bluuebunny/crossref_metadata_2025_split huggingface dataset:
Viscoelastic properties of polyarylene ether nitriles/thermotropic liquid crystalline polymer blend
Authors: Wu Defeng , Zhang Yisheng , Wu Lanfeng , Jin Lifeng , Zhang Ming , Zhou Weidong , Yan Changhao 
Published: January 2008

AbstractPolyarylene ether nitriles (PEN)/thermotropic liquid crystalline polymer (TLCP) blend was prepared via melt mixing. The immiscible phase morphologies, linear and nonlinear, as well as transient viscoelastic properties of the blend were studied using SEM, rheometer, and DMA. The linear dynamic viscoelastic behavior of the blend shows temperature dependence due to further evolution of the immiscible morphology and, as a result, the principle of time‐temperature superposition (TTS) is invalid. In the steady shear flow, the discrete TLCP phase is difficult to be broken up because of the high viscosity ratio of the blend systems, while is easy to be coarsened and followed by elongation, and finally, to form fibrous morphology at high TLCP content and high shear level. During this morphological evolution process, the transient stress response presents step increase and nonzero residual relaxation behavior, leading to increase of the dynamic viscoelastic responses after steady preshear. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Anionic polymerization and properties of graft copolymers consisting of alternating styrene/maleimide copolymer main chains and polyamide 6 grafts
Authors: Xu Wei , Liu Yao‐Chi , Xiong Yuan‐Qin , Miao Yan‐Ru , Xu Wei‐Jian 
Published: January 2008

AbstractThis article is focused on the synthesis of a new type of graft PA6, which contained alternating styrene/maleimide copolymer main chains and PA6 grafts, by anionic polymerization. The preprepared styrene/maleimide copolymers with acylated caprolactam (ACL) pendants were used as macroactivators for the polymerization of molten ε‐caprolactam (CL). Because of the low activating energy for the initial nucleophilic attack of CL anion on the N‐ACL, the polymerization took place in a few minutes. The macroactivators were characterized by 1H‐NMR. And the thermal properties, dimensional stability, crystallinity, and solvent resistance ability of the graft PA6 were studied, using DSC, TGA, XRD, water absorption measurement, and solubility experiment. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Solubility of carbon dioxide and cosolvents in a photoresist polymer
Authors: Balashova Ida M. , Russell Marc C. , Danner Ronald P. , Duda J. Larry 
Published: January 2008

AbstractSolubility and diffusivity of cosolvents and carbon dioxide in a photoresist polymer have been measured below the glass transition temperature bythe inverse gas chromatography and static capsule methods over a temperature range of 75–100°C and pressures up to 7000 kPa. The results showed that presence of even low pressures of CO2 increased the solubility and diffusivity of the cosolvents studied. Experiments in which exposure of the polymer to CO2 was cycled on and off indicated that the free volume introduced by the CO2 persisted in the polymer for a significant time after removal of the CO2. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Crystallization behavior of a thermoplastic polyimide derived from 3,3′,4,4′‐oxydiphthalic dianhydride and 4,4′‐oxydianiline
Authors: Zhao Guiyan , Zhang Min , Men Yongfeng , Ding Mengxian , Jiang Wei 
Published: January 2008

AbstractNonisothermal and isothermal crystallization kinetics of an aromatic thermoplastic polyimide derived from 3,3′,4,4′‐oxydiphthalic dianhydride and 4,4′‐oxydianiline have been investigated by means of differential scanning calorimetry (DSC) and wide‐angle X‐ray diffraction. The results for nonisothermal crystallization study showed that a weak melting peak appeared during the first heating process, whereas no crystallization peak appeared in the DSC curve during the subsequent cooling process. On the other hand, the study for the isothermal crystallization in the temperature range of 260–330°C showed that a new exothermic peak appeared at lower temperature for the samples crystallized for 100 min at 300°C. Moreover, the results indicated that the crystallization behaviors were largely affected by the crystallization temperature and crystallization time. During the annealing process, the melting enthalpy tended to increase with increasing annealing temperature and annealing time. More interesting was that two melting endotherms appeared when the annealing temperature was lower than 300°C. However, when the annealing temperature was higher than 330°C, only one melting endotherm appeared. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Surface modification of carbon fiber by redox‐induced graft polymerization of acrylic acid
Authors: Xu Zhiwei , Wu Xiaoqing , Sun Ying , Jiao Yanan , Li Jialu , Chen Li , Lu Liangsen 
Published: January 2008

