bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of antagonists on the conformational exchange of the retinoid X receptor alpha ligand‐binding domain
Authors: Lu Jianyun , Dawson Marcia I. , Hu Qiong Ying , Xia Zebin , Dambacher Jesse D. , Ye Mao , Zhang Xiao‐Kun , Li Ellen 
Published: September 2009

AbstractThe effect of retinoid X receptor (RXR) antagonists on the conformational exchange of the RXR ligand‐binding domain (LBD) remains poorly characterized. To address this question, we used nuclear magnetic resonance spectroscopy to compare the chemical shift perturbations induced by RXR antagonists and agonists on the RXRα LBD when partnered with itself as a homodimer and as the heterodimeric partner with the peroxisome proliferator‐activated receptor γ (PPARγ) LBD. Chemical shift mapping on the crystal structure showed that agonist binding abolished a line‐broadening effect caused by a conformational exchange on backbone amide signals for residues in helix H3 and other regions of either the homo‐ or hetero‐dimer, whereas binding of antagonists with similar binding affinities failed to do so. A lineshape analysis of a glucocorticoid receptor‐interacting protein 1 NR box 2 coactivator peptide showed that the antagonists enhanced peptide binding to the RXRα LBD homodimer, but to a lesser extent than that enhanced by the agonists. This was further supported by a lineshape analysis of the RXR C‐terminal residue, threonine 462 (T462) in the homodimer but not in the heterodimer. Contrary to the agonists, the antagonists failed to abolish a line‐broadening effect caused by a conformational exchange on the T462 signal corresponding to the RXRα LBD–antagonist–peptide ternary complex. These results suggest that the antagonists lack the ability of the agonists to shift the equilibrium of multiple RXRα LBD conformations in favor of a compact state, and that a PPARγ LBD‐agonist complex can prevent the antagonist from enhancing the RXRα LBD‐coactivator binding interaction. Copyright © 2009 John Wiley & Sons, Ltd.
Suppressing local particle oscillations in the Hamiltonian particle method for elasticity
Authors: Kondo Masahiro , Suzuki Yukihito , Koshizuka Seiichi 
Published: September 2009

AbstractThe governing equation of elasticity is discretized into motion equations of the particles in a Hamiltonian system. A weighted least‐square method is adopted to evaluate the Green–Lagrange strain. Using a symplectic scheme for the Hamiltonian system, we obtain the property of energy conservation in the discretized calculations. However, local particle oscillations occur, and they excessively decrease low frequency motion. In this study, we propose the use of an artificial potential force to suppress the local oscillations. The accuracy of the model with and without the inclusion of the artificial force is examined by analyzing a cantilever beam and wave propagation. With the inclusion of the artificial force, the local oscillations are reduced while energy conservation is maintained. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis of aliphatic polyesters by polycondensation using inorganic acid as catalyst
Authors: Sokolsky‐Papkov Marina , Langer Robert , Domb Abraham J. 
Published: September 2009

AbstractAn effective route for the synthesis of aliphatic polyesters made from adipic or sebacic acid and alkanediols, using inorganic acid as a catalyst is reported. The monomer composition, reaction time, catalyst type, and reaction conditions were optimized to yield polyesters with weight average molecular weights of 23,000 for adipic acid and 85,000 for sebacic acid‐based polyesters. The polymers melt at temperatures of 52–65°C and possess melt viscosity in the range of 5600–19,400cP. This route represents an alternative method for producing aliphatic polyesters for possible use in the preparation of degradable disposable medical supplies. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation and characterization of PVDF microporous membrane with highly hydrophobic surface
Authors: Li Qian , Xu Zhen‐Liang , Liu Min 
Published: September 2009

