bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atom Assignment in Solid‐State Structures on the Basis of X‐ray Crystallography and DFT Calculations – A Case Study on a Molecular Cu–Sb Alloy
Authors: Ahlrichs Reinhart , Fenske Dieter , Rothenberger Alexander , Schrodt Claudia , Wieber Stephan 
Published: February 2006

AbstractThe structure determination of the molecular Cu‐Sb alloy [Cu28Sb12(PEt3)12{Sb(SiMe3)2}2] was performed by DFT‐assisted X‐ray crystallography, a powerful combination of methods, widely applicable. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Impedance Characterization of a Quartz Crystal Microbalance
Authors: Vanýsek Petr , Delia Laura A. 
Published: February 2006

AbstractThe impedance characteristics of the quartz crystal used in quartz crystal microbalance is considered a higher dimension of information that can be obtained in addition to the resonant frequency change of the crystal. The impedance allows calculating the quality factor of the oscillator that is very closely related to the mechanical rigidity of the material, which is adsorbed or deposited on the quartz crystal. This paper concentrates on utilizing an impedance analyzer, often found in electroanalytical laboratories, instead of the usually required network analyzer.
Effects of Strong Ion‐Pairing on the Electrochemical Reduction of Cyclooctatetraene in Tetrahydrofuran in the Presence of Lithium Ion. Peak Coalescence Does Not Imply Potential Inversion
Authors: Fry Albert J. 
Published: February 2006

AbstractThe first study of the voltammetric reduction of cyclooctatetraene (COT) in tetrahydrofuran (THF) in the presence of lithium ion is reported. A single wave is observed at −2.23 V vs. Ag/0.1 M AgNO3. Density functional calculations have been carried out on a variety of COT/Li/THF species in order to clarify the nature and role of ion pairing in this system. The dominant species in solution are the COT/Li/(THF)2 anion radical and the COT/Li2/(THF)4 dianion. Computer simulations have been carried out to further understand the effects of ion pairing on the reduction. The simulations show that coalescence of two waves into one can occur in the presence of strong ion pairing even when the second reduction potential is negative of the first.
The Direct Electrochemical Oxidation of Ammonia in Propylene Carbonate: A Generic Approach to Amperometric Gas Sensors
Authors: Ji Xiaobo , Banks Craig E. , Compton Richard G. 
Published: February 2006

AbstractThe direct electrochemical oxidation of ammonia in propylene carbonate is reported for the first time. The voltammetric responses at glassy carbon, boron‐doped diamond, edge and basal plane pyrolytic graphite electrodes are explored and compared with the outcome indicating that the optimum electrode substrate for analytical purposes in this solvent is glassy carbon. Proof‐of‐concept is shown for the amperometric detection of ammonia using basal plane pyrolytic graphite electrodes abrasively modified with glassy carbon spheres. Given the significantly lower vapor pressure of propylene carbonate in comparison to water the implications for extending the life‐time of practical sensors are evident. Propylene carbonate shows a wide potential window with glassy carbon electrodes permitting this approach to be used for a potential diversity of gaseous analytes.
Amperometric Sensor for Trichloroacetic Acid Based on Myoglobin/Colloidal Gold Nanoparticles Immobilized in Titania Sol–Gel Matrix
Authors: Li Yancai , Yang Weiwei , Bai Yu , Sun Changqing 
Published: February 2006

AbstractA new amperometric sensor for the determination of trichloroacetic acid (TCA) was developed based on the immobilization of myoglobin/colloidal gold nanoparticles in titania sol–gel matrix. The sensor showed a pair of well‐defined and nearly reversible cyclic voltammetric peaks for the Mb Fe(III)/Fe(II) with a formal potential (E°′) of −335 mV and a peak‐to‐peak separation was 61 mV vs. Ag/AgCl (3.0 M KCl) at 100 mV s−1 in 0.1 M pH 7.0 phosphate buffer solutions (PBS). The formal potential of the Mb Fe(III)/Fe(II) couple shifted linearly with the pH with a slope of −51.3 mV/pH, indicating that an electron transfer accompanies single‐proton transportation. The sensor displayed a good electrocatalytic response toward the reduction of TCA and the catalytic mechanism was also discussed. The overpotential for the reduction of TCA was lowered by at least 0.8 V compared with that obtained at bare glassy carbon electrode. The linear range spans the concentration of TCA from 2.0×10−6 to1.2×10−5 M and the detection limit was 1.2×10−7 M. In addition, the stability, repeatability and selectivity of the sensor were also evaluated.
Electrochemical Reduction of 4,4′‐(2,2,2‐Trichloroethane‐1,1‐diyl)‐ bis(chlorobenzene) (DDT) and 4,4′‐(2,2‐Dichloroethane‐1,1‐diyl)‐ bis(chlorobenzene) (DDD) at Carbon Cathodes in Dimethylformamide
Authors: Mubarak Mohammad S. , Gach Philip C. , Peters Dennis G. 
Published: February 2006

