bluuebunny/crossref_metadata_2025_split huggingface dataset:
An X‐ray scattering study of water‐conditioned injection‐molded starch during isothermal heating
Authors: Cagiao M. E. , Bayer R. K. , Rueda D. R. , Baltá Calleja F. J. 
Published: January 2003

AbstractThe in situ structure variation of injection‐molded starch (as processed and after water conditioning) during heat treatment was investigated by means of wide‐angle X‐ray scattering using synchrotron radiation. Results confirm that the crystal structure of potato starch is destroyed after injection molding, while as‐processed corn starch preserves some degree of crystallinity. This residual crystallinity in corn starch is related to the crystalline Vh‐form, made of complexes of amylose with lipids. Furthermore, it is shown that both starch types can develop crystallinity by water conditioning: potato starch yields the crystal B‐form, while corn starch yields the crystal A‐form coexisting with the persistent Vh‐form. Upon isothermal heating of samples under vacuum, a rapid decrease of crystallinity, which is a function of both time and treatment temperature, is detected. Crystallinity variations are discussed in terms of water evaporation, the leveling‐off values of crystallinity being dependent on the temperature of the isothermal treatment. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 17–21, 2003
Nonisothermal cure kinetics in the synthesis of polybenzoxazine–clay nanocomposites
Authors: Shi Zixing , Yu Dingsheng , Wang Yizhong , Xu Riwei 
Published: January 2003

AbstractThe ability to understand and model the mechanism of cure kinetics accurately is crucial for the production of thermosetting resin‐based nanocomposites. This article reports on work performed to elucidate an accurate model of cure kinetics for the formation of polybenzoxazine–montorillonite nanocomposites through the use of differential scanning calorimetry with nonisothermal methods, including single‐heating and multiple‐heating methods. The results indicated that both the Kissinger and Ozawa methods for calculating the activation energy gave fairly close results of 115 and 120 kJ/mol, respectively. The reaction order was about 1.31, calculated from the single‐heating method based on the autocatalytic method, and a comparison was made of the dynamic curing behaviors in the syntheses of polybenzoxazine and polybenzoxazine–montorillonite nanocomposites. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 194–200, 2003
Investigation of electropolymerized polypyrrole composite film: Characterization and application to gas sensors
Authors: Bhat N. V. , Gadre A. P. , Bambole V. A. 
Published: January 2003

AbstractPolypyrrole–Polymethylmethacrylate (PMMA + PPy) composite films were prepared electrochemically by means of codeposition at constant potential. The films were characterized by using Infrared spectroscopy, wide‐angle X‐ray diffraction analysis, and scanning electron microscopy. The appearance of standard and some new absorption bands for PPy and PMMA confirms the composite formation. The mechanical properties of the conducting PMMA+ PPy films were studied and found to be improved with respect to the control PPy films. The electrical conductivity of the PMMA + PPy film was measured by using standard four‐ and two‐probe methods. The conductivity of the films was found to depend on the pyrrole content. These conducting composites were further used as gas sensors by observing the change in the current when exposed to ammonia gas. The film gives a fast and reproducible response towards ammonia gas. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88:22–29, 2003
Properties of poly(vinyl chloride) blended with an emulsion copolymer of N‐cyclohexylmaleimide and methyl methacrylate
Authors: Yang Liting , Sun Donghai , Li Yanfang , Liu Guodong , Gao Jungang 
Published: January 2003

AbstractEmulsion‐polymerized copolymers of methyl methacrylate and N‐cyclohexylmaleimide were synthesized and used for blending with poly(vinyl chloride) (PVC) to improve the heat resistance of PVC. The thermal stabilities of the blends with different copolymer contents were characterized by thermogravimetric analysis, torsional braid analysis, and the Vicat softening temperature. The mechanical properties and rheological behavior of the blends were also determined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 201–205, 2003
Rheological properties and morphology of compatibilized poly(butylene terephthalate)/linear low‐density polyethylene alloy
Authors: Yang Jinghui , Shi Dean , Gao Ying , Song Yongxian , Yin Jinghua 
Published: January 2003

