Background:To evaluate the discriminatory ability of imaging modalities'scoring systems in the prediction of COVID-19 adverse outcomes like ICU admission,ventilatory support,or mortality.Methods:We searched PUBMED...Background:To evaluate the discriminatory ability of imaging modalities'scoring systems in the prediction of COVID-19 adverse outcomes like ICU admission,ventilatory support,or mortality.Methods:We searched PUBMED,EBSCO,WEB OF SCIENCE,and SCOPUS.Two authors independently screened the resulting papers for fulfillment criteria.Meta-DiSc version 1.4,RevMan version 5.4,and MedCalc version 19.1 were used for test accuracy analysis,sensitivity and specificity analysis,and pooling Area under the curve for discriminatory assessment,respectively.Results:Regarding mortality prediction,the computed tomography(CT)showed significantly higher sensitivity[80%;95%CI 0.74-0.85]and positive likelihood ratio(PLR)[4.4195%CI 2.94-6.61]relative to the Lung Ultrasound Score(LUS)approach,while the LUS approached the CT scan with specificity of 81%[95%CI 0.78-0.83]and negative likelihood ratio(NLR)of[0.32;95%CI 0.16-0.64].The pooled area under ROC for LUS was[AUC=0.777,95%CI 0.701-0.852;p<0.001,I2=74.86%,p=0.019]while the pooled area under ROC for CT severity score was[AUC=0.855,95%CI 0.78-0.93;p<0.001,I2=93.73%,p<0.001].Regarding adverse outcomes prediction,the LUS had a slightly higher specificity of[78%;95%CI 0.75-0.80]and PLR of[3.60;95%CI 2.28-5.68]compared to CT score.The pooled AUC using LUS was(0.77,95%CI 0.719-0.832;p<0.001),while using CT severity score was(0.843,95%CI 0.787-0.898;p<0.001),and using X-ray scores was(0.814,95%CI 0.751-0.878;p<0.001).Conclusion:CT severity score showed a better discriminatory ability in pre-dicting COVID-19 adverse outcomes,as in-hospital mortality,ICU admission,and need for ventilatory support compared to LUS and X-RAY scores,while the LUS,being more specific,had a slightly better prognostic value.展开更多
Rotary ionic engines(RIEs)with multi-coaxial contra-rotating propellers(12.6 cm diameter)and their axial thrust are investigated in laboratory conditions,in air at atmospheric pressure,for the first time.The goal is t...Rotary ionic engines(RIEs)with multi-coaxial contra-rotating propellers(12.6 cm diameter)and their axial thrust are investigated in laboratory conditions,in air at atmospheric pressure,for the first time.The goal is to evaluate more advantageous configurations that may be scaled up and further help with development of rotary ionic drones.The propellers are designed with regular pin-emitter electrodes placed coaxially inside a cylindrical collector electrode.When high voltage is applied,propellers spin generating conventional axial thrust which is measured with an electronic scale in a“see-saw”setup.Up to 40 mN thrust was obtained in single propeller RIE at 2600 rpm,0.34 mA,37.5 kV,and an optimal collector electrode diameter of 17 cm.More thrust can be obtained with two and three propellers at constant current per propeller but at a decreased efficiency.Varying the axial propeller-separation showed that propeller-interaction is minimal above 5 cm.Thrust-to-power and thrust-tocurrent ratios were calculated and compared.We experimentally confirm here for the first time that within certain limits,the thrust-to-power variation can be assessed by the propeller kinetic energy-to-power ratio and also by the impedance of the gap(voltage-to-current ratio).A comparison of RIE arrays performance with one,two,and three coaxial propellers and the same total number of propellers per array(six)is also performed.RIE arrays with multi-coaxial propellers can provide larger thrust densities than single-propeller arrays.Also,arrays employing two coaxial propeller unit may be more weight effective.展开更多
文摘Background:To evaluate the discriminatory ability of imaging modalities'scoring systems in the prediction of COVID-19 adverse outcomes like ICU admission,ventilatory support,or mortality.Methods:We searched PUBMED,EBSCO,WEB OF SCIENCE,and SCOPUS.Two authors independently screened the resulting papers for fulfillment criteria.Meta-DiSc version 1.4,RevMan version 5.4,and MedCalc version 19.1 were used for test accuracy analysis,sensitivity and specificity analysis,and pooling Area under the curve for discriminatory assessment,respectively.Results:Regarding mortality prediction,the computed tomography(CT)showed significantly higher sensitivity[80%;95%CI 0.74-0.85]and positive likelihood ratio(PLR)[4.4195%CI 2.94-6.61]relative to the Lung Ultrasound Score(LUS)approach,while the LUS approached the CT scan with specificity of 81%[95%CI 0.78-0.83]and negative likelihood ratio(NLR)of[0.32;95%CI 0.16-0.64].The pooled area under ROC for LUS was[AUC=0.777,95%CI 0.701-0.852;p<0.001,I2=74.86%,p=0.019]while the pooled area under ROC for CT severity score was[AUC=0.855,95%CI 0.78-0.93;p<0.001,I2=93.73%,p<0.001].Regarding adverse outcomes prediction,the LUS had a slightly higher specificity of[78%;95%CI 0.75-0.80]and PLR of[3.60;95%CI 2.28-5.68]compared to CT score.The pooled AUC using LUS was(0.77,95%CI 0.719-0.832;p<0.001),while using CT severity score was(0.843,95%CI 0.787-0.898;p<0.001),and using X-ray scores was(0.814,95%CI 0.751-0.878;p<0.001).Conclusion:CT severity score showed a better discriminatory ability in pre-dicting COVID-19 adverse outcomes,as in-hospital mortality,ICU admission,and need for ventilatory support compared to LUS and X-RAY scores,while the LUS,being more specific,had a slightly better prognostic value.
基金supported by a grant of the Romanian Ministry of Education and Research,CCCDI,project number PN-Ⅲ-P2-2.1-PED-2019-3646,within PNCDI Ⅲ.
文摘Rotary ionic engines(RIEs)with multi-coaxial contra-rotating propellers(12.6 cm diameter)and their axial thrust are investigated in laboratory conditions,in air at atmospheric pressure,for the first time.The goal is to evaluate more advantageous configurations that may be scaled up and further help with development of rotary ionic drones.The propellers are designed with regular pin-emitter electrodes placed coaxially inside a cylindrical collector electrode.When high voltage is applied,propellers spin generating conventional axial thrust which is measured with an electronic scale in a“see-saw”setup.Up to 40 mN thrust was obtained in single propeller RIE at 2600 rpm,0.34 mA,37.5 kV,and an optimal collector electrode diameter of 17 cm.More thrust can be obtained with two and three propellers at constant current per propeller but at a decreased efficiency.Varying the axial propeller-separation showed that propeller-interaction is minimal above 5 cm.Thrust-to-power and thrust-tocurrent ratios were calculated and compared.We experimentally confirm here for the first time that within certain limits,the thrust-to-power variation can be assessed by the propeller kinetic energy-to-power ratio and also by the impedance of the gap(voltage-to-current ratio).A comparison of RIE arrays performance with one,two,and three coaxial propellers and the same total number of propellers per array(six)is also performed.RIE arrays with multi-coaxial propellers can provide larger thrust densities than single-propeller arrays.Also,arrays employing two coaxial propeller unit may be more weight effective.
