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As an important indicator for measuring the quality of business environment of different countries, ease of doing business (EDB) issued by the World Bank (WB) provides an important reference for investors in making decisions on transnational investment. The calculation method for EDB issued by the WB is improved using a technique for order preference by similarity to an ideal solution (TOPSIS) method based on Mahalanobis distance. Based on various indicator data in 2019, business environments in 121 countries participating in "the Belt and Road Initiative (BRI)" were empirically analysed and compared through such models. The result showed that TOPSIS method based on Mahalanobis distance can more fully utilise information and take the effect of negative ideal points into account. Therefore, compared with ranking method by the WB, TOPSIS method based on Mahalanobis distance is more applicable for ranking BRI countries. The ranking results indicated significant geographical characteristics. The EDB rankings obtained through the WB overestimate the business environments of countries in Central and Eastern Europe while underestimate those in Southeast Asia, Africa, etc. [ABSTRACT FROM AUTHOR]

Grey resource model is the core model in the grey ecological resource exploitation theory for describing and forecasting development stages of resource efficiency. In order to define the application range of grey resource model, this study deduces the ranges of secondary parameter packages based on the coverage operations of grey numbers, and then deduces that of the development coefficient. Finally the admissible region of non-homogeneous class ratio for grey resource model is obtained in the form of both mathematical formula and numerical simulation of China's wind power industry and science & technology industry. [ABSTRACT FROM AUTHOR]

The grey prediction model with convolution integral GMC (1, n) is a multiple grey model with exact solutions. To further improve prediction accuracy and describe better the relationship between cause and effect, we introduce nonlinear parameters into GMC (1, n) model and additionally apply a convolution integral to produce an improved forecasting model here designated as NGMC (1, n). The model solving process applied the least-squares method to evaluate the structure parameters of the model: convolution was used to obtain an exact solution with this improved greymodel. The nonlinear optimisation took the parameters as the decision variables with the objective of minimising forecasting errors. TheGMC (1, 2) and NGMC (1, 2) models were used to predict China's industrial SO2 emissions from the basis of the economic output level as the influencing factor. Results indicated that NGMC (1, 2) can effectively describe the nonlinear relationship between China's economic output and SO2 emissions with an improved accuracy over current GMC (1, 2) models. [ABSTRACT FROM AUTHOR]

The grey dynamic model by convolution integral with the first-order derivative of the 1-AGO data and n series related, abbreviated as GDMC(1, n), performs well in modelling and forecasting of a grey system. To improve the modelling accuracy of GDMC(1, n), n interpolation coefficients (taken as unknown parameters) are introduced into the background values of the n variables. The parameters optimization is formulated as a combinatorial optimization problem and is solved collectively using the particle swarm optimization algorithm. The optimized result has been verified by a case study of the economic output of high-tech industry in China. Comparisons of the obtained modelling results from the optimized GDMC(1, n)model with the traditional one demonstrate that the optimal algorithm is a good alternative for parameters optimization of the GDMC(1, n) model. The modelling results can assist the government in developing future policies regarding high-tech industry management. [ABSTRACT FROM AUTHOR]

Objective: The expression of B-cell lymphoma 2 (Bcl-2) seems to be influenced by the endocrine environment. Numerous reports demonstrate the diverse expression of Bcl-2 family members under sex steroid regulation. With the exception of estrogen-related tumors, androgen-related tumors have shown their characteristics in Bcl-2 expression. In this study, the status of Bcl-2 expression in male hepatocellular carcinoma (HCC) patients was examined to verify the high incidence of HCC in males. Methods: Tumor tissue microarray was used to examine Bcl-2 expression levels in 374 HCC cases including 306 males and 68 females. Kaplan-Meier method, log-rank test, and Cox proportional hazards model were applied to investigate the predictive value of Bcl-2 in HCC patients. Results: Immunohistochemistry analysis showed that male patients with higher Bcl-2 levels had significantly longer median survival time and recurrence time than those with lower levels. However, no significant differences in outcomes were found between different Bcl-2 levels in female patients. When the male patients were stratified into several age points, the level of Bcl-2 expression showed poorer predictive efficiency in the 45-49 and 55-60 age groups in andropause-age patients compared with other age groups. Bcl-2 was an independent prognostic factor for both overall survival (P < 0.0001) and recurrence time (P = 0.0001) in male patients. After excluding male patients in the 45-60 age group, the predictive efficiency was enhanced (n = 147, OS, P = 0.0002, TTR, P < 0.0001). Conclusions: Bcl-2 expression is an independent predictor of survival and recurrence in male HCC. Bcl-2 levels may also be regulated by androgens or androgen receptors in male HCC patients. Bcl-2 levels change and exhibit poor predictive efficiency when androgen levels vary dramatically (andropause age). [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate the utility of a preoperative model of end-stage liver disease (MELD) score and Child-Turcotte-Pugh (CTP) score in predicting the prognosis after othotopic liver transplantation (OLT) for chronic severe hepatitis B (CSHB) and explore the prognostic factors. The outcome of 137 patients who underwent OLT using donors after cardiac death (DCDs) for CSHB in our center was reviewed retrospectively. Survival analysis was performed using the Kaplan-Meier method; the log-rank test was used for univariate analysis; and the Cox proportional hazards regression model was used for prognostic factors screening. The overall mortality rate was 33.6% (46/137); and 1-month, 6-month, 1-year, and 5-year patient survival rates were 75.8, 72.0, 71.0, and 60.1%, respectively. Most patients (33/46) died during the first month after OLT. The area under the curve values generated by the receiver operating characteristics curves were 0.82 [95% confidence interval (CI) 0.72–0.92] and 0.68 (95% CI 0.58–0.79), respectively ( P < 0.01), for the MELD and CTP models in predicting 1-month mortality after OLT. Patients with a preoperative MELD score <33.8 or a CTP score <12.5 had significantly better prognosis than those with higher scores ( P < 0.05). Other mortality predictors include hepatic encephalopathy, preoperative infection, serum creatinine ≥1.5 mg/dl. The MELD score was more efficient than the CTP score for evaluating the short-term prognosis in patients with CSHB undergoing OLT using DCDs, which should be taken into consideration during graft allocation. [ABSTRACT FROM AUTHOR]