bluuebunny/crossref_metadata_2025 huggingface dataset:
Screening for diabetic retinopathy
Authors: Cummings Mike
Published: August 2002

An Erratum has been published for the article in Practical Diabetes International 19(3) 2002, 89.
Bexley diabetes retinal screening programme
Authors: Cranston Ian C. , Whitefield L. , Illet G. , Ibrahim Sharaf
Published: August 2002

An Erratum has been published for this article in Practical Diabetes International 19(3) 2002, 89
Drug treatment in obesity
Authors: Wales John K.
Published: August 2002

Antiobesity drug therapy should only be considered as a treatment option when a hypocaloric diet, increased exercise and some degree of behavioural modifications have been undertaken by the patient. As a test of patient motivation, these manoeuvres should produce some degree of measurable weight loss before antiobesity drugs begin and targets for weight loss made. At present there are two antiobesity drugs licensed in the UK – orlistat and sibutramine – which have different modes of action, different side effects and contra‐indication profiles and do not work in all obese patients; but there are newer and different drugs being developed. Prescribers of antiobesity drugs should feel confident in their use. If possible drugs that increase body weight should be avoided in overweight and obese patients. Copyright © 2002 John Wiley & Sons, Ltd.
Collaborative study on drug use in pregnancy: the results of the follow‐up 10 years after (Novi Sad Centre)
Authors: Sabo A. , Stanulović M. , Jakovljević V. , Grujić Z.
Published: August 2002

An international multicenter study entitled Collaborative Study on Drug Use in Pregnancy (DUP) was initiated in 1987 by the Mario Negri Institute (Milano) and co‐sponsored by the WHO Regional Office for Europe (Copenhagen). The study covered the use of medicines during pregnancy, labour and postpartum period. The Novi Sad centre contributed with 296 questionnaires. The aim of the study was to evaluate the pharmacotherapy by means of comparison, to identify problems in a particular settings and to plan actions toward improvement. The prescribing of some medicines in the Novi Sad center was found to be at the extreme, being among the lowest in the use of iron preparations during pregnancy and among the highest in the use of ergot alkaloids in the postpartum period. Educational efforts have been made to change this practice after the conclusion of the study in 1989. Ten years later, in 1999, the same questionnaire was applied to 100 women in the postpartum period in the same nursery, the Department of Obstetrics and Gynecology in Novi Sad. The results have shown a distinct improvement with the increase of iron prescribing during pregnancy and almost complete abandonment of postpartum use of ergot alkaloids. In the second study period some other inconsistencies with accepted therapeutical principles were identified. For example, although the use of analgesics fell from 22.3 to 8%, the selection changed towards the high use of metamizole (noraminophenazone) and no use of paracetamol (acetaminophen). It was concluded that international pharmacoepidemiological studies such as DUP, could substantially contribute to the improvement of pharmacotherapy if followed by appropriate actions in changing the prescribing behaviour of the physicians and information directed to the target population. Copyright © 2001 John Wiley & Sons, Ltd.
Revitalizing the General Practice Research Database: plans, challenges, and opportunities
Authors: Wood Louise , Coulson Rosalind
Published: August 2002

The General Practice Research Database (GPRD) is the world's largest computerized database of anonymized longitudinal patient records from general practice and is a unique public health research tool. Several issues have threatened the viability of the database in recent years; in April 1999 responsibility for its management and financial control was transferred to the UK Medicines Control Agency (MCA). This presentation outlines the MCA's plans and future vision for the GPRD. © Crown copyright 2001. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Co‐prescribing of medications used to treat obstructive lung disease, congestive heart failure and depression among users of topical beta blockers: estimates from three US Veterans Affairs Medical Centers
Authors: Valuck Robert J. , Perlman Jay I. , Anderson Carolyn , Wortman George I.
Published: August 2002

Purpose

To estimate the frequency of co‐prescribing of medications used to treat obstructive lung disease, congestive heart failure, and depression among US armed service veterans for whom topical beta blockers (TBB) have been prescribed.

Methods

Prescription data from the computerized medical record systems of three US Veterans Affairs Medical Centers were obtained during Fall 1999 to identify patients for whom active prescriptions existed for TBB and/or drugs commonly used to treat obstructive lung disease, congestive heart failure, and depression.

Results

Among TBB users, the estimated co‐prescribing rate of medications used to treat obstructive lung disease is in the range of 7.8–9.7%, of medications used to treat congestive heart failure is in the range of 4.3–25.1%, and of medications used to treat depression is in the range of 8.8–11.7%. The total number of TBB users with a concurrent prescription for one or more of the conditions studied was in the range of 30.2–45.7%.

Conclusions

Since TBB may cause systemic side‐effects and thus potentially cause exacerbations of selected chronic conditions, it is important for researchers and prescribers to be aware of the frequency with which their patients with glaucoma may have other concomitant conditions. Copyright © 2001 John Wiley & Sons, Ltd.
Privacy issues and the monitoring of sumatriptan in the New Zealand Intensive Medicines Monitoring Programme
Authors: Coulter David M.
Published: August 2002

Purpose

The purpose of this paper is to describe how the New Zealand (NZ) Intensive Medicines Monitoring Programme (IMMP) functions in relation to NZ privacy laws and to describe the attitudes of patients to drug safety monitoring and the privacy of their personal and health information.

