bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel imidazole derivative curing agent for epoxy resin: Synthesis, characterization, and cure kinetic
Authors: Fang Wang , Jun Xiao , Jing‐Wen Wang , Shu‐Qin Li 
Published: September 2007

AbstractA novel imidazole derivative (named as EMI‐g‐BGE) was synthesized through the reaction of 2‐ethyl‐4‐methyl imidazole (EMI) and butyl glycidyl ether (BGE) and characterized by elemental analysis, FTIR spectroscopy, and 1H NMR spectroscopy. The curing kinetic of diglycidyl ether of bisphenol A (DGEBA) epoxy resin with EMI‐g‐BGE as curing agent was studied by nonisothermal DSC technique at different heating rates. Dynamic DSC scans indicated that EMI‐g‐BGE was an effective curing agent of epoxy resin. The apparent activation energy Ea was 71.8 kJ mol−1 calculated through Kissinger method, and the kinetic parameters were determined by Málek method for the kinetic analysis of the thermal treatment obtained by DSC measurement. A two‐parameter (m, n) autocatalytic model (Šesták‐Berggren equation) was found to be the most adequate selected kinetic model. In addition, the predicted curves from the kinetic model fit well with the nonisothermal DSC thermogram. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of crystallization temperature on crystal modifications and crystallization kinetics of poly(L‐lactide)
Authors: Pan Pengju , Zhu Bo , Kai Weihua , Dong Tungalag , Inoue Yoshio 
Published: September 2007

AbstractThe crystalline structure of poly(L‐lactide) (PLLA) have been found to quite depend on the crystallization temperatures (Tcs), especially in the range of 100−120°C, which is usually used as the crystallization temperature for the industrial process of PLLA. The analysis of wide‐angle X‐ray diffraction and Fourier transformed infrared spectroscopy revealed that 110°C is a critical temperature for PLLA crystallization. At Tc < 110°C and Tc ≥ 110°C, the α′ and α crystals were mainly produced, respectively. Besides, the structural feature of the α′‐form was illustrated, and it was found that the α′‐form has the larger unit cell dimension than that of the α‐form. Moreover, the crystallization kinetics of the α′ and α crystals are different, resulting in the discontinuousness of the curves of spherulite radius growth rate (G) versus Tc and the half time in the melt‐crystallization (t1/2) versus Tc investigated by Polarized optical microscope and Differential scanning calorimetry, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of solvent plasticization on polypropylene microcellular foaming process and foam characteristics
Authors: Kaewmesri W. , Rachtanapun P. , Pumchusak J. 
Published: September 2007

AbstractIn this research, the effect of crystalline fraction of polypropylene (PP) on cell nucleation behavior was overcome by an introduction of solvent‐plasticized step to the microcellular foaming in a solid‐state batch‐foaming process. Utilizing the plasticization performance of the solvent facilitated the PP to be foamed at the temperatures lower than its melting point with the dramatic development in the cellular morphology of the final foams. In consequence of the heterogeneous cell nucleation sites induction and the crystalline loss, which were induced by solvent, a high cell density (i.e., 109–1010cells/cm3) was promoted without the cell sacrificing at the elevated temperatures (155 and 165°C) and favorable PP microcellular foams were accomplished. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mechanical properties and porosity of polylactide for biomedical applications
Authors: Sawalha Hassan , Schroën Karin , Boom Remko 
Published: September 2007

AbstractIn this study, the strength, ductility, and porosity of polylactide films prepared by immersion precipitation and film casting in air were investigated. To induce extra porosity in the films, dodecane was added to the polymer casting solution. The structure, porosity, and mechanical properties of the films were evaluated. The ultimate strength and elastic modulus of neat poly(L‐lactide) prepared by film casting were at least twice those of the same film prepared in methanol, whereas the ductility of these films was considerably higher than that for air. The porosity, size of pores, and interconnectivity of pores increased gradually with increasing dodecane concentration. This dodecane‐induced porosity (as high as 80%), progressively reduced the ultimate strength and modulus of practically all films but remarkably improved the ductility of films prepared in air, and this can be related to a decrease in the crystallization temperature. For films prepared in water or poly(D,L‐lactide) films in general, the ultimate strength, modulus, and ductility of films prepared in water were significantly lower than those of air‐cast poly(L‐lactide) films. In summary, the results obtained in this research show that it is possible to tailor the properties of films for various biomedical applications through the use of the polymer type, preparation method, and dodecane‐induced porosity as tools. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mast Cells Appearing in Long‐term Skeletal Muscle Cell Cultures of Rat
Authors: Cheng Chang‐xie , Li Yong‐nan , Ohno Hiroshi , Sawanobori Kazuko , Li Yan‐chao , Shimada Osamu , Atsumi Saoko 
Published: September 2007

