How to properly consider the impacts of non-hydrostatic perturbations is one of the challenging issues in developing non-hydrostatic dynamics solvers(NHDSs) for high-resolution atmospheric models. To overcome the dr...How to properly consider the impacts of non-hydrostatic perturbations is one of the challenging issues in developing non-hydrostatic dynamics solvers(NHDSs) for high-resolution atmospheric models. To overcome the drawbacks of current approaches to tackling this issue, this study analyzed the differences between hydrostatic dynamics solvers(HDSs) and their non-hydrostatic counterparts.The analysis then motivated a flexible approach to adjusting existing hydrostatic atmospheric models,especially those adopted in climate simulations for the impacts of non-hydrostatic perturbations.In this approach, the impacts of non-hydrostatic perturbations, reflecting the differences between HDSs and NHDSs, were encapsulated into a single term in the vertical momentum equation for the atmosphere. At each time step, this term was estimated by a separate sub-model, and then it was used to adjust the dynamics of the atmosphere. The adjustment was optional, and could be turned on and off flexibly by utilizing different initial conditions. The approach was illustrated using the Weather Research and Forecasting(WRF) model as an example, and was preliminarily validated by running the 3D baroclinic-wave test case in the model. Results showed that the modified dynamics solver produced simulation results that were very close to those given by the standard NHDS in the WRF model, implying that the approach was basically effective in capturing the non-hydrostatic features of the atmosphere.展开更多
Based on the statics theory, a novel and feasible twice-suspended-mass method(TSMM) was proposed to deal with the seldom-studied issue of fault diagnosis for damping springs of large vibrating screen(LVS). With the st...Based on the statics theory, a novel and feasible twice-suspended-mass method(TSMM) was proposed to deal with the seldom-studied issue of fault diagnosis for damping springs of large vibrating screen(LVS). With the static balance characteristic of the screen body/surface as well as the deformation compatibility relation of springs considered, static model of the screen surface under a certain load was established to calculate compression deformation of each spring. Accuracy of the model was validated by both an experiment based on the suspended mass method and the properties of the 3D deformation space in a numerical simulation. Furthermore, by adopting the Taylor formula and the control variate method, quantitative relationship between the change of damping spring deformation and the change of spring stiffness, defined as the deformation sensitive coefficient(DSC), was derived mathematically, from which principle of the TSMM for spring fault diagnosis is clarified. In the end, an experiment was carried out and results show that the TSMM is applicable for diagnosing the fault of single spring in a LVS.展开更多
Arteriovenous fistula (AVF) involving the inferior mesenteric vessels is rare, and the affected patients usually present with abdominal pain, mass, or features of established portal hypertension. Colonic ischemia is...Arteriovenous fistula (AVF) involving the inferior mesenteric vessels is rare, and the affected patients usually present with abdominal pain, mass, or features of established portal hypertension. Colonic ischemia is a less common and more serious manifestation of AVE We report a case of ischemic colitis secondary to inferior mesentedc AVF in a patient who underwent a previous liver transplantation, subsequently developed portal vein stenosis, and then presented with acute lower gastrointestinal bleeding. He underwent percutaneous transhepatic placement of a portal vein stent and left colectomy.展开更多
