Bleeding from esophageal varices (EVs) is a catastrophic complication of chronic liver disease. Many years ago, surgical procedures such as esophageal transection or distal splenorenal shunting were the only treatment...Bleeding from esophageal varices (EVs) is a catastrophic complication of chronic liver disease. Many years ago, surgical procedures such as esophageal transection or distal splenorenal shunting were the only treatments for EVs. In the 1970s, interventional radiology procedures such as transportal obliteration, left gastric artery embolization, and partial splenic artery embolization were introduced, improving the survival of patients with bleeding EVs. In the 1980s, endoscopic treatment, endoscopic injection sclerotherapy (EIS), and endoscopic variceal ligation (EVL), further contributed to improved survival. We combined IVR with endoscopic treatment or EIS with EVL. Most patients with EVs treated endoscopically required follow- up treatment for recurrent varices. Proper management of recurrent EVs can significantly improve patients’ quality of life. Recently, we have performed EVL at 2-mo (bimonthly) intervals for the management of EVs. Longer intervals between treatment sessions resulted in a higher rate of total eradication and lower rates of recurrence and additional treatment.展开更多
A study of flow rate limitation in an open wedge channel is reported in this paper. Under microgravity condition, the flow is controlled by the convection and the viscosity in the channel as well as the curvature of t...A study of flow rate limitation in an open wedge channel is reported in this paper. Under microgravity condition, the flow is controlled by the convection and the viscosity in the channel as well as the curvature of the liquid free surface. A maximum flow rate is achieved when the curvature cannot balance the pressure difference leading to a collapse of the free surface. A 1-dimensional theoretical model is used to predict the critical flow rate and calculate the shape of the free surface. Computa- tional Fluid Dynamics tool is also used to simulate the phenomenon. Results show that the 1-dimensional model overestimates the critical flow rate because extra pressure loss is not included in the governing equation. Good agreement is found in 3-dim- ensional simulation results. Parametric study with different wedge angles and channel lengths show that the critical flow rate increases with increasing the cross section area; and decreases with increasing the channel length. The work in this paper can help understand the surface collapsing without gravity and for the design in propellant management devices in satellite tanks.展开更多
Editor＇s comments Formaldehyde （HCHO） emitted from chemical manufacturing plants including methanol-gasoline/diesel fuel vehicles and the construction and decoration materials is one of the major air pollutions, wh...Editor＇s comments Formaldehyde （HCHO） emitted from chemical manufacturing plants including methanol-gasoline/diesel fuel vehicles and the construction and decoration materials is one of the major air pollutions, which induces photochemical pollution and hazards human health. Great efforts have been made for the reduction or control of the emission of HCHO to satisfy the stringent environmental regulations. Now, a new study supported by the National Natural Science Foundation of China reports mesoporous manganese oxide with novel nanostructures for the decomposition of HCHO. The obtained manganese oxide nanomaterials showed high catalytic activities for oxidative decomposition of HCHO at low temperatures. Complete conversion of HCHO to CO2 and H2O were achieved, and no harmful by- products were detected in effluent gases. The catalytic activities of these nanomaterials are significantly higher than those of previously reported manganese oxide octahedral molecular sieve （OMS-2） nanorods , MnO x powders, and alumnina-supported mangnaese-palladium oxide catalysts. These results provide a new route for the removal of HCHO and other air pollutions.展开更多
文摘Bleeding from esophageal varices (EVs) is a catastrophic complication of chronic liver disease. Many years ago, surgical procedures such as esophageal transection or distal splenorenal shunting were the only treatments for EVs. In the 1970s, interventional radiology procedures such as transportal obliteration, left gastric artery embolization, and partial splenic artery embolization were introduced, improving the survival of patients with bleeding EVs. In the 1980s, endoscopic treatment, endoscopic injection sclerotherapy (EIS), and endoscopic variceal ligation (EVL), further contributed to improved survival. We combined IVR with endoscopic treatment or EIS with EVL. Most patients with EVs treated endoscopically required follow- up treatment for recurrent varices. Proper management of recurrent EVs can significantly improve patients’ quality of life. Recently, we have performed EVL at 2-mo (bimonthly) intervals for the management of EVs. Longer intervals between treatment sessions resulted in a higher rate of total eradication and lower rates of recurrence and additional treatment.
文摘A study of flow rate limitation in an open wedge channel is reported in this paper. Under microgravity condition, the flow is controlled by the convection and the viscosity in the channel as well as the curvature of the liquid free surface. A maximum flow rate is achieved when the curvature cannot balance the pressure difference leading to a collapse of the free surface. A 1-dimensional theoretical model is used to predict the critical flow rate and calculate the shape of the free surface. Computa- tional Fluid Dynamics tool is also used to simulate the phenomenon. Results show that the 1-dimensional model overestimates the critical flow rate because extra pressure loss is not included in the governing equation. Good agreement is found in 3-dim- ensional simulation results. Parametric study with different wedge angles and channel lengths show that the critical flow rate increases with increasing the cross section area; and decreases with increasing the channel length. The work in this paper can help understand the surface collapsing without gravity and for the design in propellant management devices in satellite tanks.
文摘Editor＇s comments Formaldehyde （HCHO） emitted from chemical manufacturing plants including methanol-gasoline/diesel fuel vehicles and the construction and decoration materials is one of the major air pollutions, which induces photochemical pollution and hazards human health. Great efforts have been made for the reduction or control of the emission of HCHO to satisfy the stringent environmental regulations. Now, a new study supported by the National Natural Science Foundation of China reports mesoporous manganese oxide with novel nanostructures for the decomposition of HCHO. The obtained manganese oxide nanomaterials showed high catalytic activities for oxidative decomposition of HCHO at low temperatures. Complete conversion of HCHO to CO2 and H2O were achieved, and no harmful by- products were detected in effluent gases. The catalytic activities of these nanomaterials are significantly higher than those of previously reported manganese oxide octahedral molecular sieve （OMS-2） nanorods , MnO x powders, and alumnina-supported mangnaese-palladium oxide catalysts. These results provide a new route for the removal of HCHO and other air pollutions.
