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Tarn TJ, Bejczy A, Yun X, Li Z. Effect of motor dynamics on nonlinear feedback robot arm control. ACTA ACUST UNITED AC 1991. [DOI: 10.1109/70.68075] [Citation(s) in RCA: 216] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lewis AJ, Yun X, Spooner DE, Kurz MJ, McKenzie ER, Sales CM. Exposure pathways and bioaccumulation of per- and polyfluoroalkyl substances in freshwater aquatic ecosystems: Key considerations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 822:153561. [PMID: 35101505 DOI: 10.1016/j.scitotenv.2022.153561] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/22/2022] [Accepted: 01/26/2022] [Indexed: 05/24/2023]
Abstract
Due to the bioaccumulative behavior, toxicity, and recalcitrance to degradation, per- and polyfluoroalkyl substances (PFAS) are a focus for many researchers investigating freshwater aquatic ecosystems. PFAS are a diverse set of chemicals that accumulate and transport quite differently in the environment depending on the length of their fluoroalkyl chains and their functional groups. This diversity in PFAS chemical characteristics combined with varying environmental factors also impact the bioaccumulation of these compounds in different organisms. In this review, we evaluate environmental factors (such as organic carbon, proteins, lipids, and dissolved cations) as well as PFAS characteristics (head group, chain-length, and concentration) that contribute to the significant variation seen in the literature of bioaccumulation metrics reported for organisms in aquatic ecosystems. Of the factors evaluated, it was found that PFAS concentration, dissolved organic matter, sediment organic matter, and biotransformation of precursor PFAS tended to significantly impact reported bioaccumulation metrics the most. Based on this review, it is highly suggested that future studies provide sufficient details of important environmental factors, specific organism traits/ behavior, and PFAS concentrations/compounds when reporting on bioaccumulation metrics to further fill data gaps and improve our understanding of PFAS in aquatic ecosystems.
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Review |
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Yun X, Kumar V. An approach to simultaneous control of trajectory and interaction forces in dual-arm configurations. ACTA ACUST UNITED AC 1991. [DOI: 10.1109/70.97873] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Yang Y, Yun X, Liu M, Jiang Y, Li QX, Wang J. Concentrations, distributions, sources, and risk assessment of organochlorine pesticides in surface water of the East Lake, China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:3041-50. [PMID: 24177859 DOI: 10.1007/s11356-013-2269-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 10/21/2013] [Indexed: 05/05/2023]
Abstract
East Lake resides in the urban area of Wuhan City and is the largest urban lake in China. The concentrations of 16 organochlorine pesticides (OCPs) were analyzed in 108 surface water samples collected from the East Lake. The total concentrations of OCPs ranged from not detected to 120 ng L(-1) with predominance of δ-HCH, heptachlor, and α-HCH. The mean values of HCHs and DDTs were 7.40 and 5.70 ng L(-1), respectively, accounting for 40 and 31 % of the total OCPs. For the five lakelets in East Lake, Houhu Lake exhibited the highest concentrations of HCHs, DDTs, and total OCPs, which has been used actively for fisheries and surrounded by suburban rural areas and farmlands. Historical lindane or technical HCH input was probably the source of HCH, while technical DDTs might be the source of DDT in the East Lake. The ratio between heptachlor and its metabolic products indicated recent input of heptachlor. Although the combining ecological risks for all aquatic species in the East Lake calculated by species sensitivity distribution reached approximately 10(-5), the OCPs in the East Lake had slight effects on aquatic organisms. The carcinogenic risks and non-carcinogenic hazard indices of DDTs and HCHs indicated that water in the East Lake was not suitable as water sources for human. However, the results indicated the water quality was safe for people to swim in the urban lake.
