Temporal and spatial variations of concentrations of heavy metals including mercury （Hg）, zinc （Zn）, lead （Pb）, arsenic （As）, copper （Cu）, and cadmium （Cd） in the sediments of the Yangshan Deepwater Harbor...Temporal and spatial variations of concentrations of heavy metals including mercury （Hg）, zinc （Zn）, lead （Pb）, arsenic （As）, copper （Cu）, and cadmium （Cd） in the sediments of the Yangshan Deepwater Harbor were determined based on 6 cruises in autumn and winter, respectively, from 2010 to 2013. The results demonstrated that the overall concentrations of heavy metals were low and distributed in uniform patterns. The concentrations of Hg, Zn, Pb, and Cd in autumn were significantly higher than those in winter with small fluctuations for As and Cu in terms of seasonal variations. Results of factor analysis showed that Pb, Cd, and Zn were derived from inland industrial and shipping discharges as well as the degradation of organic pollutants in marine environment. While agricultural pollutions, cargo shifting and construction debris from reclamation projects contributed to the sources of Cu, As, and Hg. Ecological risk assessment by Mean Sediment Quality Guideline Quotient （SQG-Q） revealed that the degree for eco-risk of the sediments was low-and-moderate in autumn, higher than that in winter. Hg and Cu were the dominant eco-risk factors. The results of Index of geoaccumulation （Igeo） showed that the whole sites of the sea area were barely influenced by Hg, As, Zn, and Pb, and the extents of Cd and Cu contaminations were in low grade. Contamination degree of all the six heavy metals could be ranked as the following： Cd〉Pb〉Zn〉Hg〉As. According to the results of integrated score of factor analysis, the contamination degree for heavy metals in sediments of the Yangshan Deepwater Harbor was low, despite sites No.5, No.4 and No.3, which were heavily contaminated compared with others.展开更多
Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous toxic organic pollutants in the natural environment that are strongly associated with socioeconomic activities.Exploring the distribution,sources,and ecological tox...Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous toxic organic pollutants in the natural environment that are strongly associated with socioeconomic activities.Exploring the distribution,sources,and ecological toxicity of PAHs is essential to abate their pollution and biological risks.The 16 priority PAHs in different lakeside city estuarine sediments in the northern Taihu Lake in China were determined using gas chromatography-mass spectrometry.Results showed that total concentrations of PAHs(ΣPAHs)ranged from 672.07 to 5858.34 ng g^(^(-1)),with a mean value of 2121.37 ng g^(^(-1)).High-molecular-weight PAHs(4-6 rings)were dominant,accounting for 85%of theΣPAHs detected.Due to the barrier of gate/dam in the estuarine area,the concentrations of PAHs in the sediments were significantly different between the river mouth and lake side.Changes in total organic carbon(TOC)content and the spatial distribution of PAHs in the sediments were consistent.Sediment pollution assessment explored using the fuzzy evaluation model indicated 75%of slight PAH pollution.Some estuarine sediments(22%)concentrated in the east of the Wuli Lake in the Meiliang bay of the Taihu Lake were moderately or heavily polluted.The PAHs may lead to occasional detrimental biological consequences in the area.Diagnostic ratios and principal component analysis-multiple linear regression suggested vehicle emission and natural gas combustion as the primary PAH contributors(81%).展开更多
Lost foam casting(LFC) process is a special casting method in which polymeric foam patterns with refractory coatings are utilized as a mould component. In this work, four types of foam: expandable polyethylene(EPE), e...Lost foam casting(LFC) process is a special casting method in which polymeric foam patterns with refractory coatings are utilized as a mould component. In this work, four types of foam: expandable polyethylene(EPE), expandable polypropylene(EPP) and expandable polystyrene(EPS) foams with two different densities were employed as pattern materials. LFC and conventional green sand mould casting methods were used to cast a low carbon steel, A216 Grade WCB. Both casting processes were carried out at 1,580 °C. Chemical analysis results showed that the carbon contamination level was high and was influenced by pattern type. Metallographic investigations revealed a significant increase in the percentage of pearlite phase in all LFC samples. Densities of manufactured samples were calculated in order to evaluate porosity of the products. It was determined that the densities of the LFC samples were lower than the green sand mould cast reference sample(RS). Vickers hardness tests were also carried out and increments in hardness values with increased carbon content was observed.展开更多
