Publications by authors named "Yuying Pan"

5 Publications

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Evaluation of the acute toxic effects of crude oil on intertidal mudskipper (Boleophthalmus pectinirostris) based on antioxidant enzyme activity and the integrated biomarker response.

Environ Pollut 2021 Oct 9;292(Pt A):118341. Epub 2021 Oct 9.

School of Marine Sciences, University of Maine, Orono, 04469, USA.

With the development of marine oil industry, oil spill accidents will inevitably occur, further polluting the intertidal zone and causing biological poisoning. The muddy intertidal zone and Boleophthalmus pectinirostris were selected as the research objects to conduct indoor acute exposure experiments within 48 h of crude oil pollution. Statistical analysis was used to reveal the activity changes of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in the gills and liver of mudskipper. Then, integrated biomarker response (IBR) indicators were established to comprehensively evaluate the biological toxicity. The results showed that the activities of SOD, CAT and GST in livers were higher than those in gills, and the maximum induction multipliers of SOD, CAT and GPx in livers appeared earlier than those in gills. Both SOD and GPx activities were induced at low pollutant concentrations and inhibited at high pollutant concentrations. For the dose-effect, the change trends of CAT and SOD were roughly inversed. There was substrate competition between GPx and CAT, with opposite trends over time. The activating mechanism of GST was similar to that of GPx, and the activation time was earlier than that of GPx. In terms of dose-effect trends, the IBR showed that the antioxidant enzymes activities in biological tissues were induced by low and inhibited by high pollutant concentrations. Overall, SOD and GPx in gills and CAT and GST in livers of the mudskippers were suitable as representative markers to comprehensively analyze and evaluate the biotoxicity effects of oil pollution in the intertidal zone. The star plots and IBR values obtained after data standardization were consistent with the enzyme activity differences, which can be used as valid supplementary indexes for biotoxicity evaluation. These research findings provide theoretical support for early indicators of biological toxicity after crude oil pollution in intertidal zones.
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http://dx.doi.org/10.1016/j.envpol.2021.118341DOI Listing
October 2021

Three-dimensional migration and resistivity characteristics of crude oil in heterogeneous soil layers.

Environ Pollut 2021 Jan 4;268(Pt A):115309. Epub 2020 Aug 4.

School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhoushan, China. Electronic address:

An experimentally induced three-dimensional petroleum seepage flume was used to investigate its migration in heterogeneous soil layers and a method for monitoring resistivity was adopted, under conditions of fluctuating water levels and rainfall. The corresponding mechanisms were then analyzed based on the resistivity characteristics and combined with three-dimensional inversion images. Finally, physical and chemical property analysis was conducted to verify the results of resistivity monitoring. The results demonstrated that: (1) In the process of natural oil leakage, the variation of soil resistivity presents a concave shape in the resistivity profile. Thus, oil migration exhibited the following patterns. At first, circular migration front was dominant in a vertical direction. Subsequently, after vertical migration was impeded, lateral migration was dominant. As the crude oil gradually accumulated, the migration front broke through the limitation of lithologic interface and continued vertically. (2) By comparing the two resistivity monitoring methods, namely the Wenner and Pole-pole methods, it was demonstrated that the inversion resistivity measured by Wenner method was closer to the true resistivity, and the resistivity variations were more distinguishable. (3) The resistivity inversion profile demonstrated that the low resistivity anomaly of the crude oil leakage area was related to the low water content of the soil layer in the test area. (4) Fluctuations in water level increased the diffusion range of crude oil beyond the original pollution source area, especially horizontally. (5) Percolation of rainfall caused the water level to rise, and the crude oil was evenly distributed in the soil layers above the capillary zone. (6) Through sample analysis and verification, it was demonstrated that the resistivity method can accurately and intuitively present the characteristics of crude oil migration. These results provide theoretical support for the rapid determination of the migration range and characteristics of crude oil in heterogeneous soil layers.
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http://dx.doi.org/10.1016/j.envpol.2020.115309DOI Listing
January 2021

Study on diesel vertical migration characteristics and mechanism in water-bearing sand stratum using an automated resistivity monitoring system.

Environ Sci Pollut Res Int 2018 Feb 24;25(4):3802-3812. Epub 2017 Nov 24.

Qingdao Institute of Marine Geology, China Geological Survey, Qingdao, China.

