bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biomechanical models for the pathogenesis of specific distal upper extremity disorders
Authors: Steven Moore J. 
Published: August 2002

AbstractBackgroundKnowledge of the pathogenesis of most disorders that occur in the distal upper extremity is generally lacking. The individual roles of postulated etiologic factors, such as biomechanical or psychosocial exposures, are poorly understood and their potential interactions even less so. This article proposes biomechanical or physiological models of pathogenesis for specific distal upper extremity disorders.MethodsTendon entrapment of the dorsal wrist compartments (tenosynovitis), peritendinitis, lateral epicondylitis, and carpal tunnel syndrome are common specific neuromusculoskeletal disorders of the upper extremities observed among workers. The normal anatomy and function of the targeted structures is considered the initial state; their pathology is considered the final state. Using biomechanical or physiological principles combined with clinical observations and experimental studies, pathways leading from the initial state to the final state are proposed. Each model defined a critical biomechanical or physiological attribute that was considered to best characterize ‘dose.’ Two temporal patterns of exposure (duration vs. repetition) were used to characterize ‘dosage.’ The roles of long‐term exposure vs. unaccustomed work were mentioned, but not incorporated into the models.ResultsCompressive force transmitted to the extensor retinaculum was considered the critical factor in the model for tendon entrapment at the dorsal wrist compartments. Two models were proposed for lateral epicondylitis. One emphasized the role of eccentric exertions; the other emphasized contact pressure from the radial head. The model for peritendinitis relied on localized muscle fatigue. Seven plausible models were presented for carpal tunnel syndrome.ConclusionsIt is possible to propose biologically plausible models of pathogenesis that are both coherent with current knowledge of tissue responses and consistent with clinical observations; however, more than one model was plausible for some conditions. Additional research is needed to determine which, if any, of the proposed models might be correct. Such models may be useful to health care providers and ergonomists in the context of primary, secondary, or tertiary prevention. Am. J. Ind. Med. 41:353–369, 2002. © 2002 Wiley‐Liss, Inc.
Effects of iron on the degradation of triphenyltin by pyoverdins isolated from Pseudomonas chlororaphis
Authors: Yamaoka Yukiho , Inoue Hiroyuki , Takimura Osamu , Oota Sinji 
Published: August 2002

AbstractThe yellow compound pyoverdin was isolated from the bacteria Pseudomonas chlororaphis, isolated from mud in Japan. A study of the effects of iron, phosphorus, manganese and zinc on degradation of triphenyltin (TPT) by pyoverdin (20 mg) was carried out in distilled water (30 ml) containing 6 µg l−1 concentration of TPT at 20 °C for 48 or 96 h. The organotins in water were analyzed by gas chromatograph–mass spectrometry in the selected ion mode. The degradation of TPT by pyoverdin decreased with increase of phosphorus at 0–35 mg l−1 and Fe‐EDTA at 0–2 mg l−1 concentrations. Also, degradation of diphenyltin by pyoverdin decreased with increase of Mn‐EDTA at 0–1 mg l−1 and Zn‐EDTA at 0–1 mg l−1. On the other hand, degradation of TPT by pyoverdin was found to be unaffected by manganese and zinc in water. Copyright © 2002 John Wiley & Sons, Ltd.
Carbonylrhodium complexes of pyridine ligands and their catalytic activity towards carbonylation of methanol
Authors: Kumari Nandini , Sharma Manab , Das Pankaj , Dutta Dipak Kumar 
Published: August 2002

AbstractThe cis‐[Rh(CO)2ClL] (1) complexes, where L = 2‐methylpyridine (a), 3‐methylpyridine (b), 4‐methylpyridine (c), 2‐phenylpyridine (d), 3‐phenylpyridine (e), 4‐phenylpyridine (f), undergo oxidative addition reactions with various electrophiles, like CH3I, C2H5I, C6H5CH2Cl or I2, to yield complexes of the types [Rh(CO)(COR)ClXL] (2) (where R = CH3 (i), C2H5 (ii), X = I; R = C6H5CH2 (iii), X = Cl) or [Rh(CO)ClI2L] (3) and [Rh(CO)2ClI2L] (4). The pseudo‐first‐order rate constants of CH3I addition with complexes 1 containing pyridine (g) and 2‐substituted pyridine (a and d) ligands were found to follow the order pyridine >2‐methylpyridine >2‐phenylpyridine. The catalytic activity of complexes 1 containing different pyridine ligands (a–g) on carbonylation of methanol was studied and, in general, a higher turnover number was obtained compared with that of the well‐known species [Rh(CO)2I2]−. Copyright © 2002 John Wiley & Sons, Ltd.
Effect of ultrasound on electrochemically initiated acrylamide polymerization
Authors: Yildiz Gülcemal , Çatalgil‐Giz Huceste , Giz Ahmet 
Published: August 2002

