bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self‐Assembly of Arborescent Polystyrene‐graft‐Poly(ethylene oxide) Copolymers at the Air/Water Interface
Authors: Njikang Gabriel N. , Cao Lan , Gauthier Mario 
Published: March 2008

AbstractAFM imaging was used to investigate the influence of molecular structure and composition on the formation of Langmuir monolayers by arborescent PS‐graft‐PEO copolymers at the air/water interface. Even without compression, these molecules associate spontaneously at the air/water interface and form stable monolayers that are easily transferred onto solid substrates as Langmuir/Blodgett films. The copolymers either form aggregates with a low association level, large island‐like clusters, or ribbon‐like superstructures. The different behaviors of the copolymers are rationalized in terms of the influence of their composition and of the structure of the arborescent PS cores on the assembly process.magnified image
The Effect of Activation/Deactivation Processes on the Microcomposition and Microsequence Structure of Controlled/Living Copolymers
Authors: Shi Ying , Qin Xuelian , Guo Yumei , Xie Meiran , Zhang Yiqun 
Published: March 2008

AbstractA new method is proposed to study the process of controlled/living radical copolymerization as well as the structures of the products. Computer simulation has been carried out to produce this LRP or CRP propagation including the activation/deactivation process. The information about segment distribution was obtained for the first time. The results show that under a stationary condition, controlled/living copolymer's composition and sequence distribution are totally identical to those prepared from the conventional free radical copolymerization (FRcP). In other words, the activation/deactivation process of controlled/living radical copolymerization has no effect on copolymer's microcomposition and microsequence structure.magnified image
p16INK4adownregulation is involved in immortalization of primary human prostate epithelial cells induced by telomerase
Authors: Shao Genze , Balajee Adayabalam S. , Hei Tom K. , Zhao Yongliang 
Published: March 2008

AbstractProstate cancer is a major cause of cancer death among male population. Therefore, development of appropriate model systems is critical for understanding the molecular basis of prostate cancer progression. In this study, introduction of human telomerase (hTERT) into normal human prostate epithelial cells (PrECs) renders them higher telomerase activity, elongated telomere length and an extended proliferative lifespan. The immortal mass culture of PrEC–hTERT cell line with stabilized telomere length has been established using hTERT transfection. However, activation of hTERT alone appears to be insufficient for immortalization of PrEC cells because methylation ofp16INK4apromoter has been found to be involved in the immortalization process. p53 was functionally intact and no mutations ofp53gene were identified in the immortalized PrECs. In addition, the immortal PrECs show a near diploid complement of chromosomes albeit a few reciprocal and non‐reciprocal translocations are identified. They are anchorage dependent and do not form tumors in immunosuppressed host animals. Therefore, premalignantly transformed human PrECs provide a valuable model for prostate cancer research. © 2008 Wiley‐Liss, Inc.
Pleiotrophin inhibits transforming growth factor β1‐induced apoptosis in hepatoma cell lines
Authors: Park Tae Jun , Jeong Bo Ra , Tateno Chise , Kim Hong Seok , Ogawa Tomohiro , Lim In Kyoung , Yoshizato Katsutoshi 
Published: March 2008

AbstractPleiotrophin (PTN) is a hepatocyte growth factor and considered to play roles in liver fibrogenesis and hepatocarcinogenesis. In this study we examined the mechanism of the action of PTN in these pathological processes. First, we confirmed that hepatic stellate cells (HSCs) and Kupffer cells, and also later hepatocytes in hyperplastic nodules increased PTN mRNA expressions during carbon tetrachloride‐induced liver fibrosis. Then, the relationship between PTN and transforming growth factor β1 (TGFβ1), a known potent pro‐fibrogenetic cytokine, in carcinogenesis was investigated using hepatoma cell lines. Huh‐7 human hepatoma cells weakly expressed PTN, but HepG2 human hepatoma cells and FaO rat hepatoma cells did not. Recombinant (r) TGFβ1 induced the cultured Huh‐7 cells to undergo apoptosis, which was inhibited by rPTN. Huh‐7 cells became resistant to TGFβ1‐, but not mitomycin C‐induced apoptosis when transfected with PTN gene, indicating the specificity of the PTN anti‐apoptotic activity. Poly ADP ribose polymerase, procaspase‐8 and procaspase‐3 were not cleaved in the TGFβ1‐reluctant cells. The TGFβ1‐induced caspase‐3 activation was also suppressed in Huh‐7 and FaO cells both transduced with PTN gene‐bearing adenoviruses. In summary, PTN was expressed in HSCs, Kupffer cells, and hepatocytes in fibrotic liver. We propose that PTN specifically antagonizes the TGFβ1 activity during liver fibrosis. © 2008 Wiley‐Liss, Inc.
Task‐specific craniocervical dystonia
Authors: Schramm Axel , Naumann Markus , Reiners Karlheinz , Classen Joseph 
Published: March 2008

