bluuebunny/crossref_metadata_2025_split huggingface dataset:
Patterning Semiconductor Nanocrystals in Polymer Films
Authors: Paquet C. , Kumacheva E. 
Published: September 2007

AbstractThis paper reports a method of patterning semiconductor nanocrystals (NCs) in a polymer film. By combining lithographic concept with polymerization‐induced phase separation in a NC‐monomer mixture, we produced topographic and lateral compositional patterns in NC‐polymer films. The quality of the patterns was controlled by the competition between the rate of polymerization‐induced phase separation and the change in viscosity of the polymerizing mixture.
Polymer‐Bound Pyridine‐Bis(oxazoline). Preparation through Click Chemistry and Evaluation in Asymmetric Catalysis
Authors: Tilliet Mélanie , Lundgren Stina , Moberg Christina , Levacher Vincent 
Published: September 2007

AbstractA pyridine‐bis(oxazoline) ligand was efficiently immobilized by copper(I)‐catalyzed azide‐alkyne cycloaddition onto a polystyrene resin. The so obtained click‐pybox resin 1a was associated with various metal salts (YbCl3, LuCl3, CuOTf) and the resulting resin‐bound catalysts were explored in ring‐opening of cyclohexene oxide, silylcyanation of benzaldehyde and alkynylation of imines. These new polymer‐supported catalysts exhibit good to excellent performances in terms of catalytic activity, enantioselectivity and recyclability.
PuPHOS and CamPHOS Ligands in the Intermolecular Catalytic Pauson–Khand Reaction
Authors: Lledó Agustí , Solà Jordi , Verdaguer Xavier , Riera Antoni , Maestro Miguel A. 
Published: September 2007

AbstractThe first asymmetric intermolecular cobalt‐catalyzed Pauson–Khand reaction is described. The use of the hemilabile CamPHOS ligand provides good conversions and selectivity up to 28 % ee. The catalytic process was studied by in situ FT‐IR and it was found that both bridged and non‐bridged complexes were present in the reaction mixture. Our results suggest that recognition between the alkyne substrate and the ligand is essential to attain stereocontrol in the catalytic cyclization.
Adaptive multiobjective optimization of process conditions for injection molding using a Gaussian process approach
Authors: Zhou Jian , Turng Lih‐Sheng 
Published: September 2007

AbstractSelecting the proper process conditions for the injection‐molding process is treated as a multiobjective optimization problem, where different objectives, such as minimizing the injection pressure, volumetric shrinkage/warpage, or cycle time, present trade‐off behaviors. As such, various optima may exist in the objective space. This paper presents the development of an integrated simulation‐based optimization system that incorporates the design of computer experiments, Gaussian process (GP) for regression, multiobjective genetic algorithm (MOGA), and levels of adjacency to adaptively and automatically search for the Pareto‐optimal solutions for different objectives. Since the GP approach can provide both the predictions and the estimations of the predictions simultaneously, a nondominated sorting procedure on the predicted variances at each iteration step is performed to intelligently select extra samples that can be used as additional training samples to improve the GP surrogate models. At the same time, user‐defined adjacency constraint percentages are employed for evaluating the convergence of iteration. The illustrative applications in this paper show that the proposed optimization system can help mold designers to efficiently and effectively identify optimal process conditions. © 2007 Wiley Periodicals, Inc. Adv Polym Techn 26:71–85, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20092
Unified model for nonideal multicomponent molecular diffusion coefficients
Authors: Leahy‐Dios Alana , Firoozabadi Abbas 
Published: September 2007

AbstractMulticomponent diffusion is important in a variety of applications. In order to calculate diffusion flux, molecular diffusion coefficients are required, where fluid nonideality and the multicomponent nature of the mixture have a significant effect. A unified model for the calculation of diffusion coefficients of gas, liquid and supercritical states of nonpolar multicomponent mixtures is presented. A new correlation is proposed for the binary infinite dilution‐diffusion coefficients. The generalized Vignes relation is used in multicomponent mixtures. Nonideality is rigorously described by the fugacity derivatives evaluated by the volume‐translated Peng‐Robinson equation of state. Predictions for highly nonideal gas and liquid multicomponent mixtures demonstrate the reliability of the proposed methodology. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Successful treatment of cytomegalovirus‐associated hemophagocytic syndrome by intravenous immunoglobulins
Authors: Hot Arnaud , Madoux Marie Hélène Girard , Viard Jean P. , Coppéré Brigitte , Ninet Jacques 
Published: September 2007

