Accumulation of heavy metals in urban soil can pose adverse impacts on public health and terrestrial ecosystems. We developed a mass balance-based regression model to simulate the heavy metal accumulation in urban soi...Accumulation of heavy metals in urban soil can pose adverse impacts on public health and terrestrial ecosystems. We developed a mass balance-based regression model to simulate the heavy metal accumulation in urban soils as a function of time and to explore connections between metal concentration and urbanization processes. Concentrations of Cd and Zn in 68 residential soil samples in the urban area of Beijing were used. The background concentrations, the loss rates and the input fluxes of Cd and Zn in urban soils of Beijing during the last three decades were estimated using a regression of the time series of accumulations of the metals. Based on the regression estimates, we simulated the general trends of Cd and Zn accumulation in the soils from 1978 to 2078. The concentrations of Cd and Zn in urban soil generally increased with the population growth, vehicle use and coal consumption. The mean concentrations of Cd and Zn in urban soil of Beijing would increase by 3 fold over the next 70 years for the current development scenario. The mass balance-based regression approach, which is able to reconstruct the history data of urban soil pollution, provides fundamental information for urban planning and environmental management.展开更多
From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ exper...From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.展开更多
AIM: To analyze and calculate the relative cost of various childhood glaucoma surgical interventions per mm Hg intraocular pressure(IOP) reduction($/mm Hg).METHODS: Representative index studies were reviewed to quanti...AIM: To analyze and calculate the relative cost of various childhood glaucoma surgical interventions per mm Hg intraocular pressure(IOP) reduction($/mm Hg).METHODS: Representative index studies were reviewed to quantitate the reduction of mean IOP and glaucoma medications for each surgical intervention in childhood glaucoma. A US perspective was adopted, using Medicare allowable costs to calculate cost/mm Hg IOP reduction($/mm Hg) at 1y postoperatively.RESULTS: At 1y postoperatively, the cost/mm Hg IOP reduction was $226/mm Hg for microcatheter-assisted circumferential trabeculotomy, $284/mm Hg for cyclophotocoagulation, $288/mm Hg for conventional ab-externo trabeculotomy, $338/mm Hg for Ahmed glaucoma valve, $350/mm Hg for Baerveldt glaucoma implant, $351/mm Hg for goniotomy, and $400/mm Hg for trabeculectomy.CONCLUSION: Microcatheter-assisted circumferential trabeculotomy is the most cost-efficient surgical method to lower IOP in childhood glaucoma, while trabeculectomy is the least cost-efficient surgical method.展开更多
Recently, there has been considerable effort to bring together quaternion-based representations of spatial displacements with curve design techniques in Computer Aided Geometric Design (CAGD) to develop methods for sy...Recently, there has been considerable effort to bring together quaternion-based representations of spatial displacements with curve design techniques in Computer Aided Geometric Design (CAGD) to develop methods for synthesizing freeform Cartesian motions. These methods have a wide range of applications from computer graphics,Cartesian motion planning for robot manipulators to task specification and motion approximation for spatial mechanism design. This paper compares the use of quaternions, dual quaternions, and double quaternions for freeform motion synthesis in a CAD environment.展开更多
Tuning cell shape by altering the biophysical properties of biomaterial substrates on which cells operate would provide a potential shape-driven pathway to control cell phenotype.However,there is an unexplored dimensi...Tuning cell shape by altering the biophysical properties of biomaterial substrates on which cells operate would provide a potential shape-driven pathway to control cell phenotype.However,there is an unexplored dimensional scale window of three-dimensional(3D)substrates with precisely tunable porous microarchitectures and geometrical feature sizes at the cell’s operating length scales(10–100μm).This paper demonstrates the fabrication of such highfidelity fibrous substrates using a melt electrowriting(MEW)technique.This advanced manufacturing approach is biologically qualified with a metrology framework that models and classifies cell confinement states under various substrate dimensionalities and architectures.Using fibroblasts as a model cell system,the mechanosensing response of adherent cells is investigated as a function of variable substrate dimensionality(2D vs.3D)and