Objective To explore the influence of laparoscopic CO2 pneumoperitoneum on blood metastasis of colorectal cancer.Methods Sixty colorectal cancer patients were randomly divided into laparoscopic surgery group and open surgery group.RT-PCR was used to detect the expressions of CK20mRNA before treatment,in operation and after operation,and effect of different surgical methods on the metastasis of tumor cells in peripheral blood was analyzed.Results There were no significant differences in positive expression of CK20mRNA before treatment,in operation and after operation between two groups (P ＞ 0.05).There was no significant difference in 3-year survival rate between the two groups (P ＞ 0.05).Conclusion Laparoscopic CO2 pneumoperitoneum does not increase the positive rate of CK20mRNA in peripheral blood in treatment of patients with laparoscopic resection of colorectal cancer.

Objective To explore the influence of laparoscopic CO2 pneumoperitoneum on blood metastasis of colorectal cancer.Methods Sixty colorectal cancer patients were randomly divided into laparoscopic surgery group and open surgery group.RT-PCR was used to detect the expressions of CK20mRNA before treatment,in operation and after operation,and effect of different surgical methods on the metastasis of tumor cells in peripheral blood was analyzed.Results There were no significant differences in positive expression of CK20mRNA before treatment,in operation and after operation between two groups (P ＞ 0.05).There was no significant difference in 3-year survival rate between the two groups (P ＞ 0.05).Conclusion Laparoscopic CO2 pneumoperitoneum does not increase the positive rate of CK20mRNA in peripheral blood in treatment of patients with laparoscopic resection of colorectal cancer.

Objective The experiment project was designed to explore the variation of NaI (Tl) gamma spectrometer channels with environmental temperature. ⁶⁰Co and ¹⁵²Eu were used to verify the reliability of the correction methods. Methods Two correction methods were applicated, which were curve fitting correction method and known measurement peak correction method. Results The experimental results showed that temperature changes had an effect on NaI (Tl) measured spectra peak. The relative peak will shift to the right at 5℃ by 9.6%, and to the left at 60℃ by 16%, with the reference temperature set at 25℃. The two methods are based on the channel change due to temperature changes, and they could effectively correct the temperature peak-drift. Conclusion In order to make the measured spectrum information accurate and reliable in field monitoring, it is suggested to monitor the environmental temperature so as to correct the measured data.