bluuebunny/crossref_metadata_2025_split huggingface dataset:
The interaction of zinc pyrithione with mitochondria from rat liver and a study of the mechanism of inhibition of ATP synthesis
Authors: Bragadin Marcantonio , Manente Sabrina , Marton Daniele , Cima Francesca , Rigobello Maria Pia , Bindoli Alberto 
Published: October 2003

AbstractThe interactions of zinc pyrithione (ZnPT) with rat liver mitochondria were investigated. Since most of the organometals, principally the triorganotin compounds, induce the inhibition of ATP synthesis in rat liver mitochondria, the efficiency of the ATP synthesis was measured in the presence of ZnPT. The results indicate that ZnPT inhibits ATP synthesis. In order to individuate the molecular mechanism responsible for a failure in ATP synthesis, all of the steps involved in ATP synthesis or in its inhibition were investigated separately, i.e. the respiratory chain, the uncoupling effect, the ATPase and the opening of a permeability pore. All of the steps are inhibited by ZnPT, but the crucial one, the one responsible for the inhibition of ATP synthesis, seems to be the opening of a small‐size cyclosporine‐sensitive pore. The results are different from those obtained using other organometallic compounds, but are similar to those obtained when using methylmercury and Zn2+, both of which also induce the opening of a cyclosporine‐sensitive pore. However, although Hg2+ and Zn2+ would seem to induce the opening of large‐size pores, in the case of ZnPT the pores involved are of a small size. This action mechanism seems to exclude the possibility that ZnPT is a deliverer of Zn2+. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Bis(triphenyltin) oxalate
Authors: Diop Libasse , Mahieu Bernard , Mahon Mary F. , Molloy Kieran C. , Okio Kochikpa Y. A. 
Published: October 2003

AbstractThe centrosymmetric structure of bis(triphenyltin) oxalate contains essentially four‐coordinated tin and monodentate carboxylate moieties despite a Mössbauer quadrupole splitting of 2.8 mm s−1 and a 119Sn NMR chemical shift of −503 ppm. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Bis(norfloxacin)dilead(II) tetranitrate, [Pb2(H‐Norf)2(ONO2)4]
Authors: Chen Zhen‐Feng , Zhou Hong‐Li , Liang Hong , Li Yan , Xiong Ren‐Gen , You Xiao‐Zeng 
Published: October 2003

AbstractThe centrosymmetric binuclear structure of [Pb2(H‐Norf)2(ONO2)4]shows the geometry around each lead(II) atom to be distorted trigonal bipyramidal with Pb–O distances ranging from 2.357(3) to 2.769(4) Å. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Crystal structure of the first alkaline earth metal compound with the antibacterial drug sulfasalazine: [Sr(H‐Sulf)(H2O)6](H‐Sulf)·3H2O
Authors: Chen Zhen‐Feng , Kang Shu , Liang Hong , Yi Feng , Yu Kai‐Bei , Xiong Ren‐Gen , You Xiao‐Zeng 
Published: October 2003

AbstractThe structure of [Sr(H‐Sulf)(H2O)6](H‐Sulf)·3H2O features a seven‐coordinated distorted capped octahedral geometry around strontium(II) with SrO distances ranging from 2.445(5) to 2.606(5) Å. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Bis(indole‐3‐acetato)(1,10‐phenanthroline) cadmium(II)
Authors: Chen Zhen‐Feng , Huang Ling , Liang Hong , Hu Rui‐Xiang , Shi Shao‐Ming , Fun Hoong‐Kun 
Published: October 2003

AbstractThe structure of Cd(phen)(indole‐3‐acetato)2 has twofold symmetry and features a six‐coordinated distorted octahedral geometry around cadmium(II), defined by an N2O4 donor set, with Cd–O distances ranging from 2.214(3) to 2.526(3) Å. Copyright © 2003 John Wiley & Sons, Ltd.
Short communication: Carbon–Silicon coupling between fluorenyl Grignard reagents and dichlorosilanes for synthesis of novel copolymers and chemical properties of the copolymers
Authors: Kitamura Naoyuki , Yamamoto Takakazu 
Published: October 2003

AbstractA series of novel silicon‐containing fluorene polymers has been prepared by carbon–silicon (C–Si) coupling between fluorenyl Grignard reagents and dichlorosilanes, and their optical and thermal properties have been studied. Copyright © 2003 John Wiley & Sons, Ltd.
Palladium‐catalysed cyclocarbonylation reactions in dimethyl carbonate, an eco‐friendly solvent and ring‐opening reagent
Authors: Vasapollo Giuseppe , Mele Giuseppe , Maffei Annamaria , Sole Roberta Del 
Published: October 2003