AIM: To study the effects of endotoxin on portal hemodynamic of normal and noncirrhotic portal hypertensive rats. METHODS: Normal rats were intraperitoneally injected with 0.1, 0.25, 0.5, 1.0, 2.0, 4.0mg.kg(-1) of lip...AIM: To study the effects of endotoxin on portal hemodynamic of normal and noncirrhotic portal hypertensive rats. METHODS: Normal rats were intraperitoneally injected with 0.1, 0.25, 0.5, 1.0, 2.0, 4.0mg.kg(-1) of lipopolysaccharide(LPS) respectively, portal vein ligation(PVL) and intrahepatic portal occlusion (IPO) rats as well as sham-operated rats were treated with an intraperitoneal injection of 1.0mg.kg(-1) of LPS, the portal vein pressure(PVP), portal venous flow(PVF), inferior vena cava pressure(IVCP) and portal vein resistance(PVR) were detected 4 hours after injection. RESULTS: PVF of the 5 groups of rats accepting intraperitoneal injection of LPS were increased from 14.0 to 18.0, 22.2, 26.2, 34.8, 39.6, 38.8 mL.min(-1) 4 hours after injection of LPS(P【0.01). PVP of the 4 groups of rats accepting more than 0.1mg/kg.b.w of LPS was increased from 1.04 to 1.25, 1.50, 1.80, 1.95, 2.05 kPa(P【0.01). The increments of PVF and PVP were in a dose-dependent manner of LPS. PVR of the 5 groups of rats was decreased from 51 to 42,44,48,45,44,47 kPa.min.L(-1) (P【0.05) and no dose-dependent manner was observed. PVF of PVL, IPO and sham-operated rats increased from 22.6 to 32.8, 22.0 to 28.0, 14.0 to 34.8 mL.min(-1) (P【0.01), and PVP increased from 1.86 to 2.24, 1.74 to 1.95, 1.04 to 1.80 kPa(P【0.01), PVR decreased from 71 to 61, 67 to 61, 52 to 44 kPa.min.L(-1) after intraperitoneal injection of 1mg.kg(-1) of LPS. The increments of PVF and PVP of PVL and IPO rats were significantly less than the sham-operated rats(P【0.01), There was no significant difference between the amounts of PVR decreased in the two groups of PHT model rats and sham-operated rats(P】0.05) after intraperitoneal injection 1mg.kg(-1) of LPS. CONCLUSION: Endotoxin could prompt portal hypertension of the normal and noncirrhotic portal hypertensive rats by increasing portal blood flow mainly.展开更多
Arterioportal fistula(APF)is a rare cause of portal hypertension and may lead to death.APF can be congenital,post-traumatic,iatrogenic(transhepatic intervention or biopsy)or related to ruptured hepatic artery aneurysm...Arterioportal fistula(APF)is a rare cause of portal hypertension and may lead to death.APF can be congenital,post-traumatic,iatrogenic(transhepatic intervention or biopsy)or related to ruptured hepatic artery aneurysms.Congenital APF is a rare condition even in children.In this case report,we describe a 73-year-old woman diagnosed as APF by ultrasonography,computed tomography,and hepatic artery selective arteriography.The fistula was embolized twice but failed,and she still suffered from alimentary tract hemorrhage.Then,selective arteriography of the hepatic artery was performed again and venae coronaria ventriculi and short gastric vein were embolized.During the 2-year follow-up,the patient remained asymptomatic.We therefore argue that embolization of venae coronaria ventriculi and short gastric vein may be an effective treatment modality for intrahepatic APF with severe upper gastrointestinal bleeding.展开更多
Mansonic schistosomiasis is the main cause of portal hypertension in Brazil. Hepatosplenic (HS) form is manifested by hepatomegaly mainly on the left hepatic lobe associated with large splenomegaly and bleeding due to...Mansonic schistosomiasis is the main cause of portal hypertension in Brazil. Hepatosplenic (HS) form is manifested by hepatomegaly mainly on the left hepatic lobe associated with large splenomegaly and bleeding due to esophageal varices with high mortality rates.展开更多
Objective:To evaluate the safety and efficiency of transvenous embolization of dural arteriovenous fistula of cavernous region by multiple venous routes. Methods: Twenty seven patients with dural arteriovenous fistu...Objective:To evaluate the safety and efficiency of transvenous embolization of dural arteriovenous fistula of cavernous region by multiple venous routes. Methods: Twenty seven patients with dural arteriovenous fistula of cavernous region were treated by transvenous embolization with micro-coils. The transvenous routes included inferior petrosal sinus, superior ophthalmic vein and facial vein. Results: Clinical cure was achieved in 23 cases and significant improvement of symptoms in 4 cases. Complete anglographic obliteration was documented in 22 patients (82%). Residual shunting were left in 2 patients via pterygoid drainage and 1 case via inter-cavernous sinus, 2 cases via inferior petrosal sinus, disappeared one month later by manual compression carotid artery. Headache and vomiting were the most common symptoms after embolization. Three patients had diplopia and relieved within two months after embolization. There was no permanent procedure-related morbidity. The clinic follow up ranged from 5 months to 6 years, and there was not recurrence case. Conclusion: Transvenous embolization via different venous routes is a safe and efficient method for dural arteriovenous fistula of cavernous region treatment.展开更多