AbstractCarbon fibers were modified by graft polymerization with acrylic acid (AA) using KMnO4/H2SO4 redox‐induced system. The carbon fibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy. After grafting, the absorbability of treated fibers might be enhanced and more pieces of tiny fragments stuck to the fiber surface. It was confirmed that grafting AA led to a remarkable increase in oxygen‐containing functional groups of fiber surface. An about twofold increase in retained surface carboxylic acid groups occurred. The adhesion between carbon fiber and epoxy matrix was inspected by interlaminar shear strength and SEM. It was noted that the functionalized grafting coating of fiber surface gave rise to a strong interfacial bond, with little debonding. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Intercalated clays from pentaerythritol stearate for use in polymer nanocomposites
Authors: Bartels J. , Beall G. W. , Grah M. , Jin K. , Speer D. , Yarbrough J. 
Published: January 2008

AbstractSmectite clays treated with quaternary ammonium salts have been utilized for decades in paints, greases, cosmetics, and personal care products as rheological modifiers. They have also been used in industrial wastewater treatment extensively. In more recent times these surface modified clays have demonstrated benefits in polymer/clay nanocomposites. The use of quaternary ammonium modifiers limits the usefulness of these composites in food packaging because they are not approved for direct food contact. It would be advantageous to have surface modifying chemicals acceptable for direct food contact in these composites. This article reports research conducted on a promising surface modifier pentaerythritol stearate (PS), which is approved by the FDA for inclusion in food as a preservative. The surface modification of montmorillonite with PS is reported in detail as well as the production of nanocomposites with selected polymers made with the modified clay. Molecular modeling and purification of commercial PS samples indicate that the mono‐ and diesters are the critical surface modifiers, although the as received commercial material works well in forming intercalated clay complexes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Increased Dosage of DYRK1A and Brain Volumetric Alterations in a YAC Model of Partial Trisomy 21
Authors: Sebrié Catherine , Chabert Caroline , Ledru Aurélie , Guedj Fayçal , Po Chrystelle , Smith Desmond J. , Rubin Edward , Rivals Isabelle , Beloeil Jean‐Claude , Gillet Brigitte , Delabar Jean‐Maurice 
Published: January 2008

AbstractA yeast artificial chromosome (YAC) transgenic murine model of partial trisomy 21 overexpressing five human genes—including DYRK1A, which encodes a serine threonine kinase involved in cell cycle control—has been shown to present an increase in brain weight. We analyzed this new phenotype by measuring total and regional brain volumes at different ages, using a 7 Tesla magnetic resonance imaging volumetric approach. Volumetric measurements showed a total volume increase of 13.6% in adult mice. Changes in brain morphogenesis were already visible at a very early postnatal stage (postnatal days 2–7). Region‐specific changes were characterized from postnatal day 15 to 5 months. These results, made it possible to define region‐specific effects of DYRK1A overexpression, with the strongest increase seen in the thalamus–hypothalamus area (24%). Anat Rec, 291:254–262, 2008. © 2008 Wiley‐Liss, Inc.
Histomorphometric and Densitometric Changes in the Femora of Spinal Cord Transected Mice
Authors: Picard Sylvain , Lapointe Nicolas P. , Brown Jacques P. , Guertin Pierre A. 
Published: January 2008