AbstractThe pathophysiology of dystonia is incompletely understood. Unlike many other focal dystonias, cervical dystonia, a frequent dystonia leading to twisting of the head, does not appear to be related to overuse or acquisition of a demanding motor skill. Here, we report development of task‐specific dystonia of the neck muscles in a 67‐year‐old patient following bilateral traumatic arm amputation at the age of 15. To compensate for the amputation, the patient learned to write with a pen held in his mouth. After several years of practicing this unusual and demanding skill, symptoms of task‐specific cervical dystonia (CD) developed. This dystonia later became permanent, and independent of the motor activity that initially triggered the dystonic muscular contractions. This singular case raises the possibility that the pathophysiology of CD may share common elements with that of focal dystonias in different body regions. © 2008 Movement Disorder Society
Conservation properties of the bridging domain method for coupled molecular/continuum dynamics
Authors: Xu Mei , Belytschko Ted 
Published: March 2008

AbstractAn overlaid domain decomposition method, called the bridging domain method, for the coupled simulation of molecular/continuum systems is analyzed. In this method, compatibility between the atomistic and the continuum subdomains is enforced by Lagrange multipliers. Two forms are considered: (1) a consistent constraint form, which employs the exact non‐diagonal Lagrange multiplier equations and thus enforces compatibility exactly, but is computationally demanding and (2) a diagonalized constraint form, which is computationally more efficient. It is shown that the consistent constraint form conserves linear momentum, angular momentum and energy. The diagonalized constraint form dissipates energy. The diagonalized form is shown to be more effective in suppressing spurious reflections at the interface. Copyright © 2008 John Wiley & Sons, Ltd.
Representation of elastomers in industrial applications
Authors: Baaser H. 
Published: March 2008

AbstractA material model is presented to describe inelastic effects in elastomeric components. In static cases, stress softening and permanent deformations are identified as cause of inelasticity. Both effects are covered separately in the constitutive law. This permits the largely modular design of a material description on the basis of user interfaces in commercial FE programs and allows for easier parameter adjustment as the effects can be clearly allocated and identified. The hyperelastic part of the material answer is defined by any freely chosen function of the strain energy, while the inelastic part is of a non‐linear, isotropic hardening type. The presented model is realized in the ABAQUS Finite Element system. The efficiency of the implementation is shown on an example from the hydraulic sealing technology. Further on, we discuss a modification applied to finite viscoelasticity to represent amplitude dependence as observed our in experiments. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Newton methods for nonlinear inverse problems with random noise
Authors: Bauer Frank , Hohage Thorsten , Munk Axel 
Published: March 2008

AbstractWe study the convergence of regularized Newton methods applied to nonlinear operator equations in Hilbert spaces if the data are perturbed by random noise. We show that under certain conditions it is possible to achieve the minimax rates of the corresponding linearized problem if the smoothness of the solution is known. If the smoothness is unknown and the stopping index is determined by Lepskij's balancing principle, we show that the rates remain the same up to a logarithmic factor due to adaptation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A two immiscible liquids penetration model for surface‐driven capillary flows
Authors: Fazio Riccardo , Iacono Salvatore , Jannelli Alessandra , Cavaccini Giovanni , Pianese Vittoria 
Published: March 2008

AbstractThis is a mathematical and numerical study of liquid dynamics in a horizontal capillary. We present a two‐liquids model which takes into account the effects of real phenomena like the outside flow dynamics. Moreover, we report on results obtained by an adaptive numerical method. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Linear interpolation for image conversion between square structure and hexagonal structure
Authors: He Xiangjian , Li Jianmin 
Published: March 2008