AbstractThe rheological behavior of PBT/LLDPE and PBT/LLDPE‐g‐AA blends [where PBT is poly(butylene terephthalate), LLDPE is linear low‐density polyethylene, and AA is acrylic acid] under a capillary flow was investigated with a capillary rheometer. The Utracki equation was used to describe the viscosity–composition dependence of PBT/LLDPE and PBT/LLDPE‐g‐AA blends at low shear stresses. However, at high shear stresses, this equation was not suitable for these blending systems. There existed a maximum on the curves of the entrance pressure drop versus the blending compositions, and the interlayer slip factor β in the Utracki equation was related not only to the shear stress but also to the elasticity difference of the two blending components. Morphological observations indicated that at high shear rates, there existed two different morphologies at different positions of the extrudates, and this was the reason that the Utracki equation failed. Near the wall of the capillary, low‐viscosity PBT stratified, and this resulted in an additional decrease in the viscosities of the blending systems. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 206–213, 2003
Peel‐strength behavior of bilayer thermal‐sprayed polymer coatings
Authors: Yan F. Y. , Gross K. A. , Simon G. P. , Berndt C. C. 
Published: January 2003

AbstractWe prepared various bilayer polymer coatings of ethylene methacrylic acid (EMAA) copolymer and ionomer by the thermal‐spray process under a range of preheat temperatures (PTs) to investigate their ability to be repaired. The thermal properties, crystallinity, microstructure, and interface strength of the coatings were investigated with differential scanning calorimetry, X‐ray diffraction, scanning electron microscopy, and mechanical testing. Processing parameters influenced the final morphological structure of the coatings. The crystallinity of the coatings increased with a higher final temperature, whereas the coating density decreased. The decrease in density was attributed to the appearance of bubbles, 250 μm in size, formed in the coatings during the spray process. For the monolayer coating of polymer on a metal substrate, a higher PT produced a greater contact area of the coating to the substrate. The adhesion of EMAA ionomer to steel was always lower than that of EMAA copolymer to steel. This may have been largely due to the interfacial adhesion between the polymer and steel being dominated by strong secondary bond interactions. Experimental results also indicate that the peel strength between polymers was at least twofold stronger than that between the polymer and the steel substrate for PTs greater than 100°C. The mixed bilayer coating of ionomer on copolymer produced the highest peel strength. The interface between the plastic layers was clearly visible under the scanning electron microscope at lower PTs, becoming more diffuse with an increase in PT. On the basis of these observations, the adhesion mechanism between polymers was explained by the formation of welding points. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 214–226, 2003
Analysis of the development of isotropic residual stresses in a bismaleimide/spiro orthocarbonate thermosetting resin for composite materials
Authors: Alcoutlabi Mataz , McKenna Gregory B. , Simon Sindee L. 
Published: January 2003

AbstractIn this article, we extend our model of isotropic residual stress development in thermosets to a novel thermosetting resin system: bismaleimide/spiro orthocarbonate. In this system, the cure shrinkage and resulting isotropic residual stresses are reduced through a ring‐opening reaction that occurs independently of the addition reaction. The modeling effort includes a parametric analysis of the effects of various parameters, including the volume changes involved in the reactions, the relative rates and orders of the reactions, the cure history, and the values of the bulk moduli and thermal expansion coefficients. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 227–244, 2003
Properties of n‐butyl methacrylate copolymer latex films derived from crosslinked latex particles
Authors: Mohd Ghazaly H. , Daniels E. S. , Dimonie V. L. , Klein A. , Sperling L. H. , El‐Aasser M. S. 
Published: January 2003

AbstractFilms obtained from copolymer latexes of n‐butyl methacrylate (BMA) with a series of crosslinking monomers [i.e., a macromonomer crosslinker (Mac), ethylene glycol dimethacrylate (EGDMA), and aliphatic urethane acrylate] exhibited differences in their tensile properties and swelling behaviors. For P(BMA‐co‐EGDMA) copolymer, a dependence on the initiator type was obtained. It is postulated that the network microstructures for the various copolymers evolved as the result of the copolymerization reactions between the monomer pairs during the synthesis in the miniemulsion free‐radical copolymerization. These network microstructures are, therefore, hypothesized to influence the mechanical properties of the resultant films. Copolymers prepared with Mac were tough in comparison with copolymers made with EGDMA. The presence of longer linear or lightly crosslinked poly(n‐butyl methacrylate) (PBMA) chains and the looseness of the crosslinked network structures in the PBMA‐co‐Mac copolymers appear to be the factors responsible for the differences. All of the copolymer films disintegrated into swollen individual microgels when they were immersed in tetrahydrofuran. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 42–49, 2003
Synthesis of well‐defined, functionalized polymer latex particles through semicontinuous emulsion polymerization processes
Authors: Tang Jiansheng , Ding Tianhua , Daniels Eric S. , Dimonie Victoria L. , Klein Andrew , El‐Aasser Mohamed S. 
Published: January 2003

