With the progress of plant genome research, more than 50 plant metallothionein_like (MT_L) genes have been found, but only several MT_L proteins have been detected and no experimental structural information for MT_L p...With the progress of plant genome research, more than 50 plant metallothionein_like (MT_L) genes have been found, but only several MT_L proteins have been detected and no experimental structural information for MT_L proteins has been reported so far. Since detailed knowledge of the protein tertiary structure is required to understand its biological function, a method is needed to determine the structure of these proteins. In this study, the structural data of known mammal MT was used to determine the interatomic distance constraints of the CXC and CXXC motifs and the metal_sulfur chelating cluster. Then several possible MT conformations were predicted using a distance geometry algorithm. The statistical analysis was used to select those with much lower target function values and lower conformation energies as the predicted tertiary structural models of the cysteine_rich (CR) domains of these proteins. A suitable prediction method for modeling the CR domain of the plant MT_L protein was constructed. The accurately predicted result for the known structure of an MT protein from blue crab suggests that this method is practicable. The tertiary structures of CR domains of rape MT_L protein LSC54 was then modeled with this method.展开更多
The discovery of intrinsically disordered proteins (IDP) (i.e., biologically active proteins that do not possess stable secondary and/or tertiary structures) came as an unexpected surprise, as the existence of suc...The discovery of intrinsically disordered proteins (IDP) (i.e., biologically active proteins that do not possess stable secondary and/or tertiary structures) came as an unexpected surprise, as the existence of such proteins is in contradiction to the traditional "sequence →structure →function" paradigm. Accurate prediction of a protein's predisposition to be intrinsically disordered is a necessary prerequisite for the further understanding of principles and mechanisms of protein folding and function, and is a key for the elaboration of a new structural and functional hierarchy of proteins. Therefore, prediction of IDPs has attracted the attention of many researchers, and a number of prediction tools have been developed. Predictions of disorder, in turn, are playing major roles in directing laboratory experiments that are leading to the discovery of ever more disordered proteins, and thereby leading to a positive feedback loop in the investigation of these proteins. In this review of algorithms for intrinsic disorder prediction, the basic concepts of various prediction methods for IDPs are summarized, the strengths and shortcomings of many of the methods are analyzed, and the difficulties and directions of future development of IDP prediction techniques are discussed.展开更多
After a systematic review of 38 current intelligent city evaluation systems (ICESs) from around the world, this research analyzes the secondary and tertiary indicators of these 38 ICESs from the perspec- tives of sc...After a systematic review of 38 current intelligent city evaluation systems (ICESs) from around the world, this research analyzes the secondary and tertiary indicators of these 38 ICESs from the perspec- tives of scale structuring, approaches and indicator selection, and determines their common base. From this base, the fundamentals of the City Intelligence Quotient (City IOD Evaluation System are developed and five dimensions are selected after a clustering analysis. The basic version, City IQ Evaluation System 1.0, involves 275 experts from 14 high-end research institutions, which include the Chinese Academy of Engineering, the National Academy of Science and Engineering (Germany), the Royal Swedish Academy of Engineering Sciences, the Planning Management Center of the Ministry of Housing and Urban-Rural Development of China, and the Development Research Center of the State Council of China. City IQ Evaluation System 2.0 is further developed, with improvements in its universality, openness, and dy- namic adjustment capability. After employing deviation evaluation methods in the IQ assessment, City IQ Evaluation System 3.0 was conceived. The research team has conducted a repeated assessment of 41 intelligent cities around the world using City IQ Evaluation System 3.0. The results have proved that the City IQ Evaluation System, developed on the basis of intelligent life, features more rational indicators selected from data sources that can offer better universality, openness, and dynamics, and is more sen- sitive and precise.展开更多
