首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 437 毫秒
1.
To identify plants of the Alps through analysis of their roots is currently extremely difficult when using traditional identification methods such as dichotomous keys and/or illustrated atlases. Besides genetic analysis, other analytical methods, such as chromatographic analysis, could also be useful for root identification. Chromatographic fingerprints of root extracts of six species (Betula pendula, Picea abies, Fagus sylvatica, Larix decidua, Fraxinus excelsior and Corylus avellana) were analyzed in order to understand whether these species have a chromatographic fingerprint that identifies them, and hence to ascertain whether they can be identified by applying the method of analysis presented below. One hundred and sixty-two root samples were collected in various areas of the Alps and subjected to high-performance liquid chromatography (HPLC) analysis. Multivariate analysis techniques (e.g. cluster analysis) were employed for statistical analysis of chromatographic fingerprints. This study revealed that the chromatographic fingerprints of birch, spruce and larch samples were similar and that the method can therefore clearly identify the respective species. Instead, chromatographic fingerprint samples of beech, hazel and ash presented greater variability. Research proposals based on the results obtained in this study were also developed in order to implement and facilitate studies regarding plant roots.  相似文献   

2.
High-performance liquid chromatographic (HPLC) was developed for fingerprint analysis of Pseudostellaria heterophylla (Miq.) Pax. Liquid chromatography-electrospray ionization-time-of-flight mass spectrometry (LC-TOF-MS) technique was first employed to identify the components of the fingerprint. Twelve major peaks in chromatographic fingerprint were analyzed by on-line LC-TOF-MS analysis; one cyclic peptide was unequivocally identified and five cyclic peptides were tentatively assigned based on their MS data. These cyclic peptides served as the marker peaks in the HPLC fingerprints. The chromatographic fingerprints have been analyzed by similarity index calculations and hierarchical clustering analysis (HCA). The result showed that the HPLC fingerprints could be used to determine the optimal harvest time for P. heterophylla (Miq.) Pax and to authenticate the species of the herb.  相似文献   

3.
Near infrared spectroscopy (NIR) is a promising technique for continuous blood glucose monitoring for diabetic patients. Four interferents, at physiological concentrations, were introduced to study how the glucose predictions varied with a standard multivariate calibration model. Lactate and ethanol were found to interfere strongly with the glucose predictions unless they were included in the calibration models. Lactate was mistaken for glucose and gave erroneously high glucose predictions, with a dose response of 0.46 mM/mM. The presence of ethanol resulted in too low glucose predictions, with a dose response of −0.43 mM/mM. Acetaminophen, a known interferent in the glucose monitoring devices used for diabetes management today, was not found to be an interferent in NIR spectroscopy, nor was caffeine. Thus, interferents that may appear in high concentrations, such as ethanol and lactate, must be included in the calibration or model building of future NIR-based glucose measurement devices for diabetes monitoring.  相似文献   

4.
A method for microbial cell surface fingerprinting using surface plasmon resonance (SPR) is suggested. Four different Escherichia coli mutants have been used as model cells. Cell surface fingerprints were generated by registration of the interaction between the cell mutants and four different surfaces, with different physical and chemical properties, when a cell suspension was flown over the surface. Significant differences in fingerprint pattern between some of the mutants were observed. At the same time, the physical properties of the cell surfaces were determined using microelectrophoresis, contact angle measurements and aqueous two-phase partitioning and compared to the SPR fingerprints. The generated cell surface fingerprints and the physical property data were evaluated with multivariate data analysis that showed that the cells were separated into individual groups in a similar way using principal component analysis plots (PCA).  相似文献   

5.
A method for microbial cell surface fingerprinting using surface plasmon resonance (SPR) is suggested. Four different Escherichia coli mutants have been used as model cells. Cell surface fingerprints were generated by registration of the interaction between the cell mutants and four different surfaces, with different physical and chemical properties, when a cell suspension was flown over the surface. Significant differences in fingerprint pattern between some of the mutants were observed. At the same time, the physical properties of the cell surfaces were determined using microelectrophoresis, contact angle measurements and aqueous two-phase partitioning and compared to the SPR fingerprints. The generated cell surface fingerprints and the physical property data were evaluated with multivariate data analysis that showed that the cells were separated into individual groups in a similar way using principal component analysis plots (PCA).  相似文献   

