应变-旋转(Strain-Rotation,S-R)和分解定理为分析几何非线性问题提供了合理可靠的理论基础,但用有限元求解时会遇到大变形发生后的网格畸变问题。近年提出的虚单元法(Virtual element method,VEM)适用于一般的多边形网格,因此,该文尝...应变-旋转(Strain-Rotation,S-R)和分解定理为分析几何非线性问题提供了合理可靠的理论基础,但用有限元求解时会遇到大变形发生后的网格畸变问题。近年提出的虚单元法(Virtual element method,VEM)适用于一般的多边形网格,因此,该文尝试使用一阶虚单元求解基于S-R和分解定理的二维几何非线性问题,以克服网格畸变的影响。基于重新定义的多项式位移空间基函数,推演获得一阶虚单元分析线弹性力学问题时允许位移空间向多项式位移空间的投影表达式;按照虚单元法双线性格式的计算规则,分析处理基于更新拖带坐标法和势能率原理的增量变分方程;进而建立离散系统方程及其矩阵表达形式,并编制MATLAB求解程序;采用常规多边形网格和畸变网格,应用该文算法分析均布荷载下的悬臂梁和均匀内压下的厚壁圆筒变形。结果与已有文献和ANSYS软件的对比表明:该文算法在两种网格中均可有效执行且具备足够数值精度。总体该文算法为基于S-R和分解定理的二维几何非线性问题求解提供了一种鲁棒方法。展开更多
Objective:To establish the quality standards for the preparation of Xiao’er Qingre enema in hospitals.Method:Thin-layer chromatography(TLC)was used to identify Radix Isatidis and Glycyrrhizae in the prescription.The ...Objective:To establish the quality standards for the preparation of Xiao’er Qingre enema in hospitals.Method:Thin-layer chromatography(TLC)was used to identify Radix Isatidis and Glycyrrhizae in the prescription.The content of(R,S)-Goitrin was determined by high-performance liquid chromatography(HPLC).Results:In TLC identification,there was no interference between the negative controls of Radix Isatidis and glycyrrhizae,and the spots were well-separated.The HPLC results of(R,S)-Goitrin showed a good linear relationship between the peak area and concentration within the range of 0.476-95.2μg·mL-1(r=0.9999).Conclusion:The TLC and HPLC methods established in this experiment are simple,reproducible,and specific,making them suitable for the quality control Xiao’er Qingre enema preparation in hospitals.展开更多
Introduction: Glomerular damage during Gougerot-Sjgren syndrome is much rarer than interstitial damage, and is essentially extra-membranous and membrano-proliferative glomerulonephritis. Observation: We report the cas...Introduction: Glomerular damage during Gougerot-Sjgren syndrome is much rarer than interstitial damage, and is essentially extra-membranous and membrano-proliferative glomerulonephritis. Observation: We report the case of a 44-year-old woman with primary Sjgrens syndrome, confirmed by clinical dryness syndrome, positive anti-SSA and anti-SSB antibodies, and a salivary gland biopsy revealing grade 4 lymphocytic sialadenitis according to CHISHOLMs classification. Later, the patient developed nephrotic syndrome, along with hypertension. Renal function remained normal with a creatinine level of 9.3 mg/l, and hematuria was absent. Only antinuclear antibodies tested positive, while anti-PLA2R antibodies were negative. A renal biopsy was performed, which was complicated on the same day by hemodynamic instability with hematuria. Renal CT scan with contrast injection revealed a posterior perirenal hematoma without contrast extravasation. Additionally, bilateral renal vein thrombosis was incidentally discovered, suggesting extramembranous glomerulonephritis. The patients hemodynamic status stabilized after fluid resuscitation with isotonic saline solution (0.9%), without the need for blood transfusion. Renal biopsy confirmed extramembranous glomerulonephritis with interstitial fibrosis and minimal tubular atrophy. The initial etiological assessment was negative. The patient was started on oral corticosteroids, angiotensin-converting enzyme inhibitors, and therapeutic anticoagulation for renal vein thrombosis. The patients condition improved, with the disappearance of the syndrome and spontaneous regression of the hematoma. Discussion: The association of nephrotic syndrome and renal vein thrombosis primarily suggests glomerulopathy, in particular extra-membranous glomerulonephritis. Sjgrens syndrome can be associated with extra-membranous glomerulonephritis without being its direct cause. Like, it is possible that it is a cause of glomerulonephritis, essentially extra membranous and membrano-proliferative. Conclusion: Sjgrens syndrome is generally underestimated cause of glomerulonephritis, which should be considered in cases of extra-membranous glomerulonephritis.展开更多
The seepage characteristics of multiscale porous media is of considerable significance in many scientific and engineering fields.The Darcy permeability is one of the key macroscopic physical properties to characterize...The seepage characteristics of multiscale porous media is of considerable significance in many scientific and engineering fields.The Darcy permeability is one of the key macroscopic physical properties to characterize the seepage capacity of porous media.Therefore,based on the statistically fractal scaling law of porous media,fractal geometry is applied to model the multiscale pore structures.And a two-dimensional fractal orifice-throat model with multiscale and tortuous characteristics is proposed for the seepage flow through porous media.The analytical expression for Darcy permeability of porous media is derived,which is validated by comparing with available experimental data.The results show that the Darcy permeability is significantly influenced by porosity,orifice-throat fractal dimension,minimum to maximum diameter ratio,orifice-throat ratio and tortuosity fractal dimension.The present results are helpful for understanding the seepage mechanism of multiscale porous media,and may provide theoretical basis for unconventional oil and gas exploration and development,porous phase transition energy storage composites,CO2 geological sequestration,environmental protection and nuclear waste treatment,etc.展开更多
