RESUMO
We describe an apparatus used to measure the electron-antineutrino angular correlation coefficient in free neutron decay. The apparatus employs a novel measurement technique in which the angular correlation is converted into a proton time-of-flight asymmetry that is counted directly, avoiding the need for proton spectroscopy. Details of the method, apparatus, detectors, data acquisition, and data reduction scheme are presented, along with a discussion of the important systematic effects.
RESUMO
We report the first result for the electron-antineutrino angular correlation (a coefficient) in free neutron ß decay from the aCORN experiment. aCORN uses a novel method in which the a coefficient is proportional to an asymmetry in proton time of flight for events where the ß electron and recoil proton are detected in delayed coincidence. Data are presented from a 15 month run at the NIST Center for Neutron Research. We obtained a=-0.1090±0.0030(stat)±0.0028(sys), the most precise measurement of the neutron a coefficient reported to date.
RESUMO
Carmustine is a chemotherapeutic agent frequently employed in the treatment of malignant brain tumors. The side effect of pulmonary fibrosis occurs in 20 to 30 percent of patients receiving this drug. Herein we report a case of presumed carmustine-induced pulmonary fibrosis occurring with an unusual lobar distribution.
Assuntos
Carmustina/efeitos adversos , Fibrose Pulmonar/induzido quimicamente , Adulto , Neoplasias Encefálicas/tratamento farmacológico , Feminino , Glioma/tratamento farmacológico , Humanos , Fibrose Pulmonar/fisiopatologia , Capacidade Vital/fisiologiaRESUMO
The effect of 0.25 mg of terbutaline sulfate, a beta 2-adrenergic agent, on the right and left ventricular ejection fractions (RVEF and LVEF, respectively) was studied in 30 patients with severe stable chronic obstructive pulmonary disease (COPD) with a mean forced expiratory volume in 1 s of 0.79 +/- 0.06 L. All bronchodilator therapy was withdrawn 48 hours before the study. The ECG-synchronized gated equilibrium radionuclide ventriculography showed decreased RVEF in 27 patients and LVEF in 16 patients. Both the RVEF and LVEF significantly increased after the terbutaline injection; this increase was noted both in patients with normal and decreased ejection fractions. We conclude that the increase in ejection fractions after terbutaline injection may contribute to the good clinical response to this drug seen in patients with severe stable COPD even though the bronchodilator effect may be minimal.
