bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymer‐Dispersed Liquid Crystals Based on Polystyrene and EBBA: Analysis of Phase Diagrams and Morphologies Generated
Authors: Hoppe Cristina E. , Galante María J. , Oyanguren Patricia A. , Williams Roberto J. J. 
Published: June 2003

AbstractAs an example of thermoplastic/liquid crystal blends that do not exhibit a liquid‐liquid immiscibility region in their phase diagrams, a polystyrene (PS)/N‐4‐ethoxybenzylidene‐4′‐butylaniline (EBBA) blend was analyzed. The complete phase diagram was built up using thermal transitions determined by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The boundary of the nematic + isotropic region was fitted with the Flory‐Huggins‐Maier‐Saupe model, extended to consider the polydispersity of PS. Main factors controlling the morphologies generated by thermal‐induced phase separation (TIPS) were the initial EBBA concentration in the blend and the cooling rate. Cooling at a fast rate led to small nematic domains with a narrow size distribution. Slow cooling rates led to the coexistence of very large and small dispersed domains. This was because of the large extent of coalescence of the droplets first generated associated with the continuation of the nucleation/growth process in a medium of increasing viscosity. The use of fast cooling rates might be important for the generation of a narrow size‐distribution of nematic droplets by TIPS in polymer‐dispersed liquid crystals (PDLC) used in electrooptical devices.Micrograph obtained by transmission optical microscopy without crossed polarizers, showing nematic domains dispersed in a glassy matrix arising by a fast cooling of the blend from 130 °C; composition of blend: 70 wt.‐% EBBA.magnified imageMicrograph obtained by transmission optical microscopy without crossed polarizers, showing nematic domains dispersed in a glassy matrix arising by a fast cooling of the blend from 130 °C; composition of blend: 70 wt.‐% EBBA.
Macromolecular Crystal Engineering Based on Segmented Polymers: Influence of Heteroatoms on the Thermal Properties and Crystallization of m,n‐Polyurethanes Derived from Long‐Chain, Heteroatom‐Containing, Monodisperse α,ω‐Diols
Authors: McKiernan Robin L. , Cardoen Grégoire , Boutevin Bernard , Améduri Bruno , Gido Samuel P. , Penelle Jacques 
Published: June 2003

AbstractLong‐chain heteroatom‐containing telechelic diols with 29–32 atoms in the backbone were synthesized by a one‐step, free‐radical telomerization of 10‐undecene‐1‐ol with commercially available α,ω‐dithiols. The oxygen and sulfur atoms caused a decrease in the melting point and enthalpy of the diols, compared to the corresponding purely aliphatic diols. The heteroatom‐containing α,ω‐diols HO(CH2)11S(CH2)2X(CH2)2S(CH2)11OH, where X = CH2, O, or O(CH2)2O, were reacted in the melt with 1,6‐diisocyanatohexane OCN(CH2)6NCO, producing a series of polyurethanes containing an increasing amount of heteroatoms. Characterization by differential scanning calorimetry, infra‐red spectroscopy, thermogravimetric analysis, and wide angle x‐ray scattering of the m,n‐polyurethane series showed that, like the telechelic diols they were synthesized from, the heteroatoms caused a decrease in the melting point and enthalpy. However, they did not affect either the decomposition temperature or the crystal structure/packing.Typical decomposition behavior of all the heteroatom‐containing m,6‐polyurethane.magnified imageTypical decomposition behavior of all the heteroatom‐containing m,6‐polyurethane.
Synthesis of Poly(ethylene terephthalate)‐block‐Poly(tetramethylene oxide) Copolymer by Direct Polyesterification of Reactive Oligomers
Authors: Saint‐Loup René , Robin Jean‐Jacques , Boutevin Bernard 
Published: June 2003

