bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of a Proton Conducting Filler on the Physico‐Chemical Properties of SPEEK‐Based Membranes
Authors: Mecheri B. , D'Epifanio A. , Pisani L. , Chen F. , Traversa E. , Weise F. C. , Greenbaum S. , Licoccia S. 
Published: August 2009

AbstractComposite membranes based on sulphonated polyetherether ketone (SPEEK) having a 60% degree of sulphonation (DS = 0.6) and containing 23 and 50 wt.‐% hydrated tin oxide (SnO2·nH2O) were prepared and characterised. The lower water uptake (WU) and the higher conductivity values recorded for the composite membranes with respect to pure SPEEK reference suggested the involvement of SnO2·nH2O in the proton conduction mechanism. Pulsed‐field‐gradient spin‐echo (PFGSE) NMR was employed to obtain a direct measurement of water self‐diffusion coefficient in the membranes. Differences were observed between the unfilled SPEEK and the composites, including departures from the normal correlation between water diffusivity and proton conductivity in the case of composites. To better understand the SnO2·nH2O effect on the proton transport properties of the SPEEK‐based membrane, we employed an analytical model that predicts the membrane conductivity as a function of its hydration level and porous structure. The comparison of the model results with the experimental proton conductivity values demonstrated that the tin oxide phase provides additional paths between the water clusters for proton transport, resulting in reduced tortuosity and enhanced proton conductivity. Moreover, the composite showed reduced methanol crossover with respect to the unfilled membrane.
The determinants of health‐care expenditure: new results from semiparametric estimation
Authors: Herwartz Helmut , Theilen Bernd 
Published: August 2009

AbstractRecent cross‐country studies have questioned the existence of a systematic relationship between per capita health‐care expenditure (HCE) and explanatory variables such as income, population ageing and total public expenditure. We reexamine this issue mainly focussing at a flexible semiparametric estimation method that allows the parameters of the model to depend on a state variable. Using the age structure of the population as the state variable, we find that the income elasticity increases with population ageing, while other explanatory variables are not significantly influenced by it. Additionally we find that the HCE relationship becomes more and more unstable in ageing economies. These results explain the difficulty to identify both the influence of population ageing and income on HCE in previous studies. Furthermore they indicate that international convergence of HCE across countries crucially depends on the convergence of the population age structure. We also discuss the policy implications of our results regarding the design of a fair health‐care financing system and the evolution of HCE to avoid budgetary problems. Copyright © 2009 John Wiley & Sons, Ltd.
Comments on contingency management and conditional cash transfers
Authors: Higgins Stephen T. 
Published: August 2009

AbstractThis essay discusses research on incentive‐based interventions to promote healthy behavior change, contingency management (CM) and conditional cash transfers (CCT). The overarching point of the essay is that CM and CCT are often treated as distinct areas of inquiry when at their core they represent a common approach. Some potential bi‐directional benefits of recognizing this commonality are discussed. Distinct intellectual traditions probably account for the separate paths of CM and CCT to date, with the former being rooted in behavioral psychology and the latter in microeconomics. It is concluded that the emerging field of behavioral economics, which is informed by and integrates principles of each of those disciplines, may provide the proper conceptual framework for integrating CM and CCT. Copyright © 2009 John Wiley & Sons, Ltd.
Transient storage processes in a steep headwater stream
Authors: Scordo Elisa B. , Moore R. Dan 
Published: August 2009