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Liu M, Yang Y, Yun X, Zhang M, Wang J. Concentrations, distribution, sources, and ecological risk assessment of heavy metals in agricultural topsoil of the Three Gorges Dam region, China. ENVIRONMENTAL MONITORING AND ASSESSMENT 2015; 187:147. [PMID: 25716527 DOI: 10.1007/s10661-015-4360-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/09/2015] [Indexed: 06/04/2023]
Abstract
Concentrations, distribution, sources, and ecological risk of seven heavy metals including chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), and mercury (Hg) in agricultural topsoil samples of the Three Gorges Dam region, China were investigated in this study. Among seven heavy metals, Zn had the highest mean concentration (149 mg kg(-1)) in the agricultural topsoil, followed by Cr (66 mg kg(-1)), Cu (52.2 mg kg(-1)), Pb (13.0 mg kg(-1)), Ni (8.5 mg kg(-1)), Cd (0.29 mg kg(-1)), and Hg (0.08 mg kg(-1)). Enrichment factor (EF) values of Zn, Cu, Cd, and Hg were higher than 1.5, indicating that Zn, Cu, Cd, and Hg were the major pollutants in this study area. The average potential ecological risk index (RI) value was 147, suggesting that heavy metals in the agricultural topsoil in the study area had a low ecological risk. The result of factor analysis (FA) and correlation analysis showed that long-term use of chemical fertilizer and pesticides, natural rock weathering, and atmospheric deposition were the several main sources of seven heavy metals in agricultural topsoil of the Three Gorges Dam region. Factor analysis-multiple linear regression (FA-MLR) results indicated that the most important source in this area was long-term use of chemical fertilizer and pesticides, which contributed 70 % for Cu and Zn, 62 % for Cd, and 72 % for Hg. More attention must be paid to the extensive use of chemical fertilizers and pesticides containing heavy metals which have been accumulated in the agricultural soil.
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Zhou J, Wei Y, Liu D, Ge X, Zhou F, Yun X, Jiang J, Gu J. Identification of 1,4GalT II as a Target Gene of p53-mediated HeLa Cell Apoptosis. J Biochem 2007; 143:547-54. [DOI: 10.1093/jb/mvn003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Yun X, Yang Y, Liu M, Wang J. Concentrations and risk assessment of polychlorinated biphenyls and polybrominated diphenyl ethers in surface sediments from the East Lake, China. ECOTOXICOLOGY (LONDON, ENGLAND) 2015; 24:172-80. [PMID: 25336043 DOI: 10.1007/s10646-014-1370-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/11/2014] [Indexed: 05/22/2023]
Abstract
The concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in surface sediment samples collected from the East Lake, China in winter 2012 and summer 2013 were analyzed in this study. The total PCB and PBDE concentrations ranged from not detected to 107.1 ng g(-1) dw and from 9.7 to 151.3 ng g(-1) dw, respectively. PCB-28, 101 and 180 were dominant congeners in both winter and summer. BDE-28 (44 %) was the dominant congener in winter and summer, followed by BDE-99 (28 %) and BDE-47 (26 %). The concentrations of PCBs in the sediment samples collected in summer were higher than those in winter, while the concentrations of PBDEs did not show much seasonal variations. Source analysis showed that the PCBs probably originated from urban runoff, industrial pollution and atmospheric deposition, and the PBDEs probably originated from historical usage of penta-BDE mixtures. Potential eco-toxicological risks caused by PCBs were found in about 5 % of the sampling sites; PBDEs had moderate eco-toxicological risk in 80 % sampling sites in the East Lake, China.
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Liu Y, Yun X, Gao M, Yu Y, Li X. Analysis of regulatory T cells frequency in peripheral blood and tumor tissues in papillary thyroid carcinoma with and without Hashimoto's thyroiditis. Clin Transl Oncol 2014; 17:274-80. [PMID: 25387566 DOI: 10.1007/s12094-014-1222-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 08/24/2014] [Indexed: 01/15/2023]
Abstract
PURPOSE Regulatory T cells (Treg) suppress the immune reaction. The aim of the present study was to investigate the clinicopathologic significance and roles of Treg in papillary thyroid carcinoma (PTC) patients with and without Hashimoto's thyroiditis. METHODS Flow cytometry was used to detect the percentage of CD4+CD25+CD127low/- Treg among CD4+ T cells in peripheral blood. FoxP3+ Treg were detected by immunohistochemistry in the tumor tissues. RESULTS The percentage of CD4+CD25+CD127low/- Treg among CD4+ T cells was significantly higher in PTC patients than that in multinodular goiter (MNG) patients. There were large numbers of tumor-infiltrating FoxP3+ Treg in primary PTC and metastatic lymph nodes tissues; however, there was no FoxP3 expression in the MNG tissues. Higher percentage of Treg both in peripheral blood and tumor tissues was associated with extrathyroidal extension and lymph nodes metastasis. The percentage of CD4+CD25+CD127low/- Treg among CD4+ T cells in peripheral blood of PTC patients with Hashimoto's thyroiditis (HT) was significantly lower, whereas the infiltration of FoxP3+ Treg in tissues of PTC with HT tended to be increased. CONCLUSIONS We concluded that the percentage of Treg increased in peripheral blood as well as in the tumor tissues of PTC patients compared with that of MNG patients. The high percentage of Treg was associated with aggressiveness. There may be a compensatory expansion of Treg at the sites of inflammation in tissues of PTC with HT contributing to the immune response suppression.
