Accelerate processor, efficient software and pervasive connections provide sensor nodes with more powerful computation and storage ability, which can offer various services to user. Based on these atomic services, dif...Accelerate processor, efficient software and pervasive connections provide sensor nodes with more powerful computation and storage ability, which can offer various services to user. Based on these atomic services, different sensor nodes can cooperate and compose with each other to complete more complicated tasks for user. However, because of the regional characteristic of sensor nodes, merging data with different sensitivities become a primary requirement to the composite services, and information flow security should be intensively considered during service composition. In order to mitigate the great cost caused by the complexity of modeling and the heavy load of single-node verification to the energy-limited sensor node, in this paper, we propose a new distributed verification framework to enforce information flow security on composite services of smart sensor network. We analyze the information flows in composite services and specify security constraints for each service participant. Then we propose an algorithm over the distributed verification framework involving each sensor node to participate in the composite service verification based on the security constraints. The experimental results indicate that our approach can reduce the cost of verification and provide a better load balance.展开更多
DEAR EDITOR,Major depressive disorder (MDD), commonly known as depression, is a mental disease characterized by a core symptom of low mood. It lasts at least two weeks (Badamasi et al., 2019;Wang et al., 2019) and is ...DEAR EDITOR,Major depressive disorder (MDD), commonly known as depression, is a mental disease characterized by a core symptom of low mood. It lasts at least two weeks (Badamasi et al., 2019;Wang et al., 2019) and is frequently accompanied by low self-esteem, loss of interest in routinely enjoyable activities, low energy, and unexplained pain (Huey et al., 2018;Park et al., 2012;Post & Warden, 2018;Rice et al., 2019;Xiao et al., 2018). Approximately 2%–8% of adults with MDD commit suicide (Richards & O'Hara, 2014;Strakowski & Nelson, 2015), and around half of suicidal individuals suffer depression or other mood disorders (Bachmann, 2018).展开更多
In cloud computing,fairness is one of the most significant indicators to evaluate resource allocation algorithms,which reveals whether each user is allocated as much as that of all other users having the same bottlene...In cloud computing,fairness is one of the most significant indicators to evaluate resource allocation algorithms,which reveals whether each user is allocated as much as that of all other users having the same bottleneck.However,how fair an allocation algorithm is remains an urgent issue.In this paper,we propose Dynamic Evaluation Framework for Fairness(DEFF),a framework to evaluate the fairness of an resource allocation algorithm.In our framework,two sub-models,Dynamic Demand Model(DDM) and Dynamic Node Model(DNM),are proposed to describe the dynamic characteristics of resource demand and the computing node number under cloud computing environment.Combining Fairness on Dominant Shares and the two sub-models above,we finally obtain DEFF.In our experiment,we adopt several typical resource allocation algorithms to prove the effectiveness on fairness evaluation by using the DEFF framework.展开更多
