| 1. |
- Pietrow, A. G. M., et al.
(författare)
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A comparative study of two X2.2 and X9.3 solar flares observed with HARPS-N : Reconciling Sun-as-a-star spectroscopy and high-spatial resolution solar observations in the context of the solar-stellar connection
- 2024
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Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 682
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Tidskriftsartikel (refereegranskat)abstract
- Context. Stellar flares cannot be spatially resolved, which complicates ascertaining the physical processes behind particular spectral signatures. Due to their proximity to Earth, solar flares can serve as a stepping stone for understanding their stellar counterparts, especially when using a Sun-as-a-star instrument and in combination with spatially resolved observations.Aims. We aim to understand the disk-integrated spectral behaviors of a confined X2.2 flare and its eruptive X9.3 successor, which had energies of 2.2 × 1031 erg and 9.3 × 1031 erg, respectively, as measured by Sun-as-a-star observations with the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N).Methods. The behavior of multiple photospheric (Na D1 & D2, Mg I at 5173 Å, Fe I at 6173 Å, and Mn I at 4031 Å) and chromospheric (Ca II H & K, Hα, Hβ, and He ID3) spectral lines were investigated by means of activity indices and contrast profiles. A number of different photospheric lines were also investigated by means of equivalent widths, and radial velocity measures, which were then related to physical processes directly observed in high-resolution observations made with the Swedish 1-m Solar Telescope (SST) and the Atmospheric Imaging Assembly (AIA) on board of the Solar Dynamics Observatory (SDO).Results. Our findings suggest a relationship between the evolving shapes of contrast profile time and the flare locations, which assists in constraining flare locations in disk-integrated observations. In addition, an upward bias was found in flare statistics based on activity indices derived from the Ca II H & K lines. In this case, much smaller flares cause a similar increase in the activity index as that produced by larger flares. Hα-based activity indices do not show this bias and are therefore less susceptible to activity jitter. Sodium line profiles show a strongly asymmetric response during flare activity, which is best captured with a newly defined asymmetrical sodium activity index. A strong flare response was detected in Mn I line profiles, which is unexpected and calls for further exploration. Intensity increases in Hα, Hβ, and certain spectral windows of AIA before the flare onset suggest their potential use as short-term flare predictors.
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| 2. |
- Wingbrant, Helena, et al.
(författare)
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MISiCFET chemical sensors for applications in exhaust gases and flue gases
- 2002
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Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 433-4, s. 953-956
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Tidskriftsartikel (refereegranskat)abstract
- A chemical gas sensor based on a silicon carbide field effect transistor with a catalytic gate metal has been under development for a number of years. The choice of silicon carbide as the semiconductor material allows the sensor to operate at high temperatures, for more than 6 months in flue gases at 300degreesC and for at least three days at 700degreesC. The chemical inertness of silicon carbide and a buried gate design makes it a suitable sensor technology for applications in corrosive environments such as exhaust gases and flue gases from boilers. The selectivity of the sensor devices is established through the choice of type and structure of the gate metal as well as the operation temperature. In this way NH3 sensors with low cross sensitivity to NOx have been demonstrated as potential sensors for control of selective catalytic reduction (SCR) of NOx by urea injection into diesel exhausts. Here we show that sensors with a porous platinum or iridium gate show different temperature ranges for NH3 detection. The hardness of the silicon carbide makes it for example more resistant to water splash at cold start of a petrol engine than existing technologies, and a sensor which can control the air to fuel ratio, before the exhaust gases are heated, has been demonstrated. Silicon carbide sensors are also tested in flue gases from boilers. Efficient regulation of the combustion in a boiler will decrease fuel consumption and reduce emissions.
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| 3. |
- Ahlström, A., et al.
