bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of diazepam and its metabolites in human urine by liquid chromatography/tandem mass spectrometry using a hydrophilic polymer column
Authors: Umezawa Hironobu , Lee Xiao‐Pen , Arima Yoshiko , Hasegawa Chika , Marumo Akemi , Kumazawa Takeshi , Sato Keizo 
Published: July 2008

AbstractDiazepam and its major metabolites, nordazepam, temazepam and oxazepam, in human urine samples, were analyzed by liquid chromatography (LC)/tandem mass spectrometry (MS/MS) using a hydrophilic polymer column (MSpak GF‐310 4B), which enables direct injection of crude biological samples. Matrix compounds in urine were eluted first from the column, while the target compounds were retained on the polymer stationary phase. The analytes retained on the column were then eluted into an acetonitrile‐rich mobile phase using a gradient separation technique. All compounds showed base‐peak ions due to [M + H]+ ions on LC/MS with positive ion electrospray ionization, and product ions were produced from each [M + H]+ ion by LC/MS/MS. Quantification was performed by selected reaction monitoring. All compounds spiked into urine showed method recoveries of 50.1–82.0%. The regression equations for all compounds showed excellent linearity in the range of 0.5–500 ng/mL of urine. The limits of detection and quantification for each compound were 0.1 and 0.5 ng/mL of urine, respectively. The intra‐ and inter‐day coefficients of variation for all compounds in urine were not greater than 9.6%. The data obtained from actual determination of diazepam and its three metabolites, oxazepam, nordazepam and temazepam, in human urine after oral administration of diazepam, are also presented. Copyright © 2008 John Wiley & Sons, Ltd.
Automated determination of precursor ion, product ion, and neutral loss compositions and deconvolution of composite mass spectra using ion correlation based on exact masses and relative isotopic abundances
Authors: Grange Andrew H. , Sovocool G. Wayne 
Published: July 2008

AbstractAfter an accidental, deliberate, or weather‐related dispersion of chemicals (dispersive event), rapid determination of elemental compositions of ions in mass spectra is essential for tentatively identifying compounds. A direct analysis in real time (DART)® ion source interfaced to a JEOL AccuTOF® mass spectrometer provided exact masses accurate to within 2 mDa for most ions in full scan mass spectra and relative isotopic abundances (RIAs) accurate to within 15–20% for abundant isotopic ions. To speed determination of the correct composition for precursor ions and most product ions and neutral losses, a three‐part software suite was developed. Starting with text files of m/z ratios and their ion abundances from mass spectra acquired at low, moderate, and high collision energies, the ion extraction program (IEP) compiled lists for the most abundant monoisotopic ions of their exact masses and the RIAs of the +1 and +2 isotopic peaks when abundance thresholds were met; precursor ions; and higher‐mass, precursor‐related species. The ion correlation program (ICP) determined if a precursor ion composition could yield a product ion and corresponding neutral loss compositions for each product ion in turn. The input and output program (IOP) provided the ICP with each precursor ion:product ion pair for multiple sets of error limits and prepared correlation lists for single or multiple precursor ions. The software determined the correct precursor ion compositions for 21 individual standards and for three‐ and seven‐component mixtures. Partial deconvolution of composite mass spectra was achieved based on exact masses and RIAs, rather than on chromatography. Published in 2008 by John Wiley & Sons, Ltd.
Role of multivesicular bodies and their components in the egress of enveloped RNA viruses
Authors: Calistri A. , Salata C. , Parolin C. , Palù G. 
Published: July 2008

AbstractAs an enveloped virus buds, the nascent viral capsid becomes wrapped in a plasma membrane‐derived lipid envelope, and a membrane fission event is thus necessary to separate the virion from the host cell. This membrane fission event is well characterised in the case of enveloped RNA viruses, where it is promoted by late assembly domains (L‐domains) present at the level of specific viral structural proteins. Research conducted over the past 10 years has demonstrated that L‐domains represent docking sites for cellular proteins essential for the biogenesis of a cellular organelle, the multivesicular body (MVB). In this way, enveloped RNA viruses hijack the MVB components to the cellular site where the budding is executed. This review will focus on the cellular machinery exploited by enveloped RNA viruses in order to be released from infected cells. The role of ubiquitin and lipids in viral budding will also be discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Analysis of simulated scanning of atomic‐scale silicon surface by atomic force microscopy
Authors: Lin Zone‐Ching , Liu Shih‐Che 
Published: July 2008

