Influence Function-Based Empirical Likelihood And Generalized Confidence Intervals For Lorenz Curve

This thesis aims to solve confidence interval estimation problems for Lorenz curve. First, we propose new nonparametric confidence intervals with influence function-based empirical likelihood method. It is shown that the limiting distributions of log-empirical likelihood ratios are standard Chi-square distributions. Then the ``exact\u27\u27 parametric intervals based on generalized pivotal quantities for Lorenz ordinates are also developed. Extensive simulation studies are conducted to evaluate the finite sample performance of the proposed methods. Finally, our methods are applied on real income data sets

Health care costs of cardiovascular disease in China: a machine learning-based cross-sectional study

BackgroundCardiovascular disease (CVD) causes substantial financial burden to patients with the condition, their households, and the healthcare system in China. Health care costs for treating patients with CVD vary significantly, but little is known about the factors associated with the cost variation. This study aims to identify and rank key determinants of health care costs in patients with CVD in China and to assess their effects on health care costs.MethodsData were from a survey of patients with CVD from 14 large tertiary grade-A general hospitals in S City, China, between 2018 and 2020. The survey included information on demographic characteristics, health conditions and comorbidities, medical service utilization, and health care costs. We used re-centered influence function regression to examine health care cost concentration, decomposing and estimating the effects of relevant factors on the distribution of costs. We also applied quantile regression forests—a machine learning approach—to identify the key factors for predicting the 10th (low), 50th (median), and 90th (high) quantiles of health care costs associated with CVD treatment.ResultsOur sample included 28,213 patients with CVD. The 10th, 50th and 90th quantiles of health care cost for patients with CVD were 6,103 CNY, 18,105 CNY, and 98,637 CNY, respectively. Patients with high health care costs were more likely to be older, male, and have a longer length of hospital stay, more comorbidities, more complex medical procedures, and emergency admissions. Higher health care costs were also associated with specific CVD types such as cardiomyopathy, heart failure, and stroke.ConclusionMachine learning methods are useful tools to identify determinants of health care costs for patients with CVD in China. Findings may help improve policymaking to alleviate the financial burden of CVD, particularly among patients with high health care costs

Abnormal Alterations of Regional Spontaneous Neuronal Activity in Inferior Frontal Orbital Gyrus and Corresponding Brain Circuit Alterations: A Resting-State fMRI Study in Somatic Depression

Background: Major depressive disorders often involve somatic symptoms and have been found to have fundamental differences from non-somatic depression (NSD). However, the neural basis of this type of somatic depression (SD) is unclear. The aim of this study is to use the amplitude of low-frequency fluctuation (ALFF) and functional connectivity (FC) analyses to examine the abnormal, regional, spontaneous, neuronal activity and the corresponding brain circuits in SD patients.Methods: 35 SD patients, 25 NSD patients, and 27 matched healthy controls were selected to complete this study. The ALFF and seed-based FC analyses were employed, and the Pearson correlation was determined to observe possible clinical relevance.Results: Compared with NSD, the SD group showed a significant ALFF increase in the right inferior temporal gyrus; a significant ALFF decrease in left hippocampus, right inferior frontal orbital gyrus and left thalamus; and a significant decrease in the FC value between the right inferior frontal orbital gyrus and the left inferior parietal cortex (p < 0.05, corrected). Within the SD group, the mean ALFF value of the right inferior frontal orbital gyrus was associated with the anxiety factor scores (r = –0.431, p = 0.010, corrected).Conclusions: Our findings suggest that abnormal differences in the regional spontaneous neuronal activity of the right inferior frontal orbital gyrus were associated with dysfunction patterns of the corresponding brain circuits during rest in SD patients, including the limbic-cortical systems and the default mode network. This may be an important aspect of the underlying mechanisms for pathogenesis of SD at the neural level

Proportional Hazards Model for Right Censored Survival Data with Longitudinal Covariates

The proportional hazards model is one of the most widely used tools in analyzing survival data. In medical and epidemiological studies, the interrelationship between time-to-event variable and longitudinal covariates is often the primary research interest. Thus, joint modeling of survival data and longitudinal data has received very much attention in statistical literature, but it's a considerably difficult problem due to censoring on the survival time and that the longitudinal covariate process is in fact a completely unknown and not completely observed stochastic process. Up to now, all existing works made parametric or semi-parametric assumptions on the longitudinal covariate process, and resulting inferences critically depends on validity of these not justifiable assumptions. This dissertation does not make any parametric or semi-parametric assumptions on the longitudinal covariate process. We use the empirical likelihood method to derive the maximum likelihood estimator (MLE) for the proportional hazards model based on right censored survival data with longitudinal covariates. Computation algorithm is developed here and our simulation studies show that our MLE performs very well

