After gene mutation, the pcDNA3.1/APP595/596 plasmid was transfected into HEK293 cells to establish a cell model of Alzheimer＇s disease. The cell model was treated with donepezil or compound Danshen tablets after cul...After gene mutation, the pcDNA3.1/APP595/596 plasmid was transfected into HEK293 cells to establish a cell model of Alzheimer＇s disease. The cell model was treated with donepezil or compound Danshen tablets after culture for 72 hours. Reverse transcription-PCR showed that the mRNA expression of amyloid protein precursor decreased in all groups following culture for 24 hours, and that there was no significant difference in the amount of decrease between donepezil and compound Danshen tablets. Our results suggest that compound Danshen tablets can reduce expression of the mRNA for amyloid protein precursor in a transgenic cell model of Alzheimer＇s disease, with similar effects to donepezil.展开更多
Based on the research of computer model on unified seismogenic process of grouped earthquakes in tectonic blockunder tectonodynamic force, some characteristics of seismic activity and some features of earthquake precu...Based on the research of computer model on unified seismogenic process of grouped earthquakes in tectonic blockunder tectonodynamic force, some characteristics of seismic activity and some features of earthquake precursoryfield have been studied, including activity of grouped earthquakes, the relationship between earthquake activityand earthquake precursors, the cause of earthquake precursors and so on. By comparing research between the results of theoretical model and practical earthquake cases, some physical explanation for seismogenic process,some characteristics of earthquake activity, and the features of earthquake precursory field have been given.展开更多
In this study, the initial perturbations that are the easiest to trigger the Kuroshio Extension （KE） transition connecting a basic weak jet state and a strong, fairly stable meandering state, are investigated using ...In this study, the initial perturbations that are the easiest to trigger the Kuroshio Extension （KE） transition connecting a basic weak jet state and a strong, fairly stable meandering state, are investigated using a reduced-gravity shallow water ocean model and the CNOP （Conditional Nonlinear Optimal Perturbation） approach. This kind of initial perturbation is called an optimal precursor （OPR）. The spatial structures and evolutionary processes of the OPRs are analyzed in detail. The results show that most of the OPRs are in the form of negative sea surface height （SSH） anomalies mainly located in a narrow band region south of the KE jet, in basic agreement with altimetric observations. These negative SSH anomalies reduce the merid- ional SSH gradient within the KE, thus weakening the strength of the jet. The KE jet then becomes more convoluted, with a high-frequency and large-amplitude variability corresponding to a high eddy kinetic energy level; this gradually strengthens the KE jet through an inverse energy cascade. Eventually, the KE reaches a high-energy state characterized by two well defined and fairly stable anticyclonic meanders. Moreover, sensitivity experiments indicate that the spatial structures of the OPRs are not sensitive to the model parameters and to the optimization times used in the analysis.展开更多
Based on the theoretical expression of the three-dimension rheologic inclusion model, we analyze in detail the spatio-temporal changes on the ground of the bulk-strain produced by a spherical rheologic inclusion in a ...Based on the theoretical expression of the three-dimension rheologic inclusion model, we analyze in detail the spatio-temporal changes on the ground of the bulk-strain produced by a spherical rheologic inclusion in a semi-infinite rheologic medium. The results show that the spatio-temporal change of bulk-strain produced by the hard inclusion has three stages of different characteristics, which are similar to most of those geodetic deformation curves, but those by a soft inclusion do not. The α-stage is a long stage in which the precursors in both the near source region and the far field develop from the focal region to the periphery. The β-stage indicates a very rapid propagation of the precursors, so that they almost appear everywhere. During the γ-stage, the precursors in the far-field converge from the periphery, and the precursors in the near source region develop outwards. The theoretical results have been used to explain tentatively the stage characteristics of the spatio-temporal change of earthquake precursors.展开更多
Concentration and source rate of precursor vapors participating in particle formation and subsequent growth were investigated during the Pearl River Delta intensive campaign （PRD2004, October 2004） in southeastern C...Concentration and source rate of precursor vapors participating in particle formation and subsequent growth were investigated during the Pearl River Delta intensive campaign （PRD2004, October 2004） in southeastern China. Four new particle formation event days and a typical non-event day were selected for our analysis. Atmospheric sulphuric acid, the important precursor vapor in nucleation and growth, were simulated with a pseudo steady-state model based on the measurements of SO2, NOx, 03, CO, non-methane hydrocarbon （NMHC） and ambient particle number concentrations as well as modeled photolysis frequencies obtained from measurements. The maximum midday sulphuric