No abstract

Background: Healthy obesity means obese individuals remain free of metabolic health complications. Several researches link microbiota changes to obesity, focus on metabolic role of IL-6 and its ability to alter fat metabolism and correlate circulating calprotectin concentration to morbid obesity. This study evaluated the relative abundance of gut microbiota (Prevotella and γ-Proteobacteria), estimated the serum levels of inflammatory mediators (IL-6 and calprotectin) and studied the correlation between them in healthy obese and normal weight adults. Methods: 33 healthy obese (HO) and 14 normal weight (NW) controls were included. Serum levels of IL-6 and calprotectin were estimated by ELISA. Abundances of Prevotella and γ-Proteobacteria were determined in stool using real time PCR. Results: IL-6 and calprotectin levels were significantly lower in HO than in NW (p=0.001, p=0.001 respectively) with significant negative correlation between IL-6 and body mass index (BMI) in HO (r=-0.438, p=0.011) and negative but statistically insignificant correlation with BMI in NW groups (r=-0.024, p=0.935). There was negative but statistically insignificant correlation between calprotectin and BMI in HO (r=-0.075, p=0.677) and NW (r=-0.381, p=0.179). Prevotella and γ-Proteobacteria abundances were higher in HO than in NW and insignificant (p=0.31, p=0.55 respectively) with significant positive correlation between Prevotella and γ-Proteobacteria abundance in HO (r=0.436, p=0.011), positive and insignificant correlations between abundance of Prevotella and levels of IL-6 in HO and NW (r=0.303, P=0.086 vs r=0.316, p=0.272 respectively). Conclusion: IL-6 and calprotectin have role in regulation of energy homeostasis. Elevated abundances of Prevotella and γ-Proteobacteria may be the primary shifts in gut microbiota of HO.

Two-dimensional structures like plates and cylindrical shells must be analyzed in the two directions simultaneously to get a true analysis of these structures, but in traditional methods these structures are analyzed by solving each direction alone as one-dimensional structures without taking into consideration the effect of the other direction. This approximation in analysis tends to give big differences in deformations, displacements, and straining actions. Due to theory of plasticity, the plane strain in X-direction tends to contribute of strain in Y-direction. To make a fruitful comparison between spatial and traditional methods one model solved in textbooks was taken into consideration. This model is a cylindrical shell solved by spatial method with the same conditions of the solved traditional method model, but with 3-d model. The straining actions of two methods were compared. Normal force in the spatial method was bigger than traditional method by 4 times, the transverse bending moments in traditional method were much bigger than corresponding values in spatial method by values ranging between 40-140%, and the longitudinal normal stresses in traditional method were bigger than spatial method in compression by 40% and in tension by 100%. This proved that traditional method overestimates the straining action and stresses compared to the spatial method based on 3 dimensional analyses.