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A new strategy to enhance the photocatalytic properties of graphitic carbon nitride is reported via constructing an effective NiO decorated Ti/TiO2NT/TiO2/g-C3N4 S-scheme heterostructure photocatalyst thin film (Ti/TiO2NT/TiO2/g-C3N4/NiO). This thin film photocatalyst can separate hydrogen gas and oxygen gas into different sides of the Ti substrate. Owing to the synergistic effect of the NiO as co-catalyst and the formation of Step-scheme (S-scheme) heterojunction between g-C3N4 and TiO2, the electrons and holes were successfully separated to their opposing active centers, which is beneficial to inhibiting the recombination of the charge carriers. The gas evolution rate of Ti/TiO2NT/TiO2/g-C3N4/NiO is 7.97 μmol h−1 cm−2 under the irradiation of high-pressure mercury lamp, which was 3 and 1.3 times as high as that of the Ti/TiO2NT/g-C3N4 and Ti/TiO2NT/TiO2/g-C3N4, respectively. Firstly, benefiting from the well-matched band structure, a direct S-scheme Ti/TiO2NT/g-C3N4 heterojunction thin film is constructed easily driven by the built-in electric field across the Ti/TiO2NT/g-C3N4 interface. Furthermore, the introduction of the TiO2 layer on the TiO2NT will broaden light absorption range and increase the heterojunction area, which in turn conduces to effective charge separation. In addition, NiO as a co-catalyst cannot only accelerate the charge separation but also provide plentiful catalytic sites and decompose H2O2 produced by g-C3N4. The thin film photocatalysts can be recycled again, which is different from traditional powdered photocatalysts. This work constructs a NiO decorated Ti/TiO2NT/TiO2/g-C3N4 S-scheme heterostructure photocatalyst thin film, and provides a new insight to promote photocatalytic activity of g-C3N4 under the synergetic impact of S-scheme heterostructure and NiO co-catalyst. A novel NiO decorated Ti/TiO2NT/TiO2/g-C3N4 S-scheme heterostructure photocatalyst thin film was fabricated to enhance photocatalytic activity for water splitting. [ABSTRACT FROM AUTHOR]

This paper aims to study the stability region of hydropower plants (HPPs) at high‐voltage direct current (HVDC) sending terminal, to theoretically predict the frequency stability of isolated HPPs under small disturbances. The overall transfer function of the system is derived, and the Hurwitz stability criterion is applied to deduce the stability region. The theoretical analysis of the stability region and time‐domain simulation results of the system show good consistency, and this proves the accuracy of the model. The focus of this paper is mainly on the influence of the hydraulic‐mechanical aspects. Improperly tuned governor parameters and unfavourable design of the surge tank could lead to the frequency instability of HPPs, which appears as divergent oscillations of the frequency of units. A key suggestion of this paper is that the control strategy should consider the factors from not only the electrical side but also hydraulic‐mechanical aspects, for enhancing the stability of the HVDC sending terminal. Besides, the influence mechanism and parameter tuning of frequency limitation controller (FLC) are investigated and the results demonstrate its capability of quick compensation for power disturbances at the HVDC receiving terminal. [ABSTRACT FROM AUTHOR]

Abstract Background The prognosis of most hepatocellular carcinoma (HCC) patients is poor due to the high metastatic rate of the disease. Understanding the molecular mechanisms underlying HCC metastasis is extremely urgent. The role of CD24 and NDRG2 (N-myc downstream-regulated gene 2), a candidate tumor suppressor gene, has not yet been explored in HCC. Methods The mRNA and protein expression of CD24 and NDRG2 was analyzed in MHCC97H, Huh7 and L-02 cells. Changes in cell adhesion, migration and invasion were detected by up- or down-regulating NDRG2 by adenovirus or siRNA. The expression pattern of NDRG2 and CD24 in HCC tissues and the relationship between NDRG2 and HCC clinical features was analyzed by immunohistochemical and western blotting analysis. Results NDRG2 expression was negatively correlated with malignancy in HCC. NDRG2 exerted anti-tumor activity by regulating CD24, a molecule that mediates cell-cell interaction, tumor proliferation and adhesion. NDRG2 up-regulation decreased CD24 expression and cell adhesion, migration and invasion. By contrast, NDRG2 down-regulation enhanced CD24 expression and cell adhesion, migration and invasion. Immunohistochemical analysis of 50 human HCC clinical specimens showed a strong correlation between NDRG2 down-regulation and CD24 overexpression (P = 0.04). In addition, increased frequency of NDRG2 down-regulation was observed in patients with elevated AFP serum level (P = 0.006), late TNM stage (P = 0.009), poor differentiation grade (P = 0.002), tumor invasion (P = 0.004) and recurrence (P = 0.024). Conclusions Our findings indicate that NDRG2 and CD24 regulate HCC adhesion, migration and invasion. The expression level of NDRG2 is closely related to the clinical features of HCC. Thus, NDRG2 plays an important physiological role in HCC metastasis.