AbstractSpiral Architecture (SA) is a relatively new and powerful image structure consisting of hexagonal pixels arranged in a onedimensional coordinate system. However, all the existing hardware for capturing image and for displaying image are produced based on traditional square image structure. In this paper, we present a software approach to represent an image on SA based on linear interpolation method. We perform edge detection on SA to demonstrate the advantages of image processing on SA. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The influence of semi‐rigid connections on the shakedown of elasto‐plastic frames
Authors: Kaliszky Sándor , Lógó János 
Published: March 2008

AbstractThe main structural elements of steel framed multi‐storey structures are the columns, the beams and their connections. The assumption has been widely applied in the past that the connections are either rigid or pinned. The actual behaviour of the connections is however somewhere between these limits, they are semi‐rigid. The aim of this paper is to analyze the effect of the semi‐rigid connections on the shakedown of steel structures under multi‐parameter static loading. In the analysis, to control the plastic behavior of the structure, bound on the complementary strain energy of the residual forces is applied. The formulation of the problem yields to nonlinear mathematical programming. The results of the numerical calculation show that the semi‐rigid connections can influence significantly the magnitude of the shakedown parameter. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elliptic grid generation methods for scattering from multiple obstacles
Authors: Villamizar Vianey , Acosta Sebastian 
Published: March 2008

AbstractA novel finite difference time domain method for acoustic scattering on generalized curvilinear coordinates is briefly described. Scattering over two‐dimensional complex regions consisting of multiple scatterers are analyzed. The grid generation algorithm decomposes regions with finite number of holes to contiguous single‐hole subregions. Individual grids are obtained for each subregions and they are matched with smoothness across interfaces. The new algorithm is an extension to multiple obstacles of the technique introduced in [V. Villamizar, M. Weber, Boundary‐Conforming Cordinates with Grid Line Control for Acoustic Scattering from Complexly Shaped Obstacles, Numer. Meth. Part Differ. Equ. 23 (2007) 1445–1467]. The method is successfully applied to approximate the pressure field resulting from the acoustic scattering of a plane wave from two complexly‐shaped obstacles. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Configurational‐force‐based structural updates and adaptive remeshing strategies
Authors: Zimmermann Dominik , Miehe Christian 
Published: March 2008

AbstractThe application of configurational forces in h ‐adaptive strategies for fracture mechanics and inelasticity is investigated. Starting from a global Clausius‐Planck inequality, dual equilibrium conditions are derived by means of a Coleman‐type exploitation method. The remaining reduced dissipation inequality is used for the derivation of evolution equations for the internal variables. In fracture mechanics, crack loading conditions as well as a normality rule for the crack propagation are obtained. In the discrete setting, the crack propagation is governed by a configurational‐force‐driven update of the geometry model. The material balance equation is used to set up a h ‐adaptive refinement indicator. A relative global criterion is defined used for the decision on mesh refinement. In addition, a criterion on the element level is evaluated controlling the local refinement procedure. The capability of the proposed procedures is demonstrated by means of numerical examples. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
For the majority of patients with diabetes blood pressure and lipid management is not in line with recommendations. Results from a large population‐based cohort in Germany
Authors: Raum Elke , Lietzau Susanne , Stegmaier Christa , Brenner H. , Rothenbacher Dietrich 
Published: March 2008