AbstractMast cells are known to be involved in type I allergy and to be localized in almost all tissues in the body. However, they have slightly different properties depending on their tissue of residence. Although mast cells are found in skeletal muscle tissue, there have been no reports of their appearance in cultured skeletal muscles. We report here that mast cells appear in long‐term cultures of skeletal muscles from neonatal rats and rat fetuses. When muscle cells were disseminated and cultured in minimum essential medium with 10% fetal calf serum and 10% horse serum, oval cells containing large granules started to appear on myotube sheets at 5 days of culture. These oval cells continued to proliferate for 2–3 months, and showed immunoreactivity for histamine, tryptase, FcεRI, and c‐kit. They showed metachromatic staining with 0.5% toluidine blue at pH 0.5 and were stained with both Alcian blue and safranin. Biochemically measured histamine content per dish was significantly higher in 2‐month than in 5‐day culture. From these results, we concluded that these oval cells were mast cells. Because proteases from mast cells have been reported previously to affect myoblast proliferation, the present findings suggest that there may be some interaction between mast cells and muscle cell proliferation or differentiation. The present finding that mast cells are easily obtained from ordinary skeletal muscle cultures provides a useful method for the study of the diverse functions of mast cells. Anat Rec, 1424‐1430, 2007. © 2007 Wiley‐Liss, Inc.
Large Image Microscope Array for the Compilation of Multimodality Whole Organ Image Databases
Authors: Namati Eman , de Ryk Jessica , Thiesse Jacqueline , Towfic Zaid , Hoffman Eric , Mclennan Geoffrey 
Published: September 2007

AbstractThree‐dimensional, structural and functional digital image databases have many applications in education, research, and clinical medicine. However, to date, apart from cryosectioning, there have been no reliable means to obtain whole‐organ, spatially conserving histology. Our aim was to generate a system capable of acquiring high‐resolution images, featuring microscopic detail that could still be spatially correlated to the whole organ. To fulfill these objectives required the construction of a system physically capable of creating very fine whole‐organ sections and collecting high‐magnification and resolution digital images. We therefore designed a large image microscope array (LIMA) to serially section and image entire unembedded organs while maintaining the structural integrity of the tissue. The LIMA consists of several integrated components: a novel large‐blade vibrating microtome, a 1.3 megapixel peltier cooled charge‐coupled device camera, a high‐magnification microscope, and a three axis gantry above the microtome. A custom control program was developed to automate the entire sectioning and automated raster‐scan imaging sequence. The system is capable of sectioning unembedded soft tissue down to a thickness of 40 μm at specimen dimensions of 200 × 300 mm to a total depth of 350 mm. The LIMA system has been tested on fixed lung from sheep and mice, resulting in large high‐quality image data sets, with minimal distinguishable disturbance in the delicate alveolar structures. Anat Rec 290:1377‐1387, 2007. © 2007 Wiley‐Liss, Inc.
Synthesis and In‐Vitro Activity of Novel 1β‐Methylcarbapenems Having Spiro[2,4]heptane Moieties
Authors: Park Hyeong Beom , Jo Nam Hyun , Hong Joon Hee , Chei Jung Hoon , Cho Jung‐Hyuck , Yoo Kyung Ho , Oh Chang‐Hyun 
Published: September 2007

AbstractThe synthesis of a new series of 1β‐methylcarbapenems having spiro[2,4]heptane moieties is described. Their in‐vitro antibacterial activities against both gram‐positive and gram‐negative bacteria were tested and the effect of substituents on the pyrrolidine ring was investigated. Most compounds were shown to be more active than the compared meropenem and imipenem against Escherichia coli. One particular compound, IIIb, having hydroxy a moiety showed the most potent antibacterial activity.
SDX‐308 and SDX‐101, Non‐Steroidal Anti‐Inflammatory Drugs, as Therapeutic Candidates for Treating Hematologic Malignancies Including Myeloma
Authors: Lentzsch Suzanne , Elliott Gary , Roodman G. David 
Published: September 2007