acid concentrations vary from 4.53 × 10^7 to 2.17 × 10^8 molecules cm^-3, the corresponding source rate via reaction of OH and SO2 range between 2.37 × 10^6 and 1.16 × 10^7 molecules cm^-3 s^-1. Nucleation mode growth rate was derived from size spectral evolution during the events to be 6.8-13.8 nm h^-1. Based on the growth rate, concentration of the vapors participating in subsequent growth were estimated to vary from 1.32 × 10^8 to 2.80 × 10^8 molecules cm^-3 with corresponding source rate between 7.26 × 10^6 and 1.64 × 10^7 molecules cm^-3 s^-1. Our results show the degree of pollution is larger in PRD. Sulphuric acid concentrations are fairly high and have a close correlation with new particle formation events. Budget analysis shows that sulphuric acid alone is not enough for required growth; other nonvolatile vapors are needed. However, sulphuric acid plays an important role in growth; the contribution of sulphuric acid to growth in PRD is 12.4%-65.2%.展开更多
Spatial scanning is done for two regions in Chinese Mainland,where displayed a denseprecursory network during 1994～1998.The two regions are the mid-southern segment of theNorth-south seismic belt(20°～35°N,...Spatial scanning is done for two regions in Chinese Mainland,where displayed a denseprecursory network during 1994～1998.The two regions are the mid-southern segment of theNorth-south seismic belt(20°～35°N,95°～110°E)and North China(36°～42°N,110°～120°E).We took 0.5°×0.5°as a spatial window with a step of 0.25°and 4 months as atemporal window with a step of 1 month.For the two regions,the anomaly density is scannedfrom 1994 and 1995 respectively in the two regions.The precursory anomalies are all fromthe Division of Seismic Trend in China and the Division of Seismic Trend in the Capital Area,Center for Analysis and Prediction,China Seismological Bureau.A seismogenic tectonicmodel is introduced to explain the scanning results.In the model,the frictional strength ofthe focal sources is distributed randomly.After the boundary plate motion rate and all othergeological parameters are given,the stress of the sources in the system changesinhomogenously due to the variation of the frictional展开更多
Different tectonic elements may play different roles and their deformation styles and types of anomalies are also different in the process of deformation.Such differences may be the cause of the phenomena of the depar...Different tectonic elements may play different roles and their deformation styles and types of anomalies are also different in the process of deformation.Such differences may be the cause of the phenomena of the departure from the region with obvious anomalies from the coming epicenter,which are called "departure of precursors from epicenter." From some new experimental and numerical modeling results,five types of deformation elements are identified according to their roles in the process of deformation in a region.They are the brake(or locked),slip,yield,sensitive,and valve elements.Spatial distribution of different elements,especially sensitive and slip elements,are discussed by taking the bend fault,extension,compression,and complex en-echelon faults as examples.These elements with different roles may overlap each other in some cases or be separated in other cases.It is obvious that for different fault geometry,the spatial layout of these elements is different and thus the position and style of展开更多
In this work, we present results of an investigation of environmental precursors of infectious epidemic of dengue fever in the Metropolitan Area of Rio de Janeiro, RJ, Brazil, obtained by a numerical model with repres...In this work, we present results of an investigation of environmental precursors of infectious epidemic of dengue fever in the Metropolitan Area of Rio de Janeiro, RJ, Brazil, obtained by a numerical model with representation of infection and reinfection of the population. The period considered extend between 2000 and 2011, in which it was possible to pair meteorological data and the reporting of dengue patients worsening. These data should also be considered in the numerical model, by assimilation, to obtain simulations of Dengue epidemics. The model contains compartments for the human population, for the vector Aedes aegypti and four virus serotypes. The results provide consistent evidence that worsening infection and disease outbreaks are due to the occurrence of environmental precursors, as the dynamics of the accumulation of water in the breeding and energy availability in the form of metabolic activation enthalpy during pre-epidemic periods.展开更多
基金supported by the Bureau of Traditional Chinese Medicine of Guangdong Province, No. 2010463the National Science and Technology"12~(th) Five-years"Major Special-purpose Foundation,No.2011ZX09201-201-01
文摘After gene mutation, the pcDNA3.1/APP595/596 plasmid was transfected into HEK293 cells to establish a cell model of Alzheimer＇s disease. The cell model was treated with donepezil or compound Danshen tablets after culture for 72 hours. Reverse transcription-PCR showed that the mRNA expression of amyloid protein precursor decreased in all groups following culture for 24 hours, and that there was no significant difference in the amount of decrease between donepezil and compound Danshen tablets. Our results suggest that compound Danshen tablets can reduce expression of the mRNA for amyloid protein precursor in a transgenic cell model of Alzheimer＇s disease, with similar effects to donepezil.