AbstractThe object of this study was the synthesis of thermoplastic elastomer compounds by direct copolyesterification of reactive oligomers of poly(ethylene terephthalate) (PET) and of poly(tetramethylene oxide) (PTMO). PET was glycolysed to synthesise hydroxytelechelic oligomers of PET. Commercially available hydroxytelechelic PTMO was modified to synthesise carboxytelechelic oligomers. The chemical structures of these oligomers were investigated by 1H NMR and size exclusion chromatography. Multiblock poly(ester‐ether) was then obtained by polyesterification of the hydroxytelechelic and carboxytelechelic oligomers, using different catalysts and different reaction conditions. The best stoichiometric ratio was determined to lead to the highest Mn. The chemical structure of the synthesised poly(ester‐ether) was investigated by size exclusion chromatography and 1H NMR. The thermal and thermomechanical behaviour of the synthesised poly(ester‐ether) was investigated by differential scanning calorimetry and by dynamic mechanical analysis, and showed a thermoplastic elastomer behaviour. This product could also be an interesting way of chemically recycling PET waste.Polyesterification of hydroxytelechelic PET with carboxytelechelic PTMO.magnified imagePolyesterification of hydroxytelechelic PET with carboxytelechelic PTMO.
A Comprehensive Experimental and Theoretical Investigation of the Styrene/2‐Ethylhexyl Acrylate Emulsion Copolymerization
Authors: Kammona Olga , Pladis Prokopis , Frantzikinakis Costas E. , Kiparissides Costas 
Published: June 2003

AbstractIn the present study an experimental and theoretical investigation on the styrene/2‐ethylhexyl acrylate emulsion copolymerization is reported. Kinetic experiments were carried out in a laboratory batch reactor, to analyze the effects of the initial styrene mole fraction, non‐ionic surfactant, and initiator concentrations on the reaction kinetics, copolymer composition and particle size distribution of the latex. All kinetic experiments were run through the full conversion. A comprehensive mathematical model was developed to describe the dynamic behavior of the styrene/2‐ethylhexyl acrylate batch emulsion copolymerization. The model includes a detailed kinetic mechanism, the thermodynamics of the emulsion mixture, dynamic molar species balances in the polymer and aqueous phases, the rate of particle formation, and growth and diffusion controlled phenomena. Detailed dynamic species mass balances are derived to follow the evolution of the particle nucleation rate, total number of particles, polymerization rate and particle size distribution in a batch reactor. The proposed particle nucleation mechanism accounts for both homogeneous and micellar particle nucleation. The capabilities of the present model are demonstrated by comparison of model predictions with the experimental data on conversion and particle size distribution (PSD). It is shown that the model is capable of correctly reflecting the time evolution of conversion, particle size and PSD over substantial variations of the process operating conditions.Comparison of model predictions and experimental measurements on average particle size.magnified imageComparison of model predictions and experimental measurements on average particle size.
Acute cardiac failure in neuroleptic malignant syndrome☆
Authors: Sparrow Patrick , Murnaghan Dermot , Kearney Peter , Hogan John , Sheppard Mary N. 
Published: June 2003

AbstractWe present a case of rapid onset acute cardiac failure developing as part of Neuroleptic malignant syndrome in a 35‐year‐old woman following treatment with Thioridazine and Lithium. Post mortem histology of cardiac and skeletal muscle showed similar changes of focal cellular necrosis and vacuolation suggesting a common disease process.
Comparing methodological quality and consistency of international guidelines for the management of patients with chronic heart failure
Authors: Kulig Michael , Erika Schulte , Norbert Willich Stefan 
Published: June 2003

AbstractBackground:Guidelines (GLs) for the management of heart failure (HF) are of great importance in order to define and disseminate therapeutic recommendations based on scientific evidence. The aim was to analyse and to compare the methodological quality of HF GLs as well as to evaluate the consistency of therapeutic recommendations.Methods:Eleven international GLs for the management of chronic HF were identified by search of the internet, electronic databases and references of published literature. Their methodological quality was assessed by two different appraisal instruments: (1) according to the US National Guideline Clearinghouse (NGC) on a scale from 0 to 17 points, (2) according to the German Guideline Clearinghouse (Agency for Quality in Medicine, AQUMED) on a scale from 0 to 44 points. Clinical criteria for assessment of the consistency of the recommendations included diagnostic testing, pharmacological and non‐pharmacological treatment.Results:The quality scores of the GLs varied substantially with a range of 1.5–15.5 points (NGC) and 8–30 points (AQUMED). The greatest variation was found in the dimensions ‘development’ and ‘evidence’. Only 3 of the 11 GLs (≈30%) were rated as methodologically well prepared. The recommendations on diagnostic procedures and medical management were rather consistent among the different GLs.Conclusions:Published international GL recommendations on medical management of patients with chronic HF are broadly consistent. The methodological quality of the GLs, however, varies to a great extent. Improvement is needed in most methodological aspects, especially in the dimensions ‘evidence’ and ‘applicability’.
Differences between general practitioners and cardiologists in diagnosis and management of heart failure: a survey in every‐day practice
Authors: Rutten Frans H. , Grobbee Diederick E. , Hoes Arno W. 
Published: June 2003

