BACKGROUND: Bracket dropping is often seen in clinic. Can these shed brackets be used again; what should be done to treat these brackets; is the bond strength of these recycled brackets different from those new ones, these questions are often concerned by orthodontists in their clinic and are the purpose of our study as well.OBJECTIVE: To evaluate the shear bond strength and compare two base-cure methods of recycled brackets. DESIGN: Grouping control study. SITTING: Department of Orthodontics, the Affiliated Hospital of Medical College, Qingdao University; Department of Materials, Dental School, Beijing University. MATERIALS: The teeth were collected from Oral Surgery, the Affiliated Hospital of Medical College, Qingdao University. The age was from 11 to 19 years. The gender was half male and half female. Intact enamel of the crown was required, but decayed, fracture, tetracycline pigmentation teeth or fluorosis teeth were excluded. Patients provided the confirmed consent for this experiment.METHODS: The experiment was carried out in Stomatology College of Peaking University in December 2005. Thirty ex vivo teeth were selected randomly from those prepared enamel surfaces, used as sample for rebounding. The edgewise brackets of swallow-tailed brackets were bonded on each tooth and rebonded after 24 hours. The teeth were cleaned and divided randomly into 3 groups. There were 10 teeth in each group. Group 1 was bonded with new brackets; group 2 with recycled brackets whose adhesive remnant were burned and got rid of; group 3 with recycled brackets whose adhesive remnant in the groove of the base were stored. Bracket was provided by Standard edgewise, Orsu Company, Hangzhou, China. After 24 hours, the shear bond strength was tested with material testing machine (Autogragh, Shimadzu, Japan). Adhesive remnant index (ARI) was added up. MAIN OUTCOME MEASURES: Shear strength of old metal bracket after rebonding and adhesive remnant.RESULTS: ① Shear bond strength: The shear bond strengths were (10.094±3.158 9) in group 1, (10.266±2.406 0) in group 2 and (8.898±1.365 9) in group 3. There were no statistically significant differences among the three groups (P > 0.05). ② ARI scores: ARI scores were 51.7%, 58.3% and 35.0% in the three groups, respectively. There were statistically significant differences between group 2 and 3. CONCLUSION: In vitro study indicates that the recycled metal brackets can reach good bond strength and that maybe there is chemical bond between new and old adhesive.

This study investigated the effect of arctigenin (Arc) on the cell activation, cytokines expression, proliferation, and cell-cycle distribution of mouse T lymphocytes. Mouse lymphocytes were prepared from lymph node and treated with Phorbol-12-myristate-13-acetate (PMA)/Ionimycin (Ion) and/or Arc. CD69, CD25, cytokines, proliferation and cell cycle were assayed by flow cytometry. The results showed that, at concentrations of less than 1.00 micromol x L(-1), Arc expressed non-obvious cell damage to cultured lymphocytes, however, it could significantly down-regulate the expression of CD69 and CD25, as well as TNF-alpha, IFN-gamma, IL-2, IL-4, IL-6 and IL-10 on PMA/Ion stimulated lymphocytes. At the same time, Arc could also inhibit the proliferation of PMA/Ion-activated lymphocytes and exhibited lymphocyte G 0/G1 phase cycle arrest. These results suggest that Arc possesses significant anti-inflammatory effects that may be mediated through the regulation of cell activation, cytokines expression and cell proliferation.

Objective Evaluate data of 1270 cases with free flap transplant,to find the problems in the process of operation,and then to analyse its causes and how to prevent and solve it,as well as providing reference for clinical colleagues. Methods To study 1270 cases of free flaps,musculocutaneous flap and perforator flap who was treated in our hospital from October 2000 to October 2010 retrospectively. A total of 722 cases of the group were followed-up 6 months to 5 years. To detective and search the problems and imperfection from designing,harvesting,tranfer,to the management and function of donor site after free flap transplantion.And also to analysis the couse of problems and operation failure,discuss the conclude of and to provide advisable measure. Results Total 1270 free flaps were transplanted successfully except 64 can-celled or failured for some reason, the success rate was 95.0％, the postopertive necrosis rate was 3.8％.Seventy-six cases were encountered vascular complications venous crisis in 42,arterial crisis in 38.Fifty-five cases were saved successfully without surgery,and 15 cases survived completely by vessel explorative operation. Five cases were partial necrosis and 7 cases necrosis. The rate of postoperative infection of emergency cases and chronic one were 4.7％ (682 cases)and 8.8％(588 cases) which show the infective incidence of latter was higher than former. In addition, there were many other problems were found such as distal flaps necrosis,contracture,deformation,impairment function of doner site,etc. Conclusion Preventing and management timely to vessle crisis is the key to flap suvive. The principle of dissecting flap should be followed strictly,and control the indications of modified processing during flap harvest,keep the proper flap tension were technical requirements in flap transplantion. Right way of donor site closed and management of insufficient timely were equally important to prevent and solve to complications and dysfunction.

