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1.
Determination of Tanshinones in Danshen (Salvia miltiorrhiza) by High‐Performance Liquid Chromatography with Fluorescence Detection after pre‐Column Derivatisation 下载免费PDF全文
Naoya Kishikawa Akiko Yamanouchi Mahmoud Hamed El‐Maghrabey Kaname Ohyama Naotaka Kuroda 《Phytochemical analysis : PCA》2018,29(1):112-117
Introduction
Tanshinones are a major class of bioactive ingredients in the traditional herbal medicines, Danshen (Salvia miltiorrhiza). A sensitive and reliable determination method for tanshinones is useful to ensure the quality of Danshen.Objective
To develop a sensitive and selective analytical method for tanshinones by high‐performance liquid chromatography (HPLC) with fluorescence detection after pre‐column derivatisation.Methodology
The proposed method depends on derivatisation reaction of tanshinones with 4‐carbomethoxybenzaldehyde and ammonium acetate forming intensely fluorescent imidazole derivative.Results
The proposed method provided excellent sensitivity with the detection limits of 3.3 nM (66 fmol/injection), 3.2 nM (64 fmol/injection) and 2.0 nM (40 fmol/injection) for cryptotanshinone, tanshinone I and tanshinone IIA, respectively, without the necessity of complicated instrumentations. The developed method is successfully applied to quantify the contents of tanshinones in Danshen.Conclusion
The developed method is the first analytical method for tanshinones by fluorescence detection. Since the derivatisation reaction is selective for the o‐quinone structure of tanshinone, the developed method will become a suitable mean for the discovering of tanshinone type diterpenoids from herbal samples. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献2.
Background
In this paper a novel method for prostate segmentation in transrectal ultrasound images is presented. 相似文献3.
Stéphanie Jaubert-Possamai Gaël Le Trionnaire Joël Bonhomme Georges K Christophides Claude Rispe Denis Tagu 《BMC biotechnology》2007,7(1):63
Background
RNA interference (RNAi) is a powerful method to inhibit gene expression in a sequence specific manner. 相似文献4.
Background
Suppression Subtractive Hybridization PCR (SSH PCR) is a sophisticated cDNA subtraction method to enrich and isolate differentially expressed genes. Despite its popularity, the method has not been thoroughly studied for its practical efficacy and potential limitations. 相似文献5.
Background
"Protein-trap" is a method that allows epitope-tagging of endogenous proteins. This method allows for the identification of endogenously expressed proteins that exhibit specific localization of interest. This method has been recently reported for its application in the study of Drosophila development by using a relatively large epitope, green-fluorescent-protein (GFP). 相似文献6.
Robert Tibshirani 《BMC bioinformatics》2006,7(1):106-6
Background
In this short article, we discuss a simple method for assessing sample size requirements in microarray experiments. 相似文献7.
Background
Proteomic protein identification results need to be compared across laboratories and platforms, and thus a reliable method is needed to estimate false discovery rates. The target-decoy strategy is a platform-independent and thus a prime candidate for standardized reporting of data. In its current usage based on global population parameters, the method does not utilize individual peptide scores optimally. 相似文献8.
Thomas Mailund Gerth S Brodal Rolf Fagerberg Christian NS Pedersen Derek Phillips 《BMC bioinformatics》2006,7(1):29-8
Background
The neighbor-joining method by Saitou and Nei is a widely used method for constructing phylogenetic trees. The formulation of the method gives rise to a canonical Θ(n 3) algorithm upon which all existing implementations are based. 相似文献9.
Background
The estimation of the difference between two evolutionary distances within a triplet of homologs is a common operation that is used for example to determine which of two sequences is closer to a third one. The most accurate method is currently maximum likelihood over the entire triplet. However, this approach is relatively time consuming. 相似文献10.