基金supported by the National Key Research and Development Program[grant number 2016YFB0200805]the National Natural Science Foundation of China[grant number 41622503]
文摘How to properly consider the impacts of non-hydrostatic perturbations is one of the challenging issues in developing non-hydrostatic dynamics solvers(NHDSs) for high-resolution atmospheric models. To overcome the drawbacks of current approaches to tackling this issue, this study analyzed the differences between hydrostatic dynamics solvers(HDSs) and their non-hydrostatic counterparts.The analysis then motivated a flexible approach to adjusting existing hydrostatic atmospheric models,especially those adopted in climate simulations for the impacts of non-hydrostatic perturbations.In this approach, the impacts of non-hydrostatic perturbations, reflecting the differences between HDSs and NHDSs, were encapsulated into a single term in the vertical momentum equation for the atmosphere. At each time step, this term was estimated by a separate sub-model, and then it was used to adjust the dynamics of the atmosphere. The adjustment was optional, and could be turned on and off flexibly by utilizing different initial conditions. The approach was illustrated using the Weather Research and Forecasting(WRF) model as an example, and was preliminarily validated by running the 3D baroclinic-wave test case in the model. Results showed that the modified dynamics solver produced simulation results that were very close to those given by the standard NHDS in the WRF model, implying that the approach was basically effective in capturing the non-hydrostatic features of the atmosphere.
基金Project(20120095110001)supported by the PhD Programs Foundation of Ministry of Education of ChinaProject(51134022,51221462)supported by the National Natural Science Foundation of China+1 种基金Project(CXZZ13_0927)supported by Research and Innovation Program for College Graduates of Jiangsu Province,ChinaProject(2013DXS03)supported by the Fundamental Research Funds for Central Universities of China
文摘Based on the statics theory, a novel and feasible twice-suspended-mass method(TSMM) was proposed to deal with the seldom-studied issue of fault diagnosis for damping springs of large vibrating screen(LVS). With the static balance characteristic of the screen body/surface as well as the deformation compatibility relation of springs considered, static model of the screen surface under a certain load was established to calculate compression deformation of each spring. Accuracy of the model was validated by both an experiment based on the suspended mass method and the properties of the 3D deformation space in a numerical simulation. Furthermore, by adopting the Taylor formula and the control variate method, quantitative relationship between the change of damping spring deformation and the change of spring stiffness, defined as the deformation sensitive coefficient(DSC), was derived mathematically, from which principle of the TSMM for spring fault diagnosis is clarified. In the end, an experiment was carried out and results show that the TSMM is applicable for diagnosing the fault of single spring in a LVS.
基金A grant from the National R & D Program for Cancer Control,Ministry of Health & Welfare,Republic of Korea, No.0620220-1
文摘Arteriovenous fistula (AVF) involving the inferior mesenteric vessels is rare, and the affected patients usually present with abdominal pain, mass, or features of established portal hypertension. Colonic ischemia is a less common and more serious manifestation of AVE We report a case of ischemic colitis secondary to inferior mesentedc AVF in a patient who underwent a previous liver transplantation, subsequently developed portal vein stenosis, and then presented with acute lower gastrointestinal bleeding. He underwent percutaneous transhepatic placement of a portal vein stent and left colectomy.
