bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of fibrillar morphology on elastomer‐modified polypropylene
Authors: Ling Zhang , Rui Huang , Liangbin Li , Gang Wang 
Published: August 2002

AbstractBlends of polypropylene (PP) with a copolymer of ethylene and octene (EOC) were studied. The effect of viscosity ratio of elastomer domains to the matrix PP ηd/ηm (where subscript d and m designate dispersed phase and matrix, respectively) on fibril formation was investigated. Fibril morphology was observed for both ηd/ηm ≈ 1 and ηd/ηm > 1 (ηd/ηm = 1.70 or 2.40). As the viscosity ratio increased further, the spherical, elliptical, and rodlike morphology appeared. Fibril formation at ηd/ηm > 1 is possibly attributed to the effect of the interface interaction between the two phases. With soft fibril formation of EOC in PP, mechanical properties of the blends such as tensile and flexural properties were not improved and the impact strength was low compared to those of blends with spherical, elliptical, and rodlike dispersed morphology. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1870–1874, 2002
Mucilages and climatic changes in the Tyrrhenian Sea
Authors: Innamorati M. , Nuccio C. , Massi L. , Mori G. , Melley A. 
Published: August 2002

Abstract1. Pelagic mucilage aggregates are composed of phytoplankton and bacteria, whilst macro‐ and micro‐phytobenthos and bacteria make up the benthic ones. During the summer of 1991 massive mucilage aggregates, both pelagic and benthic, appeared in the Tyrrhenian Sea, seriously damaging fisheries, tourism and the benthic biocoenoses. Only a few, loose benthic mucilages have persisted during the last decade although the pelagic ones have shown a great resurgence during the last autumn.2. 14C autoradiographies show that the mucilage is photosynthesized and excreted by the micro‐ and macroalgae it contains. The mucilage aggregates are a microecosystem with biological and chemical composition, and a functionality that is different from the surrounding waters. The mucilages cannot be the result of a gelification of the Dissolved Organic Matter (DOM) in the water trapping the free algae present in the water.3. Since 1991 up to the present, variations of Dissolved Inorganic Nitrogen (DIN) and Dissolved Inorganic Phosphorous (DIP) and of their ratio have been observed in the surface waters. These variations could be assumed as the cause of mucilages, however, the mucilage occurrence cannot be directly related to the change of nutrient concentrations and ratios because: i) the higher N/P ratio was persistent also during years without mucilages; ii) nutrients and their ratios have a continuous spatial distribution while mucilages have a discontinuous spatial and temporal distribution. It is suggested that mucilage aggregates are the result of a hyperproduction as a pathological response of the algae to a microbial infection. This hypothesis is also supported by some laboratory experiments.4. The observed trophic changes in the surface Tyrrhenian waters have been related to the Levantine Intermediate Waters (LIW) as they are the main source of nutrients for the surface ones. Data collected from several areas between 1982 and 1998 show that changes in the temperature, salinity and nutrient concentrations and ratios took place in the LIW, so changing the Tyrrhenian climate. Copyright © 2001 John Wiley & Sons, Ltd.
A geomorphological framework for river characterization and habitat assessment
Authors: Thomson J.R. , Taylor M.P. , Fryirs K.A. , Brierley G.J. 
Published: August 2002

Abstract1. Methods to assess the physical habitat available to aquatic organisms provide important tools for many aspects of river management, including river health monitoring, determination of river restoration/rehabilitation strategies, setting and evaluating environmental flows and as surrogates for biodiversity assessment.2. Procedures used to assess physical habitat need to be ecologically and geomorphologically meaningful, as well as practicable. A conceptual methodological procedure is presented that evaluates and links instream habitat and geomorphology.3. The heterogeneity of habitat potential is determined within geomorphic units (such as pools, runs, riffles) by assessing flow hydraulics and substrate character. These two variables are integrated as hydraulic units — patches of uniform flow and substrate.4. This methodology forms a logical extension of the River Styles framework that characterizes river form and behaviour at four inter‐related scales: catchments, landscape units, River Styles (reaches) and geomorphic units. As geomorphic units constitute the basis to assess aquatic habitat availability, and they form the building blocks of river and floodplain systems, intact reaches of a particular River Style should have similar assemblages of instream and floodplain habitat.5. An application of the hydraulic unit procedure is demonstrated in gorge, partly‐confined and alluvial River Styles from the Manning catchment in northern New South Wales, Australia. Copyright © 2001 John Wiley & Sons, Ltd.
Steroid hormones and disease activity during pregnancy in systemic lupus erythematosus
Authors: Doria Andrea , Cutolo Maurizio , Ghirardello Anna , Zampieri Sandra , Vescovi Francesca , Sulli Alberto , Giusti Massimo , Piccoli Antonio , Grella Pasquale , Gambari Pier Franca 
Published: August 2002