Methods

The IMMP undertakes prospective observational event monitoring cohort studies on new drugs. The cohorts are established from prescription data and the events are obtained using prescription event monitoring and spontaneous reporting. Personal details, prescribing history of the monitored drugs and adverse events data are stored in databases long term. The NZ Health Information Privacy Code is outlined and the monitoring of sumatriptan is used to illustrate how the IMMP functions in relation to the Code. Patient responses to the programme are described.

Results

Sumatriptan was monitored in 14 964 patients and 107 646 prescriptions were recorded. There were 2344 reports received describing 3987 adverse events. A majority of the patients were involved in the recording of events data either personally or by telephone interview. There were no objections to the monitoring process on privacy grounds.

Conclusion

Given the fact that all reasonable precautions are taken to ensure privacy, patients perceive drug safety to have greater priority than any slight risk of breach of confidentiality concerning their personal details and health information. Copyright © 2001 John Wiley & Sons, Ltd.
Telomerization of acrylic acid with mercaptans: Part 2. Kinetics of the synthesis of star‐shaped macromolecules of acrylic acid
Authors: Loubat Cédric , Boutevin Bernard
Published: August 2002

The telomerization of acrylic acid with a polyfunctional transfer agent initiated by 2,2′‐azobisisobutyronitrile, was first investigated in an organic medium (THF) at 65 °C. Transfer constants (CT) for three mercaptans, ethylene glycol bisthioglycolate, trimethylolpropane tris(2‐mercaptoacetate) and pentaerythritol tetrakis(3‐mercaptopropionate) of about 6.1, 6.3 and 7.3, respectively, were determined. From these results, it followed that a well‐defined star poly(acrylic acid) could not be synthesized via telomerization of acrylic acid in THF. Nevertheless, the same study was performed with the tetrafunctional transfer agent in water/THF mixtures. This work emphasized that the nature of the solvent plays an important role in determining the transfer constant. Thus, the value of CT for the tetrafunctional transfer agent decreased from 7.3 in THF to 1, the ‘ideal’ case for telomerization (CT ≈ 1), for the mixture of solvents water/THF (80%, 20%, v/v). With this route, it seems that acrylic acid star‐shaped macromolecules could be synthesized via telomerization.

© 2001 Society of Chemical Industry
Synthesis and characterization of hyperbranched poly(ethyl methacrylate) by quasi‐living radical polymerization of photofunctional inimer
Authors: Ishizu Koji , Shibuya Takeshi , Mori Akihide
Published: August 2002

The hyperbranched poly(ethyl methacrylate)s (PEMAs) were prepared by the quasi‐living radical polymerization of 2‐(N,N‐diethylaminodithiocarbamoyl)ethyl methacrylate (DTCM). DTCM monomer plays an important role in this polymerization system as an inimer that is capable of initiating quasi‐living radical polymerization of the vinyl group. Hyperbranched PEMAs with relatively narrow polydispersity (
M
w/
M
n ≈ 1.6) were obtained. The compact nature of the hyperbranched PEMAs is demonstrated by solution properties which are different from those of the linear analogues.

© 2002 Society of Chemical Industry
m‐Chloroaniline emulsion polymerization, macromolecular chain structure and electrochemical properties
Authors: Dai Lizong , Xu Yiting , Gal Jean‐Yves , Lu Xin , Wu Huihuang
Published: August 2002

Poly(m‐chloroaniline) (PmClAn) was synthesized by emulsion polymerization. The influences of reaction temperature and initiator concentration on polymerizations were studied. It was found that PmClAn with number‐average molecular weight of 1.85 × 103 g mol−1 was obtained by the following conditions: 80 °C, [monomer] = 0.187 × 10−3 mol l−1, [sodium lauryl sulfate] = 4.8 × 10−2 mol l−1, [potassium peroxydisulfate] = 5.6 × 10−2 mol l−1, reaction period = 2.0 h. 1H NMR, FTIR, and transmission and scanning microscopy were used for structural characterization of PmClAn. It was shown that the ratio of benzoid to quinoid units in the macromolecular chain was respectively 3:2, and that PmClAn has a typical crystalline monoclinic form. A PmClAn molecular chain configuration was also proposed on the basis of crystallographic data. Cyclic voltammetry experiments revealed the PmClAn membrane electrode electroactivity. This electroactivity increased when the polymer was proton‐doped. When Pt particles were electrodeposited onto the polymer membrane electrode, they presented a preferred orientation. Isopropanol oxidation intensities with platinized PmClAn modified electrodes were larger than with a platinized Pt electrode. We also found that oxidation occurred mainly on the Pt particles deposited on the polymer, and that the anodic peak potential changed with polymer and its doping level. These results indicated that the Pt particles interacted with the polymer and that catalytic properties could be observed.

