| 1. |
- Wang, Gang, et al.
(författare)
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Assessment of chronic bronchitis and risk factors in young adults : results from BAMSE
- 2020
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Ingår i: European Respiratory Journal. - Stockholm : Karolinska Institutet, Dept of Clinical Science and Education, Södersjukhuset. - 0903-1936 .- 1399-3003.
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Chronic bronchitis is associated with substantial morbidity among elderly adults, but little is known about its prevalence and risk factors in young adults. Our aim was to assess the prevalence and early life risk factors for chronic bronchitis in young adults. METHODS: Questionnaire data and clinical measures from the 24-year follow-up of the Swedish BAMSE cohort were used. We assessed chronic bronchitis (CB) as the combination of cough and mucus production in the morning during winter. Environmental and clinical data from birth and onwards were used for analyses of risk factors. RESULTS: At the 24-year follow-up, 75% (n=3064) participants completed the questionnaire and 2030 performed spirometry. The overall prevalence of CB was 5.5% (n=158) with similar estimates in males and females. Forty-nine percent of CB cases experienced more than 3 self-reported respiratory infections in the last year compared to 18% in non-CB subjects (p<0.001), and 37% of cases were current smokers (versus 19%). Statistically significant lower post-FEV(1)/FVC were observed in CB compared to non-CB subjects (mean z-score -0.06 versus 0.13, p=0.027). Daily smoking (adjusted Odds Ratio, aOR=3.85, p<0.001), air pollution exposure (black carbon during ages 1-4 years old, aOR=1.71 per 1 μg·m(3) increase, p=0.009) and exclusive breast-feeding during four months or more (aOR=0.66, p=0.044) were associated with CB. CONCLUSION: Chronic bronchitis in young adults is associated with recurrent respiratory infections. Besides smoking, our results support role of early life exposures, such as air pollution and exclusive breast-feeding, for respiratory health later in life.
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| 2. |
- Wang, Gang, et al.
(författare)
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Early-life risk factors for reversible and irreversible airflow limitation in young adults : findings from the BAMSE birth cohort
- 2021
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Ingår i: Thorax. - : BMJ Publishing Group Ltd. - 0040-6376 .- 1468-3296. ; 76:5, s. 503-507
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Tidskriftsartikel (refereegranskat)abstract
- We aimed to determine prevalence and early-life risk factors for reversible and irreversible airflow limitation in young adults from the general population. Among young adults in their 20s, the prevalence was 5.3% for reversible airflow limitation and 2.0% for irreversible airflow limitation. While parental asthma was the only risk factor for development of reversible airflow limitation, the risk factors for development of irreversible airflow limitation were current asthma, childhood respiratory tract infections and asthma, and exposure to air pollution.
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| 3. |
- Bergström, Hans, et al.
(författare)
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Wind power in cold climates : Ice mapping methods
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the Vindforsk V-313 project “Vindkraft i kallt klimat” the goal was to arrive at a methodology to construct a high resolution (1x1 km2) climatology of icing on wind power turbines. This is a very demanding task since observations of icing on instruments have only been routinely available in Sweden during three winter seasons and at a dozen locations. The term climatology in classical meteorology means statistics over 30 years of data, and usually in the form of direct or indirect measurements. Examples are mean temperatures (annual, monthly, maximum etc.), number of frost days, growing season, variability, number of days of precipitation, mean winds, cloudiness, solar radiation, to name a few.In the project researchers from Uppsala University, WeatherTech Scandinavia, and SMHI have been collaborating. Observations have been analysed and state-of-the-art numerical weather prediction models have been applied in case studies and tested in several sensitivity studies. Extensive model verification has been carried out. Modelled ice load and estimated production losses were also compared to measurements. The question of how to arrive at a method using only a few years to represent the long-term climatology was addressed and several methods were tested.The project has shed light on the uncertainties in modelling ice load and icing climate. The end results not only depend on which mesoscale model that is used but also on how the model is set up. In order to improve the models more accurate measurements of ice load is needed. Observations of liquid cloud water content and droplet size distributions could also be of significant value to better understand why the ice load models fail in capturing the observed ice load.
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| 4. |
- Bodvik, Rasmus, et al.
(författare)
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Aggregation and network formation of aqueous methylcellulose and hydroxypropylmethylcellulose solutions.
