bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antenatal and postnatal evidence of periventricular leukomalacia as a further indication of vascular disruption in Adams–Oliver syndrome
Authors: Papadopoulou Eleftheria , Sifakis Stavros , Raissaki Maria , Germanakis Ioannis , Kalmanti Maria 
Published: September 2008

AbstractWe describe a new family with Adams–Oliver syndrome (AOS). The propositus is a 14‐month‐old boy presenting with aplasia cutis congenita, distal limb transverse defects, growth retardation, and a wide atrial septal defect. Central nervous system abnormalities included central hypotonia, and magnetic resonance imaging (MRI) findings consistent with periventricular leukomalacia (PVL). Fetal MRI at 26 weeks' gestation had shown bilateral dilatation of lateral ventricles and periventricular cysts at the site of postnatal lesions. The patient's father and paternal grandfather also had manifestations indicative of AOS. Antenatal and postnatal MRI findings suggest that our patient's PVL represents an unusual congenital feature of AOS, possibly due to vascular disruption and decreased perfusion during critical periods of fetal brain development. © 2008 Wiley‐Liss, Inc.
Polymorphisms in the CBS gene and homocysteine, folate and vitamin B12 levels: Association with polymorphisms in the MTHFR and MTRR genes in Brazilian children
Authors: Aléssio Ana C.M. , Siqueira Lúcia H. , Bydlowski Sérgio P. , Höehr Nelci F. , Annichino‐Bizzacchi Joyce M. 
Published: September 2008

AbstractPolymorphisms in the methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR) and cystathionine β‐synthase (CBS) genes, involved in the intracellular metabolism of homocysteine (Hcy), can result in hyperhomocysteinemia. The objective of this study was to evaluate prevalence estimates of CBS T833C, G919A and the insertion of 68‐bp (844ins68) polymorphisms and their correlation with Hcy, folate and B12 in 220 children previously genotyped for MTHFR C677T, A1298C, and MTRR A66G. The prevalence of heterozygote children for 844ins68 was 19.5%. The T833C CBS mutation was identified in association with 844ins68 in all the carriers of the insertion. Genotyping for CBS G919A mutation showed that all the children presented the GG genotype. Analysis of Hcy, B12 and folate, according to the combination of the different genotypes of the C677T and A1298C MTHFR, A66G MTRR, and 844ins68 CBS showed that the 677TT/1298AA/68WW genotype is associated with an increase in Hcy, when compared to the 677CC/1298AC/68WW (P = 0.033) and the 677CT/1298AA/68WW genotypes (P = 0.034). Since B12 and folate were not different between these groups, a genetic interaction between diverse polymorphisms probably influences Hcy. Our results emphasize the role of genetic interactions in Hcy levels. © 2008 Wiley‐Liss, Inc.
Detailed analysis of the serotonin transporter gene (SLC6A4) shows no association with bipolar disorder in the Northern Swedish population
Authors: Alaerts Maaike , Ceulemans Shana , Forero Diego , Moens Lotte N. , De Zutter Sonia , Heyrman Lien , Lenaerts An‐Sofie , Norrback Karl‐Fredrik , Goossens Dirk , De Rijk Peter , Nilsson Lars‐Göran , Adolfsson Rolf , Del‐Favero Jurgen 
Published: September 2008

AbstractThrough active reuptake of serotonin into presynaptic neurons, the serotonin transporter (5‐HTT) plays an important role in regulating serotonin concentrations in the brain, and it is the site of binding for tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs). Therefore it has been hypothesized that this transporter is involved in the etiology of bipolar (BP) disorder. Inconsistent association study results for the SLC6A4 gene encoding 5‐HTT reported in literature emphasize the need for more systematic and detailed analyses of this candidate gene. We performed an extensive analysis of SLC6A4 on DNA of 254 BPI patients and 364 control individuals from a Northern Swedish isolated population. This analysis consisted of a HapMap LD‐based association study including three widely investigated polymorphisms (5‐HTTVNTR, 5‐HTTLPR, and rs3813034), a copy‐number variation (CNV) analysis and a mutation analysis of the complete coding sequence and the 3′‐UTR of SLC6A4. No single marker showed statistically significant association with BPI, nor did any of the haplotypes. In the mutation analysis 13 novel variants were detected, including 2 amino acid substitutions M389V and I587L, but these are probably not implicated in risk for BP. No deletions or duplications were detected in the CNV analysis. We conclude that variation in the SLC6A4 gene or its regulatory regions does not contribute to the susceptibility for BP disorder in the Northern Swedish population. © 2008 Wiley‐Liss, Inc.
Efficient asymmetric addition of diethylzinc to aldehydes using 3‐hydroxyazetidine derivatives as chiral ligands
Authors: Liu Ruochen , Bai Xuemei , Zhang Zhanbin , Zi Guofu 
Published: September 2008