AbstractVirus‐associated hemophagocytic syndrome (VAHS) is a rare complication in early cytomegalovirus (CMV) infection. There is no standard therapy for VAHS and the clinical course is variable. Data on the use of intravenous immunoglobulin (IVIG) in the treatment of CMV‐associated VAHS are limited. We report a previously healthy, 32‐year‐old woman who presented with general malaise, fever, chills, and splenomegaly. Laboratory examination showed marked elevation of aminotransferase, leucopoenia, and thrombocytopenia. Acute CMV‐infection was documented by the presence of immunoglobulin M anti‐CMV and positive viremia in blood sample. Bone marrow examination revealed extensive hemophagocytosis. IVIG was administered after the diagnosis of CMV‐associated VAHS. Her symptoms and laboratory abnormalities improved dramatically after the onset of the treatment and she did not require antiviral agent. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
Studies of age‐correlated features of cognitive‐behavioral development in children and adolescents with genetic disorders
Authors: Fisch Gene S. , Carpenter Nancy , Howard‐Peebles Patricia N. , Holden Jeanette J.A. , Tarleton Jack , Simensen Richard , Nance Walter 
Published: September 2007

AbstractStudies of age‐related features of cognitive‐behavioral deficits produced by genetic mutations permit us to draw inferences about how brain development may be related cognitive ability as the child ages. Except for Down syndrome (DS) and the fragile X mutation (FRAXA), little is known about the longitudinal changes in cognitive‐behavioral development in individuals with genetic abnormalities producing learning disabilities (LD) or mental retardation (MR). The purpose of this prospective study was to compare and contrast age related to cognitive abilities, adaptive and maladaptive behaviors in children and adolescents in the same age range, diagnosed with one of three genetic disorders: the FRAXA mutation, Neurofibromatosis type 1 (NF1) or Williams–Beuren syndrome (WBS). We also sought to examine whether cognitive‐behavioral abilities associated with these three genetic disorders were related systematically to age. We examined 108 children, ages 4–15 years, with FRAXA, WBS, or NF1. Results show that there is a significant negative correlation between age and IQ, and between age and adaptive behavior (DQ) scores, in children with FRAXA and WBS, but not in children with NF1. All three groups of children have unusually high proportions of maladaptive behavior, ranging from 1/6 children with NF1 to 2/3 children with FRAXA. Cognitive and adaptive behavior profiles of children with FRAXA and WBS were also surprisingly similar. Our findings suggest the need for examining longitudinal developmental cognitive‐behavioral changes in children and adolescents with all genetic disorders that produce LD or MR. © 2007 Wiley‐Liss, Inc.
Clinical phenotype of lathosterolosis
Authors: Rossi Massimiliano , D'Armiento Maria , Parisi Ida , Ferrari Paola , Hall Christine M. , Cervasio Mariarosaria , Rivasi Francesco , Balli Fiorella , Vecchione Raffaella , Corso Gaetano , Andria Generoso , Parenti Giancarlo 
Published: September 2007