A. Cadiere B. Couturaud J. Boismard P. Le Cann A. Gérard A. Mas C. Faye L. Garrelly B. Roig 《Journal of applied microbiology》2013,115(1):290-297
Aims
Virus detection has often been difficult due to a low concentration in water. In this study, we developed a new procedure based on concentration of virus particles on an innovative support: poly‐l ‐lysine dendrigrafts (DGL), coupled with directed nucleic acid extraction and real‐time PCR quantification.Methods and Results
This method was evaluated using the bacteriophage MS2 as a model virus. This virus exhibited the size and structural properties of human pathogenic enteric viruses and has often been used to assess new supports of concentration. Moreover, this bacteriophage is also a faecal contamination indicator. In this study, many water filtration conditions were tested (volume of water, concentration, etc.), and more than 80% of bacteriophage were recovered after filtration on polymer, in most conditions. We demonstrated that the method was linear (slope = 0·99 ± 0·04 and Y intercept when x = ?0·02 ± 0·28), valid (as manipulators, tested concentrations, volumes of sample and batch of polymer did not have any influence on concentration) and sensitive (allowing to concentrate up to 16 600‐fold 1 l of sample and to detect and quantify down to 750 GC l?1 and 7500 GC l?1, respectively).Conclusions
To conclude, this support exhibits high interest to retain viruses and to allow to detect low concentration of virus in water.Significance and Impact of the Study
This study gives valuable advance in the methods of concentration and diagnosis of virus in water. 相似文献11.
Background
Cytomegalovirus (CMV) is a prevalent herpesvirus with links to both stress and aging. This paper describes and validates a minimally invasive method for assessing antibodies against CMV in finger stick whole blood spot samples for use as an indirect marker of an aspect of cell-mediated immunity. 相似文献12.
Javier F Chaparro-Riggers Bernard LW Loo Karen M Polizzi Phillip R Gibbs Xiao-Song Tang Mark J Nelson Andreas S Bommarius 《BMC biotechnology》2007,7(1):77
Background
The recombination of homologous genes is an effective protein engineering tool to evolve proteins. DNA shuffling by gene fragmentation and reassembly has dominated the literature since its first publication, but this fragmentation-based method is labor intensive. Recently, a fragmentation-free PCR based protocol has been published, termed recombination-dependent PCR, which is easy to perform. However, a detailed comparison of both methods is still missing. 相似文献13.
Johannes Huth Malte Buchholz Johann M Kraus Martin Schmucker Götz von Wichert Denis Krndija Thomas Seufferlein Thomas M Gress Hans A Kestler 《BMC cell biology》2010,11(1):24
Background
Cell motility is a critical parameter in many physiological as well as pathophysiological processes. In time-lapse video microscopy, manual cell tracking remains the most common method of analyzing migratory behavior of cell populations. In addition to being labor-intensive, this method is susceptible to user-dependent errors regarding the selection of "representative" subsets of cells and manual determination of precise cell positions. 相似文献14.
Background
The hit criterion is a key component of heuristic local alignment algorithms. It specifies a class of patterns assumed to witness a potential similarity, and this choice is decisive for the selectivity and sensitivity of the whole method. 相似文献15.
Hiroshi Nishiura 《Biomedical engineering online》2011,10(1):15
Background
Real-time forecasting of epidemics, especially those based on a likelihood-based approach, is understudied. This study aimed to develop a simple method that can be used for the real-time epidemic forecasting. 相似文献16.
Background
Innovative extensions of (M) ANOVA gain common ground for the analysis of designed metabolomics experiments. ASCA is such a multivariate analysis method; it has successfully estimated effects in megavariate metabolomics data from biological experiments. However, rigorous statistical validation of megavariate effects is still problematic because megavariate extensions of the classical F-test do not exist. 相似文献17.
Background
Recent analysis of the yeast gene network shows that most genes have few inputs, indicating that enumerative gene reconstruction methods are both useful and computationally feasible. A simple enumerative reconstruction method based on a discrete dynamical system model is used to study how microarray experiments involving modulated global perturbations can be designed to obtain reasonably accurate reconstructions. The method is tested on artificial gene networks with biologically realistic in/out degree characteristics. 相似文献18.
Background
In gene expression studies a key role is played by the so called "pre-processing", a series of steps designed to extract the signal and account for the sources of variability due to the technology used rather than to biological differences between the RNA samples. At the moment there is no commonly agreed gold standard pre-processing method and each researcher has the responsibility to choose one method, incurring the risk of false positive and false negative features arising from the particular method chosen. 相似文献19.
Background
A method for inhibiting the expression of particular genes using external guide sequences (EGSs) has been developed in bacteria, mammalian cells and maize cells. 相似文献20.
Tristan?Ruysschaert Audrey?Marque Jean-Luc?Duteyrat Sylviane?Lesieur Mathias?Winterhalter Didier?Fournier