bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of functionalized SWCNTs on microstructure of PP‐g‐MA/OMMT/f‐SWCNTs nanocomposite
Authors: Gao Yao , Wang Yong , Shi Jing , Zhu Shibu , Bao Yanling , Bai Hongwei , Li Yanli 
Published: February 2009

AbstractThe aim of this work was to study the effect of functionalized single‐walled carbon nanotubes (f‐SWCNTs) on the microstructure of PP‐g‐MA/organic modified montmorillonite (OMMT)/f‐SWCNTs ternary nanocomposite. Pristine SWCNTs were chemically modified by maleic anhydride to improve the interaction between PP‐g‐MA and nanotubes. The dispersion states of OMMT in the different nanocomposites were investigated by wide angle X‐ray diffraction. The morphologies of the nanocomposites were characterized by scanning electron microscopy. Crystallization behaviors of nanocomposites were studied through differential scanning calorimetry and polarizing optical microscopy. Different than the PP‐g‐MA/OMMT binary nanocomposite, in which the OMMT is mainly in an exfoliated state, the ternary PP‐g‐MA/OMMT/f‐SWCNTs nanocomposite exhibits mostly intercalated OMMT. Furthermore, in the ternary nanocomposite, the crystallization of polymer is mainly induced by f‐SWCNTs rather than by OMMT. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Kinetic studies on the dilatometric‐free radical copolymerization of new modified laser dye monomer with methyl methacrylate and characterization of the obtained copolymer
Authors: Sayyah S. M. , Rehahn M. , Elwahy A. H. M. , Abou‐Kana M. T. H. 
Published: February 2009

AbstractThe synthesis of the new modified laser dye from fluorescein ester (II) and acryloyl chloride was performed. The structure of the new monomer 2‐(6‐acryloyloxy‐3‐oxo‐3H‐xanthene‐9‐yl)‐benzoic acid ethyl ester [AOXBE] was confirmed by 1HNMR, IR, 13CNMR, mass spectroscopy, and elemental analysis. Free radical copolymerization of AOXBE with methyl methacrylate (MMA) was discussed using dilatometric technique. The effect of different solvents on the rate of copolymerization reaction was carried out. The rate equation was found to be Rp = [Initiator]0.5473 [Monomer]1.5. It was also noticed that the increase of AOXBE concentration in the monomer feed has an inhibition effect on the rate of copolymerization. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and adsorption properties of chelating resins from thiosemicarbazide and formaldehyde
Authors: Zhang Liping , Ni Caihua , Zhu Changping , Jiang Xiang , Liu Yuping , Huang Bo 
Published: February 2009

AbstractA novel chelating resin was synthesized in just one step under mild synthetic conditions. The synthesis was carried out through the copolymerization of thiosemicarbazide and formaldehyde in an aqueous solution. The adsorption properties for some noble metal ions were investigated. The results showed that the resin had high adsorption selectivity for Au(III) and Ag(I). The adsorption capacities for the two metal ions reached up to 7.3 and 11.8 mmol/g, respectively. The adsorption rate for the two metal ions in a dilute solution was 99.9%. The adsorption fit first‐order kinetics, and an isothermal adsorption study indicated that it corresponded to Langmuir monomolecular layer adsorption. The change in the bonding energy during the chelating process was investigated with X‐ray photoelectron spectroscopy. The study revealed that nitrogen and sulfur atoms of the resins were electron donors and metal ions were electron acceptors in the process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Controlled chain branching free radical polymerization manipulate with trithiocarbonates
Authors: Wang Xiao Long , Chen Zhi , Ran Rong 
Published: February 2009

AbstractSoluble, branched (methyl) methacrylate copolymers have been prepared via facile, one‐step, batch solution free radical polymerizations taken to high conversion. Methyl methacrylate (MMA) or methacrylate has been copolymerized with the branching comonomer (BCM) using a trithiocarbonate (TTC) to inhibit gelation. The BCMs employed were tripropylene glycol diacrylate (TPGDA) and trihydroxymethylpropyl triacrylate (TMPTA). Soluble branched copolymers containing unreacted double bonds have been produced and characterized by 1H‐NMR spectroscopy. These two brancher monomers have been shown to produce regularly branched material with the small molar mass distributions in the presence of TTC. The results of DSC and Mark–Houwink constant α analyses support the production of the branched architectures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Novel fluorescence method for cure monitoring of hydrosilation‐curable silicones
Authors: Hotta Yasuhiro , Komatsu Koichi , Wang Francis W. 
Published: February 2009

