bluuebunny/crossref_metadata_2025 huggingface dataset:
Gender differences in scientific knowledge and attitudes toward science: a comparative study of four Anglo-American nations
Authors: Hayes Bernadette C. , Tariq Vicki N.
Published: August 2002

Despite a lack of empirical verification, research analysts and populist commentators have long assumed that a key factor in explaining anti-scientific attitudes among women is their greater disinterest and ignorance of scientific developments. Using nationally representative Anglo-American data from the 1993 International Social Survey Programme (ISSP) Environment Survey, the results of this analysis question that assumption. Women in the United States, Canada, Great Britain and New Zealand are indeed less knowledgeable and hold less favorable attitudes toward science than men. However, in all but the United States, these gender differences in scientific attitudes are due to male-female disparities in educational background and religious belief, not to variations in scientific knowledge. Thus, in Canada, Great Britain and New Zealand, it is not gender per se but rather differences in social background that explain citizens' views. A somewhat different pattern emerges in the United States. Here, it is differences in levels of scientific knowledge and not demographic background, including gender, which explains public variation in attitudes toward science. The implications of these findings for both research analysts and policy makers are briefly discussed.
Distributive mixing profiles for co‐rotating twin‐screw extruders
Authors: Shearer Gifford , Tzoganakis Costas
Published: August 2002

Distributive mixing was experimentally measured during polymer melt blending along the length of a co‐rotating twin‐screw extruder. A mixing limited interfacial reaction between two reactive polymer tracers was employed to gain direct evidence of the generation of interfacial area. Model reactions were performed to validate this novel experimental method. In particular, the conversion was a direct indicator of the interfacial area available for the reaction. Specially designed sampling ports were used to obtain polymer samples along the length of the extruder during its continuous operation. The mixing capabilities of conveying sections and kneading blocks were compared over a wide range of operating conditions. In conveying sections, distributive mixing was controlled by the fully filled fraction. The mixing in kneading blocks depended on the combination of the operating conditions and the stagger angle. © 2001 John Wiley & Sons, Inc. Adv Polym Techn 20: 169–190, 2001
Injection molding of ribbed plastic plates with a superplastic Zn–22% Al sheet
Authors: Yang S. Y. , Parng S. H.
Published: August 2002

This article presents the development of a hybrid process combining the forming of a superplastic zinc–aluminum sheet with injection molding. The product is a plastic part covered with a superplastic zinc–aluminum layer used mainly for electromagnetic interference (EMI) shielding. This hybrid process involves not only molding a plastic plate, but also forming a superplastic zinc–aluminum sheet with features such as ribs. This research observes the process of filling the cavity and forming the superplastic sheet with the aid of short‐shot experiments. By understanding the molding and forming process, guidelines for process control will be derived. This research further investigates the moldability of SIM systems. To make satisfactory parts, sheet thickness, melt temperature, injection parameters, and other process parameters determine the “moldability” of a specific system. The first part of the moldability study is to identify the relative importance of these process parameters. Results show that melt temperature and injection pressure are the two most critical parameters. The second part of this moldability study is to develop the moldability diagrams based on the molding area on the plane of these two key parameters. Moldability diagrams are employed to evaluate the effects of sheet thicknesses and melt inlets. It is found that a thick sheet, high melt temperature, and an inlet providing short flow length improve moldability. © 2001 John Wiley & Sons, Inc. Adv Polym Techn 20: 216–225, 2001
Reduced vitamin E antioxidant capacity in sickle cell disease is related to transfusion status but not to sickle crisis
Authors: Marwah S.S. , Blann A.D. , Rea C. , Phillips J.D. , Wright J. , Bareford D.
Published: August 2002

In homozygous sickle cell disease (SCD), decreased serum Vitamin E is present. Excessive transfusions may lead to iron overload. We hypothesised a relationship between the two and found that Vitamin E type antioxidant capacity was significantly lower in 30 SCD patients than in 30 age‐ and sex‐matched controls (P < 0.001). Antioxidant capacity was lower in 10 transfused patients compared with 20 non‐transfused patients (P < 0.001). Transfusional iron overload in SCD may increase the potential for oxidative damage, and low antioxidant capacity may compound this effect. Am. J. Hematol. 69: 144–146, 2002. © 2002 Wiley‐Liss, Inc.
Successful long‐term control with lamivudine against reactivated hepatitis B infection following intensive chemotherapy and autologous peripheral blood stem cell transplantation in non‐Hodgkin's lymphoma: Experience of 2 cases
Authors: Nakagawa Masashi , Simizu Yoshifumi , Suemura Masaki , Sato Bunzo
Published: August 2002

