Variations in the concentration, inventory, source, and ecological risk of polycyclic aromatic hydrocarbons in sediments of the Lake Chaohu.

In this study, the ecological risk assessment of PAHs pollution, the existing S-T model was improved and applied to this PAHs pollution assessment in surface sediment in Lake Chaohu. The potential sources and contributions of PAHs in the surface sediment were estimated by molecular diagnostic ratio (MDR) and positive matrix factorization (PMF). The results showed that the average concentration of 16 priority PAHs in the surface sediment was 718.16 ng/g in 2009 and 334.67 ng/g in 2020. In 2020, PAHs concentration has decreased compared to 2009 and the dominant composition has changed from high- to low-molecular-weight PAHs. The estimated PAHs mass inventory of the top 2 cm surface sediment was 2712 tons in 2009 and 1263 tons in 2020. Ecosystem risk assessment by improved S-T models suggested that the overall ecosystem risk of the studied regions was acceptable.

Meta-analysis of protein intake on the effect of Crohn's disease and ulcerative colitis.

BACKGROUND AND PURPOSE: published studies have assessed the effect of protein intake on Crohn's disease (CD) and ulcerative colitis (UC). However, the results were inconsistent. To provide a more precise estimation, a meta-analysis was performed to evaluate the association of protein intake in Crohn's disease and ulcerative colitis. METHODS: the PubMed, Chinese National Knowledge Infrastructure databases (CNKI), and Wanfang databases were searched to identify relevant studies. The summarized results of the relative risk (RR) with the corresponding 95 % confidence intervals (CI) were calculated using a random effects model. RESULTS: the final analysis included a total of nine articles. Nine studies reported on protein intake for the risk of UC and five studies reported on protein intake for the risk of CD. Overall, based on current studies, no significant association was found between protein intake and the risk of UC (RR = 1.13, 95 % CI = 0.82-1.55) or CD (RR = 1.18, 95 % CI = 0.51-2.74). A significant change was not found in the stratified analysis by study design and geographic location. CONCLUSIONS: in conclusion, the present meta-analysis suggested that dietary protein intake did not show a significant effect on the risk of UC or CD.

[Effects of drying and wetting cycles induced by tides on net ecosystem exchange of CO2 over a salt marsh in the Yellow River Delta, China.] / 潮汐作用下干湿交替对黄河三角洲盐沼湿地净生态系统CO2交换的影响.

As a unique hydrological characteristic, the tidal action can strongly affect carbon balance in a salt marsh despite their short duration. Using the eddy covariance technique, we measured the net ecosystem CO2 exchange (NEE) and its environmental factors and tidal change over a salt marsh in the Yellow River Delta. It aimed to investigate the effect of tidal process and drying and wetting cycles induced by tides on NEE. The results showed that the tidal process promoted the daytime CO2 uptake, but it didn't clearly affect the nighttime CO2 release. Tidal inundation was a major factor influencing daytime NEE. The diurnal change of NEE showed a distinct U-shaped curve on both drought and wet stages, but not with substantial variation in its amplitude during the drought stage. The drying and wetting cycles enhanced the absorption of daytime CO2. Under drought stage, the mean of the maximum photosynthetic rate (Amax), apparent quantum yield (α) and ecosystem respiration (Reco) were higher than those in wet stage. In addition, the drying and wetting cycles suppressed the nighttime CO2 release from the salt marsh but increased its temperature sensitivity.

[Effects of agricultural activities and transgenic crops on agricultural biodiversity].

Agricultural biodiversity is a key part of the ecosystem biodiversity, but it receives little concern. The monoculture, environmental pollution and habitat fragmentation caused by agricultural activities have threatened agricultural biodiversity over the past 50 years. To optimize agricultural management measures for crop production and environmental protection, we reviewed the effects of agricultural activities, including cultivation patterns, plastic mulching, chemical additions and the cultivation of transgenic crops, on agricultural biodiversity. The results showed that chemical pesticides and fertilizers had the most serious influence and the effects of transgenic crops varied with other factors like the specific transgene inserted in crops. The environmental risk of transgenic crops should be assessed widely through case-by-case methods, particularly its potential impacts on agricultural biodiversity. It is important to consider the protection of agricultural biodiversity before taking certain agricultural practices, which could improve agricultural production and simultaneously reduce the environmental impacts.

Low-dose amiodarone for the prevention of atrial fibrillation after coronary artery bypass grafting in patients older than 70 years.

BACKGROUND: Atrial fibrillation (AF) is one of the most common arrhythmia after coronary artery bypass grafting (CABG), which not only increases the suffering of the patients, but also prolongs hospital stay and enhances cost of care, especially for patients older than 70 years. This study was designed to evaluate the efficacy and safety of low-dose amiodarone in the prevention of AF after CABG, especially for the elderly. METHODS: Two hundred and ten senile patients undergoing off-pump CABG were included in this prospective, randomized, double-blind and placebo controlled study. Patients were given 10 mg/kg of amiodarone (low-dose amiodarone group, n = 100) or placebo (control group, n = 110) daily for 7 days before surgery and followed by 200 mg of amiodarone or placebo daily for 10 days postoperatively. RESULTS: Postoperative AF occurred in 16 patients (16%) receiving amiodarone and in 36 (37.7%) patients receiving placebo (P = 0.006). AF occurred at (58.13 +/- 16.63) hours after CABG in the low-dose amiodarone group and at (45.03 +/- 17.40) hours in the control group (P = 0.018). The maximum ventricular rate during AF was significantly slower in the low-dose amiodarone group ((121.42 +/- 28.91) beats/min) than in the control group ((134.11 +/- 30.57) beats/min, P = 0.036). The duration of AF was (10.92 +/- 9.56) hours for the low-dose amiodarone group compared with (14.81 +/- 10.37) hours for the control group (P = 0.002). The postoperative left ventricular ejection fraction (LVEF) was significantly improved in the low-dose amiodarone group (from (59.9 +/- 10.3)% to (63.4 +/- 11.4)%, P = 0.001), and significantly higher compared with the control group ((58.5 +/- 10.7)%, P = 0.002). Both groups had a similar incidence of complication other than rhythm disturbances (12.0% vs 16.4%, P = 0.368). The low-dose amiodarone group patients had shorter hospital stays ((11.8 +/- 3.2) days vs (13.8 +/- 4.7) days, P = 0.001) and lower cost of care (RMB (79 115 +/- 16 673) Yuan vs RMB (84 997 +/- 21 587) Yuan, P = 0.031) than that of control group patients. The in-hospital mortality was not significantly different between the two groups (1.0% vs 0.9%, P = 0.946). CONCLUSIONS: Perioperative low-dose oral amiodarone appeared to be cost-effective in the prevention and delay of new-onset postoperative AF in aged patients. It significantly reduced ventricular rate and duration of AF after CABG, decreased hospital cost and stay, as well as promoted the amelioration of left ventricular systolic function. Furthermore, low-dose amiodarone was safe to use and well tolerated with low toxic and side effects, and did not increase the risk of complications and mortality. It is proved to be a first-line therapy and as routine prophylaxis for AF after CABG, especially for elderly patients complicated with left ventricular dysfunction.