Objective To study the mechanism of Helicobacter Pylori inhibiting the healing of acetic acid - induced gastric ulcer in rats. Methods Rats were infected with Helicobacter Pylori and the model of acetic acid gastric ulcer was replicated at 4 weeks after in-fection. Amount of G cell and D cell in mucosa of gastric antrum, quantity of gastric juice and pH were measured at the 3rd,Sth, 16th day after the model was replicated. Results When the group of Hp + acetic acid ulcer compared with the group of acetic acid ulcer, the number of G cell, quantity of gastric juice increased (P < 0.01), and the number of D cell and pH decreased (P < 0.01). Conclusion Helicobacter Pylori inhibits ulcer healing through increasing gastric acid secretion.

A microfluidic chip with integrated microelectrode for real-time dopamine detection was designed and fabricated. The chip consisted of a polydimethylsiloxane ( PDMS) channel plate and a glass electrode plate. One central channel as the culture chamber of neural stem cells and two lateral channels for transport of the culture medium were integrated on the PDMS channel plate. Microelectrodes for real-time dopamine detection were integrated on the glass electrode plate. To solve the problem in demoulding the PDMS channel plate from the silicon mould, a novel demoulding method was developed. An Au-Au-Au three-electrode system was constructed, and it performed well in electrochemical detection. The performance of the microfluidic chip was primarily studied by detecting dopamine dissolved in the medium for the culture of neural stem cells. The limit of detection was 3. 92 μmol/L, the linear detection range was from 10 μmol/L to 500 μmol/L, and the detection reproducibility from different chips was less than 4%.