bluuebunny/crossref_metadata_2025_split huggingface dataset:
Excess volume of polymer/solvent mixtures and proposed model for prediction of activity of solvents based on excess volume data
Authors: Eliassi Ali , Modarress Hamid 
Published: January 2005

AbstractDensity measurements were used to evaluate the excess volume of binary mixtures of poly(ethylene glycol) in water and ethanol solvents, poly(propylene glycol) in water and ethanol solvents, and poly(vinyl alcohol) in water solvent at different temperatures for various molecular weights of polymers. The excess volumes were correlated and expressed by a polynomial in terms of the weight fraction of the polymer. The activity of the solvent was expressed in terms of three parts: excess internal energy, excess entropy, and excess volume. The excess volume was derived from the expression obtained in this work, the excess entropy was derived from Flory's lattice model, and the excess internal energy was used as a weight average of the excess volume and entropy parts. The results indicated good agreement between the activity of the solvent calculated by the proposed model and the experimental data. The proposed model has the advantage that using only simple density measurements the activity values that are necessary in the calculation of thermodynamic properties can be evaluated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1219–1227, 2005
Preparation and characterization of polypropylene–montmorillonite nanocomposites generated by in situ metallocene catalyst polymerization
Authors: Hwu Jyh‐Ming , Jiang George‐J 
Published: January 2005

AbstractAn ion‐exchange method was applied to replace sodium cations inside the interlamellar space of montmorillonite with positively charged stearyl trimethyl ammonium chloride. The d001‐spacing of montmorillonite is larger in toluene than in other solvents. The overexchanged stearyl methyl ammonium chloride in the montmorillonite layers can be completely washed out by ethanol. Polypropylene–montmorillonite nanocomposites were prepared by using the supported rac‐Et(Ind)2ZrCl2 catalyst on the montmorillonite. The nanocomposites that were polymerized by the supported catalyst were characterized by infrared spectroscopy, nuclear magnetic resonance, X‐ray diffraction, differential scanning calorimetry, scanning electron microscopy, and transmission electron microscopy. Transmission electron microcopy shows that each silicate sheet of montmorillonite is randomly dispersed into the polypropylene matrix following polymerization by using a supported catalyst. The polypropylene nanocomposites had higher crystallinity, hardness, and thermal properties than pure polypropylene. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1228–1236, 2005
Using silica nanoparticles as curing reagents for epoxy resins to form epoxy–silica nanocomposites
Authors: Liu Ying‐Ling , Li Shu‐Hsien 
Published: January 2005

AbstractNanoscale colloidal silica showed high reactivity toward curing epoxy resins to form epoxy–silica nanocomposites under mild conditions. Adding a certain amount (5000 ppm) of magnesium chloride lowered the activation energy of the reaction from 71 to 46 kJ/mol. Less and more magnesium chloride both exhibited counter action on lowering the activation energy of the curing reaction. Tin chloride dihydrate and zinc acetylacetonate hydrate were also added into the curing compositions, however, showing no significant effect on promoting the curing reaction. Through this curing reaction, epoxy–silica nanocomposites containing high silica contents up to 70 wt % were obtained. Therefore, this reaction provided a novel and convenient route in preparation of epoxy–silica nanocomposites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1237–1245, 2005
Preparation, characterization, and application of thin film composite nanofiltration membranes
Authors: Song Yujun , Liu Fuan , Sun Benhui 
Published: January 2005

