bluuebunny/crossref_metadata_2025_split huggingface dataset:
Realistic simulations of combined DNA electrophoretic flow and EOF in nano‐fluidic devices
Authors: Duong‐Hong Duc , Han Jongyoon , Wang Jian‐Sheng , Hadjiconstantinou Nicolas G. , Chen Yu Zong , Liu Gui‐Rong 
Published: January 2009

AbstractWe present a three‐dimensional dissipative particle dynamics model of DNA electrophoretic flow that captures both DNA stochastic motion and hydrodynamics without requiring expensive molecular dynamics calculations. This model enables us to efficiently and simultaneously simulate DNA electrophoretic flow and local EOF (generated by counterions near the DNA backbone), in mesoscale (∼μm) fluidic devices. Our model is used to study the electrophoretic separation of long DNA chains under entropic trapping conditions [Han and Craighead, Science 2000, 288, 1026–1029]. Our simulation results are in good agreement with experimental data for realistic geometries (tapered walls) and reveal that wall tapering in entropic traps has a profound impact in the DNA trapping behavior, an effect which was largely ignored in previous modeling.
Chip‐CE/MS using a flat low‐sheath‐flow interface
Authors: Li Fu‐An , Huang Ju‐Li , Her Guor‐Rong 
Published: January 2009

AbstractA chip‐CE/ESI/MS interface based on a low‐sheath‐flow design has been developed. A flat low‐sheath‐flow interface was fabricated to facilitate the coupling with a CE microchip. The interface consists of a PMMA reservoir block, a PMMA platform and a replaceable ESI sprayer. A CE interface was constructed by using a wire‐assisted epoxy‐fixing method to connect a 1.5 cm connecting capillary to the end of chip‐CE channel. The opposite end of the connecting capillary was tapered to approximately 40 μm od to fit tightly inside the back end of a removable fused‐silica capillary ESI sprayer, which was also tapered to give a 10 μm orifice. With this 1.5 cm connecting capillary, the sheath liquid flowed coaxially around the connecting capillary to create a low dead volume liquid junction at the interface between the connecting capillary and the ESI emitter. An advantage of the current design over existing chip‐based CE/MS interfaces is that ESI emitter can easily be replaced. The analytical utility of this microdevice was demonstrated by the analysis of two synthetic mixtures: a series histamine antagonists and a mixture of synthetic peptides.
Internally calibrated quantification of protein analytes in human serum by fluorescence immunoassays in disposable elastomeric microfluidic devices
Authors: Kartalov Emil P. , Lin David H. , Lee David T. , Anderson William F. , Taylor Clive R. , Scherer Axel 
Published: January 2009

AbstractHerein we report on reliable reproducible quantification of protein analytes in human serum by fluorescence sandwich immunoassays in disposable PDMS microfluidic chips. The system requires 1000 times less sample than typical clinical blood tests and is specifically shown to measure ferritin down to 250 pM in human serum. The in‐built calibration method of spiking the serum with known concentrations of commercially available antigen avoids common sources of error and improves the reliability of the test results. The reported microfluidic system is an important new tool for fundamental scientific research, offering sensitive immunoassay measurements in small but complex biosamples. The system is also a further step towards comprehensive affordable “point‐of‐care” biomedical diagnostics.
Simple, fast and high‐throughput single‐cell analysis on PDMS microfluidic chips
Authors: Yu Linfen , Huang Huaiqing , Dong Xiuling , Wu Dapeng , Qin Jinhua , Lin Bingcheng 
Published: January 2009

