BACKGROUND:During the treatment of posterolateral tibial plateau fractures through the fibular head approach,the gap between the fibular head and the lateral plateau cannot accommodate the posterior placement of a plate for all patients.OBJECTIVE:To analyze,via finite element analysis,the differences in fixation strength resulting from varying the angles and quantities of horizontal arm variable angle screws in the plate during the treatment of posterolateral tibial plateau fractures through the fibular head approach.METHODS:A finite element model was established based on CT images of the knee to ankle joints of a 30-year-old healthy adult male volunteer.The models were divided into two categories:posteriorly placed group and non-posteriorly placed group based on whether the lateral locking compression plate was posteriorly placed.The posteriorly placed group was further subdivided into groups A-D based on the offset angle of the two variable angle screws(0°,5°,10°,and 15°).The non-posteriorly placed group was subdivided into groups E and F based on offset angles(0° and 15°).Finite element analysis was used to evaluate the von Mises stress distribution,maximum von Mises stress,and compressive displacement under loads of 250,500,and 750 N,exploring the mechanical differences between the groups.RESULTS AND CONCLUSION:(1)Finite element analysis results showed that under a 750 N load,the maximum compressive displacement trend of the internal fixation device was D＜B=C=F＜A＜E.The trend for maximum von Mises stress was B＜C＜A＜D＜F＜E.The trend for maximum compressive displacement on the bone was C=D＜B＜A＜F＜E,and for maximum von Mises stress,it was B＜C＜A＜F＜D＜E.The displacement and stress trends for the six models were similar under loads ranging from 250 N to 750 N.(2)These results suggest that for posterolateral tibial plateau fractures fixed through the fibular head approach,posterior placement of the plate should aim to accommodate two screws.If only one screw can be fixed during surgery,variable angle screws should be offset in the range of 0-15° to increase the probability of securing two screws.

BACKGROUND:During the treatment of posterolateral tibial plateau fractures through the fibular head approach,the gap between the fibular head and the lateral plateau cannot accommodate the posterior placement of a plate for all patients.OBJECTIVE:To analyze,via finite element analysis,the differences in fixation strength resulting from varying the angles and quantities of horizontal arm variable angle screws in the plate during the treatment of posterolateral tibial plateau fractures through the fibular head approach.METHODS:A finite element model was established based on CT images of the knee to ankle joints of a 30-year-old healthy adult male volunteer.The models were divided into two categories:posteriorly placed group and non-posteriorly placed group based on whether the lateral locking compression plate was posteriorly placed.The posteriorly placed group was further subdivided into groups A-D based on the offset angle of the two variable angle screws(0°,5°,10°,and 15°).The non-posteriorly placed group was subdivided into groups E and F based on offset angles(0° and 15°).Finite element analysis was used to evaluate the von Mises stress distribution,maximum von Mises stress,and compressive displacement under loads of 250,500,and 750 N,exploring the mechanical differences between the groups.RESULTS AND CONCLUSION:(1)Finite element analysis results showed that under a 750 N load,the maximum compressive displacement trend of the internal fixation device was D＜B=C=F＜A＜E.The trend for maximum von Mises stress was B＜C＜A＜D＜F＜E.The trend for maximum compressive displacement on the bone was C=D＜B＜A＜F＜E,and for maximum von Mises stress,it was B＜C＜A＜F＜D＜E.The displacement and stress trends for the six models were similar under loads ranging from 250 N to 750 N.(2)These results suggest that for posterolateral tibial plateau fractures fixed through the fibular head approach,posterior placement of the plate should aim to accommodate two screws.If only one screw can be fixed during surgery,variable angle screws should be offset in the range of 0-15° to increase the probability of securing two screws.

Objective To explore the effect of oxaliplatin ( OXA) on enhancing radiosensitivity in human hepatocellular carcinoma cell line HepG2 . Methods 50% inhibition concentration ( IC50 ) of HepG2 cells treated with OXA was measured by using MTT method at 6, 12, 24, 48 hours. Then clone formation assay was applied to obtain sensitizing enhancement ratio ( SER) of OXA combing IR, according to the survival fraction of three groups 10?14 days after treatments:placebo?treated group ( C) ,radiation group ( IR, single dose of 1 Gy,2 Gy,4 Gy,6 Gy,8 Gy,10 Gy) and IR synchronizing OXA group ( IR+3 mg/L OXA) . The proportions of cell apoptosis were analyzed using flow cytometry at 24 hours after treatment. At last, we semi?quantitative tested the expression of extracellular regulated protein kinase 1/2 ( ERK 1/2 ) and DNA damage repair protein Ku?70 of the C,IR and IR+OXA groups. Statistical analysis was performed by T test. Results The IC50 of OXA on HepG2 cells is 54?4 mg/L at 6 hours,29?1 mg/L at 12 hours,17?8 mg/L at 24 hours and 10?5 mg/L at 48 hours.3 mg/L was selected in clone formation assay at which 80?90% HepG2 cells survived at 24 hours. The SER ( SF2 ) is calculated as 1?59. Flow cytometry showed the proportion of survival cells in IR+OXA group is significantly lower than those of IR group ( P=0?005) ,OXA group ( P=0?008) and C group ( P=0?001) . The expressions of ERK 1/2 were inhibited in IR and IR+OXA groups compared by that of control group. But the expression of ERK 1/2 in IR group showed increasing after 48 hours which was higher than that of IR+OXA group. For Ku?70,the changes of expression were similar with that of ERK 1/2. Conclusion Oxaliplatin presented enhancing radiosensitivity in human hepatocellular carcinoma cell line HepG2 in vitro.

OBJECTIVE:To optimize the formulation of Dimemorfan phosphate tablets. METHODS:Using 60 min dissolution rate of dimemorfan phosphate as index,L9(34) orthogonal test was used to optimize the amount of starch,microcrystalline cellu-lose,croscarmellose sodium and concentration of HPMC E5 solution. The friability,hardness,60 min dissolution rate and main component were detected. The similarity of dissolution curves of Dimemorfan phosphate tablets was compared with that of imported tablets in 0.1 mol/L hydrochloric acid,pH 6.8 phosphate buffer,water and pH 4.0 acetate buffer. RESULTS:The optimized formu-lation of Dimemorfan phosphate tablet(1 000 tablets)was composed of dimemorfan phosphate 10 g,starch 60 g,microcrystalline cellulose 40 g,10% HPMC E5 solution and croscarmellose sodium 25 g. The friability,hardness,60 min dissolution rate and main component of 3 batches of Dimemorfan phosphate tablets prepared by optimized prescription were 0.42%-0.58%,9.8-10.5 kg,94.89%-96.21% and 99.21%-99.52%,respectively. In 4 dissolution mediums,similar factors f2 of dissolution curves between prepared tablets and imported tablets were above 50. CONCLUSIONS:Dimemorfan phosphate tablets were prepared successfully. The optimized formulation is rational. The dissolution behavior of prepared tablets is similar to that of imported tablets in vitro.

Objective To investigate the clinical effects of subeutanous fistula excision for the long-path low anus fistula.Methods Operation for long-path low anus fistula,fistula length＞5cm,divided the pafients into two groups.The therapeutic group:using subcutanous fistula excision;the control group:using fistula icision.Comparing the healing time,arIus malformation,recurrence rate.Results Therapeutic group 47 cases heal,the healing time was 12 days;no anus malformation;no arms ineontenience.In the control group,the healing time was 23 days;anus malformation 23 cases;anus gas incontenience 12 cases.Conclusion To use subcutanous fistula excision for the longpath low anus fistula has the advantages of short healing time,no anus malformation,less pain,and low reccurrent rate.