Based on a typical prototype of a soil slope in engineering practice, a numerical model of a three-stage soil slope supported by the anchor frame structure was established by means of FLAC3D code. The dynamic response...Based on a typical prototype of a soil slope in engineering practice, a numerical model of a three-stage soil slope supported by the anchor frame structure was established by means of FLAC3D code. The dynamic responses of three-stage soil slope and frame structure were studied by performing a series of bidirectional Wenchuan motions in terms of the failure mode of three-stage structure, the acceleration of soil slope, the displacement of frame structure, and the anchor stress of frame structure. The response accelerations in both horizontal and vertical directions are the most largely amplified at the slope top of each stage subjected to different shaking cases. The platforms among the stages reduce the amplification effect of response acceleration. The residual displacement of frame structure increases significantly as the intensity of shaking case increases. The frame structure at each stage presents a combined displacement mode consisting of a translation and a rotation around the vertex. The anchor stress of frame structure is mainly increased by the first intense pulse of Wenchuan seismic wave, and it is sensitive to the intensity of shaking case. The anchor stress of frame structure at the first stage is the most considerably enlarged by earthquake loading.展开更多
Based on introducing geological structure of Tanggu area, the authors analyzed the sedimentary environment of Paleogene Dongying Formation, and further analyzed its geothermal occurrence. The studied area spans two gr...Based on introducing geological structure of Tanggu area, the authors analyzed the sedimentary environment of Paleogene Dongying Formation, and further analyzed its geothermal occurrence. The studied area spans two grade IV tectonic units which are Beitang depression and Banqiao depression. The studied area is mainly located in the Tanggu nose-like structure which is the secondary structure of Beitang depression. Its existence affects the sedimentary distribution of the part strata of Paleogene. The depositions of Dongying Ⅲ ( SQEd3 ) and Dongying Ⅱ ( SQEd2 ) are mainly delta front facies and lake sand bars which are propitious to the geothermal fluid enrichment. The favorable enrichment region of geothermal fluid is located in south Hetou- Tanggu. Most of Dongying Ⅰ ( SQEd1 ) changes into swamp plain deposition, only the northeast part of this area is the distributary riverway facies with developed sand layers. There is the favorable enrichment region of geothermal fluid. The hydraulic connection is weak among the geothermal reservoirs of Dongying Formation and its overlying Guantao and Minghuazhen formations. The underlying Shahejie Formation geothermal reservoir pro- vides a steady stream of fluid supply and ground pressure protection for Dongying Formation geothermal reservoir.展开更多
The early universe inflation is well known as a promising theory to explain the origin of large-scale structure of universe and to solve the early universe pressing problems. For a reasonable inflation model, the pote...The early universe inflation is well known as a promising theory to explain the origin of large-scale structure of universe and to solve the early universe pressing problems. For a reasonable inflation model, the potential during inflation must be very flat, at least, in the direction of the inflaton. To construct the inflaton potential all the known related astrophysics observations should be included. For a general tree-level hybrid inflation potential, which is notdiscussed fully so far, the parameters in it are shown how to be constrained via the astrophysics data observed and to be obtained to the expected accuracy, and to be consistent with cosmology requirements.展开更多
The interactions between the new organometallic complexes, ferrocenesubstituted dithioocarborane conjugates (denoted as FcSB1, FcSB2 and FcSBCO) and hemoglobin (Hb) are investigated by electrochemistry, fluorescen...The interactions between the new organometallic complexes, ferrocenesubstituted dithioocarborane conjugates (denoted as FcSB1, FcSB2 and FcSBCO) and hemoglobin (Hb) are investigated by electrochemistry, fluorescence and UVvis absorption spectroscopy. The results demonstrate that FcSB1, FcSB2 and FcSBCO can bind to the heme iron center through the replacement of the weakly bound H20/02 in the distal heme pocket of Hb by their sulfur donor atoms, inducing the allosteric change from the R state (oxygenated conformation, relax) to T state (deoxygenated conformation, tense). The binding affinity is in the order of FcSBCO〉FeSB2〉FeSB1. Moreover, the fluorescence study illustrates that the three ferrocenecarborane conjugates differently affect the quarterly and tertiary structures as well as the polarity in the surrounding of the Trp and Tyr residues in Hb. Typically, FcSB2 mainly induces alterations of the microenvironment around the 1337Trp residue which is located on the cql32 interface of Hb. Such distinct influences are attributed to the structural features of FcSB1, FcSB2 and FcSBCO containing hydrophobic ferrocenyl and carboranyl units as well as C=O group. Screening the proteinbinding behavior can signify the potential bioactivity of such molecules and may be helpful in the future development of promising multifunctional metallodrugs.展开更多
