bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microchip‐based small, dense low‐density lipoproteins assay for coronary heart disease risk assessment
Authors: Wang Hua , Wang Hui‐Min , Jin Qing‐Hui , Cong Hui , Zhuang Gui‐Sheng , Zhao Jian‐Long , Sun Cheng‐Long , Song Hong‐Wei , Wang Wei 
Published: April 2008

AbstractSmall, dense low‐density lipoprotein (sdLDL) has been accepted as an emerging cardiovascular risk factor, and there has been an increasing interest in analytical methods for sdLDL profiling for diagnosis. Serum sdLDL may be measured by different laboratory techniques, but all these methods are laborious, time‐consuming, and costly. Recently, we have demonstrated that a low‐temperature bonding of quartz microfluidic chips for serum lipoproteins analysis (Zhuang, G., Jin, Q., Liu, J., Cong, H. et al., Biomed. Microdevices 2006, 8, 255–261). In contrast to this previous study, we chose SDS as anionic surfactant to modify both lipoproteins and the channel surface to minimize lipoprotein adsorption and improve the resolution of lipoprotein separation. Two major LDL subclass patterns including large, buoyant LDL (lLDL), sdLDL, and high‐density lipoprotein (HDL) were effectively separated with high reproducibility. RSD values of the migration time (min) and peak areas of standard LDL and HDL were 6.28, 4.02, 5.02, and 2.5%, respectively. Serum lipoproteins of 15 healthy subjects and 15 patients with coronary heart disease (CHD) were separated by microchip CE. No peaks of sdLDL were detected in serum samples of healthy subjects while sdLDL fractional peaks were observed in patients' entire serum samples. These results suggested that the microchip‐based sdLDLs assay was a simple, rapid, and highly efficient technique and significantly improved the analysis of CHD risk factors.
Continuous and precise particle separation by electroosmotic flow control in microfluidic devices
Authors: Kawamata Takahiro , Yamada Masumi , Yasuda Masahiro , Seki Minoru 
Published: April 2008

AbstractA new scheme has been described for continuous particle separation using EOF in microfluidic devices. We have previously reported a method for particle separation, called “pinched flow fractionation (PFF)”, in which size‐dependent and continuous particle separation can be achieved by introducing pressure‐driven flows with and without particles into a pinched microchannel. In this study, EOF was employed to transport fluid flows inside a microchannel. By controlling the applied voltage to electrodes inserted in each inlet/outlet port, the flow rates from both inlets, and flow rates distributed to each outlet could be accurately tuned, thus enabling more effective separation compared to the pressure‐driven scheme. In the experiment, the particle behaviors were compared between EOF and pressure‐driven flow schemes. In addition, micrometer‐ and submicrometer‐sized particles were accurately separated and individually collected using a microchannel with multiple outlet branch channels, demonstrating the high efficiency of the presented scheme.
A stochastic multi‐antenna matrix channel model for efficient link‐level simulations
Authors: Falletti Emanuela , Sellone Fabrizio 
Published: April 2008

AbstractThe availability of realistic propagation channel models and computationally affordable channel simulators is a fundamental brick for the design of effective wireless mobile communication systems, since fading mitigation techniques in both temporal and spatial domains attract nowadays main designers' interest.This paper proposes a novel channel model and related channel simulator expressly conceived for link‐level simulations of wireless communication links wherein both transmitters (TXs) and receivers (RXs) may be equipped with an array of antennas. Physical propagation effects generating spatial and temporal fading, along with the possible presence of scatterers, are taken into account. The structure of the channel simulator is designed to maintain affordable computational burden, through an efficient time‐varying finite impulse response (FIR) filter bank implementation. Copyright © 2008 John Wiley & Sons, Ltd.
Free surface tracking with polynomial reconstruction and error correction
Authors: Kim Hyoseob , Jung Byung Soon , Hall Kevin 
Published: April 2008