文摘Based on the research of computer model on unified seismogenic process of grouped earthquakes in tectonic blockunder tectonodynamic force, some characteristics of seismic activity and some features of earthquake precursoryfield have been studied, including activity of grouped earthquakes, the relationship between earthquake activityand earthquake precursors, the cause of earthquake precursors and so on. By comparing research between the results of theoretical model and practical earthquake cases, some physical explanation for seismogenic process,some characteristics of earthquake activity, and the features of earthquake precursory field have been given.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41576015, 41306023, 41490644 and 41490640)the Natural Science Foundation Of China (NSFC) Innovative Group (Grant No. 41421005)+1 种基金the NSFC–Shandong Joint Fund for Marine Science Research Centers (Grant No. U1406401)support from the University of Naples Parthenope (Grant No. DSTE315)
文摘In this study, the initial perturbations that are the easiest to trigger the Kuroshio Extension （KE） transition connecting a basic weak jet state and a strong, fairly stable meandering state, are investigated using a reduced-gravity shallow water ocean model and the CNOP （Conditional Nonlinear Optimal Perturbation） approach. This kind of initial perturbation is called an optimal precursor （OPR）. The spatial structures and evolutionary processes of the OPRs are analyzed in detail. The results show that most of the OPRs are in the form of negative sea surface height （SSH） anomalies mainly located in a narrow band region south of the KE jet, in basic agreement with altimetric observations. These negative SSH anomalies reduce the merid- ional SSH gradient within the KE, thus weakening the strength of the jet. The KE jet then becomes more convoluted, with a high-frequency and large-amplitude variability corresponding to a high eddy kinetic energy level; this gradually strengthens the KE jet through an inverse energy cascade. Eventually, the KE reaches a high-energy state characterized by two well defined and fairly stable anticyclonic meanders. Moreover, sensitivity experiments indicate that the spatial structures of the OPRs are not sensitive to the model parameters and to the optimization times used in the analysis.
文摘Based on the theoretical expression of the three-dimension rheologic inclusion model, we analyze in detail the spatio-temporal changes on the ground of the bulk-strain produced by a spherical rheologic inclusion in a semi-infinite rheologic medium. The results show that the spatio-temporal change of bulk-strain produced by the hard inclusion has three stages of different characteristics, which are similar to most of those geodetic deformation curves, but those by a soft inclusion do not. The α-stage is a long stage in which the precursors in both the near source region and the far field develop from the focal region to the periphery. The β-stage indicates a very rapid propagation of the precursors, so that they almost appear everywhere. During the γ-stage, the precursors in the far-field converge from the periphery, and the precursors in the near source region develop outwards. The theoretical results have been used to explain tentatively the stage characteristics of the spatio-temporal change of earthquake precursors.
基金China National Basic Research and Development Program （Grant Nos. 2002CB410801, 2002CB211605） National Natural Science Foundation of China （Grant No. 40405025）.
