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排序方式: 共有342条查询结果,搜索用时 312 毫秒
1.
Rudy Van Cauwenbergh Harry Robberecht Veerle Van Vlaslaer Annie De Smet Marie-Paule Emonds Nina Hermans 《Journal of trace elements in medicine and biology》2007,21(4):225-233
Graphite furnace atomic absorption spectrometry, with Zeeman background correction and after improved matrix modification, was used to measure the plasma selenium content of healthy blood bank donors in the central part of Belgium.
The mean plasma selenium concentration of 80 men and 80 women was 79.7±4.4 ng/mL with a range of 55.0–117.4 ng/mL.
There was no gender difference observed. Plasma selenium level was significantly highest for the adult group, aged 45–64 years, compared to the others, except the young adults (18–24 years).
The mean plasma selenium concentration measured corresponded well with literature data for Belgium. The obtained values were found to be in the medium range, compared with recent literature values for the European countries. 相似文献
2.
Leucine rich repeat kinases 1 and 2 (LRRK1 and LRRK2) are paralogs which share a similar domain organization, including a serine-threonine kinase domain, a Ras of complex proteins domain (ROC), a C-terminal of ROC domain (COR), and leucine-rich and ankyrin-like repeats at the N-terminus. The precise cellular roles of LRRK1 and LRRK2 have yet to be elucidated, however LRRK1 has been implicated in tyrosine kinase receptor signaling1,2, while LRRK2 is implicated in the pathogenesis of Parkinson''s disease3,4. In this report, we present a protocol to label the LRRK1 and LRRK2 proteins in cells with 32P orthophosphate, thereby providing a means to measure the overall phosphorylation levels of these 2 proteins in cells. In brief, affinity tagged LRRK proteins are expressed in HEK293T cells which are exposed to medium containing 32P-orthophosphate. The 32P-orthophosphate is assimilated by the cells after only a few hours of incubation and all molecules in the cell containing phosphates are thereby radioactively labeled. Via the affinity tag (3xflag) the LRRK proteins are isolated from other cellular components by immunoprecipitation. Immunoprecipitates are then separated via SDS-PAGE, blotted to PVDF membranes and analysis of the incorporated phosphates is performed by autoradiography (32P signal) and western detection (protein signal) of the proteins on the blots. The protocol can readily be adapted to monitor phosphorylation of any other protein that can be expressed in cells and isolated by immunoprecipitation. 相似文献
3.
Performing music on the basis of reading a score requires reading ahead of what is being played in order to anticipate the necessary actions to produce the notes. Score reading thus not only involves the decoding of a visual score and the comparison to the auditory feedback, but also short-term storage of the musical information due to the delay of the auditory feedback during reading ahead. This study investigates the mechanisms of encoding of musical information in short-term memory during such a complicated procedure. There were three parts in this study. First, professional musicians participated in an electroencephalographic (EEG) experiment to study the slow wave potentials during a time interval of short-term memory storage in a situation that requires cross-modal translation and short-term storage of visual material to be compared with delayed auditory material, as it is the case in music score reading. This delayed visual-to-auditory matching task was compared with delayed visual-visual and auditory-auditory matching tasks in terms of EEG topography and voltage amplitudes. Second, an additional behavioural experiment was performed to determine which type of distractor would be the most interfering with the score reading-like task. Third, the self-reported strategies of the participants were also analyzed. All three parts of this study point towards the same conclusion according to which during music score reading, the musician most likely first translates the visual score into an auditory cue, probably starting around 700 or 1300 ms, ready for storage and delayed comparison with the auditory feedback. 相似文献
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6.
Van Damme V Gómez-Paniagua H de Vicente MC 《Molecular breeding : new strategies in plant improvement》2011,28(4):597-610
Crop genetic resources carry variation useful for overcoming the challenges of modern agriculture. Molecular markers can facilitate
the selection of agronomically important traits. The pervasiveness of genomics research has led to an overwhelming number
of publications and databases, which are, nevertheless, scattered and hence often difficult for plant breeders to access,
particularly those in developing countries. This situation separates them from developed countries, which have better endowed
programs for developing varieties. To close this growing knowledge gap, we conducted an intensive literature review and consulted
with more than 150 crop experts on the use of molecular markers in the breeding program of 19 food security crops. The result
was a list of effectively used and highly reproducible sequence tagged site (STS), simple sequence repeat (SSR), single nucleotide
polymorphism (SNP), and sequence characterized amplified region (SCAR) markers. However, only 12 food crops had molecular
markers suitable for improvement. That is, marker-assisted selection is not yet used for Musa spp., coconut, lentils, millets, pigeonpea, sweet potato, and yam. For the other 12 crops, 214 molecular markers were found
to be effectively used in association with 74 different traits. Results were compiled as the GCP Molecular Marker Toolkit, a free online tool that aims to promote the adoption of molecular approaches in breeding activities. 相似文献
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8.
