[Health Assessment of the Stream Ecosystem in Beijing, China].

With economic development, the health of river ecosystems is becoming severely threatened because of the increasing effects of human activities on river ecosystems. Here, 101 sites along regional river systems in Beijing rivers were investigated from autumn 2020 to summer 2021. A total of 34 metrics, including aquatic organisms, hydrology, water quality, and habitat, were calculated to be the candidate indicators. Principal component and correlation analyses were used to select the core metrics from the candidate indicators, and the weight of each core metric was estimated using the entropy method. The integrated index of stream ecological health was constructed to assess the health condition of the Beijing rivers. The results of the PCA and correlation analyses revealed that eleven metrics were selected as the core metrics to construct the integrated index of stream ecological health, including water temperature, flow velocity, BOD5, NH4+-N, Cu, the density of phytoplankton and zooplankton, the Shannon-Wiener diversity index of macroinvertebrates and fish, the BMWP index, and the qualitative habitat evaluation index. According to the health assessment results, 4.95% of the sampling sites were healthy, 23.76% were subhealthy, and 71.29% were in a fair or below healthy state. The river health status showed strong spatial heterogeneity, and the river health statuses in the northern and western regions were relatively good, whereas the river health status in the central and southeastern regions were relatively poor. The results of four aspects stream ecosystem assessment showed that the overall water quality of the rivers was "subhealthy" and the aquatic organisms and habitat were "general poor," but the hydrology was "poor." The evaluation results of five water systems demonstrated that the Chaobai River had the best health status, followed by that of the Yongding River, Daqing River, and Jiyun River, and the Beiyun River had the worst health status. Maintaining river ecological baseflow, ensuring river system connectivity, and improving and restoring the river habitat environment are the key aspects of river ecological restoration and protection in Beijing in the future.

[Analysis of epidemic situation of malaria in Yunnan Province from 2011 to 2013].

OBJECTIVE: To understand the epidemic situation and characteristics of malaria in Yunnan Province, so as to provide the reference for malaria elimination. METHODS: The data of malaria reported in the information system were collected and analyzed in Yunnan Province from 2011 to 2013. RESULTS: From 2011 to 2013, totally 2 256 malaria cases were found in Yunnan Province, with a morbidity of 0.162 8 per million and three of them were death cases. The local cases mainly distributed along the boundary and accounted for 29.48%, while the imported cases mainly came from Myanmar and accounted for 70.52%. The number of endemic counties with local malaria cases decreased from 37 to 10 during the three years. The number of imported cases reached the peak in May and the local cases in June. The patients were mainly aged from 20 to 49 years old (accounted for 70.58%), and 85.24% of the cases were peasants and laborers. Totally 86.66% of cases were laboratory confirmed cases, and 13.14% were clinically diagnosed. The proportions of cases reported by hospitals, health service centers and CDCs were 33.02%, 37.06% and 29.92%, respectively. CONCLUSIONS: The prevalence of malaria in Yunnan Province decreased from 2011 to 2013. The work of malaria cases double-checked by province-level CDCs is effective. However, the awareness and accurately diagnostic capability of clinical doctors still should be strengthened.

Metabolomic analysis of the toxic effect of chronic low-dose exposure to acephate on rats using ultra-performance liquid chromatography/mass spectrometry.

To study the toxic effect of chronic exposure to acephate at low-dose levels, a metabolomics approach based on ultra-performance liquid chromatography/mass spectrometry (UPLC-MS) was applied. Three different doses of 0.5 mg/kg/day, 1.5 mg/kg/day, and 4.5 mg/kg/day acephate were administered to Wistar rats for 24 weeks. Endogenous metabolite profiles were obtained with UPLC-MS for all rats at six time points after treatment. Some metabolites like dimethylthiophosphate and uric acid in urine were detected at week 4. Dimethylthiophosphate, which had the most significant elevations compared with other biomarkers, was considered as an early, sensitive biomarker of exposure to acephate. Moreover, there were some endogenous metabolite changes, which demonstrated that the doses of 1.5 mg/kg/day and 4.5 mg/kg/day of acephate led to renal injury and perturbed the normal metabolic processes of rats, including glucose, nucleic acid, and protein metabolism. A connection between exposure to acephate and the metabolic disturbance has been found and interpreted. Our study indicates that the metabolomics approach based on UPLC-MS of urine provides more information on toxicity than the conventional toxicological evaluation methods in measuring changes and can be considered as a promising technique for the study of the toxic effect of acephate.