文摘AIM: To study the effects of endotoxin on portal hemodynamic of normal and noncirrhotic portal hypertensive rats. METHODS: Normal rats were intraperitoneally injected with 0.1, 0.25, 0.5, 1.0, 2.0, 4.0mg.kg(-1) of lipopolysaccharide(LPS) respectively, portal vein ligation(PVL) and intrahepatic portal occlusion (IPO) rats as well as sham-operated rats were treated with an intraperitoneal injection of 1.0mg.kg(-1) of LPS, the portal vein pressure(PVP), portal venous flow(PVF), inferior vena cava pressure(IVCP) and portal vein resistance(PVR) were detected 4 hours after injection. RESULTS: PVF of the 5 groups of rats accepting intraperitoneal injection of LPS were increased from 14.0 to 18.0, 22.2, 26.2, 34.8, 39.6, 38.8 mL.min(-1) 4 hours after injection of LPS(P【0.01). PVP of the 4 groups of rats accepting more than 0.1mg/kg.b.w of LPS was increased from 1.04 to 1.25, 1.50, 1.80, 1.95, 2.05 kPa(P【0.01). The increments of PVF and PVP were in a dose-dependent manner of LPS. PVR of the 5 groups of rats was decreased from 51 to 42,44,48,45,44,47 kPa.min.L(-1) (P【0.05) and no dose-dependent manner was observed. PVF of PVL, IPO and sham-operated rats increased from 22.6 to 32.8, 22.0 to 28.0, 14.0 to 34.8 mL.min(-1) (P【0.01), and PVP increased from 1.86 to 2.24, 1.74 to 1.95, 1.04 to 1.80 kPa(P【0.01), PVR decreased from 71 to 61, 67 to 61, 52 to 44 kPa.min.L(-1) after intraperitoneal injection of 1mg.kg(-1) of LPS. The increments of PVF and PVP of PVL and IPO rats were significantly less than the sham-operated rats(P【0.01), There was no significant difference between the amounts of PVR decreased in the two groups of PHT model rats and sham-operated rats(P】0.05) after intraperitoneal injection 1mg.kg(-1) of LPS. CONCLUSION: Endotoxin could prompt portal hypertension of the normal and noncirrhotic portal hypertensive rats by increasing portal blood flow mainly.
文摘Arterioportal fistula(APF)is a rare cause of portal hypertension and may lead to death.APF can be congenital,post-traumatic,iatrogenic(transhepatic intervention or biopsy)or related to ruptured hepatic artery aneurysms.Congenital APF is a rare condition even in children.In this case report,we describe a 73-year-old woman diagnosed as APF by ultrasonography,computed tomography,and hepatic artery selective arteriography.The fistula was embolized twice but failed,and she still suffered from alimentary tract hemorrhage.Then,selective arteriography of the hepatic artery was performed again and venae coronaria ventriculi and short gastric vein were embolized.During the 2-year follow-up,the patient remained asymptomatic.We therefore argue that embolization of venae coronaria ventriculi and short gastric vein may be an effective treatment modality for intrahepatic APF with severe upper gastrointestinal bleeding.
文摘Mansonic schistosomiasis is the main cause of portal hypertension in Brazil. Hepatosplenic (HS) form is manifested by hepatomegaly mainly on the left hepatic lobe associated with large splenomegaly and bleeding due to esophageal varices with high mortality rates.
文摘Objective:To evaluate the safety and efficiency of transvenous embolization of dural arteriovenous fistula of cavernous region by multiple venous routes. Methods: Twenty seven patients with dural arteriovenous fistula of cavernous region were treated by transvenous embolization with micro-coils. The transvenous routes included inferior petrosal sinus, superior ophthalmic vein and facial vein. Results: Clinical cure was achieved in 23 cases and significant improvement of symptoms in 4 cases. Complete anglographic obliteration was documented in 22 patients (82%). Residual shunting were left in 2 patients via pterygoid drainage and 1 case via inter-cavernous sinus, 2 cases via inferior petrosal sinus, disappeared one month later by manual compression carotid artery. Headache and vomiting were the most common symptoms after embolization. Three patients had diplopia and relieved within two months after embolization. There was no permanent procedure-related morbidity. The clinic follow up ranged from 5 months to 6 years, and there was not recurrence case. Conclusion: Transvenous embolization via different venous routes is a safe and efficient method for dural arteriovenous fistula of cavernous region treatment.