AbstractObjectiveTo evaluate the management of cardiovascular risk factors in a population‐based cohort of adults with diabetes mellitus in Germany.Design and MeasurementsFor the 9953 participants (50–74 years of age) of the ESTHER study, diabetes mellitus, hypertension, dyslipidemia and the respective medication were documented at baseline by their primary care physician. Blood pressure was taken and lipid levels were determined from a blood sample drawn at recruitment. Lifestyle factors (smoking, BMI, physical activity) were documented by the participants. Prevalence of pharmacotherapy for and control of hypertension and dyslipidemia among diabetic patients with these diagnoses were assessed and determinants were evaluated by multiple logistic regression.ResultsDiabetes mellitus was present in 1375 participants (14.2%). Almost 78% of diabetic participants had physician diagnosed hypertension, 86.0% received pharmacotherapy, but only 12.8% of those with anti‐hypertensive medication achieved blood pressure levels below 130/85 mmHg. Obese participants were more likely to receive anti‐hypertensive pharmacotherapy than non‐obese ones: adjusted odds ratio (OR, 95% confidence interval (CI)): 3.58 (1.86–6.87). Gender had no influence on anti‐hypertensive pharmacotherapy. Older diabetic patients with hypertension were less likely to have sufficient blood pressure control than younger ones. Dyslipidemia was documented in 50% of diabetic patients. Diabetic participants with coronary heart disease or hypertension were more likely to receive lipid‐lowering pharmacotherapy than those without these conditions (adjusted OR 1.85 (95%CI 1.19–2.89) and 2.59 (95%CI 1.41–4.74), respectively).ConclusionsFor most elderly with diabetes cardiovascular risk factor management continues to be not in line with recommendations. Copyright © 2008 John Wiley & Sons, Ltd.
Missing item imputation for quality‐of‐life instruments with application to asthma quality‐of‐life questionnaires
Authors: Wang Jixian , Rapatz Guenter , Lowy Adam , Olson Sabine , Kuebler Juergen 
Published: March 2008

AbstractThere has been increasing use of quality‐of‐life (QoL) instruments in drug development. Missing item values often occur in QoL data. A common approach to solve this problem is to impute the missing values before scoring. Several imputation procedures, such as imputing with the most correlated item and imputing with a row/column model or an item response model, have been proposed. We examine these procedures using data from two clinical trials, in which the original asthma quality‐of‐life questionnaire (AQLQ) and the miniAQLQ were used. We propose two modifications to existing procedures: truncating the imputed values to eliminate outliers and using the proportional odds model as the item response model for imputation. We also propose a novel imputation method based on a semi‐parametric beta regression so that the imputed value is always in the correct range and illustrate how this approach can easily be implemented in commonly used statistical software. To compare these approaches, we deleted 5% of item values in the data according to three different missingness mechanisms, imputed them using these approaches and compared the imputed values with the true values. Our comparison showed that the row/column‐model‐based imputation with truncation generally performed better, whereas our new approach had better performance under a number scenarios. Copyright © 2008 John Wiley & Sons, Ltd.
Novel possibilities in the study of isolated carbon nanotubes
Authors: Avdoshenko Stanislav M. , Ioffe Il'ya N. , Kozlov Andrey A. , Markov Vitaliy Yu. , Nikolaev Evgeniy N. , Sidorov Lev N. 
Published: March 2008

AbstractWe report the first detection of carbon nanotubes in the gas phase in a matrix‐assisted laser desorption/ionization (MALDI) mass spectrometric experiment. These observations open the possibility of studying isolated nanotubes in the gas phase by means of various spectroscopic methods and a possible way to separate them. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of selected non‐authorized insecticides in peppers by liquid chromatography time‐of‐flight mass spectrometry and tandem mass spectrometry
Authors: Mezcua Milagros , Ferrer Carmen , García‐Reyes Juan F. , Martínez‐Bueno María Jesús , Albarracín Micaela , Claret María , Fernández‐Alba Amadeo R. 
Published: March 2008

AbstractIn this work, two analytical methods based on liquid chromatography coupled to electrospray time‐of‐flight mass spectrometry (LC/ESI‐TOFMS) and tandem mass spectrometry (LC/ESI‐MS/MS) are described for the identification, confirmation and quantitation of three insecticides non‐authorized in the European Union (nitenpyram, isocarbophos and isofenphos‐methyl) but detected in recent monitoring programmes in pepper samples. The proposed methodologies involved a sample extraction procedure using liquid‐liquid partition with acetonitrile followed by a cleanup step based on dispersive solid‐phase extraction. Recovery studies performed on peppers spiked at different fortification levels (10 and 50 µg kg−1) yielded average recoveries in the range 76–100% with relative standard deviation (RSD) (%) values below 10%. Identification, confirmation and quantitation were carried out by LC/TOFMS and LC/MS/MS using a hybrid triple quadrupole linear ion trap (QqLIT) instrument in multiple‐reaction monitoring (MRM) mode. The obtained limits of quantitation (LOQs) were in the range 0.1–5 µg kg−1, depending on each individual technique. Finally, the proposed methods were successfully applied to the analysis of suspected pepper samples. Copyright © 2008 John Wiley & Sons, Ltd.
Computer‐aided diagnosis using morphological features for classifying breast lesions on ultrasound
Authors: Huang Y.‐L. , Chen D.‐R. , Jiang Y.‐R. , Kuo S.‐J. , Wu H.‐K. , Moon W. K. 
Published: March 2008