AbstractA new series of chiral 3‐hydroxyazetidines has been prepared from (S)‐1‐(4‐methoxyphenyl)ethylamine. These ligands have shown excellent catalytic activities and enantiomeric selectivities in asymmetric addition of diethylzinc to aromatic aldehydes. Copyright © 2008 John Wiley & Sons, Ltd.
Slot die coating of dilute suspensions
Authors: Lin Yi‐Tsun , Chu Wen‐Bing , Liu Ta‐Jo 
Published: September 2008

AbstractAn experimental study was carried out to investigate slot die coating of dilute suspensions. Polymethyl methacrylate (PMMA) particles of different sizes were added to glycerol solutions as test fluids. The coating flow experiment was performed on a lab coater. The operating window, which is a domain in which only a stable and uniform coating solution is possible, was determined experimentally. It was found that adding particles has little effect on the physical properties of glycerol solutions, as only the fluid viscosity increases slightly. Two coating defects are commonly observed; ribbing which is caused by flow instability refers to lateral waves on the coated surface, and air entrainment which implies that air bubbles are trapped in the coating solution. Adding particles has little effect on the operating window if the coating defect is ribbing. However, the operating window can be expanded substantially if the coating defect is air entrainment. Higher the particle concentration, or the smaller the particle size, more significant is the expansion of the operating window. The maximum coating speed may increase to 80% for high suspension particle density number. A previous study reported that there exists an optimal particle size which has the largest operating window for a given pure solution; this was not found in the present work. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Undesirable effects of heating on hydrogels
Authors: Kabiri K. , Mirzadeh H. , Zohuriaan‐Mehr M. J. 
Published: September 2008

AbstractHeating is the most conventional drying method for removing water from as‐synthesized hydrogels in laboratory and industry. In this article, the effects of the heating temperature (60–200°C) and time (10 min–24 h) on swelling properties of highly absorbent hydrogels based on 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS), acrylic acid (AA), potassium acrylate (KA), and acrylamide (AM) were studied. Crosslinkers methylene bisacrylamide (MBA) and poly(ethyleneglycol) dimethacrylate (PEGDMA) were used in the syntheses. Depending on the hydrogel structural composition and its drying temperature and time, the swelling capacities were extremely changed. Generally, AA‐, KA‐, and AM‐based hydrogels showed more hydrolytic‐thermal stability than the corresponding AMPS‐based hydrogels. MBA‐crosslinked hydrogels generally exhibited higher vulnerability against heating. Swelling of PEGDMA‐crosslinked poly(AM‐KA‐AA) hydrogel was greatly increased after heating, whereas its analogousAM‐free sample exhibited huge loss of swelling. PEGDMA‐crosslinked poly(AMPS) samples also exhibited swelling reduction after drying. Rheological studies showed that the storage modulus was highly reduced (∼ 5200 Pa) after heating of MBA‐crosslinked poly(AMPS) hydrogels, which reconfirmed the crosslink cleavage. Mechanistic discussions were proposed for the thermal‐induced swelling changes. It was concluded that the chemical nature of both crosslinker and monomer must be taken into consideration to choose the temperature and time of the hydrogel drying. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mechanical properties of poly(styrene‐co‐acrylonitrile)‐modified epoxy resin/glass fiber composites
Authors: Hameed Nishar , Sreekumar P. A. , Thomas P. Selvin , Jyotishkumar P. , Thomas Sabu 
Published: September 2008