AbstractA non‐linear method, PREC, for computation of the movement of a free surface is proposed here. The method is composed of three steps: identifying the free surface by using a non‐linear function from the volume fraction matrix, updating the volume fraction matrix using a volume projection method with error correction, and treatment of the results using overshooting or undershooting. Identification of the free surface includes using a polynomial function with 2, 4, or 8 coefficients for one‐, two‐, or three‐dimensional problems, respectively. The polynomial reconstruction involves non‐negligible numerical error. The second advection step includes a linear projection method in space and time. Advection of the volume fraction matrix is computed from the occupying volume of the mesh at the previous time step. At the new time step, the error at each grid point is assumed to be similar to the error at the previous time step and is used for correction. Overshooting or undershooting develops around the free surface mesh points due to the solution's finite time increment. The third step includes truncating the numerical overshooting or undershooting volumes, i.e. isotropic spreading of the excess fluid volumes. The PREC method is evaluated for a one‐dimensional flow case and several two‐dimensional simple flow cases with circular sections (cases include transition parallel to a coordinate, transition with an intersection angle to a coordinate, and rotation). The results from the present method are compared with analytical solutions and results from a donor‐cell VOF method. As a result of these comparisons, the PREC method is validated. Copyright © 2008 John Wiley & Sons, Ltd.
Credit risk management in Greater China
Authors: Byström Hans 
Published: April 2008

AbstractIn this paper the focus is on market‐wide credit protection. More exactly, the newly introduced iTraxx Greater China credit default swap (CDS) index is examined, and to what degree this index can be used to protect against market‐wide credit risk in the Greater China area is assessed. Although the iTraxx Greater China CDS index is found to be significantly correlated with both the value and volatility of an equally weighted stock portfolio of the names in the CDS index itself, it is found to move more or less independently from some of the most widely used stock indexes in the Greater China region. Not surprisingly, considering the geographical distribution of the constituents in the iTraxx Greater China index, the major stock indexes covering mainland China are found to be particularly uncorrelated with the CDS index. Based on well‐known theoretical arguments as well as extensive empirical evidence in the literature, it is argued that this makes it difficult to manage credit risk in mainland China using the iTraxx Greater China CDS index, at least until more mainland China names have been included in the CDS index. © 2008 Wiley Periodicals, Inc. Jrl Fut Mark 28:582–597, 2008
Estimation and forecasting of stock volatility with range‐based estimators
Authors: Jacob Joshy , Vipul  
Published: April 2008

AbstractThis paper examines the estimation and forecasting performance of range‐based volatility estimators for stocks, with two‐scales realized volatility as the benchmark. There is evidence that the daily range‐based estimators provide an efficient and low‐bias alternative to the return‐based estimators. These are not downwardly biased in the presence of negative autocorrelation and low liquidity, as generally suspected. The drift is a major cause of the poor performance of Parkinson's estimator. The forecasts of volatility with these estimators are about as efficient as those with the benchmark itself but are more biased. The forecasts based on realized range are only marginally better on the criterion of bias and are about as efficient. Considering their simplicity and lower data requirement, the daily range‐based estimators appear to be more desirable. These results are particularly relevant for the option valuation and the risk management of derivative markets. © 2008 Wiley Periodicals, Inc. Jrl Fut Mark 28:561–581, 2008
It goes both ways: measurements of simultaneous evapotranspiration and fog droplet deposition at a montane cloud forest
Authors: Beiderwieden E. , Wolff V. , Hsia Y.‐J. , Klemm O. 
Published: April 2008

AbstractFluxes of latent heat, sensible heat, and water vapor, including turbulent deposition of fog droplets, were measured for two months in autumn 2005 within a subtropical montane cypress forest in Taiwan. The goal of the study was to determine whether significant evapotranspiration can occur during foggy conditions. Water vapor fluxes, QW, as determined with the Bowen Ratio method, were compared to those simultaneously measured with the eddy covariance method. The median Bowen Ratio was 1.06, and the median QW flux was 5 · 2 × 10−5 kg m−2 s−1. The vertical gradients of temperature and specific humidity over the forest, ΔT and Δq, peaked around noon during days without fog, and were reduced during foggy conditions. For 66% of the data points, ΔT and Δq were negative, corresponding to positive (upward) fluxes of sensible heat QH and latent heat QE. A Monte Carlo simulation proved that statistically significant evapotranspiration rates, i.e., upward water vapor fluxes, occurred during fog. At the same time, deposition fluxes of fog droplets occurred. Our results show that even during fog events, significant evapotranspiration may occur. Copyright © 2008 John Wiley & Sons, Ltd.
The impact of single natural vegetation elements on flow characteristics
Authors: Yagci O. , Kabdasli M. S. 
Published: April 2008