The three-dimensional structure of mesoscale eddies in the western tropical Pacific(6°S–20°N, 120°E–150°E)is investigated using a high-resolution ocean model simulation. Eddy detection and eddy t...The three-dimensional structure of mesoscale eddies in the western tropical Pacific(6°S–20°N, 120°E–150°E)is investigated using a high-resolution ocean model simulation. Eddy detection and eddy tracking algorithms are applied to simulated horizontal velocity vectors, and the anticyclonic and cyclonic eddies identified are composited to obtain their three-dimensional structures. The mean lifetime of all long-lived eddies is about 52 days, and their mean diameter is 147 km. Two typical characteristics of mesoscale eddies are revealed and possible dynamic explanations are analyzed. One typical characteristic is that surface eddies are generally separated from subthermocline eddies along the bifurcation latitude(~13°N) of the North Equatorial Current in the western tropical Pacific, which may be associated with different eddy energy sources and vertical eddy energy fluxes in subtropical and tropical gyres. Surface eddies have maximum swirl velocities of 8–9 cm s^(-1) and can extend to about 1500 m depth. Subthermocline eddies occur below 200 m, with their cores at about 400–600 m depth, and their maximum swirl velocities can reach 10 cm s^(-1). The other typical characteristic is that the meridional velocity component of the eddy is much larger than the zonal component. This characteristic might be due to more zonal eddy pairs(two eddies at the same latitude),which is also supported by the zonal wavelength(about 200 km) in the high-frequency meridional velocity component of the horizontal velocity.展开更多
Fresnel zone plates are the key optical elements for nanoscale focusing of X-ray beams with high spatial resolution. Conventional zone plates manufactured by planar nanotechnology processes are limited by the achievab...Fresnel zone plates are the key optical elements for nanoscale focusing of X-ray beams with high spatial resolution. Conventional zone plates manufactured by planar nanotechnology processes are limited by the achievable aspect ratios of their zone structures. Additionally, ultra-high resolution X-ray optics with high efficiency requires three-dimensional (3-D) shaped tilted zones. The combination of high spatial resolution and high diffraction efficiency is a fundamental problem in X-ray optics. Based on electrodynamical simulations, we find that the optimized zone plate profile for volume diffraction is given by zone structures with radially increasing tilt angles and decreasing zone heights. On-chip stacking permits the realization of such advanced 3-D profiles without significant loss of the maximum theoretical efficiency. We developed triple layer on-chip stacked zone plates with an overlay accuracy of sub-2 nm which fulfills the nanofabrication requirements. Efficiency measurements of on-chip stacked zone plates show significantly increased values compared to conventional zone plates.展开更多
文摘With the progress of plant genome research, more than 50 plant metallothionein_like (MT_L) genes have been found, but only several MT_L proteins have been detected and no experimental structural information for MT_L proteins has been reported so far. Since detailed knowledge of the protein tertiary structure is required to understand its biological function, a method is needed to determine the structure of these proteins. In this study, the structural data of known mammal MT was used to determine the interatomic distance constraints of the CXC and CXXC motifs and the metal_sulfur chelating cluster. Then several possible MT conformations were predicted using a distance geometry algorithm. The statistical analysis was used to select those with much lower target function values and lower conformation energies as the predicted tertiary structural models of the cysteine_rich (CR) domains of these proteins. A suitable prediction method for modeling the CR domain of the plant MT_L protein was constructed. The accurately predicted result for the known structure of an MT protein from blue crab suggests that this method is practicable. The tertiary structures of CR domains of rape MT_L protein LSC54 was then modeled with this method.
文摘The discovery of intrinsically disordered proteins (IDP) (i.e., biologically active proteins that do not possess stable secondary and/or tertiary structures) came as an unexpected surprise, as the existence of such proteins is in contradiction to the traditional "sequence →structure →function" paradigm. Accurate prediction of a protein's predisposition to be intrinsically disordered is a necessary prerequisite for the further understanding of principles and mechanisms of protein folding and function, and is a key for the elaboration of a new structural and functional hierarchy of proteins. Therefore, prediction of IDPs has attracted the attention of many researchers, and a number of prediction tools have been developed. Predictions of disorder, in turn, are playing major roles in directing laboratory experiments that are leading to the discovery of ever more disordered proteins, and thereby leading to a positive feedback loop in the investigation of these proteins. In this review of algorithms for intrinsic disorder prediction, the basic concepts of various prediction methods for IDPs are summarized, the strengths and shortcomings of many of the methods are analyzed, and the difficulties and directions of future development of IDP prediction techniques are discussed.