AbstractIn dimethylformamide containing tetramethylammonium tetrafluoroborate, cyclic voltammograms for reduction of 4,4′‐(2,2,2‐trichloroethane‐1,1‐diyl)bis(chlorobenzene) (DDT) at a glassy carbon cathode exhibit five waves, whereas three waves are observed for the reduction of 4,4′‐(2,2‐dichloroethane‐1,1‐diyl)bis(chlorobenzene) (DDD). Bulk electrolyses of DDT and DDD afford 4,4′‐(ethene‐1,1‐diyl)bis(chlorobenzene) (DDNU) as principal product (67–94%), together with 4,4′‐(2‐chloroethene‐1,1‐diyl)bis(chlorobenzene) (DDMU), 1‐chloro‐4‐styrylbenzene, and traces of both 1,1‐diphenylethane and 4,4′‐(ethane‐1,1‐diyl)bis(chlorobenzene) (DDO). For electrolyses of DDT and DDD, the coulometric n values are essentially 4 and 2, respectively. When DDT is reduced in the presence of a large excess of D2O, the resulting DDNU and DDMU are almost fully deuterated, indicating that reductive cleavage of the carbon–chlorine bonds of DDT is a two‐electron process that involves carbanion intermediates. A mechanistic scheme is proposed to account for the formation of the various products.
Efficient reduction of fault current through the grounding grid of a substation supplied by an overhead line
Authors: Popović Ljubivoje M. 
Published: February 2006

AbstractThe paper presents a directly applicable and reasonably accurate method for the evaluation of the effects of the counterpoise, the measure for the reduction of the fault current through the substation grounding grid. Under practical conditions the magnitude of the current diverted from a substation grounding grid by the counterpoise conductor is a very complex function of the self and mutual impedances of overhead and underground conductors, substation grounding impedance, transmission line towers resistance, proximity effect between the grounding grid and the counterpoise conductor, as well as on many other factors of lower order. Therefore certain idealizations and simplification of the real physical model were indispensable to develop the mathematical model presented here. The obtained expressions are mostly based on the general equations of a line represented by its lumped parameters and the general equations of uniform ladder circuits. Copyright © 2006 John Wiley & Sons, Ltd.
An experimental study on the transformer coil leakage current
Authors: Wahab Mohamed A. A. , Hamada M. M. , Zeitoun A. G. , Ismail G. 
Published: February 2006

AbstractThis paper is concerned with the transformer coil dc leakage current under different conditions. These conditions include in‐air, and in‐oil leakage, currents with or without artificial coil deposits. In‐oil leakage, currents are investigated when the coil is immersed in new or used transformer oil at different temperatures. The results showed that the leakage current increases with the increase in the applied voltage and oil temperatures. The rate of increase in leakage current with temperature depends on the transformer oil and coil conditions. The in‐oil leakage currents are higher than those obtained in air. The leakage currents measured in used oil are higher than those resulted in new oil. Copper deposits cause higher values of leakage current than iron deposits for the same medium, applied voltage and temperature. Deposits increase the leakage current for different coil surrounding media. A linear model for the leakage current as a function of the applied voltage under different conditions has been found and its validity has been justified by statistical consideration. The parameters of this model account for various experimental conditions. Copyright © 2006 John Wiley & Sons, Ltd.
Static and dynamic approaches for analyzing voltage stability
Authors: Lei X. , Retzmann D. 
Published: February 2006

AbstractVoltage stability analysis always involves a large number of devices with various dynamic characteristics in power system. For properly capturing static and dynamic behaviors providing insights into characteristics of the voltage stability of the system, different system models are established for different time‐scale studies. In this paper, relevant system models are discussed taking into account load characteristics. Based on these models, different approaches such as static analysis, time‐domain simulation and quasi‐steady state (QSS) approximation are implemented into a simulation program, which is used as a comprehensive tool for analyzing voltage stability. By complementary use of these approaches with the simulation program, voltage collapse stresses of the system under a critical operating condition can be analysed in steady state, and impacts of special events on the voltage stability can also be simulated with time‐domain simulations. For time‐domain simulations, a full system model and a QSS approximation can be adopted for capturing different forms of instability mechanisms. A test system is used to demonstrate the feasibility and effectiveness of the approaches implemented. Copyright © 2006 John Wiley & Sons, Ltd.
Acoustic noise generated by air power reactor in open‐air substation
Authors: Lilien Jean‐Louis 
Published: February 2006

