| 1. |
- Andres, E., et al.
(författare)
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AMANDA : Status, results and future
- 1999
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Ingår i: Proceedings, 8th International Workshop, Venice, Italy, February 23-26, 1999. Vol. 1, 2. ; , s. 63-79
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Konferensbidrag (refereegranskat)abstract
- We review the status of the AMANDA neutrino telescope. We present resultsobtained from the four-string prototype array AMANDA-B4 and describe themethods of track reconstruction and neutrino event separation. We give also firstresults of the analysis of the 10-string detector AMANDA-B10, in particular onatmospheric neutrinos and the search for magnetic monopoles. We sketch thefuture schedule on the way to a cube kilometer telescope at the South Pole,ICECUBE.
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| 2. |
- Andrés, E. C., et al.
(författare)
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The AMANDA neutrino telescope
- 1999
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Ingår i: Nuclear physics B, Proceedings supplements. - 0920-5632 .- 1873-3832. ; 77:1-3, s. 474-485
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Tidskriftsartikel (refereegranskat)abstract
- With an effective telescope area of order 104 m2 for TeV neutrinos, a threshold near ∼50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.
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| 3. |
- Andrés, E., et al.
(författare)
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Status of the AMANDA experiment
- 1999
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Ingår i: Nuclear physics B, Proceedings supplements. - : Elsevier. - 0920-5632 .- 1873-3832. ; 70:1-3, s. 448-452
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Tidskriftsartikel (refereegranskat)abstract
- The AMANDA high energy neutrino telescope has successfully been increased in size from four detector strings to ten detector strings during the 1996/1997 season. The first upward going muon-neutrino candidates have been reconstructed from the 1996 year's four-string data. Three new detector strings will be deployed during 1997/1998 to 2350 metres depth.
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| 4. |
- Bay, R. C., et al.
(författare)
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The AMANDA neutrino telescope and the indirect search for dark matter : AMANDA Colaboration
- 1998
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Ingår i: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 307:1-4, s. 243-252
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Tidskriftsartikel (refereegranskat)abstract
- With an effective telescope area of order 104m2, a threshold of ~50GeV and a pointing accuracy of 2.5°, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe its performance, focussing on the capability to detect halo dark matter particles via their annihilation into neutrinos.
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| 5. |
- Wischnewski, R., et al.
(författare)
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The AMANDA neutrino detector
- 1999
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Ingår i: Nuclear physics B, Proceedings supplements. - : Elsevier. - 0920-5632 .- 1873-3832. ; 75:1-2, s. 412-414
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Tidskriftsartikel (refereegranskat)abstract
- The first stage of the AMANDA High Energy Neutrino Detector at the South Pole, the 302 PMT array AMANDA-B with an expected effective area for TeV neutrinos of ∼ 104 m2, has been taking data since 1997. Progress with calibration, investigation of ice properties, as well as muon and neutrino data analysis are described. The next stage 20-string detector AMANDA-II with ∼800 PMTs will be completed in spring 2000.
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| 6. |
- Calén, H., et al.
(författare)
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Detector setup for a storage ring with an internal target
- 1996
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 379:1, s. 57-75
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Tidskriftsartikel (refereegranskat)abstract
- A detector setup for the cooler storage ring CELSIUS is described. The setup detects particles produced in interactions between the internal beam and a cluster-jet target. Particles emitted in the forward direction are measured by means of arrays of plastic scintillators and proportional counters. Particles, particularly photons, emitted more isotropically are measured by means of two calorimeters containing CsI(Na) crystals. The performance of the setup is given for neutral meson production in proton-proton and proton-deuteron interactions in the energy range 290-1360 MeV.
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| 7. |
- Ebbesson, L. O.E., et al.