AbstractThis paper demonstrated the chemical analysis of single cell on a cross PDMS microfluidic chip in a simple, fast, and high‐throughput mode. The pre‐stained cells were sequentially loaded into the cross section by hydrodynamic force, lysed by 0.2% SDS and subsequently the lysates were detected by LIF. Each cell can be lysed within 500 ms due to its high concentration of SDS at cross section resulted from the absence of electroosmosis after surface coating in microchannel. The reliability and quality of the analysis was confirmed by analysis of glutathione and rhodamine 123 in single K562 cells. In each run, approximately 100 cells could be analyzed in about 10 min, which demonstrated the comparatively high throughput. The proposed microfluidic method is simple, fast, and high throughput, which might be of significance in identifying the biological molecules involved in fast biochemical processes and studying heterogenous cells.
Dielectrophoretic detection and quantification of hybridized DNA molecules on nano‐genetic particles
Authors: Gagnon Zachary , Senapati Satyajyoti , Gordon Jason , Chang Hsueh‐Chia 
Published: January 2009

AbstractDNA–DNA hybridization reactions on 100 nm oligonucleotide‐functionalized silica nanoparticles are found to sensitively affect the amplitude and direction of the dielectrophoretic mobility of the particles at nanomolar target ssDNA concentrations. Such sensitivity permits visual detection of the hybridization event without fluorescent labeling and confocal microscopy by imaging the cross‐over frequency (cof) of the particle suspension on a quadrupole electrode array. Strong correlation with effective particle radius and zeta‐potential measurements suggests that the dielectrophoretic cof offers not just sensitive signatures for successful functionalization and hybridization but also those for three distinct DNA surface conformations that appear at different surface densities of hybridized DNA. A properly normalized cof calibration chart allows simplified quantification of the target ssDNA concentrations. These results provide a simple, rapid and portable genetic detection method compatible for use outside the laboratory.
Parental attitudes, body image disturbance and disordered eating amongst adolescents and young adults: A review
Authors: Rodgers Rachel , Chabrol H. 
Published: January 2009

AbstractObjectiveThe purpose of this paper was to review the existing literature regarding the contribution of parental influences to the sociocultural pressures on body image disturbance and disordered eating so as to highlight principal findings so that parents can be given practical information and identify areas that require further research.MethodsRelevant articles were located through Pubmed, Sciencedirect and PsychInfo, as well as the screening of bibliographies.ResultsThe available data suggest that parents are strong communicators of sociocultural pressures. Parental influences via verbal messages and active encouragement have been shown to have more impact on offspring's body concerns and eating behaviours than modelling effects. Both mothers and fathers are important sources of influence for their offspring.ConclusionConsidering the role of parents could help improve public health management. Futher exploration of the way adolescents and young adults interpret and perceive parental attitudes and of potential protective factors is necessary. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association.
A two‐component two‐phase dissipative particle dynamics model
Authors: Tiwari Anupam , Abraham John 
Published: January 2009

AbstractDissipative particle dynamics (DPD)‐based models for two‐phase flows are attractive for simulating fluid flow at the sub‐micron level. In this study, we extend a DPD‐based two‐phase model for a single‐component fluid to a two‐component fluid. The approach is similar to that employed in the DPD formulation for two immiscible liquids. Our approach allows us to control the density ratio of the liquid phase to the gas phase, which is represented independently by the two components, without changing the temperature of the liquid phase. To assess the accuracy of the model, we carry out simulations of Rayleigh–Taylor instability and compare the penetration rates of the spikes and bubbles formed during the simulations with prior results reported in the literature. We show that the results are in agreement with both experimental data and predictions from Youngs' model. We report these results for a broad range of Atwood numbers to illustrate the capability of the model. Copyright © 2008 John Wiley & Sons, Ltd.
On a robust test for SETAR‐type nonlinearity in time series analysis
Authors: Hung King Chi , Cheung Siu Hung , Chan Wai‐Sum , Zhang Li‐Xin 
Published: January 2009