BACKGROUND The influence of bile contamination on the infectious complications of patients undergoing pancreaticoduodenectomy(PD)has not been thoroughly evaluated.AIM To evaluate the effect of preoperative biliary dra...BACKGROUND The influence of bile contamination on the infectious complications of patients undergoing pancreaticoduodenectomy(PD)has not been thoroughly evaluated.AIM To evaluate the effect of preoperative biliary drainage and bile contamination on the outcomes of patients who undergo PD.METHODS The database of 4101 patients who underwent PD was reviewed.Preoperative biliary drainage was performed in 1964 patients(47.9%),and bile contamination was confirmed in 606 patients(14.8%).RESULTS The incidence of postoperative infectious complications was 37.9%in patients with preoperative biliary drainage and 42.4%in patients with biliary contamination,respectively.Patients with extrahepatic bile duct carcinoma,ampulla of Vater carcinoma,and pancreatic carcinoma had a high frequency of preoperative biliary drainage(82.9%,54.6%,and 50.8%)and bile contamination(34.3%,26.2%,and 20.2%).Bile contamination was associated with postoperative pancreatic fistula(POPF)Grade B/C,wound infection,and catheter infection.A multivariate logistic regression analysis revealed that biliary contamination(odds ratio 1.33,P=0.027)was the independent risk factor for POPF Grade B/C.The three most commonly cultured microorganisms from bile(Enterococcus,Klebsiella,and Enterobacter)were identical to those isolated from organ spaces.CONCLUSION In patients undergoing PD,bile contamination is related to postoperative infectious complication including POPF Grade B/C.The management of biliary contamination should be standardised for patients who require preoperative biliary drainage for PD,as the main microorganisms are identical in both organ spaces and bile.展开更多
基金supported by the Study on the Analysis of the Impacts of Reclamation Engineering on Marine Ecological Environment in Yangshan Deepwater Harbor and Protecting Measures of Shanghai Municipal Science and Technology Commission (No. 12231203402)
文摘Temporal and spatial variations of concentrations of heavy metals including mercury （Hg）, zinc （Zn）, lead （Pb）, arsenic （As）, copper （Cu）, and cadmium （Cd） in the sediments of the Yangshan Deepwater Harbor were determined based on 6 cruises in autumn and winter, respectively, from 2010 to 2013. The results demonstrated that the overall concentrations of heavy metals were low and distributed in uniform patterns. The concentrations of Hg, Zn, Pb, and Cd in autumn were significantly higher than those in winter with small fluctuations for As and Cu in terms of seasonal variations. Results of factor analysis showed that Pb, Cd, and Zn were derived from inland industrial and shipping discharges as well as the degradation of organic pollutants in marine environment. While agricultural pollutions, cargo shifting and construction debris from reclamation projects contributed to the sources of Cu, As, and Hg. Ecological risk assessment by Mean Sediment Quality Guideline Quotient （SQG-Q） revealed that the degree for eco-risk of the sediments was low-and-moderate in autumn, higher than that in winter. Hg and Cu were the dominant eco-risk factors. The results of Index of geoaccumulation （Igeo） showed that the whole sites of the sea area were barely influenced by Hg, As, Zn, and Pb, and the extents of Cd and Cu contaminations were in low grade. Contamination degree of all the six heavy metals could be ranked as the following： Cd〉Pb〉Zn〉Hg〉As. According to the results of integrated score of factor analysis, the contamination degree for heavy metals in sediments of the Yangshan Deepwater Harbor was low, despite sites No.5, No.4 and No.3, which were heavily contaminated compared with others.