AbstractThis study examined hyporheic exchange flow and transient storage processes within a steep headwater stream, using both hydrometric and tracer approaches. Vertical hydraulic gradients varied systematically with location within step‐pool units, with upwelling located in a relatively narrow zone immediately below the step. Downward hydraulic gradients were greatest immediately above channel steps, and in that zone, gradients were also correlated with step height. Hydraulic conductivity tended to be lower in downwelling zones than in upwelling and neutral locations. Transient storage areas determined from reach‐scale tracer tests tended to increase with discharge, whereas transient exchange coefficients were not correlated with discharge. Transient storage exchange fluxes estimated from the reach‐scale tracer tests were an order of magnitude greater than hyporheic exchange fluxes estimated by scaling up local estimates based on Darcy's Law and piezometer measurements. This difference could be explained by the presence of lateral hyporheic flow paths and/or the influences of transient storage in pools. Tracer injections into infiltrometers using Rhodamine WT and sodium chloride allowed visual determination of hyporheic discharge zones and calculation of residence times for hyporheic flow through the step (pool inflow) and transport through the downstream pool (pool outflow). These tests indicated that residence time in pools can be comparable to hyporheic residence times, although the lack of replication in time and space limits the drawing of strong inferences. Copyright © 2009 John Wiley & Sons, Ltd.
The impact of Quaternary sea level changes on the evolution of the Amazonian lowland
Authors: Irion Georg , Müller Jens , Morais Jáder O. , Keim Gertrud , de Mello Jose Nunes , Junk Wolfgang J. 
Published: August 2009

AbstractCoring and acoustic surveying (3·5 kHz) in both rivers and lakes in Central Amazonia provide additional insights into the Late Quaternary hydrological and sedimentological development of the Amazon River and its tributaries. Erosion and accumulation phases were found to be linked to Quaternary sea level changes. The low sea level phase during the last glacial maximum caused deep incision of the Amazon River and erosion in major tributaries such as the Rio Negro, 1500 km upstream from the Amazon mouth. A 3·5‐kHz profiling suggests a lowering of the water level by at least 30 m at Manaus. During that phase, the slope of the Amazon valley must have increased, resulting in an increase in bed load transport capacity. The subsequent sea level rise caused a backwater effect far upstream, with silting up of the Amazon valley and the tributary inflows. Former river systems changed into Ria lakes. The floodplains of the Amazon River, the várzea, were formed approximately 5000 years ago when the sea level approached its present‐day level. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of atmospheric pressure and temperature on entrapped gas content in peat
Authors: Waddington J. M. , Harrison K. , Kellner E. , Baird A. J. 
Published: August 2009

AbstractEntrapped biogenic gas in peat can greatly affect peatland biogeochemical and hydrological processes by altering volumetric water content, peat buoyancy, and ‘saturated’ hydraulic conductivity, and by generating over‐pressure zones. These over‐pressure zones further affect hydraulic gradients which influence water and nutrient flow direction and rate. The dynamics of entrapped gas are of global interest because the loss of this gas to the atmosphere via ebullition (bubbling) is likely the dominant transport mechanism of methane (CH4) to the atmosphere from peatlands, which are the largest natural terrestrial source per annum of atmospheric CH4. We investigated the relationship between atmospheric pressure and temperature on volumetric gas content (VGC) and CH4 ebullition using a laboratory peat core incubation experiment.Peat cores were incubated at three temperatures (one core at 4 °C, three cores at 11 °C, and one core at 20 °C) in sealed PVC cylinders, instrumented to measure VGC, pore‐water CH4 concentrations, and ebullition (volume and CH4 concentrations). Ebullition events primarily occurred (71% of the time) during periods of falling atmospheric pressure. The duration of the drop in atmospheric pressure had a larger control on ebullition volume than the magnitude of the drop. VGC in the 20 °C core increased from the onset of the experiment and reached a fluctuating but time‐averaged constant level between experiment day 30 and 115. The change in VGC was low for the 11 °C cores for the initial period of the experiment but showed large increases when the growth chamber temperature increased to 20 °C due to a malfunction. The core maintained at 4 °C showed only a small increase in entrapped gas content throughout the experiment. The 20 °C core showed the largest increase in VGC. The increases in VGC occurred despite pore‐water concentrations of CH4 being below the equilibrium solubility level. Copyright © 2009 John Wiley & Sons, Ltd.
Intracellular imaging of host‐pathogen interactions using combined CARS and two‐photon fluorescence microscopies
Authors: Robinson Iain , Ochsenkühn Michael Andreas , Campbell Colin J. , Giraud Gerard , Hossack William J. , Arlt Jochen , Crain Jason 
Published: August 2009

