Related to complexity, there is a wide diversity of concepts, ranging from ‘‘systemic" to ‘‘complex", implying a need for a unified terminology. Per different authors, the main drivers of complexity can ...Related to complexity, there is a wide diversity of concepts, ranging from ‘‘systemic" to ‘‘complex", implying a need for a unified terminology. Per different authors, the main drivers of complexity can be found in human behaviour and uncertainty. This complexity, structural or dynamic can be organizational, technological, or nested in their relationship. ISO international standard 31000:2009 definition of risk management ‘‘coordinated activities to direct and control an organization with regard to risk", when applied to economic sectors, industry, services, project, or activity, it requires the use of models or theories as guidelines. Therefore, as its basic elements comprehend human behaviour and/or uncertainty, risk management to be effective and adapted as much as possible to reality, must be operational within complex systems, as already demonstrated in different R&D environments. Risk management faces demanding challenges when approaching specific and endogenous needs, such as the mining sector. This paper presents a multivariable function analysis methodology approach based on complex system modelling and through real data corresponding to a risk management tool in the mining sector.展开更多
As coal mining is extended from shallow to deep areas along the western coalfield,it is of great significance to study weakly cemented sandstone at different depths for underground mining engineering.Sandstones from d...As coal mining is extended from shallow to deep areas along the western coalfield,it is of great significance to study weakly cemented sandstone at different depths for underground mining engineering.Sandstones from depths of 101.5,203.2,317.3,406.9,509.9 and 589.8 m at the Buertai Coal Mine were collected.The characteristic strength,acoustic emission(AE),and energy evolution of sandstone during uniaxial compression tests were analyzed.The results show that the intermediate frequency(125-275 kHz)of shallow rock mainly occurs in the postpeak stage,while deep rock occurs in the prepeak stage.The initiation strength and damage strength of the sandstone at different depths range from 0.23 to 0.50 and 0.63 to 0.84 of peak strength(σ_(c)),respectively,decrease exponentially and are a power function with depth.The precursor strength ranges from 0.88σ_(c)to 0.99σ_(c),increases with depth before reaching a depth of 300 m,and tends to stabilize after 300 m.The ratio of the initiation strength to the damage strength(k)ranges from 0.25 to 0.62 and decreases exponentially with depth.The failure modes of sandstone at different depths are tension-dominated mixed tensile-shear failure.Shear failure mainly occurs at the unstable crack propagation stage.The count of the shear failure bands before the peak strength increases gradually,and increases first and then decreases after the peak strength with burial depth.The cumulative input energy,released elastic energy and dissipated energy increase with depth.The elastic release rate ranges from 0.46×10^(-3)to 198.57×10^(-3)J/(cm^(3)s)and increases exponentially with depth.展开更多
To investigate the nature of gas hydrates in the Makran area,new high-resolution geophysical data were acquired between 2018-2019.The data collected comprise multibeam and two-dimensional multi-channel seismic reflect...To investigate the nature of gas hydrates in the Makran area,new high-resolution geophysical data were acquired between 2018-2019.The data collected comprise multibeam and two-dimensional multi-channel seismic reflection data.The multibeam bathymetry data show East-North-East(ENE)ridges,piggy-back basins,canyon and channel systems,and the morphology of the abyssal plain.Continuous and discontinuous bottom simulating reflectors(BSRs)occur in the piggy-back basins on most of the seismic profiles available.The BSRs cut the dipping layers with strong amplitude and reversed polarity.Discontinuous BSRs indicate a transition along a dipping high-permeable sand layers from gas-rich segment to the gas hydrate-bearing segment and sugge st alternating sediments of fine and relatively coarse grain size.Double BSRs are highly dynamic and attributed to slumps occurring in the study area.The BSRs induced by slumps are located both at deep and shallow depths,responding to the temperature or pressure variation.For the first time,BSRs are observed in the abyssal plain of the Makran area,being associated with anticline structures,which do not show large spatial continuity and are strongly conditioned by structural conditions such as anticlines and fluid migration pathways,including deep fault,gas chimney,and high-permeable sedimentary layer.Our results may help to assess the gas hydrate potential within the piggy-back basins and to determine the most promising target areas.Moreover,results about the abyssal plain BSR may help to locate hydrocarbon reservoirs in the deep ocean.展开更多
