Biomechanical study of polymethyl methacrylate for strengthening and repairing pedicle screws
The volume of 1:2 mixed PMMA intensive repair material was 3 ~ 5ml, and the bilateral pedicles were respectively treated with the same CCD pedicle screw as before, and the above extraction experiment was performed after 1 hour at room temperature. The specimen was sawed along the length of the pedicle screw and the distribution of PMMA in the screw channel was observed. Results The maximum extraction force of CCD pedicle screw in normal pedicle is (825. 5±254.7) N; in the normal pedicle after strengthening and in the pedicle with failure repair, CCD vertebral arch The maximum extraction force of root screws was (1711.1*488.8)N and (1832.4*497.4)N, which was higher than the maximum extraction force of normal pedicle screws. The difference was significant (P myocardial ischemia on rat atrioventricular compartment) The influence of dehydrogenase in the junction area Wu Honghai Wu Baojin Xie Hong Zhu Yongze Department of Human Anatomy, Yangzhou University Medical College Yangzhou 225001 Myocardial ischemia is often accompanied by arrhythmia, and there is little report on the influence of myocardial ischemia on the dehydrogenase of cardiac conduction system. Therefore, we studied the changes of lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) in the atrioventricular junction of rats after myocardial ischemia. Materials and Methods: 26 SD rats, weighing 200g, male The EKG test was normal and randomly divided into 0.5 hour, 1 hour, 3 hours, 6 hours, 12 hours, 24 hours experimental group and control group. The experimental group was injected with isoproterenol 5m/Kg subcutaneously. In the experimental group, the EKG of the experimental group showed S-T segment depression and T wave depression. Etc., all of them showed myocardial ischemia. Continuous frozen section (slice thickness 8pm), nitroblue tetrazolium (NBT) staining showed LDH, SDH. Image analysis results: 1. Control group atrioventricular junction LDH, SDH staining Compared with normal myocardium, LDH and SDH staining were higher than that of the control group, and LDH and SDH staining gradually increased with time, but SDH staining no longer increased after 6 hours. At the time of myocardial ischemia, the normal myocardial LDH increased slightly in a short time (0.5 hours), while the SDH staining decreased slightly, but the change was not significant. Conclusion: 1. Under normal circumstances, the aerobic metabolism of the atrioventricular junction area, no Oxygen metabolism was lower than that of normal myocardium; 2. Myocardial ischemia had an effect on glucose metabolism in the atrioventricular junction of rats, which showed that anaerobic metabolism gradually increased, while aerobic metabolism gradually increased after a short-term increase. The effect of ischemia on the normal myocardial glucose metabolism in rats is that the anaerobic metabolism of myocardial ischemia is slightly enhanced and the aerobic metabolism is slightly decreased.
Study on the protective effect of Hsp70 on ischemia-reperfusion myocardium Fu Qing Xiong Fan Li Ping Ding Chengyu Zeng Qingyun Wang Qiao Tian Zongwen Hubei Pharmaceutical Inspection College 430064 The Department of Human Anatomy, Wuhan University Medical College HsP70 is the most abundant of the Hsp family, is the main One of the chaperone proteins can be significantly elevated in emergency cells. Ischemia-reperfusion causes a series of stress responses, induces the expression of specific genes including HSP70, and synthesizes new proteins to protect stress cells. To investigate the relationship between HsP70 and myocardial ischemia-reperfusion injury, the dynamic changes of HsP70 expression in HsP70 and myocardial ischemia-reperfusion injury at different time points were observed. We used SP immunohistochemical method to detect and image HsP70 in normal myocardium, ischemia 30 min myocardial tissue, ischemia-reperfusion 1-hour myocardial tissue, and ischemia-reperfusion 2-hour myocardial tissue. The results showed that the expression products of HsP70 immunostained cells were stained in the cytoplasm, which were diffuse fine particles and diffuse coarse particles, and the nuclear and cell membranes were negative. There was a significant difference in the positive reaction in different groups. The myocardial ischemia was expressed in 30 minutes, and the positive part showed a light yellow fine particle reaction, which was mostly in the focal area. With the prolongation of ischemia-reperfusion time, the myocardial tissue showed a positive range of positive reaction for 1 hour after ischemia-reperfusion, and the coloration was deepened, showing brownish yellow coarse granularity. Myocardial tissue with ischemia and reperfusion for 2 hours showed a markedly lighter coloration and a focal distribution. Quantitative analysis of HSP70 expression average optical density between the four groups were significant (P changes in morphology and function of myocardial local frozen) Zhao Baiqin Zhang Ming Zhu Jiaguang Chen Rukun Zhejiang University
The CHAIR embodies excellent industrial design, showing pure beauty, almost rigorous details, creating a sedentary new network chair, suitable for 95% of the population and the environment. Arc chair back design gives the back a rely on, breathable fabric is comfortable and cool. Only for a comfortable, intimate waist force design, to avoid the hole waist to bear greater pressure, accelerate the lumbar muscle injury. Thickness elastic sponge cushion, high elastic is not easy to deformation, upgrade the thickened elastic sponge design, give the chair more comfortable elastic, high elastic material, let it sedentary is not easy to deformation.
Conference Room Chairs,Meeting Chairs,Conference Room Table And Chairs,Conference Room Chairs With Wheels
FOSHAN CITY LESHUN RONGHUI FURNITURE CO.LTD , https://www.ronghuifurniture.com