A detailed and accurate inventory map of landslides is crucial for quantitative hazard assessment and land planning.Traditional methods relying on change detection and object-oriented approaches have been criticized f...A detailed and accurate inventory map of landslides is crucial for quantitative hazard assessment and land planning.Traditional methods relying on change detection and object-oriented approaches have been criticized for their dependence on expert knowledge and subjective factors.Recent advancements in highresolution satellite imagery,coupled with the rapid development of artificial intelligence,particularly datadriven deep learning algorithms(DL)such as convolutional neural networks(CNN),have provided rich feature indicators for landslide mapping,overcoming previous limitations.In this review paper,77representative DL-based landslide detection methods applied in various environments over the past seven years were examined.This study analyzed the structures of different DL networks,discussed five main application scenarios,and assessed both the advancements and limitations of DL in geological hazard analysis.The results indicated that the increasing number of articles per year reflects growing interest in landslide mapping by artificial intelligence,with U-Net-based structures gaining prominence due to their flexibility in feature extraction and generalization.Finally,we explored the hindrances of DL in landslide hazard research based on the above research content.Challenges such as black-box operations and sample dependence persist,warranting further theoretical research and future application of DL in landslide detection.展开更多
The periphery of the Qinghai-Tibet Plateau is renowned for its susceptibility to landslides.However,the northwestern margin of this region,characterised by limited human activities and challenging transportation,remai...The periphery of the Qinghai-Tibet Plateau is renowned for its susceptibility to landslides.However,the northwestern margin of this region,characterised by limited human activities and challenging transportation,remains insufficiently explored concerning landslide occurrence and dispersion.With the planning and construction of the Xinjiang-Tibet Railway,a comprehensive investigation into disastrous landslides in this area is essential for effective disaster preparedness and mitigation strategies.By using the human-computer interaction interpretation approach,the authors established a landslide database encompassing 13003 landslides,collectively spanning an area of 3351.24 km^(2)(36°N-40°N,73°E-78°E).The database incorporates diverse topographical and environmental parameters,including regional elevation,slope angle,slope aspect,distance to faults,distance to roads,distance to rivers,annual precipitation,and stratum.The statistical characteristics of number and area of landslides,landslide number density(LND),and landslide area percentage(LAP)are analyzed.The authors found that a predominant concentration of landslide origins within high slope angle regions,with the highest incidence observed in intervals characterised by average slopes of 20°to 30°,maximum slope angle above 80°,along with orientations towards the north(N),northeast(NE),and southwest(SW).Additionally,elevations above 4.5 km,distance to rivers below 1 km,rainfall between 20-30 mm and 30-40 mm emerge as particularly susceptible to landslide development.The study area’s geological composition primarily comprises Mesozoic and Upper Paleozoic outcrops.Both fault and human engineering activities have different degrees of influence on landslide development.Furthermore,the significance of the landslide database,the relationship between landslide distribution and environmental factors,and the geometric and morphological characteristics of landslides are discussed.The landslide H/L ratios in the study area are mainly concentrated between 0.4 and 0.64.It means the landslides mobility in the region is relatively low,and the authors speculate that landslides in this region more possibly triggered by earthquakes or located in meizoseismal area.展开更多
Pulmonary embolism(PE),a form of venous thromboembolism,is a relatively frequent car-diovascular emergency,and a potentially life-threatening condition that needs prompt identification and treatment.[1]PE is often mis...Pulmonary embolism(PE),a form of venous thromboembolism,is a relatively frequent car-diovascular emergency,and a potentially life-threatening condition that needs prompt identification and treatment.[1]PE is often misdiagnosed or unrecogn-ized with many patients experiencing atypical sympt-oms.[2,3]Early diagnosis and treatment of PE are import-ant.In this case,PE was found in a 73-year-old male pa-tient with three-vessel coronary artery disease who un-derwent percutaneous coronary intervention(PCI)for concomitant acute myocardial infarction(MI).展开更多
