Site engineering seismic survey provides basic data for seismic effect analysis. As an important parameter of soil, shear-wave velocity is usually obtained through wave velocity testing in borehole. In this paper, the...Site engineering seismic survey provides basic data for seismic effect analysis. As an important parameter of soil, shear-wave velocity is usually obtained through wave velocity testing in borehole. In this paper, the passive source surface-wave method is introduced into the site engineering seismic survey and practically applied in an engineering site of Shijingshan District. By recording the ubiquitous weak vibration on the earth surface, extract the dispersion curve from the surface-wave components using the SPAC method and obtain the shear-wave velocity structure from inversion. Over the depth of 42 m under- ground, it totally consists of five layers with interface depth of 3.31, 4.50, 7.23, 17.41, and 42.00 m; and shear-wave velocity of 144.0, 198.3, 339.4, 744.2, and 903.7 m/s, respectively. The inversion result is used to evaluate site classification, determine the maximum shear modulus of soil, provide basis for further seismic hazard analysis and site assessment or site zoning, etc. The result shows that the passive source surface-wave method is feasible in the site engineering seismic survey and can replace boreholes,shorten survey period, and reduce engineering cost to some extent.展开更多
Objective:This study determined the relationship between esophageal cancer in middle-aged and elderly patients and body mass index(BMI)and waist-to-hip ratio(WHR).Methods:A hospital-based case-control study was adopte...Objective:This study determined the relationship between esophageal cancer in middle-aged and elderly patients and body mass index(BMI)and waist-to-hip ratio(WHR).Methods:A hospital-based case-control study was adopted.Two hundred eighty-two patients who were diagnosed with esophageal cancer through clinical endoscopy,X-ray examination,or histopathologic evaluation,and underwent surgery or received chemotherapy were enrolled as cases.The control group consisted of 282 patients without any cancers or esophageal diseases who were hospitalized during the same period in the same hospital.Face-to-face interviews were con-ducted using standard survey forms,and the height,weight,waist circumference,and hip circum-ference were measured to calculate the BMI and WHR.The odds ratio(OR)and 95%confidence interval(CI)between the patient BMI and WHR and esophageal cancer were estimated using a multi-factor logistic regression model.Results:There was no statistical difference between the case and control groups with respect to age,gender,occupation,educational background,place of residence,and history of high blood pressure(P>0.05);however,there were more cases who smoked cigarettes and consumed alcohol than controls(P<0.05).Single-factor logistic regression analysis showed that the risk for esopha-geal cancer in overweight and obese patients was 1.53-and 1.82-fold that of normoweight patients,respectively.The risk for esophageal cancer in patients with a WHR in the highest quartile was 1.85-fold the control patients with a WHR in the lowest quartile.After confounding factors,such as gender and age,were adjusted,multi-factor logistic regression analysis indicated that the risk for esophageal cancer in overweight and obese patients increased by 59.4%(OR=1.594)and 78.2%(OR=1.782),respectively,when compared with normoweight patients.Conclusion:BMI and WHR are important risk factors for esophageal cancer.Overweight and obese patients are at increased risk for esophageal cancer.Maintaining a normal weight may be a factor in preventing esophageal cancer.展开更多
基金supported by National Natural Science Foundation of China (No. 41174085)Chinese Academy of Sciences (KZZD-EW-TZ-19)China Geological Survey (12120113101400)
文摘Site engineering seismic survey provides basic data for seismic effect analysis. As an important parameter of soil, shear-wave velocity is usually obtained through wave velocity testing in borehole. In this paper, the passive source surface-wave method is introduced into the site engineering seismic survey and practically applied in an engineering site of Shijingshan District. By recording the ubiquitous weak vibration on the earth surface, extract the dispersion curve from the surface-wave components using the SPAC method and obtain the shear-wave velocity structure from inversion. Over the depth of 42 m under- ground, it totally consists of five layers with interface depth of 3.31, 4.50, 7.23, 17.41, and 42.00 m; and shear-wave velocity of 144.0, 198.3, 339.4, 744.2, and 903.7 m/s, respectively. The inversion result is used to evaluate site classification, determine the maximum shear modulus of soil, provide basis for further seismic hazard analysis and site assessment or site zoning, etc. The result shows that the passive source surface-wave method is feasible in the site engineering seismic survey and can replace boreholes,shorten survey period, and reduce engineering cost to some extent.
文摘Objective:This study determined the relationship between esophageal cancer in middle-aged and elderly patients and body mass index(BMI)and waist-to-hip ratio(WHR).Methods:A hospital-based case-control study was adopted.Two hundred eighty-two patients who were diagnosed with esophageal cancer through clinical endoscopy,X-ray examination,or histopathologic evaluation,and underwent surgery or received chemotherapy were enrolled as cases.The control group consisted of 282 patients without any cancers or esophageal diseases who were hospitalized during the same period in the same hospital.Face-to-face interviews were con-ducted using standard survey forms,and the height,weight,waist circumference,and hip circum-ference were measured to calculate the BMI and WHR.The odds ratio(OR)and 95%confidence interval(CI)between the patient BMI and WHR and esophageal cancer were estimated using a multi-factor logistic regression model.Results:There was no statistical difference between the case and control groups with respect to age,gender,occupation,educational background,place of residence,and history of high blood pressure(P>0.05);however,there were more cases who smoked cigarettes and consumed alcohol than controls(P<0.05).Single-factor logistic regression analysis showed that the risk for esopha-geal cancer in overweight and obese patients was 1.53-and 1.82-fold that of normoweight patients,respectively.The risk for esophageal cancer in patients with a WHR in the highest quartile was 1.85-fold the control patients with a WHR in the lowest quartile.After confounding factors,such as gender and age,were adjusted,multi-factor logistic regression analysis indicated that the risk for esophageal cancer in overweight and obese patients increased by 59.4%(OR=1.594)and 78.2%(OR=1.782),respectively,when compared with normoweight patients.Conclusion:BMI and WHR are important risk factors for esophageal cancer.Overweight and obese patients are at increased risk for esophageal cancer.Maintaining a normal weight may be a factor in preventing esophageal cancer.