- 2010
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Ingår i: Colloids and Surfaces A. - : Elsevier. - 0927-7757 .- 1873-4359. ; 354:1-3, s. 162-171
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Tidskriftsartikel (refereegranskat)abstract
- Solution properties of methylcellulose (MC) and hydroxypropylmethylcellulose (HPMC) have been investigated as a function of temperature and concentration using a broad range of experimental techniques. Novelties include the extensive comparison between MC and HPMC solutions as well as the combination of techniques, and the use of Cryo transmission electron microscopy (Cryo-TEM). The correlation between rheology and light scattering results clearly demonstrates the relation between viscosity change and aggregation. Cryo-TEM images show the network structures formed. Viscosity measurements show that for both MC and HPMC solutions sudden changes in viscosity occur as the temperature is increased. The onset temperature for these changes depends on polymer concentration and heating rate. For both MC and HPMC solutions the viscosity on cooling is very different compared to on heating, demonstrating the slow equilibration time. The viscosity changes in MC and HPMC solutions are dramatically different; for MC solutions the viscosity increases by several orders of magnitude when a critical temperature is reached, whereas for HPMC solutions the viscosity decreases abruptly at a given temperature, followed by an increase upon further heating. Light and (SAXS) small-angle X-ray scattering shows that the increase in viscosity, for MC as well as for HPMC solutions, is due to extensive aggregation of the polymers. Light scattering also provides information on aggregation kinetics. The SAXS measurements allow us to correlate aggregation hysteresis to the viscosity hysteresis, as well as to extract some structural information. Cryo-TEM images give novel information that a fibrillar network is formed in MC solutions, and the strong viscosity increase occurs when this network spans the whole solution volume. For HPMC solutions the behaviour is more complex. The decrease in viscosity can be related to the formation of compact objects, and the subsequent increase to formation of fibrillar structures, which are more linear and less entangled than for MC.
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| 5. |
- Fransson, Emma, 1973-, et al.
(författare)
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Exploring salivary cortisol and recurrent pain in mid-adolescents living in two homes
- 2014
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Ingår i: BMC Psychology. - : Springer Science and Business Media LLC. - 2050-7283. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Each year, around 50.000 children in Sweden experience a separation between their parents. Joint physical custody (JPC), where the child alternates homes between the parents for about equal amount of time, has become a common living arrangement after parental separation. Children in two homes could benefit from everyday contact with both parents and access to both parents' financial resources. However, children could experience stress from being constantly moving and potentially exposed to parental conflicts. Still, studies on JPC and biological functioning related to stress, are lacking. The aim of this study was to investigate how living arrangements (intact family/JPC) relate to HPA-axis activity and recurrent pain in mid-adolescents.METHODS: Mid-adolescents (106 girls and 51 boys) provided demographic details, self-reports of recurrent pain (headache, stomachache, neck/shoulder and back pain) and salivary samples. Salivary cortisol samples were collected: 1) immediately at awakening, 2) +30 minutes, 3) +60 minutes, and 4) at 8 p.m. The cortisol awakening response (CAR) was computed using an established formula. Additionally, the diurnal decline between the waking and 8 p.m. samples was computed.RESULTS: Hierarchical multiple regressions showed that living arrangements (intact family/JPC) was not associated with morning cortisol (CAR), the diurnal cortisol decline or with recurrent pain. However, sex was a significant predictor of both cortisol measures and recurrent pain with girls exhibiting a higher cortisol awakening response and a greater diurnal decline value as well as reporting more recurrent pain than did boys.CONCLUSIONS: Living arrangements were not associated with HPA-axis activity or recurrent pain in this group of well-functioning mid-adolescents. Although this study is the first to investigate how living arrangements relate to HPA-axis functioning and additional studies are needed, the tentative findings suggest that these mid-adolescents have adapted to their living arrangements and that other factors play a more pertinent role for HPA-functioning and subjective health.
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| 6. |
- Fransson, Emma, et al.
