针对目前基于属性的可搜索加密方案存在密钥泄露以及不支持属性撤销的问题,提出了一种云环境下,安全高效、可支持属性撤销的基于CP-ABE(ciphertext-policy attribute based encryption)的可搜索加密方案。该方案不仅可支持细粒度的访问...针对目前基于属性的可搜索加密方案存在密钥泄露以及不支持属性撤销的问题,提出了一种云环境下,安全高效、可支持属性撤销的基于CP-ABE(ciphertext-policy attribute based encryption)的可搜索加密方案。该方案不仅可支持细粒度的访问控制,具有较高的计算效率,且用户密钥使用随机值盲化后提交服务器,保证了用户密钥的保密性和安全性。该方案支持用户属性的撤销,并在属性撤销过程中,将密文更新的大部分工作转移给云服务提供商完成,方案在保证安全性的前提下,进一步降低了用户的计算代价。方案的安全性基于DL(decisional linear)假设,在通用模型下具有选择明文攻击安全,抗合谋攻击,前向安全和后向安全。展开更多
Monoclonal antibody (MAb) to rat liver cyto-chrome P-450j isozyme, an activating enzyme specific to nitrosamine metabolism, was used coupled with immunoblotting, densitometer scanning of SDS-PAGE gels and immunohistoc...Monoclonal antibody (MAb) to rat liver cyto-chrome P-450j isozyme, an activating enzyme specific to nitrosamine metabolism, was used coupled with immunoblotting, densitometer scanning of SDS-PAGE gels and immunohistochemical technique. The trace P-450HSj isozyme (Mr. 51.5 Kd) was found in human gastric mucosa. It was similar to P-450j in molecular weight, catalytic and immunochemical properties. The concentrations of P-450HSj in mucosa of lesser curvature were higher than those in greater curvature. This might be one of the important reasons that lesser curvature is the commonest area for gastric carcinoma. But there was possibly less P-450HSj in gastric mucosa with cancer. Im-munohistochemically, P-450HSj was discovered in the cytoplasm of some glandular epithelial cells, especially in the glands with hyperplastic and intestinal metaplastic changes adjacent to carcinoma. It was also found in some normal glands and in tumor cells of high-differentiated adenocarcinoma, but not in those of low-differentiated ones. Following subjects are discussed: (1) the method of detecting trace P-450HSj, (2) the rule of distribution of P-450HSj, and (3) the relationship between the isozyme and the occurrence of gastric cancer caused by nitrosa-mines.展开更多
目的探讨慢性阻塞性肺疾病(简称慢阻肺)伴或不伴低氧血症患者血清单核细胞趋化蛋白-1(MCP-1)、血清淀粉样蛋白A(SAA)水平与认知功能的关系,以期为慢阻肺患者筛查预测早期认知功能损伤的血清学指标,同时探讨低氧血症在认知障碍发生中的...目的探讨慢性阻塞性肺疾病(简称慢阻肺)伴或不伴低氧血症患者血清单核细胞趋化蛋白-1(MCP-1)、血清淀粉样蛋白A(SAA)水平与认知功能的关系,以期为慢阻肺患者筛查预测早期认知功能损伤的血清学指标,同时探讨低氧血症在认知障碍发生中的作用。方法纳入2013年1月至2017年1月于华北理工大学附属医院住院的62例慢阻肺患者,依据血气分析将其分为慢阻肺缺氧组(25例)和慢阻肺无缺氧组(37例),同期30例健康体检人群为对照组。采用酶联免疫吸附法测定慢阻肺患者及对照人群血清MCP-1、SAA浓度,逆转录聚合酶链反应检测外周血单核细胞中MCP-1、SAA的m RNA表达水平,应用蒙特利尔认知评估量表(Mo CA量表)进行认知功能测定。分析三组人群在血清MCP-1、SAA水平及外周血MCP-1 m RNA、SAA m RNA水平表达有无差异及与认知功能损伤的关系。结果血清MCP-1、SAA水平及外周血单核细胞MCP-1 m RNA、SAA m RNA水平表达水平趋势一致,慢阻肺患者血清MCP-1、SAA水平及外周血单核细胞MCP-1 m RNA、SAA m RNA水平高于健康对照组,差异有统计学意义(均P<0.05);慢阻肺缺氧组和慢阻肺无缺氧组Mo CA评分总分较对照组低,其中缺氧组Mo CA评分降低更明显,差异有统计学意义(均P<0.05)。血清SAA、MCP-1水平及外周血单核细胞MCP-1 m RNA、SAA m RNA水平与Mo CA总分呈负相关(均P<0.05)。结论慢阻肺患者血清SAA、MCP-1水平及外周血单核细胞MCP-1 m RNA、SAA m RNA水平高低与患者认知障碍程度呈正相关,低氧血症可能是慢阻肺患者发生认知功能受损的因素之一。展开更多
This paper shows how a faulty approach to the study of mineral inclusions in zircon can lead to misleading interpretations of the geological context.We present and discuss two well-documented examples.Zircon grains se...This paper shows how a faulty approach to the study of mineral inclusions in zircon can lead to misleading interpretations of the geological context.We present and discuss two well-documented examples.Zircon grains separated from HP metamorphic jadeitite of the Rio San Juan Complex,Dominican Republic,and from UHP pyrope quartzite