bluuebunny/crossref_metadata_2025_split huggingface dataset:
The multiple propensity score for analysis of dose–response relationships in drug safety studies
Authors: Wang Jixian , Donnan Peter T. , Steinke Douglas , MacDonald Thomas M. 
Published: August 2002

AbstractIn order to detect adverse drug reactions, large observational drug safety studies are necessary as randomized clinical trials rarely have enough power. However, in order to obtain reliable results the issue of confounding, especially confounding by indication, should be addressed. We proposed a multiple propensity score, which is an extension of the propensity score, to reduce the bias in a dose–response analysis in a drug safety study. The multiple propensity score has similar properties to the propensity score in Rosenbaum and Rubin.1Using the propensity score for bias reduction of the risk ratio was considered. We used the multiple propensity score in a study of the dose–response relationship between diclofenac prescriptions and hospitalization for gastrointestinal bleeding and perforation using a record linkage database. We found that the unadjusted risk ratios were biased downwards due to confounders and that this bias was reduced by using stratification based on the multiple propensity score. Copyright © 2001 John Wiley & Sons, Ltd.
The use of surrogate endpoints in clinical trials: focus on clinical trials in cardiovascular diseases
Authors: Lonn Eva 
Published: August 2002

AbstractSurrogate endpoints include a wide range of laboratory or physical measurements used in clinical trials as a substitute for meaningful clinical endpoints that directly assess effects of the intervention(s) tested on mortality and/or morbidity. These surrogate endpoints are frequently employed in clinical trials and when used judiciously, can accelerate and focus the study of new therapies and can greatly enhance our understanding of their mechanisms of action. The current review provides a definition of surrogate endpoints, proposes practical criteria for establishing their validity, outlines some of the advantages, disadvantages and specific statistical considerations associated with their use in clinical trials and attempts also to highlight drug approval issues associated with the use of these endpoints. A number of examples are also provided related to the use of surrogate endpoints in clinical trials with special emphasis on their use in cardiovascular medicine. Copyright © 2001 John Wiley & Sons, Ltd.
Electrolyte diffusion in a chitosan membrane
Authors: Vasconcelos C L de , Rocha A N L , Pereira M R , Fonseca J L C 
Published: August 2002

AbstractChitosan membranes were manufactured and used in the study of diffusion of aqueous potassium chloride solution. Diffusion was found to be outside the Fickian regime, this deviation being correlated with possible changes in the membrane structure during the experiments as well as to the occurrence of osmosis.© 2001 Society of Chemical Industry
Part 14. Synthesis and properties of new polyketoamine polymers containing cycloalkanone moieties in the main chain
Authors: Aly Kamal I , Abbady Mahmoud A , Mahgoub Safaa A , Hussein Mahmoud A 
Published: August 2002

AbstractA new interesting class of polyketoamine polymers based on diarylidenecycloalkanone were synthesized by suspension polycondensation. These polymers were synthesized via polymerization of 2,5‐bis(4‐chloroacetylbenzylidene)cyclopentanone and 2,6‐bis(4‐chloroacetylbenzylidene)cyclohexanone with different aliphatic and aromatic diamines including, p‐phenylenediamine, m‐phenylenediamine, o‐phenylenediamine, 4,4′‐diaminodiphenylmethane, 4,4′‐diaminodiphenylether, 4,4′‐diaminodiphenylsulfone, hydrazine hydrate, 1,2‐diaminoethane, 1,3‐diaminopropane and 1,8‐diaminooctane.Model compounds were prepared by condensation of 2,5‐bis(4‐chloroacetylbenzylidene)cyclopentanone and/or 2,6‐bis(4‐chloroacetylbenzylidene)cyclohexanone with aniline in dry benzene, and their structure was confirmed by elemental analysis and spectroscopy. The structure of the polymers obtained was also confirmed by the same methods. Moreover, the identification of the polymers was carried out by other techniques, eg crystallinity from X‐ray spectroscopy, viscosimetry, thermogravimetric analysis; the morphological properties of selected examples were tested by scanning electron microscopy. The electrical conductivity of selected examples is about 10−12 ohm cm−1. The results are in accord with the structure.© 2002 Society of Chemical Industry
Gallium Contacts onp‐type silicon substrates
Authors: Stuckings M. F. , Fischer B. , Giroult G. , Cuevas A. , Stocks M. J. , Blakers A. W. 
Published: August 2002