AbstractDimethyl carbonate (DMC) is used as an alternative and eco‐friendly solvent for selective cyclocarbonylation reactions of allyl phenol derivatives for the synthesis of lactones; in some cases, depending on the reaction condition, DMC behaves as a ring‐opening reagent producing methoxycarbonyl compounds. Copyright © 2003 John Wiley & Sons, Ltd.
Demethylation of methylarsenic species by Mycobacterium neoaurum
Authors: Lehr Corinne R. , Polishchuk Elena , Radoja Una , Cullen William R. 
Published: October 2003

AbstractMycobacterium neoaurum demethylates both methylarsonic acid and methylarsonous acid to mixtures of arsenate and arsenite. After 28 days of incubation, the yields of inorganic arsenic were 27% from arsenate and 43% from arsenite. A time study of the demethylation of methylarsonic acid by M. neoaurum showed that demethylation occurs rapidly during the growth and stationary phases of the bacterium, and indicates that MMA(V) is reductively demethylated to arsenite. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Crystal structure of a two‐dimensional coordination polymer: tetraaqua‐1,2,4,5‐benzenetetracarboxylato(pyrazine)dizinc(II) dihydrate
Authors: Yang Shi‐Yao , Long La‐Sheng , Huang Rong‐Bin , Zheng Lan‐Sun , Ng Seik Weng 
Published: October 2003

AbstractThe structure of {[Zn2(1,2,4,5‐btc)(pz)(H2O)4]·2(H2O)}n (1,2,4,5‐btc = 1, 2, 4, 5‐benzenetetracarboxylate, pz = pyrazine) is a two‐dimensional coordination network. The zinc(II) center is in a distorted octahedral NO5 coordination environment that is defined by one nitrogen atom of pyrazine, three oxygen atoms of carboxyl groups from 1,2,4,5‐benzenetetracarboxylate tetraanions and two water molecules. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Tris(η5‐cyclopentadienyl)‐tetrahydrofuran‐praseodymium
Authors: Junk Peter C. 
Published: October 2003

AbstractThe title compound is mononuclear with three η5‐cyclopentadienyl ligands and one tetrahydrofuran ligand. If the centroids of the cyclopentadienyl ligands are taken as the point of binding to praseodymium, then the environment about the metal centre is considered as a distorted tetrahedron. Copyright © 2003 John Wiley & Sons, Ltd.
Efficiency of ultraviolet/ozone treatments in the improvement of the dyeability and light fastness of wool
Authors: Micheal M. N. , El‐Zaher N. A. 
Published: October 2003

AbstractIn this study, we evaluated the effect of ultraviolet/ozone treatments for different times on the characteristics of wool fabrics with respect to wettability, permeability, yellowness index, and weight loss. The beneficial effects of this treatment on dyeability, color parameters, light fastness characteristics, and the change in color difference after exposure of the treated dyed samples to artificial daylight for about 150 h was investigated. The results indicated that the improvement in wetting processes may have been due to to surface modifications; this meant that an increase in the amorphousity of the treated samples, the oxidation of the cystine linkage on the surface of the fabrics, and the formation of free‐radical species encouraged dye penetration and aggregation inside the fiber pores as well as bond formation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3668–3675, 2003
Surface plasmon resonance spectroscopic comparison of spiroxazine monolayer and polymeric thin film
Authors: Hur Youngjune , Lee Minsu , Jin Sung‐Ho , Gal Yeong‐Soon , Kim Jae‐Ho , Kim Sung‐Hoon , Koh Kwangnak 
Published: October 2003

AbstractPhotochromic dye has recently attracted much interest in optical applications because of its reversible photoswitching properties by light irradiation. To apply those aspects of photochromism to actual photonic devices, the form of the thin film must be favorable to the photochromic molecular system. In this study, a polymeric thin film and self‐assembled monolayer were constructed with a photochromic spiroxazine derivative that is well known for its good fatigue properties. Their photoisomerization properties were characterized through surface plasmon resonance (SPR). As a result of ultraviolet irradiation to these thin films, the SPR angle shift clearly appeared as the optical thickness (Refractive index × Geometrical thickness) change in both of the films. The Fresnel calculation based on measurement results showed that the angle shift of the polymeric thin film mainly corresponded to the change of the refractive index. For the spiroxazine monolayer, the geometrical thickness change caused the resonance angle to shift dominantly. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3459–3465, 2003
Tentative study on kinetics of bulk polymerization of methyl methacrylate in presence of montmorillonite
Authors: Liu Guo‐Dong , Zhang Liu‐Cheng , Qu Xiong‐Wei , Wang Bo‐Tao , Zhang Yan 
Published: October 2003