AbstractSpinal cord injury (SCI) leads generally to significant bone tissue loss within a few months to a few years post–trauma. Although, increasing data from rat models are available to study the underlying mechanisms of SCI‐associated bone loss, little is known about the extent and rapidity of bone tissue changes in mouse models of SCI. The objectives are to characterize and describe quantitatively femoral bone tissue changes during 1 month in adult paraplegic mice. Histomorphometric and densitometric measurements were performed in 3‐ to 4‐month‐old CD1 mice spinal cord transected at the low‐thoracic level (Th9/10). We found a general decrease in bone volume (−22%), trabecular thickness (−10%), and trabecular number (−14%) within 30 days post‐transection. Dual‐energy X‐ray absorptiometric measurements revealed no change in bone mineral density but a significant reduction (−14%) in bone mineral content. These results show large structural changes occurring within only a few weeks post–spinal cord transection in the femora of adult mice. Given the increasing availability of genetic and molecular research tools for research in mice, this murine model may be useful to study further the cellular and molecular mechanisms of demineralization associated with SCI. Anat Rec, 291:303–307, 2008. © 2008 Wiley‐Liss, Inc.
Ultrastructure of Anterior Uterus of the Oviduct and the Stored Sperm in Female Soft‐Shelled Turtle,Trionyx sinensis
Authors: Han Xiangkun , Zhangli Li , Li Meiying , Bao Huijun , Hei Nainan , Chen Qiusheng 
Published: January 2008

AbstractUltrastructure of sperm storage in female soft‐shelled turtle,Trionyx sinensiswas examined under light and electron microscopes. Sperm storage tubules are restricted to the anterior of the uterus. These tubules developed either by folding or fusion of the oviductal mucosal folds and are lined by both ciliated and secretory cells. Ciliated cells are characterized by a few microvilli and prominent cilia in the apical membranes. A prominent feature of the secretory cell is the presence of secretory granules in the supranuclear region. The size, shape, and electron density of these granules vary markedly. The secretory product is released mainly by exocytosis into the oviductal lumen, where it appears as flocculent material. The unique structure in the base of the epithelium, the basal border of the cell—the basal lamina—and a blood vessel layer, is presumed to be a important barrier, by which the nourishment exchange and the microenvironment maintenance are ensured. The gland cell is presented with numerous, round, membrane‐bound secretory granules of moderate to high electron densities. We divide these granules into three types according to their appearance: (1) membrane bounded granules with high‐homogeneous electron density, (2) membrane bounded granules with moderate‐homogeneous electron density, (3) membrane bounded, electron dense granules with concentric structures. These granules are presented as different stages of the secretions in the gland cell. The junction complexes are markedly distributed between cells, which are important in keeping stability and the microenvironment maintenance of the sperm storage tubules. Sperm stored in the tubules are heterogeneous in cytology. In addition to the mature sperm in the lumen, sperm with large chromatic granules are found, which are presumed to be immature sperm and are being in the process of nuclear condensation. Several spermatozoa in the tubules are exhibited with definitive indications of degeneration of the nuclei. The nuclear volume increases. The electron density of the central cores in mitochondria declines, combined with the deterioration of concentric membrane structure. Those changes are possibly due to the long time storage of the sperm in sperm storage tubules, and the leakage of reactive oxygen species is suggested to be a major cause. We conclude that the ultrastructure character of sperm storage in the oviduct ofTrionyx sinensisis unique, in addition to having a basal function in secretion and the cilia swing, the tubules also provide an available microenvironment for the sperm to long time stored. The degenerative sperm in the tubules might be related to paternity‐specific reproductive adaptations, and the sperm competition might occur during long time storage. Anat Rec, 291:335–351, 2008. © 2008 Wiley‐Liss, Inc.
Prenatal growth retardation, microcephaly, and eye coloboma in infant with multiple congenital anomalies: Further delineation of presumed new dysmorphic syndrome
Authors: Cuturilo Goran , Jovanovic Ida , Vukomanovic Goran , Djukic Milan , Stefanovic Igor , Atanskovic‐Markovic Marina 
Published: January 2008