文摘应变-旋转(Strain-Rotation,S-R)和分解定理为分析几何非线性问题提供了合理可靠的理论基础,但用有限元求解时会遇到大变形发生后的网格畸变问题。近年提出的虚单元法(Virtual element method,VEM)适用于一般的多边形网格,因此,该文尝试使用一阶虚单元求解基于S-R和分解定理的二维几何非线性问题,以克服网格畸变的影响。基于重新定义的多项式位移空间基函数,推演获得一阶虚单元分析线弹性力学问题时允许位移空间向多项式位移空间的投影表达式;按照虚单元法双线性格式的计算规则,分析处理基于更新拖带坐标法和势能率原理的增量变分方程;进而建立离散系统方程及其矩阵表达形式,并编制MATLAB求解程序;采用常规多边形网格和畸变网格,应用该文算法分析均布荷载下的悬臂梁和均匀内压下的厚壁圆筒变形。结果与已有文献和ANSYS软件的对比表明:该文算法在两种网格中均可有效执行且具备足够数值精度。总体该文算法为基于S-R和分解定理的二维几何非线性问题求解提供了一种鲁棒方法。
基金Xi’an Science and Technology Plan Project(Project number:23YXYJ0163)Education and Teaching Reform Research Project of Xi,an Medical University in(2023)(Project number:S202311840061)First Affiliated Hospital of Xi’an Medical University of China(Fund number:XYYFY-2023-01).
文摘Objective:To establish the quality standards for the preparation of Xiao’er Qingre enema in hospitals.Method:Thin-layer chromatography(TLC)was used to identify Radix Isatidis and Glycyrrhizae in the prescription.The content of(R,S)-Goitrin was determined by high-performance liquid chromatography(HPLC).Results:In TLC identification,there was no interference between the negative controls of Radix Isatidis and glycyrrhizae,and the spots were well-separated.The HPLC results of(R,S)-Goitrin showed a good linear relationship between the peak area and concentration within the range of 0.476-95.2μg·mL-1(r=0.9999).Conclusion:The TLC and HPLC methods established in this experiment are simple,reproducible,and specific,making them suitable for the quality control Xiao’er Qingre enema preparation in hospitals.
文摘Introduction: Glomerular damage during Gougerot-Sjgren syndrome is much rarer than interstitial damage, and is essentially extra-membranous and membrano-proliferative glomerulonephritis. Observation: We report the case of a 44-year-old woman with primary Sjgrens syndrome, confirmed by clinical dryness syndrome, positive anti-SSA and anti-SSB antibodies, and a salivary gland biopsy revealing grade 4 lymphocytic sialadenitis according to CHISHOLMs classification. Later, the patient developed nephrotic syndrome, along with hypertension. Renal function remained normal with a creatinine level of 9.3 mg/l, and hematuria was absent. Only antinuclear antibodies tested positive, while anti-PLA2R antibodies were negative. A renal biopsy was performed, which was complicated on the same day by hemodynamic instability with hematuria. Renal CT scan with contrast injection revealed a posterior perirenal hematoma without contrast extravasation. Additionally, bilateral renal vein thrombosis was incidentally discovered, suggesting extramembranous glomerulonephritis. The patients hemodynamic status stabilized after fluid resuscitation with isotonic saline solution (0.9%), without the need for blood transfusion. Renal biopsy confirmed extramembranous glomerulonephritis with interstitial fibrosis and minimal tubular atrophy. The initial etiological assessment was negative. The patient was started on oral corticosteroids, angiotensin-converting enzyme inhibitors, and therapeutic anticoagulation for renal vein thrombosis. The patients condition improved, with the disappearance of the syndrome and spontaneous regression of the hematoma. Discussion: The association of nephrotic syndrome and renal vein thrombosis primarily suggests glomerulopathy, in particular extra-membranous glomerulonephritis. Sjgrens syndrome can be associated with extra-membranous glomerulonephritis without being its direct cause. Like, it is possible that it is a cause of glomerulonephritis, essentially extra membranous and membrano-proliferative. Conclusion: Sjgrens syndrome is generally underestimated cause of glomerulonephritis, which should be considered in cases of extra-membranous glomerulonephritis.
文摘The seepage characteristics of multiscale porous media is of considerable significance in many scientific and engineering fields.The Darcy permeability is one of the key macroscopic physical properties to characterize the seepage capacity of porous media.Therefore,based on the statistically fractal scaling law of porous media,fractal geometry is applied to model the multiscale pore structures.And a two-dimensional fractal orifice-throat model with multiscale and tortuous characteristics is proposed for the seepage flow through porous media.The analytical expression for Darcy permeability of porous media is derived,which is validated by comparing with available experimental data.The results show that the Darcy permeability is significantly influenced by porosity,orifice-throat fractal dimension,minimum to maximum diameter ratio,orifice-throat ratio and tortuosity fractal dimension.The present results are helpful for understanding the seepage mechanism of multiscale porous media,and may provide theoretical basis for unconventional oil and gas exploration and development,porous phase transition energy storage composites,CO2 geological sequestration,environmental protection and nuclear waste treatment,etc.
