bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectroscopic Examination of Protein Adsorption from Seawater onto Titanium
Authors: Taylor G. T. , Troy P. J. , Nullet M. , Sharma S. K. , Liebert B. E. , Mower H. F.
Published: June 2005

Several noninvasive optical and electrochemical techniques were adapted to examine partitioning of protein from seawater onto polished titanium with the use of the plant enzyme ribulose-1,5,-bisphosphate carboxylase-oxygenase (Rubisco) as a model. Protein films, varying in surface concentrations from 0.011 to 3.606 μg cm−2, were prepared by exposing polished Ti surfaces to seawater amended with 0.04–90.80 μg mL−1 of 3H-Rubisco. Mean film thickness, d, measured by ellipsometry, increased linearly over most of the range of irreversibly bound protein (Γirr = 0.011–2.491 μg cm−2). Spatial coverages of the films were more heterogeneous at low surface coverages, indicative of heterogeneous adsorption resulting in barren Ti oxide surface sites and insular protein clusters. The thickness of the underlying Ti oxide layer, also measured by ellipsometry, was highly variable and indicated that oxidation of the surface was suppressed at high protein coverages during two-hour exposures to seawater. Vibrational spectra of surface films, from submonolayer (0.03 μg cm−2) to multilayer (3.61 μg cm−2), were obtained with the use of Fourier transform infrared reflection-absorption spectrometry (FT-IRAS). Peak areas of amide I and II bands varied linearly with Γirr, permitting noninvasive measurement of protein mass at the surface. Relative intensities of the amide II/amide I bands, band composition of the amide III, and peak frequencies varied with surface concentration, indicating unfolding of adsorbed proteins. Vibrational spectroscopic and ellipsometric evidence suggests that protein structure is most altered at low surface concentrations. Electrochemical impedance spectroscopy (EIS) performed from 100 /μHZ to 100 kHz on replicate test surfaces revealed that the electrochemical behavior of the titanium/protein interface was consistent with that of a parallel RC circuit. The charge transfer resistance, Rct, of the interface varied as a two-state function of protein concentration. The Rct increased more rapidly within the monolayer domain (0.12 to 2.8 MΩ cm2) than in the multilayer domain (2.8 to 4.9 MΩ cm2), indicating that impedance to electron flow across the interface is most influenced by protein monolayer formation and is less affected by additional layers. Estimations of rates of oxidation or dissolution of the substratum were inversely proportional to protein surface concentrations. Together these techniques provide internally consistent measurements of surface film thickness, adsorbate mass, gross chemical composition, interface organization, electrical impedance, capacitance, and oxide layer thickness. These data are useful for determining the physical state of the interface, its dynamics, and the potential oxidation rates of the substratum underlying the surface film.
Graphite Furnace Atomic Absorption Spectrometric Determination of Iron, Cobalt, Nickel, and Copper at Parts-Per-Billion Level in High-Purity Lanthanum Fluoride
Authors: Jaganathan James , Aggarwal Ishwar
Published: June 2005

This paper describes an analytical method for the quantitation of iron, cobalt, nickel, and copper in lanthanum fluoride at trace levels with graphite furnace atomic absorption spectrometry (GFAAS) without using any matrix modifier. These metals were preconcentrated in HNO3 and analyzed directly. The detection limits for iron, cobalt, nickel, and copper were found to be 3, 1, 2, and 2 ppb, respectively. The average precision of measurements (°/o RSD) for all the elements was <10%.
Intracellular Distribution of Desmoplakin in Human Odontoblasts
Authors: Sawa Yoshihiko , Kuroshima Shin-ichiro , Yamaoka Yuji , Yoshida Shigemitsu
Published: June 2005

Coexpression of desmosomal proteins and vimentin has been reported in a specific mesenchymal phenotype. This study investigated the expression of vimentin-binding desmosomal proteins in human dental pulp fibroblasts (DPF) and odontoblasts. The dental pulp has no cells expressing desmocollin (DSC) 1–3, desmoglein (DSG) 1–3, junction plakoglobin (JUP), or desmoplakin (DPK) 1 and 2 except for odontoblasts expressing DPK. A confocal image by laser-scanning microscopy demonstrated the diffuse distribution of DPK in the cytoplasm throughout the odontoblast processes. In culture, the mRNA expression of JUP and DPK1, but not DSC1–3 and DSG1–3, was detected in all DPF clones tested and also in odontoblast-like cells (OB) expressing osteocalcin and dentin sialophosphoprotein mRNAs established in the differentiation medium. The DPF having the potential to differentiate into OB expressed vimentin, but not DPK before culturing in the differentiation medium, whereas OB expressed vimentin-binding DPK1. These results suggest that DPF usually expresses DPK1 mRNA, and that the DPK1 production and the bonding of vimentin to DPK1 occur in DPF with the differentiation into odontoblasts.
Optimal Processing Method to Obtain Four-color Confocal Fluorescent Images of the Cytoskeleton and Nucleus in Three-dimensional Chondrocyte Cultures
Authors: Blanc Antoine , Tran-Khanh Nicolas , Filion Dominic , Buschmann Michael D.
Published: June 2005

