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- Lindqvist, A, et al.
(författare)
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Artery blood pressure oscillation after active standing up: an indicator of sympathetic function in diabetic patients
- 1997
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Ingår i: Clinical Physiology. - : Wiley. - 1365-2281 .- 0144-5979. ; 17:2, s. 159-169
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Tidskriftsartikel (refereegranskat)abstract
- Dynamic artery blood pressure (Finapres) response to active standing up, normally consisting of initial rise, fall and recovery above the baseline (overshoot), was compared with the early steady-state artery blood pressure level to measure sympathetic vasomotor function in healthy subjects (n = 23, age 35 +/- 9 years; mean +/-SD) and in type I diabetic patients without autonomic neuropathy (AN) (group 1: n = 18, 38 +/- 13 years), with AN but no cardiovascular drugs (group 2a: n = 7, 44 +/- 11 years) and with both AN and cardiovascular drugs (group 2b: n = 10, 47 +/- 7 years). Systolic and diastolic overshoot were similar in the control (15 +/- 13/15 +/- 11 mmHg) and group 1 subjects. Systolic overshoot disappeared in 57% of patients in group 2a (-1 +/- 9 mmHg; P < 0.03), whereas artery blood pressure still overshot in diastole (8 +/- 7 mmHg; NS). Systolic overshoot disappeared in all patients in group 2b (-22 +/- 22 mmHg; P < 0.0006) and diastolic overshoot disappeared in 60% of these patients (-6 +/- 16 mmHg; P = 0.0006). Systolic early steady-state level was not lower in group 2a than in group 1 (NS), but it was impaired in group 2b (P < 0.006), in which six diabetic patients had a pathological response beyond the age-related reference values. There was a strong association between the overshoot and steady-state levels (P for chi 2 < 0.001, n = 58). Overshoot of the control subjects and patients in group 2b correlated to their respective steady-state blood pressure levels (r > or = 0.76; P < or = 0.001). In conclusion, baroreceptor reflex-dependent overshoot of the artery blood pressure after active standing up diminishes with the development of AN and it is associated with the early steady-state level of the artery blood pressure.
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| 2. |
- Söderholm, S, et al.
(författare)
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A photoemission spectroscopy and X-ray absorption study of Bi(2)Sr(2)CaCu(2)O(8) single crystal with adsorbed Cs: On the origin of states affected by electron doping and evidence for spatially resolved electron doping
- 1996
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Ingår i: Journal of Physics: Condensed Matter. - : IOP Publishing. - 1361-648X .- 0953-8984. ; 8, s. 1307-1320
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Tidskriftsartikel (refereegranskat)abstract
- The influence of electron doping, via deposition of small amounts of Cs, on the electronic structure of has been studied by high-resolution photoelectron spectroscopy (PES) and x-ray absorption spectroscopy (XAS), utilizing synchrotron radiation. The changes in the electronic structure were monitored by PES of the valence band and of the O 1s, Bi 4f, Bi 5d, Ca 2p and Sr 3d core levels, and by XAS at the O 1s, Cu 2p and Ca 2p edges. The experimental data suggest that the loss of the Fermi edge and the loss of spectral intensity down to about 2 eV below the Fermi level, and the substantial loss of spectral intensity of the pre-edge structure in the O 1s XAS spectrum are mainly due to annihilation of states with O 2p character in the Cu - O layer. It is evident from bulk- and surface-sensitive XAS spectra that the electron doping by Cs affects the electronic structure more strongly close to the surface. This implies that the doping occurs locally and that the charge transfer between the different layers in the unit cell is not uniform. Thus it seems possible to alter the electronic properties of locally through spatially resolved electron doping. When larger amounts of Cs are deposited, a chemical reaction occurs which causes a disruption of the Bi - O layer. This deposition regime is characterized by the presence of caesium oxide and reduced (metallic) Bi.
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