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- Banik, Trisanu, et al.
(författare)
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Understanding dynamics of tropical cyclones in the Bay of Bengal using lightning data
- 2021
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Ingår i: Meteorology and atmospheric physics (Print). - : Springer Nature. - 0177-7971 .- 1436-5065. ; 133:5, s. 1505-1522
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, we are studying the dynamics of 11 tropical cyclones (TCs) over the Bay of Bengal (BoB) using the World Wide Lightning Location Network (WWLLN) lightning data during 2013–2017. Detailed investigation of Lightning Stroke Count (LSC) shows that the initial phase of the TC intensification over BoB is associated with high lightning activity both in the eye region and rainband region. The study of different category TCs shows the weak and moderate-intensity TCs during both in pre-monsoon and post-monsoon seasons are lightning populated (specifically inner bands) during and prior to the intensification phase. Peak Maximum Sustained Wind Speed (MSWS), which is linked to sea surface temperatures (SSTs), is preceded by the peak LSC with a time lag of 6–12 h. The LSC peaks in the eye region and rain band for different categories of TCs between small to moderate wind shear range. The present study highlights that the monitoring of real-time lightning activity could provide supportive information on the existing forecast techniques. But further analyses are required over BoB to quantify the relationship between TC intensification and lightning activity both in space and time.
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| 2. |
- Hansson, Nicolaj C., et al.
(författare)
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The impact of calcium volume and distribution in aortic root injury related to balloon-expandable transcatheter aortic valve replacement
- 2015
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Ingår i: JOURNAL OF CARDIOVASCULAR COMPUTED TOMOGRAPHY. - : ELSEVIER SCIENCE INC. - 1934-5925. ; 9:5, s. 382-392
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Tidskriftsartikel (refereegranskat)abstract
- Background: A detailed assessment of calcium within the aortic root may provide important additional information regarding the risk of aortic root injury during transcatheter heart valve replacement (TAVR). Objective: We sought to delineate the effect of calcium volume and distribution on aortic root injury during TAVR. Methods: Thirty-three patients experiencing aortic root injury during TAVR with a balloon-expandable valve were compared with a control group of 153 consecutive TAVR patients without aortic root injury (as assessed by post-TAVR multidetector CT). Using commercial software to analyze contrast-enhanced pre-TAVR CT scans, caltium volume was determined in 3 regions: (1) the overall left ventricular outflow tract (LVOT), extending 10 mm down from the aortic annulus plane; (2) the upper LVOT, extending 2 mm down from the annulus plane; and (3) the aortic valve region. Results: Calcium volumes in the upper LVOT (median, 29 vs 0 mm(3); P less than .0001) and overall LVOT (median, 74 vs 3 mm(3); P = .0001) were higher in patients who experienced aortic root injury compared with the control group. Calcium in the aortic valve region did not differ between groups. Upper LVOT calcium volume was more predictive of aortic root injury than overall LVOT calcium volume (area under receiver operating curve [AUG]; 0.78; 95% confidence interval, 0.69-0.86 vs AUC, 0.71; 95% confidence interval, 0.62-0.82; P = .010). Upper LVOT calcium below the noncoronary cusp was significantly more predictive of aortic root injury compared to calcium underneath the right coronary cusp or the left coronary cusp (AUC, 0.81 vs 0.68 vs 0.64). Prosthesis oversizing greater than20% (likelihood ratio test, P = .028) and redilatation (likelihood ratio test, P = .015) improved prediction of aortic root injury by upper LVOT calcium volume. Conclusion: Calcification of the LVOT, especially in the upper LVOT, located below the noncoronary cusp and extending from the annular region, is predictive of aortic root injury during TAVR with a balloon-expandable valve. (C) 2015 Society of Cardiovascular Computed Tomography. All rights reserved.
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