AbstractThis study constructs a contact‐mode atomic force microscopy (AFM) simulation measurement model with constant force mode to simulate and analyze the outline scanning measurement by AFM. The simulation method is that when the probe passes the surface of sample, the action force of the atom of sample received by the atom of the probe can be calculated by using Morse potential. Through calculation, the equivalent force on the cantilever of probe can be acquired. By using the deflection angle equation for the cantilever of probe developed and inferred by this study, the deflection angle of receiving action force can be calculated. On the measurement point, as the deflection angle reaches a fixed deflection angle, the scan height of this simulation model can be acquired. By scanning in the right order, the scan curve of the simulation model can be obtained. By using this simulation measurement model, this study simulates and analyzes the scanning of atomic‐scale surface outline. Meanwhile, focusing on the tip radii of different probes, the concept of sensitivity analysis is employed to investigate the effects of the tip radius of probe on the atomic‐scale surface outline. As a result, it is found from the simulation on the atomic‐scale surface that within the simulation scope of this study, when the tip radius of probe is greater than 12 nm, the effects of single atom on the scan curve of AFM can be better decreased or eliminated. SCANNING 30: 392–404, 2008. © 2008 Wiley Periodicals, Inc.
Structural organization of the cytoskeleton in SV40 human corneal epithelial cells cultured on nano‐ and microscale grooves
Authors: Karuri Nancy W. , Nealey Paul F. , Murphy Christopher J. , Albrecht Ralph M. 
Published: July 2008

AbstractThe basement membrane of human corneal epithelial cells (HCECs) has a three‐dimensional nanoscale architecture, which includes pores, bumps and fibers that may influence cell–substrate adhesion and spreading in the overlying cells. We previously demonstrated that nano‐ and microscale groove and ridge patterns influence the morphological response and the adhesive response of HCECs to a nominal wall shear stress. Cell–substrate adhesion is mediated by adhesion receptors that bind to extracellular matrix components and anchor the cytoskeleton (CSK) of cells to extracellular elements. Here we investigate the CSK organization in SV40‐transformed HCECs grown on nano‐ and microscale groove and ridge patterns. X‐ray lithography was used to fabricate uniform groove and ridge patterns with features ranging in size from 200 nm to 2 µm grooves. Scanning electron microscopy and transmission electron microscopy were used to investigate CSK structure and the distribution of ‐β1 integrin adhesion receptors. CSK elements aligned with the patterns; however, the spatial organization of these elements was influenced by feature size. Larger CSK bundles lay on top of the ridges and ran parallel to the patterns, whereas smaller CSK bundles, whose width was proportional to the groove size, spanned the grooves. ‐β1 integrins co‐localized with the CSK and had a higher density at the poles of aligned spindle‐shaped cells. Differences in organization seen on the different topographical feature sizes may be indicative of differences in extracellular matrix organization. This may explain, in part, previous observations regarding the dependence of cell adhesive responses on the size of topographic features in the substrate. SCANNING 30: 405–413, 2008. © 2008 Wiley Periodicals, Inc.
No silver bullet for inquiry: Making sense of teacher change following an inquiry‐based research experience for teachers
Authors: Blanchard Margaret R. , Southerland Sherry A. , Granger Ellen M. 
Published: July 2008

