bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Amperometric Immunosensor Based on Layer‐by‐Layer Assembly of L‐Cysteine and Nanosized Prussian Blue on Gold Electrode for Determination of Human Chorionic Gonadotrophin
Authors: Wang Jinfen , Yuan Ruo , Chai Yaqin , Yin Bing , Xu Yang , Guan Shu 
Published: February 2009

AbstractA novel amperometric immunosensor based on L‐cysteine/nanosized Prussian blue bilayer films ({NPB/L‐cys}2) and gold nanoparticles (nano‐Au) was fabricated for determination of human chorionic gonadotrophin (HCG). First, L‐cys and NPB was self‐assembled by layer‐by‐layer (LBL) technology to form {NPB/L‐cys}2 bilayer films on the gold electrode. Subsequently, nano‐Au layer was immobilized on the {NPB/L‐cys}2 bilayer films by electrodepositing gold chloride tetrahydrate and then anti‐HCG was assembly on the nano‐Au layer. Finally hemoglobin (Hb) was employed to block sites against nonspecific binding. With the electrocatalytic ability of Hb and NPB for the reduction of H2O2, the current signal of the antigen‐antibody reaction was amplified and the enhanced sensitivity was achieved. In this study, the assembly process and performance of the immunosensor were characterized by cyclic voltammetry (CV) and the morphology was researched by scanning electron microscopy (SEM). The immunosensor performed a high sensitivity and a wide linear response to HCG in two ranges from 0.5 to 10 mIU/mL and from 10 to 200 mIU/mL with a relatively low detection limit of 0.2 mIU/mL at 3 times the background noise, as well as good stability and long‐term life.
Amperometric Biosensor Based on Immobilization of Oxalate Oxidase in a Mucin/Chitosan Matrix
Authors: Benavidez Tomás E. , Capra Raúl H. , Alvarez Cecilia I. , Baruzzi Ana M. 
Published: February 2009

AbstractAn amperometric electrode for oxalate determination immobilizing the oxalate oxidase in a mucin/chitosan (muc/chit) gel with glutaraldehyde as crosslinking agent is presented. The effect of muc/chit weight ratio and volume percent (vol.%) of glutaraldehyde was studied. A very low dynamic response was observed in the case of 100% chitosan with 5 vol.% crosslinking agent. The addition of mucin to chitosan for enzyme immobilization resulted in a biosensor with much better performance, concerning to dynamic response, sensitivity, and stability, with 75% of the initial response after two months. The ratio muc/chit 70/30 was considered optimum for the immobilization. A slight crosslinking and the incorporation of mucin largely influences the swelling and diffusion of the analyte; a direct effect of these properties on the calibration slope was found; the hydrophilic environment for the biomolecule also favor the enzymatic activity through a higher enzyme‐substrate interaction.
Time domain simulation of soil–foundation–structure interaction in non‐uniform soils
Authors: Jeremić Boris , Jie Guanzhou , Preisig Matthias , Tafazzoli Nima 
Published: February 2009

AbstractPresented here is a numerical investigation of the influence of non–uniform soil conditions on a prototype concrete bridge with three bents (four span) where soil beneath bridge bents are varied between stiff sands and soft clay. A series of high‐fidelity models of the soil–foundation–structure system were developed and described in some details. Development of a series of high‐fidelity models was required to properly simulate seismic wave propagation (frequency up to 10Hz) through highly nonlinear, elastic plastic soil, piles and bridge structure. Eight specific cases representing combinations of different soil conditions beneath each of the bents are simulated. It is shown that variability of soil beneath bridge bents has significant influence on bridge system (soil–foundation–structure) seismic behavior. Results also indicate that free field motions differ quite a bit from what is observed (simulated) under at the base of the bridge columns indicating that use of free field motions as input for only structural models might not be appropriate. In addition to that, it is also shown that usually assumed beneficial effect of stiff soils underneath a structure (bridge) cannot be generalized and that such stiff soils do not necessarily help seismic performance of structures. Moreover, it is shown that dynamic characteristics of all three components of a triad made up of earthquake, soil and structure play crucial role in determining the seismic performance of the infrastructure (bridge) system. Copyright © 2009 John Wiley & Sons, Ltd.
High‐precision finite element analysis of elastoplastic dynamic responses of super‐high‐rise steel frames
Authors: Ohsaki Makoto , Miyamura Tomoshi , Kohiyama Masayuki , Hori Muneo , Noguchi Hirohisa , Akiba Hiroshi , Kajiwara Koichi , Ine Tatsuhiko 
Published: February 2009