AbstractObjectivesTo analyze the variation of steroid hormone levels during pregnancy in patients with systemic lupus erythematosus (SLE). Moreover, to investigate whether, during gestation, there is any relationship between steroid concentration and SLE activity.MethodsSeventeen consecutive pregnant SLE patients and 8 matched healthy pregnant controls were studied prospectively. Disease activity was evaluated by European Consensus Lupus Activity Measure (ECLAM) score modified for pregnancy. The following hormones were evaluated: testosterone, 17β‐estradiol (estradiol), cortisol, dehydroepiandrosterone sulfate (DHEAS), and progesterone.ResultsDisease activity score significantly varied during pregnancy and postpartum (P< 0.05), being decreased in the third trimester and increased in the second trimester and postpartum. Serum levels of all steroids varied significantly during pregnancy and the postpartum period both in patients and in healthy subjects. In SLE patients, estradiol, progesterone, and DHEAS concentrations were found to be significantly reduced compared with controls. Serum level profiles of estradiol and progesterone were different from those observed in controls. No differences in the steroid levels were observed between patients taking prednisone ≤5 mg/day or >5 mg/day, apart from cortisol, which was, as expected, lower in the latter group.ConclusionsThe major hormonal alteration observed during pregnancy in SLE patients was an unexpected lack of estrogen serum level increase, and, to a lesser extent, progesterone serum level increase, during the second and—even more—the third trimester of gestation. This lack of increase probably was due to placental compromise. Therefore, these steroid hormone variations may result in a lower humoral immune response activation, probably related to a change in the estrogen/androgen balance, that in turn could account for the decrease in disease activity observed during the third trimester in pregnant SLE patients.
The number of deformed joints as a surrogate measure of damage in rheumatoid arthritis
Authors: Orces Carlos H. , Del Rincón Inmaculada , Abel Michael P. , Escalante Agustín 
Published: August 2002

AbstractObjectiveTo evaluate the reliability and validity of the number of deformed joints (NDJ) as a surrogate measure of joint damage in rheumatoid arthritis (RA).MethodsWe tested interrater reliability and validity in determining the NDJ as a surrogate for joint damage in consecutive patients with RA. We rated each of 48 joints as normal or abnormal in terms of alignment and range of motion, and expressed the results as the total number of deformed joints. We compared the NDJ with the severity of damage on a plain radiograph of the hands, scored using Sharp's technique, as the gold standard measure of joint damage. We also compared the correlation between the NDJ and radiographic joint damage, on the one hand, and disease duration, performance‐based measures of physical function, and the self‐reported level of disability.ResultsThe interrater reliability of the NDJ was excellent, with an intraclass correlation among four examiners of 0.94. To assess validity of the NDJ, we studied 273 RA patients from 5 clinical settings. Their average NDJ was 14 (range 0–43), and their average Sharp's score for joint space narrowing and erosions combined was 106 (range 4–309). The NDJ and the total Sharp's score were highly correlated (r = 0.83). Both measures were correlated to a similar degree with disease duration (r = 0.51 for each measure), grip strength (r = −0.49 for NDJ, and r = −0.51 for Sharp's score), walking velocity (r = −0.44 for NDJ, and r = −0.45 for Sharp's score), the timed button test (r = −0.62 for NDJ, and r = −0.57 for Sharp's score), and the Modified Health Assessment Questionnaire (r = 0.38 for NDJ, and r = 0.38 for Sharp's score). Both the Sharp's score and the NDJ worsened significantly in 38 patients for whom 1–2 year followup data were available.ConclusionThe NDJ is reliable and is strongly associated with the standard
measure of joint damage in RA. Because it is easily performed in a clinical setting, it could be used as an economical surrogate of joint damage in studies of the long‐term outcome of RA.
Bounded rationality and satisficing in young people's Web‐based decision making
Authors: Agosto Denise E. 
Published: August 2002