AbstractInquiry is seen as central to the reform of science teaching and learning, but few teachers have experience with scientific inquiry and thus possess very naïve conceptions of it. One promising form of professional development, research experiences for teachers (RETs), allows teachers to experience scientific inquiry in the hopes that these experiences will then translate to inquiry in the classroom. As intuitively pleasing as these programs are, scant evidence documents their effectiveness. For this study, four secondary science teachers were followed back to their classrooms following a 6‐week, marine ecology RET. The research employed qualitative and quantitative data collection to answer these questions: What were the teachers' initial conceptions and enactment of classroom inquiry, and how did they change after the RET?; How did changes in the nature and use of questions highlight changes in inquiry enactment?; and How were the teachers' changes linked to the RET and are there changes that cannot be explained by the RET experience? Teachers who entered the program with more sophisticated, theory‐based understanding of teaching and learning were more apt to understand inquiry as a model and to use classroom‐based inquiry throughout their teaching following the program. Implications for professional development are discussed. © 2008 Wiley Periodicals, Inc. Sci Ed 93: 322–360, 2009
African American perspectives and informal science educational experiences
Authors: Simpson Jamila S. , Parsons Eileen Carlton 
Published: July 2008

AbstractThis qualitative study examined the perspectives of African American parents as it pertained to informal science education. The following questions guided this study: (1) What are the desires of African American parents/guardians with respect to informal science programs and experiences for their children?; (2) What happens in Jordan Academy, an enrichment program that has successfully recruited African American students?; and (3) What are the African American parents'/guardians' opinions of the program? We inductively and deductively analyzed classroom observations; academy curriculum; photos and videotaped class sessions students' written responses to open‐ended items on the program's evaluation; and teachers' and parents' responses to semistructured, audio‐recorded interviews. We viewed the analysis results from Boykin's Black cultural ethos (BCE). We further interpreted the study's findings from a critical sociocultural perspective that employed a model synthesized from Cole's cultural‐historical framework, Bronfenbrenner's ecological systems theory, and Boykin's triple quandary. Results indicated that most of the African American parents' desires and opinions align with seven of the nine dimensions of Boykin's BCE. The parents' opinions highlight the potential impact of culture on parental choice to enroll their children into an informal science program. The study has important implications for practices within and research on informal science education. © 2008 Wiley Periodicals, Inc.Sci Ed93:293–321, 2009
Insider attack attribution using signal strength‐based hyperbolic location estimation
Authors: Laurendeau Christine , Barbeau Michel 
Published: July 2008

AbstractA rogue insider, in a wireless network, is an authenticated member that exploits possession of a valid identity in order to launch an attack. A typical example is the transmission of a verifiable message containing false or incomplete information. An important step, in enabling the network authorities to attribute an attack message to its originator, involves locating the physical source of the transmission. We propose a probabilistic scheme to determine the location of a transmitting rogue, with a degree of confidence, using the relative signal strength received by neighboring devices, even if the effective isotropic radiated power (EIRP) employed by the rogue is unknown. The relative received signal strength (RSS) between pairs of trusted receivers are combined with a range of possible EIRP values to construct an area in Euclidian space bounded by minimum and maximum distance hyperbolas. The area contained within the intersection of multiple hyperbola pairs pinpoints the location of the rogue transmitter with a specific level of confidence. Copyright © 2008 John Wiley & Sons, Ltd.
Sequential continual reassessment method for two‐dimensional dose finding
Authors: Yuan Ying , Yin Guosheng 
Published: July 2008

AbstractIt is common to encounter two‐dimensional dose finding in phase I trials, for example, in trials combining multiple drugs, or in single‐agent trials that simultaneously search for the maximum tolerated dose (MTD) and the optimal treatment schedule. In these cases, the traditional single‐agent dose‐finding methods are not directly applicable. We propose a simple and adaptive two‐dimensional dose‐finding design that can accommodate any type of single‐agent dose‐finding method. In particular, we convert the two‐dimensional dose‐finding trial to a series of one‐dimensional dose‐finding subtrials along shortened line search segments by fixing the dose level of one drug. We then conduct the subtrials sequentially. Based on the MTD obtained from the completed one‐dimensional trial, we eliminate the doses that lie outside of the search range based on the partial order, and thereby efficiently shrink the two‐dimensional dose‐finding space. The proposed design dramatically reduces the sample size and still maintains good performance. We illustrate the design through extensive simulation studies motivated by clinical trials evaluating multiple drugs or dose and schedule combinations. Copyright © 2008 John Wiley & Sons, Ltd.
The interplay of job demands, job resources and cognitive outcomes in informatics
Authors: Van de Ven Bart , Vlerick Peter , de Jonge Jan 
Published: July 2008

