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Objective:To study the effects of rolling blood pump parameters and blood concentration on hemolysis during extracorporeal circulation.Methods:According to the extracorporeal hemolysis experiment standard, an extracorporeal circulation experimental device was built to analyze the influences of circulation time (0 ~ 90 min), blood flow rate (1~4 L/min), and blood volume fraction (60%, 70%) on the hemolysis of blood samples in the circulatory system. The results of hemolysis were analyzed using first-order linear regression.Results:The longer the blood pump circulation time, the greater the hemolysis rate; the higher the blood flow rate, the greater the hemolysis rate. When the flow rate is 1 and 2 L/min, the hemolysis rate curve has an inflection point that changes with time, i.e. when the circulation time exceeds 30 min, the slope of the hemolysis rate curve suddenly increases. However, when the flow rate is 3 and 4 L/min, the hemolysis mutation phenomenon is not obvious. Compared to the blood sample with blood volume fraction of 70%, a blood sample with a blood volume fraction of 60% is less prone to hemolysis.Conclusions:The longer the blood pump circulation time and the higher the blood flow rate, the more easily the red blood cells are destroyed, i.e. the hemolysis rate is directly proportional to the circulation time and blood flow rate. When the circulation time increases to a certain degree, an inflection point appears in the hemolysis rate curve, and the hemolysis trend will be significantly enhanced.
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Objective@#To evaluate the effectiveness of health belief model-based health education intervention in improving blood pressure control of patients with hypertension in community settings.@*Methods@#From September 2016 to September 2017, 400 newly diagnosed patients with hypertension were recruited from 6 community healthcare centers with comparable population size and health services in the Shunyi District of Beijing. All community healthcare centers were randomly assigned to the intervention group (206 patients) and the control group (194 patients). Patients in the intervention group received 3 lectures (20-30 min for each) of health belief model-based health education. Patients in the control group received usual care. The basic characteristics, health beliefs, and health literacy were collected, and blood pressure was measured before and after the intervention, respectively. The difference-in-difference model was used to analyze the change of blood pressure and the influencing factors between two groups before and after the intervention.@*Results@#A total of 134 patients in the intervention group and 129 patients in the control group completed the study. After adjusting for the age, gender, family income, medical insurance, chronic diseases and family history, the score of perceived barriers was increased by 1.65 (P=0.016), and perceived seriousness was decreased by 0.73 (P=0.018). The systolic blood pressure of patients was decreased by 7.37 mmHg (1 mmHg=0.133 kPa, P=0.001) and diastolic blood pressure was decreased by 4.07 mmHg (P=0.014), respectively. The β (95%CI) values were -7.37 (-11.88,-2.86) and -4.07 (-7.30, -0.84). The perceived susceptibility and self-efficacy had a significant influence on the blood pressure of patients (P<0.05).@*Conclusion@#Health belief model-based health education intervention could significantly improve the blood pressure control of patients with hypertension in the community settings.
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Objective To investigate the influence of thrombus entrance shape, suction rate and blood flow velocity on thrombus aspiration of rotary cutting and suctioned thrombectomy devices, so as to provide theoretical support for the design and optimization of such devices. Methods Three models with different thrombus entrance shapes (‘L’-style, ‘8’-style and ‘0’-style) were established to study the influence of thrombus entrance shape on the thrombectomy; different suction rates (75, 100, 125, 150 mL/min) and different blood flow velocities (0-10 cm/s, at interval of 1 cm/s) were set to discuss how the suction rate and blood flow velocity affected the thrombectomy based on ‘8’-style thrombus entrance. Results The thrombus could not be aspirated evenly in ‘L’-style model, and there was no significantly difference in aspiration between ‘8’ -style model and ‘0’-style model. But the ‘8’-style model was better than ‘0’-style model in lateral thrombus suction. The suction rate that was greater than 100 mL/min provided a limited effect on improvement of thrombectomy effect. The best suction effect was reached when blood flow velocity was less than 1 cm/s, and the effect of thrombectomy was decreasing gradually with blood flow velocity increasing. Conclusions The thrombus entrance shape, suction rate and blood flow velocity had a great impact on thrombectomy greatly. A wide and short thrombus entrance shape, an appropriate increase of suction rate and decrease of blood flow velocity would contribute significantly to the improvement of thrombectomy effect. These results can be used as guidance for the optimal design of rotary cutting and suctioned thrombectomy devices.
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Objective To determine whether chronic stress could potentiate learning and memory impairment in old mice, and, if so, what the underlying mechanism is. Methods Sixty male mice were divided randomly into control group and chronic stress group. Mice in stress group were stressed everyday by one of the stressors including cold exposure, restraint, level shake and so on. The ability of learning and memory was determined by Morris water maze test, and the histopathologic changes in CA3 field of the hippocampus were examined under a light micro-scope. Serum corticosterone level was determined by enzyme-linked immunosorbent assay. Western blot was per-formed to determine the expression of β-site amyloid precursor protein-cleaving enzyme 1 and Aβ1-42 in hippocam-pus of the brain. Results Compared with the control group, the results showed that chronic stress could increase the escape latency and swimming distance of old mice during training session in the Morris water maze test. The neuropathological changes were characterized by the decreased neuron number,soma shrinkage and condensation,or nuclear pyknosis in the CA3 field of hippocampus in the stress group. On the other hand, the expression of Aβ1-42 and BACE1 protein in hippocampus were increased, as well as the serum corticosterone concentration in the stress group. Conclusion Chronic stress can potentiate learning and memory impairment and pathological damage in CA3 field of the hippocampus in old mice, which may be related to chronic stress up-regulated the levels of BACE1 and Aβ1-42 mediated by corticosterone.