文摘After a systematic review of 38 current intelligent city evaluation systems (ICESs) from around the world, this research analyzes the secondary and tertiary indicators of these 38 ICESs from the perspec- tives of scale structuring, approaches and indicator selection, and determines their common base. From this base, the fundamentals of the City Intelligence Quotient (City IOD Evaluation System are developed and five dimensions are selected after a clustering analysis. The basic version, City IQ Evaluation System 1.0, involves 275 experts from 14 high-end research institutions, which include the Chinese Academy of Engineering, the National Academy of Science and Engineering (Germany), the Royal Swedish Academy of Engineering Sciences, the Planning Management Center of the Ministry of Housing and Urban-Rural Development of China, and the Development Research Center of the State Council of China. City IQ Evaluation System 2.0 is further developed, with improvements in its universality, openness, and dy- namic adjustment capability. After employing deviation evaluation methods in the IQ assessment, City IQ Evaluation System 3.0 was conceived. The research team has conducted a repeated assessment of 41 intelligent cities around the world using City IQ Evaluation System 3.0. The results have proved that the City IQ Evaluation System, developed on the basis of intelligent life, features more rational indicators selected from data sources that can offer better universality, openness, and dynamics, and is more sen- sitive and precise.
基金Projects(51878667,51678571)supported by the National Natural Science Foundation of ChinaProject(2018zzts657)supported by the Central South University Postgraduates’Innovation,ChinaProject(2018JJ2517)supported by the Hunan Provincial Natural Science Foundation of China。
文摘Based on a typical prototype of a soil slope in engineering practice, a numerical model of a three-stage soil slope supported by the anchor frame structure was established by means of FLAC3D code. The dynamic responses of three-stage soil slope and frame structure were studied by performing a series of bidirectional Wenchuan motions in terms of the failure mode of three-stage structure, the acceleration of soil slope, the displacement of frame structure, and the anchor stress of frame structure. The response accelerations in both horizontal and vertical directions are the most largely amplified at the slope top of each stage subjected to different shaking cases. The platforms among the stages reduce the amplification effect of response acceleration. The residual displacement of frame structure increases significantly as the intensity of shaking case increases. The frame structure at each stage presents a combined displacement mode consisting of a translation and a rotation around the vertex. The anchor stress of frame structure is mainly increased by the first intense pulse of Wenchuan seismic wave, and it is sensitive to the intensity of shaking case. The anchor stress of frame structure at the first stage is the most considerably enlarged by earthquake loading.
基金Supported by Project of Dongying Geothermal Resources Survey in Tanggu area of Tianjin(Tianjin Land and Housing Task[2008]No.003)
文摘Based on introducing geological structure of Tanggu area, the authors analyzed the sedimentary environment of Paleogene Dongying Formation, and further analyzed its geothermal occurrence. The studied area spans two grade IV tectonic units which are Beitang depression and Banqiao depression. The studied area is mainly located in the Tanggu nose-like structure which is the secondary structure of Beitang depression. Its existence affects the sedimentary distribution of the part strata of Paleogene. The depositions of Dongying Ⅲ ( SQEd3 ) and Dongying Ⅱ ( SQEd2 ) are mainly delta front facies and lake sand bars which are propitious to the geothermal fluid enrichment. The favorable enrichment region of geothermal fluid is located in south Hetou- Tanggu. Most of Dongying Ⅰ ( SQEd1 ) changes into swamp plain deposition, only the northeast part of this area is the distributary riverway facies with developed sand layers. There is the favorable enrichment region of geothermal fluid. The hydraulic connection is weak among the geothermal reservoirs of Dongying Formation and its overlying Guantao and Minghuazhen formations. The underlying Shahejie Formation geothermal reservoir pro- vides a steady stream of fluid supply and ground pressure protection for Dongying Formation geothermal reservoir.
文摘The early universe inflation is well known as a promising theory to explain the origin of large-scale structure of universe and to solve the early universe pressing problems. For a reasonable inflation model, the potential during inflation must be very flat, at least, in the direction of the inflaton. To construct the inflaton potential all the known related astrophysics observations should be included. For a general tree-level hybrid inflation potential, which is notdiscussed fully so far, the parameters in it are shown how to be constrained via the astrophysics data observed and to be obtained to the expected accuracy, and to be consistent with cosmology requirements.
