Objective To investigate the effects of implant length,diameter,and abutment angle on bone stress distributions around maxillary central incisors,and determine the optimal parameter combination.Methods A three-dimensional(3D)model of the maxilla was reconstructed based on CBCT data.Using an orthogonal table,a total of 16 dental implant 3D models were established,varying in length,diameter,and abutment angle.These models were assembled with the maxillary and rigid-body models.Finite element analysis was performed using the transient dynamics module of ANSYS.Orthogonal experiments and one-way analysis of variance(ANOVA)were conducted on the obtained stress data.Results The implant diameter showed a statistically significant effect on the maximum von Mises stress in cortical bone(P=0.010),while implant length(P=0.229)and abutment angle(P=0.844)did not demonstrate a statistical significance.The optimal parameter combination for cortical bone stress was 5.0 mm implant diameter,12 mm implant length,and 0° abutment angle.In cancellous bone,implant length(P=0.001),diameter(P=0.011),and abutment angle(P=0.013)all had statistically significant effects on the maximum von Mises stress.The optimal parameter combination for cancellous bone stress was 14 mm implant length,5.0 mm implant diameter,and 5° abutment angle.Conclusions Implant diameter significantly affects the stress of both cortical and cancellous bone.Clinically,a larger diameter should be preferred to reduce the stress peak.Implant length is the next most important factor,while abutment angle has the least effect.

Objective To investigate the effects of implant length,diameter,and abutment angle on bone stress distributions around maxillary central incisors,and determine the optimal parameter combination.Methods A three-dimensional(3D)model of the maxilla was reconstructed based on CBCT data.Using an orthogonal table,a total of 16 dental implant 3D models were established,varying in length,diameter,and abutment angle.These models were assembled with the maxillary and rigid-body models.Finite element analysis was performed using the transient dynamics module of ANSYS.Orthogonal experiments and one-way analysis of variance(ANOVA)were conducted on the obtained stress data.Results The implant diameter showed a statistically significant effect on the maximum von Mises stress in cortical bone(P=0.010),while implant length(P=0.229)and abutment angle(P=0.844)did not demonstrate a statistical significance.The optimal parameter combination for cortical bone stress was 5.0 mm implant diameter,12 mm implant length,and 0° abutment angle.In cancellous bone,implant length(P=0.001),diameter(P=0.011),and abutment angle(P=0.013)all had statistically significant effects on the maximum von Mises stress.The optimal parameter combination for cancellous bone stress was 14 mm implant length,5.0 mm implant diameter,and 5° abutment angle.Conclusions Implant diameter significantly affects the stress of both cortical and cancellous bone.Clinically,a larger diameter should be preferred to reduce the stress peak.Implant length is the next most important factor,while abutment angle has the least effect.

Objective:To analyze the clinical data on hospitalized spinal cord injury patients with calf muscle vein thromboses (MCVTs) seeking prevention and treatment techniques.Methods:The medical records of 423 patients with spinal cord injury were collected. Those with MCVT constituted the observation group, while those without served as controls. Their clinical data were compared.Results:The risk factors for MCVT were screened in logistic regression analyses. The results showed that age, an ASIA grade of A or B, spinal fusion, preventive anticoagulation, physiotherapy treatment and a homocysteine level >15μmol/L were risk factors for the occurrence of a MCVT.Conclusions:Age, an ASIA grade of A or B, spinal fusion or an elevated serum homocysteine level are all risk factors for MCVT. Active anticoagulation and physical therapy may reduce the risk.

OBJECTIVE： To evaluate the efficacy and safety of icotinib in the treatment of advanced non-small cell lung cancer （NSCLC）， and to provide evidence-based reference for clinical drug use. METHODS： Retrieved from the Cochrane library， PubMed， Sciencedirect， CNKI， Wanfang database and VIP， RCTs about icotinib or icotinib combined with routine treatment or with other drugs （trial group） versus routine treatment or other drugs （control group） in the treatment of advanced NSCLC were collected. After literature screening， data extraction and literature quality evaluation with Cochrane collaboration bias risk assessment tool 5.1.0， Meta-analysis was performed by using Rev man 5.3 statistical software. RESULTS： A total of 27 RCTs were included， involving 2 345 patients. Results of Meta-analysis showed that response rate [OR＝1.64， 95％CI（1.36， 1.97）， P＜0.000 01] and disease control rate [OR＝1.68， 95％CI（1.39， 2.04）， P＜0.000 01] in trial group were significantly higher than control group； the incidence of ADR in trial group [OR＝0.59， 95％CI（0.48， 0.72）， P＜0.000 01] was significantly lower than control group. CONCLUSIONS： Icotinib shows good efficacy and safety in the treatment of advanced NSCLC.

Objective Non-muscle myosin heavy chain ⅡA (NMHC ⅡA ) plays a significant role in tumor progression and metastasis .Our prior study showed that the expression of NMHC ⅡA was much higher in human bladder cancer sample than that in adjacent tissue .The increased level of NM HC ⅡA expression was correlated with worse prognosis .However ,the role of NMHC ⅡA is unknown in the invasion and metastasis of bladder cancer .Methods RT-PCR and western blotting were used to examine NMHC ⅡA expression lev-els in normal bladder epithelial cells and bladder cancer cell lines .T he migration and invasion ability of cells was tested by wound healing assay and Transwell invasion assay ,respectively .Results Our study showed that knockdown of NMHC ⅡA inhibited migration and invasion in bladder cancer cell line .Conclusion The study indicated that NM HC ⅡA expression increased the invasion and metastasis ability of bladder cancer cell line in vitro .

