Objective:In order to solve the problem that traditional theoretical examination has become more and more difficult to comprehensively and accurately evaluate the students' understanding, taking the endodontics course as the breakthrough, this study investigates the application of process evaluation method based on the "four-step" teaching method in the endodontics experimental courses. Meanwhile, the characteristics and feasibility and significance of the study are expounded.Methods:A total of 64 students were selected from two grades majoring in Stomatology in Medical School of Shenzhen University, and they were taught and assessed according to the new or old course designs. At the end of the course, comparisons of course assessment scores between the two grades were finished and the questionnaire survey was conducted to evaluate the teaching effect. SPSS 23.0 was used to perform the independent-samples t-test. Results:The analysis showed that 84.38%(27/32) of the students thought that the "four-step" teaching method helped with the learning of endodontics and significantly improved the scores of the experimental course; 90.62%(29/32) of the students thought it was helpful to stimulate self-learning skills. Compared with the students in the Class of 2018, the students in the Class of 2019 had significantly higher experimental examination scores [(87.29±4.13) vs. (84.07±1.77), P<0.01], while the scores of theoretical examination showed no significant difference between the two grades [(78.07±5.70) vs. (76.52±6.49)]. Conclusions:This teaching reform has provided the opportunities for practical operations, improved the quality of practical teaching and also stimulated the interest in independent learning of students. Moreover, it can accumulate experience for the reform of other dental experimental courses.

Objective:In order to solve the problem that traditional theoretical examination has become more and more difficult to comprehensively and accurately evaluate the students' understanding, taking the endodontics course as the breakthrough, this study investigates the application of process evaluation method based on the "four-step" teaching method in the endodontics experimental courses. Meanwhile, the characteristics and feasibility and significance of the study are expounded.Methods:A total of 64 students were selected from two grades majoring in Stomatology in Medical School of Shenzhen University, and they were taught and assessed according to the new or old course designs. At the end of the course, comparisons of course assessment scores between the two grades were finished and the questionnaire survey was conducted to evaluate the teaching effect. SPSS 23.0 was used to perform the independent-samples t-test. Results:The analysis showed that 84.38%(27/32) of the students thought that the "four-step" teaching method helped with the learning of endodontics and significantly improved the scores of the experimental course; 90.62%(29/32) of the students thought it was helpful to stimulate self-learning skills. Compared with the students in the Class of 2018, the students in the Class of 2019 had significantly higher experimental examination scores [(87.29±4.13) vs. (84.07±1.77), P<0.01], while the scores of theoretical examination showed no significant difference between the two grades [(78.07±5.70) vs. (76.52±6.49)]. Conclusions:This teaching reform has provided the opportunities for practical operations, improved the quality of practical teaching and also stimulated the interest in independent learning of students. Moreover, it can accumulate experience for the reform of other dental experimental courses.

BACKGROUND:In vitro culture of tissue-engineered bone is an important method for bone repair. Three-dimensional (3D) printed bone stents combined with bioreactor culture are of significance in bone tissue engineering. OBJECTIVE:To study thein vivo repair effect of the 3D printed biomaterial scaffold with human mesenchymal stem cells (hMSCs) cultured in bioreactor. METHODS:The scaffold was constructed by poly(lactic-co-glycolic acid)/hydroxyapatite (PLGA/HA)via 3D printing and freeze-dying techniques, and then hMSCs were seeded onto the scaffold and cultured in bioreactors. Al rabbits were numbered and divided into control (No.1 and 2), experimental 1 (No. 3 and 4) and experimental 2 (No. 5 and 6) groups, and each group had two subgroups positive and negative. The rabbit left distal femur in each group was modeled into bone defect and the single PLGA/HA scaffold, PLGA/HA scaffold carrying non-induced hMSCs were implanted in the positive and negative groups of the control group, respectively; the PLGA/HA-201405-1 and PLGA/HA-201405-2carrying induced hMSCs were implanted into the positive and negative subgroups of the experimental 1 and 2 groups, respectively. Additionaly, the right femur in the experimental 2 group was driled only. The osteogenesis ability and biodegradability were determined using electron microscope, thein vivorepair was observed through CT examination, and the histopathological examination was performed after bone healing. RESULTS AND CONCLUSION:The scaffold with topological structure suitable for cellseeding was prepared. A large number of new calcium nodules were observed under electron microscope in the experimental groups indicating overt achievement in bone healing. These results suggest that the prepared scaffold achieves a good repair effect preliminarily.

