| 1. |
- Abdollahi Sani, Negar, et al.
(författare)
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All-printed diode operating at 1.6 GHz
- 2014
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 111:33, s. 11943-11948
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Tidskriftsartikel (refereegranskat)abstract
- Printed electronics are considered for wireless electronic tags and sensors within the future Internet-of-things (IoT) concept. As a consequence of the low charge carrier mobility of present printable organic and inorganic semiconductors, the operational frequency of printed rectifiers is not high enough to enable direct communication and powering between mobile phones and printed e-tags. Here, we report an all-printed diode operating up to 1.6 GHz. The device, based on two stacked layers of Si and NbSi2 particles, is manufactured on a flexible substrate at low temperature and in ambient atmosphere. The high charge carrier mobility of the Si microparticles allows device operation to occur in the charge injection-limited regime. The asymmetry of the oxide layers in the resulting device stack leads to rectification of tunneling current. Printed diodes were combined with antennas and electrochromic displays to form an all-printed e-tag. The harvested signal from a Global System for Mobile Communications mobile phone was used to update the display. Our findings demonstrate a new communication pathway for printed electronics within IoT applications.
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| 2. |
- Andersson, Mats R., et al.
(författare)
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Electroluminescence from Substituted Poly(thiophenes) : From Blue to Near-Infrared
- 1995
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Ingår i: Macromolecules. - : American Chemical Society. - 0024-9297 .- 1520-5835. ; 28:22, s. 7525-7529
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Tidskriftsartikel (refereegranskat)abstract
- We report a systematic approach to the control of the conjugation length along the poly(thiophene) backbone. The planarity of the main chain can be permanently modified by altering the pattern of substitution and character of the substituents on the poly(thiophene) chain, and the conjugation length is thus modified. We obtain blue, green, orange, red, and near-infrared electroluminescence from four chemically distinct poly(thiophenes). The external quantum efficiencies are in the range of 0.01-0.6%.
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| 3. |
- Dahl, Andreas, et al.
(författare)
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Traffic-generated emissions of ultrafine particles from pavement-tire interface
- 2006
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Ingår i: Atmospheric Environment. - : Elsevier. - 1352-2310 .- 1873-2844. ; 40:7, s. 1314-1323
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Tidskriftsartikel (refereegranskat)abstract
- In a road simulator study, a significant source of sub-micrometer fine particles produced by the road-tire interface was observed. Since the particle size distribution and source strength is dependent on the type of tire used, it is likely that these particles largely originate from the tires, and not the road pavement. The particles consisted most likely of mineral oils from the softening filler and fragments of the carbon-reinforcing filler material (soot agglomerates). This identification was based on transmission electron microscopy studies of collected ultrafine wear particles and on-line thermal treatment using a thermodesorber. The mean particle number diameters were between 15-50 nm, similar to those found in light duty vehicle (LDV) tail-pipe exhaust. A simple box model approach was used to estimate emission factors in the size interval 15-700 nm. The emission factors increased with increasing vehicle speed, and varied between 3.7 x 10(11) and 3.2 x 10(12) particles vehicle(-1) km(-1) at speeds of 50 and 70 km h(-1). This corresponds to between 0.1-1% of tail-pipe emissions in real-world emission studies at similar speeds from a fleet of LDV with 95% gasoline and 5% diesel-fueled cars. The emission factors for particles originating from the road-tire interface were, however, similar in magnitude to particle number emission factors from liquefied petroleum gas-powered vehicles derived in test bench studies in Australia 2005. Thus the road-tire interface may be a significant contributor to particle emissions from ultraclean vehicles. (c) 2005 Elsevier Ltd. All rights reserved.
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| 4. |
- Gustafsson, Berit, 1966-, et al.
(författare)
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Longitudinal pathways of engagement, social interaction skills,hyperactivity and conduct problems in preschool children
- 2021
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Ingår i: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564 .- 1467-9450. ; 62:2, s. 170-184
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Tidskriftsartikel (refereegranskat)abstract
- Preschool children’s engagement/social interaction skills can be seen as aspects of positive functioning, and also act as protective aspects of functioning.On the other hand, hyperactivity/conduct problems are risk aspects that negatively affect children’s everyday functioning. Few studies have investigatedsuch orchestrated effects on mental health in young children over time. The aims of the study are rst, to identify homogeneous groups of children havingsimilar pathways in mental health between three time points. Second, to examine how children move between time points in relation to risk and protectivefactors. Alongitudinal study over 3 years, including 197 Swedish preschool children was used. Questionnaire data collected from preschool teachers.Statistical analysis using person-oriented methods with repeated cluster analyses. Children high in engagement/social skills and low in conduct problemscontinue to function well. Children with low engagement/social skills exhibiting both hyperactivity and conduct problems continue to have problems.Children with mixed patterns of protective factors and risk factors showed mixed outcomes. The stability of children’s pathways was quite high if theyexhibited many positive protective factors but also if they exhibited many risk factors. Children exhibiting a mixed pattern of protective and risk factorsmoved between clusters in a less predictable way. That stability in mental health was related to the simultaneous occurrence of either many protectivefactors or many risk factors supports the notion of orchestrated effects. The results indicate that early interventions need to have a dual focus, includingboth interventions aimed at enhancing child engagement and interventions focused on decreasing behavior problem.
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| 5. |
- Gustafsson, Berit M., 1966-, et al.