AbstractLathosterolosis (LS) is a defect of cholesterol biosynthesis due to the deficiency of the enzyme sterol‐C5‐desaturase. Only two patients have been described to date, both presenting with multiple malformations, mental retardation, and liver involvement. In addition in one of them pathological examination revealed mucolipidosis‐like inclusions on optic microscopy analysis, and peculiar lysosomal lamellar bodies on electron microscopy analysis. This study is focused on a better characterization of the clinical phenotype of LS. We describe a further case in a fetus, sibling of the first patient reported, presenting with neural tube defect, craniofacial and limb anomalies, and prenatal liver involvement. The fetal phenotype suggests the possible occurrence of significant intrafamilial variability in LS, and expands the phenotypic spectrum of the disease. Histological examination of autopsy samples from the fetus and skin fibroblasts from the living sibling suggested that the mucolipidosis‐like picture previously reported is not a constant feature of LS, being possibly associated with the most severe biochemical defects, but confirmed the ultrastructural finding of lamellar inclusions. The LS phenotype appears to be characterized by the distinctive association of a recognizable pattern of congenital anomalies, involving axial and appendicular skeleton, liver, central nervous and urogenital systems, and lysosomal storage. This condition partially overlaps with other defects of sterol metabolism, suggesting intriguing pathogenic links among these conditions. © 2007 Wiley‐Liss, Inc.
MYO15A (DFNB3) mutations in Turkish hearing loss families and functional modeling of a novel motor domain mutation
Authors: Kalay Ersan , Uzumcu Abdullah , Krieger Elmar , Çaylan Refik , Uyguner Oya , Ulubil‐Emiroglu Melike , Erdol Hidayet , Kayserili Hülya , Hafiz Gunter , Başerer Nermin , Heister Angelien J.G.M. , Hennies Hans C. , Nürnberg Peter , Başaran Seher , Brunner Han G. , Cremers Cor W.R.J. , Karaguzel Ahmet , Wollnik Bernd , Kremer Hannie 
Published: September 2007

AbstractMyosin XVA is an unconventional myosin which has been implicated in autosomal recessive nonsyndromic hearing impairment (ARNSHI) in humans. In Myo15A mouse models, vestibular dysfunction accompanies the autosomal recessive hearing loss. Genomewide homozygosity mapping and subsequent fine mapping in two Turkish families with ARNSHI revealed significant linkage to a critical interval harboring a known deafness gene MYO15A on chromosome 17p13.1‐17q11.2. Subsequent sequencing of the MYO15A gene led to the identification of a novel missense mutation, c.5492G → T (p.Gly1831Val) and a novel splice site mutation, c.8968 − 1G → C. These mutations were not detected in additional 64 unrelated ARNSHI index patients and in 230 Turkish control chromosomes. Gly1831 is a conserved residue located in the motor domains of the different classes of myosins of different species. Molecular modeling of the motor head domain of the human myosin XVa protein suggests that the Gly1831Val mutation inhibits the powerstroke by reducing backbone flexibility and weakening the hydrophobic interactions necessary for signal transmission to the converter domain. © 2007 Wiley‐Liss, Inc.
Effects of hyperbranched poly(amido‐amine)s structures on synthesis of Ag particles
Authors: Sun Youyi , Liu Yaqing , Guizhe Zhao , Zhang Qijin 
Published: September 2007

AbstractThe synthesis of Ag particles stabilized poly (N,N′‐methylene bisacrylamide N‐aminoethyl piperazine) (MBA‐AEPZ) and poly(N,N′‐dodecyl diacrylamide N‐aminoethyl piperazine) (MDA‐AEPZ) was reported. The effects of hyperbranched polymer structures and hyperbranched polymer concentrations were studied on the size and size distribution of Ag particles, which were determined from the UV plasmon absorption band and transmission electronmicroscopic analyses. The data show that slight change (10.3 and 9.7 nm) and large change on particle size (3.9 and ∼ 200 nm) were observed with increase in concentrations of poly(MBA‐AEPZ) and poly(MDA‐AEPZ) at the same M:D, respectively. The difference is explained in terms of a mechanism of structure‐dependent stabilization. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Reactive extrusion to synthesize intumescent flame retardant with a solid acid as catalyst and the flame retardancy of the products in polypropylene
Authors: Liu Yuan , Wang Qi 
Published: September 2007