AbstractBackground:Data on diagnosis and management of heart failure in every‐day care are scarce.Aims:To compare general practitioners’ and cardiologists’ diagnostic work‐up and management of patients with (suspected) heart failure.Methods:In a cross‐sectional survey we studied a sample of 103 files of patients coded as heart failure in primary care (31 general practices), and 99 files of out‐patients coded as heart failure from 9 hospitals in the Netherlands. We defined patients as heart failure ‘GP patients’, when they were managed by a general practitioner without co‐treatment of a cardiologist.Results:Patients managed in general practice were older (mean age 79 years (S.D. 8.5) and more often female than ‘cardiology patients’ (mean age 64 years (S.D. 11.7)). Ischaemic heart disease (31 vs. 57%) was more prevalent in ‘cardiology patients’. Additional investigations such as chest radiography (51% vs. 84%), electrocardiography (39% vs. 100%), and (Doppler‐) echocardiography (12% vs. 97%) were performed more often in ‘cardiology patients’. Most patients received diuretics (85% vs.79%). Angiotensin converting enzyme inhibitors (40% vs. 76%), beta‐blockers (9% vs. 30%), spironolactone (11% vs. 32%), and angiotensin‐II‐antagonists (6% vs. 13%) were prescribed much more often to ‘cardiology patients’.Conclusion:General practitioners more often treat elderly, female patients with heart failure than cardiologists. General practitioners use less additional investigations and prescribe less potentially beneficial medication, compared to cardiologists. Population characteristics only partly explain these differences, suggesting that the physician's attitude has an important bearing on the uptake of treatment.
The development of plumage polymorphism in male Madagascar paradise flycatcher Terpsiphone mutata
Authors: Mizuta Taku 
Published: June 2003

AbstractThe development of plumage polymorphism in male Madagascar paradise flycatcher Terpsiphone mutata (Linnaeus, 1766) was investigated in north‐western Madagascar. Four distinct morphs were observed, namely, white‐coloured with long tails (WL), rufous‐coloured with long tails (RL), rufous‐coloured with tails of middle length (RM), and rufous‐coloured with short tails (RS). Females were rufous and had short tails. Indivudual males were marked and re‐observed during 1994–98. RS males changed to RM in the following seasons. Among RM males, some individuals retained RM, others changed to RL or WL. RM males which changed to WL in the next season had possessed white patches on their belly, whereas RM males which changed to RL had not had such patches. Neither WL nor RL males changed their morphs. Nestlings were rufous regardless of their father's morph. One nestling changed to RS in the next season. From these results and the difference of body size among four morphs, it is deduced that RS males are one year old, and change to RM males in the next season. RM males change to RL or WL males after one or two years. RL and WL are two stable terminal plumages, and they may be genetically determined morphs.
The home range of the Sonso community of chimpanzees from the Budongo Forest, Uganda
Authors: Newton‐Fisher Nicholas E. 
Published: June 2003

AbstractEarly studies of chimpanzees in the Budongo Forest, Uganda, reported only rough estimates for home range size. This study aimed to quantify home range size and habitat composition for chimpanzees of the Sonso community in this forest. Home range is the habitually used portion of the total area over which an animal travels, and for chimpanzees the home range is shared by the community. From data collected in 1994 and 1995, the home range for this community was estimated to cover an area of 6.78 km2using the minimum convex polygon analysis technique and 6.89 km2using fixed kernel analysis. Habitat was highly heterogeneous. The small home range and consequent high local population density (approximately 6.8 individuals km−1) suggests that the Sonso region is highly productive in chimpanzee foods, possibly in contrast to other parts of the forest. This estimate of home range size is among the smallest reported for habituated chimpanzees, but comparisons with other sites are confounded by methodological and analytical differences. Future studies of chimpanzee ranging patterns should endeavour to use precise locations and the latest analytical techniques to ensure accurate estimation of range size and structure, and intersite comparability.
Tree fruiting phenology in Kalinzu Forest, Uganda
Authors: Muhanguzi Hosea D. R. , Obua Joseph , Oryem‐Origa Hannington , Vetaas Ole R. 
Published: June 2003

