AIM： To evaluate the effectiveness of three-dimensional endoanal ultrasound （3D-EAUS） in the assessment of anal fistulae with and without H202 enhancement. METHODS： Sixty-one patients （37 males, aged 17-74 years...AIM： To evaluate the effectiveness of three-dimensional endoanal ultrasound （3D-EAUS） in the assessment of anal fistulae with and without H202 enhancement. METHODS： Sixty-one patients （37 males, aged 17-74 years） with anal fistulae, which were not simple low types, were evaluated by physical examination and 3D-EAUS with and without enhancement. Fistula classification was determined with each modality and compared to operative findings as the reference standard. RESULTS： The accuracy of 3D-EAUS was significantly higher than that of physical examination in detecting the primary tract （84.4% vs 68.7%, P = 0.037） and secondary extension （81.8% vs 62.1%, P = 0.01） and localizing the internal opening （84.2% vs 59.7%, P = 0.004）. A contrast study with H202 detected several more fistula components including two primary suprasphincteric fistula tracks and one supralevator secondary extension, which were not detected on non-contrast study. However, there was no significant difference in accuracy between 3D-EAUS and H202- enhanced 3D-EAUS with respect to classification of the primary tract （84.4% vs 89.1%, P = 0.435） or secondary extension （81.8% vs 86.4%, P = 0.435） or localization of the internal opening （84.2% vs 89.5%, P = 0.406）. CONCLUSION： 3D-EAUS was highly reliable in the diagnosis of an anal fistula. H2O2 enhancement was helpful at times and selective use in difficult cases may be economical and reliable.展开更多
Numerical investigation of a supersonic jet from the nose of a lifting-body vehicle opposing a hypersonic flow with the freestream Mach number being 8.0 at 40 km altitude was carried out by solving the three-dimension...Numerical investigation of a supersonic jet from the nose of a lifting-body vehicle opposing a hypersonic flow with the freestream Mach number being 8.0 at 40 km altitude was carried out by solving the three-dimensional, time-accurate Navier-Stokes equations with a hybrid meshes approach. Based on the analysis of the flow field structures and aerodynamic characteristics, the behaviours relevant to the LPM jet were discussed in detail, including the drag reduction effect, the periodic oscillation and the feedback loop. The obtained results show that the flow oscillation characteristic of the LPM jet is low-frequency and high-amplitude while that of the SPM jet is high-frequency and low-amplitude. Compared with the clearly dominant frequencies of the LPM jet, the SPM jet exhibits a broad-band structure. The LPM jet can sustain drag reduction effect until the angle of attack is 8°, and the lift-to-drag ratio of the vehicle is effectively improved by 6.95% at angle of attack of 6°. The self-sustained oscillation process was studied by a typical oscillating cycle of the drag force coefficient and the variation of the instantaneous pressure distribution,which reveals an off-axial flapping motion of the conical shear layer. The variation of the subsonic recirculation zone ahead of the vehicle nose strengthens the understanding of the jet behavior including the source of instability in the long penetration mode and the mechanism of the feedback loop. The aim of this paper is to advance the technology readiness level for the counterflowing jet applied as an active control technology in hypersonic flows by gaining a better insight of the flow physics.展开更多
Objective:To evaluate the prevalence of primary iris and/or ciliary body cysts in eyes with shallow anterior chamber and their effect on the narrowing of the anterior chamber angle.Methods:Among the general physical c...Objective:To evaluate the prevalence of primary iris and/or ciliary body cysts in eyes with shallow anterior chamber and their effect on the narrowing of the anterior chamber angle.Methods:Among the general physical check-up population,subjects with shallow anterior chambers,as judged by van Herick technique,were recruited for further investigation.Ultrasound biomicroscope(UBM) was used to detect and measure the cysts located in the iris and/or ciliary body,the anterior chamber depth(ACD),the angle opening distance at 500 μm(AOD500),and the trabecular-iris angle(TIA).A-scan ultrasonography was used to measure the ocular biometry,including lens thickness,axial length,lens/axial length factor(LAF),and relative lens position(RLP).The effect of the cyst on narrowing the corresponding anterior chamber angle and the entire angle was evaluated by the UBM images,ocular biometry,and gonioscopic grading.The eye with unilateral cyst was compared with the eye without the cyst for further analysis.Results:Among the 727 subjects with shallow anterior chamber,primary iris and ciliary body cysts were detected in 250(34.4%) patients;among them 96(38.4%) patients showed unilateral single cyst,21(8.4%) patients had unilateral double cysts,and 42(16.8%) patients manifested unilateral multiple and multi-quadrants cysts.Plateau iris configuration was found in 140 of 361(38.8%) eyes with cysts.The mean size of total cysts was(0.6547±0.2319) mm.In evaluation of the effect of the cyst size and location on narrowing the corresponding angle to their position,the proportion of the cysts causing corresponding angle narrowing or closure among the cysts larger than 0.8 mm(113/121,93.4%) was found to be significantly higher than that of the cysts smaller than 0.8 mm(373/801,46.6%),and a significant higher proportion was also found in the cysts located at iridociliary sulcus(354/437,81.0%) than in that at the pars plicata(131/484,27.1%).In evaluating the effect of the cyst on the entire anterior chamber angle,the eyes with multiple and multi-quadrants cysts manifested significant narrowing of the entire anterior chamber angle as compared with the eyes without cysts,based on the data analysis in comparison of TIA,AOD500,and gonioscopic grading evaluation.The unilateral single or double cysts in the eyes had no significant effect on narrowing of anterior chamber angle as compared with eyes without cysts.The iris and/or ciliary body cysts did not seem to affect the axial length,ACD,lens thickness,RLP,LAF.Conclusions:The prevalence of primary iris and ciliary body cyst was 34.4% in the subjects with shallow anterior chamber.The cysts larger than 0.8 mm,locating at iridociliary sulcus,or multiple and extensive cysts were inclined to cause the angle narrowing or closure.展开更多
文摘AIM： To evaluate the effectiveness of three-dimensional endoanal ultrasound （3D-EAUS） in the assessment of anal fistulae with and without H202 enhancement. METHODS： Sixty-one patients （37 males, aged 17-74 years） with anal fistulae, which were not simple low types, were evaluated by physical examination and 3D-EAUS with and without enhancement. Fistula classification was determined with each modality and compared to operative findings as the reference standard. RESULTS： The accuracy of 3D-EAUS was significantly higher than that of physical examination in detecting the primary tract （84.4% vs 68.7%, P = 0.037） and secondary extension （81.8% vs 62.1%, P = 0.01） and localizing the internal opening （84.2% vs 59.7%, P = 0.004）. A contrast study with H202 detected several more fistula components including two primary suprasphincteric fistula tracks and one supralevator secondary extension, which were not detected on non-contrast study. However, there was no significant difference in accuracy between 3D-EAUS and H202- enhanced 3D-EAUS with respect to classification of the primary tract （84.4% vs 89.1%, P = 0.435） or secondary extension （81.8% vs 86.4%, P = 0.435） or localization of the internal opening （84.2% vs 89.5%, P = 0.406）. CONCLUSION： 3D-EAUS was highly reliable in the diagnosis of an anal fistula. H2O2 enhancement was helpful at times and selective use in difficult cases may be economical and reliable.