(författare)
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Exploring salivary cortisol and recurrent pain in mid-adolescents living in two homes
- 2014
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Ingår i: International Journal of Behavioral Medicine. - : Springer Science and Business Media LLC. - 1070-5503 .- 1532-7558. ; 21, s. S23-S23
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Every year, around 50.000 children in Sweden experience a separation between their parents. Joint physical custody (JPC), where the child alternates homes between the parents for about equal amount of time, has become a common living arrangement after parental separation. Children living in two homes can benefit from everyday contact with both parents and access to both parents’ financial resources. However, children can also experience stress from constantly moving and from exposure to any parental conflict. Yet, research on JPC and stress-related biological functioning is limited. The aimof this study was to investigate how living arrangements (intact family/JPC) relate toHPA-axis activity and recurrent pain in mid-adolescents. Methods: Mid-adolescents (106 girls and 51 boys) provided demographic details, self-reports of recurrent pain (headache, stomachache, neck/shoulder and back pain) and salivary samples. Salivary cortisol samples were collected: 1) immediately at awakening, 2) +30 minutes, 3) +60 minutes, and 4) at 8 p.m. Results: Hierarchical regressions showed that living arrangements did not predict morning cortisol levels, the diurnal cortisol rhythm nor recurrent pain. However, sex was significantly associated with both morning cortisol and recurrent pain. Conclusion: Living arrangements were not linked to HPA-axis activity or recurrent pain in this group of well-functioning mid-adolescents. Although this is the first study investigating how living arrangements relate to HPA-axis functioning, which means that additional research is needed, the findings suggest that these mid-adolescents have adapted to their living arrangements and that other factors seem more pertinent for HPA-functioning and subjective health complaints.
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| 7. |
- Thorsson, Petra, 1987-, et al.
(författare)
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Modelling atmospheric icing : A comparison between icing calculated with measured meteorological data and NWP data
- 2015
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Ingår i: Cold Regions Science and Technology. - : Elsevier. - 0165-232X .- 1872-7441. ; 119, s. 124-131
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Tidskriftsartikel (refereegranskat)abstract
- In this case study several periods of measured active icing events have been compared with calculated activeicing. Icing events from three winter seasons in Sweden have been selected as a base for studying how well acommonly used method to calculate icing can capture icing events, aswell as to try out a newapproach. Anotherpurpose is to enlighten parties interested in atmospheric icing of the challenges of calculating icing. For thosewith little knowledge of Numerical Weather Prediction (NWP) models it can be hard to understand why thereare differences between two models, or even the same model using different physical parameterisation schemes.In this study data fromtwoNWP models have been used to calculate icing, aswell as being compared with a newapproach using meteorological measurements to calculate icing. Using meteorological measurements to calculateicing is an interesting alternative as it is computationally less expensive than using aNWP model to generatethe necessary data.All tested methods could at times capture the dynamics of the measured icing, though there are on occasion largedifferences between the different calculated icing and also between calculations and measurements. This highlightsthe importance of having an understanding of NWP models when studying atmospheric icing; there canbe a large spread between different models, and also when using the same model with different schemes. Theresults show that calculated icing is comparable to measured icing and that the methodologies investigatedare viable options for calculating atmospheric icing.
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| 8. |
- Um-Bergström, Petra, et al.
(författare)
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Lung function development after preterm birth in relation to severity of Bronchopulmonary dysplasia
- 2017
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Ingår i: BMC Pulmonary Medicine. - : BIOMED CENTRAL LTD. - 1471-2466. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Background: Bronchopulmonary dysplasia (BPD) is a strong risk factor for respiratory morbidity in children born preterm. Our aims were to evaluate lung function in adolescents born preterm with and without a history of BPD, and to assess lung function change over time from school age.Methods: Fifty-one individuals born in Stockholm, Sweden between gestational ages 24 to 31 weeks (23 neonatally diagnosed with respiratory distress syndrome (RDS) but not BPD, and 28 graded as mild (n = 17), moderate (n = 7) or severe (n = 4) BPD) were examined in adolescence (13-17 years of age) using spirometry, impulse oscillometry (IOS), plethysmography, and ergospirometry. Comparison with lung function data from school age (6-8 years of age) was also performed.Results: Adolescents with a history of BPD had lower forced expiratory volume in 1 s (FEV1) compared to those without BPD (-0.61 vs.-0.02 z-scores, P < 0.05), with lower FEV1 values significantly associated with BPD severity (P for trend 0.002). Subjects with severe BPD had higher frequency dependence of resistance, R5-20, (P < 0.001 vs. non-BPD subjects) which is an IOS indicator of peripheral airway involvement. Between school age and adolescence, FEV1/FVC z-scores decreased in all groups and particularly in the severe BPD group (from -1.68 z-scores at 6-8 years to -2.74 z-scores at 13-17 years, p < 0.05 compared to the non-BPD group).Conclusions: Our results of spirometry and IOS measures in the BPD groups compared to the non-BPD group suggest airway obstruction including involvement of peripheral airways. The longitudinal result of a decrease in FEV1/FVC in the group with severe BPD might implicate a route towards chronic airway obstruction in adulthood.
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