AbstractPoly(styrene‐co‐acylonitrile) was used to modify diglycedyl ether of bisphenol‐A type epoxy resin cured with diamino diphenyl sulfone and the modified epoxy resin was used as the matrix for fiber‐reinforced composites (FRPs) to get improved mechanical properties. E‐glass fiber was used as fiber reinforcement. The tensile, flexural, and impact properties of the blends and composites were investigated. The blends exhibited considerable improvement in mechanical properties. The scanning electron micrographs of the fractured surfaces of the blends and tensile fractured surfaces of the composites were also analyzed. The micrographs showed the influence of morphology on the properties of blends. Results showed that the mechanical properties of glass FRPs increased gradually upon fiber loading. Predictive models were applied using various equations to compare the mechanical data obtained theoretically and experimentally. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermodynamic study of a water–dimethylformamide–polyacrylonitrile ternary system
Authors: Tan Lianjiang , Pan Ding , Pan Ning 
Published: September 2008

AbstractExperimental cloud‐point data were obtained by cloud‐point titration. The phase diagram for a ternary system of water–dimethylformamide–polyacrylonitrile was determined by numerical calculation on the basis of the extended Flory–Huggins theory and was found to agree well with the cloud‐point data. To construct the theoretical phase diagram, three binary interaction parameters were obtained with different methods. The ternary phase diagram was used to investigate the mechanism of fiber formation. The skin–core structure and fingerlike pores in polyacrylonitrile fiber may be effectively eliminated if the composition of the spinning solution is properly chosen, and consequently, homogeneous polyacrylonitrile fiber with a bicontinuous structure and good mechanical properties can be obtained through the spinning process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of novel microspherical MgCl2‐based titanium catalyst for propylene polymerization
Authors: Ling Yongtai , Chen Wei , Xie Lunjia , Liu Yuexiang , Zheng Gang 
Published: September 2008

AbstractLowering the particle size of support is one of methods to reduce breakage of supported catalyst during polymerization, which may cause serious problems for fine polymer particles from those broken catalysts. Microspheric MgCl2 support could be obtained by emulsion way, but we found that they easily aggregated after emulsification and they are difficult to keep good spherical morphology. Up until now, hardly paper on the morphology improvement of micro size supports has been published. With the addition of an amount of Poly(propylene glycol)(PPG), microspheric MgCl2 supports with good morphology were obtained. 1, 3, 15, 35, 80% PPG were added, respectively, and the results of SEM study on obtained particles showed that appropriate addition of PPG obviously improved the morphology of supports. The optimist dosage was 3% in our experiment and the activity of catalyst supported on obtained support was 32.3 kg PP/g cat h. The function of PPG was explored preliminarily. In spite of the improvement of morphology the activity of supported catalyst was decreased gradually compared to those without PPG. So the further XRD and IR analysis were carried out to find reasons. The results indicated that PPG might plug pores of support and interfere with the reaction between supports and TiCl4. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Continuous polymerization of ε‐caprolactone initiated by titanium phenoxide in a twin‐screw extruder
Authors: Machado A. V. , Bounor‐Legare V. , Gonçalves N. D. , Melis F. , Cassagnau P. , Michel A. 
Published: September 2008

AbstractThe continuous polymerization of ε‐caprolactone initiated by titanium phenoxide was carried out in both an internal mixer and a twin‐screw extruder. The polymerization was performed under different processing conditions, including various temperatures and screw speeds. To perform a kinetic study, samples were collected along the time axis (internal mixer) and along the screw axis (extruder). Size exclusion chromatography and proton nuclear magnetic resonance were used to study the evolution of the conversion degree with mixing time and with the extruder. The rheological behavior was also characterized. Temperature had a strong effect on conversion in the internal mixer, whereas in the twin‐screw extruder, both temperature and screw speed played major roles. The specificity of the titanium phenoxide to lead to high‐molar‐mass poly(ε‐caprolactone) under these processing conditions was also confirmed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Specific interactions in poly(styrene‐co‐2‐hydroxyethyl acrylate)/poly(styrene‐co‐N,N‐dimethylacrylamide) systems
Authors: Bouzouia Fatiha , Djadoun Said 
Published: September 2008