AbstractThis study aimed to evaluate a reactive fluorescent probe, 9,10‐bis‐(phenylethynyl) anthracene (BPEA), for cure monitoring of hydrosilation‐curable silicones. The hydrosilation‐curable silicones consisted of a vinyl‐terminated polydimethylsiloxane prepolymer, a methylhydrosiloxane‐dimethylsiloxane copolymer, and an inhibitor, 1,3‐divinyltetramethyldisiloxane. The hydrosilation reaction was catalyzed with the solution of a platinum catalyst in the prepolymer. The catalyst solution also contained a trace amount of the reactive fluorescent probe. Three hydrosilation‐curable silicones, with the prepolymer of varying molar mass, were investigated. Each of the hydrosilation‐curable silicones was mixed with the catalyst solution at the mass ratio of 1 : 1 to initiate the cure. During the cure of each mixture at 22°C, the elastic modulus of the mixture and the fluorescence spectrum of the probe at the excitation wavelength of 360 nm were measured. Initially, the elastic modulus changed slowly, but then increased rapidly as a result of the increase in molar mass. The elastic modulus leveled off and reached a plateau value at the setting time. The ratio of the fluorescence intensities at 422 and 466 nm increased steadily, and then leveled off and reached a plateau value at the setting time, in agreement with the setting time determined from the change in elastic modulus. The reactive fluorescent probe, BPEA, can therefore be used for nondestructive fluorescence monitoring of hydrosilation‐curable silicones. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Properties of high modulus PEEK yarns for aerospace applications
Authors: Shekar R. Indu , Kotresh T. M. , Rao P. M. Damodhara , Kumar Kamal 
Published: February 2009

AbstractA study has been carried out on the influence of extrusion and drawing related process parameters with an object of obtaining high modulus poly ether ether ketone yarns that can be tailor made to meet critical requirements of aerospace applications. The influence of the interaction between rheological properties, spinning process variables, and drawing conditions has been given special attention to engineer a yarn that exhibit excellent structure property relationships. The wide angle X‐ray diffraction results suggest that drawing carried out above glass transition temperature (Tg) influences the structure that include unit cell parameters, density, and mechanical properties. The degree of orientation characterized in terms of sonic velocity measured as high as 3 km/s with sonic modulus of 105 gpd. With progressive increase in draw temperature, crystallinity was found to increase, and useful properties were observed at an optimum draw temperature of 200°C (may be region of maximum crystallization rate) primarily attributed to the maximum crystallization temperature and the heat setting effect. Thermal studies (TGA) indicate that these materials can be used in high temperature applications (up to 250°C) for long time exposure and 500°C for short term exposure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Optical resolution of (R,S)‐2‐phenyl‐1‐propanol through enantioselective ethycellulose membranes
Authors: Yang Meng , Zhao Min , Xie Sheng‐Ming , Yuan Li‐Ming 
Published: February 2009

AbstractEnantioselective membrane was prepared using ethyl cellulose (EC) as membrane material. The flux and permselective properties of membrane using aqueous solution of (R,S)‐2‐phenyl‐1‐propanol as feed solution was studied. The employed membrane process was a pressure driven process. All kinds of important conditions including preparation and operation of membranes were investigated in this experimentation. When the membrane was prepared with 18 wt % EC, 20 wt % N,N‐dimethylformamide in casting solution, 13 min evaporation time and 0°C temperature of water bath for the gelation of the membrane, and the operating pressure and feed solution of (R,S)‐2‐phenyl‐1‐propanol were 0.2 MPa and 1.5 mg/mL, respectively, over 90% of enantiomeric excess (e.e.) and 44.2 (mg/m2 h) of flux were obtained. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Polymeric coatings for protection of historic monuments: Opportunities and challenges
Authors: Sadat‐Shojai Mehdi , Ershad‐Langroudi Amir 
Published: February 2009

