bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel polymer electrolytes prepared by copolymerization of ionic liquid monomers
Authors: Yoshizawa Masahiro , Ogihara Wataru , Ohno Hiroyuki
Published: September 2002

Ionic liquid monomer couples were prepared by the neutralization of 1‐vinylimidazole with vinylsulfonic acid or 3‐sulfopropyl acrylate. These ionic liquid monomer couples were viscous liquid at room temperature and showed low glass transition temperature (Tg) at −83 °C and −73 °C, respectively. These monomer couples were copolymerized to prepare ion conductive polymer matrix. Thus prepared ionic liquid copolymers had no carrier ions, and they showed very low ionic conductivity of below 10−9 S cm−1. Equimolar amount of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to imidazolium salt unit was then added to generate carrier ions in the ionic liquid copolymers. Poly(vinylimidazolium‐co‐vinylsulfonate) containing equimolar LiTFSI showed the ionic conductivity of 4 × 10−8 S cm−1 at 30 °C. Advanced copolymer, poly(vinylimidazolium‐co‐3‐sulfopropyl acrylate) which has flexible spacer between the anionic charge and polymer main chain, showed the ionic conductivity of about 10−6 S cm−1 at 30 °C, which is 100 times higher than that of copolymer without spacer. Even an excess amount of LiTFSI was added, the ionic conductivity of the copolymer kept this conductivity. This tendency is completely different from the typical polyether systems. Copyright © 2002 John Wiley & Sons, Ltd.
The Diabetic Foot Ulcer Scale (DFS): a quality of life instrument for use in clinical trials
Authors: Abetz Linda , Sutton Monica , Brady Lesley , McNulty Pauline , Gagnon Dennis D.
Published: September 2002

The diabetic foot ulcer scale (DFS) questionnaire is a specific instrument designed to assess the impact of foot ulcers and their treatment on quality of life in people with diabetes. Based on the results of semi‐structured interviews and focus‐group discussions with foot ulcer patients and caregivers, the DFS consists of 58 items grouped into 11 domains: leisure, physical health, daily activities, emotions, noncompliance, family, friends, positive attitude, treatment, satisfaction, and financial.

Two studies have been conducted to develop and validate the DFS. The first of these included 173 patients with diabetes and current foot ulcers (n = 48), healed foot ulcers (n = 54), or no history of foot ulcers (n = 71). A generic measure of health status, the SF‐36, was used to test construct validity.

The DFS had good internal consistency. Significant differences between patients with current ulcers and those with healed ulcers were observed in the mean scores for the leisure, emotions, and financial domains (p < 0.05). Marked differences were also observed in physical health, daily activities, and friends domains, indicating that the DFS is able to discriminate patients with healed ulcers from those with current ulcers.

The DFS was further evaluated in a relevant clinical setting (n = 288); confirmatory factor analysis confirmed the hypothesised factor structure of the DFS, but with slight suggestions for improved scaling. The DFS scales also demonstrated adequate test–retest reliability and sensitivity to change in wound status over time, indicating its appropriateness for use in clinical trials. Copyright © 2002 John Wiley & Sons, Ltd.
An Eastern art form for a Western disease: randomised controlled trial of yoga in patients with poorly controlled insulin‐treated diabetes
Authors: Kerr David , Gillam Elvira , Ryder Jackie , Trowbridge Stephen , Cavan David , Thomas Peter
Published: September 2002

There is increasing interest in the use of complimentary therapies. At present, there is a paucity of data examining the effectiveness of such therapies in patients with diabetes. We have examined the influence of providing yoga for patients with diabetes that is poorly controlled despite the best efforts of the multidisciplinary team.

After obtaining ethical approval, 37 patients with poorly controlled diabetes were randomised to a traditional intensive education programme and simple exercises or a 16 week (32 session) Hatha yoga plan.

Participation in regular yoga sessions did not improve glycaemic control but insulin requirements remained stable in the yoga group and increased in the controls. Although quality of life was not altered, all but one subject in the yoga group opted to continue with yoga long term after completion of the study. Copyright © 2002 John Wiley & Sons, Ltd.
Diabetes dietitian or diabetes educator?
Authors: Worth JM , Vyas A
Published: September 2002

Diabetes services are under increasing pressure to provide concerted treatment, better education and preventative care for people with diabetes, although resources are often constrained. This article proposes the value of advanced practitioners, particularly that of the specialist dietitian, within the multi‐disciplinary team (MDT), to help achieve an optimal form of diabetes care within the demands of our current climate. Copyright © 2002 John Wiley & Sons, Ltd.
Life is sweet in Fiji: the availability of diabetes healthcare and health education, and diabetes awareness amongst diabetic patients in Fiji
Authors: Kuruvatti Jay , Price Hermione
Published: September 2002

During an elective visit to Fiji we assessed the knowledge of diabetes possessed by patients who attended the hospital Diabetic Clinic in Lautoka. All the patients interviewed had type 2 diabetes and 15.4% were treated with insulin, 80.8% with oral therapy and 3.8% with diet alone. Blindness was the commonest complication known to patients but almost a quarter could not describe any diabetic complication. All patients had seen a hospital doctor regarding their diabetes; 17.9% also saw a private general practitioner, 80.8% had seen the diabetes nurse, 60.8% a dietician, and 57.7% a chiropodist. When asked about causative factors 12.8% thought diabetes was caused by overeating, 12.8% thought it was due to too much sugar in the diet, and the remaining 60.3% did not know.