AbstractThe present study investigates the issue of match between job demands and job resources in the prediction of employees' cognitive well‐being. Job demands and job resources, as well as job‐related strains (and concepts concerned with positive well‐being), are not one‐dimensional concepts. At a very basic level they comprise physical, cognitive and/or emotional components. The triple match principle proposes that the strongest, interactive relationships between job demands and job resources are observed when job demands, job resources and strains are based on qualitatively identical dimensions. In this study, we specifically hypothesize that cognitive job resources are most likely to moderate the relationship between cognitive job demands and cognitive outcomes. Two measures of cognitive well‐being are included: learning motivation and professional efficacy. Using a web‐based questionnaire, data were collected in a sample of 207 informatics. Results partially confirm our hypotheses both in terms of main and in terms of interaction effects. Informatics with high cognitive job demands have a higher feeling of competence than informatics with low cognitive job demands. This effect is stronger when matching high cognitive job resources are available. These findings are in line with earlier research on the interaction effects in the prediction of employees' cognitive well‐being at work. Copyright © 2008 John Wiley & Sons, Ltd.
Gender differences in psychological risk factors for development of heart disease
Authors: Espnes Geir Arild , Byrne Don 
Published: July 2008

AbstractWhile coronary heart disease (CHD) for decades was understood as mainly a male disease group, it has through the last years become increasingly evident that it is now an important disease causing premature death also in the female populations throughout the Westernized world. The present paper scrutinizes via literature searches and discussions of relevant data the sex and gender differences in psychological risk factors for CHD with an emphasis on female risk. It is concluded that the risk factor picture in females is, due to limited research, still far from clear, even if there are indications of sex differences in both the risk factors picture and the trajectories of the disease development. Copyright © 2008 John Wiley & Sons, Ltd.
An examination of socio‐culturally specific stress and coping factors on smoking status among African American women
Authors: Fernander Anita , Schumacher Mitzi 
Published: July 2008

AbstractSmoking cessation is critical to reduce the health disparate status of African American (AA) women, however studies reveal that AA women are less likely to quit. Socio‐culturally congruent research is needed that provides explanations as to why AA women choose to smoke in order to develop appropriate cessation interventions for this population. The purpose of the study was to determine whether socio‐cultural stress and coping factors influence smoking among AA women. One hundred ninety‐eight AA females completed the John Henry Scale for Active Coping, the Perceived Stress Scale, the Index of Race‐Related Stress, and an investigator‐developed demographic and smoking survey. Significant associations between frequency of race‐related stress events and perceived general stress (p < 0.001) and between perceived general stress and smoking status were found (p < 0.001). In addition, the socio‐demographic variables of marital status, income, and education were found to moderate the association between general stress and smoking status. Specifically, the association between general stress and smoking status was stronger for women who were less educated, had lower incomes, and were single. Stress is a contributor to smoking among AA women and particular socio‐cultural factors may account for stress and should be addressed in future smoking intervention programs for AA women. Copyright © 2008 John Wiley & Sons, Ltd.
TEM‐Based Metrology for HfO2 Layers and Nanotubes Formed in Anodic Aluminum Oxide Nanopore Structures
Authors: Perez Israel , Robertson Erin , Banerjee Parag , Henn‐Lecordier Laurent , Son Sang Jun , Lee Sang Bok , Rubloff Gary W. 
Published: July 2008