AbstractNon‐steroidal anti‐inflammatory drugs have been shown to inhibit carcinogenesis in colon cancer, and to induce apoptosis in a variety of tumor cell lines. Some anti‐tumor effects are thought to be related to their cyclooxygenase‐2‐inhibitory activity, but recent studies have shown that non‐steroidal anti‐inflammatory drugs exert their anti‐tumor effect via cyclooxygenase‐2‐independent mechanism. SDX‐308 (CEP‐18082) is a non‐cyclooxygenase‐2‐inhibiting indole‐pyran analog and is structurally related to SDX‐101, an R‐enantiomer of etodolac. SDX‐308 has a potent anti‐myeloma effect and shows synergism in combination with other drugs for the treatment of chronic lymphocytic leukemia. In addition SDX‐308 inhibits osteoclast formation and activity and thereby might be an attractive drug for the treatment of diseases with increased osteoclast activity such as osteolytic lesions in multiple myeloma and metastatic carcinomas, as well as osteoporosis. This review covers future application of SDX‐308 as an anti‐myeloma drug regulating increased osteoclast activity.
Nickel‐Catalyzed Mizoroki–Heck‐ versus Michael‐Type Addition of Organoboronic Acids to α,β‐Unsaturated Alkenes through Fine‐Tuning of Ligands
Authors: Lin Pao‐Shun , Jeganmohan Masilamani , Cheng Chien‐Hong 
Published: September 2007

AbstractVarious arylboronic acids reacted with activated alkenes in the presence of [Ni(dppe)Br2], ZnCl2, and H2O in CH3CN at 80 °C to give the corresponding Mizoroki–Heck‐type addition products in good to excellent yields. Furthermore, 1 equivalent of the hydrogenation product of the activated alkene was also produced. By tuning the ligands of the nickel complexes and the reaction conditions, Michael‐type addition was achieved in a very selective manner. Thus, various p‐ and o‐substituted arylboronic acids or alkenylboronic acid reacted smoothly with activated alkenes in CH3CN at 80 °C for 12 h catalyzed by Ni(acac)2, P(o‐anisyl)3, and K2CO3 to give the corresponding Michael‐type addition products in excellent yields. However, for m‐substituted arylboronic acids, the yields of Michael‐type addition products are very low. The cause of this unusual meta‐substitution effect is not clear. By altering the solvent or phosphine ligand, the product yields for m‐substituted arylboronic acids were greatly improved. In contrast to previous results in the literature, the present catalytic reactions required water for Mizoroki–Heck‐type products and dry reaction conditions for Michael‐type addition products. Possible mechanistic pathways for both addition reactions are proposed.
Simultaneous versus sequential pharmacokinetic‐pharmacodynamic population analysis using an Iterative Two‐Stage Bayesian technique
Authors: Proost Johannes H. , Schiere Sjouke , Eleveld Douglas J. , Wierda J. Mark K. H. 
Published: September 2007

AbstractA method for simultaneous pharmacokinetic‐pharmacodynamic (PK‐PD) population analysis using an Iterative Two‐Stage Bayesian (ITSB) algorithm was developed. The method was evaluated using clinical data and Monte Carlo simulations.Data from a clinical study with rocuronium in nine anesthetized patients and data generated by Monte Carlo simulation using a similar study design were analysed by sequential PK‐PD analysis, PD analysis with nonparametric PK data and simultaneous PK‐PD analysis. Both PK and PD data sets were ‘rich’ with respect to the number of measurements per individual. The accuracy and precision of the estimated population parameters were evaluated by comparing their mean error (ME) and root mean squared error (RMSE), respectively. The influence of PD model misspecification on the results was also investigated.The simultaneous PK‐PD analysis resulted in slightly more precise population parameter estimates than the sequential PK‐PD analysis and the nonparametric PK method. In the presence of PD model misspecification, however, simultaneous analysis resulted in poor PK parameter estimates, while sequential PK‐PD analysis performed well.In conclusion, ITSB is a valuable technique for PK‐PD population analysis of rich data sets. The sequential PK‐PD method is better suited for the analysis of rich data than the simultaneous analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Nutrient intakes in women and risks of anophthalmia and microphthalmia in their offspring
Authors: Shaw Gary M. , Carmichael Suzan L. , Laurent Cecile , Louik Carol , Finnell Richard H. , Lammer Edward J. 
Published: September 2007

