The effects of oxidative stress induced by occlusal interference and the regulatory mechanism of UCP3 on masseter in rats / 实用口腔医学杂志

The occlusal interference model in rats was established. In the masseter the level of MDA was increased, but both SOD and GPX were decreased in the presence of the occlusal interference, while the expression of UCP3 was higher than that in the control group (P ＜ 0. 05) .The findings indicate that the occlusal interference can induce the oxidative damage of masseter in rats, which has a correlation with UCP3.

Effect of composting process on phytotoxicity and speciation of copper, zinc and lead in sewage sludge and swine manure.

The concentration and bioavailability of heavy metals in composted organic wastes have negative environmental impacts following land application. Aerobic composting procedures were conducted to investigate the influences of selected parameters on heavy metal speciation and phytotoxicity. Results showed that both of sewage sludge (SSC) and swine manure (SMC) composting systems decreased the pH, the content of organic matter (OM) and dissolved organic carbon (DOC), and total amounts of Cu, Zn and Pb. Sequential extraction showed that readily extractible fractions of exchangeable and carbonate in Cu and Zn increased during SSC composting but decreased during SMC composting, thus their bioavailability factors (BF) enhanced in SSC but declined in SMC. The fraction of reducible iron and manganese (FeMnOX) of Cu and Zn in SSC and FeMnOX-Cu in SMC decreased, but FeMnOX-Zn in SMC gradually increased in the process of compost. In contrast, the changes of Pb distributions were similar in two organic wastes. Pb was preferentially bound to the residual fraction and its BF decreased. The evolution of heavy metal distributions and BF depended on not only total metal concentrations but also the other properties, such as pH, decomposition of OM and decline of DOC. The germination rate (RSG), root growth (RRG) and germination index (GI) of pakchoi (Brassica Chinensis L.) increased during the composting process. Linear regression analysis demonstrated that GI, which could represent phytotoxic behavior to the plants, could be poorly predicted by BF or total amount of metals, i.e., BF-Zn, T-Cu. However, the inclusion of other physicochemical parameters (pH, OM and DOC) could enhance the linear regression significances (R).

Development and biomechanical evaluation of interlocking expanding compressive screws for femoral neck fracture / 中华创伤骨科杂志

Objective To explore the methods of internal fixation for femoral neck fractures and evaluate the biomechanical characteristics of the interlocking expanding compressive screw (IECS)of Type HZS. Methods Based on the special biomechanical characteristics of the femoral neck fracture, the device of internal fixation was designed to consist of main screw, bifurcate screw, boost screw cap, washer, compressive screw cap, oblique interlocking screw and main screw cap. Its biomechanical performances were evaluated through comparison with those of the dynamic compressive screw (DCS), twin compressive screw (2CS) and three cannulated screws (3CS) respectively. Results The mechanical performances of the femoral neck fracture fixed with the interlocking expanding compressive screw were superior to those of the others in displacement ,axial and level stiffness, torsional strength and stiffness and terminal loading. Conclusion Interlocking expanding compressive screw can efficiently withstand the splitting, torsional, shearing, tensional and compressive forces in the fracture, and is simple, safe and easy to use. [