BACKGROUND Triglyceride(TG)and its related metabolic indices,all recognized as surrogates of insulin resistance,have been demonstrated to be relevant to clinical prognosis.However,the relative value of these TG-relate...BACKGROUND Triglyceride(TG)and its related metabolic indices,all recognized as surrogates of insulin resistance,have been demonstrated to be relevant to clinical prognosis.However,the relative value of these TG-related indices for predicting cardiovascular events among patients with acute coronary syndrome(ACS)has not been examined.METHODS The TG,the triglyceride-glucose(TyG)index,the atherogenic index of plasma,TG to high-density lipoprotein cholesterol ratio,and the lipoprotein combine index were assessed in 1694 ACS patients undergoing percutaneous coronary intervention.The primary endpoint was major adverse cardiovascular event(MACE),which was the composite of all-cause mortality,stroke,myocardial infarction,or unplanned repeat revascularization.RESULTS During a median follow-up of 31 months,345 patients(20.4%)had MACE.The risk of the MACE was increased with higher TG and the four TG-derived metabolic indices[TG-adjusted hazard ratio(HR)=1.002,95%CI:1.001-1.003;TyG index-adjusted HR=1.736,95%CI:1.398-2.156;atherogenic index of plasma-adjusted HR=2.513,95%CI:1.562-4.043;TG to high-density lipoprotein cholesterol ratio-adjusted HR=1.148,95%CI:1.048-1.258;and lipoprotein combine index-adjusted HR=1.009,95%CI:1.004-1.014;P<0.001 for all indices].TG and all the four indices significantly improved the predictive ability for MACE in addition to the baseline model.Among them,TyG index showed the best ability for predicting MACE compared with the other three indices from all the three measurements(P<0.05 for all comparison).CONCLUSIONS TG and TG-derived metabolic indices were all strongly associated with MACE among ACS patients undergoing percutaneous coronary intervention.Among all the indices,TyG index showed the best ability to predict the risk of MACE.展开更多
OBJECTIVE To determine the association of serum complement C1q levels with cardiovascular outcomes among patients with acute coronary syndrome(ACS)undergoing percutaneous coronary intervention(PCI),and evaluate the va...OBJECTIVE To determine the association of serum complement C1q levels with cardiovascular outcomes among patients with acute coronary syndrome(ACS)undergoing percutaneous coronary intervention(PCI),and evaluate the value of C1q modified by high-sensitivity C-reactive protein(hs-CRP)levels as an independent predictor.METHODS As a single-center prospective observational study,we analyzed 1701 patients who had received primary or elective PCI for ACS at Beijing Anzhen Hospital,Capital Medical University,Beijing,China between June 1,2016 and November 30,2017.The associations of C1q modified by hs-CRP with major adverse cardiovascular events(MACE)were determined in survival analysis.RESULTS Patients with the lowest C1q tertile had the highest cumulative risk of MACE(log-rank P=0.007).In fully adjusted Cox regression models,stratifying the total population according to hs-CRP dichotomy,C1q was significantly associated with MACE in patients with hs-CRP levels less than 2 mg/L but not in those with 2 mg/L or more(P_(interaction)=0.02).In patients with hs-CRP levels less than 2 mg/L,with the lowest C1q tertile as reference,the risk of MACE was reduced by 40.0%in the middle C1q tertile[hazard ratio(HR)=0.600,95%CI:0.423–0.852,P=0.004]and by 43.9%in the highest C1q tertile(HR=0.561,95%CI:0.375–0.840,P=0.005).CONCLUSIONS Serum complement C1q is significantly associated with cardiovascular outcomes in patients with ACS undergoing PCI,only when hs-CRP levels are less than 2 mg/L.This finding implicates the usefulness of C1q for the risk stratification in ACS patients with reduced systemic inflammation.展开更多
