bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper(I)‐Assembled Pseudorotaxanes Bearing Bis(nitrile) Ligands: Selective Formation of Large Chelate Rings
Authors: Sakellariou Efstathia G. , Collin Jean‐Paul , Dietrich‐Bucheker Christiane O. , Sauvage Jean‐Pierre 
Published: January 2004

AbstractThe syntheses of two novel CuI‐bis(benzonitrile) complexes of the type [Cu(dCNn)2][PF6] {where dCNn = NCPhO(CH2)nOPhCN, n = 3, 4} are described. Both compounds have been characterized by X‐ray crystallography. To our surprise, and although the two complexes were quite similar, two very distinct structures were obtained. For the [Cu(dCN4)2][PF6] complex, a tetrahedral geometry was observed whereas for [Cu(dCN3)2][PF6], a polymeric assembly was formed. A further extension of this work involved the syntheses of two threaded species bearing the M30 macrocycle, Cu metal and a dCNn ligand. The formation of the desired complexes was confirmed by means of mass spectrometry as well as 1‐D and 2‐D 1H NMR spectroscopy. Finally, the cyclic voltammograms of all 4 new species were recorded giving rise to redox potentials ranging from +0.88 to +1.25 V. These new threaded complexes are of particular interest since they can form the basis of novel rotaxane structures. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Microporous Zinc Phosphonocarboxylate with a Zeolite ABW Framework via the Trialkyl Phosphonocarboxylate Route: In situ Synthesis and Characterization of Na[Zn(O3PC2H4CO2)]·H2O
Authors: Zhang Xian‐Ming 
Published: January 2004

AbstractA new zinc phosphonocarboxylate Na[Zn(O3PC2H4CO2)]·H2O (1) has been hydrothermally synthesized by base‐catalyzed hydrolysis of trimethyl 3‐phosphonopropionate. An X‐ray crystallographic study revealed that 1 consists of parallel stacked inorganic hexagonal sheets which are connected by organic −C−C−C−O− pillars forming a three‐dimensional framework with the same topology as ABW‐type zeolites. The accessible channel of 1 consisting of 22 atoms is larger than those of ABW‐type zeolites and the metal phosphonates Zn(O3PC2H4NH2) and Zn(O3PC2H4CO2H)·1.5H2O. TGA shows the trapped water molecules in 1 can be thermally removed without damage to the framework. Furthermore, dehydrated 1 is stable up to 340 °C. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Probing DNA Hybridization by Impedance Measurement Based on CdS‐Oligonucleotide Nanoconjugates
Authors: Xu Ying , Cai Hong , He Pin‐Gang , Fang Yu‐Zhi 
Published: January 2004

AbstractA novel, sensitive DNA hybridization detection protocol, based on DNA‐quantum dots nanoconjugates coupled with electrochemical impedance spectroscopy (EIS) detection, is described. The amino‐linked ss‐DNA probe was covalently immobilized onto a self‐assembled mercaptoacetic acid monolayer modified gold electrode; after hybridization with the target ssDNA‐CdS nanoconjugates, EIS was used to detect the change of interfacial electron‐transfer resistance (Ret) of the redox marker, [Fe(CN)6]4−/3−, from solution to transducer surface. The results showed that when target ssDNA‐CdS nanoconjugates hybridized with probe oligonucleotide, a double helix film formed on the electrode, a remarkably increased Ret value was observed. Only complementary DNA sequence had an obvious signal compared with three‐base mismatched or non‐completely matched sequences under the optimized experimental conditions. Due to having more negative charges, space resistance and the semiconductor property, CdS nanoparticle labels on target DNA could improve the sensitivity to two orders of magnitude when compared with non‐CdS tagged DNA sequences.
A New Optically Reflective Thin Layer Electrode (ORTLE) Window: Gold on a Thin Porous Alumina Film Used to Observe the Onset of Water Reduction
Authors: Miney Paul G. , Schiza Maria V. , Myrick Michael L. 
Published: January 2004

