1. |
- Ohrwall, G, et al.
(author)
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Femtosecond interatomic Coulombic decay in free neon clusters: Large lifetime differences between surface and bulk
- 2004
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In: Physical Review Letters. - 1079-7114. ; 93:17
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Journal article (peer-reviewed)abstract
- A quantitative determination of 2s vacancy lifetimes in surface and bulk atoms of free Ne clusters has been made. While for free atoms the 2s inner-valence hole has a ps lifetime, it reduces to 6+/-1 fs for cluster bulk atoms. For surface atoms, the lifetime is on average longer than 30 fs. The lifetime estimate was obtained from fits of high-resolution photoelectron spectra of Ne clusters. The shortening of the lifetime is attributed to the coordination dependent interatomic Coulombic decay, which is extremely sensitive to internuclear distances.
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2. |
- G. Öhrwall, M. Tchaplyguine, M. Gisselbrecht, M. Lundwall, R. Feifel, T. Rander, J. Schulz, R. R. T. Marinho, A. Lindgren, S. L. Sorensen, S. Svensson and O. Björneholm
(author)
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Observation of elastic scattering effects on photoelectron angular distributions in free Xe clusters
- 2003
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In: J. Phys. B: At. Mol. Opt. Phys. ; :36, s. 3937-
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Journal article (peer-reviewed)
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3. |
- Kruger, R., et al.
(author)
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Orbital ordering in LaMnO3 investigated by resonance Raman spectroscopy
- 2004
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 92
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Journal article (peer-reviewed)abstract
- Orbital ordering leads to an unconventional excitation spectrum that we investigate by resonance Raman scattering using incident photon energies between 1.7 and 5.0 eV. We use spectral ellipsometry to determine the corresponding dielectric function. Our results show resonant behavior of the phonon Raman cross section when the laser frequency is close to the orbiton-excitation energy of 2 eV in LaMnO3. We show an excellent agreement between theoretical calculations based on the Franck-Condon mechanism activating multiphonon Raman scattering in first order of the electron-phonon coupling and the experimental data of phonons with different symmetries.
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4. |
- Linseisen, J, et al.
(author)
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Consumption of added fats and oils in the European Prospective Investigation into Cancer and Nutrition (EPIC) centres across 10 European countries as assessed by 24-hour dietary recalls
- 2002
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In: Public Health Nutrition. - 1475-2727. ; 5:6B, s. 1227-1242
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Journal article (peer-reviewed)abstract
- Objective: To evaluate the consumption of added fats and oils across the European centres and countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). Design and setting: 24-Hour dietary recalls were collected by means of standardised computer-guided interviews in 27 redefined EPIC centres across 10 European countries. Subjects: From an initial number of 36 900 subjects, single dietary recalls from 22 924 women and 13 031 men in the age range of 35-74 years were included. Results: Mean daily intake of added fats and oils varied between 16.2 g (Varese, Italy) and 41.1 g (Malmo, Sweden) in women and between 24.7 g (Ragusa, Italy) and 66.0 g (Potsdam, Germany) in men. Total mean lipid intake by consumption of added fats and oils, including those used for sauce preparation, ranged between 18.3 (Norway) and 37.2 g day(-1) (Greece) in women and 28.4 (Heidelberg, Germany) and 51.2 g day(-1) (Greece) in men. The Mediterranean EPIC centres with high olive oil consumption combined with low animal fat intake contrasted with the central and northern European centres where fewer vegetable oils, more animal fats and a high proportion of margarine were consumed. The consumption of added fats and oils of animal origin was highest in the German EPIC centres, followed by the French. The contribution of added fats and oils to total energy intake ranged from 8% in Norway to 22% in Greece. Conclusions: The results demonstrate a high variation in dietary intake of added fats Oil and oils in EPIC, providing a good opportunity to elucidate the role of dietary fats in cancer aetiology.
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5. |
- Schulz, A, et al.
(author)
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Arctic ozone loss in threshold conditions: Match observations in 1997/1998 and 1998/1999
- 2001
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In: JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES. - : AMER GEOPHYSICAL UNION. - 0747-7309. ; 106:D7, s. 7495-7503
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Journal article (peer-reviewed)abstract
- Chemical ozone loss rates inside the Arctic polar vortex were determined in early 1998 and early 1999 by using the Match technique based on coordinated ozonesonde measurements. These two winters provide the only opportunities in recent years to investigat
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6. |
- Schulz, B., et al.