© 2002 Society of Chemical Industry
Rural electrification using photovoltaic battery charging stations: a performance study in northern Thailand
Authors: Sriuthaisiriwong Y. , Kumar S.
Published: August 2002

The installed capacity of photovoltaic battery charging stations (PV BCS) in Thailand is more than 1·5 MWp. A study on the performance and usefulness of ten PV BCS showed that all the observed systems still provide electricity to the villagers, underlining the long life and robust capabilities of the PV‐based electrification. Most users of the system have changed their lighting system from wood and kerosene to battery‐powered lamps, and find the system useful. The major malfunctioning component is the charge controller. The efficiency seems to be low, owing to the loss of opportunity of using small (6 V) batteries and not using the system throughout the daytime. Shallow‐discharge car/motor cycle batteries are used. Some do not use the system owing to specific reasons (cost, battery performance, distance of BCS from home, etc.). Training and an organisational set up to take care of the system is important if the performance of PV BCS is to be increased. Copyright © 2001 John Wiley & Sons, Ltd.
Photovoltaics literature survey (No. 7)
Authors: Keevers Mark J.
Published: August 2002

In order to help keep readers up‐to‐date in the field, each issue of Progress in Photovoltaics will contain a list of recently published journal articles most relevant to its aims and scope. This list is drawn primarily from recent issues of IEEE Transactions on Electron Devices, Journal of Applied Physics, Progress in Photovoltaics, Solar Energy and Solar Energy Materials and Solar Cells, with additional journals surveyed if space permits. To assist the reader, the list is separated into broad categories, but please note these classifications are by no means strict. Also note that inclusion in the list is not an endorsement of a paper's quality. If you have any suggestions please email Mark Keevers at m.keevers@unsw.edu.au. Copyright © 2000 John Wiley & Sons, Ltd.
High‐rate deposition of epitaxial layers for efficient low‐temperature thin film epitaxial silicon solar cells
Authors: Oberbeck Lars , Schmidt Jan , Wagner Thomas A. , Bergmann Ralf B.
Published: August 2002

Low–temperature deposition of Si for thin‐film solar cells has previously been hampered by low deposition rates and low material quality, usually reflected by a low open‐circuit voltage of these solar cells. In contrast, ion‐assisted deposition produces Si films with a minority‐carrier diffusion length of 40 μm, obtained at a record deposition rate of 0.8 μm/min and a deposition temperature of 650°C with a prebake at 810°C. A thin‐film Si solar cell with a 20‐μm‐thick epitaxial layer achieves an open‐circuit voltage of 622 mV and a conversion efficiency of 12.7% without any light trapping structures and without high‐temperature solar cell process steps. Copyright © 2001 John Wiley & Sons, Ltd.
Negative treatment outcomes of behavioral parent training programs
Authors: Assenany Amy E. , McIntosh David E.
Published: August 2002

The purposes of this review were to: (a) outline the literature on negative treatment outcomes of behavioral parent training programs, (b) detail variables found to be predictive of negative treatment outcomes, and (c) suggest future directions of study. We suggest that despite scores of studies documenting positive outcomes of behavioral parent training programs, negative treatment outcomes occur for a sizeable minority of families. Existing research has documented a relationship between a number of contextual stressors and negative outcomes. More research is necessary before the knowledge of the current literature can be applied to clinical practice. Suggestions for needed research are given, including determining which contextual life stressors play a critical role in the relationship, assessing the effect of contextual stressors on various treatments, and determining how contextual life stressors impact the treatment process. © 2002 Wiley Periodicals, Inc.
Longitudinal factor structure of the WISC‐III among students with disabilities
Authors: Watkins Marley W. , Canivez Gary L.
Published: August 2002

If the factor structure of a test does not hold over time (i.e., is not invariant), then longitudinal comparisons of standing on the test are not meaningful. In the case of the Wechsler Intelligence Scale for Children‐Third Edition (WISC‐III), it is crucial that it exhibit longitudinal factorial invariance because it is widely used in high‐stakes special education eligibility decisions. Accordingly, the present study analyzed the longitudinal factor structure of the WISC‐III for both configural and metric invariance with a group of 177 students with disabilities tested, on average, 2.8 years apart. Equivalent factor loadings, factor variances, and factor covariances across the retest interval provided evidence of configural and metric invariance. It was concluded that the WISC‐III was measuring the same constructs with equal fidelity across time which allows unequivocal interpretation of score differences as reflecting changes in underlying latent constructs rather than variations in the measurement operation itself. © 2001 John Wiley & Sons, Inc.
Validity of the home and community social behavior scales: Comparisons with five behavior‐rating scales
Authors: Merrell Kenneth W. , Streeter Angela L. , Boelter Eric W. , Caldarella Paul , Gentry Amanda
Published: August 2002

Three separate studies focusing on convergent and discriminant validity evidence for the Home and Community Social Behavior Scales are presented. The HCSBS is a 65‐item social behavior‐rating scale for use by parents and caretakers of children and youth ages 5–18. It is a parent‐rating version of the School Social Behavior Scales. Within these studies, relationships with five behavior‐rating scales were examined: the Social Skills Rating System, Conners Parent Rating Scale–Revised‐Short Form, Child Behavior Checklist, and the child and adolescent versions of the Behavior Assessment System for Children. HCSBS Scale A, Social Competence, evidenced strong positive correlations with measures of social skills and adaptability, strong negative correlations with measures of externalizing behavior problems, and modest negative correlations with measures of internalizing and atypical behavior problems. HCSBS Scale B, Antisocial Behavior, evidenced strong positive correlations with measures of externalizing behavior problems, modest positive correlations with measures of internalizing and atypical behavior problems, and strong negative correlations with measures of social skills and adaptability. These results support the HCSBS as a measure of social competence and antisocial behavior of children and youth. © 2001 John Wiley & Sons, Inc.
A simple method for the precise and simultaneous determination of primary and multiple secondary kinetic deuterium isotope effects in organic reactions at natural abundance
Authors: Zhang Ben‐Li , Pionnier Sébastien
Published: August 2002