AbstractThe fabrication and unique characteristics of a new type of thin layer electrode, an optically reflective thin layer electrode (ORTLE), are described. The electrode was fabricated by the anodization of a thin layer of aluminum sputtered onto a plain glass microscope slide to create a 750 nm‐thick porous alumina film. A thin film of gold was then sputtered atop the porous and transparent alumina film. The gold layer remained porous to allow solution into the pores but was optically thick and reflective. Reflectance measurements made through the microscope slide did not interrogate the bulk solution, but show spectral features that shift with the optical properties of the material filling the pores of the alumina film. A simple series of experiments, in which the potential of the ORTLE was stepped negatively to various values in an aqueous sodium sulfate solution, shows that interference fringes shift measurably in the ORTLE spectrum at potentials several hundred millivolts positive of the potential at which gas evolution was visible to the naked eye.
Nanoparticle‐Structured Ligand Framework as Electrode Interfaces
Authors: Kariuki Nancy N. , Luo Jin , Han Li , Maye Mathew M. , Moussa Laura , Patterson Melissa , Lin Yuehe , Engelhard Mark H. , Zhong Chuan‐Jian 
Published: January 2004

AbstractNanostructured thin film assemblies derived from metal or oxide nanocrystal cores and functionalized molecular shells provide large surface‐to‐volume ratio and three‐dimensional ligand frameworks. In this article, we report results of an investigation of the nanostructured materials for electroanalysis. Monolayer‐capped gold nanoparticles of 2‐nm core diameter and carboxylic acid‐functionalized alkyl thiols were assembled on electrode surfaces via an exchange‐crosslinking‐precipitation reaction route, and were studied as a model system. The network assemblies exhibit open frameworks in which the void space forms channels with the nanometer sized cores defining its size and the shell structures defining its chemical specificity. Such nanostructures were exploited to demonstrate the viability of responsive materials for interfacial incorporation and fluxes of ionic species. The nanomaterials were characterized by an array of techniques, including cyclic voltammetry, electrochemical quartz‐crystal nanobalance, flow injection analysis, and surface infrared reflection spectroscopy. The current responses and mass loading as a result of the incorporation of ionic species into the nanostructure have been analyzed. The potential application of the nanostructured thin films for electrochemical detection in microfluidic systems is also discussed.
Interdigited Phospholipid/Alkanethiol Bilayers Assembled on APTMS‐Supported Gold Colloid Electrodes
Authors: Cheng Wenlong , Han Xiaojun , Wang Erkang , Dong Shaojun 
Published: January 2004

AbstractThe preparative procedure of a kind of phospholipid/alkanethiol bilayers on a planar macroelectrode was copied to the as‐prepared gold colloid electrodes. The electrochemical and spectral results show that the bilayers on colloid electrodes are interdigited, which are different from their 2‐D counterparts on a planar macroelectrode.
Solubilization of Multiwall Carbon Nanotubes by 3‐Aminopropyltriethoxysilane Towards the Fabrication of Electrochemical Biosensors with Promoted Electron Transfer
Authors: Luong John H. T. , Hrapovic Sabahudin , Wang Dashan , Bensebaa Farid , Simard Benoit 
Published: January 2004

AbstractA simple procedure has been described for the fabrication of multi‐wall carbon nanotube (CNT) based electrochemical sensors. 3‐Aminopropyltriethoxysilane (APTES) induced solubilization of CNTs allowed for the modification of electrode surfaces. With glucose oxidase (GOx), a flavin (FAD) containing enzyme as a model system, APTES was used as a solubilizing agent for CNTs as well as an immobilization matrix for GOx to construct a mediatorless biosensor. Our biosensor was able to efficiently monitor direct electroactivity of GOx at the electrode surface. A well‐defined glucose response was observed at −0.45 V (vs. Ag/AgCl) whereas relevant physiological levels (0.1 mM) of three common interfering species, uric acid, ascorbic acid, and acetaminophen, resulted in no response. Although CNTs modified by APTES acted as semiconductors to reduce the exposed sensing surface, we reasoned nanoscale “dendrites” of CNTs modified by APTES formed a network and projected outwards from the electrode surface and acted like bundled ultra‐microelectrodes that allowed access to the active FAD site and facilitated direct electron transfer to the immobilized enzyme. The glucose biosensor prepared using a carbon fiber (11 μm) exhibited picoamperometric current response within 5 s with detection limits of 5–10 μM.
A Self‐Contained Microelectrochemical Cavity System Comprised of a Polymer and Phospholipid Membrane Suspended over a Picoliter Volume
Authors: Evans Stephanie R. , Fritsch Ingrid 
Published: January 2004