(författare)
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Propylthiouracil-induced hypothyroidism in coho salmon, Oncorhynchus kisutch : Effects on plasma total thyroxine, total triiodothyronine, free thyroxine, and growth hormone
- 1998
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Ingår i: Fish Physiology and Biochemistry. - 0920-1742. ; 19:4, s. 305-313
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Tidskriftsartikel (refereegranskat)abstract
- Thyroid hormones transiently increase during parr-smolt transformation in coho salmon, Oncorhynchus kisutch, and are believed to trigger morphological, physiological, behavioural, and neural changes. The effectiveness of propylthiouracil (PTU) to induce hypothyroidism in smolting coho salmon was determined by immersing coho salmon, Oncorhynchus kisutch, in 30 mg 1-1 PTU from May 1, two weeks prior to the consistent annual total thyroxine (TT4) peak in mid-May, until the last sampling date. Plasma was obtained at two sampling dates from control and PTU -treated coho salmon: May 15, during the plasma TT4 peak; and May 26, after the TT4 peak. Radioimmunoassays were used to measure plasma TT4, total triiodothyronine (TT3), free thyroxine (FT4), and salmon growth hormone (sGH). The PTU -treatment inhibited the natural smoltification-related increases in plasma TT4, TT3 and GH levels compared with controls, but PTU-treatment did not affect these hormone levels when they were low. PTU -treatment increased FT4 and decreased TT3 and sGH levels in the May 26 sample. In the May 15 sample, FT4 levels were unaffected by PTU-treatment, whereas TT4 levels were decreased. These data demonstrate the ability of PTU to induce hypothyroidism in salmonids as shown by the decrease in TT4 and TT3. These data demonstrate that PTU treatment by immersion can induce hypothyroidism in salmonids as shown by: (1) the inhibition of the natural increases of TT4 and TT3; (2) the increase in FT4 levels corresponding to the lowered TT3 levels, suggesting an inhibition of thyroxine 5′-monodeiodinase activity. We also show for the first time that PTU treatment can lower plasma GH levels in salmonids. This lowering of plasma GH level is associated with the decrease in TT3 levels and the increase in FT4 levels. Lhe PLU induced lowering in GH levels may contribute to the observed changes in FT4 and TT3, since GH is known to increase thyroxine 5′-monodeiodinase activity.
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| 8. |
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| 9. |
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| 10. |
- Ekström, Lars, 1959, et al.
(författare)
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Intervertebral disc response to cyclic loading--an animal model.
- 1996
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Ingår i: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine. - 0954-4119. ; 210:4, s. 249-58
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Tidskriftsartikel (refereegranskat)abstract
- The viscoelastic response of a lumbar motion segment loaded in cyclic compression was studied in an in vivo porcine model (N = 7). Using surgical techniques, a miniaturized servohydraulic exciter was attached to the L2-L3 motion segment via pedicle fixation. A dynamic loading scheme was implemented, which consisted of one hour of sinusoidal vibration at 5 Hz, 50 N peak load, followed by one hour of restitution at zero load and one hour of sinusoidal vibration at 5 Hz, 100 N peak load. The force and displacement responses of the motion segment were sampled at 25 Hz. The experimental data were used for evaluating the parameters of two viscoelastic models: a standard linear solid model (three-parameter) and a linear Burger's fluid model (four-parameter). In this study, the creep behaviour under sinusoidal vibration at 5 Hz closely resembled the creep behaviour under static loading observed in previous studies. Expanding the three-parameter solid model into a four-parameter fluid model made it possible to separate out a progressive linear displacement term. This deformation was not fully recovered during restitution and is therefore an indication of a specific effect caused by the cyclic loading. High variability was observed in the parameters determined from the 50 N experimental data, particularly for the elastic modulus E1. However, at the 100 N load level, significant differences between the models were found. Both models accurately predicted the creep response under the first 800 s of 100 N loading, as displayed by mean absolute errors for the calculated deformation data from the experimental data of 1.26 and 0.97 percent for the solid and fluid models respectively. The linear Burger's fluid model, however, yielded superior predictions particularly for the initial elastic response.
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| 11. |
- Falkenberg, C, et al.
(författare)
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Alpha1-microglobulin and bikunin in rats with collagen II-induced arthritis : plasma levels and liver mRNA content
- 1997
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 46:2, s. 8-122
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Tidskriftsartikel (refereegranskat)abstract
- The plasma proteins alpha1-microglobulin (alpha1-m) and bikunin are synthesized in the liver as a common precursor which is cleaved just before secretion. Half of plasma alpha1-m is covalently linked to fibronectin and alpha1-inhibitor-3, and more than 95% of bikunin is part of pre-alpha-inhibitor, inter-alpha-inhibitor and related large molecules. Both alpha1-m and bikunin have been shown to be involved in inflammation, but the regulation of their synthesis is not clear. The authors have measured the plasma and urinary concentrations of alpha1-m and bikunin as well as their hepatic mRNA levels in rats during the development of collagen-induced arthritis. Also, the plasma concentrations of acknowledged acute-phase proteins were measured. The results suggested a biphasic inflammatory reaction: an early response after 1 week, represented by an elevated fibronectin level; and a late response after 3 weeks, represented by elevated alpha1-acid glycoprotein and decreased albumin and alpha1-inhibitor-3 levels. The alpha1-m-bikunin mRNA content in liver was slightly reduced after 1 week and elevated after 3 weeks, but the total concentrations of free and bound alpha1-m and bikunin in plasma were unchanged. The free bikunin fraction as well as the fibronectin/alpha1-m complex in plasma, however, were elevated after 1 week. Urinary bikunin levels were also elevated after 1 week, whereas urinary alpha1-m levels remained unchanged. The results thus suggest that free bikunin in plasma is increased and excreted in the urine at an early stage during the development of collagen-induced arthritis. Later, when the synthesis rate of alpha1-m-bikunin is elevated, both proteins are most likely directed to other locations in the body.
