In this paper a new approach for time discretization of an integro-differential equation of parabolic type is proposed. The methods are based on the backward-Euler and Crank-Nicolson Schemes but the memory and computa...In this paper a new approach for time discretization of an integro-differential equation of parabolic type is proposed. The methods are based on the backward-Euler and Crank-Nicolson Schemes but the memory and computational requirements are greatly reduced without assuming more regularities on the solution u.展开更多
Interconnection network plays an important role in scalable high performance computer （HPC） systems. The TH Express-2 interconnect has been used in MilkyWay-2 system to provide high-bandwidth and low-latency interpr...Interconnection network plays an important role in scalable high performance computer （HPC） systems. The TH Express-2 interconnect has been used in MilkyWay-2 system to provide high-bandwidth and low-latency interprocessot communications, and continuous efforts are devoted to the development of our proprietary interconnect. This paper describes the state-of-the-art of our proprietary interconnect, especially emphasizing on the design of network interface. Several key features are introduced, such as user-level communication, remote direct memory access, offload collective operation, and hardware reliable end-to-end communication, etc. The design of a low level message passing infrastructures and an upper message passing services are also proposed. The preliminary performance results demonstrate the efficiency of the TH interconnect interface.展开更多
In liver cirrhosis, the circulatory hemodynamic alterations of portal hypertension signifi cantly contribute to many of the clinical manifestations of the disease. In the physiopathology of this vascular alteration, m...In liver cirrhosis, the circulatory hemodynamic alterations of portal hypertension signifi cantly contribute to many of the clinical manifestations of the disease. In the physiopathology of this vascular alteration, mesen- teric splanchnic vasodilation plays an essential role by initiating the hemodynamic process. Numerous studies performed in cirrhotic patients and animal models have shown that this splanchnic vasodilation is the result of an important increase in local and systemic vasodilators and the presence of a splanchnic vascular hyporesponsiveness to vasoconstrictors. Among the molecules and factors known to be potentially involved in this arterial vasodilation, nitric oxide seems to have a crucial role in the physiopathology of this vascular alteration. However, none of the wide variety of mediators can be described as solely responsible, since this phenomenon is multifactorial in origin. Moreover, angiogenesis and vascular remodeling processes alsoseem to play a role. Finally, the sympathetic nervous system is thought to be involved in the pathogenesis of the hyperdynamic circulation associated with portal hypertension, although the nature and extent of its role is not completely understood. In this review, we discuss the different mechanisms known to contribute to this complex phenomenon.展开更多
目的采用meta分析探讨能谱增强CT中标准化碘密度(normalized iodine concentrations,NIC)诊断结直肠癌淋巴结转移的价值。方法检索建库至2022年10月期间PubMed、Embase、Cochrane、Web of Science、CBM、CNKI、万方、维普数据库,筛选NI...目的采用meta分析探讨能谱增强CT中标准化碘密度(normalized iodine concentrations,NIC)诊断结直肠癌淋巴结转移的价值。方法检索建库至2022年10月期间PubMed、Embase、Cochrane、Web of Science、CBM、CNKI、万方、维普数据库,筛选NIC诊断结直肠癌淋巴结转移相关的文献。采用诊断准确性研究的质量评价工具-2对文献进行偏倚风险评价,运用Meta-DiSc1.4进行数据统计,计算Spearman相关系数并绘制综合受试者工作特征曲线(sROC)以分析有无阈值效应引起的异质性。I2<50%采用固定效应合并效应量;I2≥50%采用随机效应合并效应量。采用Stata 14.0进行敏感性分析,以Deeks漏斗图检测发表偏倚。结果纳入7篇文献,共计717枚淋巴结,转移淋巴结314枚、非转移淋巴结403枚。按照能谱增强CT中的动脉期(arterial phase,AP)和静脉期(venous phase,VP)将其分为两个亚组。Meta DiSc1.4显示,两亚组均不存在阈值效应引起的异质性(均P>0.05)。进而根据I2结果,选择对应的效应模型合并效应量。结果(AP、VP)分别为:灵敏度=0.76(0.71~0.80)、0.67(0.61~0.73);特异度=0.71(0.66~0.75)、0.87(0.82~0.91);阳性似然比=2.83(1.85~4.31)、5.39(3.79~7.67);阴性似然比=0.33(0.23~0.46)、0.34(0.22~0.54);诊断比值比(diagnostic odds ratio,DOR)=10.00(4.38~22.82)、17.27(10.39~28.69);曲线下面积(area under the curve,AUC)=0.8354、0.8945。亚组-AP及亚组-VP敏感性分析显示研究稳定,并且不存在发表偏倚(P>0.05)。结论NIC有助于区分结直肠癌患者转移性和非转移性淋巴结。在灵敏度方面,AP的NIC更优;在特异度、阳性似然比、阴性似然比、DOR、AUC方面,VP的NIC具有更高的诊断价值。展开更多
文摘In this paper a new approach for time discretization of an integro-differential equation of parabolic type is proposed. The methods are based on the backward-Euler and Crank-Nicolson Schemes but the memory and computational requirements are greatly reduced without assuming more regularities on the solution u.
