UiO-66 Selective Enrichment Integrated with Thermal Desorption GC-MS for Detection of Benzene Homologues in Ambient Air.

In this study, UiO-66 was selected as sorbent media packed in the tube to selectively enrich trace levels of benzene homologues such as benzene, toluene, and xylene (BTX) in ambient air prior to thermal desorption (TD)-GC-MS determination. A series of experiments were conducted to obtain the optimal TD conditions. The results indicated that the optimal TD parameters were as follows: desorption temperature of 180°C, desorption flow rate of 50 mL min-1, and desorption time of 30 min. Furthermore, the method based on UiO-66 enrichment integrated with TD-GC-MS for trace levels of BTX was successfully developed. It exhibited a good linearity (R 2 > 0.99) in the range of 50-1000 ng, except for p, m-xylene in the range of 100-2000 ng, and achieved the recovery of 69.4-101.3%, and the relative standard deviation of 3.8-6.4%. The detection limits of BTX were 1.6-4.0 ng; according to 10 L of sampling volume, the method detection limits would be in the range of 0.16-0.40 µg m-3. Additionally, the method was successfully applied to determine BTX in indoor air and showed good selectivity and sensitivity. In summary, the findings in this work revealed that UiO-66 was an attractive adsorbent for selective enrichment trace levels of BTX compounds in ambient air, which was favorable for the subsequent detection by TD-GC-MS.

[Neuroendocrine neoplasm of digestive system with different grades: a clinicopathologic and prognostic study].

OBJECTIVE: To study the clinicopathologic and prognostic features of neuroendocrine neoplasm of digestive system with different grades. METHODS: The clinicopathologic features of 139 cases of neuroendocrine neoplasm occurring in digestive system were retrospectively reviewed and graded according to the 2010 World Health Organization classification of tumours of the digestive system. Immunohistochemical study for synaptophysin, chromogranin A and Ki-67 was carried out. The follow-up and survival data were analysed using Kaplan-Meier method. Prognostic factors were tested by Log-rank testing and independent risk factors were analysed using Cox regression model. RESULTS: Amongst the 139 cases studied, there were 88 cases (63.3%) of grade 1 tumors, 9 cases (6.5%) of grade 2 tumors and 42 cases (30.2%) of grade 3 tumors. There was diffusely positive staining for synaptophysin and chromogranin A in most of the grade 1 and grade 2 tumors. The staining in grade 3 tumors however was focal (P < 0.05). The differences in tumor size, depth of invasion, presence of tumor emboli, perineural permeation, nodal involvement, distant metastasis and survival rate amongst the three groups was statistically significant (P < 0.05). CONCLUSIONS: There is significant difference in the clinicopathologic and prognostic features of neuroendocrine neoplasm of digestive system with different grades. It is considered as an independent prognostic factor and represents a useful tool for prognostic evaluation of such tumors, both in clinical practice and research.

[Association of HER2 protein expression with clinicopathologic features and prognosis in Chinese patients with gastric carcinoma].

OBJECTIVE: To evaluate the epidemiological status of HER2 protein expression in Chinese patients with gastric carcinoma, and to study its clinical and prognostic significance and the association with the clinicopathological features. METHODS: The clinical data were reviewed in 860 patients with gastric carcinoma admitted to Guangdong General Hospital from 2003 to 2010. The HER2 status was evaluated using immunohistochemistry (IHC). The modified HercepTest scoring criterion was used to assess HER2 protein expression. The association between HER2 expression and clinicopathological features was analyzed by χ(2) test. Kaplan-Meier analysis, log-rank test and Cox regression model were used for the survival analysis. RESULTS: The median age of the patients was 59 years, and the male-to-female ratio was 2.06:1. Positive expression of HER2 protein (3+) was found in 77 (9.0%) cases of gastric carcinoma, and in 69 (8.9%) advanced gastric cancers. There was significantly positive association between HER2 over-expression and tumor differentiation, Lauren classification and WHO classification. No significant association was observed between HER2 protein expression and patients' age, gender, tumor location and clinical stage. There was no statistically significant difference in survival rate between patients with positive HER2 expression and negative ones. CONCLUSION: Though there was significantly positive association between HER2 expression status and tumor differentiation, histological type, it may be of limited prognostic value in gastric cancer patients.