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Research Support, Non-U.S. Gov't |
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Yun X, Lewis AJ, Stevens-King G, Sales CM, Spooner DE, Kurz MJ, Suri R, McKenzie ER. Bioaccumulation of per- and polyfluoroalkyl substances by freshwater benthic macroinvertebrates: Impact of species and sediment organic carbon content. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 866:161208. [PMID: 36581279 DOI: 10.1016/j.scitotenv.2022.161208] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 06/17/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) in aquatic environments have caused global concern due to their persistence, toxicity, and potential bioaccumulation of some compounds. As an important compartment of the aquatic ecosystem, sediment properties impact PFAS partitioning between aqueous and solid phases, but little is known about the influence of sediment organic carbon content on PFAS bioaccumulation in benthic organisms. In this study, three freshwater benthic macroinvertebrates - worms (Lumbriculus variegatus), mussels (Elliptio complanata) and snails (Physella acuta) - were exposed for 28 days to PFAS spiked synthetic sediment equilibrated with a synthetic surface water. Using microcosms, sediment organic carbon content - 2%, 5% and 8% - was manipulated to assess its impact on PFAS bioaccumulation. Worms were found to have substantially greater PFAS bioaccumulation compared to mussels and snails. The bioaccumulation factors (BAFs) and biota sediment accumulation factors (BSAFs) in worms were both one to two magnitudes higher than in mussels and snails, likely due to different habitat-specific uptake pathways and elimination capacities among species. In these experiments, increasing sediment organic carbon content decreased the bioaccumulation of PFAS to benthic macroinvertebrates. In worms, sediment organic carbon content was hypothesized to impact PFAS bioaccumulation by affecting PFAS partitioning and sediment ingestion rate. Notably, the BSAF values of 8:2 fluorotelomer sulfonic acid (FTS) were the largest among 14 PFAS for all species, suggesting that the benthic macroinvertebrates probably have different metabolic mechanisms for fluorotelomer sulfonic acids compared to fish evaluated in published literature. Understanding the impact of species and sediment organic carbon on PFAS bioaccumulation is key to developing environmental quality guidelines and evaluating potential ecological risks to higher trophic level species.
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Ailing Z, Jing Y, Jingli L, Yun X, Xiaojian Z. Further evidence that a variant of the gene NUDT15 may be an important predictor of azathioprine-induced toxicity in Chinese subjects: a case report. J Clin Pharm Ther 2016; 41:572-4. [PMID: 27381176 DOI: 10.1111/jcpt.12420] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 06/14/2016] [Indexed: 12/12/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Thiopurine methyltransferase (TPMT) enzyme is an important component in the metabolism of azathioprine (AZA). Its mutation may lead to AZA-induced toxicity. The dysfunctional genetic variant TPMT *3C is of low frequency among Asians. Moreover, AZA-induced toxicity still occurs in some patients with normal TPMT activity. This suggests that additional factors, including other genetic variants, may contribute to such toxicity. Recent studies described a strong association between a variant of the NUDT15, a gene that mediates the hydrolysis of some nucleoside diphosphate derivatives, and thiopurine-related myelosuppression in Asians. We report the first case of a Chinese patient with AZA-induced severe toxicity with no clinically significant TPMT variant but with the NUDT15 c.415C>T allele. CASE SUMMARY A 40-year-old Chinese patient with PBC-AIH overlap syndrome had been receiving for one month, azathioprine (50 mg/day) and methylprednisolone (24 mg/day) based on his TPMT*3C wild-type genotype. The patient developed serious myelosuppression and hair loss. AZA was stopped, and the patient was given liver-protective drugs and supportive treatment. TPMT and NUDT15 gene sequencing suggests that NUDT15 c.415C>T mutation was the likely cause of the adverse reaction. WHAT IS NEW AND CONCLUSION NUDT15 c.415C>T may be another predictor of AZA-induced leukocytopenia. If further well-controlled studies validate this association with sufficient predictive power, NUDT15 and TPMT genotyping before starting AZA treatment may become appropriate.