The methods by which the ever‐increasing financial burden of diabetes in Fiji can be reduced are discussed. We feel that the prevention of diabetes and the early detection of complications would be the most cost‐effective methods to improve overall diabetes care in Fiji. However, the whole diabetes care service in Fiji is constrained by the poor economic state of the country and the low profile of diabetes in the healthcare plans of the country. Copyright © 2002 John Wiley & Sons, Ltd.
ACE inhibitors and diabetes: from HOPE to PROGRESS
Authors: Kennon Brian , Fisher Miles
Published: September 2002

The HOPE study was a large, multi‐centre study conducted in many countries, which recruited patients over the age of 55 who were at high cardiovascular risk, either because of the presence of existing vascular disease, or because of the presence of diabetes and at least one other cardiovascular risk factor. Ramipril reduced the end‐point of cardiovascular death, myocardial infarction and stroke, and these effects were greater than could be explained by blood pressure lowering alone. Recent criticism has focused on slight differences in baseline risk factors between placebo and intervention groups, but these may have been incorrectly interpreted and the influence on the results exaggerated. It is now up to the reader, armed with differing interpretations of the same data, to return to the primary publications, read these and draw their own conclusions. The recently published PROGRESS study examined the use of perindopril plus or minus a diuretic in reducing the risk of recurrence of stroke in patients with a previous stroke. The results indicate benefit from blood pressure reduction in these patients, but no added benefit was seen with the use of an ACE inhibitor. Two other large studies on the use of ACE inhibitors in patients who are at high cardiovascular risk are currently under way. Copyright © 2002 John Wiley & Sons, Ltd.
Flexibility improvement of epoxy resin by liquid rubber modification
Authors: Kaynak C , Ozturk A , Tincer T
Published: September 2002

The objective of this study was to improve the flexibility of diglycidyl ether of bisphenol‐A based epoxy resin by using a liquid rubber. For this purpose, hydroxyl terminated polybutadiene (HTPB) was used at two concentrations of 1 % and 1.5 % by weight. In order to improve compatibility between liquid rubber and epoxy, a silane coupling agent (SCA) was also used. Bending test specimens were moulded by using four different orders of mixing of HTPB with SCA and hardener to investigate the compatibility of HTPB and epoxy matrix. Three‐point bending tests indicated that the specimens containing HTPB rubber had higher flexibility than neat epoxy specimens. Moreover, liquid rubber modification resulted in increased plastic strain at failure due to the possible decrease in crosslinking density with the change in reactions path. Fractographic examinations under scanning electron microscope indicated the formation of rubber domains in the epoxy matrix. The deformed rubber domains and increased incidence of deformation lines, especially in the third and fourth group specimens, assessed the improvement in flexibility.

© 2002 Society of Chemical Industry
Preparation and characterization of hyperbranched polyacrylate copolymers by self‐condensing vinyl copolymerization (SCVCP)
Authors: Hong Chun‐Yan , Pan Cai‐Yuan
Published: September 2002

A series of hyperbranched polyacrylate copolymers have been synthesized by self‐condensing vinyl copolymerization (SCVCP) of 2‐(2‐bromopropionyloxy)‐ethyl acrylate (BPEA) and methyl acrylate (MA) in the presence of CuBr and bipyridine. The structures and properties of the polymers obtained are characterized by NMR and SEC/RALLS/DV/RI measurements. The effects of reaction conditions on molecular weight (MW), molecular weight distribution (MWD) and degree of branching (DB) are investigated.

© 2002 Society of Chemical Industry
Synthesis of carboxy‐terminated telechelic oligostyrenes by Dead End Polymerization
Authors: David Ghislain , Boutevin Bernard , Robin Jean‐Jacques , Loubat Cedric , Zydowicz Nathalie
Published: September 2002

Styrene was polymerized with 4,4′‐azobiscyanovaleric acid (ACVA) in order to obtain carboxy‐telechelic polystyrene (CTPS) using the Dead‐End Polymerization (DEP) conditions. First, we focused on experimental conditions leading to oligomers with molecular weights about 2000 g mol−1. Second, we demonstrated by‐products of ACVA radicals are also synthesized in the DEP conditions by combination or by disproportionation. The purification of CTPS was investigated in order to extract the by‐products of ACVA. An extraction of these by‐products in H2O pH 7 is suggested. Finally, the acid functionality of oligostyrene is evaluated by 1H NMR and conductimetric titrations. A functionality about 2 is obtained that confirmed the synthesis of CTPS.

Copyright © 2002 Society of Chemical Industry
Dynamic mechanical and dielectric relaxation behaviour of poly(methacrylate)s containing saturated rings with seven and eight members in the side‐chains
Authors: Díaz‐Calleja Ricardo , García‐Bernabé Abel , Sánchez‐Martínez Enrique , Hormazábal Andrea , Gargallo Ligia , Radić Deodato
Published: September 2002

Dynamic mechanical and dielectric behaviour of poly(cycloheptyl methacrylate), poly(cycloheptylmethyl methacrylate) and poly(cyclooctyl methacrylate) have been investigated. The study was performed by determining the components of the complex relaxation modulus E* and the complex dielectric permittivity ϵ*. Results are discussed in terms of the effect of the size and structure of the side ring. The saturated ring group shows mechanical and dielectric activity at low temperature that is analyzed in terms of the Fuoss–Kirkwood equation. The free volume for the three polymers was determined. The conductive and interfacial phenomena were studied by MacDonald and Coelho models, where the dipolar contribution was introduced.