AbstractA 2‐dimensional framework of UV‐polymerized 10,12‐pentacosadiynoic acid integrated with dipalmitoylphophatidyl choline phospholipids was suspended over a ca. 10 μm‐diameter and 8‐μm‐deep microcavity that contained electrodes. The membrane was assembled at the air‐water interface of a Langmuir‐Blodgett trough and deposited onto a mercaptoundecanoic‐acid‐modified gold surface that surrounds the microcavity opening during an upward stroke from a subphase of 10 mM potassium ferrocyanide in 0.1 M KCl and 1 mM CaCl2, and covered with a drop of pure electrolyte to minimize evaporation. Cyclic voltammetry confirmed that the redox solution was trapped beneath the membrane and was calculated to be only ca. 0.6 pL volume, consistent with the geometry of the microcavity. Such interfaces to microstructures hold promise for novel biosensor materials and biomimetic phospholipid membranes.
Reductive H2O2 Detection at Nanoparticle Iridium/Carbon Film Electrode and Its Application as L‐Glutamate Enzyme Sensor
Authors: You Tianyan , Niwa Osamu , Kurita Ryoji , Iwasaki Yuzuru , Hayashi Katsuyoshi , Suzuki Koji , Hirono Shigeru 
Published: January 2004

AbstractWe prepared a thin film electrode consisting of a 3.3% atomic concentration of iridium nanoparticles dispersed in graphite‐like carbon (Ir‐NDC) by a simple RF sputtering method. The film structure was characterized by TEM, XPS and AFM. The TEM results showed that the Ir particles, whose average size was 2 nm, were homogenously dispersed in the carbon matrix. XPS revealed two chemical states of Ir (Ir(0) and Ir(IV)) in the film. The Ir‐NDC film electrode exhibited excellent electrocatalytic ability with regard to H2O2 reduction with low atomic concentration compared to the bulk Ir electrode. The effect of L‐ascorbic acid can be suppressed due to the reductive detection of hydrogen peroxide. We applied this electrode for enzymatic glutamate detection. At a detection potential of −0.15 V (vs. Ag/AgCl), we could measure the concentration of glutamate without interferences from ascorbic acid and oxygen.
Wavelet‐based non‐stationary seismic rocking response of flexibly supported tanks
Authors: Chatterjee Pranesh , Basu Biswajit 
Published: January 2004

AbstractThe non‐stationary rocking response of liquid storage tanks under seismic base excitations including soil interaction has been developed based on the wavelet domain random vibration theory. The ground motion has been characterized through statistical functionals of wavelet coefficients of the ground acceleration history. The tank–liquid–foundation system is modelled as a multi‐degree‐of‐freedom (MDOF) system with both lateral and rocking motions of vibration of the foundation. The impulsive and convective modes of vibration of the liquid in the tank have been considered. The wavelet domain coupled dynamic equations are formulated and then solved to get the expressions of instantaneous power spectral density function (PSDF) in terms of functionals of input wavelet coefficients. The moments of the instantaneous PSDF are used to obtain the stochastic responses of the tank in the form of coefficients of hydrodynamic pressure, base shear and overturning base moment for the largest expected peak responses. Parametric variations are carried out to study the effects of various governing parameters like height of liquid in the tank, height–radius ratio of the tank, ratio of total liquid mass to mass of foundation, and shear wave velocity in the soil medium, on the responses of the tank. Copyright © 2003 John Wiley & Sons, Ltd.
An attenuation model for distant earthquakes
Authors: Chandler Adrian , Lam Nelson 
Published: January 2004

