Objective To calculate effective dose based on the dose-area Product (DAP) measured in dental cone beam computed tomograhic (CBCT) scanning and using a conversion coefficient.Methods The method of the DAP was used to calculate the effective dose from KODAK 9500 dental CBCT scanner with fields of view (FOV) of 16 cm×15 cm and 12 cmu×8 cm.The DAP-values (mGy · cm2) were measured using a transmission ionization chamber connected to an electrometer (Doseguard 100,RTI Electronics AB,Sweden) and the chamber was placed directly on the exit of the X-ray tube.All measurements were repeated three times and averaged on each FOV data.The conversion coefficient of 0.080 μSv/mGy · cm2 was used to estimate the effective dose on the basis of DAP values,which was quoted from a literature.Results DAP values were found between the two FAOs to vary from 512 to 1 083 mGy · cm2,and the effective doses calculated with 0.080 μSv/mGy · cm2were 41 to 87 μSv.The effective doses given in this paper was lower than those reported in other literatures.Conclusions DAP measurement was found to be well defined and easy-to-use method of determining effective dose for some CBCT Units.However,determination of specific conversion coefficient in the CBCT must be further developed.

Objective To study the effect of thrombin on proliferation and invasion of esophageal cancer cell line Eca109, and to explore its possible mechanism. Methods The proliferation and invasion of Eca 109 cells treated with thrombin were detected by MTT and Transwell assay, respectively. The activity of matrix metalloproteinase 2 (MMP-2) and MMP-9 in the supernatant of Eca109 cells was detected by gelatin zymography. Reverse transcription polymerase chain reaction (PCR) and immunocytochemistry were used to study the mRNA expression of protease-activated receptor 1 (PAR-1), the important receptor of thrombin, and subcellular localization of PAR-1 protein in Eca109 cells, respectively. Results Thrombin could promote Eca109 cells proliferation in a dose-dependent manner. Cell proliferative rates of 0.5 U/ml and 1.0 U/ml thrombin were 34.38 % and 57.19 %, respectively (P< 0.05). Compared to that of control group, the number of Eca109 cells incubated with 1.0 U/ml thrombin invading through the basement membrane of Transwell was increased (303.33 ±6.66 vs. 116.33 ±11.51, P< 0.05). When treated with various concentrations of thrombin for 24 h, the activities of MMP-2 and MMP-9, especially MMP-9, in the supernatant of Eca109 cells were increased in a dose-dependent manner. Eca109 cells expressed PAR-1 mRNA, and PAR-1 protein was mainly located on the cellular membrane. Conclusion Thrombin increases proliferation and invasion of esophageal cancer Eca109 cells and enhances the activities of MMP-2 and MMP-9 in cells supernatant, which might be induced by activation of PAR-1 located on cellular membrane.

Objective To investigate the expression of hypoxia-inducible factor-1 alpha (HIF-1 α),vascular endothelial growth factor-A (VEGF-A) and vascular endothelial growth factor-D (VEGF-D)in hypoxic environment as well as the relationship between HIF-lα and VEGF-D.Methods Human esophageal cancer cell line EC9706 was cultured under hypoxia environment for 6,12 and 24 h,the cell radiosensitivity was evaluated by survival curve.HIF-1 α siRNA was constructed and transfected into human EC9706 cells.Protein expressions of HIF-1 α,VEGF-A and VEGF-D were analyzed by Western blot before and after RNA interference.Results EC9706 cells under hypoxia showed radioresistance with a SF2 of 0.62 higher than that of normoxic cells of 0.43.Moreover,the protein expressions of HIF-1α,VEGF-A and VEGF-D were all increased (F =205.24,227.88,130.55,P ＜0.05) due to hypoxia treatment.On the contrary,after HIF-1α siRNA transfer,the protein expressions of HIF-1α,VEGF-A and VEGF-D in EC9706 cells were not influenced by hypoxia treatment.Conclusions EC9706 cells in hypoxic environment was radioresistance,and the upexpressions of HIF1α,VEGF-A and VEGF-D may be involved.

Objective To explore the influences of selenium,age,sex,education level,occupation and other factors on cognitive function in elderly of rural areas in Shandong Province.Methods Rural Chinese aged 65 years or older were sampled from Gaomi County and Zichuan County from 2006 to 2007 in Shandong,Province by cluster sampling method.Demographic characteristics were collected,and cognitive functions were surveyed using dementia community survey(CSID),including dementia test,CERAD word list learning,recall test,Indiana University (IU) story recall test and impact test on animals.The nail samples were collected and the selenium content was tested using 2,3-diamino-naphthalene fluorescence assay.The relationship between selenium and other related factors(age,sex,education level,occupation,et al) With cognitive function was analyzed.Results A total of 1 000 people aged 65 years or older were investigated.In which,457 were males,and 543 were females.Most elderly were farmers and illiteracy.The differences of CSID total scores and IU story recall scores between different selenium groups were statistically significant(F =2.56,9.18,P ＜ 0.05 or ＜ 0.01).Multiple linear regression model analysis showed,age,sex,education level,occupation,hypertension and nail selenium content had significant impact on CSID scores(t =-9.942,-6.848,5.391,2.276,-2.863,2.309,all P ＜ 0.05).Age,sex,education level,occupation and nail selenium content had significant impact on IU story recall test (t =-4.252,-2.021,8.203,2.528,4.490,all P ＜ 0.05).While age,sex,education level,occupation were main influence factors to animal fluency test(t =-7.951,-6.166,7.544,2.824,all P＜ 0.05).Conclusions Selenium is a protective factor for cognitive function of elderly in Shandong Province.Besides,age,sex and education level also have impact on cognitive ability of rural elderly.

Objective To investigate the application of CT image and cone beam computed tomography (CBCT) image registration based on 3D Slicer software in image-guided radiotherapy for uterine cervical neoplasms. Methods Based on 3D Slicer software and Slicer RT toolkit, 10 positioning CT images and 50 CBCT images of 10 patients with uterine cervical neoplasms in Henan Provincial People's Hospital between January 2018 and October 2018 had rigid registration and b-spline deformation registration respectively. The dice similarity coefficient (DSC) and Hausdorff distance (HD) of the bladder, rectum, femoral head, spinal cord, and body of CT-CBCT images were compared by using paired t-test before and after the registration. Results Pre-registration, rigid registration and after b-spline deformation registration of CT images and CBCT images, the DSC in the bladder (0.459±0.177, 0.528±0.184, 0.542±0.187, respectively), the rectum (0.564±0.141, 0.632±0.091, 0.684±0.097, respectively), the femoral head (0.695±0.088, 0.833± 0.030, 0.865±0.027, respectively), the spinal cord (0.587±0.119, 0.746±0.085, 0.834±0.032, respectively) and the body surface (0.922±0.013, 0.948±0.011, 0.959±0.009, respectively) showed an increased trend; HD in the bladder (12.8±7.2, 12.2±7.1, 11.7±7.3, respectively), the rectum (5.0±1.8, 4.4±1.2, 3.4±1.2, respectively), the femoral head (3.6±1.2, 1.8±0.5, 1.5 ±0.5, respectively), the spinal cord (4.0 ±1.0, 2.7 ±1.3, 1.8 ±0.5, respectively) and the body surface (6.3±2.1, 5.2±2.0, 4.3±2.0, respectively) showed a decreased trend. The differences of pairwise comparison in the same parts were statistically significant (all P < 0.05). Conclusions Both rigid registration and b-spline deformation registration of CT-CBCT images based on 3D Slicer softwarecan improve the radiotherapy accuracy of uterine cervical neoplasms, and b-spline deformation registration has more significant advantages.