© 2002 Society of Chemical Industry
Mission applicability assessment of integrated power components and systems
Authors: Raffaelle R. P. , Hepp A. F. , Landis G. A. , Hoffman D. J.
Published: September 2002

The need for smaller, lightweight, autonomous power systems has increased with the current focus on micro‐ and nanosatellites. Small‐area, high‐efficiency, thin‐film batteries and solar cells are an attractive choice for such applications. The NASA Glenn Research Center, Johns Hopkins Applied Physics Laboratory, Lithium Power Technologies, MicroSat Systems, and others, have been working on the development of autonomous monolithic packages combining these elements, or what are called integrated power supplies (IPS). These supplies can be combined with individual satellite components and are capable of providing continuous power, even under intermittent illumination associated with a spinning or earth‐orbiting satellite. This paper discusses the space mission applicability, benefits, and current development efforts associated with IPS components and systems. The characteristics and several mission concepts for an IPS that combines thin‐film photovoltaic power generation with thin‐film lithium ion energy storage are described. Based on this preliminary assessment, it is concluded that the most likely and beneficial application of an IPS will be for small ‘nanosatellites’ or in specialized applications serving as a decentralized or as a distributed power source or uninterruptible power supply. Copyright © 2002 John Wiley & Sons, Ltd.
CIGS2 thin‐film solar cells on flexible foils for space power
Authors: Dhere Neelkanth G. , Ghongadi Shantinath R. , Pandit Mandar B. , Jahagirdar Anant H. , Scheiman David
Published: September 2002

CuIn1−xGaxS2(CIGS2) thin‐film solar cells on flexible stainless steel foil are of interest for space power because of the near optimum bandgap, potential for higher specific power, and superior radiation resistance. This paper describes development of CIGS2 solar cells on 127‐μm and 20‐μm‐thick, flexible SS foils for space power. A large‐area, dual‐chamber, deposition system has been fabricated. Cu‐rich Cu‐Ga/In layers were sputter‐deposited on unheated Mo‐coated foils.p‐type CIGS2 thin films were obtained by etching Cu‐rich surface layer from CIGS2 films prepared by sulfurization in Ar:H2S 1:0.04 mixture at 475°C for 60 min with an intermediate 30‐min annealing step at 135°C. Solar cells were completed by deposition of CdS/ZnO/ZnO:Al layers and Ni/Al contact fingers. AM0 PV parameters of a CIGS2 solar cell on 127‐μm‐thick SS foil measured at NASA‐GRC were:VOC = 802.9 mV,JSC = 25.07 mA/cm2, FF = 60.06%, and efficiency = 8.84%. For this cell, AM1.5 PV parameters measured at NREL wereVOC = 763 mV,JSC = 20.6 mA/cm2, FF = 67.4%, and efficiency = 10.4%. Copyright © 2002 John Wiley & Sons, Ltd.
Single‐junction InGaP/GaAs solar cells grown on Si substrates with SiGe buffer layers
Authors: Ringel S. A. , Carlin J. A. , Andre C. L. , Hudait M. K. , Gonzalez M. , Wilt D. M. , Clark E. B. , Jenkins P. , Scheiman D. , Allerman A. , Fitzgerald E. A. , Leitz C. W.
Published: September 2002

Single junction InGaP/GaAs solar cells displaying high efficiency and record high open‐circuit voltage values have been grown by metal–organic chemical vapor deposition on Ge/graded SiGe/Si substrates. Open‐circuit voltages of 980 mV under AM0 conditions have been verified to result from a single GaAs junction, with no evidence of Ge‐related sub‐cell photoresponse. AM0 efficiencies close to 16% have been measured for a large number of small‐area cells, the performance of which is limited by non‐fundamental current losses due to significant surface reflection resulting from> 10% front‐surface metal coverage and wafer handling during the growth sequence for these prototype cells. It is shown that at the material quality currently achieved for GaAs grown on Ge/SiGe/Si substrates, namely a 10 ns minority‐carrier lifetime that results from complete elimination of anti‐phase domains, and maintaining a threading dislocation density of ∼8 × 105 cm−2, 19–20% AM0 single‐junction GaAs cells are imminent. Experiments show that the high performance is not degraded for larger‐area cells, with identical open‐circuit voltages and higher short‐circuit current (due to reduced front metal coverage) values being demonstrated, indicating that large‐area scaling is possible in the near term. Comparison with a simple model indicates that the voltage output of these GaAs‐on‐Si cells follows the ideal behavior expected for lattice‐mismatched devices, demonstrating that unaccounted‐for defects and issues that have plagued other methods to epitaxially integrate III–V cells with Si are resolved by using SiGe buffers and proper GaAs nucleation methods. These early results already show the enormous and realistic potential of the virtual SiGe substrate approach for generating high‐efficiency, lightweight and strong III–V solar cells. Copyright © 2002 John Wiley & Sons, Ltd.
Progress in the development of metamorphic multi‐junction III–V space solar cells
Authors: Sinharoy Samar , Patton Martin O. , Valko Thomas M. , Weizer Victor G.
Published: September 2002

