| 1. |
- Miller, AB, et al.
(författare)
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Fruits and vegetables and lung cancer: Findings from the European Prospective Investigation Into Cancer and Nutrition
- 2004
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136. ; 108:2, s. 269-276
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Tidskriftsartikel (refereegranskat)abstract
- Intake of fruits and vegetables is thought to protect against the development of lung cancer. However, some recent cohort and case-control studies have shown no protective effect. We have assessed the relation between fruit and vegetable intake and lung cancer incidence in the large prospective investigation on diet and cancer, the European Prospective Investigation Into Cancer and Nutrition (EPIC). We studied data from 478,021 individuals that took part in the EPIC study, who were recruited from 10 European countries and who completed a dietary questionnaire during 1992-1998. Follow-up was to December 1998 or 1999, but for some centres with active follow-up to June 2002. During follow-up, 1,074 participants were reported to have developed lung cancer, of whom 860 were eligible for our analysis. We used the Cox proportional hazard model to determine the effect of fruit and vegetable intake on the incidence of lung cancer. We paid particular attention to adjustment for smoking. Relative risk estimates were obtained using fruit and vegetable intake categorised by sex-specific, cohort-wide quintiles. After adjustment for age, smoking, height, weight and gender, there was a significant inverse association between fruit consumption and lung cancer risk: the hazard ratio for the highest quintile of consumption relative to the lowest being 0.60 (95% Confidence Interval 0.46-0.78), p for trend 0.0099. The association was strongest in the Northern Europe centres, and among current smokers at baseline, and was strengthened when the 293 lung cancers diagnosed in the first 2 years of follow-up were excluded from the analysis. There was no association between vegetable consumption or vegetable subtypes and lung cancer risk. The findings from this analysis can be regarded as re-enforcing recommendations with regard to enhanced fruit consumption for populations. However, the effect is likely to be small compared to smoking cessation.
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| 2. |
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| 4. |
- Hallen, A, et al.
(författare)
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Implanted p(+)n-junctions in silicon carbide
- 2003
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Ingår i: APPLICATION OF ACCELERATORS IN RESEARCH AND INDUSTRY. ; , s. 653-657
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Konferensbidrag (refereegranskat)abstract
- Ion implantation is considered a key technology for the realisation of silicon carbide electronic devices. Here we will give an overview of the field and present some recent results of ion implanted 4H SiC epitaxial layers. Mainly Al ions of keV energies have been used at different fluence, flux and target temperature. The samples have been investigated by secondary ion mass spectrometry (SIMS), channeling Rutherford backscattering (RBS-c) and transmission electron microscopy (TEM), both as-implanted and after annealing up to 1900 degreesC. Also the electrical activation of Al-implanted and annealed material has been investigated by scanning spreading resistance microscopy (SSRM). The damage accumulation, monitored by RBS-c, is linear with ion fluence but depends strongly on implantation temperature and ion flux. Annealing at temperatures above 1700 degreesC is needed to remove the damage and to electrically activate implanted Al ions. At these high annealing temperatures, however, dislocation loops are formed that have a negative influence on device performance.
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| 5. |
- Janson, M S, et al.
(författare)
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Diffusion of dopants and impurities in device structures of SiC, SiGe and Si
- 2001
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Ingår i: DIFFUSIONS IN MATERIALS. ; , s. 597-609
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Konferensbidrag (refereegranskat)abstract
- Silicon Carbide (SiC) has a high thermal stability and for most elements temperatures in excess of 2000 degreesC are anticipated to reach reasonable diffusivities (greater than or equal to 10(-13) cm(2)/s). We demonstrate, however, that light elements, like hydrogen and lithium, exhibit a considerable mobility already at less than or equal to 400 degreesC, Technologically, the principal interest in these light elements arises because of their ability to electrically passivate shallow acceptors and donors as well as deep level defects in common semiconductors (SiC, Si, GaAs). Indeed, for both hydrogen and lithium the diffusion kinetics is shown to be strongly affected by trapping and de-trapping at boron impurities in the SiC layers. Evidence is also provided that hydrogen migrates as a positively charged ion in p-type SiC. Furthermore, similar to that in crystalline silicon, transient enhanced diffusion of ion-implanted boron is observed in SiC. The initial boron diffusivity during postimplant annealing at 1600 degreesC is enhanced by more than two orders of magnitude compared to equilibrium conditions. For Silicon Germanium (SiGe) diffusion of the n-type dopants Sb and P is studied. Comparing results from strained and relaxed SiGe layers annealed under inert and oxidizing conditions it is unambiguously shown that the diffusion of Sb is almost exclusively mediated by vacancies. On the other hand, P diffusion is predominantly assisted by Si self-interstitials and in this case compositional and strain effects in the SiGe layers are competing.
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| 6. |
- Naver, Lars, et al.