AbstractA significant reduction in contact resistance of palladium/silicon contacts was realised by the use of a thin intermediate gallium layer. The contact resistance of the palladium/gallium/silicon contact was found to be similar to aluminium/silicon contacts on 0.5 Ω cm silicon. Solar cells processed on 1 Ω cm substrates with this structure demonstrated better contact properties than conventional aluminium/silicon contacts. The improved characteristics are believed to be a result of gallium/silicon alloying at low temperature (400°C). The palladium layer is critical as aluminium/gallium/silicon layers show dramatically increased contact resistance. The palladium silicide may interact with the aluminium layer to form a stable ternary compound, preventing aluminium from penetrating deeper into the silicon. Copyright © 2001 John Wiley & Sons, Ltd.
Manufacturing technology for terrestrial PV systems: high efficiency crystalline Si through amorphous Si
Authors: Kaneiwa Minoru , Nomoto Katsuhiko 
Published: August 2002

AbstractIn order to meet the rapidly growing demands for solar power photovoltaic systems, grounded on public consciousness of global environmental issues, Sharp has increased the production of solar cells and modules 50‐fold in last 7 years. Efforts to establish manufacturing technologies of solar cells for terrestial use and approaches toward high light‐to‐electricity conversion efficiency using silicon material (crystalline to amorphous ) are described. Copyright © 2002 John Wiley & Sons, Ltd.
Manufacturing technology for ribbon silicon (EFG) wafers and solar cells
Authors: Schmidt W. , Woesten B. , Kalejs J.P. 
Published: August 2002

AbstractManufacturing of wafers and solar cells based on edge‐defined film‐fed growth (EFG) ribbon technology has been scaled up to 20 MW in the ASE group. Highly automated manufacturing lines for wafers and solar cells have been constructed and solar cell efficiencies optimized to above the 14% level. The technology developed for these production lines incorporates new low‐cost processes with minimal environmental impact and waste materials production. Copyright © 2002 John Wiley & Sons, Ltd.
Photophysical characteristics of soluble oligo(p‐phenylenevinylene)–fullerene dyad
Authors: Yang Junlin , Lin Hongzhen , Wang Shu , Li Yuliang , Bai Fenglian , Zhu Daoben 
Published: August 2002

AbstractThe fact that C60 is a good acceptor has stimulated interest in covalently linked complexes, including polymers and oligomers. Photoinduced charge transfer in these systems has great potential for use in photovoltaic devices. In this study, an alternating conjugated oligomer of alkylated carbazole and dialkoxyl‐substituted phenylene, with pendant C60 moieties, (PPV‐AFCAR) was prepared and characterized. The excited‐state properties of PPV–AFCAR were investigated with steady‐state spectroscopy and lifetime measurements. After photoexcitation, photoinduced energy transfer from the oligomer chain to the pendant moiety occurred in great proportion, but a charge‐separation process did not. Whether the energy‐transfer process was measurable or not depended on the system temperature. At 77 K, a quantum yield of more than 50% for energy transfer was found by the fitting of a linear combination of the excitation spectra of the precursor oligomer, the alternating conjugated oligomer of alkylated carbazole and dialkoxyl‐substituted phenylene PPV–ACAR, and the absorption spectra of C60. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3981–3988, 2001
Determination of the equilibrium constant for the reaction between bisphenol A and diphenyl carbonate
Authors: Gross Stephen M. , Bunyard W. Clayton , Erford Karen , Roberts George W. , Kiserow Douglas J. , DeSimone Joseph M. 
Published: August 2002

AbstractDespite the industrial significance of poly(bisphenol A carbonate), there is a scarcity of open literature on the equilibrium of the melt‐phase process. In fact, the equilibrium constant (Keq) for this reaction has never been measured directly. This article describes a process on the basis of NMR for the measurement of Keq for the reaction between bisphenol A and diphenyl carbonate in the presence and absence of a catalyst. The apparent enthalpy and entropy were calculated using a van't Hoff plot. Decomposition of bisphenol A is a common side reaction in the melt‐phase reaction performed at high temperatures in the presence of catalyst. The effect of these side reactions on the Keq in the presence of catalyst is determined. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 171–178, 2002
Synthesis and properties of aromatic polyamides based on a benzonorbornane bis(ether carboxylic acid)
Authors: Hsiao Sheng‐Huei , Huang Tai‐Lin 
Published: August 2002

