bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micro fabrication of microlens arrays by micro dispensing
Authors: Cheng Hsin‐Chung , Wang Chau‐Hsiang , Huang Chiung‐Fang , Shen Yung‐Kang , Lin Yi , Sheu Dong‐Yea , Hu Yi‐Han 
Published: June 2009

AbstractIn this study, master of the microlens arrays is fabricated using micro dispensing technology, and then electroforming technology is employed to replicate the Ni mold insert of the microlens arrays. Finally, micro hot embossing is performed to replicate the molded microlens arrays from the Ni mold insert. The resin material is used as the dispensing material, which is dropped on a glass substrate. The resin is exposed to a 380 W halogen light. It becomes convex under surface tension on the glass substrate. A master for the microlens arrays is then obtained. A 150‐nm‐thick copper layer is sputtered on the master as an electrically conducting layer. The electroforming method replicates the Ni mold insert from the master of the microlens arrays. Finally, micro hot embossing is adopted to replicate the molded microlens arrays. The micro hot embossing experiment employs optical films of polymethylmethacrylate (PMMA) and polycarbonate (PC). The processing parameters of micro hot embossing are processing temperature, embossing pressure, embossing time, and de‐molding temperature. Taguchi's method is applied to optimize the processing parameters of micro hot embossing for molded microlens arrays. An optical microscope and a surface profiler are utilized to measure the surface profile of the master, the Ni mold insert and the molded microlens arrays. AFM is employed to measure the surface roughness of the master, the Ni mold insert and the molded microlens arrays. The sag height and focal length are determined to elucidate the optical characteristics of the molded microlens arrays. Copyright © 2009 John & Sons, Ltd.
Effect of electron beam irradiation on mechanical and thermal properties of waste polyamide copolymer blended with nitrile‐butadiene rubber
Authors: El‐Nemr Khaled F. , Hassan Medhat M. , Ali Magdy A. 
Published: June 2009

AbstractIn the present study, the effect of electron beam irradiation on the morphological, thermal, and mechanical properties of waste polyamide copolymer (WPA‐66/6) blended with different contents of acrylonitrile butadiene rubber (NBR) were studied. The prepared blends were subjected to irradiation doses up to 150 kGy and the structural modifications were discussed; non‐irradiated blends were used as control. Mechanical properties, namely, tensile strength (TS), yield strength, elongation at break, and hardness, were followed up as functions of irradiation dose and degree of loading with rubber content. On the other hand, the influence of irradiation dose on the thermal parameters, melting temperature, heat of fusion, ΔHm of the recycled PA copolymer, and its blend with NBR were also investigated. Copyright © 2009 John Wiley & Sons, Ltd.
Arg‐85 and Thr‐430 in murine 5‐aminolevulinate synthase coordinate acyl‐CoA‐binding and contribute to substrate specificity
Authors: Lendrihas Thomas , Zhang Junshun , Hunter Gregory A. , Ferreira Gloria C. 
Published: June 2009

Abstract5‐Aminolevulinate synthase (ALAS) controls the rate‐limiting step of heme biosynthesis in mammals by catalyzing the condensation of succinyl‐coenzyme A and glycine to produce 5‐aminolevulinate, coenzyme‐A (CoA), and carbon dioxide. ALAS is a member of the α‐oxoamine synthase family of pyridoxal 5′‐phosphate (PLP)‐dependent enzymes and shares high degree of structural similarity and reaction mechanism with the other members of the family. The X‐ray crystal structure of ALAS from Rhodobacter capsulatus reveals that the alkanoate component of succinyl‐CoA is coordinated by a conserved arginine and a threonine. The functions of the corresponding acyl‐CoA‐binding residues in murine erthyroid ALAS (R85 and T430) in relation to acyl‐CoA binding and substrate discrimination were examined using site‐directed mutagenesis and a series of CoA‐derivatives. The catalytic efficiency of the R85L variant with octanoyl‐CoA was 66‐fold higher than that of the wild‐type protein, supporting the proposal of this residue as key in discriminating substrate binding. Substitution of the acyl‐CoA‐binding residues with hydrophobic amino acids caused a ligand‐induced negative dichroic band at 420 nm in the CD spectra, suggesting that these residues affect substrate‐mediated changes to the PLP microenvironment. Transient kinetic analyses of the R85K variant‐catalyzed reactions confirm that this substitution decreases microscopic rates associated with formation and decay of a key reaction intermediate and show that the nature of the acyl‐CoA tail seriously affect product binding. These results show that the bifurcate interaction of the carboxylate moiety of succinyl‐CoA with R85 and T430 is an important determinant in ALAS function and may play a role in substrate specificity.
Modeling the effects of obesity and weight gain on PSA velocity
Authors: Rundle Andrew G. , Neugut Alfred I. 
Published: June 2009

