ABSTRACT
To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2 - 300 keV band and the Kashima NICT radio observatory in the 1.4 - 1.7 GHz band with a net exposure of about 2 ks on 25 March 2016, just before the loss of the Hitomi mission. The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1,000 and 100 GRPs were simultaneously observed at the main and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main or inter-pulse phases. All variations are within the 2 sigma fluctuations of the X-ray fluxes at the pulse peaks, and the 3 sigma upper limits of variations of main- or inter-pulse GRPs are 22% or 80% of the peak flux in a 0.20 phase width, respectively, in the 2 - 300 keV band. The values become 25% or 110% for main or inter-pulse GRPs, respectively, when the phase width is restricted into the 0.03 phase. Among the upper limits from the Hitomi satellite, those in the 4.5-10 keV and the 70-300 keV are obtained for the first time, and those in other bands are consistent with previous reports. Numerically, the upper limits of main- and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) ×10-11 erg cm-2, respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magnetosphere and the number of photon-emitting particles temporally increases. However, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a > 0.02% brightening of the pulse-peak flux under such conditions.
ABSTRACT
BACKGROUND: There have been few well-designed studies that assess the cost-effectiveness of near-patient immediate testing. METHODS: We analyzed the economic outcome of immediate testing for C-reactive protein (CRP) and white blood cell count (WBC) in 305 new outpatients with acute infections. Patients were randomized into two groups: 147 patients were tested immediately for CRP and WBC before the physician's initial consultation (advance testing), and 154 patients were not subjected to advance testing. The subsequent prescribing decision and the drug/testing/personnel costs were compared between the groups. RESULTS: In the advance-testing group, the initial consultation was followed by a total of 84 prescriptions of oral antibiotics, against 158 in the other group. Comparing the total costs of oral and parenteral antibiotics between the two groups, a 30% reduction was achieved with advance testing ( yen105,830 vs. yen151,102). However, the savings were largely offset by frequent prescription of newer, expensive influenza neuraminidase inhibitors. Advance testing also significantly reduced additional laboratory use. More frequent urgent testing increased personnel costs in the non-advance-testing group. Overall, total cost was somewhat higher in the advance-testing group ( yen1,028,827 vs. yen984,105). CONCLUSIONS: The cost per antibiotic prescription reduced with advance testing was yen604 (approximately 5.8 US dollars) in our clinical setting. Judicious use of antivirals and introduction of a simple CRP test kit would improve cost-effectiveness.
