Endoscopic ultrasound(EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde ...Endoscopic ultrasound(EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography(ERCP).EUSguided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ultrasound and fluoroscopy imaging in addition to standard ERCP devices and techniques.EUS-guided biliary drainage is an attractive option because of its minimally invasive,single step procedure which provides internal biliary decompression.Multiple investigators have reported high success and low complication rates.Unfortunately,high quality prospective data are still lacking.We provide detailed review of the use of EUS for biliary drainage from the perspective of practicing endoscopists with specific focus on the technical aspects of the procedure.展开更多
AIM：To explore the role of prostaglandin F2α（PGF2α） on pacemaker activity in interstitial cells of Cajal（ICC）from mouse small intestine. METHODS：In this study,effects of PGF2αin the cultured ICC cells were in...AIM：To explore the role of prostaglandin F2α（PGF2α） on pacemaker activity in interstitial cells of Cajal（ICC）from mouse small intestine. METHODS：In this study,effects of PGF2αin the cultured ICC cells were investigated with patch clamp technology combined with Ca 2＋ image analysis. RESULTS：Externally applied PGF2α（10μmol/L）produced membrane depolarization in current-clamp mode and increased tonic inward pacemaker currents in voltage-clamp mode.The application of flufenamic acid（a non-selective cation channel inhibitor）or niflumic acid（aCl channel inhibitor）abolished the generation of pacemaker currents but only flufenamic acid inhibited the PGF2α-induced tonic inward currents.In addition,the tonic inward currents induced by PGF2αwere not inhibited by intracellular application of 5’-[-thio]diphosphate trilithium salt.Pretreatment with Ca 2＋ free solution, U-73122,an active phospholipase C inhibitor,and thapsigargin,a Ca 2＋ -ATPase inhibitor in endoplasmic reticulum,abolished the generation of pacemaker currents and suppressed the PGF2α-induced tonic inward currents.However,chelerythrine or calphostin C,protein kinase C inhibitors,did not block the PGF2α-induced effects on pacemaker currents.When recording intracellular Ca 2＋ （[Ca 2＋ ]i）concentration using fluo-3/AM,PGF2α broadly increased the spontaneous[Ca 2＋ ]i oscillations. CONCLUSION：These results suggest that PGF2αcan modulate pacemaker activity of ICC by acting non-selective action channels through phospholipase C-dependent pathway via[Ca2＋]i regulation展开更多
Based on viscous drag-induced breakup mechanism, a simple model was proposed to predict the dripping droplet size as a function of controllable parameters in flow focusing micro devices. The size of thread before brea...Based on viscous drag-induced breakup mechanism, a simple model was proposed to predict the dripping droplet size as a function of controllable parameters in flow focusing micro devices. The size of thread before breakup was also investigated through laminar flow theory. Experiments and numerical simulations by VOF are carried out simultaneously to validate the theoretical analysis, showing that droplet size decreases rapidly with the increase of the flow rate ratio and capillary number.展开更多
Pancreatic pseudocysts are complications of acute or chronic pancreatitis. Initial diagnosis is accomplished most often by cross-sectional imaging. Endoscopic ultrasound with fine needle aspiration has become the pref...Pancreatic pseudocysts are complications of acute or chronic pancreatitis. Initial diagnosis is accomplished most often by cross-sectional imaging. Endoscopic ultrasound with fine needle aspiration has become the preferred test to help distinguish pseudocyst from other cystic lesions of the pancreas. Most pseudocysts resolve spontaneously with supportive care. The size of the pseudocyst and the length of time the cyst has been present are poor predictors for the potential of pseudocyst resolution or complications, but in general, larger cysts are more likely to be symptomatic or cause complications. The main two indications for some type of invasive drainage procedure are persistent patient symptoms or the presence of complications (infection, gastric outlet or biliary obstruction, bleeding). Three different strategies for pancreatic pseudocysts drainage are available: endoscopic (transpapillary or transmural) drainage, percutaneous catheter drainage, or open surgery. To date, no prospective controlled studies have compared directly these approaches. As a result, the management varies based on local expertise, but in general, endoscopic drainage is becoming the preferred approach because it is less invasive than surgery, avoids the need for external drain, and has a high long-term success rate. A tailored therapeutic approach taking into consideration patient preferences and involving multidisciplinary team of therapeutic endoscopist, interventional radiologist and pancreatic surgeon should be considered in all cases.展开更多
