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We present an early-stage prototype of a positron emission tomograph (PET) based on 3 × 3 × 20 mm GAGG(Ce) scintillators optically coupled to 3 × 3 mm silicon photomultipliers (SiPMs) (Onsemi fc30035-smt). The detectors are read out by a Weeroc 32-channel Petiroc2A chip, allowing for precise charge and time measurements and designed specifically for SiPMs readout. In the report, the energy and time resolutions of the system measured with Ti-44 source are presented, the imaging capabilities of the system are discussed. [ABSTRACT FROM AUTHOR]

In this work a simulation of the electron drift which accounts for diffusion for different configurations of the electric field for the ReD detector has been carried out. An estimate of the reconstruction error of the event coordinates, caused both by nonuniformity of the field and by the focusing of electrons as they pass through the detector grid, is obtained. [ABSTRACT FROM AUTHOR]

Focal adhesion kinase (FAK) is a critical component in transducing signals downstream of both integrins and growth factor receptors. To determine how the loss of FAK affects the epidermis in vivo, we have generated a mouse model with a keratinocyte-restricted deletion of fak (FAKK5 KO mice). FAKK5 KO mice displayed three major phenotypes – irregularities of hair cycle, sebaceous glands hypoplasia, and a thinner epidermis – pointing to defects in the proliferative capacity of multipotent stem cells found in the bulge. FAK-null keratinocytes in conventional primary culture undergo massive apoptosis hindering further analyses, whereas the defects observed in vivo do not shorten the mouse lifespan. These results suggest that the structure and the signaling environment of the native tissue may overcome the lack of signaling through FAK. Our findings point to the importance of in vivo and three-dimensional in vitro models in analyses of cell migration, proliferation, and survival. Surprisingly, the difference between FAKloxP/+ and FAKK5 KO mice in wound closure was not statistically significant, suggesting that in vivo loss of FAK does not affect migration/proliferation of basal keratinocytes in the same way as it affects multipotent stem cells of the skin.Oncogene (2006) 25, 1081–1089. doi:10.1038/sj.onc.1209130; published online 10 October 2005 [ABSTRACT FROM AUTHOR]

Virtually all in vitro studies of the effects of rhinovirus on human airway epithelium have used cells grown under conditions known to produce low levels of differentiation. The relevance of the results to native epithelium is questionable. Here we grew primary cultures of human tracheal or nasal epithelium under three conditions. One condition produced pseudostratified, mucociliary cells virtually indistinguishable from native epithelium. The other two conditions produced undifferentiated squamous cells lacking cilia. Cells were infected for 6 h with rhinovirus-16. After a 24-h incubation period, we determined levels of viral RNA in the cells, numbers of infectious viral particles released in the mucosal medium, expression of a variety of epithelial cytokines and other proteins, release of IL-6 and IL-8, and transepithelial electrical resistance and voltage. After infection, levels of viral RNA in the poorly differentiated cells were 30 or 130 times those in the differentiated. Furthermore, expression of mRNA for inflammatory cytokines, release of infectious particles, and release of IL-6 and IL-8 were closely correlated with the degree of viral infection. Thus well-differentiated cells are much more resistant to viral infection and its functional consequences than are poorly differentiated cells from the same source. ion transport; porous-bottomed inserts; short-circuit current; transepithelial electrical resistance. [ABSTRACT FROM AUTHOR]