[Characterization of Microplastic Pollution of Sediments from Urban Lakes].

In recent years, microplastics (MPs) in the environment has become a topic of increasing concern. In this study, typical urban lakes, such as Yushan Lake and Nanhu Lake in Maanshan City, were selected to study the physical morphology and spatial distribution characteristics of MPs in sediments in spring and summer and to explore the sources of MPs in the lakes. On average, MPs in sediments occurred with a content of (0.0284±0.0597) g·kg-1 and abundance of (278.9±529.1) n·kg-1 in spring, and (0.0317±0.0778) g·kg-1 and (277.1±395.6) n·kg-1 in summer, respectively. Using a paired sample T-test, it was found that there was no significant correlation difference between the content (N=22, t=-0.269, P=0.791) and the abundance (N=22, t=0.035, P=0.973) of MPs in the spring and summer sediments. Regarding shape, the MPs in the sediments in the study area were divided into three types:fiber, film, and particle, accounting for 52.9%, 28.9%, and 18.2%, respectively. Size-fraction analysis indicated MPs<1 mm made up the majority, accounting for 83.9% of the total number. It was found that the MPs were mainly polyethylene (PE) and polypropylene (PP) polymers with seriously weathered surfaces. The sediments, which were adjacent either to land with a large stream of people and vehicles or to areas with frequent watersports, had notably high abundance of MPs, revealing the close correlation between the spatial distribution of MPs in lake sediments and human activities. It is thought that atmospheric precipitation (fiber), stormwater, washing of clothes (fiber), degradation of large plastics in the lake, and fishing activities (fishing nets, foam) are the main sources of MPs in lake sediments.

Reduced plasma level of irisin in first trimester as a risk factor for the development of gestational diabetes mellitus.

BACKGROUND: The aim of this prospective cohort study was to investigate the association of first trimester irisin concentrations and the subsequent development of gestational diabetes mellitus (GDM). METHODS: This cohort study was conducted at three maternity centers in China from July 2015 to June 2016. Data for fasting plasma glucose (FPG) and irisin concentrations in the first trimester and one-step GDM screening with 75-g oral glucose tolerance test (OGTT) performed between 24 and 28 weeks of gestation were collected and analyzed. RESULTS: Plasma from women was available for 1150 women, of whom 135 (11.7%) developed GDM. The median value of irisin in those included women was 141.2 (IQR, 99.4-192.9) ng/ml. In multivariate models comparing the first (Q1), second (Q2) and third (Q3) quartiles against the fourth (Q4) quartile of irisin, levels of irisin in Q1 and Q2 were associated with GDM, and increased risk of GDM by 440% (odds ratios [OR] = 5.40; 95% confidence intervals [CI]: 2.35-11.40) and 283% (OR: 3.83; 95%CI: 1.63-8.01). A model containing known risk factors plus irisin compared with a model containing known risk factors without irisin showed a greater discriminatory ability to predict GDM, the area under the curve (AUC) increased from 0.776 to 0.809. A significant difference in the AUC between the clinical variables alone and the addition of irisin level was observed (difference, 0.034; P = 0.03). CONCLUSIONS: Reduced plasma levels of irisin in first trimester was associated with the increased risk of GDM and might be useful in identifying women at risk for GDM for early prevention strategies.

[Effects of different vegetation restoration patterns on the diversity of soil nitrogen-fixing microbes in Hulunbeier sandy land, Inner Mongolia of North China].

By using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and sequence analysis, this paper studied the nifH gene diversity and community structure of soil nitrogen-fixing microbes in Hulunbeier sandy land of Inner Mongolia under four years management of five vegetation restoration modes, i. e., mixed-planting of Agropyron cristatum, Hedysarum fruticosum, Caragana korshinskii, and Elymus nutans (ACHE) and of Agropyron cristatum and Hedysarum fruticosum (AC), and mono-planting of Caragana korshinskii (UC), Agropyron cristatum (UA), and Hedysarum fruticosum (UH), taking the bare land as the control (CK). There existed significant differences in the community composition of nitrogen-fixing microbes among the five vegetation restoration patterns. The Shannon index of the nifH gene was the highest under ACHE, followed by under AC, UC, UA, and UH, and the lowest in CK. Except that UH and CK had less difference in the Shannon index, the other four vegetation restoration modes had a significantly higher Shannon index than CK (P < 0.05). The phylogenetic analysis showed that the soil nitrogen-fixing microbes under UA, UH, and UC were mainly of cyanobacteria, but the soil nitrogen-fixing microbes under AC and ACHE changed obviously, mainly of proteobacteria, and also of cyanobacteria. The canonical correlation analysis showed that the soil total phosphorus, available phosphorus, total nitrogen, and nitrate nitrogen contents under the five vegetation restoration modes had significant effects on the nitrogen-fixing microbial communities, and there existed significant correlations among the soil total phosphorus, available phosphorus, total nitrogen, and nitrate nitrogen. It was suggested that the variations of the community composition of soil nitrogen-fixing microbes under the five vegetation restoration modes were resulted from the interactive and combined effects of the soil physical and chemical factors.

[Optimization of conservation network system for inter-basin wetland ecosystem in Huang-Huai-Hai Region].

By using systematic conservation planning (SCP) method, and taking catchment as planning unit, an optimization of conservation network system for the inter-basin wetland ecosystem in Huang-Huai-Hai Region was conducted, with a comprehensive consideration of 3-dimensional (lateral, longitudinal and vertical) connectivity and Inter-basin Water Transfer Project and by the methods of irreplaceability analysis and gap identification. The efficacy of the optimized conservation network system was evaluated, as compared with the existing conservation network system. According to the principles of irreplaceability and connectivity, the wetland conservation gaps could be divided into two types, i.e. , be conserved in priority and in general. After the optimization, the conservation status of the inter-basin wetland ecosystem in Huang-Huai-Hai Region had an overall improvement. The conserved percentage of the wetland types was from about 20% up to 46.8%, and, for each wetland type, its conserved level increased to some extent, almost above 40%. Both in the near future and in the long term, more attention should be paid to the conservation of lake wetland. In addition, the integration of ecosystem service function and biodiversity and the combination of protection with restoration would be the main task for the wetland ecosystem conservation planning in the future.