Least Squares and Robust Rank-Based Double Bootstrap Analyses for Time-Series Intervention Designs.

Time-series intervention designs that include two or more phases have been widely discussed in the healthcare literature for many years. A convenient model for the analysis of these designs has a linear model part (to measure changes in level and trend) plus a second part that measures the random error structure; the error structure is assumed to follow an autoregressive time-series process. Traditional generalized linear model approaches widely used to estimate this model are less than satisfactory because they tend to provide substantially biased intervention tests and confidence intervals. We describe an updated version of the original double bootstrap approach that was developed by McKnight et al. (2000) to correct for this problem. This updated analysis and a new robust version were recently implemented in an R package (McKean & Zhang, 2018). The robust method is insensitive to outliers and problems associated with common departures from normality in the error distribution. Monte Carlo studies as well as published data are used to demonstrate the properties of both versions. The R code required to perform the analyses is provided and illustrated.

[Analysis on the disease burden and its impact factors of coal worker's pneumoconiosis inpatients].

OBJECTIVE: To obtain the baseline data and decision of quantitative analysis for the allocation of scarce health care resources,and for the health policymaking about easing the disease burden, to provide estimation of the economic costs and the disability-adjusted life years (DALYs) loss of the coal worker's pneumoconiosis (CWP) and to explore the influencing factors of the disease burden. METHODS: The CWP inpatients from the Institute of Occupational Diseases Prevention and Control of a Coal Mining Group for 2011 were recruited in the study. Multiple dimensions of the disease burden were measured in the inception cohort of the 194 CWP inpatients: the direct economic burden, the indirect economic burden and the DALYs loss. The direct economic burden of the inpatients included hospitalization expenses and food allowances and nutritional supplements. The indirect economic burden was estimated using the DALYs and human capital approach,and the influencing factors of hospitalization expenses were analyzed in this study. RESULTS: The estimated direct economic burden for the 194 CWP inpatients for 2011 was approximately 4.68 million yuan and direct burden per capita was 24 108.05 yuan, and their indirect burden about 6.98 million yuan and indirect burden per capita 35 977.36 yuan. The study discovered that 1 681.53 health years were lost for the CWP inpaitents and per capita health years loss (8.67±3.65) years. CONCLUSION: The medical cost, the indirect cost and the DALYs loss of CWP are all sizable. Age and length of stay in the hospital are the major influencing factors for high hospitalization expenses. The hospitalization expenses of the CWP inpatients increase with their age and length of stay in the hospital. Taking effective measures to reduce the morbility is the key point to reduce the CWP burden.

Controllable synthesis of recyclable core-shell γ-Fe2O3@SnO2 hollow nanoparticles with enhanced photocatalytic and gas sensing properties.

Composite materials containing different components with well-defined structures may cooperatively enhance their performance and extend their applications. In this work, core-shell γ-Fe2O3@SnO2 hollow nanoparticles (NPs) were synthesized by a low-cost and environmentally friendly seed-mediated hydrothermal method. Firstly, the γ-Fe2O3 hollow NPs were synthesized by a template-free method. Then they were used as the cores for the growth of SnO2 shells. The thickness of the shell can be simply tailored by controlling the reaction time. Various techniques, including SEM, XRD, TEM and HRTEM, were employed to investigate the morphology, structure and formation process of the special core-shell hollow structures. The combination of magnetic semiconductor (γ-Fe2O3) and wide band-gap semiconductor (SnO2) endowed them with great potential to be used as recyclable photocatalysts. Experiments on photo-degradation of Rhodamin B (RhB) dye in the presence of the samples showed that the hybrid structures possessed higher photocatalytic activities than the monomer structures of SnO2 and γ-Fe2O3 materials indicating a strong coupling enhancement effect between the wide and narrow band-gap semiconductors. Moreover, the gas sensing tests of the γ-Fe2O3@SnO2 hollow NPs revealed that the samples exhibited fast response and recovery rates, which enable them to be promising materials for gas sensors.