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| 2. |
- Durr, Hermann A., et al.
(författare)
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A Closer Look Into Magnetism : Opportunities With Synchrotron Radiation
- 2009
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Ingår i: IEEE transactions on magnetics. - 0018-9464 .- 1941-0069. ; 45:1, s. 15-57
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Forskningsöversikt (refereegranskat)abstract
- The unique properties of synchrotron radiation, such as broad energy spectrum, variable light polarization, and flexible time structure, have made it an enormously powerful tool in the study of magnetic phenomena and materials. The refinement of experimental techniques has led to many new research opportunities, keeping up with the challenges put up by modern magnetism research. In this contribution, we review some of the recent developments in the application of synchrotron radiation and particularly soft X-rays to current problems in magnetism, and we discuss future perspectives.
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| 3. |
- Bammann, Karin, et al.
(författare)
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Assessment of diet, physical activity and biological, social and environmental factors in a multi-centre European project on diet- and lifestyle-related disorders in children (IDEFICS)
- 2006
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Ingår i: Journal of Public Health. - 0943-1853 .- 1613-2238. ; 14, s. 279-289
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is a major public health problem in developed countries. We present a European project, called Identification and Prevention of Dietary and Lifestyle-induced Health Effects in Children and Infants (IDEFICS), that focuses on diet- and lifestyle-related diseases in children. This paper outlines methodological aspects and means of quality control in IDEFICS. IDEFICS will use a multicentre survey design of a population-based cohort of about 17,000 2- to 10-year-old children in nine European countries (Belgium, Cyprus, Estonia, Germany, Greece, Hungary, Italy, Spain and Sweden). The project will investigate the impact of dietary factors such as food intake and food preferences, lifestyle factors such as physical activity, psychosocial factors and genetic factors on the development of obesity and other selected diet- and lifestyle-related disorders. An intervention study will be set up in pre-school and primary school settings in eight of the survey centres. Standardised survey instruments will be designed during the first phase of the project and applied in the surveys by all centres. Standard operation procedures (SOPs) will be developed, as well as a plan for training the personnel involved in the surveys. These activities will be accompanied by a quality control strategy that will encompass the evaluation of process and result quality throughout the project. IDEFICS will develop comparable Europe-wide health indicators and instruments for data collection among young children. Establishment of a new European cohort within IDEFICS will provide a unique opportunity to document the development of the obesity epidemic in the current generation of young Europeans and investigate the impact of primary prevention in European children populations.
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| 4. |
- Dietzek, Benjamin, et al.
(författare)
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Protochlorophyllide a: A Comprehensive Photophysical Picture
- 2009
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Ingår i: ChemPhysChem. - : Wiley. - 1439-7641 .- 1439-4235. ; 10:1, s. 144-150
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Tidskriftsartikel (refereegranskat)abstract
- The photochemistry of protochlorophyllide a, a precursor in the biosynthesis of chlorophyll and substrate of the light regulated enzyme protochlorophyllide oxidoreductase, is investigated by pump-probe spectroscopy. Upon excitation into the lowest lying Q-band the light induced changes ore recorded over a wide range of probe wavelengths in the visible and near-IR region between 500 and 1000 nm. Following excitation, an initial ultrafast 450 Is process is observed related to the motion out of the Franck-Condon region on the excited state surface; thus directly unraveling previous suggestions based on time-resolved fluorescence measurements (ChemPhysChem 2006, 7, 1727-1733). Furthermore, the data reveals a previously concealed photointermediate, whose formation on a nanosecond timescale matches the overall fluorescence decay and is assigned to a triplet state. The implications of this finding with respect to the photochemistry of NADPH.-protochlorophyllide oxidoreductase (POR) ore discussed.
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| 5. |
- Dietzek, Benjamin, et al.
(författare)
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The excited-state chemistry of protochlorophyllide a: A time-resolved fluorescence study
- 2006
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Ingår i: ChemPhysChem. - : Wiley. - 1439-7641 .- 1439-4235. ; 7:8, s. 1727-1733
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Tidskriftsartikel (refereegranskat)abstract
- The excited-state processes of protochlorophyllide a, the precursor of chlorophyll a in chlorophyll biosynthesis, are studied using picosecond time-resolved fluorescence spectroscopy. Following excitation into the Soret band, two distinct fluorescence components, with emission maxima at 640 and 647 nm, ore observed. The 640 nm emitting component appears within the time resolution of the experiment and then decays with a time constant of 27 ps. In contrast, the 647 nm emitting component is built up with a 3.5 ps rise time and undergoes a subsequent decay with a time constant of 3.5 ns. The 3.5 ps rise kinetics are attributed to relaxations in the electronically excited state preceding the nanosecond fluorescence, which is ascribed to emission out of the thermally equilibrated S, state. The 27 ps fluorescence, which appears within the experimental response of the streak camera, is suggested to originate from a second minimum on the excited-state potentiol-energy surface. The population of the secondary excited state is suggested to reflect a very fast motion out of the Franck-Condon region along a reaction coordinate different from the one connecting the Franck-Condon region with the S-1 potential-energy minimum. The 27 ps-component is an emissive intermediate on the reactive excited-state pathway, as its decay yields the intermediate photoproduct, which has been identified previously (J. Phys. Chem. B 2006, 110, 4399-4406). No emission of the photoproduct is observed. The results of the time-resolved fluorescence study allow a detailed spectral characterization of the emission of the excited states in protochlorophyllide a, and the refinement of the kinetic model deduced from ultrafast absorption measurements.