The invention of atomic force microscopy(AFM) has provided new technology for measuring specific molecular interaction forces.Using AFM single-molecule force spectroscopy(SMFS) techniques,CD20-Rimximab rupture forces ...The invention of atomic force microscopy(AFM) has provided new technology for measuring specific molecular interaction forces.Using AFM single-molecule force spectroscopy(SMFS) techniques,CD20-Rimximab rupture forces were measured on purified CD20 proteins,Raji cells,and lymphoma patient B cells.Rimximab molecules were linked onto AFM tips using AFM probe functionalization technology,and purified CD20 proteins were attached to mica using substrate functionalization technology.Raji cells(a lymphoma cell line) or lymphoma patient cells were immobilized on a glass substrate via electrostatic adsorption and chemical fixation.The topography of the purified CD20 proteins,Raji cells,and patient lymphoma cells was visualized using AFM imaging and the differences in the rupture forces were analyzed and measured.The results showed that the rupture forces between the CD20 proteins on Raji cells and Rituximab were markedly smaller than those for purified CD20 proteins and CD20 proteins on lymphoma patient B cells.These findings provide an effective experimental method for investigating the mechanisms underlying the variable efficacy of Rituximab.展开更多
Probe anodic oxidation by atomic force microscope (AFM) is one of the most important techniques in fabricating nano structures and devices. The technique was further studied in this paper. By analyzing the distributio...Probe anodic oxidation by atomic force microscope (AFM) is one of the most important techniques in fabricating nano structures and devices. The technique was further studied in this paper. By analyzing the distribution of the electric field on substrate surface the dependence of oxide characters on field was discussed. The impacts of various parameters on oxide fabrication were experimentally studied. Based on these studies, we realized the oxidative cutting and welding of carbon nanotube (CNT) by the AFM based oxidation technique and provided a novel technique for the assembly and fabrication of CNT based nano devices.展开更多
Elucidating the underlying mechanisms of cell physiology is currently an important research topic in life sciences. Atomic force microscopy methods can be used to investigate these molecular mechanisms. In this study,...Elucidating the underlying mechanisms of cell physiology is currently an important research topic in life sciences. Atomic force microscopy methods can be used to investigate these molecular mechanisms. In this study, single-molecule force spectroscopy was used to explore the specific recognition between the CD20 antigen and anti-CD20 antibody Rituximab on B lymphoma cells under near-physiological conditions. The CD20-Rituximab specific binding force was measured through tip functionalization. Distribution of CD20 on the B lymphoma cells was visualized three-dimensionally. In addition, the relationship between the intramolecular force and the molecular extension of the CD20-Rituximab complex was analyzed under an external force. These results facilitate further investigation of the mechanism of Rituximab’s anti-cancer effect.展开更多
天然高分子水凝胶以其良好的生物相容性以及生物可降解性在生物医学领域得到了广泛应用,然而由于缺乏合适的观测手段,目前对于纳米尺度下天然状态水凝胶的精细结构及其特性仍然不完全清楚.原子力显微镜(atomic force microscopy,AFM)的...天然高分子水凝胶以其良好的生物相容性以及生物可降解性在生物医学领域得到了广泛应用,然而由于缺乏合适的观测手段,目前对于纳米尺度下天然状态水凝胶的精细结构及其特性仍然不完全清楚.原子力显微镜(atomic force microscopy,AFM)的出现为生物材料研究提供了新的强大技术手段,但目前利用AFM对天然高分子水凝胶纳米结构进行原位成像的研究还较为缺乏.本文利用AFM对4种不同类型食虫植物(茅膏菜、捕虫堇、瓶子草、捕蝇草)分泌的天然水凝胶黏液的结构进行了高分辨率原位成像与分析.分别将茅膏菜黏液和捕虫堇黏液平铺至云母表面,在空气中进行的AFM成像结果清晰地显示,茅膏菜黏液和捕虫堇黏液中均含有大量纳米纤维结构,且纳米纤维自组装行为具有多样性.分别将瓶子草黏液和捕蝇草黏液平铺至载玻片表面,在去离子水溶液中进行的AFM成像结果揭示了瓶子草黏液和捕蝇草黏液中均含有大量纳米颗粒,对纳米颗粒进行的统计分析显示,捕蝇草黏液中的纳米颗粒尺寸显著大于瓶子草黏液中纳米颗粒的尺寸.研究结果加深了人们对食虫植物分泌的天然水凝胶黏液的认识,为天然生物材料精细纳米结构研究提供了新的方法和视角.展开更多
生物黏液在生命活动过程中起着重要的调控作用,然而由于缺少合适的观测手段,目前对于天然状态下生物黏液功能界面超微结构的认知还很不足.原子力显微镜(atomic force microscopy,AFM)的出现为原位研究生物材料的结构和特性提供了新的强...生物黏液在生命活动过程中起着重要的调控作用,然而由于缺少合适的观测手段,目前对于天然状态下生物黏液功能界面超微结构的认知还很不足.原子力显微镜(atomic force microscopy,AFM)的出现为原位研究生物材料的结构和特性提供了新的强大工具,但现有的研究主要在空气环境下进行观测,研究结果难以完全反映溶液状态下的生物材料结构.本文以食虫植物茅膏菜分泌的黏液为研究对象,利用AFM直接在液相环境下实现了对生物黏液纳米结构的高分辨率成像及分析.分别将茅膏菜黏液平铺至载玻片和云母表面,在溶液环境下的AFM成像结果显示茅膏菜黏液中含有大量纳米颗粒.作为对照,在空气中进行的AFM成像结果显示干燥后的茅膏菜黏液中含有大量纳米纤维结构,表明了茅膏菜黏液在空气环境下与溶液环境下的结构差异.进一步利用AFM多参数成像方法对溶液环境下茅膏菜黏液纳米颗粒和纳米纤维的机械特性进行了可视化表征并揭示了纳米颗粒和纳米纤维机械特性的显著差异.研究结果为生物黏液功能界面超微结构原位成像及机械特性研究提供了新的方法和思路,对于生物材料研究具有广泛的基础意义.展开更多
