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The isothermal deformation behavior of Ni-Cr-Mo low alloy SA508Gr.4N steel at deformation temperature of 850-1200 ℃, strain rate of 0.001-1 s-1, and true strain of 0.9 was studied by using Gleeble-1500D thermal simulation testing machine.The physically based flow stress model including dynamic recovery and dynamic recrystallization and the dynamic recrystallization grain size model were established,and the suitable forging process to avoid the coarse grain structure heredities was put forward.The results show that as the deformation temperature increases and the strain rate decreases, the dynamic recrystallization volume fraction and grain size gradually increase; the true stress-true strain curve of SA508Gr.4N steel has an obvious discontinuous dynamic recrystallization phenomenon;by comparing the experimental value with the predicted value of the model, the correlation coefficient (R) and mean relative error (MRE) of the flow stress model are 0.998 and 4.76%, respectively, and the correlation coefficient (R) and mean relative error (MRE) of the dynamic recrystallization grain size model are 0.991 and 8.69%, respectively. The two models have high accuracy.

Aim: To explore whether routine biopsies at the high incidence spot of esophagogastric junction (EGJ) cancer are justified in endoscopic screening., Methods: This was a multicenter population-based study conducted in eight high-risk areas in China. A total of 37396 participants underwent endoscopic examination. Biopsies were obtained from visible mucosal abnormalities or from normal-appearing mucosa at the high incidence spot of esophagogastric junction cancer when no abnormality was detected. Specimens showing high-grade intraepithelial neoplasia (HIN) or higher grade lesions were deemed as pathologically "positive". The ratios of positive pathologic diagnosis between participants with abnormal and normal-appearing mucosa were compared using the Pearson χ(2) test. Odds ratios and 95% confidence intervals, adjusted for potential confounders, were calculated using logistic regression., Results: A total of 37520 individuals participated in this study and 37396 (99.7%) participants had full information and were suitable for analysis. During endoscopic examinations, 9.11% (3405/37396) participants were found to have visible mucosal lesions. Of the participants who had normal-appearing mucosa at the EGJ, only 0.28% (94/33991) were diagnosed with HIN or higher grade lesions, whereas 6.05% (206/3405) of participants with abnormalities at the EGJ had a positive pathologic result. After controlling for other variables, visible abnormal mucosa detected under endoscopy strongly predicted a positive pathologic result (OR = 32.51, 95%CI: 23.96-44.09). The proportion of participants with "positive" pathologic diagnoses increased as the total number of endoscopic examinations performed by the doctors increased (< 5000 cases vs 5000-10000 cases vs > 10000 cases, Z = -2.7207, P = 0.0065, Cochran Armiger trend test). The same trend was found between the proportion of participants with positive pathologic diagnoses and the total number of years the doctors performed endoscopy (< 5 years vs 5-10 years vs > 10 years, Z = -10.3222, P < 0.001, Cochran Armiger trend test)., Conclusion: Additional routine biopsies from the high incidence spot of EGJ cancer are of limited value and are unjustified.

Aim: To explore the DNA image cytometry (DNA-ICM) technique as a primary screening method for esophageal squamous precancerous lesions., Methods: This study was designed as a population-based screening study. A total of 582 local residents aged 40 years-69 years were recruited from Linzhou in Henan and Feicheng in Shandong. However, only 452 subjects had results of liquid-based cytology, DNA-ICM and pathology. The sensitivity and specificity of DNA-ICM were calculated and compared with liquid-based cytology in moderate dysplasia or worse., Results: Sensitivities of DNA-ICM ranging from at least 1 to 4 aneuploid cells were 90.91%, 86.36%, 79.55% and 77.27%, respectively, which were better than that of liquid-based cytology (75%). Specificities of DNA-ICM were 70.83%, 84.07%, 92.65% and 96.81%, but the specificity of liquid-based cytology was 91.91%. The sensitivity and specificity of a combination of liquid-based cytology and DNA-ICM were 84.09% and 85.78%, respectively., Conclusion: It is possible to use DNA-ICM technique as a primary screening method for esophageal squamous precancerous lesions.

Background: The incidence and mortality of esophageal cancer (EC) in some rural areas with poor health resources in China are the highest around the world. In these areas, screening programs for EC are conducted for prevention and control. However, costs associated with esophageal cancer screening have not been characterized in detail. This study is aimed to estimate the screening, early diagnosis and treatment costs of EC using micro-costing methods, which could provide basic cost inputs for further systematic health economic evaluation., Materials and Methods: Micro-costing methods were adopted to collect data on quantity and unit cost of used resources. Data was obtained from face-to-face interview with medical staff, local hospitals' database, and experts' input. We used 80% capacity utilization and 3% discount rate to annualize capital investments, and all costs were adjusted to year 2008 using the gross domestic production deflator, and then converted from Chinese currency unit to international dollars (I$) using purchasing power parity., Results: Screening costs per case were around I$60. For severe dysplasia, carcinoma in situ and intramucosal carcinoma, the costs per capita of endoscopic mucosal resection were I$1292~I$1620, and around I$450 for argon plasma coagulation. For submucosal carcinoma (T1N0M0), and invasive carcinoma treated by esophagectomy, the treatment costs ranged from I$1485 to I$2171. The costs of treatment of invasive carcinoma were: I$497~I$685.2 for radiotherapy; I$4652~I$7966.15 for chemotherapy; I$1928~I$2805 for combination of esophagectomy and radiotherapy; I$6632~I$8082 for esophagectomy, radiotherapy and chemotherapy in combination., Conclusion: The cost analysis found screening, early diagnosis and treatment for EC could provide great cost savings. The results provide important information for further health economic evaluation, and to help the local policy makers on updating such screening program in high risk areas in China.