基金supported by the Aerospace International Innovation Talent Cultivation Project of Program China Scholarship Councilthe National Natural Science Foundation of China(Grant No.11502291)
文摘Numerical investigation of a supersonic jet from the nose of a lifting-body vehicle opposing a hypersonic flow with the freestream Mach number being 8.0 at 40 km altitude was carried out by solving the three-dimensional, time-accurate Navier-Stokes equations with a hybrid meshes approach. Based on the analysis of the flow field structures and aerodynamic characteristics, the behaviours relevant to the LPM jet were discussed in detail, including the drag reduction effect, the periodic oscillation and the feedback loop. The obtained results show that the flow oscillation characteristic of the LPM jet is low-frequency and high-amplitude while that of the SPM jet is high-frequency and low-amplitude. Compared with the clearly dominant frequencies of the LPM jet, the SPM jet exhibits a broad-band structure. The LPM jet can sustain drag reduction effect until the angle of attack is 8°, and the lift-to-drag ratio of the vehicle is effectively improved by 6.95% at angle of attack of 6°. The self-sustained oscillation process was studied by a typical oscillating cycle of the drag force coefficient and the variation of the instantaneous pressure distribution,which reveals an off-axial flapping motion of the conical shear layer. The variation of the subsonic recirculation zone ahead of the vehicle nose strengthens the understanding of the jet behavior including the source of instability in the long penetration mode and the mechanism of the feedback loop. The aim of this paper is to advance the technology readiness level for the counterflowing jet applied as an active control technology in hypersonic flows by gaining a better insight of the flow physics.
基金Project (No. 2012KYA107) supported by the Health Bureau of Zhejiang Province,China
文摘Objective:To evaluate the prevalence of primary iris and/or ciliary body cysts in eyes with shallow anterior chamber and their effect on the narrowing of the anterior chamber angle.Methods:Among the general physical check-up population,subjects with shallow anterior chambers,as judged by van Herick technique,were recruited for further investigation.Ultrasound biomicroscope(UBM) was used to detect and measure the cysts located in the iris and/or ciliary body,the anterior chamber depth(ACD),the angle opening distance at 500 μm(AOD500),and the trabecular-iris angle(TIA).A-scan ultrasonography was used to measure the ocular biometry,including lens thickness,axial length,lens/axial length factor(LAF),and relative lens position(RLP).The effect of the cyst on narrowing the corresponding anterior chamber angle and the entire angle was evaluated by the UBM images,ocular biometry,and gonioscopic grading.The eye with unilateral cyst was compared with the eye without the cyst for further analysis.Results:Among the 727 subjects with shallow anterior chamber,primary iris and ciliary body cysts were detected in 250(34.4%) patients;among them 96(38.4%) patients showed unilateral single cyst,21(8.4%) patients had unilateral double cysts,and 42(16.8%) patients manifested unilateral multiple and multi-quadrants cysts.Plateau iris configuration was found in 140 of 361(38.8%) eyes with cysts.The mean size of total cysts was(0.6547±0.2319) mm.In evaluation of the effect of the cyst size and location on narrowing the corresponding angle to their position,the proportion of the cysts causing corresponding angle narrowing or closure among the cysts larger than 0.8 mm(113/121,93.4%) was found to be significantly higher than that of the cysts smaller than 0.8 mm(373/801,46.6%),and a significant higher proportion was also found in the cysts located at iridociliary sulcus(354/437,81.0%) than in that at the pars plicata(131/484,27.1%).In evaluating the effect of the cyst on the entire anterior chamber angle,the eyes with multiple and multi-quadrants cysts manifested significant narrowing of the entire anterior chamber angle as compared with the eyes without cysts,based on the data analysis in comparison of TIA,AOD500,and gonioscopic grading evaluation.The unilateral single or double cysts in the eyes had no significant effect on narrowing of anterior chamber angle as compared with eyes without cysts.The iris and/or ciliary body cysts did not seem to affect the axial length,ACD,lens thickness,RLP,LAF.Conclusions:The prevalence of primary iris and ciliary body cyst was 34.4% in the subjects with shallow anterior chamber.The cysts larger than 0.8 mm,locating at iridociliary sulcus,or multiple and extensive cysts were inclined to cause the angle narrowing or closure.