AbstractUsing the mixture of triethyl phosphate (TEP) and N,N‐dimethylacetamide (DMAc) as solvent, PVDF microporous membranes with highly hydrophobic surface were prepared by a modified NIPS method with a dual coagulation process. The effects of the exposure time on these membranes before being immersed into the coagulation bath and the composition in the coagulation bath on precipitation rate, membrane morphology, membrane hydrophobicity, membrane mechanical property, and membrane performance were studied. The morphologies and hydrophobicities of PVDF microporous membranes were investigated by scanning electron microscopy (SEM) and contact angle (CA) measurement. The precipitation processes were observed by light transmittance measurement. The pore size distribution was determined by liquid permeation technique. PVDF microporous membrane obtained by passing evaporation period of 60 min before being immersed into the water bath showed a high water CA of 122.1°. Using ethanol (EtOH) as coagulation bath, the water CAs of the top surface and bottom surface of the membrane increased to 125.9 and 132.6°, respectively. To further improve PVDF membrane hydrophobicity, a dual coagulation process was used and the mixed solvent (TEP–DMAc) was added into the first coagulation bath for 30 sec. Increase in the TEP–DMAc content led to the change in the morphology type of the membrane, that is, from an asymmetric structure with a dense top surface to a symmetric structure with a skinless top surface, and the pore size distribution widened greatly. By increasing the mass ratio of TEP to DMAc, the denseness of the membrane surface decreased significantly. Adding 60 wt% of TEP–DMAc to the first coagulation bath and the mass ratio of TEP to DMAc was 60:40, the CA reached to a maximum as high as 136.6°, and PVDF microporous membrane showed a high porosity of 80% and an excellent mechanical property of 3.14 MPa tensile strength and 61.79% elongation ratio. Copyright © 2009 John Wiley & Sons, Ltd.
A new elaboration concept of polypropylene/unmodified Montmorillonite nanocomposites by reactive extrusion based on direct injection of polypropylene aqueous suspensions
Authors: Aloui M. , Soulestin J. , Lacrampe M.‐F. , Krawczak P. , Rousseaux D. , Marchand‐Brynaert J. , Devaux J. , Quiévy N. , Sclavons M. 
Published: September 2009

AbstractNanocomposites based on polypropylene (PP) and unmodified Montmorillonite were prepared using a novel elaboration route based on a water‐assisted extrusion process. Unmodified Montmorillonite, high shear compounding together with injection of aqueous suspension and reactive processing technology were used. Different aqueous suspensions containing cationic or anionic surfactants, and a compatibilizer (PP‐g‐MA) were injected during extrusion to promote clay dispersion. For a comparison purpose, a commercial PP/clay masterbatch was melt mixed to PP. Structural, morphological, and rheological characterizations indicate clearly that the cationic suspensions ease the dispersion of clay platelets in the PP matrix. No full exfoliation is, however, obtained, and the system remains still less homogeneous than the nanocomposite based on the commercial masterbatch. Nevertheless, mechanical and thermal characterizations of the nanocomposites based on cationic surfactants demonstrate the efficiency to disperse clay in the polymer matrix, and the effect on the ductility compared to usual PP nanocomposites is promising. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Synthesis and characterization of phosphorus‐containing polysulfone
Authors: Petreus Oana , Avram Ecaterina , Serbezeanu Diana 
Published: September 2009

AbstractChemical modification of a chloromethylated polysulfone (CMPS) was performed by reacting the chlorometyl group with PH bond of 9,10‐dihydro‐oxa‐10‐phosphophenanthrene‐10‐oxide (DOPO). A kinetic study of phosphorylation of CMPS with different chlorine content was reported. The obtained polymers bearing cyclic bulky groups containing phosphorus were characterized by analytical methods; Fourier transforms spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). The thermal stability of phosphorus‐modified polysulfone was evaluated by dynamic thermogravimetric analysis in nitrogen gas. The polymers were readily soluble in polar organic solvent, such as N‐methylpyr‐rolidone (NMP), N,N‐dimethylacetamide (DMAc), and N,N‐dimethylformamide (DMF). Differential scanning calorimeter (DSC) and dynamic mechanical analysis (DMA) proved an amorphous morphology of these polymers. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Development of a rheo‐dielectric sensor for online shear stress measurement during the injection molding process
Authors: Peng Yiyan , Li Haimei , Turng Lih‐Sheng 
Published: September 2009

