流体障碍物是近来提出的一种加速火焰由缓燃转变为爆震(Deflagration to Detonation Transition,简称DDT)的新技术。为探索流体障碍物的设计准则,以带有不同类型障碍物的爆震管段为研究对象开展数值研究。结果表明:流体障碍物对火焰的...流体障碍物是近来提出的一种加速火焰由缓燃转变为爆震(Deflagration to Detonation Transition,简称DDT)的新技术。为探索流体障碍物的设计准则,以带有不同类型障碍物的爆震管段为研究对象开展数值研究。结果表明:流体障碍物对火焰的加速作用优于固体障碍物。射流的存在加强了火焰面贴近射流一侧的湍流强度。当射流的动量一定时,对火焰加速传播过程的促进效果与射流初始速度不是单调递增的关系,存在某一最优初速使得火焰加速效果最好。展开更多
A hybrid model is proposed in this study to predict rectal tumour response during radiotherapy treatment. As the oxygen partial pressure distribution (pO<sub>2</sub>) is a data which is naturally represent...A hybrid model is proposed in this study to predict rectal tumour response during radiotherapy treatment. As the oxygen partial pressure distribution (pO<sub>2</sub>) is a data which is naturally represented at the microscopic scale, we firstly estimate the optimal pO<sub>2</sub> distribution using both a diffusion equation and a discrete multi-scale model (that we proposed in a previous study). The aim is to use the effectiveness in algorithmic complexity of the discrete model and its multi-scale aspect in this work to estimate biological information at cellular scale and then construct them at macroscopic scale. Secondly, the obtained pO<sub>2</sub> distribution results are used as an input of a biomechanical model in order to simulate tumour volume evolution during radiotherapy. FDG PET images of 21 rectal cancer patients undergoing radiotherapy are used to simulate the tumour evolution during the treatment. The simulated results using the proposed hybride model, allow the interpretation of tumour aggressiveness.展开更多
Computational modeling continues to evolve in applications of hydrology and hydraulics, and the field of Computational Hydrology and Hydraulics has grown into a significant technology in both engineering and computati...Computational modeling continues to evolve in applications of hydrology and hydraulics, and the field of Computational Hydrology and Hydraulics has grown into a significant technology in both engineering and computational mathematics. In this paper, the fundamental issue of assessment of computational error is addressed by determination of an “equivalent” mathematical statement, as a partial differential equation (“PDE”) that describes the original mathematical PDE statement and computational solution of it. In other words, given that the computational model does not exactly solve the governing PDE and that the computational processes used to approximate the governing PDE further moves the computational outcome away from the exact solution, what “alternate” or “equivalent” PDE does the resulting computational model exactly solve? In this paper it is shown that development of such an equivalent PDE enables an assessment of computational error by direct comparison of the equivalent PDE to the original PDE targeted to being solved. As an example, the USGS Diffusion Hydrodynamic Model (“DHM”) is examined as to development of an equivalent PDE that describes the DHM computational modeling outcome, which is then compared to the actual outcomes resulting from application of the DHM model.展开更多
The pathological processes of Alzheimer's disease and type 2 diabetes mellitus have been demonstrated to be linked together. Both PDE9 inhibitors and PPARγ agonists such as rosiglitazone exhibited remarkable prec...The pathological processes of Alzheimer's disease and type 2 diabetes mellitus have been demonstrated to be linked together. Both PDE9 inhibitors and PPARγ agonists such as rosiglitazone exhibited remarkable preclinical and clinical treatment effects for these two diseases. In this study, a series of PDE9 inhibitors combining the pharmacophore of rosiglitazone were discovered. All the compounds possessed remarkable affinities towards PDE9 and four of them have the IC_(50) values 5n mol/L. In addition, these four compounds showed low cell toxicity in human SH-SY5Y neuroblastoma cells.Compound 11a, the most effective one, gave the IC_(50) of 1.1 nmol/L towards PDE9, which is significantly better than the reference compounds PF-04447943 and BAY 73-6691. The analysis of putative binding patterns and binding free energy of the designed compounds with PDE9 may explain the structure–activity relationships and provide evidence for further structural modifications.展开更多
