Experimental evidence of planar channeling in a periodically bent crystal

The usage of a Crystalline Undulator (CU) has been identified as a promising solution for generating powerful and monochromatic $\gamma$-rays. A CU was fabricated at SSL through the grooving method, i.e., by the manufacturing of a series of periodical grooves on the major surfaces of a crystal. The CU was extensively characterized both morphologically via optical interferometry at SSL and structurally via X-ray diffraction at ESRF. Then, it was finally tested for channeling with a 400 GeV/c proton beam at CERN. The experimental results were compared to Monte Carlo simulations. Evidence of planar channeling in the CU was firmly observed. Finally, the emission spectrum of the positron beam interacting with the CU was simulated for possible usage in currently existing facilities

High-efficiency deflection of high energy protons due to channeling along the (110) axis of a bent silicon crystal

A deflection efficiency of about 61% was observed for 400 GeV/c protons due to channeling, most strongly along the 〈110〉 axis of a bent silicon crystal. It is comparable with the deflection efficiency in planar channeling and considerably larger than in the case of the 〈111〉 axis. The measured probability of inelastic nuclear interactions of protons in channeling along the 〈110〉 axis is only about 10% of its amorphous level whereas in channeling along the (110) planes it is about 25%. High efficiency deflection and small beam losses make this axial orientation of a silicon crystal a useful tool for the beam steering of high energy charged particles

Reproductive toxicity of taurohyodeoxycolic acid.

The reproductive toxicity of taurohyodeoxycholic acid (3 alpha, 6 alpha-dihydroxy-5-beta-cholanoyl-2-amino-ethyl-sulfonic acid, THDCA, Io, Praxis, CAS 2958-04-5), a new synthetized biliary acid patented in Europe, Japan and the United States for prevention and therapy of gallstones and related symptoms, was assayed by performing segment I (fertility and general reproductive performance) and segment II (teratology) studies. In the first study THDCA was administered (100, 220 or 500 mg/kg by oral route) to male and female rats prior to and in the early stage of pregnancy. No adverse effects or dose-related abnormalities were observed in the reproductive performance of either sex; no death or evidence of teratogenicity in fetuses were also observed. In the second study THDCA was administered (100, 220 or 500 mg/kg by oral route) to rats and rabbits during the fetal organogenesis period. No maternal toxicity, teratogenicity or adverse effects on growth of embryos and fetuses and no reduction of the viability index were observed. From these studies the no-effect dose can be estimated at 500 mg/kg

In vitro and in vivo mutagenicity studies on taurohyodeoxycolic acid.

The mutagenicity of a new biliary acid, taurohyodeoxycholic acid (THDCA, Io, Praxis, CAS 2958-04-5), was assayed by using 5 different tests. The Ames test (reverse mutation assay on Salmonella typhimurium) and the DNA damage and repair test (in Saccharomyces cerevisiae) allowed to study the genetic THDCA-induced mutations in prokaryotes and eukaryotes (doses of 100, 200 and 400 micrograms/plate or 100, 200 and 400 micrograms/ml, respectively). In vivo and in vitro chromosomal aberrations were studied by using micronucleus test in mice (doses of 100, 220 and 500 mg/kg in oral study and 50, 100 and 200 mg/kg in subcutaneous study) and human lymphocytes cytogenetic test (doses of 50, 100, 220 and 500 micrograms/ml of THDCA). At last the host-mediated assay was performed on THDCA-treated mice (following oral or subcutaneous administration) in order to test the potential mutagenic activity of its metabolites on a S. typhimurium strain. The results obtained in these studies showed that THDCA did not induce any signs of promutagenic, mutagenic or clastogenic direct or metabolite-mediated activity