6.
A combination method of multi-wavelength fingerprinting and multi-component quantification by high performance liquid chromatography (HPLC) coupled with diode array detector (DAD) was developed and validated to monitor and evaluate the quality consistency of herbal medicines (HM) in the classical preparation Compound Bismuth Aluminate tablets (CBAT). The validation results demonstrated that our method met the requirements of fingerprint analysis and quantification analysis with suitable linearity, precision, accuracy, limits of detection (LOD) and limits of quantification (LOQ). In the fingerprint assessments, rather than using conventional qualitative “Similarity” as a criterion, the simple quantified ratio fingerprint method (SQRFM) was recommended, which has an important quantified fingerprint advantage over the “Similarity” approach. SQRFM qualitatively and quantitatively offers the scientific criteria for traditional Chinese medicines (TCM)/HM quality pyramid and warning gate in terms of three parameters. In order to combine the comprehensive characterization of multi-wavelength fingerprints, an integrated fingerprint assessment strategy based on information entropy was set up involving a super-information characteristic digitized parameter of fingerprints, which reveals the total entropy value and absolute information amount about the fingerprints and, thus, offers an excellent method for fingerprint integration. The correlation results between quantified fingerprints and quantitative determination of 5 marker compounds, including glycyrrhizic acid (GLY), liquiritin (LQ), isoliquiritigenin (ILG), isoliquiritin (ILQ) and isoliquiritin apioside (ILA), indicated that multi-component quantification could be replaced by quantified fingerprints. The Fenton reaction was employed to determine the antioxidant activities of CBAT samples in vitro, and they were correlated with HPLC fingerprint components using the partial least squares regression (PLSR) method. In summary, the method of multi-wavelength fingerprints combined with antioxidant activities has been proved to be a feasible and scientific procedure for monitoring and evaluating the quality consistency of CBAT.  相似文献   

7.
Thirty-four Campylobacter jejuni or coli strains, isolated from various livestock and darkling beetles from two Dutch poultry farms during different broiler production cycles, were subjected to Penner serotyping and polymerase chain reaction (PCR) fingerprint analysis. Ten different Penner serotypes were determined in the isolates. Visual scoring of the PCR fingerprints resulted in 14 clearly different profiles. Some strains with identical Penner serotypes exhibited different PCR fingerprints and conversely strains with different serotypes produced identical PCR fingerprints. Discrepancies between Penner serotyping and PCR fingerprinting were most obvious between isolates from different animal sources. Indications for the occurrence of genomic rearrangements were found. The inconsistency between serotyping and fingerprinting of Campylobacter strains suggests that conventional typing methods should be used in combination with fingerprinting if the epidemiological factors that contribute to Campylobacter colonization of live chickens are to be assessed reliably.  相似文献   

8.
9.
The expressed sequence tag (EST) data provide a powerful tool for identification of transcribed DNA sequences. However, as EST are relatively short, many exons are poorly covered by EST, thus reducing the utility of EST data. Recently, signature sequence tag (SST) fingerprints were proposed as an alternative to EST fingerprints. Given a fingerprint set of probes, SST of a clone is a subset of probes from the fingerprint set that hybridize with the clone. We demonstrate that besides being a powerful technique for screening cDNA libraries, SST technology provides for very accurate gene predictions. Even with a small fingerprint set (600-800 probes), SST-based gene recognition outperforms many conventional and EST-based methods. The increase in the size of the fingerprint set to 1500 probes provides almost perfect gene recognition. Even more importantly, SST-based gene predictions miss very few exons and, therefore, provide an opportunity to bypass the cDNA sequencing step on the way from finished genomic sequence to mutation detection in gene-hunting projects. Because SST data can be obtained in a highly parallel and inexpensive way, SST technology has a potential of complementing EST technology for gene hunting.  相似文献   

10.
Sudden loading injuries to the low back are a concern. Current models are limited in their ability to quantify the time-varying nature of the sudden loading event. The method of approach used six males who were subjected to sudden loads. Response data (EMG and kinematics) were input into a system identification model to yield time-varying torso stiffness estimates. The results show estimates of system stiffness in good agreement with values in the literature. The average root mean square error of the model's predictions of sagittal motion was equal to 0.1 deg. In conclusion, system identification can be implemented with minimal error and used to gain more insight into the time-dependent trunk response to sudden loads.  相似文献   