文摘流体障碍物是近来提出的一种加速火焰由缓燃转变为爆震(Deflagration to Detonation Transition,简称DDT)的新技术。为探索流体障碍物的设计准则,以带有不同类型障碍物的爆震管段为研究对象开展数值研究。结果表明:流体障碍物对火焰的加速作用优于固体障碍物。射流的存在加强了火焰面贴近射流一侧的湍流强度。当射流的动量一定时,对火焰加速传播过程的促进效果与射流初始速度不是单调递增的关系,存在某一最优初速使得火焰加速效果最好。
文摘A hybrid model is proposed in this study to predict rectal tumour response during radiotherapy treatment. As the oxygen partial pressure distribution (pO<sub>2</sub>) is a data which is naturally represented at the microscopic scale, we firstly estimate the optimal pO<sub>2</sub> distribution using both a diffusion equation and a discrete multi-scale model (that we proposed in a previous study). The aim is to use the effectiveness in algorithmic complexity of the discrete model and its multi-scale aspect in this work to estimate biological information at cellular scale and then construct them at macroscopic scale. Secondly, the obtained pO<sub>2</sub> distribution results are used as an input of a biomechanical model in order to simulate tumour volume evolution during radiotherapy. FDG PET images of 21 rectal cancer patients undergoing radiotherapy are used to simulate the tumour evolution during the treatment. The simulated results using the proposed hybride model, allow the interpretation of tumour aggressiveness.
文摘Computational modeling continues to evolve in applications of hydrology and hydraulics, and the field of Computational Hydrology and Hydraulics has grown into a significant technology in both engineering and computational mathematics. In this paper, the fundamental issue of assessment of computational error is addressed by determination of an “equivalent” mathematical statement, as a partial differential equation (“PDE”) that describes the original mathematical PDE statement and computational solution of it. In other words, given that the computational model does not exactly solve the governing PDE and that the computational processes used to approximate the governing PDE further moves the computational outcome away from the exact solution, what “alternate” or “equivalent” PDE does the resulting computational model exactly solve? In this paper it is shown that development of such an equivalent PDE enables an assessment of computational error by direct comparison of the equivalent PDE to the original PDE targeted to being solved. As an example, the USGS Diffusion Hydrodynamic Model (“DHM”) is examined as to development of an equivalent PDE that describes the DHM computational modeling outcome, which is then compared to the actual outcomes resulting from application of the DHM model.
基金supported by the National Key R&D Program of China (2017YFB0202600)Natural Science Foundation of China (Nos. 81522041,81373258,21572279,81602955,and 21402243)+3 种基金Science Foundation of Guangdong Province (Nos. 2014A020210009,2016A030310144)The Fundamental Research Funds for the Central Universities (Sun Yat-Sen University,No. 17ykjc03 and 17ykpy20)Guangdong Province Higher Vocational Colleges & Schools Pearl River Scholar Funded Scheme (2016)Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase) under Grant No. U1501501 for providing the supercomputing service
文摘The pathological processes of Alzheimer's disease and type 2 diabetes mellitus have been demonstrated to be linked together. Both PDE9 inhibitors and PPARγ agonists such as rosiglitazone exhibited remarkable preclinical and clinical treatment effects for these two diseases. In this study, a series of PDE9 inhibitors combining the pharmacophore of rosiglitazone were discovered. All the compounds possessed remarkable affinities towards PDE9 and four of them have the IC_(50) values 5n mol/L. In addition, these four compounds showed low cell toxicity in human SH-SY5Y neuroblastoma cells.Compound 11a, the most effective one, gave the IC_(50) of 1.1 nmol/L towards PDE9, which is significantly better than the reference compounds PF-04447943 and BAY 73-6691. The analysis of putative binding patterns and binding free energy of the designed compounds with PDE9 may explain the structure–activity relationships and provide evidence for further structural modifications.