AbstractThis study presents the development of a novel rheo‐dielectric sensing technique, based on dielectrostriction measurement, for online injection molding process monitoring. Dielectrostriction, defined as a variation of dielectric properties of material under deformation, detects evolution of molecular orientation during injection molding and enables online shear stress measurement. The dielectrostriction effect resembles the well‐known birefringence phenomenon. As birefringence in polymers is described by the stress‐optical relationship (Fuller, Optical Rheometry of Complex Fluids, Oxford University Press, New York (1995); Janeschitz‐Kriegl, Polymer Melt Rheology and Flow Birefringence, Springer, Berlin (1983); Saiz and Rainde, Dipole Moments and Birefringence of Polymers, Prentice‐Hall, New Jersey (1992)), a stress‐dielectric relationship exists for and is applicable to dielectrostriction. In addition,dielectrostriction measurements can be performed on both transparent and opaque materials with a much simpler data acquisition technique. To demonstrate the feasibility of the dieletrostriction measurement, a planar capacitor sensor rosette has been developed and attached to the surface of an injection mold to obtain the dielectrostriction signal under various processing conditions. The calculated shear stresses of polymer melts based on dielectrostriction signals were validated by agreement with simulation predictions. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Preparation and biodegradation of copolyesters based on poly(ethylene terephthalate) and poly(ethylene glycol)/oligo(lactic acid) by transesterification
Authors: Tan Licheng , Chen Yiwang , Zhou Weihua , Li Fan , Chen Lie , He Xiaohui 
Published: September 2009

AbstractThe poly(ethylene terephthalate‐co‐ethyleneoxide‐co‐DL‐lactide) copolymers were successfully prepared by the melt reaction between poly(ethylene terephthalate), poly(ethylene glycol), and DL‐oligo(lactic acid) without any catalysts. The transesterification between ethylene terephthalate, ethyleneoxide, and lactide segments during the reaction was confirmed by the 1H NMR analysis. The effect of reaction temperatures and the starting feed ratios on the molecular microstructures, molecular weights, solubility, thermal properties, and degradability of the copolyesters was extensively studied. The values of crystallization temperature, melting temperature, crystallization, and melting enthalpy of the copolyesters were found to be influenced by the reaction temperatures, starting feed ratios, etc. The copolyesters showed good tensile properties and were found to degrade in the soil burial experiments during the period of 3 months. The morphology of the copolyester films were also investigated by scanning electron microscopy during soil burial degradation. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Photopatterning and degradation study of dextran‐glycidyl methacrylate hydrogels
Authors: Lo Chi‐Wei , Jiang Hongrui 
Published: September 2009

AbstractAn approach to synthesizing photopatternable enzymatic degradable dextran hydrogel is presented. The glycidyl methacrylate derivatized dextran (Dex‐GMA) was first prepared by reacting dextran with glycidyl methacrylate at 45°C with grafting efficiency of 10%. The degree of substitution (DS) was confirmed by 1H‐NMR. Next, Dex‐GMA hydrogels were prepared by crosslinking in the presence of a crosslinker: N,N′‐ methylene‐bisacrylamide (NMBA), and a photoinitiator: 2,2′‐dimethoxy‐2‐phenyl acetophenone (DMPA) in dimethyl sulfoxide (DMSO) solution. Further, the Dex‐GMA hydrogels were photopatterned using liquid‐phase photopolymerization (LP3) technique. The structure size ranged from 5 mm to 300 μm and three different shapes of structures‐ ‐ —round, square, and star‐ ‐ —were demonstrated. The patterned Dex‐GMA hydrogel structures not only exhibited mechanical robustness but also biodegradability. The dextranase‐catalyzed degradation of Dex‐GMA hydrogels with different DS was investigated at 37°C. The morphology of the degraded Dex‐GMA hydrogels determined by SEM revealed the degree of enzymatic degradation due to dextranase. The Dex‐GMA hydrogel was fully degraded by dextranase with concentration of 2 U/ml in 5 days. The Dex‐GMA hydrogel also showed the ability to be readily integrated with microfluidics. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Negotiating un/familiar embodiments: investigating the corporeal dimensions of South Korean international student mobilities in Auckland, New Zealand
Authors: Collins Francis Leo 
Published: September 2009

AbstractThis paper discusses the friction involved in the transnational lives of South Korean international students living and studying in Auckland, New Zealand. In particular, it focuses on the ways in which these individuals negotiate familiar and unfamiliar embodiments as a part of their everyday lives in Auckland. Through three ethnographic case studies – the role of interpersonal networks in the negotiation of urban space, the online/off‐line use of internet cafes, and the story of a group of volunteer students – this paper reflects on the different processes of embodiment in ways that offer useful insights into practices and experiences of transnationalism. This includes understanding the small details of the everyday lives of international students in Auckland and the reciprocal relationship they have with other bodies and the urban spaces they come to inhabit. Moreover, the paper illustrates the manner that scholarly understandings of transnationalism can be expanded through a focus on the embodied dimensions of everyday life. It suggests that much of what is considered transnationalism is in fact part of the ordinary everyday practices that individuals such as international students use to negotiate and make familiar the different material and immaterial spaces they encounter in migration. Copyright © 2009 John Wiley & Sons, Ltd.
Correction for misclassification of a categorized exposure in binary regression using replication data
Authors: Dalen Ingvild , Buonaccorsi John P. , Sexton Joseph A. , Laake Petter , Thoresen Magne 
Published: September 2009

