bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluoropassivation and gelatin sealing of polyester arterial prostheses to skip preclotting and constrain the chronic inflammatory response
Authors: Xie Xingyi , Guidoin Robert , Nutley Mark , Zhang Ze 
Published: February 2010

AbstractFluoropassivation and gelatin coating have been applied to polyethylene terephthalate (PET) vascular prosthesis to combine the advantages of both polytetrafluoroethylene (PTFE) and PET materials, and to eliminate the preclotting procedure. The morphological, chemical, physical, and mechanical properties of such prostheses were investigated and compared with its original model. Fluoropassivation introduced OCF3, CF3, and CFCF2 structures onto the surface of the polyester fibers. However, the surface fluorine content was only 28–32% compared to the 66% in expanded PTFE (ePTFE) grafts. The fluoropassivation decreased the hydrophilicity, slightly increased the water permeability, and marginally lowered the melting point and the crystallinity of the PET fibers. After gelatin coating, the fluoropassivated and nonfluoropassivated prostheses showed similar surface morphology and chemistry. While gelatin coating eliminated preclotting, it also renders the prostheses slightly stiffer. The original prosthesis had the highest bursting strength (275 N), with the fluoropassivated and gelatin‐sealed devices showing similar bursting strength between 210 and 230 N. Fluoropassivation and gelatin coating lowered the retention strength by 23 and 30% on average, respectively. In vitro enzymatic incubation had only marginal effect on the surface fluorine content of the nongelatin‐sealed prostheses. However, the gelatin‐sealed ones significantly lost their surface fluorine after in vitro enzymatic incubation (by 69–85%) or in vivo 6‐month implantation (by 51–60%), showing the lability of the fluoropolymer layer under the hostile biological environment. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Characterization of an air‐spun poly(L‐lactic acid) nanofiber mesh
Authors: François Sébastien , Sarra‐Bournet Christian , Jaffre Antoine , Chakfé Nabil , Durand Bernard , Laroche Gaétan 
Published: February 2010

AbstractIt was previously showed that PLLA nanofiber mesh promoted good endothelial cell proliferation. A new technique was developed to produce nanofibers by air jet spinning inside the tubular shape of vascular prostheses and to characterize this nanofiber mesh. Polymer macromolecule stability was assessed by gel permeation chromatography. Thermal analyses were conducted with differential scanning calorimetry and dynamic mechanical analysis on PLLA nanofibers obtained with 4% and 7% solutions (w/v) in chloroform. Polyethylene terephthalate (PET) was also treated with atmospheric pressure dielectric barrier discharge under air or nitrogen atmosphere to optimize PLLA nanofiber adherence, assessed by peel tests. Air spinning induced a reduction of number‐average molecular weight (Mn) for the 7% PLLA solution but not for the 4% solution. The nanofibers were more crystalline and less sensible to viscoelastic relaxation as a function of aging in the 4% solution than in the 7% solution. Discharge treatment of the PET promoted identical surface modification on PET film and PET textile surfaces. Moreover, the best PLLA nanofibers adhesion results were obtained under nitrogen atmosphere. This study demonstrates that it is possible to coat the internal side of tubular vascular prostheses with PLLA nanofibers, and provides a better understanding of the air spinning process as well as optimizing nanofibers adhesion. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Increased trabecular bone formation in mice lacking the growth factor midkine
Authors: Neunaber Claudia , Catala-Lehnen Philip , Beil F Timo , Marshall Robert P , Kanbach Vincent , Baranowsky Anke , Lehmann Wolfgang , Streichert Thomas , Ignatius Anita , Muramatsu Takashi , Schinke Thorsten , Amling Michael 
Published: February 2010

