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- Ciulla, M. M., et al.
(författare)
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Different effects of antihypertensive therapies based on losartan or atenolol on ultrasound and biochemical markers of myocardial fibrosis: results of a randomized trial
- 2004
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Ingår i: Circulation. - 1524-4539. ; 110:5, s. 552-7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In hypertensive left ventricular hypertrophy (LVH), myocardial texture is altered by a disproportionate increase in fibrosis, but there is insufficient clinical evidence whether antihypertensive therapy or individual agents can induce regression of myocardial fibrosis. METHODS AND RESULTS: We compared the effects of an angiotensin II receptor antagonist with a beta-blocker on myocardial collagen volume (assessed by echoreflectivity and serum collagen markers) in 219 hypertensive patients with echocardiographically documented LVH. Patients were allocated randomly to receive losartan 50 to 100 mg/d (n=111) or atenolol 50 to 100 mg/d (n=99) with or without hydrochlorothiazide 12.5 to 25 mg/d for 36 weeks. Echoreflectivity analysis was conducted on ultrasound tracings of the midapex septum with specifically designed and validated software. A color histogram of reflecting echoes was obtained, and its spread (broadband [BB], previously shown to correlate directly with collagen volume fraction on endomyocardial biopsies) was used as the primary outcome measure. Mean color scale and serum markers of collagen synthesis (PIP, PIIIP) or degradation (CITP) were secondary outcome variables. Echoreflectivity analysis proved feasible in 106 patients (losartan 52, atenolol 54). Losartan reduced BB over 36 weeks (from 114.5 to 104.3 color levels, P<0.02), whereas atenolol treatment was associated with an increase in BB (from 109.0 to 113.6 color levels, P=NS), the difference between treatments being -12.8 color levels (95% CI -23.6 to -2.0, P=0.02). Secondary end points (mean color scale and collagen markers) also changed in the direction of decreased collagen in patients receiving losartan, but differences between groups were not statistically significant. CONCLUSIONS: In hypertensive patients with LVH, losartan decreases myocardial collagen content, whereas atenolol does not. The difference between the 2 treatments is statistically significant.
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| 3. |
- Andersen, Torben, et al.
(författare)
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The Swedish 50 m ELT
- 2002
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Ingår i: Beyond conventional adaptive optics; ESO Conference and Workshop Proceedings. - 3923524617 ; 58, s. 7-10
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Konferensbidrag (refereegranskat)
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| 4. |
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| 5. |
- Owner-Petersen, Mette, et al.
(författare)
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Multi-conjugate Adaptive Optics for the Swedish ELT Investigation of the Effects of Laser Guide Stars at a finite Distance.
- 2002
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Ingår i: Beyond conventional adaptive optics : a conference devoted to the development of adaptive optics for extremely large telescopes. Proceedings of the Topical Meeting held May 7-10, 2001, Venice, Italy.. - 3923524617 ; 58, s. 299-299
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Konferensbidrag (refereegranskat)abstract
- In a recent paper we presented a procedure for optimal analyticalcontrol of several deformable mirrors based on only the measured guidestar wavefronts. The expected performance was evaluated for variousguide star configurations using up to three deformable mirrors. Forsimplicity the guide stars were assumed to be infinitely distant. Inthis paper we address the effect of using laser guide stars in 90 kmaltitude for the wavefront measurements. As a consequence of this, theimage of a distant science star will not be adequately corrected bycounteracting the wavefront error measured by a laser guide star in thesame direction as the science star. This problem will be more pronouncedthe larger is the telescope diameter. We present a modified version ofthe mirror control algorithm taking the finite distance of the laserguide stars into account and some preliminary performance evaluationswith special emphasis on the consequences for ELTs.
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| 6. |
- Sips, A. C. C., et al.
(författare)
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An international database for the study of the formation of ITBs in tokamaks
- 2002
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Ingår i: Plasma Physics and Controlled Fusion. - 0741-3335 .- 1361-6587. ; 44, s. A391-A398
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Tidskriftsartikel (refereegranskat)abstract
- For the first time, data from eight,different tokamaks have been combined in an international database for internal transport barriers (ITBs). An analysis of the data for the formation of an ITB with dominant ion heating shows a clear dependence of the threshold power on the minor radius and line-averaged electron density for the formation of ion ITBs. The dependence of ITB formation on the toroidal magnetic field is weak. For the formation of ITBs with dominant electron heating, the database is smaller, but for the threshold power a strong increase with plasma size and a weak toroidal field dependence could also be identified. Based on these results, an expression for the power required to form an ITB is given using global variables only. These results give a basis for the analysis of the database using local values (like magnetic shear) and a detailed comparison with theory-based models.
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| 7. |
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