| 1. |
- Blomstrand, Peter, et al.
(författare)
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Exercise echocardiography : a methodological study comparing peak‐exercise and post‐exercise image information
- 1992
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Ingår i: Clinical Physiology. - : John Wiley & Sons. - 0144-5979 .- 1365-2281. ; 12:5, s. 553-565
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Tidskriftsartikel (refereegranskat)abstract
- It is unclear whether echocardiography at peak bicycle exercise adds information to registrations obtained recumbent immediately after the test and what factors influence image quality. Therefore, exercise echocardiography was performed consecutively and prospectively in 66 men, unselected with regard to echocardiography, one month after an episode of unstable coronary artery disease. Of 594 segments (9 × 66), 569 (96%) were adequately visualized recumbent at rest. The corresponding figures recumbent directly after exercise, seated before exercise, and seated at peak exercise were 544 (92%), 474 (80%), and 428 (72%), respectively. In the majority of our patients, acceptable images at peak exercise were obtained for the septal region, while for the anterior, lateral, and inferior segments the success rate varied from 50 to 70%. Recumbent after exercise, the success rate was acceptable for most segments, possibly with the exception of the apical and lateral segments. Fifty‐five patients developed new wall motion abnormalities or worsening of wall motion in connection with exercise. Echocardiography at peak exercise provided more information than afterwards in patients with images of good quality. However, in patients with inferior image quality, the registrations obtained recumbent after the test revealed wall motion abnormalities which were not obtained seated at peak exercise. Patients with worse image quality had significantly higher respiratory rate and weight, and rated a higher degree of dyspnoea at peak exercise than those with good quality. We conclude that in middle aged men with coronary artery disease, image acquisition at peak bicycle exercise and immediately after exercise are of complementary value.
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| 2. |
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| 3. |
- HAKANSSON, MC, et al.
(författare)
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DIMER FORMATION AND ELECTRONIC-STRUCTURE ON THE GE(100)(2X1)-SB SURFACE
- 1992
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Ingår i: Surface Science. - 0039-6028 .- 1879-2758. ; 278:1-2, s. L131-L134
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Tidskriftsartikel (refereegranskat)abstract
- Deposition of antimony on Ge(100)2 X 1 results in a well-ordered, highly passivated surface. From a comparison between core-level data and angle-resolved photoemission data, we conclude that the observed 2 x 1 reconstruction is caused by the formation of symmetric Sb-Sb dimers on the Ge surface.
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| 4. |
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| 5. |
- Karlsson, Anders, et al.
(författare)
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Transient wave propagation in gyrotropic media
- 1992
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Ingår i: Invariant inbedding and inverse problems. - 0898713056 ; , s. 77-89
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In this paper transient electromagnetic wave propagation in an inhomogeneous, cold plasma is considered. It is assumed that a constant magnetic induction is present and that the plasma is spatially inhomogeneous in the direction of the magnetic induction. Losses in the plasma are modeled with a collision frequency ν. The direct problem, which is to calculate the reflected and transmitted responses of the plasma, is considered in this paper. Special attention is paid to the precursor effects in the plasma and several examples of precursor effects in an inhomogeneous plasma are showed.
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| 6. |
- Karlsson, Anders, et al.
(författare)
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Wave splitting and imbedding equations for a spherically symmetric dispersive medium
- 1992
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Ingår i: Invariant inbedding and inverse problems. - 0898713056 ; , s. 103-113
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The direct problem of time dependent electromagnetic scattering in the dispersive sphere is solved by a wave splitting technique. The electric field is expanded in a series involving vector spherical harmonics, leading to a system of wave equations for each term. These systems are reduced to scalar wave equations for each term, which are solved via reflection operators. Some preliminary numerical results are presented.
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| 7. |
- Karlsson, J A, et al.
(författare)
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Relationship of airway responsiveness to agents causing bronchoconstriction and cough in sensitized guinea-pigs
- 1992
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Ingår i: Pulmonary Pharmacology. - 0952-0600. ; 5:3, s. 191-198
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Tidskriftsartikel (refereegranskat)abstract
- The relationship between airway responsiveness to bronchoconstrictor- and cough-inducing stimuli has been examined in Ascaris suum-sensitized conscious guinea-pigs. Guinea-pigs were sensitized to Ascaris suum [4000 PNU and 100 mg Al(OH)3 i.p. on days 1 and 7] and then challenged with aerosolized antigen on days 21, 28 and 35. At day 35, antigen-exposure produced an early bronchoconstrictor response (EBR) and in about 50% of the animals also a late bronchoconstrictor response (LBR) commencing 4-8 h later. The bronchial responsiveness to inhaled histamine was increased in sensitized guinea-pigs and increased further 20-24 h after acute antigen challenge. Guinea-pigs developing only EBR were equally sensitive to histamine as those having both EBR and LBR. In contrast, the cough and reflex bronchoconstriction produced by inhaled citric acid (0.40 M, acting on capsaicin-sensitive sensory neurons) and cigarette smoke (3 min exposure; exciting both capsaicin-sensitive neurons and rapidly adapting stretch receptors) were not altered by sensitization. Furthermore, acute antigen challenge did not alter the effect of citric acid as measured 24 h later. The antigen-induced airway hyperresponsiveness to histamine was not accompanied by an altered sensitivity of airway sensory nerves mediating cough (and reflex bronchoconstriction), demonstrating that bronchial- (airway obstruction) and sensory- (cough) hyperresponsiveness involve separate and independent mechanisms.