AbstractBACKGROUND There is a paucity of information about risk factors for the human eye anomalies anophthalmia and microphthalmia. In this population‐based case‐control study we investigated whether periconceptional intakes of supplemental folic acid, dietary folate, vitamin A, and several other nutrients were associated with these eye defects. METHODS This study included data on deliveries that had estimated due dates from 1997–2002 and were part of the National Birth Defects Prevention Study (the National Birth Defects Prevention Study is a population‐based case‐control study of a wide spectrum of birth defects, incorporating data from 10 birth defects surveillance systems in the United States [Arkansas, California, Georgia/Centers for Disease Control and Prevention, Iowa, Massachusetts, New Jersey, New York, North Carolina, Texas, and Utah]). Cases were those infants or fetuses born with either anophthalmia or microphthalmia. Liveborn infants without major malformations were eligible as controls. Maternal interviews were conducted, primarily by telephone, in English or Spanish. Participation in the interview was 71% among case mothers and 68% among control mothers. Interviews were completed with 89 case mothers and 4,143 control mothers. A shortened version of the food frequency questionnaire from the Nurse's Health Study was used to assess frequency of intake of 58 food items during the year before pregnancy. RESULTS Our results did not indicate reduced risks for these eye malformations associated with maternal intake of vitamin supplements containing folic acid. The data did not show an association between malformation risk and higher or lower intakes of vitamin A. We also did not observe strong evidence that an abundance or a lack of dietary intake of any other nutrient was associated with increased risk of the studied eye malformations. CONCLUSIONS Our observations contribute to a limited body of findings on these rare eye defects. © 2007 Wiley‐Liss, Inc.
Experimental induction of palate shelf elevation in glutamate decarboxylase 67‐deficient mice with cleft palate due to vertically oriented palatal shelf
Authors: Iseki Sachiko , Ishii‐Suzuki Masako , Tsunekawa Naoko , Yamada Yoko , Eto Kazuhiro , Obata Kunihiko 
Published: September 2007

AbstractBACKGROUND:Gamma‐aminobutyric acid is an inhibitory neurotransmitter, synthesized by two isoforms of glutamate decarboxylase (GAD), GAD65 and ‐67. Unexpectedly, inactivation of GAD67 induces cleft palate in mice. Reduction of spontaneous tongue movement resulting from decreased motor nerve activity has been related to the development of cleft palate in GAD67−/− fetuses. In the present study, development of cleft palate was examined histologically and manipulated with culture of the maxilla and partial resection of fetal tongue.METHODS:GAD67−/− mice and their littermates were used. Histological examination and immunohistochemistry were performed conventionally. Organ culture of the maxilla was carried out as reported previously. Fetuses were maintained alive under anesthesia and tips of their tongues were resected.RESULTS:Elevation of palatal shelves, the second step of palate formation, was not observed in GAD67−/− mice. In wild‐type mice, GAD67 and gamma‐aminobutyric acid were not expressed in the palatal shelves, except in the medial edge epithelium. During 2 days of culture of maxillae dissected from E13.5–E14.0 GAD67−/− fetuses, elevation and fusion of the palatal shelves were induced. When E13.5–15.5 mutant fetuses underwent partial tongue resection, the palatal shelves became elevated within 30 min.CONCLUSIONS:These results suggest that the potential for palate formation is maintained in the palatal shelves of GAD67−/− fetuses, but it is obstructed by other, probably neural, factors, resulting in cleft palate. Birth Defects Research (Part A) 2007. © 2007 Wiley‐Liss, Inc.
The Log Multinomial Regression Model for Nominal Outcomes with More than Two Attributes
Authors: Blizzard L. , Hosmer D. W. 
Published: September 2007