AbstractThis study investigated Simon's behavioral decision‐making theories of bounded rationality and satisficing in relation to young people's decision making in the World Wide Web, and considered the role of personal preferences in Web‐based decisions. It employed a qualitative research methodology involving group interviews with 22 adolescent females. Data analysis took the form of iterative pattern coding using QSR NUD*IST Vivo qualitative data analysis software. Data analysis revealed that the study participants did operate within the limits of bounded rationality. These limits took the form of time constraints, information overload, and physical constraints. Data analysis also uncovered two major satisficing behaviors—reduction and termination. Personal preference was found to play a major role in Web site evaluation in the areas of graphic/multimedia and subject content preferences. This study has related implications for Web site designers and for adult intermediaries who work with young people and the Web.
Leaving the neighborhood: molecular mechanisms involved during epithelial‐mesenchymal transition
Authors: Savagner P. 
Published: August 2002

AbstractSeveral molecular mechanisms contribute directly and mechanically to the loss of epithelial phenotype. During epithelial–mesenchymal transition (EMT), adherens junctions and desmosomes are at least partially dissociated. At the same time, a massive cytoskeleton reorganization takes place, involving the rho family and the remodeling of the actin microfilament mesh. Numerous pathways have been described in vitro that control phenotype transition in specific cell models. In vivo developmental studies suggest that transcriptional control, activated by a specific pathway involving Ras, Src and potentially the Wnt pathway, is an essential step. Recent functional and localization experiments indicate that the slug/snail family of transcription factors functions overall as an epithelial phenotype repressor and could represent a key EMT contributor. BioEssays 23:912–923, 2001. © 2001 John Wiley & Sons, Inc.
Educational advocacy for children with autism
Authors: Mulick James. A. , Butter Eric M. 
Published: August 2002

AbstractThere exists a great divide between parents' demands for intensive behavioral interventions for their children with autism and the public education system's reluctance to support early intensive behavioral intervention programs. More and more, professionals with expertise in applied behavior analysis are being asked to advocate for effective, early behavioral intervention for autism in education litigation brought about by frustrated parents. The progress made in recent years in the behavioral treatment of children with autism and the schools' lack of adherence to the requirements of IDEA have made it possible for educational policy change through effective advocacy by behavioral interventionists. This paper discusses preparing for educational advocacy on behalf of young children with autism. We explore the personal and emotional reasons why parents choose to engage in the financially risky endeavor of educational litigation. We then outline an approach to developing expert testimony based upon evaluation of the target child and his/her educational history. Issues related to assessment, training, and ethical practice are addressed. Copyright © 2002 John Wiley & Sons, Ltd.
The red‐edge effects: 30 years of exploration
Authors: Demchenko Alexander P. 
Published: August 2002

AbstractIn 1970, three laboratories independently made a discovery that, for aromatic fluorophores embedded into different rigid and highly viscous media, the spectroscopic properties do not conform to classical rules. The fluorescence spectra can depend on excitation wavelength, and the excited‐state energy transfer, if present, fails at the ‘red’ excitation edge. These red‐edge effects were related to the existence of excited‐state distribution of fluorophores on their interaction energy with the environment and the slow rate of dielectric relaxation of this environment. In these conditions the site‐selection can be provided by variation of the energy of illuminating light quanta, and the behaviour of selected species can be followed as a function of time and other variables. These observations found extensive application in different areas of research: colloid and polymer science, molecular biophysics, photochemistry and photobiology. In particular, they led to the development of very productive methods of studying the dynamics of dielectric relaxations in protein and membranes, using the tryptophan emission and the emission of a variety of probes. These studies were extended to the time domain with the observation of new site‐selective effects in emission intensity and anisotropy decays. They stimulated the emergence and development of cryogenic energy‐selective and single‐molecular techniques that became valuable tools in their own right in chemistry and biophysics research. Site‐selection effects were discovered for electron‐transfer and proton‐transfer reactions if they depended on the dynamics of the environment. This review is focused on the progress in the field of red‐edge effects, their applications and prospects. Copyright © 2002 John Wiley & Sons, Ltd.
Secondary and tertiary structure of nucleotide‐binding domain of αsubunit of Na+/K+‐ATPase
Authors: Hofbauerová Kateřina , Kopecký Vladimír , Ettrich Rüdiger , Ettrichová Olga , Amler Evžen 
Published: August 2002

