AIM:To find out if by combining 2 ultrasound based elastographic methods:acoustic radiation force impulse(ARFI)elastography and transient elastography(TE),we can improve the prediction of fibrosis in patients with chr...AIM:To find out if by combining 2 ultrasound based elastographic methods:acoustic radiation force impulse(ARFI)elastography and transient elastography(TE),we can improve the prediction of fibrosis in patients with chronic hepatitis C.METHODS:Our study included 197 patients with chronic hepatitis C.In each patient,we performed,in the same session,liver stiffness(LS)measurements by means of TE and ARFI,respectively,and liver biopsy(LB),assessed according to the Metavir score.10 LS measurements were performed both by TE and ARFI;median values were calculated and expressed in kilopascals(kPa)and meters/second(m/s),respectively.Only TE and ARFI measurements with IQR<30%andSR≥60%were considered reliable.RESULTS:On LB 13(6.6%)patients had F0,32(16.2%) had F1,52(26.4%)had F2,47(23.9%)had F3,and 53(26.9%)had F4.A direct,strong correlation was found between TE measurements and fibrosis(r=0.741),between ARFI and fibrosis(r=0.730)and also between TE and ARFI(r=0.675).For predicting significant fibrosis(F≥2),for a cutoff of 6.7 kPa,TE had 77.5% sensitivity(Se)and 86.5%specificity(Sp)[area under the receiver operating characteristic curve(AUROC)0.87] and for a cutoff of 1.2 m/s,ARFI had 76.9%Se and 86.7%Sp(AUROC 0.84).For predicting cirrhosis(F=4),for a cutoff of 12.2 kPa,TE had 96.2%Se and 89.6% Sp(AUROC 0.97)and for a cutoff of 1.8 m/s,ARFI had 90.4%Se and 85.6%Sp(AUROC 0.91).When both elastographic methods were taken into consideration,for predicting significant fibrosis(F≥2),(TE≥6.7 kPa and ARFI≥1.2 m/s)we obtained 60.5%Se,93.3% Sp,96.8%positive predictive value(PPV),41.4%negative predictive value(NPV)and 68%accuracy,while for predicting cirrhosis(TE≥12.2 kPa and ARFI≥1.8 m/s) we obtained 84.9%Se,94.4%Sp,84.9%PPV,94.4% NPV and 91.8%accuracy.CONCLUSION:TE used in combination with ARFI is highly specific for predicting significant fibrosis;therefore when the two methods are concordant,liver biopsy can be avoided.展开更多
Proper design of rock bolt support in underground mines is critical to avoid incidents, accidents and loss of production. The traditional design approach only considers the axial(tensile) capacity and this is clearly ...Proper design of rock bolt support in underground mines is critical to avoid incidents, accidents and loss of production. The traditional design approach only considers the axial(tensile) capacity and this is clearly not the situation in situ, where a rock bolt is subjected to both axial and shear/bending loads which determines its overall performance and failure behaviour. To demonstrate and analyse the shear displacement in bedded roof, scaled physical models of underground excavation were created. From the models it was found that the shear displacement between the layers depends on the vertical roof deformation and thickness of beds. To analyse the effect of combined loading on rock bolt design for suspension and beam building models, analytical methods were used to calculate the required spacing of rock bolt for a given safety factor. Numerical models were then created using Rocscience RS2 software to establish the stresses on the rock bolt. The results show a significant reduction in safety factor for suspension as demonstrated in an example(reduced from 3.5 to 2.0) and beam building(2.0 to 1.36) when the rock bolt capacities are calculated considering the effect of combined loading as opposed to just the axial or shear loads.展开更多
With the recent advancement in nanotechnology,nanoparticles(NPs)offer an ample variety of smart functions than conventional materials in various aspects.As compared to larger particles,NPs possess unique characteristi...With the recent advancement in nanotechnology,nanoparticles(NPs)offer an ample variety of smart functions than conventional materials in various aspects.As compared to larger particles,NPs possess unique characteristics and excellent abilities,such as low toxicity,chemical stability,surface functionality,and biocompatibility.These advantageous properties allow them to be widely utilized in many applications,including biomedical applications,energy applications,IT applications,and industrial applications.In order to fulfill the increasing demands of NP applications,existing NP synthesis methods need to be improved based on the requirements of different applications to further their usage.A comprehensive understanding of the relationships between synthesis parameters and properties of NPs can help us better fine-tune them with designed properties and minimal toxicity.This review paper will discuss the commonly used synthesis methods of functionalized NPs,as well as future directions and challenges to develop various synthesis methods further.展开更多
