ABSTRACT
We report measurements of the pi;{-}p-->pi;{0}n differential cross sections at six momenta (104-143 MeV/c) and four angles (0 degrees -40 degrees ) by detection of gamma-ray pairs from pi;{0}-->gammagamma decays using a photon-pair spectrometer at TRIUMF. This kinematic region exhibits a vanishing zero-degree cross section from destructive interference between s and p waves, thus yielding special sensitivity to pion-nucleon dynamics. Our data and previous data do not agree, with important implications for earlier claims of large isospin-violating effects.
ABSTRACT
New data are presented on the p(e,e'p)pi(0) reaction at threshold at a four-momentum transfer of Q(2) = 0.05 GeV(2)/c(2). The data were taken with the three-spectrometer setup of the A1 Collaboration at the Mainz Microtron MAMI. The complete center of mass solid angle was covered up to a center of mass energy of 4 MeV above threshold. Combined with measurements at three different values of the virtual photon polarization epsilon, the structure functions sigma(T), sigma(L), sigma(TT), and sigma(TL) are determined. The results are compared with calculations in heavy baryon chiral perturbation theory and with a phenomenological model. The measured cross section is significantly smaller than both predictions.
ABSTRACT
Cefoxitin has been the prophylactic antibiotic of choice for appendectomy and colorectal surgery at this institution. Recent information suggests that cefazolin and metronidazole given as a single intravenous preparation could be a cost-effective alternative to cefoxitin or cefotetan for surgical antimicrobial prophylaxis of uncomplicated appendectomies. This study was conducted to determine the efficacy, toxicity, and cost of the current antibiotic regimens used for prophylaxis of uncomplicated appendectomies, to evaluate the efficacy, toxicity and cost of the cefazolin plus metronidazole combination in uncomplicated appendectomies, and to facilitate a cooperative working relationship between the Departments of Pharmacy and General Surgery. Although the numbers involved were small, this study suggests that the cefazolin/metronidazole combination is cost-effective. It is suggested that research is warranted in evaluating combinations such as this as cost-effective alternatives to current therapy.