Objective To investigate the changes of internal fixation stress under different angles of interior fracture line and different screw placement modes in the case of A?type distal femoral fracture. Methods A 24?year?old healthy male volunteer was recruited to collect the right femur data. CATIA V5R21 software produced a 10 mm fracture gap at the external side of the femur 6.5 cm proximal to the joint line and different angle fracture lines were generated on the internal of the femur at the same height. Based on the actual measured dimensions, the three?dimensional (3D) model of the locking plate and screw was reconstructed using CATIA V5R21 software, ignoring the screw surface threads and then the assembly of the internal fixation of the titanium plate, screws and femur was done. All models were meshed using Hypermesh 13.0 software. The assembled 3D model was input into ABAQUS 6.14 to generate a finite element model. Preliminary finite element biomechanical analysis was performed using the four medial fracture line angles and the stress distribution of the internal fixation under the three screw placement modes, and then the analysis was continued after the optimal screw placement method was re?determined. Results Under an axial loading of 700 N, with the increase of the angle of the fracture line, the stress of the lateral internal fixation gradually increased, and the displacement of the proximal end of the fracture gradually increased. The sequential screw placement method was superior to the leaping screw placement method. The placement of the first screw at the proximal end of the fracture was critical to the distribution of the internal fixation stress. Conclusions The operation plan of the type A of distal femoral fracture needs to be confirmed according to the internal and external fracture′s condition. When the fracture line is at a excessive positive angle or a negative angle, a simple lateral fixation may not provide a stable fracture fixation so that other fixation methods are needed.

Objective To investigate the changes of internal fixation stress under different angles of interior fracture line and different screw placement modes in the case of A?type distal femoral fracture. Methods A 24?year?old healthy male volunteer was recruited to collect the right femur data. CATIA V5R21 software produced a 10 mm fracture gap at the external side of the femur 6.5 cm proximal to the joint line and different angle fracture lines were generated on the internal of the femur at the same height. Based on the actual measured dimensions, the three?dimensional (3D) model of the locking plate and screw was reconstructed using CATIA V5R21 software, ignoring the screw surface threads and then the assembly of the internal fixation of the titanium plate, screws and femur was done. All models were meshed using Hypermesh 13.0 software. The assembled 3D model was input into ABAQUS 6.14 to generate a finite element model. Preliminary finite element biomechanical analysis was performed using the four medial fracture line angles and the stress distribution of the internal fixation under the three screw placement modes, and then the analysis was continued after the optimal screw placement method was re?determined. Results Under an axial loading of 700 N, with the increase of the angle of the fracture line, the stress of the lateral internal fixation gradually increased, and the displacement of the proximal end of the fracture gradually increased. The sequential screw placement method was superior to the leaping screw placement method. The placement of the first screw at the proximal end of the fracture was critical to the distribution of the internal fixation stress. Conclusions The operation plan of the type A of distal femoral fracture needs to be confirmed according to the internal and external fracture′s condition. When the fracture line is at a excessive positive angle or a negative angle, a simple lateral fixation may not provide a stable fracture fixation so that other fixation methods are needed.

This article summarizes and analyzes the reported synthetic routes of brivudine in patent and literature.2′-Deoxyuridine was employed as starting material, affording brivudine through iodization, heck coupling, hydrolysis, decarboxylation, bromination and recrystallization.After optimization of reaction conditions of each step, a synthetic route suitable for industrial production was achieved with simple synthetic process, high yield and excellent purity.

