An economic and facilely prepared dopamine ( DA) sensor have been successfully fabricated by the electrodeposition of copper on single-walled carbon nanotubes ( SWNTs )/Nafion-modified glassy carbon electrode. The morphology of the material was observed by scanning electron microscopy ( SEM) and element composition of the material was investigated by energy dispersive X-ray spectroscopy ( EDX ) . Tests with various scan rates and pH conditions indicated that an adsorption-controlled process occured in the electrochemical system. The mechanism of the electrode reaction of dopamine involved a two-electron process which was accompanied by a deprotonation step. Electrochemical parameters were calculated with the electron transfer number as 2 . 67 , the charge transfer coefficients as 0 . 6 , the apparent heterogeneous electron transfer rate constant as 1. 38 s-1 . Under the optimal conditions with differential pulse voltammetric measurement, the linear equation was Ipa(μA)=-0. 054c (μmol/L)-3. 82(R2=0. 9988), with linear range of 5-100 μmol/L and detection limit of 0 . 0135 μmol/L ( S/N=3 ) . The main advantages of sensor included facile fabrication approach, high sensitivity, good stability and high reproducibility. The sensor was applied to the detection of DA in volunteer urine by differential pulse voltammetry with favorable recoveries of 96 . 5%-100 . 4% and relative standard deviations (RSDs) of 1. 2%-2. 4%.

Objective:To evaluate clincal value of preoperative peripheral blood CD4/CD8 and neutrophil to lymphocyte ratio (NLR) in papillary thyroid carcinoma (PTC) coexisted with Hashimoto’s thyroiditis (HT) .Methods:Clinicopathological data of 202 patients diagnosed as PTC treated with operation from Jul.2016 to Jun.2019 were retrospectively analyzed. They were divided into Treatment Group including 94 PTC coexisted with HT and Control Group including 108 thyroid cancer according to the postoperateive pathology report. CD4+ and CD8+ subsets in peripheral blood were analyzed by flowcytometer and blood counts were measured before surgery.Results:There was no significant difference in gender, tumor size, number of lesions or lymph node metastasis between the two goups. In comparison with Control Group, median age was lower (39.5 vs 50.5, P=0.001) and CD4/CD8 raito (1.9731.973 Cvs 1.24141973 CD P=0.001) was higher in Treatment group. There was a higher proportion of bilateral lobe thyroidectomy in Treatment Group (40/94 vs 26/108, P=0.005) . A multivariate model analysis identified CD4/CD8 raito as independent risk factor for incidence of PTC coexisted with HT [ OR=0.035, 95% CI (0.009-0.093) , P=0.001]. The NLR level of thyroid cancer patients was correlated with lateral lymph node metastasis negatively (correlation coefficients=-0.286, P=0.045) . Conclusions:PTC might have some connection with HT mediated by body inmune status. Preoperative NLR level is correlated with lateral lymph node metastasis.