AbstractBACKGROUND:Ten years ago an unusual association of prenatal growth retardation, microcephaly, coloboma of the iris/eye anomalies, congenital heart defects, and urogenital anomalies was reported for the first time in three siblings. Autosomal recessive inheritance was presumed. This finding has been included in London Winter‐Baraitser Dysmorphology Database as a separate entity, but still has not been classified as a distinct syndrome.CASE:We report an infant with an association of prenatal growth retardation, microcephaly, facial dysmorphism, eye anomalies, congenital heart defects, and testis retention. Mild craniofacial dysmorphism consists of sloped forehead, bulbous nose tip, and micrognathia. Eye anomalies include coloboma of the iris, choroidea, and optic nerve as well as lens dislocation. The patient also presents with ventricular and atrial septal defects, hypoplastic mitral valve, persistent left superior vena cava, accessory spleen, and club foot.CONCLUSIONS:To the best of our knowledge, this is the second family and the fourth case with this pattern of birth defects reported worldwide so far. We presume that this combination of multiple congenital anomalies and growth retardation constitutes a newly recognized syndrome of likely autosomal recessive inheritance. So far no data suggest etiological impact of consanguinity, parental age, or environmental factors. Birth Defects Research (Part A) 2008. © 2008 Wiley‐Liss, Inc.
FTIR microspectroscopic analysis of the effects of certain drugs on oxidative stress and brain protein structure
Authors: Carmona P. , Rodríguez‐Casado A. , Alvarez I. , de Miguel E. , Toledano A. 
Published: January 2008

AbstractThis study reports the changes in lipids and proteins of different brain areas of nicotine, D(+)‐amphetamine, and nicotine and D(+)‐amphetamine treated rats by monitoring lipid peroxidation and protein β‐sheet formation using infrared microspectroscopy. Compared with the untreated brain samples, the peroxide level is relatively higher in the amphetamine‐treated brain sections, both in the cortex and hippocampus area. However, this peroxide increase is attenuated when administering amphetamine plus nicotine. Analogous drug‐dependent trends for protein β‐sheet content are observed, which suggests a connection between lipid oxidation involved in oxidative stress and β‐sheet protein structure generally present in neurodegenerative diseases. The above property of nicotine is of interest, in the sense that it might reduce the production of β‐amyloid proteins in Alzheimer's disease. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 548–554, 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
Rescue angioplasty after failed fibrinolysis foracute myocardial infarction: Predictors of a failed procedure and 1‐year mortality
Authors: Kunadian Babu , Vijayalakshmi Kunadian , Dunning Joel , Sutton Andrew GC , Muir Douglas F , Wright Robert A , Hall James A , de Belder Mark A 
Published: January 2008

AbstractBackground:Rescue angioplasty (rPCI) for failed fibrinolysis is associated with a low mortality if successful, but a high mortality if it fails. The latter may reflect a high‐risk group or harm in some patients. Predictors of success or failure of rPCI may aid selection of patients to be treated.Methods:Unselected patients referred for rPCI from March 1994 to March 2005 were studied to determine the predictors of a failed procedure and 1‐year mortality.Results:Of 440 patients undergoing emergency coronary angiography for failed fibrinolysis (1‐year mortality 18%), 101 had thrombolysis in myocardial infarction flow grade (TFG) 3 in the infarct‐related vessel. rPCI was attempted in 318 of 339 patients with <TFG 3 flow, but not in 21 patients (angiography‐produced TFG 3 [n = 7] or unsuitable anatomy [n = 14]). Of the rPCI cohort, 77% had a successful procedure (no in‐lab death or emergency coronary artery bypass grafting and TFG 3 in the infarct‐related vessel); rPCI failed in 23%. One‐year mortality rates for successful and failed rPCI were 14 and 43%, respectively. Patients with failed rPCI were older and more likely to be diabetic, have anterior MI, be interhospital transfers, be in cardiogenic shock, and less likely to be a current smoker. Shock was the only independent predictor of failed rPCI. Age group >75 years, shock, and final TFG < 3 were independent predictors of 1‐year mortality.Conclusions:Cardiogenic shock is an independent predictor of a failed rPCI. Age group >75 years and shock were the only independent clinical predictors of 1‐year mortality. These clinical variables may help in selecting patients for either a strategy of rescue angioplasty after failed fibrinolysis, or in selecting specific patients who might do better with a policy of primary angioplasty. © 2008 Wiley‐Liss, Inc.
Failed percutaneous coronary intervention: A decade of experience in 21,000 patients
Authors: Mattichak Stephen J. , Dixon Simon R. , Shannon Francis , Boura Judith A. , Safian Robert D. 
Published: January 2008

