abtract background: in nuclear medicine, phantoms are mainly used to evaluate the overall performance of the imaging systems and practically there is no phantom exclusively designed for the evaluation of the software performance.  in this study the hoffman brain phantom was used for quantitative evaluation of reconstruction techniques. the phantom is modified to acquire tomographic and planar i...

Epithelial cells and other groups of cells acquire a polarity orthogonal to their apical-basal axes, referred to as Planar Cell Polarity (PCP). The process by which these cells become polarized requires a signaling pathway using Frizzled as a receptor. Responding cells sense cues from their environment that provide directional information, and they translate this information into cellular asymm...

Planar cell polarity (PCP) regulates the orientation of cells in epithelia and of mesenchymal cells during gastrulation. In this issue, Narimatsu et al. (2009) report that the Smurf E3 ubiquitin ligases are required for localized protein degradation of a core PCP factor to generate cellular asymmetry.

Planar cell polarity (PCP) is the uniform orientation and alignment of a group of cells orthogonal to the apical-basal axis within a tissue. Originally described in insects, it is now known that PCP is required for many processes in vertebrates, including directional cell movement, polarized cell division, ciliary orientation, neural tube closure, heart development and lung branching. In this r...

We demonstrate complementary differences in the behavior of B lymphoblastoid cells adhering to LFA-1 or its counter-receptor ICAM-1. The interaction of B lymphoblastoid cells with glass-supported planar bilayers bearing LFA-1 or ICAM-1 was observed by time-lapse video microscopy, and the distribution of adhesion receptors on cells interacting with the planar bilayers was studied by immunofluore...

density functional theory (dft) calculations were performed to investigate the properties of planar, tubular and conical forms of silicon nanostructures. the evaluated parameters including averaged bond lengths, binding energies, gap energies and dipole moments were then evaluated for the optimized models of study. the results indicated that the bond lengths between silicon atoms are different ...