Tissue engineering of articular cartilage requires accurate imaging of the chondrocyte cytoskeleton. Past studies have applied various fixation and permeabilization protocols without optimization of parameters. In this study, we have examined procedures using glutaraldehyde and paraformaldehyde as fixatives and Triton X-100 and Octyl-POE as permeabilizing detergents. A four-color fluorescence confocal method was developed to simultaneously image actin, tubulin, vimentin, and the nucleus. We found optimal preservation and morphology of the chondrocyte cytoskeleton after simultaneous fixation and permeabilization with glutaraldehyde and Triton X-100. These images displayed less cellular shrinkage and higher-resolution filamentous structures than with paraformaldehyde or when permeabilization followed fixation.
N-Terminal Pro-B-Type Natriuretic Peptide after High-Dose Chemotherapy: A Marker Predictive of Cardiac Dysfunction?
Authors: Sandri Maria T , Salvatici Michela , Cardinale Daniela , Zorzino Laura , Passerini Rita , Lentati Paola , Leon Maria , Civelli Maurizio , Martinelli Giovanni , Cipolla Carlo M
Published: June 2005

Background: Chronic cardiac dysfunction may develop after administration of aggressive chemotherapy, sometimes leading to development of congestive heart failure (CHF). Recently, N-terminal pro-B-type natriuretic peptide (NT-proBNP) was implicated as a marker of CHF. In this study we evaluated the predictive role of NT-proBNP in patients treated with high-dose chemotherapy (HDC).

Methods: NT-proBNP was measured after 62 chemotherapy treatments in 52 patients affected by aggressive malignancies. Blood samples were drawn before the start of HDC, at the end of HDC administration, and 12, 24, 36, and 72 h thereafter. In these patients, echocardiograms were performed regularly during a 1-year follow-up.

Results: Seventeen patients (33%) had persistently increased NT-proBNP, 19 patients (36%) had only transient increases (concentrations went back to baseline at 72 h), and 16 (31%) had no increases [mean (SD) values at 72 h, 1163 (936) ng/L vs 185 (101) ng/L vs 39 (19) ng/L, respectively; P <0.0001]. Only patients with persistently increased NT-proBNP had a significant worsening of the left ventricular diastolic indexes from baseline to 12 months [ratio of peak early to peak late flow velocities from 1.42 (0.33) to 0.78 (0.11); P <0.0001; isovolumetric relaxation time from 90 (15) to 141 (26) ms; P <0.0001; E-wave deceleration time from 162 (17) to 224 (32) ms; P = 0.0004] and of the left ventricular ejection fraction [from 62.8 (3.4)% to 45.6 (11.5)%; P <0.0001].

Conclusions: Persistently increased NT-proBNP early after administration of HDC is strongly associated with development of cardiac dysfunction. This finding has important implications for identifying patients at risk of developing chemotherapy-induced cardiotoxicity.
Calculation of Gibbs Energy of Interaction (ΔG
0
int) of Neutral Benzoic Acids and their Anions
Authors: Gumtya S. K. , Lahiri Sujit Chandra
Published: June 2005

Quantitative correlation of the solubility phenomena and understanding of the dissolution mechanism are complex due to interplay of different types of intermolecular forces in the solubilization processes.

Attempts have been made to understand the solubilization process by determining the ΔG
0
int terms for neutral benzoic acid and substituted benzoic acids using the solubility values of neutral acids reported from our laboratory and the scaled particle theory. Similarly, ΔG
0
int terms for the anions are also calculated. ΔG
0
int values for neutral (HA) and charged ions (A−) are opposite. Different aspects of solubility and dissociation processes for the substituted acids and the effects of substitution have been explained with success.

The limitations of the method have also been emphasized.
Extraordinary Superplastic Ductility of Magnesium Alloy ZK60
Authors: Lapovok R. , Cottam R. , Thomson P.F. , Estrin Y.
Published: June 2005

Exceptionally high tensile ductility of commercial Mg alloy ZK60 is reported. It was achieved by equal channel angular pressing without any extra processing steps. The tensile ductility at 220 °C was 2040% and 1400% for the strain rates of 3 × 10−4 s−1 and 3 × 10−3 s−1, respectively. The strain rate sensitivity of the flow stress exhibited a value slightly above 0.5, which is characteristic of superplastic deformation. The grain structure associated with this behavior was shown to be bi-modal with further separation in two fractions with different grain sizes within the small grain size population.
Formation of Mg–Cu–Ni–Ag–Zn–Y–Gd Bulk Glassy Alloy by Casting into Cone-shaped Copper Mold in Air Atmosphere
Authors: Park E.S. , Kim D.H.
Published: June 2005

A new Mg–Cu–Ni–Ag–Zn–Y–Gd alloy with significantly improved glass forming ability (GFA) was developed in this work. Mg65Cu7.5Ni7.5Ag5Zn5Y5Gd5 bulk metallic glass (BMG) with a diameter of 14 mm was successfully fabricated by conventional copper mold casting method in air atmosphere. The critical cooling rate for glass formation was estimated to be about 20 K/s. When the maximum diameter for glass formation was compared with those previously reported for Mg-based alloys, the Mg65Cu7.5Ni7.5Ag5Zn5Y5Gd5 alloy showed the highest GFA. However, when the GFA was compared with those of Mg-TM-RE alloys (TM: Cu, Ni, Zn, and Ag; RE: Y and Gd), the significant improved GFA of the Mg–Cu–Ni–Zn–Ag–Y–Gd alloy cannot be properly represented by ΔTx, Trg, K, and γ parameters. In contrast to most of the Mg-based BMGs reported so far, the Mg65Cu7.5Ni7.5Ag5Zn5Y5Gd5 BMG exhibits yielding and plastic deformation during compressive loading.
Oxidation Behavior of Cu60Zr30Ti10 Bulk Metallic Glass
Authors: Tam C.Y. , Shek C.H.
Published: June 2005

