Maternal Smoking During Pregnancy and ADHD: Results From a Systematic Review and Meta-Analysis of Prospective Cohort Studies.

Objective: Findings on maternal smoking during pregnancy and ADHD risk in children are inconsistent. A meta-analysis was performed to summarize effects of exposure to maternal smoking during pregnancy on ADHD risk in children. Method: We conducted a systematic literature search to select articles up to June 2016. Only prospective cohort studies were included. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated. Results: Pooled RR estimates based on 12 cohort studies including 17,304 pregnant women suggested that maternal smoking during pregnancy was associated with an increased risk of ADHD (pooled RR = 1.58, 95% CI = [1.33, 1.88]). Conclusion: Results from this study indicate that maternal smoking during pregnancy is related to an increased risk of ADHD in children. There is an urgent need to increase maternal awareness of smoking risk and quitting smoking to mitigate the ADHD risk in children.

[Characteristics of Nitrogen and Phosphorus Concentration Dynamics in Natural Ditches Under an Irrigation-Drainage Unit in the Jianghan Plain].

The paddy field in Jianghan Plain usually exists in the form of an irrigation-drainage unit, and the natural ditch is the main part of the unit. A continuous in situ monitoring of the natural ditch water level and water quality through the entire rice growing season in 2015 was conducted to investigate the dynamics of ditch water level and nitrogen and phosphorus concentration in the ditch. Another objective was to determine the effect of these factors. Results showed that during the entire rice growing season, the ditch water depth was maintained between 30 to 70 cm, and the water depth was higher during irrigation events than during rainfall events. Fertilization was the main factor affecting the nitrogen concentration in the ditch water. Two peaks of total nitrogen (TN) concentration appeared on June 18 and July 30 because of topdressing. In the early stage of rice growing, ammonia nitrogen (NH4+-N) concentration was higher than that of nitrate nitrogen (NO3--N). External disturbances (such as rainfall and irrigation events) were the main factors affecting the total phosphorus (TP) concentration in the ditch water. The dynamic of TP concentration in the ditch water was large, and it was consistent with that of the particulate phosphorus (PP) concentration. Drainage of the irrigation-drainage was mainly controlled artificially. The period from rice transplanting to 3 days after the first top dressing was critical in preventing the outflow of ditch water. During the rice harvest stage, the TN and TP concentration were 0.22 and 0.06 mg·L-1, and the water quality reached theⅡclass standard for surface water quality. This reduced the risk from drainage from the irrigation-drainage unit to the surrounding water environment.

[Characteristics of Nitrogen and Phosphorus Emissions in the Gufu River Small Watershed of the Three Georges Reservoir Area].

To study the seasonal change characteristics and form composition of nitrogen and phosphorus output concentration and pollutant discharge load with rainfall characteristics at the outlet of Gufu river small watershed,the quality and quantity of water combined with natural rainfall events were monitored from January to December 2014.The results showed that the annual runoff volume of the Gufu river small watershed was 0.6×108 m3.The runoff was concentrated in raining season (from July to September),accounting for 63.9%.There was significant (P<0.01) positive correlation between the runoff flow and the annual rainfall.The annual emission of total nitrogen (TN) was 1432 t·a-1,and the emission was 853 t·a-1 during the raining season,accounting for 59.6% of annual TN emission content.The dissolved nitrogen was the main form of nitrogen emission,and the emission load of each month accounted for 55.4%-91.3% of TN.The positive correlation between the nitrate nitrogen concentration and rainfall was significant (P<0.05).The annual emission of total phosphorus (TP) was 563.1 t·a-1,and the content during the raining season accounted for 78.6% of TP annual emission content.The particle phosphorus (PP) was the main form of phosphorus emission,and the emission load of each month accounted for 41.9%-79.5% of TP.There was significant (P<0.01) positive correlation between the annual rainfall,sediment and TP,PP.The correlation between the total dissolved phosphorus concentration and rainfall was significant (P<0.05).

Aberrant Global and Regional Topological Organization of the Fractional Anisotropy-weighted Brain Structural Networks in Major Depressive Disorder.

BACKGROUND: Most previous neuroimaging studies have focused on the structural and functional abnormalities of local brain regions in major depressive disorder (MDD). Moreover, the exactly topological organization of networks underlying MDD remains unclear. This study examined the aberrant global and regional topological patterns of the brain white matter networks in MDD patients. METHODS: The diffusion tensor imaging data were obtained from 27 patients with MDD and 40 healthy controls. The brain fractional anisotropy-weighted structural networks were constructed, and the global network and regional nodal metrics of the networks were explored by the complex network theory. RESULTS: Compared with the healthy controls, the brain structural network of MDD patients showed an intact small-world topology, but significantly abnormal global network topological organization and regional nodal characteristic of the network in MDD were found. Our findings also indicated that the brain structural networks in MDD patients become a less strongly integrated network with a reduced central role of some key brain regions. CONCLUSIONS: All these resulted in a less optimal topological organization of networks underlying MDD patients, including an impaired capability of local information processing, reduced centrality of some brain regions and limited capacity to integrate information across different regions. Thus, these global network and regional node-level aberrations might contribute to understanding the pathogenesis of MDD from the view of the brain network.