(författare)
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No major differences in perinatal and maternal outcomes between uninterrupted embryo culture in time-lapse system and conventional embryo culture
- 2023
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Ingår i: Human Reproduction. - : Oxford University Press. - 0268-1161 .- 1460-2350. ; 38:12, s. 2400-2411
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Tidskriftsartikel (refereegranskat)abstract
- STUDY QUESTION: Is embryo culture in a closed time-lapse system associated with any differences in perinatal and maternal outcomes in comparison to conventional culture and spontaneous conception?SUMMARY ANSWER: There were no significant differences between time-lapse and conventional embryo culture in preterm birth (PTB, <37 weeks), low birth weight (LBW, >2500 g) and hypertensive disorders of pregnancy for singleton deliveries, the primary outcomes of this study.WHAT IS KNOWN ALREADY: Evidence from prospective trials evaluating the safety of time-lapse incubation for clinical use show similar embryo development rates, implantation rates, and ongoing pregnancy and live birth rates when compared to conventional incubation. Few studies have investigated if uninterrupted culture can alter risks of adverse perinatal outcomes presently associated with IVF when compared to conventional culture and spontaneous conceptions.STUDY DESIGN, SIZE, DURATION: This study is a Swedish population-based retrospective registry study, including 7379 singleton deliveries after fresh embryo transfer between 2013 and 2018 from selected IVF clinics. Perinatal outcomes of singletons born from time-lapse-cultured embryos were compared to singletons from embryos cultured in conventional incubators and 71 300 singletons from spontaneous conceptions. Main perinatal outcomes included PTB and LBW. Main maternal outcomes included hypertensive disorders of pregnancy (pregnancy hypertension and preeclampsia).PARTICIPANTS/MATERIALS, SETTING, METHODS: From nine IVF clinics, 2683 singletons born after fresh embryo transfer in a time-lapse system were compared to 4696 singletons born after culture in a conventional incubator and 71 300 singletons born after spontaneous conception matched for year of birth, parity, and maternal age. Patient and treatment characteristics from IVF deliveries were cross-linked with the Swedish Medical Birth Register, Register of Birth Defects, National Patient Register and Statistics Sweden. Children born after sperm and oocyte donation cycles and after Preimplantation Genetic testing cycles were excluded. Odds ratio (OR) and adjusted OR were calculated, adjusting for relevant confounders.MAIN RESULTS AND THE ROLE OF CHANCE: In the adjusted analyses, no significant differences were found for risk of PTB (adjusted OR 1.11, 95% CI 0.87-1.41) and LBW (adjusted OR 0.86, 95% CI 0.66-1.14) or hypertensive disorders of pregnancy; preeclampsia and hypertension (adjusted OR 0.99, 95% CI 0.67-1.45 and adjusted OR 0.98, 95% CI 0.62-1.53, respectively) between time-lapse and conventional incubation systems. A significantly increased risk of PTB (adjusted OR 1.31, 95% CI 1.08-1.60) and LBW (adjusted OR 1.36, 95% CI 1.08-1.72) was found for singletons born after time-lapse incubation compared to singletons born after spontaneous conceptions. In addition, a lower risk for pregnancy hypertension (adjusted OR 0.72 95% CI 0.53-0.99) but no significant difference for preeclampsia (adjusted OR 0.87, 95% CI 0.68-1.12) was found compared to spontaneous conceptions. Subgroup analyses showed that some risks were related to the day of embryo transfer, with more adverse outcomes after blastocyst transfer in comparison to cleavage stage transfer.LIMITATIONS, REASONS FOR CAUTION: This study is retrospective in design and different clinical strategies may have been used to select specific patient groups for time-lapse versus conventional incubation. The number of patients is limited and larger datasets are required to obtain more precise estimates and adjust for possible effect of additional embryo culture variables.WIDER IMPLICATIONS OF THE FINDINGS: Embryo culture in time-lapse systems is not associated with major differences in perinatal and maternal outcomes, compared to conventional embryo culture, suggesting that this technology is an acceptable alternative for embryo incubation.
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| 4. |
- Ekberg, Marie, et al.