It is well documented that cytotoxic treatment in patients carrying the hepatitis B virus (HBV) enhances the risk of severe hepatic damage. Recently lamivudine has been reported to be effective in suppressing the replication of HBV under such conditions. Here we report two cases with HBV carrier status and with non‐Hodgkin's lymphoma who were successfully treated with high‐dose chemotherapy followed by autologous peripheral blood stem cell transplantation with the administration of lamivudine to prevent HBV flare‐up. The antiviral effect of lamivudine was fair, and no objective side effect was experienced during the transplant procedure. Both patients were followed carefully for more than a year without the appearance of the resistant virus. The rebound phenomenon in which HBV proliferates abruptly has not been experienced after withdrawal of lamivudine. We suggest that lamivudine is indicated both in the treatment of HBV viremia and in the prevention of proliferation of HBV in patients with HBV carrier status undergoing high‐dose myeloablative chemotherapy. Am. J. Hematol. 70:60–63, 2002.
Introduction: Evolutionary theory and the search for a unified theory of fertility
Authors: Bock John
Published: August 2002

Demography and evolutionary biology share common origins but have divergent emphasis on the role of theory in understanding population phenomena. A unified theory of fertility would be beneficial in explaining variation in demographic characteristics across geographic and temporal gulfs and in integrating disparate perspectives. The six papers in this thematic collection represent a nascent but vital field: human evolutionary demography. These papers examine the ways in which evolutionary theory can inform, strengthen, and focus research on topics of long‐standing interest to demographers by explicitly modeling the relationship of socioecological variables to life history traits. The papers demonstrate that an understanding of human life history evolution and the use of evolutionary theory as an organizing framework can lead to a productive reassessment of five areas, which are of long‐standing concern to demographers, and which conventional demographic approaches have had limited success in understanding. These are conflicts of interest between parents and children and between men and women, the allocation of resources to competing and/or alternative forms of investment in reproduction and parenting, resource flow within the household, demographic transitions and particularly the fertility transition associated with economic development, and variation in life history characteristics such as fertility and mortality across populations. Future research integrating models of trait‐environment correlation with models of individual information processing and decision‐making will help identify areas of focus, revitalize current models, and play a leading role in the development of a unified theory of fertility applicable across societies and times. Am. J. Hum. Biol. 14: 145–148, 2002.© 2002 Wiley‐Liss, Inc.
Use of surnames for a demo‐ecological analysis: A study in southwest Sardinia
Authors: Caravello Gianumberto , Tasso Miro
Published: August 2002

This study used surnames collected in 12 municipalities of Sulcis, a historic‐geographical region located in southwest Sardinia (Italy). An ecological index of similarity was drawn as the main analysis. The distribution of surnames was also used to determine the diversity of municipality populations by using another ecological index. Two municipalities have a high percentage of Genoese surnames and this element reflects a specific history and culture, different from other Sardinian localities. These peculiarities are evident in the topological representation, which graphically emphasizes the links between the populations studied. Two other municipalities can be distinguished from the remaining eight. Above all, historical, socioeconomic, cultural, and geographic considerations are useful in the appropriate interpretation of the results. Am. J. Hum. Biol. 14:391–397, 2002. © 2002 Wiley‐Liss, Inc.
Biomechanical models for the pathogenesis of specific distal upper extremity disorders
Authors: Steven Moore J.
Published: August 2002

Background

Knowledge 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.

Methods

Tendon 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.

Results

Compressive 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.

Conclusions

It 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

The 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

The 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

Acrylamide 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

Hydrogels 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

Novel 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

A 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

The 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

The 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

Dispersion 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

The 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

To 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

In 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

The 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

The 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

The 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

The 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

The 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
Microporous membranes prepared from blends of polysulfone and sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide)
Authors: Schauer Jan , Albrecht Wolfgang , Weigel Thomas , Kůdela Vlastimil , Pientka Zbynek
Published: August 2002

Membranes were prepared from solutions containing Udel‐type polysulfone (PSf) and sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (SPPO). Polymer solutions in 1‐methyl‐2‐pyrrolidone were cast on a nonwoven textile and precipitated in a water bath. The permeabilities and selectivities of the prepared membranes depended on the concentrations of both polymers in the casting solution. The higher the concentration of PSf, the lower were the permeabilities to water and average pore sizes of the membranes. On the other hand, a very small amount of SPPO in the casting solution (about 1–4 wt % relative to the casting solution weight) brought about a considerable increase in water permeabilities and had a small influence on the average pore sizes. The effects were most pronounced if SPPO with a degree of sulfonation of 20–40% was used. The considerable increase in water permeabilities was explained by separation of the PSf and SPPO phases during precipitation in water and by the concentration of hydrophilic SPPO on the surface of the membrane and its pores. The determinations of the oriented concentration potentials proved the presence of a negative surface charge in the membranes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 134–142, 2001
Orientational effect of mica in fumed silica reinforced composites
Authors: Bokobza L. , Nugay N.
Published: August 2002

