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- Abrahamsson, M. L. A., et al.
(author)
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Ruthenium-manganese complexes for artificial photosynthesis : Factors controlling intramolecular electron transfer and excited-state quenching reactions
- 2002
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 41:6, s. 1534-1544
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Journal article (peer-reviewed)abstract
- Continuing our work toward a system mimicking the electron-transfer steps from manganese to P-680(+) in photosystem II (PS II), we report a series of ruthenium(II)-manganese(II) complexes that display intramolecular electron transfer from manganese(II) to photooxidized ruthenium(III). The electron-transfer rate constant (k(ET)) values span a large range, 1 X 10(5)-2 x 10(7) s(-1), and we have investigated different factors that are responsible for the variation. The reorganization energies determined experimentally (lambda = 1.5-2.0 eV) are larger than expected for solvent reorganization in complexes of similar size in polar solvents (typically lambda approximate to 1.0 eV). This result indicates that the inner reorganization energy is relatively large and, consequently, that at moderate driving force values manganese complexes are not fast donors. Both the type of manganese ligand and the link between the two metals are shown to be of great importance to the electron-transfer rate. In contrast, we show that the quenching of the excited state of the ruthenium(II) moiety by manganese(II) in this series of complexes mainly depends on the distance between the metals. However, by synthetically modifying the sensitizer so that the lowest metal-to-ligand charge transfer state was localized on the nonbridging ruthenium(II) ligands, we could reduce the quenching rate constant in one complex by a factor of 700 without changing the bridging ligand. Still, the manganese(II)-ruthenium (III) electrontransfer rate constant was not reduced. Consequently, the modification resulted in a complex with very favorable properties.
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| 2. |
- Akesson, A, et al.
(author)
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Cadmium exposure in pregnancy and lactation in relation to iron status
- 2002
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In: American Journal of Public Health. - : American Public Health Association. - 1541-0048 .- 0090-0036. ; 92:2, s. 284-287
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Journal article (peer-reviewed)abstract
- Objectives. The purpose of this study was to determine the impact of iron status on cadmium dose among pregnant women. Methods. Iron status and cadmium concentration in blood, urine, and placenta were determined among women followed for 2 years from early pregnancy. Results. Blood cadmium and urinary cadmium were correlated with iron status throughout the study period. Urinary cadmium increased longitudinally among women with exhausted iron stores during their pregnancy. The increase in urinary cadmium with age was more pronounced in multiparous than in nulliparous women. Conclusions. Iron deficiency during pregnancy leads to increased cadmium absorption and body burden. Multiparous women exhibit additional increases with increasing age.
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| 7. |
- Haftenberger, M, et al.
(author)
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Overweight, obesity and fat distribution in 50-to 64-year-old participants in the European Prospective Investigation into Cancer and Nutrition (EPIC)
- 2002
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In: Public Health Nutrition. - 1475-2727. ; 5:6B, s. 1147-1162
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Journal article (peer-reviewed)abstract
- Objective: To describe anthropometric characteristics of participants of the European Prospective Investigation into Cancer and Nutrition (EPIC). Design: A cross-sectional analysis of baseline data of a European prospective cohort study. Subjects: This analysis includes study populations from 25 centres in nine European countries. The British populations comprised both a population-based and a 'health-conscious' group. The analysis was restricted to 83 178 men and 163 851 women aged 50-64 years, this group being represented in all centres. Methods: Anthropometric examinations were undertaken by trained observers using standardised methods and included measurements of weight, height, and waist and hip circumferences. In the 'health-conscious' group (UK), anthropometric measures were predicted from self-reports. Results: Except in the 'health-conscious' group (UK) and in the French centres, mean body mass index (BMI) exceeded 25.0 kg m(-2). The prevalence of obesity (BMI greater than or equal to 30 kg m(-2)) varied from 8% to 40% in men, and from 5% to 53% in women, with high prevalences (> 25%) in the centres from Spain, Greece, Ragusa and Naples (Italy) and the lowest prevalences (< 10%) in the French centres and the 'health-conscious' group (UK). The prevalence of a large waist circumference or a high waist-to-hip ratio was high in centres from Spain, Greece, Ragusa and Naples (Italy) and among women from centres in Germany and Bilthoven (The Netherlands). Conclusions: Anthropometric measures varied considerably within the EPIC population. These data provide a strong base for further investigation of anthropometric measures in relation to the risk of chronic diseases, especially cancer.
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| 9. |
- Klipstein-Grobuschl, K, et al.
(author)
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Trends in self-reported past alcoholic beverage consumption and ethanol intake from 1950 to 1995 observed in eight European countries participating in the European Investigation into Cancer and Nutrition (EPIC)
- 2002
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In: Public Health Nutrition. - 1475-2727. ; 5:6B, s. 1297-1310
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Journal article (peer-reviewed)abstract
- Objective: to describe the trends of self-reported past consumption of alcoholic beverages and ethanol intake from 1950. to 1995 within the European Prospective Investigation into Cancer and Nutrition (EPIC). Design: Data-on consumption of beer/cider, wine and liqueur/spirits were obtained age 20, 30 and 40 years to calculate average consumption and retrospectively at ethanol intake for the time periods 1950-1975 (at age 20), 1960-1985 (at age 30) and 1970-1995 (at age 40). Regression analysis was conducted with-the time period data to assess trends in past alcoholic beverage consumption and ethanol intake with time. Setting: The EPIC project. Subjects: In total, 392 064 EPIC participants (275 249 women and 116 815 men) from 21 study centres in eight European countries. Results: Generally, increases in beer/cider consumption were observed for-most EPIC centres for 1950-1975, 1960-1985 and 1970-1995. Trends in wine consumption differed according to geographical location: downward trends with time were observed for men in southern European EPIC centres, upward trends for those in middle/northern European study centres. For women, similar but less pronounced trends were observed. Because wine consumption was the major contributor to ethanol intake for both men and women in most study. centres,time trends for ethanol intake showed a similar geographical pattern to that of wine consumption. Conclusion: The different trends, in alcoholic beverage consumption and ethanol intake suggest that information depicting lifetime history of ethanol intake should be and chronic diseases, included in analyses of the relationship between ethanol, particularly in multi-centre studies such as EPIC.
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| 10. |
- Lumpkin, A. H., et al.
(author)
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Evidence for microbunching "sidebands" in a saturated free-electron laser using coherent optical transition radiation
- 2002
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In: Physical Review Letters. - 1079-7114. ; 88:23, s. 4-4
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Journal article (peer-reviewed)abstract
- We report the first measurements of z -dependent coherent optical transition radiation (COTR) due to electron-beam microbunching at high gains (>10(4) ) including saturation of a self-amplified spontaneous emission free-electron laser (FEL). In these experiments the fundamental wavelength was near 530 nm, and the COTR spectra exhibit the transition from simple spectra to complex spectra (5% spectral width) after saturation. The COTR intensity growth and angular distribution data are reported as well as the evidence for transverse spectral dependencies and an "effective" core of the beam being involved in microbunching.
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