AbstractAir power reactors are often used in substations for different purposes such as fault current limiter, reactive power consumption, harmonic filtering, and grounding impedance. They are also used in test laboratories for electric material testing. If the basic design is in relation with its electric duties, the design rules also include some restrictions for thermodynamics, structural dynamics, and acoustics. The full interaction between these four engineering fields is particularly important for acoustic noise produced by the reactor. This noise level is limited by international rules. The aim of this paper is to present a simple analytical method to evaluate the acoustics of such air power reactors and to compare such a method with more sophisticated numerical evaluations. Last but not least, some trends in noise control methods are described. Detailed tests results are presented for validation of the proposed method to properly evaluate the acoustics of single core reactors. Copyright © 2006 John Wiley & Sons, Ltd.
Motion correction and the use of motion covariates in multiple‐subject fMRI analysis
Authors: Johnstone Tom , Ores Walsh Kathleen S. , Greischar Larry L. , Alexander Andrew L. , Fox Andrew S. , Davidson Richard J. , Oakes Terrence R. 
Published: February 2006

AbstractThe impact of using motion estimates as covariates of no interest was examined in general linear modeling (GLM) of both block design and rapid event‐related functional magnetic resonance imaging (fMRI) data. The purpose of motion correction is to identify and eliminate artifacts caused by task‐correlated motion while maximizing sensitivity to true activations. To optimize this process, a combination of motion correction approaches was applied to data from 33 subjects performing both a block‐design and an event‐related fMRI experiment, including analysis: (1) without motion correction; (2) with motion correction alone; (3) with motion‐corrected data and motion covariates included in the GLM; and (4) with non–motion‐corrected data and motion covariates included in the GLM. Inclusion of covariates was found to be generally useful for increasing the sensitivity of GLM results in the analysis of event‐related data. When motion parameters were included in the GLM for event‐related data, it made little difference if motion correction was actually applied to the data. For the block design, inclusion of motion covariates had a deleterious impact on GLM sensitivity when even moderate correlation existed between motion and the experimental design. Based on these results, we present a general strategy for block designs, event‐related designs, and hybrid designs to identify and eliminate probable motion artifacts while maximizing sensitivity to true activations. Hum. Brain Mapp, 2006. © 2006 Wiley‐Liss, Inc.
Neuregulin regulates the formation of radial glial scaffold in hippocampal dentate gyrus of postnatal rats
Authors: Zheng Chang‐Hong , Feng Linyin 
Published: February 2006

AbstractIn the rodent hippocampus, the radial glial scaffold consists of radial glial cells (RGCs) and plays important roles in neurogenesis in this area after birth. However, the mechanisms that maintain the radial glial scaffold in the postnatal dentate gyrus (DG) area remain elusive. In the present work, we studied the role of Neuregulin (NRG) in the formation and maintenance of the radial glial scaffold in the hippocampal DG of postnatal rats using slice culture. We found that ErbB4 receptors were expressed in vimentin‐positive RGCs in DG of postnatal day 6 (P6) rats. Treatment with NRG and Ab‐3, the inhibitor of ErbB4, revealed that in P6 rats exogenous NRG promoted the proliferation of Vimentin‐positive RGCs in DG. On the other hand, endogenous NRG was found necessary for maintaining the characteristic morphological and immunohistochemical features of these cells. These results indicated that NRG plays a critical role in the formation and maintenance of the radial glial scaffold in the hippocampal DG of postnatal rats. J. Cell. Physiol. 207: 530–539, 2006. © 2006 Wiley‐Liss, Inc.
New polyurethane‐based material for vascular corrosion casting with improved physical and imaging characteristics
Authors: Krucker Thomas , Lang Axel , Meyer Eric P. 
Published: February 2006

