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A 3-year-old, 4.8 kg, male intact, mixed breed dog was referred for bal-loon pulmonary valvuloplasty (BPV). Echocardiography was consistent with severe type A pulmonic stenosis and BPV was recommended. During BPV, the balloon ca-t...
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A 3-year-old, 4.8 kg, male intact, mixed breed dog was referred for bal-loon pulmonary valvuloplasty (BPV). Echocardiography was consistent with severe type A pulmonic stenosis and BPV was recommended. During BPV, the balloon ca-theter failed to deflate despite multiple attempts at repositioning and the use of different deflation syringes. After approximately two minutes of cardiopulmonary arrest, forceful retrograde traction resulted in removal of the fully inflated balloon. Cardiopulmonary resuscitation was unsuccessful. Post-mortem evaluation by a board-certified pathologist identified rupture of the cranial vena cava and he-mothorax, suspected to be secondary to forceful removal of the fully inflated bal-loon. Manufacturer's evaluation of the balloon catheter used in the procedure identified multiple kinks and a segment of stretched catheter shaft suspected to be the cause for the inability to deflate. A manufacturing defect present prior to use or predisposing to stretching of the catheter segment could not be ruled out. Kinking and/or stretching of the catheter during BPV were possible causes as well. Although the inability to deflate a balloon catheter seems to be a very rare occur-rence, it should be considered as a potential complication of BPV.(c) 2023 Elsevier B.V. All rights reserved.
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Extreme and isolated eigenvalues are known to be harmful to the convergence of an iterative solver. These eigenvalues can be produced by strong heterogeneity in the underlying physics. We can improve the quality of the spectrum by...
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Extreme and isolated eigenvalues are known to be harmful to the convergence of an iterative solver. These eigenvalues can be produced by strong heterogeneity in the underlying physics. We can improve the quality of the spectrum by 'deflating' the harmful eigenvalues. In this work, deflation is applied to linear systems in reservoir simulation. In particular, large, sudden differences in the permeability produce extreme eigenvalues. The number and magnitude of these eigenvalues is linked to the number and magnitude of the permeability jumps. Two deflation methods are discussed. Firstly, we state that harmonic Ritz eigenvector deflation, which computes the deflation vectors from the information produced by the linear solver, is unfeasible in modern reservoir simulation due to high costs and lack of parallelism. Secondly, we test a physics-based subdomain-levelset deflation algorithm that constructs the deflation vectors a priori. Numerical experiments show that both methods can improve the performance of the linear solver. We highlight the fact that subdomain-levelset deflation is particularly suitable for a parallel implementation. For cases with well-defined permeability jumps of a factor 10(4) or higher, parallel physics-based deflation has potential in commercial applications. In particular, the good scalability of parallel subdomain-levelset deflation combined with the robust parallel preconditioner for deflated system suggests the use of this method as an alternative for AMG. (C) 2015 Elsevier Inc. All rights reserved.
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In this paper we discuss the deflation criterion used in the extended QR algorithm based on the chasing of rotations. We provide absolute and relative perturbation bounds for this deflation criterion. Further, we present a general...
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In this paper we discuss the deflation criterion used in the extended QR algorithm based on the chasing of rotations. We provide absolute and relative perturbation bounds for this deflation criterion. Further, we present a generalization of aggressive early deflation to the extended QR algorithms. Aggressive early deflation is the key technique for the identification and deflation of already converged, but hidden, eigenvalues. Often these possibilities for deflation are not detected by the standard technique. We present numerical results underpinning the power of aggressive early deflation also in the context of extended QR algorithms. We further generalize these ideas by the transcription of middle deflations.
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The volumes of soil losses on tilled slopes in the areas with both erosion and deflation development depend on the melting water runoff with corrections for weather, topography, and plants during the period of maximum showers as w...
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The volumes of soil losses on tilled slopes in the areas with both erosion and deflation development depend on the melting water runoff with corrections for weather, topography, and plants during the period of maximum showers as well as for silt storms duration. Soil Losses during the 20 years long period on lands without vegetation comprise 7 Vha due to melting waters runoff, 18 t/ha due to showers, and 15 t/ha due to silt storms.
