RESUMEN
The differential cross sections of the Σ^{-}pâΛn reaction were measured accurately for the Σ^{-} momentum (p_{Σ}) ranging from 470 to 650 MeV/c at the J-PARC Hadron Experimental Facility. Precise angular information about the Σ^{-}pâΛn reaction was obtained for the first time by detecting approximately 100 reaction events at each angular step of Δcosθ=0.1. The obtained differential cross sections show a slightly forward-peaking structure in the measured momentum regions. The cross sections integrated for -0.7≤cosθ≤1.0 were obtained as 22.5±0.68 [statistical error(stat.)] ±0.65 [systematic error(syst.)] mb and 15.8±0.83(stat)±0.52(syst) mb for 470
RESUMEN
The cross sections of the ^{7}Be(n,α)^{4}He reaction for p-wave neutrons were experimentally determined at E_{c.m.}=0.20-0.81 MeV slightly above the big bang nucleosynthesis (BBN) energy window for the first time on the basis of the detailed balance principle by measuring the time-reverse reaction. The obtained cross sections are much larger than the cross sections for s-wave neutrons inferred from the recent measurement at the n_TOF facility in CERN, but significantly smaller than the theoretical estimation widely used in the BBN calculations. The present results suggest the ^{7}Be(n,α)^{4}He reaction rate is not large enough to solve the cosmological lithium problem, and this conclusion agrees with the recent result from the direct measurement of the s-wave cross sections using a low-energy neutron beam and the evaluated nuclear data library ENDF/B-VII.1.
RESUMEN
OBJECTIVE: To determine how the mortality of patients with rheumatoid arthritis (RA) behave in comparison with that of patients with malignant rheumatoid arthritis (MRA). METHODS: The mortality of RA patients selected at randam identified in 1991-2000 (n = 104) was compared with that of 18 MRA patients. Hazard ratios of death were calculated with a multivariate survival analysis. A clinical study of patients with both RA and MRA was performed in mortality. RESULTS: Excess mortality was seen in MRA patients in Kaplan-Meier survival curves (p = 0.02 by log-rank test). MRA patients were treated more often with cytostatic and immunosuppressive drugs. Infection was the main cause of death in both RA and MRA patients. Vasculitis was not reported as the cause of death in MRA patients. Secondary amyloidosis played an important role in RA death rather than MRA. CONCLUSION: There remained an excess mortality in MRA patients compared with RA, and infection was attributable to the key cause of death in both RA and MRA suggesting therapeutic side effects.