AbstractThe conservation and protection of historic monuments or culturally significant structures have recently attracted much attention from material scientists. This review is given of the various aspects of the monuments protection such as the main reasons of damaging and spoiling of the historical monuments, the factor of contact angle as one of the essential parameters in the selection of polymeric coatings, and some of usual types of polymeric materials used for monument protection. There has been growing interest in developing novel materials for using in protective fields. Nowadays, the polymeric coatings, especially those with high hydrophobicity, are widely used to decrease or even stop further deterioration of historical monument. This review presents some of the most well‐known polymers used as protective materials such as acrylics, alkoxysilanes, fluorinated polymers, and hybrid organic–inorganic coatings. Furthermore, hybrid organic–inorganic coatings as a new class of materials are increasingly interesting materials because of their extraordinary properties deriving from the combination of the different building blocks and it is attempted to focus on this materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of silica hybrid nanoparticles modified with photofunctional polymers and construction of colloidal crystals
Authors: Ishizu Koji , Tokuno Yoko , Lee Dong Hoon , Uchida Satoshi , Ozawa Masaaki 
Published: February 2009

AbstractPhotofunctional polymer as silane coupling agent (PFD) was prepared by free radical copolymerization of 4‐vinylbenzyl N,N‐diethyldithiocarbamate (VBDC) and methyl methacrylate (MMA) in the presence of (3‐mercaptopropyl)trimethoxysilane (MPMS) as chain transfer agent. Next, silane (SiO2; the average diameter Dn = 192 nm) nanoparticles was surface‐modified with PFD and 3‐(trimethoxysilyl)propyl methacrylate (γ‐MPS) by covalent bond formed between silanol groups and silane coupling agents. The PFD and γ‐MPS functionalizations changed the silica surface into hydrophobic nature and provided grafting initiation sites and methacrylate terminal groups respectively. We performed the construction of hybrid nanocomposites by using these modified SiO2 nanoparticles. It was found from electron microscopy observations that SiO2 particles were packed into repeating cubic arrangements in a poly(methyl methacrylate) (PMMA) matrix such as colloidal crystals. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Pulpal Regeneration Following Allogenic Tooth Transplantation into Mouse Maxilla
Authors: Unno Hideki , Suzuki Hironobu , Nakakura‐Ohshima Kuniko , Jung Han‐Sung , Ohshima Hayato 
Published: February 2009

AbstractAutogenic tooth transplantation is now a common procedure in dentistry for replacing a missing tooth. However, there are many difficulties in clinical application of allogenic tooth transplantation because of immunological rejection. This study aims to clarify pulpal regeneration following allogenic tooth transplantation into the mouse maxilla by immunohistochemistry for 5‐bromo‐2′‐deoxyuridine (BrdU) and nestin, and by the histochemistry for tartrate‐resistant acid phosphatase (TRAP). The upper right first molar (M1) of 2‐week‐old mice was extracted and allografted in the original socket in both the littermate and non‐littermate after the extraction of M1. Tooth transplantation weakened the nestin‐positive reactions in the pulp tissue that had shown immunoreactivity for nestin before operation. On postoperative Days 5–7, tertiary dentin formation commenced next to the preexisting dentin where nestin‐positive odontoblast‐like cells were arranged in all cases of the littermate group until Day 14, except for one case showing immunological rejection in the pulp chamber. In the non‐littermate group, bone‐like tissue formation occurred in the pulp chamber in addition to tertiary dentin formation until Day 14. The rate of tertiary dentin was 38%, and the rate of the mixed form of dentin and bone‐like tissue formation was 23% (the remainder was immunological rejection). Interestingly, the periodontal tissue recovered even in the case of immunological rejection in which the pulp chamber was replaced by sparse connective tissue. These results suggest that the selection of littermate or non‐littermate is decisive for the survival of odontoblast‐lineage cells and that the immunological rejection does not influence the periodontal regeneration. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Landmark‐Based Analysis of the Morphological Relationship Between Endocranial Shape and Traces of the Middle Meningeal Vessels
Authors: Bruner Emiliano , Mantini Simone , Ripani Maurizio 
Published: February 2009