of the Dora Maira Massif,northern Italy,were studied using cathodoluminescence(CL)techniques,in combination with mineral inclusion and age data.In general,zircon from both localities shows inherited magmatic core domains with oscillatory zoning and metamorphic rims.The magmatic cores of zircon from the jadeitite yield ages of 115–117 Ma and host jadeite and omphacite which are of metamorphic origin and formed at about 78 Ma.Zircon from lawsonite blueschist,representing the country rock of the jadeitite,contains domains with oscillatory zoning that are nearly identical in age to the zircon cores from the adjacent jadeitite,and also contains younger metamorphic minerals such as lawsonite,albite,phengite(Si3.68),chlorite,and omphacite.Similar observations were made on the magmatic cores of zircon from the pyrope quartzite.These are about 275 Ma in age and host pyrope,phengite(Si3.55),talc,and kyanite,all of which formed during UHP metamorphism at about 35 Ma.Zircon from the biotite-phengite-gneiss country rock(metagranite)shows oscillatory zoning and yields ages that are identical to those of the magmatic cores of zircon from pyrope quartzite,which thus reflect granitic intrusion ages.The country-rock zircon also encloses metamorphic minerals with ages of about 35 Ma.Such minerals are,for example,garnet and phengite,as well as a polymineralic assemblage of clinopyroxene+garnet+phengite+quartz,that point to formation at UHP metamorphic conditions around 40 kbar/750℃.Based on these examples we suggest an effective approach centered on key evidence from CL studies to show that magmatic domains of zircon may actually contain pseudo-inclusions which were not entrapped during an early stage of formation,but were instead introduced during later metamorphic or metasomatic events along microcracks representing pathways for fluid influx.Cathodoluminescence microscopy is thus an excellent tool for avoiding such pitfalls by allowing distinction between true inclusions and pseudo-inclusions in zircon.展开更多
Engine-variable pump-variable motor drive system is a complex nonlinear system. In order to improve system response speed and stability,a sliding-mode variable-structure control based on a feedback linearization theor...Engine-variable pump-variable motor drive system is a complex nonlinear system. In order to improve system response speed and stability,a sliding-mode variable-structure control based on a feedback linearization theory is analyzed in this research. A standardized system model is established and linearized by the feedback linearization theory,and the input dimension is reduced through the relationship between variables which has simplified the linearization process. Then the sliding-mode controller using an exponential reaching law is designed and the Lyapunov stability of this algorithm is verified. The simulation results show that the sliding-mode variable-structure controller based on the feedback linearization theory can improve system response speed,reduce overshoot and achieve stronger robustness,so the vehicle speed control requirements can be satisfied well.展开更多
