bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation of body mass index and responder status in heart failure patients after cardiac resynchronization therapy: Does the obesity paradox exist?
Authors: Clemens Marcell , Nagy-Baló E. , Herczku Cs. , Karányi Zs. , Édes I. , Csanádi Z. 
Published: March 2010

Abstract

Aims: We investigated the influence of body mass index (BMI) on the prevalence of responder status in chronic heart failure patients after cardiac resynchronization therapy (CRT).

Methods: Data on 169 patients with resynchronization therapy were analyzed. Patients were categorized on the basis of the BMI measured at device implantation according to the WHO classification, as normal (BMI: 18.5–24.9 kg/m2), overweight (BMI: 25–29.9 kg/m2) or obese (BMI:≥30 kg/m2). Patients were considered responders if left ventricular ejection fraction was increased by at least 5% at 6-month follow-up.

Results: The mean age in the study population was 60.9±10.86 years (females 29%). The BMI subgroups did not exhibit any significant differences in baseline characteristics (age, gender, left ventricular ejection fraction or NYHA class). Elevated BMIs were associated with higher prevalence of responder status (overweight: 71.4%, obese: 63.0%) relative to subjects with a normal BMI (44.7%) (p=0.015).

Conclusions: In this CRT population, overweight status was associated with a more favorable response to CRT, indicating that the response may possibly be influenced by factors other than those directly related to the heart status or the technical details of the CRT.
Proton Transfer in Monoclinic Zirconia: A Theoretical Study
Authors: Mantz Yves A. , Gemmen Randall S. 
Published: March 2010

AbstractIn solid oxide fuel cells, the mechanism of hydrogen oxidation is complex. During this process, protonated forms of monoclinic zirconia may be formed, motivating their study within the framework of density-functional theory (DFT). Using the HCTH/120 exchange-correlation functional, the monoclinic phase of zirconia is, correctly, predicted to be more stable than cubic or tetragonal polymorphs at 0 K, in agreement with previous theoretical results. Several local minima are identified of a proton in monoclinic zirconia, modeled using (up to) a 3×3×3 arrangement of unit cells, in which the proton is bonded to one of the two available oxygen atom types, O1 or O2. The lowest energy structure of the proton bonded to O1 is favored by 0.39 eV compared to that of the proton bonded to O2. Based upon a vibrational analysis as well as finite-temperature Born-Oppenheimer molecular dynamic simulations, this preference of the proton for O1 is suggested to persist at fuel cell operating temperatures.
Accurate ab initio Calculations of Methane Dimer Interaction Energies and Molecular Dynamics Simulation of Fluid Methane
Authors: Li Arvin Huang-Te , Chao Sheng Der 
Published: March 2010

AbstractIntermolecular interaction potentials of the methane dimers have been calculated for 12 symmetric conformations using the Hartree-Fock (HF) self-consistent theory, the second-order M�ller-Plesset (MP2) perturbation theory, and the coupled-cluster with single and double and perturbative triple excitations (CCSD(T)) theory. The HF calculations yield unbound potentials largely due to the exchange-repulsion interaction. In MP2 and CCSD(T) calculations, the basis set effects on the repulsion exponent, the equilibrium bond length, the binding energy, and the asymptotic behavior of the calculated intermolecular potentials have been thoroughly studied. We have employed basis sets from the Slater-type orbitals fitted with Gaussian functions, Pople�s medium size basis sets to Dunning�s correlation consistent basis sets. With increasing basis size, the repulsion exponent and the equilibrium bond length converge at the 6-31G** basis set and the 6-311++G(2d, 2p) basis set, respectively, while a large basis set (aug-cc-pVTZ) is required to converge the binding energy at a chemical accuracy (˜0.01 kcal/mol). We used the BSSE corrected results that systematically converge to the destined potential curve with increasing basis size. The binding energy calculated and the equilibrium bond length using the CCSD(T) method are close to the results at the basis set limit. For molecular dynamics simulation, a 4-site potential model with sites located at the hydrogen atoms was used to fit the ab initio potential data. This model stems from a hydrogen-hydrogen repulsion mechanism to explain the stability of the dimer structure. MD simulations using the ab initio PES show good agreement on both the atom-wise radial distribution functions and the self-diffusion coefficients over a wide range of experimental conditions.
Peak/Plateau Strength in Nanoscale Multilayer Thin Films: Constrained vs Unconstrained Dislocation Nucleation
Authors: Li Qizhen , Anderson Peter M. 
Published: March 2010