porous microarchitecture(randomly oriented,“non-woven”vs.precision-stacked,“woven”).Single-cell confinement states are modeled using confocal fluorescence microscopy in conjunction with an automated single-cell bioimage data analysis workflow that extracts quantitative metrics of the whole cell and sub-cellular focal adhesion protein features measured.The extracted multidimensional dataset is employed to train a machine learning algorithm to classify cell shape phenotypes.The results show that cells assume distinct confinement states that are enforced by the prescribed substrate dimensionalities and porous microarchitectures with the woven MEW substrates promoting the highest cell shape homogeneity compared to non-woven fibrous substrates.The technology platform established here constitutes a significant step towards the development of integrated additive manufacturing—metrology platforms for a wide range of applications including fundamental mechanobiology studies and 3D bioprinting of tissue constructs to yield specific biological designs qualified at the single-cell level.展开更多
Satellite precipitation estimation has become a major source of data for global moisture and regional environmental monitoring.This preliminary study first reviews the current status of such applications especially fo...Satellite precipitation estimation has become a major source of data for global moisture and regional environmental monitoring.This preliminary study first reviews the current status of such applications especially for tropical cyclone landfalls,and the science behind rainfall estimation based on microwave emission.One of the most popular integrated rain retrieval product,the NASA TRMM 3B42 data,is validated by ground-based observations for ten landfalling tropical cyclones during 2007-2010 in the Taiwan Region.While there is a general trend of underestimation by most satellite rainfall products compared with ground observations,the rainfall distributions within tropical cyclones are quite well revealed.This gives a reasonably good volumetric total rainfall within the cyclones,and thus sub-synoptic-scale rainfall footprints.However,there are large case-to-case variations for satellite rainfall estimates to capture individual convective episodes.In addition,land effects including those from topography are still the major difficulties.As a consequence of these factors,mesoscale rainfall footprints can deviate quite largely from those observed by ground measurements during tropical cyclone landfalls.Potential pathways to improve the current satellite rainfall products are discussed,which include development of statistical correction methodologies that consider different rainfall mechanisms;consideration of topographic effect and disaggregation of current rainfall products.展开更多
Artificial intelligence (AI) is a very active computer science research field aiming to develop systems that mimic human intelligence and is helpful in many human activities,including medicine.Therefore,it is no surpr...Artificial intelligence (AI) is a very active computer science research field aiming to develop systems that mimic human intelligence and is helpful in many human activities,including medicine.Therefore,it is no surprise that innovation plays an important role in delivering better medical and health.展开更多
Introduction Thoracic surgery has evolved at an exponential pace since the first clinical lung resection in 1882.The first pneumonectomy was performed in 1895,the first lobectomy in 1901,while double lumen endotrachea...Introduction Thoracic surgery has evolved at an exponential pace since the first clinical lung resection in 1882.The first pneumonectomy was performed in 1895,the first lobectomy in 1901,while double lumen endotracheal intubation for pulmonary resection did not occur until 1950.The 1990s saw the development of game-changer video-assisted thoracoscopic surgeries(VATS),while the 2000s gave witness to the explosive boom of robotic surgeries.As Abraham Lincoln once said,“The best way to predict the future is to create it”,in this article we discuss the current cutting-edge technologies and attempt to predict the future of thoracic surgery in 10 years’time.展开更多