A method for the determination of kinetic isotope effects (KIEs) in organic reactions using natural abundance deuterium NMR is proposed. The method consists of the determination of the site‐specific H/D isotopic ratios of the starting reactant and the product in a reaction run under pseudo‐first‐order kinetic conditions. Using simple and easy experimental procedures, primary and/or multiple secondary KIEs can be measured simultaneously with high precision. The application of this approach to different types of reaction is described. The primary and α‐secondary KIEs for C—H(D) bond breaking of —CDH— can be measured separately. The uncertainty in the determination of small secondary KIEs can reach less than 1%. The results show that some remote secondary KIEs are not negligible. The advantages and limitations of the method are discussed. One of its merits is that the method can even be used in complex situations when there are branch reactions and when the reaction is reversible. The performance depends essentially on the signal separation in the NMR spectra. Copyright © 2001 John Wiley & Sons, Ltd.
Cyclopolymerization of dipropargylfluorene by transition‐metal catalysts
Authors: Gal Yeong‐Soon , Jin Sung‐Ho , Park Jong‐Wook , Lee Won‐Chul , Lee Hyo‐San , Kim Sang‐Youl
Published: August 2002

A fluorene‐containing spiro‐type conjugated polymer, poly(dipropargylfluorene), was synthesized via the cyclopolymerization of dipropargylfluorene by Mo‐ and W‐based transition‐metal catalysts. The polymerization of dipropargylfluorene proceeded well by MoCl5 catalyst itself to give a quantitative yield of polymer. The Mo‐based catalysts are more effective than those of W‐based catalysts. The structure of poly(dipropargylfluorene) was characterized by various instrumental methods (NMR, IR, and UV–visible spectroscopies) to have the conjugated polymer backbone carrying fluorene moieties. Analysis of the 13C NMR spectrum revealed that the polymer structure consists of only six‐membered rings. The resulting poly(dipropargylfluorene)s were brown or black powder and soluble in aromatics and halogenated hydrocarbons such as benzene, chlorobenzene, tetrahydrofuran, chloroform, and methylene chloride. Thermal and morphological properties of the polymer are also discussed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4101–4109, 2001
Long‐lived species generated via irradiation of poly(methyl methacrylate) containing pyrene
Authors: Szadkowska‐Nicze M. , Mayer J.
Published: August 2002

The fate of long‐lived species [pyrene (Py) radical cations and Py–cyclohexadienyl‐type radicals] generated by electron‐beam irradiation at room temperature in poly(methyl methacrylate) (PMMA) doped with Py is described. The separation of reacting solute intermediates and the relaxation phenomena seem to be the main factors limiting the reactivity of long‐lived Py species in the PMMA matrix. The temperature‐stimulated recombination of ionic species in PMMA doped with Py results in Py excited‐state formation. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4110–4118, 2001
Organic–inorganic hybrid networks by the sol–gel process and subsequent photopolymerization
Authors: Müh Ekkehard , Stieger Markus , Klee Joachim E. , Frey Holger , Mülhaupt Rolf
Published: August 2002

Organic–inorganic hybrid materials were prepared by a convenient two‐step curing procedure based on sol–gel condensation and subsequent photopolymerization. Novel bismethacrylate‐based hybrid monomers with pendant, condensable alkoxysilane groups were prepared by Michael addition and possessed number‐average molecular weights between 580 and 1600 g/mol. The formation of inorganic networks by sol–gel condensation of the alkoxysilane groups in the presence of aqueous methacrylic acid was monitored with rheological measurements. The condensation conversion was monitored with solid‐state 29Si cross‐polarization/magic‐angle spinning NMR spectroscopy. Subsequent photopolymerization led to organic–inorganic hybrid networks and low volume shrinkage, ranging from 4.2 to 8.3%, depending on the molecular weight of the hybrid monomer applied. Highly filled composite materials with glass filler fractions greater than 75% showed attractive mechanical properties with Young's moduli of 2700–6200 MPa. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4274–4282, 2001
Synthesis and characterization of soluble, fluorescent poly(arylene ether)s, poly(arylene thioether)s, and poly(arylene sulfone)s containing 1,3,5‐triphenylbenzene segments
Authors: Shaikh Abbas‐Alli G. , Hay Allan S.
Published: August 2002