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Case Reports |
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Ge J, Liu M, Yun X, Yang Y, Zhang M, Li QX, Wang J. Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China. CHEMOSPHERE 2014; 103:256-262. [PMID: 24387912 DOI: 10.1016/j.chemosphere.2013.12.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 11/26/2013] [Accepted: 12/04/2013] [Indexed: 06/03/2023]
Abstract
Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the surface water of the East Lake, China were investigated in winter (2012) and summer (2013). A hundred and eight samples were collected from 36 sampling sites and analyzed for the 31 PCB and 10 PBDE congeners. Concentrations of both PCBs and PBDEs showed obvious seasonal variations. The average PCB concentrations in the East Lake ranged from 3.17 to 6.09 ng L(-1) in winter and 0.19 to 0.99 ng L(-1) in summer. CB-44, 105, 118 and 179 were dominant in both winter and summer. The average PBDE concentrations in the East Lake ranged from 2.92 to 5.54 ng L(-1) in winter and 0.67 to 1.51 ng L(-1) in summer. BDE-47 was predominant in both winter and summer, which accounted for more than 37% of the total PBDEs concentration from all sampling sites. Independent-Samples t-test showed statistical significance of ΣPCBs and ΣPBDEs between winter and summer samples. The analysis of distribution, pattern and seasonal variations indicated the different potential sources of PCBs and PBDEs in the East Lake. The potential eco-toxicological risk was also discussed in the study.
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Li H, Yun X, Li J, Shi L, Fok AS, Madden MJ, Labuz JF. Strengthening of a model composite restoration using shape optimization: a numerical and experimental study. Dent Mater 2009; 26:126-34. [PMID: 19818487 DOI: 10.1016/j.dental.2009.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 09/01/2009] [Accepted: 09/09/2009] [Indexed: 11/18/2022]
Abstract
OBJECTIVE This study aims to validate a cavity shape optimization approach for improving the debonding resistance of dental restorations by carrying out fracture tests on restored model teeth with standard and optimized cavity designs. METHOD The bio-mimetic stress-induced material transformation (SMT) optimization method was incorporated into the finite element (FE) program ABAQUS as a user material (UMAT) subroutine. The method uses stress minimization to optimize the cavity shape of a MOD restoration in an artificial premolar with special reference to the tooth-restoration interface under occlusal loads. The mechanical performance of the optimized design was first verified through FE analysis and then compared with that of the conventional design using fracture tests on model teeth. RESULTS The SMT optimization process indicated a T-shape cavity as a more favorable design for the MOD restoration in the artificial premolar. Compared with the conventional parallel wall, or undercut design, the T-shape cavity was shown numerically to reduce the interfacial stresses by up to 69%, and experimentally to increase the mean debonding resistance of the model teeth by 23% (p<0.05). SIGNIFICANCE Cavity shape optimization can help increase the debonding resistance of restored teeth by reducing the interfacial stresses between tooth and restoration under occlusal loads.
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Validation Study |
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Dong Y, Li LL, Wang RX, Yu XW, Yun X, Liu RZ. Reproductive outcomes in recurrent pregnancy loss associated with a parental carrier of chromosome abnormalities or polymorphisms. GENETICS AND MOLECULAR RESEARCH 2014; 13:2849-56. [PMID: 24535899 DOI: 10.4238/2014.january.17.4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The subsequent reproductive outcomes in couples with a history of recurrent pregnancy loss (RPL) associated with chromosome abnormalities or polymorphisms are generally not reported in China. Many RPL carrier couples have decided not to have children. The present study recorded the subsequent delivery, miscarriage, and unpregnancy outcomes of 113 RPL carrier couples and 226 non-carrier couples, and compared differences in reproductive outcomes between couples with different types of chromosome abnormalities or polymorphisms and chromosome normal couples. Our results showed that couples with RPL associated with parental chromosome abnormalities or polymorphisms did not have significantly lower live birth rates than non-carrier couples in China. These results suggest the current guidance given to Chinese RPL couples.