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The McMurdo Dry Valleys, Antarctica (MDV) are among the oldest landscapes on Earth, and some landforms there present an intriguing apparent contradiction such that millions of years old surface deposits maintain their meter-scale ...
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The McMurdo Dry Valleys, Antarctica (MDV) are among the oldest landscapes on Earth, and some landforms there present an intriguing apparent contradiction such that millions of years old surface deposits maintain their meter-scale morphology despite the fact that measured erosion rates are 0.1-4 m Ma~(-1). We analyzed the concentration of cosmic ray-produced ~(10)Be and ~(26)Al in quartz sands from regolith directly above and below two well-documented ash deposits in the MDV, the Arena Valley ash (~(40)Ar/~(39)Ar age of 4.33 Ma) and the Hart ash (K-Ar age of 3.9 Ma). Measured concentrations of ~(10)Be and ~(26)Al are significantly less than expected given the age of the in situ air fall ashes and are best interpreted as reflecting the degradation rate of the overlying sediments. The erosion rate of the material above the Arena Valley ash that best explains the observed isotope profiles is 3.5 ± 0.41 X 10~(-5) g cm~(-2) yr~(-1) (～0.19 m Ma~(-1)) for the past ～4 Ma. For the Hart ash, the erosion rate is 4.8 ± 0.21 x 10~(-4) g cm~(-2) yf~(-1) (～2.6 m Ma~(-1)) for the past ～I Ma. The
concentration profiles do not show signs of mixing, creep, or deflation caused by sublimation of ground ice. These results indicate that the slow, steady lowering of the surface without vertical mixing may allow landforms to maintain their meter-scale morphology even though they are actively eroding.
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The McMurdo Dry Valleys, Antarctica (MDV) are among the oldest landscapes on Earth, and some landforms there present an intriguing apparent contradiction such that millions of years old surface deposits maintain their meter-scale ...
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The McMurdo Dry Valleys, Antarctica (MDV) are among the oldest landscapes on Earth, and some landforms there present an intriguing apparent contradiction such that millions of years old surface deposits maintain their meter-scale morphology despite the fact that measured erosion rates are 0.1-4 m Ma~(-1). We analyzed the concentration of cosmic ray-produced ~(10)Be and ~(26)Al in quartz sands from regolith directly above and below two well-documented ash deposits in the MDV, the Arena Valley ash (~(40)Ar/~(39)Ar age of 4.33 Ma) and the Hart ash (K-Ar age of 3.9 Ma). Measured concentrations of ~(10)Be and ~(26)Al are significantly less than expected given the age of the in situ air fall ashes and are best interpreted as reflecting the degradation rate of the overlying sediments. The erosion rate of the material above the Arena Valley ash that best explains the observed isotope profiles is 3.5 ± 0.41 X 10~(-5) g cm~(-2) yr~(-1) (～0.19 m Ma~(-1)) for the past ～4 Ma. For the Hart ash, the erosion rate is 4.8 ± 0.21 x 10~(-4) g cm~(-2) yf~(-1) (～2.6 m Ma~(-1)) for the past ～I Ma. The concentration profiles do not show signs of mixing, creep, or deflation caused by sublimation of ground ice. These results indicate that the slow, steady lowering of the surface without vertical mixing may allow landforms to maintain their meter-scale morphology even though they are actively eroding.
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The presence of axillary artery aneurysm and/or thrombus in overhead throwing athletes has been linked, theoretically, with the finding of compression by the humeral head induced by a diagnostic arm maneuver. However, whether this...
