ObjectiveTo compare the capability of optimized acellular(OA) allograft and xenograft reparing rat sciatic nerve defect by observing the immunological rejection, early functional recovery and nerve regeneration in the adult rats, which had been made a 1.0cm long gap in the continuity of the sciatic nerve.MethodsThe right sciatic nerve of adult Sprague-Dawley(SD) rats were exposed and 1.0cm long segment of the nerves were removed and repaired by fresh rabbit nerve and autofrafts, OA rat and rabbit nerve. After 1 and 3 months respectively,sciatic functional index (SFI),electrophysiological and histology studies were detected to evaluate immunological rejection,early functional recovery and nerve regeneration. ResultsThe immunological rejection, functional recovery and nerve regeneration in OA xenografts were compared with that in OA allografts, autografts and fresh allografts. One month after the surgery, the levels of CD8+ T cells and macrophages that infiltrated the grafts,the SFI and the axon density at the midpoints of them were similar within OA grafts and autografts(P ＞ 0.05),but all statistically distinguishable from fresh allografts(P ＜ 0.05).And better results were got after 2 months(P ＜ 0.05).ConclusionsThe results imply that OA xenografts is as good as OA allografts,which can be immunologically tolerated and that the removal of cellular material and preservation of the matrix are beneficial for promoting regeneration and functional recovery through an OA procedure.And this gives another promising option to repair peripheral nerve defect.

In the present study, the effect of serum (fetal bovine serum, FBS) on cellular uptake behaviors of DNA tetrahedron (TDNs) was investigated.Fluorescence-labeled TDNs were synthesized by self-assembly and purified with HPLC to achieve TDNs product with purity of 95%.By means of flow cytometry and confocal microscopy, the kinetics of TDNs endocytosis in HeLa cells in the presence or absence of FBS was compared.The results showed that TDNs remained intact in complete medium and cell lysate for more than 12 hours.FBS increased the amount of internalized TDNs in HeLa cells, whereas it did not change the route of caveolin-dependent endocytosis.Herein, our study provided a new insight into the effects of biomolecules on the interaction between cells and DNA nanostructures, which helped the future development of DNA-based intracellular nanocarriers.

BACKGROUND:Santoni put forward the cortical bone trajectory technology by changing the traditional pedicle screw placement for lumbar internal fixation in order to obtain better control of the screw and bone in 2009. OBJECTIVE:To analyze biomechanical stability of cortical bone trajectory system in the lumbar fusion. METHODS:Twenty fresh newborn calf L3/4, L5/6 motion segment specimens were obtained, and their ranges of motion were detected under different states, as normal controls. Subsequently, twenty samples were divided into cortical bone trajectory screw group and traditional pedicle screw group, which underwent cortical bone trajectory screw fixation combined with posterior lumbar fusion and traditional pedicle screw fixation combined with posterior lumbar fusion, respectively. Without destruction, ranges of motion were detected under different states in both groups. In the revision group, after the test in the traditional pedicle screw group, screw was withdrawn, and cortical bone trajectory screw was used to detect its range of motion under different states. RESULTS AND CONCLUSION:Ranges of motion at bending to the left and right, anteflexion, posterior extension and axial rotation were significantly lower in the cortical bone trajectory screw group and traditional pedicle screw group than in the normal control group (P<0.05). No significant difference in bending to the left and right, anteflexion, posterior extension and axial rotation was detected between the cortical bone trajectory screw and revision groups and traditional pedicle screw group (P>0.05). These results confirmed that cortical bone trajectory technology combined with posterior lumbar fusion can obtain identical stability as the traditional pedicle screw fixation combined with posterior lumbar fusion. Simultaneously, it is a new choice for revision after traditional pedicle screw fixation.