AbstractThe nucleotide‐binding domain of the α subunit of mouse brain Na+/K+‐ATPase was expressed and isolated from Escherichia coli cells. A model structure was constructed by comparative modeling with and without docked ATP. This was compared with the secondary structure determination from UV circular dichroism and Raman spectroscopy. Thus, we support the quality of the model and the correct folding of the recombinant protein. ATP binding was followed by Raman difference spectroscopy, and its influence on the secondary structure of the N domain seems to not be significant. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 242–246, 2002
Limited conformational change of β‐lactoglobulin when adsorbed at the air–water interface
Authors: Meinders Marcel B. J. , De Jongh Harmen H. J. 
Published: August 2002

AbstractDetailed insight can be obtained from proteins at and near the air–water interface using external reflection IR and circular dichroism techniques. Besides information on local protein concentrations and surface layer thickness, it is shown that β‐lactoglobulin displays a limited unfolding at the interface. The conformational change is comparable to that observed upon heat‐induced aggregation of the protein and can be understood in view of the high surface concentration of the protein (∼40% volume fraction). The layer thickness and the conformational properties of the protein do not depend on the bulk concentration. After adsorption of β‐lactoglobulin to a preformed lipid monomolecular layer a similar conformational change is induced, suggesting that the folding properties of the protein itself determine the extent of conformational changes at the interfaces. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 319–322,2002
Studies of low molecular weight samples of glucuronans with various acetylation degree
Authors: Pau‐Roblot Corinne , Petit Emmanuel , Sarazin Catherine , Courtois Josiane , Courtois Bernard , Barbotin Jean Noël , Séguin Jean Paul 
Published: August 2002

AbstractPartially acetylated, high molecular weight glucuronans were produced by a Sinorhizobium meliloti mutant strain. Two native glucuronan samples with various degrees of acetylation were sonicated to obtain lower molecular weight samples and with low viscosity suitable for chemical modification and 13C NMR experiments. The average degree of substitution (DS) of the polymer was estimated by Fourier transform infrared (FTIR) and NMR. 13C NMR spectra were obtained and used to suggest a complete assignment of the signals. The nuclear Overhauser effect spectroscopy (NOESY) and heteronuclear multi‐bond coherence (HMBC) experiments were used to elucidate connectivities between the various residues and deduce the linkage of these residues within the polysaccharide. © 2002 Wiley Periodicals, Inc. Biopolymers 64: 34–43, 2002
Statistical reconciliation of the elemental and molecular biomass composition of Saccharomyces cerevisiae
Authors: Lange H. C. , Heijnen J. J. 
Published: August 2002

AbstractA systematic mathematical procedure capable of detecting the presence of a gross error in the measurements and of reconciling connected data sets by using the maximum likelihood principle is applied to the biomass composition data of yeast. The biomass composition of Saccharomyces cerevisiae grown in a chemostat under glucose limitation was analyzed for its elemental and for its molecular composition. Both descriptions initially resulted in conflicting results concerning the elemental composition, molecular weight, and degrees of reduction. The application of the statistical reconciliation method, based on elemental balances and equality relations, is used to obtain a consistent biomass composition. Simultaneously, the error margins of the data sets are significantly reduced in the reconciliation process. On the basis of statistical analysis it was found that inclusion of about 4% water in the list of biomass constituents is essential to adequately describe the dry biomass and match both set of measurements. The reconciled carbon content of the biomass varied 4% from the ones obtained from the molecular analysis. The proposed method increases the accuracy of biomass composition data of its elements and its molecules by providing a best estimate based on all available data and thus provides an improved and consistent basis for metabolic flux analysis as well as black box modeling approaches. © 2001 John Wiley & Sons Inc. Biotechnol and Bioeng 75: 334–344, 2001.
Preparation, stability, and in vitro performance of vesicles made with diblock copolymers
Authors: Lee James C‐M. , Bermudez Harry , Discher Bohdana M. , Sheehan Maureen A. , Won You‐Yeon , Bates Frank S. , Discher Dennis E. 
Published: August 2002

