bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Large Electrochemical Capacitance of Microporous Doped Carbon Obtained by Using a Zeolite Template
Authors: Ania C. O. , Khomenko V. , Raymundo‐Piñero E. , Parra J. B. , Béguin F. 
Published: June 2007

AbstractA novel microporous templated carbon material doped with nitrogen is synthesized by using a two‐step nanocasting process using acrylonitrile (AN) and propylene as precursors, and Na–Y zeolite as a scaffold. Liquid‐phase impregnation and in situ polymerization of the nitrogenated precursor inside the nanochannels of the inorganic scaffold, followed by gas‐phase impregnation with propylene, enables pore‐size control and functionality tuning of the resulting carbon material. The material thereby obtained has a narrow pore‐size distribution (PSD), within the micropore range, and a large amount of heteroatoms (i.e., oxygen and nitrogen). In addition, the carbon material inherits the ordered structure of the inorganic host. Such features simultaneously present in the carbon result in it being ideal for use as an electrode in a supercapacitor. Although presenting a moderately developed specific surface area (SBET = 1680 m2 g–1), the templated carbon material displays a large gravimetric capacitance (340 F g–1) in aqueous media because of the combined electrochemical activity of the heteroatoms and the accessible porosity. This material can operate at 1.2 V in an aqueous medium with good cycleability—‐beyond 10 000 cycles—and is extremely promising for use in the development of high‐energy‐density supercapacitors.
Exploring candidate gene associations with neuropsychological performance
Authors: McQueen Matthew B. , Bertram Lars , Lange Christoph , Becker K.D. , Albert Marilyn S. , Tanzi Rudolph E. , Blacker Deborah 
Published: June 2007

AbstractWe hypothesize that quantitative phenotypes related to Alzheimer's disease (AD), rather than the dichotomous disease phenotype, will increase the statistical power for identifying genetic risk factors. Neuropsychological test scores, which allow for the measurement of loss of cognitive function over time, are a particularly promising option for this approach. Using data from a cohort study of prodromal AD in 365 community‐recruited subjects with and without memory problems with a baseline and often one or more follow‐up administrations of a detailed neuropsychological test battery, we performed both cross‐sectional and longitudinal analyses using the known AD gene APOE and four other putative AD genes as predictors. APOE and a promoter polymorphism in insulin degrading enzyme (IDE_4U) showed evidence for association with cross‐sectional and longitudinal changes in memory (P = 0.016–0.025) and other cognitive functions. APOE and a polymorphism in the alpha‐2‐macroglobulin gene (A2M18i) also showed evidence for association with cross‐sectional and longitudinal changes in executive functioning (P = 0.010–0.042). In some cases, longitudinal analysis offered stronger evidence for association than could be seen cross‐sectionally. These preliminary results suggest that this approach has promised the development of a quantitative phenotype related to AD, but more elaborate methods will be required to address multiple comparisons issues in the setting of correlated data. © 2007 Wiley‐Liss, Inc.
Cure behavior of epoxy resin containing castor oil and cashew nut shell liquid and its derivative
Authors: Mathew G. , Rhee J. M. , Hwang B. S. , Nah C. 
Published: June 2007

AbstractThe cure behavior of epoxy resin with a conventional amide‐type hardener (HD) was investigated in the presence of castor oil (CO), cashew nut shell liquid (CNSL), and cashew nut shell liquid–formaldehyde resin (CFR) with dynamic differential scanning calorimetry (DSC). The activation energy of the curing reaction was also calculated on the basis of nonisothermal DSC thermograms at various heating rates. A one‐stage curing was noted in the case of epoxy resin filled with CO, whereas the epoxy resin with CNSL and CFR showed a two‐stage curing process. A competitive cure reaction was noted for the epoxy resin/CNSL(or CFR)/HD blends. In the absence of HD, CFR showed lower values of curing enthalpy than that of CNSL. The activation energy of epoxy resin curing increased with increasing CNSL and CFR loading. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
SEM study of the morphologic change of high‐density polyethylene surface grafted with glycidyl methacrylate
Authors: Li Zhirong , Wang Huiliang 
Published: June 2007

