Rheumatic diseases are a group of chronic disorders characterized by abnormalities in the immune system， while portal hypertension occurs due to increased blood flow or heightened resistance in the portal venous system or obstruction of hepatic venous outflow. Both rheumatic diseases and their medications can lead to noncirrhotic portal hypertension. The hypercoagulable state associated with rheumatic diseases can result in thrombosis within the portal and hepatic venous systems， and damage to the intrahepatic portal system and hepatic sinusoidal endothelial system can lead to porto-sinusoidal vascular disease and hepatic sinusoidal obstruction syndrome. Moreover， drugs used for the treatment of rheumatic diseases may cause liver parenchymal injury， which further leads to liver fibrosis and cirrhosis， or they may damage the hepatic vascular endothelium and thus cause noncirrhotic portal hypertension. This article elaborates on the mechanisms and characteristics by which common rheumatic diseases and their therapeutic agents lead to portal hypertension， in order to provide insights and assistance for clinical diagnosis， treatment， and follow-up monitoring.

OBJECTIVE: The triply periodic minimal surface (TPMS) Gyroid porous scaffolds were built with identical porosity while varying pore sizes were used by fluid mechanics finite element analysis (FEA) to simulate the in vivo microenvironment. The effects of scaffolds with different pore sizes on cell adhesion, proliferation, and osteogenic differentiation were evaluated through calculating fluid velocity, wall shear stress, and permeability in the scaffolds. METHODS: Three types of gyroid porous scaffolds, with pore sizes of 400, 600 and 800 μm, were established by nTopology software. Each scaffold had dimensions of 10 mm × 10 mm × 10 mm and isotropic internal structures. The models were imported to the ANSYS 2022R1 software, and meshed into over 3 million unstructured tetrahedral elements. Boun- dary conditions were set with inlet flow velocities of 0.01, 0.1, and 1 mm/s, and outlet pressure of 0 Pa. Pressure, velocity, and wall shear stress were calculated as fluid flowed through the scaffolds using the Navier-Stokes equations. At the same time, permeability was determined based on Darcy' s law. The compressive strength of scaffolds with different pore sizes was evaluated by ANSYS 2022R1 Static structural analysis. RESULTS: A linear relationship was observed between the wall shear stress and fluid velocity at inlet flow rates of 0.01, 0.1 and 1 mm/s, with increasing velocity leading to higher wall shear stress. At the flow velocity of 0.1 mm/s, the initial pressures of scaffolds with pore sizes of 400, 600 and 800 μm were 0.272, 0.083 and 0.079 Pa, respectively. The fluid pressures were gradually decreased across the scaffolds. The average flow velocities were 0.093, 0.078 and 0.070 mm/s, the average wall shear stresses 2.955, 1.343 and 1.706 mPa, permeabilities values 0.54×10^-8 1.80×10^-8 and 1.89×10^-8 m² in the scaffolds with pore sizes of 400, 600 and 800 μm. The scaffold surface area proportions according with optimal wall shear stress range for cell growth and osteogenic differentiation were calcula-ted, which was highest in the 600 μm scaffold (27.65%), followed by the 800 μm scaffold (17.30%) and the 400 μm scaffold (1.95%). The compressive strengths of the scaffolds were 23, 26 and 34 MPa for the 400, 600 and 800 μm pore sizes. CONCLUSION The uniform stress distributions appeared in all gyroid scaffold types under compressive stress. The permeabilities of scaffolds with pore sizes of 600 and 800 μm were significantly higher than the 400 μm. The average wall shear stress in the scaffold of 600 μm was the lowest, and the scaffold surface area proportion for cell growth and osteogenic differentiation the largest, indicating that it might be the most favorable design for supporting these cellular activities.
Tissue Scaffolds/chemistry* ; Porosity ; Finite Element Analysis ; Osteogenesis ; Cell Differentiation ; Cell Proliferation ; Tissue Engineering/methods* ; Hydrodynamics ; Humans ; Stress, Mechanical ; Cell Adhesion

Objective To improve the method of bedside blind placement of bengmark nasointestinal tube, and evaluate its application effect in severe acute pancreatitis (SAP) patients. Methods Combined with clinical practice experience, the "four-point testing method" "four-point auscultation method" and "gently shaking method" were applied to the traditional blind placement, so as to form a standard, operative and highly-qualified blind placement method of the blind placement of the bengmark nasointestinal tube. A total of 50 SAP patients hospitalized in the Gastroenterology Department of Xinqiao Hospital Affiliated to Army Medical University from November 1st, 2016 to March 31st, 2018 were recruited to evaluate the catheterization success rate of the new catheterization method, time-consuming of catheterization, vital signs, catheter-related complications, patient satisfaction, and other indicators. Results The success rate of bedside blind placement of bengmark nasointestinal tube in 50 patients with SAP was 96% (48/50). The median catheterization time was 22.8 (minimum 10 to longest 60) min. There was no statistical significance in the differences of blood pressure, heart rate, respiration, and oxyhemoglobin saturation before and after catheterization (P＞ 0.05). No arrhythmia, bleeding, perforation, misplaced airways, and other related complications occurred. The satisfaction degree of catheterization was 100% (50/50). Conclusions The improved bedside blind placement of bengmark nasointestinal tube has the advantages of strong operability, easy to learn and use, and at the same time has good results in the preliminary application of SAP patients. It can be used in further randomized controlled trials with higher intensity of demonstration and can be used in severe patients.