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Sample records for quantitative analysis method

  1. Method and apparatus for chromatographic quantitative analysis

    DOEpatents

    Fritz, James S.; Gjerde, Douglas T.; Schmuckler, Gabriella

    1981-06-09

    An improved apparatus and method for the quantitative analysis of a solution containing a plurality of anion species by ion exchange chromatography which utilizes a single eluent and a single ion exchange bed which does not require periodic regeneration. The solution containing the anions is added to an anion exchange resin bed which is a low capacity macroreticular polystyrene-divinylbenzene resin containing quarternary ammonium functional groups, and is eluted therefrom with a dilute solution of a low electrical conductance organic acid salt. As each anion species is eluted from the bed, it is quantitatively sensed by conventional detection means such as a conductivity cell.

  2. Uncertainty of quantitative microbiological methods of pharmaceutical analysis.

    PubMed

    Gunar, O V; Sakhno, N G

    2015-12-30

    The total uncertainty of quantitative microbiological methods, used in pharmaceutical analysis, consists of several components. The analysis of the most important sources of the quantitative microbiological methods variability demonstrated no effect of culture media and plate-count techniques in the estimation of microbial count while the highly significant effect of other factors (type of microorganism, pharmaceutical product and individual reading and interpreting errors) was established. The most appropriate method of statistical analysis of such data was ANOVA which enabled not only the effect of individual factors to be estimated but also their interactions. Considering all the elements of uncertainty and combining them mathematically the combined relative uncertainty of the test results was estimated both for method of quantitative examination of non-sterile pharmaceuticals and microbial count technique without any product. These data did not exceed 35%, appropriated for a traditional plate count methods.

  3. Some selected quantitative methods of thermal image analysis in Matlab.

    PubMed

    Koprowski, Robert

    2016-05-01

    The paper presents a new algorithm based on some selected automatic quantitative methods for analysing thermal images. It shows the practical implementation of these image analysis methods in Matlab. It enables to perform fully automated and reproducible measurements of selected parameters in thermal images. The paper also shows two examples of the use of the proposed image analysis methods for the area of ​​the skin of a human foot and face. The full source code of the developed application is also provided as an attachment. The main window of the program during dynamic analysis of the foot thermal image.

  4. Improved method and apparatus for chromatographic quantitative analysis

    DOEpatents

    Fritz, J.S.; Gjerde, D.T.; Schmuckler, G.

    An improved apparatus and method are described for the quantitative analysis of a solution containing a plurality of anion species by ion exchange chromatography which utilizes a single element and a single ion exchange bed which does not require periodic regeneration. The solution containing the anions is added to an anion exchange resin bed which is a low capacity macroreticular polystyrene-divinylbenzene resin containing quarternary ammonium functional groups, and is eluted therefrom with a dilute solution of a low electrical conductance organic acid salt. As each anion species is eluted from the bed, it is quantitatively sensed by conventional detection means such as a conductivity cell.

  5. A Quantitative Method for Microtubule Analysis in Fluorescence Images.

    PubMed

    Lan, Xiaodong; Li, Lingfei; Hu, Jiongyu; Zhang, Qiong; Dang, Yongming; Huang, Yuesheng

    2015-12-01

    Microtubule analysis is of significant value for a better understanding of normal and pathological cellular processes. Although immunofluorescence microscopic techniques have proven useful in the study of microtubules, comparative results commonly rely on a descriptive and subjective visual analysis. We developed an objective and quantitative method based on image processing and analysis of fluorescently labeled microtubular patterns in cultured cells. We used a multi-parameter approach by analyzing four quantifiable characteristics to compose our quantitative feature set. Then we interpreted specific changes in the parameters and revealed the contribution of each feature set using principal component analysis. In addition, we verified that different treatment groups could be clearly discriminated using principal components of the multi-parameter model. High predictive accuracy of four commonly used multi-classification methods confirmed our method. These results demonstrated the effectiveness and efficiency of our method in the analysis of microtubules in fluorescence images. Application of the analytical methods presented here provides information concerning the organization and modification of microtubules, and could aid in the further understanding of structural and functional aspects of microtubules under normal and pathological conditions.