AbstractThe spatial and temporal variations in species composition and abundance of trees that fruited in mechanically logged, intensively pit‐sawn and essentially undisturbed forest areas in Kalinzu Forest (0°17′S, 0°30′S and 30°00′, 30°07′E) were assessed. The duration and frequency of fruiting episodes of selected pioneer, understorey and canopy tree species were also determined. These phenology aspects were monitored for 18 months (between February 1997 and July 1998) in 99 plots, each 20 m × 20 m in size. Eighty species consisting of 1489 trees fruited during the study. Most of the species were recorded in the undisturbed forest area and least in the mechanically logged areas. Monthly number of individuals and species that fruited in each forest condition were significantly related to monthly rainfall. Two pioneer species (Musanga leo‐errerae and Trema orientalis), one sub‐canopy (Funtumia africana) and canopy (Parinari excelsa) species had extended fruiting phases (>5 months). Two understorey species (Oxyancius speciosus and Tabernaemontana spp.) had an extended phase while the third (Teclea nobilis) had a short (≤5 months) fruiting phase. Of the selected species, only Strombosia scheffleri (a sub‐canopy species) and P. excelsa had more than one fruiting episode.
A validated symptoms questionnaire (Chinese GERDQ) for the diagnosis of gastro‐oesophageal reflux disease in the Chinese population
Authors: Wong W. M. , Lam K. F. , Lai K. C. , Hui W. M. , Hu W. H. C. , Lam C. L. K. , Wong N. Y. H. , Xia H. H. X. , Huang J. Q. , Chan A. O. O. , Lam S. K. , Wong B. C. Y. 
Published: June 2003

SummaryBackground and aims: To develop a validated gastro‐oesophageal disease (GERD) symptom questionnaire for the Chinese population.Methods: One hundred Chinese patients with GERD and 101 healthy Chinese controls were presented with a 20‐item GERD questionnaire in the Chinese language (Chinese GERDQ). Quality of life in GERD patients was assessed by SF‐36. A standard dose of proton pump inhibitors for 4 weeks was prescribed to 35 patients with newly diagnosed GERD. The Chinese GERDQ was performed before, 4 weeks and 8 weeks after treatment. Concept, content, construct, discriminant validity and reliability of the questionnaire were assessed.Results: Seven items were selected by logistic regression to account for most of the differences between controls and GERD patients with a good reproducibility and internal consistency. A cut‐off score of equal or greater than 12 was determined to discriminate between controls and GERD patients with a sensitivity of 82% and a specificity of 84%. The Chinese GERDQ correlated negatively with five domains of the SF‐36 and discriminated between GERD patients who reported symptomatic improvement during proton pump inhibitor treatment and symptoms deterioration upon withdrawal of proton pump inhibitor treatment.Conclusions: The Chinese GERDQ could be used in epidemiological studies to assess the frequency and severity of GERD in patient populations and in interventional studies of GERD.
Review article: clinic‐based testing for Helicobacter pylori infection by enzyme immunoassay of faeces, urine and saliva
Authors: Kabir S. 
Published: June 2003

SummaryEnzyme immunoassays have been used to detect Helicobacter pylori infection in human body materials such as faeces, urine and saliva. The stool antigen assay (HpSA), which uses polyclonal anti‐H. pylori antibody as a capture reagent, has been widely used in the pre‐treatment diagnosis of the infection in adults and children. Although the assay has the potential for monitoring eradication therapy, there are controversies over its use, especially at an early stage after treatment. The efficacy of the stool antigen assay can be modified by using monoclonal antibodies towards well characterized H. pylori faecal antigens. Two types of enzyme immunoassays (enzyme‐linked immunosorbent assay [ELISA] and immunochromatography) have been used to detect antibodies to H. pylori in urine. Immunochromatography of urine is a rapid assay well suited for epidemiological studies. The salivary ELISA, used in a number of studies, has shown inconsistent results with less than optimum sensitivity and specificity. Urinary and salivary immunoassays may not distinguish between past and present infections, thus limiting their potential to monitor eradication therapy.
Mycophenolate mofetil in refractory inflammatory bowel disease
Authors: Ford A. C. , Towler R. J. , Moayyedi P , Chalmers D. M. , Axon A. T. R. 
Published: June 2003