AbstractAmphiphilic copolymers of poly(styrene‐co‐2‐hydroxyethyl acrylate) (SHEA) and poly(styrene‐co‐N, N‐dimethylacrylamide) (SAD) of different compositions were prepared by free radical copolymerization and characterized by different techniques. Depending on the nature of the solvent and the densities of interacting species incorporated within the polystyrene matrices, novel materials as blends or interpolymer complexes with properties different from those of their constituents were elaborated when these copolymers are mixed together. The specific interpolymer interactions of hydrogen bonding type and the phase behavior of the elaborated materials were investigated by differential scanning calorimetry (DSC) and Fourier transform infra red spectroscopy (FTIR). The specific interactions of hydrogen bonding type that occurred within the SHEA and within their blends with the SAD were evidenced by FTIR qualitatively by the appearance of a new band at 1626 cm−1 and quantitatively using appropriate spectral curve fitting in the carbonyl and amide regions. The variation of the glass transition temperature with the blend composition behaved differently with the densities of interacting species. The thermal degradation behavior of the materials was studied by thermogravimetry. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Evaluation of adhesion strength, flammability, and degradation of HBCD‐containing polyurethane adhesives
Authors: Amrollahi M. , Sadeghi G. Mir Mohamad 
Published: September 2008

AbstractIn this work, moisture curable flame retardant HTPB‐based polyurethane adhesives were synthesized. The influence of HBCD (Hexabromocyclododecane) as flame retardant on adhesion, degradation and change in flammability of synthesized HTPB‐based polyurethane has been studied. Relationship between phase separation in hard and soft domains and adhesion has also been investigated. FTIR analysis was used to determine phase separation in synthesized adhesives. Lap shear test was used to determine adhesion properties of adhesives applied on aluminum and glass substrates. Thermal Gravimetry analysis and Limited Oxygen Index (LOI) tests were carried out on flame retardant adhesives to evaluate effect of HBCD on degradation and flammability. Addition of HBCD to adhesives leads to reduction of thermal stability and lap shear strength for all substrates, in spite of flame retardant adhesives show higher LOI value. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Development of a predictive model for polymer/solvent diffusion coefficient calculations
Authors: Perioto F. R. , Alvarez M. E. T. , Araujo W. A. , Wolf‐Maciel M. R. , Maciel Filho R. 
Published: September 2008

AbstractA new calculation procedure for free‐volume parameters is considered in this work by using viscosity prediction methods and the Levenberg‐Marquardt calculation scheme. All parameters used in the Vrentas–Duda free‐volume theory can be estimated from pure component properties. The prediction results are compared with experimental data for some polymer/solvent systems. The diffusion coefficient calculated by Vrentas–Duda theory can be used in the modeling of membrane separation processes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Bifunctional oligoetherols with carbazole ring
Authors: Lubczak Renata 
Published: September 2008

AbstractA new synthetic method for bifunctional oligoetherols with carbazole ring was presented. 9‐(2,3‐Epoxypropyl)carbazole was obtained from carbazole and epichlorohydrine. The epoxide ring opening occurred upon the consecutive reaction with ethylene glycol to give the semiproduct well soluble in ethylene oxide and propylene oxide and reactive toward these epoxides at temperatures above 60–90°C to form oligoetherols. Structure of these oligoetherols and their physical properties and application for synthesis of linear polyurethanes were studied in details. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Physicochemical characterization of carrageenans—A critical reinvestigation
Authors: Berth Gisela , Vukovic Jasna , Lechner M. Dieter 
Published: September 2008

AbstractKappa‐, iota‐, and lambda‐carrageenan (food grade) were analyzed by static light scattering (MALS in batch mode) in 0.1M NaNO3 at 25 and 60°C, earlier heated up to 90°C or not. At 25°C, there was a strong tendency for a concentration‐dependent aggregation in the order lambda < kappa < iota. At 60°C, all samples were molecularly dispersed. The strongly temperature‐dependent refractive index increments (equilibrium dialysis) differ. Data interpretation in terms of the wormlike chain model using the Skolnik‐Odijk‐Fixman approach led to an intrinsic persistence length around 3 to 4 nm and expansion factors as high as 1.5 and above in a thermodynamically good solvent for all three types. Triple‐detector HPSEC (DRI, MALS, viscometry) on the three commercial samples plus a degraded (by acidic hydrolysis) kappa‐carrageenan in the same solvent/eluant at 60°C yielded a uniform and slightly curved [η]‐M relationship for 5 × 103 ≤ M/(g mol) ≤ 3 × 106 and a nearly identical molar mass dependence of the radius of gyration. HPSEC at 25°C on kappa‐carrageenan confirmed formation of soluble aggregates. Special emphasis was put on analytical and methodological aspects. The reliability of the experimental data was demonstrated by analogous measurements on dextran calibration standards. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Biodegradation of low‐density polyethylene‐banana starch films
Authors: Torres Apolonio Vargas , Zamudio‐Flores Paul Baruk , Salgado‐Delgado René , Bello‐Pérez Luís Arturo 
Published: September 2008