AbstractThe kinetics of the bulk polymerization of methyl methacrylate (MMA) in the presence of montmorillonite (MMT) were studied. The effect of MMT on the radical polymerization of MMA was researched by determining the polymerization rate dilatometrically. It was assumed that there were both bimolecular and monomolecular termination processes involved in the termination of the radicals in the polymerization. It was found that a lower benzoyl peroxide (BPO) concentration promotes a higher fraction of monomolecular mode in chain termination. The results show that there is an optimal ratio of MMT to initiator that increases the bulk polymerization rate of MMA. The X‐ray results show that the layer structure of the formed PMMA–MMT composites was also affected by the BPO concentration. With lower initiator concentration, less pronounced layer structure will be observed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3690–3695, 2003
A rheological and morphological study of treated PVC
Authors: Place S. , Fugit J. L. , Prochazka F. , Taverdet J. L. 
Published: October 2003

AbstractThis article reports a rheological and morphological study of poly(vinyl chloride) (PVC) that was subjected to a treatment capable of decreasing the simultaneous mass transfers occurring between liquid food (or simulant) and PVC packaging. The storage modulus (G′), loss modulus (G″), and the loss angle (tan δ), have been used to determine the glass transition temperature using a Rheometric Scientific Dynamic Analyzer. Young's modulus was measured on a dynamometer, and a morphological characterization was carried out with an optical microscope. The obtained results show that treated PVC behaves like a composite material, which is in agreement with a previously established model. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3497–3502, 2003
Effect of ultrafine, fully vulcanized acrylate powdered rubber on the mechanical properties and crystallization behavior of nylon 6
Authors: Ding Xuejia , Xu Riwei , Yu Dingsheng , Chen Hong , Fan Run 
Published: October 2003

AbstractNylon 6 (PA6) is a widely used engineering plastic. However, its poor toughness limits its applications. Therefore, toughening PA6 has been a point of interest in the field of PA6 modification. Generally, toughening a plastic with an elastomer reduces the stiffness and heat distortion temperature of the matrix. It has been an important goal of polymer researchers to find a way of toughening PA6 without reductions in its stiffness and heat distortion temperature. In this study, a new kind of material—an ultrafine, fully vulcanized acrylate powdered rubber (UFAPR)—was used to toughen PA6 through melt blending. The influence of UFAPR on the isothermal crystallization kinetics and nonisothermal crystallization behavior of PA was studied with differential scanning calorimetry. The results showed that, with the addition of a little UFAPR, the crystallization rate of PA could be increased, the crystallization temperature could be augmented, and the crystal size distribution of the crystal grain could be narrowed. The changes in the free energy perpendicular to the crystal nucleus were consistent with the results of an Avrami equation according to the theory of Hoffman. The unit surface free energy of the radially developing crystal spherulites decreased with an increasing amount of UFAPR. The results for the mechanical properties, crystalline structure, and crystallization kinetics of PA6/UFAPR composites showed that UFAPR was not only a good toughening agent for PA6 but also an excellent nucleation agent for PA6. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3503–3511, 2003
Morphology of nylon 6/acrylonitrile–butadiene–styrene blends compatibilized by a methyl methacrylate/maleic anhydride copolymer
Authors: Araújo E. M. , Hage E. , Carvalho A. J. F. 
Published: October 2003

AbstractThe morphologies of nylon 6/acrylonitrile–butadiene–styrene blends compatibilized with a methyl methacrylate/maleic anhydride copolymer, with 3–20 wt % maleic anhydride, were examined by transmission electron microscopy. Some staining techniques were employed for identifying the various phases. The binary blends were immiscible and exhibited poor mechanical properties that stemmed from the unfavorable interactions among their molecular segments. This produced an unstable and coarse phase morphology and weak interfaces among the phases in the solid state. The presence of the copolymer in the blends clearly led to a more efficient dispersion of the acrylonitrile–butadiene–styrene phase and consequently optimized Izod impact properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3512–3518, 2003
Metal‐ion‐retention properties of the poly(2‐acrylamido‐2‐methyl‐1‐propanosulfonic acid‐co‐4‐vinyl pyridine) resin
Authors: Rivas Bernabé L. , Villegas Sandra 
Published: October 2003