Mechanical properties play an important role in regulating cellular activities and are critical for unlocking the mysteries of life. Atomic force microscopy (AFM) enables researchers to measure mechanical properties o...Mechanical properties play an important role in regulating cellular activities and are critical for unlocking the mysteries of life. Atomic force microscopy (AFM) enables researchers to measure mechanical properties of single living cells under physiological conditions. Here, AFM was used to investigate the topography and mechanical properties of red blood cells (RBCs) and three types of aggressive cancer cells (Burkitt's lymphoma Raji, cutaneous lymphoma Hut, and chronic myeloid leukemia K562). The surface topography of the RBCs and the three cancer cells was mapped with a conventional AFM probe, while mechanical properties were investigated with a microsphere glued onto a tip-less cantilever. The diameters of RBCs are significantly smaller than those of the cancer cells, and mechanical measurements indicated that Young's modulus of RBCs is smaller than those of the cancer cells. Aggressive cancer cells have a lower Young's modulus than that of indolent cancer cells, which may improve our understanding of metastasis.展开更多
基金supported in part by National Natural Science Foundation of China(61502368,61303033,U1135002 and U1405255)the National High Technology Research and Development Program(863 Program)of China(No.2015AA017203)+1 种基金the Fundamental Research Funds for the Central Universities(XJS14072,JB150308)the Aviation Science Foundation of China(No.2013ZC31003,20141931001)
文摘Accelerate processor, efficient software and pervasive connections provide sensor nodes with more powerful computation and storage ability, which can offer various services to user. Based on these atomic services, different sensor nodes can cooperate and compose with each other to complete more complicated tasks for user. However, because of the regional characteristic of sensor nodes, merging data with different sensitivities become a primary requirement to the composite services, and information flow security should be intensively considered during service composition. In order to mitigate the great cost caused by the complexity of modeling and the heavy load of single-node verification to the energy-limited sensor node, in this paper, we propose a new distributed verification framework to enforce information flow security on composite services of smart sensor network. We analyze the information flows in composite services and specify security constraints for each service participant. Then we propose an algorithm over the distributed verification framework involving each sensor node to participate in the composite service verification based on the security constraints. The experimental results indicate that our approach can reduce the cost of verification and provide a better load balance.
基金supported by the National Natural Science Foundation of China(31700910)Applied Basic Research Programs of Science and Technology Commission Foundation of Yunnan Province(2017FB109)
文摘DEAR EDITOR,Major depressive disorder (MDD), commonly known as depression, is a mental disease characterized by a core symptom of low mood. It lasts at least two weeks (Badamasi et al., 2019;Wang et al., 2019) and is frequently accompanied by low self-esteem, loss of interest in routinely enjoyable activities, low energy, and unexplained pain (Huey et al., 2018;Park et al., 2012;Post & Warden, 2018;Rice et al., 2019;Xiao et al., 2018). Approximately 2%–8% of adults with MDD commit suicide (Richards & O'Hara, 2014;Strakowski & Nelson, 2015), and around half of suicidal individuals suffer depression or other mood disorders (Bachmann, 2018).
