Sans measurement of deuterium trapping at dislocations and grain boundaries in palladium

Small angle neutron scattering (SANS) measurements have been made on deformed single crystal and polycrystalline palladium with and without deuterium dissolved in the solution phase at room temperature. The net scattering cross section for the same sample with and without deuterium loading shows a behavior expected from deuterium correlation with dislocations forming rod-like scattering structures. We conclude from these scattering measurements that the trapped deuterium is within 2-3 Burgers vectors of the dislocation core. On average 1-3 deuterons per A are trapped at dislocations in the deformed samples. The measurements indicate the straight, rod-like correlation geometry extends on average 50-100 A along the dislocations. Net scattering from a well annealed polycrystalline palladium sample exhibiting a behavior expected from surfaces has been observed. This net scattering is attributed to deuterium trapped at grain boundaries in the polycrystalline sample. A value of 0.4 +/- 0.2 trapped deuterons per A2 of grain boundary area is calculated from the well annealed polycrystalline scattering measurement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29076/1/0000111.pd

In vivo imaging and quantitative analysis of leukocyte directional migration and polarization in inflamed tissue

Directional migration of transmigrated leukocytes to the site of injury is a central event in the inflammatory response. Here, we present an in vivo chemotaxis assay enabling the visualization and quantitative analysis of subtype-specific directional motility and polarization of leukocytes in their natural 3D microenvironment. Our technique comprises the combination of i) semi-automated in situ microinjection of chemoattractants or bacteria as local chemotactic stimulus, ii) in vivo near-infrared reflected-light oblique transillumination (RLOT) microscopy for the visualization of leukocyte motility and morphology, and iii) in vivo fluorescence microscopy for the visualization of different leukocyte subpopulations or fluorescence-labeled bacteria. Leukocyte motility parameters are quantified off-line in digitized video sequences using computer-assisted single cell tracking. Here, we show that perivenular microinjection of chemoattractants [macrophage inflammatory protein-1alpha (MIP-1alpha/Ccl3), platelet-activating factor (PAF)] or E. coli into the murine cremaster muscle induces target-oriented intravascular adhesion and transmigration as well as polarization and directional interstitial migration of leukocytes towards the locally administered stimuli. Moreover, we describe a crucial role of Rho kinase for the regulation of directional motility and polarization of transmigrated leukocytes in vivo. Finally, combining in vivo RLOT and fluorescence microscopy in Cx3CR1(gfp/gfp) mice (mice exhibiting green fluorescent protein-labeled monocytes), we are able to demonstrate differences in the migratory behavior of monocytes and neutrophils.Taken together, we propose a novel approach for investigating the mechanisms and spatiotemporal dynamics of subtype-specific motility and polarization of leukocytes during their directional interstitial migration in vivo

Morphology and interdiffusion behavior of evaporated metal films on crystalline diindenoperylene films

We present a transmission electron microscopy (TEM)/Rutherford backscattering spectrometry (RBS)/x-ray-diffraction (XRD) study of Au evaporated on crystalline organic thin films of diindenoperylene (DIP). Cross-sectional TEM shows that the preparation conditions of the Au film (evaporation rate and substrate temperature) strongly determine the interfacial morphology. In situ XRD during annealing reveals that the organic layer is thermally stable up to about 150 degreesC, a temperature sufficient for most electronic applications. The x-ray measurements show that the "as-grown" Au layer exhibits a large mosaicity of around 10degrees. Upon annealing above approximate to120 degreesC the Au film starts to reorder and shows sharp (111)-diffraction features. In addition, temperature dependent RBS measurements indicate that the Au/DIP interface is thermally essentially stable against diffusion of Au in the DIP layer up to approximate to100 degreesC on the time scale of hours, dependent on the Au thickness. (C) 2003 American Institute of Physics

Equine Third Metacarpal Bone Assessment by Quantitative Ultrasound and Dual-Energy-X-Ray absorptiometry

peer reviewe

Use of multisite quantitative ultrasonography for noninvasive assessment of bone in horses

OBJECTIVE: To evaluate the usefulness of multisite quantitative ultrasonography for noninvasive assessment of bone in horses. SAMPLE POPULATION: 12 healthy horses and both forelimbs from 8 clinically normal horses. PROCEDURE: For in vivo measurements, various regions of interest (ROI) were examined on the third metacarpal bone, radius, and tibia. Precision error for speed of sound (SOS) measurements was obtained by measuring each ROI of 4 horses 10 times with probe repositioning. Additionally, 3 operators measured each aspect of the third metacarpal bone of 6 horses 5 times each. For ex vivo measurements, third metacarpal bones were examined at 9 ROI, and SOS measurements were performed before and after soft tissue removal. One ROI of a single forelimb was subjected to 96 ex vivo measurements with 3 different contact media. RESULTS: The lateral aspect of the third metacarpal bone had significantly higher SOS values than the dorsal and medial aspect of the third metacarpal bone. No difference was obtained between SOS values of the lateral and medial aspect of the radius. The tibia had significantly higher SOS values than the lateral aspect of the radius and the dorsal and medial aspect of the third metacarpal bone. Intraoperator coefficients of variation ranged from 0.62 to 3.15%, and interoperator coefficients of variation ranged from 0.78 to 2.70%. Values of SOS were highest when silicone oil was used as the contact medium. CONCLUSIONS AND CLINICAL RELEVANCE: Speed of sound measurements obtained by quantitative ultrasonography in axial transmission mode can be used to precisely measure superficial cortical bone properties of third metacarpal bone, radius, and tibia in horses

Quantitative ultrasound and dual-X-ray absorptiometry-measurements of the third metacarpal bone in horses

The purpose of the study was to examine the relationship between in vivo and ex vivo quantitative ultrasound (QUS) measurements with and without soft tissue and ex vivo dual X-ray absorptiometry (DXA) at different aspects and levels of the third metacarpal bone (MC III) in horses. Both MC III of 8 clinically normal horses were divided in 9 sites (lateral, medial, dorsal aspect; proximal, mid, distal level). Speed of sound (SOS) measurements were performed with a QUS multisite device (Sunlight Ltd., Rehovot, Israel) and a DXA device (Hologic Inc., Bedford, USA) was used to evaluate cortical bone mineral density (BMD) at each site. Ex vivo data on MC III were analysed with a mixed model to test the hypothesis of no difference between aspect and level in QUS and DXA while adjusting for fixed member and for random horse effects. Pearson correlation coefficients between SOS and BMD obtained on MC III with soft tissue were calculated for each member and site. A mixed model was used to determine whether there is a difference between in vivo and ex vivo SOS data while adjusting for fixed aspect, level, and member and random horse effects. Highly significant (p0.05). The study suggests that, in horses, SOS results can not be explained only by BMD, but could reflect additional properties of bone, such as elasticity, architecture or bone strength. Our results indicate that soft tissue does not influence ex vivo SOS measurement results