Background: Hypertension has been declared as a global public health crisis by the World Health Organization, because of its high prevalence. It affects the health of one billion people worldwide and is directly responsible for the deaths of more than 10 million people per year. The purpose of our research was to explore the influence of occupational stress and psychological health on hypertension of miners who work in a noisy environment and provide decision reference for relevant departments to keep miners' health.Methods: A case-control study was carried out in this research. The study subjects were divided into case groups and control groups based on whether they had hypertension or not. Effort-Reward Imbalance questionnaire and Self-Reporting Inventory questionnaire were used to investigate the psychological health status and occupational stress of the target population. General information was balanced between case and control groups through propensity score matching method. After propensity score matching, a multifactorial analysis was used to explore the impact of occupational stress and psychological health on hypertension.Results: According to the result of the multivariate analysis, psychological health was hazard to hypertension (t = 5.080, P<0.001) and occupational stress was not a direct risk factor for hypertension (t = 1.760, P = 0.080). The model was statistically significant (χ2 = 20.4, P<0.01).Conclusions: For miners working in the noisy environment, psychological status was a direct risk factor to hypertension, while occupational stress was an indirect factor. [ABSTRACT FROM AUTHOR]

• A delay of 3 months was found for the effect of air pollutants (PM 2.5 , SO 2 , NO 2 , and CO) to tuberculosis incidence. However, the effect of PM 10 to tuberculosis incidence was delayed by 9 months. • A single pollutant model showed that all air pollutants (PM 2.5 , PM 10 , SO 2 , NO 2 , CO, and O 3) in this study would have an increased risk of tuberculosis. It found that if concentrations of PM 2.5 , PM 10 , SO 2 , NO 2 , CO, and O 3 increased by 1 μg/m3 (or 1 mg/m3), the number of tuberculosis cases would increase by 0.09%, 0.08%, 0.58%, 0.42%, 6.9%, and 0.57%, respectively. • The results of this optimal multi-pollutant model showed that the optimal model was a two-factor model (PM 10 + NO 2) and factors in the model have an increased risk of tuberculosis. This study aimed to explore the impact of atmospheric pollutants on the incidence of tuberculosis (TB), and provide new ideas for the prevention and control of TB in the future. It explored the relationship between air pollutants and meteorological factors, as well as between air pollutants and heating through Spearman correlation analysis and rank sum test. Additionally, it analyzed the relationship between air pollutants and TB incidence using the general additive model. Statistical analysis results at the p < 0.05 level were considered significant. Three months after exposure to air pollutants (PM 2.5 , SO 2 , NO 2 , and CO) TB incidence increased. However, TB incidence increased 9 months after exposure to PM 10. The single pollutant model showed when concentrations of PM 2.5 , PM 10 , SO 2 , NO 2 , CO, and O 3 increased by 1 μg/m3 (or 1 mg/m3), the number of TB cases increased by 0.09%, 0.08%, 0.58%, 0.42%, 6.9%, and 0.57%, respectively. The optimal multi-pollutant model was a two-factor model (PM 10 + NO 2). Air pollutants including PM 2.5 , PM 10 , SO 2 , NO 2 , CO, and O 3 increased the risk of TB. Few studies have been conducted in this area of research, especially regarding the mechanism. The results of this study should contribute to the understanding of TB incidence and prompt additional research. [ABSTRACT FROM AUTHOR]