AbstractIn this experimental study, measurements were conducted to explore the impacts of different forms of individual natural vegetative elements within the flow domain on velocity and turbulence characteristics. All the experiments were performed in a flume measuring 26 m in length, 0·98 m in width and 0·85 m in depth, and real tree saplings were utilized to represent the vegetation element. In order to analyse this commonly observed nature phenomenon in floodplains, trees with wide trunks were classified into three groups on the basis of their volume versus height relation. Throughout the velocity measurements three acoustic Doppler velocimeters were employed. Time‐averaged velocity, streamwise and vertical turbulence intensities and turbulent kinetic energy parameters were examined. Additionally, a formulation that gives the velocity profile at a certain distance downstream of vegetation was introduced and the validity of the proposed formulation was checked with experimental data. It is seen that despite their porous structures, the presence of vegetation considerably disturbs the flow field and dissipates a remarkable amount of energy by turbulence. Copyright © 2008 John Wiley & Sons, Ltd.
Ten‐year water table recovery after clearcutting and draining boreal forested wetlands of eastern Canada
Authors: Marcotte Philippe , Roy Vincent , Plamondon André P. , Auger Isabelle 
Published: April 2008

AbstractIn boreal forested wetlands, the observed increase in the water table level after clearcutting (watering‐up) is often a threat to sustained ecosystem productivity. Hydrologic recovery refers to the processes by which a water table progressively drops back to its initial level after the cut. In eastern Canada, drainage is used operationally after clearcutting wet sites in order to lower the water table level and accelerate hydrologic recovery. The objective of this study was to evaluate the duration of the watering‐up caused by timber harvesting and the extent to which drainage affected the water table recovery on five peatlands and three hydromorphic mineral sites located in the St. Lawrence Lowlands of Québec (Canada). The mixed wood stands studied are dominated by balsam fir (Abies balsamea (L.) Mill.), eastern white cedar (Thuja occidentalis L.), and red maple (Acer rubrum L). Results indicate that, 10 years after clearcutting, water table levels in undrained plots are still 5 to 7 cm higher than the pre‐cut levels. The slight recovery in water table level plateaued after the third year. Rainfall interception by vegetation was also monitored, and after 10 years had reached nearly 50% of the pre‐cut rate. The immediate water table drawdown following drainage mitigated watering‐up within 40 m of a ditch. The persistent watering‐up observed in this study should encourage using sylvicultural systems adapted to boreal forested wetlands in order to prevent productivity loss and stand conversion. Copyright © 2008 John Wiley & Sons, Ltd.
Nanocomposite Ti/hydrocarbon plasma polymer films from reactive magnetron sputtering as growth support for osteoblast‐like and endothelial cells
Authors: Grinevich Andrey , Bacakova Lucie , Choukourov Andrei , Boldyryeva Hanna , Pihosh Yuriy , Slavinska Danka , Noskova Lenka , Skuciova Maria , Lisa Vera , Biederman Hynek 
Published: April 2008

AbstractNanocomposite Ti/hydrocarbon plasma polymer (Ti/ppCH) films were deposited by DC magnetron sputtering of titanium target in n‐hexane, argon, or a mixture of these two gases. The resultant films were heterogeneous, with inorganic regions of nanometer scale distributed within a plasma polymer matrix. The titanium content was controlled by adjusting the argon/n‐hexane ratio in the working gas. In the pure n‐hexane atmosphere, the Ti concentration was found to be below 1 at %, whereas in pure argon it reached 20 at %, as measured by Rutherford backscattering spectroscopy and elastic recoil detection analysis (RBS/ERDA). A high level of titanium oxidation is detected with TiO2, substoichiometric titania, and titanium carbide, composing an inorganic phase of the composite films. In addition, high hydrogen content is detected in films rich with titanium. Ti‐deficient and Ti‐rich films proved equally good substrates for adhesion and growth of cultured human osteoblast‐like MG 63 cells. In these cells, the population densities on days 1, 3, and 7 after seeding, spreading area on day 1, formation of talin‐containing focal adhesion plaques as well as concentrations of talin and osteocalcin (per mg of protein) were comparable to the values obtained in cells on the reference cell culture materials, represented by microscopic glass coverslips or a polystyrene dish. An interesting finding was made when the Ti/ppCH films were seeded with calf pulmonary artery endothelial cells of the line CPAE. The cell population densities, the spreading area and also the concentration of von Willebrand factor, a marker of endothelial cell maturation, were significantly higher on Ti‐rich than on Ti‐deficient films. On Ti‐rich films, these parameters were also higher or similar in comparison with the reference cell culture materials. Thus, both types of films could be used for coating bone implants, of which the Ti‐rich film remains effective in enhancing the endothelialization of blood contacting artificial materials. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Poly(L‐lactide)‐b‐poly(ethylene oxide) copolymers with different arms: Hydrophilicity, biodegradable nanoparticles, in vitro degradation, and drug‐release behavior
Authors: Liu Qing , Cai Chen , Dong Chang‐Ming 
Published: April 2008