Oil spills frequently occur on both land and sea. Petroleum in mobile phase will cause serious pollution in the sediment and can form a secondary pollution source. Therefore, it is very important to study the migration of petroleum in sediments ideally in a rapid and simplified approach. The release of diesel was simulated using fine beach sand to construct a model aquifer, and dynamic monitoring was carried out using an automated monitoring system including a resistivity probe originally developed by our research group. The mobile phase migration fronts were determined accurately using wavelet analysis method combined with resistivity curve method. Then, a relationship between resistivity and the joint oil-water content was established. The main conclusions were as follows. The seepage velocity of the diesel with high mobility at the initial stage of infiltration was faster, followed by a period when gravity seepage was dominant, and finally a redistribution period at the later stage, which was mainly an oil-water displacement process. The resistivity trends for diesel infiltration in different water-saturated soil layers varied with depth. The resistivity in the vadose zone fluctuated significantly, increasing initially and later decreasing. The resistivity change in the capillary zone was relatively small and constant in the initial stage; then, it increased and subsequently decreased. The resistivity in the saturated zone was basically unchanged with depth, and the value became slightly larger than the background value over time. Overall, for a large volume of mobile phase diesel leakage, the arrival migration fronts can be detected by wavelet analysis combined with resistivity curves. The thickness of the oil slick in the capillary zone can be estimated by resistivity changes. The relationships between resistivity and both the moisture content and oil-water joint saturation are in agreement with the linear models. The research results provide basic data and a new data processing method for monitoring of contaminated sites following major oil spills using the resistivity method.
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http://dx.doi.org/10.1007/s11356-017-0698-3DOI Listing
February 2018

Human health risk assessment of heavy metals in a replaced urban industrial area of Qingdao, China.

Environ Monit Assess 2016 Apr 16;188(4):229. Epub 2016 Mar 16.

College of Environmental Science and Engineering, Tongji University, Shanghai, China.

The aim of this study was risk characterization of a replaced urban industrial land located north of Qingdao, in relation to heavy metals values. Soil concentrations of Cd, Pb, Cu, Ni, Cr, and Zn were analyzed. It was observed that the components of Cd, Pb, Cu, Ni, Cr, and Zn are about 2.22, 8.07, 4.70, 6.81, 2.65, and 3.0-folds, respectively, when compared with the local natural background values in Qingdao. The spatial distribution of heavy metals indicated that these hotspots for Cr and Zn located in the southwestern part, Ni and Cd in the middle of the south area, Pb in the northwest, and Cu in the middle of the east area. The values of pollution index and Nemerow integrated pollution index revealed that 100 % of soil samples were moderately or heavily contaminated by six heavy metals. From these results, human health risk assessment for sensitive population was performed according to two different land uses. For non-carcinogenic risk, the direct oral ingestion appeared to be the main exposure pathway followed by dermal and inhalation absorption. The HI values of Pb and Cr characterized for children were larger than 1, while HI values of each metal for adults in two scenarios were lower than 1. Besides, carcinogenic risk from inhalation exposure to Cr for children and adults in two scenarios all exceeded the safety limit.
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http://dx.doi.org/10.1007/s10661-016-5224-4DOI Listing
April 2016

Day 3 and day 5 morphological predictors of embryo viability.

Reprod Biomed Online 2003 Apr-May;6(3):323-31

Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, ASB 1+3, Room 082, Boston, MA 02115, USA.

Controlling multiple pregnancies in patients undergoing artificial reproductive procedures requires consideration of single embryo transfers. Therefore, refinements for embryo evaluation are needed that select for the most developmentally competent embryo. The present study was designed to identify day 3 and day 5 morphological predictors of viability following transfers in which the morphology and fate of each embryo was precisely determined. Assessments on day 3 included cell number, and the extent of fragmentation and asymmetry, and on day 5, the developmental stage. Embryos resulting in a viable fetus at 11 weeks gestation were considered developmentally competent. The relationships among individual and collective embryo morphological characteristics were evaluated. Analysis of the interactions among morphological characteristics of embryos transferred on day 3 enabled identification of a multivariable selection order. Assessment of day 5 embryos revealed that expanding and expanded blastocysts exhibited comparable developmental potential that was superior to that of either morulae or early blastocysts. However, expanding or expanded blastocysts derived from 7-cell or 8-cell embryos were developmentally superior to those derived from other cleavage stages, regardless of fragmentation or asymmetry. Collectively, these findings further understanding of morphological predictors of viability, thereby improving the ability to select the most viable embryo for transfer.
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http://dx.doi.org/10.1016/s1472-6483(10)61852-4DOI Listing
December 2003
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