Objective To establish a quality standard of huangqi baoxin mixture and improve its quality control system. Methods The qualitative analysis of Astragalus membranaceus,Salvia miltiorrhiza,Forsythia,and Angelica were performed by TLC.The content determination of astragalosideⅣin the huangqi baoxin mixture was conducted by HPLC-ELSD. Results As-tragalus membranaceus,Salvia miltiorrhiza,Forsythia,and Angelica in the huangqi baoxin mixture could be accurately identified by TLC.The linear range of astragaloside Ⅳ was 1.224-10.20 μg (r=0.999 5).RSDs of precision,stability,and reproducibility tests were lower than 3.0%;the recovery was 96.2%-102.9% with RSD at 2.20% (n=6). Conclusion The established quan-titative method is simple,accurate,and reliable with high specificity which can be used to control the quality of huangqi baoxin mixture.

Objective: To investigate the social support of medical students during the outbreak of COVID-19 and its mediating effect on the correlation between epidemic exposure and depression with anxiety. Methods: A total of 5 593 medical students were enrolled, and Social Support Rating Scale(SSRS), Patient Health Questionnaire-9 and 7-tiem Generalize Anxiety Disorder Scale were used to measure. Results: The social support score of SSRS of male students was lower than that of female students (t=-4.36, P<0.05) and juniors and seniors scored lower than other grades(F=4.84, P<0.05). Epidemic exposure proportion was positively correlated with both depressive proportionand anxiety proportion(r=0.05, 0.06, P<0.01), while epidemic exposure and depressive proportion and anxiety proportion were negatively correlated with social support score(r=-0.05, -0.25, -0.19, P<0.01). After controlling for gender and grade, the mediating effect of social support in the correlation between epidemic exposure and depression accounted for 26.6% of the total effect, and the mediating effect of subjective support and supportive utilization was 32.3% and 25.7% respectively. After controlling for gender and grade, the mediating effect of social support in the correlation between epidemic exposure and depression accounted for 20.0% of the total effect, and the mediating effect of subjective support and supportive utilization was 15.9% and 12.2% respectively. Conclusion Social support has partially mediating effect in the correlation between epidemic exposure with depression and anxiety.

Objective To study the efficacy of different anti-adhesion agents used in preventing tubal obstruction after recanalization.Methods Five hundred and eight patients with tubal obstruction were divided into 245 cases in control group,108 cases in chitosan group;113 cases in sodium hyaluronate group and 42 cases in lipiodol group.The patients in control group were injected with anti-inflammation agents after recanalizatian,while other groups were injected with chitosan,sodium hyaluronate or lipiodol at dose of 2-3 ml in every therapeutic group.The rate of location of tubal obstruction and tubal recanalization were recorded during operation.Then patients in every group were followed up on tubal patency after 3 months,and pregnancy rate after 12 months.Results Among 1016 fallopian tubes in 508 patients,there were 330 tubes occlusion at isthmus portion and 563 tubes occlusion at interstitial portion of fallopian tube.Thirtyseven fallopian tubes were ablated because of ectopic pregnancy,86 fallopian tubes were unobstructed.(1)The recanalization rate were 95.7% (179/187) in chitosan group,97.9% (191/195) in sodium hyaluronate group,98.7% (75/76) in lipiodol group and 97.7% (425/435) in control group,which did not show statistical difference (P＞0.05).(2) The rates of tubal patency after 3 months of 91.7% (99/108) in chitosan group and 88.5% (100/113) in sodium hyaluronate group were significantly higher than 71.4% (30/42) in lipiodol group and 74.3% (182/245) in control group (P ＜0.05).(3)The rates of intrauterine pregnancy after 12 months were 48.1% (52/108) in chitosan group and 41.6% (47/113) in sodium hyaluronate group,which were significantly higher than 23.8% (10/42) in lipiodol group and 24.1% (59/245) in control group (P ＜ 0.05).Conclusion Chitosan and sodium hyaluronate could be effective to prevent tubal obstruction after interventional recanalization and increase pregnancy rate.