AbstractAcrylamide was polymerized under different voltages with ammonium persulfate as the initiator at room temperature. The polymerization reactions were performed in two different ways. In one case, the reaction was performed in a classical, three‐electrode electrochemistry cell, and in the other, the cell was placed in an ultrasonic bath, and ultrasound was applied during the reaction. Both reactions were performed at room temperature. The conversion was rapid; even in the normal electrochemical case, the composite rate constant was comparable to the case with free‐radical polymerization of acrylamide at 50–70°C. When ultrasound was applied, the conversion values increased more. The heterogeneity index and molecular weights of the polymers produced with and without ultrasound were measured with size exclusion chromatography. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 83–89, 2002; DOI 10.1002/app.10233
Swelling behavior of hydrogels for colon‐site drug delivery
Authors: Yin Yihua , Yang Yajiang , Xu Huibi 
Published: August 2002

AbstractHydrogels based on n‐alkyl methacrylate esters (n‐AMA), acrylic acid, and acrylamide crosslinked with 4,4′‐di(methacryloylamino)azobenzene were prepared. Swelling behavior of the hydrogels was studied by the immersion of slabs in buffered solutions at pH 2.2–7.4. The diffusion of water into the slabs was discussed on the stress relaxation model of polymer chains. The results obtained are in good agreement with Schott's second‐order diffusion kinetics. The constants A and B of Schott's kinetics equation depend on the balance of hydrophobicity/hydrophilicity, the rigidity/flexibility, and the degree of crosslinking. The factors that exert the greatest influence on the swelling behavior of the gels include the degree of crosslinking, the lengths of the n‐AMA side chains, and pH values. By adjusting these factors, the degree of swelling of the hydrogels in the small intestine can be controlled, and consequently the drugs may avoid being released before arriving in the colon. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2835–2842, 2002; DOI 10.1002/app.10259
Polymeric sodium alginate interpenetrating network beads for the controlled release of chlorpyrifos
Authors: Kulkarni Anandrao R. , Soppimath Kumaresh S. , Aminabhavi Tejraj M. , Dave Ashok M. 
Published: August 2002

AbstractNovel polymeric sodium alginate (Na‐Alg) interpenetrating network (IPN) beads have been prepared by crosslinking Na‐Alg blend with gelatin (GE) or egg albumin (EA) using glutaraldehyde (GA) as the crosslinking agent. These beads were used for the controlled release of chlorpyrifos. The swelling experiments were performed in water at different temperatures, and these data were used to calculate the molecular mass (MC) between crosslinks as well as diffusion coefficients. Diffusion coefficients calculated from desorption data were lower by about two orders of magnitude than those calculated from sorption results. Higher values of MC were obtained for the gelatin‐based IPNs than the neat Na‐Alg and egg albumin‐based matrices. Size of the beads did not vary significantly either by the network or by increasing the exposure time to the crosslinking agent. The scanning electron microscopy (SEM) was used to understand the surface characteristics of the beads. Differential scanning calorimetry (DSC) indicated a molecular level dispersion of chlorpyrifos in the polymer matrix. The percentage entrapment efficiency showed a dependence on the type of network polymer as well as time of exposure to the crosslinking agent. The encapsulation efficiency decreased with an increase in time of exposure to the crosslinking agent. In vitro release experiments have been performed to follow the release kinetics of chlorpyrifos from the matrices. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 911–918, 2002
Synthesis and properties of novel phosphorus‐containing bismaleimide/epoxy resins
Authors: Shu Wei‐Jye , Yang Bo‐Yi , Chin Wei‐Kuo , Perng Li‐Hsiang 
Published: August 2002

AbstractA novel soluble phosphorus‐containing bismaleimide (BMI) monomer, bis(3‐maleimidophenyl)phenylphosphine oxide (BMIPO), was synthesized by the imidization of bis(3‐aminophenyl) phenylphosphine oxide, in which its structural characterization was identified with 1H‐NMR, 13C‐NMR, and Fourier transform infrared spectra. The BMIPO resin, with five‐membered imide rings and high phenyl density, was an excellent flame retardant with a high glass‐transition temperature (Tg), onset decomposition temperature, and limited oxygen index. In phosphorus‐containing BMI/epoxy/4,4′‐methylene dianiline (DDM)‐cured resins, homogeneous products were obtained from all proportions without phase separation. Because of the higher reactivity of BMIPO/DDM relative to that of 4,4′‐bismaleimidodiphenylmethane (BMIM)/DDM, the increase in the BMIPO/BMIM ratio in this blending resin increased the recrosslinking hazards of the postcuring stage and so lowered the Tg value and thermal stability. The thermal stability of the BMI/epoxy‐cured system was lower than that of the epoxy‐cured system because of the introduction of a phosphide group into BMIPO, whereas for the Tg value and flame retardancy, the former was significantly higher than the latter: the higher the BMIPO content in the blend, the higher the flame retardancy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2080–2089, 2002; DOI 10.1002/app.10607
Investigation of microstructure of the N‐vinyl‐2‐pyrrolidone/methyl methacrylate copolymers by NMR spectroscopy
Authors: Brar A. S. , Kumar Rajeev 
Published: August 2002

AbstractThe copolymers containing N‐vinyl‐2‐pyrrolidone (V) and methyl methacrylate (M) units of different compositions were synthesized by free radical bulk polymerization. The copolymer composition of these copolymers was determined by CHN analysis. The distortionless enhancement by polarization transfer (DEPT) technique was used to resolve the methine, methylene, and methyl resonance signals in the V/M copolymer. Comonomer reactivity ratios were determined by the Kelen–Tudos (KT) and nonlinear least‐square error‐in‐variable (EVM) methods. 1H–13C Heteronuclear shift quantum correlation spectroscopy (HSQC) and 1H–1H homonuclear total correlation spectroscopy (TOCSY) spectra were used for the resolution of the proton nuclear magnetic resonance (1H NMR) spectrum of the V/M copolymers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1328–1336, 2002
Unsaturated polyester resins based on recycled PET: Preparation and curing behavior
Authors: Lu Mangeng , Kim Sangwook 
Published: August 2002

AbstractThe oligomers obtained from the glycolysis of Poly(ethlene terephthalate) (PET) waste were reacted with maleic anhydride to form a series of unsaturated polyester resins. The obtained resin was used to study the curing reaction with styrene by differential scanning calorimetry. The heats of reaction for styrene and polyester vinyl groups were measured by extrapolating the experimental results. Various kinetic parameters have been obtained using Kissinger expressions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1052–1057, 2001
Electrical characteristics of fluorinated carbon black‐filled poly(vinylidene fluoride) composites
Authors: Wu Guozhang , Zhang Cheng , Miura Tadashi , Asai Shigeo , Sumita Masao 
Published: August 2002

AbstractDispersion and electrical properties of fluorinated carbon black‐filled poly(vinylidene fluoride) (PVDF) composites were studied as a function of the fluorine content. It was found that with increasing the fluorine content carbon particles tend to stick together to form large aggregates. The percolation concentration increases to a high concentration, whereas the percolation process becomes gradual. The temperature dependence of resistivity measurements show that the fluorinated carbon black‐filled PVDF composites exhibit a high PTC intensity and a low NTC effect. These phenomena were discussed in terms of thermodynamic interactions between fluorinated carbon and the PVDF matrix. The dielectric behavior was also investigated in this study. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1063–1070, 2001
Solvent composition and rheology of starch–DMSO–water solutions
Authors: De Vasconcelos C. L. , Pereira M. R. , Fonseca J. L. C. 
Published: August 2002