AbstractIntracellular imaging is a key tool in the investigation of host‐pathogen interactions. Advances in this area are particularly sought to understand the effect of viral infection processes on the host cell and its metabolic functions including those cases where host cell lipid metabolism is modulated as a result of infection. We demonstrate the use of combined coherent anti‐Stokes Raman scattering (CARS) and two‐photon fluorescence microscopies to image fibroblast cells infected by cytomegalovirus. CARS is used to image the host cell membrane, lipid droplets and morphology of the nucleus. Cell nuclei are found to expand during infection, approximately doubling in area. Some cells also show accumulations of lipid droplets at the nuclear periphery. Using a genetically modified virus strain expressing the green fluorescent protein also enables two‐photon imaging of the same cells to reveal the location, nature and extent of viral protein expression. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new strategy to improve the predictive ability of the local lazy regression and its application to the QSAR study of melanin‐concentrating hormone receptor 1 antagonists
Authors: Li Jiazhong , Li Shuyan , Lei Beilei , Liu Huanxiang , Yao Xiaojun , Liu Mancang , Gramatica Paola 
Published: August 2009

AbstractIn the quantitative structure‐activity relationship (QSAR) study, local lazy regression (LLR) can predict the activity of a query molecule by using the information of its local neighborhood without need to produce QSAR models a priori. When a prediction is required for a query compound, a set of local models including different number of nearest neighbors are identified. The leave‐one‐out cross‐validation (LOO‐CV) procedure is usually used to assess the prediction ability of each model, and the model giving the lowest LOO‐CV error or highest LOO‐CV correlation coefficient is chosen as the best model. However, it has been proved that the good statistical value from LOO cross‐validation appears to be the necessary, but not the sufficient condition for the model to have a high predictive power. In this work, a new strategy is proposed to improve the predictive ability of LLR models and to access the accuracy of a query prediction. The bandwidth of k neighbor value for LLR is optimized by considering the predictive ability of local models using an external validation set. This approach was applied to the QSAR study of a series of thienopyrimidinone antagonists of melanin‐concentrating hormone receptor 1. The obtained results from the new strategy shows evident improvement compared with the commonly used LOO‐CV LLR methods and the traditional global linear model. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Purification of adenoviral vectors by combined anion exchange and gel filtration chromatography
Authors: Eglon Marc N. , Duffy Aoife M. , O'Brien Timothy , Strappe Padraig M. 
Published: August 2009

AbstractBackgroundAdenoviral vectors are used extensively in human gene therapy trials and in vaccine development. Large‐scale GMP production requires a downstream purification process, and liquid chromatography is emerging as the most powerful mode of purification, enabling the production of vectors at a clinically relevant scale and quality. The present study describes the development of a two‐step high‐performance liquid chromatography (HPLC) process combining anion exchange (AIEX) and gel filtration (GF) in comparison with the caesium chloride density gradient method.MethodsHEK‐293 cells were cultured in ten‐layer CellStacks™ and infected with 10 pfu/cell of adenoviral vector expressing green fluorescent protein (Ad5‐GFP). Cell‐bound virus was harvested and benzonase added to digest DNA, crude lysate was clarified by centrifugation and filtration prior to HPLC. Chromatography fractions were added to HEK‐293 cells and GFP expression measured using a fluorescent plate reader.ResultsUsing AIEX then GF resulted in an adenoviral vector with purity comparable to Ad5‐GFP purified by CsCl, whereas the reverse process (GF–AIEX) showed a reduced purity by electrophoresis and required further buffer exchange of the product. The optimal process (AIEX–GF) resulted in a vector yield of 2.3 × 107 pfu/cm2 of cell culture harvested compared to 3.3 × 107 pfu/cm2 for CsCl. The process recovery for the HPLC process was 36% compared to 27.5% for CsCl and total virion to infectious particle ratios of 18 and 11, respectively, were measured.ConclusionsWe present a simple two‐step chromatography process that is capable of producing high‐quality adenovirus at a titre suitable for scale‐up and clinical translation. Copyright © 2009 John Wiley & Sons, Ltd.
AFM‐ and NSOM‐based force spectroscopy and distribution analysis of CD69 molecules on human CD4+ T cell membrane
Authors: Hu Mingqian , Chen Jianan , Wang Jiongkun , Wang Xiaoping , Ma Shuyuan , Cai Jiye , Chen Crystal Y. , Chen Zheng W. 
Published: August 2009