AbstractLarge magnitude earthquakes generated at source–site distances exceeding 100km are typified by low‐frequency (long‐period) seismic waves. Such induced ground shaking can be disproportionately destructive due to its high displacement, and possibly high velocity, shaking characteristics. Distant earthquakes represent a potentially significant safety hazard in certain low and moderate seismic regions where seismic activity is governed by major distant sources as opposed to nearby (regional) background sources. Examples are parts of the Indian sub‐continent, Eastern China and Indo‐China. The majority of ground motion attenuation relationships currently available for applications in active seismic regions may not be suitable for handling long‐distance attenuation, since the significance of distant earthquakes is mainly confined to certain low to moderate seismicity regions. Thus, the effects of distant earthquakes are often not accurately represented by conventional empirical models which were typically developed from curve‐fitting earthquake strong‐motion data from active seismic regions. Numerous well‐known existing attenuation relationships are evaluated in this paper, to highlight their limitations in long‐distance applications. In contrast, basic seismological parameters such as the Quality factor (Q‐factor) could provide a far more accurate representation for the distant attenuation behaviour of a region, but such information is seldom used by engineers in any direct manner. The aim of this paper is to develop a set of relationships that provide a convenient link between the seismological Q‐factor (amongst other factors) and response spectrum attenuation. The use of Q as an input parameter to the proposed model enables valuable local seismological information to be incorporated directly into response spectrum predictions. The application of this new modelling approach is demonstrated by examples based on the Chi‐Chi earthquake (Taiwan and South China), Gujarat earthquake (Northwest India), Nisqually earthquake (region surrounding Seattle) and Sumatran‐fault earthquake (recorded in Singapore). Field recordings have been obtained from these events for comparison with the proposed model. The accuracy of the stochastic simulations and the regression analysis have been confirmed by comparisons between the model calculations and the actual field observations. It is emphasized that obtaining representative estimates for Q for input into the model is equally important.Thus, this paper forms part of the long‐term objective of the authors to develop more effective communications across the engineering and seismological disciplines. Copyright © 2003 John Wiley & Sons, Ltd.
Response to orthogonal components of ground motion and assessment of percentage combination rules
Authors: Heredia‐Zavoni Ernesto , Machicao‐Barrionuevo Raquel 
Published: January 2004

AbstractThe effects of horizontal components of ground motion on the linear response of torsionally stiff and torsionally flexible systems, on soft and firm soil conditions, are examined. A one‐story, two‐way asymmetric structural system is used, subjected to uncorrelated ground motion components along their principal directions. Spectral densities for ground accelerations in firm and soft soils are modeled based on recorded data from large intensity Mexican earthquakes. It is shown that for firm soils, in general, these effects are important in the case of torsionally flexible systems that are stiff under translation, or for torsionally stiff systems that are flexible in translation. The percentage combination rules usually specified in seismic design codes are assessed against the dynamic response. Such combination rules can result in overly conservative design forces or underestimated design forces, particularly for torsionally flexible structures. Given the relative magnitude of the response to each ground motion component, it was found that using different percentage values in the combination rules has no significant effect on improving the estimation of the total response. Copyright © 2003 John Wiley & Sons, Ltd.
Gastrulation events in the prestreak pig embryo: Ultrastructure and cell markers
Authors: Fléchon Jacques‐E , Degrouard Jeril , Fléchon Bernadette 
Published: January 2004

AbstractThe epithelial versus mesenchymal phenotypes of embryonic ectoderm and mesoderm cells of the prestreak stage pig embryos were examined by electron microscopy and molecular marker analysis. During this period the embryonic disc remained flat or slightly convex while becoming oval or pyriform in shape. Mesenchyme cells expressing vimentin were present between the embryonic disc and the underlying visceral endoderm before a primitive streak (or groove) was apparent. The migration of mesenchyme appeared to occur in lateral and posterior directions from a mass of quiescent cells located in the pointed end of the pyriform embryonic disc that expressed Brachyury; these cells are proposed to be the precursors of the primitive streak and/or form the equivalent of the mouse early gastrula organizer (EGO). Cells with the TEC‐1 (or SSEA‐1) epitope, the marker most frequently used to characterize pluripotent cells, were initially distributed randomly in the embryonic ectoderm and then were found to localize in an anterior crescent which may contain the precursor cells of ectoderm and neurectoderm. As mitotic figures were found only in the anterior crescent, it is proposed that at least some of these proliferating cells migrate toward the EGO. While cytokeratins were barely detectable in the embryonic ectoderm cells, vimentin expression was supposed to be associated with the migratory capacity of these cells. These findings indicate that the early step of gastrulation, migration of extraembryonic mesoderm, occurs at a prestreak stage during which the embryonic disc becomes polarized. genesis 38:13–25, 2004. © 2003 Wiley‐Liss, Inc.
Neurophysiological distinction of action words in the fronto‐central cortex
Authors: Hauk Olaf , Pulvermüller Friedman 
Published: January 2004