AbstractContinuous epidemiologic exposure data are often categorized according to one or more cut points before inclusion in a regression analysis involving some outcome variable. If the original data are subject to measurement error, the categorized data will be afflicted with misclassification, which is differential, and which induces biases in naïve methods that ignore the misclassification. We propose a method for measurement error adjustment in these settings, when there are replicate data available on the original measurements, and when the outcome variable is dichotomous. Working on the continuous measurements, conditional densities of the exposure given the outcome are estimated and used to obtain odds ratios. The estimation of densities is done either parametrically or nonparametrically. The method is compared with the naïve approach of simply categorizing the erroneous mean measurements in simulation studies, and although the nonparametric method is more variable, it has the best overall performance, the greatest differences being observed in settings where the effects and/or the measurement errors are large. The performance of the parametric method is highly dependent on the model fit. Applying the methods to a real‐life data set from the Framingham Heart Study produced larger estimated odds ratios for coronary heart disease as a result of elevated systolic blood pressure, as compared with naïve odds ratios. We provide some discussion of alternative procedures that might be considered including regression calibration, SIMEX and the use of estimated misclassification probabilities. Copyright © 2009 John Wiley & Sons, Ltd.
Left ventricular cardiac function in fetuses with congenital diaphragmatic hernia and the effect of fetal endoscopic tracheal occlusion
Authors: Van Mieghem T. , Gucciardo L. , Doné E. , Van Schoubroeck D. , Graatsma E. M. , Visser G. H. A. , Verhaeghe J. , Deprest J. 
Published: September 2009

AbstractObjectivesThe pre‐existing compression of the left ventricle in congenital diaphragmatic hernia (CDH) could be aggravated by the amplified lung growth after fetoscopic endoluminal tracheal occlusion (FETO). Our aim was to document left ventricular (LV) size and function in fetuses with isolated left‐sided CDH and to document the effect of FETO on the fetal heart.MethodsWe determined cardiac axis, LV diameters, ejection fraction, shortening fraction, mitral E/A index and myocardial performance index (MPI) in 27 fetuses with isolated left‐sided CDH, and compared these with values in a reference population (n = 117). In fetuses with severe CDH that subsequently underwent FETO and/or reversal of occlusion, additional measurements were obtained 24 h before and after each fetal intervention. We recorded fetal electrocardiograms non‐invasively in six CDH fetuses and compared the duration of the QRS complex with data obtained from 12 controls.ResultsLV end‐diastolic diameter was 32% smaller in CDH fetuses than in controls (P < 0.0001) but LV function was comparable. QRS duration was no different between CDH and control fetuses. FETO did not affect cardiac size but reduced the MPI (P = 0.004). Reversal of FETO had no significant effect on cardiac size and function.ConclusionsCDH fetuses have a smaller left ventricle than do healthy fetuses. There is no overall adverse impact of CDH and FETO on LV cardiac function. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Gestational sac volume: comparison between SonoAVC and VOCAL measurements at 11 + 0 to 13 + 6 weeks of gestation
Authors: Borenstein M. , Azumendi Perez G. , Molina Garcia F. , Romero M. , Anderica J. R. 
Published: September 2009