The oxidation kinetics of Cu60Zr30Ti10 bulk metallic glass and its crystalline counterpart were studied in oxygen environment over the temperature range of 573–773 K. The oxidation kinetics, measured with thermogravimetric analysis, of the metallic glass follows a linear rate law between 573 and 653 K and a parabolic rate law between 673 and 733 K. It was also found that the oxidation activation energy of metallic glass is lower than that of its crystalline counterpart. The x-ray diffraction pattern showed that the oxide layer is composed of Cu2O, CuO, ZrO2, and metallic Cu. Cu enrichment on the topmost oxide layer of the metallic glass oxidized at 573 K was revealed by x-ray photoelectron spectroscopy while there was a decrease in Cu content in the innermost oxide layer. The oxide surface morphologies observed from scanning electron microscopy showed that ZrO2 granules formed at low temperatures while whiskerlike copper oxides formed at higher temperatures.
Photoluminescence of Lu2O3:Eu3+ Phosphors Obtained by Glycine-nitrate Combustion Synthesis
Authors: Chen Qiwei , Shi Ying , Chen Jiyang , Shi Jianlin
Published: June 2005

Eu3+-doped Lu2O3 phosphors were synthesized through a novel solution combustion route using glycine as the fuel. The influence of the glycine-to-nitrate (G/N) mole ratio on the crystallite size, specific surface area, morphology, and photoluminescence of the synthesized phosphors was investigated. The ignition temperature on the properties of the products was also studied. With G/N ratio increasing from 1.0 to 1.7, the grain size increased from 35 to 118 nm accordingly, resulting in the obvious changes of the photoluminescence properties. Concentration dependence of the emission intensity revealed that the quenching concentration of europium dopant was around 5 mol% for G/N- 1.7. The intensity of the peak emission due to the 5D0 → 7F2 transition of the Eu3+ ions dropped as the grain size decreased. The charge transfer band position of Eu3+-doped lutetia phosphors shifted toward lower energy (red shift) with the reduction of crystallite sizes and also with the increase of Eu3+ concentrations.
Hardening by Crystallization During Superplastic Flow in a Powder-metallurgy-processed Zr65Al10Ni10Cu15 Glass Metallic Alloy
Authors: Jeong H.G. , Kim W.J.
Published: June 2005

The superplastic behavior of the Zr65Al10Ni10Cu15 glass metallic alloy produced by the powder metallurgy method was examined in the supercooled liquid region. A tensile elongation as large as 750% was obtained at 6.3 × 10−3 s−1 at 697 K. Large strain hardening took place during the course of deformation and systematic trend was observed in the hardening behavior. Plots of stress versus strain and strain rate versus stress at 697 K showed that Newtonian viscous flow governed the plastic flow until the onset of strain hardening. Microstructure and differential scanning calorimetry analyses as well as flow stress versus testing time curves provided consistent evidence that the strain hardening was induced by crystallization. Crystallization was enhanced in the gauge region (deformed region) as compared to the grip region (undeformed region). Crystallization is expected to decrease tensile ductility by decreasing the strain-rate-sensitivity value and increasing the degree of brittleness. Hardening by crystallization, however, can contribute to neck stability if crystallization is enhanced in the neck region. The strain hardening and plastic stability parameters were measured as a function of strain for different strain rates at 696 K. The strain hardening parameter remained highly positive until failure. Because of this, the neck stability parameter (I) could be I < 0 in the entire hardening region. The contribution of hardening by crystallization to neck stability was found to be much more significant than that by grain growth in the superplastic metallic alloys. Reducing the specimen heating-and-holding time was suggested to promote superplasticity deformation without delaying initiation of crystallization. The largest tensile strain in the hardening region where crystallization may be obtained at the strain rates and temperatures where crystallization rate is controlled to be the lowest while maintaining I ≤ 0 throughout deformation.
Titania Nano-network Film Templated from Microphase-separated Block Copolymer and its Photocatalysis in Fractured Form
Authors: Lu Shih-Yuan , Chang Chia-Hao , Yu Chi-Hsien , Chen Hsin-Lung , Lo Yih Hsing
Published: June 2005

A thin-frame nano-network film of titania with backbone diameter of 20–30 nm was obtained from precursor templating of nano-porous polymer with nano-channels 50 nm in width. The nano-porous polymer templates were prepared by selective removal of the polyisoprene (PI) domain with ozone from the bicontinuous structure formed through blending a symmetric polystyrene-block-polyisoprene (PS-b-PI) copolymer with a PS homopolymer (h-PS). The titania network possessed the preferred anatase crystallinity for photocatalytic applications and a specific surface area of 53 m2/g, comparable to that of Degussa P25, a widely used commercial photocatalyst. Photocatalytic performance of the fractured titania network film was also comparable to that of Degussa P25 in both gas-phase NO oxidation and liquid phase methylene blue degradation. The much larger overall structure size of the fractured titania network film, however, offers advantages over the nano-particulate form of P25, namely, easy handling and rapid recycling from treated streams.
Influence of Zirconia Sol-gel Coatings on the Fracture Strength of Brittle Materials
Authors: Sánchez-González Estíbaliz , Miranda Pedro , Díaz-Parralejo Antonio , Pajares Antonia , Guiberteau Fernando
Published: June 2005