AbstractThe design of a semicontinuous emulsion polymerization process, primarily based on theoretical calculations, has been carried out with the objective of achieving overall independent control over the latex particle size, the monodispersity in the particle size distribution, the homogeneous copolymer composition, the concentration of functional groups (e.g., carboxyl groups), and the glass‐transition temperature with n‐butyl methacrylate/n‐butyl acrylate/methacrylic acid as a model system. The surfactant coverage on the latex particles is very important for maintaining a constant particle number throughout the feed process, and this results in the formation of monodisperse latex particles. A model has been set up to calculate the surfactant coverage from the monomer feed rate, surfactant feed rate, desired solid content, and particle size. This model also leads to an equation correlating the polymerization rate to the instantaneous conversion of the monomer or comonomer mixture. This equation can be used to determine the maximum polymerization rate, only below or at which monomer‐starved conditions can be achieved. The maximum polymerization rate provides guidance for selecting the monomer feed rate in the semicontinuous emulsion polymerization process. The glass‐transition temperature of the resulting carboxylated poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) copolymer can be adjusted through variations in the compositions of the copolymers with the linear Pochan equation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 30–41, 2003
A novel emitting polymer with bipolar carrier transporting abilities
Authors: Wang G. , Zhang J. P. , Wang L. X. , Jing X. B. , Wang F. S. 
Published: January 2003

AbstractA luminescent bipolar polymer containing 1,3,4‐oxadiazole and triphenylamine has been synthesized. A smooth and dense thin film of polymer is easily obtained by spin coating its chloroform solution. This film exhibits a strong blue fluorescence under the irritation of ultraviolet (UV) light. The synthesized polymer possesses a high glass transition temperature (Tg) of 167°C. A single‐layer electroluminescence (EL) device indium‐tin oxide (ITO)/polymer/Mg:Ag emitted blue light with a turn‐on voltage of 13 V. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88:50–53, 2003
Embryonic origin of the caudal mesenteric artery in the mouse
Authors: Gest Thomas R. , Carron Michael A. 
Published: January 2003

AbstractIt is commonly held that the caudal mesenteric artery (CaMA, or inferior mesenteric artery in humans) arises in the same manner as the celiac and cranial mesenteric artery (CrMA, or superior mesenteric artery in humans), i.e., from the remodeling of the vitelline system of arteries that surrounds and supports the yolk sac. Conflicting evidence about the precise manner in which the CaMA arises was presented in studies of the luxate syndrome (Carter: J. Genet. 1954;52:1–35) and sirenomelia (Schreiner and Hoornbeek: J. Morphol. 1973;141:345–358) in the mouse. These studies suggested that the CaMA arises from the remodeling of the medial umbilical arterial roots. Later studies of blood vessel development in the hindlimb of the Dominant hemimelic mouse (Gest: Anat. Rec. 1984;208:296; Anat. Rec. 1987;218:49A; Gest and Roden: Anat. Rec. 1988;220:37–38A) also supported the results of the previous studies. The present investigation tests the hypothesis that the CaMA arises as a result of the regression and remodeling of the medial umbilical arterial roots. Vascular corrosion casts of 9.5‐13.5‐day‐old mouse embryos were observed by scanning electron microscopy (SEM). The results of the present investigation agree with the aforementioned studies. The medial umbilical roots initially conduct the blood to the placenta. On days 10‐12 the medial umbilical roots regress and remodel into the CaMA, while the lateral umbilical roots take over the blood supply to the placenta. On the basis of our results, we conclude that the CaMA arises from the medial umbilical roots and not from the remodeling of the vitelline system of arteries, as previously assumed. Anat Rec Part A 271A:192–201, 2003. © 2003 Wiley‐Liss, Inc.
Morphology and distribution of nitric oxide synthase‐, neurokinin‐1 receptor‐, calretinin‐, calbindin‐, and neurofilament‐M‐immunoreactive neurons in the myenteric and submucosal plexuses of the rat small intestine
Authors: Sayegh Ayman I. , Ritter Robert C. 
Published: January 2003