AbstractAlthough CD69 is well known as an early T cell‐activation marker, the possibility that CD69 are distributed as nano‐structures on membrane for immune regulation during T cell activation has not been tested. In this study, nanoscale features of CD69 expression on activated T cells were determined using the atomic force microscopy (AFM) topographic and force‐binding nanotechnology as well as near‐field scanning optical microscopy (NSOM)‐/fluorescence quantum dot (QD)‐based nanosacle imaging. Unstimulated CD4+ T cells showed neglectable numbers of membrane CD69 spots binding to the CD69 Ab‐functinalized AFM tip, and no detectable QD‐bound CD69 as examined by NSOM/QD‐based imaging. In contrast, Phytohemagglutinin (PHA)‐activated CD4+ T cells expressed CD69, and displayed many force‐binding spots binding to the CD69 Ab‐functionalized AFM tip on about 45% of cell membrane, with mean binding‐rupture forces 276 ± 71 pN. Most CD69 molecules appeared to be expressed as 100–200 nm nanoclusters on the membrane of PHA‐activated CD4+ T cells. Meanwhile, NSOM/QD‐based nanoscale imaging showed that CD69 were non‐uniformly distributed as 80–200 nm nanoclusters on cell‐membrane of PHA‐activated CD4+ T cells. This study represents the first demonstration of the nano‐biology of CD69 expression during T cell activation. Copyright © 2009 John Wiley & Sons, Ltd.
Raman and IR spectra of the cation‐deficient Aurivillius layered crystal Bi2W2O9
Authors: Ma̧czka M. , Macalik L. , Hanuza J. 
Published: August 2009

AbstractRaman and IR spectra of Bi2W2O9, the m = 2 member of the cation‐deficient Aurivillius phase, have been measured. The obtained spectra are discussed using the factor group approach for the orthorhombic Pna21(C2v9) space group. The results are compared with those obtained for Bi2WO6 and some m = 2 members of Aurivillius family of bismuth layered ferroelectrics. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation and characterization of sizable macroporous epoxy resin‐based monolithic supports for flow‐through systems
Authors: Nguyen Anh Mai , Dinh Ngoc Phuoc , Cam Quach Minh , Sparrman Tobias , Irgum Knut 
Published: August 2009

AbstractThis paper presents further results from our efforts to prepare sizable macroporous monolithic materials from epoxy resins and polyamines by emulsion polymerization. For their uses as supports in flow systems, the study aimed at developing materials possessing maximum fluid permeability, high mechanical stability, and a controlled porosity and surface area. Characterization of the materials has been carried out using different techniques, focusing on morphological and mechanical features, and on the surface chemistry. Morphology and porosity were studied with SEM, nitrogen adsorption/desorption, mercury intrusion porosimetry (MIP), and 2H NMR cryoporosimetry. The chemical composition of the bulk structures and their surfaces was studied by means of bulk elemental analysis and X‐ray photoelectron spectroscopy, and potentiometric titration was used to assess the relative amounts of amines and epoxy groups. Essentially, the morphological features were a high fluid permeability, but rather low specific surface area. Convective flow was facilitated by large, interconnected, and evenly spaced macropores which were formed by nonporous skeletons of the connected‐rod type. Despite the interfacial nature of the polymerization, the bulk and the surface of the fully cured materials showed similar elemental compositions. All materials were found to have a high surface density of hydroxyl groups, which facilitates functionalization reactions.
Functionalization of epoxy‐based monoliths for ion exchange chromatography of proteins
Authors: Dinh Ngoc Phuoc , Cam Quach Minh , Nguyen Anh Mai , Shchukarev Andrei , Irgum Knut 
Published: August 2009