AbstractIt has been suggested that the processing of action words referring to leg, arm, and face movements (e.g., to kick, to pick, to lick) leads to distinct patterns of neurophysiological activity. We addressed this issue using multi‐channel EEG and beam‐former estimates of distributed current sources within the head. The categories of leg‐, arm‐, and face‐related words were carefully matched for important psycholinguistic factors, including word frequency, imageability, valence, and arousal, and evaluated in a behavioral study for their semantic associations. EEG was recorded from 64 scalp electrodes while stimuli were presented visually in a reading task. We applied a linear beam‐former technique to obtain optimal estimates of the sources underlying the word‐evoked potentials. These suggested differential activation in frontal areas of the cortex, including primary motor, pre‐motor, and pre‐frontal sites. Leg words activated dorsal fronto‐parietal areas more strongly than face‐ or arm‐related words, whereas face‐words produced more activity at left inferior‐frontal sites. In the right hemisphere, arm‐words activated lateral‐frontal areas. We interpret the findings in the framework of a neurobiological model of language and discuss the possible role of mirror neurons in the premotor cortex in language processing. Hum. Brain Mapp. 21:191–201, 2004. © 2004 Wiley‐Liss, Inc.
Neural mechanisms underlying reaching for remembered targets cued kinesthetically or visually in left or right hemispace
Authors: Butler Andrew J. , Fink Gereon R. , Dohle Christian , Wunderlich Gilbert , Tellmann Lutz , Seitz Rudiger J. , Zilles Karl , Freund Hans‐Joachim 
Published: January 2004

AbstractReaching for a target involves integrative coordinate transformation processes between the representation of the target location, the sensorimotor information of limb of reach, and body space. Although right hemisphere dominance for visuospatial information processing is well established, corresponding right hemisphere dominance for kinesthetic spatial information processing remains to be demonstrated. We explored neural mechanisms of encoding target locations using 15O‐butanol positron emission tomography (PET) in normal volunteers in a factorial experiment, where modality (visual/kinesthetic) and hemispace of target presentation (left/right of midsagittal plane) were varied systematically. After target presentation, subjects reached to the encoded target location. PET data analysis using SPM99 showed increased neural activity (P < 0.05, corrected) associated with left hemispace target presentation in right hemisphere areas (sensorimotor, anterior cingulate, insular, and temporo‐occipital cortex) only. By contrast, right hemispace target presentation activated bilateral temporo‐occipital cortex, which extended into the right temporo‐parietal cortex and left sensorimotor cortex. A significant interaction of hemispace and modality of target presentation observed in right temporo‐parietal cortex resulted from an increase in neural activity with kinesthetic target presentation in right hemispace. The data support an important role for the right temporo‐parietal area in visuospatial processing and suggest a specific role of the right hemisphere in kinesthetic spatial processing. Hum. Brain Mapp. 21:165–177, 2004. © 2004 Wiley‐Liss, Inc.
Liberating HR through technology
Authors: Shrivastava Samir , Shaw James B. 
Published: January 2004

AbstractWorkforce management applications are expected to drive the next phase of enterprise‐wide applications market growth. But will firms actually benefit from these applications? Horror stories of failed technology implementation efforts abound and hardly inspire confidence. Treating installation of HR technology as a form of innovation, we introduce a model that describes the technology implementation process. The model brings to the fore various issues that merit the attention of academics and practitioners alike. It appears that firms that undertake technology initiatives with a view to enable the HR function to focus more on value‐added activities are the ones most likely to realize the full potential of technology. © 2004 Wiley Periodicals, Inc.
Promoting organizational learning and self‐renewal in Taiwanese companies: The role of HRM
Authors: Jaw Bih‐Shiaw , Liu Weining 
Published: January 2004

AbstractThis study identifies key characteristics of human resource management (HRM) practices that
contribute to promoting positive learning attitudes and creating a self‐renewal organizational climate. We
use a behavioral perspective to develop a framework to show the relationships among learning‐oriented HRM,
positive learning attitudes, and a self‐renewal organizational climate. Structural equation analysis is
applied to empirically test the relationships and the path model suggests that a learning‐oriented HRM
plays an important role in either directly creating a self‐renewal organizational climate or indirectly
facilitating positive learning attitudes that foster organizational self‐renewal. © 2004 Wiley
Periodicals, Inc.