AbstractAn estimate of the risk or prevalence ratio, adjusted for confounders, can be obtained from a log binomial model (binomial errors, log link) fitted to binary outcome data. We propose a modification of the log binomial model to obtain relative risk estimates for nominal outcomes with more than two attributes (the “log multinomial model”). Extensive data simulations were undertaken to compare the performance of the log multinomial model with that of an expanded data multinomial logistic regression method based on the approach proposed by Schouten et al. (1993) for binary data, and with that of separate fits of a Poisson regression model based on the approach proposed by Zou (2004) and Carter, Lipsitz and Tilley (2005) for binary data. Log multinomial regression resulted in “inadmissable” solutions (out‐of‐bounds probabilities) exceeding 50% in some data settings. Coefficient estimates by the alternative methods produced out‐of‐bounds probabilities for the log multinomial model in up to 27% of samples to which a log multinomial model had been successfully fitted. The log multinomial coefficient estimates generally had lesser relative bias and mean squared error than the alternative methods. The practical utility of the log multinomial regression model was demonstrated with a real data example. The log multinomial model offers a practical solution to the problem of obtaining adjusted estimates of the risk ratio in the multinomial setting, but must be used with some care and attention to detail. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inference Methods for the Conditional Logistic Regression Model with Longitudinal Data
Authors: Craiu Radu V. , Duchesne Thierry , Fortin Daniel 
Published: September 2007

AbstractThis paper considers inference methods for case‐control logistic regression in longitudinal setups. The motivation is provided by an analysis of plains bison spatial location as a function of habitat heterogeneity. The sampling is done according to a longitudinal matched case‐control design in which, at certain time points, exactly one case, the actual location of an animal, is matched to a number of controls, the alternative locations that could have been reached. We develop inference methods for the conditional logistic regression model in this setup, which can be formulated within a generalized estimating equation (GEE) framework. This permits the use of statistical techniques developed for GEE‐based inference, such as robust variance estimators and model selection criteria adapted for non‐independent data. The performance of the methods is investigated in a simulation study and illustrated with the bison data analysis. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solid‐phase synthesis of 4,8‐disubstituted‐8,9‐dihydropyrazino[2,3‐g]quinazolin‐7(6H)‐ones
Authors: Zhang Yandong , Yao Chao , Houghten Richard A. , Yu Yongping 
Published: September 2007

AbstractAn approach for the solid‐phase synthesis of 4,8‐disubstituted‐8,9‐dihydropyrazino[2,3‐g]quinazolin‐7(6H)‐ones from 4‐chloro‐7‐fluoro‐6‐nitroquinazoline scaffold is described. A chemoselective reaction of resin‐bound arylamines (3) with 4‐chloro‐7‐fluoro‐6‐nitroquinazoline (8) yielded resin‐bound 4‐arylamino‐7‐fluoro‐6‐nitroquinazolines (4), which were reacted with amino acid methyl esters to afford the corresponding resin‐bound compound (5). Following the reduction of nitro group and intramolecular cyclization of 5, resin‐bound 4,8‐disubstituted‐8,9‐dihydropyrazino[2,3‐g]quinazolin‐7(6H)‐one (6) was yielded. The desired products (7) were obtained in good yields and purities after cleavage from the resin. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 439–443, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Inhibition of autophosphorylation of epidermal growth factor receptor by a small peptide not employing an ATP‐competitive mechanism
Authors: Abe Mineo , Kuroda Yoshihiro , Hirose Munetaka , Kato Masaki , Murakami Masahiro , Watanabe Yoshihiko , Nakano Minoru , Handa Tetsurou 
Published: September 2007

AbstractPreviously we found that short peptides surrounding major autophosphorylation sites of EGFR (VPEY1068INQ, DY1148QQD, and ENAEY1173LR) suppress phosphorylation of purified EGFR to 30–50% at 4000 μM. In an attempt to improve potencies of the peptides, we modified the sequences by substituting various amino acids for tyrosine or by substituting Gln and Asn for Glu and Asp, respectively. Among the modified peptides, Asp/Asn‐ and Glu/Gln‐substitution in DYQQD (NYQQN) and ENAEYLR (QNAQYLR), respectively, improved inhibitory potencies. The inhibitory potency of NYQQN was not affected by the concentration of ATP, while that of QNAQYLR was affected. Docking simulations showed different mechanisms of inhibition for the peptides: inhibition by binding to the ATP‐binding site (QNAQYLR) and inhibition by binding to a region surrounded by αC, the activation loop, and the catalytic loop and interfering with the catalytic reaction (NYQQN). The inhibitory potency of NYQQN for insulin receptor drastically decreased, whereas QNAQYLR inhibited autophosphorylation of insulin receptor as well as EGFR. In conclusion, NYQQN is not an ATP‐competitive inhibitor and the binding site of this peptide appears to be novel as a tyrosine kinase inhibitor. NYQQN could be a promising seed for the development of anti‐cancer drugs having specificity for EGFR. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 40–51, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com