(författare)
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Broad spectrum of time of detection, primary symptoms and disease progression in infants with HIV-1 infection
- 2001
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Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer Science and Business Media LLC. - 0934-9723 .- 1435-4373. ; 20:3, s. 159-166
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Tidskriftsartikel (refereegranskat)abstract
- The relationship between time of HIV-1 detection, appearance of symptoms and disease progression was studied in all 24 HIV-1-infected infants from a cohort of 117 children who were born to HIV-1-infected mothers and monitored from birth. HIV isolation from plasma and mononuclear cells, HIV-1 DNA PCR (polymerase chain reaction) and, retrospectively, a quantitative assay for HIV-1 RNA were used for virus detection. Two infants possibly exhibited a symptomatic primary HIV infection. More children with than without symptoms during the first year of life progressed to immunological class 3 (P=0.013) and to AIDS or death (P=0.003) during follow-up. HIV-1 was detected within 4 days of age in 4 of 16 infants: 3 of them became symptomatic within 1 year, as did 6 of the remaining 12 infants (not statistically significant). All four infants in whom virus was detected within 4 days of age progressed to severe immunosuppression, compared to 6 of 14 in whom the virus detection test was initially negative prior to the first positive result (n.s.). Two children with previous repeatedly negative HIV detection tests were diagnosed with HIV-1 infection at 8 and 9 months, respectively. Repeated blood sampling is needed for the diagnosis of HIV-1 infection in perinatally exposed infants, and virus detection tests for exclusion of HIV-1 infection must be used with caution.
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| 7. |
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| 8. |
- Elmasry, A., et al.
(författare)
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Obstructive sleep apnoea and urine catecholamines in hypertensive males: a population-based study
- 2002
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Ingår i: Eur Respir J. ; 19:3
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Tidskriftsartikel (refereegranskat)abstract
- Studies addressing the relationship between obstructive sleep apnoea (OSA) and sympathoadrenal activity have been criticized for poor control of factors known to confound sympathetic function, including hypertension. The aim of this study was to investigate the relationship between OSA and urinary catecholamines in a population-based sample of hypertensive males. In 1994, 2,668 males aged 40-79 yrs answered a questionnaire regarding sleep disorders and somatic diseases. Of those who reported hypertension, an age-stratified sample of 116 was selected for monitoring of breathing during sleep and overnight urine analysis. Subjects with OSA, defined as apnoea-hypopnoea index > or = 10 x h(-1), had higher concentrations of urinary normetanephrine (182+/-57 versus 141+/-45 micromol x mol(-1) creatinine, p<0.001) and metanephrine (70+/-28 versus 61+/-28 micromol mol(-1) creatinine, p<0.05) in comparison to subjects without OSA. In a multiple regression analysis, there was an association between variables of sleep-disordered breathing and normetanephrine and metanephrine concentrations, independent of major confounding factors. The authors concluded that, in a population-based sample of hypertensive males, obstructive sleep apnoea is associated with increased urinary concentrations of extraneuronal metabolites of catecholamines independent of major confounding factors, suggesting increased sympathoadrenal activity. Elevated sympathoadrenal activity may explain the increased cardiovascular morbidity associated with obstructive sleep apnoea.
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| 9. |
- Gunnbjornsdottir, M. I., et al.
(författare)
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Obesity and nocturnal gastro-oesophageal reflux are related to onset of asthma and respiratory symptoms
- 2004
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Ingår i: Eur Respir J. - : European Respiratory Society (ERS). ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have identified obesity as a risk factor for asthma in both children and adults. An increased prevalence of asthma in subjects with gastro-oesophageal reflux (GOR) and obstructive sleep apnoea syndrome has also been reported. The aim of this investigation was to study obesity, nocturnal GOR and snoring as independent risk factors for onset of asthma and respiratory symptoms in a Nordic population. In a 5-10 yr follow-up study of the European Community Respiratory Health Survey in Iceland, Norway, Denmark, Sweden and Estonia, a postal questionnaire was sent to previous respondents. A total of 16,191 participants responded to the questionnaire. Reported onset of asthma, wheeze and night-time symptoms as well as nocturnal GOR and habitual snoring increased in prevalence along with the increase in body mass index (BMI). After adjusting for nocturnal GOR, habitual snoring and other confounders, obesity (BMI >30) remained significantly related to the onset of asthma, wheeze and night-time symptoms. Nocturnal GOR was independently related to the onset of asthma and in addition, both nocturnal GOR and habitual snoring were independently related to onset of wheeze and night-time symptoms. This study adds evidence to an independent relationship between obesity, nocturnal gastro-oesophageal reflux and habitual snoring and the onset of asthma and respiratory symptoms in adults.
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| 10. |
- Janson, M S, et al.
(författare)
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Channeled implants in 6H silicon carbide
- 2000
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Ingår i: SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2. ; , s. 889-892
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Konferensbidrag (refereegranskat)abstract
- Implants of MeV B-11, Al-27 and Ga-69 into the <0001> channel of 6H-SiC have been performed and concentration versus depth profiles have been obtained utilizing secondary ion mass spectrometry (SIMS). The experiment shows that the deepest channeled Ga ions reach a depth of 6.6 mum, which is 4 times deeper than the projected range of a random angle implantation, while the deepest channeled B ions only exceed the random projected range by 40%. Measurements at several implantation fluences show that implantation induced damage quench the deep channeling at fluences around 2 and 10x10(13) cm(-2) for Al and Ga, respectively, while only a minor fluence dependence is found in the B implants at fluences up to 2.6x10(14) cm(-2). The ion mass dependence of these effects is explained by the electronic to nuclear stopping ratios. Monte Carlo simulations of the channeling implants have also been performed and good agreements are found between simulations and experimental data.
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