AbstractA set of new aromatic polyamides containing ether and benzonorbornane units were synthesized by the direct phosphorylation polycondensation of 3,6‐bis(4‐carboxyphenoxy)benzonorbornane with various aromatic diamines. The polymers were produced in high yields and moderate to high inherent viscosities (0.64–1.70 dL/g). The polyamides derived from rigid diamines such as p‐phenylenediamine and benzidine were semicrystalline and insoluble in organic solvents. The other polyamides were amorphous and organosoluble and afforded flexible and tough films via solution casting. These films exhibited good mechanical properties, with tensile strengths of 95–101 MPa, elongations at break of 13–25%, and initial moduli of 1.97–2.33 GPa. The amorphous polyamides showed glass‐transition temperatures between 176 and 212 °C (by differential scanning calorimetry) and softening temperatures between 194 and 213 °C (by thermomechanical analysis). Most of the polymers did not show significant weight loss before 450 °C in nitrogen or in air. Some properties of these polyamides were also compared with those of homologous counterparts without the pendent norbornane groups. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 947–957, 2002
Photochemical modification of polymer surface by the pendant photobase generator containing oxime‐urethane groups and its application to an image‐recording material
Authors: Chae Kyu Ho , Jang Hee Jung 
Published: August 2002

AbstractCopolymers containing oxime‐urethane groups were prepared by the copolymerization of methyl methacrylate and benzophenoneoximinocarbonylaminoethyl methacrylate (BCM), and their photochemical properties were examined from the UV and IR absorption spectral changes. The decomposed fraction of oxime‐urethane groups in the copolymer increased with irradiation time, but it decreased with the content of BCM units in the copolymer. Changes of the surface properties of the copolymer film on irradiation were studied by measurements of the contact angle and dyeing with an acid dye. The surface of the copolymer film changed to become more hydrophilic upon irradiation with 254 nm of UV light. After the irradiated copolymer films were treated with HCl or methanol, changes of the contact angle of water on irradiation were compared. The copolymer film was dyed by acid dyes after treatment of the irradiated film with HCl. The degree of dyeing increased with irradiation time and BCM units in the copolymer, but it was unaffected by the film thickness. Various colors were developed on the irradiated area depending on the acid dye as the developer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1200–1207, 2002
Synthesis of well‐defined second‐generation dendritic polymers of isoprene (I) and styrene (S): (S2I)3, (SI′I)3, (I″I′I)3, and (I′2I)4
Authors: Chalari Ioanna , Hadjichristidis Nikos 
Published: August 2002

AbstractThe synthesis of second‐generation (G‐2) dendritic polymers of isoprene (I) and styrene (S) was achieved with anionic polymerization high‐vacuum techniques and by performing the following steps: (1) selective reaction of a living chain with the chlorosilane group of 4‐(chlorodimethylsilyl)styrene (a dual‐functionality compound) to produce a macromonomer, (2) addition of a second living chain (same or different) to the double bond of the macromonomer, (3) polymerization of I with the anionic sites, and (4) reaction of the produced off‐center living species with trichloromethyl silane or tetrachlorosilane (CH3SiCl3 or SiCl4). The combined characterization results showed that the G‐2 dendritic macromolecules synthesized—(S2I)3, (SI′I)3, (I″I′I)3, (I′2I)4—have a high molecular and compositional homogeneity. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1519–1526, 2002
Synthesis of multihydroxyl branched polyethers by cationic copolymerization of 3,3‐bis(hydroxymethyl)oxetane and 3‐ethyl‐3‐(hydroxymethyl)oxetane
Authors: Chen Yu , Bednarek Melania , Kubisa Przemysław , Penczek Stanisław 
Published: August 2002