AbstractNanotubes are fabricated by atomic layer deposition (ALD) into nanopore arrays created by anodic aluminum oxide (AAO). A transmission electron microscopy (TEM) methodology is developed and applied to quantify the ALD conformality in the nanopores (thickness as a function of depth), and the results are compared to existing models for ALD conformality. ALD HfO2 nanotubes formed in AAO templates are released by dissolution of the Al2O3, transferred to a grid, and imaged by TEM. An algorithm is devised to automate the quantification of nanotube wall thickness as a function of position along the central axis of the nanotube, by using a cylindrical model for the nanotube. Diffusion‐limited depletion occurs in the lower portion of the nanotubes and is characterized by a linear slope of decreasing thickness. Experimentally recorded slopes match well with two simple models of ALD within nanopores presented in the literature. The TEM analysis technique provides a method for the rapid analysis of such nanostructures in general, and is also a means to efficiently quantify ALD profiles in nanostructures for a variety of nanodevice applications.
Evaluation of Novel Back‐flush Filtration for Removal of Homopolymer from Starch‐g‐PMMA
Authors: Comer Chris M. , Jessop Julie L. P. 
Published: July 2008

AbstractStarch‐g‐poly(methyl methacrylate) (PMMA) was prepared by emulsion photopolymerization without photoinitiator. Grafting efficiency was determined for two types of starch (high‐amylose and amylopectin) and at several illumination times. Since clogging of the graft copolymer prevented vacuum filtration and Soxhlet extraction was too time‐consuming, a new method to separate the PMMA homopolymer from the graft copolymer was developed. Back‐flush filtration uses an intermittent pressure pulse to clean the filter as the homopolymer is separated from the graft copolymer. Back‐flush filtration was shown to be more efficient by reducing the separation time and solvent use, and the grafting efficiencies obtained with back‐flush filtration compare favorably with those from Soxhlet extraction for the starch‐g‐PMMA copolymer systems studied. More accurate grafting efficiencies could be obtained by applying a nonstick coating to the inside chamber of the back‐flush filtration unit.
Lateral shear‐St. Venant torsion coupled vibration of asymmetric‐plan frame structures
Authors: Kuang J. S. , Ng S. C. 
Published: July 2008

AbstractFree vibration analysis is presented for asymmetric‐plan frame structures. Emphasis of the analysis is given to the lateral–torsional vibration of the structures, where lateral shear vibrations in two orthogonal directions are coupled with St. Venant torsion vibration. Based on the continuum approach in tall building analysis, the governing equation of coupled vibration of the problem is developed, and the corresponding eigenvalue equation is then derived. A theoretical method of solution is proposed to solve the eigenvalue problem and a general solution is given to determine the natural frequencies and associated mode shapes of the structure. By following the proposed calculation procedure, frequencies of the coupled vibration are quickly determined and the corresponding mode shapes can clearly be displayed. The numerical investigation pertaining to coupled vibration analysis of a general asymmetric‐plan frame building shows that the results from the proposed method and FEM analysis agree very well. Copyright © 2008 John Wiley & Sons, Ltd.
Phytotoxic effects of cyanobacteria extract on Lemna minor and Myriophyllum spicatum phyto‐tolerance and superoxide dismutase activity
Authors: Yi Ding , Yijun Zhao , Xue Bai , Zhihui Fang , Kai Cheng 
Published: July 2008

AbstractThe research on the effects of microcystins on aquatic plants has increased. Some aquatic plants have some tolerance to microcystins but the mechanism of the tolerance is still unknown. In this experiment, we used microcystins of different concentrations to study the toxic effect in Lemna minor and Myriophyllum spicatum. Experiments were carried out with a range of microcysitns levels (equivalent to 0, 0.1, 0.5, 1.0, and 4.3 mg/L). The growth of L. minor (as fresh weight) and chlorophyll a content were significantly reduced and superoxide dismutase (SOD) activity was significantly decreased at microcystins concentration up to 0.5 mg/L. The growth of M. spicatum was affected, only weakly, by microcystins and 0.5 mg/L and these treatments caused significant decrease in chlorophyll a content. Besides, the SOD activity of M. spicatum positively correlated to microcystins concentration (P < 0.01). The result indicated that M. spicatum was more tolerant to microcystins than L. minor and the induced SOD activity may contribute to the tolerance. The experiment also indicated that catalase (CAT) activity was not significantly influenced by microcystin for both the two tested aquatic plants. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009.