AbstractThe water‐insoluble resin poly(2‐acrylamido‐2‐methyl‐1‐propanosulfonic acid‐co‐4‐vinyl pyridine), through a radical polymerization solution, was synthesized with ammonium persulfate as an initiator and N,N‐methylene bisacrylamide as a crosslinking reagent. The metal‐ion‐retention properties were studied by batch and column equilibrium procedures for the following metal ions: Hg(II), Cu(II), Cd(II), Zn(II), Pb(II), and Cr(III). These properties were investigated under competitive and noncompetitive conditions. The effects of the pH, maximum retention capacity, and regeneration capacity were studied. The resin showed a high retention ability for Hg(II) ions at pH 2.0. The retention of Hg(II) ions from a mixture of ions was greater than 90%. The resin showed a high selectivity for Hg(II) with respect to other metal ions. The Hg(II)‐loaded resin was able to be recovered with 4M HClO4. The retention capacity was kept after four cycles of adsorption and desorption. The retention properties for Hg(II) were very similar with the batch and column methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3556–3562, 2003
Kinetics and parameters affecting degradation of purified natural rubber
Authors: Phetphaisit Chor. Wayakron , Phinyocheep Pranee 
Published: October 2003

AbstractPurified natural rubber (PNR) was obtained by treatment of high ammonia NR latex with proteinase enzyme for 24 h, followed by double centrifugation. The PNR was later redispersed into latex form with 0.5% (w/v) sodium dodecyl sulfate. The degradation of PNR was performed in latex form by using a combination of the radical initiator potassium persulfate (K2S2O8) and propanal. The intrinsic viscosity [η] of the degraded rubber or liquid rubber that was obtained depended on various parameters such as the initiator concentration, amount of propanal, dry rubber content, reaction time, and temperature. It was found that the [η] of the rubber can be reduced from 4.31 to 0.19 for the PNR after a 25‐h reaction time using 5% dry rubber content PNR latex, 1 part per hundred rubber (phr) of K2S2O8, and 32 phr of propanal at 80°C. The kinetics of the degradation reaction were investigated. The highest rate constant found was 11.33 × 10−2 s−1. The activation energy of the degradation reaction was 76.56 kJ mol−1. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3546–3555, 2003
Synthesis, thermal behavior, and cone calorimetry of organophosphorus epoxy materials
Authors: Hussain M. , Varley R. J. , Zenka M. , Simon G. P. 
Published: October 2003

AbstractAn organophosphorus epoxy resin with diglycidyl ether of bisphenol A (DGEBA), which has improved fire performance, was synthesized from the reaction of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide and DGEBA. The epoxy resin was then cured with an isomeric mixture of 3,5‐diethyltoluene‐2,4‐diamine and 3,5‐diethyltoluene‐2,6‐diamine. The reaction kinetics were measured by Fourier transform IR, 1H‐NMR, and differential scanning calorimetry. The effect of the incorporation of a phosphorus species into the epoxy network structures was also measured using thermogravimetric, thermal conductivity, and dynamic mechanical thermal analyses. The fire performance was measured using cone calorimetry, which showed that a significant improvement was achieved by the addition of only 1–4% phosphorus into the epoxy backbone. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3696–3707, 2003
Morphology and properties of soy protein plastics modified with chitin
Authors: Zheng Hua , Tan Zhan'ao , Ran Zhan Yuan , Huang Jin 
Published: October 2003

AbstractA series of bioplastics from isolated soy protein (SPI) and chitin (CH) was prepared with glycerol as a plasticizer by blending and compression molding. Their morphology and properties were investigated by wide‐angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC), dynamical mechanical thermal analysis (DMTA), scanning electron microscopy (SEM), and tensile and water‐absorption tests. The added CH as a filler cannot strongly interact with SPI molecules and, hence, this results in phase separation in blends. However, the rigid nature of the CH molecules enhanced the tensile strength and Young's modulus, but decreased the breaking elongation of the materials. When the CH content was higher than 10 wt %, the water absorption of the blends were obviously lower than that of the sheets without CH, resulting from the formation of a CH framework in the blends. Both soy protein and CH exhibit good biodegradability, biocompatibility, and bioactivity, and their composites may become a promising biomaterial. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3676–3682, 2003
Preparation and characterization of poly(ether ester) thermoplastic elastomers containing the 2,6‐naphthalenedicarboxyl group
Authors: Ahn Tae Hwan , Park Yun Heum , Kim Seong Hun , Baik Doo Hyun 
Published: October 2003