文摘AIM:To find out if by combining 2 ultrasound based elastographic methods:acoustic radiation force impulse(ARFI)elastography and transient elastography(TE),we can improve the prediction of fibrosis in patients with chronic hepatitis C.METHODS:Our study included 197 patients with chronic hepatitis C.In each patient,we performed,in the same session,liver stiffness(LS)measurements by means of TE and ARFI,respectively,and liver biopsy(LB),assessed according to the Metavir score.10 LS measurements were performed both by TE and ARFI;median values were calculated and expressed in kilopascals(kPa)and meters/second(m/s),respectively.Only TE and ARFI measurements with IQR<30%andSR≥60%were considered reliable.RESULTS:On LB 13(6.6%)patients had F0,32(16.2%) had F1,52(26.4%)had F2,47(23.9%)had F3,and 53(26.9%)had F4.A direct,strong correlation was found between TE measurements and fibrosis(r=0.741),between ARFI and fibrosis(r=0.730)and also between TE and ARFI(r=0.675).For predicting significant fibrosis(F≥2),for a cutoff of 6.7 kPa,TE had 77.5% sensitivity(Se)and 86.5%specificity(Sp)[area under the receiver operating characteristic curve(AUROC)0.87] and for a cutoff of 1.2 m/s,ARFI had 76.9%Se and 86.7%Sp(AUROC 0.84).For predicting cirrhosis(F=4),for a cutoff of 12.2 kPa,TE had 96.2%Se and 89.6% Sp(AUROC 0.97)and for a cutoff of 1.8 m/s,ARFI had 90.4%Se and 85.6%Sp(AUROC 0.91).When both elastographic methods were taken into consideration,for predicting significant fibrosis(F≥2),(TE≥6.7 kPa and ARFI≥1.2 m/s)we obtained 60.5%Se,93.3% Sp,96.8%positive predictive value(PPV),41.4%negative predictive value(NPV)and 68%accuracy,while for predicting cirrhosis(TE≥12.2 kPa and ARFI≥1.8 m/s) we obtained 84.9%Se,94.4%Sp,84.9%PPV,94.4% NPV and 91.8%accuracy.CONCLUSION:TE used in combination with ARFI is highly specific for predicting significant fibrosis;therefore when the two methods are concordant,liver biopsy can be avoided.
基金This work was supported by the Minerals Research Institute of Western Australia(MRIWA)Mining3 and Peabody Energy.
文摘Proper design of rock bolt support in underground mines is critical to avoid incidents, accidents and loss of production. The traditional design approach only considers the axial(tensile) capacity and this is clearly not the situation in situ, where a rock bolt is subjected to both axial and shear/bending loads which determines its overall performance and failure behaviour. To demonstrate and analyse the shear displacement in bedded roof, scaled physical models of underground excavation were created. From the models it was found that the shear displacement between the layers depends on the vertical roof deformation and thickness of beds. To analyse the effect of combined loading on rock bolt design for suspension and beam building models, analytical methods were used to calculate the required spacing of rock bolt for a given safety factor. Numerical models were then created using Rocscience RS2 software to establish the stresses on the rock bolt. The results show a significant reduction in safety factor for suspension as demonstrated in an example(reduced from 3.5 to 2.0) and beam building(2.0 to 1.36) when the rock bolt capacities are calculated considering the effect of combined loading as opposed to just the axial or shear loads.
文摘With the recent advancement in nanotechnology,nanoparticles(NPs)offer an ample variety of smart functions than conventional materials in various aspects.As compared to larger particles,NPs possess unique characteristics and excellent abilities,such as low toxicity,chemical stability,surface functionality,and biocompatibility.These advantageous properties allow them to be widely utilized in many applications,including biomedical applications,energy applications,IT applications,and industrial applications.In order to fulfill the increasing demands of NP applications,existing NP synthesis methods need to be improved based on the requirements of different applications to further their usage.A comprehensive understanding of the relationships between synthesis parameters and properties of NPs can help us better fine-tune them with designed properties and minimal toxicity.This review paper will discuss the commonly used synthesis methods of functionalized NPs,as well as future directions and challenges to develop various synthesis methods further.
