| 1. |
- Alder, V A, et al.
(författare)
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Macro- and micrograzing effects on phytoplankton communities
- 1989
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Ingår i: The expedition Antarktis VII/3 (EPOS LEG 2) of RV "Polarstern" in 1988/89. - Bremerhaven : Alfred- Wegener-Institut für Polar Meeresforschung. ; , s. 123-130
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Lundmark, Jöns, et al.
(författare)
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Paroxetine : pharmacokinetic and antidepressant effect in the elderly
- 1989
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Ingår i: Acta Psychiatrica Scandinavica. - : Wiley. - 0001-690X .- 1600-0447. ; 80:S350, s. 76-80
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the pharmacokinetic properties, efficacy, and tolerability of paroxetine in elderly depressed patients, a clinical study was set up - initially at Aalborg Psychiatric Hospital in Denmark, and subsequently at the University Hospital in Linköping, Sweden. A total of 21 patients with a median age of 72 years were included in the study. After a single dose of 20 or 30mg of paroxetine followed by two drug-free days, treatment continued with 20 or 30mg daily for seven weeks. The majority of patients showed a continuous reduction in their HAMD scores, starting in the second week of treatment. Paroxetine was well tolerated at the doses given, and side-effects were mostly mild and transient. Steady-state, pre-dose plasma levels of paroxetine showed considerable variability, and the median steady-state concentration was higher in elderly patients compared with data from a previous study in young volunteers. Elimination half-lives also showed variability between these elderly patients, but tended to be longer after cessation of multiple dosing than after a single dose. They also tended to be longer than in the young volunteers. The results of this study do not advocate reduced doses of paroxetine in the elderly, but further studies are warranted.
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| 3. |
- Hertz, H.M., et al.
(författare)
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High voltage measurement system based on a capacitively coupled Pockels cell
- 1987
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Ingår i: Proc. SPIE - Int. Soc. Opt. Eng. (USA). ; 701, s. 8-226
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A fiber-optical system for measurements of fast high voltage pulses has been developed. The system is based on capacitively coupled Pockels cell voltage sensor and features excellent rejection of electrical interference, large bandwidth and practically unlimited voltage range. The authors describe the principle of operation and give a preliminary discussion of the performance of the measurement system
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| 4. |
- Ståhlberg, F., et al.
(författare)
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Determination of flow velocities from magnetic resonance multiple spin-echo images : A phantom study
- 1987
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 28:5, s. 643-648
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to evaluate a method for the quantification of through-plane flow velocities by magnetic resonance imaging (MRI) from the flow characteristics of conventional multiple spin-echo (MSE) signals. Simulated inflow-outflow-dependent signals, as well as images of a flow phantom were generated and the logarithm of the flow-dependent signal value was plotted against echo time. The normalized slope of the resulting curve was calculated using a least-square fit to simulated and experimental data and was corrected for T2 relaxation effects by subtraction of a slope obtained at zero flow. After this correction, and with certain restrictions regarding the flow velocity (v), maximum number of echoes in the slope calculation and slice thickness (L), the normalized slope of the MSE signal becomes equal to the quotient v/L, and from this relation the flow velocity can be determined. The validity of the proposed method was examined for different flow velocities and for two opposite flow directions. The influence of the size of the region of interest and the number of spin echoes used in the calculation of the slope on the accuracy of the velocity determination was also studied. The sensitivity of the method to flow-induced phase changes was examined in the phantom by comparing the results obtained with different strengths of the slice-selective gradient as well as by comparing results from even-echo data with those from odd-echo data. When applied to simulated signal data, the method was found to be strictly valid only for a small velocity range, while for the flow phantom, the calculated velocities corresponded to measured velocities for values up to and over 100 mm/s. In the phantom experiment, the method was found to be insensitive to effects induced by combined changes of the slice thickness and the slice-selective gradient as well as to so-called even-echo rephasing effects. It is concluded that the examined method promises to be a rapid and easily interpretable alternative to other methods, e.g. magnetic resonance velocity-phase encoding, for the determination of flow velocities in vivo.
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