The gridded sea level anomaly（SLA） data-set provided by AVISO is used to track the propagation of intraseasonal Kelvin waves in the Indonesian Throughflow（ITF） region. The large root mean square of intraseasonal S...The gridded sea level anomaly（SLA） data-set provided by AVISO is used to track the propagation of intraseasonal Kelvin waves in the Indonesian Throughflow（ITF） region. The large root mean square of intraseasonal SLA along the Sumatra and Java coast is closely related to the propagation of intraseasonal Kelvin waves that derive from the equatorial Indian Ocean. These Kelvin waves are further found to propagate following different pathways at the Lombok Strait. Pathway A propagates eastward throughout the Sumba Strait and Savu Sea to reach the Ombai Strait. Pathway B penetrates into Lombok and propagates northward to reach the Makassar Strait. Pathway C propagates southeastward along the southwest coast of the Sumba Island. The equatorial Kelvin waves take around 15 days to travel from the equatorial Indian Ocean to Lombok Strait, and around 5 days to penetrate into the Makassar and Ombai straits. The Kelvin wave-induced SLA persists in the ITF region for an additional 5 days and then diminishes subsequently. The phase speeds of these intraseasonal Kelvin waves along Pathways A, B, and C are 1.91–2.86, 1.69, and 1.96 m s^-1,respectively—in agreement with the first two baroclinic modes of Kelvin waves.展开更多
Turbulent penetration can occur when hot and cold fluids mix in a horizontal T-junction pipe at nuclear plants. Caused by the unstable turbulent penetration, temperature fluctuations with large amplitude and high freq...Turbulent penetration can occur when hot and cold fluids mix in a horizontal T-junction pipe at nuclear plants. Caused by the unstable turbulent penetration, temperature fluctuations with large amplitude and high frequency can lead to time-varying wall thermal stress and even thermal fatigue on the inner wall. Numerous cases, however, exist where inner wall temperatures cannot be measured and only outer wall temperature measurements are feasible. Therefore, it is one of the popular research areas in nuclear science and engineering to estimate temperature fluctuations on the inner wall from measurements of outer wall temperatures without damaging the structure of the pipe. In this study, both the one-dimensional(1D) and the two-dimensional(2D) inverse heat conduction problem(IHCP) were solved to estimate the temperature fluctuations on the inner wall. First, numerical models of both the 1D and the 2D direct heat conduction problem(DHCP) were structured in MATLAB, based on the finite difference method with an implicit scheme. Second, both the 1D IHCP and the 2D IHCP were solved by the steepest descent method(SDM), and the DHCP results of temperatures on the outer wall were used to estimate the temperature fluctuations on the inner wall. Third, we compared the temperature fluctuations on the inner wall estimated by the 1D IHCP with those estimated by the 2D IHCP in four cases:(1) when the maximum disturbance of temperature of fluid inside the pipe was 3℃,(2) when the maximum disturbance of temperature of fluid inside the pipe was 30℃,(3) when the maximum disturbance of temperature of fluid inside the pipe was 160℃, and(4) when the fluid temperatures inside the pipe were random from 50℃ to 210℃.展开更多
文摘Endoscopic ultrasound(EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography(ERCP).EUSguided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ultrasound and fluoroscopy imaging in addition to standard ERCP devices and techniques.EUS-guided biliary drainage is an attractive option because of its minimally invasive,single step procedure which provides internal biliary decompression.Multiple investigators have reported high success and low complication rates.Unfortunately,high quality prospective data are still lacking.We provide detailed review of the use of EUS for biliary drainage from the perspective of practicing endoscopists with specific focus on the technical aspects of the procedure.
基金Supported by Research Fund from Chosun Hospital 2008
文摘AIM：To explore the role of prostaglandin F2α（PGF2α） on pacemaker activity in interstitial cells of Cajal（ICC）from mouse small intestine. METHODS：In this study,effects of PGF2αin the cultured ICC cells were investigated with patch clamp technology combined with Ca 2＋ image analysis. RESULTS：Externally applied PGF2α（10μmol/L）produced membrane depolarization in current-clamp mode and increased tonic inward pacemaker currents in voltage-clamp mode.The application of flufenamic acid（a non-selective cation channel inhibitor）or niflumic acid（aCl channel inhibitor）abolished the generation of pacemaker currents but only flufenamic acid inhibited the PGF2α-induced tonic inward currents.In addition,the tonic inward currents induced by PGF2αwere not inhibited by intracellular application of 5’-[-thio]diphosphate trilithium salt.Pretreatment with Ca 2＋ free solution, U-73122,an active phospholipase C inhibitor,and thapsigargin,a Ca 2＋ -ATPase inhibitor in endoplasmic reticulum,abolished the generation of pacemaker currents and suppressed the PGF2α-induced tonic inward currents.However,chelerythrine or calphostin C,protein kinase C inhibitors,did not block the PGF2α-induced effects on pacemaker currents.When recording intracellular Ca 2＋ （[Ca 2＋ ]i）concentration using fluo-3/AM,PGF2α broadly increased the spontaneous[Ca 2＋ ]i oscillations. CONCLUSION：These results suggest that PGF2αcan modulate pacemaker activity of ICC by acting non-selective action channels through phospholipase C-dependent pathway via[Ca2＋]i regulation
基金Supported by the National Natural Science Foundation of China(50876100)the Grade A Technology Development Foundation of USTC(ZC9850340103)
文摘Based on viscous drag-induced breakup mechanism, a simple model was proposed to predict the dripping droplet size as a function of controllable parameters in flow focusing micro devices. The size of thread before breakup was also investigated through laminar flow theory. Experiments and numerical simulations by VOF are carried out simultaneously to validate the theoretical analysis, showing that droplet size decreases rapidly with the increase of the flow rate ratio and capillary number.
