RESUMO
BACKGROUND/PURPOSE: Maxillary posterior teeth have close anatomical proximity to the maxillary sinus floor. The aim of this retrospective study was to evaluate the associations between maxillary sinus membrane thickening and the adjacent teeth health by cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT images were collected from 235 Taiwanese patients. The sinus mucosal thickening >2â¯mm is considered a pathologic sinus membrane. Demographic data such as sex, age, the thickness of sinus membrane, and the adjacent teeth health were recorded, graded, and analyzed. RESULTS: A total prevalence of maxillary sinus membrane thickening of 36.6% (86/235) was found in this study. The sinus membrane thickening was significantly associated with periodontal bone loss (pâ¯<â¯0.001) and periapical lesions (pâ¯<â¯0.001), respectively. A multivariate logistic regression model demonstrated that males had a significantly higher risk of sinus membrane thickening than females (OR: 2.08, 95% CIâ¯=â¯1.21-3.56). The patients in the age group ≥60 years showed a 4.35-fold increased risk of sinus membrane thickening compared with the patients in the age group ≤35 years (95% CI: 1.94-9.77). Severe periodontal bone loss was significantly associated with mucosal thickening with an OR of 4.78 as compared with normal to mild group (95% CI: 1.69-13.58). The patients having teeth with apical lesions had a 5.04 time OR for sinus membrane thickening than those having teeth without apical lesions (95% C.I.: 2.37-10.69). CONCLUSION: The prevalence of maxillary sinus membrane thickening was more frequently occurred in male and older people. Periodontal bone loss and periapical lesions were significantly associated with maxillary sinus membrane thickening.
RESUMO
Looking for alternative energy sources has been an inevitable trend since the oil crisis, and close attentioned has been paid to hydrogen energy. The proton exchange membrane (PEM) water electrolyzer is characterized by high energy efficiency, high yield, simple system and low operating temperature. The electrolyzer generates hydrogen from water free of any carbon sources (provided the electrons come from renewable sources such as solar and wind), so it is very clean and completely satisfies the environmental requirement. However, in long-term operation of the PEM water electrolyzer, the membrane material durability, catalyst corrosion and nonuniformity of local flow, voltage and current in the electrolyzer can influence the overall performance. It is difficult to measure the internal physical parameters of the PEM water electrolyzer, and the physical parameters are interrelated. Therefore, this study uses micro-electro-mechanical systems (MEMS) technology to develop a flexible integrated microsensor; internal multiple physical information is extracted to determine the optimal working parameters for the PEM water electrolyzer. The real operational data of local flow, voltage and current in the PEM water electrolyzer are measured simultaneously by the flexible integrated microsensor, so as to enhance the performance of the PEM water electrolyzer and to prolong the service life.
RESUMO
We evaluated peripheral nerve regeneration using a biodegradable multi-layer microbraided polylactic acid (PLA) fiber-reinforced conduit. Biodegradability of the PLA conduit and its effectiveness as a guidance channel were examined as it was used to repair a 10 mm gap in the rat sciatic nerve. As a result, tube fragmentation was not obvious and successful regeneration through the gap occurred in all the conduits at 8 weeks after operation. These results indicate the superiority of the PLA materials and suggest that the multi-layer microbraided PLA fiber-reinforced conduits provide a promising tool for neuro-regeneration.
