A technique is proposed for measuring the linear birefringence and linear diattenuation of an optical sample using a polarimeter. In the proposed approach, the principal axis angle (alpha), phase retardance (beta), diattenuation axis angle (thetad), and diattenuation (D) are derived using an analytical model based on the Mueller matrix formulation and the Stokes parameters. The dynamic measurement ranges of the four parameters are shown to be alpha = 0 approximately 180 degrees, beta = 0 approximately 180 degrees, theta(d) = 0 approximately 180 degrees, and D = 0 approximately 1, respectively. Thus, full-range measurements are possible for all parameters other than beta. In this study, the proposed methodology does not require the principal birefringence axes and diattenuation axes to be aligned. In addition, the linear birefringence and linear diattenuation properties are decoupled within the analytical model, and thus the birefringence properties of the sample can be solved directly without any prior knowledge of the diattenuation parameters. Also, the characteristic parameters in the baked polarizer with linear birefringence are successfully extracted from an optically equivalent model and proved by the respective simulation and experiment introduced in this study.

AIMTo evaluate the association between mortality-to-incidence ratios (MIRs) and health disparities.METHODSIn this study, we used the GLOBOCAN 2012 database to obtain the cancer incidence and mortality data for 57 countries, and combined this information with the World Health Organization (WHO) rankings and total expenditures on health/gross domestic product (e/GDP). The associations between variables and MIRs were analyzed by linear regression analyses and the 57 countries were selected according to their data quality.RESULTSThe more developed regions showed high gastric cancer incidence and mortality crude rates, but lower MIR values than the less developed regions (0.64 vs 0.80, respectively). Among six continents, Oceania had the lowest (0.60) and Africa had the highest (0.91) MIR. A good WHO ranking and a high e/GDP were significantly associated with low MIRs (P = 0.001 and P = 0.001, respectively).CONCLUSIONThe MIR variation for gastric cancer would predict regional health disparities.

There are no clinical guidelines for the timing of cholecystectomy (CCY) after performing therapeutic endoscopic retrograde cholangiopancreatography (ERCP) for choledocholithiasis. We tried to analyze the clinical practice patterns, medical expenses, and subsequent outcomes between the early CCY, delayed CCY, and no CCY groups of patients. 1827 choledocholithiasis patients who underwent therapeutic ERCP were selected from the nationwide population databases of two million random samples. These patients were further divided into early CCY, delayed CCY, and no CCY performed. In our analysis, 1440 (78.8%) of the 1827 patients did not undergo CCY within 60 days of therapeutic ERCP, and only 239 (13.1%) patients underwent CCY during their index admission. The proportion of laparoscopic CCY increased from 37.2% to 73.6% in the delayed CCY group. There were no significant differences (p = 0.934) between recurrent biliary event (RBE) rates with or without early CCY within 60 days of ERCP. RBE event-free survival rates were significantly different in the early CCY (85.04%), delayed CCY (89.54%), and no CCY (64.45%) groups within 360 days of ERCP. The method of delayed CCY can reduce subsequent RBEs and increase the proportion of laparoscopic CCY with similar medical expenses to early CCY in Taiwan’s general practice environment.