AbstractBiodegradable and amphiphilic poly(L‐lactide)‐b‐poly(ethylene oxide) copolymers with different arms (PLLA‐b‐PEO having one, two, four, and six arms) were successfully synthesized via a two‐step synthetic strategy. The hydrophilicity–hydrophobicity balance of these copolymers was mainly controlled by both the arm number of copolymers (i.e., macromolecular architecture) and the poly(ethylene oxide) (PEO) composition. Biodegradable nanoparticles could be generated by direct injection of these PLLA‐b‐PEO copolymers solutions into distilled water, and their critical micelles concentrations decreased with the increasing arm number of copolymers. Moreover, both the hydrophilic PEO composition and the arm number of copolymers controlled the average size of PLLA‐b‐PEO nanoparticles, and the nanoparticles with adjustable sizes (20–85 nm) completely meet the size prerequisite (less than 100 nm) for targeted drug delivery. In vitro degradation of PLLA‐b‐PEO nanoparticles showed that the PLLA composition gradually increased over the degradation time, and the degree of crystallinity of PLLA block within copolymers increased simultaneously. Furthermore, the nimodipine drug loading efficiency of the PLLA‐b‐PEO copolymers was apparently higher than that of PLLA homopolymers. The drug‐release experiments demonstrated that these biodegradable nanoparticles might be used for a short‐time controlled release system. Consequently, this will provide a facile method not only to design new PLLA‐based biomaterials from both the macromolecular architecture and the hydrophilicity–hydrophobicity balance, but also to fabricate biodegradable nanoparticles with adjustable sizes for drug delivery. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
In situ observation of surface oxide layers on medical grade Ni‐Ti alloy during straining
Authors: Undisz A. , Schrempel F. , Wesch W. , Rettenmayr M. 
Published: April 2008

AbstractMedical grade Ni‐Ti alloys with shape memory or pseudo‐elastic behavior exhibit good biocompatibility because of an electrochemically passive oxide layer on the surface. In this work, the mechanical stability of surface oxide layers is investigated during reversible pseudo‐elastic deformation of commonly applied medical grade Ni‐Ti wires. Surface oxide layers with varying thickness were generated by varying annealing times under air atmosphere. The thicknesses of the surface oxide layers were determined by means of Rutherford backscattering spectrometry. In situ scanning electron microscopy investigations reveal a damage mechanism, which is assumed to have a significant influence on the biocompatibility of the material. The conditions that lead to the appearance of cracks in the surface oxide layer or to the flaking of surface oxide layer particles are identified. The influence of the thickness of the surface oxide layer on the damage mode is characterized. The possible impact of the damaged surface oxide layer on the material's biocompatibility and the potentials to reduce or avoid the damage are discussed. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
A new generation of bio‐derived ceramic materials for medical applications
Authors: González P. , Borrajo J. P. , Serra J. , Chiussi S. , León B. , Martínez‐Fernández J. , Varela‐Feria F. M. , de Arellano‐López A. R. , de Carlos A. , Muñoz F. M. , López M. , Singh M. 
Published: April 2008

AbstractA new generation of bio‐derived ceramics can be developed as a base material for medical implants. Specific plant species are used as templates on which innovative transformation processes can modify the chemical composition maintaining the original biostructure. Building on the outstanding mechanical properties of the starting lignocellulosic templates, it is possible to develop lightweight and high‐strength scaffolds for bone substitution.In vitroandin vivoexperiments demonstrate the excellent biocompatibility of this new silicon carbide material (bioSiC) and how it gets colonized by the hosting bone tissue because of its unique interconnected hierarchic porosity, which opens the door to new biomedical applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Inhibition of osteoblastic metalloproteinases in mice prevents bone loss induced by oestrogen deficiency
Authors: Schiltz Corinne , Marty Caroline , de Vernejoul Marie‐Christine , Geoffroy Valerie 
Published: April 2008