Cytochrome P-450 is widely distributed in different species of animals. As a terminal oxidase ot the microsomal monooxygenase system, cytochrome P-450 is the key element of the enzyme system. Because of its broad subs...Cytochrome P-450 is widely distributed in different species of animals. As a terminal oxidase ot the microsomal monooxygenase system, cytochrome P-450 is the key element of the enzyme system. Because of its broad substrate specificity, it is involved in the biotransformation of many xenobiotic and endogenous compounds which are important in envitonmental protection, pharmacology and carcinogenicity. Microsomal P-450 is also a展开更多
文摘针对目前基于属性的可搜索加密方案存在密钥泄露以及不支持属性撤销的问题,提出了一种云环境下,安全高效、可支持属性撤销的基于CP-ABE(ciphertext-policy attribute based encryption)的可搜索加密方案。该方案不仅可支持细粒度的访问控制,具有较高的计算效率,且用户密钥使用随机值盲化后提交服务器,保证了用户密钥的保密性和安全性。该方案支持用户属性的撤销,并在属性撤销过程中,将密文更新的大部分工作转移给云服务提供商完成,方案在保证安全性的前提下,进一步降低了用户的计算代价。方案的安全性基于DL(decisional linear)假设,在通用模型下具有选择明文攻击安全,抗合谋攻击,前向安全和后向安全。
文摘Monoclonal antibody (MAb) to rat liver cyto-chrome P-450j isozyme, an activating enzyme specific to nitrosamine metabolism, was used coupled with immunoblotting, densitometer scanning of SDS-PAGE gels and immunohistochemical technique. The trace P-450HSj isozyme (Mr. 51.5 Kd) was found in human gastric mucosa. It was similar to P-450j in molecular weight, catalytic and immunochemical properties. The concentrations of P-450HSj in mucosa of lesser curvature were higher than those in greater curvature. This might be one of the important reasons that lesser curvature is the commonest area for gastric carcinoma. But there was possibly less P-450HSj in gastric mucosa with cancer. Im-munohistochemically, P-450HSj was discovered in the cytoplasm of some glandular epithelial cells, especially in the glands with hyperplastic and intestinal metaplastic changes adjacent to carcinoma. It was also found in some normal glands and in tumor cells of high-differentiated adenocarcinoma, but not in those of low-differentiated ones. Following subjects are discussed: (1) the method of detecting trace P-450HSj, (2) the rule of distribution of P-450HSj, and (3) the relationship between the isozyme and the occurrence of gastric cancer caused by nitrosa-mines.
文摘目的探讨慢性阻塞性肺疾病(简称慢阻肺)伴或不伴低氧血症患者血清单核细胞趋化蛋白-1(MCP-1)、血清淀粉样蛋白A(SAA)水平与认知功能的关系,以期为慢阻肺患者筛查预测早期认知功能损伤的血清学指标,同时探讨低氧血症在认知障碍发生中的作用。方法纳入2013年1月至2017年1月于华北理工大学附属医院住院的62例慢阻肺患者,依据血气分析将其分为慢阻肺缺氧组(25例)和慢阻肺无缺氧组(37例),同期30例健康体检人群为对照组。采用酶联免疫吸附法测定慢阻肺患者及对照人群血清MCP-1、SAA浓度,逆转录聚合酶链反应检测外周血单核细胞中MCP-1、SAA的m RNA表达水平,应用蒙特利尔认知评估量表(Mo CA量表)进行认知功能测定。分析三组人群在血清MCP-1、SAA水平及外周血MCP-1 m RNA、SAA m RNA水平表达有无差异及与认知功能损伤的关系。结果血清MCP-1、SAA水平及外周血单核细胞MCP-1 m RNA、SAA m RNA水平表达水平趋势一致,慢阻肺患者血清MCP-1、SAA水平及外周血单核细胞MCP-1 m RNA、SAA m RNA水平高于健康对照组,差异有统计学意义(均P<0.05);慢阻肺缺氧组和慢阻肺无缺氧组Mo CA评分总分较对照组低,其中缺氧组Mo CA评分降低更明显,差异有统计学意义(均P<0.05)。血清SAA、MCP-1水平及外周血单核细胞MCP-1 m RNA、SAA m RNA水平与Mo CA总分呈负相关(均P<0.05)。结论慢阻肺患者血清SAA、MCP-1水平及外周血单核细胞MCP-1 m RNA、SAA m RNA水平高低与患者认知障碍程度呈正相关,低氧血症可能是慢阻肺患者发生认知功能受损的因素之一。
基金financially supported by the German Research Foundation (No. SCHE-517/10-1)
文摘This paper shows how a faulty approach to the study of mineral inclusions in zircon can lead to misleading interpretations of the geological context.We present and discuss two well-documented examples.Zircon grains separated from HP metamorphic jadeitite of the Rio San Juan Complex,Dominican Republic,and from UHP pyrope quartzite of the Dora Maira Massif,northern Italy,were studied using cathodoluminescence(CL)techniques,in combination with mineral inclusion and age data.In general,zircon from both localities shows inherited