Unveiling the visible-light-driven photodegradation pathway and products toxicity of tetracycline in the system of Pt/BiVO4 nanosheets.

The antibiotics pollution has currently captured increasing concerns due to its potential hazards to the environment and human health. The development of efficient and viable techniques for the removal of antibiotics is one of the research hotspots in fields of wastewater treatment and pharmaceutical industry. Although the photodegradation of antibiotics is widely studied, the evolution and toxicity of degradation intermediates have been rarely documented. Herein, Pt nanoparticles (NPs) decorated BiVO4 nanosheets (Pt/BiVO4 NSs) that exhibit excellent tetracycline (TC) photodegradation activity and stability have been prepared. Especially, the TC degradation efficiency reaches ca. 88.5% after 60 min under visible light irradiation, which is superior to most of the metal loaded two-dimensional photocatalysts reported hitherto. The excellent photocatalytic activity is attributable to the enhanced light absorption capacity and charge separation efficiency in Pt/BiVO4 NSs. h+, •O2- and •OH are the main active species for TC degradation, resulting in three possible degradation pathways. Furthermore, we first verify that TC solutions treated by Pt/BiVO4 NSs are harmless to Escherichia coli K-12 and various bacteria in natural rivers, which would not stimulate Escherichia coli to produce antibiotics resistance genes (ARGs). This work develops an environmentally friendly photodegradation strategy using Pt/BiVO4 NSs with potentials for efficient remediation of antibiotics pollution in wastewater.

Current trends and future prediction of novel coronavirus disease (COVID-19) epidemic in China: a dynamical modeling analysis.

The novel coronavirus disease 2019 (COVID-19) infection broke out in December 2019 in Wuhan, and rapidly overspread 31 provinces in mainland China on 31 January 2020. In the face of the increasing number of daily confirmed infected cases, it has become a common concern and worthy of pondering when the infection will appear the turning points, what is the final size and when the infection would be ultimately controlled. Based on the current control measures, we proposed a dynamical transmission model with contact trace and quarantine and predicted the peak time and final size for daily confirmed infected cases by employing Markov Chain Monte Carlo algorithm. We estimate the basic reproductive number of COVID-19 is 5.78 (95%CI: 5.71-5.89). Under the current intervention before 31 January, the number of daily confirmed infected cases is expected to peak on around 11 February 2020 with the size of 4066 (95%CI: 3898-4472). The infection of COVID-19 might be controlled approximately after 18 May 2020. Reducing contact and increasing trace about the risk population are likely to be the present effective measures.

The impact of air pollution on the transmission of pulmonary tuberculosis.

In this paper, we investigate the relationship between the air pollution and tuberculosis cases and its prediction in Jiangsu, China by using the time-series analysis method, and find that the seasonal ARIMA(1, 1, 0)×(0, 1, 1)12 model is the preferred model for predicting the TB cases in Jiangsu, China. Furthermore, we evaluate the relationship between AQI, PM2.5, PM10 and the number of TB cases, and find that the prediction accuracy of the ARIMA model is improved by adding monthly PM2.5 with 0-month lag as an external variable, i.e., ARIMA(1, 1, 0)×(0, 1, 1)12+PM2.5. The results show that ARIMAX model can be a useful tool for predicting TB cases in Jiangsu, China, and it can provide a scientific basis for the prevention and treatment of TB.

Dynamics and asymptotic profiles of steady states of an SIRS epidemic model in spatially heterogenous environment.

This paper performs qualitative analysis on a reaction-diffusion SIRS epidemic system with ratio-dependent incidence rate in spatially heterogeneous environment. The threshold dynamics in the term of the basic reproduction number R0 is established. And the asymptotic profile of endemic equilibrium is determined if the diffusion rate of the susceptible individuals is small. The results show that restricting the movement of susceptible individuals can effectively control the number of infectious individuals.

Bifurcation structure of nonconstant positive steady states for a diffusive predator-prey model.

In this paper, we make a detailed descriptions for the local and global bifurcation structure of nonconstant positive steady states of a modified Holling-Tanner predator-prey system under homogeneous Neumann boundary condition. We first give the stability of constant steady state solution to the model, and show that the system exhibits Turing instability. Second, we establish the local structure of the steady states bifurcating from double eigenvalues by the techniques of space decomposition and implicit function theorem. It is shown that under certain conditions, the local bifurcation can be extended to the global bifurcation.

Awareness and associated factors of tobacco hazards among middle school personnel in Shanghai / 中国学校卫生

Objective@#To understand current situation of the awareness of tobacco hazards among middle school personnel in Shanghai and to explore its influencing factors,and to provide reference for making targeted measures to control tobacco hazards in schools.@*Methods@#A total of 30 middle schools in Shanghai were selected by stratified cluster sampling method. The questionnaires were used to investigate the smoking prevalence and tobacco hazard awareness of 3 007 faculty members.@*Results@#The total smoking rate of school personnel in Shanghai was 8.25%; the complete correct rate on the harm of smoking and second-hand smoke was only 19.72% and 23.74%, respectively. The correct awareness rate of harm caused by tobacco, such as stroke, osteoporosis and heart disease, was less than 50%. Gender, education level, smoking behavior and tobacco control training were related with tobacco hazards perception level.@*Conclusion@#The smoking rate among middle school personnel in Shanghai has been generally improved, but the faculty and staff have an unbalanced understanding of tobacco hazards. The school's tobacco control education should be targeted. Smoking, men and personnel with relatively low education levels are the key groups in school tobacco control education.

[Effects of artificial vegetation on the spatial heterogeneity of soil moisture and salt in coastal saline land of Chongming Dongtan, Shanghai].

By the methods of classical statistics and geostatistics, this paper studied the spatial heterogeneity of surface soil (0-20 cm layer) moisture and salt contents under three kinds of artificial vegetation in coastal salt land in Chongming Dongtan of Shanghai. The soil moisture content in different plots was in order of Cynodon dactylon > Taxodium distichum > Nerium indicum, and the coefficient of variation was 13.9%, 13.4% and 12.9%, respectively. The soil electric conductivity was in the order of N. indicum > C. dactylon > T. distichum, and the coefficient of variation was 79.2%, 55.4% and 15. 9%, respectively. Both the soil moisture content and the salt content were in moderate variation. The theoretical models of variogram for the soil moisture and salt contents in different plots varied, among which, the soil electric conductivity fitted better, with R2 between 0.97 and 0.99. When the artificial vegetation varied from N. indicum to T. distichum and then to C. dactylon, the spatial heterogeneity of soil moisture content changed from weak to strong, in which, the variability was random under N. indicum. When the vegetation varied from C. dactylon to T. distichum and to N. indicum, the spatial heterogeneity of soil electric conductivity changed from moderate to strong. Under different vegetations, the soil electric conductivity was mostly in positive correlation, whereas the soil moisture content was in negative correlation. The spatial pattern of soil moisture and salt contents under T. distichum was in striped distribution, that under C. dactylon was in large plaque and continuous distribution, whereas under N. indicum, the spatial pattern of soil moisture content was in small breaking plaque distribution, and that of soil salt content was in striped distribution.