A series of hydraulic model tests with horizontal movable seabed under regular wave actions have been carried out to investigate the dynamic interactions between water waves and seabed soil. Seabed dynamic stresses fr...A series of hydraulic model tests with horizontal movable seabed under regular wave actions have been carried out to investigate the dynamic interactions between water waves and seabed soil. Seabed dynamic stresses from experiments are, tound to differ from theoretical resuhs. The response of p0 in permeable seabed has a small decay and phase shift to the nonlinear wave actions, and the dynamic stresses, σs/p0, σh/p0 and u/p0, contain different phase shift characteristics. Such phenomena will strongly affect the dynamic stress path in seabed. If the phase shifts of σs. and σh are neglected, the stress path will become a straight line; otherwise, it will become an elliptical curve. In phase shift cases, the long axis of the p - q diagram will be shortened when the depth increases, and the short axis will become longer when the phase shift increases. For the p＇ - q＇ diagram, the larger the phase lag of u, the longer the short axis. Relative results offer useful information for the analysis of seabed stability.展开更多
A sub-array of the Large High Altitude Air Shower Observatory(LHAASO),KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV.Even though the detecto...A sub-array of the Large High Altitude Air Shower Observatory(LHAASO),KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV.Even though the detector construction is still underway,half of the KM2A array has been operating stably since the end of 2019.In this paper,we present the KM2A data analysis pipeline and the first observation of the Crab Nebula,a standard candle in very high energy γ-ray astronomy.We detect γ-ray signals from the Crab Nebula in both energy ranges of 10-100 TeV and>100 TeV with high significance,by analyzing the KM2A data of 136 live days between December 2019 and May 2020.With the observations,we test the detector performance,including angular resolution,pointing accuracy and cosmic-ray background rejection power.The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE=(1.13±0.05stat±0.08sys)×10^(-14).(E/20 TeV)-309±0.06stat±0.02syscm^(-2) s^(-1) TeV^(-1).It is consistent with previous measurements by other experiments.This opens a new window of γ-ray astronomy above 0.1 PeV through which new ultrahigh-energy γ-ray phenomena,such as cosmic PeVatrons,might be discovered.展开更多
The first Water Cherenkov detector of the LHAASO experiment(WCDA-1)has been operating since April 2019.The data for the first year have been analyzed to test its performance by observing the Crab Nebula as a standard ...The first Water Cherenkov detector of the LHAASO experiment(WCDA-1)has been operating since April 2019.The data for the first year have been analyzed to test its performance by observing the Crab Nebula as a standard candle.The WCDA-1 achieves a sensitivity of 65 mCU per year,with a statistical threshold of 5 cr.To accomplish this,a 97.7%cosmic-ray background rejection rate around 1 TeV and 99.8%around 6 TeV with an ap proximate photon acceptance of 50%is achieved after applying an algorithm to separate gamma-induced showers.The angular resolution is measured using the Crab Nebula as a point source to be approximately 0.45°at 1 TeV and better than 0.2°above 6 TeV,with a pointing accuracy better than 0.05°.These values all match the design specifications.The energy resolution is found to be 33%for gamma rays around 6 TeV.The spectral energy distribution of the Crab Nebula in the range from 500 GeV to 15.8 TeV is measured and found to be in agreement with the results from other TeV gamma ray observatories.展开更多
基金supported by the National Natural Science Foundation of China(No.41401588)supported by the State Scholarship Fund organized by China Scholarship Council+1 种基金the support from the Brook Byers Institute for Sustainable Systems,Hightower Chairthe Georgia Research Alliance at the Georgia Institute of Technology
文摘Accumulation of heavy metals in urban soil can pose adverse impacts on public health and terrestrial ecosystems. We developed a mass balance-based regression model to simulate the heavy metal accumulation in urban soils as a function of time and to explore connections between metal concentration and urbanization processes. Concentrations of Cd and Zn in 68 residential soil samples in the urban area of Beijing were used. The background concentrations, the loss rates and the input fluxes of Cd and Zn in urban soils of Beijing during the last three decades were estimated using a regression of the time series of accumulations of the metals. Based on the regression estimates, we simulated the general trends of Cd and Zn accumulation in the soils from 1978 to 2078. The concentrations of Cd and Zn in urban soil generally increased with the population growth, vehicle use and coal consumption. The mean concentrations of Cd and Zn in urban soil of Beijing would increase by 3 fold over the next 70 years for the current development scenario. The mass balance-based regression approach, which is able to reconstruct the history data of urban soil pollution, provides fundamental information for urban planning and environmental management.