Theoretical calculations have shown that highest‐efficiency III–V multi‐junction solar cells require alloy structures that cannot be grown on a lattice‐matched substrate. Ever since the first demonstration of high‐efficiency metamorphic single‐ junction 1.1 and 1.2 eV InGaAs solar cells, interest has grown in the development of multi‐junction cells of this type, using graded buffer layer technology. Essential Research Incorporated (ERI) is currently developing a dual‐junction 1.6 eV InGaP/1.1 eV InGaAs tandem cell (projected practical air‐mass zero (AM0), one‐sun efficiency of 27%, and 100‐sun efficiency of 31.1%) under a Ballistic Missile Defense Command (BMDO) SBIR Phase II program. A second ongoing research effort involves the development of a 2.1 eV AlGaInP/1.6 eV InGaAsP/1.2 eV InGaAs triple‐junction concentrator tandem cell (projected practical AM0 efficiency 36.5% under 100 suns) under a SBIR Phase II program funded by the Air Force. We are in the process of optimizing the dual‐junction cell performance. For the triple‐junction cell, we have developed the bottom and the middle cell, and are in the process of developing the layer structures needed for the top cell. A progress report is presented in this paper. Copyright © 2002 John Wiley & Sons, Ltd.
Quantum dot solar cells
Authors: Raffaelle Ryne P. , Castro Stephanie L. , Hepp Aloysius F. , Bailey Sheila G.
Published: September 2002

We have been investigating the synthesis of quantum dots of CdSe, CuInS2, and CuInSe2 for use in an intermediate bandgap solar cell. We have prepared a variety of quantum dots, using the typical organometallic synthesis routes pioneered by Bawendi et al. in the early 1990s. However, unlike previous work in this area, we have also utilized single‐source precursor molecules in the synthesis process. We present XRD, TEM, SEM and EDS characterization of our initial attempts at fabricating these quantum dots. Investigation of the size distributions of these nanoparticles via laser light scattering and scanning electron microscopy is also presented. Theoretical estimates on appropriate quantum dot composition, size, and inter‐dot spacing along with potential scenarios for solar cell fabrication is discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Phase behaviors of partially ionized hydrogels in aqueous salt solutions: Applicability of the modified double‐lattice model
Authors: Hong Young Pyo , Bae Young Chan
Published: September 2002

We investigated the effect of charge densities of the gel network and ionic strength of solution on swelling behaviors of ionized gels. We used the modified double‐lattice model, Flory–Erman's elastic model, and the ideal Donnan theory to describe swelling behaviors of the electrolyte bounded hydrogels. Energy parameters (ϵ/k, δϵ/k) were obtained from fitting liquid–liquid equilibria data of the linear poly‐N‐isopropylacrylamide/water system and two adjustable model parameters obtained from a nonelectrolyte hydrogel system. Calculated values agreed with experimental data for the given systems. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2333–2338, 2002
Processing, mechanical properties, and fracture behavior of cereal protein/poly(hydroxyl ester ether) blends
Authors: Wang C. , Carriere C. J. , Willett J. L.
Published: September 2002

Blends of poly(hydroxy ester ether) (PHEE), a recently developed bisphenol A ether‐based synthetic biodegradable thermoplastic polymer, with a soybean protein isolate and two hydrolyzed wheat glutens were studied. Blends of the proteins with PHEE were produced from 20 to 70% by weight of protein content. Young's moduli of the protein/PHEE blends fall in the range of 0.8–1.5 GPa with tensile strengths ranging from 10 to 30 MPa. Critical stress‐intensity factors of the blends ranged from 2 to 9 MPa‐m1/2 depending on the amount of protein added. Morphological analysis indicated a moderate degree of adhesion between the protein and PHEE phases in the blends. In general, as the protein content was increased the materials lost ductility and failed in a brittle manner; however, the mechanical properties of several compositions were comparable to commercial thermoplastics such as polystyrene. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2324–2332, 2002
Crystallization behavior of a propylene/ethylene copolymer: Nucleation and a clarifying additive
Authors: Martin C. P. , Vaughan A. S. , Sutton S. J. , Swingler S. G.
Published: September 2002

The isothermal crystallization behavior of a propylene/ethylene copolymer containing a clarifying additive has been studied in detail and compared with the equivalent unclarified grade. Differential scanning calorimetry was used to obtain crystallization exotherms for both the unclarified system and the clarified analogue. Avrami analysis of these data was then performed, using both linear and nonlinear data‐fitting techniques. Linear analysis revealed a change from a primary to a secondary crystallization process in the clarified system at about 50% relative crystallinity. Nonlinear techniques, however, led to more reliable estimates of the Avrami parameters and provided estimates of crystallization‐induction times. By combining the preceding with isothermal crystal‐growth‐rate data, the nucleation density in each material was obtained as a function of crystallization temperature. In the unclarified case, this fell exponentially with temperature. The nucleation density in the sorbitol‐clarified copolymer was 103–106 times greater than in the unclarified material, but decreased only slowly with increasing crystallization temperature throughout the temperature range investigated here. This final result appears entirely contradictory to previous morphological work in which a distinct morphological transition was observed at 128 °C and associated with a marked reduction in the nucleating efficiency of the sorbitol. Possible explanations for this apparent contradiction are considered. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2178–2189, 2002
Reversible melting of polyethylene extended‐chain crystals detected by temperature‐modulated calorimetry
Authors: Pak Jeongihm , Wunderlich Bernhard
Published: September 2002