11.
Quality control of herbal medicines   总被引:8,自引:0,他引:8  
Different chromatographic and electrophoretic techniques commonly used in the instrumental inspection of herbal medicines (HM) are first comprehensively reviewed. Chemical fingerprints obtained by chromatographic and electrophoretic techniques, especially by hyphenated chromatographies, are strongly recommended for the purpose of quality control of herbal medicines, since they might represent appropriately the "chemical integrities" of the herbal medicines and therefore be used for authentication and identification of the herbal products. Based on the conception of phytoequivalence, the chromatographic fingerprints of herbal medicines could be utilized for addressing the problem of quality control of herbal medicines. Several novel chemometric methods for evaluating the fingerprints of herbal products, such as the method based on information theory, similarity estimation, chemical pattern recognition, spectral correlative chromatogram (SCC), multivariate resolution, etc. are discussed in detail with examples, which showed that the combination of chromatographic fingerprints of herbal medicines and the chemometric evaluation might be a powerful tool for quality control of herbal products.  相似文献   

12.
为筛选牛尾菜抗氧化作用的药效活性物质,提升牛尾菜的药材质量控制标准,该研究测定了13批牛尾菜的高效液相指纹图谱,并进行相似度评价和聚类分析,采用偏最小二乘回归分析法将共有峰与抗氧化的抑制率进行关联性分析,并进行单体化合物抗氧化试验验证。结果表明:(1)该文建立了含有14个主要共有峰的13 批牛尾菜HPLC指纹图谱。(2)13批牛尾菜样品聚为两类。(3)指纹图谱中的1、2、3、5、6、9、14号峰面积与抗氧化效果呈正相关,4、7、8、10、11、12号峰与抗氧化效果呈负相关,其中9、11、3、4、5号峰的VIP值均大于1。(4)9号峰为齐墩果酸,10号峰为熊果酸,9 号峰对ABTS 自由基的清除能力最大。该研究认为牛尾菜抗氧化作用不是单一成分起作用,而是多种成分综合作用的结果,其中9号峰(齐墩果酸)可能是牛尾菜具有抗氧化作用的物质基础。  相似文献   

13.
建立滁菊的HPLC指纹图谱,结合化学计量学手段对不同滁菊的指纹图谱进行分析研究,以期为滁菊的质量控制和产地追溯提供依据。采用HPLC法建立指纹图谱,并用中药色谱指纹图谱相似度评价系统(2012版)和系统聚类、主成分分析2种化学计量学法对指纹图谱和特征峰进行分析。分析结果发现样品有27个共有峰,12个滁菊样品具有较高的相似度,杭菊与滁菊的相似度较差,聚类分析与主成分分析结果和相似度分析结果一致。将HPLC指纹图谱与化学计量学结合可对滁菊进行鉴别和质量评价,为其质量控制和追溯提供了理论参考。  相似文献   

14.
A high-performance liquid chromatography-diode array detection-tandem mass spectrometry (HPLC-DAD-MS(n)) method has been firstly developed for chemical fingerprint analysis of rhizomes of Gymnadenia conopsea R. Br. and rapid identification of major compounds in the fingerprints. Comparing the UV and MS spectra with those of reference compounds, seven main peaks in the fingerprints were identified as adenosine (1), 4-hydroxybenzyl alcohol (2), 4-hydroxybenzyl aldehyde (3), dactylorhin B (4), loroglossin (5), dactylorhin A (6) and militarine (7). Compounds 4-7 were succinate derivative esters and firstly discovered from this species. The Computer Aided Similarity Evaluation System (CASES) for chromatographic fingerprint of traditional Chinese medicine was employed to evaluate the similarities of 10 samples of the rhizomes of G. conopsea collected from Sichuan, Qinghai and Hebei provinces, Tibet autonomous region of China, and Nepal. These samples from different sources had similar chemical fingerprints. This method is specific and may serve for quality identification and comprehensive evaluation of this traditional Tibetan remedy.  相似文献   

15.
为建立猫须草药材HPLC指纹图谱分析方法,采用高效液相色谱法,以Phenomenex Synergi 4u hydro-RP 250×4.60 mm为色谱柱,以甲醇-0.1%甲酸溶液为流动相梯度洗脱,检测波长254 nm,流速1.0 mL·min-1,柱温40 ℃。结果表明,建立的猫须草药材HPLC指纹图谱,确定了15个共有峰,各猫须草样品指纹图谱与对照指纹图谱的相似度均在0.9以上。该方法简单、准确、重复性好,为更好地控制猫须草药材质量提供有效可靠的方法。  相似文献   