AbstractScanning electron microscopy (SEM) study of the morphologic change of high‐density polyethylene (HDPE) surface grafted with glycidyl methacrylate (GMA) was reported. Radiation‐induced grafting of GMA onto HDPE was carried out in acetone and dichloromethane solution, respectively. The effects of irradiation dose, atmosphere, and swelling time on grafting were investigated. Generally, the extent of grafting increased with irradiation dose, but for the grafting carried out in acetone solution, the extent of grafting initially increased with irradiation dose and then remained almost constant. The extent of grafting was higher in acetone solution than in dichloromethane solution at the same irradiation dose. The extent of grafting in nitrogen was higher than that in air. The successful grafting of GMA onto HDPE was confirmed by weighing and FTIR analysis. SEM investigations showed that the morphologies of the PE samples grafted in acetone solution were quite different to those grafted in dichloromethane. The grafting of GMA carried out in acetone was mainly on HDPE surface and that carried out in dichloromethane was mainly in the bulk of HDPE. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Thermal and kinetic properties of poly(lactic acid) and transglutaminase‐crosslinked wheat gluten blends
Authors: Mohamed Abdellatif A. , Xu Jingyuan 
Published: June 2007

AbstractWheat gluten (10 g) was crosslinked (XL) using 10 units of transglutaminase. Different blends of XL gluten and poly(lactic acid) (PLA) were mixed in a Brabender mixer at 180°C for 10 min. Neat PLA and blends were analyzed using modulated DSC (MDSC). Neat PLA displayed a glass transition (Tg) and exothermic (Cry) followed by endothermic (Mel) transitions. The profile showed a Tg of 0.46 J/g/°C, Cry with 29.9 J/g, whereas Mel exhibited 28.7 J/g. XL wheat gluten displayed one Tg with 0.45 J/g/°C. Samples were subjected to repeated heating and cooling cycles to show the level of compatibility between the two polymers. The activation energy (Ea) and pre‐exponential factor (Z) were determined according to Borchardt and Daniels (B/D) kinetics approach. The blends showed increased Ea values with an increase in the amount of XL gluten. In the presence of 5 and 20% XL gluten, the Ea of PLA increased from 150 to 200 kJ/mol, respectively. A higher number of cycles caused an increase in Ea. The Tg temperature of different PLA/XL gluten blends can be predicted by Gordon–Taylor equation and its modified forms. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Atom transfer radical polymerizations of methyl methacrylate and styrene with an iniferter reagent as the initiator
Authors: Zhang Wei , Zhu Xiulin , Cheng Zhenping , Zhu Jian 
Published: June 2007

AbstractThree novel iniferter reagents were synthesized and used as initiators for the polymerizations of methyl methacrylate (MMA) and styrene (St) in the presence of copper(I) bromide and N,N,N′,N″,N″‐pentamethyldiethylenetriamine at 90 and 115°C, respectively. All the polymerizations were well controlled, with a linear increase in the number‐average molecular weights during increased monomer conversions and relatively narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight ≤ 1.36) throughout the polymerization processes. The polymerization rate of MMA was faster in bulk than that in solution and was influenced by the different polarities of the solvents. A slight change in the chemical structures of the initiators had no obvious effect on the polymerization rates of MMA and St. The initiator efficiency toward MMA was lower than that toward St. The results of 1H‐NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrum analysis, and chain‐extension experiments demonstrated that well‐defined poly(methyl methacrylate) and polystyrene bearing photolabile groups could be obtained via atom transfer radical polymerization (ATRP) with three iniferter reagents as initiators. The polymerization mechanism for this novel initiation system was a common ATRP process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Fabrication and electrical characterization of electrospun polyacrylonitrile‐derived carbon nanofibers
Authors: Agend Farima , Naderi Nader , Fareghi‐Alamdari Reza 
Published: June 2007