AbstractMacroporous epoxy‐based monoliths prepared by emulsion polymerization have been modified for use in ion exchange chromatography (IEC) of proteins. Strong anion exchange functionality was established by iodomethane quaternization of tertiary amine present on the monolith surface as a part of the polymer backbone. The modification pathway to cation exchange materials was via incorporation of glycidyl methacrylate (GMA) brushes which were coated using atom transfer radical polymerization (ATRP). Strong (SO3–) and weak (COO–) cation exchange groups were thereafter introduced onto the GMA‐grafted monoliths by reactions with sodium hydrogen sulfite and iminodiacetic acid, respectively. Grafting was confirmed by XPS, gravimetric measurement, and chromatographic behavior of the modified materials toward model proteins. In incubation experiments the proteins were recovered quantitatively with no obvious signs of unfolding after contact with the stationary phase for >2 h. Chromatographic assessments on the functionalized columns as well as problems associated with flow‐through modification by ATRP are discussed.
Methodologies for soil erosion and land degradation assessment in mediterranean‐type ecosystems
Authors: Ries J. B. 
Published: August 2009

AbstractThe detection of spatial distribution and temporal development of soil erosion processes and forms on abandoned land still represents a great scientific challenge. Abandoned fields as a result of land use changes during the past century can frequently be found in the Mediterranean. The former fields are generally used for grazing and therefore are highly complex concerning the variability of soil erosion processes.A three‐step research method is used for assessment and evaluation of soil erosion processes. By means of rainfall simulations, test plot monitoring and large‐scale aerial photography, erosion processes are quantified and scenarios are presented for three test sites in northeast Spain.With a large‐scale test plot monitoring the development of soil erosion processes can be evaluated. Areas with predominantly increasing soil erosion activity are classified as unstable, whereas areas with unchanged or decreasing soil erosion activity are classified as vulnerable or stable. Forty to 70 years after abandonment and change to grazing all observed test areas show a progressive degradation. The proportion of unstable areas reaches around 50 per cent. The extension of unstable areas, characterised by a combination of increasing erosion activity and decreasing vegetation cover, is highest within the semi‐arid Ebro Basin reaching 29 per cent of the whole area. Dense vegetation cover does not always correlate with stability in erosion and increase in cover does not generally lead to a stabilisation of erosion processes. Even under increasing vegetation cover of more than 60 per cent high erosion and runoff rates are possible particularly in connected rills and on sheep trails. Therefore, grazing on abandoned fields is the critical factor leading to further degradation. Copyright © 2009 John Wiley & Sons, Ltd.
Venous drainage in retrograde island flap: An experimental study using fluorescence tracing technique
Authors: Jing Zhi‐Zhen , Chang Shi‐Min , You Mu‐Rong , Yu Guang‐Rong 
Published: August 2009

AbstractThe pathway of venous drainage in retrograde island flaps was investigated by fluorescence tracing technique using the saphenous fasciocutaneous flap in New Zealand White rabbits. Forty animals were allocated into four groups according to the different times at 30 minutes (I), 24 hours (II), 72 hours (III), and 7 days (IV) after the operation. According to the different routes to give tracer, each group was further allocated into two subgroups of the artery injection and vein injection. For each animal, one hindlimb was assigned as the experimental side, the contralateral side as control without giving tracer. The erythrocytes were separated, labeled with fluorescein isothiocyanate (FITC), detected, and injected into the artery or vein. Subsequently, the flaps were harvested 5 seconds after injection and immediately frozen, sectioned, and observed under microscope. In group I and II, the fluorescence was observed mainly around the vessel adventitia of the vein and artery and tunica intima of the artery. In group III, there was weak fluorescence observed in the lumen of vein. In group IV, fluorescence was distributed principally in the lumen of the vein. In addition, fluorescence was not observed in the saphenous nerve in group I and there was mild fluorescence in the saphenous nerve in groups II, III, and IV. These findings suggest that the venous return is through “bypass route” in earlier period. In later period, the venous retrograde return is through “bypass route” and “incompetent valves route;” however, “incompetent valves route” becomes the main route. © 2009 Wiley‐Liss, Inc. Microsurgery 2010.