AbstractThere has been growing interest in exploiting potential forecast gains from the nonlinear structure of self‐exciting threshold autoregressive (SETAR) models. Statistical tests have been proposed in the literature to help analysts check for the presence of SETAR‐type nonlinearities in observed time series. However, previous studies show that classical nonlinearity tests are not robust to additive outliers. In practice, time series outliers are not uncommonly encountered. It is important to develop a more robust test for SETAR‐type nonlinearity in time series analysis and forecasting. In this paper we propose a new robust nonlinearity test and the asymptotic null distribution of the test statistic is derived. A Monte Carlo experiment is carried out to compare the power of the proposed test with other existing tests under the influence of time series outliers. The effects of additive outliers on nonlinearity tests with misspecification of the autoregressive order are also studied. The results indicate that the proposed method is preferable to the classical tests when the observations are contaminated with outliers. Finally, we provide illustrative examples by applying the statistical tests to three real datasets. Copyright © 2009 John Wiley & Sons, Ltd.
Interfacial Properties of Copper‐coated Graphite Electrodes: Coating Thickness Dependence
Authors: Nobili F. , Dsoke S. , Mancini M. , Marassi R. 
Published: January 2009

AbstractCopper‐coated graphite electrodes have been prepared by physical vapour deposition (PVD) and characterised as anodes for Li‐ion batteries. The interfacial properties of the electrodes coated with copper layers of different thicknesses have been studied using impedance spectroscopy and compared with those of unmodified electrodes. A general enhancement of the performances of the coated electrodes in terms of decreased solid electrolyte interface (SEI) and charge transfer resistances has been found. The charge transfer resistance decreases at any intercalation potential for metal layer thickness of the order of 250–300 Å to increase again for thicker deposits. While in general the decrease in the charge transfer resistance may be related to a sort of catalytic effect of the metal layer in increasing the lithium desolvation rate, it is apparent that above a certain critical thickness value the layer acts as a barrier to the lithium ion transfer at the interface.
Cross‐commodity analysis and applications to risk management
Authors: Börger Reik , Cartea Álvaro , Kiesel Rüdiger , Schindlmayr Gero 
Published: January 2009

AbstractThe understanding of joint asset return distributions is an important ingredient for managing risks of portfolios. Although this is a well‐discussed issue in fixed income and equity markets, it is a challenge for energy commodities. In this study we are concerned with describing the joint return distribution of energy‐related commodities futures, namely power, oil, gas, coal, and carbon. The objective of the study is threefold. First, we conduct a careful analysis of empirical returns and show how the class of multivariate generalized hyperbolic distributions performs in this context. Second, we present how risk measures can be computed for commodity portfolios based on generalized hyperbolic assumptions. And finally, we discuss the implications of our findings for risk management analyzing the exposure of power plants, which represent typical energy portfolios. Our main findings are that risk estimates based on a normal distribution in the context of energy commodities can be statistically improved using generalized hyperbolic distributions. Those distributions are flexible enough to incorporate many characteristics of commodity returns and yield more accurate risk estimates. Our analysis of the market suggests that carbon allowances can be a helpful tool for controlling the risk exposure of a typical energy portfolio representing a power plant. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 29:197–217, 2009
Aerobic fitness is associated with hippocampal volume in elderly humans
Authors: Erickson Kirk I. , Prakash Ruchika S. , Voss Michelle W. , Chaddock Laura , Hu Liang , Morris Katherine S. , White Siobhan M. , Wójcicki Thomas R. , McAuley Edward , Kramer Arthur F. 
Published: January 2009

