Based on the CT data and the structure characteristics of the femoral fractures during different healing stages, medical FE models of fractured femur treated with locking compression plate (LCP)were built. Under the physiological load of a standard body weight (70 kg) and the constraint condition, the stress distributions of LCP and fractured femur during healing were calculated by means of three-dimensional finite element analysis (3D-FEA). The results showed that the stress distribution in the LCP and the fractured femur was similar, during the initial stage which there was no newly formed bone or soft tissue in fracture site. The maximum von Mises stress (371.23,272.76 MPa) in the fractured femur was much higher than that in natural femur, and the intensive stress was concentrated mainly in the proximal area of the fractured femur. With the growth of bony callus bone in fracture site, the intensity of stress in proximal femur decreased. Contrasted to the two cases mentioned above, the value of the maximum von Mises stress (68. 17 MPa) in bony callus bone stage decreased significantly, and was lower than the safe strength of natural bone. Therefore, appropriate training which is benefitial for the growth to new bone could be arranged for the better rehabilitation.
Biomechanical Phenomena ; Bone Plates ; Femoral Fractures ; pathology ; Femur ; pathology ; Finite Element Analysis ; Humans ; Stress, Mechanical

Objective To investigate the correlation between procalcitonin (PCT) and infarct related artery (IRA) spontaneous recanalization (SR) in patients with ST-segment elevation myocardial infarction (STEMI), and to investigate the value of PCT in predicting SR. Methods A retrospective study was conducted. A total of 263 STEMI patients who received emergency coronary angiography from January 2013 to April 2016 in cardiology department of Gansu Provincial Hospital were retrospectively included. Depending on the thrombolysis in myocardial infarction trial (TIMI) grade, the patients were divided into two groups, SR group (TIMI 2-3 grade) and non-SR group (NSR group, TIMI 0-1 grade). The baseline characteristics, serum PCT, high sensitivity C-reactive protein (hs-CRP) and biochemical makers before primary percutaneous coronary intervention (PCI) were compared. According to the value of PCT, the patients were divided into four quartile groups. SR rate of every groups were compared. Multiple logistic regression analysis was used to determine the independent predictor of SR. Receiver operating characteristic (ROC) curve was plotted to assess the diagnostic value of PCT for SR. Results In 263 STEMI patients, SR occurred in 77 patients and SR rate was 29.3%. There were no statistical differences in gender, age, body mass index (BMI), past medical history and IRA between the two groups, indicating that the baseline characteristics were matched. Compared with NSR group, utilization rate of the statins were significantly higher (35.1% vs. 22.6%, P < 0.05), the value of PCT, hs-CRP, uric acid (UA) in SR group were significantly lower [PCT (μg/L): 0.059±0.036 vs. 0.103±0.048, hs-CRP (mg/L): 3.07±4.13 vs. 5.93±7.80, UA (mmol/L): 321.4±77.4 vs. 354.2±114.1, all P < 0.05]. The quartile value of PCT were < 0.058, 0.058-0.078, 0.079-0.110, > 0.110 μg/L. SR rate were 48.5% (32/66), 29.9% (20/67), 26.9% (18/67) and 11.1% (7/63), respectively. SR rate of Quartile 1 was significantly higher than the other three groups (all P < 0.05). It was shown by multiple logistic regression analysis that PCT [odds ratio (OR) = 0.432, 95% confidence interval (95%CI) = 0.108-0.863, P = 0.016], hs-CRP (OR = 0.708, 95%CI = 0.516-0.905, P = 0.037) were independent predictors for SR. The area under the ROC curve (AUC) of PCT for predicting SR was greater than that of hs-CRP [0.784 (95%CI = 0.721-0.847) vs. 0.686 (95%CI = 0.619-0.753), P < 0.05]. When the cut-off value of PCT was 0.067 μg/L, the sensitivity was 81.6%, and the specificity was 66.7%. Conclusion PCT was independent predictor of SR, which has a power value in predicting IRA recanalization in patients with STEMI.

Objective: To observe blood levels of cystetine C (Cys C) and superoxide dismutase (SOD) in patients with obstructive sleep apnea syndromes (OSAS) related hypertension (HP). Methods: A total of 102 HP patients received polysomgography (PSG) in our hospital from 2013-01 to 2013-12 were studied. According to apnea hypopnea index (AHI), the patients were divided into 2 groups: OSAS with HP (OH) group, n=55 patients with AHI≥5 and HP group,n=47 patients with AHI<5; in addition, there was a Control group,n=45 normal subjects with PSG examination at the same period. The general conditions, biochemical and sleep parameters were studied, the differences among 3 groups were analyzed by SPSS 17.0 software. Results: In OH group, HP group and Control group, blood levels of Cys C were (1.06 ± 0.27) mg/L, (0.91 ± 0.19) mg/L and (0.79 ± 0.32) mg/L respectively; SOD were (127.63 ± 63.19) U/mL, (149.14 ± 60.12) U/mL and (181.54 ± 59.37) U/mL respectively, allP<0.05. Based on clinical conditions, OH group was further divided into Mild, Moderate and Severe sub-groups, blood levels of Cys C and SOD were similar among different sub-groups,P>0.05. Conclusion: Blood levels of Cys C in OH and HP groups were higher than Control group, Cys C in OH group was higher than HP group; SOD levels in OH and HP groups were lower than Control group, SOD in OH group was lower than HP group. The relationships between Cys C, SOD and OH severity were unclear.

Objective: To investigate the influence of aluminum chloride (AlCl₃) solution on the embryon-ic development of zebrafish and neurobehavior of juvenile fish. Methods: The embryos of zebrafishat 6 hours after fertilization were exposed to AlCl₃ solution at a concentration of 0, 55.0, 60.5, 66.6, 73.5, 80.5, or 100.0 mg/L, and embryonic hatching rates at 48 and 72 hours after fertilization were calculated. The embryos of zebrafishat 6 hours after fertilization were exposed to AlCl₃ solution at a concentration of 0, 60.0, 72.0, 86.4, 103.7, or 124.4 mg/L, and the embryonic mortality rates at 12, 24, 48, 72, and 96 hours after fertilization were calculat-ed. The embryos of zebrafish at 6 hours after fertilization were exposed to AlCl₃ solution at a concentration of 0, 50, 100, 200, 400, or 800 μg/L, and the changes in the neurobehavior of juvenile fish were observed after hatching, including touch-escape reaction at 72 hours after fertilization and autonomic movement and panic es-cape reflex at 7 days after fertilization. Results: Compared with the 0 mg/L group, the≥66.6 mg/L group had a sig-nificant reduction in embryonic hatching rate at 48 and 72 hours after fertilization, and the ≥72.0 mg/L group had a significant increase in embryonic mortality rate at 96 hours after fertilization (P<0.05) . Compared with the 0 μg/L group, the≥100 μg/L group had a significant reduction in the number of times of touch-escape reaction (P<0.05) .Compared with the 0 and 50 μg/L groups, the 100-800 μg/L groups had significant reductions in total movement distance and average speed (P<0.05) . Compared with the dark period before illumination, all groups had a significant increase in movement speed during the light period of the panic escape reflex test (i.e., the third minute) (P<0.05) ; within 2 minutes after the light was turned off, there was no significant change in movement speed in the 0-200 μg/L groups (P>0.05) ; the 400 and 800 μg/L groups had a significant increase in movement speed (P<0.05) . Conclusion AlCl₃ exposure may cause embryonic developmental disorder in zebrafish and ab-normal neurobehavior in juvenile fish.

Objective To explore the influencing factors hindering compliance of discharged patients with coronary heart disease on enhanced external counterpulsation(EECP),and to provide basis for formulating corresponding intervention strategies.Methods A semi-structured interview method was used to conduct in-depth interviews on 19 patients with coronary heart disease who received EECP treatment during hospitalization in Gansu Provincial Hospital from March 2020 to August 2021 but withdrew from the EECP treatment program after discharge.According to phenomenological theory,the Colaizzi 7-step analysis method was applied to analyze the interview data.Results Cognitive factors(insufficient understanding of the disease and EECP treatment),objective factors(distance,transportation,economy,time,epidemic impact)and psychological factors were all influencing factors that hinder the compliance of patients discharged from coronary heart disease with EECP treatment.Conclusion In order to improve the enthusiasm and compliance of discharged patients with coronary heart disease to participate in EECP treatment,the medical staff should formulate intervention measures according to the influencing factors of the lack of EECP treatment compliance of discharged patients with coronary heart disease from the cognitive factors,objective factors and psychological factors of patients.