(författare)
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Mortality risks among heavy-smokers with special reference to women: a long-term follow-up of an urban population
- 2007
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 1573-7284 .- 0393-2990. ; 22:5, s. 301-309
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Tidskriftsartikel (refereegranskat)abstract
- Increased mortality risks associated with smoking are well established among men. There are very few population-based studies comprising a sufficient number of heavily smoking women, measuring the direct effect of smoking on mortality risks. Between 1974 and 1992, 8,499 women and 13,888 men attended a health screening programme including reporting of smoking habits. Individuals were followed for total mortality until 2005. All-cause, cancer, cardiovascular, lung cancer and respiratory mortality were calculated in smoking categories < 10 g per day, 10-19 g per day, and >= 20 g per day with never-smokers as a reference group and with adjustments for co-morbidities, socio-economic and marital status. For respiratory mortality and lung cancer adjustments for FEV1, socio-economic and marital status were performed. Smoking was associated with a two to almost threefold increased mortality risk among women and men. The relative risk (RR) with 95% confidence interval, (CI) for women who smoked 10-19 g per day was 2.44 (2.07-2.87), and for those who smoked 20 g per day or more the RR (95% CI) was 2.42 (2.00-2.92). Smoking was a strong risk factor for cardiovascular mortality among women, the RR (95% CI) for women who smoked 10-19 g per day was 4.52 (3.07-6.64). Ex-smoking women showed increased risks of all-cause mortality; RR (95% CI) 1.26 (1.04-1.52) cancer (excluding lung cancer); RR (95% CI) 1.42 (1.07-1.88) and lung cancer RR (95% CI) 2.71 (1.02-7.23) mortality. However, the cardiovascular; RR (95% CI) 1.18 (0.69-2.00) and respiratory; RR (95% CI) 0.79 (0.16-3.84) mortality risks were not statistically significant. This study confirms that as for men, middle-aged heavily smoking women have a two to threefold increased mortality risk. Adjustments for co-morbidity, socio-economic and marital status did not change these results.
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| 5. |
- Kraen, M., et al.
(författare)
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Fibroblast growth factor 23 is an independent marker of COPD and is associated with impairment of pulmonary function and diffusing capacity
- 2021
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 0954-6111. ; 182
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Tidskriftsartikel (refereegranskat)abstract
- Fibroblast growth factor 23 (FGF23) is a phosphaturic hormone that in recent years has been reported to have significant effects on numerous tissues. Chronic obstructive pulmonary disease (COPD) is associated with hypophosphatemia but the evidence for elevated plasma levels of FGF23 in COPD subjects is ambiguous. Recently, FGF23 has even been shown to be involved in the inflammatory pathways activated in COPD, so FGF23 could be a novel biomarker for COPD and impairment of pulmonary function. The purpose was thus to explore the association of FGF23 with COPD and measures of pulmonary function. This was a cross sectional study of 450 subjects who underwent spirometry, body plethysmography, determination of diffusing capacity (DL,CO) and biomarker analysis of FGF23, interleukin (IL)-1 receptor antagonist, IL-6 and IL-8. Forty-four participants were excluded due to missing data or renal impairment (eGFR <45 mL/min/m2). Spirometry identified 123 subjects with COPD. FGF23 levels were elevated in COPD subjects compared to non COPD subjects, and this remained significant after adjustment for age, sex and smoking habits (OR = 1.6, p = 0.02). Linear regression showed significant relationships between FGF23 and FEV1 (β = −0.15, p = 0.003), RV/TLC (β = 0.09, p = 0.05) and DL, CO (β = −0.24, p < 0.001). In conclusion we found that plasma levels of FGF23 are elevated in COPD subjects even when adjusting for traditional risk factors. Furthermore, FGF23 is associated with impairment in lung function as measured by FEV1 and DL,CO. Further studies are needed to establish whether FGF23 could serve as a novel biomarker of COPD and emphysema development.
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| 6. |
- Kraen, M., et al.