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| 8. |
- Landin-Olsson, M., et al.
(författare)
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Islet cell and thyrogastric antibodies in 633 consecutive 15- to 34-yr-old patients in the diabetes incidence study in Sweden
- 1992
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 41:8, s. 1022-1027
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Tidskriftsartikel (refereegranskat)abstract
- The effect of age on ICA and thyrogastric antibodies at diagnosis of IDDM was evaluated in 633 consecutively diagnosed Swedish diabetic patients aged 15-34 yr and in 282 volunteers of the same age. ICAs were present in 61% (383 of 633) of the patients and in 2% (5 of 282) of control subjects. When the initial classification was considered, ICAs were detected in 69% (327 of 473) of patients with IDDM, 23% (19 of 83) of those with NIDDM, 50% (36 of 72) of those with unclassifiable diabetes, and 20% (1 of 5) of those with secondary diabetes. The frequency of ICA fell significantly (P < 0.001) with age in IDDM patients from 77% (104/135) in those 15-19 yr old to 52% (50 of 96) in 30- to 34-yr-old IDDM patients. The low frequency of ICA in 30- to 34-yr-old IDDM patients was confined to men (42%, 28 of 66). The frequency of gastric (H+, K+-ATPase) antibodies was significantly (P < 0.05) higher in IDDM patients (10%, 47 of 449) than in patients with NIDDM (3%, 3 of 80) and unclassifiable diabetes (4%, 3 of 72). In conclusion, the frequency of ICA at the diagnosis of IDDM in young adult subjects decreases with increasing age, particularly in men. The frequent finding of ICA in patients considered to have NIDDM or unclassifiable diabetes indicates that misclassification of diabetes is frequent in young adult patients recently diagnosed with diabetes.
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| 9. |
- LELAY, G, et al.
(författare)
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CORE-LEVEL SPECTROSCOPY STUDY OF THE INITIAL FORMATION OF TIN GERMANIUM INTERFACES
- 1992
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Ingår i: Applied Surface Science. - 0169-4332 .- 1873-5584. ; 56-8, s. 178-184
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the initial stages of the Schottky barrier formation at Sn/Ge(100) interfaces, in comparison with Sn/Ge(111) ones, with high resolution core-level spectroscopy measurements (Ge 3d and Sn 4d shallow core levels) using synchrotron radiation. A detailed, stringent decomposition of the core lines reveals three different components for both Ge and Sn on the two surfaces. The three components of the Sn 4d line on the Ge(100)2 x 1-Sn surface are interpreted as due to three different adsorption sites simultaneously occupied, while the persistence of the surface components in the Ge 3d core lines suggests that the building block of the reconstruction remains an asymmetric Ge dimer.
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| 10. |
- LELAY, G, et al.
(författare)
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SURFACE CORE-LEVEL SHIFTS ON GE(100) - C(4X2) TO 2X1 AND 1X1 PHASE-TRANSITIONS
- 1992
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 45:12, s. 6692-6699
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Tidskriftsartikel (refereegranskat)abstract
- By comparing, under identical experimental conditions, high-resolution synchrotron-radiation core-level photoemission spectra taken from both Ge(111) and Ge(100) samples, we establish that the decomposition of the Ge 3d lines from the clean Ge(100) 2 x 1 surface at room temperature requires two surface components shifted by -0.23 and -0.60 eV relative to the bulk one. This deconvolution is fully consistent with the asymmetric-dimer reconstruction model of this surface. We further study the reversible phase transitions that occur on this surface: 2 x 1 <--> c(4 x 2) at low temperature; 2 x 1 <--> 1 x 1 at high temperature. We show from both core-level and valence-band studies that the number of dimer bonds is essentially conserved in these transitions. We also suggest, by comparing a dimer with an Ising spin, that these transitions correspond, respectively, to an antiferromagnetic ordering at low temperatures and to a paramagnetic disordering at high temperatures.
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