基金supported by the following funding sources:Science Committee of the Republic of Armenia Grant No.18T-1C180Australian Research Council and research grant Nos.DP180102629,DP170102389,DP170102204,DP150103061,FT130100303,and FT130100018+22 种基金Austrian Federal Ministry of Education,Science and Research,and Austrian Science Fund No.P 31361-N36Natural Sciences and Engineering Research Council of Canada,Compute Canada and CANARIEChinese Academy of Sciences and research grant No.QYZDJ-SSW-SLH011National Natural Science Foundation of China and research grant Nos.11521505,11575017,11675166,11761141009,11705209,and 11975076LiaoNing Revitalization Talents Program under contract No.XLYC1807135Shanghai Municipal Science and Technology Committee under contract No.19ZR1403000Shanghai Pujiang Program under Grant No.18PJ1401000the CAS Center for Excellence in Particle Physics(CCEPP)the Ministry of Education,Youth and Sports of the Czech Republic under Contract No.LTT17020Charles University grants SVV260448 and GAUK 404316European Research Council,7th Framework PIEF-GA-2013-622527Horizon 2020 Marie Sklodowska-Curie grant agreement No.700525’NIOBE,’Horizon 2020 Marie Sklodowska-Curie RISE project JENNIFER grant agreement No.644294Horizon 2020 ERC-Advanced Grant No.267104NewAve No.638528(European grants)L’Institut National de Physique Nucléaire et de Physique des Particules(IN2P3)du CNRS(France),BMBF,DFG,HGF,MPG and AvH Foundation(Germany)Department of Atomic Energy and Department of Science and Technology(India)Israel Science Foundation grant No.2476/17United States-Israel Binational Science Foundation grant No.2016113Istituto Nazionale di Fisica Nucleare and the research grants BELLE2Japan Society for the Promotion of Science,Grant-in-Aid for Scientific Research grant Nos.16H03968,16H03993,16H06492,16K05323,17H01133,17H05405,18K03621,18H03710,18H05226,19H00682,26220706,and 26400255the National Institute of Informatics,and Science Information NETwork 5(SINET5)the Ministry of Education,Culture,Sports,Science,an
文摘From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.
文摘AIM: To analyze and calculate the relative cost of various childhood glaucoma surgical interventions per mm Hg intraocular pressure(IOP) reduction($/mm Hg).METHODS: Representative index studies were reviewed to quantitate the reduction of mean IOP and glaucoma medications for each surgical intervention in childhood glaucoma. A US perspective was adopted, using Medicare allowable costs to calculate cost/mm Hg IOP reduction($/mm Hg) at 1y postoperatively.RESULTS: At 1y postoperatively, the cost/mm Hg IOP reduction was $226/mm Hg for microcatheter-assisted circumferential trabeculotomy, $284/mm Hg for cyclophotocoagulation, $288/mm Hg for conventional ab-externo trabeculotomy, $338/mm Hg for Ahmed glaucoma valve, $350/mm Hg for Baerveldt glaucoma implant, $351/mm Hg for goniotomy, and $400/mm Hg for trabeculectomy.CONCLUSION: Microcatheter-assisted circumferential trabeculotomy is the most cost-efficient surgical method to lower IOP in childhood glaucoma, while trabeculectomy is the least cost-efficient surgical method.
文摘Recently, there has been considerable effort to bring together quaternion-based representations of spatial displacements with curve design techniques in Computer Aided Geometric Design (CAGD) to develop methods for synthesizing freeform Cartesian motions. These methods have a wide range of applications from computer graphics,Cartesian motion planning for robot manipulators to task specification and motion approximation for spatial mechanism design. This paper compares the use of quaternions, dual quaternions, and double quaternions for freeform motion synthesis in a CAD environment.