AbstractThe peak/plateau strength of multilayer thin films is analyzed in terms of the stress to bow out a dislocation loop from an interface. Comparison of approximate analytic models to experimental data suggests that the bow out is “constrained” by nearby interfaces, at least for e-NbN/Mo and e-Ni/Cu films. Estimates of the interfacial pinning distance to form the bow out are ˜20b for e-NbN/Mo and ˜70b for e-Ni/Cu around peak/plateau strength (b is the magnitude of Burgers vector).
Study and Optimization of Silicon-CVD Diamond Interface for SOD Applications
Authors: Mazellier Jean-Paul , Arnault Jean-Charles , Lions Mathieu , Andrieu François , Truche Robert , Previtali Bernard , Saada Samuel , Bergonzo Philippe , Deleonibus Simon , Cristoloveanu Sorin , Faynot Olivier 
Published: March 2010

AbstractWith respect to Silicon-on-Diamond approaches as an alternative to SOI where diamond is used as the buried dielectric, we have in recent works demonstrated the feasibility of a novel approaches where the CVD diamond layer is grown on silicon using Bias Enhanced Nucleation (BEN) over large area substrates, then smoothed and assembled to successfully enable the fabrication of first prototypes of silicon-on-diamond substrates. The key novelty to those SOD substrates were that only a very thin box dielectric diamond layer is used (typically from 150 to 500nm thick), as required by the current SOI technology. However we had also observed that the silicon-diamond interface quality to be sensitive to the nature of the nucleation interface. Thus the current contribution here studies the chemical nature of various capping materials used to solve the issue of electrical defects in case of direct silicon-diamond interface and at the same time to enable the whole system to benefit from the high thermal conductivity of diamond when compared to other standard electrical insulating materials.
Characterization of Nano-crystalline Diamond Films Grown Under Continuous DC Bias During Plasma Enhanced Chemical Vapor Deposition
Authors: Mortet Vincent , Zhang Liang , Echert Maxie , Soltani Ali , D'Haen Jan , Douhéret Olivier , Moreau Myriam , Osswald Sebastian , Neyts Erik , Troadec David , Wagner Patrick , Bogaerts Annemie , Van Tendeloo Gustaaf , Haenen Ken 
Published: March 2010

AbstractNanocrystalline diamond films have generated much interested due to their diamond-like properties and low surface roughness. Several techniques have been used to obtain a high re-nucleation rate, such as hydrogen poor or high methane concentration plasmas. In this work, the properties of nano-diamond films grown on silicon substrates using a continuous DC bias voltage during the complete duration of growth are studied. Subsequently, the layers were characterised by several morphological, structural and optical techniques. Besides a thorough investigation of the surface structure, using SEM and AFM, special attention was paid to the bulk structure of the films. The application of FTIR, XRD, multi wavelength Raman spectroscopy, TEM and EELS yielded a detailed insight in important properties such as the amount of crystallinity, the hydrogen content and grain size. Although these films are smooth, they are under a considerable compressive stress. FTIR spectroscopy points to a high hydrogen content in the films, while Raman and EELS indicate a high concentration of sp2 carbon. TEM and EELS show that these films consist of diamond nano-grains mixed with an amorphous sp2 bonded carbon, these results are consistent with the XRD and UV Raman spectroscopy data.
Novel Concepts for Low-pressure, Low-temperature Nanodiamond Growth Using MW-linear Antenna Plasma Sources
Authors: Vlček Jan , Fendrych František , Taylor Andrew , Kratochvílová Irena , Fekete Ladislav , Nesládek Miloš , Liehr Michael 
Published: March 2010