Abstract
Midkine (Mdk) and pleiotrophin (Ptn) comprise a family of heparin-binding growth factors known primarily for their effects on neuronal cells. Since transgenic mice overexpressing Ptn have been reported to display increased bone density, we have previously analyzed Ptn-deficient mice but failed to detect any abnormality of skeletal development and remodeling. Together with the finding that Mdk expression increases in the course of primary osteoblast differentiation, we reasoned that Mdk, rather than Ptn, could play a physiologic role in bone formation. Here, we show that Mdk-deficient mice display an increased trabecular bone volume at 12 and 18 months of age, accompanied by cortical porosity. Histomorphometric quantification demonstrated an increased bone-formation rate compared with wild-type littermates, whereas bone resorption was differentially affected in trabecular and cortical bone of Mdk-deficient mice. To understand the effect of Mdk on bone formation at the molecular level, we performed a genome-wide expression analysis of primary osteoblasts and identified Ank and Enpp1 as Mdk-induced genes whose decreased expression in Mdk-deficient osteoblasts may explain, at least in part, the observed skeletal phenotype. Finally, we performed ovariectomy and observed bone loss only in wild-type but not in Mdk-deficient animals. Taken together, our data demonstrate that Mdk deficiency, at least in mice, results in an increased trabecular bone formation, thereby raising the possibility that Mdk-specific antagonists might prove beneficial in osteoporosis therapy. © 2010 American Society for Bone and Mineral Research
A gradient‐directed Monte Carlo approach for protein design
Authors: Hu Xiangqian , Hu Hao , Beratan David N. , Yang Weitao 
Published: February 2010

AbstractWe develop a new global optimization strategy, gradient‐directed Monte Carlo (GDMC) sampling, to optimize protein sequence for a target structure using RosettaDesign. GDMC significantly improves the sampling of sequence space, compared to the classical Monte Carlo search protocol, for a fixed backbone conformation as well as for the simultaneous optimization of sequence and structure. As such, GDMC sampling enhances the efficiency of protein design. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
Rethinking climate refugees and climate conflict: Rhetoric, reality and the politics of policy discourse
Authors: Hartmann Betsy 
Published: February 2010

AbstractThis paper critically examines the perceived threat of ‘climate refugees’ and ‘climate conflict’. It locates the ideological roots of these concepts in development theories and policy narratives about demographically induced migration, environmental refugees and environmental security. While alarmist rhetoric around climate refugees and conflict has been deployed by a variety of actors, including U.N. agencies, development NGOs, national governments, security pundits and popular media, the paper concentrates on its strategic use by U.S. defence interests. It raises the question of how the portrayal of climate change as a security threat could further militarise the provision of development assistance and distort climate policy. Copyright © 2010 John Wiley & Sons, Ltd.
Upscaling spatio‐temporal patterns of cation fluxes in acid forest soils
Authors: Zirlewagen Dietmar , von Wilpert Klaus 
Published: February 2010

AbstractOne main problem with current research on spatio‐temporal modeling of ion fluxes in forest soils is the separation of space and time effects in the soil‐monitoring concept. This article describes an approach to overcome this weakness. Time trends of point information on soil‐solution data (base‐cation concentrations and fluxes) are scaled by linking them to soil‐chemical data which is available in higher spatial resolution and can be upscaled to an area base. This approach is based on a combined evaluation of bulk soil and soil‐solution data using both statistical and process‐oriented methods. Multiple‐linear‐regression analyses coupled with geostatistics were developed to predict spatial patterns of exchangeable cation percentages. In a second step, empirical ion‐distribution coefficients were adapted according to Gapon using data of suction‐cup plots and bulk‐soil samples. Seasonally adjusted time‐series data of soil‐solution chemistry were then connected with the maps of the predicted exchangeable‐cation percentages by means of the Gapon equations. This evaluation step provided both time‐ and space‐dependent maps of cation concentrations in the soil solution. Finally, using the results of a water‐budget model it was possible to derive spatio‐temporal patterns of soil cation fluxes. Methodological limitations and the results of verification processes are discussed. The methods described can only be used in acidic soils and should not be used in soil layers rich in humus, since adsorption to C compounds differs from adsorption to clay minerals. The time increments of the models should be not shorter than yearly in order to suppress annual periodicity. Although the Gapon equations were not based on laboratory‐determined exchange solutions at quasi‐equilibrium, but rather on field data from the suction‐cup technique, the exchangeable‐cation percentages showed steady functions of selectivity coefficients. The methods tested at a watershed scale may be flexible enough to be applied at other scales as well.
Nitrogen mineralization from an organically managed soil and nitrogen accumulation in lettuce
Authors: Ribeiro Henrique M. , Fangueiro David , Alves Fátima , Ventura Rita , Coelho Dulce , Vasconcelos Ernesto , Cunha‐Queda Cristina , Coutinho João , Cabral Fernanda 
Published: February 2010