AbstractA new framework is presented for analysis of dynamic collapse behavior of steel frames using large‐scale parallel finite element method based on the domain decomposition method. The analysis software is based on ADVC as a part of the E‐Simulator that takes advantage of recent development of computer science and high‐performance parallel computing in computational mechanics. By making an analysis model with fine meshing, a complicated sequence of local buckling of columns and beams can be simulated. Numerical results are shown for dynamic collapse analysis of single‐story and 5‐story frame models to show that the global and local behaviors are simultaneously simulated by a high‐precision finite element analysis. Eigenvalue analysis is also carried out for a 31‐story frame to demonstrate that dynamic analysis can be carried out for a structure discretized to solid elements with more than 70 million DOFs. Copyright © 2009 John Wiley & Sons, Ltd.
Detachment and infiltration variations as consequence of regolith development in a Pyrenean badland system
Authors: Nadal‐Romero E. , Regüés D. 
Published: February 2009

AbstractThe Araguás experimental catchment has been monitored to study badland dynamics in the Central Pyrenees. Previous studies of weathering processes within the catchment reported strong regolith dynamics associated with seasonal variations in the temperature and moisture regimes. A preliminary analysis of hydrological response and suspended sediment transport data recorded at a gauging station also demonstrated seasonal trends. The main objective of the present study is to understand the effect of regolith dynamics on sediment detachment and infiltration processes, based on field studies using simulated rainfall. The experiment design was based on seasonal differences in the physical conditions of surface regolith and the general trends of hydro‐sedimentological responses. Rainfall simulations were conducted on small plots using a pressure nozzle. Similar experimental rainfall conditions were set for all plots (rainfall intensity around 45 mm h–1).The results showed strong variations in the infiltration and detachment responses closely associated with the regolith conditions and crusting development. Infiltration showed seasonal differences in time lag and intensity: average infiltration rates ranged from very low (2·05 mm h–1) to moderated high values (44·04 mm h–1) associated to regolith development conditions. Maximum sediment concentration, as an indicator of particles produced by detachment, also ranged from moderate (3 g l–1) to extreme values (145 g l–1). Mean and minimum infiltration rates showed negative correlations with initial moisture content. Sediment concentration showed a positive correlation with time lag, ponding, and sealing time, and a negative correlation with initial moisture. In terms of seasonal trends, infiltration and erosion responses were relatively stable during spring and autumn, whereas wide variations were recorded in infiltration rates and sediment detachment during summer and winter. As a general conclusion, the obtained results indicate that seasonal differences in detachment and infiltration depend on the nature of regolith development. Copyright © 2009 John Wiley & Sons, Ltd.
On the adjustment for covariates in genetic association analysis: a novel, simple principle to infer direct causal effects
Authors: Vansteelandt Stijn , Goetgeluk Sylvie , Lutz Sharon , Waldman Irwin , Lyon Helen , Schadt Eric E. , Weiss Scott T. , Lange Christoph 
Published: February 2009

AbstractIn genetic association studies, different complex phenotypes are often associated with the same marker. Such associations can be indicative of pleiotropy (i.e. common genetic causes), of indirect genetic effects via one of these phenotypes, or can be solely attributable to non‐genetic/environmental links between the traits. To identify the phenotypes with the inducing genetic association, statistical methodology is needed that is able to distinguish between the different causes of the genetic associations. Here, we propose a simple, general adjustment principle that can be incorporated into many standard genetic association tests which are then able to infer whether an SNP has a direct biological influence on a given trait other than through the SNP's influence on another correlated phenotype. Using simulation studies, we show that, in the presence of a non‐marker related link between phenotypes, standard association tests without the proposed adjustment can be biased. In contrast to that, the proposed methodology remains unbiased. Its achieved power levels are identical to those of standard adjustment methods, making the adjustment principle universally applicable in genetic association studies. The principle is illustrated by an application to three genome‐wide association analyses. Genet. Epidemiol. 33:394–405, 2009. © 2009 Wiley‐Liss, Inc.
Measurement of cortical thickness from MRI by minimum line integrals on soft‐classified tissue
Authors: Aganj Iman , Sapiro Guillermo , Parikshak Neelroop , Madsen Sarah K. , Thompson Paul M. 
Published: February 2009

