Strict Limit on CPT Violation from Polarization of Gamma-Ray Bursts

We report the strictest observational verification of CPT invariance in the photon sector, as a result of gamma-ray polarization measurement of distant gamma-ray bursts (GRBs), which are brightest stellar-size explosions in the universe. We detected the gamma-ray polarization of three GRBs with high significance, and the source distances may be constrained by a well-known luminosity indicator for GRBs. For the Lorentz- and CPT-violating dispersion relation E_{\pm}^2=p^2 \pm 2\xi p^3/M_{Pl}, where \pm denotes different circular polarization states of the photon, the parameter \xi is constrained as |\xi|<O(10^{-15}). Barring precise cancellation between quantum gravity effects and dark energy effects, the stringent limit on the CPT-violating effect leads to the expectation that quantum gravity presumably respects the CPT invariance.Comment: 4 pages; accepted for publication in Physical Review Letters; redshift estimates of GRBs changed (i.e z=0.382 was wrong for GRB 110721A) and calculations of \xi limit improved from the previous versio

Prediction for the Development of Postoperative Infections in the Operation of Esophageal Cancer Compared with Gastric Surgery

The purpose of this study was to assess the point at which the postoperative infection has occurred in order to decide upon the proper duration of prophylactic antibiotic use. Another goal of this study was to determine whether prediction for the development of postoperative infections in major surgery such as esophagectomy should be the same as that in routine gastroenterological surgery. Twenty-five patients who underwent transthoracic esophagectomy and 127 patients who underwent gastrectomy were studied.　　 On the third day after gastric surgery, the body temperature of patients who developed an infection was higher than that of the patients who did not develop an infection. The relative changes in peripheral white blood count (WBC), and C-reactive protein (CRP) concentration on the third and fourth days were more predictive of the development of infection than the absolute values. Almost all patients with systemic inflammatory response syndrome (SIRS) on the third day after gastric surgery developed an infection. On the other hand, the incidence of SIRS in patients who did not develop an infection was high on both the third and fourth days after esophageal surgery. It was nearly impossible to predict who would develop an infection in esophageal surgery. The high incidence of postoperative infections, and their significant consequences justify planned successive postoperative antibiotic use in esophageal surgery