基金The work presented in this paper was supported by the National Science Foundation under Award No.CMMI-MME-1554150。
文摘Tuning cell shape by altering the biophysical properties of biomaterial substrates on which cells operate would provide a potential shape-driven pathway to control cell phenotype.However,there is an unexplored dimensional scale window of three-dimensional(3D)substrates with precisely tunable porous microarchitectures and geometrical feature sizes at the cell’s operating length scales(10–100μm).This paper demonstrates the fabrication of such highfidelity fibrous substrates using a melt electrowriting(MEW)technique.This advanced manufacturing approach is biologically qualified with a metrology framework that models and classifies cell confinement states under various substrate dimensionalities and architectures.Using fibroblasts as a model cell system,the mechanosensing response of adherent cells is investigated as a function of variable substrate dimensionality(2D vs.3D)and porous microarchitecture(randomly oriented,“non-woven”vs.precision-stacked,“woven”).Single-cell confinement states are modeled using confocal fluorescence microscopy in conjunction with an automated single-cell bioimage data analysis workflow that extracts quantitative metrics of the whole cell and sub-cellular focal adhesion protein features measured.The extracted multidimensional dataset is employed to train a machine learning algorithm to classify cell shape phenotypes.The results show that cells assume distinct confinement states that are enforced by the prescribed substrate dimensionalities and porous microarchitectures with the woven MEW substrates promoting the highest cell shape homogeneity compared to non-woven fibrous substrates.The technology platform established here constitutes a significant step towards the development of integrated additive manufacturing—metrology platforms for a wide range of applications including fundamental mechanobiology studies and 3D bioprinting of tissue constructs to yield specific biological designs qualified at the single-cell level.
文摘Satellite precipitation estimation has become a major source of data for global moisture and regional environmental monitoring.This preliminary study first reviews the current status of such applications especially for tropical cyclone landfalls,and the science behind rainfall estimation based on microwave emission.One of the most popular integrated rain retrieval product,the NASA TRMM 3B42 data,is validated by ground-based observations for ten landfalling tropical cyclones during 2007-2010 in the Taiwan Region.While there is a general trend of underestimation by most satellite rainfall products compared with ground observations,the rainfall distributions within tropical cyclones are quite well revealed.This gives a reasonably good volumetric total rainfall within the cyclones,and thus sub-synoptic-scale rainfall footprints.However,there are large case-to-case variations for satellite rainfall estimates to capture individual convective episodes.In addition,land effects including those from topography are still the major difficulties.As a consequence of these factors,mesoscale rainfall footprints can deviate quite largely from those observed by ground measurements during tropical cyclone landfalls.Potential pathways to improve the current satellite rainfall products are discussed,which include development of statistical correction methodologies that consider different rainfall mechanisms;consideration of topographic effect and disaggregation of current rainfall products.
基金LHT received support for article research from the Natural Science Foundation of China through grant 81571475Health Bureau of Zhejiang Province through grant 2010KYA122+1 种基金QS received support from the Natural Science Foundation of China through grant 81671956Zhejiang Provincial Program for the Cultivation of High-level Innovative Health Talents Program.
文摘Artificial intelligence (AI) is a very active computer science research field aiming to develop systems that mimic human intelligence and is helpful in many human activities,including medicine.Therefore,it is no surprise that innovation plays an important role in delivering better medical and health.
文摘Introduction Thoracic surgery has evolved at an exponential pace since the first clinical lung resection in 1882.The first pneumonectomy was performed in 1895,the first lobectomy in 1901,while double lumen endotracheal intubation for pulmonary resection did not occur until 1950.The 1990s saw the development of game-changer video-assisted thoracoscopic surgeries(VATS),while the 2000s gave witness to the explosive boom of robotic surgeries.As Abraham Lincoln once said,“The best way to predict the future is to create it”,in this article we discuss the current cutting-edge technologies and attempt to predict the future of thoracic surgery in 10 years’time.