AbstractEstimating the thickness of the cerebral cortex is a key step in many brain imaging studies, revealing valuable information on development or disease progression. In this work, we present a framework for measuring the cortical thickness, based on minimizing line integrals over the probability map of the gray matter in the MRI volume. We first prepare a probability map that contains the probability of each voxel belonging to the gray matter. Then, the thickness is basically defined for each voxel as the minimum line integral of the probability map on line segments centered at the point of interest. In contrast to our approach, previous methods often perform a binary‐valued hard segmentation of the gray matter before measuring the cortical thickness. Because of image noise and partial volume effects, such a hard classification ignores the underlying tissue class probabilities assigned to each voxel, discarding potentially useful information. We describe our proposed method and demonstrate its performance on both artificial volumes and real 3D brain MRI data from subjects with Alzheimer's disease and healthy individuals. Hum Brain Mapp 2009. © 2009 Wiley‐Liss, Inc.
Age effects on the regulation of adult hippocampal neurogenesis by physical activity and environmental enrichment in the APP23 mouse model of Alzheimer disease
Authors: Mirochnic Sebastian , Wolf Susanne , Staufenbiel Matthias , Kempermann Gerd 
Published: February 2009

AbstractAn active lifestyle is to some degree protective against Alzheimer's disease (AD), but the biological basis for this benefit is still far from clear. We hypothesize that physical and cognitive activity increase a reserve for plasticity by increasing adult neurogenesis in the hippocampal dentate gyrus (DG). We thus assessed how age affects the response to activity in the murine APP23 model of AD compared with wild type (WT) controls and studied the effects of physical exercise (RUN) and environmental enrichment (ENR) in comparison with standard housing (CTR) at two different ages (6 months and 18 months) and in both genotypes. At 18 months, both activity paradigms reduced the hippocampal human Aβ1‐42/Aβ1‐40 ratio when compared with CTR, despite a stable plaque load in the hippocampus. At this age, both RUN and ENR increased the number of newborn granule cells in the DG of APP23 mice when compared with CTR, whereas the levels of regulation were equivalent to those in WT mice under the same housing conditions. At 6 months, however, neurogenesis in ENR but not RUN mice responded like the WT. Quantifying the number of cells at the doublecortin‐positive stage in relation to the number of cells on postmitotic stages we found that ENR overproportionally increased the number of the DCX‐positive “late” progenitor cells, indicative of an increased potential to recruit even more new neurons. In summary, the biological substrates for activity‐dependent regulation of adult hippocampal neurogenesis were preserved in the APP23 mice. We thus propose that in this model, ENR even more than RUN might contribute to a “neurogenic reserve” despite a stable plaque load and that age affects the outcome of an interaction based on “activity.” © 2009 Wiley‐Liss, Inc.
Kinetics of atrazine biodegradation by suspended and immobilized mixed microbial cells cultivated in continuous systems
Authors: Tafoya‐Garnica Angélica , Macías‐Flores Alberto , Ruiz‐Ordaz Nora , Juárez‐Ramírez Cleotilde , Galíndez‐Mayer Juvencio 
Published: February 2009