基金supported by the National Basic Research Program of China (2010CB732404, 2010CB923303)the National Natural Science Foundation of China (21175020, 90713023, 20925104)+4 种基金the Project of High Technology Research and Development Program of China (2007AA022007)Gongdong Province (2011B090400357)the Natural Science Foundation of Jiangsu Province (BK2008149, BK2010052)C. W. acknowledges the Fundamental Research Funds for the Central Universities (ZYGX2011J099)the support by the Open Research Fund of State Key Laboratory of Bioelectronics, Southeast University (2011E09)
文摘The interactions between the new organometallic complexes, ferrocenesubstituted dithioocarborane conjugates (denoted as FcSB1, FcSB2 and FcSBCO) and hemoglobin (Hb) are investigated by electrochemistry, fluorescence and UVvis absorption spectroscopy. The results demonstrate that FcSB1, FcSB2 and FcSBCO can bind to the heme iron center through the replacement of the weakly bound H20/02 in the distal heme pocket of Hb by their sulfur donor atoms, inducing the allosteric change from the R state (oxygenated conformation, relax) to T state (deoxygenated conformation, tense). The binding affinity is in the order of FcSBCO〉FeSB2〉FeSB1. Moreover, the fluorescence study illustrates that the three ferrocenecarborane conjugates differently affect the quarterly and tertiary structures as well as the polarity in the surrounding of the Trp and Tyr residues in Hb. Typically, FcSB2 mainly induces alterations of the microenvironment around the 1337Trp residue which is located on the cql32 interface of Hb. Such distinct influences are attributed to the structural features of FcSB1, FcSB2 and FcSBCO containing hydrophobic ferrocenyl and carboranyl units as well as C=O group. Screening the proteinbinding behavior can signify the potential bioactivity of such molecules and may be helpful in the future development of promising multifunctional metallodrugs.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41576014 & 41330963)the National Basic Research Program of China (Grant No. 2013CB956202)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA11010101)the National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers (Grant No. U1406401)
文摘The three-dimensional structure of mesoscale eddies in the western tropical Pacific(6°S–20°N, 120°E–150°E)is investigated using a high-resolution ocean model simulation. Eddy detection and eddy tracking algorithms are applied to simulated horizontal velocity vectors, and the anticyclonic and cyclonic eddies identified are composited to obtain their three-dimensional structures. The mean lifetime of all long-lived eddies is about 52 days, and their mean diameter is 147 km. Two typical characteristics of mesoscale eddies are revealed and possible dynamic explanations are analyzed. One typical characteristic is that surface eddies are generally separated from subthermocline eddies along the bifurcation latitude(~13°N) of the North Equatorial Current in the western tropical Pacific, which may be associated with different eddy energy sources and vertical eddy energy fluxes in subtropical and tropical gyres. Surface eddies have maximum swirl velocities of 8–9 cm s^(-1) and can extend to about 1500 m depth. Subthermocline eddies occur below 200 m, with their cores at about 400–600 m depth, and their maximum swirl velocities can reach 10 cm s^(-1). The other typical characteristic is that the meridional velocity component of the eddy is much larger than the zonal component. This characteristic might be due to more zonal eddy pairs(two eddies at the same latitude),which is also supported by the zonal wavelength(about 200 km) in the high-frequency meridional velocity component of the horizontal velocity.
文摘Fresnel zone plates are the key optical elements for nanoscale focusing of X-ray beams with high spatial resolution. Conventional zone plates manufactured by planar nanotechnology processes are limited by the achievable aspect ratios of their zone structures. Additionally, ultra-high resolution X-ray optics with high efficiency requires three-dimensional (3-D) shaped tilted zones. The combination of high spatial resolution and high diffraction efficiency is a fundamental problem in X-ray optics. Based on electrodynamical simulations, we find that the optimized zone plate profile for volume diffraction is given by zone structures with radially increasing tilt angles and decreasing zone heights. On-chip stacking permits the realization of such advanced 3-D profiles without significant loss of the maximum theoretical efficiency. We developed triple layer on-chip stacked zone plates with an overlay accuracy of sub-2 nm which fulfills the nanofabrication requirements. Efficiency measurements of on-chip stacked zone plates show significantly increased values compared to conventional zone plates.