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The presence of axillary artery aneurysm and/or thrombus in overhead throwing athletes has been linked, theoretically, with the finding of compression by the humeral head induced by a diagnostic arm maneuver. However, whether this intermittent compression is incidental or of pathological significance has yet to be determined. Flow-mediated vasodilation (FMD), intima-media thickness (IMT) and maximum vasodilatory capacity were measured locally (3rd portion of the axillary artery) and downstream (brachial artery) in individuals previously tested for inducible axillary artery compression (compressor group [COMP]: n=8, mean (SD) age: 23 (4) y; "noncompressor" control group [NONCOMP]: n=8, 26 (4) y). A high-resolution ultrasound machine recorded arterial diameter and blood flow velocity. A rapid inflation/deflation pneumatic cuff placed distal to the site of measurement induced reactive hyperemia. Custom-designed wall tracking software with synchronized Doppler waveform analysis detected changes in arterial diameter, blood flow velocity and shear rate from baseline to 3min after cuff deflation. Glyceryl trinitrate and/or ischemic hand grip exercises were administered to induce maximum vasodilation. No significant differences in FMD, IMT or maximum vasodilator capacity were observed between groups at the axillary artery. However, the downstream brachial FMD response was significantly diminished in the COMP group (6.38 [3.28]%) compared with the NONCOMP group (10.38 [2.74]%; p=0.006) despite a comparable shear rate between groups (COMP: 81.92 (44.55) s(-1); NONCOMP: 83.18 (40.02) s(-1); p=0.961). Pooled data revealed a significant negative relationship (r=-0.52, p=0.038) between the FMD response and degree of arterial compression. These results suggest a chronic change in downstream vascular function in individuals demonstrating clinically significant inducible axillary artery compression.
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The presence of axillary artery aneurysm and/or thrombus in overhead throwing athletes has been linked, theoretically, with the finding of compression by the humeral head induced by a diagnostic arm maneuver. However, whether this...
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The presence of axillary artery aneurysm and/or thrombus in overhead throwing athletes has been linked, theoretically, with the finding of compression by the humeral head induced by a diagnostic arm maneuver. However, whether this intermittent compression is incidental or of pathological significance has yet to be determined. Flow-mediated vasodilation (FMD), intima-media thickness (IMT) and maximum vasodilatory capacity were measured locally (3rd portion of the axillary artery) and downstream (brachial artery) in individuals previously tested for inducible axillary artery compression (compressor group [COMP]: n=8, mean (SD) age: 23 (4) y; "noncompressor" control group [NONCOMP]: n=8, 26 (4) y). A high-resolution ultrasound machine recorded arterial diameter and blood flow velocity. A rapid inflation/deflation pneumatic cuff placed distal to the site of measurement induced reactive hyperemia. Custom-designed wall tracking software with synchronized Doppler waveform analysis detected changes in arterial diameter, blood flow velocity and shear rate from baseline to 3min after cuff deflation. Glyceryl trinitrate and/or ischemic hand grip exercises were administered to induce maximum vasodilation. No significant differences in FMD, IMT or maximum vasodilator capacity were observed between groups at the axillary artery. However, the downstream brachial FMD response was significantly diminished in the COMP group (6.38 [3.28]%) compared with the NONCOMP group (10.38 [2.74]%; p=0.006) despite a comparable shear rate between groups (COMP: 81.92 (44.55) s(-1); NONCOMP: 83.18 (40.02) s(-1); p=0.961). Pooled data revealed a significant negative relationship (r=-0.52, p=0.038) between the FMD response and degree of arterial compression. These results suggest a chronic change in downstream vascular function in individuals demonstrating clinically significant inducible axillary artery compression.
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OBJECTIVE: To assess a sigmoidal equation for describing airway closure. DESIGN: Experimental study. SETTING: University laboratory. PARTICIPANTS: Eight piglets mechanically ventilated on zero end-expiratory pressure (ZEEP). INTER...