A hot compression experiment （1073 1473 K, strain rates of 0. 001-10 s -1 ） of SAS08GR. 4N low alloy steel was performed using a Gleeble-3800 thermal-mechanical simulator, and the hot deformation behavior of the ste...A hot compression experiment （1073 1473 K, strain rates of 0. 001-10 s -1 ） of SAS08GR. 4N low alloy steel was performed using a Gleeble-3800 thermal-mechanical simulator, and the hot deformation behavior of the steel was investigated by analyzing both the true stress true strain curves and its microstructures. The thermal de formation equation and hot deformation activation energy （Q） of SA508GR. 4N steel were obtained by regression with a classic hyperbolic sine function. The hot processing map of SAS08GR. 4N steel was also established. An empirical equation for the stress peak was described for practical applications. The SA508GR. 4N steel showed a critical Zener-Hollomon parameter （lnZc） for dynamic recrystallization （DRX） of 37.44, below which full DRX may occur. The sensitivity of the SA508GR. 4N steel increased linearly with test temperature, such that higher temperatures led to enhanced workability.展开更多
Using a Gleeble-1500D thermal-mechanical simulator,the hot-deformation behavior and critical strain in the dynamic recrystallization of SA508Gr.4N steel were investigated by compression tests from 1050 to 1250℃ with ...Using a Gleeble-1500D thermal-mechanical simulator,the hot-deformation behavior and critical strain in the dynamic recrystallization of SA508Gr.4N steel were investigated by compression tests from 1050 to 1250℃ with strain rates from 0.001 to 0.1 s^-1.Stress-strain curves were fitted by a nonlinear fitting method.Based on these tests,the flow stress constitutive equations of the work-hardening dynamical recovery period and dynamical recrystallization period Were established for SA508Gr.4N steel.The stress-strain curves of SA508Gr.4N steel predicted by the established models are in a good agreement with the experimental ones.Curves of ln θ -ε and --(a)(lnθ)/(a)ε-ε (where θ is the work-hardening rate and ε is true strain)were plotted from experimental data.A critical strain (εc)and a peak strain (εp)of dynamic recrystallization were obtained and exhibited a linear relationship,i.e.,εc =0.386εp.The predicted model of εc could be described by the equation of εc=1.604×10^-3Z^0.127.展开更多
The effect of manganese(Mn)on the microstructure,tensile and impact properties of SA508Gr.4N steel has been experimentally investigated.The influence of Mn content on the substructure of SA508Gr.4N steel was investiga...The effect of manganese(Mn)on the microstructure,tensile and impact properties of SA508Gr.4N steel has been experimentally investigated.The influence of Mn content on the substructure of SA508Gr.4N steel was investigated using the scanning electron microscope,electron back-scattered diffractometer and transmission electron microscope.It was found that the increased Mn content had a beneficial effect on both strength and toughness.Examination of microstructure revealed smaller size of block and larger number of high-angle grain boundaries with higher Mn content.The change of the ultimate tensile strength and toughness with increasing Mn content was attributed to the increased hardenability,the number of high-angle grain boundaries and the crack propagation path by the block refining.展开更多
基金supported by the National Key Research and Development Program of China(2021YFB3901205)the National Institute of Natural Hazards,Ministry of Emergency Management of China(2023-JBKY-57)。
文摘A detailed and accurate inventory map of landslides is crucial for quantitative hazard assessment and land planning.Traditional methods relying on change detection and object-oriented approaches have been criticized for their dependence on expert knowledge and subjective factors.Recent advancements in highresolution satellite imagery,coupled with the rapid development of artificial intelligence,particularly datadriven deep learning algorithms(DL)such as convolutional neural networks(CNN),have provided rich feature indicators for landslide mapping,overcoming previous limitations.In this review paper,77representative DL-based landslide detection methods applied in various environments over the past seven years were examined.This study analyzed the structures of different DL networks,discussed five main application scenarios,and assessed both the advancements and limitations of DL in geological hazard analysis.The results indicated that the increasing number of articles per year reflects growing interest in landslide mapping by artificial intelligence,with U-Net-based structures gaining prominence due to their flexibility in feature extraction and generalization.Finally,we explored the hindrances of DL in landslide hazard research based on the above research content.Challenges such as black-box operations and sample dependence persist,warranting further theoretical research and future application of DL in landslide detection.