AbstractCarbon nanofibers were produced from a polyacrylonitrile/N,N‐dimethylformamide precursor solution by an electrospinning process and later pyrolysis at temperatures ranging from 500 to 1100°C in an N2 atmosphere for about 1 h. The morphological structure of the nanofibers was studied with scanning electron microscopy. Scanning electron microscopy images of carbonized polyacrylonitrile nanofibers without a gold coating showed that the carbonized polyacrylonitrile nanofibers possessed electrical properties. The thermal behavior of the nanofibers was studied with thermogravimetric analysis. An indirect four‐point‐probe method was used for the measurement of the conductivity of nanofiber mats. The conductivity increased sharply with the pyrolysis temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Properties of montmorillonite‐containing natural rubber
Authors: Jurkowska B. , Jurkowski B. , Oczkowski M. , Pesetskii S. S. , Koval V. , Olkhov Y. A. 
Published: June 2007

AbstractA melt compounding process was used to prepare hybrid nanocomposites based on natural rubber (NR) and montmorillonite (MMT) modified with octadecylamine. Cured rubber was subjected to complex testing. Most likely modified MMT participates in physical networking of a low‐temperature topological region (soft amorphous fraction) of NR networked by low energy junctions. There was a significant difference between behavior of NR containing modified and neat montmorillonite and also those measured at low strain (5–50%) and above 150–170%. Because of this, to optimize compounding process of nanocomposite it is necessary to apply properties those determined under conditions as much as possible close to the usage conditions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
The search experience variable in information behavior research
Authors: Erdelez Joi L. Moore, Sanda , He Wu 
Published: June 2007

AbstractA conceptually relaxed utilization of the variable “search experience” makes it difficult for researchers to perform meaningful cross‐study comparisons. The purpose of this study was to examine how search experience is defined and measured when used as a research variable. We implemented a qualitative analysis of 32 library and information science (LIS) research articles. We found that there was inconsistent terminology usage and measurements. Specifically, there were 21 unique labels to describe the search experience and 18 different measurements. The majority of the studies used a generic label “search experience” and relied on the reader to grasp specific context of the electronic information retrieval environment to which the variable applies from the description of the overall research design. In addition, there was a strong preference for measures that represented subjective self‐reporting about the level of exposure to some information retrieval system. It is evident that there is a need for articles to contain detailed definitions of search experience variables for readers to truly understand the findings.
High school students' Information seeking and use for class projects
Authors: Chung Jin Soo , Neuman Delia 
Published: June 2007

AbstractThis study details the activities and strategies that 11th grade students with high academic abilities used during their information seeking and use to complete class projects in a Persuasive Speech class. The study took place in a suburban high school in Maryland, and participants included 21 junior honors students, their teacher, and their library media specialist. Each student produced a 5–7‐minute speech on a self‐chosen topic. Conducted in the framework of qualitative research in a constructivist paradigm (E.G. Guba, & Y.S. Lincoln, 1998), the study used data collected from observations, individual interviews, and documents students produced for their projects—concept maps, paragraphs, outlines, and research journals. Interview and observation data were analyzed using the constant comparative method (B. Glaser & A. Strauss, 1967) with the help of QSR NVivo 2 (QSR International Pty Ltd, 2002); students' documents were analyzed manually. The findings show that students' understanding, strategies, and activities during information seeking and use were interactive and serendipitous and that students learned about their topics as they searched. The research suggests that high school honors students in an information‐rich environment are especially confident with learning tasks requiring an exploratory mode of learning.
Identifications of FIRST radio sources in the NOAO Deep Wide‐Field Survey
Authors: El Bouchefry K. , Cress C.M. 
Published: June 2007