AbstractIndustrial applications of PE MWCVD diamond grown on large area substrates, 3D shapes, at low substrate temperatures and on standard engineering substrate materials require novel plasma concepts. Based on the pioneering work of the group at AIST in Japan, high-density coaxial delivery type of plasmas have been explored [1]. However, an important challenge is to obtain commercially interesting growth rates at very low substrate temperatures. In the presented work we introduce the concept of novel linear antenna sources, designed at Leybold Optics Dresden, using high-frequency pulsed MW discharge. We present data on high plasma densities in this type of discharge (> 10 E11 cm-3), accompanied by data from OES for CH4 – CO2 - H2 gas chemistry and the basic properties of the nano-crystalline diamond (NCD) films grown.
Investigation of Gd2@C90, Gd2C2@C92, and Gd2@C79N by Raman Spectroscopy
Authors: Burke Brian G. , Chan Jack , Williams Keith A. , Ge Jiechao , Shu Chunying , Fu Wujun , Dorn Harry C. , Puretzky Alexander , Geohegan David 
Published: March 2010

AbstractThe structure and vibrational spectrum of Gd2 and Gd2C2 endofullerenes are studied through Raman spectroscopy and universal force field (UFF) calculations. Hindered rotations, shown by both theory and experiment, indicate the formation of a Gd–cage bond, which reduces the ideal symmetry of the cage. We have conducted Raman studies of Gd2@C90, Gd2@C79N, and Gd2C2@C92. We have also studied Y2C2@C92 for comparison. Several modes have been identified which provide information about the endohedral complex.
Plasma Synthesis: A Novel Way of Making Catalysts
Authors: Biberger Maximilian Albert , Leamon D. , Qi X. , Sawayda R. , Yin Q. 
Published: March 2010

AbstractIn the present paper a novel method of manufacturing mobile emission control catalysts (MECC) is presented. The manufacturing of these novel catalysts consists of three steps: In a first processing step micron sized powders consisting of an oxide powder, typically Al2O3 or SiO2 or the like, and micron sized precious metal powders, Pt, Pd, Rh or the like, are co-fed into a DC plasma gun. Inside the gun the powders are vaporized at temperatures of approximately 25,000 K. After the powders are vaporized the vapor is rapidly quenched at rates of approximately 1,000,000 K/s. This process step yields so-called Nano on Nano Catalysts™, where nano clusters of precious metals atoms are condensed onto the nano sized oxide particles. In a second processing step these Nano on Nano Catalysts™ are dispersed in water. This step is followed by a third, and final processing step, where the Nano on Nano Catalysts™ are integrated onto the final support, i.e. the monoliths (or honeycombs), which ultimately are canned and located downstream of a vehicle’s engine.
Catalysts manufactured under the above conditions are then tested against reference catalysts, both under fresh and aged conditions. Test results show that the plasma based catalysts have better light off temperatures after aging than the reference catalysts if they contain the same amount of precious metals as the reference catalyst. If the precious metal amount for the plasma based catalysts is reduced to approx. half the amount of the reference catalysts then both catalysts show approx. the same light off temperatures after aging.
Above results show that with catalysts based on plasma technology one can either lower the light off temperatures while maintaining the precious metal content compared to reference catalysts, or match the performance of the reference catalysts while reducing the precious metal content to approx. 50%, compared to the reference catalysts.
The Future of TCO Materials: Stakes and Challenges
Authors: Baraton Marie-Isabelle 
Published: March 2010

AbstractThe field of major applications of transparent conducting oxides (TCOs) continues to expand, thus generating a growing demand for new materials with lower resistivity and higher transparency over extended wavelength ranges. Moreover, p-type TCOs are opening new horizons for high-performance devices based on p-n junctions.
Among the most commonly used TCO materials are zinc oxide (ZnO), indium tin oxide (ITO), tin oxide (SnO2), and indium oxide (In2O3). Still, design and synthesis of improved TCO materials leading to a marked increase in conductivity and robustness remain highly desirable while a more detailed understanding of the conductivity mechanisms is critical to further improvement. For example, there is an accelerating effort worldwide by both academia and industry to develop a transparent conductor that can meet or beat the performance of the commonly used ITO at lower costs and with more physical resilience.
This article reviews new developments in TCO materials to be used in various applications spanning from photovoltaics to lighting, smart windows, or gas sensors. The financial stakes, far from being negligible in the TCOs market, and the current scientific and technological challenges to be taken up are analyzed.
Surface Structure of Pd3Fe(111) and Effects of Oxygen Adsorption
Authors: Yang Xiaofang , Welch Lindsey A. , Fu Jie , Koel Bruce E. 
Published: March 2010