AbstractMatrix metalloproteinases (MMPs) are key mediators in extra‐cellular matrix remodelling and implicated primarily in bone growth, and particularly in osteoclastic bone resorption. We hypothesise that MMPs have a role in the increased bone remodelling resulting from oestrogen deficiency. Transgenic (TG) mice overexpressing TIMP‐1 in their osteoblastic cells and their wild‐type (WT) littermates were ovariectomised. One month after surgery, bone mineral density (BMD) and bone microarchitecture were assessed. Primary cells from WT and TG mice were used to determine how TIMP‐1 affects osteoclast and osteoblastic cells. The reduction of BMD induced by ovariectomy in WT mice was not observed in the transgenic mice. The transgene overexpression also dampened the post‐ovariectomy increase in bone resorption in contrast to the WT mice. In vivo, osteoclastic surfaces and D‐pyridinoline were not increased in TG mice, and ex vivo, the differentiation of osteoclasts from TG bone marrow precursor cells were unaffected by in vivo oestrogen deficiency or treatment. We showed also that TIMP‐1 overexpression reduces and delays the osteoblastic proliferation and differentiation respectively, and reduced the generation of the active form of TGFβ1 in the supernatant of TG osteoblasts. Our findings support the hypothesis that in vivo inhibition of osteoblastic MMPs prevented the bone loss induced by oestrogen deficiency, with a significant decrease in bone resorption. This effect was presumably resulting from (1) a direct inhibition of osteoclastic resorption activity by the TIMP‐1 and (2) the modification in the local activation of extra‐cellular signalling factors such as TGFβ1 and the OPG/RANKL ratio. J. Cell. Biochem. 104: 1803–1817, 2008. © 2008 Wiley‐Liss, Inc.
Inhibition of adipocyte differentiation by phytoestrogen genistein through a potential downregulation of extracellular signal‐regulated kinases 1/2 activity
Authors: Liao Qing‐Chuan , Li Ya‐Lin , Qin Yan‐Fang , Quarles L. Darryl , Xu Kang‐Kang , Li Rong , Zhou Hong‐Hao , Xiao Zhou‐Sheng 
Published: April 2008

AbstractIn the current study, we investigated the effects of genistein on adipogenic differentiation of mouse bone marrow‐derived mesenchymal stem cell (BMSC) cultures and its potential signaling pathway. The terminal adipogenic differentiation was assessed by western‐blotting analysis of adipogenic‐specific proteins such as PPARγ, C/EBPα, and aP2 and the formation of adipocytes. Treatment of mouse BMSC cultures with adipogenic cocktail resulted in sustained activation of extracellular signal‐regulated kinases 1 and 2 (ERK1/2), which are members of the mitogen‐activated protein kinase (MAPK) family, at the early phase of adipogenesis (from days 3 to 9). Inhibition of ERK1/2 activation by PD98059, a specific MEK inhibitor, reversed the induced adipogenic differentiation. Genistein dose‐dependently decreased the phosphorylation of ERK1/2 in mouse BMSC cultures. Genistein incubation for the entire culture period, as well as that applied during the early phase of the culture period, significantly inhibited the adipogenic differentiation of mouse BMSC cultures. While genistein was incubated at the late stage (after day 9), no inhibitory effect on adipogenic differentiation was observed. BMSC cultures treated with genistein in the presence of fibroblast growth factor‐2 (FGF‐2), an activator of the ERK1/2 signaling pathway, expressed normal levels of ERK1/2 activity, and, in so doing, are capable of undergoing adipogenesis. Our results suggest that activation of the ERK1/2 signaling pathway during the early phase of adipogenesis (from days 3 to 9) is essential to adipogenic differentiation of BMSC cultures, and that genistein inhibits the adipogenic differentiation through a potential downregulation of ERK1/2 activity at this early phase of adipogenesis. J. Cell. Biochem. 104: 1853–1864, 2008. © 2008 Wiley‐Liss, Inc.