A Priori Subcell Limiting Approach for the FR/CPR Method on Unstructured Meshes

A priori subcell limiting approach is developed for high-order flux reconstruction/correction procedure via reconstruction (FR/CPR) methods on two-dimensional unstructured quadrilateral meshes. Firstly, a modified indicator based on modal energy coefficients is proposed to detect troubled cells, where discontinuities exist. Then, troubled cells are decomposed into nonuniform subcells and each subcell has one solution point. A second-order finite difference shock-capturing scheme based on nonuniform nonlinear weighted (NNW) interpolation is constructed to perform the calculation on troubled cells while smooth cells are calculated by the CPR method. Numerical investigations show that the proposed subcell limiting strategy on unstructured quadrilateral meshes is robust in shock-capturing.     

Synthesis and automated fluorine-18 radiolabeling of new PSMA-617 derivatives with a CuAAC radiosynthetic approach

In the last decade, the development of new radiopharmaceuticals for the imaging and therapy of prostate cancer has been a highly active and important area of research, especially focusing on the prostate-specific membrane antigen (PSMA), an antigen which is upregulated in prostate, as well as in other tumor cells. A large variety of PSMA ligands have been radiolabeled, to date. Among the various derivatives, PSMA-617 resulted to be one of the most interesting in terms of interaction with the antigen and clinical properties, and its lutetium-177 labeled version has recently been approved by regulatory agencies for therapeutic purposes. For this reasons, the radiolabeling with fluorine-18 of a PSMA-617 derivative might be of interest. Beside other methodologies to radiolabel macromolecules with fluorine-18, the “click-chemistry” approach resulted to be very useful, and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) is considered one of most efficient and reliable. This paper proposes the synthesis of a suitable precursor for the radiolabeling with fluorine-18 of a new PSMA-617 derivative. The whole radiosynthetic procedure has been fully automated, and the final product, which proved to be stable in plasma, has been obtained with radiochemical yield and purity suitable for subsequent preclinical studies.     

基于HPLC指纹图谱、多指标成分含量测定结合化学计量学的怀牛膝质量评价＊

目的 本实验采用HPLC方法建立来自3个产地15批怀牛膝药材的指纹图谱，并对β-蜕皮甾酮，25R-牛膝甾酮，25S-牛膝甾酮进行含量测定，同时通过化学计量学的方法对15批怀牛膝进行质量评价。方法 选用Waters SunFire C₁₈（150 mm×4.6 mm，5 μm）色谱柱，检测波长280 nm，以乙腈-0.1%甲酸水梯度洗脱，流速为1.0 mL·min^-1，柱温25℃，进样量10 μL。以β-蜕皮甾酮峰为参照峰，运用软件《中药色谱指纹图谱相似度评价系统（2012版）》对15批怀牛膝药材进行相似度分析，使用Metabo Analyst 5.0网站进行聚类热图分析，使用SIMCA 14.1软件进行PCA和PLS-DA分析。结果 标定了31个共有指纹峰，指认了3个已知成分，并对其进行含量测定，化学计量学分析结果将15批怀牛膝药材样品分为3类，并且筛选了不同产地间潜在的差异性成分。结论 该方法具有良好的精密度、重复性以及稳定性，可为怀牛膝的质量评价与控制提供科学依据及参考。