16.
藏药花锚指纹图谱研究   总被引:6,自引:0,他引:6  
采用反相高效液相色谱-二极管阵列的检测方法,对不同产地的10批野生花锚药材的水溶性成分进行了分析,建立了花锚药材的指纹图谱,并对栽培花锚进行了指纹图谱的特征比较。结果证明,栽培花锚中的主要化学成分及数量符合花锚药材的指纹特征,可以代替野生花锚药材入药。  相似文献   

17.
Polymerase chain reaction identification of Salmonella serotypes   总被引:1,自引:0,他引:1  
Seventy-seven Salmonella isolates comprising 61 different serotypes were subjected to polymerase chain reaction (PCR) fingerprinting using two primersets. Primerset L1/G1, amplifying the spacer regions between the 16S and 23S rRNA genes, resulted in simple PCR fingerprints. However, in some cases PCR amplification of different Salmonella serotypes with primerset L1/G1 resulted in identical fingerprint profiles. Fingerprints obtained with the ERIC primerset, that matches the enterobacterial repetitive intergenic consensus sequence, were more complicated but were serotype-specific. Consequently, fingerprinting with the ERIC primerset is applicable for typing Salmonella up to the serotype level. Fingerprinting with the L1 and G1 primers requires an additional treatment of the amplification product for accurate typing of salmonellas. Phage typing is not possible with either primerset.  相似文献   

18.
Components of fermentation processes such as protein, polysaccharide and lipid, as well as microbes, such as fungi grown on solid substrates, are difficult to measure in situ. The potential of Fourier Transform Infrared (FTIR) analysis of solid-state fermentations from mid-infrared absorption spectra has been investigated. The problem under consideration was to build a calibration model containing no irrelevant information to enable a multivariate mathematical approach for prediction of component concentrations. Methods for solid sample preparation and preprocessing of FTIR data were developed to assure Beer-Lambert law compliance and produce a well-conditioned multivariate system. The model was tested using composite samples of zein protein, corn starch and azolectin lipid, and corn samples containing known levels of fungal contamination. Preliminary concentration estimates were remarkably close to the correct values, with less than 5% standard error of prediction for all components measured.  相似文献   

19.
Metabolic fingerprinting of biofluids like urine is a useful technique for detecting differences between individuals. With this approach, it might be possible to classify samples according to their biological relevance. In Part 1 of this work a method for the comprehensive screening of metabolites was described, using two different liquid chromatography (LC) column set-ups and detection by electrospray ionization mass spectrometry (ESI-MS). Data pretreatment of the resulting data described in is needed to reduce the complexity of the data and to obtain useful metabolic fingerprints. Three different approaches, i.e., reduced dimensionality (RD), MarkerLynx, and MS Resolver, were compared for the extraction of information. The pretreated data were then subjected to multivariate data analysis by partial least squares discriminant analysis (PLS-DA) for classification. By combining two different chromatographic procedures and data analysis, the detection of metabolites was enhanced as well as the finding of metabolic fingerprints that govern classification. Additional potential biomarkers or xenobiotic metabolites were detected in the fraction containing highly polar compounds that are normally discarded when using reversed-phase liquid chromatography.  相似文献   

20.
In the Markham Valley of Papua New Guinea, multivariate graphical displays of serological, anthropometric, and dermatoglyphic population structures are compared pursuant to the hypothesis that fingerprints have a slower velocity of evolutionary change and, therefore, are preferable biological markers for prehistorical reconstructions. Samples from nine villages, which represent three geographical and linguistic populations, are plotted in two dimensions using appropriate multivariate techniques for maximally portraying between sample variability. Both the serological and morphometric displays are found lacking in close clusters, which demonstrates a lack of congruence with the shared languages and, presumably, the ethnohistorical origins of the three populations. These discrepancies between biology and prehistory appear to reflect recent environmental and stochastic perturbations. On the other hand, fingerprint displays conform closely to language affiliations, relatively undisturbed by environmental variation and genetic drift. The relative congruence between ethnohistorical affiliation and fingerprint diversity is further corroborated by comparing the three measures of population structure with geographical distances, using partial rank correlations. In terms of explained variance, the level of association with fingerprints is more than twice than with anthropometry, and 13 times greater than with serology. Whereas metric and serological data provide distorted portrayals of known biohistorical relationships among the study populations, fingerprint data mirror these relationships. The theoretical foundations and consequences of this observation are discussed with respect to the broader question of polygenic versus monogenic biological markers.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号