The melting and crystallization of extended‐chain crystals of polyethylene are analyzed with standard differential scanning calorimetry and temperature‐modulated differential scanning calorimetry. For short‐chain, flexible paraffins and polyethylene fractions up to 10 nm length, fully reversible melting was possible for extended‐chain crystals, as is expected for small molecules in the presence of crystal nuclei. Up to 100 nm length, full eutectic separation occurs with decreasingly reversible melting. The higher‐molar‐mass polymers form solid solution crystals and retain a rapidly decreasing reversible component during their melting that decreases to zero about 1.5 K before the end of melting. An attempt is made to link this reversible melting to the known, detailed morphology and phase diagram of the analyzed sample that was pressure‐crystallized to reach chain extension and practically complete crystallization. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2219–2227, 2002
Relating fracture energy to entanglements at partially miscible polymer interfaces
Authors: Gorga Russell E. , Narasimhan Balaji
Published: September 2002

A new model has been developed to calculate the areal chain density of entanglements (Σeff) at partially miscible polymer–polymer interfaces. The model for Σeff is based on a stochastic approach that considers the miscibility of the system. The values agree between Σeff calculated from the model and literature values for the reinforced interfaces. Using Σeff calculated from the model, the interfacial width, and the average distance between entanglements, an equation for the fracture energy of nonreinforced polymer interfaces is proposed. This equation is used to model the transition from chain pullout to crazing. As a function of system miscibility, the model for Σeff also accurately predicts a maximum in mode I fracture energy (Gc) as a result of the transition from gradient‐driven to miscibility‐limited interdiffusion, which is observed experimentally. As Σeff increases, the fracture energy increases accordingly. Compared with a recent model developed by Brown, the new model correctly predicts a reduced Gc (attributed to chain pullout) when the interfacial width is less than the average distance between entanglements. Theoretical predictions of the change in fracture energy with respect to interfacial width agree with the experimental measurements. Finally, it is postulated that the use of a miscibility criterion for Gc may reveal the universal nature of the pullout to crazing transition. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2292–2302, 2002
Molecular weight and aggregation of Aeromonas gum treated with dimethyl sulfoxide in aqueous solution
Authors: Xu Xiaojuan , Zhang Lina , Norisuye Takashi
Published: September 2002

Aeromonas (A) gum, an acidic hetero polysaccharide, in 0.2 M LiCl/dimethyl sulfoxide (DMSO) was fractionated satisfactorily according to the nonsolvent addition method. Eight fractions were chosen to examine their aggregation behavior in aqueous solution. The weight‐average molecular weight (Mw), radius of gyration 〈S2〉1/2, and intrinsic viscosities [η] of the fractions in 0.2 M LiCl/DMSO and 0.5 M NaCl aqueous solution at 25 °C were measured by static light scattering and viscometry. The results indicated that the A gum was aggregated in 0.5 M NaCl aqueous solution at 25 °C, and the aggregates were broken in 0.2 M LiCl/DMSO. The apparent weight‐average aggregation number (Nap) of the fractions increased with the process of fractionation, that is,Napincreased from 1.1 to 15 with decreasingMwof the single chain. The fractions obtained by treating with DMSO were more easily dissociated in the aqueous solution, and itsNapwas lower than that of the A gum fractions that were not treated with DMSO. Moreover, the A gum molecules with relatively lowMwaggregated easily to form a compact spherelike structure in the aqueous solution. Elemental analysis and13C NMR spectroscopy indicated that DMSO was adsorbed on the A gum molecules caused by the fractionation program; DMSO not only prevented the polysaccharide aggregation but also increased the solubility. A model has been proposed to describe the aggregation behavior of the A gum chains with DMSO overcoat in the aqueous solution. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2269–2276, 2002
Interfacial tension of poly(lactic acid)/polystyrene blends
Authors: Biresaw G. , Carriere C. J.
Published: September 2002

Poly(lactic acid) (PLA) is a biodegradable synthetic polyester with unique properties that make it an excellent candidate for biomaterial blends. It provides improved moisture resistance to blends with biopolymers and biodegradability/biocompatibility to blends with synthetic polymers, without impairing the useful properties of blend components. The successful development of materials from blends of PLA requires an understanding of the factors affecting the interfacial properties of such blends. In this work, the effect of temperature on the interfacial tension of PLA/polystyrene (PS) blends was measured at 170–200 °C with the imbedded fiber retraction (IFR) method. IFR allows for the direct measurement of the interfacial tension of blends with high molecular weight/high viscosity components. In the temperature range studied, the interfacial tension of PLA/PS was independent of temperature and had a value of 5.4 ± 1.3 dyn/cm. The interfacial tension was also calculated from the surface energies of PLA and PS with geometric mean (GM), harmonic mean (HM), and Antonoff's equations and from solubility parameters with the procedure of Luciani et al. IFR measured values were similar to those predicted by the procedure of Luciani et al. and Antonoff's equations, which gave 4.4 and 3.0 ± 1.4 dyn/cm, respectively. The GM and HM methods predicted much lower values of 1.1 ± 0.5 and 1.7 ± 1.1 dyn/cm, respectively. Published 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2248–2258, 2002
Significant glass‐transition‐temperature increase through hydrogen‐bonded copolymers
Authors: Kuo Shiao‐Wei , Xu Hongyao , Huang Chih‐Feng , Chang Feng‐Chih
Published: September 2002

