ABSTRACT
Glass fibers are widely used in cement-based precast products, given the reinforcing requirements for toughness and strength. However, inferior alkali resistance hinders the effectiveness of glass fibers in reinforcing cement-based materials. In this paper, nanoparticle coatings were applied on the surface of alkali-resistant glass fiber (ARGF) as a protective layer via the in situ chemical reaction of oleic acid (OA) and potassium permanganate (PP). The morphology and constituents of the as-prepared ARGFs were examined using scanning electron microscopy (SEM) and obtaining X-ray photoelectron spectroscopy (XPS) measurements. Mass loss and strength retention were investigated to characterize alkali resistance of modified ARGFs. Results showed that ARGFs could be optimally coated by a layer of MnO2-based nanoparticles consisting of approximately 70% MnO2, 18% MnO, and 12% MnSiO3, when modified with an optimum OA to PP ratio of 10 for 24 h. The dissolution of ARGFs matrix in 4% and 10% NaOH solutions were distinctly delayed to 28 d, as a consequence of the introduction of the MnO2-based nanoparticle layer, compared with nontreated ARGF occurring at 3 d in 4% NaOH solution. For the optimally modified ARGFs, the mass loss was controlled to 1.76% and 2.91% after 90 d of corrosion in 4% and 10% NaOH solutions, and the retention of tensile strength was increased by approximately 25%. With respect to the increment in alkali-resistant performance, the modified ARGFs can be promising candidates for wide applications in alkaline cement-based products.
ABSTRACT
BACKGROUND: Gallbladder polyps are one indication for cholecystectomy, but this procedure carries some disadvantages, including the potential for severe injury and high risk of post-operative complications. Laparoscopy combined with endoscopic surgery is a minimally invasive treatment option. We herein report a young patient with a gallbladder polyp who was successfully discharged from the hospital after laparoscopic-assisted endoscopy. This procedure may offer an alternative in the management of such lesions. CASE SUMMARY: A 24-year-old female patient was hospitalized primarily for a gallbladder polyp. Due to the surgical risk associated with cholecystectomy and the low post-operative quality of life, the woman underwent laparoscopic-assisted transumbilical gastroscopy for gallbladder-preserving polypectomy under endotracheal intubation and general anaesthesia. The operation went smoothly. CONCLUSION: We conclude laparoscopic-assisted transumbilical gastroscopy for gallbladder-preserving polypectomy is a safe and effective technique for the treatment of gallbladder polyps.
