The inhalation,exhalation,electronics system and clinical application of Newport E360 ventilator are introduced.Study and technical analysis are given on the working principles of dual servo gas delivery system(one for air and the other for oxygen).The safety system and circuit system are studied and analyzed to provide reference for engineers in equpiment department in hospital.

Objective To investigate effect of peripheral blood miR-21 expression on the clinicopathological features of gastric cancer before and after gastric surgery.Methods The peripheral blood was collected on the operative day and postoperative 7 d in 42 patients with primary gastric cancer surgery.The real-tine quantitative PCR was adopted to detect the relative expression of miR-21 in plasma with U6 as an internal reference gene.Results The plasma miR-21 expression level after gastric cancer operation was significantly down-regulated compared with before operation(P <0.01),the overall relative expression level was dropped by an average of 18.2 times;and it was found that the postoperative miR-21 expression in the patients with the tumor family history was up-regulated,the postoperative plasma miR-21 expression in the patients without the tumor family history was decreased by 22 times compared with before operation(P <0.05);the experimental results also fund that as the patient′s differentiation degree was changed from high to low,the lymph node metastasis rate was gradually increased,while postoperative average miR-21 expression was changed from low to high,showing the relative expression times of miR-21 were distributed in the four differentiated zones of high,middle,middle-low and low,which showed the correlation with the distribution of the lymph node metastasis rate in these four differentiation zones.Conclusion The peripheral blood MiR-21 detection has the clinical significance to early auxiliary diagnosis and the judgement of postoperative malignant degree.