In this work, the effect of a sol-gel ZrO2–3 mol% Y2O3thin film on the fracture properties of a variety of brittle substrates was investigated. The results suggest that the film does not have any appreciable influence on the fracture behavior of crystalline substrates but dramatically affects the fracture properties of amorphous layers. In particular, a significant reduction of average fracture strength and a major increase of the Weibull modulus were observed on coated glassy slides. The origin of such variations is attributed to the generation of a homogeneous flaw population in the vitreous substrates, and the possible mechanisms for the production of flaws are analyzed. Implications of these results for the practical use of coated glassy layers are discussed.
New Method for Determining Young’s Modulus by Non-ideally Sharp Indentation
Authors: Ma Dejun , Ong Chung Wo , Wong Sing Fai , He Jiawen
Published: June 2005

In a previously developed method for estimating Young’s modulus E by depth-sensing indentation with spherical-tipped Berkovich indenter, the E value is deduced from several functional relationships (established by finite element analysis) relating nominal hardness/reduced elastic modulus ratio (Hn/Er) and elastic work/total work ratio (We/W). These relationships are specified for different absolute bluntness/maximum displacement ratios (Δh/hm). This paper reports the generalization of the method by proposing a function to replace all the above mentioned Hn/Er−We/W relationships. The function contains only a parameter Vr ≡ Videal/Vblunt instead of Δh/hm, where Videal is defined as the indented volume bounded by the cross-sectional areas measured at the maximum displacement hm for an ideally sharp indenter, and Vblunt is that of the real indenter. The use of Vr to replace Δh/hm is for the purpose of extending the application of the method for non-spherical tipped Berkovich indenters. The effectiveness of the method for materials of prominent plasticity was demonstrated by performing tests on carbon steel and aluminum alloy using three Berkovich indenters with different tip shapes.
Electrical Properties of Ultrathin Al2O3 Films Grown by Metalorganic Chemical Vapor Deposition for Advanced Complementary Metal-oxide Semiconductor Gate Dielectric Applications
Authors: Skordas Spyridon , Papadatos Filippos , Consiglio Steven , Eisenbraun Eric T. , Kaloyeros Alain E. , Gusev Evgeni P.
Published: June 2005

The electrical properties of ultrathin amorphous Al2O3 films, grown by low temperature metal-organic chemical vapor deposition from aluminum(III) 2,4-pentanedionate and water as co-reactants, were examined for potential applications as gate dielectrics in emerging complementary metal-oxide semiconductor technologies. High-frequency capacitance–voltage and current–voltage techniques were used to evaluate Al2O3 films deposited on silicon oxynitride on n-type silicon (100) substrates, with thickness ranging from 2.5 to 6.5 nm, as a function of postdeposition annealing regimes. Dielectric constant values ranging from 11.0 to11.5 were obtained, depending on the annealing method used. Metal-insulator-semiconductor devices were demonstrated with net equivalent oxide thickness values of 1.3 nm. Significant charge traps were detected in the as-deposited films and were mostly passivated by the subsequent annealing treatment. The main charge injection mechanism in the dielectric layer was found to follow a Poole–Frenkel behavior, with post-annealed films exhibiting leakage current an order of magnitude lower than that of equivalent silicon oxide films.
Shape and Internal Structure of Silver Nanoparticles Embedded in Glass
Authors: Hofmeister H. , Tan G.L. , Dubiel M.
Published: June 2005

The structural characteristics of silver nanoparticles embedded in glass by various routes of fabrication were studied in detail using high-resolution electron microscopy to find out if they are influenced by interaction with the surrounding glass matrix. Besides the formation conditions, the strength of the interaction between metal and glass governs the size-dependent changes of lattice spacings in such nanoparticles. However, determination of these changes is not straightforward because of complicated particle configurations and the interference nature of the lattice imaging technique. Imaging of lattice plane fringes and careful diffractogram analysis allowed the exclusion of any kind of tetragonal lattice distortion or transformation to hexagonal lattice type that may be deduced at first sight. Instead, the formation of twin faults in these nanoparticles turned out to be the essential structural feature and the main source of confusion about the lattice structure observed. The variety of particle forms is comparable to particles supported on oxide carriers. It is composed of single-crystalline particles of nearly cuboctahedron shape, particles containing single twin faults, multiple twinned particles containing parallel twin lamellae, and multiple twinned particles composed of cyclic twinned segments arranged around axes of 5-fold symmetry. The more twin planes involved in the particle composition, the more complicated is the interpretation of lattice spacings and lattice fringe patterns due to superposition of several twin segments.
Kinetics of Pb-rich Phase Particle Coarsening in Sn–Pb Solder Under Isothermal Annealing–cooling Rate Dependence
Authors: Vianco Paul , Rejent Jerome , Zender Gary , Kilgo Alice
Published: June 2005