<b><span style="font-family:Verdana;">Objectives: </span></b></span><span><span><span style="font-family:""><span style="font-family:Ver...<b><span style="font-family:Verdana;">Objectives: </span></b></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Early identification of patients with the novel coronavirus in</span><span style="font-family:Verdana;">duced-disease 2019 (COVID-19) and pneumonia is currently challenging.</span><span style="font-family:Verdana;"> Few data are available on validated scores predictive of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. The Portuguese Society of Intensive Care (PSIC) proposed a risk score whose main goals were to predict a higher probability of COVID-19 and optimize hospital resources, adjusting patients’ intervention. This study aimed to validate the PSIC risk score applied to inpatients with pneumonia.</span><b><span style="font-family:Verdana;"> Methods:</span></b><span style="font-family:Verdana;"> A retrospective analysis of 207 patients with pneumonia admitted to a suspected/confirmed </span><span style="font-family:Verdana;">SARS-CoV-2 infection specialized ward (20/03 to 20/05/2020) was per</span><span style="font-family:Verdana;">formed. Score variables were analyzed to determine the significance of the indepen</span><span style="font-family:Verdana;">dent predictive variables on the probability of a positive SARS-CoV-2</span><span style="font-family:Verdana;"> rRT-PCR test. The binary logistic regression modeling approach was selected. The best cut-off value was obtained with the Receiver Operating Characteristic (ROC) curve together with the evaluation of the discriminatory power through the Area Under the Curve (AUC).</span><b><span style="font-family:Verdana;"> Results: </span></b><span style="font-family:Verdana;">The validation cohort included</span><b> </b><span style="font-family:Verdana;">145 patients. Typical chest computed-tomography features (OR, 12.16;95%</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">CI, 3.32</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">44.50) and contact with a positive SARS-CoV-2 patient (OR, 6.56;95%</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">CI, 1.33</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">32.30) were the most significant independent predictive variables. A score ≥</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">10 increased suspicion for</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">SARS-CoV-2 pneumonia</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. The AUC</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">was</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0.82 (</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">95%</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">CI, 0.73</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0.91</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">) demonstrating the good discriminating power for COVID-19 probability stratification in inpatients with pneumonia. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><b><span style="font-family:Verdana;">Conclusions: </span></b></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The application of the PSIC score to inpatients with pneumonia may be of value in predicting the risk of COVID-19.</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Further studies from other centers are needed to validate this score widely.展开更多
Submarine seep plumes are a natural phenomenon in which different types of gases migrate through deep or shallow subsurface sediments and leak into seawater in pressure gradient.When detected using acoustic data,the l...Submarine seep plumes are a natural phenomenon in which different types of gases migrate through deep or shallow subsurface sediments and leak into seawater in pressure gradient.When detected using acoustic data,the leaked gases frequently exhibit a flame-like structure.We numerically modelled the relationship between the seismic response characteristic and bubble volume fraction to establish the bubble volume fraction in the submarine seep plume.Results show that our models are able to invert and predict the bubble volume fraction from field seismic oceanography data,by which synthetic seismic sections in different dominant frequencies could be numerically simulated,seismic attribute sections(e.g.,instantaneous amplitude,instantaneous frequency,and instantaneous phase)extracted,and the correlation between the seismic attributes and bubble volume fraction be quantitatively determined with functional equations.The instantaneous amplitude is positively correlated with bubble volume fraction,while the instantaneous frequency and bubble volume fraction are negatively correlated.In addition,information entropy is introduced as a proxy to quantify the relationship between the instantaneous phase and bubble volume fraction.As the bubble volume fraction increases,the information entropy of the instantaneous phase increases rapidly at the beginning,followed by a slight upward trend,and finally stabilizes.Therefore,under optimal noise conditions,the bubble volume fraction of submarine seep plumes can be inverted and predicted based on seismic response characteristics in terms of seismic attributes.展开更多
Even when damaged by injury or disease bone tissue has the remarkable ability to regenerate.When this process is limited by large size bone defects,tissue engineering is responsible for restoring,maintaining or improv...Even when damaged by injury or disease bone tissue has the remarkable ability to regenerate.When this process is limited by large size bone defects,tissue engineering is responsible for restoring,maintaining or improving tissue function.Scaffolds are support structures,designed to be implanted in the damaged site,supporting mechanical loads and protecting the regenerating bone tissue.In this paper,3D-printed PLA scaffolds with three different porosity values and two different geometries were experimentally and numerically characterized.Micro-CT analysis showed that fused filament fabrication can be used to produce scaffolds with the desired porosity and 100%of interconnected pores.Under monotonical compression,scaffolds apparent compressive modulus increased from 89 to 918 MPa,while yield stress increased from 2.9 to 27.5 MPa as porosity decreased from 70 to 30%.Open porosity decreased up to 8%on aligned scaffolds and 14%on staggered scaffolds,after compression,while scaffold’s surface-to-volume ratio highest reduction(7.48 to 4.55 mm−1)was obtained with aligned low porosity scaffolds.Micro-CT volume reconstruction allowed for scaffold simplified numerical models to be built and analyzed.Excellent agreement was found when predicting scaffold’s apparent compressive modulus.Overall,it can be concluded that 3D printing is a viable scaffold manufacturing technique for trabecular bone replacement.展开更多