AbstractThe rheology of starch–DMSO–water solutions was studied as a function of water content and temperature. A correlation between flow regime, temperature, and water content was presented so as to characterize amylose conformation change in a novel way. Rheological behavior was characterized using an empirical equation to classify fluids under study as Newtonian, pseudoplastic, or dilatant. The temperature effect was analyzed through the determination of the apparent activation energy and preexponential constant. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1285–1290, 2001
Analysis of butyl acrylate diffusion in a glassy polystyrene matrix to predict gradient structure
Authors: Jasso Carlos F. , Valdéz J. , Pérez J. H. , Laguna O. 
Published: August 2002

AbstractTo be able to control composition structure in gradient polymers prepared by sequential polymerization, diffusion phenomena has to be considered, particularly for the first 100% weight increment in a glassy polymer matrix. With that purpose, an analytical model to predict diffusion in that region has been developed for amorphous polymers. The inclusion of a relaxation time to estimate surface concentration changes during sorption led to diffusion coefficients one order of magnitude higher than Fickian coefficients. However, adding a volume increment term to account for polymer swelling, diffusion coefficients went up to 48 times the Fickian values. Experimentally, butyl acrylate with a small amount of photosensitizer was diffused into a slightly crosslinked polystyrene slab matrix at different temperatures in the glassy region. After fixing the gradient composition by photopolymerization, chemical structures throughout the slab were determined by FTIR. The proposed model was confronted with experimental sorption showing a close fit at the different temperatures in the region of interest. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1343–1348, 2001
Synthesis and properties of graft copolymer derived from polyurethane and dihydroxyacrylate of bisphenol A
Authors: Roşu Dan , Ciobanu Constantin , Caşcaval Constantin N. 
Published: August 2002

AbstractIn this investigation, polyurethane was grafted with dihydroxyacrylate of bisphenol A, in basic medium, at 80°C. The grafting process was studied using an acrylate–urethane model compound. The grafting degree of polyurethane with dihydroxyacrylate of bisphenol A was 9% by weight. An alkylation mechanism of the synthesis of the graft copolymer was suggested. The addition of the acrylic double bond to the NH–urethane structures takes place in the first stage, and the reaction can be continued as a transposition in the ortho position of the aromatic ring in the second stage. The synthesized graft copolymer was crosslinked at 140°C in the presence of pyridine. The crosslinked copolymer shows high mechanical properties as compared to polyurethane, as well as an improvement of polyurethane's thermal stability. The solubility parameter of the synthesized crosslinked copolymer was estimated to have a value of 11.57 (cal/mol)1/2. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1802–1813, 2001
Effects of ethyl acetate on the soap‐free emulsion polymerization of 4‐vinylpyridine and styrene
Authors: Ni Henmei , Ma Guanghui , Nagai Masatoshi , Omi Shinzo 
Published: August 2002

AbstractThe properties and morphologies of poly(4‐vinylpyridine‐co‐styrene) [P(4VP/St)] lattices, prepared by soap‐free emulsion polymerization using the water‐soluble initiator 2,2′‐azobis(2‐amidinopropane) · 2HCl (V50), were greatly affected by the addition of ethyl acetate (EA). The properties and morphologies of the resultant lattices were characterized by measuring the zeta potential, viscosity average molecular weight, particle size and distribution, glass‐transition temperature (Tg), and photographs taken by SEM and TEM. The effects of two kinds of monomer feeding modes, that is, the batch and semicontinuous emulsion copolymerization, were also investigated. For batch emulsion copolymerization, by charging EA, the core–shell morphology resulting from the disparate reactivity ratios of the 4VP(1)/St(2) copolymerization system (r1 = 1.04, r2 = −0.73) disappeared. Instead, first a bimodal particle size distribution, with an apparently asymmetric composition structure, and then spherical microspheres were obtained as the amount of EA charged increased from 2 to 10 wt %. The particle size increased twofold by the addition of EA. The zeta potential of particles increased from +64.4 to more than +100 mV, and viscosity average molecular weight decreased from 9.70 to 0.97 × 105 g/mol, as EA increased from 0 to 8 wt %. With the semicontinuous copolymerization, raspberry‐like particles were obtained by charging 10 wt % EA, whereas a sandwich‐like morphology was obtained without EA. The DSC curves showed one Tg for all the lattices prepared with charging EA, but two Tg's for the latex prepared without using EA, regardless of the monomer feeding modes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1988–2001, 2001
Novel method of preparation of a charged mosaic membrane by using dipole‐like microspheres. II. Preparation of dumbbell/egg‐like microspheres
Authors: Ni Henmei , Ma Guanghui , Nagai Masatoshi , Omi Shinzo 
Published: August 2002