The coarsening behavior of the Pb-rich phase particles in 63Sn–37Pb (wt%) solder was investigated following isothermal annealing treatments. Samples were exposed to cooling rates of 0.1, 1.0, 10, and 100 °C/min. Annealing temperatures were 25, 55, 70, 85, and 100 °C, and times were 2–100 days. The mean particle diameter decreased from 1.8 × 10−3 to 0.8 × 10−3 mm with increased cooling rate, indicating two solidification regimes: one for cooling rates ≤1 °C/min and the other for cooling rates of ≥10 °C/min. The Pb-rich phase particles coarsened more quickly in samples made at the two fastest cooling rates. There was little Pb-rich phase particle coarsening at 25 and 55 °C for all annealing times. Coarsening rate kinetics were examined specifically for the 10 and 100 °C/min data using the expression Atnexp[−ΔH/RT]. The values of n were 0.23 ± 0.11 and 0.36 ± 0.13, respectively; n was not sensitive to annealing temperature. The corresponding 1/n values indicated that the coarsening mechanism changed from a fast diffusion to a bulk diffusion controlled process with a faster cooling rate. The apparent activation energy ΔH ranged from 16 ± 8 to 41 ± 8 kJ/mol; the values increased with cooling rate from 10 to 100 °C/min. The ΔH value was sensitive to annealing temperature only for the faster cooling rate of 100 °C/min. Together, the n and ΔH values indicated that an accelerated, fast diffusion mechanism with low activation barriers characterized the Pb-rich phase coarsening in samples exposed to a slower cooling rate, greater annealing, or a combination of the two conditions. That mechanism likely originated from the in situ development of recover/recrystallization microstructures in the Sn-rich phase. At faster cooling rates, those microstructures were not as well developed, so coarsening was controlled more by the higher activation barriers of bulk diffusion processes.
Thermal Degradation Behavior of Indium Tin Oxide Thin Films Deposited by Radio Frequency Magnetron Sputtering
Authors: Kim Yong-Nam , Shin Hyun-Gyoo , Song Jun-Kwang , Cho Dae-Hyoung , Lee Hee-Soo , Jung Yeon-Gil
Published: June 2005

The thermal degradation behavior of indium tin oxide (ITO) thin films coated on glass substrates using radio frequency (rf) magnetron sputtering was investigated over the temperature range of 100–400 °C in air. The resistivity of ITO films increases abruptly after the thermal degradation temperature of 250 °C is reached, with a slight increase from 200 to 250 °C. The x-ray photoelectron spectrometry intensity ratio of O/(In + Sn) in thermally degraded ITO films is higher than that in normal films. The carrier concentration gradually decreases up to 200 °C, sharply drops between 200 and 250 °C with increasing temperature, and then saturates from 275 °C. The Hall mobility drops suddenly at 275 °C. The diffusion of oxygen into oxygen interstitials and oxygen vacancies and the chemisorption of oxygen into grain boundaries decrease the carrier concentration and the Hall mobility, respectively. The former mainly affects the resistivity of ITO films below 250 °C, and the later above 250 °C.
Nanoindentation of Polymers with a Sharp Indenter
Authors: Zhang C.Y. , Zhang Y.W. , Zeng K.Y. , Shen L.
Published: June 2005

A five-step indentation scheme is proposed to extract the elastic and viscoelastic properties of polymeric materials using a sharp indenter. In the formulation, analytical solutions to the elastic-viscoelastic deformation based on the concept of “effective indenters” proposed by both Pharr and Bolshakov [Understanding nanoindentation unloading curves. J. Mater. Res.17, 2660 (2002)] and Sakai [Elastic recovery in the unloading process of pyramidal microindentation. J. Mater. Res.18, 1631 (2003)] were derived. Indentation experiments on polymethylmethacrylate following the five-step scheme were performed. The elastic-viscoelastic parameters were extracted by fitting the solution based on Sakai’s effective indenter to the experimental results using a genetic algorithm. It was found that the solution based on Sakai's effective indenter was able to correctly extract the elastic properties. Based on this prediction and the experimental results, Pharr and Bolshakov's effective indenter profile could be determined. The extracted elastic-viscoelastic parameters using the solution based on Pharr and Bolshakov's effective indenter were independent of the reloading levels.
In situ Observation of Fracture Sequence of Physical Vapor Deposited TiN Film on (1120) Sapphire
Authors: Kim Young-Gu , Kim Do Kyung
Published: June 2005

The critical parameters for the structural stability of physical vapor deposited TiN film on (1120) sapphire were investigated by analyzing the adhesion strength and failure mechanism through in situ observations of the fracture sequence during scratch tests and static normal indentation. TiN was deposited by arc ion plating on (1120) sapphire, and the thickness of the TiN film was controlled to 700 nm. Delamination of TiN film was monitored in situ from below the contact through a transparent sapphire substrate, using zoom optics mounted into a video imaging sensor. In situ observation enables us to detect the failure origin of TiN coating on sapphire. The failure origin of TiN film on (1120) sapphire was identified as both rhombohedral and basal twinning of the sapphire substrate. Rhombohedral twinning was initiated first, and basal twinning ensued. Twinning-induced plastic deformation of the sapphire substrate triggered the initiation of interfacial delamination of the TiN coating. The plastic deformation of the substrate ultimately induced failure of the protective coating.
Effect of Processing Conditions on the Piezoelectric Properties of Sol-gel Derived Pb(Zr,Ti)O3 Films for Micromechanical Applications
Authors: Pérez J. , Vilarinho P.M. , Kholkin A.L. , Herrero J. Manuel , Zaldo C.
Published: June 2005