AbstractObjectivesTo develop and evaluate a computer‐aided diagnosis (CAD) system with automatic contouring and morphological analysis to aid in the classification of breast tumors using ultrasound.MethodsWe evaluated 118 breast lesions (34 malignant and 84 benign tumors). Each tumor contour was automatically extracted from the digitized ultrasound image. Nineteen practical morphological features from the extracted contour were calculated and principal component analysis (PCA) was applied to find independent features. A support vector machine (SVM) classifier utilized the selected principal vectors to identify the breast tumor as benign or malignant. In this study, all the cases were sampled with k‐fold cross‐validation (k = 10) to evaluate the performance by receiver–operating characteristics (ROC) curve analysis.ResultsThe areas under the ROC curves for the proposed CAD systems using all morphological features and the lower‐dimensional principal vector were 0.91 and 0.90, respectively. The classification ability for breast tumors using morphological information was good.ConclusionsThis system differentiates benign from malignant breast tumors well and therefore provides a clinically useful second opinion. Moreover, the morphological features are nearly setting‐independent and thus available to various ultrasound machines. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Cost-effectiveness of cemented versus cementless total hip arthroplasty. A Markov decision analysis based on implant cost
Authors: Marinelli M. , Soccetti A. , Panfoli N. , de Palma L. 
Published: March 2008

AbstractBackgroundProbabilistic decision analysis is a means of reflecting the uncertainty parameter in models and of presenting it in a comprehensible manner to decision-makers.Materials and methodsA cost-effectiveness model was constructed to compare the cementless and cemented total hip prostheses implanted at our department in terms of lifetime costs and quality-adjusted life-years (QALY). Revision rates were obtained from the Orthopaedic Prosthesis Register of the Laboratory of Medical Technology, Istituti Ortopedici Rizzoli, Bologna, Italy.ResultsThe risk of early revision (at 5 years of follow-up) for cementless and cemented prostheses was 1.6% and 1.4%, respectively, resulting in equal QALY for the two implant types. Analysis of mean cost and QALY indicated that use of either implant is not associated with cost savings.DiscussionManagement with cementless or cemented total hip prostheses in a theoretical cohort of 70-year-old patients with fracture of the femoral neck or arthritis involving the hip is not significantly different according to the probabilistic results from the model.
Effects of growth factors and kinase inhibitors on the properties of human adipose‐stromal cells in different culture conditions
Authors: Cheon Sang Jin , Kim Jeung Il , Lee Jung Sub 
Published: March 2008

AbstractThe best‐fit environments for the proliferation and differentiation of human adipose tissue‐derived stromal cells (hADSCs) may require specific media and stimuli. The characteristics of hADSCs cultured in different media might be different. We evaluated the effects of growth factors on the proliferation and differentiation of hADSCs and compared the effects of these growth factors on hADSCs cultured in different serum‐contained media. The effects of kinase inhibitors on the proliferation of hADSCs were also examined.The combination of insulin—transferrin—selenium (ITS) and fibroblast growth factor (FGF) induced the greatest increase in proliferation, while the combination of ITS and epidermal growth factor (EGF) showed the second‐greatest effect in the human serum (HS)‐contained media. By contrast, in the fetal bovine serum (FBS)‐contained media, ITS had little effect while FGF had better results than the combination of ITS and EGF. The inhibitory potency of the kinase inhibitors was different in the two different media. These results suggest that hADSCs may have different characteristics according to the culture conditions, and that extrapolations of results from animal studies, using FBS media, may not correlate to findings in human studies using HS.