AbstractThe dumbbell‐like/egglike microspheres of poly(4‐vinylpyridine/n‐butyl acrylate)/polystyrene [P(4VP/nBA)/PS] were prepared by soap‐free seed emulsion polymerization. The effects of various polymerization parameters, such as the amount of ethyl acetate (EA) in the continuous phase, swelling time, degree of crosslinking of seed polymer, polymerization temperature, and compatibility of seed polymer and the secondary polymer, and so forth, on the formation of dumbbell‐like/egglike morphology were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that secondary particles could be eliminated either by drastically increasing the number of seed particles or by stripping EA from the seed latex by dialysis and evaporation under a vacuum. Swelling the seed particle with the secondary monomer was essential for the preparation of egglike microspheres. For the localization of PS domains on one side of the egglike particle, the most effective factors were to elevate the polymerization temperature up to 90°C and simultaneously to lower the compatibility of the polymer on the seed particle surface with the phase of PS, while using the uncrosslinked seed latex. Crosslinking the seed latex was not suitable for localizing the PS domains in the seed particle, especially when the degree of crosslinking exceeded 0.5 wt % of EGDMA. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2002–2017, 2001
Kinetic effects of selenium on degradation of ethylene–propylene copolymer
Authors: Zaharescu T. , Jipa S. , Mihalcea I. 
Published: August 2002

AbstractThe antioxidation protection of elementary selenium added to an ethylene–propylene copolymer (EPR) at different concentrations (0.1, 0.2, and 0.5 phr) was studied. Oxygen uptake measurements were isothermally performed at 180°C on polymer samples stabilized with increasing concentrations of Se. Experimental data have revealed the enhancement in induction periods and the decrease in oxidation rates for unaged elastomer samples. Stabilized polymer specimens exposed to γ‐radiation have presented the highest effects at 0.5 phr of selenium concentration for all irradiation doses (50, 100, 150, and 250 kGy). Influence of selenium on the competition between crosslinking and oxidation occurred in γ‐irradiated ethylene–propylene elastomers discussed on the basis of kinetic treatment on studied thermal degradation process. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2053–2057, 2001
Morphology, structure, and rheological property of linear low‐density polyethylene grafted with acrylic acid
Authors: Huang H. L. , Yao Z. H. , Yang J. H. , Wang Y. , Shi D. A. , Yin J. H. 
Published: August 2002

AbstractThe chain structure, spherulite morphology, and rheological property of LLDPE‐g‐AA were studied by using electronspray mass spectroscopy, 13C–NMR, and rheometer. Experimental evidence proved that AA monomers grafted onto the LLDPE backbone formed multiunit AA branch chains. It was found that AA branch chains could hinder movement of the LLDPE main chain during crystallization. Spherulites of LLDPE became more anomalous because of the presence of AA branch chains. Rheological behavior showed that AA branch chains could act as an inner plasticizer at the temperature range of 170–200°C, which made LLDPE‐g‐AA easy to further process. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2538–2544, 2001
Interaction of self‐nucleation and the addition of a nucleating agent on the crystallization behavior of isotactic polypropylene
Authors: Wang Kefeng , Mai Kancheng , Han Zhiwu , Zeng Hanmin 
Published: August 2002

AbstractThe relationship between heterogeneous or homogeneous nucleation and self‐nucleation of polypropylene (PP) and PP nucleated by an organic phosphate salt (PPA) was studied by DSC. For pure PP, it homogeneously nucleated during cooling after melting at the selected temperature (Ts) of 170–200°C for 3 min, but at the Ts of 160–168°C self‐nucleation occurred; PPA only nucleated heterogeneously at the Ts of 168–200°C, and there existed self nucleation at the Ts of 160–168°C. The double melting peaks of PP and PPA at the Ts of 162°C were observed. Once the self‐nucleation occurred, the change of the crystallization temperature and heat of fusion of PP is more significant than that of PPA with the change of the Ts, depending upon the crystallization conditions. Results were explained by homogeneous nucleation, heterogeneous nucleation, self‐nucleation, and annealing crystallization. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 78–84, 2001