Objective:To evaluate the efficacy of 3D printed individualised prosthesis in treating bone and joint defects in upper limbs remained after earlier microsurgical repairs.Methods:From June 2019 to September 2021, 12 patients were treated in the Institute of Orthopaedic Trauma of PLA, the 80th Group Army Hospital for bone and joint defects in upper limb that had been remained after earlier repairs with soft tissue flaps. The defects were: 1 in completely severed wrist, 2 defects of digit metacarpal bone, 4 defects of interphalangeal joint, 4 defects of bones in radiocarpal joint and 1 defect of lunate bone. The area of soft tissue defect ranged from 1.5 cm×3.0 cm to 12.0 cm×18.0 cm, and the length of bone defects ranged from 2.5 to 8.5(average 3.64) cm. For incompletely severed and completely severed limbs, replantation of severed limbs (digits) were performed in the primary surgery and the repair of soft tissue defects were performed in the second stage surgery. The remaining defects of bone and joint were reconstructed by 3D printed individualised prostheses in the third stage surgery. Finger soft tissue defects were covered with a local flap in the primary surgery, and bone and joint defects were reconstructed with a 3D printed prosthesis in the second surgery. Finger soft tissue defects were covered with a local flap in the first phase, and bone and joint defects were reconstructed with a 3D printed prosthesis in the second phase. After the surgery, the bone integration between the broken end of the bone joint defect and the prosthesis was determined based on the X-ray results and the Paley fracture healing score standard. Simultaneously measured the Total Active Motion(TAM) of the forearm and hand joints. At 1, 2, 3, 6, 9 and 12 months after hospital discharge. Follow-up X-ray examinations were taken followed by examinations on the recovery of soft tissues and bones. The upper limb function was graded according to the Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association.Results:Postoperative follow-up at outpatient clinic lasted for 6 to 26 months, with an average of 11.5 months. All flaps were free from necrosis and infection, also there was no infection in bones and joints. According to the Paley fracture healing scale, 10 patients were in excellent and 2 in good. In addition, according to the Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association, 5 patients achieved upper limb function in excellent, 5 in good and 2 in fair. The ranges of motion of the affected wrists were 30°-42°(average 37.3°) for the implanted prostheses of distal end of radius and the radial shaft. Wrist flexion 40° to 55°(average 43.5°). The range of motion of finger and wrist was 60° to 70°(average 65.7°) with a metacarpal and phalangeal bone prosthesis.Conclusion:3D printed individually customised prostheses are safe, accurate and effective in repair of the remained bone and joint defects in upper limbs after primary and early stages of microsurgical flap repairs. It can effectively restore anatomical structures of bone and joint in upper limbs.

Objective:To investigate the surgical efficacy of split liver transplantation.Methods:Patients who underwent liver transplantation at the Affiliated Hospital of Qingdao University between January 2015 and December 2022 were retrospectively analyzed. They were divided into split liver transplantation group ( n=60) and whole liver transplantation group ( n=765)according to graft types.In the split liver transplantation group, there were 23 males and 37 females, aged (52.5±10.2) years, and the body mass index was (22.4±3.3) kg/m 2. In the whole liver transplantation group, there were 630 males and 135 females, aged (51.2±9.6) years, and body mass index was (24.5±3.7) kg/m 2.The basic data of the two groups were matched 1∶1 using the propensity score matching method. The independent sample t test and χ2 test were used to compare the intraoperative and postoperative recovery of the two groups of donors and recipients. The overall survival rate and the graft survival rate of the two groups were analyzed by Kaplan-Meier method and the cumulative survival rate was compared by the Log-rank test. Results:Fifty-one well-matched pairs of data with similar baseline characteristics were obtained. The ratio of graft mass to recipient body weight in the matched split liver transplantation group was (1.78±0.55)%. Operation time( M(IQR))(10.8(1.5)hours vs. 8.0(1.9)hours, U=6.608, P<0.01) and cold ischaemia time(5.4(1.3)hours vs. 4.6(2.2)hours, U=2.825, P=0.005) were significantly longer in the split liver transplantation group than those in the whole liver transplantation group. Intra-operative anhepatic phase(53.0(15.0)minutes vs. 57.0(24.0)minutes, U=1.048, P=0.295),bleeding volume(1 000(1 400)ml vs. 1 200(1 200)ml, U=0.966, P=0.334) and intraoperative instillation of red blood cells(9.0(6.5)U vs. 11.0(11.0)U, U=1.732, P=0.083) were not significantly different between the two groups. However,the split liver transplantation group showed significantly longer postoperative intensive care unit stay(5.0(3.0)days vs. 4.0(4.0)days, U=2.677, P=0.007) and postoperative hospital stay(30.0(15.0)days vs. 26.0(15.0)days, U=2.237, P=0.025) and significantly higher incidence of postoperative complications(56.8%(29/51) vs. 36.6%(19/51), χ2=3.935, P=0.047) than the whole liver transplantation group. Furthermore,levels of alanine transaminase and aspartate aminotransferase were significantly higher on postoperative days 1,4 and 7 in the split liver transplantation group(all P<0.05) than in the whole liver transplantation group;however,there were no significant differences in these levels on postoperative days 14 and 28. The time to restoration of normal liver function in both groups(12.5(13.7)days vs. 9.0(12.5)days, U=1.607, P=0.108) was not statistically significant. Furthermore,the median follow-up time after surgery was 25.6 months in both groups. In postoperative years 1,2,3 and 5, the graft survival rates were 88.1%,80.8%,77.8% and 66.7% in the whole liver transplantation group and 80.3%,70.3%,67.3% and 60.5% in the split liver transplantation group( P=0.171),respectively. The patient survival rates in post-operative years 1,2,3 and 5 were 88.1%,80.8%,77.8% and 66.7% in the whole liver transplantation group and 80.3%,75.9%,70.3% and 63.3% in the split liver transplantation group,respectively( P=0.252). However,the differences of graft survival rates and patient survival rates between the two groups were not significant. Conclusion:Although it affects the early recovery of patients after liver transplantation,split liver transplantation has no effect on long-term survival rates and demonstrates surgical efficacy similar to that of whole liver transplantation.