AbstractThe cationic ring‐opening polymerization of 3,3‐bis(hydroxymethyl)oxetane (BHMO) and the copolymerization of BHMO with 3‐ethyl‐3‐(hydroxymethyl)oxetane (EOX) were studied. Medium molecular weight polymers (number‐average molecular weight ≈ 2 × 103) were obtained in bulk polymerization. Poly[3,3‐bis(hydroxymethyl)oxetane], as highly insoluble, was only characterized by gel permeation chromatography and NMR methods in the esterified form. Copolymers of BHMO and EOX that were slightly soluble in organic solvents were characterized in more detail. In a copolymerization from a 1:1 mixture, the comonomers were consumed at equal rates. Matrix‐assisted laser desorption/ionization time‐of‐flight analysis confirmed that a random 1:1 copolymer was formed. 13C NMR analysis indicated that in contrast to previously described homopolymers of EOX in which the degree of branching was limited, the homopolymers of BHMO were highly branched. This pattern was preserved in the copolymers; EOX units were predominantly linear, whereas BHMO units were predominantly branched. The copolymerization of BHMO with EOX provides, therefore, a route to multihydroxyl branched‐polyethers with various degrees of branching containing OH groups exclusively as ≡CCH2OH units. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1991–2002, 2002
Reversible nonlinear conduction behavior for high‐density polyethylene/graphite powder composites near the percolation threshold
Authors: Zheng Qiang , Song Yihu , Wu Gang , Yi Xiaosu 
Published: August 2002

AbstractThe reversible nonlinear conduction (RNC) behavior of high‐density polyethylene/graphite powder composites with various graphite powder volume concentrations slightly above the threshold has been studied. The relationships between the current density (J) and electric field (E) of the composites, as shown in J(E) curves, can be well described by the scaling functions of J/Jc ∼ (E/Ec) when E < Ec and J/Jc ∼ (E/Ec) when E > Ec, where Jc is the crossover current density and Ec is the crossover electric field. The results indicate that Jc scales with the linear conductivity σ0 as Jc ∼ σ. It is believed that the macroscopic RNC is a combined result of the microscopic conduction processes, involving electronic transporting along carbon chains and tunneling or hopping across thin polymer bridges. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2833–2842, 2001
Hydrogels for colon‐specific drug delivery: Swelling kinetics and mechanism of degradation in vitro
Authors: Yin Yihua , Yang Yajiang , Xu Huibi 
Published: August 2002

AbstractHydrogels based on n‐alkyl methacrylate esters (n‐AMA) of various chain lengths, acrylic acid, and acrylamide crosslinked with 4,4′‐di(methacryloylmino)azobenzene were prepared. Swelling kinetics and the mechanism of degradation in vitro of the hydrogels as well as the mutual relations between both were studied by the immersion of slabs in buffered solutions at pH 7.4. The diffusion of water into the slabs was discussed on the stress‐relaxation model of polymer chains. The results obtained agreed well with Schott's second‐order diffusion kinetics. The gels are degradable by anaerobes in the colon. The results obtained showed that the degradation of networks proceeded via a pore mechanism. The factors influencing the swelling and degradation of the gels include the degree of crosslinking, the lengths of the n‐AMA side chains, and the composition. These hydrogels have the potential for colon‐specific drug delivery. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 3128–3137, 2001
Bonding of a viscoelastic periodic rough surface to a rigid layer
Authors: Hui C. Y. , Lin Y. Y. , Creton Costantino 
Published: August 2002

AbstractA theoretical analysis is performed for the study of the bonding of a viscoelastic rough surface to a rigid substrate. The mechanics of contact and adhesion are studied with the Dugdale–Barenblatt model for surface interaction. Exact solutions are obtained for arbitrary surface profiles and loading histories. Detailed solutions are given for a power‐law viscoelastic material. This solution is used to determine the time for the self‐bonding of surfaces (solid sintering under zero load). The time to self‐bonding is shown to be extremely sensitive to the aspect ratio of the asperities. A closed form expression is derived for the time needed to achieve full contact when the surfaces are compressed with a load that increases linearly with time. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 545–561, 2002; DOI 10.1002/polb.10113
X‐ray studies on the double melting behavior of poly(butylene terephthalate)
Authors: Yasuniwa Munehisa , Tsubakihara Shinsuke , Ohoshita Kazuhito , Tokudome Shin'Ichi 
Published: August 2002

