细菌性肝脓肿螺旋CT的征象分析

目的探讨细菌性肝脓肿螺旋CT的征象。方法回顾性分析39例资料完整并经手术或治疗后证实的细菌性肝脓肿的螺旋CT表现,包括临床、平扫、动态增强表现。结果临床特点发热或1个月内发热病史,血常规—白细胞增高;病灶单发24例,个病灶以上15例,病灶总数57个。平扫表现肝内低密度灶,边缘模糊或清晰,病灶内密度不均,可见环形带及分房样2改变;可伴气体、结石以及胸腔少量积液。增强表现a)动脉期表现低密度病灶周围肝组织强化明显,而病灶本身或边缘无明显强化或轻度强化;伴肝段一过性强化12例。)门静脉期表现()ba病灶呈不规则强化4例;()b环征(单、二、三环)例;()30c多房状征或花瓣征5例。c)延迟期表现病灶缩小或不变,水肿带消失或模糊,脓肿壁或分隔呈“持续强化征”。结论临床发热及白细胞增高和螺旋CT扫描病灶表现为病灶积气、动脉期无明显强化或轻度强化、门静脉期呈“环征”强化、延迟期呈“持续强化征”对细菌性肝脓肿的诊断及鉴别诊断有重要价值

Synthesis of different ruthenium nickel bimetallic nanostructures and an investigation of the structure-activity relationship for benzene hydrogenation to cyclohexane

The catalytic properties of catalysts are generally highly dependent on their nanostructures in most heterogeneous catalytic reactions. Therefore, to acquire targeted catalytic activity, selectivity, and stability, catalysts with a specific nanostructure should be designed and synthesized. Herein, Ru-Ni bimetallic nanoparticles with different nanostructures, Ru-Ni alloy, Ru@Ni, and Ru clusters-on-Ni on carbon, have been synthesized by annealing Ru-Ni/C in flowing N2+10% H2 at different temperatures. The various nanostructures of the Ru-Ni bimetallic nanoparticles have been characterized and their catalytic behaviors were evaluated using benzene hydrogenation to cyclohexane. The relationship between the Ru-Ni bimetallic nanostructures and their catalytic performance is presented. It was found that Ru-Ni alloy/C and Ru clusters-on-Ni/C are much more active than Ru@Ni/C. This study also provides a simple method to design and control the nanostructures of the Ru-Ni bimetallic nanoparticles. ? 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies