| 1. |
- Acker, Pascal, et al.
(författare)
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π-Conjugation Enables Ultra-High Rate Capabilities and Cycling Stabilities in Phenothiazine Copolymers as Cathode-Active Battery Materials
- 2019
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Ingår i: Advanced Functional Materials. - : John Wiley & Sons. - 1616-301X .- 1616-3028. ; 29:45
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, organic battery cathode materials have emerged as an attractive alternative to metal oxide–based cathodes. Organic redox polymers that can be reversibly oxidized are particularly promising. A drawback, however, often is their limited cycling stability and rate performance in a high voltage range of more than 3.4 V versus Li/Li+. Herein, a conjugated copolymer design with phenothiazine as a redox‐active group and a bithiophene co‐monomer is presented, enabling ultra‐high rate capability and cycling stability. After 30 000 cycles at a 100C rate, >97% of the initial capacity is retained. The composite electrodes feature defined discharge potentials at 3.6 V versus Li/Li+ due to the presence of separated phenothiazine redox centers. The semiconducting nature of the polymer allows for fast charge transport in the composite electrode at a high mass loading of 60 wt%. A comparison with three structurally related polymers demonstrates that changing the size, amount, or nature of the side groups leads to a reduced cell performance. This conjugated copolymer design can be used in the development of advanced redox polymers for batteries.
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| 2. |
- Aderne, Rian E., et al.
(författare)
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On the energy gap determination of organic optoelectronic materials : the case of porphyrin derivatives
- 2022
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Ingår i: Materials Advances. - : Royal Society of Chemistry. - 2633-5409. ; :3, s. 1791-1803
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Tidskriftsartikel (refereegranskat)abstract
- The correct determination of the ionization potential (IP) and electron affinity (EA) as well as the energy gap is essential to properly characterize a series of key phenomena related to the applications of organic semiconductors. For example, energy offsets play an essential role in charge separation in organic photovoltaics. Yet there has been a lot of confusion involving the real physical meaning behind those quantities. Experimentally the energy gap can be measured by direct techniques such as UV-Vis absorption, or indirect techniques such as cyclic voltammetry (CV). Another spectroscopic method is the Reflection Electron Energy Loss Spectroscopy (REELS). Regarding data correlation, there is little consensus on how the REELS' energy gap can be interpreted in light of the energies obtained from other methodologies such as CV, UV-Vis, or photoemission. In addition, even data acquired using those traditional techniques has been misinterpreted or applied to derive conclusions beyond the limits imposed by the physics of the measurement. A similar situation also happens when different theoretical approaches are used to assess the energy gap or employed to explain outcomes from experiments. By using a set of porphyrin derivatives as model molecules, we discuss some key aspects of those important issues. The peculiar properties of these porphyrins demonstrate that even straightforward measurements or calculations performed in a group of very similar molecules need a careful interpretation of the outcomes. Differences up to 660 meV (similar to 190 meV) are found comparing REELS (electrochemical) measurements with UV-Vis energy gaps, for instance. From the theoretical point of view, a reasonable agreement with electrochemical measurements of the IP, EA, and the gap of the porphyrins is only obtained when the calculations involve the full thermodynamics of the redox processes. The purpose of this work is to shed light on the differences and similarities of those aforementioned characterization methods and provide some insight that might help one to develop a critical analysis of the different experimental and theoretical methodologies.
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| 3. |
- Agmo Hernández, Víctor, et al.
(författare)
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Enhanced interpretation of adsorption data generated by liquid chromatography and by modern biosensors
- 2013
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1317, s. 22-31
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Tidskriftsartikel (refereegranskat)abstract
- In this study we demonstrate the importance of proper data processing in adsorption isotherm estimations. This was done by investigating and reprocessing data from five cases on two closely related platforms: liquid chromatography (LC) and biosensors. The previously acquired adsorption data were reevaluated and reprocessed using a three-step numerical procedure: (i) preprocessing of adsorption data, (ii) adsorption data analysis and (iii) final rival model fit. For each case, we will discuss what we really measure and what additional information can be obtained by numerical processing of the data. These cases clearly demonstrate that numerical processing of LC and biosensor data can be used to gain deeper understanding of molecular interactions with adsorption media. This is important because adsorption data, especially from biosensors, is often processed using old and simplified methods. (C) 2013 Elsevier B.V. All rights reserved.
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| 4. |
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| 5. |
- Alavian-Ghavanini, Ali, et al.
(författare)
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Prenatal Bisphenol A Exposure is Linked to Epigenetic Changes in Glutamate Receptor Subunit Gene Grin2b in Female Rats and Humans
- 2018
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Bisphenol A (BPA) exposure has been linked to neurodevelopmental disorders and to effects on epigenetic regulation, such as DNA methylation, at genes involved in brain function. High doses of BPA have been shown to change expression and regulation of one such gene, Grin2b, in mice. Yet, if such changes occur at relevant doses in animals and humans has not been addressed. We investigated if low-dose developmental BPA exposure affects DNA methylation and expression of Grin2b in brains of adult rats. Furthermore, we assessed associations between prenatal BPA exposure and Grin2b methylation in 7-year old children. We found that Grin2b mRNA expression was increased and DNA methylation decreased in female, but not in male rats. In humans, prenatal BPA exposure was associated with increased methylation levels in girls. Additionally, Iow APGAR scores, a predictor for increased risk for neurodevelopmental diseases, were associated with higher Grin2b methylation levels in girls. Thus, we could link developmental BPA exposure and Iow APGAR scores to changes in the epigenetic regulation of Grin2b, a gene important for neuronal function, in a sexual dimorphic fashion. Discrepancies in exact locations and directions of the DNA methylation change might reflect differences between species, analysed tissues, exposure level and/or timing.
