Heliostats are sensitive to the wind load, thus as a key indicator, the study on the static and dynamic stability bearing capacity for heliostats is very important. In this work, a numerical wind tunnel was establishe...Heliostats are sensitive to the wind load, thus as a key indicator, the study on the static and dynamic stability bearing capacity for heliostats is very important. In this work, a numerical wind tunnel was established to calculate the wind load coefficients in various survival stow positions. In order to explore the best survival stow position for the heliostat under the strong wind, eigenvalue buckling analysis method was introduced to predict the critical wind load theoretically. Considering the impact of the nonlinearity and initial geometrical imperfection, the nonlinear post-buckling behaviors of the heliostat were investigated by load-displacement curves in the full equilibrium process. Eventually, combining B-R criterion with equivalent displacement principle the dynamic critical wind speed and load amplitude coefficient were evaluated. The results show that the determination for the best survival stow position is too hasty just by the wind load coefficients. The geometric nonlinearity has a great effect on the stability bearing capacity of the heliostat, while the effects of the material nonlinearity and initial geometrical imperfection are relatively small. And the heliostat is insensitive to the initial geometrical imperfection. In addition, the heliostat has the highest safety factor for wind-resistant performance in the stow position of 90-90 which can be taken as the best survival stow position. In this case, the extreme survival wind speeds for the static and dynamic stability are 150 m/s and 36 m/s, respectively.展开更多
AIM: To examine the allegations in malpractice litigations related to gastrointestinal endoscopy in Japan. METHODS: A retrospective review of cases tried in the civil court system during the 21-year period from 1985 t...AIM: To examine the allegations in malpractice litigations related to gastrointestinal endoscopy in Japan. METHODS: A retrospective review of cases tried in the civil court system during the 21-year period from 1985 to 2005, identified in a computerized legal database, was undertaken. RESULTS: Eighteen malpractice litigations and a total of 30 allegations were identified. Of the 18 (44%) malpractice litigations, 8 (44%) were related to eso- phagogastroduodenoscopy, 4 (22%) to colonoscopy, 4 (22%) to endoscopic sphincterotomy, and 2 (11%) to endoscopic retrograde cholangiopancreatography. Seventeen (94%) cases pertained to complications, and the remaining (6%) case pertained to misdiagnosis. In 10 cases, the patient died of the complications. Allegations were categorized as: (1) performance error during the endoscopic procedure (n = 12, 40%); (2) lack of informed consent (n = 9, 30%); (3) performance error during the treatment after the endoscopic procedure (n = 4, 13%); (4) premedication error (n = 3, 10%); (5) diagnostic error (n = 1, 3%); and (6) indication error for the endoscopic procedure (n = 1, 3%). CONCLUSION: These data may aid in the design of risk prevention strategies to be used by gastrointestinal endoscopists.展开更多
AIM:To examine the frequency and prevention of musculoskeletal pain in Japanese gastrointestinal endoscopists and non-endoscopist physicians.METHODS:Questionnaires were sent to 275 endoscopists and 173 non-endoscopist...AIM:To examine the frequency and prevention of musculoskeletal pain in Japanese gastrointestinal endoscopists and non-endoscopist physicians.METHODS:Questionnaires were sent to 275 endoscopists and 173 non-endoscopists working in Hiroshima University Hospital and its affiliated hospitals.RESULTS:The completed questionnaires were returned by 190(69%)endoscopists and 120(69%)non-endoscopists.The frequency of pain in the hand and wrist,and especially the left thumb,was significantly higher in endoscopists than in non-endoscopists(17%vs 6%,P=0.004).Using multivariate analysis,the only significant factor associated with this pain was the age of the endoscopist(odds ratio 2.77,95%confidence interval,1.23-6.71,P=0.018).Interestingly,endoscopists had made significantly fewer modifications to their endoscopic practices than non-endoscopists(12%vs 33%,P <0.0001)to prevent pain.CONCLUSION:Pain in the hand and wrist may be endoscopy-related.However,endoscopists made little modifications in practice to prevent such pain.More attention to prevention appears necessary.展开更多
基金Project(CYB14010)supported by Chongqing Graduate Student Research Innovation Project,ChinaProject(51405209)supported by the National Natural Science Foundation of China
文摘Heliostats are sensitive to the wind load, thus as a key indicator, the study on the static and dynamic stability bearing capacity for heliostats is very important. In this work, a numerical wind tunnel was established to calculate the wind load coefficients in various survival stow positions. In order to explore the best survival stow position for the heliostat under the strong wind, eigenvalue buckling analysis method was introduced to predict the critical wind load theoretically. Considering the impact of the nonlinearity and initial geometrical imperfection, the nonlinear post-buckling behaviors of the heliostat were investigated by load-displacement curves in the full equilibrium process. Eventually, combining B-R criterion with equivalent displacement principle the dynamic critical wind speed and load amplitude coefficient were evaluated. The results show that the determination for the best survival stow position is too hasty just by the wind load coefficients. The geometric nonlinearity has a great effect on the stability bearing capacity of the heliostat, while the effects of the material nonlinearity and initial geometrical imperfection are relatively small. And the heliostat is insensitive to the initial geometrical imperfection. In addition, the heliostat has the highest safety factor for wind-resistant performance in the stow position of 90-90 which can be taken as the best survival stow position. In this case, the extreme survival wind speeds for the static and dynamic stability are 150 m/s and 36 m/s, respectively.
文摘AIM: To examine the allegations in malpractice litigations related to gastrointestinal endoscopy in Japan. METHODS: A retrospective review of cases tried in the civil court system during the 21-year period from 1985 to 2005, identified in a computerized legal database, was undertaken. RESULTS: Eighteen malpractice litigations and a total of 30 allegations were identified. Of the 18 (44%) malpractice litigations, 8 (44%) were related to eso- phagogastroduodenoscopy, 4 (22%) to colonoscopy, 4 (22%) to endoscopic sphincterotomy, and 2 (11%) to endoscopic retrograde cholangiopancreatography. Seventeen (94%) cases pertained to complications, and the remaining (6%) case pertained to misdiagnosis. In 10 cases, the patient died of the complications. Allegations were categorized as: (1) performance error during the endoscopic procedure (n = 12, 40%); (2) lack of informed consent (n = 9, 30%); (3) performance error during the treatment after the endoscopic procedure (n = 4, 13%); (4) premedication error (n = 3, 10%); (5) diagnostic error (n = 1, 3%); and (6) indication error for the endoscopic procedure (n = 1, 3%). CONCLUSION: These data may aid in the design of risk prevention strategies to be used by gastrointestinal endoscopists.
文摘AIM:To examine the frequency and prevention of musculoskeletal pain in Japanese gastrointestinal endoscopists and non-endoscopist physicians.METHODS:Questionnaires were sent to 275 endoscopists and 173 non-endoscopists working in Hiroshima University Hospital and its affiliated hospitals.RESULTS:The completed questionnaires were returned by 190(69%)endoscopists and 120(69%)non-endoscopists.The frequency of pain in the hand and wrist,and especially the left thumb,was significantly higher in endoscopists than in non-endoscopists(17%vs 6%,P=0.004).Using multivariate analysis,the only significant factor associated with this pain was the age of the endoscopist(odds ratio 2.77,95%confidence interval,1.23-6.71,P=0.018).Interestingly,endoscopists had made significantly fewer modifications to their endoscopic practices than non-endoscopists(12%vs 33%,P <0.0001)to prevent pain.CONCLUSION:Pain in the hand and wrist may be endoscopy-related.However,endoscopists made little modifications in practice to prevent such pain.More attention to prevention appears necessary.
