[Objective]To analyze the change of intervertebral disc Von Mises stress on the adjacent segment after "U" shape dynamic fixation for lumbar with finite element method. [Method]The three-dimensional finite element models of the lumbar dynamic fixation and rigid fixation were established by using Mimics11.11 and Abaqus6.51 softwares.Loads used in this study were axial compressive,flexion,extension,lateral bending,and rotation forces.The intervertebral disc Von Mises stress of the adjacent segment was analyzed and compared.[Result]In the same shearing load of 500 N,the intervertebral disc Von Mises stress of the adjacent segment in the dynamic fixation model was lower than rigid fixation model under axial compressive,flexion,extension,lateral bending,and rotation forces,especially at lateral of the intervertebral disc,and there were significant difference between dynamic fixation group and rigid fixation group(P

Continuing medical education refers to the completion of basic medical education for inservice education,which is to guarantee the sustainable development of physicians in clinical and scientific research ability,and is the essential means to safeguard and improve the level of medical treatment.Traditional continuing medical education is given priority to the form of regularly organize workshops,so it has some limitations to oral and maxillofacial surgery.MOOC teaching is a kind of large-scale open new online teaching mode.This study provides an overview of the MOOC development,characteristics and development situation in the medical teaching.The necessity and feasibility of MOOC based teaching protocol in oral and maxillofacial surgery continuing medical education has been discussed.And curriculum transformation,construction of education model and possible challenges have also been analyzed and discussed in this paper.

Synthetic burn dressing remains the central theme for burn dressing development. The advantages and disadvantages of current available dressings were reviewed. As one of the most successful dressings, the hydrogel burn dressing, its combination with other materials and related progress in researches were presented in detail. Finally, the trend in development of synthetic burn dressing was presented.
Bandages, Hydrocolloid ; Burns ; therapy

Objective To evaluate the safety of Renaissance spine robot assisted system in spinal injury.Methods From March 2014 to May 2016,38 patients with spinal disease received spinal surgery assisted by spine robot system.They were 20 males and 18 females,with an average age of 42 years (range,from 12 to 69 years).There were 10 lumbar fractures,8 thoracic fractures and 20 spinal deformities.Pedicle screw implantation was conducted in 30 patients (PS group) and percutaneous vertebroplasty in 8 (PV group).One side was chosen randomly to use Mazor spine robot assisted system (assisted group) and the opposite side the conventional method (non-assisted group).The anteroposterior and lateral X-rays and CT scan of the lumbar and/or thoracic spine were performed in all patients after surgery.The precision of pedicle screws implantation in PS group was evaluated by the Abul-Kasimhierarchy grading system;location of the puncture trajectory,time used for puncture and radiation exposure time in PV group were evaluated.Results 208 pedicle screws were implanted in PS group,including 120 lumbar ones and 88 thoracic ones.For lumbar pedicle screw implantation,the excellent to good rate was 95.0％ (57/60) in the assisted group,significantly higher than that in the non-assisted group (80.0％,48/60) (P ＜ 0.05).For thoracic pedicle screw implantation,the excellent to good rate was 95.5％ (42/44) in the assisted group,significantly higher than that in the non-assisted group (77.3％,34/44) (P ＜ 0.05).There were 24 puncture trajectories in 8 patients in PV group,showing no pedicle penetration or cement leaking in any case.The mean time used for puncture was 5.5 ± 1.4 min in the assisted group,significantly shorter than that in the non-assisted group (17.8 ± 7.5 min) (P ＜ 0.05);the X-ray exposure time was 14.0 ± 4.0 s in the assisted group,significantly shorter than that in the non-assisted group (22.4 ± 6.0 s) (P ＜ 0.05).Conclusions Renaissance spine robot-assisted system deserves more clinical application,because in spinal surgery it can make pedicle screw implantation more precise and safer,and can reduce operation time and X-ray exposure time in percutaneous vertebroplasty.