Soil water management plays an important role in the response of kiwi plants （Actinidia deliciosa A. Chev.）. In GuimarSes district soil moisture content is monitored in kiwifi＇uit orchard as a routine parameter. Dr...Soil water management plays an important role in the response of kiwi plants （Actinidia deliciosa A. Chev.）. In GuimarSes district soil moisture content is monitored in kiwifi＇uit orchard as a routine parameter. Drip irrigation system is the method used. This crop tends to have high water requirements and extends over a wide area in Portugal, requiring innovative solutions to achieve better benefits. A method that correlates soil and crop conditions with the parameters of remote sensing was established in this study. To assess the level of accuracy of soil moisture measurements from satellites, it is important to compare satellite image with ground real data （namely the frequency domain reflectometry （FDR）, Diviner 2000）. The combination of multispectral satellite images produces an image representative of vegetation vigour, density and health. In this study, Landsat satellite images （2011 and 2013） are used and vegetation indexes are calculated for different periods of time, using the software Idrisi Taiga. The information of vegetation indexes is crossed with data of soil moisture, in situ, to establish a correlation between both of them. Thus, it allows to improve the soil water content monitoring, in particular for the soil water balance optimization and its effect on kiwi biornass production.展开更多
Polymeric coronary stents,like the ABSORB^(TM)are commonly used to treat atherosclerosis due to their bioresorbable and cell-compatible polymer structure.However,they face challenges such as high strut thickness,high ...Polymeric coronary stents,like the ABSORB^(TM)are commonly used to treat atherosclerosis due to their bioresorbable and cell-compatible polymer structure.However,they face challenges such as high strut thickness,high elastic recoil,and lack of radiopacity.This study aims to address these limitations by modifying degradable stents produced by additive manufacturing with poly(lactic acid)(PLA)and poly(ε-caprolactone)(PCL)with degradable metallic coatings,specifically zinc(Zn)and magnesium(Mg),deposited via radiofrequency(rf)magnetron sputtering.The characterisation included the evaluation of the degradation of the coatings,antibacterial,anti-thrombogenicity,radiopacity,and mechanical properties.The results showed that the metallic coatings inhibited bacterial growth,though Mg exhibited a high degradation rate.Thrombogenicity studies showed that Zn-coated stents had anticoagulant properties,while Mgcoated and controls were thrombogenic.Zn coatings significantly improved radiopacity,enhancing contrast by 43%.Mechanical testing revealed that metallic coatings reduced yield strength and,thus,diminished elastic recoil after stent expansion.Zn-coated stents improved cyclic compression resistance by 270%for PCL stents,with PLA-based stents showing smaller improvements.The coatings also enhanced crush resistance,particularly for Zn-coated PCL stents.Overall,Zn-coated polymers have emerged as the premier prototype due to their superior biological and mechanical performance,appropriate degradation during the stent life,and ability to provide the appropriate radiopacity to medical devices.展开更多
Given their technical and economic advantages,the application of explosive substances to rock mass excavation is widely used.However,because of serious environmental restraints,there has been an increasing need to use...Given their technical and economic advantages,the application of explosive substances to rock mass excavation is widely used.However,because of serious environmental restraints,there has been an increasing need to use complex tools to control environmental effects due to blast-induced ground vibrations.In the present study,an artificial neural network(ANN)with k-fold cross-validation was applied to a dataset containing 1114 observations that was obtained from published results;furthermore,quantitative and qualitative parameters were considered for ground vibration amplitude prediction.The best ANN model obtained has a maximum coefficient of determination of 0.840 and a mean absolute error of 5.59 and it comprises 17 input parameters,12 neurons in a one-layer hidden layer,and a sigmoid transfer function.Compared with the traditional models,the model obtained using the proposed methodology demonstrated better generalization ability.Furthermore,the proposed methodology offers an ANN model with higher prediction ability.展开更多
文摘Related to complexity, there is a wide diversity of concepts, ranging from ‘‘systemic" to ‘‘complex", implying a need for a unified terminology. Per different authors, the main drivers of complexity can be found in human behaviour and uncertainty. This complexity, structural or dynamic can be organizational, technological, or nested in their relationship. ISO international standard 31000:2009 definition of risk management ‘‘coordinated activities to direct and control an organization with regard to risk", when applied to economic sectors, industry, services, project, or activity, it requires the use of models or theories as guidelines. Therefore, as its basic elements comprehend human behaviour and/or uncertainty, risk management to be effective and adapted as much as possible to reality, must be operational within complex systems, as already demonstrated in different R&D environments. Risk management faces demanding challenges when approaching specific and endogenous needs, such as the mining sector. This paper presents a multivariable function analysis methodology approach based on complex system modelling and through real data corresponding to a risk management tool in the mining sector.