Infrared and birefringence measurements are used to characterize the orientational behavior of fumed silica and mica hybrid‐reinforced poly(dimethylsiloxane) composites. Results of equilibrium stress–strain and swelling experiments are also reported and correlated with the orientational data. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 215–222, 2001
Nanoparticles carrying hydroxyl groups produced by microemulsion
Authors: Özer F. , Beşkardeş M. O. , Zareie H. , Pi̇şki̇n E.
Published: August 2002

Methylmethacrylate and 2‐hydroxyethylmethacrylate were polymerized in oil‐in‐water microemulsions that were stabilized by cetyltrimetylammonium bromide (CTAB). Microemulsions that prepared changed continuously from transparent microemulsions to turbid emulsions by increasing the HEMA weight percentage as a comonomer. Polymerization was initiated with an oil‐soluble initiator, azobisizobutyronitrile (AIBN). Stable P(MMA‐HEMA) latexes were obtained about 40 nm in diameter. Molecular weights of the copolymers were in the range of 1.89–2.03 × 106. The glass transition temperatures of these copolymers, which were obtained by differential scanning calorimeter, were in the range of 95–99°C. The comonomer ratio in the final copolymers were obtained from the nuclear magnetic resonance spectra, which were smaller than the comonomer ratios used in the original recipes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 237–242, 2001
Polymerization of benzoguanamine and pyromellitic dianhydride under microwave radiation and its third‐order optical nonlinearities
Authors: Lu Jianmei , Chen Naiyong , Ji Shunjun , Sun Zhenrong , Ding Meixiang , Zhu Xinlin
Published: August 2002

Polycondensation and imidization of benzoguanamine and pyromellitic dianhydride under microwave radiation were studied. The effects of the microwave radiation time (power), the composition of the monomer on the imidization, and the polymer yield were discussed. The polycondensates' third‐order optical nonlinearities and time responses were measured by a phase conjugate forward, 3‐dimensional degenerate, four‐wave mixing technique. At the same time they were compared with relevant conventional thermopolymerization. The results showed that the polycondensates had high third‐order nonlinear optical coefficients [polyimide (PI) χ(3) = 1.181 × 10−13 esu] and fast time responses (22 ps). The third‐order nonlinear optical coefficients under microwave radiation were higher than that of conventional thermopolymerization (microwave radiation PI χ(3) = 1.181 × 10−13 esu: thermopolymerization PI χ(3) = 0.686 × 10−13 esu). The experimental results also showed that the third‐order optical nonlinearities were not only affected by the length of the polycondensate chain, but also the polycondensate π‐electron density distribution, which was explained and confirmed by computation with the semiempirical Austin method. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1356–1363, 2001
Photolysis of poly(benzyl methacrylate)s and poly(benzyl acrylate)s in solution and films
Authors: Itoh Yoshihiro , Goshima Toshiyuki , Shirai Hirofusa
Published: August 2002

Methacrylate and acrylate copolymers containing benzyl or 1‐phenylethyl groups and their monomeric model compounds were irradiated with a 254‐nm light in CH2Cl2 and solid films. Low molecular weight and polymeric products were analyzed by gas chromatography (GC) and NMR spectroscopy, respectively, and main‐chain scission efficiencies were determined by gel permeation chromatography (GPC). The results indicate that the ester bond cleavage in the side chain produces alkyl radicals in the main chain, leading to main‐chain scission and crosslinking. The higher stability of tertiary alkyl radicals formed in methacrylate polymers lead to the predominant main‐chain scission in solution. On the other hand, acrylate polymers were less susceptible to photodegradation. The degradabilities of the polymer films reflected those of the polymer solutions, although crosslinking preferentially occurred. The distinct effect of oxygen on the degradation was also observed in solution and films. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2227–2236, 2001
Polymer–inorganic nanocomposites prepared by hydrothermal method: Preparation and characterization of PVA–transition‐metal sulfides
Authors: Qian X. F. , Yin J. , Yang Y. F. , Lu Q. H. , Zhu Z. K. , Lu J.
Published: August 2002