Lead zirconate titanate (PZT) films of composition close to the morphotropic phase boundary were deposited onto standard Si/SiO2/Ti/Pt substrates using a modified sol-gel process. The preparation conditions were optimized to obtain high-quality films at sufficiently low temperature (Ta - 500 °C). The dielectric, ferroelectric, and piezoelectric properties of the films were then measured as a function of the annealing temperature and the number of distillations to evaluate their suitability for micromechanical applications. The maximum values of the longitudinal charge and voltage piezoelectric coefficients were d33 ∼ 65 pm/V and g33 ∼ 4 × 10−3 Vm/N, respectively. The results indicate that the piezoelectric properties improved and became saturated with increasing number of distillations and are almost independent on Ta. Only moderate decrease of the piezoelectric response with frequency suggests that the investigated PZT films can be used in high-frequency piezoelectric applications. The results are discussed in terms of the microstructure and interface effects on the piezoelectric deformation in ferroelectric thin films.
Cesium Extraction from Cs0.8Ba0.4Ti8O16 Hollandite Nuclear Waste Form Ceramics in Nitric Acid Solutions
Authors: Luca Vittorio , Cassidy David , Drabarek Elizabeth , Murray Keith , Moubaraki Boujemaa
Published: June 2005

The leaching of Cs from well-characterized Cs-bearing hollandite powders with ideal formula Cs0.8Ba0.4Ti8O16 was studied at 200 °C under static oxidizing conditions achieved using dilute nitric acid solutions. A variety of techniques were used to elucidate the leaching mechanism including x-ray powder diffraction, magnetic susceptibility, x-ray absorption near edge structure, and electron microscopy. Under the conditions of the study, Cs is leached from Cs-hollandite according to a deceleratory rate law with contracting geometries. The principal reaction products are rutile and brookite. The leaching mechanism involves the formation of a quasi-continuous, and hence relatively impermeable, secondary titanium oxide phase (rutile and/or brookite) on the surfaces of the hollandite crystallites. The driving force for the leaching reaction appears to be the oxidation of Ti3+ in the structure by the oxidizing acid, which then promotes extraction of Cs and Ba from the hollandite tunnels followed by tunnel destabilization and transformation to rutile and brookite.
Transformation Mechanism from Carbon Nanotubes to n-diamond
Authors: Wen Bin , Li Tingju , Dong Chuang , Jin Junze
Published: June 2005

Nanocrystal n-diamond particles were synthesized after a pyrogenation of carbon nanotubes and colloidal Fe(OH)3 at atmospheric pressure. The product was investigated with x-ray diffraction, transmission electron microscopy, thermal gravimetric analysis, and differential thermal analysis. The results indicate that the n-diamond can be synthesized with the carbon nanotubes as carbon source. The formation mechanism of the n-diamond is suggested in this paper. With the increase of temperature and hence the carbon diffusion in iron, the phase sequence is from Fe(OH)3 into Fe2O3, α–Fe, γ–Fe, and then liquid iron. When carbon in the liquid iron is saturated, graphite separated out of the liquid iron. With the decrease of temperature, the carbon in γ–Fe is separated out, and the n-diamond nuclei form and grow.
Thickness Effect on Thermally Induced Phase Transformations in Sputtered Titanium-nickel Shape-memory Films
Authors: Wan D. , Komvopoulos K.
Published: June 2005

The effect of the film thickness on the phase transformations encountered in sputtered titanium-nickel (TiNi) shape-memory films due to thermal cycling in the temperature range of −150 to 150 °C was examined in the context of electrical resistivity (ER) measurements. A hysteresis in the ER response was observed for film thickness greater than 300 nm. This phenomenon is characteristic of shape-memory materials and is attributed to the rhombohedral (R) phase produced during cooling from the high-temperature cubic austenite phase to the low-temperature monoclinic martensite phase. The decrease of the TiNi film thickness below 300 nm resulted in a smaller ER hysteresis, leading eventually to its disappearance for film thickness less than ∼50 nm. The results indicate that spatial constraints introduced by the film surface and film/substrate interface generate a resistance force, which prevents lattice distortion and twinning. The inhibition of these mechanisms, which control self-accommodation R-phase transformation, leads to the suppression and eventual disappearance of the shape memory effect for film thickness less than ∼100 nm.
Sex Differentiation and Early Gonadal Development in Brook Trout
Authors: Sacobie Charles F D , Benfey Tillmann J
Published: June 2005

Gonadal differentiation in brook trout Salvelinus fontinalis, as determined from samples collected weekly from 42 to 1,572 degree-days (°C) posthatch, occurs between 393 and 464 degree-days posthatch. During this interval, the gonad transforms from a structure containing several developing primordial germ cells into either a gonad with well-developed perinucleolar oocytes or a gonad with cavities that ultimately develop into sperm ducts or the gonadal circulatory system. Brook trout demonstrate differentiated development, in which the gonad develops directly into a testis or an ovary, and anatomical differentiation precedes cytological differentiation in both ovaries and testes. The data provided by this study should aid in the development of techniques for hormonal sex reversal in brook trout.
The Economic Toll of Intimate Partner Violence Against Women in the United States
Authors: Max Wendy , Rice Dorothy P. , Finkelstein Eric , Bardwell Robert A. , Leadbetter Steven
Published: June 2005

This study provides estimates of the economic cost of intimate partner violence perpetrated against women in the US, including expenditures for medical care and mental health services, and lost productivity from injury and premature death. The analysis uses national survey data, including the National Violence Against Women Survey and the Medical Expenditure Panel Survey, to estimate costs for 1995. Intimate partner violence against women cost $5.8 billion dollars (95% confidence interval: $3.9 to $7.7 billion) in 1995, including $320 million ($136 to $503 million) for rapes, $4.2 billion ($2.4 to $6.1 billion) for physical assault, $342 million ($235 to $449 million) for stalking, and $893 million ($840 to $946 million) for murders. Updated to 2003 dollars, costs would total over $8.3 billion. Intimate partner violence is costly in the US. The potential savings from efforts to reduce this violence are substantial. More comprehensive data are needed to refine cost estimates and monitor costs over time.
Couple Age Discrepancy and Risk of Intimate Partner Homicide
Authors: Breitman Noelia , Shackelford Todd K. , Block Carolyn Rebecca
Published: June 2005