AbstractVascular corrosion casting has been established as a method to reconstruct the three‐dimensional (3D) structure of blood vessels of organs and tissues. After replacing the blood volume with a low viscosity resin, the surrounding tissue is removed to replicate the vascular architecture, typically using scanning electron microscopy (SEM). To date available casting resins have had significant limitations such as lack of viscosity, leading to insufficient perfusion of smallest capillaries in organs and tissues of smaller species, interaction with surrounding tissue or fragility of resulting casts. We have reported here about a new polyurethane‐based casting resin (PU4ii†) with superior physical and imaging characteristics. Low viscosity, timely polymerization, and minimal shrinking of PU4ii produces high quality casts, including the finest capillaries. These casts are highly elastic while retaining their original structure to facilitate postcasting tissue dissection and pruning of casts. SEM images illustrate the high reproduction quality, including endothelial cell imprints, features that allow one to discern arterial and veinal vessels. For quantitative analysis, casts from PU4ii can be imaged using micro‐computed tomography to produce digital 3D reconstructions. The inherent fluorescence of PU4ii is sufficient to reproduce casts with or without tissue using confocal microscopy (CM). Because of the simplified casting procedure, the high reproducibility and the superior reproduction quality, a combination of vascular corrosion casting using PU4ii with advanced imaging technologies has great potential to support the description of vascular defects and drug effects in disease models using mutant mice. Microsc. Res. Tech. 69:138–147, 2006. © 2006 Wiley‐Liss, Inc.
Microscopy of the Drosophila facet eye: Vademecum for standardized fixation, embedding, and sectioning
Authors: Hess Michael W. , Pfaller Kristian , Hampölz Bernhard , Longato Stefano , Teis David , Flörl Angelika , Gutleben Karin , Huber Lukas A. 
Published: February 2006

AbstractWe describe here a standardized method for histological processing of the Drosophila compound eye. Primary fixation with 2.5% glutaraldehyde, obligatorily supplemented with 0.1% household detergent regularly yielded the best structural preservation, as compared with that of other, more complicated fixation protocols tested. Notably, it proved indispensable not only to cut off the fly's head to facilitate the penetration of the reagents but also to open the chitinous head capsule. For this, we locally pierced the cuticle between the eyes, leaving the head structurally almost intact, a prerequisite for precisely aligning the head for microtomy. We developed a two‐step re‐embedding procedure allowing for exact and reproducible orientation of the fly heads. Thus, highly comparable series of cross sections through a representative number of ommatidia were obtained. The feasibility of our embedding and sectioning approach is finally demonstrated by three‐dimensional reconstructions of the middle segments of the R1, R7, and R8 photoreceptor cells. We present reconstructions from structurally modified ommatidia, as seen after RNAi‐mediated depletion of the endosomal adaptor protein p14, and from normal ommatidia corresponding to the wildtype. Microsc. Res. Tech. 69:93–98, 2006. © 2006 Wiley‐Liss, Inc.
Microscopy under pressure—An optical chamber system for fluorescence microscopic analysis of living cells under high hydrostatic pressure
Authors: Frey Benjamin , Hartmann Markus , Herrmann Martin , Meyer‐Pittroff Roland , Sommer Karl , Bluemelhuber Gerrit 
Published: February 2006

AbstractHigh hydrostatic pressure (HHP) becomes more and more interesting for life science research, since it can be employed to inactivate various cells. To directly monitor “cells under pressure,” the development of an optical high‐pressure chamber is required. Therefore, an optical pressure chamber that can be used for up to 300 MPa was constructed. This chamber has already been described as a tool for in situ observation of dynamic changes of microscopic structures in bright field as well as phase contrast. In combination with an inverted microscope, we obtained brilliant microscopic color pictures with an optical resolution more than 0.56 μm. Here, we demonstrate the capabilities of the HHP cell, in combination with epifluorescence microscopy. Using a nonadherent human B‐cell line (Raji, ATCC CCL 86), stained with the fluorescent dyes propidium iodide, Hoechst 33342, or dihexyloxacarbocyanine iodide, we were able to show that the system is suitable to perform fluorescence microscopic analyses, with pressures up to 300 MPa, with viable mammalian cells. Microsc. Res. Tech. 69:65–72, 2006. © 2006 Wiley‐Liss, Inc.
Distribution of neurotrophin and TrK receptor‐like immunoreactivity in the adrenal gland of birds
Authors: Arcamone Nadia , Lucini Carla , Maruccio Lucianna , Castaldo Luciana , Gargiulo Giuliana , De Girolamo Paolo 
Published: February 2006