The bisphenol 4,4″‐dihydroxy‐5′‐phenyl‐m‐terphenyl (4), containing a 1,3,5‐triphenylbenzene moiety, was synthesized from a pyrylium salt obtained by the reaction of benzaldehyde with p‐methoxyacetophenone with boron trifluoride etherate as a condensing agent. Polymers were obtained from 4 by a nucleophilic displacement reaction with various activated difluoro monomers and with K2CO3 as a base. A series of new poly(arylene ether)s (8a–8f) were obtained that contained phenyl‐substituted m‐terphenyl segments in the polymer chain. Polymers with inherent viscosities of 0.41–0.99 dL/g were obtained in yields greater than 96%. The polymers were soluble in a variety of organic solvents, including nonpolar solvents such as toluene. Clear, transparent, and flexible films cast from CHCl3 showed high glass‐transition temperatures (Tg = 198–270 °C) and had excellent thermal stability, as shown by temperatures of 5% weight loss greater than 500 °C. 4 was converted via N,N‐dimethyl‐O‐thiocarbamate into the masked dithiol 4,4″‐bis(N,N′‐dimethyl‐S‐thiocarbamate)‐5′‐phenyl‐m‐terphenyl and was polymerized with activated difluoro compounds in the presence of a mixture of Cs2CO3 and CaCO3 as a base in diphenyl sulfone as a solvent. A series of new poly(arylene thioether)s (9a–9e) were obtained with Tg values similar to those of 8a–8e. 9a–9e were further oxidized into poly(arylene sulfone)s with Tg values 40–80 °C higher than those for 8a–8e and 9a–9e. These polymers also had good solubility in organic solvents. A sulfonic acid group was selectively introduced onto the pendent phenyl group of polymers 8a and 8f by reaction with chlorosulfonic acid. The polymers were soluble in dipolar aprotic solvents and formed films via casting from dimethylformamide. Polymers 8a–8f, 11a, and 11f showed blue and red fluorescence under ultraviolet–visible light with emission maxima at 380–440 nm. © 2002 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 496–510, 2002; DOI 10.1002/pola.10136
Controlled ring‐opening polymerization of propylene oxide catalyzed by double metal‐cyanide complex
Authors: Huang Yi‐Jun , Qi Guo‐Rong , Wang Yu‐Hua
Published: August 2002

A double metal‐cyanide catalyst based on Zn3[Co(CN)6]2 was prepared. This catalyst is very effective for the ring‐opening polymerization of propylene oxide. Polyether polyols of moderate molecular weight having low unsaturation (<0.015 meq/g) can be prepared under mild conditions. The molecular weight of polymer is entirely controlled by a reacted monomer‐to‐initiator ratio. The polymers prepared with stepwise addition of monomer exhibit a narrower molecular weight distribution as compared with those prepared with one‐step addition of monomer. Various compounds containing active hydrogen, except basic compounds and low‐carbon carboxylic acid, may be used as initiators. The reaction rate increases with increasing catalyst amount and decreases with rising initiator concentration. Polymerization involves a rapid exchange reaction between the active species and the dormant species. It was also proven that, to a certain extent, the chain termination of this catalytic system is reversible or temporary. 13C NMR analysis showed that the polymer has a random distribution of the configurational sequences and head‐to‐tail regiosequence. It is assumed that the polymerization proceeds via a cationic coordination mechanism. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1142–1150, 2002
Silicon‐methoxide‐modified clays and their polystyrene nanocomposites
Authors: Zhu Jin , Start Paul , Mauritz Kenneth A. , Wilkie Charles A.
Published: August 2002

Silicon‐methoxide‐containing modified clays were obtained through cationic exchange between the sodium clay and the ammonium cation of [3‐(trimethoxysilyl)propyl]octadecyldimethylammonium chloride (Si18). The nanocomposites were prepared through bulk polymerization of styrene in which the Si18 clay was dispersed. The silicon‐methoxide offers the possibility of reaction between the methoxide and a clay hydroxyl group to link together the cation and the clay. The nanocomposites were characterized by X‐ray diffraction, transmission electron microscopy, and atomic force microscopy. Their thermal stability and flame retardancy were measured by thermogravimetric analysis (TGA) and cone calorimetry. Linkage between the silicon and the clay apparently occurs in the clay but is not likely to occur in the nanocomposite, perhaps because of the presence of the polystyrene spreading the distance between the reactive sites, which makes reaction more difficult. The results from TGA and cone calorimetry were similar to those obtained with other nanocomposites. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1498–1503, 2002
Microwave‐assisted ring‐opening polymerization of ϵ‐caprolactone
Authors: Liao L. Q. , Liu L. J. , Zhang C. , He F. , Zhuo R. X. , Wan K.
Published: August 2002

Ring‐opening polymerization of ϵ‐caprolactone was carried out smoothly and effectively with constant microwave powers of 170, 340, 510, and 680 W, respectively, with a microwave oven at a frequency of 2.45 GHz. The temperature of the polymerization ranged from 80 to 210 °C. Poly(ϵ‐caprolactone) (PCL) with a weight‐average molar mass (Mw) of 124,000 g/mol and yield of 90% was obtained at 680 W for 30 min using 0.1% (mol/mol) stannous octanoate as a catalyst. When the polymerization was catalyzed by 1% (w/w) zinc powder, the Mw of PCL was 92,300 g/mol after the reaction mixture was irradiated at 680 W for 270 min. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1749–1755, 2002
Novel neodymium (III) isopropoxide‐methylaluminoxane catalyst for isoprene polymerization
Authors: Dong Weimin , Masuda Toshio
Published: August 2002

