| 11. |
- de Villiers, SHL, et al.
(författare)
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Active immunization against nicotine suppresses nicotine-induced dopamine release in the rat nucleus accumbens shell
- 2002
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Ingår i: Respiration. - : S. Karger AG. - 0025-7931 .- 1423-0356. ; 69:3, s. 247-253
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> Tobacco smoking is the largest preventable cause of morbidity and premature mortality in the world. Although its medical consequences are well documented, 20–50% of the population even in developed countries remain tobacco smokers. The drugs presently used in smoking cessation have limited efficiency and, therefore, there is a need for alternative and improved treatments. One novel approach in this regard may be provided by immunization against nicotine. <i>Objective:</i> The present study in male Wistar rats investigated if active immunization with a novel nicotine immunogen, IP18-KLH, may generate nicotine-selective antibodies and, furthermore, whether this treatment might prevent nicotine from exerting its stimulating effect on the mesolimbic, dopaminergic reward system in the brain. <i>Methods:</i> Enzyme-linked immunosorbent assay (ELISA) was used to determine the titer of nicotine antibodies in plasma after immunization with IP18-KLH in Freund’s adjuvant. Competitive ELISA was used to assess the selectivity of the antibodies. Finally, we used in vivo voltammetry to investigate whether active immunization with IP18-KLH could prevent nicotine-induced dopamine release in the shell of nucleus accumbens (NAC<sub>shell</sub>). <i>Results:</i> The present study shows that active immunization with IP18-KLH generates antibodies that are highly selective for nicotine. Furthermore, immunization with IP18-KLH prevented the nicotine-induced increase in dopamine release in the NAC<sub>shell</sub>, a biochemical correlate to the rewarding properties of nicotine. <i>Conclusions:</i> Active immunization with IP18-KLH prevents a central effect of nicotine that is considered critical for the induction of nicotine dependence. Consequently, active immunization may provide long-term protection against initiation of tobacco dependence, an effect that may prove particularly advantageous in relapse prevention.
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| 12. |
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| 13. |
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| 14. |
- Marinovic, Tomislav, 1991, et al.
(författare)
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Fast Characterization of Mutually Coupled Array Antennas Using Isolated Antenna Far-Field Data
- 2021
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 69:1, s. 206-218
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Tidskriftsartikel (refereegranskat)abstract
- A new method is proposed to analyze antenna arrays including mutual coupling, which is based on the concept of multiple scattering and relates to the iterative Jacobi and Gauss-Seidel methods. The method employs sampled far-field data of an isolated element, which can be obtained by any full-wave simulator and consists of far fields for excitation at the antenna feed and for plane waves with different angles of incidence. Mutual interactions between the array elements are modeled by approximating the incident field as a single dual-polarized plane wave taken from the spherical wave expansion of the scattered field from any other element in the array. The accuracy and run-time performances of the method are evaluated mainly by comparing simulations for several array geometries to MoM-based full-wave solutions. The method is primarily intended as a tool for the fast sequential analysis of arrays while varying the array lattice, particularly in case of irregular or sparse lattices and complex elements requiring dense meshes in full-wave simulators. The applications of the method may thus range from the systematic analysis of mutual coupling to optimization and synthesis.
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| 15. |
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| 16. |
- Young, A., et al.
(författare)
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Accurate Beam Prediction Through Characteristic Basis Function Patterns for the MeerKAT/SKA Radio Telescope Antenna
- 2013
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 61:5, s. 2466-2473
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Tidskriftsartikel (refereegranskat)abstract
- A novel beam expansion method is presented that requires employing only a few Characteristic Basis Function Patterns (CBFPs) for the accurate prediction of antenna beam patterns. The method is applied to a proposed design of the MeerKAT/SKA radio telescope, whose antenna geometry is subject to small deformations caused by mechanical or gravitational forces. The resulting deformed pattern, which is affected in a nonlinear fashion by these deformations is then sampled in a few directions only after which the interpolatory CBFPs accurately predict the entire beam shape (beam calibration). The procedure for generating a set of CBFPs-and determining their expansion coefficients using a few reference point sources in the sky-is explained, and the error of the final predicted pattern relative to the actual pattern is examined. The proposed method shows excellent beam prediction capabilities, which is an important step forward towards the development of efficient beam calibration methods for future imaging antenna systems.
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