Ultravilolet-radiation-induced graft polymerization of acrylamide onto the melt-blown polypropylene filter element by dynamic method.

By dynamic method under UV irradiation, commercial melt-blown polypropylene (PPMB) filter element was modified with acrylamide (AAm) using benzophenone (BP) as initiator. Attenuated total reflection-Fourier transform infrared spectroscopy and scanning electron microscope verified that polyacrylamide chain was grafted on the fiber surface of PPMB filter element. Elemental content analysis with energy dispersive X-ray of fibers revealed that the polymerization content in the inner part of filter element was relatively higher than that in the outer. Degree of grafting changed with initiator concentration, monomer concentration, reaction temperature and reached 2.6% at the reaction condition: CBP=0.06 mol/L, CAAm=2.0 mol/L, irradiation time: 80 min, temperature: 600 degrees C. Relative water flux altered with the hydrophilicity and pore size of filter element. In the antifouling test, the modified filter gave greater flux recovery (approximately 70%) after filtration of the water extract of Liuweidihuang, suggesting that the fouling layer was more easily reversible due to the hydrophilic nature of the modified filter.

[Effect of laparoscopic proctectomy and open proctectomy on plasma levels of vascular endothelial growth factor].

OBJECTIVE: To investigate the effect of laparoscopic and open proctectomy on plasma levels of vascular endothelial growth factor (VEGF). METHODS: From January 2011 to December 2012, 100 rectal cancer patients in Shantou Central Hospital were enrolled in the study. Patients were divided into laparoscopic (LR) group and open (OR) group based on the decision of the patients. There were 63 patients in the LR group (44 cases undergoing low anterior resection and 19 abdominoperineal resection) and 37 patients in the OR group(26 cases undergoing low anterior resection and 11 abdominoperineal resection). Double antibody sandwich enzyme-linked immunohistochemistry was used to detect the level of VEGF on 1-day before and 1-day, 3-day, 7-day after operation. RESULTS: In the LR group, the postoperative levels of VEGF increased slowly, and the level of VEGF was significantly higher than that before operation until the 7-day after operation(P<0.05) regardless of the procedure. In the OR group, all the postoperative levels of VEGF were significantly increased(P<0.05). There was no significant difference of the VEGF level on 1-day before and 1-day after operation between the two groups(all P>0.05). The VEGF level in the OR group was significantly higher than that in the LR group on the day 3 and day 7 after operation(P<0.05). CONCLUSION: Compared with open approach, laparoscopic proctectomy has smaller short-term impact on the plasma level of VEGF in rectal cancer patients.