| 1. |
- Stenhamre, Hanna, et al.
(författare)
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Influence of pore size on the redifferentiation potential of human articular chondrocytes in poly(urethane urea) scaffolds
- 2011
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Ingår i: Journal of tissue engineering and regenerative medicine. - : Hindawi Limited. - 1932-7005 .- 1932-6254. ; 5:7, s. 578-588
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Tidskriftsartikel (refereegranskat)abstract
- The chemical and physical properties of scaffolds affect cellular behaviour, which ultimately determines the performance and outcome of tissue-engineered cartilage constructs. The objective of this study was to assess whether a degradable porous poly(urethane urea) scaffold could be a suitable material for cartilage tissue engineering. We also investigated whether the post-expansion redifferentiation and cartilage tissue formation of in vitro expanded adult human chondrocytes could be regulated by controlled modifications of the scaffold architecture. Scaffolds with different pore sizes, < 150 µm, 150-300 µm and 300-500 µm, were seeded with chondrocytes and subjected to chondrogenic and osteogenic induction in vitro. The poly(urethane urea) scaffold with the smaller pore size enhanced the hyaline-like extracellular matrix and thus neocartilage formation. Conversely, the chondrocytes differentiated to a greater extent into the osteogenic pathway in the scaffold with the larger pore size. In conclusion, our results demonstrate that poly(urethane urea) may be useful as a scaffold material in cartilage tissue engineering. Furthermore, the chondrogenic and the osteogenic differentiation capacity of in vitro expanded human articular chondrocytes can be influenced by the scaffold architecture. By tailoring the pore sizes, the performance of the tissue-engineered cartilage constructs might be influenced and thus also the clinical outcome in the long run.
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| 2. |
- Tayli, Doruk, et al.
(författare)
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Accurate and Efficient Evaluation of Characteristic Modes
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A new method to improve the accuracy and efficiency of CM decomposition for perfectly conducting bodies is presented. The method uses the expansion of the Green dyadic in spherical vector waves. This expansion is utilized in the MoM solution of the EFIE to factorize the real part of the impedance matrix. The factorization is then employed in the computation of CM, which improves the accuracy as well as the computational speed. An additional benefit is a rapid computation of far fields. The method can easily be integrated into existing MoM solvers. Several structures are investigated illustrating the improved accuracy and performance of the new method.
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| 5. |
- Johansson, Kristin, 1983-, et al.
(författare)
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Oxygen-scavenging coatings and films based on lignosulfonates and laccase
- 2012
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Ingår i: Journal of Biotechnology. - Amsterdam : Elsevier. - 0168-1656 .- 1873-4863. ; 161:1, s. 14-18
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Tidskriftsartikel (refereegranskat)abstract
- Laccase and lignosulfonates were included in coating colors and embedded in latex-based or starch-based films and coatings on foil or board. After 6 days at 23C and 100% relative humidity, the oxygen content in airtight chambers decreased from 1.0% (synthetic gas consisting of 99% N2 and 1% O2) to 0.3% in the presence of board coated with lignosulfonate and laccase, while the oxygen content remained unchanged in control experiments without enzyme. The water stability of lignosulfonate-containing latex-based coatings and starch-based films was improved after laccase-catalyzed oxidation of lignosulfonates, which indicates polymerization to products with lower solubility in water. Furthermore, the E' modulus of starch-based films increased with 30%, which indicates laccase-catalyzed polymerization of lignosulfonates resulting in increased stiffness of the film. The results suggest that laccases and lignosulfonates can be used as an oxygen-scavenging system in active packaging and that enzyme-catalyzed polymerization of lignosulfonates contributes to improved water stability and mechanical properties. 2012 Elsevier B.V.
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| 6. |
- Järkestig Berggren, Ulrika, et al.
(författare)
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Disabled students' experiences of higher education in Sweden, the Czech Republic, and the United States : a comparative institutional analysis
- 2016
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Ingår i: Disability & Society. - : Informa UK Limited. - 0968-7599 .- 1360-0508. ; 31:3, s. 339-356
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Tidskriftsartikel (refereegranskat)abstract
- Students with disabilities face obstacles in their encounters with higher education. The aim of this study is to investigate how the institutional context shapes students' experiences of unequal opportunities in higher education. In comparing disabled students' experiences from universities in Sweden, the Czech Republic, and the United States, the study makes visible the kind of experiences that students share and how experiences differ between these countries within the global context of higher education. The study has shown that students' possibilities for equal participation are shaped by the institutional context that is based on medical diagnosis and compensation for an inaccessible education.
