Based on the CT data and the structure characteristics of the femoral fractures during different healing stages, medical FE models of fractured femur treated with locking compression plate (LCP)were built. Under the physiological load of a standard body weight (70 kg) and the constraint condition, the stress distributions of LCP and fractured femur during healing were calculated by means of three-dimensional finite element analysis (3D-FEA). The results showed that the stress distribution in the LCP and the fractured femur was similar, during the initial stage which there was no newly formed bone or soft tissue in fracture site. The maximum von Mises stress (371.23,272.76 MPa) in the fractured femur was much higher than that in natural femur, and the intensive stress was concentrated mainly in the proximal area of the fractured femur. With the growth of bony callus bone in fracture site, the intensity of stress in proximal femur decreased. Contrasted to the two cases mentioned above, the value of the maximum von Mises stress (68. 17 MPa) in bony callus bone stage decreased significantly, and was lower than the safe strength of natural bone. Therefore, appropriate training which is benefitial for the growth to new bone could be arranged for the better rehabilitation.
Biomechanical Phenomena ; Bone Plates ; Femoral Fractures ; pathology ; Femur ; pathology ; Finite Element Analysis ; Humans ; Stress, Mechanical

Objective To understand HIV incidence in community residents and epidemiological characteristics of newly detected HIV infection cases in Dali,Yunnan province.Methods A cohort study was conducted among 146720 community residents who were tested to be HIV negative during 2010-2011,they were followed-up from June 1,2014 to May 31,2015.Results A total of 136356 community residents received follow up (92.9％).The follow-up time was 0.23-5.40 years (medium:3.43 years),cumulatively 459675 person years,and 78 people were found to be HIV positive.The incidence rate of HIV infection was 0.170/1000 person years.The incidence rate was 0.037/1000 person years in age group 15-29 years,0.288/1000 person years in age group 30-44 years,0.210/1000 person years in age group 45-59 years,0.204/1000 person years in age ≥60 years;0.213/1 000 person years in males,0.130/1000 person years in females;0.248/1000 person years inHan ethnic group,0.149/1000 person years in Minorities;0.194/1000 in people with education level ≤junior middle school,0.046/1000 person years in people with education level ＞ junior middle school;0.070/1000 person years in the unmarried,0.194/1000 person years in the married and 0.425/1000person years in the divorced/widowed.Cox proportional hazards regression analysis showed that being male (HR=l.731),aged 30-44 years (HR=13.158),aged 45-59 years (HR=10.329),aged ≥60years (HR=8.291),unmarried (HR=3.162) and divorced/widowed (HR=2.689) were the risk factors for HIV infection,while the education level ＞ junior middle school (HR=0.132) was the protective factor for HIV infection.Conclusions By medium 3.43 years follow up,the cohort study showed that incidence rate HIV infection was 0.170/1000 person years in the community residents in Dali.Male,middle aged and old people,people with low education level,the unmarried and the divorced/widowed had relatively higher risk to be infected with HIV,Close attention should be paid to the prevention and control of AIDS in these populations.

OBJECTIVE: To explore the expression of the RNA-binding protein tristetraprolin in lung adenocarcinoma cells and its molecular mechanism for inhibiting autophagy. METHODS: Quantitative real-time PCR and Western blotting were performed to detect the expression of autophagy-related genes (including Beclin1, LC3-Ⅱ/LC3-Ⅰ and SQSTM1/p62) in cultured lung adenocarcinoma cells at 24, 48 and 72 h after transient transfection with a tristetraprolin-overexpressing plasmid and the empty plasmid. The effects of transfection with the tristetraprolin-overexpressing plasmid and empty plasmids in the presence or absence of tumor necrosis factor- (TNF-) on the expressions of nuclear factor-κB (NF-κB) p65, c-rel, and p50 were examined in lung adenocarcinoma cells using immunofluorescence assay and Western blotting. The cells were also transfected with the IκBα-mut plasmid and the tristetraprolin-overexpressing plasmid, either alone or in combination, and the changes in the expressions of tristetraprolin and autophagy-related genes were detected using RT-qPCR and Western blotting. RESULTS: The expressions of tristetraprolin were significantly reduced at both the mRNA and protein levels in lung adenocarcinoma cells ( < 0.001). Overexpression of tristetraprolin in the cells significantly lowered the expressions of autophagy-related genes Beclin1 and the ratio of LC3-Ⅱ/LC3-Ⅰ at the mRNA and protein levels ( < 0.001), obviously lowered the expressions of NF-κB p65 and c-rel, and almost totally blocked the nuclear translocation of NF-κB p65 and c-rel ( < 0.05); the expression of p50, however, did not undergo significant changes in response to tristetraprolin overexpression ( > 0.05). The inhibitory effect of tristetraprolin overexpression on autophagy was abrogated by transfection of the cells with IκBα-mut plasmid, which blocked the NF-κB signaling pathway. Co-transfection of the cells with IκBα-mut also attenuated the inhibitory effect of tristetraprolin overexpression on Beclin1 and the LC3-Ⅱ/LC3-Ⅰ ratio at both the mRNA and protein levels ( < 0.05). CONCLUSIONS The expression of tristetraprolin is low in lung adenocarcinoma cells. Tristetraprolin overexpression causes inhibition of autophagy in lung adenocarcinoma cells possibly by blocking NF-κB p65 and c-rel nuclear translocation.
Autophagy ; Cell Line ; Humans ; Lung Neoplasms ; NF-kappa B ; Signal Transduction ; Tristetraprolin