AbstractIn this paper we present the results of an optical and near infrared identification of 514 radio sources from the FIRST survey (Faint Images of the Radio Sky Survey at Twenty centimetres) with a flux‐density limit of 1 mJy in the NOAO Deep Wide‐Field Survey (NDWFS) Boötes field. Using optical (Bw, R, I) and K band data with approximate limits of Bw ∼ 25.5 mag, R ∼ 25.8 mag, I ∼ 25.5 mag and K ∼ 19.4 mag, optical counterparts have been identified for 378 of 514 FIRST radio sources. This corresponds to an identification rate of 34% in four bands (BwRIK), 60% in optical bands (BwRI) and 74% in the I band. Photometric redshifts for these sources have been computed using the hyperz code. The inclusion of quasar template spectra in hyperz is investigated. We note that the photometric data are, in many cases, best matched to templates with very short star‐formation timescales and the inferred ages of identified galaxies depend strongly on the assumptions about the star‐formation timescale. The redshifts obtained are fairly consistent with those expected from the K ‐z relation for brighter radio sources but there is more scatter in the K ‐z diagram at z < 1. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Contribution to the study of composite spectra: XII. Spectroscopic orbits of eight southern stars
Authors: Carquillat J.‐M. , Prieur J.‐L. 
Published: June 2007

AbstractWe present the results of a radial‐velocity study of eight southern SB1 spectroscopic binaries with composite spectra: HD 34318‐9, HD 47579‐80, HD 70442‐3, HD 74946‐7, HD 102171‐2, HD 120901‐2, HD 168701‐2, and HD 174191‐2. The observations were made at Haute‐Provence observatory with the CORAVEL instrument between 1982 and 2006. From the radial‐velocity measurements of the cool components, we derive the orbital elements of those spectroscopic binaries. Using all the available data, we obtain an estimation of the orbital inclination and the angular separation of the two components. Finally we discuss the rotation‐revolution synchronism of the cool components. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Absolute bioavailability of sitagliptin, an oral dipeptidyl peptidase‐4 inhibitor, in healthy volunteers
Authors: Bergman Arthur , Ebel David , Liu Fang , Stone Julie , Wang Amy , Zeng Wei , Chen Li , Dilzer Stacy , Lasseter Kenneth , Herman Gary , Wagner John , Krishna Rajesh 
Published: June 2007

AbstractThe purpose of this study was to determine the absolute bioavailability of sitagliptin, an orally active, potent and highly selective dipeptidyl peptidase‐4 inhibitor recently approved in the United States for the treatment of type 2 diabetes. The effect of a high fat meal on sitagliptin pharmacokinetics was also assessed. The study was performed in two parts. Intravenous doses (2 h infusion) of 25, 50 and 100 mg were administered double‐blind to 10 (8 active, 2 placebo) subjects in a fixed‐sequence manner in Part I. In Part II, 12 subjects were randomized to each of three open‐label treatments: an intravenous 100 mg dose; a single oral 100 mg final market image tablet administered following a high fat meal and a single oral 100 mg final market image tablet administered fasted. Following each dose, plasma and urine were collected at pre‐specified times for evaluation of sitagliptin pharmacokinetics. All doses were generally well tolerated in both parts of the study. Following rising intravenous doses of sitagliptin, AUC0−∞ increased dose‐proportionally, indicating that plasma clearance is independent of dose over the dose range evaluated. Renal clearance of unchanged sitagliptin accounted for approximately 70% of the total plasma clearance of sitagliptin, indicating that sitagliptin is primarily cleared via renal excretion. Averaged across doses, the mean total plasma clearance was 416 ml/min. The mean absolute bioavailability of sitagliptin was 87% with a 90% CI of (81%, 93%). The AUC0−∞ and Cmax geometric mean ratios (fed/fasted) and 90% CIs were 1.03 (0.97, 1.11) and 0.94 (0.86, 1.03), respectively, and were contained within the bounds of (0.80, 1.25). Additionally, the high‐fat meal had no significant effect on Tmax or apparent terminal t1/2. Thus, food does not affect the pharmacokinetics of sitagliptin and therefore can be administered without regard to food. Copyright © 2007 John Wiley & Sons, Ltd.
Pharmacokinetics and dose proportionality of three Tramadol Contramid®OAD tablet strengths
Authors: Karhu David , El‐Jammal Ali , Dupain Thibaut , Gaulin Delphine , Bouchard Sylvie 
Published: June 2007