AbstractPd-Fe alloys have attracted attention in PEM fuel cell research because they were found to be comparable to Pt electrocatalysts in oxygen reduction reaction (ORR) kinetics at the cathode. In this study, the surface morphology of a Pd3Fe(111) single-crystal sample and oxygen reaction on the surface were investigated by low energy electron diffraction (LEED), low energy ion scattering (LEIS), x-ray photoelectron spectroscopy (XPS), and scanning tunneling microscopy (STM) under ultra-high vacuum (UHV) conditions. Strong segregation of Pd atoms was observed after annealing in UHV. Particularly, Pd single adatoms and dimers were found on the surface after high temperature annealing, which differs from most other well-studied binary alloy systems. Low free energy of Pd, strain relaxation, and interaction between Pd and Fe, are potentially responsible for the formation of this unusual surface. Adsorption of oxygen reversed the segregation trend and oxidized surface Fe. Ordered surface phases were observed after oxygen exposures at elevated temperatures. The reducing activity of Fe atoms in the alloy inhibited Pd oxidation, and weakened Pd-O interactions on Pd3Fe(111) are consistent with enhanced ORR kinetics.
Effect of Dilatation on the Elasto-Plastic Response of Bulk Metallic Glasses Under Indentation
Authors: Prasad Anamika , Dao Ming , Ramamurty Upadrasta 
Published: March 2010

AbstractElasto-plastic response of bulk metallic glasses (BMGs) follows closely the response of granular materials through pressure dependent (or normal stress) yield locus and shear stress induced material dilatation. On a micro-structural level, material dilatation is responsible for stress softening and formation of localized shear band, however its influence on the macro-scale flow and deformation is largely unknown. In this work, we systematically analyze the effect of material dilatation on the gross indentation response of Zr-based BMG via finite element simulation. The strengthening/softening effect on the load-depth response and corresponding stress-strain profiles are presented in light of differences in elastic-plastic regimes under common indenters. Through comparison with existing experimental results, we draw conclusions regarding selection of suitable dilatation parameters for accurately predicting the gross response of BMGs
Direct Cell Printing With Microfabricated Quill-Pen Cantilevers
Authors: Hynes William F. , Gracias Alison , Fahrenkopf Nicholas M. , Raof Nurazhani Abdul , Raja Waseem K. , Lee Katherine , Xie Yubing , Bergkvist Magnus , Cady Nathaniel C. 
Published: March 2010

AbstractA novel direct cell printing technique has been developed to control and manipulate the position of cells on solid surfaces. The method utilizes microfabricated polymeric “quill-pen” cantilevers to transfer living cells onto a wide variety of surfaces. In contrast with existing cell deposition methods, such as ink jet or laser ablation methods, the quill-pen approach imparts minimal thermal and shear stress to cells, preserving cell viability and biological functionality. Deposition of both bacterial and mammalian cells into defined patterns has been demonstrated using this method. The size of printed, cell-containing droplets could be controlled by varying the geometry of the quill-pen stylus and by varying printing conditions such as contact time, relative humidity, and surface hydrophobicity. Initial experiments using 10 μm diameter polymer beads demonstrated that the number of beads per droplet could be controlled by varying spot size and particle concentration in the printing solution. Spots could be printed ranging from 20 μm and 100 μm in diameter with approximate volumes ranging from 1-250 pL. We demonstrated deposition of both cells and beads onto a variety of solid surfaces including agarose gel, polystyrene, polyethylene, and glass. Printed cells have also been immobilized on glass and polymer surfaces using biocompatible hydrogel materials (both alginic acid and hyaluronic acid-based matrices) as well as poly-L-lysine. Similar to polymer beads, the number of cells in printed droplets was shown to be dependent upon the size of the droplet, and could be varied by adjusting the concentration of cells present in the printing fluid. As few as one cell per spot could be achieved by adjusting these parameters. The viability and proliferation of printed cells has been evaluated using live optical imaging to observe cell growth and division. Both bacterial cells (Escherichia coli) and mammalian cells were able to divide and proliferate for at least 96 hr post-printing (experiments were discontinued after 96 hr). Live/dead staining was also used to confirm the viability of printed cells. Rat mammary adenocarcinoma MTLn3 cells and mouse embryonic stem cells were also shown to survive the printing process for at least 24 - 96 hr post-printing. These results demonstrate the feasibility of the printing method and its compatibility with a wide range of cell types. It is especially noteworthy that embryonic stem cells could survive the printing process (and proliferate on the printing substrate). This novel printing method has applications for tissue engineering, cell-to-cell signaling studies, and for directly interfacing cells with nanodevices and biosensors.
Biosensor for Dielectric Spectroscopy of Mitochondria and for Monitoring Ion Activities
Authors: Padmaraj Divya , Pande Rohit , Zagozdzon-Wosik Wanda , Xie Lei-Ming , Pijanowska Dorota G , Miller John H , Grabiec Piotr B , Jaroszewicz Bohdan , Widger William , Wosik Jarek 
Published: March 2010

