The aim of the study was to investigate the associations between physical activity (PA)-related miRNAs and metabolic syndrome (MetS). A case-control study was conducted in 209 subjects with MetS and 234 controls. The MetS was defined by the International Diabetes Foundation (IDF) criteria of 2005. Serum PA-related miRNAs were detected by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assays. Association analysis was performed by logistic regression models. The expression levels of miR-126 and miR-130a were lower in the highest metabolic equivalent hours per week (MET-h/week) quartile than in the lowest quartile [miR-126: Q5 vs. Q1, median (5-95%), 1.67 (0.54, 2.45) vs. 1.35 (0.45, 2.45), p=0.012; miR-130a: Q5 vs. Q1, median (5-95%), 0.90 (0.44, 1.35) vs. 0.53 (0.26, 1.01), p<0.001]. However, miR-197 exhibited a trend with increased MET-h/week [Q5 vs. Q1, median (5-95%), 1.35 (0.45, 2.63) vs. 2.18 (0.87, 4.77), p=0.009]. MiR-126 increased MetS risk significantly while the effect of miR-197 was opposite (miR-126: OR=1.37, 95% CI 1.07-1.75; p=0.012; miR-197: OR=0.68, 95% CI 0.51-0.92; p=0.010). Individuals in the highest MET-h/week quartile had lower prevalence and odds rate of MetS compared with those in the lowest quartile (Q4 vs. Q1: OR=0.58, 95% CI 0.33-1.05; p for trend=0.026). However, further adjustment of both PA associated miRNAs abolished that association. All these results suggested that the association between PA and MetS risk might partly depend on miR-126 and miR-197.
Objective:To investigate the principles of treatment for severe acute pancreatitis(SAP).Methods:A retrospective analysis of the clinical data of 78 cases of SAP.Three groups were divided according to different treatment methods,including early operation group 21 cases,dealy operation group 12 cases and non-operation group 45 cases.Results:The complication mobidity rate was 28.5%(6/21)、 75%(9/12)、 46.6%(21/45)respectively in early operation group、dealy operation group and non-operation group;the mortality rate was 14.3%(3/21)、 33.3%(4/12)、 17.8%(8/45)respectively in early operation group、dealy operation group and non-operation group.There were significant differences among the three groups(P0.05).The complication mobidity and mortality rates were the lowest in early operation group,conversely,and those were the highest in dealy operation group.As for the non-operation group,in the midist of them.Conclusion:The treatment of SAP should depend on the synthesized principle.The proper operation timing and methods will improve the treatment effect.
This study proposed a dynamic parameters’ identification method for the feeding system of computer numerical control machine tools based on internal sensor. A simplified control model and linear identification model of the feeding system were established, in which the input and output signals are from sensors embedded in computer numerical control machine tools, and the dynamic parameters of the feeding system, including the equivalent inertia, equivalent damping, worktable damping, and the overall stiffness of the mechanical system, were solved by the least square method. Using the high-order Taylor expansion, the nonlinear Stribeck friction model was linearized and the parameters of the Stribeck friction model were obtained by the same way. To verify the validity and effectiveness of the identification method, identification experiments, circular motion testing, and simulations were conducted. The results obtained were stable and suggested that inertia and damping identification experiments converged fast. Stiffness identification experiments showed some deviation from simulation due to the influences of geometric error and nonlinear of stiffness. However, the identification results were still of reference significance and the method is convenient, effective, and suited for industrial condition.
Owing to high hardness and high brittleness of SiC ceramic, it is difficult to machine into structural ceramic components with desired surface quality and dimensional accuracy. In this paper, a method of polishing SiC ceramic by underwater femtosecond laser was proposed. The influence of laser frequency and pulse energy on surface morphologies, 3 D profiles, depth and surface roughness of polished SiC ceramics during underwater femtosecond laser processing was investigated in detail. The experimental results indicated that the removal depth during underwater polishing increased and then decreased with the increase of laser frequency and pulse energy. The surface roughness increased as laser frequency increased. The surface roughness decreased and then increased with the increase of pulse energy. Through laser parameter optimization, a high quality polished surface without cracks, pits and debris redopesition was obtained under laser frequency of 40 kHz and pulse energy of 40 μJ. At this point, the average removal depth of 32.19 μm and the average surface roughness of 0.72 μm were obtained. The proposed method in this paper significantly improve surface finishment and higher dimensional accuracy of the machined SiC ceramic components.
Silicon carbide (SiC) ceramics, due to their excellent mechanical properties and oxidation resistance at elevated temperature, have a widespread application in microelectronics and aerospace. However, the machining of SiC ceramics into the desired structural ceramic components presents a challenge because of their high hardness and high brittleness. In this paper, a novel method of underwater femtosecond laser polishing SiC ceramics was proposed. We investigated the influence of scan trajectory, such as scanning pitch and polishing mode, and femtosecond laser pulse energy on surface roughness and polishing depth during underwater polishing processing. The experimental results indicated that the polishing depth decreased with the increasing scanning pitch, and then tending to saturate. A deep cavity was obtained under the condition of high laser pulse energy and small scanning pitch during polishing. However, the obtained surface quality was rough at this condition, which could be used for rough polishing operation because the high material removal rate is the primary concern. In addition, the cross-scanning polishing mode achieved the better surface quality without cracks and pits than the transverse polishing mode, but the polishing efficiency was low. In addition, under appropriate machining conditions, the smooth polished surface with surface roughness 0.76 µm was obtained by using 15 µm scanning pitch together with high laser pulse energy and cross-scanning polishing mode.
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