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OBJECTIVE: To assess a sigmoidal equation for describing airway closure. DESIGN: Experimental study. SETTING: University laboratory. PARTICIPANTS: Eight piglets mechanically ventilated on zero end-expiratory pressure (ZEEP). INTERVENTIONS: Control and lung saline lavage. MEASUREMENTS AND RESULTS: Lungs were inflated up to transpulmonary pressure of 30[Symbol: see text]cmH(2)O at constant flow (0.12[Symbol: see text]l[Symbol: see text]s(-1)) then deflated at the same flow rate up to the point at which oesophageal pressure was constant, which was assumed to represent complete airway closure. The deflation volume-transpulmonary pressure curve was fitted to: (1) a sigmoidal equation focusing on inflexion point and pressure at maximal compliance increase and (2) an exponential equation above an inflexion point determined by eyeballing. Data deviate from the exponential equation at the point of airway closure onset. The zero-volume intercept was determined. Complete airway closure was reached at -8.3[Symbol:see text]+/-[Symbol: see text]3.5[Symbol: see text]cmH(2)O in control conditions and at -1.3[Symbol: see text]+/-[Symbol: see text]3.7[Symbol: see text]cmH(2)O after lavage (p[Symbol: see text]<[Symbol: see text]0.05). Between control and lavage, onset of airway closure was 3.0[Symbol: see text]+/-[Symbol: see text]1.9 vs. 6.0[Symbol: see text]+/-[Symbol: see text]2.8[Symbol: see text]cmH(2)O (p[Symbol: see text]<[Symbol: see text]0.05), inflexion point 3.2[Symbol: see text]+/-[Symbol: see text]1.8 vs. 7.7[Symbol: see text]+/-[Symbol: see text]2.6[Symbol: see text]cmH(2)O (p[Symbol: see text]<[Symbol: see text]0.001), pressure at maximal compliance increase -1.9[Symbol: see text]+/-[Symbol: see text]0.7 vs. -0.03[Symbol: see text]+/-[Symbol: see text]2.1[Symbol: see text]cmH(2)O (p[Symbol: see text]<[Symbol: see text]0.05) and zero-volume intercept -1.5[Symbol: see text]+/-[Symbol: see text]1.4 vs. 0.3[Symbol: see text]+/-[Symbol: see text]2.3[Symbol: see text]cmH(2)O (p[Symbol: see text]<[Symbol: see text]0.05). CONCLUSIONS: During mechanical ventilation airways stay open and close around ZEEP in control but are closed above ZEEP after lavage. Inflexion point might reflect onset of airways closure in control. Pressure at maximal compliance increase was not a marker of complete airways closure. In control and lavage, pressure at maximal compliance increase and zero-volume intercept were reasonably equivalent.
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BACKGROUND: This study aimed to examine serial operative trends with patients who have experienced surgical implant deflation. In addition, the economic impact of deflation on practice caseload was analyzed. METHODS: A retrospecti...
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BACKGROUND: This study aimed to examine serial operative trends with patients who have experienced surgical implant deflation. In addition, the economic impact of deflation on practice caseload was analyzed. METHODS: A retrospective review was conducted to examine patients who experienced deflation from 2000 to 2007. Patient demographics, implant data, and the presence of secondary (performed at explantation) or tertiary (performed later) procedures were examined. Financial information was tabulated to determine the economic multiplier effect (i.e. the expected value of revenue from secondary and tertiary procedures divided by explantation cost) of taking on deflation cases in a practice. RESULTS: For this study, 285 patients with an average age of 38.4 years were identified. The average time to explantation was 50 months. Slightly more than half of the patients (55%) had both implants replaced at the time of explantation, whereas 59% switched to silicone implants and 41% continued with saline implants. A larger implant was chosen by 54% of the patients (average increase, 82 ml), whereas 18% underwent secondary procedures at the time of explantation including mastopexy (n = 22), facial rejuvenation (n = 8), liposuction (n = 7), or a combination of the two (n = 8). Tertiary procedures were performed for 31% of the patients after their explantation/reimplantation (average time frame, 13 months). The tertiary procedures included replacement with silicone (33.7%), liposuction (24.7%), abdominoplasty (11.2%), facial rejuvenation (13.5%), or nonsurgical rejuvenation using Botox, Restylane, or laser procedure (33.7%). Economic multiplier analysis showed that the financial impact of revenue derived from implant deflation on downstream practice revenue is 1.02. CONCLUSION: At the time of explantation, replacement with silicone after saline deflation is common (59% of patients). In this study, patients who chose replacement with saline had a significant tendency to replace with silicone (33%) as a tertiary procedure. Saline deflation represents a substantial opportunity for practice development. In particular, it has a positive impact on patient retention for additional aesthetic surgical or nonsurgical procedures. Economic multiplier analysis can be used to quantify the financial impact of saline deflation.
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