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| 12. |
- Hedlund, Petter, et al.
(författare)
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Pituitary adenylate cyclase-activating polypeptide, helospectin, and vasoactive intestinal polypeptide in human corpus cavernosum
- 1995
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Ingår i: British Journal of Pharmacology. - 0007-1188 .- 1476-5381. ; 116:4, s. 2258-2266
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Tidskriftsartikel (refereegranskat)abstract
- 1. The distribution and effects of pituitary adenylate cyclase-activating polypeptide (PACAP-27 and -38), helospectin (Hel-1 and Hel-2), and vasoactive intestinal polypeptide (VIP), were investigated in isolated preparations of human corpus cavernosum (CC). 2. Immunohistochemistry revealed coinciding profiles of nerve structures that showed immunoreactivities for VIP and PACAP, and VIP and Hel. Confocal microscopy showed the co-existence of VIP- and PACAP-immunoreactivities, and VIP- and Hel-immunoreactivities in most (90%) varicose nerve structures. 3. As determined by radioimmunoassay, the amounts of VIP, PACAP-27, and PACAP-38 in the preparations were 61.7 +/- 11.6, 0.1 +/- 0.05, and 3.7 +/- 0.5 pmol g-1 wet weight of tissue (pmol g-1 wet wt.), respectively. In tissue from patients with diabetes, the content of VIP was lower (13.7 +/- 0.5 pmol g-1 wet wt.), whereas that of PACAP (-27 and -38) was unchanged. 4. Cyclic nucleotide levels were determined in preparations exposed to PACAP-27, PACAP-38, Hel-1, Hel-2, and VIP. All the peptides, but Hel-2, significantly increased the concentrations of cyclic AMP, whereas the levels of cyclic GMP were unchanged. 5. The peptides concentration-dependently relaxed noradrenaline-contracted preparations. The order of potency was VIP > PACAP 27 > Hel-1 > Hel-2 > PACAP-38. 6. Hel-1, VIP and PACAP-27 effectively counteracted electrically induced contractions. At 10(-6) M, the highest peptide concentration used, the inhibitory effects obtained reached 96 +/- 3%, 87 +/- 6%, and 80 +/- 3%, respectively. 7. The results suggest that PACAP and Hel-1 are co-localized with VIP in nerve structures within the human cavernous tissue, and that the peptides are effective relaxants of CC preparations in vitro. The role of the investigated peptides for penile erection remains to be established.
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| 13. |
- Hult, E, et al.
(författare)
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In vivo measurement of spinal column viscoelasticity--an animal model.
- 1995
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Ingår i: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine. - 0954-4119. ; 209:2
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Tidskriftsartikel (refereegranskat)abstract
- The goal of this study was to measure the in vivo viscoelastic response of spinal motion segments loaded in compression using a porcine model. Nine pigs were used in the study. The animals were anaesthetized and, using surgical techniques, four intrapedicular screws were inserted into the vertebrae of the L2-L3 motion segment. A miniaturized servohydraulic exciter capable of compressing the motion segment was mounted on to the screws. In six animals, a loading scheme consisting of 50 N and 100 N of compression, each applied for 10 min, was used. Each loading period was followed by 10 min restitution with zero load. The loading scheme was repeated four times. Three animals were examined for stiffening effects by consecutively repeating eight times 50 N loading for 5 min followed by 5 min restitution with zero load. This loading scheme was repeated using a 100 N load level. The creep-recovery behavior of the motion segment was recorded continuously. Using non-linear regression techniques, the experimental data were used for evaluating the parameters of a three-parameter standard linear solid model. Correlation coefficients of the order of 0.85 or higher were obtained for the three independent parameters of the model. A survey of the data shows that the viscous deformation rate was a function of the load level. Also, repeated loading at 100 N seemed to induce long-lasting changes in the viscoelastic properties of the porcine lumbar motion segment.