基金This work was supported by the National Natural Science Foundation of China(Nos.U1910206,51874312,51861145403)Science and Technology Project of Inner Mongolia Autonomous Region(No.2019GG140)Major Scientific and Technological Innovation Project of Shandong Province(Nos.2019SDZY01,2019SDZY02).These sources of supports are gratefully acknowledged.
文摘As coal mining is extended from shallow to deep areas along the western coalfield,it is of great significance to study weakly cemented sandstone at different depths for underground mining engineering.Sandstones from depths of 101.5,203.2,317.3,406.9,509.9 and 589.8 m at the Buertai Coal Mine were collected.The characteristic strength,acoustic emission(AE),and energy evolution of sandstone during uniaxial compression tests were analyzed.The results show that the intermediate frequency(125-275 kHz)of shallow rock mainly occurs in the postpeak stage,while deep rock occurs in the prepeak stage.The initiation strength and damage strength of the sandstone at different depths range from 0.23 to 0.50 and 0.63 to 0.84 of peak strength(σ_(c)),respectively,decrease exponentially and are a power function with depth.The precursor strength ranges from 0.88σ_(c)to 0.99σ_(c),increases with depth before reaching a depth of 300 m,and tends to stabilize after 300 m.The ratio of the initiation strength to the damage strength(k)ranges from 0.25 to 0.62 and decreases exponentially with depth.The failure modes of sandstone at different depths are tension-dominated mixed tensile-shear failure.Shear failure mainly occurs at the unstable crack propagation stage.The count of the shear failure bands before the peak strength increases gradually,and increases first and then decreases after the peak strength with burial depth.The cumulative input energy,released elastic energy and dissipated energy increase with depth.The elastic release rate ranges from 0.46×10^(-3)to 198.57×10^(-3)J/(cm^(3)s)and increases exponentially with depth.
基金the Laboratory for Marine Mineral Resources,Qingdao National Laboratory for Marine Science and Technology(No.MMRKF201810)the China Geological Survey(Nos.DD20190582,DD20191009,DD20160214)funded by the Shandong Province"Taishan Scholar"Construction Project。
文摘To investigate the nature of gas hydrates in the Makran area,new high-resolution geophysical data were acquired between 2018-2019.The data collected comprise multibeam and two-dimensional multi-channel seismic reflection data.The multibeam bathymetry data show East-North-East(ENE)ridges,piggy-back basins,canyon and channel systems,and the morphology of the abyssal plain.Continuous and discontinuous bottom simulating reflectors(BSRs)occur in the piggy-back basins on most of the seismic profiles available.The BSRs cut the dipping layers with strong amplitude and reversed polarity.Discontinuous BSRs indicate a transition along a dipping high-permeable sand layers from gas-rich segment to the gas hydrate-bearing segment and sugge st alternating sediments of fine and relatively coarse grain size.Double BSRs are highly dynamic and attributed to slumps occurring in the study area.The BSRs induced by slumps are located both at deep and shallow depths,responding to the temperature or pressure variation.For the first time,BSRs are observed in the abyssal plain of the Makran area,being associated with anticline structures,which do not show large spatial continuity and are strongly conditioned by structural conditions such as anticlines and fluid migration pathways,including deep fault,gas chimney,and high-permeable sedimentary layer.Our results may help to assess the gas hydrate potential within the piggy-back basins and to determine the most promising target areas.Moreover,results about the abyssal plain BSR may help to locate hydrocarbon reservoirs in the deep ocean.
