ABSTRACT
Objective:To compare the application effects of high-definition two-dimensional (HD-2D) and glasses-free three-dimensional (GF-3D) display systems in thoracoscopy teaching.Methods:A total of 40 clinical medicine interns with no surgical experience from The First Affiliated Hospital of Guangzhou Medical University were recruited and were required to participate in a 1-week training course of endoscopy. They were then randomly allocated to the HD-2D group and GF-3D group and asked to perform three tasks: peg transfer, circular cutting, and suture knotting. Their performance was measured with a system that scored speed and precision. SPSS 25.0 was used to conduct t-test, Pearson Chi-square test and Fisher exact test for the comparison. Results:The mean time for the peg transfer test in GF-3D group was shorter than that in HD-2D group, without statistically significant difference [(63.20±21.11) s vs. (71.15± 17.26) s, P = 0.212]. The mean time for the circular cutting test in GF-3D group was shorter than that in HD-2D group, without statistically significant difference [(112.50±16.67) s vs. (118.15±24.43) s, P=0.410]. The mean time for the suture knotting test in GF-3D group was shorter than that in HD-2D group, with statistically significant difference [(301.50±32.77) s vs. (341.75±57.23) s, P=0.019]. The total score in GF-3D group was higher than that in HD-2D group, with statistically significant difference [(78.33±5.88) points vs. (72.08±6.83) points, P=0.005]. Conclusion:The GF-3D display system is clearly superior to the HD-2D system because it reduces the surgical learning curve, and is therefore suitable for basic teaching and skills training.
ABSTRACT
BACKGROUND:There are many postmenopausal women taking hormone, which leads to much loss of bone mass, further inducing fragility fractures. The studies on the hormone exposure combined with ovariectomy-induced osteoporotic model are still immature, and the related molecular mechanism remains unclear. OBJECTIVE: To establish the rat osteoporotic model induced by ovariectomy combined with glucocorticoid exposure and to explore the underlying molecular mechanism. METHODS: Thirty 3-month-old female Sprague-Dawley rats were randomly divided into blank control, sham and model groups (n=10 per group). The rats in the blank control group received no intervention; rats in the sham group were clipped off a little of coeliac adipose tissue; the model rats received bilateral ovariectomy and 4-week administration of glucocorticoid. RESULTS AND CONCLUSION:At 4 weeks after modeling, compared with blank control and sham groups, the model group showed significantly lower bone mineral density of the femur, number of bone trabeculae and bone volume/total volume, and significantly wider bone trabecular spacing. Additionally, the model group revealed the damaged bone trabecular structure and thiner cortical bone. The expression level of Runx2 was downregulated whereas both collagen type 1α1 and peroxisome proliferators activated receptor γ mRNA were upregulated in the model group. These findings suggest that ovariectomized rats exposed to glucocorticoid rapidly develop femur osteoporosis, maybe by downregulating the expression of Runx2, as well as upregualting collagen type 1α1 and peroxisome proliferators activatedreceptor γ mRNA.