基金supported in part by Program for Changjiang Scholars and Innovative Research Team in University No.IRT1078The Key Program of NSFC-Guangdong Union Foundation No.U1135002The Fundamental Research Funds for the Central Universities No.JY0900120301
文摘In cloud computing,fairness is one of the most significant indicators to evaluate resource allocation algorithms,which reveals whether each user is allocated as much as that of all other users having the same bottleneck.However,how fair an allocation algorithm is remains an urgent issue.In this paper,we propose Dynamic Evaluation Framework for Fairness(DEFF),a framework to evaluate the fairness of an resource allocation algorithm.In our framework,two sub-models,Dynamic Demand Model(DDM) and Dynamic Node Model(DNM),are proposed to describe the dynamic characteristics of resource demand and the computing node number under cloud computing environment.Combining Fairness on Dominant Shares and the two sub-models above,we finally obtain DEFF.In our experiment,we adopt several typical resource allocation algorithms to prove the effectiveness on fairness evaluation by using the DEFF framework.
基金supported by the National Natural Science Foundation of China (60904095)National High Technology Research and Development Program of China (2009AAO3Z316)CAS FEA International Partnership Program for Creative Research Teams
文摘The invention of atomic force microscopy(AFM) has provided new technology for measuring specific molecular interaction forces.Using AFM single-molecule force spectroscopy(SMFS) techniques,CD20-Rimximab rupture forces were measured on purified CD20 proteins,Raji cells,and lymphoma patient B cells.Rimximab molecules were linked onto AFM tips using AFM probe functionalization technology,and purified CD20 proteins were attached to mica using substrate functionalization technology.Raji cells(a lymphoma cell line) or lymphoma patient cells were immobilized on a glass substrate via electrostatic adsorption and chemical fixation.The topography of the purified CD20 proteins,Raji cells,and patient lymphoma cells was visualized using AFM imaging and the differences in the rupture forces were analyzed and measured.The results showed that the rupture forces between the CD20 proteins on Raji cells and Rituximab were markedly smaller than those for purified CD20 proteins and CD20 proteins on lymphoma patient B cells.These findings provide an effective experimental method for investigating the mechanisms underlying the variable efficacy of Rituximab.
基金Supported by the National Natural Science Foundation of China (Grant No. 60635040)Nation High technology Research and Development Program of China ("863" Program) (Grant No. 2009AA03Z316)
文摘Probe anodic oxidation by atomic force microscope (AFM) is one of the most important techniques in fabricating nano structures and devices. The technique was further studied in this paper. By analyzing the distribution of the electric field on substrate surface the dependence of oxide characters on field was discussed. The impacts of various parameters on oxide fabrication were experimentally studied. Based on these studies, we realized the oxidative cutting and welding of carbon nanotube (CNT) by the AFM based oxidation technique and provided a novel technique for the assembly and fabrication of CNT based nano devices.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60904095 and 60635040)the National High Technology Research and Development Program of China (Grant No. 2009AA03Z316)the CAS FEA International Partnership Program for Creative Research Teams and the State Key Laboratory of Drug Research.
文摘Elucidating the underlying mechanisms of cell physiology is currently an important research topic in life sciences. Atomic force microscopy methods can be used to investigate these molecular mechanisms. In this study, single-molecule force spectroscopy was used to explore the specific recognition between the CD20 antigen and anti-CD20 antibody Rituximab on B lymphoma cells under near-physiological conditions. The CD20-Rituximab specific binding force was measured through tip functionalization. Distribution of CD20 on the B lymphoma cells was visualized three-dimensionally. In addition, the relationship between the intramolecular force and the molecular extension of the CD20-Rituximab complex was analyzed under an external force. These results facilitate further investigation of the mechanism of Rituximab’s anti-cancer effect.
