排序方式: 共有78条查询结果,搜索用时 62 毫秒
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Dietmar Eberbeck Christian Bergemann Frank Wiekhorst Uwe Steinhoff Lutz Trahms 《Journal of nanobiotechnology》2008,6(1):4
The binding reaction of the biomolecules streptavidin and anti-biotin antibody, both labelled by magnetic nanoparticles (MNP),
to biotin coated on agarose beads, was quantified by magnetorelaxometry (MRX). Highly sensitive SQUID-based MRX revealed the
immobilization of the MNP caused by the biotin-streptavidin coupling. We found that about 85% of streptavidin-functionalised
MNP bound specifically to biotin-agarose beads. On the other hand only 20% of antibiotin-antibody functionalised MNP were
specifically bound. Variation of the suspension medium revealed in comparison to phosphate buffer with 0.1% bovine serum albumin
a slight change of the binding behaviour in human serum, probably due to the presence of functioning (non heated) serum proteins. Furthermore, in human serum an additional non-specific binding occurs, being independent from
the serum protein functionality. 相似文献
73.
Background
Alignment of RNA secondary structures is important in studying functional RNA motifs. In recent years, much progress has been made in RNA motif finding and structure alignment. However, existing tools either require a large number of prealigned structures or suffer from high time complexities. This makes it difficult for the tools to process RNAs whose prealigned structures are unavailable or process very large RNA structure databases. 相似文献74.
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Schleyer E Pursche S Köhne CH Schuler U Renner U Gschaidmeier H Freiberg-Richter J Leopold T Jenke A Bonin M Bergemann T le Coutre P Gruner M Bornhäuser M Ottmann OG Ehninger G 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2004,799(1):23-36
An isocratic online-enrichment HPLC-assay was developed allowing for the simple and fast separation and quantitation of STI-571 and its main metabolite N-desmethyl-STI (N-DesM-STI) in plasma, urine, cerebrospinal fluid (CSF), culture media and cell preparations in various concentrations using UV-detection at 260 nm. The analytical procedure consists of an online concentration of STI-571 and N-DesM-STI in the HPLC system followed by the elution on a ZirChrom-PBD analytical column. Time of analysis is 40 min including the enrichment time of 5 min. The detection limit is 10 ng/ml in plasma, CSF, culture medium (RPMI) and 25 ng/ml in urine for both STI-571 and N-DesM-STI. The intra-day precision, as expressed by the coefficient of variation (CV), in plasma samples ranges between 1.74 and 8.60% for STI-571 and 1.45 and 8.87% for N-DesM-STI. The corresponding values for urine measurements are 2.17-7.54% (STI-571) and 1.31-9.51% (N-DesM-STI). The inter-day precision analyzed over a 7-month time period was 8.31% (STI-571) or 6.88% (N-DesM-STI) and 16.45% (STI-571) or 14.83% (N-DesM-STI) for a concentration of 1000 ng/ml in plasma and 750 ng/ml in urine, respectively. Moreover, we demonstrate that with an alternative, but more time and labor consuming sample preparation and the implementation of electrochemical detection, a detection limit < 10 ng/ml can be achieved. The method described was used to perform pharmacokinetic measurements of STI-571 and N-desmethyl-STI in patient samples and for kinetic measurements of intracellular STI-571 and N-DesM-STI following in vitro incubation. 相似文献
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77.
Tracy L Bergemann 《遗传学报》2010,37(4)
This research provides a new way to measure error in microarray data in order to improve gene expression analysis.Microarray data contains many sources of error.In order to glean information about mRNA expression levels,the true signal must first be segregated from noise.This research focuses on the variation that can be captured at the spot level in cDNA microarray images.Variation at other levels,due to differences at the array,dye,and block levels,can be corrected for by a variety of existing normalization procedures.Two signal quality estimates that capture the reliability of each spot printed on a microarray are described.A parametric estimate of within-spot vari ance,referred to here as σ s2pot,assumes that pixels follow a normal distribution and are spatially correlated.A non-parametric estimate of error,called the mean square prediction error(MSPE),assumes that spots of high quality possess pixels that are similar to their neighbors.This paper will provide a framework to use either spot quality measure in downstream analysis,specifically as weights in regression models.Using these spot quality estimates as weights can result in greater efficiency,in a statistical sense,when modeling microarray data. 相似文献
78.
Olfactory memory: the long and short of it 总被引:2,自引:2,他引:0
It has been proposed that memory for odors does not have a short-term (or
working) memory system. The distinction between short- and long- term
memory in other sensory modalities has been generally supported by three
main lines of evidence: capacity differences between the proposed systems,
evidence of differential coding, and differential memory losses in
neuropsychological patients. The present paper examines these issues in an
effort to establish a similar distinction for the memory of olfactory
stimuli. Each of these lines of evidence is examined in relation to the
literature on olfactory memory. Based on this examination, it seems that
there is at least preliminary support from each of these lines of evidence
to advocate a distinction between a long- and short-term memory for
olfactory stimuli. Emphasis is placed upon the qualitative similarity of
olfactory memory to other memory systems. This similarity is further
highlighted through an examination of the literature pertinent to serial
position effects in memory for olfactory stimuli.
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