| 1. |
- da Silva, Cristina, et al.
(författare)
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Prosthesis-patient mismatch after transcatheter aortic valve implantation : impact of 2D-transthoracic echocardiography versus 3D-transesophageal echocardiography
- 2014
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Ingår i: The International Journal of Cardiovascular Imaging. - : Springer Science and Business Media LLC. - 1569-5794 .- 1875-8312 .- 1573-0743. ; 30:8, s. 1549-1557
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the role of 2D-transthoracic echocardiography (2D-TTE) and 3D-transesophageal echocardiography (3D-TEE) in the determination of aortic annulus size prior transcatheter aortic valve implantation (TAVI) and its' impact on the prevalence of patient prosthesis mismatch (PPM). Echocardiography plays an important role in measuring aortic annulus dimension in patients undergoing TAVI. This has great importance since it determines both eligibility for TAVI and selection of prosthesis type and size, and can be potentially important in preventing an inadequate ratio between the prosthetic valvular orifice and the patient's body surface area, concept known as prosthesis-patient mismatch (PPM). A total of 45 patients were studied pre-TAVI: 20 underwent 3D-TEE (men/women 12/8, age 84.8 +/- A 5.6) and 25 2D-TTE (men/women 9/16, age 84.4 +/- A 5.4) in order to measure aortic annulus diameter. The presence of PPM was assessed before hospital discharge and after a mean period of 3 months. Moderate PPM was defined as indexed aortic valve area (AVAi) a parts per thousand currency sign 0.85 cm(2)/m(2) and severe PPM as AVAi < 0.65 cm(2)/m(2). Immediately post-TAVI, moderate PPM was present in 25 and 28 % of patients worked up using 3D-TEE and 2D-TTE respectively p value = n.s) and severe PPM occurred in 10 % of the patients who underwent 3D-TEE and in 20 % in those with 2D-TTE (p value = n.s). The echocardiographic evaluation 3 months post-TAVI showed 25 % moderate PPM in the 3D-TEE group compared with 24 % in the 2D-TTE group (p value = n.s) and no cases of severe PPM in the 3DTEE group comparing to 20 % in the 2D-TTE group (p = 0.032). Our results indicate a higher incidence of severe PPM in patients who performed 2DTTE compared to those performing 3DTEE prior TAVI. This suggests that the 3D technique should replace the 2DTTE analysis when investigating the aortic annulus diameter in patients undergoing TAVI.
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| 2. |
- Henning, G., et al.
(författare)
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Exploring the stability of super heavy elements: First measurement of the fission barrier of 254No
- 2014
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 66
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Konferensbidrag (refereegranskat)abstract
- The gamma-ray multiplicity and total energy emitted by the heavy nucleus 254No have been measured at 2 different beam energies. From these measurements, the initial distributions of spin I and excitation energy E * of 254No were constructed. The distributions display a saturation in excitation energy, which allows a direct determination of the fission barrier. 254No is the heaviest shell-stabilized nucleus with a measured fission barrier. © Owned by the authors, published by EDP Sciences, 2014.
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| 3. |
- Henning, G., et al.
(författare)
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Fission Barrier of Superheavy Nuclei and Persistence of Shell Effects at High Spin: Cases of No-254 and Th-220
- 2014
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 113:26
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Tidskriftsartikel (refereegranskat)abstract
- We report on the first measurement of the fission barrier height in a heavy shell-stabilized nucleus. The fission barrier height of No-254 is measured to be B-f = 6.0 +/- 0.5 MeV at spin 15 (h) over bar and, by extrapolation, B-f = 6.6 +/- 0.9 MeV at spin 0 (h) over bar. This information is deduced from the measured distribution of entry points in the excitation energy versus spin plane. The same measurement is performed for Th-220 and only a lower limit of the fission barrier height can be determined: B-f (I) > 8 MeV. Comparisons with theoretical fission barriers test theories that predict properties of superheavy elements.
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