AbstractObjectivesTo assess the novel three‐dimensional (3D) tool, Sonography‐based Automated Volume Count™ (SonoAVC) in the calculation of gestational sac volume at 11 + 0 to 13 + 6 weeks of gestation, to correlate the measurements with those obtained using Virtual Organ Computed‐aided AnaLysis™ (VOCAL) and to study the reproducibility of SonoAVC volume calculation of this irregularly shaped structure.MethodsWe acquired 3D volumes of the uterus in 65 pregnancies at 11 + 0 to 13 + 6 weeks of gestation. We performed volume calculation of the gestational sac, excluding the fetus and the placenta, using VOCAL with 15° 12‐step rotation. We then repeated the calculation with three different SonoAVC settings and compared both techniques. In 30 cases we assessed the reproducibility of the SonoAVC volume calculations.ResultsIn 95% of cases it was possible to calculate the gestational sac volume with SonoAVC. This volume increased with advancing gestation and the volumes were expressed as delta values to compare the measurements made with VOCAL and the three different SonoAVC settings. There was no difference between delta values of gestational sac volume calculated using VOCAL and SonoAVC with high and medium growth settings. Reproducibility analysis showed good results.ConclusionGestational sac volume calculation is feasible with SonoAVC in most cases and does not differ from that performed using VOCAL. High and medium growth SonoAVC settings seem to be more accurate for gestational sac volume calculation, although larger studies are required for standardization of the technique. The reproducibility analysis showed similar results to those previously published. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Prognostic Significance of the Metastatic Lymph Node Ratio in Gastric Cancer Patients
Authors: Fukuda Naoto , Sugiyama Yasuyuki , Midorikawa Akira , Mushiake Hiroyuki 
Published: September 2009

AbstractBackgroundLymph node metastasis is considered one of the most important prognostic factors in gastric cancer. However, the optimal system for accurate staging of lymph node metastasis for patients with gastric cancer remains controversial. This study was designed to investigate the prognostic significance of the metastatic lymph node ratio (MLR), which is calculated by dividing the number of metastatic lymph nodes by the total number of nodes harvested from patients with gastric cancer.MethodsWe retrospectively analyzed the clinical data of 186 consecutive patients diagnosed with gastric cancer who underwent curative gastrectomy at our hospital. The lymph node status was classified according to three systems: the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) system; the Japanese Gastric Cancer Association (JGCA) system; and an MLR‐based system (MLR0: 0, MLR1: 0.01–0.19, MLR2: ≥0.2). The influence of the MLR on patient survival was determined using univariate Kaplan‐Meier survival analysis, the generalized Wilcoxon test, and analysis with the multivariate Cox proportional hazards model.ResultsThe 5‐year survival rate of the patients with MLR0, MLR1, and MLR2 was 88.6%, 59.4%, and 13.4%, respectively. In addition to the MLR, the UICC/AJCC N category, JGCA n category, tumor stage (pT category), and tumor diameter significantly influenced the 5‐year survival rate, as determined by univariate analysis. Multivariate analyses revealed that of the three factors used to stage lymph node involvement, MLR was the most significant prognostic factor.ConclusionsThe MLR is an important and easy‐to‐assess prognostic factor that should be considered for staging lymph node metastasis in patients with gastric cancer.
Multi‐Factor Investigation of Early Postoperative Cardiac Arrhythmia for Elderly Patients with Esophageal or Cardiac Carcinoma
Authors: Xue Lei , Pan Tiewen , Xu Zhifei , Zhao Xuewei , Zhong Lei , Wu Lihui , Wu Bin , Qin Xiong 
Published: September 2009

AbstractBackgroundThe purpose of the present study was to analyze the risk multi‐factors of postoperative cardiac arrhythmia for elderly patients with esophageal or cardiac carcinoma.MethodsA total of 756 operations for elderly patients (>65 years of age) with esophageal or cardiac carcinoma were performed in our department from January 1997 to December 2006. These included 197 cases (26.1%) of various types of cardiac arrhythmia after operation. Logistic regression was adopted to analyze the risk multi‐factors of postoperative cardiac arrhythmia.ResultsIt showed that complications of other diseases before operation, selection of operation method, duration of anesthesia and operation, postoperative pain, anoxia, hypovolemia, acid–alkali disequilibrium, and electrolyte imbalance might be the risk factors of postoperative cardiac arrhythmia in elderly patients with esophageal or cardiac carcinoma, whereas minimally invasive endoscopic operation might be a protective factor.ConclusionsIn order to decrease the risk factors leading to postoperative cardiac arrhythmia for elderly patients with esophageal or cardiac carcinoma, it was necessary to completely evaluate the functions of heart and lung, improve the nutrition and metabolism of heart muscle, conduct effective breathing exercises, and correct the existing cardiac arrhythmia of such patients before operation, and perform the minimally invasive operation, shorten operation duration, relieve pain efficiently during the perioperative period, and correct hypovolemia and acid–alkali disequilibrium and electrolyte imbalance.