基金supported by the National Key Research and Development Program of China(2021YFB3901205)National Institute of Natural Hazards,Ministry of Emergency Management of China(2023-JBKY-57)。
文摘The periphery of the Qinghai-Tibet Plateau is renowned for its susceptibility to landslides.However,the northwestern margin of this region,characterised by limited human activities and challenging transportation,remains insufficiently explored concerning landslide occurrence and dispersion.With the planning and construction of the Xinjiang-Tibet Railway,a comprehensive investigation into disastrous landslides in this area is essential for effective disaster preparedness and mitigation strategies.By using the human-computer interaction interpretation approach,the authors established a landslide database encompassing 13003 landslides,collectively spanning an area of 3351.24 km^(2)(36°N-40°N,73°E-78°E).The database incorporates diverse topographical and environmental parameters,including regional elevation,slope angle,slope aspect,distance to faults,distance to roads,distance to rivers,annual precipitation,and stratum.The statistical characteristics of number and area of landslides,landslide number density(LND),and landslide area percentage(LAP)are analyzed.The authors found that a predominant concentration of landslide origins within high slope angle regions,with the highest incidence observed in intervals characterised by average slopes of 20°to 30°,maximum slope angle above 80°,along with orientations towards the north(N),northeast(NE),and southwest(SW).Additionally,elevations above 4.5 km,distance to rivers below 1 km,rainfall between 20-30 mm and 30-40 mm emerge as particularly susceptible to landslide development.The study area’s geological composition primarily comprises Mesozoic and Upper Paleozoic outcrops.Both fault and human engineering activities have different degrees of influence on landslide development.Furthermore,the significance of the landslide database,the relationship between landslide distribution and environmental factors,and the geometric and morphological characteristics of landslides are discussed.The landslide H/L ratios in the study area are mainly concentrated between 0.4 and 0.64.It means the landslides mobility in the region is relatively low,and the authors speculate that landslides in this region more possibly triggered by earthquakes or located in meizoseismal area.
文摘Pulmonary embolism(PE),a form of venous thromboembolism,is a relatively frequent car-diovascular emergency,and a potentially life-threatening condition that needs prompt identification and treatment.[1]PE is often misdiagnosed or unrecogn-ized with many patients experiencing atypical sympt-oms.[2,3]Early diagnosis and treatment of PE are import-ant.In this case,PE was found in a 73-year-old male pa-tient with three-vessel coronary artery disease who un-derwent percutaneous coronary intervention(PCI)for concomitant acute myocardial infarction(MI).
基金supported by the National Key Research and Development Program of China (2017YFC 0908800)the Beijing Municipal Administration of Hospitals’ Mission Plan (SML20180601)+2 种基金the China Postdoctoral Science Foundation (2021M692253)the Beijing Postdoctoral Research Foundation (2021-ZZ023)the Beijing Municipal Health Commission (Jing 19-15)
文摘BACKGROUND Triglyceride(TG)and its related metabolic indices,all recognized as surrogates of insulin resistance,have been demonstrated to be relevant to clinical prognosis.However,the relative value of these TG-related indices for predicting cardiovascular events among patients with acute coronary syndrome(ACS)has not been examined.METHODS The TG,the triglyceride-glucose(TyG)index,the atherogenic index of plasma,TG to high-density lipoprotein cholesterol ratio,and the lipoprotein combine index were assessed in 1694 ACS patients undergoing percutaneous coronary intervention.The primary endpoint was major adverse cardiovascular event(MACE),which was the composite of all-cause mortality,stroke,myocardial infarction,or unplanned repeat revascularization.RESULTS During a median follow-up of 31 months,345 patients(20.4%)had MACE.The risk of the MACE was increased with higher TG and the four TG-derived metabolic indices[TG-adjusted hazard ratio(HR)=1.002,95%CI:1.001-1.003;TyG index-adjusted HR=1.736,95%CI:1.398-2.156;atherogenic index of plasma-adjusted HR=2.513,95%CI:1.562-4.043;TG to high-density lipoprotein cholesterol ratio-adjusted HR=1.148,95%CI:1.048-1.258;and lipoprotein combine index-adjusted HR=1.009,95%CI:1.004-1.014;P<0.001 for all indices].TG and all the four indices significantly improved the predictive ability for MACE in addition to the baseline model.Among them,TyG index showed the best ability for predicting MACE compared with the other three indices from all the three measurements(P<0.05 for all comparison).CONCLUSIONS TG and TG-derived metabolic indices were all strongly associated with MACE among ACS patients undergoing percutaneous coronary intervention.Among all the indices,TyG index showed the best ability to predict the risk of MACE.