AbstractVesicles made completely from diblock copolymers—polymersomes—can be stably prepared by a wide range of techniques common to liposomes. Processes such as film rehydration, sonication, and extrusion can generate many‐micron giants as well as monodisperse, ∼100 nm vesicles of PEO‐PEE (polyethyleneoxide‐polyethylethylene) or PEO‐PBD (polyethyleneoxide‐polybutadiene). These thick‐walled vesicles of polymer can encapsulate macromolecules just as liposomes can but, unlike many pure liposome systems, these polymersomes exhibit no in‐surface thermal transitions and a subpopulation even survive autoclaving. Suspension in blood plasma has no immediate ill‐effect on vesicle stability, and neither adhesion nor stimulation of phagocytes are apparent when giant polymersomes are held in direct, protracted contact. Proliferating cells, in addition, are unaffected when cultured for an extended time with an excess of polymersomes. The effects are consistent with the steric stabilization that PEG‐lipid can impart to liposomes, but the present single‐component polymersomes are far more stable mechanically and are not limited by PEG‐driven micellization. The results potentiate a broad new class of technologically useful, polymer‐based vesicles. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 135–145, 2001.
Determination of 3‐deoxy‐D‐arabino‐heptulosonate 7‐phosphate productivity and yield from glucose in Escherichia coli devoid of the glucose phosphotransferase transport system
Authors: Báez José Luis , Bolívar Francisco , Gosset Guillermo 
Published: August 2002

AbstractThe effect of inactivation of the glucose phosphotransferase transport system (PTS) on 3‐deoxy‐D‐arabino‐heptulosonate 7‐phosphate (DAHP) productivity and yield from glucose in Escherichia coli is reported. Strains used in this study were the PTS+ PB103 and its PTS− glucose+ derivative NF9. Their aroB− derivatives PB103B and NF9B were constructed to allow accurate measurement of total carbon flow into the aromatic pathway. The measured specific rates of DAHP synthesis were 0.55 and 0.94 mmol/g‐dcw · h and the DAHP molar yields from glucose were 0.43 and 0.71 mol/mol for the PTS+ aroB−and the PTS− glucose+ aroB−strains, respectively. For the latter strain, this value represents 83% of the maximum theoretical yield for DAHP synthesis from glucose. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 530–535, 2001.
Reactor optimization for α‐1,2 glucooligosaccharide synthesis by immobilized dextransucrase
Authors: Dols‐Lafargue Marguerite , Willemot René‐Marc , Monsan Pierre F. , Remaud‐Simeon Magali 
Published: August 2002

AbstractThe immobilization of dextransucrase in Ca‐alginate beads relies on the close association between dextran polymer and dextransucrase. However, high amounts of dextran in the enzyme preparation drastically limit the specific activity of the immobilized enzyme (4 U/mL of alginate beads). Moreover, even in the absence of diffusion limitation at the batch conditions used, the enzyme behavior is modified by entrapment so that the dextran yield increases and the α‐1,2 glucooligosaccharides (GOS) are produced with a lower yield (46.6% instead of 56.7%) and have a lower mean degree of polymerization than with the free dextransucrase. When the immobilized catalyst is used in a continuous reaction, the reactor flow rate necessary to obtain high conversion of the substrates is very low, leading to external diffusion resistance. As a result, dextran synthesis is even higher than in the batch reaction, and its accumulation within the alginate beads limits the operational stability of the catalyst and decreases glucooligosaccharide yield and productivity. This effect can be limited by using reactor columns with length to diameter ratio ≥20, and by optimizing the substrate concentrations in the feed solution: the best productivity obtained was 3.74 g · U−1 · h−1, with an α‐1,2 GOS yield of 36%. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 276–284, 2001.