The role of hydrogen bonding in promoting intermolecular cohesion and higher glass‐transition temperatures of polymer is a subject of longstanding interest. A series of poly(vinylphenol‐co‐vinylpyrrolidone) copolymers were prepared by the free‐radical copolymerization of acetoxystyrene and vinylpyrrolidone; this was followed by the selective removal of the acetyl protective group, with corresponding and significant glass‐transition‐temperature increases after this procedure. The incorporation of acetoxystyrene into poly(vinylpyrrolidone) resulted in lower glass‐transition temperatures because of the reduced dipole interactions in its homopolymers. However, the deacetylation of acetoxystyrene to transform the poly(vinylphenol‐co‐vinylpyrrolidone) copolymer enhanced the higher glass‐transition temperature because of the strong hydrogen bonding in the copolymer chain. The thermal properties and hydrogen bonding of these two copolymers were investigated with differential scanning calorimetry and Fourier transform infrared spectroscopy, and good correlations between the thermal behaviors and IR results were observed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2313–2323, 2002
Learning as discourse change: A sociocultural mechanism
Authors: Wickman Per‐Olof , Östman Leif
Published: September 2002

This paper deals with a theoretical mechanism for learning and a methodological approach for analyzing meaning making in classroom talk and action. It examines the potential of the approach for illuminating learning on a discursive level, i.e., how discourses change and how individuals become participants of new practices. Our approach involves a high‐resolution analysis of how meaningful relations are built in encounters between individuals and between individuals and the world. The approach is based mainly on the work of the later Wittgenstein, but also on pragmatism and sociocultural research. To demonstrate how our approach can be used, we analyze what university students learn during a practical on insects. We specifically demonstrate how the encounters with physical pinned insects contribute to the meaning students make and how these encounters interact with other experiences during laboratory work. © 2002 Wiley Periodicals, Inc. Sci Ed 86:601–623, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10036
Towards renewed research questions from the outcomes of the European project Labwork in Science Education
Authors: Séré Marie‐Geneviève
Published: September 2002

A research project about labwork at Upper secondary and Undergraduate levels was launched in 1996, funded by the European Commission. Seven research groups from six European countries participated in the surveys at European scale and carried out a number of case‐studies. This common work allowed numerous discussions which, months later, permit to articulate renewed directions of research about labwork. In this paper, new research questions are presented, drawing upon the outcomes of the project. One of them was to disclose numerous potential objectives which can be aimed for in a laboratory. This means that conscious choices must be taken among objectives. These are studied in this paper under the three classical headings of conceptual/epistemological/procedural objectives. © 2002 Wiley Periodicals, Inc. Sci Ed 86:624–644, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10040
Scientists as writers
Authors: Yore Larry D. , Hand Brian M. , Prain Vaughan
Published: September 2002

This study attempted to establish an image of a science writer based on a synthesis of writing theory, models, and research literature on academic writing in science and other disciplines and to contrast this image with an actual prototypical image of scientists as writers of science. The synthesis was used to develop a questionnaire to assess scientists' writing habits, beliefs, strategies, and perceptions about print‐based language. The questionnaire was administered to 17 scientists from science and applied science departments of a large Midwestern land grant university. Each respondent was interviewed following the completion of the questionnaire with a custom‐designed semistructured protocol to elaborate, probe, and extend their written responses. These data were analyzed in a stepwise fashion using the questionnaire responses to establish tentative assertions about the three major foci (type of writing done, criteria of good science writing, writing strategies used) and the interview responses to verify these assertions. Two illustrative cases (a very experienced, male physical scientist and a less experienced, female applied biological scientist) were used to highlight diversity in the sample. Generally, these 17 scientists are driven by the academy's priority of publishing their research results in refereed, peer‐reviewed journals. They write their research reports in isolation or as a member of a large research team, target their writing to a few journals that they also read regularly, use writing in their teaching and scholarship to inform and persuade science students and other scientists, but do little border crossing into other discourse communities. The prototypical science writer found in this study did not match the image based on a synthesis of the writing literature in that these scientists perceived writing as knowledge telling not knowledge building, their metacognition of written discourse was tacit, and they used a narrow array of genre, strategies, target audiences, and expectations for their writing. © 2002 Wiley Periodicals, Inc.Sci Ed86:672–692, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.10042
Graph‐based tools for re‐engineering
Authors: Cremer Katja , Marburger André , Westfechtel Bernhard
Published: September 2002

Maintenance of legacy systems is a challenging task. Often, only the source code is still available, while design or requirements documents have been lost or have not been kept up‐to‐date with the actual implementation. In particular, this applies to many business applications which are run on a mainframe computer and are written in COBOL. Many companies are confronted with the difficult task of migrating these systems to a client/server architecture with clients running on PCs and servers running on the mainframe. REforDI (REengineering for DIstribution) is a graph‐based environment supporting this task. REforDI provides integrated code analysis, re‐design, and code transformation for COBOL applications. To prepare the application for distribution, REforDI assists in the transition to an object‐based architecture, according to which the source code is subsequently transformed into Object COBOL. Internally, REforDI makes heavy use of generators to reduce the implementation effort and thus to enhance adaptability. In particular, graph‐based tools for re‐engineering are generated from a formal specification which is based on programmed graph transformations. Copyright © 2002 John Wiley & Sons, Ltd.
A semantic entropy metric
Authors: Etzkorn Letha H. , Gholston Sampson , Hughes William E.
Published: September 2002

This paper presents a new semantically‐based metric for object‐oriented systems, called the Semantic Class Definition Entropy (SCDE) metric, which examines the implementation domain content of a class to measure class complexity. The domain content is determined using a knowledge‐based program understanding system. The metric's examination of the domain content of a class provides a more direct mapping between the metric and common human complexity analysis than is possible with traditional complexity measures based on syntactic aspects (software aspects related to the format of the code). Additionally, this metric represents a true design metric that can measure complexity early in the life cycles of software maintenance and software development. The SCDE metric is correlated with analyses from a human expert team, and is also compared to syntactic complexity measures. Copyright © 2002 John Wiley & Sons, Ltd.
Syntactic reductions for efficient deadlock analysis
Authors: De Francesco Nicoletta , Santone Antonella
Published: September 2002