基金This research was financially supported by the National Science Council , Taiwan under the project entitled"TheStudy of the Dynamic Behavior of Foundation Soil beneath Nearshore structures under Wave Loading Action (I)"withthe project number of NSC-91-2211-E-019-013
文摘A series of hydraulic model tests with horizontal movable seabed under regular wave actions have been carried out to investigate the dynamic interactions between water waves and seabed soil. Seabed dynamic stresses from experiments are, tound to differ from theoretical resuhs. The response of p0 in permeable seabed has a small decay and phase shift to the nonlinear wave actions, and the dynamic stresses, σs/p0, σh/p0 and u/p0, contain different phase shift characteristics. Such phenomena will strongly affect the dynamic stress path in seabed. If the phase shifts of σs. and σh are neglected, the stress path will become a straight line; otherwise, it will become an elliptical curve. In phase shift cases, the long axis of the p - q diagram will be shortened when the depth increases, and the short axis will become longer when the phase shift increases. For the p＇ - q＇ diagram, the larger the phase lag of u, the longer the short axis. Relative results offer useful information for the analysis of seabed stability.
基金Supported in China by National Key R&D program of China under the grants(2018YF A0404201.2018YFA0404202.2018YF A0404203)by NSFC(12022502,190527,135011,11761141001.U1931112,11775131,U1931201,11905043,U1931108)by NSFSPC(ZR2019MA014),and in Thailand by RTA6280002 from Thailand Science Research and Innovation。
文摘A sub-array of the Large High Altitude Air Shower Observatory(LHAASO),KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV.Even though the detector construction is still underway,half of the KM2A array has been operating stably since the end of 2019.In this paper,we present the KM2A data analysis pipeline and the first observation of the Crab Nebula,a standard candle in very high energy γ-ray astronomy.We detect γ-ray signals from the Crab Nebula in both energy ranges of 10-100 TeV and>100 TeV with high significance,by analyzing the KM2A data of 136 live days between December 2019 and May 2020.With the observations,we test the detector performance,including angular resolution,pointing accuracy and cosmic-ray background rejection power.The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE=(1.13±0.05stat±0.08sys)×10^(-14).(E/20 TeV)-309±0.06stat±0.02syscm^(-2) s^(-1) TeV^(-1).It is consistent with previous measurements by other experiments.This opens a new window of γ-ray astronomy above 0.1 PeV through which new ultrahigh-energy γ-ray phenomena,such as cosmic PeVatrons,might be discovered.
基金Supported by the following grants:the National Key R&D program of China(2018YFA0404201,2018YFA0404202,2018YFA0404203)the National Natural Science Foundation of China(12022502,11905227,U1931112,11635011,11761141001,Y811A35,11675187,U1831208,U1931111)in Thailand by RTA6280002 from Thailand Science Research and Innovation。
文摘The first Water Cherenkov detector of the LHAASO experiment(WCDA-1)has been operating since April 2019.The data for the first year have been analyzed to test its performance by observing the Crab Nebula as a standard candle.The WCDA-1 achieves a sensitivity of 65 mCU per year,with a statistical threshold of 5 cr.To accomplish this,a 97.7%cosmic-ray background rejection rate around 1 TeV and 99.8%around 6 TeV with an ap proximate photon acceptance of 50%is achieved after applying an algorithm to separate gamma-induced showers.The angular resolution is measured using the Crab Nebula as a point source to be approximately 0.45°at 1 TeV and better than 0.2°above 6 TeV,with a pointing accuracy better than 0.05°.These values all match the design specifications.The energy resolution is found to be 33%for gamma rays around 6 TeV.The spectral energy distribution of the Crab Nebula in the range from 500 GeV to 15.8 TeV is measured and found to be in agreement with the results from other TeV gamma ray observatories.