Objective To compare the difference of the spinal cord injury rehabilitation physician training systems between Harvard Uni-versity and Capital Medical University. Methods The spinal cord injury rehabilitation physician training systems of Capital Medical Univer-sity and Harvard University were investigated, including the degree training time, residence training time, training fee and institution. Re-sults Degree education time was more in the basic science in Harvard University than in Capital Medical University. The residence training time was 7 years and 5 years for Harvard University and Capital Medical University, respectively, and the ratio of specialties and sub-spe-cialties was not significantly different. There was a total of 26 spinal cord injury community rehabilitation clinics in Harvard University sys-tem, and none in Capital Medical University. Conclusion Some light can be drawn from the spinal cord injury rehabilitation physician train-ing system of Harvard University, to improve the scholastic building of Capital Medical University.

OBJECTIVETo explore the anesthetic effects of repeated administration of propofol combined with vitamin C in mice.

METHODSForty mice were subjected to daily intraperitoneal injections of 80 mg/kg propofol (P80 group), 70 mg/kg propofol and 50 mg/kg vitamin C (P70+Vc50 group), 55 mg/kg propofol and 100 mg/kg vitamin C (P55+Vc100 group), or 50 mg/kg propofol and 200 mg/kg vitamin C (P50+Vc200 group) for 6 consecutive days, and the anesthesia induction time and anesthesia duration were recorded.

RESULTSCompared with the P80 group, the mice in P55 + Vc100 group and P50 + Vc200 group showed significantly shorter anesthesia duration on the first 3 days (P<0.05). In all the groups, anesthesia duration was significantly shortened in the following days compared with that on day 1 (P<0.01); anesthesia duration was shorter on day 3 than on day 2 in P50 + Vc200 group (P<0.01), and was shorter on days 4, 5, and 6 than on day 2 in all the groups (P<0.01). In all the groups, the rate of loss of righting reflex (LORR) decreased gradually with time in a similar pattern.

CONCLUSIONVitamin C can reduce the dose of propofol without obviously affecting the anesthetic effect to reduce the incidence of drug tolerance and potential dose-related side effects of propofol.

Anesthesia ; Anesthesia Recovery Period ; Anesthetics, Intravenous ; administration & dosage ; pharmacology ; Animals ; Ascorbic Acid ; administration & dosage ; pharmacology ; Drug Tolerance ; Mice ; Propofol ; administration & dosage ; pharmacology

Objective To investigate the effects of short-segment pedicle screws system on type A thoracic and lumbar spine fracture with or without pedicle screws on the fractured level. Methods 23 patients with type A thoracic and lumbar spine fracture were included, in which 11 cases received traditional short-segment pedicle screws system without pedicle screws on the fractured level (group A), and other 12 cases with pedicle screws on the fractured level (group B). The anterior vertebral height, posterior vertebral height and local kyphosis an-gle were measured before and after operation. Results All pedicle screws were successfully implanted with good location and stability. The vertebral height and kyphosis angle significantly improved after operation in both groups (P<0.05), and the improvement of kyphosis angle was more in group B than in group A (P<0.05). Conclusion Short-segment pedicle screws system with pedicle screws on the fractured level may fine correct the kyphosis angle in short term.

Objective To investigate whether the abnormal stress could cause the ultrastructural change of the rats′condylar cartilage in vivo .Methods Fifty‐four SD male rats were randomly divided into condylar neck osteotomy operation(OO)group ,con‐dylar neck fracture operation(FO) group ,and control group ,with 12 rats in each group .Then the OO group rats ,FO group rats and control group rats were executed and sampled at 1st week ,3rd week and 5th week separately to observe the structure of condyle with light microscope(LM ) ,scanning electron microscope (SEM ) and transmission electron microscope (TEM ) .Results LM showed that the general condylar thickness of OO group and FO group were thinner than that of control group at 3rd and 5th week . SEM showed that the collagen and fibre were exposed in the OO group and FO group at 3rd week and 5th week ,the fibre was bro‐ken in the OO group at 5th week .TEM showed that the hypertrophic cell in OO group was more mature than those of FO group and control group at 3rd week .The arrange of fibre was disorder in OO group at 1st week ,the fibre was more disorder and there was even leak in OO group at 5th week .Conclusion The abnormal stress in vivo could result in the ultrastructural change of the rats′condyle ,and this change relates with the stess change degree and affects the growth and development of condyle .

Objective To explore the anesthetic effects of repeated administration of propofol combined with vitamin C in mice. Methods Forty mice were subjected to daily intraperitoneal injections of 80 mg/kg propofol (P80 group), 70 mg/kg propofol and 50 mg/kg vitamin C (P70+Vc50 group), 55 mg/kg propofol and 100 mg/kg vitamin C (P55+Vc100 group), or 50 mg/kg propofol and 200 mg/kg vitamin C (P50+Vc200 group) for 6 consecutive days, and the anesthesia induction time and anesthesia duration were recorded. Results Compared with the P80 group, the mice in P55 + Vc100 group and P50 + Vc200 group showed significantly shorter anesthesia duration on the first 3 days (P<0.05). In all the groups, anesthesia duration was significantly shortened in the following days compared with that on day 1 (P<0.01);anesthesia duration was shorter on day 3 than on day 2 in P50+Vc200 group (P<0.01), and was shorter on days 4, 5, and 6 than on day 2 in all the groups (P<0.01). In all the groups, the rate of loss of righting reflex (LORR) decreased gradually with time in a similar pattern. Conclusions Vitamin C can reduce the dose of propofol without obviously affecting the anesthetic effect to reduce the incidence of drug tolerance and potential dose-related side effects of propofol.