AbstractReactive extrusion and solid acid catalysis technologies were adopted in the pentaerythritol–melamine phosphate (PER‐MP) reaction to synthesize intumescent flame retardant, melamine salt of pentaerythritol phosphate (MPP), which was applied in flame retardant polypropylene (PP). This environment‐friendly synthesis method provided a solution to the problems of conventional methods. On one hand, reactive extrusion in a twin screw extruder can effectively mix and transfer viscous materials that usually results in a tough stir in a conventional reactor, and achieve a continuous synthesis process. On the other hand, the solid acid, silicotungstic acid (STA) serving as a catalyst, can maintain a satisfactory conversion even with a low extrusion temperature and a short residence time, thus effectively suppressing foaming in the process of the reaction. Furthermore, without removal like other catalysts in general chemical reactions, STA was kept in produced MPP to constitute a synergism flame retardant system, therefore further improved the flame retardancy. LOI and UL94 test showed that the STA‐catalyzed MPP (by reactive extrusion) possessed much better flame retardancy in PP when compared with the noncatalyzed MPP (by reactive extrusion), as well as present commercial MPP (by POCl3 method). In our investigation, the catalytic and synergistic effects of STA, as well as the related factors of the reactive extrusion affecting the conversion of the PER‐MP reaction, flame retardancy and mechanical performance of the corresponding flame retardant PP, were systematically investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Insulation performance and microstructure in modified polyethylene by MPE
Authors: Wang X. , Tu D. M. , Lei C. , Du Q. G. 
Published: September 2007

AbstractElectrical measurements have shown to be able to provide useful information on physical, chemical, and microstructural properties of dielectric material. In this article, the depolarization characteristics of low‐density polyethylene blended with a small amount of metallocene catalyzed polyethylene were measured by pulsed electro‐acoustic method under various stresses. According to space charge limited current theory, the derivation of quantities such as mean volume density of space charge, apparent trap‐controlled mobility, trap depth distribution, and threshold stress were discussed. The test results showed that low‐density polyethylene blended with 1 wt % metallocene catalyzed polyethylene could effectively decrease deep trap density, increase shallow trap density, and then improve the mobility of charges. We also measured the breakdown voltage and tensile strength of the blends. It was found that low‐density polyethylene blended with a small amount of metallocene catalyzed polyethylene could effectively improve its breakdown voltage and tensile strength but reduce the material tenacity. Finally, mechanical relax and crystalline morphology of blends were studied by dynamic mechanical measurement, wide‐angle X‐ray diffraction, and small‐angle X‐ray scattering experiments. The results showed that the improvement of electrical properties and mechanical strength in the blends were relevant to the crystalline morphology. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
FTIR spectroscopic study of the effect of microwave heating on the transformation of cellulose I into cellulose II during mercerization
Authors: Moharram M. A. , Mahmoud Osama M. 
Published: September 2007

AbstractFourier transform infrared (FTIR) spectroscopy techniques were used in the study of the effect of microwave (MW) heating on the structural properties of cotton fibers and on the mercerization mechanism of these fibers. Samples of the fibers were microwave heated for different times and different microwave powers. Also, mixtures of cotton fibers and aqueous solution of NaOH with different concentrations were exposed to microwave radiation for different times and different powers. It was found that microwave heating of cotton fibers under these experimental conditions causes no observable changes in their spectral features apart from slight changes in the intensities of the absorption bands. The determined values of the absorbances ratio A1375 cm−1/A2900 cm−1revealed that microwave heating for short periods and at low powers decreases the crystallinity of cotton as the result of the drying effect of microwave heating, while microwave heating for longer periods and at higher power results in recristallyzation of the fibers. The analysis of the experimentally obtained data revealed that microwave heating that causes molecular motions by migration of ions and rotations of the dipoles produces no considerable effects on the mechanism of mercerization but only reduces the concentration of NaOH in the solution and the time of treatment which are needed for the complete transformation of cellulose lattice type I into cellulose lattice type II without any heating. Also it was found that the magnitude of reductions depends on the applied power. Moreover the results proved that the deconvolution and the second derivatives of the FTIR spectra of cotton fibers can be used as a useful tool for distinguishing cellulose lattice type II from cellulose lattice type I. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Surface characterization and properties of functionalized nonwoven
Authors: Wei Qufu , Yu Liangyan , Hou Dayin , Huang Fenglin 
Published: September 2007