(author)
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Hydration dynamics of human fingernails : An ellipsometric study
- 2002
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In: Physical Review E. ; 65
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Journal article (peer-reviewed)abstract
- We use spectroscopic ellipsometry to obtain the complex refractive index, (n) over tilde =n+ik, of human fingernails. By studying the change of (n) over tilde upon hydration and dehydration, we reveal three different time domains with typical time constants of 4, 150, and 3200 min. A simple model that takes into account the presence of one fast and one slow process is fully consistent with the observed hydration and dehydration dynamics. We attribute these processes to "free" water incorporated between the keratin filaments and water more tightly "bound" in keratin complexes, respectively. From our model we determine the hydration profiles of "free" and "bound" water during, both, hydration and dehydration.
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7. |
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8. |
- Hjartaker, A, et al.
(author)
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Consumption of dairy products in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: data from 35955 24-hour dietary recalls in 10 European countries
- 2002
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In: Public Health Nutrition. - 1475-2727. ; 5:6B, s. 1259-1271
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Journal article (peer-reviewed)abstract
- Objectives: To describe and compare the consumption of dairy products in cohorts included in the European Prospective Investigation into-Cancer and Nutrition (EPIC). Methods: Data from single 24-hour dietary recall interviews collected through a highly standardised computer-based program (EPIC-SOFT) in 27 redefined centres in 10 European countries between 1995 and 2000. From a total random sample of 36 900, 22 924 women and 13 031 men were selected after exclusion of subjects under 35 and over 74 years of age. Results: A high total consumption of dairy products was reported in most of the centres in Spain and in the UK cohort sampled from the general population, as well as in the Dutch, Swedish and Danish centres. A somewhat low consumption was reported in the Greek centre-and in some of the Italian centres (Ragusa and Turin). In all centres and for both sexes, milk constituted the dairy sub-group with the largest proportion (in grams) of total dairy consumption, followed by yoghurt and other fermented milk products, and cheese. Still, there was a wide range in the contributions of the different dairy sub-groups between centres. The Spanish and Nordic centres generally reported a high consumption of milk,, the Swedish and Dutch centres reported a high consumption of yoghurt and other fermented milk products, whereas the highest consumption of cheese was reported in the French centres. Conclusion: The results demonstrate both quantitative and qualitative disparities in dairy product consumption among the EPIC centres. This offers a sound starting point for analyses of associations between dairy intake and chronic diseases such as cancer.
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9. |
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10. |
- Ohrwall, G, et al.
(author)
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Observation of elastic scattering effects on photoelectron angular distributions in free Xe clusters
- 2003
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In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 36:19, s. 3937-3949
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Journal article (peer-reviewed)abstract
- We report an observation of substantial deviations in the photoelectron angular distribution for photoionization of atoms in free Xe clusters compared to the case of photoionization of free atoms. The cross section, however, seems not to vary between the cluster and free atoms. This observation was made in the vicinity of the Xe 4d Cooper minimum, where the atomic angular distribution is known to vary dramatically. The angular distribution of electrons emitted from atoms in the clusters is more isotropic than that of free atoms over the entire kinetic energy range studied. Furthermore, the angular distribution is more isotropic for atoms in the interior of the clusters than for atoms at the surface. We attribute this deviation to elastic scattering of the outgoing photoelectrons. We have investigated two average cluster sizes, (N) approximate to 4000 and 1000 and found no significant differences between these two cases.
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11. |
- Pfeiffer, K, et al.
(author)
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A comparison of thermally and photochemically cross-linked polymers for nanoimprinting
- 2003
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In: Microelectronic Engineering. - 1873-5568. ; 67-8, s. 266-273
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Journal article (peer-reviewed)abstract
- The characteristics and benefits of two types of cross-linking prepolymers with low glass transition temperature (T-g) for nanoimprinting are reported. They are soluble in organic solvents and their solutions can be processed like those of common thermoplastics. The imprinted patterns receive high thermal and mechanical stability through cross-linking polymerization. The course of the polymerization was investigated to determine the appropriate conditions for the imprint process. In thermally cross-linked polymers mr-I 9000, the cross-linking occurs during imprinting. Process time and temperature depend on the polymerization rate. Volume shrinkage during the polymerization does not adversely affect imprinting. Photochemically cross-linked polymers mr-L 6000 make possible imprint temperatures below 100 T and short imprint times. The T-g of the prepolymer determines the imprint temperature. The cross-linking reaction and structural stabilization is performed after imprinting. 50-nm trenches and sub-50-nm dots confirm the successful application of the polymers.
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12. |
- Pfeiffer, K, et al.
(author)
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Polymer stamps for nanoimprinting
- 2002
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In: Microelectronic Engineering. - 1873-5568. ; 61-2, s. 393-398
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Journal article (peer-reviewed)abstract
- Stamp fabrication for nanoimprinting can be significantly simplified, when specialized crosslinking polymers are applied to pattern definition. The polymer patterns can be used as stamps themselves. Two possibilities are reported: (1) An e-beam sensitive resist was developed, which enables the fabrication of polymer-on-silicon stamps. Patterns with a feature size of 70 nm could be created. (2) Full plastic stamps were obtained by a casting-moulding technique, which enable pattern transfer from any conventional mould. The quality of the two stamp variants were proved by imprinting experiments. (C) 2002 Elsevier Science B.V. All rights reserved.