AbstractThe active aromatic polyamide layers of thin film composite nanofiltration (NF‐TFC) membranes were prepared via interfacial polymerization (IP) from three different types of polyamine: p‐phenylenediamine (PPD), m‐phenylenediamine (MPD), or piperazine (PRP), and trimesoyl chloride (TMC) on polysulfone/sulfonated polysulfone (PSf/SPSf) alloy substrates. Chemical components, cross section structures, and thermal properties of the polyamide active layers and the bulk membranes, characterized by Fourier transfer IR spectroscopy and attenuated total reflection IR spectroscopy, scanning electron microscopy, and differential scanning calorimetry and thermogravimetry, respectively, revealed an interpenetrating layer between the polyamide active layer and the substrate. A ridge–valley structural active layer was formed on the PSf/SPSf substrate for the NF‐TFC membrane with a thick polyacrylamide (PA) layer. Compared with the NF‐TFC membranes on PSf substrates, those on PSf/SPSf alloy substrates had a higher permeability without losing the selectivity by introducing the hydrophilic SPSf into the hydrophobic PSf substrates. The binding between the modified substrate and the active PA layer was also improved. Good separation performances using these NF‐TFC membranes were obtained in the polyvalent ion separation, the ground water softening, and the treatment of wastewater from adipic acid plants in a wide pH range. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1251–1261, 2005
Identification of caprolactam oligomers and related compounds in aqueous extracts of nylon‐6
Authors: Jenke Dennis , Poss Mitchell , Sadain Salma , Story James , Smith Walter , Reiber Duane 
Published: January 2005

AbstractCyclic oligomers of caprolactam were isolated from a multilayered polyolefin plastic film containing a nylon‐6 layer and subsequently characterized. Nylon‐6 was extracted with aqueous solutions and the levels of the oligomers were measured in the resulting extracts. Oligomers up to n = 5 were present at high and comparable levels in all the nylon‐6 extracts. The levels of the oligomers dropped off rapidly with increased compound size after n = 5, with the heptamer being barely observable in the extract chromatograms. The effect of extracting solution pH on the compound's concentration in the extract was small, except for the monomer, whose accumulation was significantly decreased at low pH. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1262–1274, 2005
Genescene: An ontology‐enhanced integration of linguistic and co‐occurrence based relations in biomedical texts
Authors: Leroy Gondy , Chen Hsinchun 
Published: January 2005

AbstractThe increasing amount of publicly available literature and experimental data in biomedicine makes it hard for biomedical researchers to stay up‐to‐date. Genescene is a toolkit that will help alleviate this problem by providing an overview of published literature content. We combined a linguistic parser with Concept Space, a co‐occurrence based semantic net. Both techniques extract complementary biomedical relations between noun phrases from MEDLINE abstracts. The parser extracts precise and semantically rich relations from individual abstracts. Concept Space extracts relations that hold true for the collection of abstracts. The Gene Ontology, the Human Genome Nomenclature, and the Unified Medical Language System, are also integrated in Genescene. Currently, they are used to facilitate the integration of the two relation types, and to select the more interesting and high‐quality relations for presentation. A user study focusing on p53 literature is discussed. All MEDLINE abstracts discussing p53 were processed in Genescene. Two researchers evaluated the terms and relations from several abstracts of interest to them. The results show that the terms were precise (precision 93%) and relevant, as were the parser relations (precision 95%). The Concept Space relations were more precise when selected with ontological knowledge (precision 78%) than without (60%).
Developing a protocol for bioinformatics analysis: An integrated information behavior and task analysis approach
Authors: Bartlett Joan C. , Toms Elaine G. 
Published: January 2005

AbstractThe purpose of this research is to capture, understand, and model the process used by bioinformatics analysts when facing a specific scientific problem. Integrating information behavior with task analysis, we interviewed 20 bioinformatics experts about the process they follow to conduct a typical bioinformatics analysis—a functional analysis of a gene, and then used a task analysis approach to model that process. We found that each expert followed a unique process in using bioinformatics resources, but had significant similarities with their peers. We synthesized these unique processes into a standard research protocol, from which we developed a procedural model that describes the process of conducting a functional analysis of a gene. The model protocol consists of a series of 16 individual steps, each of which specifies detail for the type of analysis, how and why it is conducted, the tools used, the data input and output, and the interpretation of the results. The linking of information behavior and task analysis research is a novel approach, as it provides a rich high‐level view of information behavior while providing a detailed analysis at the task level. In this article we concentrate on the latter.
Mechanisms regulating toxicant disposition to the embryo during early pregnancy: An interspecies comparison
Authors: Carney Edward W. , Scialli Anthony R. , Watson Rebecca E. , DeSesso John M. 
Published: January 2005