文摘Pancreatic pseudocysts are complications of acute or chronic pancreatitis. Initial diagnosis is accomplished most often by cross-sectional imaging. Endoscopic ultrasound with fine needle aspiration has become the preferred test to help distinguish pseudocyst from other cystic lesions of the pancreas. Most pseudocysts resolve spontaneously with supportive care. The size of the pseudocyst and the length of time the cyst has been present are poor predictors for the potential of pseudocyst resolution or complications, but in general, larger cysts are more likely to be symptomatic or cause complications. The main two indications for some type of invasive drainage procedure are persistent patient symptoms or the presence of complications (infection, gastric outlet or biliary obstruction, bleeding). Three different strategies for pancreatic pseudocysts drainage are available: endoscopic (transpapillary or transmural) drainage, percutaneous catheter drainage, or open surgery. To date, no prospective controlled studies have compared directly these approaches. As a result, the management varies based on local expertise, but in general, endoscopic drainage is becoming the preferred approach because it is less invasive than surgery, avoids the need for external drain, and has a high long-term success rate. A tailored therapeutic approach taking into consideration patient preferences and involving multidisciplinary team of therapeutic endoscopist, interventional radiologist and pancreatic surgeon should be considered in all cases.
基金supported by the National Natural Science Foundation of China(NSFC)[grant numbers 41476025,41506036,41306031]NSFC-Shandong Joint Fund for Marine Science Research Centers[grant number U1406404]+1 种基金China Postdoctoral Science Foundation Funded Project[grant number 2014M561883]Postdoctoral Innovation Foundation of Shandong Province[grant number 201403019]
文摘The gridded sea level anomaly（SLA） data-set provided by AVISO is used to track the propagation of intraseasonal Kelvin waves in the Indonesian Throughflow（ITF） region. The large root mean square of intraseasonal SLA along the Sumatra and Java coast is closely related to the propagation of intraseasonal Kelvin waves that derive from the equatorial Indian Ocean. These Kelvin waves are further found to propagate following different pathways at the Lombok Strait. Pathway A propagates eastward throughout the Sumba Strait and Savu Sea to reach the Ombai Strait. Pathway B penetrates into Lombok and propagates northward to reach the Makassar Strait. Pathway C propagates southeastward along the southwest coast of the Sumba Island. The equatorial Kelvin waves take around 15 days to travel from the equatorial Indian Ocean to Lombok Strait, and around 5 days to penetrate into the Makassar and Ombai straits. The Kelvin wave-induced SLA persists in the ITF region for an additional 5 days and then diminishes subsequently. The phase speeds of these intraseasonal Kelvin waves along Pathways A, B, and C are 1.91–2.86, 1.69, and 1.96 m s^-1,respectively—in agreement with the first two baroclinic modes of Kelvin waves.
基金supported by the National Natural Science Foundation of China(Project No.51276009)Program for New Century Excellent Talents in University(No.NCET-13-0651)
文摘Turbulent penetration can occur when hot and cold fluids mix in a horizontal T-junction pipe at nuclear plants. Caused by the unstable turbulent penetration, temperature fluctuations with large amplitude and high frequency can lead to time-varying wall thermal stress and even thermal fatigue on the inner wall. Numerous cases, however, exist where inner wall temperatures cannot be measured and only outer wall temperature measurements are feasible. Therefore, it is one of the popular research areas in nuclear science and engineering to estimate temperature fluctuations on the inner wall from measurements of outer wall temperatures without damaging the structure of the pipe. In this study, both the one-dimensional(1D) and the two-dimensional(2D) inverse heat conduction problem(IHCP) were solved to estimate the temperature fluctuations on the inner wall. First, numerical models of both the 1D and the 2D direct heat conduction problem(DHCP) were structured in MATLAB, based on the finite difference method with an implicit scheme. Second, both the 1D IHCP and the 2D IHCP were solved by the steepest descent method(SDM), and the DHCP results of temperatures on the outer wall were used to estimate the temperature fluctuations on the inner wall. Third, we compared the temperature fluctuations on the inner wall estimated by the 1D IHCP with those estimated by the 2D IHCP in four cases:(1) when the maximum disturbance of temperature of fluid inside the pipe was 3℃,(2) when the maximum disturbance of temperature of fluid inside the pipe was 30℃,(3) when the maximum disturbance of temperature of fluid inside the pipe was 160℃, and(4) when the fluid temperatures inside the pipe were random from 50℃ to 210℃.