magmatic core domains with oscillatory zoning and metamorphic rims.The magmatic cores of zircon from the jadeitite yield ages of 115–117 Ma and host jadeite and omphacite which are of metamorphic origin and formed at about 78 Ma.Zircon from lawsonite blueschist,representing the country rock of the jadeitite,contains domains with oscillatory zoning that are nearly identical in age to the zircon cores from the adjacent jadeitite,and also contains younger metamorphic minerals such as lawsonite,albite,phengite(Si3.68),chlorite,and omphacite.Similar observations were made on the magmatic cores of zircon from the pyrope quartzite.These are about 275 Ma in age and host pyrope,phengite(Si3.55),talc,and kyanite,all of which formed during UHP metamorphism at about 35 Ma.Zircon from the biotite-phengite-gneiss country rock(metagranite)shows oscillatory zoning and yields ages that are identical to those of the magmatic cores of zircon from pyrope quartzite,which thus reflect granitic intrusion ages.The country-rock zircon also encloses metamorphic minerals with ages of about 35 Ma.Such minerals are,for example,garnet and phengite,as well as a polymineralic assemblage of clinopyroxene+garnet+phengite+quartz,that point to formation at UHP metamorphic conditions around 40 kbar/750℃.Based on these examples we suggest an effective approach centered on key evidence from CL studies to show that magmatic domains of zircon may actually contain pseudo-inclusions which were not entrapped during an early stage of formation,but were instead introduced during later metamorphic or metasomatic events along microcracks representing pathways for fluid influx.Cathodoluminescence microscopy is thus an excellent tool for avoiding such pitfalls by allowing distinction between true inclusions and pseudo-inclusions in zircon.
基金Supported by the National Natural Science Foundation of China(No.51275126)the China Aerospace Science and Technology CorporationHarbin Institute of Technology Joint Technical Innovation Center Fund Project(CASC-HIT15-1A04)
文摘Engine-variable pump-variable motor drive system is a complex nonlinear system. In order to improve system response speed and stability,a sliding-mode variable-structure control based on a feedback linearization theory is analyzed in this research. A standardized system model is established and linearized by the feedback linearization theory,and the input dimension is reduced through the relationship between variables which has simplified the linearization process. Then the sliding-mode controller using an exponential reaching law is designed and the Lyapunov stability of this algorithm is verified. The simulation results show that the sliding-mode variable-structure controller based on the feedback linearization theory can improve system response speed,reduce overshoot and achieve stronger robustness,so the vehicle speed control requirements can be satisfied well.
文摘Cytochrome P-450 is widely distributed in different species of animals. As a terminal oxidase ot the microsomal monooxygenase system, cytochrome P-450 is the key element of the enzyme system. Because of its broad substrate specificity, it is involved in the biotransformation of many xenobiotic and endogenous compounds which are important in envitonmental protection, pharmacology and carcinogenicity. Microsomal P-450 is also a
