Objective:To analyze the morphological characteristics of damaged Hero642 Ni-Ti dental files, and explain the relationship between deformation and fracture.Methods:71 discarded files were observed under naked eyes and stereomicroscope. 5 of which were observed under S360 scanning electronic microscope (SEM), and typical photos were taken for analysis.Results:The damage of Hero642 Ni-Ti dental files was characterized by fracture, tightened or loosened spiral and some kind of deformation detected at more than 35 times magnification. Under SEM, the dimple pattern was represented in the fracture surface of the files. Conclusion:Most Hero642 Ni-Ti files fractured within 4 mm from the tip which belongs to the pattern of ductile fracture.

OBJECTIVE: To observe the clinical effect of perforated bovine amnion combined with recombinant bovine basic fibroblast growth factor (rb-bFGF) on degree Ⅱ burn wounds.METHODS: A total of 43 patients with small and medium-size thermal burn were collected, and the area of testing wound was 1% -2%. The wounds with the same nature were divided into three groups: perforated bovine amnion (treatment group), bovine amnion (control 1 group), and vaseline gauze dressing (control 2 group). All the three groups combined with rb-bFGF. RESULTS: Compared with control 1 group (P < 0.01) and control 2 group (P < 0.05), the treatment group could obviously decrease the healing time of deep degree Ⅱ burn wounds. For superficial degree Ⅱ burn wounds, compared with the control 2 group, the treatment group could also decrease the healing time; however, there was no significant difference between treatment group and control 1 group (P > 0.05). Dressing was not changed frequently, and the pain was relieved. Rash or other adverse effects were not detected in the three groups.CONCLUSION: The combination of perforated bovine amnion and rb-bFGF can obviously promote the healing of burn wounds.

Objective: To summarize the peri-operative management experience of pulmonary endarterectomy (PEA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Methods: A total of 56 CTEPH patients received PEA in our hospital from 2015-01 to 2016-11 were retrospectively analyzed. Our study was focused on the medication in respiratory and circulatory system during ICU stay, peri-operative application of vasoactive drug and target drug to pulmonary hypertension (HP), usage of ventilators, mechanical assisted devices and other management experiences. Results: No peri-operative death occurred. There were 2/56 (3.6%) patients with lung reperfusion, 2 (3.6%) with PH crisis. Compared with pre-operation, the post-operative pulmonary artery hemodynamics parameters were improved as right heart catheter measured pulmonary artery systolic pressure (PASP) decreased from (85.05±22.40) mmHg to (36.83 ±17.21) mmHg and pulmonary vascular resistance decreased from (773.84±342.95) dyn·s·cm-5 to (293.59±214.95) dyn·s·cm-5. Post-operative oxygen saturation was maintained at (95-100) % in all patients. Echocardiography found that PASP from pre-operation (85.03±25.78) mmHg decreased to (39.44±19.24) mmHg at follow-up period, P<0.01.Conclusion: A comprehensive peri-operative management of PEA was helpful to improve pulmonary hemodynamics in CTEPH patients; meanwhile, effective prevention and treatment of severe complication could obviously reduce peri-operative mortality.