A well‐known problem in the verification of concurrent systems based on model checking is state explosion: concurrent systems are often represented by automata with a prohibitive number of states. A reduction technique to reduce state explosion in deadlock checking is presented. The method is based on an automatic syntactic simplification of a calculus of communicating systems (CCS) specification, which keeps the parts of the program structure that may lead to a deadlock and deletes the other parts. Copyright © 2002 John Wiley & Sons, Ltd.
Fetotoxicity caused by the interaction between zinc and arsenic in mice
Authors: Fascineli Maria Luiza , Sidney Hunter E. , De Grava Kempinas Wilma
Published: September 2002

Arsenic is an environmental pollutant that induces congenital malformations in experimental models and can contribute to human birth defects. The environmental exposure to arsenic is relatively small when compared with the doses required to cause teratogenicity in mice and other laboratory animals. In order to study the action of zinc in the arsenic‐induced teratogenicity, in the present work mice were either pretreated with zinc and later with arsenic or were treated simultaneously with zinc and arsenic in vivo and in vitro. Following administration of arsenate on gestation day 8, pregnant females were killed on the 17th day of gestation; maternal and fetal data were collected by laparotomy and used to calculate reproductive parameters. Fetuses were analyzed for the presence of external malformation and, after the appropriate processing, visceral and skeletal analyses were accomplished. Conceptuses were exposed in whole embryo culture to arsenicals on gestation day 8 (3–6 somite stage). After a 26 h culture period, morphological development was assessed. Neither pretreatment with zinc nor simultaneous administration of zinc prevented arsenic teratogenicity in these experimental models. Teratogenesis Carcinog. Mutagen. 22:315–327, 2002. © 2002 Wiley‐Liss, Inc.
Effects of glucose on cloning efficiency and mutagenesis of fetal rat cells
Authors: Donovan Paul J. , Smith George T. , Riggs Charles W. , Alexandrov Valerii A.
Published: September 2002

In a previous study, treatment of rats with 10% glucose in the drinking water, as fetuses during gestation and for 1.5 months after delivery, significantly enhanced tumor incidence that resulted from N‐methyl‐N‐nitrosourea (MNU, 20 mg/kg) given transplacentally on gestation day 21, with a 1.6‐fold increase in overall tumor incidence. We investigated whether glucose would have an effect on MNU‐induced mutation in fetal F‐344 rat somatic cells as measured in an in vivo/in vitro assay. Rat fetuses were exposed transplacentally to MNU on gestation day 16 and to a 10% glucose solution from gestation day 7 to day 17. Cells were isolated on gestation day 17 for determination of cloning efficiency and for selection of 6‐thioguanine (6‐TG)‐resistant HGPRT mutants. Cloning efficiency of the fetal cells exposed to MNU alone was 22.6±2.3% S.E., while that for cells from fetuses exposed to MNU+glucose was 27.5±1.6% S.E., which was a significant difference (P=0.018). This indicates an effect of glucose on cell proliferation and survival. MNU treatment significantly increased the mutation frequency of fetal cells from a spontaneous value of 0.4×10−6 per viable cell to (8.8±1.8 S.E.,)×10−6 (P=0.0087). The coexposure to MNU and glucose yielded a mutant frequency per plate of 0.62±0.05 S.E., which was a 1.5‐fold increase compared to MNU alone (0.43±0.11 S.E., P=0.075. In summary, the data indicate that glucose during pregnancy increases proliferation/survival of fetal cells and possibly also mutation rate. Teratogenesis Carcinog. Mutagen. 22:329–334, 2002. Published 2002 Wiley‐Liss, Inc.
Rat ventral prostate microsomal biotransformation of ethanol to acetaldehyde and 1‐hydroxyethyl radicals: its potential contribution to prostate tumor promotion
Authors: Castro G.D. , Delgado de Layño A.M.A. , Costantini M.H. , Castro J.A.
Published: September 2002

Rat ventral prostate microsomal fraction was able to biotransform ethanol to acetaldehyde and 1‐hydroxyethyl radicals (1HEt) in the presence of NADPH and oxygen. The enzymatic processes involved were not inhibited by desferrioxamine, CO, SKF 525A, 4‐methylpyrazole, or polyclonal antibody against P450 reductase but they were significantly inhibited by diethyldithiocarbamate, 2‐mercapto‐1‐methylimidazol, thiobenzamide, or diphenyleneiodonium chloride. Results would suggest the partial participation in these ethanol bioactivation processes of flavin containing monooxygenase (FMO) and/or other flavin dependent oxidases/peroxidases and of a non‐iron metal‐containing enzymes. Acetaldehyde and free radicals production by prostate microsomal fraction might potentially contribute to tumor promotion in heavy alcohol drinkers. Teratogenesis Carcinog. Mutagen. 22:335–341, 2002. © 2002 Wiley‐Liss, Inc.
Teratogenic effects of N‐ethyl‐N‐nitrosourea (ENU) on larvae of the self‐fertilizing fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae)
Authors: Lee Jae‐Seong , Chang Sung Yeoul , Kim Il‐Chan , Han Myung‐Soo , Lee Young‐Sik , Lee Yong‐Sung
Published: September 2002