基金supported by the National Key Research and Development Program of China(2017 YFC0908800)the China Postdoctoral Science Foundation(2021M692253)the Beijing Postdoctoral Research Foundation(2021-ZZ-023)。
文摘OBJECTIVE To determine the association of serum complement C1q levels with cardiovascular outcomes among patients with acute coronary syndrome(ACS)undergoing percutaneous coronary intervention(PCI),and evaluate the value of C1q modified by high-sensitivity C-reactive protein(hs-CRP)levels as an independent predictor.METHODS As a single-center prospective observational study,we analyzed 1701 patients who had received primary or elective PCI for ACS at Beijing Anzhen Hospital,Capital Medical University,Beijing,China between June 1,2016 and November 30,2017.The associations of C1q modified by hs-CRP with major adverse cardiovascular events(MACE)were determined in survival analysis.RESULTS Patients with the lowest C1q tertile had the highest cumulative risk of MACE(log-rank P=0.007).In fully adjusted Cox regression models,stratifying the total population according to hs-CRP dichotomy,C1q was significantly associated with MACE in patients with hs-CRP levels less than 2 mg/L but not in those with 2 mg/L or more(P_(interaction)=0.02).In patients with hs-CRP levels less than 2 mg/L,with the lowest C1q tertile as reference,the risk of MACE was reduced by 40.0%in the middle C1q tertile[hazard ratio(HR)=0.600,95%CI:0.423–0.852,P=0.004]and by 43.9%in the highest C1q tertile(HR=0.561,95%CI:0.375–0.840,P=0.005).CONCLUSIONS Serum complement C1q is significantly associated with cardiovascular outcomes in patients with ACS undergoing PCI,only when hs-CRP levels are less than 2 mg/L.This finding implicates the usefulness of C1q for the risk stratification in ACS patients with reduced systemic inflammation.
基金Item Sponsored by National Energy Application Technology Research and Engineering Demonstrative Project of China(NY201501)
文摘A hot compression experiment （1073 1473 K, strain rates of 0. 001-10 s -1 ） of SAS08GR. 4N low alloy steel was performed using a Gleeble-3800 thermal-mechanical simulator, and the hot deformation behavior of the steel was investigated by analyzing both the true stress true strain curves and its microstructures. The thermal de formation equation and hot deformation activation energy （Q） of SA508GR. 4N steel were obtained by regression with a classic hyperbolic sine function. The hot processing map of SAS08GR. 4N steel was also established. An empirical equation for the stress peak was described for practical applications. The SA508GR. 4N steel showed a critical Zener-Hollomon parameter （lnZc） for dynamic recrystallization （DRX） of 37.44, below which full DRX may occur. The sensitivity of the SA508GR. 4N steel increased linearly with test temperature, such that higher temperatures led to enhanced workability.
文摘Using a Gleeble-1500D thermal-mechanical simulator,the hot-deformation behavior and critical strain in the dynamic recrystallization of SA508Gr.4N steel were investigated by compression tests from 1050 to 1250℃ with strain rates from 0.001 to 0.1 s^-1.Stress-strain curves were fitted by a nonlinear fitting method.Based on these tests,the flow stress constitutive equations of the work-hardening dynamical recovery period and dynamical recrystallization period Were established for SA508Gr.4N steel.The stress-strain curves of SA508Gr.4N steel predicted by the established models are in a good agreement with the experimental ones.Curves of ln θ -ε and --(a)(lnθ)/(a)ε-ε (where θ is the work-hardening rate and ε is true strain)were plotted from experimental data.A critical strain (εc)and a peak strain (εp)of dynamic recrystallization were obtained and exhibited a linear relationship,i.e.,εc =0.386εp.The predicted model of εc could be described by the equation of εc=1.604×10^-3Z^0.127.
基金This work was supported financially by the National Key Research and Development Program of China(No.2016YFB0300203).
文摘The effect of manganese(Mn)on the microstructure,tensile and impact properties of SA508Gr.4N steel has been experimentally investigated.The influence of Mn content on the substructure of SA508Gr.4N steel was investigated using the scanning electron microscope,electron back-scattered diffractometer and transmission electron microscope.It was found that the increased Mn content had a beneficial effect on both strength and toughness.Examination of microstructure revealed smaller size of block and larger number of high-angle grain boundaries with higher Mn content.The change of the ultimate tensile strength and toughness with increasing Mn content was attributed to the increased hardenability,the number of high-angle grain boundaries and the crack propagation path by the block refining.