Nanocomposites of poly(vinyl alcohol) (PVA) with iron, cobalt, or nickel sulfides were successfully prepared using a hydrothermal process by an in situ reaction with CS2 at 140°C for 8 h. XRD results showed that pure phases of FeS2, CoS2, and NiS were obtained in the as‐prepared nanocomposites. They also showed that the crystallinity of PVA was largely decreased after incorporation of the nano‐sized sulfides. This was also confirmed by IR spectroscopy. SEM photographs showed that the sulfide particles were homogeneously dispersed in the PVA matrix. UV‐visible spectroscopy was also used to characterize the as‐prepared nanocomposites. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2744–2749, 2001
Flow behavior of polyacrylamide solution. III. Mathematical treatment
Authors: Yang Mu‐Hoe
Published: August 2002

The flow behavior of polyacrylamide solutions was systematically determined over a wide range of temperatures (20–50°C) and concentrations (20–50 ppm) by using a coaxial cylinder viscometer. The results indicated that the rheological behavior of low‐concentration polyacrylamide solution behaves similar to non‐Newtonian fluids at all these concentrations. The effect of temperature on the consistency coefficient and flow behavior index of polyacrylamide solution of the different concentrations followed an Arrhenius‐type relationship. Moreover, the effect of concentration on consistency coefficient and flow behavior index followed an exponential‐law relationship at the temperatures used. The rheological constants for the Arrhenius and exponential‐law models were determined. The combined effect of temperature and concentration on the coefficient of dynamic shear stress can be represented by a single equation: shear stress = 2.446 × 10−7exp(0.0639C + 3613/RT)(shear rate)2.337 exp(−0.00707C−245/RT). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2784–2789, 2001
The dynamic adsorption of benzene vapor on the ACF activated by phosphoric acid
Authors: Fu Ruowen , Liu Ling , Zeng Hanmin
Published: August 2002

The dynamic adsorption behaviors of benzene vapor on phosphoric acid‐activated carbon fiber (ACF‐P) were investigated by gas chromatography. The experimental results showed that ACF‐P that was activated at >350°C, like steam‐activated carbon fiber (ACF‐W), has good dynamic adsorption properties for benzene vapor. However, the saturation adsorption capacities of ACF‐P and ACF‐W are different. The dynamic adsorption conditions apparently do not affect the effluent concentration before the breakthrough point, but do change the operation loading and usage efficiency. The adsorbed ACF‐P can be regenerated, and good dynamic adsorbability can be recovered by heating treatment. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1841–1847, 2002
A review of littoral tourism, sport and leisure activities: consequences on marine flora and fauna
Authors: Bellan Gerard L. , Bellan‐Santini Denise R.
Published: August 2002

1. A report on the scientific aspects of the consequences of tourism and other leisure activities on the marine flora and fauna has been prepared on behalf of the French Ministry of the Environment. This involved an exhaustive bibliographical review resulting in a series of proposals to address some of the issues highlighted.

2. Our knowledge is too often based on observations of the deeds and misdeeds of tourism along with only a small amount of experimental study.

3. The main proposals are that there should be: (1) a compilation of all studies ordered by and for the State and its decentralized services, local communities and private companies; (2) definition of priority species and ecosystems; (3) observations on the direct and indirect impacts by tourists and sportsmen on the natural environment for each one of the large biotopes; (4) quantification of the impact of recreational fishing; (5) an integration of biological, sociological, economic and judicial disciplines in the management of the marine environment. Copyright © 2001 John Wiley & Sons, Ltd.
Calnexin is associated with and induced by overexpressed human complement protein C2
Authors: Tsukamoto Hiroshi , Tousson Albert , Circolo Antonella , Marchase Richard B. , Volanakis John E.
Published: August 2002

C2 is a serum glycoprotein that is essential for activation of the classical and lectin pathways of the complement system. We reported previously that in transiently transfected COS cells, C2 accumulates in the endoplasmic reticulum‐Golgi intermediate compartment (ERGIC). Transfection with a cDNA corresponding to a variant C2 mRNA in which exon 17 is spliced out, C2Δ(17), resulted in retention of the mutant polypeptide in the ER. We now show that calnexin, a lectin‐like chaperone, colocalizes with wild‐type (wt) C2 and C2Δ(17). Biosynthetic labeling and sequential immunoprecipitation experiments indicated that colocalization is due to a physical association between calnexin and C2. Immunofluorescence analysis indicated that calnexin was upregulated in cells transfected with either C2 species. Upregulation of calnexin was not affected by castanospermine, which inhibits glucosidases I and II. However, castanospermine inhibited translocation of calnexin to the ERGIC in wt C2 transfected cells. Upregulation of calnexin was also observed in cells transfected with the complement protein factor B, a glycoprotein with extensive structural and functional similarities to C2, but not in cells transfected with complement proteins C3 or factor D, which have no structural similarity to C2, and low or no glycan content, respectively. Calnexin upregulation by transfection with C2 or factor B, but not factor D, was also demonstrated by quantitative analysis of calnexin immunoprecipitates from biosynthetically labeled cells. Increased calnexin expression by overexpressed C2 and factor B appears to be triggered either by the high glycan content of these proteins or, since it also occurs in the presence of castanospermine, by shared features of the structure of these two proteins. Anat Rec 267:7–16, 2002. © 2002 Wiley‐Liss, Inc.
Cholinergic and noncholinergic innervation of the smooth muscle layers in the bovine abomasum
Authors: Pfannkuche Helga , Reiche Dania , Hoppe Susanne , Schemann Michael
Published: August 2002