AbstractObjectives:The purpose of this study was to evaluate the incidence, mechanisms, and in‐hospital outcomes after failed percutaneous coronary intervention (PCI).Background:The most common causes of PCI failure are severe dissection, no‐reflow, and uncrossable total occlusions.Methods:Demographic, clinical, procedural, and quality assurance data were recorded in a prospective database to determine the incidence and outcome of failed PCI. Data were analyzed according to the year of PCI: prestent era (PSE 1993–1995), first generation stent era (FGSE 1996–2000), and contemporary stent era (CSE 2000–2003).Results:PCI (20,884) were performed over a 10‐year‐period from 1993 through 2003, including 4,344 (20.8%) in the PSE, 9,114 (43.6%) in the FGSE, and 7,426 (35.6%) in the CSE; 19,171 (91.8%) were successful and 1,704 (8.2%) were failures. Nearly 90% of PCI failures are due to no‐reflow or uncrossable total occlusions. Among PCI failures, 7.5% were treated medically and 0.7% required emergency coronary artery bypass grafting (ECABG). PCI success was independently associated with PCI during CSE (OR 1.86, P < 0.0001). ECABG decreased sixfold from 1.2% in the PSE to 0.2% in the CSE.Conclusions:Contemporary PCI patients have better procedural outcomes and fewer in‐hospital adverse events than patient treated before the availability of stents. However, recanalization of total occlusions and avoiding no‐reflow will have the most impact on future PCI success. © 2008 Wiley‐Liss, Inc.
Doublecortin (DCX) and doublecortin‐like (DCL) are differentially expressed in the early but not late stages of murine neocortical development
Authors: Boekhoorn Karin , Sarabdjitsingh Angela , Kommerie Hendrik , de Punder Karin , Schouten Theo , Lucassen Paul J. , Vreugdenhil Erno 
Published: January 2008

AbstractDuring corticogenesis, radial glia‐derived neural progenitors divide and migrate along radial fibers to their designated positions within the cortical plate. The microtubule‐associated proteins doublecortin (DCX) and doublecortin‐like (DCL) are critically involved in neuronal migration and division, and may function in a partially redundant pathway. Since little is known about the important early stages of corticogenesis, when neurogenesis is extensive, we addressed a possible differential role by examining spatiotemporal expression patterns of DCX, DCL, and the radial glia marker vimentin during murine development. We found expression patterns of DCL and DCX to differ remarkably prior to embryonic day (E)13. DCL was already expressed at E9 and largely overlapped with vimentin, whereas DCX expression started modestly from E10/E11 onward. DCL was mainly found in the ventricular zone, often in mitotic cells and in pial‐oriented radial fibers. In contrast, DCX was expressed in tangential fibers in the outer cortical regions. After E13, DCX and DCL expression largely overlapped but DCL expression had disappeared from the ventricular zone. Also, DCL levels were attenuated, whereas DCX remained high beyond E17. In conclusion, DCX and DCL are differentially expressed, particularly during early corticogenesis, consistent with their different functional roles. Given its involvement in mitosis, DCL appears to have a unique role in the early neuroepithelium that is different from later developmental stages when DCX is coexpressed. J. Comp. Neurol. 507:1639–1652, 2008. © 2008 Wiley‐Liss, Inc.
Ab Initio Study of the Magneto‐Optical Rotation of Diastereoisomers
Authors: Kula Mathias , Cappelli Chiara , Coriani Sonia , Rizzo Antonio 
Published: January 2008

AbstractExperimental studies on the natural optical activity and Faraday rotation of the three different stereoisomers of tartaric acid were reported recently by Ruchon et al. [Chem. Phys. Lett. 2005, 412, 411]. The authors noted that the Faraday rotation of the meso (R,S) system differed from those of the (S,S) and (R,R) enantiomers, and derived a simple dipole–dipole interaction model to describe what they claim to be a “new property”. We present the results of both density functional theory (DFT) and coupled cluster calculations for a structurally elementary model system composed of two chiral carbon atoms presenting three diastereoisomers (C2H2Cl2F2), as well as a detailed DFT study of the natural and magnetic‐field‐induced optical rotation of tartaric acid. The effects of electron correlation, basis set, and conformational flexibility are analyzed. It is found that the specific Faraday rotations of the chiral (R,R) and meso forms of tartaric acid (for λ=632.8 nm) differ by about 3 %, a value which is quite close in magnitude—but of opposite sign—to that obtained with the simplified model proposed by Ruchon and co‐workers.