文摘<b><span style="font-family:Verdana;">Objectives: </span></b></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Early identification of patients with the novel coronavirus in</span><span style="font-family:Verdana;">duced-disease 2019 (COVID-19) and pneumonia is currently challenging.</span><span style="font-family:Verdana;"> Few data are available on validated scores predictive of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. The Portuguese Society of Intensive Care (PSIC) proposed a risk score whose main goals were to predict a higher probability of COVID-19 and optimize hospital resources, adjusting patients’ intervention. This study aimed to validate the PSIC risk score applied to inpatients with pneumonia.</span><b><span style="font-family:Verdana;"> Methods:</span></b><span style="font-family:Verdana;"> A retrospective analysis of 207 patients with pneumonia admitted to a suspected/confirmed </span><span style="font-family:Verdana;">SARS-CoV-2 infection specialized ward (20/03 to 20/05/2020) was per</span><span style="font-family:Verdana;">formed. Score variables were analyzed to determine the significance of the indepen</span><span style="font-family:Verdana;">dent predictive variables on the probability of a positive SARS-CoV-2</span><span style="font-family:Verdana;"> rRT-PCR test. The binary logistic regression modeling approach was selected. The best cut-off value was obtained with the Receiver Operating Characteristic (ROC) curve together with the evaluation of the discriminatory power through the Area Under the Curve (AUC).</span><b><span style="font-family:Verdana;"> Results: </span></b><span style="font-family:Verdana;">The validation cohort included</span><b> </b><span style="font-family:Verdana;">145 patients. Typical chest computed-tomography features (OR, 12.16;95%</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">CI, 3.32</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">44.50) and contact with a positive SARS-CoV-2 patient (OR, 6.56;95%</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">CI, 1.33</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">32.30) were the most significant independent predictive variables. A score ≥</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">10 increased suspicion for</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">SARS-CoV-2 pneumonia</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. The AUC</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">was</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0.82 (</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">95%</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">CI, 0.73</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0.91</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">) demonstrating the good discriminating power for COVID-19 probability stratification in inpatients with pneumonia. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><b><span style="font-family:Verdana;">Conclusions: </span></b></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">The application of the PSIC score to inpatients with pneumonia may be of value in predicting the risk of COVID-19.</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Further studies from other centers are needed to validate this score widely.
基金Supported by the Natural Science Foundation of Shandong Province(No.ZR2022MD074)the Laboratory for Marine Mineral Resources+3 种基金Qingdao National Laboratory for Marine Science and Technology(No.MMRKF201810)the National Natural Science Foundation of China(No.41606077)the National Key R&D Program of China:HighPrecision Characterization Technology of Gas Hydrate Reservoir(No.2017YFC0307406-03)supported by the Shandong Province Taishan Scholar Construction Project。
文摘Submarine seep plumes are a natural phenomenon in which different types of gases migrate through deep or shallow subsurface sediments and leak into seawater in pressure gradient.When detected using acoustic data,the leaked gases frequently exhibit a flame-like structure.We numerically modelled the relationship between the seismic response characteristic and bubble volume fraction to establish the bubble volume fraction in the submarine seep plume.Results show that our models are able to invert and predict the bubble volume fraction from field seismic oceanography data,by which synthetic seismic sections in different dominant frequencies could be numerically simulated,seismic attribute sections(e.g.,instantaneous amplitude,instantaneous frequency,and instantaneous phase)extracted,and the correlation between the seismic attributes and bubble volume fraction be quantitatively determined with functional equations.The instantaneous amplitude is positively correlated with bubble volume fraction,while the instantaneous frequency and bubble volume fraction are negatively correlated.In addition,information entropy is introduced as a proxy to quantify the relationship between the instantaneous phase and bubble volume fraction.As the bubble volume fraction increases,the information entropy of the instantaneous phase increases rapidly at the beginning,followed by a slight upward trend,and finally stabilizes.Therefore,under optimal noise conditions,the bubble volume fraction of submarine seep plumes can be inverted and predicted based on seismic response characteristics in terms of seismic attributes.
基金This work was supported by FCT,through IDMEC under LAETA(project UIDB/50022/2020)CeFEMA(UID/CTM/04540/2019)+1 种基金CERENA(UIDB/04028/2020)IPFN activities also received financial support from FCT through Projects UIDB/50010/2020 and UIDP/50010/2020.