Johan Ceusters Anne M. Borland Elsje Londers Veerle Verdoodt Christof Godts Maurice P. De Proft 《Physiologia plantarum》2009,135(2):174-184
CAM requires a substantial investment of resources into storage carbohydrates to account for nocturnal CO2 uptake, thereby restricting carbohydrate partitioning to other metabolic activities, including dark respiration, growth and acclimation to abiotic stress. Flexible modulation of carbon flow to the different competing sinks under changing environmental conditions is considered a key determinant for the growth, productivity and ecological success of the CAM pathway. The aim of the present study was to examine how shifts in carbohydrate partitioning could assure maintenance of photosynthetic integrity and a positive carbon balance under conditions of increasing water deprivation in CAM species. Measurements of gas exchange, leaf water relations, malate, starch and soluble sugar (glucose, fructose and sucrose) contents were made in leaves of the CAM bromeliad Aechmea ‘Maya’ over a 6‐month period of drought and subsequently over a 2‐month period of recovery from drought. Results indicated that short‐term influences of water stress were minimized by elevating the level of respiratory recycling, and carbohydrate pools were maintained at the expense of export for growth while providing a comparable nocturnal carbon gain to that in well‐watered control plants. Longer term drought resulted in a disproportionate depletion of key carbohydrate reserves. Sucrose, which was of minor importance for providing substrate for the dark reactions under well‐watered conditions, became the major source of carbohydrate for nocturnal carboxylation as drought progressed. Flexibility in terms of the major carbohydrate source used to sustain dark CO2 uptake is therefore considered a crucial factor in meeting the carbon and energy demands under limiting environmental conditions. Recovery from CAM‐idling was found to be dependent on the restoration of the starch pool, which was used predominantly for provision of substrate for nocturnal carboxylation, while net carbon export was limited. The conservation of starch for the nocturnal reactions might be adaptive with regard to responding efficiently to a return of water stress. 相似文献
9.
Veerle Vanderheyden Takuya Wakai Geert Bultynck Humbert De Smedt Jan B. Parys Rafael A. Fissore 《Cell calcium》2009,46(1):56-64
Egg activation and further embryo development require a sperm-induced intracellular Ca2+ signal at the time of fertilization. Prior to fertilization, the egg's Ca2+ machinery is therefore optimized. To this end, during oocyte maturation, the sensitivity, i.e. the Ca2+ releasing ability, of the inositol 1,4,5-trisphosphate receptor type 1 (IP3R1), which is responsible for most of this Ca2+ release, markedly increases. In this study, the recently discovered specific Polo-like kinase (Plk) inhibitor BI2536 was used to investigate the role of Plk1 in this process. BI2536 inactivates Plk1 in oocytes at the early stages of maturation and significantly decreases IP3R1 phosphorylation at an MPM-2 epitope at this stage. Moreover, this decrease in Plk1-dependent MPM-2 phosphorylation significantly lowers IP3R1 sensitivity. Finally, using in vitro phosphorylation techniques we identified T2656 as a major Plk1 site on IP3R1. We therefore propose that the initial increase in IP3R1 sensitivity during oocyte maturation is underpinned by IP3R1 phosphorylation at an MPM-2 epitope(s). 相似文献
10.
Elisa Greggio Jean-Marc Taymans Eugene Yuejun Zhen Renée Vancraenenbroeck Peng Sun Howard Jaffe Kalpana Merchant 《Biochemical and biophysical research communications》2009,389(3):449-454
Mutations in leucine-rich repeat kinase 2 (LRRK2) are a common cause of inherited Parkinson’s disease (PD). The protein is large and complex, but pathogenic mutations cluster in a region containing GTPase and kinase domains. LRRK2 can autophosphorylate in vitro within a dimer pair, although the significance of this reaction is unclear. Here, we mapped the sites of autophosphorylation within LRRK2 and found several potential phosphorylation sites within the GTPase domain. Using mass spectrometry, we found that Thr1343 is phosphorylated and, using kinase dead versions of LRRK2, show that this is an autophosphorylation site. However, we also find evidence for additional sites in the GTPase domain and in other regions of the protein suggesting that there may be multiple autophosphorylation sites within LRRK2. These data suggest that the kinase and GTPase activities of LRRK2 may exhibit complex autoregulatory interdependence. 相似文献