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Robbert J. J. Gobbens 《Tijdschrift voor gerontologie en geriatrie》2017,48(4):160-168
Frail older people have an increased risk of limitations in performing activities of daily living, hospitalization, nursing home admission, and premature death. In this study we determined the difference in experiencing quality of life between frail and non-frail older people. We also investigated the associations between physical, psychological and social components of frailty and the physical and mental dimensions of quality of life. 374 people of 75 years and older filled in a questionnaire, the Senioren Barometer. This questionnaire contained the Tilburg Frailty Indicator (TFI) to assess frailty and the SF-12 for assessing quality of life. The study showed that frail older people on average experience a lower quality of life than non-frail older people. A considerable part of the variance of the physical and mental dimensions of quality of life could be explained by the fifteen components of frailty, after controlling for the background characteristics of the respondents, 33.2% and 36.5%, respectively. The frailty components physical inactivity, physical tiredness, and depressive symptoms were associated with the physical dimension as well as the mental dimension of quality of life. The results confirm the importance of multidimensional assessment of frailty. In addition, they provide a direction to healthcare and welfare professionals in performing interventions with the aim of increasing the quality of life of older people. 相似文献
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Danica Zivkovic Robbert Créton Gideon Zwaan René Dohmen 《Development genes and evolution》1991,200(6):320-329
Summary InLymnaea stagnalis, mesoderm induction occurs at the 24-cell stage, when the apical tip of the macromere 3D establishes a close contact with a number of micromeres. Via its tip, the macromere 3D is supposed to receive an inductive signal from the micromeres, resulting in the determination of the mesodermal stem cell 4d at the next division. In view of the possibility that transcellular ionic currents might somehow be involved, either in the processes that bring about this particular configuration of blastomeres or in the induction process itself, we mapped the electric field around the embryo during the 24-cell stage, using a vibrating probe. We detected a reversal of the current direction as compared to the uncleaved egg, whilst the polarity of the field along the animal-vegetal axis was maintained. We also mapped the localization of Ca2+-stimulated AT-Pase, an enzyme that drives the Ca2+-efflux from the cell. We found that this enzyme is localized exclusively along the cytoplasmic face of the apical plasma membrane of macromere 3D, and that its presence is restricted to the period from 110 to 135 min after the fifth cleavage, when there is close contact between macormere 3D and the micromeres. Since the localization of the Ca2+-stimulated ATPase coincides both in time and space with the induction of the mesoderm-mother cell, we suggest that localized calcium fluxes may play a role in this induction process. 相似文献
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Chris M. Vermeer Lena Depaz Emily van den Berg Tom Koelmans Robbert Kleerebezem 《Biotechnology and bioengineering》2023,120(3):687-701
Medium-chain-length polyhydroxyalkanoate (mcl-PHA) production by using microbial enrichments is a promising but largely unexplored approach to obtain elastomeric biomaterials from secondary resources. In this study, several enrichment strategies were tested to select a community with a high mcl-PHA storage capacity when feeding octanoate. On the basis of analysis of the metabolic pathways, the hypothesis was formulated that mcl-PHA production is more favorable under oxygen-limited conditions than short-chain-length PHA (scl-PHA). This hypothesis was confirmed by bioreactor experiments showing that oxygen limitation during the PHA accumulation experiments resulted in a higher fraction of mcl-PHA over scl-PHA (i.e., a PHA content of 76 wt% with an mcl fraction of 0.79 with oxygen limitation, compared to a PHA content of 72 wt% with an mcl-fraction of 0.62 without oxygen limitation). Physicochemical analysis revealed that the extracted PHA could be separated efficiently into a hydroxybutyrate-rich fraction with a higher Mw and a hydroxyhexanoate/hydroxyoctanoate-rich fraction with a lower Mw. The ratio between the two fractions could be adjusted by changing the environmental conditions, such as oxygen availability and pH. Almost all enrichments were dominated by Sphaerotilus sp. This is the first scientific report that links this genus to mcl-PHA production, demonstrating that microbial enrichments can be a powerful tool to explore mcl-PHA biodiversity and to discover novel industrially relevant strains. 相似文献
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The molecular basis of complementation by a mixture of two different types of octopine T-region mutants (LBA4060 and LBA4210) was studied. Six randomly chosen cellular clones derived from a tumor obtained after mixed infection were analyzed for their T-DNA content via Southern blot hybridization. The clones appeared to contain T-DNA that originated from each of both mutants, indicating that they developed from doubly infected single cells. Genetic complementation, therefore, might explain at least in part the observed complementation phenomenon. However, complementation as a result of cross-feeding between separately transformed cells could not be excluded. Following protoplast isolation, small aggregates might have formed that developed into the clones analyzed. 相似文献
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