AbstractBACKGROUNDHemodilution theory states that higher blood volume in obese men effectively dilutes circulating PSA levels resulting in lower PSA test results. Here we apply hemodilution theory to model the effect of weight gain on PSA velocity.METHODSHemodilution formulas were used to model PSA velocity for a series of plausible scenarios in which initial weight and weight gain were varied. The formulas were also applied to published summary data on weight, weight change and PSA velocity from the Prostate Cancer Prevention Trial (PCPT).RESULTSUnder hemodilution theory, PSA velocity is understood to be influenced by total circulating PSA mass (ng of PSA) and BMI at the initial test and total circulating PSA mass and BMI at the subsequent test. PSA velocity in a man with a stable BMI of 35 is estimated to be 13% lower than in a man with a stable BMI of 25. A gain of 4 BMI units is predicted to attenuate PSA velocity by as much as 25%. When applied to summary data from the PCPT, the formulas estimate that a 10 pound weight gain causes a −0.028 ng/ml change in PSA, which closely matches PCPT results where a 10 pound weight gain caused a −0.024 ng/ml change in PSA. We provide software to implement the hemodilution formulas to model PSA velocity for different weights and changes in weight through time (http://www.eheintl.com/psa.jsp).CONCLUSIONStable obesity and weight gain both independently attenuate PSA velocity, potentially obscuring clinically relevant changes in circulating PSA. Prostate 69: 1573–1578, 2009. © 2009 Wiley‐Liss, Inc.
Inhibition of Aβ42 aggregation using peptides selected from combinatorial libraries
Authors: Baine Michael , Georgie Daniel S. , Shiferraw Elelta Z. , Nguyen Theresa P. T. , Nogaj Luiza A. , Moffet David A. 
Published: June 2009

AbstractIncreasing evidence suggests that the aggregation of the small peptide Aβ42 plays an important role in the development of Alzheimer's disease. Inhibiting the initial aggregation of Aβ42 may be an effective treatment for preventing, or slowing, the onset of the disease. Using an in vivo screen based on the enzyme EGFP, we have searched through two combinatorially diverse peptide libraries to identify peptides capable of inhibiting Aβ42 aggregation. From this initial screen, three candidate peptides were selected and characterized. ThT studies indicated that the selected peptides were capable of inhibiting amyloid aggregation. Additional ThT studies showed that one of the selected peptides was capable of disaggregating preformed Aβ42 fibers. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
On analysing warranty data from repairable items
Authors: Marshall Sarah E. , Chukova Stefanka 
Published: June 2009

AbstractFitting models to failure data is an important topic in reliability. The resulting models can be useful both for manufacturers as well as for end‐users. In this paper we provide details of some methods from the literature which can be used as a starting point when analysing and fitting models to failure data from repairable items. In particular we focus on obtaining analytical estimates of the intensity of a non‐homogeneous Poisson process. We illustrate some of these methods on failure data from the warranty database of a major car manufacturer. Copyright © 2009 John Wiley & Sons, Ltd.
A control chart based on likelihood ratio test for monitoring process mean and variability
Authors: Zhang Jiujun , Zou Changliang , Wang Zhaojun 
Published: June 2009

AbstractRecently, monitoring the process mean and variance simultaneously by using a single chart has drawn more and more attention. In this paper, we propose a new single chart that integrates the EWMA procedure with the generalized likelihood ratio (GLR) test statistics for jointly monitoring both the process mean and variance. It can be easily designed and constructed, and its average run length can be evaluated by a two‐dimensional Markov chain model. Owing to the good properties of the GLR test and EMWA, computation results show that it provides quite a robust and satisfactory performance in various cases, including the detection of the decrease in variability and the individual observation at the sampling point, which are very important in many practical applications but may not be well handled by the existing approaches in the literature. The application of our proposed method is illustrated by a real data example from chemical process control. Copyright © 2009 John Wiley & Sons, Ltd.
Regulation of dynamin 2 and G protein‐coupled receptor kinase 2 in rat nucleus accumbens during acute and repeated cocaine administration
Authors: Schroeder Joseph A. , Mccafferty Mary R. , Unterwald Ellen M. 
Published: June 2009