AbstractThe dose of toxicant reaching the embryo is a critical determinant of developmental toxicity, and is likely to be a key factor responsible for interspecies variability in response to many test agents. This review compares the mechanisms regulating disposition of toxicants from the maternal circulation to the embryo during organogenesis in humans and the two species used predominantly in regulatory developmental toxicity testing, rats and rabbits. These three species utilize fundamentally different strategies for maternal‐embryonic exchange during early pregnancy. Early postimplantation rat embryos rely on the inverted visceral yolk sac placenta, which is in intimate contact with the uterine epithelium and is equipped with an extensive repertoire of transport mechanisms, such as pinocytosis, endocytosis, and specific transporter proteins. Also, the rat yolk sac completely surrounds the embryo, such that the fluid‐filled exocoelom survives through most of the period of organogenesis, and can concentrate compounds such as certain weak acids due to pH differences between maternal blood and exocelomic fluid. The early postimplantation rabbit conceptus differs from the rat in that the yolk sac is not closely apposed to the uterus during early organogenesis and does not completely enclose the embryo until relatively later in development (∼GD13). This suggests that the early rabbit yolk sac might be a relatively inefficient transporter, a conclusion supported by limited data with ethylene glycol and one of its predominant metabolites, glycolic acid, given to GD9 rabbits. In humans, maternal‐embryo exchange is thought to occur via the chorioallantoic placenta, although it has recently been conjectured that a supplemental route of transfer could occur via absorption into the yolk sac. Knowledge of the mechanisms underlying species‐specific embryonic disposition, factored together with other pharmacokinetic characteristics of the test compound and knowledge of critical periods of susceptibility, can be used on a case‐by‐case basis to make more accurate extrapolations of test animal data to the human. Birth Defects Research (Part C) 72:345–360, 2005. © 2005 Wiley‐Liss, Inc.
The feasibility of adjuvant interferon α‐2b in children with high‐risk melanoma
Authors: Navid Fariba , Furman Wayne L. , Fleming Martin , Rao Bhaskar N. , Kovach Sandra , Billups Catherine A. , Cain Alvida M. , Amonette Rex , Jenkins Jesse J. , Pappo Alberto S. 
Published: January 2005

AbstractBACKGROUNDIt has been shown that induction high‐dose interferon α‐2b (IFN‐α‐2b) followed by maintenance therapy improves recurrence‐free survival in adults with high‐risk, resected melanoma. In this study, the feasibility and toxicity of this regimen were evaluated in newly diagnosed pediatric patients with Stage III melanoma involving regional lymph nodes.METHODSFifteen patients age ≤ 18 years with newly diagnosed Stage III melanoma were enrolled on an institutional protocol. Patients were treated with wide local excision, sentinel lymph node biopsy, lymph node dissection, and adjuvant biotherapy, consisting of induction therapy with 20 million IU/m2 per day IFN‐α‐2b intravenously 5 times per week for 4 weeks followed by maintenance therapy with IFN‐α‐2b 10 million IU/m2 per day subcutaneously 3 times per week for 48 weeks. Patients were monitored for toxicity and tumor recurrence.RESULTSAll patients completed induction therapy, and nine patients completed maintenance therapy. Three patients currently are receiving maintenance, 2 patients developed recurrent disease on maintenance therapy, and 1 patient stopped maintenance therapy 5 weeks early. During induction therapy, Grade 3–4 toxicities included 14 episodes of neutropenia in 11 patients, 3 episodes of leukopenia in 2 patients, and 6 episodes of liver transaminase elevations in 5 patients. Dose modifications were required in four patients. During maintenance therapy, Grade 3–4 toxicities included 23 episodes of neutropenia in 10 patients and 2 episodes of liver transaminase elevations in 2 patients. Three patients required dose modifications. All toxicities were reversible with interruption or dose modification of therapy, and no patients were taken off study due to toxicity.CONCLUSIONSHigh dose IFN‐α‐2b for 4 weeks followed by a lower dose maintenance phase for 48 weeks was feasible in children with Stage III melanoma and was associated with tolerable toxicity. Cancer 2005. © 2005 American Cancer Society.
Current‐mode programmable piecewise‐linear neural synapses
Authors: Balsi Marco , Giuliani Giancarlo 
Published: January 2005

