[Analysis of Heavy Metal Pollution Evaluation and Correlation of Farmland Soil and Vegetables in Zhaotong City].

A farmland area in Zhaotong City was taken as the research object， and the method of point-to-point collaborative sampling was used to collect farmland soil and vegetables in Zhaotong and test the content of six heavy metals， namely As， Pb， Cu， Zn， Cd， and Cr. The geo-accumulation index and potential ecological risk index were used to evaluate the heavy metal pollution of soil. The health risk model was used to evaluate the risk to the human body imposed by vegetables. The results showed that Cu， Zn， Pb， Cd， and Cr pollution existed in the research area. Compared with the risk screening value of farmland， the over-standard rates were 34.35%， 6.87%， 2.29%， 80.15%， and 6.11%， respectively； Pb， Cd， and Cr were found in vegetables. Compared with the pollutant limit in food， the over-standard rates were 6.87%， 15.27%， and 36.64%， respectively. According to the soil pollution evaluation， Cd in the soil showed a strong ecological risk， and other heavy metals in the soil showed a mild ecological risk. The human health risk evaluation model showed that both non-carcinogenic risk and carcinogenic risk were out of the acceptable range and had a greater influence on children. Correlation analysis showed that As in the soil had an antagonistic effect on Cu and Zn absorption by vegetables， whereas Cr in the soil could promote Cu and Zn absorption by vegetables.

Outcome of papillary thyroid microcarcinoma: Study of 1,990 cases.

The present study examines the requirement of prophylactic neck node dissection in papillary thyroid microcarcinoma (PTMC) patients by analyzing high-risk factors of neck lymph node metastasis in PTMC. The clinical pathological data was a review of 1,990 patients diagnosed between January 2013 and January 2014. The data included information on patient gender, age, tumor size, multifocal, tumor pathological staging, bilateral thyroid cancer, the subtypes, BRAFV600E mutation, human telomerase reverse transcriptase (hTERT), extrathyroidal invasion and neck lymph node metastasis. The univariate analysis (χ2 test) showed that a number of factors were significantly associated with neck lymph node metastasis in PTMC (P<0.05): Male gender, aged <45 years, extrathyroidal invasion, bilateral thyroid cancer, various subtypes (package type, follicular variant, diffuse sclerosing variant, eosinophils, tall cell and column variant), BRAFV600E mutation-positive, hTERT mutation-positive, pt3/4 and multifocality. The multivariate analysis (regression binary logistic) showed that the male gender, <45 years, tumor size >5 mm, extrathyroidal invasion, bilateral thyroid tumors, multifocality, BRAFV600E mutation-positive, hTERT mutation-positive and pt3/4 are associated with the neck lymph node metastasis in PTMC (P<0.05). These paired analysis results show that the subtypes of PTMC with tumor size >5 mm is more common than the specific types of PTMC in which the tumor is ≤5 mm in neck lymph node metastasis. The neck lymph node metastasis incidence of the >45 years age group patients without high-risk factors in PTMC is 8.13 and 6.80%, respectively. In conclusion, PTMC patients with high-risk factors only are recommended to undergo a prophylactic lymph node dissection.