On the influence of the architecture of poly(ethylene glycol)-based thermoresponsive polymers on cell adhesion     

Katja Uhlig  Bj?rn Boysen  Andreas Lankenau  Magnus Jaeger  Erik Wischerhoff  Jean-Fran?ois Lutz  André Laschewsky  Claus Duschl 《Biomicrofluidics》2012,6(2)

Thermoresponsive polymer surface coatings are a promising tool for cell culture applications. They allow for a mild way of cell detachment that preserves the activity of membrane proteins—a prerequisite for reliable cell analysis. To enlarge the application range of these coatings to cells with different adhesion properties, we synthesized various novel poly(ethylene glycol)-based thermoresponsive polymers and describe how (i) their chemical structure and (ii) their surface density affect their efficiency. In order to quantify the influence of both factors, the time for cell spreading and rounding efficiency were observed. As a result, efficiency of cell rounding, which is closely correlated to cell detachment, is less affected by both factors than the time needed for cell spreading. This time can effectively be adjusted by the molecular architecture which includes the length of the polymer backbone and the side chains. Based on this work, recommendations are given for future optimization of functionality of thermoresponsive polymer coatings for cell culture applications.  相似文献   

Maximal oxygen uptake versus maximal power output in children     

Dencker M  Thorsson O  Karlsson MK  Lindén C  Wollmer P  Andersen LB 《Journal of sports sciences》2008,26(13):1397-1402

Maximal oxygen uptake VO(2max)) is considered the optimal method to assess aerobic fitness. The measurement of VO(2max), however, requires special equipment and training. Maximal exercise testing with determination of maximal power output offers a more simple approach. This study explores the relationship between [Vdot]O(2max) and maximal power output in 247 children (139 boys and 108 girls) aged 7.9-11.1 years. Maximal oxygen uptake was measured by indirect calorimetry during a maximal ergometer exercise test with an initial workload of 30 W and 15 W x min(-1) increments. Maximal power output was also measured. A sample (n = 124) was used to calculate reference equations, which were then validated using another sample (n = 123). The linear reference equation for both sexes combined was: VO(2max) (ml x min(-1)) = 96 + 10.6 x maximal power + 3.5 . body mass. Using this reference equation, estimated VO(2max) per unit of body mass (ml x min(-1) x kg(-1)) calculated from maximal power correlated closely with the direct measurement of VO(2max) (r = 0.91, P <0.001). Bland-Altman analysis gave a mean limits of agreement of 0.2+/-2.9 (ml x min(-1) x kg(-1)) (1 s). Our results suggest that maximal power output serves as a good surrogate measurement for VO(2max) in population studies of children aged 8-11 years.  相似文献   

Max Weber: A Family Portrait: Guenther Roth, <Emphasis Type="Italic">Max Webers deutsch-englische Familiengeschichte 1800–1950, mit Briefen und Dokumenten</Emphasis> (Tübingen: Mohr Siebeck, 2001), 721 pp. + index,ISBN: 3-16-147557-7, 84 €     

Magnus?BrechtkenEmail author 《Minerva》2004,42(4):445-450

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Happy objects,happy men? Affect and materiality in vocational training     

Magnus Åberg  Maria Hedlin 《Gender and education》2015,27(5):523-538

This article investigates the prevailing social inertia of vocational training. Previous research indicates that gendered social norms contribute to sustaining gender segregation. Few studies, however, have paid attention to how the interplay of emotional and material factors impact on gender norms in vocational training. The article builds on an ethnographic study in a Swedish upper-secondary educational programme traditionally dominated by masculinity norms, namely the Building and Construction programme. Employing Sara Ahmed's notion of happy objects, the article centres on vocational students' expressed joy in the practical work and shows how joy contributes to sustaining and challenging dominant masculinity patterns. Though students enjoyed practical work, the study indicates that a particular version of happiness was normalised which ruled out non-heterosexual and female students. The article suggests that further studies of social inertia in vocational training need to account for the interconnectedness of the emotional, material, and corporeal dimensions of gender.  相似文献   

Yes, now we can: Technological change and the exploitation of entrepreneurial opportunities     

Rögnvaldur J. Saemundsson  Magnus Holmén 《The Journal of High Technology Management Research》2011,22(2):102-113

The paper investigates how technological change in an industry influence which individuals will identify and exploit entrepreneurial opportunities. We propose that the introduction of new development tools will change knowledge-barriers to entry because they enable the abstraction of specialized knowledge that was previously needed for development. Empirically we test the argument using data from the web design industry in a Nordic country during the period 1992–2003. We compare the education and experience of founders before and after the introduction of web administration tools in 1998 and find a significant difference, which supports the main thesis of our argument.  相似文献   

Thinking about the future at school     

Magnus Haavelsrud 《Prospects》1983,13(1):7-19

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An introduction to the debate on peace education     

Magnus Haavelsrud 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1983,29(3):275-280

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In Search of ‘Mode 2’: the Nature of Knowledge Production in Norway     

Gulbrandsen  Magnus  Langfeldt  Liv 《Minerva》2004,42(3):237-250

This article investigates the contention that we are seeing the emergence of new forms of knowledge production, transforming the expectations and assessment of fundamental research. We examine three dimensions in the assessment of research. Our studies show little evidence of any significant change in practice in the three sectors in which research is undertaken in Norway.  相似文献   

Implicit sequence learning is preserved in dyslexic children     

Filomena Inácio  Luís Faísca  Christian Forkstam  Susana Araújo  Inês Bramão  Alexandra Reis  Karl Magnus Petersson 《Annals of dyslexia》2018,68(1):1-14

This study investigates the implicit sequence learning abilities of dyslexic children using an artificial grammar learning task with an extended exposure period. Twenty children with developmental dyslexia participated in the study and were matched with two control groups—one matched for age and other for reading skills. During 3 days, all participants performed an acquisition task, where they were exposed to colored geometrical forms sequences with an underlying grammatical structure. On the last day, after the acquisition task, participants were tested in a grammaticality classification task. Implicit sequence learning was present in dyslexic children, as well as in both control groups, and no differences between groups were observed. These results suggest that implicit learning deficits per se cannot explain the characteristic reading difficulties of the dyslexics.  相似文献   

Can virtual environments enhance the learning of historical chronology?     

Nigel Foreman  Stephen Boyd-Davis  Magnus Moar  Liliya Korallo  Emma Chappell 《Instructional Science》2008,36(2):155-173

Historical time and chronological sequence are usually conveyed to pupils via the presentation of semantic information on printed worksheets, events being rote-memorised according to date. We explored the use of virtual environments in which successive historical events were depicted as “places” in time–space, encountered sequentially in a fly-through. Testing was via “Which came first, X or Y?” questions and picture-ordering. University undergraduates experiencing the history of an imaginary planet performed better after a VE than after viewing a “washing line” of sequential images, or captions alone, especially for items in intermediate list positions. However, secondary children 11–14 years remembered no more about successive events in feudal England when they were presented virtually compared with either paper picture or 2-D computer graphic conditions. Primary children 7–9 years learned more about historical sequence after studying a series of paper images, compared with either VE or computer graphic conditions, remembering more in early/intermediate list positions. Reasons for the discrepant results are discussed and future possible uses of VEs in the teaching of chronology assessed.  相似文献