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| 7. |
- Järkestig Berggren, Ulrika
(författare)
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Framväxten av ett nytt yrke och dess påverkan på professionellas handlingsutrymme
- 2011
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Ingår i: Arbetsmarknad & Arbetsliv. - Karlstad : Karlstads universitet. - 1400-9692 .- 2002-343X. ; 17:4, s. 109-120
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Tidskriftsartikel (refereegranskat)abstract
- Socialpolitiska reformer tar initiativ till styrformer över professionella gruppers utveckling inom välfärdssektorns verksamheter. I takt med att krav på kontroll och styrning har ökat, har professioner förlorat i autonomi och nya yrkesgrupper har tillkommit med uppdrag att utöva styrning och administration. I denna artikel granskas hur implementeringen av yrkesgruppen personligt ombud, från psykiatrireformen 1995, påverkar befintliga professionellas handlingsutrymme genom att personliga ombud i sin praktik utvecklar styrande inslag.
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| 8. |
- Kiviruusu, Olli, et al.
(författare)
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Interpersonal Conflicts and Development of Self-Esteem from Adolescence to Mid-Adulthood. A 26-Year Follow-Up
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:10
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the association between interpersonal conflicts and the trajectory of self-esteem from adolescence to mid-adulthood. The directionality of effects between self-esteem and interpersonal conflicts was also studied. Participants of a Finnish cohort study in 1983 at age 16 (N = 2194) were followed up at ages 22 (N = 1656), 32 (N = 1471) and 42 (N = 1334) using postal questionnaires. Measures covered self-esteem and interpersonal conflicts including, conflicts with parents, friends, colleagues, superiors, partners, break-ups with girl/boyfriends, and divorces. Participants were grouped using latent profile analysis to those having "consistently low", "decreasing", or "increasing" number of interpersonal conflicts from adolescence to adulthood. Analyses were done using latent growth curve models and autoregressive cross-lagged models. Among both females and males the self-esteem growth trajectory was most favorable in the group with a consistently low number of interpersonal conflicts. Compared to the low group, the group with a decreasing number of interpersonal conflicts had a self-esteem trajectory that started and remained at a lower level throughout the study period. The group with an increasing number of interpersonal conflicts had a significantly slower self-esteem growth rate compared to the other groups, and also the lowest self-esteem level at the end of the study period. Cross-lagged autoregressive models indicated small, but significant lagged effects from low self-esteem to later interpersonal conflicts, although only among males. There were no effects to the opposite direction among either gender. Our results show that those reporting more and an increasing number of interpersonal conflicts have a lower and more slowly developing self-esteem trajectory from adolescence to mid-adulthood. While the result was expected, it does not seem to imply an effect from interpersonal conflicts to low self-esteem. Rather, if anything, our results seem to suggest that those with low self-esteem are more prone to later interpersonal conflicts.
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| 9. |
- Lai, Zonghe, 1948
(författare)
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Activated Recrystallization of Non-Sag Tungsten Wire
- 1994
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The objective of the present investigation was to explore the mechanism of activated recrystallization of heavily drawn doped (non-sag) tungsten wire material. The recrystallization can be induced at low temperatures by the presence of some metals, such as palladium, nickel, iron and others, on the wire surface, which is important as it can seriously deteriorate the mechanical properties of non-sag tungsten wires, when the wires serve as reinforcement material in metal matrix composites. This investigation, which included the recrystallization nucleation mechanism of doped tungsten wire, the short-circuit paths for activator diffusion into tungsten wire, the activated recrys- tallization mechanism of non-sag tungsten wire, and the precipitation of activators in recrystallized tungsten wire, was carried out using atom probe field ion microscopy, optical metallography and electron microscopy. TEM observations about the initial stage of recrystallization of 0.18 mm doped tungsten wire showed that the formation, through dislocation rearrangement, of new grains with a relative misorientation could play a critical role in the recrystallization process. The impeding effect of potassium bubbles both on dislocation rearrangement and boundary migration resulted in the abnormal recrystallization behaviour of the heavily drawn doped tungsten wire. In addition, it was found that the non- orientation of recrystallized tungsten grains could originate either from the grains with a non- orientation in the starting material or from the newly nucleated grains. These observations could explain the recrystallization features of tungsten wire which the current theory could not account for. The activated recrystallization was studied both for nickel plated and palladium plated 0.18 mm cold drawn doped tungsten wire. A recrystallized structure formed in both types of wires after annealing at 1100°C for 100 hours, but their structural features were different. The recrystallization behaviour caused by palladium presence was very similar to that of undoped tungsten wire, whereas the behaviour of nickel plated wire was similar to the general recrystallization of doped wire, except for the much lower recrystallization temperature. This indicated that palladium was more effective as an activator than nickel was. It was shown, using APFIM analysis, that grain boundaries and lattice dislocations could act as fast paths for diffusion of activators in tungsten wire during annealing. The presence of the large potassium bubbles and the segregation of activators on potassium bubbles indicated that the effect of activators was to neutralize the impeding influence of potassium bubbles on dislocation movement and boundary migration. Two types of nickel rich precipitates were found. One was a Ni(W) solid solution, which formed on the bubbles at grain boundaries, and another type, with Ni4W structure, was found on the potassium bubbles connected with dislocations. Palladium rich precipitates were present only in triple junctions. Their structure could not be established.
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