文摘天然高分子水凝胶以其良好的生物相容性以及生物可降解性在生物医学领域得到了广泛应用,然而由于缺乏合适的观测手段,目前对于纳米尺度下天然状态水凝胶的精细结构及其特性仍然不完全清楚.原子力显微镜(atomic force microscopy,AFM)的出现为生物材料研究提供了新的强大技术手段,但目前利用AFM对天然高分子水凝胶纳米结构进行原位成像的研究还较为缺乏.本文利用AFM对4种不同类型食虫植物(茅膏菜、捕虫堇、瓶子草、捕蝇草)分泌的天然水凝胶黏液的结构进行了高分辨率原位成像与分析.分别将茅膏菜黏液和捕虫堇黏液平铺至云母表面,在空气中进行的AFM成像结果清晰地显示,茅膏菜黏液和捕虫堇黏液中均含有大量纳米纤维结构,且纳米纤维自组装行为具有多样性.分别将瓶子草黏液和捕蝇草黏液平铺至载玻片表面,在去离子水溶液中进行的AFM成像结果揭示了瓶子草黏液和捕蝇草黏液中均含有大量纳米颗粒,对纳米颗粒进行的统计分析显示,捕蝇草黏液中的纳米颗粒尺寸显著大于瓶子草黏液中纳米颗粒的尺寸.研究结果加深了人们对食虫植物分泌的天然水凝胶黏液的认识,为天然生物材料精细纳米结构研究提供了新的方法和视角.
文摘生物黏液在生命活动过程中起着重要的调控作用,然而由于缺少合适的观测手段,目前对于天然状态下生物黏液功能界面超微结构的认知还很不足.原子力显微镜(atomic force microscopy,AFM)的出现为原位研究生物材料的结构和特性提供了新的强大工具,但现有的研究主要在空气环境下进行观测,研究结果难以完全反映溶液状态下的生物材料结构.本文以食虫植物茅膏菜分泌的黏液为研究对象,利用AFM直接在液相环境下实现了对生物黏液纳米结构的高分辨率成像及分析.分别将茅膏菜黏液平铺至载玻片和云母表面,在溶液环境下的AFM成像结果显示茅膏菜黏液中含有大量纳米颗粒.作为对照,在空气中进行的AFM成像结果显示干燥后的茅膏菜黏液中含有大量纳米纤维结构,表明了茅膏菜黏液在空气环境下与溶液环境下的结构差异.进一步利用AFM多参数成像方法对溶液环境下茅膏菜黏液纳米颗粒和纳米纤维的机械特性进行了可视化表征并揭示了纳米颗粒和纳米纤维机械特性的显著差异.研究结果为生物黏液功能界面超微结构原位成像及机械特性研究提供了新的方法和思路,对于生物材料研究具有广泛的基础意义.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60904095 and 61175103)CAS FEA International Partnership Program for Creative Research Teams and the State Key Laboratory of Drug Research
文摘Mechanical properties play an important role in regulating cellular activities and are critical for unlocking the mysteries of life. Atomic force microscopy (AFM) enables researchers to measure mechanical properties of single living cells under physiological conditions. Here, AFM was used to investigate the topography and mechanical properties of red blood cells (RBCs) and three types of aggressive cancer cells (Burkitt's lymphoma Raji, cutaneous lymphoma Hut, and chronic myeloid leukemia K562). The surface topography of the RBCs and the three cancer cells was mapped with a conventional AFM probe, while mechanical properties were investigated with a microsphere glued onto a tip-less cantilever. The diameters of RBCs are significantly smaller than those of the cancer cells, and mechanical measurements indicated that Young's modulus of RBCs is smaller than those of the cancer cells. Aggressive cancer cells have a lower Young's modulus than that of indolent cancer cells, which may improve our understanding of metastasis.