AbstractDeterioration of the hippocampus occurs in elderly individuals with and without dementia, yet individual variation exists in the degree and rate of hippocampal decay. Determining the factors that influence individual variation in the magnitude and rate of hippocampal decay may help promote lifestyle changes that prevent such deterioration from taking place. Aerobic fitness and exercise are effective at preventing cortical decay and cognitive impairment in older adults and epidemiological studies suggest that physical activity can reduce the risk for developing dementia. However, the relationship between aerobic fitness and hippocampal volume in elderly humans is unknown. In this study, we investigated whether individuals with higher levels of aerobic fitness displayed greater volume of the hippocampus and better spatial memory performance than individuals with lower fitness levels. Furthermore, in exploratory analyses, we assessed whether hippocampal volume mediated the relationship between fitness and spatial memory. Using a region‐of‐interest analysis on magnetic resonance images in 165 nondemented older adults, we found a triple association such that higher fitness levels were associated with larger left and right hippocampi after controlling for age, sex, and years of education, and larger hippocampi and higher fitness levels were correlated with better spatial memory performance. Furthermore, we demonstrated that hippocampal volume partially mediated the relationship between higher fitness levels and enhanced spatial memory. Our results clearly indicate that higher levels of aerobic fitness are associated with increased hippocampal volume in older humans, which translates to better memory function. © 2009 Wiley‐Liss, Inc.
Numerical simulation of snow melting on pavement surface with heat dissipation pipe embedded
Authors: Nagai Niro , Miyamoto Shigenobu , Nishiwaki Masaya , Takeuchi Masanori 
Published: January 2009

AbstractProgrammed software was developed in order to numerically simulate time variation of the temperature field and snow depth around a pipe‐in‐pile snow‐melting system, using meteorological data. The system utilized underground piles as the heat exchanger between underground soil and water flowing inside the pipes. The water was pumped into heat dissipation pipes embedded beneath the pavement surface, on which snow melted. The unsteady three‐dimensional heat conduction inside the pavement and the underground soil was numerically solved. On the surface, the heat balance of conduction, convection, and radiation was considered. Snow fall depth was estimated by rainfall weather data, ratio of snowfall to rainfall, and dry density of snowfall. For simulating the snow layer, an unsteady one‐dimensional heat conduction was solved while incorporating partial absorption of solar radiation. Experiments for measuring time variation of the temperature field and snow depth around the system were conducted for verification of the software. The obtained simulation results showed good agreements with experimental data, demonstrating the utility and validity of the software. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20226
New supplying evaporation precursor method with CVD
Authors: Oshima Motohiro , Komeda Akiko , Tominaga Koji , Nakao Motoi , Shimizu Tetsuo , Senda Jiro , Ishida Kozo 
Published: January 2009

AbstractWe propose a novel system of chemical vapor deposition (CVD), i.e., flash boiling spray CVD (SF‐CVD) to eliminate several kinds of problems, such as the decomposition of precursors in the supply line and evaporator. In this method, liquid precursors are supplied directly to the vacuum chamber through an injector, just like fuel for an automobile engine, without any vaporizers, so as to induce an unsteady and intermittent flash boiling spray in the chamber. However, it is necessary to keep the lowest ambient pressure possible because the saturated vapor pressure of the precursors is very low. Thus, this is very useful for modifying the saturated vapor pressure of the precursors. A technique of lowering the vaporization pressure is proposed by mixing a more saturated vapor‐pressure organic solvent with a precursor. To determine the principles underlying FS‐CVD, we first formed SiO2film on the Si substrate. A mixed solution of tetraethylorthosilicate (TEOS) and n‐pentane was used as the mixing solution. The film thickness distribution of SiO2film on a 100‐mm‐diameter Si wafer was ±4% using this method. Furthermore, this method enabled us to control film with various thicknesses by optimizing the injection duration, cycle, and injection cycle per second. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20235
Classification of fixed urological cells using Raman tweezers
Authors: Harvey Tim J. , Hughes Caryn , Ward Andrew D. , Faria Elsa Correia , Henderson Alex , Clarke Noel W. , Brown Mick D. , Snook Richard D. , Gardner Peter 
Published: January 2009