Objective:To evaluate the feasibility of placement of S 2 alar iliac screw (S 2AI) using free-hand technique for sacrapelvic fusion in lumbar degenerative scoliosis. Methods:Eighteen patients with Lumbar Degenerative Scoliosis treated by S 2AI screw fixation at Department of Orthopedics, General Hospital of Southern Theater Command of People′s Liberation Army and Department of Orthopedics, 89th hospital of People′s Liberation Army from August 2014 to October 2018 were analyzed retrospectively. There were 5 males and 13 females, aged 63.2 years old (range:55 to 71 years old).Parameters of spine including: Cobb Angle, C 7 plumb line -center sacral vertical line (C 7PL-CSVL), lumbar lordosis(LL), sagittal vertical axis(SVA), pelvic incidence(PI), pelvic tilt(PT), sacral slope (SS) and pI-LL were measured on the whole spine X-ray before operation and at final follow-up. Pelvic CT scan was performed postoperatively to assess the accuracy of S 2AI placement. Oswestry disability Index (ODI) was also recorded. The data were compared by paired t test or Wilcoxon tests. Results:All patients were followed up for 23.7 months (range: 12~62 months).At the last follow up, Cobb Angle decreased from (32.28±4.97) °preoperative to (6.56±3.20) ° ( t=41.142, P<0.01) and C 7PL-CSVL deceased from (1.11±2.07) cm preoperative to (0.18±1.08) cm ( t=41.142, P=0.06) .LL improved from (-22.39±13.07) °preoperative to (-36.39±4.29) ° ( t=4.470, P<0.01) , PI-LL decreased from (26.83±14.83)°preoperative to (13.72±8.3)° ( t=4.396, P<0.01) , PT decreased from (27.94±4.26) °to (23.39±6.08) ° ( t=2.680, P=0.02) , and SS increased from (22.22±6.36) °to (26.28±7.24) ° ( t=-2.178, P=0.04) .SVA decreased from (6.54±4.51) cm preoperative to (2.62±1.29) cm ( t=3.052, P=0.01) .ODI decreased from 0.58(0.40) ( M( QR)) to 0.18 (0.15) ( Z=-4.567, P<0.01) .No complications such as nerve and blood vessel injury occurred during the operation. A total of 32 S 2AI screws were placed, 3 screws were placed with mild to moderate cortical breaches, 2 were perforated the pelvis ventrally, 1 was perforated posteriorly, with no clinically notable neurovascular or visceral complications. Eight patients finished the SRS-22 questionnaire, with mean score of 4.4 in terms of satisfaction with management. Conclusions:Free-hand technique of S 2AI screw placement for sacrapelvic fusion in degenerative lumbar scoliosis is safe and feasible.S 2AI fixation in DLS can provide great correction of deformity, maintain the stability of lumbo-pelvic area and improve the clinical symptoms.

Objective:To evaluate the feasibility of placement of S 2 alar iliac screw (S 2AI) using free-hand technique for sacrapelvic fusion in lumbar degenerative scoliosis. Methods:Eighteen patients with Lumbar Degenerative Scoliosis treated by S 2AI screw fixation at Department of Orthopedics, General Hospital of Southern Theater Command of People′s Liberation Army and Department of Orthopedics, 89th hospital of People′s Liberation Army from August 2014 to October 2018 were analyzed retrospectively. There were 5 males and 13 females, aged 63.2 years old (range:55 to 71 years old).Parameters of spine including: Cobb Angle, C 7 plumb line -center sacral vertical line (C 7PL-CSVL), lumbar lordosis(LL), sagittal vertical axis(SVA), pelvic incidence(PI), pelvic tilt(PT), sacral slope (SS) and pI-LL were measured on the whole spine X-ray before operation and at final follow-up. Pelvic CT scan was performed postoperatively to assess the accuracy of S 2AI placement. Oswestry disability Index (ODI) was also recorded. The data were compared by paired t test or Wilcoxon tests. Results:All patients were followed up for 23.7 months (range: 12~62 months).At the last follow up, Cobb Angle decreased from (32.28±4.97) °preoperative to (6.56±3.20) ° ( t=41.142, P<0.01) and C 7PL-CSVL deceased from (1.11±2.07) cm preoperative to (0.18±1.08) cm ( t=41.142, P=0.06) .LL improved from (-22.39±13.07) °preoperative to (-36.39±4.29) ° ( t=4.470, P<0.01) , PI-LL decreased from (26.83±14.83)°preoperative to (13.72±8.3)° ( t=4.396, P<0.01) , PT decreased from (27.94±4.26) °to (23.39±6.08) ° ( t=2.680, P=0.02) , and SS increased from (22.22±6.36) °to (26.28±7.24) ° ( t=-2.178, P=0.04) .SVA decreased from (6.54±4.51) cm preoperative to (2.62±1.29) cm ( t=3.052, P=0.01) .ODI decreased from 0.58(0.40) ( M( QR)) to 0.18 (0.15) ( Z=-4.567, P<0.01) .No complications such as nerve and blood vessel injury occurred during the operation. A total of 32 S 2AI screws were placed, 3 screws were placed with mild to moderate cortical breaches, 2 were perforated the pelvis ventrally, 1 was perforated posteriorly, with no clinically notable neurovascular or visceral complications. Eight patients finished the SRS-22 questionnaire, with mean score of 4.4 in terms of satisfaction with management. Conclusions:Free-hand technique of S 2AI screw placement for sacrapelvic fusion in degenerative lumbar scoliosis is safe and feasible.S 2AI fixation in DLS can provide great correction of deformity, maintain the stability of lumbo-pelvic area and improve the clinical symptoms.