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Research Support, Non-U.S. Gov't |
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Abstract
Western rehabilitation techniques were first introduced into China in the early 1980s. The predominantly 'medical model' of health care in China has resulted in a shortage of rehabilitation personnel and limited experience determining the needs of clients. Occupational therapy practitioners in China are learning their new roles and clients, having never had any contact with occupational therapy, are unaware what services can be offered. The purpose of this research was to determine the most frequently self-identified functional problems (in the ares of self-care productivity and leisure) identified by 113 in-patients in four different hospitals in China, in order to assist therapists to develop programmmes that are responsive to clients' needs. Using the Canadian Occupational Performance Measure, both males and females identified significantly more self-care than leisure or productivity problems (P = 0.01). Females identified more productivity problems than males (P = 0.01) while males appeared to consider leisure difficulties as a priority more frequently than women. The study was jointly undertaken by a Canadian and a Chinese researcher. To our knowledge, this is the first time that occupational therapy personnel in China have formally surveyed clients about their rehabilitation needs, in order to develop priorities for programming.
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Comparative Study |
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Liu M, Yang Y, Yun X, Zhang M, Li QX, Wang J. Distribution and ecological assessment of heavy metals in surface sediments of the East Lake, China. ECOTOXICOLOGY (LONDON, ENGLAND) 2014; 23:92-101. [PMID: 24258532 DOI: 10.1007/s10646-013-1154-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/12/2013] [Indexed: 06/02/2023]
Abstract
Concentrations and risk assessment of chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), lead (Pb), cadmium (Cd) and mercury (Hg) were investigated in 106 samples of surface sediments from the East Lake, China in this study. The mean concentration of Zn was highest among the eight heavy metals (225 mg kg(-1)), followed by As (191 mg kg(-1)), Cr (145 mg kg(-1)), Cu (55 mg kg(-1)), Ni (27.1 mg kg(-1)), Pb (7.93 mg kg(-1)), Cd (0.94 mg kg(-1)) and Hg (0.21 mg kg(-1)). Niuchao Hu was less polluted by heavy metals compare to the other four lakelets of the East Lake. The correlations among these heavy metals and the results of principal component analysis indicated that the distribution of Cd, Pb and Hg was related to anthropogenic activities, whereas Cu, As and Cr were affected by the parent rocks. Zinc and Ni were influenced both by anthropogenic activities and parent rocks. Based on the Sediment Quality Guidelines, the results of toxicity assessment indicated that adverse effects caused by Cr and As would be expected frequently. Nickel, Zn, Cd and Hg may cause adverse effects occasionally and Cu and Pb may cause toxicity infrequently. Arsenic was found to have the highest acute toxicity by toxic units (TUs), followed by Cr, Ni, Zn, Hg, Cu, Cd and Pb. The potential ecological risk index analysis indicated that As, Cd and Hg had considerable or high ecological risk, whereas Cr, Ni, Cu, Zn and Pb had low ecological risk. The potential ecological risk index (RI) of the heavy metals in the surface sediments of East Lake was 483, indicating considerable ecological risk. Close attention should be paid to pollution of the heavy metals in East Lake, China.
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Yun X, Yang Y, Liu M, Wang J. Distribution and ecological risk assessment of organochlorine pesticides in surface sediments from the East Lake, China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:10368-10376. [PMID: 24756687 DOI: 10.1007/s11356-014-2893-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/04/2014] [Indexed: 06/03/2023]
Abstract
Organochlorine pesticides (OCPs) are ubiquitous pollutants, and their presence in urban lakes is a concern for human and ecological health. Surface sediments in the East Lake, China, were collected in winter 2012 and summer 2013 to investigate concentrations, distribution patterns, possible sources, and potential ecological risks of OCPs in this area. The total concentrations of 14 OCPs ranged from 6.3 to 400 ng g(-1) dry weight (dw) with an average concentration of 79 ng g(-1) dw. The mean values of hexachlorocyclohexanes (HCHs) (α-, β-, γ-, and δ-HCH) and dichlorodiphenyltrichloroethanes (DDTs) (p,p'-DDE, p,p'-DDD, and p,p'-DDT) were 36 and 7.6 ng g(-1) dw, accounting for 45 and 10 % of the total OCPs, respectively. The concentrations of OCPs in sediment samples collected in winter were significantly higher than those in summer, especially the HCHs, of which in winter were two times greater than summer. Composition analyses indicated that DDTs and endosulfan were mainly from historical contribution. Historical use of technical HCH and new input of lindane were probably the source of HCHs in the East Lake. Most sampling sites of HCHs and DDTs were found to have the potential ecological risk based on levels specified in the sediment quality standards.