Supplementary document for Characterizing chiroptical properties of 2D/3D structures based on an improved coupled dipole theory - 6817933.pdf

Characterizing chiroptical properties of 2D/3D structures based on an improved coupled dipole theor

Silkworm Pupa Protein Hydrolysate Induces Mitochondria-Dependent Apoptosis and S Phase Cell Cycle Arrest in Human Gastric Cancer SGC-7901 Cells

Silkworm pupae (Bombyx mori) are a high-protein nutrition source consumed in China since more than 2 thousand years ago. Recent studies revealed that silkworm pupae have therapeutic benefits to treat many diseases. However, the ability of the compounds of silkworm pupae to inhibit tumourigenesis remains to be elucidated. Here, we separated the protein of silkworm pupae and performed alcalase hydrolysis. Silkworm pupa protein hydrolysate (SPPH) can specifically inhibit the proliferation and provoke abnormal morphologic features of human gastric cancer cells SGC-7901 in a dose- and time-dependent manner. Moreover, flow cytometry indicated that SPPH can induce apoptosis and arrest the cell-cycle in S phase. Furthermore, SPPH was shown to provoke accumulation of reactive oxygen species (ROS) and depolarization of mitochondrial membrane potential. Western blotting analysis indicated that SPPH inhibited Bcl-2 expression and promoted Bax expression, and subsequently induced apoptosis-inducing factor and cytochrome C release, which led to the activation of initiator caspase-9 and executioner caspase-3, cleavage of poly (ADP-ribose) polymerase (PARP), eventually caused cell apoptosis. Moreover, SPPH-induced S-phase arrest was mediated by up-regulating the expression of E2F1 and down-regulating those of cyclin E, CDK2 and cyclin A2. Transcriptome sequencing and gene set enrichment analysis (GSEA) also revealed that SPPH treatment could affect gene expression and pathway regulation related to tumourigenesis, apoptosis and cell cycle. In summary, our results suggest that SPPH could specifically suppress cell growth of SGC-7901 through an intrinsic apoptotic pathway, ROS accumulation and cell cycle arrest, and silkworm pupae have a potential to become a source of anticancer agents in the future

Additional file 1 of Measuring and improving performance of clinicians: an application of patient-based records

Additional file 1: Table A1. Definitions of clinician level variables. Table A2. Part of fact table of procedure level. Table A3. Fact table of proceduregrading. Table A4. Fact table of procedure role. Figure A1. Dendrogram ofClustering. Figure A2. Distribution of continuous demographic characteristic by clusters (n=244). Fig. A3. Distribution of classified demographic characteristic by clusters (n=244). Fig. A4. Distribution of SPS by clusters (n =244)

Rating hospital performance in China:review of publicly available measures and development of a ranking system

BACKGROUND: In China, significant emphasis and investment in health care reform since 2009 has brought with it increasing scrutiny of its public hospitals. Calls for greater accountability in the quality of hospital care have led to increasing attention toward performance measurement and the development of hospital ratings. Despite such interest, there has yet to be a comprehensive analysis of what performance information is publicly available to understand the performance of hospitals in China. OBJECTIVE: This study aims to review the publicly available performance information about hospitals in China to assess options for ranking hospital performance. METHODS: A review was undertaken to identify performance measures based on publicly available data. Following several rounds of expert consultation regarding the utility of these measures, we clustered the available options into three key areas: research and development, academic reputation, and quality and safety. Following the identification and clustering of the available performance measures, we set out to translate these into a practical performance ranking system to assess variation in hospital performance. RESULTS: A new hospital ranking system termed the China Hospital Development Index (CHDI) is thus presented. Furthermore, we used CHDI for ranking well-known tertiary hospitals in China. CONCLUSIONS: Despite notable limitations, our assessment of available measures and the development of a new ranking system break new ground in understanding hospital performance in China. In doing so, CHDI has the potential to contribute to wider discussions and debates about assessing hospital performance across global health care systems