基金Acknowledgements This work was partially supported by the National High-tech R＆D Program of China （863 Program） （2012AA01A301, 2013AA014301, 2013AA01A208）, and by the National Basic Research Program of China （973 Program） （2011CB309705）, and by the National Natural Science Foundation of China （Grant Nos. 61120106005, 61303063 and 61272482）.
文摘Interconnection network plays an important role in scalable high performance computer （HPC） systems. The TH Express-2 interconnect has been used in MilkyWay-2 system to provide high-bandwidth and low-latency interprocessot communications, and continuous efforts are devoted to the development of our proprietary interconnect. This paper describes the state-of-the-art of our proprietary interconnect, especially emphasizing on the design of network interface. Several key features are introduced, such as user-level communication, remote direct memory access, offload collective operation, and hardware reliable end-to-end communication, etc. The design of a low level message passing infrastructures and an upper message passing services are also proposed. The preliminary performance results demonstrate the efficiency of the TH interconnect interface.
基金Supported by the Grants from the Ministerio de Educacióny Ciencia, No. SAF2006-0314the Ministerio de Cienciae Innovación, No. SAF2009-08354
文摘In liver cirrhosis, the circulatory hemodynamic alterations of portal hypertension signifi cantly contribute to many of the clinical manifestations of the disease. In the physiopathology of this vascular alteration, mesen- teric splanchnic vasodilation plays an essential role by initiating the hemodynamic process. Numerous studies performed in cirrhotic patients and animal models have shown that this splanchnic vasodilation is the result of an important increase in local and systemic vasodilators and the presence of a splanchnic vascular hyporesponsiveness to vasoconstrictors. Among the molecules and factors known to be potentially involved in this arterial vasodilation, nitric oxide seems to have a crucial role in the physiopathology of this vascular alteration. However, none of the wide variety of mediators can be described as solely responsible, since this phenomenon is multifactorial in origin. Moreover, angiogenesis and vascular remodeling processes alsoseem to play a role. Finally, the sympathetic nervous system is thought to be involved in the pathogenesis of the hyperdynamic circulation associated with portal hypertension, although the nature and extent of its role is not completely understood. In this review, we discuss the different mechanisms known to contribute to this complex phenomenon.
文摘目的采用meta分析探讨能谱增强CT中标准化碘密度(normalized iodine concentrations,NIC)诊断结直肠癌淋巴结转移的价值。方法检索建库至2022年10月期间PubMed、Embase、Cochrane、Web of Science、CBM、CNKI、万方、维普数据库,筛选NIC诊断结直肠癌淋巴结转移相关的文献。采用诊断准确性研究的质量评价工具-2对文献进行偏倚风险评价,运用Meta-DiSc1.4进行数据统计,计算Spearman相关系数并绘制综合受试者工作特征曲线(sROC)以分析有无阈值效应引起的异质性。I2<50%采用固定效应合并效应量;I2≥50%采用随机效应合并效应量。采用Stata 14.0进行敏感性分析,以Deeks漏斗图检测发表偏倚。结果纳入7篇文献,共计717枚淋巴结,转移淋巴结314枚、非转移淋巴结403枚。按照能谱增强CT中的动脉期(arterial phase,AP)和静脉期(venous phase,VP)将其分为两个亚组。Meta DiSc1.4显示,两亚组均不存在阈值效应引起的异质性(均P>0.05)。进而根据I2结果,选择对应的效应模型合并效应量。结果(AP、VP)分别为:灵敏度=0.76(0.71~0.80)、0.67(0.61~0.73);特异度=0.71(0.66~0.75)、0.87(0.82~0.91);阳性似然比=2.83(1.85~4.31)、5.39(3.79~7.67);阴性似然比=0.33(0.23~0.46)、0.34(0.22~0.54);诊断比值比(diagnostic odds ratio,DOR)=10.00(4.38~22.82)、17.27(10.39~28.69);曲线下面积(area under the curve,AUC)=0.8354、0.8945。亚组-AP及亚组-VP敏感性分析显示研究稳定,并且不存在发表偏倚(P>0.05)。结论NIC有助于区分结直肠癌患者转移性和非转移性淋巴结。在灵敏度方面,AP的NIC更优;在特异度、阳性似然比、阴性似然比、DOR、AUC方面,VP的NIC具有更高的诊断价值。