文摘Even when damaged by injury or disease bone tissue has the remarkable ability to regenerate.When this process is limited by large size bone defects,tissue engineering is responsible for restoring,maintaining or improving tissue function.Scaffolds are support structures,designed to be implanted in the damaged site,supporting mechanical loads and protecting the regenerating bone tissue.In this paper,3D-printed PLA scaffolds with three different porosity values and two different geometries were experimentally and numerically characterized.Micro-CT analysis showed that fused filament fabrication can be used to produce scaffolds with the desired porosity and 100%of interconnected pores.Under monotonical compression,scaffolds apparent compressive modulus increased from 89 to 918 MPa,while yield stress increased from 2.9 to 27.5 MPa as porosity decreased from 70 to 30%.Open porosity decreased up to 8%on aligned scaffolds and 14%on staggered scaffolds,after compression,while scaffold’s surface-to-volume ratio highest reduction(7.48 to 4.55 mm−1)was obtained with aligned low porosity scaffolds.Micro-CT volume reconstruction allowed for scaffold simplified numerical models to be built and analyzed.Excellent agreement was found when predicting scaffold’s apparent compressive modulus.Overall,it can be concluded that 3D printing is a viable scaffold manufacturing technique for trabecular bone replacement.
文摘Soil water management plays an important role in the response of kiwi plants （Actinidia deliciosa A. Chev.）. In GuimarSes district soil moisture content is monitored in kiwifi＇uit orchard as a routine parameter. Drip irrigation system is the method used. This crop tends to have high water requirements and extends over a wide area in Portugal, requiring innovative solutions to achieve better benefits. A method that correlates soil and crop conditions with the parameters of remote sensing was established in this study. To assess the level of accuracy of soil moisture measurements from satellites, it is important to compare satellite image with ground real data （namely the frequency domain reflectometry （FDR）, Diviner 2000）. The combination of multispectral satellite images produces an image representative of vegetation vigour, density and health. In this study, Landsat satellite images （2011 and 2013） are used and vegetation indexes are calculated for different periods of time, using the software Idrisi Taiga. The information of vegetation indexes is crossed with data of soil moisture, in situ, to establish a correlation between both of them. Thus, it allows to improve the soil water content monitoring, in particular for the soil water balance optimization and its effect on kiwi biornass production.
基金The authors acknowledge Fundaçao para a Ciencia e Tecnologia(FCT),Portugal,for the support through the Research Centre CEMMPRE(UIDB/00285/2020).
文摘Polymeric coronary stents,like the ABSORB^(TM)are commonly used to treat atherosclerosis due to their bioresorbable and cell-compatible polymer structure.However,they face challenges such as high strut thickness,high elastic recoil,and lack of radiopacity.This study aims to address these limitations by modifying degradable stents produced by additive manufacturing with poly(lactic acid)(PLA)and poly(ε-caprolactone)(PCL)with degradable metallic coatings,specifically zinc(Zn)and magnesium(Mg),deposited via radiofrequency(rf)magnetron sputtering.The characterisation included the evaluation of the degradation of the coatings,antibacterial,anti-thrombogenicity,radiopacity,and mechanical properties.The results showed that the metallic coatings inhibited bacterial growth,though Mg exhibited a high degradation rate.Thrombogenicity studies showed that Zn-coated stents had anticoagulant properties,while Mgcoated and controls were thrombogenic.Zn coatings significantly improved radiopacity,enhancing contrast by 43%.Mechanical testing revealed that metallic coatings reduced yield strength and,thus,diminished elastic recoil after stent expansion.Zn-coated stents improved cyclic compression resistance by 270%for PCL stents,with PLA-based stents showing smaller improvements.The coatings also enhanced crush resistance,particularly for Zn-coated PCL stents.Overall,Zn-coated polymers have emerged as the premier prototype due to their superior biological and mechanical performance,appropriate degradation during the stent life,and ability to provide the appropriate radiopacity to medical devices.
基金the support of CERENA–Center for Natural Resources and Environment(strategic project FCT-UID/ECI/04028/2019),Portugal.
文摘Given their technical and economic advantages,the application of explosive substances to rock mass excavation is widely used.However,because of serious environmental restraints,there has been an increasing need to use complex tools to control environmental effects due to blast-induced ground vibrations.In the present study,an artificial neural network(ANN)with k-fold cross-validation was applied to a dataset containing 1114 observations that was obtained from published results;furthermore,quantitative and qualitative parameters were considered for ground vibration amplitude prediction.The best ANN model obtained has a maximum coefficient of determination of 0.840 and a mean absolute error of 5.59 and it comprises 17 input parameters,12 neurons in a one-layer hidden layer,and a sigmoid transfer function.Compared with the traditional models,the model obtained using the proposed methodology demonstrated better generalization ability.Furthermore,the proposed methodology offers an ANN model with higher prediction ability.