The intrinsic innervation of muscle layers in the mammalian gastrointestinal tract has been mainly studied in nonruminants. The aim of this study was to identify intrinsic motor neurones in the bovine abomasum that innervate the circular and longitudinal muscles. Circular (CMN) and longitudinal muscle motor neurones (LMN) were selectively labeled by application of the retrograde tracer 1,1′‐didodecyl‐3,3,3′,3′‐tetramethyl indocarbocyanine perchlorate (DiI) onto the muscle layers. The transmitter phenotype was determined by immunohistochemical detection of choline acetyltransferase (ChAT), nitric oxide synthase (NOS), and neurone‐specific enolase (NSE). On average, the myenteric ganglia contained 61 ± 19 NSE‐positive cell bodies, of which 89% were ChAT‐positive and 10% were NOS‐positive. Only 0.7% of NSE‐positive neurones (41 of 5,777) contained both ChAT and NOS. Application of DiI onto the circular and longitudinal muscles revealed on average 60 ± 27 (n = 4) and 68 ± 36 (n = 4), respectively, labeled cell bodies in the myenteric plexus. For the circular and longitudinal muscles the proportions of ascending to descending neurones were 76 : 24% and 54 : 46%, respectively. While most ascending CMN were ChAT‐positive (96%), 51% of the descending CMN were ChAT‐negative. All ascending and 95% of descending LMN were ChAT‐positive. It was concluded that cholinergic excitatory innervation is predominant in both muscle layers of the abomasum. Whereas the circular muscle receives cholinergic excitatory and nitrergic inhibitory innervation, the longitudinal muscle is only innervated by cholinergic pathways. This innervation pattern is different from that in gastric muscle layers in monogastric animals. Anat Rec 267:70–77, 2002. © 2002 Wiley‐Liss, Inc.
Substituent‐dependent, positive and negative modulation of Bombyx mori adenylate cyclase by synthetic octopamine/tyramine analogues
Authors: Aoyama Masato , Nakane Toshiya , Ono Takako , Khan Md. Anwar Arfien , Ohta Hiroto , Ozoe Yoshihisa
Published: August 2002

Octopamine (OCT)/tyramine (TYR) analogues, mainly including p‐ and β‐substituted phenylethylamines, were prepared as probes for the ligand‐binding site(s) of adenylate cyclase‐coupled OCT or TYR receptors, and were examined for their effects on cAMP production in the head membranes of Bombyx mori larvae. Small structural changes in OCT and TYR proved to lead to three types of OCT/TYR analogues: (1) compounds that increase the cAMP level by themselves and also depress OCT‐stimulated cAMP production, (2) compounds that do not stimulate cAMP production by themselves but inhibit OCT‐stimulated cAMP production, and (3) compounds that are not active in either the stimulation of cAMP production or the inhibition of OCT‐stimulated cAMP production. Tyramine, which belongs to the second group, also inhibited the basal level of cAMP production at high concentrations. The data indicate that two biogenic amine systems that positively and negatively regulate the level of the second messenger cAMP are present in the head part of B. mori larvae. This finding points to the necessity of separately evaluating the positive and negative regulatory effects in order to quantitatively understand the structure‐activity relationships of OCT receptor ligands. Arch. Insect Biochem. Physiol. 47:1–7, 2001. © 2001 Wiley‐Liss, Inc.
Sampling and concentration values of incomplete bibliographies
Authors: Egghe L.
Published: August 2002

This article studies concentration aspects of bibliographies. More, in particular, we study the impact of incompleteness of such a bibliography on its concentration values (i.e., its degree of inequality of production of its sources). Incompleteness is modeled by sampling in the complete bibliography. The model is general enough to comprise truncation of a bibliography as well as a systematic sample on sources or items. In all cases we prove that the sampled bibliography (or incomplete one) has a higher concentration value than the complete one. These models, hence, shed some light on the measurement of production inequality in incomplete bibliographies.