AbstractWe developed a BioMEMS device to study cell- mitochondrial physiological functionalities. The pathogenesis of many diseases including obesity, diabetes, heart failure as well as aging has been linked to functional defects of mitochondria. This is understandable as the mitochondria produces up to 90% of ATP, and plays a critical role in cell signaling and apoptosis. The synthesis of ATP is determined by the electrical potential across the inner mitochondrial membrane (IMM) and by the pH difference due to proton flux across it. Therefore, electrical characterization by E-fields with complementary chemical testing was used here. Mitochondrial ion channels present in the IMM control specific ion fluxes, and maintain ion homeostasis, matrix volume, IMM potential etc and thus serve a central role in cell growth and death related processes. Defects in ion channels (Channelopathies) are being attributed to many diseases like cancer, neurodegeneration, etc. Complete physiological roles of various ion channels and their interactions are still unknown, hindering the development of targeted therapeutic agents. The BioMEMS device was fabricated as an SU-8 based microfluidic system with gold electrodes on SiO2/Si wafers for electromagnetic interrogation. Ion Sensitive Field Effect Transistors (ISFETs) were incorporated for proton studies important in electron transport chain, together with monitoring Na+, K+, Ca++ions for ion channel studies. ISFETs are chemically sensitive MOSFET devices, their threshold voltage is directly proportional to the electrolytic H+ ion variation. These ISFETs (sensitivity ˜55 mV/pH for H+) were further realized as specific ion sensitive CHEMFETs by depositing a poly-HEMA layer sandwiched between the gate and a final specific ion sensitive membrane. Electrodes for dielectric spectroscopy studies of mitochondria were designed as 2- and 4-probe structures for optimized operation over a wide frequency range. In addition, to limit polarization effects (which masks actual impedance for high conductivity solutions at low frequencies), a 4-electrode set-up with unique meshed pickup electrodes (7.5×7.5 μm2 loops with 4 μm wires) was fabricated. An electrical model was developed for the mitochondrial sample, and its frequency response correlated with impedance spectroscopy experiments of sarcolemmal mitochondria. Using the mesh electrode structure, we obtained a reduction of 83.28% in impedance at 200 Hz. COMSOL simulations of selected electrical structures in this sensor were compared with experimental results to better understand the physical system. The simultaneous measurement of membrane potential, ion concentrations and pH would enhance diagnostics and studies of mitochondrial diseases.
Advanced Solid State NMR Techniques for the Investigation of the Organic-Mineral Interfaces in Biomaterials
Authors: Laurencin Danielle , Guerrero Gilles , Amalric Julien , Bonhomme Christian , Gervais Christel , Smith Mark E , Mutin Hubert 
Published: March 2010

AbstractHigh resolution solid state NMR experiments were carried out on several compounds, to see how this technique can now be used to investigate in detail the surface structure of different biomaterials. First, because the surface of titanium implants can be functionalized by phosphonic acids, for instance to prevent bacterial adhesion,17O NMR experiments were performed on model TiO2 surfaces functionalized by 17O enriched phosphonic acids, to look at the mode of grafting of these coupling agents. Results bring clear evidence of the formation of Ti-O-P bridges and of the presence of residual P=O and P-OH groups. Second, given that calcium phosphates are widely present in biological hard tissues and synthetic biomaterials, 43Ca correlation experiments were performed on 43Ca enriched materials (hydroxyapatite and calcium benzoate), to see how the proximities between this nucleus and neighbouring atoms can be analyzed. Results show that both Ca…C and Ca…H proximities can be evidenced, and could thus help elucidate interface structures. All in all, these studies should pave the way to future investigations of biomaterials, and in particular of the structure of organic-inorganic interfaces.