AbstractExposure to cocaine causes many neuroadaptations including alterations in several neurotransmitter receptors and transporters. This study investigated potential mechanisms of cocaine‐induced receptor and transporter regulation by measuring levels of two proteins involved in receptor and transporter trafficking, dynamin 2 and G protein‐coupled receptor kinase 2 (GRK2). Male Fischer rats received three daily injections of cocaine, 15 mg/kg, in a binge‐pattern (at 1 h intervals) for 1, 3, or 14 days. Brain regions of interest were collected 30 min after the last injection and proteins measured by Western blot. Acute binge‐pattern cocaine administration produced a significant increase in both dynamin 2‐ and GRK2‐immunoreactivity (227% and 358% of control) in the nucleus accumbens and GKR2 (150% of control) in the caudate putamen. Tolerance to this effect occurred, as levels of both proteins returned to baseline after 3 days of cocaine. In contrast, dynamin 2 and GRK2 were significantly decreased in the nucleus accumbens after chronic cocaine. This pattern of regulation was unique to the nucleus accumbens and not seen in the frontal cortex or substantia nigra. Pretreatment with either the dopamine (DA) D1 receptor antagonist SCH 23390 or D2 receptor antagonist eticlopride prior to acute cocaine blocked the upregulation of dynamin 2 and GRK2 in the nucleus accumbens. However, only eticlopride was effective in attenuating the decrease in these proteins following chronic cocaine exposure. These results demonstrate that two proteins involved in receptor and transporter trafficking are selectively regulated in the nucleus accumbens following acute versus chronic cocaine exposure, and dopamine receptor activation is required for this regulation. Synapse 63:863–870, 2009. © 2009 Wiley‐Liss, Inc.
In vitro autoradiography and in vivo evaluation in cynomolgus monkey of [18F]FE‐PE2I, a new dopamine transporter PET radioligand
Authors: Varrone Andrea , Steiger Carsten , Schou Magnus , Takano Akihiro , Finnema Sjoerd J. , Guilloteau Denis , Gulyás Balázs , Halldin Christer 
Published: June 2009

AbstractThis study evaluated the in vitro and in vivo characteristics of a new dopamine transporter (DAT) radioligand, [18F]fluoroethyl(FE)PE2I, by autoradiography from postmortem human brain and by positron emission tomography (PET) in three cynomolgus monkeys. In the autoradiography experiments, high [18F]FE‐PE2I accumulation was observed in caudate and putamen that was selectively abolished by GBR12909 or β‐CIT but not by maprotiline. High doses of citalopram (>5 μM) also inhibited [18F]FE‐PE2I binding in the striatum. In vitro Ki of the radioligand was 12 nM at rodent dopamine transporter. [18F]FE‐PE2I brain uptake measured by PET was ∼4–5% of the injected dose, with highest uptake in striatum followed by midbrain and thalamus, lower uptake in neocortex, and lowest in cerebellum. Peak specific binding in striatum was reached ∼40 min and in midbrain 20–30 min postinjection. The ratio‐to‐cerebellum was 7–10 in striatum and 1.5–2.3 in midbrain. BPND measured with simplified reference tissue method using the cerebellum as reference region was 4.5 in striatum and 0.6 in midbrain. No displacement was shown after citalopram or maprotiline administration, while GBR12909 decreased the binding in striatum and midbrain to the level of cerebellum. [18F]FE‐PE2I showed relatively fast elimination and metabolism with the presence of two metabolite peaks with similar retention time as the labeled metabolites of [11C]PE2I. [18F]FE‐PE2I showed in vivo selectivity for the DAT and compared with [11C]PE2I, it showed faster kinetics and earlier peak equilibrium. The potential influence of the two radiometabolites on PET quantification requires further evaluation. Synapse 63:871–880, 2009. © 2009 Wiley‐Liss, Inc.
Cytogenotoxicity induced by PBDE‐47 combined with PCB153 treatment in SH‐SY5Y cells
Authors: He Weihong , Wang Aiguo , Xia Tao , Gao Ping , Xu Bayi , Xu Zhixia , He Ping , Chen Xuemin 
Published: June 2009

AbstractPolybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are important recalcitrant halogenated compounds that have been regarded as major environmental pollutants. Recently, their concurrent appearance in the environment and humans and their structural and toxicological profile similarities have sparked interest in the potential toxicologic consequences of their coexposure. The aim of the current study was to evaluate the cytogenotoxic effects induced by 2,2′,4,4′‐tetrabromodiphenyl ether (PBDE‐47) combined with 2,2′,4,4′,5,5′‐hexachlorobiphenyl (PCB153) treatment in human neuroblastoma cells (SH‐SY5Y) in vitro. SH‐SY5Y cells were exposed to different concentrations of PBDE‐47 (0, 2, 4, 8 μM) with or without PCB153 (5 μM) for 24 h. Thereafter, the cell viability, DNA damage, chromosomal abnormalities, and DNA‐protein crosslinks (DPC) were determined. The results show that PBDE‐47 and PCB153 alone and in combination induce DNA damage, with an increase in the frequency of micronuclei (MN) and DPC formation with increasing PBDE‐47 concentration. In cells coexposed to PBDE‐47 and PCB153, the cell viability significantly decreased while the MN frequency, DNA damage and DPC formation were all obviously increased compared to those of cells treated with the corresponding concentrations of PBDE‐47 or PCB153 alone. Factorial analysis suggests that there were interactions between PBDE‐47 and PCB153. The results imply that PBDE‐47 interacts with PCB153 to inhibit cell viability and induce DNA damage, DPC formation, and chromosome abnormalities. © 2009 Wiley Periodicals, Inc. Environ Toxicol 25: 564–572, 2010.
Relationship of intertwin crown–rump length discrepancy to chorionicity, fetal demise and birth‐weight discordance
Authors: Bhide A. , Sankaran S. , Sairam S. , Papageorghiou A. T. , Thilaganathan B. 
Published: June 2009

AbstractObjectivesTo study the frequency and clinical significance of crown–rump length (CRL) discrepancy at 11–14 weeks of gestation in twin pregnancies from an unselected population.MethodsThis was a retrospective analysis of all twin pregnancies that underwent a routine 11–14‐week scan at a large teaching hospital. Fetal loss was defined as fetal demise of one or both twins after 14 weeks.ResultsA total of 507 twin pregnancies were studied; 382 (75.3%) were dichorionic and 125 (24.7%) were monochorionic twins. The discrepancy in CRL was expressed as a percentage of the CRL of the larger twin. The 95th and 99th centile for CRL discrepancy in twins was 12.2% and 19.3%, respectively. The discrepancy in CRLs in monochorionic and dichorionic twins was not significantly different (Mann–Whitney U = 22 406, P = 0.302). In 39 twin pairs, there was subsequent intrauterine death of one or both twins. Fetal loss was more common in monochorionic twins (24/125) than in dichorionic twins (15/382) (chi‐square = 30.9, P < 0.001). In monochorionic twins, the discrepancy in CRLs in the 24 cases with subsequent loss was significantly greater than in the 101 twin pairs with no subsequent loss (Mann–Whitney U = 896, P = 0.048). The discrepancy in CRLs in 15 dichorionic twins with subsequent loss was not different from that in the 367 twins with no loss (Mann–Whitney U = 2116.5, P = 0.129). The CRL discrepancy was significantly correlated with birth‐weight discordance in twins (Spearman's rho = 0.128, P = 0.006). However, this was due to a significant correlation in dichorionic twins (Spearman's rho = 0.127, P = 0.016) but not in monochorionic twins (Spearman's rho = 0.145, P = 0.14).ConclusionsFetal loss is significantly associated with discrepancy in CRL at the 11–14‐week scan in monochorionic twins and discordance in birth weights is significantly associated with discrepancy in CRL in dichorionic twins. However, intertwin CRL discrepancy is of limited value in screening for these adverse events. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Quality of nuchal translucency measurements in The Netherlands: a quantitative analysis
Authors: Koster M. P. H. , Wortelboer E. J. , Engels M. A. J. , Stoutenbeek P. H. , Elvers L. H. , Visser G. H. A. , Schielen P. C. J. I. 
Published: June 2009