AbstractNonwoven materials have been increasingly used in many industries. The surface properties of nonwoven materials are of importance in these applications. In this study, functional nonwoven materials were prepared by sputtering deposition of copper (Cu), zinc oxide (ZnO), and polytetrafluoroethylene (PTFE) on the surface of polypropylene (PP) fibers. Atomic Force Microscopy (AFM) and Environmental Scanning Electron Microscopy (ESEM) were employed to study the surface morphology and chemical compositions. The observations by AFM revealed the formation of functional nanostructures on the fibre surfaces and the ESEM examination confirmed the formation of functional compositions on the fiber surface. The metallic coating of Cu significantly improved the surface conductivity of the material. The transmittance analysis indicated that the ZnO coating obviously increased the ultra‐violet absorption of the material. The surface hydrophobicity of the nonwoven material was enhanced by the sputter coating of PTFE. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Real‐time ultrasonic monitoring of the injection‐molding process
Authors: He Bobing , Zhang Xiaoqing , Zhang Qin , Fu Qiang 
Published: September 2007

AbstractIn this study, a noninvasive and nondestructive ultrasonic technique has been used to monitor the polymer injection‐molding process in an attempt to establish a fundamental understanding of the processing/morphology/ultrasonic signal relationships. The ultrasonic technique not only can provide information on solidification affected by various temperatures and pressures but also can reflect the evolution of the crystal morphology and phase morphology of polymer blends. In addition, the periodic vibration of the dynamic‐packing injection‐molding process, in which the melt is forced to move repeatedly in a chamber by two pistons that move reversibly with the same frequency as the solidification progressively occurs from the mold wall to the molding core part, can also be monitored with the ultrasonic velocity and attenuation. Our results indicate that the ultrasonic technique is sensitive and promising for the real‐time monitoring of the injection‐molding process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Poly(ether urethane) flexible cyanate ester resins: Synthesis, characterization, and performance in commercial epoxy and polyurethane applications
Authors: Kumar T. Pazhani , Sivasankar B. 
Published: September 2007

AbstractA poly(ether urethane)‐based cyanate ester resin (PEUCER) with a biphenyl polyether backbone obtained from polymeric 4,4′‐diphenylmethanediisocyanate, bisphenol A, polyether polyols of three different molecular weights, and cyanogen bromide was synthesized to obtain a polymer with better functional and physical properties, such as adhesion, flexibility, and thermal stability. The synthesis of the poly(ether urethane)‐based 4,4′‐(oxybiphenyl propane) cyanate ester involved three steps: the formation of the poly(ether urethane) NCO‐terminated prepolymer, the formation of the OH‐terminated poly (ether urethane) prepolymer (PEU–PP), and the esterification reaction of cyanate to produce PEUCER. PEUCER was cyclotrimerized to yield a triazine‐ring‐containing polymer, which possessed better adhesion at high temperatures and better impact resistance. PEU–PP and PEUCER were characterized with wet chemical analysis, spectral methods, and thermal methods. PEUCER showed better performance with respect to thermal and adhesion properties with a single‐part polyurethane lamination adhesive and also showed better performance as a toughening agent in a two‐part epoxy laminate system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of silver nanocrystals by a modified polyol method
Authors: Bregado‐Gutiérrez Julio , Saldívar‐García Armando J. , López Hugo F. 
Published: September 2007

AbstractA modification of the polyol method has been shown to result in improved efficiency and enhanced kinetics for the synthesis of silver nanocrystals when compared with the traditional polyol method. The Ag nanocrystals produced were characterized using X‐ray diffraction and transmission electron microscopy. Accordingly, the exhibited Ag crystal structure, corresponding lattice constants, and resultant particle sizes were determined by these means. In addition, using Fourier transform infrared spectroscopy, it was found that a solid‐state reaction between the AgNO3 and the Poly (vinylpyrrolidone) (PVP) takes place prior to their dissolution in ethylene glycol. Moreover, when crystals grow under total rest conditions, they do not develop a spherical morphology as in the traditional polyol method, but a well‐defined geometric shape showing preferential crystallographic growth directions. Under the experimental conditions of this work, the exhibited nanocrystal shapes were quasi‐planar hexagonal. Apparently, PVP interacts with the FCC crystal structure promoting growth on the {100} preferential direction by playing the role of an atomic arranger. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008