| 1. |
- Gladnishki, KA, et al.
(författare)
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Angular Momentum Population in the Projectile Fragmentation of 238U at 750 MeV/nucleon
- 2004
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 69:2
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Tidskriftsartikel (refereegranskat)abstract
- A systematic study of the population probabilities of nanosecond and microsecond isomers produced following the projectile fragmentation of U-238 at 750 MeV/nucleon has been undertaken at the SIS/FRS facility at GSI. Approximately 15 isomeric states in neutron-deficient nuclei around A similar to 190 were identified and the corresponding. isomeric ratios determined. The results are compared with a model based on the statistical abrasion-ablation description of relativistic fragmentation and simple assumptions concerning gamma cascades in the final nucleus (sharp cutoff). This model represents an upper limit for the population of isomeric states in relativistic projectile fragmentation. When the decay properties of the states above the isomer are taken into account, as opposed to the sharp cutoff approximation, a good agreement between the experimental and calculated angular momentum population is obtained.
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| 2. |
- Gladnishki, KA, et al.
(författare)
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Isomer spectroscopy in the neutron-deficient lead region following projectile fragmentation
- 2003
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Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 34:4, s. 2395-2398
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Tidskriftsartikel (refereegranskat)abstract
- Projectile fragmentation of a 750 MeV/nucleon U-238 beam was used to populate neutron-deficient nuclei around A similar to190. Isomeric states in Hg, Tl, Pb, Bi, and Po isotopes were identified and their lifetimes determined, with the ultimate aim of measuring their isomeric ratios to provide information on the spin population in such reactions.
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| 3. |
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| 4. |
- Lemme, Max C., 1970-, et al.
(författare)
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Subthreshold characteristics of p-type triple-gate MOSFETs
- 2003
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Ingår i: ESSDERC 2003. - NEW YORK : IEEE. ; , s. 123-126
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Konferensbidrag (refereegranskat)abstract
- The fabrication and characterization of triple-gate p-type metal-oxide semiconductor field effect transistors (p-MOSFETs) on SOI material with multiple channels is described. To demonstrate the beneficial effects of the triple-gate structure on scaling, output and transfer characteristics of 70nm printed gate length p-MOSFETs with 22nm MESA width are presented. The geometrical influence of triple-gate MESA width on subthreshold behavior is investigated in short- and long channel devices. The temperature dependence of subthreshold characteristics is discussed.
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| 5. |
- Heuser, M, et al.
(författare)
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Fabrication of wire-MOSFETs on silicon-on-insulator substrate
- 2002
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Ingår i: Microelectronic Engineering. - 0167-9317 .- 1873-5568. ; 61-2, s. 613-618
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the simulation and fabrication of N-type wire-MOSFETs with a multigate structure fabricated on silicon-on-insulator (SOI) material. Both simulations as well as experiments show that short channel effects (SCE) can be reduced by decreasing the channel width of the transistors below 100 nm. The triple-sided gate generates principally higher potential barriers in the channel, suppressing punch through effects significantly. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 6. |
- Lemme, Max C., 1970-, et al.
(författare)
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Influence of channel width on n- and p-type nano-wire-MOSFETs on silicon on insulator substrate
- 2003
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Ingår i: Microelectronic Engineering. - 0167-9317 .- 1873-5568. ; 67-8, s. 810-817
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Tidskriftsartikel (refereegranskat)abstract
- The fabrication and characterization of nanoscale n- and p-type multi-wire metal-oxide semiconductor field effect transistors (MOSFETs) with a triple gate structure on silicon-on-insulator material (SOI) is described in this paper. Experimental results are compared to simulation with special emphasis on the influence of channel width on the subthreshold behavior. Experiment and simulation show that the threshold voltage depends strongly on the wire width at dimensions below 100 urn. It is further shown that the transition from partial to full channel depletion is dependent on channel geometry. Finally, an increased on-current per chip area is demonstrated for triple-gate SOI MOSFETs compared to planar SOI devices. (C) 2003 Elsevier Science B.V. All rights reserved.
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| 7. |
- Lemme, Max C., 1970-, et al.
(författare)
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Subthreshold behavior of triple-gate MOSFETs on SOI material
- 2004
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Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101 .- 1879-2405. ; 48:4, s. 529-534
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Tidskriftsartikel (refereegranskat)abstract
- The fabrication of n-type multi-wire MOSFETs on SOI material with triple-gate structures is presented. The output and transfer characteristics of devices with a gate length of 70 nm and a MESA width of 22 nm demonstrate clearly the suppression of short channel effects (SCE). In addition, these triple-gate structures are compared with planar SOI devices of comparable dimensions. The influence of biasing the substrate (back gate) is analyzed and compared to simulation data.
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| 8. |
- Lumsden, A, et al.
(författare)
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Neurobiology.
- 2001
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Ingår i: Current Opinion in Neurobiology. - 0959-4388 .- 1873-6882. ; 11:3, s. 259-66
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Forskningsöversikt (refereegranskat)
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| 9. |
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| 10. |
- Schänzer, Anne, et al.
(författare)
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Direct stimulation of adult neural stem cells in vitro and neurogenesis in vivo by vascular endothelial growth factor.
- 2004
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Ingår i: Brain pathology (Zurich, Switzerland). - 1015-6305. ; 14:3, s. 237-48
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Tidskriftsartikel (refereegranskat)abstract
- Hypoxia as well as global and focal ischemia are strong activators of neurogenesis in the adult mammalian central nervous system. Here we show that the hypoxia-inducible vascular endothelial growth factor (VEGF) and its receptor VEGFR-2/Flk-1 are expressed in clonally-derived adult rat neural stem cells in vitro. VEGF stimulated the expansion of neural stem cells whereas blockade of VEGFR-2/Flk-1-kinase activity reduced neural stem cell expansion. VEGF was also infused into the lateral ventricle to study changes in neurogenesis in the ventricle wall, olfactory bulb and hippocampus. Using a low dose (2.4 ng/d) to avoid endothelial proliferation and changes in vascular permeability, VEGF stimulated adult neurogenesis in vivo. After VEGF infusion, we observed reduced apoptosis but unaltered proliferation suggesting a survival promoting effect of VEGF in neural progenitor cells. Strong expression of VEGFR-2/Flk-1 was detected in the ventricle wall adjacent to the choroid plexus, a site of significant VEGF production, which suggests a paracrine function of endogenous VEGF on neural stem cells in vivo. We propose that VEGF acts as a trophic factor for neural stem cells in vitro and for sustained neurogenesis in the adult nervous system.These findings may have implications for the pathogenesis and therapy of neurodegenerative diseases.
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