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13. |
- Steward, C. G., et al.
(author)
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Severe pulmonary hypertension: a frequent complication of stem cell transplantation for malignant infantile osteopetrosis
- 2004
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In: Br J Haematol. - 0007-1048. ; 124:1, s. 63-71
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Journal article (peer-reviewed)abstract
- This report describes eight infants who developed acute severe pulmonary arterial hypertension (PAH) at days -2 to +89 after allogeneic stem cell transplantation (SCT) for malignant infantile osteopetrosis (MIOP). They were taken from a total of 28 children (frequency 29%) transplanted for this disease at three institutions between 1996 and 2002. Typical presentations were acute dyspnoea, hypoxia and brady/tachycardia usually in the absence of fever, crepitations or other evidence of infection. Six patients (75%) required assisted ventilation and five (62%) died. There was clinical or pathological evidence of veno-occlusive disease (VOD) in three children, but absence of VOD in the remaining five suggests that a separate disease process may be responsible for the PAH. Responses to nitric oxide (NO), defibrotide (DF), nicardipine and steroids in varying combinations were disappointing. Three children showed sustained improvement after administration of epoprostenol (EP, prostacyclin) in conjunction with NO and/or DF and remain well and free of PAH 25, 31 and 32 months post-transplant. PAH must therefore be excluded in any child who becomes acutely breathless after SCT for osteopetrosis.
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14. |
- Tchaplyguine, Maxim, et al.
(author)
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The size of neutral free clusters as manifested in the relative bulk-to-surface intensity in core level photoelectron spectroscopy
- 2004
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In: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 120:1, s. 345-356
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Journal article (peer-reviewed)abstract
- A new approach for obtaining an estimate of the effective size of the free neutral clusters is proposed. The approach relies on an experimental measure of the surface and interior or "bulk" cluster atoms provided by the x-ray photoelectron spectroscopy and on a model for the attenuation of photoelectrons ejected from the bulk of the cluster as the result of the ionizing irradiation. The experimental part gives the ratio of the electron signal from the bulk cluster atoms to that from the cluster surface atoms for a wide range of cluster sizes and electron kinetic energies. The attenuated response of the bulk atoms is modeled using an exponential law with the cluster size and kinetic-energy-dependent electron escape depth as parameters. For the experimental size range, model-based calculations for Ar, Kr, and Xe clusters are presented. The cluster size estimates obtained from comparison of the model calculations and experimental results agree well with those determined from the parameters of the cluster creation process. The combination of experiment and modeling also makes it possible to estimate the effective escape depth for electron propagation in free clusters. For Ar, Kr, and Xe clusters of varying mean size, absolute determination of the surface and bulk electron binding energies of the core levels used in the experiments has also been made. (C) 2004 American Institute of Physics.
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17. |
- Yurganov, L.N., et al.
(author)
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A Quantitative Assessment of the 1998 Carbon Monoxide Emission Anomaly in the Northern Hemisphere Based on Total Column and Surface Concentration Measurements
- 2004
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In: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 109:15, s. D15305-
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Journal article (peer-reviewed)abstract
- Carbon monoxide abundances in the atmosphere have been measured between January 1996 and December 2001 in the high Northern Hemisphere (HNH) (30degrees-90degreesN) using two different approaches: total column amounts of CO retrieved from infrared solar spectra and CO mixing ratios measured in situ at ground-based stations. The data were averaged, and anomalies of the CO HNH burden ( deviations of the total tropospheric mass between 30degreesN and 90degreesN from the mean seasonal profile, determined as the 5 year average) were analyzed. The anomalies obtained from in situ and total column data agree well and both show two maxima, by far the largest in October 1998 and a lower one in August 1996. A noticeable decrease of the positive 1998 summer anomaly with increasing height was found. A box model was applied, and anomalies in source rates were obtained under the assumption of insignificant interannual sink variations. In August 1998 the HNH emission anomaly was estimated to be 38 Tg month(-1). The annual 1998 emission positive anomaly was 96 Tg yr(-1). Nearly all excess CO may be attributed to the emissions from boreal forest fires. According to available inventories, biomass burning emits around 52 Tg yr(-1) during the "normal'' years; therefore total biomass emissions in 1998 were as large as 148 Tg yr(-1). In August 1998, CO contribution from the biomass burning was twice as large as that from fossil fuel combustion. The results were compared to available emission inventories.
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