Although national level studies in the United States and Canada find that extreme partner age discrepancy is a risk factor for intimate partner homicide in opposite-sex couples, these studies carry two caveats: They are limited to cohabiting marital or common-law couples and they are not detailed enough to explore alternative explanations for the age discrepancy-homicide risk association. Using the Chicago Homicide Dataset, which includes all homicides that occurred in Chicago from 1965 to 1996, we analyze the 2,577 homicides in which the victim was killed by a current or former legal spouse, common-law spouse, or heterosexual boyfriend or girlfriend, and in which the woman was at least 18 years of age. Within each of 14 categories of couple age discrepancy, we estimate the population of intimate heterosexual couples and calculate the population-based risk of homicide. The results replicate national level findings showing that the risk of intimate partner homicide is considerably elevated for couples with a large discrepancy between their ages—where the man is at least 16 years older than the woman or the woman is at least 10 years older than the man. This risk pattern occurs regardless of whether the man or the woman was the homicide offender. We then investigate whether the link between partner age discrepancy and homicide risk is explained by the offender’s arrest record. Results show that the higher risk of intimate partner homicide for age discrepant couples is robust, and does not depend on the previous arrest record of the offender. Discussion addresses other possible explanations for the increased risk of partner homicide for age discrepant couples, and the practical implications of these findings.
Detecting Ongoing Intimate Partner Violence in the Emergency Department Using a Simple 4-Question Screen: The OVAT
Authors: Ernst Amy A. , Weiss Steven J. , Cham Elaine , Hall Louise , Nick Todd G.
Published: June 2005

We wanted to prospectively evaluate the use of a brief screening tool for ongoing intimate partner violence (IPV), the OVAT, and to validate this tool against the present Index of Spouse Abuse (ISA). The design was a prospective survey during randomized 4-hour shifts in an urban emergency department setting. The scale consists of four questions developed based on our previous work. The ISA was compared as the gold standard for detection of present (ongoing) IPV. Of 362 eligible patients presenting during 75 randomized 4-hour shifts, 306 (85%) completed the study. The prevalence of ongoing IPV using the OVAT was 31% (95% CI 26% to 36%). For the ISA, the prevalence was 20% (95% CI 16% to 25%). Compared with the ISA, the sensitivity of the OVAT in detecting ongoing IPV was 86%, specificity 83%, negative predictive value 96%, positive predictive value 56%, with an accuracy of 84%. In conclusion, four brief questions can detect ongoing IPV to aid in identifying the victim.
Antiretroviral Therapy in Resource-Poor Countries: Illusions and Realities
Authors: Desvarieux Moïse , Landman Roland , Liautaud Bernard , Girard Pierre-Marie
Published: June 2005

The prospects for antiretroviral therapy in resource-poor settings have changed recently and considerably with the availability of generic drugs, the drastic price reduction of brand-name drugs, and the simplification of treatment. However, such cost reductions, although allowing the implementation of large-scale donor programs, have yet to render treatment accessible and possible in the general population.

Successfully providing HIV treatment in high-prevalence/high-caseload countries may require that we redefine the problem as a public health mass therapy program rather than a multiplication of clinical situations. The public health goal cannot simply be the reduction of morbidity and mortality for those treated but must be the reduction in morbidity and mortality for the many, that is, at a population level.
Outcome Evaluation of a Public Health Approach to Suicide Prevention in an American Indian Tribal Nation
Authors: May Philip A. , Serna Patricia , Hurt Lance , DeBruyn Lemyra M.
Published: June 2005

Objectives. We evaluated the efficacy of 15 years of a public health–oriented suicidal-behavior prevention program among youths living on an American Indian reservation.

Methods. All suicides, suicide attempts, and suicidal gestures were monitored. Age-specific analyses over time were used to assess outcomes.

Results. Both descriptive and linear regression analyses indicated that a substantial drop occurred in suicidal gestures and attempts. Suicide deaths neither declined significantly nor increased, although the total number of self-destructive acts declined by 73% (P=.001).

Conclusions. Data from this community-based approach document a remarkable downward trend—measured by both magnitude and temporal trends in the specifically targeted age cohorts—in suicidal acts. The sequential decrease in age-specific rates of suicide attempts and gestures is indicative of the program’s success.
Brazil and Access to HIV/AIDS Drugs: A Question of Human Rights and Public Health
Authors: Galvão Jane
Published: June 2005

I explore the relationship between public health and human rights by examining the Brazilian government’s policy of free and universal access to anti-retroviral medicines for people with HIV/AIDS.

The Brazilian government’s management of the HIV/AIDS epidemic arose from initiatives in both civil society and the governmental sector following the democratization of the country. The dismantling of authoritarian rule in Brazil was accompanied by a strong orientation toward human rights, which formed the sociopolitical framework of Brazil’s response to the HIV/AIDS epidemic.