(författare)
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Matrix Metalloproteinases in COPD and atherosclerosis with emphasis on the effects of smoking
- 2019
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- Background Matrix metalloproteinases (MMP´s) are known biomarkers of atherosclerosis. MMP´s are also involved in the pathophysiological processes underlying chronic obstructive pulmonary disease (COPD). Cigarette smoking plays an important role in both disease states and is also known to affect the concentration and activity of MMP´s systemically. Unfortunately, the epidemiological data concerning the value of MMP´s as biomarkers of COPD and atherosclerosis with special regards to smoking habits are limited. Methods 450 middle-aged subjects with records of smoking habits and tobacco consumption were examined with comprehensive spirometry, carotid ultrasound examination and biomarker analysis of MMP-1, -3, -7, -10 and -12. Due to missing data 33 subjects were excluded. Results The remaining 417 participants were divided into 4 different groups. Group I (n = 157, no plaque and no COPD), group II (n = 136, plaque but no COPD), group III (n = 43, COPD but no plaque) and group IV (n = 81, plaque and COPD). Serum levels of MMP-1,-7,-10-12 were significantly influenced by smoking, and MMP-1, -3, -7 and-12 were elevated in subjects with COPD and carotid plaque. This remained statistically significant for MMP-1 and-12 after adjusting for traditional risk factors. Conclusion COPD and concomitant plaque in the carotid artery were associated with elevated levels of MMP-1 and -MMP-12 even when adjusting for risk factors. Further studies are needed to elucidate if these two MMP´s could be useful as biomarkers in a clinical setting. Smoking was associated with increased serum levels of MMP´s (except for MMP-3) and should be taken into account when interpreting serum MMP results.
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| 7. |
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| 8. |
- Nakagomi, S, et al.
(författare)
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Substrate bias amplification of a SiC junction field effect transistor with a catalytic gate electrode
- 2004
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Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 457-460, s. 1507-1510
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Tidskriftsartikel (refereegranskat)abstract
- The drain current-voltage (I-d-V-D) characteristics of a chemical gas sensor based on a catalytic metal insulator silicon carbide field effect transistor (SiC-FET) were measured in H-2 or O-2 ambient while applying negative substrate bias, V-sub, at temperatures up to 600degreesC. An increase in the negative V-sub gives rise to an increase of the drain voltage at a given drain current level, which can be used to adjust the device baseline. In addition, we found that the difference in drain voltage between H-2 and O-2 ambient at a given drain current level (the gas response to H-2) increases for an increased negative substrate bias. By modifying an equation for the drain current in a SIT (static induction transistor), the influence of substrate bias on the amplification factors, mu and eta, was estimated using the temperature dependence of the I-d-V-D characteristics. From this, the effect of substrate bias on the gas response to hydrogen was calculated. It was clarified that the increase in the gas response caused by the negative substrate bias is due to a substrate bias dependence of the amplification factor of the short channel device.
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| 9. |
- Plymoth, Amelie, et al.
(författare)
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Protein expression patterns associated with progression of chronic obstructive pulmonary disease in bronchoalveolar lavage of smokers
- 2007
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Ingår i: Clin Chem. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 53:4, s. 636-44
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We modeled the expression of proteins in baseline bronchoalveolar lavage (BAL) samples from asymptomatic 60-year-old lifelong current smokers or healthy never-smokers, who were reevaluated after 6 to 7 years to record clinical outcome. METHODS: Applying a technology toolbox consisting of replicate 2-dimensional gel separations, image annotation, and mass spectrometry identification, we catalogued a global set of proteins that were differentially expressed in individuals by presence, absence, and intensity scores. RESULTS: By use of multivariate analysis, we selected a subset of proteins that accurately separated smokers from never-smokers based on composite scoring. Follow-up after 6 to 7 years identified a group of individuals who had progressed to chronic obstructive pulmonary disease (COPD), Global Initiative for Chronic Obstructive Lung Disease stage 2. The baseline BAL samples of these eventual COPD patients shared a distinct protein expression profile that could be identified using partial least-squares discriminant analysis. This pattern was not observed in BAL samples of asymptomatic smokers free of COPD at 6- to 7-year follow-up. CONCLUSIONS: Our model suggests that certain patterns of protein expression occurring in the airways of long-term smokers may be detected in smokers susceptible to a progression of COPD disease, before disease is clinically evident.
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| 10. |
- Sartorius, B, et al.
(författare)
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An outbreak of mumps in Sweden, February-April 2004
- 2005
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Ingår i: Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin. - 1560-7917. ; 10:9, s. 191-3
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Tidskriftsartikel (refereegranskat)
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