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Brown AS, Yun X, McKenzie ER, Heron CG, Field JA, Salice CJ. Spatial and temporal variability of per- and polyfluoroalkyl substances (PFAS) in environmental media of a small pond: Toward an improved understanding of PFAS bioaccumulation in fish. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163149. [PMID: 37011692 DOI: 10.1016/j.scitotenv.2023.163149] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/23/2023] [Accepted: 03/25/2023] [Indexed: 05/27/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are highly fluorinated compounds with many industrial applications, for instance as ingredients in fire-suppressing aqueous film-forming foams (AFFF). Several PFAS have been demonstrated to be persistent, bioaccumulative and toxic. This study better characterizes the bioaccumulation of PFAS in freshwater fish through a spatial and temporal analysis of surface water and sediment from a stormwater pond in a former Naval air station (NAS) with historic AFFF use. We sampled environmental media from four locations twice per week for five weeks and sampled fish at the end of the sampling effort. The primary PFAS identified in surface water, sediment, and biota were perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) followed by perfluorooctanoic acid (PFOA) in environmental media and perfluoroheptane sulfonate (PFHpS) in biota. We observed significant temporal variability in surface water concentrations at the pond headwaters following stochastic events such as heavy rainfall for many compounds, particularly PFHxS. Sediment concentrations varied most across sampling locations. In fish, liver tissue presented the highest concentrations for all compounds except PFHxS, which was highest in muscle tissue, suggesting the influence of fine-scale aqueous PFAS fluctuations on tissue distribution. Calculated log bioaccumulation factors (BAFs) ranged from 0.13 to 2.30 for perfluoroalkyl carboxylates (PFCA) and 0.29-4.05 for perfluoroalkane sulfonates (PFSA) and fluctuated greatly with aqueous concentrations. The variability of PFAS concentrations in environmental media necessitates more frequent sampling efforts in field-based studies to better characterize PFAS contamination in aquatic ecosystems as well as exercising caution when considering single time-point BAFs due to uncertainty of system dynamics.
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Ge J, Yun X, Liu M, Yang Y, Zhang M, Wang J. Distribution, potential source and ecotoxicological risk of polychlorinated biphenyls and polybrominated diphenyl ethers in the surface water of the Three Gorges Dam region of the Yangtze River, China. ECOTOXICOLOGY (LONDON, ENGLAND) 2014; 23:978-987. [PMID: 24748369 DOI: 10.1007/s10646-014-1241-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/05/2014] [Indexed: 06/03/2023]
Abstract
Distributions, potential sources and ecotoxicological risks of PCBs and PBDEs in surface water of the Three Gorges Dam (TGD) region (Yangtze River, China) were investigated. Samples were collected from 18 sites from upstream (UTGD) and downstream (DTGD) of the TGD. Thirty-two PCBs and ten PBDEs were analyzed. ΣPCBs from the UTGD and DTGD ranged from 10.6 to 26.1 and 1.7 to 29.8 ng L(-1), respectively. ΣPBDEs from the UTGD and DTGD ranged from 2.0 to 17.6 and 0.8 to 11.1 ng L(-1), respectively. The total concentrations of PCBs and PBDEs showed a declining trend from the UTGD to DTGD. Independent-samples t test analysis showed no statistical significance of ΣPCBs and ΣPBDEs between the UTGD and DTGD samples. Principal component analysis indicated the difference of potential sources and levels of PCBs and PBDEs in the study area. The potential eco-toxicological risk of PCBs in surface water of the TGD region is very low, whereas special attention needs to be paid to PBDEs in the study area.
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Zhou QH, Xiao WP, Yun X. Epidural anaesthesia with goal-directed administration of ropivacaine improves haemodynamic stability when combined with general anaesthesia in elderly patients undergoing major abdominal surgery. Anaesth Intensive Care 2013; 41:82-9. [PMID: 23362895 DOI: 10.1177/0310057x1304100114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of epidural ropivacaine may result in significant haemodynamic fluctuations during combined epidural and general anaesthesia. We designed this study to investigate whether epidural anaesthesia with a goal-directed approach, when combined with general anaesthesia, improved haemodynamic stability in elderly patients undergoing major abdominal surgery. Seventy-five elderly patients undergoing major abdominal surgery were randomly and evenly assigned to one of three groups receiving intraoperative epidural anaesthesia with either ropivacaine 0.1% (Group 1), ropivacaine 0.375% (Group 2) or ropivacaine 0.375% for abdominal wall pain and ropivacaine 0.1% for visceral pain (Group 3). General anaesthesia was induced using a target-controlled infusion of combined propofol and remifentanil. The remifentanil target concentration was adjusted according to the mean arterial pressure and heart rate, and vasoactive agents were administered to maintain stable haemodynamics. The need for vasoactive drug administrations was 1.4 (standard deviation 0.9) in Group 3 (n=24), representing a significantly lower frequency of administration compared with Groups 1 (n=24) and 2 (n=24) (P <0.05 versus Group 1; P <0.01 versus Group 2). The total intraoperative dose of remifentanil was significantly greater in Group 1 (P <0.01 versus Group 2; P <0.05 versus Group 3) but did not differ significantly between Groups 2 and 3. Goal-directed epidural anaesthesia with different ropivacaine concentrations can improve haemodynamic stability when combined with general anaesthesia for elderly patients undergoing major abdominal surgery.