基金supported by the National Natural Science Foundation of China (No. 41673107)the National Water Pollution Control and Treatment Science and Technology Major Project, China (No. 2017ZX07203-005)the Major Project of Jiangsu Provincial Department of Education, China (No. 20KJA170001)。
文摘Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous toxic organic pollutants in the natural environment that are strongly associated with socioeconomic activities.Exploring the distribution,sources,and ecological toxicity of PAHs is essential to abate their pollution and biological risks.The 16 priority PAHs in different lakeside city estuarine sediments in the northern Taihu Lake in China were determined using gas chromatography-mass spectrometry.Results showed that total concentrations of PAHs(ΣPAHs)ranged from 672.07 to 5858.34 ng g^(^(-1)),with a mean value of 2121.37 ng g^(^(-1)).High-molecular-weight PAHs(4-6 rings)were dominant,accounting for 85%of theΣPAHs detected.Due to the barrier of gate/dam in the estuarine area,the concentrations of PAHs in the sediments were significantly different between the river mouth and lake side.Changes in total organic carbon(TOC)content and the spatial distribution of PAHs in the sediments were consistent.Sediment pollution assessment explored using the fuzzy evaluation model indicated 75%of slight PAH pollution.Some estuarine sediments(22%)concentrated in the east of the Wuli Lake in the Meiliang bay of the Taihu Lake were moderately or heavily polluted.The PAHs may lead to occasional detrimental biological consequences in the area.Diagnostic ratios and principal component analysis-multiple linear regression suggested vehicle emission and natural gas combustion as the primary PAH contributors(81%).
文摘Lost foam casting(LFC) process is a special casting method in which polymeric foam patterns with refractory coatings are utilized as a mould component. In this work, four types of foam: expandable polyethylene(EPE), expandable polypropylene(EPP) and expandable polystyrene(EPS) foams with two different densities were employed as pattern materials. LFC and conventional green sand mould casting methods were used to cast a low carbon steel, A216 Grade WCB. Both casting processes were carried out at 1,580 °C. Chemical analysis results showed that the carbon contamination level was high and was influenced by pattern type. Metallographic investigations revealed a significant increase in the percentage of pearlite phase in all LFC samples. Densities of manufactured samples were calculated in order to evaluate porosity of the products. It was determined that the densities of the LFC samples were lower than the green sand mould cast reference sample(RS). Vickers hardness tests were also carried out and increments in hardness values with increased carbon content was observed.
文摘BACKGROUND The influence of bile contamination on the infectious complications of patients undergoing pancreaticoduodenectomy(PD)has not been thoroughly evaluated.AIM To evaluate the effect of preoperative biliary drainage and bile contamination on the outcomes of patients who undergo PD.METHODS The database of 4101 patients who underwent PD was reviewed.Preoperative biliary drainage was performed in 1964 patients(47.9%),and bile contamination was confirmed in 606 patients(14.8%).RESULTS The incidence of postoperative infectious complications was 37.9%in patients with preoperative biliary drainage and 42.4%in patients with biliary contamination,respectively.Patients with extrahepatic bile duct carcinoma,ampulla of Vater carcinoma,and pancreatic carcinoma had a high frequency of preoperative biliary drainage(82.9%,54.6%,and 50.8%)and bile contamination(34.3%,26.2%,and 20.2%).Bile contamination was associated with postoperative pancreatic fistula(POPF)Grade B/C,wound infection,and catheter infection.A multivariate logistic regression analysis revealed that biliary contamination(odds ratio 1.33,P=0.027)was the independent risk factor for POPF Grade B/C.The three most commonly cultured microorganisms from bile(Enterococcus,Klebsiella,and Enterobacter)were identical to those isolated from organ spaces.CONCLUSION In patients undergoing PD,bile contamination is related to postoperative infectious complication including POPF Grade B/C.The management of biliary contamination should be standardised for patients who require preoperative biliary drainage for PD,as the main microorganisms are identical in both organ spaces and bile.
