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Objective To establish a simultaneous detection approach for 34 emerging contaminants(ECs)in tap water by liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).Human health risk assessment was performed according to the detection results from 43 tap water samples.Methods Tap water samples were concentrated and extracted by solid phase extraction,and then blown to near dry by nitrogen at 40℃.The sample extracts were dissolved in methanol-water solution(95:5,VN)to 0.5 mL for analyzing.Agilent Jet Stream Electrospray Ionization(AJS ESI)and the multiple reaction monitoring(MRM)mode were performed for MS to acquire the data of 34 ECs.A database including precursor ion,product ion and retention times was established accordingly.Results The average linear correlation coefficients(r)of 34 kinds of ECs was 0.995 9.The limits of detection were 0.01～0.60 ng/L and the recoveries were between 60.7％and 119.8％.The intra-group precisions were between 0.05％～9.89％and the intra-day precisions were between 0.20％～14.40％for the spiked samples.The method was applied to analyze 43 tap water samples and a total of 15 ECs were detected.According to the results,the detection rate of caffeine was the highest(84％),and the concentration range was ND～74.42 ng/L.Among all the ECs detected,1,2,3-benzotriazole had the highest concentration(ND～361.15 ng/L),where detection rate was 44％.Humans may be exposed to these ECs by drinking the tap water.The human health risk assessments of 12 kinds of ECs were carried out,however,the estimated risk was negligible(risk quotient＜0.01).Conclusion The method is simple,highly sensitive and selective,and could meet the detection needs of ECs at trace level in tap water.There was no human health risk posed for ECs identified in 43 tap water samples analyzed by this method.
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Objective To compare the corneal biomechanical parameters identified from uniaxial tensile test under fast and slow loading. Methods The stress-strain and stress relaxation data were obtained from uniaxial tensile tests on corneal strips from 15 healthy adult rabbits at average loading rate of 0.16 mm/s and 0.02 mm/s, respectively. A visco-hyperelastic model was applied to analyze the loading and unloading data from the fast tensile tests, where the model parameter set was denoted by Gvh. The first-order Ogden model and second-order Prony series model were used to fit stress-strain and stress relaxation data from the slow tensile tests, respectively, in which the model parameter set was denoted by Gvh. Correlation analysis was used to compare the correlation of parameters between Gvh and GOP. Results All the goodness-of-fits to the three data sets were greater than 0.95. There were significant differences in 5 (μ, A1, A2, τ1, τ2,) of the 6 parameters between Gvh and GOP (P<0.05), and the Ogden model parameters was positively correlated between the two groups. Conclusions There are differences in corneal biomechanical parameters identified by data from uniaxial tensile tests under fast and slow loading. The results provide a preliminary research basis for further exploring the use of clinical data to identify corneal biomechanical properties.
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Objective:To discuss the autoimmune response on the mechanism and clinical significance of nerve root injury induced by the non-compressive nucleus pulposus protrusion.Methods:Forty-eight female SD rats were randomly divided.Twenty-four female SD rats were recruited as model group,and the others as control.After ten days,twenty days and forty days,the pain threshold of left hind leg and the levels of TNF-α, CD4+, CD8+T cells were measured, the nerve root changes in morphology were observed by HE.Results:Compared with the control group,model group in ten days,twenty days,which left hind leg pain threshold,the proportion of CD4,CD8+T cell and the expression of TNF-αare significantly different.After forty days,these two groups have no statistical differ-ence.After ten days,lumbar nerve root cross-sectional myelin of model group was partial disintegrated.The worst damage happened in twenty days,and almost recovered to normal in forty days.Conclusion:T cell-mediated autoimmunity and TNF-αplay an important role to the nerve root injury in the early time of the non-compressive nucleus pulposus protrusion.
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Through comparative study on Naotaifang containing serum and plasma proteomics (peptide), this article revealed differential proteins (peptides) in the Naotaifang. The characteristics of differential proteins were identified with mass spectrometry. It provides scientific evidences for the pharmacodynamic material basis and Chinese herbal medicine plasma pharmacological method development in the exploration of Naotaifang. A total of 20 healthy adult SD rats were randomly divided into the control group, Naotaifang treatment group according to their weights. Ten rats in each group. Intragastric administration of medication was given for seven consecutive days. Before surgery, rats were fed with water but without food. One hour after the last drug administration, 10% chloral hydrate was injected for intraperitoneal anesthesia. Blood was taken through the common carotid artery. Serum and plasma samples were made after blood was taken from each rat. Serum and plasma samples of five rats were randomly selected from each group. And the two-dimensional electrophoresis (2-DE) technique was used in the comparative study of serum pro-teomics (peptide). The 300 DPI scanning and PDQuest 7.3.0 were used in the analysis. The ESI-MS/MS was used to identify important differences in proteins and screen characteristic serum and plasma protein. The results showed that 20 differential proteins of 5 plasma samples were identified. There were 15 types of proteins expressing up-regulation and 5 types expressing down-regulation. Comparative analysis on the 2-DE gel pictures of Naotaifang containing serum, 19 differential proteins of 5 plasma samples were identified, among which 15 types of proteins express up-regulation and 4 down-regulation. Comparative analysis on the 2-DE gel pictures of Naotaifang containing serum and Naotaifang containing plasma showed that 24 differential proteins of 5 plasma samples were identified, among which 9 types of proteins express up-regulation and 15 down-regulation. The highly expressed proteins were selected to MALDI-TOF-MS between Naotaifang containing serum and Naotaifang containing plasma. There were six successful-ly identified proteins, which were inter-alpha trypsin inhibitor, heavy chain 3, group-specific component, comple-ment factor B, Receptor Complexed with A Heterodimeric Fc, isoform CRA-d, Transferrin. It was concluded that protein with obvious changes in the Naotaifang containing serum and plasma may be related with fibrinolysis and an-ticoagulant. These proteins are involved in angiogenesis, inflammation and other pathological regulations of physiolog-ical processes. They are of great significance in the study of effective target and its signal transduction pathway of Naotaifang.