Objective To investigate the cellular immunologic response of TH 17/Treg cells in the peripheral blood of pelvic tuberculosis patients and explore their roles in the pathogenesis of pelvic tuberculosis.Methods The intracellular flow cytometry was performed to evaluate the expressions of TH 17 and Treg cells in 46 pelvic tuberculosis patients and 25 healthy controls in childbearing age.Twenty-eight of the 46 pelvic tuberculosis patients were followed up to monitor the variation of the TH17/Treg cells after 3 months and 6 months of anti-tuberculosis treatment.Results The percentage of TH 17 cells in the peripheral blood of pelvic tuberculosis patients was (3.26 ± 1.30) ％ which was significantly lower than that of healthy controls [(4.92 ± 1.71) ％,P ＜ 0.01].The percentage of Treg cells in the patients was (5.18 ± 1.53) ％ which was significantly higher than that of healthy controls [(3.26 ± 1.10) ％,P ＜ 0.01].The percentage of TH17 cells in the pelvic tuberculosis patients after 6 months of treatment was (4.67 ± 1.75) ％ which was significantly higher than that in the patients before treatment and after 3 months treatment [(3.26 ± 1.30) ％,P ＜ 0.01 and (3.70 ± 1.06) ％,P ＜0.01,respectively].The percentage of Treg cells in pelvic tuberculosis patient after 6 months of treatment was (3.93 ±0.94)％ which was significantly lower than that in the patients before treatment and after 3 months of treatment [(5.18 ± 1.53)％,P ＜0.01 and (4.94 ± 1.51) ％,P ＜ 0.01,respectively].The percentage of Treg cells in the patients after 6 months of treatment was still significantly higher than that of controls (P ＜ 0.05).The TH 17/Treg ratio before treatment was significantly lower than that of healthy controls (P ＜ 0.01),and the TH 17/Treg ratio was increased after 3 months of treatment but it did not show significant difference compared with that before treatment.The TH 17/Treg ratio after 6 months of treatment (1.18 ± 0.34) ％ was significantly increased in contrast to those after 3 months of treatment and before treatment [(0.77 ± 0.21) ％,P ＜ 0.01 and (0.55 ± 0.13) ％,P ＜ 0.01,respectively].The TH 17/Treg ratio could not rise to the normal level even after 6 months of treatment.Conclusion Both the TH 17 and Treg cells may involve in the immunologic responses of pelvic tuberculosis patients and the imbalance of TH1T/Treg cells may remain persistently.

Objective To observe the protein degredation of empty puparium cases ofC. megacephala after weathering and to explore its practical significance on postmortem interval estimation in forensic science. MethodsThe standardized feeding was used inC. megacephala, and the empty puparium cases were collected and put into the forest. They were taken back 5 days, and 10 days later, respectively. The spectra were collected and preprocessed, and then the absorption peaks of amides were read, and curve fitting was performed in the average spectra of each group. The statistical analysis was performed by SPSS 19.0.Results Compared to control group, ifve days post weathering, the position of amideⅠabsorption peak showed blue shift, but the amideⅡabsorption peak showed no shift, moreover, none of the amide absorption peaks showed changes inpeak intensity. For the secondary structures, α-helix decreased and β-sheet increased slightly, however, β-turn did not change; Ten days post weathering, the positions of both amideⅠandⅡabsorption peaks showed blue shift, and an obviousshoulder peak appeared in amide I absorption peak. Meanwhile, both of amideⅠandⅡabsorption peaks showed decreased in peak intensity. Moreover, for the secondary structures, α-helix and β-sheet showed the same tendency as in the 5th day group, except for the β-turn increased dramaticlly.Conclusion The spectra of the empty puparium cases of C. megacephala showed that the absorption peaks of amideⅠandⅡpresented certain characteristic features within ten days post weathering, and estimate relative long-time postmortem interval.

Objective To explore the value of lipidic degradation in puparium cases of C.megacephala during weathering in postmortem interval estimation. Methods The puparium cases of reared C.megacephala were collected, and laid outdoor. They were taken back 5 days and 10 days later, and then be stored at -20℃. The samples of control group were cleaned and cryopreserved immediately. The spectra were collected and preprocessed. The peak position and peak height were read and performed statistical analysis by SPSS 19.0 software. Results Compared to control group, the positions of Vas CH3 band showed no shift, and the Vas CH2 band showed blue shift, meanwhile, the Vs CH2 band disappeared in both experimental groups, moreover, the Vs CH3 band showed red shift only in 10d group;except of the Vs CH3 band in 5d group, the intensities of both the other two lipidic bands reduced in both experimental groups. Compared with 5day group, the Vs CH3 band showed red shift in 10d group, meanwhile, the differences of all the lipidic bands had statistical signiifcance. Conclusion Detection of lipidic degradation in puparium cases of C. megacephala during weathering by micro-FTIR provides a novel way to estimate postmortem interval and performs its potential for forensic applications.