AbstractCellular Neural Networks with piecewise linear connection have been proposed by several authors as a generalization of the basic paradigm, which allows for more complex functionality. None of the prototypes realized to date, however, provides for such kind of synapses. As a feasibility study, a current‐mode subthreshold CMOS piecewise‐linear synapse circuit is developed in this paper. Copyright © 2003 John Wiley & Sons, Ltd.
Autonomous driving control for ITS by using learning automaton network with multiple environments
Authors: Shiraishi Kazuaki , Hamagami Tomoki , Koakutsu Seiichi , Hirata Hironori 
Published: January 2005

AbstractIn this paper, the application of the learning automaton (LA) network with multiple environments is proposed for the adaptive controller for ITS autonomous driving. The LA network, which we introduced previously, has the ability to learn which deals with both multiple reinforcement signals and information of multiple environments at the same time. This feature is found to be useful for improving the response of adaptation in dynamic environments such as highways. In order to evaluate the practical advantage of using the network, we designed a simulational highway system, constructed an autonomous travel controller using the simple LA and the LA network, and executed comparative experiments evaluating the performance of adaptation response and collision avoidance. The results show that the performance of the LA network with multiple environments is superior to that using simple LA application with regard to stability and safety. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 150(4): 36–43, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10363
A pulsed power supply with sag compensation using controlled gradational voltage
Authors: Suzuki Akihiro , Yamada Masaki , Tashiro Shojirou , Iwata Akihiko 
Published: January 2005

AbstractA pulsed power supply with sag compensation using controlled gradational voltage to increase the flatness of output waveforms has been developed. The sag compensation circuit consists of compensation units connected in series. Each compensation unit consists of capacitances, diodes, and semiconductor switches. The capacitances of each unit are charged with different voltages by 2n(V0,2V0,4V0,…). The compensation voltage, which has 2n−1 steps, is generated by switching the semiconductor switches of each unit in a binary sequence. Using this method, compensation voltage waveforms up to 6.2 kV with 31 steps can be obtained with five compensation units. The sag compensation circuit has been adapted to a direct switch‐type pulsed power supply, which generates 7 kV pulsed voltage with a pulse width of 700µs, thus realizing sag compensation. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 150(4): 54–63, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20017
Perspective on concentration polarization effects in electrochromatographic separations
Authors: Tallarek Ulrich , Leinweber Felix C. , Nischang Ivo 
Published: January 2005

AbstractThis work illustrates the appearance and electrohydrodynamic consequences of concentration polarization in the particulate and monolithic fixed beds used in capillary electrochromatography and related electrical‐field assisted processes. Key property of most porous materials is the co‐existence of bulk, quasi‐electroneutral macroporous regions and mesoporous compartments which are ion‐permselective (due to electrical double‐layer overlap) causing different transport numbers for co‐ionic and counterionic species, e.g., background electrolyte components, or the analytes. For a cathodic electroosmotic flow the (cation) permselectivity, together with diffusive and electrokinetic transport induces depleted and enriched concentration polarization zones at the anodic and cathodic interfaces, respectively, in dependence of the mobile phase ionic strength and applied electrical fields. At high field strength a secondary, nonequilibrium electrical double layer may be created in the depleted concentration polarization zones of a material stimulating electroosmosis of the second kind. The potential of this induced‐charge electroosmosis with respect to nonlinear flow velocities and electrokinetic instability mixing (basically destroying the concentration polarization zones) is analyzed in view of the pore space morphology in random‐close packings of spherical‐shaped, porous particles and hierarchically structured monoliths. Possible applications based on a fine‐tuning of the illustrated effects emerge for microfluidic pumping and mixing, or the intensification of sample recovery in adsorption processes. With this perspective we want to focus the attention on concentration polarization in electrochromatographic systems by presenting and discussing original data acquired on relevant microscopic as well as macroscopic scales, and point towards the importance of related effects in colloid and membrane science.*
Conductivity properties of carrier ampholyte pH gradients in isoelectric focusing
Authors: Stoyanov Alexander V. , Das Champak , Fredrickson Carl K. , Fan Z. Hugh 
Published: January 2005