(författare)
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Hyperactivity precedes conduct problems in preschool children : a longitudinal study.
- 2018
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Ingår i: BJPsych Open. - : Cambridges Institutes Press. - 2056-4724. ; 4:4, s. 186-191
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Tidskriftsartikel (refereegranskat)abstract
- Background: Externalising problems are among the most common symptoms of mental health problems in preschool children.Aims: To investigate the development of externalising problems in preschool children over time, and the way in which conduct problems are linked to hyperactivity problems.Method: In this longitudinal study, 195 preschool children were included. Latent growth modelling of conduct problems was carried out, with gender and hyperactivity at year 1 as time-invariant predictors.Results: Hyperactivity was a significant predictor for the intercept and slope of conduct problems. Children with more hyperactivity at year 1 had more conduct problems and a slower reduction in conduct problems. Gender was a significant predictor for the slope of conduct problems.Conclusions: Children with more initial hyperactivity have less of a reduction in conduct problems over time. It is important to consider the role of hyperactivity in studies of the development of conduct problems.Declaration of interest: None.
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| 6. |
- Gustafsson, Berit M., 1966-
(författare)
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Identifying Patterns of Emotional and Behavioural Problems in Preschool children : Facilitating Early Detection
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mental health problems often debut in early childhood and may last throughout adulthood, thereby making early detection and intervention especially important. The overarching aim of the present thesis was to identify patterns of emotional and behavioural problems indicating mental health problems in preschool children. To facilitate the detection of such problems early on, one available screening instrument Strengths and Difficulties Questionnaire (SDQ), was validated. The development and interaction of externalising problems in preschool children were studied over time. Functioning and behaviour and their relations to protective and risk indicators in both environmental and personal characteristics were explored. The long-term goal was to increase knowledge about early identification of emotional and behavioural problems in preschool children in order to facilitate early intervention.In Study I (n=690), the subscales Hyperactivity and Conduct Problems were shown to be valid for children in the age group 1–3 years. A reasonable level of validity was found for the age group 4–5 years when using the original SDQ four-factor solution. The preschool teachers considered most of the SDQ items relevant and possible to rate. Based on the results of Study II (n=815), a score of ≥12 on the SDQ Total Problems Scale is recommended as a cut-off for Swedish preschool children. There were significant differences between boys and girls on all subscales except for the Emotional subscale. The Swedish norms for SDQ are to a large extent similar to findings from other European countries. Study III (n=195) showed that preschool children’s conduct problems decrease over time. Children exhibiting more initial hyperactivity (at year 1) have less reduction in conduct problems over time, i.e. the more hyperactivity early in life, the more conduct problems at year 3. In Study IV (n=197), children high in engagement and social interaction function well over time, even in the presence of hyperactivity, while children with low engagement and interaction alone or in combination with hyperactivity and conduct problems continue to have problems. Stability was related to the existence of a larger number of protective or risk indicators respectively.Taken together, this thesis has shown that the SDQ can be used to identify preschool children at risk of developing mental health problems later in life.
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| 7. |
- Gustafsson, Mats, et al.
(författare)
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Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material
- 2008
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Ingår i: Science of the Total Environment. - : Institutionen för klinisk och experimentell medicin. - 0048-9697 .- 1879-1026. ; 393:2-3, s. 226-240
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Tidskriftsartikel (refereegranskat)abstract
- In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic is the main reason for high particle concentrations in busy street- and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM10) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, PIXE and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM10, respectively. The results show that in the road simulator, where resuspension is minimised, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consists almost entirely of minerals from the pavement stone material, but also that S is enriched for the sub-micron particles and that Zn is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM10 emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results implies that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties.
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| 8. |
- Karlsson, Helen, et al.
(författare)
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Wear Particles from Studded Tires and Granite Pavement Induce Pro-inflammatory Alterations in Human Monocyte-Derived Macrophages : A Proteomic Study.
- 2011
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Ingår i: Chemical Research in Toxicology. - : American Chemical Society. - 0893-228X .- 1520-5010. ; 24, s. 45-53
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Tidskriftsartikel (refereegranskat)abstract
- Airborne particulate matter is considered to be one of the environmental contributors to the mortality in cancer, respiratory, and cardiovascular diseases. For future preventive actions, it is of major concern to investigate the toxicity of defined groups of airborne particles and to clarify their pathways in biological tissues. To expand the knowledge beyond general inflammatory markers, this study examined the toxicoproteomic effects on human monocyte derived macrophages after exposure to wear particles generated from the interface of studded tires and a granite-containing pavement. As comparison, the effect of endotoxin was also investigated. The macrophage proteome was separated using two-dimensional gel electrophoresis. Detected proteins were quantified, and selected proteins were identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry. Among analyzed proteins, seven were significantly decreased and three were increased by exposure to wear particles as compared to unexposed control cells. Endotoxin exposure resulted in significant changes in the expression of six proteins: four decreased and two increased. For example, macrophage capping protein was significantly increased after wear particle exposure only, whereas calgizzarin and galectin-3 were increased by both wear particle and endotoxin exposure. Overall, proteins associated with inflammatory response were increased and proteins involved in cellular functions such as redox balance, anti-inflammatory response, and glycolysis were decreased. Investigating the effects of characterized wear particles on human macrophages with a toxicoproteomic approach has shown to be useful in the search for more detailed information about specific pathways and possible biological markers.
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