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| 14. |
- Jacobson, S G, et al.
(författare)
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Digenic inheritance of a ROM1 gene mutation with a peripherin/RDS or rhodopsin mutation in families with retinitis pigmentosa
- 1999
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Ingår i: Digital Journal of Ophthalmology. - 1542-8958. ; 5:6
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Tidskriftsartikel (refereegranskat)abstract
- Two families with retinitis pigmentosa showed inheritance of an Arg-16-His ROM1 gene mutation with either an Arg-13-Trp RDS mutation or an Arg-135-Trp RHO mutation. The phenotypes of double and single heterozygotes were determined to examine the hypothesis that digenic inheritance may increase disease expression. In the family with ROM1 and RDS mutations, single heterozygotes were normal but one double heterozygote showed severe RP. Two other double heterozygotes, however, were normal by clinical and retinal function tests. In the family with ROM1 and RHO mutations, single heterozygotes with the RHO mutation all manifested RP, while a single heterozygote for the ROM1 mutation was normal. Disease severity was comparable in double heterozygotes and single heterozygotes HAVING the RHO mutation. We conclude that the Arg-16-His ROM1 gene mutation is non-pathogenic in the single heterozygous state, and there is no consistent evidence of digenic augmentation of pathogenicity in double heterozygotes carrying the Arg-16-His ROM1 mutation with either the benign Arg-13-Trp RDS mutation or the disease-causing Arg-135-Trp RHO mutation.
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| 15. |
- Ny, L, et al.
(författare)
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Carbon monoxide as a putative messenger molecule in the feline lower oesophageal sphincter of the cat
- 1995
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Ingår i: NeuroReport. - : Ovid Technologies (Wolters Kluwer Health). - 0959-4965. ; 6:10, s. 1389-1393
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Tidskriftsartikel (refereegranskat)abstract
- The distribution of the carbon monoxide (CO) producing enzymes haem oxygenase (HO) type 1 and 2 were studied in the feline lower oesophageal sphincter (LOS), as were HO activity and functional effects of CO. HO-2 immunoreactivity was observed in nerve cell bodies in the submucosal and myenteric plexus, nerve fibres, non-neuronal cells surrounding smooth muscle bundles, and in arterial endothelium, HO-1 immunoreactivity was confined to non-neuronal cells in the smooth muscle layer. CO production, indicating HO activity, was demonstrated in tissue homogenates. CO relaxed the LOS, and activated the cyclic GMP system. These results show that HO is present in the LOS, and suggest that CO can be generated by neuronal and non-neuronal structures and may have a role as a peripheral messenger.
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| 16. |
- Ny, L, et al.
(författare)
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Localization and activity of haem oxygenase and functional effects of carbon monoxide in the feline lower oesophageal sphincter
- 1996
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Ingår i: British Journal of Pharmacology. - : Wiley. - 0007-1188. ; 118:2, s. 392-399
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Tidskriftsartikel (refereegranskat)abstract
- 1. In the feline lower oesophageal sphincter (LOS), the distribution of the carbon monoxide (CO) producing enzymes haem oxygenase (HO)-1 and -2 was studied by immunohistochemistry and confocal microscopy, the HO activity was measured and the possible role for CO as a mediator of relaxation was investigated. 2. HO-2 immunoreactivity was abundant in nerve cell bodies of the submucosal and myenteric plexus. Approximately 50% of the HO-2-containing myenteric cell bodies were also nitric oxide synthase- and vasoactive intestinal peptide (VIP)-immunoreactive. In addition, HO-2 immunoreactivity was seen in nerve fibres, in non-neuronal cells dispersed in the smooth muscle and in arterial endothelium. HO-1 immunoreactivity was confined to non-neuronal cells in the smooth muscle, similar to those positive for HO-2. 3. Activity of HO, measured as CO production, was observed in LOS homogenates at a rate of 1.00 +/- 0.05 nmol mg-1 protein h-1. This production was inhibited by the HO inhibitor, zinc protoporphyrin-IX (ZnPP). 4. In isolated circular smooth muscle strips of LOS, developing spontaneous tone, exogenously administered CO evoked a concentration-dependent relaxation reaching a maximum of 93 +/- 3%. This relaxation was accompanied by an increase in cyclic GMP, but not cyclic AMP levels. The relaxant response was attenuated by methylene blue, but unaffected by tetrodotoxin. Repeated exposure to CO resulted in a progressive reduction of the relaxant response. 5. ZnPP caused a rightward-shift of the concentration-response curves for the relaxant responses to VIP, peptide histidine isoleucine, and pituitary adenylate cyclase activating peptide 27. 6. ZnPP and tin protoporphyrin-IX (another inhibitor of HO) did not affect nonadrenergic, noncholinergic relaxations induced by electrical field stimulation. Nor did ZnPP affect relaxations induced by 3-morpholino-sydnonimine or forskolin. 7. The present findings, showing localization of HO immunoreactivity to both neuronal and nonneuronal cells of the feline LOS, ability of LOS to produce CO and a relaxant effect of CO in circular LOS muscle, suggest a role for CO as a peripheral messenger.