AbstractThe potential of an organically managed Cambic Arenosol to supply nitrogen (N) from either an applied commercial organic fertilizer (granulated hen manure), a compost produced on‐farm, or four different mixtures of both fertilizers was studied in a laboratory incubation and a pot experiment with lettuce. In the incubation experiment, a significant higher apparent N mineralization occurred after hen‐manure application (53.4% of the organic N applied) compared to compost (4.5%) or mixed‐fertilizer application (8.7% to 16.7%). The apparent N mineralization in a mixed treatment consisting of compost and half rate of hen manure (15.4% of the organic N applied) was significantly higher than that estimated based on the N mineralization for compost and hen‐manure treatments (7.6%), proving that a combined application of both fertilizers enhanced organic‐N mineralization when compared to separate fertilizer supply. In the pot experiment, a higher lettuce fresh‐matter yield was obtained with hen manure (1.9 kg m–2) than with compost (1.7 kg m–2) or unfertilized control treatment (1.3 kg m–2). Combined application of compost with only a half rate of hen manure led to yields (2.0 kg m–2) equal to those obtained with only hen manure. A good correlation was observed between the N‐mineralization incubation data and the N accumulated by lettuce plants in the pot experiment (r = 0.983). Hence, in the organic production of baby‐leaf lettuce, a mixture of compost and hen manure appears to be a good fertilization alternative, since it allows a reduction by half of the typical amount of commercial fertilizer usually applied (granulated hen manure), cutting fertilization costs, and providing an amount of available N that allows maintaining lettuce yields.
Fuzzy comprehensive evaluation for selecting mini watermelon cultivars
Authors: Hou Pei , Zhang Jing , Zhang Xian 
Published: February 2010

AbstractBACKGROUND: The traditional method for selecting suitable mini watermelon cultivars has been shown to be flawed. The aim of the present study was to assess 11 mini watermelon cultivars using a new method, two‐level fuzzy comprehensive evaluation (FCE). Three different characteristics for selecting the best cultivars were chosen to establish the evaluation index system, namely commercial trait, early maturity and high yield quality. Fifteen specific factors were used to reflect these three characteristics.RESULTS: According to the final results of FCE, Linglongwang was selected as the best of the 11 cultivars overall. Autocopulation F1 of Hai 024 × Hai 011 was ranked second overall, while Heimeiren × Yun 05‐2‐1‐1 was ranked lowest overall. Hai 051 × Hai 011 was the best cultivar in early maturity but worse in commercial trait and high yield quality than some other cultivars.CONCLUSION: FCE can reflect the multiple characteristics of a cultivar objectively and precisely. This method has huge potential in selecting mini watermelon cultivars. Copyright © 2010 Society of Chemical Industry
Biofortification of lettuce (Lactuca sativa L.) with iodine: the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce grown in water culture
Authors: Voogt Wim , Holwerda Harmen T , Khodabaks Rashied 
Published: February 2010

AbstractBACKGROUND: Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce, grown in water culture.RESULTS: In both a winter and summer trial, dose rates of 0, 13, 39, 65, and 90 or 129 µg iodine L−1, applied as iodate (IO3−) or iodide (I−), did not affect plant biomass, produce quality or water uptake. Increases in iodine concentration significantly enhanced iodine content in the plant. Iodine contents in plant tissue were up to five times higher with I− than with IO3−. Iodine was mainly distributed to the outer leaves. The highest iodide dose rates in both trials resulted in 653 and 764 µg iodine kg−1 total leaf fresh weight.CONCLUSION: Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I− and IO3−. I− was more effective than IO3−. Fifty grams of iodine‐biofortified lettuce would provide, respectively, 22% and 25% of the recommended daily allowance of iodine for adolescents and adults. Copyright © 2010 Society of Chemical Industry
Influence of Stabilizer Concentration on Transport Behavior and Thermopower of CNT‐Filled Latex‐Based Composites
Authors: Kim Yeon Seok , Kim Dasaroyong , Martin Kaylan J. , Yu Choongho , Grunlan Jaime C. 
Published: February 2010