AbstractCharacterization of the enteric neurons is vital for understanding their physiological role. We have used single and dual label fluorescence and peroxidase‐based immunohistochemistry in myenteric and submucosal whole mounts from the rat small intestine to evaluate the morphology and distribution of enteric neurons immunoreactive for the following phenotypic antigens: neuronal nitric oxide synthase (NOS), neurokinin‐1 receptor (NK‐1R), calretinin (Calr), calbindin (Cal), and neurofilament‐M (NF‐M). NOS‐immunoreactive neurons had Dogiel type I morphology, were abundant in the myenteric plexus compared to the submucosal plexus, and never coexpressed NK‐1R immunoreactivity. NK‐1R‐ and Calr‐immunoreactive neurons had Dogiel type II morphology and were distributed comparably in both plexuses. NK‐1R and Calr‐immunoreactivity were coexpressed in many of the same neurons. Calbindin‐immunoreactive neurons exhibited four distinct morphologies: small and large Dogiel type II neurons, Dogiel type I neurons, and small elongated neurons. These neurons were significantly fewer in number in the myenteric plexus compared to the submucosal plexus. Neurofilament‐M‐immunoreactive neurons had three morphologies, Dogiel type II neurons, small Dogiel type II neurons, and a less common subpopulation of small, elongated, multipolar neurons. These neurons were also fewer in number in the myenteric plexus compared to the submucosal plexus. The distribution of these phenotypic markers may assist future work that elucidates the functional activities of these enteric neurons such as control of intestinal motility and adaptation to the entry of gastric contents. Anat Rec Part A 271A:209–216, 2003. © 2003 Wiley‐Liss, Inc.
VEGF modulates early heart valve formation
Authors: Dor Yuval , Klewer Scott E. , McDonald John A. , Keshet Eli , Camenisch Todd D. 
Published: January 2003

AbstractAlthough hypoxic and/or nutritional insults during gestation are believed to contribute to congenital heart defects, the mechanisms responsible for these anomalies are not understood. Given the role vascular endothelial growth factor (VEGF) plays in response to hypoxia, it is a likely candidate for mediating deleterious effects of embryonic hypoxia. The ectopic or overproduction of endogenous factors such as VEGF may contribute to specific heart defects. Here we compared hypoxia‐induced precocious production of VEGF during early heart valve development to normal VEGF production. Mouse prevalvular cardiac endocardial cushions were explanted onto hydrated type I collagen gels under normoxic or hypoxic conditions. The extent of transformation of cardiac endothelium into mesenchyme was inversely correlated with the levels of VEGF during the various culture conditions. A soluble VEGF antagonist confirmed that endogenous production of VEGF was specific for blocking normal cushion mesenchyme formation. We further demonstrated that E10.5 endocardium retains the ability to transform into cardiac mesenchyme in the absence of endogenous VEGF. Anat Rec Part A 271A:202–208, 2003. © 2003 Wiley‐Liss, Inc.
Bovine circumvallate taste buds: Taste cell structure and immunoreactivity to α‐gustducin
Authors: Tabata Shoji , Wada Azumi , Kobayashi Takahiko , Nishimura Shotaro , Muguruma Michio , Iwamoto Hisao 
Published: January 2003