Even if the Brazilian experience cannot be easily transferred to other countries, the model of the Brazilian government’s response may nonetheless serve as inspiration for finding appropriate and lifesaving solutions in other national contexts.
Work Factors and Occupational Class Disparities in Sickness Absence: Findings From the GAZEL Cohort Study
Authors: Melchior Maria , Krieger Nancy , Kawachi Ichiro , Berkman Lisa F. , Niedhammer Isabelle , Goldberg Marcel
Published: June 2005

Objectives. To estimate the contribution of stress-related and physical work factors to occupational class disparities in sickness absence from work.

Methods. Our sample consisted of 8847 men and 2886 women participating in the French GAZEL cohort study. Occupational class and medically certified sickness absence data (1995–2001) were obtained from the participants’ employer. Work characteristics (physical and stress-related) were self-reported. We calculated rate ratios with Poisson regression models; fractions of sickness absence attributable to work factors were estimated with the Miettinen formula.

Results. Sickness absence was distributed along an occupational gradient. Work characteristics accounted for 19% (women) and 21% (men) of all absences. Physical work conditions accounted for 42% and 13% of absences for musculoskeletal reasons, and work stress accounted for 48% and 40% of psychiatric absences. Overall, about 20% of the occupational class gradient in sickness absence could have been associated with deleterious work conditions.

Conclusion. Work conditions contribute to sickness absence, particularly among manual workers and clerks. Policies that decrease ergonomic constraints and work stress also could reduce the burden of ill health and sickness absence among the lowest strata of working populations.
Quality of Parental Consent in a Ugandan Malaria Study
Authors: Pace Christine , Talisuna Ambrose , Wendler David , Maiso Faustin , Wabwire-Mangen Fred , Bakyaita Nathan , Okiria Edith , Garrett-Mayer Elizabeth S. , Emanuel Ezekiel , Grady Christine
Published: June 2005

Objectives. We surveyed Ugandan parents who enrolled their children in a randomized pediatric malaria treatment trial to evaluate the parents’ levels of understanding about the treatment trial and the quality of the parents’ consents to allow their children to participate in the study.

Methods. We conducted 347 interviews immediately following enrollment at 4 Ugandan sites.

Results. A majority (78%) of the parents, most of whom where mothers (86%) had at most a primary school education. Of the participating mothers, a substantial percentage reported that they remembered being told about the study’s purpose (77%), the required number of visits (88%), the risks involved (61%), treatment allocation (84%), and their ability to discontinue their children’s participation (64%). In addition, most reported knowing the trial’s purpose (80%) and the required number of visits (78%); however, only 18% could name possible side effects from the drugs being administered, and only 19% knew that children would not all be administered identical treatments. Ninety-four percent reported that they made the enrollment decision themselves, but 58% said they felt pressure to participate because of their child’s illness, and 15% said they felt some type of pressure to participate from others; 41% reported knowing that they did not have to participate.

Conclusions. The consent Ugandan parents provided to allow their children to participate in the malaria study was of mixed quality. Parents understood many of the study details, but they were not very aware of the risks involved or of randomization. Many parents felt that they could not have refused to participate because their child was sick and they either did not know or did not believe that their child would receive treatment outside of the study. Our results indicate that further debate is needed about informed consent in treatment studies of emergent illnesses in children.
The Limits of Social Capital: Durkheim, Suicide, and Social Cohesion
Authors: Kushner Howard I. , Sterk Claire E.
Published: June 2005

Recent applications of social capital theories to population health often draw on classic sociological theories for validation of the protective features of social cohesion and social integration. Durkheim’s work on suicide has been cited as evidence that modern life disrupts social cohesion and results in a greater risk of morbidity and mortality—including self-destructive behaviors and suicide.

We argue that a close reading of Durkheim’s evidence supports the opposite conclusion and that the incidence of self-destructive behaviors such as suicide is often greatest among those with high levels of social integration. A reexamination of Durkheim’s data on female suicide and suicide in the military suggests that we should be skeptical about recent studies connecting improved population health to social capital.
A Critical Analysis of the Brazilian Response to HIV/AIDS: Lessons Learned for Controlling and Mitigating the Epidemic in Developing Countries
Authors: Berkman Alan , Garcia Jonathan , Muñoz-Laboy Miguel , Paiva Vera , Parker Richard
Published: June 2005

The Brazilian National AIDS Program is widely recognized as the leading example of an integrated HIV/AIDS prevention, care, and treatment program in a developing country. We critically analyze the Brazilian experience, distinguishing those elements that are unique to Brazil from the programmatic and policy decisions that can aid the development of similar programs in other low- and middle-income and developing countries.

Among the critical issues that are discussed are human rights and solidarity, the interface of politics and public health, sexuality and culture, the integration of prevention and treatment, the transition from an epidemic rooted among men who have sex with men to one that increasingly affects women, and special prevention and treatment programs for injection drug users.
The Right to Health Under International Law and Its Relevance to the United States
Authors: Yamin Alicia Ely
Published: June 2005

In recent years, there have been considerable developments in international law with respect to the normative definition of the right to health, which includes both health care and healthy conditions. These norms offer a framework that shifts the analysis of issues such as disparities in treatment from questions of quality of care to matters of social justice.

Building on work in social epidemiology, a rights paradigm explicitly links health with laws, policies, and practices that sustain a functional democracy and focuses on accountability. In the United States, framing a well-documented problem such as health disparities as a “rights violation” attaches shame and blame to governmental neglect. Further, international law offers standards for evaluating governmental conduct as well as mechanisms for establishing some degree of accountability.