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Randomized Controlled Trial |
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Bai JY, Pang YZ, Qi YX, Zhang XH, Yun XY. Development and Application of Est-Ssr Markers in Quails. BRAZILIAN JOURNAL OF POULTRY SCIENCE 2016. [DOI: 10.1590/1806-9061-2015-0124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Lewis AJ, Yun X, Lewis MG, McKenzie ER, Spooner DE, Kurz MJ, Suri R, Sales CM. Impacts of divalent cations (Mg 2+ and Ca 2+) on PFAS bioaccumulation in freshwater macroinvertebrates representing different foraging modes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023:121938. [PMID: 37263566 DOI: 10.1016/j.envpol.2023.121938] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 05/24/2023] [Accepted: 05/29/2023] [Indexed: 06/03/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) have extensively contaminated freshwater aquatic ecosystems where they can be transported in water and partition to sediment and biota. In this paper, three freshwater benthic macroinvertebrates with different foraging modes were exposed to environmentally relevant concentrations of eight perfluoroalkyl carboxylates (PFCA), three perfluoroalkyl sulfonates (PFSA), and three fluorotelomer sulfonates (FTS) at varying divalent cation concentrations of magnesium (Mg2+) and calcium (Ca2+). Divalent cations can impact PFAS partitioning to solids, especially to sediments, at higher concentrations. Sediment dwelling worms (Lumbriculus variegatus), epibenthic grazing snails (Physella acuta), and sediment-dwelling filter-feeding bivalves (Elliptio complanata) were selected due to their unique foraging modes. Microcosms were composed of synthetic sediment, culture water, macroinvertebrates, and PFAS and consisted of a 28-day exposure period. L. variegatus had significantly higher PFAS bioaccumulation than P. acuta and E. complanata, likely due to higher levels of interactions with and ingestion of the contaminated sediment. "High Mg2+" (7.5 mM Mg2+) and "High Ca2+" (7.5 mM Ca2+) conditions generally had statistically higher bioaccumulation factors (BAF) than the "Reference Condition" (0.2 mM Ca2+ and 0.2 mM Mg2+) for PFAS with perfluorinated chain lengths greater than eight carbons. Long-chain PFAS dominated the PFAS profiles of the macroinvertebrates for all groups of compounds studied (PFCA, PFSA, and FTS). These results indicate that the study organism has the greatest impact on bioaccumulation, although divalent cation concentration had observable impacts between organisms depending on the environmental conditions. Elevated cation concentrations in the microcosms led to significantly greater bioaccumulation in the test organisms compared to the experimental reference conditions for long-chain PFAS.
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Li LL, Dong Y, Wang RX, An N, Yun X, Liu RZ. Sperm aneuploidy and implications for genetic counseling in a pedigree of three t(1;3) balanced translocation carriers. GENETICS AND MOLECULAR RESEARCH 2015; 14:5003-9. [PMID: 25966275 DOI: 10.4238/2015.may.12.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A reciprocal translocation between the short arm of chromosome 1 and the long arm of chromosome 3 was observed in a pedigree of three carriers (proband, and his brother and mother). In this study, the three carriers had different clinical manifestations: the proband with infertility, his brother with spousal miscarriages, and his mother with no adverse reproductive history. Cytogenetic analysis of metaphase chromosomes was performed, and triple-color fluorescence in situ hybridization was applied to the detection of aneuploidy sperm related to the interchromosomal effect (ICE). An increase of aneuploidy of chromosome 21 in the proband and aneuploidy of chromosomes 13, 21, and Y in the brother were observed. Since patients with reciprocal translocations and spermatogenetic impairment are candidates, with their partners, for intracytoplasmic sperm injection, the study of the level of sperm aneuploidy rates would provide useful information for couples at risk, as well as contributing to a better understanding of the ICE.