Objective:To understand the diagnostic value of tuberculosis (TB) pathogenic detection methods (TPDM) in pathological tissue for TB.Methods:A retrospective study was conducted with 190 pathological specimens from different tissues suspected with TB from Third People′s Hospital of Shenzhen during May 2016 and May 2019. Specimens were divided into four groups according to histomorphology: group one, necrotizing granulomatous inflammation (109 cases); group two, non-necrotic granulomatous inflammation (20 cases); group three, non-granulomatous inflammation (45 cases); group four, non-tuberculous lesions (16 cases). The positive rates of each TPDM among specimens from four groups were compared. The positive rates of all TPDM for specimens from group one were compared. Meanwhile, the influence of antituberculosis treatment course on the TPDM was analyzed. Chi-square test or Fisher′s exact test was used for statistical analysis.Results:The positive rates of Ziehl-Neelsen acid-fast staining among the four groups were 17.4%(19/109), 5.0%(1/20), 4.4%(2/45) and 0(0/16), respectively. The positive rates of Mycobacterium tuberculosis (MTB) complex culture were 32.0%(32/100), 4/19, 4.8%(2/42) and 0(0/16), respectively. The positive rates of Mycobacterium tuberculosis/rifampin resistance real-time quantitative nucleic acid amplification detection system (Xpert MTB/RIF) were 74.3%(81/109), 15.0%(3/20), 13.3%(6/45) and 0(0/16), respectively. The positive rates of fluorescent quantitative polymerase chain reaction (FQ-PCR) were 63.0%(58/92), 0(0/15), 2.6%(1/38) and 0(0/10), respectively. The positive rates of simultaneous amplification and testing (SAT) were 32.4%(24/74), 0(0/10), 0(0/15) and 0(0/10), respectively. The differences of each TPDM among four groups were all statistically significant (all P<0.05). The positive rate of Xpert MTB/RIF in group one specimens was significantly higher than those of acid-fast staining, MTB culture and SAT ( χ2=71.016, 37.162 and 35.679, respectively, all P<0.01), while the difference was not statistically significant when compared with FQ-PCR ( χ2=2.517, P=0.112). The positive rate of combined TPDM (85.3%(93/109)) was significantly higher than Xpert MTB/RIF(74.3%(81/109)) ( χ2=4.100, P=0.043). The positive rates of acid-fast staining group 1A (anti-tuberculosis treatment course was less than one month) and group 1B (anti-tuberculosis treatment course was longer than one month) were 14.3%(7/49) and 20.0% (12/60), respectively ( χ2=0.612, P=0.434); those of MTB culture were 48.9% (22/45) and 18.2% (10/55), respectively ( χ2=10.721, P=0.001); those of Xpert MTB/RIF were 69.4%(34/49) and 78.3%(47/60), respectively ( χ2=1.131, P=0.287); those of FQ-PCR were 55.0%(22/40) and 69.2%(36/52), respectively ( χ2=1.965, P=0.161); those of SAT were 43.3%(13/30) and 25.0%(11/44), respectively ( χ2=2.736, P=0.098). Conclusions:The results of TPDM correlate closely with the typical histomorphological features of tuberculosis. Xpert MTB/RIF possesses significantly higher sensitivity than any other single TPDM, and is not attenuated by early anti-tuberculosis treatment. Combined TPDM could significantly improve the sensitivity of TB pathogenic detection, which is suggested to be applied when the tissue specimen is sufficient.

Objective To investigate the clinical efficacy and acting mechanism of mometasone furoate on the children with perennial allergic rhinitis. Methods A total of 178 children with perennial allergic rhinitis treated in our hospital were randomly divided into the experimental group and the control group, with 89 patients in each group. The experi-mental group received intranasal inhalation of mometasone furoate and the control group received oral administration of loratadine. Both groups were treated for 4 weeks. The rhinitis symptom scores and children's rhinoconjunctivitis related quality of life questionnaire (RQLQ) scores of the two groups before and after treatment were compared, and the serum interleukin-2 (IL-2), interleukin-4 (IL-4) and interleukin-5 (IL-5) levels of both groups were detected. Results After 4 weeks of treatment, the experimental group was significantly lower than the control group in the nasal congestion, nasal itching, throat itching and total symptom scores (P<0.05), and was also lower than the control group in the RQLQ scores such as nasal symptom, practical problem, other symptom and total scores (P<0.05). The experimental group had significantly higher IL-2 level and significantly lower IL-4 and IL-5 levels than the control group, with statistically significant differences (P<0.05). Conclusion Mometasone furoate can effectively control the clinical symptoms of children with perennial allergic rhinitis and has better overall efficacy than oral loratadine; its acting mechanism may be related to the regulation of Th1 and Th2 cell imbalance.

Objective:To construct an outpatient counseling record sheet of breastfeeding based on Delphi method, so as to standardize the consultation process of breastfeeding clinics.Methods:Through literature analysis and discussion of the research group, the expert letter questionnaire was designed by themselves. From September to October 2020, two rounds of Delphi letter inquiries were conducted with 16 experts in Hangzhou to determine the outpatient counseling record sheet of breastfeeding.Results:The positive coefficients of two rounds of expert letter inquiries were 100%, the expert authority coefficients were respectively 0.93 and 0.95, and the Kendall's coefficient of concordance were 0.135-0.204 and 0.234-0.563 ( P< 0.05) . The final counseling record sheet constructed included 8 first-level items, 99 second-level items and 94 third-level items. Conclusions:Letter consulting experts have high enthusiasm, high degree of authority and good coordination. The breastfeeding clinic consultation record based on the Delphi method is highly scientific and practical, which can be applied to breastfeeding clinics in various maternal and infant medical institutions.