AbstractFilms were prepared by extrusion using acetylated and oxidized banana starches at different concentrations mixed with low‐density polyethylene, and their biodegradation (buried in soil) at different storage times was studied. Morphological, thermal, and mechanical characteristics of the films after degradation were tested. Films made of acetylated banana starch degraded most rapidly and those prepared with oxidized starch had the slowest degradation time. The type of chemically modified starch plays an important role in degradation of film. Burying the films produced a decrease in degradation temperature at the longest storage time, and there was a longer interval in the films prepared with native banana starch, followed by those made of acetylated starch. The buried in soil films had a broad phase transition and, consequently, an increase in enthalpy. This is due to degradation of amorphous starch zones with an increase in the crystallinity. Electron scanning microscopy analysis revealed greater degradation at longer storage time and a more marked effect in the films made of modified banana starch. Mechanical properties of the films were affected by degradation, and these varied depending on the modified banana starch used. The use of biodegradable polymers such as chemically modified banana starch might be feasible for making films with a high rate of degradation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and in vitro release of D,L‐tetrahydropalmatine‐loaded graft copolymer nanoparticles
Authors: Zhai Yinglei , Qiao Yong , Xie Chaopeng , Lin Xiaona , Ma Yongzheng , Dong Anjie , Deng Liandong 
Published: September 2008

AbstractD,L‐tetrahydropalmatine (THP)‐loaded poly{[α‐maleic anhydride‐ω‐methoxy‐poly(ethylene glycol)]‐co‐(ethy cyanoacrylate)} (PEGECA) amphiphilic graft copolymer nanoparticles (PEGECAT NPs) were prepared by the nanoprecipitation technique. The effects of solvent property, temperature, copolymer composition, and drug feeding on the drug‐loaded amount and size of PEGECAT NPs were investigated. The morphological structure of PEGECAT NPs was characterized by transmission electron microscopy (TEM), proton nuclear magnetic resonance (1H NMR), and the size was measured by laser particle size analyzer (LPSA). In vitro release behaviors of drug from PEGECAT NPs were examined by high‐pressure liquid chromatography (HPLC). The results demonstrate that PEGECAT NPs take on a spherical morphology with an inner core and outer shell before and after in vitro release. THP can be incorporated into the hydrophobic core of PEGECAT NPs and the drug‐loaded amount is higher than 5%. The release of THP from PEGECAT NPs is initially fast and then slows down. The accumulated release is lower than 40% after 48 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The Hydrogenation/Transfer Hydrogenation Network in Asymmetric Reduction of Ketones Catalyzed by [RuCl2(binap)(pica)] Complexes
Authors: Sandoval Christian A. , Li Yuehui , Ding Kuiling , Noyori Ryoji 
Published: September 2008

AbstractChiral binap/pica‐RuII complexes (binap=(S)‐ or (R)‐2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl; pica=α‐picolylamine) catalyze both asymmetric hydrogenation (AH) of ketones using H2 and asymmetric transfer hydrogenation (ATH) using non‐tertiary alcohols under basic conditions. The AH and ATH catalytic cycles are linked by the metal–ligand bifunctional mechanism. Asymmetric reduction of pinacolone is best achieved in ethanol containing the Ru catalyst and base under an H2 atmosphere at ambient temperature, giving the chiral alcohol in 97–98 % ee. The reaction utilizes only H2 as a hydride source with alcohol acting as a proton source. On the other hand, asymmetric reduction of acetophenone is attained with both H2 (ambient temperature) and 2‐propanol (>60 °C) with relatively low enantioselectivity. The degree of contribution of the AH and ATH cycles is highly dependent on the ketone substrates, solvent, and reaction parameters (H2 pressure, temperature, basicity, substrate concentration, H/D difference, etc.).