RESUMO
We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed, and an upper limit of is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.
RESUMO
We present results for nu(mu) oscillation in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment. K2K uses an accelerator-produced nu(mu) beam with a mean energy of 1.3 GeV directed at the Super-Kamiokande detector. We observed the energy-dependent disappearance of nu(mu), which we presume have oscillated to nu(tau). The probability that we would observe these results if there is no neutrino oscillation is 0.0050% (4.0 sigma).
RESUMO
OBJECTIVE: primary gastric B-cell lymphoma of the mucosa-associated lymphoid tissue type has been linked to infection of the gastric mucosa with Helicobacter pylori. The eradication of this pathogen with antibiotics can lead to regression of this type of lymphoma. The objective of this study was to describe the clinical, endoscopic and histologic evolution in 6 patients with primary gastric B-cell lymphoma of the mucosa-associated lymphoid tissue type treated with eradication of H. pylori. METHOD: descriptive study of a retrospective case series. Patients with low-grade gastric mucosa-associated lymphoid tissue type lymphoma were initially treated with eradication therapy for H. pylori. We evaluated their clinical, endoscopic and histologic course in sequential follow-up visits after initial therapy. RESULTS: six patients who satisfied all selection criteria were studied. In five of six patients H. pylori was eradicated and the lymphoma showed regression within 6 to 24 months. In one patient transition of low-grade to high-grade gastric lymphoma occurred. CONCLUSIONS: these results, along with similar findings from other studies, suggest eradication of H. pylori should be the initial treatment of choice for low-grade B-cell gastric mucosa-associated lymphoid tissue type lymphoma in the early stages. The most appropriate duration of follow-up is unknown, but prolonged follow-up is indicated to detect recurrences.