three species (rat, mouse and human), and identify and characterize SP metabolites by LC‐MS/MS. Endogenous peptide metabolism is not well documented and this is particularly true for neuropeptides participating in neurogenic inflammation. In vitro, T1/2 results in pooled liver microsomes were 9.2, 5.6 and 18.6 min for rat, mouse and human liver microsomes, respectively. Five major SP metabolites were identified and quantified, including C‐terminal SP fragments SP3–11, SP5–11, SP6–11, SP8–11 as well as N‐terminal fragment SP1–7. The results suggest significant differences between species in SP metabolite concentrations. Consequently, the metabolic profile of each species is distinctive and may have a significant impact on biomolecular mechanisms involved in specific pathophysiological changes. Copyright © 2012 John Wiley & Sons, Ltd.
Simultaneous determination of sitagliptin and simvastatin in human plasma by LC‐MS/MS and its application to a human pharmacokinetic study
Authors: Burugula Laxminarayana , Mullangi Ramesh , Pilli Nageswara Rao , Makula Ajitha , Lodagala Durga Srinivas , Kandhagatla Rajnarayana 
Published: April 2012

ABSTRACTA simple, rapid and sensitive liquid chromatography–tandem mass spectrometric (LC‐MS/MS) assay method has been developed and validated for simultaneous quantification of sitagliptin and simvastatin in human plasma. Carbamazepine was used as an internal standard (IS). The analytes and IS were extracted from the human plasma by liquid–liquid extraction technique. The reconstituted samples were chromatographed on an Alltima HP C18 column using an isocratic solvent mixture [acetonitrile–5 mm ammonium acetate (pH 4.5), 85:15 (v/v)] at a flow rate of 1.0 mL/min. Method validation was performed as per Food and Drug Administration guidelines and the results met the acceptance criteria. The calibration curves obtained were linear (r2 ≥ 0.99) over the concentration range of 0.10–501 and 0.05–105 ng/mL for sitagliptin and simvastatin, respectively. The results of the intra‐ and inter‐day precision and accuracy studies were well within the acceptable limits. Both the analytes were found to be stable in a battery of stability studies. The method is precise and sensitive enough for its intended purpose. A run time of 3.0 min for each sample made it possible to analyze more than 300 plasma samples per day. The developed assay was successfully applied to a pharmacokinetic study in human volunteers. Copyright © 2012 John Wiley & Sons, Ltd.
Neuronal β‐amyloid generation is independent of lipid raft association of β‐secretase BACE1: analysis with a palmitoylation‐deficient mutant
Authors: Motoki Kazumi , Kume Hideaki , Oda Akiko , Tamaoka Akira , Hosaka Ai , Kametani Fuyuki , Araki Wataru 
Published: April 2012

Abstractβ‐Secretase, BACE1 is a neuron‐specific membrane‐associated protease that cleaves amyloid precursor protein (APP) to generate β‐amyloid protein (Aβ). BACE1 is partially localized in lipid rafts. We investigated whether lipid raft localization of BACE1 affects Aβ production in neurons using a palmitoylation‐deficient mutant and further analyzed the relationship between palmitoylation of BACE1 and its shedding and dimerization. We initially confirmed that BACE1 is mainly palmitoylated at four C‐terminal cysteine residues in stably transfected neuroblastoma cells. We found that raft localization of mutant BACE1 lacking the palmitoylation modification was markedly reduced in comparison to wild‐type BACE1 in neuroblastoma cells as well as rat primary cortical neurons expressing BACE1 via recombinant adenoviruses. In primary neurons, expression of wild‐type and mutant BACE1 enhanced production of Aβ from endogenous or overexpressed APP to similar extents with the β‐C‐terminal fragment (β‐CTF) of APP mainly distributed in nonraft fractions. Similarly, β‐CTF was recovered mainly in nonraft fractions of neurons expressing Swedish mutant APP only. These results show that raft association of BACE1 does not influence β‐cleavage of APP and Aβ production in neurons, and support the view that BACE1 cleaves APP mainly in nonraft domains. Thus, we propose a model of neuronal Aβ generation involving mobilization of β‐CTF from nonraft to raft domains. Additionally, we obtained data indicating that palmitoylation plays a role in BACE1 shedding but not dimerization.
AN ECONOMIC THEORY OF THE FOURTH HURDLE
Authors: Rogowski WH 
Published: April 2012

SUMMARYThird party payers' decision processes for financing health technologies (‘fourth hurdle’ processes) are subject to intensive descriptive empirical investigation. This paper addresses the need for a theoretical foundation of this research and develops a theoretical framework for analysing fourth hurdle processes from an economics perspective.On the basis of a decision‐analytic framework and the theory of agents, fourth hurdle processes are described as sets of institutions to maximize the value derived from finite healthcare resources. Benefits are assumed to arise from the value of better information about and better implementation of the most cost‐effective choice. Implementation is improved by decreased information asymmetries and better alignment of incentives. This decreases the effects of ex ante and ex post moral hazard on service provision. Potential indicators of high benefit include high costs associated with wrong decisions and large population sizes affected by the decision.The framework may serve as a basis both for further theoretical work, for example, on the appropriate degree of participation as well as further empirical work, for example, on comparative assessments of fourth hurdle processes. It needs to be complemented by frameworks for analysing fourth hurdle institutions developed by other disciplines such as bioethics or law. Copyright © 2012 John Wiley & Sons, Ltd.
NOVEMBER RAIN IN DORSET
Authors: Mottram Brian H. 
Published: April 2012

[The original essay, entitled Autumn, of which this is a revised version, was written some eleven years ago when its author was still at school. At that time he could not have drawn the weather map (Fig. 1). This he added recently, after rewriting the essay. “It wasn't till Weather appeared”, he writes, “that I learnt a fuller explanation of the whys and wherefores of the happenings described in the essay. I venture to think that some others as young as I was then would be more interested in meteorology generally if it was brought to them via English weather rather than Atlas climatology and school physics”.Readers may be interested to contrast his colourful account of warm‐front rain with the succinct description presented by the weather map. Both describe aspects of the weather and each approach leads to a fuller appreciation of the other.—Editors]