AbstractThe morphogenesis and evolution of the cranium are the result of structural interactions among its components, leading to covariance between traits. Soft and hard tissues exert a reciprocal physical and physiological influence, leading to the final phenotype in terms of both ontogeny and evolution. The middle meningeal vessels, interfacing the brain and the braincase, provide an opportunity to study this network, even in extinct human species. Between and within‐species variations of the vascular patterns may be mechanically influenced by the cranial morphology (structural hypothesis) or else by actual physiological responses and adaptations, mostly related to oxygen supply and/or thermoregulation (functional hypothesis). In this analysis, we tested the relationship between neurocranial shape and the general morphology of the traces of the middle meningeal vessels in a modern human population, by using landmark‐based geometrical models. Although there are some neurocranial differences between groups with different vascular patterns, they are very small or not statistically significant. Only the depth of the imprints may be more influenced by the endocranial morphology. Even if the neurocranial differences among extinct hominids are definitely larger than those within the modern species, the present analysis suggests that it is unlikely that the differences in vascular patterns among the human species are related only to the effects of different neurocranial geometry. This is rather relevant when the marked development of the meningeal network in Homo sapiens is taken into account, compared with the patterns described for nonmodern human species. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Mitochondrial complementation preventing respiratory dysfunction caused by mutant mtDNA
Authors: Sato Akitsugu , Nakada Kazuto , Hayashi Jun‐Ichi 
Published: February 2009

AbstractThe mitochondrial theory of aging is the idea that age‐associated mitochondrial dysfunction is caused by accumulation of somatic mutations in mitochondrial DNA (mtDNA). However, mitochondria are considered to be a dynamic organelle that repeats fusion and fission. Through fusion and fission, there is an extensive and continuous exchange of mtDNA and its products between mitochondria. This mitochondrial complementation prevents individuals from expression of respiratory dysfunction caused by pathogenic mutant mtDNAs. Thus, the presence of mitochondrial complementation does not support the mitochondrial theory of aging. Moreover, the presence of mitochondrial complementation enables gene therapy for mitochondrial diseases using nuclear transplantation of zygotes. © 2009 International Union of Biochemistry and Molecular Biology, Inc.
Role of peptide–peptide interactions in stabilizing peptide‐wrapped single‐walled carbon nanotubes: A molecular dynamics study
Authors: Chiu Chi‐cheng , Dieckmann Gregg R. , Nielsen Steven O. 
Published: February 2009

AbstractSingle‐walled carbon nanotubes (SWNTs) have unique properties and are projected to have a major impact in nanoscale electronics, materials science, and nanomedicine. Yet, these potential applications are hindered by the need for sample purification to separate SWNTs from each other and from metallic catalyst and amorphous carbon present in as‐synthesized samples. Common purification strategies involve dispersing SWNTs as individual tubes in aqueous solution. Towards this end, a designed helical peptide was shown to be excellent at dispersing SWNTs. However, the molecular details of the peptide‐SWNT and peptide‐peptide interactions await elucidation. Here we explore these molecular interactions using fully atomistic molecular dynamics simulations of peptide‐wrapped SWNTs. We characterize the interactions by measuring the aromatic residue‐to‐SWNT surface distance, the peptide amphiphilicity, the peptide‐SWNT crossing angle, the peptide‐SWNT contact area, the peptide helix axis‐to‐axis distance, and the inter‐peptide hydrogen bonding. We find that the peptides collectively tilt with respect to the SWNT long axis, are α‐helical, and form interpeptide hydrogen bonds through their lysine and glutamate residues, which helps to stabilize the multipeptide/SWNT complex. All hydrophobic residues interact with the SWNT and are sequestered from water. The picture that emerges from this study gives insight into subsequent peptide design. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 156–163, 2009.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
A preliminary study of human paraoxonase and PON 1 L/M55–PON 1 Q/R 192 polymorphisms in Turkish patients with coronary artery disease
Authors: Kaman Dilara , İlhan Necip , Metin Kerem , Akbulut Mehmet , Üstündağ Bilal 
Published: February 2009