AbstractThe influence of the stabilizer/SWNT ratio on the transport behavior of latex‐based polymer nanocomposites is examined in an effort to improve electrical conductivity while maintaining or improving the Seebeck coefficient (i.e., thermopower). Results show that phonon and electron transport are significantly affected by tube/tube junctions, and the carrier transport across the junctions can be manipulated by altering the stabilizer concentration. Electrical conductivity of composites containing 10 wt.‐% SWNT nearly doubles, becoming greater than 900 S · m−1, by changing the SWNT:GA ratio from 1:3 to 10:1, while thermal conductivity and Seebeck coefficient remain relatively constant (near 0.25 W · m‐K−1 and 40 µV · K−1, respectively).magnified image
Change and Convergence of Polymer Distribution During Nonrandom Degradation
Authors: Tobita Hidetaka 
Published: February 2010

AbstractThe CLD development during nonrandom degradation is investigated, assuming the rate of bond scission depends on the chain length and the position of the bond within the chain. As the degradation proceeds, the polydispersity index $({\rm PDI} = \bar {P}_{\rm w} /\bar {P}_{\rm n} )$ usually approaches a fixed value pertinent to the degradation mechanism, independent of the initial distribution. The exact limiting values are presented for several cases. These values may be useful to estimate the degradation mechanisms. For example, if the limiting PDI is smaller than 2, the bonds in larger chains may be easier to break than shorter ones, and if it is smaller than 4/3, the size effect is not enough and the breakage may tend to occur in the middle of the chain.magnified image
a‐SiC:H passivation for crystalline silicon solar cells
Authors: Ehling Christian , Werner Jürgen H. , Schubert Markus B. 
Published: February 2010

AbstractThis study aims at a better understanding of the electronic surface passivation of monocrystalline silicon wafers by thin amorphous silicon carbide (a‐SiC:H) layers. Annealing a‐SiC:H coated Si wafers in forming gas up to an annealing temperature Tan = 700 oC, reveals the correlation between the effective charge carrier lifetime τeff and structural features of the a‐SiC:H monitored by Fourier‐Transform Infra Red (FTIR) spectroscopy. Passivation layers with low carbon content yield effective lifetimes τeff > 1 ms for Tan = 600 °C. Increasing the C content lowers the thermal stability of the electronic passivation. Out of detailed FTIR measurements, the absorption strength ratio R permits statements of microvoids in the amorphous layers. Comparing R with the effective lifetimes enables a qualitative forecast concerning the temperature stability of a‐SiC:H passivation layers. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation between microstructure and residual stress of nanocrystalline silicon films
Authors: Chowdhury Amartya , Ray Swati 
Published: February 2010

AbstractThe nanocrystalline silicon films have been prepared using very high frequency PECVD technique. The deposition power density and hydrogen dilution of Silane were varied. The sizes of the grains varies from 6 nm to 32 nm for films deposited under different conditions. The stress of the nanocrystalline films have been estimated from (220) line. It is observed that compressive stress decreases and become tensile stress as Xc of the films increases with increase in power density. Whereas compressive stress increases as crystalline volume fraction increases with increase in hydrogen dilution. Maximum tensile stress and compressive stress obtained are 0.23 GPa and 5.1 GPa respectively. It is also observed that compressive stress in the film increases as grain size increases. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excimer laser wet oxidation of hydrogenated amorphous silicon
Authors: Persheyev Saydulla K. , Fan Yongchang , Reynolds Steve , Rose Mervyn J. 
Published: February 2010