Objective:To explore the significance of digital orthopedic technology in surgical plan for spinal tumor and the preliminary outcomes of 3D printed vertebral bodies in spinal tumor surgery.Methods:The clinical data of 2 patients were retrospectively analyzed who had had a 3D printed vertebral body implanted at Center of Orthopaedics, Shenzhen Hospital from June 2018 to December 2019. One was a 32-year-old male, diagnosed with cervical neurinoma; the other was a 27-year-old female, diagnosed with giant cell tumor of lumbar bone. 3D virtual reconstruction of tumor and surrounding structures was established via Mimics software for surgical plan. Virtual osteotomy was simulated, their disease models and guide templates were 3D printed, and their metal artificial vertebral bodies were 3D printed after personalized design of the vertebral body diameter, porosity and procedures of reconstruction and fixation. Lesion resection and prosthesis implantation were carried out in accordance with the preoperative plan. After operation, the motor function of cervical or lumbar vertebrae, tumor recurrence, and spinal stability reconstructed were regularly observed.Results:Resections and reconstructions went uneventfully in both cases. The 2 patients were followed up for 21 and 13 months respectively. Their postoperative images showed that their 3D printed vertebral bodies fitted the neighboring vertebral bodies well. The spinal stability was reconstructed without any loosening or periprosthetic osteolysis, and the tumors were removed completely with no recurrence in both cases. Their spinal motor function was satisfactory.Conclusions:Digital orthopedic technology can offer accurate guidance in the treatment of spinal tumors. It is necessary to consider local physiological anatomy in personalized design of a metal vertebral body 3D printed. Clinical application of 3D printed metal vertebral bodies is a new strategy for spinal reconstruction following spinal tumor resection.

Objective:To evaluate the accuracy of diffusion weighted magnetic resonance imaging (DWI-MRI) combined with high resolution temporal bone CT (HRCT) in the location diagnosis of middle ear cholesteatoma and its value in the postoperative follow-up.Methods:134 patients with inital cholesteatoma and 22 patients with suspected recurrent cholesteatoma were selected for HRCT, conventional MRI and DWI examination. Based on the intraoperative and pathological diagnosis, DWI and HRCT images were combined to evaluate the consistency between the lesion location and invasion area of the initial cholesteatoma and intraoperative lesions. The results of HRCT and DWI in the diagnosis of recurrent middle ear cholesteatoma were statistically analyzed to evaluate their diagnostic efficacy.Results:The accuracy rate of DWI combined with HRCT was 90.3%.The sensitivity, specificity, positive predictive value and negative predictive value of HRCT and DWI in the diagnosis of recurrent middle ear cholesteatoma were 27.8%, 75.0%, 83.3%, 18.8% and 100%, 75.0%, 94.7% and 100%, respectively, and the Kappa values consistent with the pathological results were 0.024 and 0.843, respectively. Chi-square test confirmed that there were differences in the diagnosis between groups ( P<0.001). Conclusions:Combined with the high sensitivity of DWI and the high resolution of HRCT, the accuracy of preoperative positioning of the newly diagnosed cholesteatoma can be improved and surgery strategy can be guided. DWI is also of high diagnostic value for recurrent cholesteatoma in the middle ear.

Objective:To investigate the factors influencing fall risk scores in elderly individuals.Methods:A total of 4 419 individuals were randomly selected using the cluster sampling method from Beijing, Nanning(Guangxi), and Yinchuan(Ningxia).Data on demographic characteristics and fall-related incidents were gathered and analyzed for their correlation with fall risk scores.Results:The fall risk score showed significant associations with various factors, such as the history of falls within one year( β=-3.607, 95% CI: -3.881 to -3.332), care methods( β=2.442, 95% CI: 2.226 to 2.658), exercise( β=0.714, 95% CI: 0.443 to 0.986), retirement( β=-0.585, 95% CI: -0.819 to -0.351), age( β=0.173, 95% CI: 0.159 to 0.187), and use of walking aids( β=-3.737, 95% CI: -4.054 to -3.421). Conclusions:Fall risk scores in older adults are influenced by a variety of factors.Factors such as no history of falls within the past year, living independently, engaging in physical activity, and being employed may contribute to lower fall risk scores in older adults.