Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices

To identify $\pi^{\pm}$ and $K^{\pm}$ in the region of $1.0\sim 2.5$ GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have checked its properties in a test beam. The obtained results have demonstrated that our aerogel was transparent enough to make up for loss of the Cherenkov photon yield due to a low refractive index. Various configurations for the photon collection system and some types of photomultipliers, such as the fine-mesh type, for a read out were also tested. From these studies, our design of a Cherenkov counter dedicated to $\pi / K$ separation up to a few GeV/c %in the momentum range of $1.0 \sim 2.5$ GeV/c with an efficiency greater than $90$ \% was considered.Comment: 21 pages, latex format (article), figures included, to be published in Nucl. Instrm. Meth.

Production of the Long-Lived Isotopes 163Ho for the Study of the Mass of Electron Neutrino

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Angioscopic Evaluation of Neointimal Coverage of Coronary Stents

Drug-eluting stents (DES) reduce coronary restenosis significantly; however, late stent thrombosis (LST) occurs, which requires long-term antiplatelet therapy. Angioscopic grading of neointimal coverage of coronary stent struts was established, and it was revealed that neointimal formation is incomplete and prevalence of LST is higher in DES when compared to bare-metal stents. It was also observed that the neointima is thicker and LST is less frequent in paclitaxel-eluting and zotarolimus-eluting stents than in sirolimus-eluting stents. Many new stents were devised and they are now under experimental or clinical investigations to overcome the shortcomings of the stents that have been employed clinically. Endothelial cells are highly anti-thrombotic. Neo-endothelial cell damage is considered to be caused by friction between the cells and stent struts due to the thin neointima between them which might act as a cushion. Therefore, development of a DES that causes an appropriate thickness (around 100 μm) of the neointima is a potential option with which to prevent neo-endothelial cell damage and consequent LST while preventing restenosis

Direct Precision Measurement of the Half-Llfe of 163Ho by Isotope-Dilution Mass Spectrometry for Neutrino-Mass Determination from Electron Capture

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Effects of Probiotics on the Expression and Localization of Avian β-defensins in the Proventriculus of Broiler Chicks

The aim of this study was to determine the effects of probiotics-feeding on the gene expression and protein localization of avian β-defensins (AvBDs) in the proventriculus of broiler chicks. Male broiler chicks were arranged in 3 groups: control group, probiotics group I and probiotics group II, which were fed with starter rations containing 0%, 0.2% or 0.4% probiotics, respectively, from day 0 (D0; at one day old) to D14. Proventriculi in all groups were collected at D0, D7 and D14 for analysis of AvBDs expression and AvBD12 protein localization. The expression of AvBDs genes was examined by reverse transcription-PCR and changes in the expression upon probiotics-feeding were examined by real-time PCR. The AvBD12 localization was examined by immunohistochemistry, and density of immunoreaction products was examined by image analysis under a microscope. Out of 14 AvBDs genes, seven AvBDs were detected in the proventriculus of chicks, namely, AvBD1, 2, 4, 6, 7, 10 and 12. The expression of the 7 detected genes did not show any significant differences between control and probiotics groups at D7 and D14. The immunoreactive (ir) -AvBD12 was localized in surface epithelium and cells in the connective tissues of proventricular glands. The ir-AvBD12 density in surface epithelium was significantly higher at D7 than at D0 or D14 in control group. At D7 and D14, the ir-AvBD12 density was significantly lower in probiotics groups than in control group. The ir-AvBD12 cells in proventricular gland increased in number with age; however, there were no significant differences between control and probiotics groups at D7 and D14. These results suggest that, although probiotics-feeding does not affect the gene expression of AvBDs, it may induce AvBD12 secretion from the surface epithelium of the proventriculus in broiler chicks