Objective:To investigate the surgical efficacy of split liver transplantation.Methods:Patients who underwent liver transplantation at the Affiliated Hospital of Qingdao University between January 2015 and December 2022 were retrospectively analyzed. They were divided into split liver transplantation group ( n=60) and whole liver transplantation group ( n=765)according to graft types.In the split liver transplantation group, there were 23 males and 37 females, aged (52.5±10.2) years, and the body mass index was (22.4±3.3) kg/m 2. In the whole liver transplantation group, there were 630 males and 135 females, aged (51.2±9.6) years, and body mass index was (24.5±3.7) kg/m 2.The basic data of the two groups were matched 1∶1 using the propensity score matching method. The independent sample t test and χ2 test were used to compare the intraoperative and postoperative recovery of the two groups of donors and recipients. The overall survival rate and the graft survival rate of the two groups were analyzed by Kaplan-Meier method and the cumulative survival rate was compared by the Log-rank test. Results:Fifty-one well-matched pairs of data with similar baseline characteristics were obtained. The ratio of graft mass to recipient body weight in the matched split liver transplantation group was (1.78±0.55)%. Operation time( M(IQR))(10.8(1.5)hours vs. 8.0(1.9)hours, U=6.608, P<0.01) and cold ischaemia time(5.4(1.3)hours vs. 4.6(2.2)hours, U=2.825, P=0.005) were significantly longer in the split liver transplantation group than those in the whole liver transplantation group. Intra-operative anhepatic phase(53.0(15.0)minutes vs. 57.0(24.0)minutes, U=1.048, P=0.295),bleeding volume(1 000(1 400)ml vs. 1 200(1 200)ml, U=0.966, P=0.334) and intraoperative instillation of red blood cells(9.0(6.5)U vs. 11.0(11.0)U, U=1.732, P=0.083) were not significantly different between the two groups. However,the split liver transplantation group showed significantly longer postoperative intensive care unit stay(5.0(3.0)days vs. 4.0(4.0)days, U=2.677, P=0.007) and postoperative hospital stay(30.0(15.0)days vs. 26.0(15.0)days, U=2.237, P=0.025) and significantly higher incidence of postoperative complications(56.8%(29/51) vs. 36.6%(19/51), χ2=3.935, P=0.047) than the whole liver transplantation group. Furthermore,levels of alanine transaminase and aspartate aminotransferase were significantly higher on postoperative days 1,4 and 7 in the split liver transplantation group(all P<0.05) than in the whole liver transplantation group;however,there were no significant differences in these levels on postoperative days 14 and 28. The time to restoration of normal liver function in both groups(12.5(13.7)days vs. 9.0(12.5)days, U=1.607, P=0.108) was not statistically significant. Furthermore,the median follow-up time after surgery was 25.6 months in both groups. In postoperative years 1,2,3 and 5, the graft survival rates were 88.1%,80.8%,77.8% and 66.7% in the whole liver transplantation group and 80.3%,70.3%,67.3% and 60.5% in the split liver transplantation group( P=0.171),respectively. The patient survival rates in post-operative years 1,2,3 and 5 were 88.1%,80.8%,77.8% and 66.7% in the whole liver transplantation group and 80.3%,75.9%,70.3% and 63.3% in the split liver transplantation group,respectively( P=0.252). However,the differences of graft survival rates and patient survival rates between the two groups were not significant. Conclusion:Although it affects the early recovery of patients after liver transplantation,split liver transplantation has no effect on long-term survival rates and demonstrates surgical efficacy similar to that of whole liver transplantation.