Orientation dependent molecular friction on organic layer compound crystals

High resolution friction force maps of the benzylammonium terminated crystalline surface of a layer compound are presented. The lateral force map acquired with an atomic force microscope, reveals a significant contrast between different molecular orientations yielding molecular rows which differ from their neighboring ones. The single crystals are formed by stacks of copper oxalate sheets sandwiched between stereoregular organic cations, resulting in highly organized surface structures. Single molecular defects are observed at small loads. The experimental results are compared with numerical calculations which indicate a transition from an unperturbed state at small loads to a distorted state at higher loads. (C) 2011 American Institute of Physics.

Validation of a statistical shape model-based 2D/3D reconstruction method for determination of cup orientation after THA

The aim of this study was to validate the accuracy and reproducibility of a statistical shape model-based 2D/3D reconstruction method for determining cup orientation after total hip arthroplasty. With a statistical shape model, this method allows reconstructing a patient-specific 3D-model of the pelvis from a standard AP X-ray radiograph. Cup orientation (inclination and anteversion) is then calculated with respect to the anterior pelvic plane that is derived from the reconstructed model.

Three-dimensional surface reconstruction within noncontact diffuse optical tomography using structured light

A main field in biomedical optics research is diffuse optical tomography, where intensity variations of the transmitted light traversing through tissue are detected. Mathematical models and reconstruction algorithms based on finite element methods and Monte Carlo simulations describe the light transport inside the tissue and determine differences in absorption and scattering coefficients. Precise knowledge of the sample's surface shape and orientation is required to provide boundary conditions for these techniques. We propose an integrated method based on structured light three-dimensional (3-D) scanning that provides detailed surface information of the object, which is usable for volume mesh creation and allows the normalization of the intensity dispersion between surface and camera. The experimental setup is complemented by polarization difference imaging to avoid overlaying byproducts caused by inter-reflections and multiple scattering in semitransparent tissue.

The Effect Of Social Support On Health As Moderated By Sex-Role Orientation

Previous research has established a significant association between social support and health; high levels of social support are consistently shown to both directly and indirectly improve health (Cohen, 1998, House et al. 1988, Rook, 2001, Schwarzer & Leppin 1989). Additional research has investigated the role of sex and gender differences in social support, health and the interaction between these variables (Barbee et al. 1993, Burda, Vaux & Schill 1984, Cleary, 1987, Rook, 2001, Shumaker & Hill, 1991). The present study aims to further examine the influence of sex-role orientation on social support and health. Forty-nine female participants completed a three-part survey assessing their sex-role orientation, perceived social support, current stress levels and physical health. Results revealed that both masculinity and femininity relate to social support network size and health outcomes. Masculinity and androgyny were significantly negatively associated with health problems, whereas undifferentiated individuals had higher rates of physical illness. These findings demonstrate the important role of gendered traits in social support and ultimately, physical health.