AbstractThe conductivity properties of natural pH gradient created by carrier ampholytes were studied during the process of isoelectric focusing (IEF). IEF was performed in capillaries (10–30 mm long) or in microchips with the same channel length. A 10–30× reduction of the conductivity of the separation medium was observed during the establishment of pH gradient. Results obtained using different IEF voltages indicate that there is a nonlinear relationship between the conductivity of an established pH gradient and the applied electric field. Our theoretical analysis using a simplified model generated values that reasonably agree with the experimental data. In addition, we found that above a certain electric field (∼300 V/cm), resolution does not increase with the applied voltage as predicated; we observed band‐broadening and gel breakdown. The approach presented in this work can be used for optimization of the IEF separation and judicious selection of IEF conditions.
Motion of single long DNA molecules through arrays of magnetic columns
Authors: Minc Nicolas , Bokov Plamen , Zeldovich Konstantin B. , Fütterer Claus , Viovy Jean‐Louis , Dorfman Kevin D. 
Published: January 2005

AbstractWe present a videomicroscopy study of T4 DNA (169 kbp) in microfluidic arrays of posts formed by the self‐assembly of magnetic beads. We observe DNA moving through an area of 10 000 µm2, typically containing 100–600 posts. We determine the distribution of the contact times with the posts and the distribution of passage times across the field of view for hundreds of DNA per experiment. The contact time is well approximated by a Poisson process, scaling like the inverse of the field strength, independent of the density of the array. The distribution of passage times allows us to estimate the mean velocity and dispersivity of the DNA during its motion over distances long compared to our field of view. We compare these values with those computed from a lattice Monte Carlo model and geometration theory. We find reasonable quantitative agreement between the lattice Monte Carlo model and experiment, with the error increasing with increasing post density. The deviation between theory and experiment is attributed to the high mobility of DNA after disengaging from the posts, which leads to a difference between the contact time and the total time lost by colliding. Classical geometration theory furnishes surprisingly good agreement for the dispersivity, while geometration theory with a mean free path significantly overestimates the dispersivity.
Antidepressant drug prescribing among elderly subjects: a population‐based study
Authors: Percudani Mauro , Barbui Corrado , Fortino Ida , Petrovich Lorenzo 
Published: January 2005

AbstractBackgroundThe patterns of antidepressant drug prescribing have rarely been studied in large and geographically defined populations of elderly subjects. In the present study we examined the prevalence and distribution of antidepressant prescribing in Lombardy, a northern Italy region with more than one and a half million elderly inhabitants.MethodsWe used the Regional Administrative Database of Lombardy. This database includes all prescriptions reimbursed by the National Health System in the population living in this region. All antidepressant prescriptions dispensed to subjects aged 65 years or above during 2001 were extracted and prevalence data calculated by dividing antidepressant users by the total number of male and female residents in each age group.ResultsDuring the 12 months surveyed 153,706 subjects were dispensed one or more prescriptions of antidepressants, yielding a prevalence of use of 9.49 subjects per 100 inhabitants (95% confidence interval 9.44, 9.53). Although the proportion of chronic users slightly decreased with age, more than 35% of those older that 85 years were moderate or chronic antidepressant users. General practitioners issued the majority of antidepressant prescriptions, and most antidepressant users were also dispensed agents for medical disorders.ConclusionsThe very high rates of antidepressant drug prescribing detected in late life suggest the need of characterising these subjects in terms of medical and psychiatric characteristics, needs and quality of life. It also suggests the need for pragmatic clinical trials, carried out in the general practice, with the aim of assessing whether antidepressants are effective in these conditions. Copyright © 2005 John Wiley & Sons, Ltd.