Objective:To construct an evaluation the index system of entrustable professional activities for resident training doctors in psychiatric department,and to provide reference for formulating training strategies and assessment standards.Entrustable professional activities refers to the ability of trainees to perform and complete spe-cific clinical tasks independently after they have been trusted.Methods:Through documental analysis and semi-structured interviews,the item database of entrustable professional activities for psychiatric resident training physi-cians was established.Delphi consultation was conducted among 63 experts in the field of psychiatry from 7 national resident training bases and 3 medical colleges in China.Indicators were comprehensively screened and sorted out,and indicators at all levels and their weights were determined by the analytic hierarchy process.Results:A hierarchi-cal evaluation index system of entrustable professional activities for psychiatric resident training doctors was con-structed,including 4 first-level indicators,17 second-level indicators and 68 third-level indicators.The weights of the first-level,second-level and third-level indicators were determined.Conclusion:The evaluation index system of en-trustable professional activities is comprehensive and systematic,which is suitable for clinical work and convenient for practical application.It could provide quantitative standards for the assessment of psychiatric residents and pro-mote the improvement of training quality.

Objective:To investigate the effects of single intermittent theta-burst stimulation on functional connectivity in patients with mild cognitive impairment(MCI).Methods:From July to November 2020, forty MCI patients were selected and randomly divided into iTBS true stimulation group and iTBS sham-stimulation group, with 20 patients in each group.iTBS targeted the left dorsolateral prefrontal cortex (DLPFC). Montreal cognitive assessment (MoCA), mini-mental state examination (MMSE), activity of daily living scale(ADL), Hamilton depression scale (HAMD) and Hamilton anxiety scale (HAMA) were evaluated at baseline.The resting state electroencephalography (rsEEG) was collected for 5 minutes before and after iTBS in the two groups.The phase lag index(PLI) of EEG functional connectivity was calculated, and the functional connectivity matrix diagram was drawn.SPSS 26.0 software was used for statistical analysis.Data were statistically analyzed by χ2 test, Wilcoxon rank sum test and independent sample t-test. Results:There were no significant differences in scores of MoCA, ADL, HAMD and HAMA between the two groups(all P>0.05). In the iTBS true stimulation group, compared with that before iTBS treatment(0.140(0.133, 0.144)), the PLI of β band increased significantly after iTBS treatment(0.146(0.136, 0.167))( P<0.05). The region of increased PLI was mainly concentrated in the central region(C3/C4-T7/T8). Compared with that before iTBS treatment(0.251(0.232, 0.299)), the PLI of α band increased after iTBS treatment(0.286(0.241, 0.359)), but the difference was not statistically significant( P>0.05). Conclusion:Single iTBS treatment can significantly increase the EEG functional connectivity in patients with MCI, indicating that iTBS targeting the left DLPFC can effectively regulate the EEG functional connectivity in patients with MCI, which may reveal the mechanism of iTBS in improving cognitive function in patients with MCI.