AbstractPoly(ether ester) elastomers (PEEs) were synthesized in which dimethyl terephthalate (DMT) was the primary diester compound in the hard segment (H/S) and dimethyl 2,6‐naphthalene dicarboxylate (NDC), which has a more rigid aromatic chemical structure than DMT, was the secondary diester in the H/S. The block PEEs with poly(tetramethylene terephthalate) (PTMT) and/or poly(tetramethylene 2,6‐naphthalate) (PTMN) as the H/S and poly(tetramethylene ether glycol terephthalate) (PTMEGT) as the soft segment (S/S) were synthesized through transesterification and polycondensation of DMT, NDC, 1,4‐butanediol (BD), and poly(tetramethylene ether) glycol (PTMEG) of molecular weight 1000. The melting temperature and heat of fusion of the PEEs decreased with increasing NDC content up to an NDC content of 44.4% in the H/S, but increased on further increase of the NDC content. In addition, the higher the fraction of NDC in the H/S, the higher the glass transition temperature of the copolymer. X‐ray diffraction analysis revealed that the crystallinity of the sample decreases as the NDC content in the H/S is increased relative to that of DMT. Increasing the PTMN content in the H/S reduced the effect of UV photodegradation on the elongation at break. The results show that the introduction of the NDC component into the H/S as a secondary diester compound improves the UV resistance of the resulting PEE. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3473–3480, 2003
Synthesis and properties of the copolymer of acrylamide with 2‐acrylamido‐2‐methylpropanesulfonic acid
Authors: Liu Yang , Xie Jian‐Jun , Zhang Xin‐Ying 
Published: October 2003

AbstractA cross‐linked copolymer of acrylamide (AM) with 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS) was prepared by solution polymerization. In this reaction, potassium persulfate (PPS) and N,N′‐methylenebisacrylamide (NMBA) were used as initiator and cross‐linker, respectively. This copolymer, poly(acrylamide‐co‐2‐acrylamido‐2‐methylpropanesulfonic acid) (PAMA), can absorb up to 1749 g/g of dry polymer in distilled water and 87 g/g of dry polymer in 0.9 wt % NaCl aqueous solution at room temperature. The PAMA also has excellent performance in absorbing pure alcohols. Its absorbencies in methanol and glycol are about 310 g/g and 660 g/g, respectively. The effects of various salt solutions on the swelling properties were studied systematically, and the relationship between the absorbency and the concentrations of the different salt solutions can be expressed as Q = kcn. Experimental results indicate that the absorbencies were stable at different water temperatures. The swelling rates of the copolymer in distilled water and a water/ethanol mixture (Vwater:Valcohol = 1:1) were also investigated, and the results showed that PAMA could absorb 992 g of distilled water per gram of dry polymer and 739 g of water/ethanol mixture per gram of dry polymer in five minutes. The PAMA has such good water retention at higher temperatures that the swollen gel can retain 71.6 and 49.5% of the maximum absorbency after being heated for 9 hours at 60 and 80 °C, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3481–3487, 2003
Synthesis and characterization of calcium‐containing poly(urethane‐urea)s
Authors: Jayakumar R. , Lee Y.‐S. , Nanjundan S. 
Published: October 2003

AbstractA calcium salt of mono(hydroxyethoxyethyl)phthalate [Ca(HEEP)2] was synthesized by the reaction of diethylene glycol, phthalic anhydride, and calcium acetate. Four different bisureas like hexamethylene bis(ω,N‐hydroxyethylurea), tolylene 2,4‐bis(ω,N‐hydroxyethylurea), hexamethylene bis(ω,N‐hydroxypropylurea), and tolylene 2,4‐bis(ω,N‐hydroxypropylurea) were prepared by reacting ethanolamine or propanolamine with hexamethylene diisocyanate (HMDI) or tolylene 2,4‐diisocyanate (TDI). Calcium‐containing poly(urethane‐urea)s (PUUs) were synthesized by reacting HMDI or TDI with 1:1 mixtures of Ca(HEEP)2 and each of the bisureas using di‐n‐butyltin dilaurate as a catalyst. The PUUs were well characterized by Fourier transform infrared, 1H‐ and 13C‐NMR (nuclear magnetic resonance), solid‐state 13C cross‐polarization–magic angle spinning NMR, viscosity, solubility, elemental, and X‐ray diffraction studies. Thermal properties of the polymers were also studied by using thermogravimetric analysis and differential scanning calorimetry. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3488–3496, 2003