We showed that N‐Ethyl‐N‐Nitrosourea (ENU) induces teratogenesis in larvae of the self‐fertilizing fish Rivulus marmoratus. We discuss this and the issue of carcinogenesis caused by ENU. Teratogenesis Carcinog. Mutagen. 22:363–367, 2002. © 2002 Wiley‐Liss, Inc.
Determination of allelic deletion of multiple endocrine neoplasm type 1 (MEN1) gene in acute myeloid leukemia (AML) by application of FISH‐TSA technique
Authors: Acar Hasan , Kaynak Murat , Yakut Tahsin , Uçar Fahri , Egeli Ünal
Published: September 2002

We have used the single and dual color fluorescence in situ hybridization (FISH) technique combined with a new detection system, tyramide signal amplification (TSA), by using the multiple endocrine neoplasm type 1 (MEN1) gene and chromosome 11 specific alpha satellite DNA probes for the study of the allelic deletion of the MEN1 gene. The MEN1 gene is a new tumor supressor gene and has been recently cloned on chromosome 11q13. FISH combined with the TSA detection system was performed on bone marrow interphase nuclei of 22 patients with acute myeloid leukemia (AML). The FISH‐TSA analysis revealed the mono allelic deletion of the MEN1 gene in 4 out of 22 patients (18.18%), 2 of 9 AML‐M2 patients (22.2%), 1 of 6 AML‐M4 patients (16.6%), and 1 of 4 AML‐M5 patients (25.0%). Our study indicates that allelic deletion of the MEN1 gene is not a major cause or a primary event in tumorigenesis of AML, although the long arm (q13 region) of chromosome 11 involves a chromosomal rearrangement in AML. Teratogenesis Carcinog. Mutagen. 22:369–375, 2002. © 2002 Wiley‐Liss, Inc.
Blocking the translation elongation factor‐1δ with its antisense mRNA results in a significant reversal of its oncogenic potential
Authors: Lei Yi‐xiong , Chen Jia‐kun , Wu Zhong‐liang
Published: September 2002

In spite of the strong evidence for the carcinogenic activity of cadmium and its related compounds, the underlying molecular mechanisms that lead to malignant transformation in cells exposed to cadmium remain unknown. Recently, Joseph et al. [J. Biol. Chem. 227:6131–6136, 2002] have identified, cloned, and characterized the mouse Translation Elongation Factor‐1δ sub‐unit (TEF‐1δ, GenBank Accession Number AF304351) as a novel cadmium‐responsive proto‐oncogene. Presently, additional studies regarding the oncogenic potential of TEF‐1δ have been carried out. Transfection of NIH3T3 cells with the pcDNA3.1 expression vector containing the TEF‐1δ cDNA in the sense (5′→3′) orientation resulted in overexpression of the encoded 31 kDa protein. Transfection‐mediated overexpression of TEF‐1δ protein resulted in transformation of the cells as evidenced from the appearance of transformed foci. Cotransfection of the cells with a mixture of plasmid DNA consisting of TEF‐1δ cDNA in the sense (5′→3′) and in the antisense (3′→5′) orientation resulted in significant inhibition of translation of the TEF‐1δ protein. Antisense TEF‐1δ mRNA‐mediated inhibition of translation of TEF‐1δ protein, furthermore, resulted in inhibition of TEF‐1δ‐mediated transformation of NIH3T3 cells as evidenced from the decrease in the number of transformed foci. These results further confirm that overexpression of TEF‐1δ is oncogenic and the antisense TEF‐1δ mRNA expression reverses its oncogenic potential. Teratogenesis Carcinog. Mutagen. 22:377–383, 2002. © 2002 Wiley‐Liss, Inc.
The managerial issues associated with global account management
Authors: Harvey Michael , Myers Mathew B. , Novicevic Milorad M.
Published: September 2002

The increase in cooperative global arrangements between suppliers and customers has grown precipitously in the

last five years. These global account management (GAM) strategies frequently are brought about due to

the initiative of the global customer, requiring the customer's supplier to manage their total global needs.

In other cases, suppliers perceive GAM as a means to develop long‐term relationships with key global

customers and at the same time hinder competitive inroads. The managerial considerations in implementing and

managing GAM teams are the focus of this article. A step‐by‐step process for management to follow

when implementing a GAM program is also discussed. © 2002 Wiley Periodicals, Inc.
Characterization of the putative maltose transporters encoded by YDL247w and YJR160c
Authors: Day Rachel E. , Higgins Vincent J. , Rogers Peter J. , Dawes Ian W.
Published: September 2002

The maltose permease family of Saccharomyces cerevisiae comprises five proteins, three of which are characterized, MAL31, MAL61 and AGT1 and two putative permeases, YDL247w (MPH2) and YJR160c (MPH3). The two uncharacterized permeases share 100% identity and have 75% identity with MAL31 and MAL61 and 55% identity with AGT1. Characterization of the genes YDL247w and YJR160c confirmed that they encode α‐glucoside permeases capable of transporting maltose, maltotriose, α‐methylglucoside and turanose. Analysis of the promoter regions identified regulatory elements, binding sites for the transcriptional activator, Malx3p and the inhibitory protein, Mig1p. Further analysis of the flanking sequences located blocks of identity covering five open reading frames, indicating that this region was involved in chromosomal block duplication. The members of the maltose permease family are proteins that have strongly overlapping but nevertheless distinct functions, which is a selective advantage for yeast, as it reflects successful adaptation to the variety of environmental conditions to which the yeast cells are exposed; such adaptability is very important in an industrial context. Copyright © 2002 John Wiley & Sons, Ltd.