A novel catalyst composed of neodymium (III) isopropoxide [Nd(OiPr)3] and methylaluminoxane (MAO) was examined in isoprene polymerization. The Nd(OiPr)3‐MAO catalyst proved to be highly effective in heptane even at low [Al]/[Nd] ratios (ca. 30) to give polyisoprene that possessed high cis‐1,4 stereoregularity (> ca. 90%), a high number‐average molecular weight (Mn ∼105), and relatively narrow molecular weight distributions (Mw/Mn = 1.9–2.8). The catalyst activity increased with an increasing [Al]/[Nd] ratio from 10 to 80 as well as temperature of aging and polymerization from 0 to 60 °C. The polymerization proceeded in the first order with respect to the monomer concentration. Aliphatic solvents (heptane and cyclohexane) achieved a higher yield and Mn of polymer than toluene as a solvent. The Mw/Mn ratio remained around 2.0, and the gel permeation chromatographic curve was always unimodal, indicating that this system is homogeneous and involves a single active site. The microstructure of polyisoprene was determined by IR, 1H NMR, and 13C NMR. The cis‐1,4 contents of the final polymers stayed in the range of 90–92%, regardless of reaction conditions, indicating the high stability of stereospecificity of the catalyst. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1838–1844, 2002
Polymerization of styrene with ionic comonomer, nonionic comonomer, or both
Authors: Xu Xiao‐Jun , Siow Kok‐Siong , Wong Ming‐Keong , Gan Leong‐Ming
Published: August 2002

Nanosized polystyrene latexes with high polymer contents were obtained from an emulsifier‐free process by the polymerization of styrene with ionic comonomer, nonionic comonomer, or both. After seeding particles were generated in an initial emulsion system consisting of styrene, water, an ionic comonomer [sodium styrenesulfonate (NaSS)] or nonionic comonomer [2‐hydroxyethyl methacrylate (HEMA)], and potassium persulfate, most of the styrene monomer or a mixture of styrene and HEMA was added dropwise to the polymerizing emulsion over 6 h. Stable latexes with high polystyrene contents (≤25%) were obtained. The latex particle weight‐average diameters were largely reduced (41 nm) by the continuous addition of monomer(s) compared with those (117 nm) obtained by the one‐pot polymerization method. Latex particles varied from about 30 to 250 nm in diameters, whereas their molar masses were within 104 to 105 g/mol. The effect of the comonomer concentration on the number of polystyrene particles per milliliter of latex and the weight‐average molar masses of the copolymers during the polymerization are discussed. The surface compositions of the latex particles were analyzed by X‐ray photoelectron spectroscopy, which indicated that the surface of the latex particles was significantly enriched in NaSS, HEMA, or both. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1634–1645, 2001
Reorganization of the structures, morphologies, and conformations of bulk polymers via coalescence from polymer–cyclodextrin inclusion compounds
Authors: Bullions T. A. , Wei M. , Porbeni F. E. , Gerber M. J. , Peet J. , Balik M. , White J. L. , Tonelli A. E.
Published: August 2002

Bulk poly(ethylene terephthalate) (PET) and bisphenol A polycarbonate (PC) samples have been produced by the coalescence of their segregated, extended chains from the narrow channels of the crystalline inclusion compounds (ICs) formed between the γ‐cyclodextrin (CD) host and PET and PC guests, which are reported for the first time. Differential scanning calorimetry, Fourier transform infrared, and X‐ray observations of PET and PC samples coalesced from their crystalline γ‐CD‐ICs suggest structures and morphologies that are different from those of samples obtained by ordinary solution and melt processing techniques. For example, as‐received PC is generally amorphous with a glass‐transition temperature (Tg) of about 150 °C; when cast from tetrahydrofuran solutions, PC is semicrystalline with a melting temperature (Tm) of about 230 °C; and after PC/γ‐CD‐IC is washed with hot water for the removal of the host γ‐CD and for the coalescence of the guest PC chains, it is semicrystalline but has an elevated Tm value of about 245 °C. PC crystals formed upon the coalescence of highly extended and segregated PC chains from the narrow channels in the γ‐CD host lattice are possibly more chain‐extended and certainly more stable than chain‐folded PC crystals grown from solution. Melting the PC crystals formed by coalescence from PC/γ‐CD‐IC produces a normal amorphous PC melt that, upon cooling, results in typical glassy PC. PET coalesced from its γ‐CD‐IC crystals, although also semicrystalline, displays a Tm value only marginally elevated from that of typical bulk or solution‐crystallized PET samples. However, after the melting of γ‐CD‐IC‐coalesced PET crystals, it is difficult to quench the resultant PET melt into the usual amorphous PET glass, characterized by a Tg value of about 80 °C. Instead, the coalesced PET melt rapidly recrystallizes during the attempted quench, and so upon reheating, it displays neither a Tg nor a crystallization exotherm but simply remelts at the as‐coalesced Tm. This behavior is unaffected by the coalesced PET sample being held above Tm for 2 h, indicating that the extended, unentangled nature of the chains in the noncrystalline regions of the coalesced PET are not easily converted into the completely disordered, randomly coiled, entangled melt. Apparently, the highly extended, unentangled characters of the PC and PET chains in their γ‐CD‐ICs are at least partially retained after they are coalesced. Initial differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared, and X‐ray observations are described here. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 992–1012, 2002
Phase behavior of tetramethylpolycarbonate blends with styrene‐based methacrylate copolymers and their interaction energies
Authors: Moon E. J. , Kim M. J. , Choi H. K. , Kim C. K.
Published: August 2002