AbstractA three‐way crossover study in 27 human volunteers was conducted to characterize the pharmacokinetics and to assess the dose proportionality of 100 mg, 200 mg and 300 mg strengths of a novel once‐a‐day tramadol controlled‐release tablet (Tramadol Contramid®OAD) following single‐dose administration. Serial blood samples were collected at predefined timepoints over a 48 h period and racemic tramadol and O‐desmethyltramadol concentrations in plasma were determined using a validated LC‐MS/MS method. Pharmacokinetic parameters were derived using noncompartmental methods. Following dose normalization and logarithmic transformation of concentration‐dependent parameters, the results were compared using analysis of variance (ANOVA). The residual variability thereby obtained was used to construct 90% classical confidence intervals. The two one‐sided tests procedure was used for all pairwise comparisons. Dose proportionality was concluded since the 90% CI for the ratio of geometric means was included in the acceptance range of 0.80–1.25 for all comparisons. Copyright © 2007 John Wiley & Sons, Ltd.
Fitting Semiparametric Additive Hazards Models using Standard Statistical Software
Authors: Schaubel Douglas E. , Wei Guanghui 
Published: June 2007

AbstractThe Cox proportional hazards model has become the standard in biomedical studies, particularly for settings in which the estimation covariate effects (as opposed to prediction) is the primary objective. In spite of the obvious flexibility of this approach and its wide applicability, the model is not usually chosen for its fit to the data, but by convention and for reasons of convenience. It is quite possible that the covariates add to, rather than multiply the baseline hazard, making an additive hazards model a more suitable choice. Typically, proportionality is assumed, with the potential for additive covariate effects not evaluated or even seriously considered. Contributing to this phenomenon is the fact that many popular software packages (e.g., SAS, S‐PLUS/R) have standard procedures to fit the Cox model (e.g., proc phreg, coxph), but as of yet no analogous procedures to fit its additive analog, the Lin and Ying (1994) semiparametric additive hazards model. In this article, we establish the connections between the Lin and Ying (1994) model and both Cox and least squares regression. We demonstrate how SAS's phreg and reg procedures may be used to fit the additive hazards model, after some straightforward data manipulations. We then apply the additive hazards model to examine the relationship between Model for End‐stage Liver Disease (MELD) score and mortality among patients wait‐listed for liver transplantation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluating Health Care Performance: Strengths and Limitations of Multilevel Analysis
Authors: Tan Alai , Freeman Jean L. , Freeman Daniel H. 
Published: June 2007

AbstractAn increasing number of health services researchers are using multilevel analysis for evaluating health care performance. This method has the distinct advantage of accounting for within‐provider correlation among patients. Alternatively, in a similar manner, estimators based on cluster sampling can also adjust for within‐provider correlation. Cluster sampling methods do not require assumptions about error distribution as multilevel analysis does. To our knowledge, no comparison has been made between multilevel analysis and cluster sampling estimators in evaluating health care performance using either a simulated or real dataset. In this paper, we compare the cluster sampling estimators to multilevel estimators in evaluating screening mammography performance using Medicare claims data. We also discuss the strengths and limitations of multilevel analysis in profiling health care providers with small caseloads. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Risk factors for faecal incontinence after rectal cancer treatment
Authors:   cooperative clinical investigators of the Dutch Total Mesorectal Excision trial, Lange M M , den Dulk M , Bossema E R , Maas C P , Peeters K C M J , Rutten H J , Klein Kranenbarg E , Marijnen C A M , van de Velde C J H 
Published: June 2007

Abstract

Background
Low anterior resection (LAR) may result in faecal incontinence. This study aimed to identify risk factors for long-term faecal incontinence after total mesorectal excision (TME) with or without preoperative radiotherapy (PRT).

Methods
Between 1996 and 1999, patients with operable rectal cancer were randomized to TME with or without PRT. Eligible patients who underwent LAR were studied retrospectively at 2 years (399 patients) and 5 years (339) after TME.

Results
At 5 years after surgery faecal incontinence was reported by 61·5 per cent of patients who had PRT and 38·8 per cent of those who did not (P &lt; 0·001). Excessive blood loss and height of the tumour were associated with long-term faecal incontinence, but only in patients treated with PRT.

Conclusion
Faecal incontinence is likely to occur after PRT and TME, especially when the perineum is irradiated.