AbstractBACKGROUND: Using a suspended or immobilized microbial community obtained through chemostat selection from agricultural soils formerly treated with triazinic herbicides, the atrazine biodegradation kinetics in continuous aerobic reaction systems was studied.RESULTS: When microbial cells were continuously cultivated on atrazine as the sole nitrogen and carbon source, atrazine removal efficiencies ηATZ near to 100% were reached, although accumulation of metabolic byproducts was detected. The fluidized‐bed biofilm reactor allowed atrazine removal rates RV, ATZ higher than that permitted by suspended cell cultures with similar removal efficiencies. In this system, the highest volumetric removal rate was obtained (RV, ATZ = 12.2 mg L−1 h−1), with herbicide removal efficiencies ηATZ near 100% and reduced accumulation of byproducts.CONCLUSIONS: With the operational conditions probed in continuous suspended‐cell culture, increasing the C:N ratio in the inflowing medium resulted in higher cell growth yields but not in better atrazine removal rates. Kinetic results showed that for similar working conditions higher RV, ATZ values and reduced amounts of degradation byproducts of recalcitrant organic compounds could be expected with multi‐stage biofilm reactors. Copyright © 2009 Society of Chemical Industry
Blood cultures for community‐acquired pneumonia: Are they worthy of two quality measures? A systematic review
Authors: Afshar Nima , Tabas Jeffrey , Afshar Kia , Silbergleit Robert 
Published: February 2009

AbstractBACKGROUND:Obtaining blood cultures (BCs) for patients hospitalized with community‐acquired‐pneumonia (CAP) has been recommended by experts and used as a measure of quality of care. However, BCs are infrequently positive in these patients and their effect on clinical management has been questioned.PURPOSE:We performed a systematic review of the literature to determine the impact of BCs on clinical management in CAP requiring hospitalization and thus its appropriateness as a quality measure.DATA SOURCES:We searched MEDLINE, MEDLINE In‐Process, and the Cochrane databases for English‐language studies that reported the effect of BCs on management of adults hospitalized with CAP. We also searched the reference lists of included studies and background articles and asked experts to review our list for completeness.STUDY SELECTION:Studies were chosen if they included adults admitted to the hospital with CAP, BCs were obtained at admission, and BC‐directed management changes were reported.DATA EXTRACTION:We abstracted study design, BC positivity, and frequency of BC‐directed management changes.DATA SYNTHESIS:Fifteen studies, all with observational cohort design, were identified and reviewed. Two included only patients with BCs positive for pneumococcus, yielding 13 studies for the primary analysis. BCs were true‐positive in 0% to 14% of cases. They led to antibiotic narrowing in 0% to 3% of patients and to antibiotic broadening ultimately associated with a resistant organism in 0% to 1% of patients.CONCLUSIONS:BCs have very limited utility in immunocompetent patients hospitalized with CAP. Pneumonia quality measures that include BCs should be reassessed. Journal of Hospital Medicine 2009;4:112–123. © 2009 Society of Hospital Medicine.
Quantitative volatile metabolite profiling of common indoor fungi: relevancy for indoor air analysis
Authors: Schuchardt Sven , Kruse Hermann 
Published: February 2009

AbstractMicroorganisms such as bacteria and molds produce an enormous variety of volatile metabolites. To determine whether typical microbial volatile metabolites can be used as indicator compounds for the detection of hidden mold in indoor environments, we examined 14 typical indoor fungal strains for their growth rates and their capability to produce volatile organic compounds (VOC) on standard clinical media and on agar medium made from building materials. Air samples from Headspace Chambers (HSC) were adsorbed daily on Tenax TA tubes and analyzed by thermal desorption gas chromatography and mass spectrometry. In parallel, metabolic activity was measured by determining oxygen demand, the microbial biomass was assessed by dry weighing. Profiling of the volatile metabolites showed that VOC production depended greatly on fungal strain, culture medium, biological activity, and time. The laboratory‐derived maximum emission rates were extrapolated to approximate indoor air concentrations in a hypothetical mold‐infested room. The extrapolated indoor air data suggest that most of the microbial‐produced VOC concentrations were below the analytical detection limit for conventional indoor air analysis. Additionally, conducted indoor air analysis in mold homes confirmed these findings for the most part. The present findings raise doubts about the utility of indicator VOC for the detection of hidden mold growth in indoor environments. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Genotypic and phenotypic characterization of Lactobacillus plantarum strains isolated from Thai fermented fruits and vegetables
Authors: Tanganurat Winee , Quinquis Benoit , Leelawatcharamas Vichien , Bolotin Alexander 
Published: February 2009