The miscibility of tetramethylpolycarbonate (TMPC) blends with styrenic copolymers containing various methacrylates was examined, and the interaction energies between TMPC and methacrylate were evaluated from the phase‐separation temperatures of TMPC/copolymer blends with lattice‐fluid theory combined with a binary interaction model. TMPC formed miscible blends with styrenic copolymers containing less than a certain amount of methacrylate, and these miscible blends always exhibited lower critical solution temperature (LCST)‐type phase behavior. The phase‐separation temperatures of TMPC blends with copolymers such as poly(styrene‐co‐methyl methacrylate), poly(styrene‐co‐ethyl methacrylate), poly(styrene‐co‐n‐propyl methacrylate), and poly(styrene‐co‐phenyl methacrylate) increase with methacrylate content, go through a maximum, and decrease, whereas those of TMPC blends with poly(styrene‐co‐n‐butyl methacrylate) and poly(styrene‐co‐cyclohexyl methacrylate) always decrease. The calculated interaction energy for a copolymer–TMPC pair is negative and increases with the methacrylate content in the copolymer. This would seem to contradict the prediction of the binary interaction model, that systems with more favorable energetic interactions have higher LCSTs. A detailed inspection of lattice‐fluid theory was performed to explain such phase behavior. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1288–1297, 2002
Conductivity enhancement mechanism of the poly(ethylene oxide)/modified‐clay/LiClO4 systems
Authors: Chen Hsien‐Wei , Chiu Chun‐Yi , Chang Feng‐Chih
Published: August 2002

This study demonstrates that adding clay that was organically modified by dimethyldioctadecylammonium chloride (DDAC) and d2000 surfactants increases the ionic conductivity of polymeric electrolyte. A.C. impedance, differential scanning calorimetric (DSC), and Fourier transform infrared (FTIR) studies revealed that the silicate layers strongly interact with the dopant salt lithium perchlorate (LiClO4) within a poly(ethylene oxide) (PEO)/clay/LiClO4 system. DSC characterization verified that the addition of a small amount of the organic clay reduces the glass‐transition temperature of PEO as a result of the interaction between the negative charge in the clay and the lithium cation. Additionally, the strength of such a specific interaction depends on the extent of PEO intercalation. With respect to the interaction between the silicate layer and the lithium cation, three types of complexes are assumed. In complex I, lithium cation is distributed within the PEO phase. In complex II, lithium cation resides in an PEO/exfoliated‐clay environment. In complex III, the lithium cation is located in PEO/agglomerated‐clay domains. More clay favors complex III over complexes II and I, reducing the interaction between the silicate layers and the lithium cations because of strong self‐aggregation among the silicate layers. Notably, the (PEO)8LiClO4/DDAC‐modified clay (DDAC‐mClay) composition can form a nanocomposite electrolyte with high ionic conductivity (8 × 10−5 S/cm) at room temperature. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1342–1353, 2002
Phase separation in poly(N‐isopropyl acrylamide)/water solutions. II. Salt effects on cloud‐point curves and gelation
Authors: Yang Yanyin , Zeng Fang , Tong Zhen , Liu Xinxin , Wu Shuizhu
Published: August 2002

The cloud‐point temperatures (Tclo's) of poly(N‐isopropyl acrylamide) (PNIPAM)/water solutions with NaCl, NaBr, or NaI were measured. All these salts reduced the Tclo's of PNIPAM/water solutions to different extents, in the following order: NaCl > NaBr > NaI. The higher the concentration of the added salt was, the more greatly Tclo dropped. A dynamic viscoelasticity investigation of the PNIPAM/water solutions with the salts indicated that during phase separation, the system changed from a homogeneous fluid into a physically crosslinked network, and the addition of salts also reduced the temperature at which this change began. The gelation temperature (Tgel) and the scaling exponent of the PNIPAM/water solutions with NaBr were obtained with dynamic scaling theory, and Tgel was found to be close to Tclo. That the addition of salts to the solution decreased Tclo and Tgel to the same extent further proved that the network structure was formed with the phase separation in the PNIPAM/water solutions. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 901–907, 2001
Proton‐conducting poly(vinylpyrrolidon)–polyphosphoric acid blends
Authors: Bozkurt A. , Meyer W. H.
Published: August 2002

Anhydrous, proton‐conducting polymer electrolytes of poly(vinylpyrrolidon) (PVP) with polyphosphoric acid (PPA) were prepared. PVP‐x‐PPA blends were obtained for 0.5 ≤ x ≤ 3, where x was the number of moles of PO per polymer repeat unit. Fourier transform infrared studies indicated protonation of the carbonyl group in the five‐member ring. Thermogravimetric analysis showed that these materials were stable up to about 180 °C. Differential scanning calorimetry data demonstrated that the addition of the acid plasticized the material, shifting the glass‐transition temperature from 180 °C for the pure polymer to −23 °C for x = 3. The temperature dependence of the mechanical properties was investigated with shear experiments. The direct‐current conductivity increased with x and reached about 10−5 S/cm at ambient temperature. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1987–1994, 2001
Participation in psychosocial group intervention among Japanese women with primary breast cancer and its associated factors
Authors: Fukui Sakiko , Kugaya Akira , Kamiya Masae , Koike Makiko , Okamura Hitoshi , Nakanishi Tatsuro , Wenner Marcus , Imoto Shigeru , Kanagawa Katsuko , Uchitomi Yosuke
Published: August 2002

Though psychosocial group intervention is considered in the West to be an important source of support for reducing psychosocial distress in cancer patients, in Asian countries, there has been no research as yet on the needs for such intervention. This study investigated the level of participation and interest in psychosocial group intervention plus any associated factors in 151 primary breast cancer patients. All were less than 65 years old at 4–18 months post‐surgery. Of the 126 subjects who responded (response rate 83%), 53 (42%) participated (participants) and 73 (58%) did not (non‐participants). Participation was greater among those with a high level of anxiety measured by the Hospital Anxiety and Depression Scale (HADS) (odds ratio [OR], 3.25; 95% confidence interval [CI], 1.07–10.42), those who had undergone surgery within the last 12 months (OR, 3.10; 95% CI, 1.35–7.55), and those who were 50–65 years old (OR, 3.08; 95% CI, 1.33–7.66). Among the non‐participants, 53 (73%) were interested in the intervention while 20 (27%) were not. Non‐participants without any interest in the psychosocial group intervention had significantly higher anxiety levels than those with interest (t=−2.08; df=71; p=0.03).