SummaryBackground:  Mycophenolate mofetil has been claimed to be effective and well tolerated in refractory inflammatory bowel disease although there is little information regarding its use in clinical practice.Aim:  To review our experience in achieving and maintaining remission in refractory inflammatory bowel disease and to document tolerability, major toxicity and efficacy.Methods:  A retrospective audit was performed of the records of all patients with inflammatory bowel disease treated with mycophenolate mofetil (1–2 g/day) over a 3‐year period.Results:  Thirty‐nine patients were identified. Almost all had been intolerant of, or had not responded to azathioprine, and 38 were steroid‐dependent. mycophenolate mofetil was discontinued in 22 patients, 11 due to intolerance and 10 because of lack of efficacy. Of the 17 on treatment at the end of the study period 16 were in remission and off all steroid therapy, but one needed infliximab to maintain remission. No major toxicity was noted and there was no major sepsis.Conclusions:  Approximately 40% of patients with severe refractory inflammatory bowel disease achieved remission and complete steroid withdrawal on mycophenolate mofetil therapy, almost 30% could not tolerate the drug, and a further 30% did not respond. Mycophenolate mofetil therapy may have a role for steroid‐dependent patients refractory to azathioprine.
Repifermin (keratinocyte growth factor‐2) for the treatment of active ulcerative colitis: a randomized, double‐blind, placebo‐controlled, dose‐escalation trial
Authors: Sandborn W. J. , Sands B. E. , Wolf D. C. , Valentine J. F. , Safdi M. , Katz S. , Isaacs K. L. , Wruble L. D. , Katz J. , Present D. H. , Loftus E. V. , Graeme‐Cook F. , Odenheimer D. J. , Hanauer S. B. 
Published: June 2003

SummaryBackground: Repifermin (keratinocyte growth factor‐2) has been shown to reduce inflammation in animal models of colitis.Aim: To evaluate repifermin for the treatment of active ulcerative colitis.Methods: Eighty‐eight patients with active ulcerative colitis were enrolled in a 6‐week, double‐blind trial. Patients were randomized to receive treatment for five consecutive days with intravenous repifermin at a dose of 1, 5, 10, 25 or 50 μg/kg, or placebo. The primary objective of the study was to evaluate the safety of repifermin. The primary efficacy outcome was clinical remission at week 4, defined as a score of zero on the endoscopic appearance and stool blood components of the Mayo score and a score of zero or unity on the stool frequency and physician's global assessment components.Results: At week 4, the rates of clinical remission in the 1, 5, 10, 25 and 50 μg/kg repifermin groups were 19%, 9%, 0%, 0% and 0%, respectively, and 11% for the placebo group (P = 0.32 for repifermin vs. placebo). The frequencies of commonly occurring adverse events and severe adverse events were similar in both groups.Conclusions: Intravenous repifermin at a dose of 1–50 μg/kg was very well tolerated, but there was no evidence that repifermin was effective for the treatment of active ulcerative colitis at these doses. An additional study to determine the efficacy of repifermin at doses of > 50 μg/kg or for a longer treatment duration may be warranted, as the maximally tolerated dose was not reached in the present study.
Is irritable bowel syndrome more likely to be persistent in those with relatives who suffer from gastrointestinal symptoms? A population‐based study at three time points
Authors: Kalantar J. S. , Locke G. R. , Talley N. J. , Zinsmeister A. R. , Fett S. L. , Melton L. J. 
Published: June 2003

SummaryBackground: We tested the hypothesis that subjects with relatives who suffered from abdominal pain or bowel dysfunction would be at an increased risk of more persistent irritable bowel syndrome.Methods: A valid, self‐report questionnaire was mailed to an age‐ and gender‐stratified random sample of residents, aged 30–64 years, in Olmsted County, MN, USA, on three occasions over a 4‐year period. Persistent irritable bowel syndrome was defined as the presence of irritable bowel syndrome on at least two of the three surveys, and fluctuating irritable bowel syndrome was defined as the presence of irritable bowel syndrome on only one of the surveys.Results: Subjects were less likely to have persistent irritable bowel syndrome over the age of 50 years [odds ratio (OR), 0.20; 95% confidence interval (CI), 0.09, 0.47]. A positive family history was reported by 23%. A family history of gastrointestinal symptoms was independently associated with persistent irritable bowel syndrome (vs. no irritable bowel syndrome: OR, 2.5; 95% CI, 1.3, 4.9) and fluctuating irritable bowel syndrome (vs. no irritable bowel syndrome: OR, 2.4; 95% CI, 1.3, 4.4). However, subjects reporting a positive family history were not more likely to report persistent vs. fluctuating irritable bowel syndrome (OR, 1.2; 95% CI, 0.5, 2.9). The use of non‐steroidal anti‐inflammatory drugs (OR, 2.3; 95% CI, 1.2, 4.3) and a history of food sensitivity (OR, 3.6; 95% CI, 1.9, 6.9) were the only other predictors of persistent irritable bowel syndrome.Conclusions: A history of abdominal pain or bowel troubles in first‐degree relatives appears to be independently associated with both persistent and fluctuating irritable bowel syndrome.