Study on the Development and Performance of a New Concrete Antifoaming Agent

Gemini surfactant acetylene glycol polyethers and polyhydrosilicone oil were used as raw materials to generate the acetylene glycol surfactants with defoaming, antifoaming properties, and polyether modification through a hydrolyzation reaction. A novel silicone surfactant based on acetylene glycol-modified polyoxysilane, which has the advantages of low surface tension and good water solubility. Its structure characterized by infrared. Finally, the new silicone surfactant prepared was emulsified with a composite emulsifier, and a new concrete defoamer was prepared by a mechanical method. The defoaming performance, foam suppression performance and surface tension were tested. The results showed that the new silicone surfactants contained functional groups of acetylene glycol and siloxane. The composite emulsifiers were Span40 and Tween60, which the HLB value was 10, the amount was 5% and the emulsification time was 30 minutes. The prepared new concrete defoamer has good defoaming and antifoaming properties with a low surface tension.

Effect of Antifoaming Agent on Colorectal Benign Tumours in Colonoscopy: A Meta-Analysis

Background: Although several trials have showed that addition of antifoaming agent to polyethylene glycol (PEG) can improve bowel preparation, whether PEG plus antifoaming agent has a beneficial role in detection of benign tumours during colonoscopy has yet to be confirmed. Our aim was to clarify whether adding simethicone to PEG solution could improve the effect of detection of colorectal benign tumours.Methods: The PubMed, EMBASE, and Cochrane Library databases were searched for articles published prior to September 2019. The outcomes included the detection rates of colorectal adenomas and polyps.Results: Twenty studies were eligible. Although there was no difference in the colorectal adenoma detection rate (ADR), a significant effect of simethicone for diminutive adenomas (< 10 mm) was revealed in the group with simethicone. We also found that simethicone could significantly improve the ADR in proximal colon, but did not affect the colorectal polyp detection rate (PDR). Furthermore, the subgroup analyses revealed that the beneficial effect of simethicone in the ADR among Asian (P=0.005) and ADR < 25% (P =0.003). Moreover, it was a significant finding that the low dose simethicone was as effective as the high dose one with respect to the detection of colorectal benign tumours.Conclusions: In summary, the addition of simethicone to PEG might benefit to improve diminutive adenomas in the right colon for colonoscopy in Asia. The low-dose simethicone was recommend to the detection of colorectal benign tumours. However, large clinical trials are necessary to validate our results and determine the ideal dose of simethicone.