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| 17. |
- Svechnikov, S., et al.
(författare)
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Spiral antenna nbn hot-electron bolometer mixer at submm requencies
- 1997
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Ingår i: IEEE Transactions on Applied Superconductivity. - : Institute of Electrical and Electronics Engineers (IEEE). - 1558-2515 .- 1051-8223. ; 7:2, s. 3395-3398
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the phonon-cooled hot-electron bolometer (HEB) as a quasioptical mixer based on a spiral antenna designed for the 0.3-1 THz frequency band and fabricated on sapphire and high resistivity silicon substrates. HEB devices were produced from superconducting 3.5-5 nm thick NbN films with a critical temperature 10-12 K and a critical current density of approximately 10/sup 7/ A/cm/sup 2/ at 4.2 K. For these devices we reached a DSB receiver noise temperature below 1500 K, a total conversion loss of L/sub t/=16 dB in the 500-700 GHz frequency range, an IF bandwidth of 3-4 GHz and an optimal LO absorbed power of /spl sime/4 /spl mu/W. We experimentally analyzed various contributions to the conversion loss and obtained an RF coupling factor of about 5 dB, internal mixer loss of 10 dB and IF mismatch of 1 dB.
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| 18. |
- Vecino, E, et al.
(författare)
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Localization of enkephalinergic neurons in the central nervous system of the salmon (Salmo salar L.) by in situ hybridization and immunocytochemistry
- 1995
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Ingår i: Journal of Chemical Neuroanatomy. - 0891-0618. ; 9:2, s. 81-97
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Tidskriftsartikel (refereegranskat)abstract
- The distribution of neurons expressing preproenkephalin (PPE) mRNA in the brain of the salmon was investigated by means of non-radioactive in situ hybridization, and directly compared with the distribution of enkephalin-immunoreactive (ENKir) neurons. This approach, utilized here for the first time in a non-mammalian vertebrate for the identification of neurons containing opioid peptides, permitted a detailed analysis of the distribution of putative enkephalinergic neurons in the salmon brain. Several cell groups containing neurons that express PPE mRNA also contain ENKir neurons. Such cell groups are located in the ventral telencephalic area, the nucleus of the rostral mesencephalic tegmentum and another nucleus immediately dorsal to it, the torus semicircularis, the valvula cerebelli and the corpus cerebelli. These cell groups consistently contain larger numbers of PPE mRNA expressing cells than ENKir ones. Some cell groups express PPE mRNA, but do not contain ENKir neurons. These cell groups are located in the dorsal telencephalic area, the inferior lobes of the hypothalamus, the pretectal area, the magnocellular superficial pretectal nucleus, the optic tectum, the oculomotor nucleus, the trochlear nucleus, the magnocellular vestibular nucleus, the secondary gustatory nucleus, the superior and medial reticular nuclei, the motor nucleus of the vagus and the ventral horn of the spinal cord. Moreover, some cell groups contain ENKir neurons, but no PPE mRNA expressing neurons. These cell groups are located in the ventromedial thalamic nucleus, the lateral tuberal nucleus, the nucleus of the lateral recess and the nucleus of the posterior recess. The majority of these periventricular ENKir neurons were of the cerebrospinal fluid-contacting type. ENKir neurons were also located in the dorsal lateral tegmental nucleus and in area B9. The results also permitted a tentative identification of enkephalinergic neurons afferent to the optic tectum, that have previously not been identified with immunocytochemistry, located in the dorsal telencephalic area, as well as enkephalinergic neurons intrinsic to the tectum that may contribute to the laminar arrangement of ENKir fibers in the optic tectum.
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| 19. |
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