AbstractIn this paper we report on preliminary investigations into using Raman tweezers to classify urological cell lines. This builds on earlier work within the group, whereby Raman tweezer methodologies were developed, and the application of this technique to differentiate between live prostate cancer (CaP) and bladder cells lines (PC‐3 and MGH‐U1 respectively) was demonstrated.In this present study we analysed chemically fixed cells using two different fixative methods; SurePathTM (a commercial available liquid based cytology media) and 4% v/v formalin/PBS fixatives. The study has been expanded from our previous live cell study to include the androgen sensitive CaP cell line LNCaP, primary benign prostate hyperplasia (BPH) cells as well as primary urethral cells. Raman light from the cells was collected using a 514.5 nm Ar‐ion laser excitation source in back‐scattering configuration mode.Principal component‐linear discriminate analysis (PC‐LDA) models of resulting cell spectra were generated and these were validated using a blind comparison. Sensitivities and specificities of > 72% and 90% respectively, for SurePath fixed cells, and > 93% and 98% respectively for 4% v/v formalin/PBS fixed cells was achieved. The higher prediction results for the formalin fixed cells can be attributed to a better signal‐to‐noise ratio for spectra obtained from these cells.Following on from this work, urological cell lines were exposed to urine for up to 12 hours to determine the effect of urine on the ability to classify these cells. Results indicate that urine has no detrimental effect on prediction results. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparative ultrasound evaluation of human trabecular bone graft properties after treatment with different sterilization procedures
Authors: Vastel L. , Masse C. , Mesnil P. , Crozier E. , Padilla F. , Laugier P. , Mitton D. , Courpied J. P. 
Published: January 2009

AbstractNew sterilization methods for human bone are likely to affect the mechanical properties of human cancellous grafts. These mechanical properties dictate the short‐ and mid‐term results of the orthopedic procedure. The aim of this study was to compare the effects on bone mechanical properties, as assessed by ultrasound velocity, of different sterilization methods used under similar conditions: bleach and sublimation, humid heat, successive baths of physiological saline with osmotic detersion, and CO2 in the supercritical phase. Alterations in mechanical properties were small with CO2 (velocity change: −2%) and humid heat (−2.5%). Osmotic detersion had a significant but moderate effect (−4.7%). The −9% change with the protocol involving bleach suggested a greater than 30% decrease in load to failure, based on earlier studies. Gamma irradiation of defatted trabecular allografts, in a dose of 10 or 25 KGy, produced no significant changes in ultrasound velocity. Powerful protein denaturants used in sterilization protocols substantially alter the mechanical resistance of the grafts, which may jeopardize the orthopedic procedure. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Phenotype‐rescue of cyclin‐dependent kinase inhibitor p16/INK4A defects in a spontaneous canine cell model of breast cancer
Authors: DeInnocentes Patricia , Agarwal Payal , Bird R. Curtis 
Published: January 2009

AbstractMammary cancer is among the most frequently observed canine tumors in unspayed female dogs resulting in death due to metastatic disease. These tumors are excellent models of human breast cancer but until recently there was only anecdotal evidence regarding underlying genetic defects. We recently reported expression defects in the cyclin‐dependent kinase p21/Cip1 and p53 among three independent canine mammary tumor (CMT) cell lines derived from spontaneous canine mammary cancers. We investigated further defects in the same three cell lines focusing on additional tumor suppressor gene defects in cyclin‐dependent kinase inhibitors. p27/KIP1 appeared normally expressed and did not appear to encode inactivating mutations. In contrast, expression of p16/INK4A was defective/absent in two cell lines and normal/slightly induced in the third cell line. To determine if defects were causative in maintaining the transformed phenotype, a p16/INK4A transgene was permanently transfected followed by selection and single cell cloning. CMT/p16 clones were characterized for transgene expression, p16 protein content and phenotype including proliferation rate, cell cycle phase distribution, contact inhibition, substrate dependent cell growth and cell morphology. All cell lines appeared unique yet clear indications of phenotype rescue due to p16/INK4A transgene complementation were observed suggesting that defects in p16 expression were present in all three. In some cases cellular senescence also appeared to be induced. These data provide evidence supporting p16/INK4A mutations as causative defects promoting transformation in canine mammary cancer and further characterizes tumor suppressor gene defects with functional consequences in these cells supporting their application as spontaneous animal models of human disease. J. Cell. Biochem. 106: 491–505, 2009. © 2009 Wiley‐Liss, Inc.