AbstractWe present results of the excimer laser wet oxidisation of submicron thick hydrogenated amorphous silicon films (a‐Si:H) deposited on silicon wafer. The a‐Si:H film irradiation was carried out by multiple‐pulses, large‐spot, 20 ns KrF (248 nm) excimer laser and fluences of 140‐300 mJ/cm2, near to the silicon ablation threshold in an air atmosphere. The oxygen and hydrogen content and bonding in the thin films were analysed by Fourier Transform Infrared Spectroscopy (FTIR) techniques in the range 400‐4000 cm–1. We demonstrate that the presence of water molecules on the silicon surface will increase oxidation by 30‐40%. The bonded hydrogen content in the films after oxidation annealing is decreased from 12 down to around 1 atomic percent. Wet oxidised surfaces present highly hydrophobic properties which appears to be determined by the amorphous silicon structure transformation and silicon surface energy modification forming a silicon/oxide (nitride) interface. (© WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
TiOxNy anti‐resonant layer ARROW waveguides
Authors: Carvalho Daniel O. , Albertin Katia F. , Alayo Marco I. 
Published: February 2010

AbstractARROW waveguides with sputtered‐TiOxNy anti‐resonant layers obtained with different nitrogen concentration in the gaseous mixture were fabricated and characterized. A study of the influence of this parameter on the losses of the waveguides is presented in this work. TiOxNy films have very high refractive indexes, which is a very important characteristic for the first ARROW layer, since this layer behaves like a Fabry‐Perot resonator in anti‐resonance. Optical and compositional properties of the TiOxNy films were also studied and the results are presented. These films were characterized by Rutherford Backscattering Spectroscopy (RBS), FTIRs, optical absorption and ellipsometry. The second anti‐resonant layer and the core of the waveguides were composed of thermally grown SiO2 and PECVD‐SiOxNy, respectively. Optical characterization results show propagation losses as low as 1.18 dB/cm for single‐mode waveguides fabricated with TiOxNy films obtained with 25% of nitrogen in the gaseous mixture. (© WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Half rotations leading to retention of stereochemistry in epoxide ring opening by selenocyanate ion: Insights from DFT modeling
Authors: Kalaiselvan Anbarasan , Muthukumar Kaliappan , Senthilnathan Dhurairajan , Maldivi Pascale , Venuvanalingam Ponnambalam 
Published: February 2010

AbstractStilbene oxide on reaction with selenocyanate ion in methanol (Culvenor et al., J Chem Soc 1949, 278) has been found to yield the corresponding stilbene with the deposition of metallic Se. For this reaction, a tentative mechanism involving “two half rotations” around the carbon–carbon bond based on the observed stereospecificity and formation of episelenide intermediate has been suggested. This reaction has been modeled at B3LYP/6‐31+G(d) level and the potential energy surface of the reaction has been explored. Computations suggest a backside attack of the selenocyanate ion to one of the epoxide carbon atoms to form a prereactive complex, two successive half‐rotations around the carbon–carbon bond in the opposite direction, the formation and decomposition of episelenide intermediate, and finally trans‐stilbene. Calculations besides agreeing excellently with experiment reveal many interesting mechanistic details that experimentalists could not unravel. Wiberg bond order analyses reveal the smooth progress in the bond changes during the course of the reaction. Solvent effect through PCM model calculations with methanol as solvent does not alter the gas phase results significantly. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
A UNIFIED APPROACH TO VARIOUS GENERALIZATIONS OF ARMENDARIZ RINGS
Authors: MARKS GREG , MAZUREK RYSZARD , ZIEMBOWSKI MICHAŁ 
Published: February 2010

AbstractLet R be a ring, S a strictly ordered monoid, and ω:S→End(R) a monoid homomorphism. The skew generalized power series ring R[[S,ω]] is a common generalization of (skew) polynomial rings, (skew) power series rings, (skew) Laurent polynomial rings, (skew) group rings, and Mal’cev–Neumann Laurent series rings. We study the (S,ω)-Armendariz condition on R, a generalization of the standard Armendariz condition from polynomials to skew generalized power series. We resolve the structure of (S,ω)-Armendariz rings and obtain various necessary or sufficient conditions for a ring to be (S,ω)-Armendariz, unifying and generalizing a number of known Armendariz-like conditions in the aforementioned special cases. As particular cases of our general results we obtain several new theorems on the Armendariz condition; for example, left uniserial rings are Armendariz. We also characterize when a skew generalized power series ring is reduced or semicommutative, and we obtain partial characterizations for it to be reversible or 2-primal.