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- Dahl, Leif, et al.
(författare)
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Catalytic behavior and characterization of (CuO)1-z(La2O3)z/2 based catalysts deposited on γ-Al2O3 and prepared in situ with 0.0≤z≤1.00 with and without addition of Pd
- 1996
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Ingår i: Catalysis Letters. - 1572-879X .- 1011-372X. ; 37:1-2, s. 69-77
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Tidskriftsartikel (refereegranskat)abstract
- (CuO)(1-z)(La2O3)(z/2) based catalysts with 0.0 less than or equal to z less than or equal to 1.0 supported on gamma-Al2O3 have been prepared in situ and the phases formed have been identified by XRD, SEM and TEM/EDS studies. The catalyst with z = 0.5 exhibited the best catalytic activity for oxidation of CO (T-50 = 295 and 390 degrees C with degrees of conversions of 93 and 92% at 450 degrees C under rich and lean conditions, respectively) and C3H6 (291 and 414 degrees C; 93 and 83%) and reduction of NO (405 degrees C; 60 and 0%). This catalyst contained appreciable amounts of the perovskite phase LaAl1-xCuxO3 and the enhanced catalytic properties are ascribed to the presence of this phase. Addition of Pd to this catalyst implied that the degree of conversion of NO increased and that the light-off temperatures for all involved gas species decreased. Ageing experiments revealed that LaAl1-xCuxO3 decomposed and that Cu containing Pd particles were formed during this procedure which in turn deteriorated the catalytic properties of the catalyst.
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| 2. |
- Granfeldt, Hans, et al.
(författare)
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The Linkoping-Lund surgical experience with the HeartMate left ventricular assist system
- 1995
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 59:Suppl. 1, s. 52-55
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Tidskriftsartikel (refereegranskat)abstract
- Four transplant candidates fulfilling the Food and Drug Administration criteria for a permanent left ventricular assist device received a pneumatic HeartMate system as a bridge to heart transplantation. All patients survived and were fully rehabilitated at the time of transplantation, which was carried out 2 to 6 months after the initial operation. There were no major complications associated with the procedures. We are impressed by the effectiveness and safety of the device.
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| 7. |
- Jansson, Kjell, 1956-
(författare)
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Treatment in Dilated Cardiomyopathy : with special emphasis on beta-adrenergic receptor blockade and angiotensin-converting enzyme inhibition
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Dilated cardiomyopathy (DCM) is a heart muscle disease of unknown origin, characterised by ventricular dilatation and impairment of systolic function. The basic treattnent is medical, according to different pharmacological principles. Evaluation of the severity of the disease and the effects of medication are important for optimal management.Fifty-four patients (42 male and 12 female) with DCM were randomized to receive treatment with either a beta-adrenergic receptor blocker (metoprolol) or an angiotensin-converting enzyme (ACE) inhibitor (captopril). Almost all patients had a history of congestive heart failure and were therefore treated with furosemide. Baseline characteristics and the effects of therapy were studied by invasive haemodynamics, echocardiography, neurohormonal function, heart rate variability and quality of life evaluation.There were favourable effects on left ventricular (LV) function with both drugs but metoprolol seemed to be superior to captopril in improving LV stroke volume and reducing LV filling pressure. There was a reduction in both systolic and diastolic dimensions and the non-invasive findings were in accordance with invasive results. Neurohormonal activation was less than expected and the levels of plasma renin activity and angiotensin II were within the normal range while the levels of atrial natriuretic peptide were increased. Urinary excretion of Aldosterone was reduced with both metoprolol and captopril therapy, but treatment with petoprolol reduced the level of ANP during exercise.Both drugs increased heart rate variability but petoprolol was superior to captopril in increasing totaol power and power in the low and very low frequency.Quality of life was assessed by a disease-specific questionnaire and wsa improved in the dimension "emotion" in both groups during treatment. In the captopril group there were also improvements in total score and in the dimension "physical activity". Improvements in quality of life dimensions, however, did not correlate to improvement in LV function.In conclusion both metoprolol and captopril were well tolerated. There were effects of beta-adrenergic receptor blockade on LV performance that were not obtained, at least not equally, during therapy with ACE inhibitor. Itreatment of patients with DCM should therefore include a beta-receptor blocker. Carefully performed, non-invasive methods can be used to evaluate the effects of therapy.
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| 8. |
- Jansson, Tomas, et al.
(författare)
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Ultrasound Doppler Vector Tomography - Measurements of Directional Blood Flow
- 1997
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Ingår i: Ultrasound in Medicine and Biology. - 0301-5629. ; 23:1, s. 47-57
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Tidskriftsartikel (refereegranskat)abstract
- An experimental system has been developed to verify the possibility of detecting flow activity using a technique called ultrasound Doppler vector tomography. A tomography algorithm is used to reconstruct blood flow vector fields using data from computer-controlled ultrasound continuous-wave Doppler scanning equipment. The result is a picture in which the brightness variations represent the reconstructed values of the curl of the velocity field (del x v). Continuous ultrasound is transmitted into a region with flow activity and the Doppler-shifted signals are received. To obtain measurement data suited for fan beam tomography, the scanning is performed in a plane from points encircling the region. Reconstructions have been achieved using measurement data from two different flow phantoms. A comparison between the experimental results and simulations shows good conformity. Copyright (C) 1997 World Federation for Ultrasound in Medicine & Biology.
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| 10. |
- Lin, Pei-yan, et al.
(författare)
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Catalytic purification of car exhausts over cobalt- and copper-based metal oxides promoted with platinum and rhodium
- 1995
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Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 6:3, s. 237-319
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Tidskriftsartikel (refereegranskat)abstract
- 25 Alumina-and silica-supported oxide-based catalysts were prepared, with the overall metal composition La(0.45)Sr(0.15)Ce(0.35)Zr(0.05)M(1.0) (M=Co or Cu) and promoted with 0-0.5 mg Pt-Rh per gram catalyst. The catalysts were evaluated with respect to light-off temperatures and redox characteristics, using NO/CO/C3H6/O2/N2 gas mixtures to simulate car exhaust. The activities for complete oxidation of propene and carbon monoxide increased with increasing content of metal oxides and noble metals. The catalysts were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) combined with energy-dispersive spectroscopy (EDS) analysis, temperature-programmed reduction (TPR), and specific surface area measurements (BET). SEM/TEM/XRD revealed that the alumina-supported catalysts contained well dispersed oxides of the added elements, whereas the silica-supported catalysts contained significantly larger particles of the copper or cobalt oxides, The TPR peak for reduction of cobalt oxide shifted toward lower temperatures with increasing content of Pt-Rh, indicating hydrogen spill-over from the noble metals to the cobalt oxide. The catalytic activity of the Co-based oxides supported on alumina and promoted with 0.49 mg Pt-Rh per gram catalysts was comparable to the activity of a commercial three-way catalyst (TWC), containing more than 4 times as much Pt-Rh.
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