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排序方式: 共有768条查询结果,搜索用时 578 毫秒
101.
Marcel A. G. Van der Heyden Mirjam Nievers Arie J. Verkleij Johannes Boonstra Paul M. P. Van Bergen en Henegouwen 《FEBS letters》1997,410(2-3)
Although all EGF receptors in EGF receptor-expressing cells are molecularly identical, they can be subdivided in two different classes that have either a high or a low affinity for EGF. Specifically the high-affinity class is associated with filamentous actin. To determine whether the interaction of the EGF receptor with actin induces its high-affinity state, we studied EGF-binding properties of an EGF receptor mutant that lacks the actin-binding site. Interestingly, we found that cells expressing this mutant receptor still display both high- and low-affinity classes of EGF receptors, indicating that the actin-binding domain does not determine the high-affinity binding state. By further mutational analysis we identified a receptor domain, within the tyrosine kinase domain, that regulates the affinity for EGF. 相似文献
102.
Ingeborg M Kooter Jeroen L A Pennings Paul H B Fokkens Daan L A C Leseman A John F Boere Miriam E Gerlofs-Nijland Flemming R Cassee Johanna A C Schalk Tom J H Orzechowski Mirjam M Schaap Timo M Breit Jan A M A Dormans Conny T M van Oostrom Annemieke de Vries Harry van Steeg 《Journal of applied physiology》2007,102(3):1185-1192
103.
Erin P. Price Derek S. Sarovich Emma J. Smith Barbara MacHunter Glenda Harrington Vanessa Theobald Carina M. Hall Heidie M. Hornstra Evan McRobb Yuwana Podin Mark Mayo Jason W. Sahl David M. Wagner Paul Keim Mirjam Kaestli Bart J. Currie 《Applied and environmental microbiology》2016,82(3):954-963
Melioidosis is a disease of humans and animals that is caused by the saprophytic bacterium Burkholderia pseudomallei. Once thought to be confined to certain locations, the known presence of B. pseudomallei is expanding as more regions of endemicity are uncovered. There is no vaccine for melioidosis, and even with antibiotic administration, the mortality rate is as high as 40% in some regions that are endemic for the infection. Despite high levels of recombination, phylogenetic reconstruction of B. pseudomallei populations using whole-genome sequencing (WGS) has revealed surprisingly robust biogeographic separation between isolates from Australia and Asia. To date, there have been no confirmed autochthonous melioidosis cases in Australia caused by an Asian isolate; likewise, no autochthonous cases in Asia have been identified as Australian in origin. Here, we used comparative genomic analysis of 455 B. pseudomallei genomes to confirm the unprecedented presence of an Asian clone, sequence type 562 (ST-562), in Darwin, northern Australia. First observed in Darwin in 2005, the incidence of melioidosis cases attributable to ST-562 infection has steadily risen, and it is now a common strain in Darwin. Intriguingly, the Australian ST-562 appears to be geographically restricted to a single locale and is genetically less diverse than other common STs from this region, indicating a recent introduction of this clone into northern Australia. Detailed genomic and epidemiological investigations of new clinical and environmental B. pseudomallei isolates in the Darwin region and ST-562 isolates from Asia will be critical for understanding the origin, distribution, and dissemination of this emerging clone in northern Australia. 相似文献
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108.
Mirjam Pijnappels Neil D Reeves Constantinos N Maganaris Jaap H van Die?n 《Journal of electromyography and kinesiology》2008,18(2):188-196
To reduce the number of falls in old age, we need to understand the mechanisms underpinning a fall, who are at risk of falling, and what interventions can prevent such individuals from falling. This paper provides an overview of our recent research on tripping and muscle strength in the elderly, addressing these questions. To prevent a fall after tripping over an obstacle, high demands are posed on lower limb muscles. It was shown that the support limb plays an important role in balance recovery by generating the appropriate joint moments during push-off. Older individuals show lower rates of moment generation in all support limb joints and a lower peak ankle moment than young adults. As strength declines with age (due to muscular, tendinous and neural alterations), leg muscle strength might be the limiting factor in preventing a fall. Indeed, high-risk fallers could be identified based on maximum leg press push-off force capacity. Resistance training can reverse the ageing-related loss of strength. Therefore, the effects of 16-weeks resistance training on tripping reactions were studied in a small group of elderly. Maximum push-off force increased significantly by training. Moreover, trainers improved more than controls in moment generation after tripping, especially around the ankle. It can be concluded that transfer of resistance training effects to balance recovery is feasible. 相似文献
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Bacterial diversity and activity along a salinity gradient in soda lakes of the Kulunda Steppe (Altai, Russia) 总被引:1,自引:0,他引:1
Foti MJ Sorokin DY Zacharova EE Pimenov NV Kuenen JG Muyzer G 《Extremophiles : life under extreme conditions》2008,12(1):133-145
Here we describe the diversity and activity of sulfate reducing bacteria along a salinity gradient in four different soda
lakes from the Kulunda Steppe (South East Siberia, Russia). For this purpose, a combination of culture-dependent and independent
techniques was applied. The general bacterial and SRB diversity were analyzed by denaturing gradient gel electrophoresis (DGGE)
targeting the 16S rDNA gene. DNA was used to detect the microbial populations that were present in the soda lake sediments,
whereas ribosomal RNA was used as a template to obtain information on those that were active. Individual DGGE bands were sequenced
and a phylogenetic analysis was performed. In addition, the overall activity of SRB was obtained by measuring the sulfate
reduction rates (SRR) and their abundance was estimated by serial dilution. Our results showed the presence of minor, but
highly active microbial populations, mostly represented by members of the Proteobacteria. Remarkably high SRR were measured at hypersaline conditions (200 g L−1). A relatively high viable count indicated that sulfate reducing bacteria could be highly active in hypersaline soda lakes.
Furthermore, the increase of sodium carbonate/bicarbonate seemed to affect the composition of the microbial community in soda
lakes, but not the rate of sulfate reduction. 相似文献