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| 6. |
- Gombert, Michael, et al.
(författare)
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CCL1-CCR8 interactions : an axis mediating the recruitment of T cells and Langerhans-type dendritic cells to sites of atopic skin inflammation.
- 2005
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 174:8, s. 5082-91
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Tidskriftsartikel (refereegranskat)abstract
- Atopic dermatitis represents a chronically relapsing skin disease with a steadily increasing prevalence of 10-20% in children. Skin-infiltrating T cells, dendritic cells (DC), and mast cells are thought to play a crucial role in its pathogenesis. We report that the expression of the CC chemokine CCL1 (I-309) is significantly and selectively up-regulated in atopic dermatitis in comparison to psoriasis, cutaneous lupus erythematosus, or normal skin. CCL1 serum levels of atopic dermatitis patients are significantly higher than levels in healthy individuals. DC, mast cells, and dermal endothelial cells are abundant sources of CCL1 during atopic skin inflammation and allergen challenge, and Staphylococcus aureus-derived products induce its production. In vitro, binding and cross-linking of IgE on mast cells resulted in a significant up-regulation of this inflammatory chemokine. Its specific receptor, CCR8, is expressed on a small subset of circulating T cells and is abundantly expressed on interstitial DC, Langerhans cells generated in vitro, and their monocytic precursors. Although DC maintain their CCR8+ status during maturation, brief activation of circulating T cells recruits CCR8 from intracytoplamic stores to the cell surface. Moreover, the inflammatory and atopy-associated chemokine CCL1 synergizes with the homeostatic chemokine CXCL12 (SDF-1alpha) resulting in the recruitment of T cell and Langerhans cell-like DC. Taken together, these findings suggest that the axis CCL1-CCR8 links adaptive and innate immune functions that play a role in the initiation and amplification of atopic skin inflammation.
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| 7. |
- Hermann-Kleiter, Natascha, et al.
(författare)
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Lasp1 misexpression influences chondrocyte differentiation in the vertebral column
- 2009
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Ingår i: International Journal of Developmental Biology. - : UPV/EHU Press. - 1696-3547 .- 0214-6282. ; 53:7, s. 983-991
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Tidskriftsartikel (refereegranskat)abstract
- The mouse mutant wavy tail Tg(Col1a1-lacZ)304ng was created through transgene insertion and exhibits defects of the vertebral column. Homozygous mutant animals have compressed tail vertebrae and wedge-shaped intervertebral discs, resulting in a meandering tail. Delayed closure of lumbar neural arches and lack of processus spinosi have been observed; these defects become most prominent during the transition from cartilage to bone. The spina bifida was resistant to folic acid treatment, while retinoic acid administration caused severe skeletal defects in the mutant, but none in wild type control animals. The transgene integrated at chromosome 11 band D, in an area of high gene density. The insertion site was located between the transcription start sites of the RpI23 and Lasp1 genes. LASP1 (an actin binding protein involved in cell migration and survival) was found to be produced in resting and hypertrophic chondrocytes in the vertebrae. In mutant vertebrae, temporal and spatial misexpression of Lasp1 was observed, indicating that alterations in Lasp1 transcription are most likely responsible for the observed phenotype. These data reveal a yet unappreciated role of Lasp1 in chondrocyte differentiation during cartilage to bone transition.
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| 10. |
- Paetzold, Martin, et al.
(författare)
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Rosetta Radio Science Investigations (RSI)
- 2007
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Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 128:1-4, s. 599-627
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Forskningsöversikt (refereegranskat)abstract
- The Rosetta spacecraft has been successfully launched on 2nd March 2004 to its new target comet 67 P/Churyurnov-Gerasimenko. The science objectives of the Rosetta Radio Science Investigations (RSI) experiment address fundamental aspects of cometary physics such as the mass and bulk density of the nucleus, its gravity field, its interplanetary orbit perturbed by nongravitational forces, its size and shape, its internal structure, the composition and roughness of the nucleus surface, the abundance of large dust grains, the plasma content in the coma and the combined dust and gas mass flux. The masses of two asteroids, Steins and Lutetia, shall be determined during flybys in 2008 and 2010. respectively. Secondary objectives are the radio sounding of the solar corona during the superior conjunctions of the spacecraft with the Sun during the cruise phase. The radio carrier links of the spacecraft Telemetry, Tracking and Command (TT&C) subsystem between the orbiter and the Earth will be used for these investigations. An Ultrastable oscillator (USO) connected to both transponders of the radio subsystem serves as a stable frequency reference source for both radio downlinks at X-band (8.4 GHz) and S-band (2.3 GHz) in the one-way mode. The Simultaneous and coherent dual-frequency downlinks via the High Gain Antenna (HGA) permit separation of contributions from the classical Doppler shift and the dispersive media effects caused by the motion of the spacecraft with respect to the Earth and the propagation of the signals through the dispersive media, respectively.
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