AbstractTen Lactobacillus strains originally isolated from Thai fruits and vegetables fermentation were characterized by various phenotypic and genotypic methods. The phenotypic analysis using the method of carbohydrate fermentation patterns (API50CHL) revealed that the isolates belonged to the L. plantarum species. This was further confirmed by 16S rRNA gene sequencing. Multilocus sequence typing (MLST) revealed a strongly clonal population structure and a low genotypic diversity in this collection. However, the analyzed L. plantarum population demonstrated a higher level of diversification after API50CHL that reflects the role of available carbohydrate sources in bacterial evolution. Our results support the postulate that a combination of conventional biochemical and genotyping methods allows a thorough characterization and identification of isolates. We propose that genotypic characterization could be complemented by biochemical characterization to discriminate L. plantarum strains. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A note on the characterization of bismuth black by Raman microspectroscopy
Authors: Trentelman Karen 
Published: February 2009

AbstractInspired by the discovery of bismuth metal used as a pigment in a fifteenth century illuminated manuscript, the identification of bismuth compounds by Raman spectroscopy is investigated. Raman spectra of bismuth metal powder, bismuth (III) sulfide (Bi2S3) and bismuth (III) oxide (α‐Bi2O3) are presented. The influence of excitation laser wavelength is explored, along with the laser‐induced oxidation of bismuth to α‐Bi2O3 and β‐Bi2O3. The implication of these results with respect to the selection of appropriate analytical protocols in the investigation of bismuth pigments in works of art is discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Organic cyclic difluoramino‐nitramines: infrared and Raman spectroscopy of 3,3,7,7‐tetrakis(difluoramino)octahydro 1,5‐dinitro‐1,5‐diazocine (HNFX)
Authors: Weck Philippe F. , Gobin Cédric , Kim Eunja , Pravica Michael G. 
Published: February 2009

AbstractWe present the first vibrational structure investigation of 3,3,7,7‐tetrakis(difluoramino)octahydro‐1,5‐dinitro‐ 1,5‐diazocine (HNFX)—and, more generally, of a member of the new class of gem‐bis(difluoramino)‐substituted heterocyclic nitramine energetic materials—using combined theoretical and experimental approaches. Optimized molecular structure and vibrational spectra of the Ci… symmetry conformer constituting the HNFX crystal were computed using density functional theory methods. Fourier transform infrared and Raman spectra of HNFX crystalline samples were also collected at ambient temperature and pressure. The average deviation of calculated structural parameters from X‐ray diffraction data is ∼1% at the B3LYP/6‐311 + + G(d,p) level of theory, suggesting the absence of significant molecular distortion induced by the crystal field. Very good agreement was found between simulated and measured spectra, allowing reliable assignment of the fundamental normal modes of vibration of the HNFX crystal. Detailed analysis of the normal modes of the C–(NF2)2 and N–NO2 moieties was performed due to their critical importance in the initial steps of the molecular homolytic fragmentation process. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of incorporated amaranth albumins on the functional properties of wheat dough
Authors: Oszvald Mária , Tamás Cecília , Rakszegi Mariann , Tömösközi Sándor , Békés Ferenc , Tamás László 
Published: February 2009

AbstractBACKGROUND: Recent developments in micro‐scale testing methodology and in methods modelling the effects of native forms of constituents by in vitro methods have provided a new approach to study the impact of added foreign proteins on dough end‐use quality. Amaranth (Amaranthus) is a member of the pseudo‐cereal family, whose storage proteins have superior nutritional quality due to their essential amino acid composition. The aim of this project was to study the effects of the incorporated amaranth albumin proteins on the rheological properties of the wheat dough.RESULTS: The mixing time requirements, dough strength and stability of the reconstructed dough increased proportionally with the amount (1, 3 and 5%) of amaranth albumin proteins incorporated. These results were supported by measurements on the non‐extractable polymeric protein ratio of the dough indicating the change in polymer size distribution.CONCLUSION: It was demonstrated that amaranth albumin proteins are capable of interacting with gluten proteins through disulfide bonds, showing similar effects to the individual glutenin subunits of wheat flour proteins. Improvements in dough strength and stability without a substantial increase in the mixing requirements are of great significance for developing energy saving technologies in the baking industry. Copyright © 2009 Society of Chemical Industry