AbstractObjectiveThe Dutch Centre for Population Research has specified quality demands for nuchal translucency (NT) measurement in The Netherlands. We performed an analysis of the quality of NT measurement in 2005–2006 and its influence on screening performance.MethodsThis was a retrospective study of records of NT measurements (n = 27 738) obtained between January 2005 and December 2006 retrieved from the Dutch National Institute for Public Health and the Environment (RIVM). The performance of each individual operator was analyzed with regard to the quality standards, which involved calculation of operator‐specific median NT‐multiples of the median (MoM) values. For the entire population of operators, a curve was determined describing the relationship between crown–rump length and NT. Detection rates (DR) and false‐positive rates (FPR) for Down syndrome were modeled with this new curve and compared to those originally obtained using previously published reference data.ResultsOnly 22% of all operators met the quality requirement of performing more than 150 NT measurements per year. However, no relationship was found between the number of measurements per operator and their median NT‐MoM. The mean of all operator‐specific median NT‐MoM values was 0.94 (target value 1.0). Overall, operators with The Fetal Medicine Foundation certificate measured a significantly higher median NT‐MoM (mean of operator‐specific medians, 0.98) as compared to the non‐certified operators (0.92). During the study period, the monthly median NT‐MoM of all operators rose steadily, from 0.86 in January 2005 to 0.96 in December 2006. Recalculation of the risk for Down syndrome after adjusting the reference NT medians using our own data led to a modeled 4% increase in DR at a 5% FPR.ConclusionImproved monitoring of NT measurement put into effect during the study period seems to have led to an improvement in the accuracy of measurements. Strict quality demands, continued monitoring and scrupulous evaluation of individual operators is likely to lead to an even better performance. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Dynamics of offshore floating wind turbines—model development and verification
Authors: Jonkman Jason M. 
Published: June 2009

AbstractThe vast deepwater wind resource represents a potential to use offshore floating wind turbines to power much of the world with renewable energy. Many floating wind turbine concepts have been proposed, but dynamics models, which account for the wind inflow, aerodynamics, elasticity and controls of the wind turbine, along with the incident waves, sea current, hydrodynamics, and platform and mooring dynamics of the floater, were needed to determine their technical and economic feasibility. This work presents the development of a comprehensive simulation tool for modelling the coupled dynamic response of offshore floating wind turbines and the verification of the simulation tool through model‐to‐model comparisons. The fully coupled time‐domain aero‐hydro‐servo‐elastic simulation tool was developed with enough sophistication to address limitations of previous studies and has features required to perform loads analyses for a variety of rotor‐nacelle assembly, tower, support platform and mooring system configurations. The developed hydrodynamics module accounts for linear hydrostatic restoring; non‐linear viscous drag; the added‐mass and damping contributions from linear wave radiation, including free‐surface memory effects; and the incident‐wave excitation from linear diffraction in regular or irregular seas. The developed mooring line module is quasi‐static and accounts for the elastic stretching of an array of homogenous taut or slack catenary lines with seabed interaction. The hydrodynamics module, the moorings module, and the overall simulation tool were tested by comparing to results of other models, including frequency‐domain models. The favourable results of all the verification exercises provided confidence to perform more thorough analyses. Copyright © 2009 John Wiley & Sons, Ltd.
Modelling and measuring flow and wind turbine wakes in large wind farms offshore
Authors: Barthelmie R. J. , Hansen K. , Frandsen S. T. , Rathmann O. , Schepers J. G. , Schlez W. , Phillips J. , Rados K. , Zervos A. , Politis E. S. , Chaviaropoulos P. K. 
Published: June 2009

AbstractAverage power losses due to wind turbine wakes are of the order of 10 to 20% of total power output in large offshore wind farms. Accurately quantifying power losses due to wakes is, therefore, an important part of overall wind farm economics. The focus of this research is to compare different types of models from computational fluid dynamics (CFD) to wind farm models in terms of how accurately they represent wake losses when compared with measurements from offshore wind farms. The ultimate objective is to improve modelling of flow for large wind farms in order to optimize wind farm layouts to reduce power losses due to wakes and loads.The research presented is part of the EC‐funded UpWind project, which aims to radically improve wind turbine and wind farm models in order to continue to improve the costs of wind energy. Reducing wake losses, or even reduce uncertainties in predicting power losses from wakes, contributes to the overall goal of reduced costs. Here, we assess the state of the art in wake and flow modelling for offshore wind farms, the focus so far has been cases at the Horns Rev wind farm, which indicate that wind farm models require modification to reduce under‐prediction of wake losses while CFD models typically over‐predict wake losses. Further investigation is underway to determine the causes of these discrepancies. Copyright © 2009 John Wiley & Sons, Ltd.