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Case Reports |
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Lyu WL, Deng W, Liu DY, Yun XY, Li CY. [Effects of two nanotopographies of ultraviolet-treated titanium implant surface on macrophage behaviour and inflammatory cytokines secretion]. ZHONGHUA KOU QIANG YI XUE ZA ZHI = ZHONGHUA KOUQIANG YIXUE ZAZHI = CHINESE JOURNAL OF STOMATOLOGY 2019; 54:183-187. [PMID: 30856696 DOI: 10.3760/cma.j.issn.1002-0098.2019.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the effects of two nanotopographies of ultraviolet (UV)-treated titanium surface on macrophage biological behaviour and inflammatory cytokines secretion, and to provide basis for clinical application of UV-treatment in dental implant modification. Methods: Titanium disks were allocated into two groups. Samples in one group were acid-etched in hydrofluoric acid (Acid Ti group), and those in the other group were acid-etched and anodized (Anodization group) to form two nanotopographies respectively. The surface morphology was evaluated by field-emission scanning electron microscopy (FE-SEM). The samples were stored in the dark for 8 weeks. Thirteen samples from each group were exposed to UV-irradiation for 48 h (Acid Ti+UV group and Anodization+UV group), UV-untreated samples from Acid Ti and Anodization groups served as control. Hydrophilicity of samples was measured using contact angle measuring device. After 4, 24 and 72 h of incubation, macrophage cell adhesion and proliferation were conducted using cell counting kit-8. Cytokine/chemokine secretions [tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α)] were measured from cell culture supernatants at 24 and 72 h using magnetic luminex assay. Cell morphology was examined using FE-SEM after 2 h of incubation. Results: Micropitted/nanopillar and micropitted/nanotubular topographies were observed in Acid Ti group and Anodization group respectively. Contact angles in Acid Ti+UV and Anodization+UV groups (20.2°±2.8° and 0.0°±0.0°) were significantly smaller than those in the Acid Ti and Anodization groups (P<0.05). Cell adhesion and proliferation in all groups at 4 and 24 h showed no difference (P>0.05). Cell proliferation in Acid Ti+UV and Anodization+UV groups at 72 h were (0.92±0.13) and (1.10±0.08) respectively, which were significantly higher than those in Acid Ti and Anodization groups. TNF-α concentration in Acid Ti+UV and Anodization+UV groups at 72 h were (1.03±0.11) and (0.87±0.10) ng/L, MCP-1 were (301.7±50.3) and (240.8±18.7) ng/L, MIP-1α were (224.9±30.6) and (233.9±14.9) ng/L respectively, which were significantly lower than those in Acid Ti and Anodization groups (P<0.05). Conclusions: UV treatment can increase hydrophilicity of two titanium surface topographies, especially of Anodization+UV group. UV-treated titanium surfaces can promote macrophage proliferation and reduce the inflammatory response in vitro.
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Zhao W, Zhang Q, Zheng H, Bai Y, Yu Y, Chen Z, Yun X, Liu SD. Resonance coupling between chiral quasi-BICs and achiral molecular excitons in dielectric metasurface J-aggregate heterostructures. OPTICS LETTERS 2023; 48:1252-1255. [PMID: 36857260 DOI: 10.1364/ol.483147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
The realization of flexible tuning and enhanced chiral responses is vital for many applications in nanophotonics. This study proposes to manipulate the collective optical responses with heterostructures consisting of chiral dielectric metasurfaces and achiral J-aggregates. Owing to the resonance coupling between the chiral quasi-bound states in the continuum (QBICs) and the achiral exciton mode, large mode splitting and anticrossing are observed in both the transmission and circular dichroism (CD) spectra, which indicates the formation of hybrid chiral eigenmodes and the realization of the strong coupling regime. Considering that the radiative and dissipative damping of the hybrid eigenmodes depends on the coherent energy exchange, the chiral resonances can be flexibly tuned by adjusting the geometry and optical constants for the heterostructure, and the CD of the three hybrid eigenmodes approach the maximum (∼1) simultaneously when the critical coupling conditions are satisfied, which can be promising for enhanced chiral light-matter interactions.
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Li H, Li J, Yun X, Fok A. Acoustic emission measurement of micro-debonding in composite restorations during polymerization. Dent Mater 2010. [DOI: 10.1016/j.dental.2009.11.092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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