These results suggest that most Japanese breast cancer patients who need psychological support can be sought out by asking whether they are willing to participate in a psychosocial group intervention. However, the minority not interested in any psychological group intervention might need other supports such as medication or individual psychotherapy. Copyright © 2001 John Wiley & Sons, Ltd.
Chemoprevention of breast cancer with selective estrogen receptor modulators: views from broadly diverse focus groups of women with elevated risk for breast cancer
Authors: Cyrus‐David M.S. , Strom S.S.
Published: August 2002

Selective estrogen receptor modulators (SERMs) are anti‐estrogens that selectively antagonize the proliferative effects of estrogens on breast cells, thereby inhibiting or reversing neoplastic progression to clinical breast cancer. The goal is to administer these agents to healthy women with an elevated risk for breast cancer. The study reported here assessed the knowledge and attitude of 26 broadly selected women with an elevated risk for breast cancer who participated in three focus groups (eight to ten per group) that discussed the use of SERMs, such as tamoxifen and raloxifen. Data were analyzed by cross‐case procedure using variable‐oriented strategies.

Acceptance of breast cancer chemoprevention treatment with SERMs was found to be influenced by various factors, including a knowledge of breast cancer risk factors, the perception of personal risk for breast cancer, and the perception of barriers and benefits to receiving chemoprevention treatment. The issues involved in making the decision to accept treatment with SERMs are discussed. Most of the participants in the groups indicated they were unlikely to accept breast cancer chemoprevention treatment with SERMs. Copyright © 2001 John Wiley & Sons, Ltd.
A model‐based map of ground temperatures for the permafrost regions of Canada
Authors: Henry Kerri , Smith Michael
Published: August 2002

A functional model of the permafrost‐climate system is applied at national scale, to produce a map of near‐surface ground temperatures in the permafrost regions of Canada. The TTOP model links the temperature at the top of permafrost (TTOP) to the climate through seasonal surface transfer functions and subsurface thermal properties. The parameters in the model were compiled at national scale for Canada, although the topographic effects of the Western Cordillera were not incorporated into the analysis. The objective of the study was accomplished by implementing the TTOP model within a Geographical Information System. The TTOP map is evaluated against the published Ground Temperature Map of Canada. The published map shows ground temperatures according to a scale of temperature classes, so TTOP values were categorized into the same classes. Across the permafrost regions of Canada, 72.1% of the area is in the same class in both maps, while 27.7% differs by one temperature class. Only 0.2% of the area differs by two temperature classes. The results suggest that the TTOP model can provide a rational and functional basis for relating near‐surface permafrost temperature and climate at national and regional scales. The model could be applied to the assessment of climate change impacts on the magnitude and distribution of permafrost temperatures. Copyright © 2001 John Wiley & Sons, Ltd.
Randomized controlled study of in‐hospital exercise training programs in children with cystic fibrosis
Authors: Selvadurai H.C. , Blimkie C.J. , Meyers N. , Mellis C.M. , Cooper P.J. , Van Asperen P.P.
Published: August 2002

The aim of this study was to compare aerobic and resistance training in children with cystic fibrosis (CF) admitted to hospital with an intercurrent pulmonary infection with a control group. The subjects were randomized into three groups on the first day of admission. The fat‐free mass (FFM) was calculated, using the skin fold thickness from four sites (biceps, triceps, subscapular, and iliac crest). Pulmonary function tests were performed within 36 hr of admission and repeated on discharge from the hospital, and again at 1 month after discharge. All subjects performed an incremental treadmill exercise test, using a modified Bruce protocol. Lower limb strength was measured using a Cybex dynamometer. An assessment of quality of life was made using the Quality of Well Being Scale, as previously reported. Activity levels were measured using a 7‐day activity diary, and subjects also wore an accelerometer on their hips. There were no significant differences between the three groups in terms of disease severity, and length of stay in hospital. Subjects in all three groups received intravenous antibiotics and nutritional supplementation as determined by the physician. Children randomized to the aerobic training group participated in aerobic activities for five sessions, each of 30‐min duration, a week. The children randomized to the resistance training group exercised both upper and lower limbs against a graded resistance machine. Subjects in the control group received standard chest physiotherapy.

Our study demonstrated that children who received aerobic training had significantly better peak aerobic capacity, activity levels, and quality of life than children who received the resistance training program. Children who received resistance training had better weight gain (total mass, as well as fat‐free mass), lung function, and leg strength than children who received aerobic training.

A combination of aerobic and resistance training may be the best training program, and future studies to assess optimal training programs for CF patients are indicated. Pediatr Pulmonol. 2002; 33:194–200. © 2002 Wiley‐Liss, Inc.