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| 6. |
- Alay, Özgü, et al.
(författare)
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Guest editorial: : eXtended Reality
- 2024
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Ingår i: IEEE Communications Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 0163-6804 .- 1558-1896. ; 62:8, s. 14-15
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- eXtended Reality (XR) technologies will play a key role in the digital (r)evolution of modern societies, as they will enable services allowing humans to experience an immersive interaction with virtual, mixed, and augmented realities (VR, MR, and AR) in different societal contexts, including education, entertainment, transportation, manufacturing, and healthcare.
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| 7. |
- Almquist, Ylva B., et al.
(författare)
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Prevailing over Adversity : Factors Counteracting the Long-Term Negative Health Influences of Social and Material Disadvantages in Youth
- 2018
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 15:9
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Tidskriftsartikel (refereegranskat)abstract
- Disadvantaged circumstances in youth tend to translate into poor health development. However, the fact that this is not always the case has been seen as indicative of differential resilience. The current study highlights factors outside the context of the family with the potential to counteract the long-term negative influences of social and material adversity in adolescence on general health status. This study was based on two waves of questionnaire data from the Northern Swedish Cohort. From the wave in 1981 (age 16), indicators of social and material conditions as well as factors related to school, peers, and spare time were derived. From the wave in 2008 (age 43), information about self-rated health was used. Ordinal logistic regression models (n = 908) showed that adversity in youth was associated with poorer self-rated health in midlife among men and women alike, net of health status at baseline. However, having an advantaged situation with regard to school, peers, or spare time appeared to protect against the detrimental influences of disadvantaged circumstances in the family context on subsequent health. This suggests that health-promoting interventions may benefit from focusing on contexts outside the family in their effort to strengthen processes of resilience among disadvantaged youths.
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| 8. |
- Ammothum Kandy, Akshay Krishna, et al.
(författare)
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Curvature Constrained Splines for DFTB Repulsive Potential Parametrization
- 2021
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Ingår i: Journal of Chemical Theory and Computation. - : American Chemical Society (ACS). - 1549-9618 .- 1549-9626. ; 17:3, s. 1771-1781
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Tidskriftsartikel (refereegranskat)abstract
- The Curvature Constrained Splines (CCS) methodology has been used for fitting repulsive potentials to be used in SCC-DFTB calculations. The benefit of using CCS is that the actual fitting of the repulsive potential is performed through quadratic programming on a convex objective function. This guarantees a unique (for strictly convex) and optimum two-body repulsive potential in a single shot, thereby making the parametrization process robust, and with minimal human effort. Furthermore, the constraints in CCS give the user control to tune the shape of the repulsive potential based on prior knowledge about the system in question. Herein, we developed the method further with new constraints and the capability to handle sparse data. We used the method to generate accurate repulsive potentials for bulk Si polymorphs and demonstrate that for a given Slater-Koster table, which reproduces the experimental band structure for bulk Si in its ground state, we are unable to find one single two-body repulsive potential that can accurately describe the various bulk polymorphs of silicon in our training set. We further demonstrate that to increase transferability, the repulsive potential needs to be adjusted to account for changes in the chemical environment, here expressed in the form of a coordination number. By training a near-sighted Atomistic Neural Network potential, which includes many-body effects but still essentially within the first-neighbor shell, we can obtain full transferability for SCC-DFTB in terms of describing the energetics of different Si polymorphs.
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| 9. |
- Anclair, Malin, et al.
(författare)
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Parental fears following their child's brain tumor diagnosis and treatment.
- 2009
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Ingår i: Journal of pediatric oncology nursing : official journal of the Association of Pediatric Oncology Nurses. - : SAGE Publications. - 1043-4542 .- 1532-8457. ; 26:2, s. 68-74
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study is to portray the illness-related threats experienced by parents of children after the diagnosis of central nervous system (CNS) tumor. Parents were asked to rate the extent to which they experienced a set of specific fears related to their child's brain tumor and its treatment. Outcomes for parents of CNS tumor patients (n = 82) were compared with those of reference parents of patients treated for acute lymphoblastic leukemia (n = 208). The fears about an illness recurrence and the late effects of treatment were most prominent among parents of CNS tumor patients. For 7 out of 11 kinds of fear, parents of CNS tumor patients expressed a stronger fear than the reference group. More than a quarter of the parents of children treated for CNS tumors feared a complete decline of the child. Parents of CNS tumor patients experience relatively heightened cancer related fears in several domains. The fear of devastating consequences felt by one fourth of parents signals the need of individualized psychological support and information at diagnosis and follow-up to facilitate parental coping with the posttreatment situation.
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| 10. |
- Andersen, Jørgen Ellegaard, et al.
(författare)
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Reducibility of quantum representations of mapping class groups
- 2010
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Ingår i: Letters in Mathematical Physics. - : Springer. - 0377-9017 .- 1573-0530. ; 91:3, s. 215-239
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we provide a general condition for the reducibility of the Reshetikhin–Turaev quantum representations of the mapping class groups. Namely, for any modular tensor category with a special symmetric Frobenius algebra with a non-trivial genus one partition function, we prove that the quantum representations of all the mapping class groups built from the modular tensor category are reducible. In particular, for SU(N) we get reducibility for certain levels and ranks. For the quantum SU(2) Reshetikhin–Turaev theory we construct a decomposition for all even levels. We conjecture this decomposition is a complete decomposition into irreducible representations for high enough levels.
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