Efficacy of premedication with activated Dimethicone or N-acetylcysteine in improving visibility during upper endoscopy

AIM:To assess the efficacy of N-acetylcysteine(NAC) and activated Dimethicone in improving endoscopic mucosal visibility.METHODS:A total of 148 patients were randomly allocated into four groups to receive one of the following premedications:group A:100 mL water alone;group B:activated Dimethicone plus water(up to 100 mL);group C:NAC plus water(up to 100 mL);and group D:activated Dimethicone and NAC plus water(up to 100 mL).A single endoscopist blinded to the patients group assessed the gastric mucosal visibility scores(range 1-4) at four sites.The sum of the scores from the four sites was considered as the total mucosal visibility score(TMVS).RESULTS:The patients in group B showed a significantly lower TMVS than those of groups A and C(P < 0.001).The TMVS in patients of group D was significantly lower than that of groups A and C(P < 0.001).The TMVS did not significantly differ between groups B and D(P > 0.05).The difference between TMVS of groups C and A was not significant(P > 0.05).CONCLUSION:Premedication with activated Dimethicone 20 min prior to the upper endoscopy leads to the best visibility.NAC does not improve visualization by itself.

Dimethicone-aided laser cutting of solar rolled glass

Solar rolled glass,with one micro-structure surface and another roughness surface,can cause diffuse refraction of the focused laser spot,and this phenomenon restricts the application of laser manufacturing.In this study,laser cutting of solar rolled glass with a thickness of 2.5 mm was successfully achieved with the help of dimethicone to ensure laser focusing.Dimethicone was coated on the top surface of the rolled glass processing zone,and a bottom–up multilayer increment with the spiral line was applied to control the cutting path.Different viscosity values of dimethicone were considered.Results showed that surface quality increased as the viscosity increased until a certain threshold was reached;afterward,the surface quality decreased or directly caused the cutting to fail.The minimum surface roughness(3.26µm)of the processed surface(chipping:Width≤113.64µm,area 215199µm)was obtained when the dimethicone viscosity and laser pulse frequency were 1000 mm/s and 43 kHz(power 25.4 W),respectively.The micro-defects on the processed surface were few,and the edge chipping width and depth of the laser processed surface were small.