AbstractThe taste buds of bovine circumvallate papillae were investigated under light and electron microscopy both by histological and immunohistochemical methods. Taste buds existed in the inner epithelium of the trench of the papillae. Under electron microscopy, two types of taste cells, type I and type II, could be classified according to the existence of dense‐cored vesicles and cytoplasmic density. Type I had electron‐lucent cytoplasm and possessed many electron‐dense cored vesicles in the apical cytoplasm. It was considered that the electron‐dense materials of the vesicles were released and constituted the pore substance. This type of cell possessed long and thick apical processes in the taste pore. Type II had denser electron cytoplasm compared with that of type I and possessed many electron‐lucent vesicles in the apical cytoplasm. This type of cell possessed microvilli in the taste pore. To know the immunoreactivity to α‐gustducin in bovine circumvallate taste buds, we used the immunoblotting method and the immunohistochemical method. The α‐gustducin reaction band at 40 kDa was displayed in the specimen of Western blots. The immunohistochemical property of the antiserum to α‐gustducin was investigated by using the avidin‐biotin complex (ABC) method and the 1.4‐nm gold and silver enhancement methods. A subset of taste cells showed the immunoreactivity under light microscopy. The electron microscopic specimens with the 1.4‐nm gold and silver enhancement method revealed that only type II cells exhibited the α‐gustducin immunoreactivity. Anat Rec Part A 271A:217–224, 2003. © 2003 Wiley‐Liss, Inc.
Porcine intrinsic cardiac ganglia
Authors: Arora R.C. , Waldmann M. , Hopkins D.A. , Armour J.A. 
Published: January 2003

AbstractThe gross, light, and electron microscopic anatomies of the porcine intrinsic cardiac nervous system were investigated in 26 pigs to facilitate functional studies in this model. Gross anatomy: Numerous ganglia and interconnecting nerves (ganglionated plexuses) were found to be concentrated in epicardial fat in five atrial and six ventricular regions. The five atrial ganglionated plexuses identified were (1) the ventral right atrial, (2) the right vena cava–right atrial, (3) the dorsal atrial, (4) the interatrial septal, and (5) the left superior vena cava–left atrial ones. Six ventricular ganglionated plexuses were identified in close proximity to the (1) roots of the aorta and pulmonary artery (craniomedial), extending along the left main coronary artery to the (2) ventral interventricular and (3) circumflex coronary arteries. (4) A ganglionated plexus was identified around the origin of the dorsal interventricular coronary artery, as well as the (5) right main and (6) right marginal coronary arteries. Isolated neurons were identified scattered throughout the cranial interventricular septum. Microscopic anatomy: Approximately 3,000 neuronal somata were estimated to compose this intrinsic cardiac nervous system. Some ganglia contained more than 100 neurons. Neuronal somata had dimensions of roughly 33.1 (short axis) by 46.3 (long axis) μm. Most were multipolar, a small population of unipolar neurons being identified in atrial and ventricular tissues. At the electron microscopic level, asymmetrical axodendritic synapses with small clear, round vesicles were identified, some containing large dense‐cored vesicles. In summary, porcine intrinsic cardiac neurons are concentrated in 11 distinct atrial and ventricular ganglionated plexuses. These extensive plexuses, along with fewer scattered neurons, display varied neuronal morphology and synaptology that represent the anatomical substrate for complex information processing within the intrinsic cardiac component of the porcine cardiac neuronal hierarchy. These anatomical data provide a framework for physiological analyses of the porcine intrinsic cardiac nervous system. Anat Rec Part A 271A:249–258, 2003. © 2003 Wiley‐Liss, Inc.
Anatomical comparison of the cephalic musculature of some members of the superfamily Myliobatoidea (chondrichthyes): Implications for evolutionary understanding
Authors: González‐Isáis Mónica 
Published: January 2003

AbstractThis article describes the anatomy of the dorsal and ventral cephalic musculature of Gymnura marmorata, G. micrura, Aetobatus narinari, Myliobatis californica, M. longirostris, Rhinoptera steindachneri, Mobula munkiana, and M. thurstoni. It was observed that muscles of the dorsal cephalic region showed little variation among species, with the exception of the dorsal longitudinal bundles and the cucullaris muscle. The ventral cephalic musculature showed wider differences, mainly in the depressor hyomandibulae, coracomandibularis, and mandibular adductor muscles. M. munkiana and M. thurstoni revealed a significant muscle reduction, while M. californica, M. longirostris, A. narinari, and R. steindachneri showed a significant development of the ventral cephalic musculature. The species in this comparative study were clearly grouped based on their feeding habits. Data gathered on the muscle arrangements correspond to other taxonomy studies conducted on these groups. However, the results of this study agree only partially with those from previously described phylogenetic models. Therefore, further phylogenetic research is recommended. Anat Rec Part A 271A:259–272, 2003. © 2003 Wiley‐Liss, Inc.