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BACKGROUND When using inductively coupled plasma-mass spectrometry (ICP-MS) to analyze soil, the zirconium hydroxide, molybdenum oxide, and tin isotopes can cause serious interference on cadmium, which makes it difficult to accurately determine cadmium in soil samples. OBJECTIVES To develop a method for accurate determination of Cd in soil samples. METHODS ICP-MS/MS was used, and 111Cd without isobaric interference was selected as the analysis line. In MS/MS mode, the oxygen introduced into the collision reaction cell can be reacted with 111Zr16O1H+, 111Mo16O+, inducing electron transfer, dehydrogenation, oxygenation and other reactions to inhibit the overlapping interference of these polyatomic ions on 111Cd. RESULTS Oxygen flow was the key factor in this method. 0.45mL/min oxygen flow can reduce oxide interference to less than 0.005μg/L when zirconium concentration was lower than 2000μg/L and molybdenum concentration was below 1000μg/L. The method has been verified by the national reference materials. The relative error of the measured value and recognized value of the 11 national reference materials was within ±7%, and the relative standard deviation (n=12) of three soil reference materials was less than 5%. CONCLUSIONS Triple quadrupole ICP-MS oxygen reaction mode can eliminate Zr and Mo polyatomic ion interference on Cd, and this method can be used for the determination of trace Cd in soil samples.

Microwave Digestion-Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry (ICP-MS/MS) was used to determine sulfur in crop samples, and a high sensitivity sulfur detection method in crop samples was provided. The measurement mode, interference elimination effect, linear range, detection limit and accuracy of the method were tested. The results show that the MS/MS oxygen mode can effectively eliminate the mass spectrum interference of sulfur, the method has high sensitivity, the detection limit of the method reaches 1.8 µg/g, and the sample with sulfur content below 2% can be directly analyzed by the method. The method was verified by national standard material, and the measured values were within the range of nominal value. It can be used as a new detection method for sulfur element analysis in crop samples.

The quality of regional geochemical survey samples is currently estimated indirectly by internal and external laboratory quality control. The method described here effectively improves the quality of geochemical samples. However, the improvement of the method is limited when the contents of the actual samples and external quality control samples have large differences. Since most elements are in accord with a normal distribution in a regional geochemical survey sample, a comparison was made between the real and standard normal distribution of the elements, which passed the normal distribution test and gave an estimate of the quality by using a comparison of the real and standard graph′s superposition using SPSS and Excel software. This method was directly applied to estimate the quality of analysis data for geochemical survey samples in Jiangxi province. The result of the normal distribution test indicated that the analysis data of the trace elements need a logarithmic conversion before the normal distribution can be studied. The quality evaluation method in this paper was not suitable for Ti, W and Cr etc in this area. The overlap ratios of 18 elements such as Co, Hg and Ga were more than 0.9. The overlap ratios of CaO and Na2O were less than 0.9. The results of the actual samples indicated that the detection limits need to be reduced in order to improve the analysis qualities of CaO and Na2O. It was a valuable attempt to directly evaluate the quality of analysis data for regional geochemical survey samples by using the method reported in this paper, which was a reference and supplement for the current methods of quality evaluation.

Knowledge of potential tumor markers may improve chemotherapeutic efficacy. Interleukin-6 (IL-6) expression in local tumor tissues is associated with cancer progression and poor prognosis in variety of cancer types. The aim of the present study was to investigate the role and potential application of IL-6 in determining the prognosis of esophageal carcinoma. KYSE170 and TE13 esophageal cancer cell lines were used to conduct cell- and animal-based experiments investigating biological changes and tumor behavior. Immunohistochemical analysis revealed that 70-80% of cancer cells exhibited positive staining for IL-6, compared with <15% of non-malignant epithelial cells. These immunohistochemical results were consistent with the mRNA expression levels detetced. The IL-6 silencing vector significantly reduced invasion and proliferation of the two cell lines and attenuated tumor growth in xenograft mouse models (P<0.05). The IL-6 silencing vector markedly reduced the presence of Ki-67 (a typical proliferation marker) and microvessel density, indicating that downregulation of IL-6 levels may greatly affect tumor growth and inhibition. The IL-6 silencing vector increased E-cadherin and matrix metalloproteinase (MMP)-9 expression levels in the two esophageal carcinoma cell lines. This vector also regulated the release of IL-6 in cell supernatant and serum in KYSE170- and TE13-tumor-bearing mice. The secretion of vascular endothelial growth factor and cluster of differentiation 31 (a nuclear protein) immunoreactive molecules were also reduced by the IL-6 silencing vector. Therefore, IL-6 may be an important trigger in the progression of angiogenesis and endothelial tube formation within the tumor, and targeting IL-6 may be a promising strategy for the treatment of esophageal cancer.

Aim: To conduct a meta-analysis to estimate the determinants of the association between erosive esophagitis (EE) and body mass index (BMI)., Methods: We identified the studies using PubMed. Studies were selected for analysis based on certain inclusion and exclusion criteria. Data were extracted from each study on the basis of predefined items. Meta-analyses were performed to verify the risk factors, such as obesity and gender., Results: Twenty-one studies were included in this systematic review. These studies demonstrated an association between increasing BMI and the presence of EE [95% confidence interval (CI): 1.35-1.88, overweight, odds ratio (OR) = 1.60, P value homogeneity = 0.003, 95% CI: 1.65-2.55, obese, OR = 2.05, P < 0.01]. The heterogeneity disappeared by stratifying for gender. No publication bias was observed in this meta-analysis by the Egger method., Conclusion: This analysis demonstrates a positive association between BMI and the presence of EE, especially in males. The risk seems to progressively increase with increasing weight.