AbstractThe double melting behavior of poly(butylene terephthalate) (PBT) was studied with differential scanning calorimetry (DSC) and wide‐angle X‐ray analysis. DSC melting curves of melt‐crystallized PBT samples, which we prepared by cooling from the melt (250 °C) at various cooling rates, showed two endothermic peaks and an exothermic peak located between these melting peaks. The cooling rate effect on these peaks was investigated. The melt‐crystallized PBT sample cooled at 24 K min−1 was heated at a rate of 1 K min−1, and its diffraction patterns were obtained successively at a rate of one pattern per minute with an X‐ray measurement system equipped with a position‐sensitive proportional counter. The diffraction pattern did not change in the melting process, except for the change in its peak height. This suggests that the double melting behavior does not originate from a change in the crystal structure. The temperature dependence of the diffraction intensity was obtained from the diffraction patterns. With increasing temperature, the intensity decreased gradually in the low‐temperature region and then increased distinctly before a steep decrease due to the final melting. In other words, the temperature‐dependence curve of the diffraction intensity showed a peak that is interpreted as proof of the recrystallization in the melting process. The peak temperature was 216 °C. The temperature‐dependence curve of the enthalpy change obtained by the integration of the DSC curve almost coincided with that of the diffraction intensity. The double melting behavior in the heating process of PBT is concluded to originate from the increase of crystallinity, that is, recrystallization. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2005–2015, 2001
Young's modulus of polyethylene in the microstrain region
Authors: Rabinowitz Stephen , Brown Norman 
Published: August 2002

AbstractThe stress–strain behavior of various polyethylenes was measured with a strain sensitivity of 2 × 10−7. Young's modulus was measured as a function of the strain rate. The shapes of the stress–strain curves in the vicinity of room temperature were nonlinear down to the lowest measurable strain. The stress–strain behavior in the microstrain region was well described by the model of the standard linear solid. From the model, the relaxation time was determined along with the relaxed and unrelaxed moduli. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2420–2429, 2001
From evidence to practice: Factors affecting the specialist breast nurse's detection of psychological morbidity in women with breast cancer
Authors: Parle Michael , Gallagher Jill , Gray Christine , Akers Gina , Liebert Barbara 
Published: August 2002

AbstractPsychological morbidity is high for women with breast cancer and is often undetected and untreated. Encouragingly, there are well‐evaluated strategies to help improve psychological outcomes, but the challenge remains as to how to transfer these to routine care settings. The National Health and Medical Research Council (NHMRC) National Breast Cancer Centre used evidence‐based psychosocial clinical practice guidelines and breast cancer treatment guidelines to develop a comprehensive specialist breast nurse (SBN) model of care and conducted a feasibility study to observe its implementation in diverse clinical conditions. Seven SBNs at four Australian cancer treatment centres implemented the model of care to support 196 women with a new diagnosis of early or locally advanced breast cancer. The SBN role in detecting women's psychological difficulties is reported here. Two months after diagnosis, 36% of women had a likely psychological disorder on the General Health Questionnaire 12‐item (GHQ12) version. The SBNs detected as many as 85% and as few as 20% of high GHQ12 scorers, depending upon a woman's psychosocial risk factors and consultation factors. Few women were referred to psychological services, suggesting other barriers to care. More specific communication skills training, psychological symptom screening questionnaires and better access to psychological services may help the implementation of the model of care. Copyright © 2001 John Wiley & Sons, Ltd.
Daily assessment of coping in patients with gastrointestinal cancer
Authors: Wasteson Elisabet , Nordin Karin , Hoffman Katarina , Glimelius Bengt , Sjödén Per‐Olow 
Published: August 2002

AbstractNinety‐five patients with gastrointestinal (GI) cancer participated in a study concerning stressful events, coping and emotional well‐being. Participants were either potentially cured (n=62) after radical surgery or non‐cured (n=33). For a period of 1 week, close to being informed about their diagnosis, they performed daily recordings of stressful events, the distress occasioned by these events and their perception of control over them, coping, worry and happiness/sadness. Anxiety and depression were assessed by a single retrospective assessment at the end of the week (Hospital Anxiety and Depression (HAD) scale). The most commonly recorded stressful events were ‘Somatic aspects’ and ‘Everyday concerns’. ‘Somatic aspects’, ‘Social aspects’ and ‘Other consequences of the disease’ were rated as most bothersome. Patients perceived that they had the highest degree of control over ‘Returning home after hospital stay’, whereas ‘Contact with the medical services’ was assigned low control. The most commonly used coping strategies were ‘Acceptance’ and ‘Relaxation’, and the least used was ‘Religion’. Significant positive correlations between the occurrence of stressful events and the use of coping strategies were demonstrated between ‘Somatic Aspects’ and ‘Acceptance’/‘Direct Action’, and between ‘Social Aspects’ and ‘Seeking Social Support’. Daily assessment of stress‐coping relationships represents a promising approach to the understanding of adaptation among cancer patients. Copyright © 2002 John Wiley & Sons, Ltd.