AbstractThe occurrence and localization of neurotrophins and their specific TrK receptor‐like proteins in the adrenal gland of chicken, duck and ostrich were examined by immunohistochemical methods. In all species studied NGF‐, TrK A‐ and TrK C‐like immunoreactivity was observed in neurons and fibers of adrenal ganglia. Thin TrK A‐ and TrK C‐like immunoreactive fibers were also observed among chromaffin cells. NT‐3‐like immunoreactivity was detected in chromaffin cells as revealed by the double immunolabelings NT‐3/chromogranin A and NT‐3/DβH. The interrenal tissue never showed IR to any neurotrophins and TrK tested, and none of the adrenal structures displayed immunoreactivity to BDNF and TrK B. Double immunolabelings NGF/TrK A, NGF/TrK C and TrK A/TrK C showed colocalization in some neurons and fibers in adrenal ganglia. In adrenal glands of the species studied, the distribution of neurotrophins and TrK receptors could suggest an involvement of NT‐3 on neuronal populations innervating adrenal ganglia by means of its high affinity receptor TrK C and low affinity receptor TrK A. In addition, NGF could be utilized by neuronal populations of adrenal ganglia through its preferential receptor TrK A by an autocrine or paracrine modality of action. Microsc. Res. Tech. 69:130–137, 2006. © 2006 Wiley‐Liss, Inc.
Effect of crosslinking on the elasticity of polyelectrolyte multilayer films measured by colloidal probe AFM
Authors: Francius Grégory , Hemmerlé Joseph , Ohayon Jacques , Schaaf Pierre , Voegel Jean‐Claude , Picart Catherine , Senger Bernard 
Published: February 2006

AbstractA homemade colloidal probe atomic force microscope was used to perform nanoindentation with a spherical probe of 5 μm in diameter, at different approach velocities in order to extract the Young's modulus, E0, of poly(L‐lysine)/hyaluronan (PLL/HA) films. This parameter is of prime importance to control cellular adhesion. The films were either kept in their native form or cross‐linked with a mixture of 1‐ethyl‐3‐(3‐dimethyl aminopropyl)carbodiimide (EDC) and N‐hydrosulfosuccinimide (sulfo‐NHS), where the EDC concentration was varied from 1 up to 100 mg mL−1 (approximately from 5 to 500 mM). A model based on Hertz mechanics was used to account for the interactions between film and probe. It is shown that the Young's modulus varies with the approach velocity for the native (PLL/HA) films, whereas for cross‐linked ones, E0 is independent from the velocity over the whole range investigated. It is found that for native films, E0 takes a value of 3 kPa at low approach velocities, a velocity domain that should be relevant in cellular adhesion processes. The Young's modulus increases with the EDC concentration used to cross‐link the films and levels off at a value of about 400 kPa for EDC concentrations exceeding 40 mg mL−1. Thus, it is possible by crosslinking PLL/HA films to control their elastic properties with the aim to alter their behavior as to the cellular adhesion. Microsc. Res. Tech. 69:84–92, 2006. © 2006 Wiley‐Liss, Inc.
Bordetella adenylate cyclase toxin induces a cascade of morphological changes of sheep erythrocytes and localizes into clusters in erythrocyte membranes
Authors: Vojtová Jana , Kofroňová Olga , Šebo Peter , Benada Oldřich 
Published: February 2006

AbstractAdenylate cyclase toxin (CyaA) of Bordetella pertussis penetrates the membrane of eukaryotic cells, producing high levels of intracellular cAMP, as well as hemolysis that results from the formation of cation‐selective toxin channels in the membrane. Using several microscopical approaches we studied the effects of CyaA action on the morphology of sheep erythrocytes during early phases preceding lysis and examined localization of CyaA molecules within the erythrocyte membrane. CyaA induced a cascade of morphological changes of erythrocytes, such as shrinkage, formation of membrane projections, and blebs and swelling. The use of an enzymatically inactive CyaA‐AC− toxoid that is unable to produce cAMP and of a CyaA‐E581K mutant exhibiting higher hemolytic activity than with CyaA showed that the hemolytic activity is responsible for the induction of morphological changes of erythrocytes. Further, immunolabeling of inserted CyaA‐232/FLAG molecules with specific anti‐FLAG antibodies and IgG‐gold particles indicated a clustered distribution of CyaA molecules in erythrocyte membrane. This was confirmed by immunofluorescence and confocal microscopy, which revealed uniform stoichiometry of CyaA clusters, suggesting CyaA binding into specific domains in erythrocyte membrane. Indeed, a decrease of CyaA binding after cholesterol depletion of erythrocytes suggests toxin targeting and binding to membrane microdomains (rafts). Microsc. Res. Tech. 69:119–129, 2006. © 2006 Wiley‐Liss, Inc.