AbstractParaoxonase 1 (PON 1) is a high‐density lipoprotein (HDL)‐associated enzyme with antioxidant function protecting low‐density lipoprotein (LDL) from oxidation. PON 1 has two amino acid polymorphisms in coding region; L/M 55 and Q/R 192. These polymorphisms modulate paraoxonase activity of the enzyme. PON 1 activity decreases in coronary artery disease (CAD). In the present study, distribution of PON 1 L/M 55 and Q/R 192 polymorphisms and the effect of these polymorphisms on the activities of PON 1, and on the severity of CAD in 277 CAD (+) patient and 92 CAD (−) subjects were examined. PON 1 L/M 55 and Q/R 192 genotypes were determined by PCR, RFLP and agarose gel electrophoresis techniques. Genotype distributions and allele frequencies for PON 1 Q/R 192 polymorphism were not significantly different between controls and CAD (+) patient group (p > 0.05), but in genotype and allele distribution of PON 1 L/M55 polymorphism, there was significantly difference among groups (p < 0.05). Genotype distributions for both polymorphisms were not significantly different between subgroups of single‐vessel disease (SVD), double‐vessel disease (DVD) and triple‐vessel disease (TVD). Serum PON 1 activity was lower in CAD (+) group than in controls and this was also statistically significant (p < 0.001). In both groups, the highest PON activities were detected in LL and RR genotypes. In summary, our results suggest that there is an association between the PON 1 L/M 55 polymorphism of paraoxonase and CAD in Turkish patients but not with PON 1 Q/R 192 polymorphism. However, it is hard to correlate these polymorphisms and severity of CAD. Copyright © 2009 John Wiley & Sons, Ltd.
Regulation of inflammation in the adipose tissue in cancer cachexia: effect of exercise
Authors: Lira Fábio S. , Rosa José C. , Zanchi Nelo E. , Yamashita Alex S. , Lopes Renato D. , Lopes Antonio C. , Batista Miguel L. , Seelaender Marília 
Published: February 2009

AbstractThe paraneoplastic syndrome of cachexia is considered a degenerative chronic inflammatory disease, being deeply related to the increase of pro‐inflammatory factors, especially tumour necrosis factor alpha (TNF‐α). It is known that the adipose tissue is affected by cachexia and contributing with the secretion of pro‐inflammatory factors which reach the adjacent tissues and the circulation. The effect of pro‐inflammatory factors is balanced by the effect of anti‐inflammatory factors, such as interleukin 10 (IL‐10). The IL‐10/TNF‐α ratio has been recently postulated as a marker for the assessment of the degree of inflammation, which correlates with disease‐associated morbidity and mortality. In order to counteract inflammation in chronic disease, our group has currently adopted chronic endurance exercise in models of cancer cachexia and chronic heart failure. Since it is clear that white adipose tissue is strongly implicated in the secretion of both pro‐ and anti‐inflammatory factors in disease, we chose to address its contribution to cachexia‐related inflammation and the effect of endurance training on the capacity of cytokine expression and secretion by this tissue. Our results show an enhancement of IL‐10 adipose tissue content, and increased IL‐10/TNF‐α ratio induced by endurance training. The mechanisms are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
A Shielding Topology Stabilizes the Early Stage Protein–Mineral Complexes of Fetuin‐A and Calcium Phosphate: A Time‐Resolved Small‐Angle X‐ray Study
Authors: Rochette Christophe N. , Rosenfeldt Sabine , Heiss Alexander , Narayanan Theyencheri , Ballauff Matthias , Jahnen‐Dechent Willi 
Published: February 2009

AbstractBiomineralization mechanisms: The serum protein α2‐HS glycoprotein/fetuin‐A is an important inhibitor that prevents pathological mineralization of calcium phosphate in soft tissues and in the extracellular fluid. TR‐SAXS and stopped‐flow analysis were used to monitor the growth of protein mineral particles nucleating from supersaturated salt solutions in the presence of the protein. It was found that fetuin‐A did not influence the formation of mineral nuclei, but did prevent the aggregation of nuclei and thus mineral precipitation.magnified imageWe report on the earliest stages of the formation of complexes of calcium phosphate in the presence of the serum protein α2‐HS glycoprotein/fetuin‐A termed calciprotein particles (CPPs). Time‐resolved small‐angle X‐ray scattering (TR‐SAXS) and stopped‐flow analysis were used to monitor the growth of protein mineral particles nucleating from supersaturated salt solutions. It was found that fetuin‐A did not influence the formation of mineral nuclei. However, fetuin‐A did prevent the aggregation of nuclei and thus mineral precipitation. Hence, fetuin‐A shielded spontaneously formed mineral nuclei, leading to stable calciprotein particles in the first stage of mineralization. Fetuin‐A is therefore critically required during the earliest stages of the formation of protein–mineral complexes in order to prevent uncontrolled mineralization.