文摘Concentration and source rate of precursor vapors participating in particle formation and subsequent growth were investigated during the Pearl River Delta intensive campaign （PRD2004, October 2004） in southeastern China. Four new particle formation event days and a typical non-event day were selected for our analysis. Atmospheric sulphuric acid, the important precursor vapor in nucleation and growth, were simulated with a pseudo steady-state model based on the measurements of SO2, NOx, 03, CO, non-methane hydrocarbon （NMHC） and ambient particle number concentrations as well as modeled photolysis frequencies obtained from measurements. The maximum midday sulphuric acid concentrations vary from 4.53 × 10^7 to 2.17 × 10^8 molecules cm^-3, the corresponding source rate via reaction of OH and SO2 range between 2.37 × 10^6 and 1.16 × 10^7 molecules cm^-3 s^-1. Nucleation mode growth rate was derived from size spectral evolution during the events to be 6.8-13.8 nm h^-1. Based on the growth rate, concentration of the vapors participating in subsequent growth were estimated to vary from 1.32 × 10^8 to 2.80 × 10^8 molecules cm^-3 with corresponding source rate between 7.26 × 10^6 and 1.64 × 10^7 molecules cm^-3 s^-1. Our results show the degree of pollution is larger in PRD. Sulphuric acid concentrations are fairly high and have a close correlation with new particle formation events. Budget analysis shows that sulphuric acid alone is not enough for required growth; other nonvolatile vapors are needed. However, sulphuric acid plays an important role in growth; the contribution of sulphuric acid to growth in PRD is 12.4%-65.2%.
基金This project was sponsored by the China Seismological Bureau(95-04-03-03-02)
文摘Spatial scanning is done for two regions in Chinese Mainland,where displayed a denseprecursory network during 1994～1998.The two regions are the mid-southern segment of theNorth-south seismic belt(20°～35°N,95°～110°E)and North China(36°～42°N,110°～120°E).We took 0.5°×0.5°as a spatial window with a step of 0.25°and 4 months as atemporal window with a step of 1 month.For the two regions,the anomaly density is scannedfrom 1994 and 1995 respectively in the two regions.The precursory anomalies are all fromthe Division of Seismic Trend in China and the Division of Seismic Trend in the Capital Area,Center for Analysis and Prediction,China Seismological Bureau.A seismogenic tectonicmodel is introduced to explain the scanning results.In the model,the frictional strength ofthe focal sources is distributed randomly.After the boundary plate motion rate and all othergeological parameters are given,the stress of the sources in the system changesinhomogenously due to the variation of the frictional
文摘Different tectonic elements may play different roles and their deformation styles and types of anomalies are also different in the process of deformation.Such differences may be the cause of the phenomena of the departure from the region with obvious anomalies from the coming epicenter,which are called "departure of precursors from epicenter." From some new experimental and numerical modeling results,five types of deformation elements are identified according to their roles in the process of deformation in a region.They are the brake(or locked),slip,yield,sensitive,and valve elements.Spatial distribution of different elements,especially sensitive and slip elements,are discussed by taking the bend fault,extension,compression,and complex en-echelon faults as examples.These elements with different roles may overlap each other in some cases or be separated in other cases.It is obvious that for different fault geometry,the spatial layout of these elements is different and thus the position and style of
文摘In this work, we present results of an investigation of environmental precursors of infectious epidemic of dengue fever in the Metropolitan Area of Rio de Janeiro, RJ, Brazil, obtained by a numerical model with representation of infection and reinfection of the population. The period considered extend between 2000 and 2011, in which it was possible to pair meteorological data and the reporting of dengue patients worsening. These data should also be considered in the numerical model, by assimilation, to obtain simulations of Dengue epidemics. The model contains compartments for the human population, for the vector Aedes aegypti and four virus serotypes. The results provide consistent evidence that worsening infection and disease outbreaks are due to the occurrence of environmental precursors, as the dynamics of the accumulation of water in the breeding and energy availability in the form of metabolic activation enthalpy during pre-epidemic periods.
