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Jasper Stevens Dirk-Jan van den Berg Sanne de Ridder Harm A.G. Niederländer Piet Hein van der Graaf Meindert Danhof Elizabeth C.M. de Lange 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(13-14):969-975
Remoxipride is a selective dopamine D2 receptor antagonist, and useful as a model compound in mechanism-based pharmacological investigations. To that end, studies in small animals with serial sampling over time are needed. For these small volume samples currently no suitable analytical methods are available. We propose analytical methods for the detection of low concentrations remoxipride in small sample volumes of plasma, brain homogenate, and brain microdialysate, using online solid phase extraction with liquid chromatography–tandem mass spectrometry. Method development, optimization and validation are described in terms of calibration curves, extraction yield, lower limit of quantification (LLOQ), precision, accuracy, inter-day- and intra-day variability. The 20 μl plasma samples showed an extraction yield of 76%, with a LLOQ of 0.5 ng/ml. For 0.6 ml brain homogenate samples the extraction yield was 45%, with a LLOQ of 1.8 ng/ml. The 20 μl brain microdialysate samples, without pre-treatment, had a LLOQ of 0.25 ng/ml. The precision and accuracy were well within the acceptable 15% range. Considering the small sample volumes, the high sensitivity and good reproducibility, the analytical methods are suitable for analyzing small sample volumes with low remoxipride concentrations. 相似文献
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Jelle R. Dalenberg Swetlana Gutjar Gert J. ter Horst Kees de Graaf Remco J. Renken Gerry Jager 《PloS one》2014,9(12)
In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores. 相似文献
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The genetic organization of the determinants of type 1, K88ab, K99 fimbriae and P(pap)pili of Escherichia coli is presented. The functions of the various gene products are described and a model for the process of fimbriae biogenesis is presented and discussed. 相似文献
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Intake rate, the rate in which herbivores can process their food, is presumed to be an important factor in habitat selection down to the scale of the foraging patch. Much attention has been given to the selection of swards of high nutritional quality, but much less has been given to the influences of sward structure on patch selection in small herbivores. In this study we tested the effects of sward density and height on the functional foraging response of barnacle geese, Branta leucopsis. The functional response curve for herbivores describes how intake rate is affected by food availability. We conducted feeding trials to determine intake rate and bite size of barnacle geese on experimentally manipulated swards. Results indicate that intake rate is mainly dependent on sward height and that there is a strong correlation between bite size and intake rate. Sward density does not influence the rate of food consumption; it is, however, a crucial parameter affecting potential total yield. We conclude that bite size is the crucial parameter influencing intake rate. Bite size is explained both by sward height and individual differences in bill morphology. Furthermore, intake rate seems to be dependent on the physical structure of the grass species consumed. 相似文献
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Miranda de Graaf Sander Herfst Jamil Aarbiou Peter C. Burgers Fatiha Zaaraoui-Boutahar Maarten Bijl Wilfred van IJcken Eefje J. A. Schrauwen Albert D. M. E. Osterhaus Theo M. Luider Bob J. Scholte Ron A. M. Fouchier Arno C. Andeweg 《PloS one》2013,8(3)
Human metapneumovirus (HMPV) encodes a small hydrophobic (SH) protein of unknown function. HMPV from which the SH open reading frame was deleted (HMPVΔSH) was viable and displayed similar replication kinetics, cytopathic effect and plaque size compared with wild type HMPV in several cell-lines. In addition, no differences were observed in infection efficiency or cell-to-cell spreading in human primary bronchial epithelial cells (HPBEC) cultured at an air-liquid interphase. Host gene expression was analyzed in A549 cells infected with HMPV or HMPVΔSH using microarrays and mass spectrometry (MS) based techniques at multiple time points post infection. Only minor differences were observed in mRNA or protein expression levels. A possible function of HMPV SH as apoptosis blocker, as proposed for several members of the family Paramyxoviridae, was rejected based on this analysis. So far, a clear phenotype of HMPV SH deletion mutants in vitro at the virus and host levels is absent. 相似文献
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Pushpa M. Jairam Pim A. de Jong Willem P. T?h. M. Mali Ivana Isgum Harry J. de Koning Carlijn van der Aalst Matthijs Oudkerk Rozemarijn Vliegenthart Yolanda van der Graaf 《PloS one》2013,8(6)