AIM: To investigate the conformity of management practices of gastrointestinal hemorrhage in cirrhotic patients with relevant guidelines. METHODS: A questionnaire on the management of digestive bleeding was completed ...AIM: To investigate the conformity of management practices of gastrointestinal hemorrhage in cirrhotic patients with relevant guidelines. METHODS: A questionnaire on the management of digestive bleeding was completed for all consecutive cirrhotic patients admitted to 31 French hospitals. RESULTS: One hundred and twenty-six bleeding events were recorded. It was the first bleeding episode in 79 patients (63%), of whom 40 (51%) had a prior diagnosis of cirrhosis and 25 (32%) had previously undergone an endoscopy. The bleeding episode was a recurrence in 46 patients (37%). The median time between onset and admission was 4 h, but exceeded 12 h in 42% of cases. There was an agreement between centers forearly vasoactive drug administration (87% of cases), association with ligation (42%) more often than sclerosis (21%) at initial endoscopy, and antibiotic prophylaxis (64%). By contrast, prescription of beta-blockade alone or in combination (0 to 100%, P = 0.003) for secondary prophylaxis and lactulose (26% to 86%, P = 0.04), differed among centers. CONCLUSION: In French hospitals, management of bleeding related to portal hypertension in cirrhotic patients is generally in keeping with the consensus. Broad variability still remains concerning beta-blockade use for secondary prophylaxis. Screening for esophageal varices, the use of antibiotic prophylaxis and patients information need to be improved.展开更多
The rate of twin pregnancies has increased over the last decades, largely because of the ongoing development of assisted reproductive technology and increased maternal age at childbearing. Twins have a higher risk of ...The rate of twin pregnancies has increased over the last decades, largely because of the ongoing development of assisted reproductive technology and increased maternal age at childbearing. Twins have a higher risk of adverse outcomes during pregnancy and the perinatal period. The prevalence of umbilical cord abnormalities is higher for twin pregnancies compared with singleton pregnancies. Some of these abnormalities are nonspecific to twinning and can also be found in singleton gestations (such as velamentous cord insertion, vasa previa, and single umbilical artery). Other abnormalities are associated with monochorionic twins, such as umbilical cord entanglement, and umbilical proximate cord insertion. Most of these abnormalities can be detected by ultrasound evaluation. The early and accurate ultrasound diagnosis of chorionicity, amnionicity, and placental and umbilical cord characteristics is crucial if we are to predict the risk of complications and to determine the best management for twin pregnancies. Histopathological examination of the placenta and umbilical cord after delivery can help to confirm prenatal diagnosis and to provide a better understanding of the physiopathology of their abnormalities. The aim of this review was to emphasize the role that the umbilical cord plays in twin complications and to describe the management of these high-risk pregnancies.展开更多
The random decrement technique （RDT）, introduced in the sixties by Cole [NASA CR- 2005, 1973], is a very performing method of analysis for vibration signature of a structure under ambient loading. But the real natur...The random decrement technique （RDT）, introduced in the sixties by Cole [NASA CR- 2005, 1973], is a very performing method of analysis for vibration signature of a structure under ambient loading. But the real nature of the random decrement signature has been misunderstood until now. Moreover, the various interpretations were made in continuous time setting, while real experimental data are obtained in discrete time. In this paper, the really implemental discrete time algorithms are studied. The asymptotic analysis as the number of triggering points go to infinity is achieved, and a Law of Large Numbers as well as a Central Limit Theorem is proved. Moreover, the limit as the discretization time step goes to zero is computed, giving more tractable formulas to approximate the random decrement. This is a new approach of the famous ＂Kac-Slepian paradox＂ [Ann. Math. Star., 30, 1215-1228 （1959）]. The main point might be that the RDT is a very efficient functional estimator of the correlation function of a stationary ergodic Gaussian process. Very fast, it is to classical estimators what Fast Fourier Transform （FFT） is to ordinary Discrete Fourier Transforms.展开更多
基金Supported by grants from the French Society of Gastroenterology
文摘AIM: To investigate the conformity of management practices of gastrointestinal hemorrhage in cirrhotic patients with relevant guidelines. METHODS: A questionnaire on the management of digestive bleeding was completed for all consecutive cirrhotic patients admitted to 31 French hospitals. RESULTS: One hundred and twenty-six bleeding events were recorded. It was the first bleeding episode in 79 patients (63%), of whom 40 (51%) had a prior diagnosis of cirrhosis and 25 (32%) had previously undergone an endoscopy. The bleeding episode was a recurrence in 46 patients (37%). The median time between onset and admission was 4 h, but exceeded 12 h in 42% of cases. There was an agreement between centers forearly vasoactive drug administration (87% of cases), association with ligation (42%) more often than sclerosis (21%) at initial endoscopy, and antibiotic prophylaxis (64%). By contrast, prescription of beta-blockade alone or in combination (0 to 100%, P = 0.003) for secondary prophylaxis and lactulose (26% to 86%, P = 0.04), differed among centers. CONCLUSION: In French hospitals, management of bleeding related to portal hypertension in cirrhotic patients is generally in keeping with the consensus. Broad variability still remains concerning beta-blockade use for secondary prophylaxis. Screening for esophageal varices, the use of antibiotic prophylaxis and patients information need to be improved.
文摘The rate of twin pregnancies has increased over the last decades, largely because of the ongoing development of assisted reproductive technology and increased maternal age at childbearing. Twins have a higher risk of adverse outcomes during pregnancy and the perinatal period. The prevalence of umbilical cord abnormalities is higher for twin pregnancies compared with singleton pregnancies. Some of these abnormalities are nonspecific to twinning and can also be found in singleton gestations (such as velamentous cord insertion, vasa previa, and single umbilical artery). Other abnormalities are associated with monochorionic twins, such as umbilical cord entanglement, and umbilical proximate cord insertion. Most of these abnormalities can be detected by ultrasound evaluation. The early and accurate ultrasound diagnosis of chorionicity, amnionicity, and placental and umbilical cord characteristics is crucial if we are to predict the risk of complications and to determine the best management for twin pregnancies. Histopathological examination of the placenta and umbilical cord after delivery can help to confirm prenatal diagnosis and to provide a better understanding of the physiopathology of their abnormalities. The aim of this review was to emphasize the role that the umbilical cord plays in twin complications and to describe the management of these high-risk pregnancies.
基金Supported by SRF for ROCS, SEMNational Natural Science Foundation of China (Grant No. 10701058)+1 种基金Science and Technology Program of Beijing Education Commission (Grant No. KM200810028002)Institute of Mathematics and Interdisciplinary Science (Capital Normal University)
文摘The random decrement technique （RDT）, introduced in the sixties by Cole [NASA CR- 2005, 1973], is a very performing method of analysis for vibration signature of a structure under ambient loading. But the real nature of the random decrement signature has been misunderstood until now. Moreover, the various interpretations were made in continuous time setting, while real experimental data are obtained in discrete time. In this paper, the really implemental discrete time algorithms are studied. The asymptotic analysis as the number of triggering points go to infinity is achieved, and a Law of Large Numbers as well as a Central Limit Theorem is proved. Moreover, the limit as the discretization time step goes to zero is computed, giving more tractable formulas to approximate the random decrement. This is a new approach of the famous ＂Kac-Slepian paradox＂ [Ann. Math. Star., 30, 1215-1228 （1959）]. The main point might be that the RDT is a very efficient functional estimator of the correlation function of a stationary ergodic Gaussian process. Very fast, it is to classical estimators what Fast Fourier Transform （FFT） is to ordinary Discrete Fourier Transforms.