  6. Quantitative mass spectrometric analysis of glycoproteins combined with enrichment methods.

    PubMed

    Ahn, Yeong Hee; Kim, Jin Young; Yoo, Jong Shin

    2015-01-01

    Mass spectrometry (MS) has been a core technology for high sensitive and high-throughput analysis of the enriched glycoproteome in aspects of quantitative assays as well as qualitative profiling of glycoproteins. Because it has been widely recognized that aberrant glycosylation in a glycoprotein may involve in progression of a certain disease, the development of efficient analysis tool for the aberrant glycoproteins is very important for deep understanding about pathological function of the glycoprotein and new biomarker development. This review first describes the protein glycosylation-targeting enrichment technologies mainly employing solid-phase extraction methods such as hydrizide-capturing, lectin-specific capturing, and affinity separation techniques based on porous graphitized carbon, hydrophilic interaction chromatography, or immobilized boronic acid. Second, MS-based quantitative analysis strategies coupled with the protein glycosylation-targeting enrichment technologies, by using a label-free MS, stable isotope-labeling, or targeted multiple reaction monitoring (MRM) MS, are summarized with recent published studies.

  7. An improved quantitative analysis method for plant cortical microtubules.

    PubMed

    Lu, Yi; Huang, Chenyang; Wang, Jia; Shang, Peng

    2014-01-01

    The arrangement of plant cortical microtubules can reflect the physiological state of cells. However, little attention has been paid to the image quantitative analysis of plant cortical microtubules so far. In this paper, Bidimensional Empirical Mode Decomposition (BEMD) algorithm was applied in the image preprocessing of the original microtubule image. And then Intrinsic Mode Function 1 (IMF1) image obtained by decomposition was selected to do the texture analysis based on Grey-Level Cooccurrence Matrix (GLCM) algorithm. Meanwhile, in order to further verify its reliability, the proposed texture analysis method was utilized to distinguish different images of Arabidopsis microtubules. The results showed that the effect of BEMD algorithm on edge preserving accompanied with noise reduction was positive, and the geometrical characteristic of the texture was obvious. Four texture parameters extracted by GLCM perfectly reflected the different arrangements between the two images of cortical microtubules. In summary, the results indicate that this method is feasible and effective for the image quantitative analysis of plant cortical microtubules. It not only provides a new quantitative approach for the comprehensive study of the role played by microtubules in cell life activities but also supplies references for other similar studies.

  8. Quantitative Phase Analysis by the Rietveld Method for Forensic Science.

    PubMed

    Deng, Fei; Lin, Xiaodong; He, Yonghong; Li, Shu; Zi, Run; Lai, Shijun

    2015-07-01

    Quantitative phase analysis (QPA) is helpful to determine the type attribute of the object because it could present the content of the constituents. QPA by Rietveld method requires neither measurement of calibration data nor the use of an internal standard; however, the approximate crystal structure of each phase in a mixture is necessary. In this study, 8 synthetic mixtures composed of potassium nitrate and sulfur were analyzed by Rietveld QPA method. The Rietveld refinement was accomplished with a material analysis using diffraction program and evaluated by three agreement indices. Results showed that Rietveld QPA yielded precise results, with errors generally less than 2.0% absolute. In addition, a criminal case which was broken successfully with the help of Rietveld QPA method was also introduced. This method will allow forensic investigators to acquire detailed information of the material evidence, which could point out the direction for case detection and court proceedings.

  9. In vivo osteogenesis assay: a rapid method for quantitative analysis.

    PubMed

    Dennis, J E; Konstantakos, E K; Arm, D; Caplan, A I

    1998-08-01

    A quantitative in vivo osteogenesis assay is a useful tool for the analysis of cells and bioactive factors that affect the amount or rate of bone formation. There are currently two assays in general use for the in vivo assessment of osteogenesis by isolated cells: diffusion chambers and porous calcium phosphate ceramics. Due to the relative ease of specimen preparation and reproducibility of results, the porous ceramic assay was chosen for the development of a rapid method for quantitating in vivo bone formation. The ceramic cube implantation technique consists of combining osteogenic cells with 27-mm3 porous calcium phosphate ceramics, implanting the cell-ceramic composites subcutaneously into an immuno-tolerant host, and, after 2-6 weeks, harvesting and preparing the ceramic implants for histologic analysis. A drawback to the analysis of bone formation within these porous ceramics is that the entire cube must be examined to find small foci of bone present in some samples; a single cross-sectional area is not representative. For this reason, image analysis of serial sections from ceramics is often prohibitively time-consuming. Two alternative scoring methodologies were tested and compared to bone volume measurements obtained by image analysis. The two subjective scoring methods were: (1) Bone Scale: the amount of bone within pores of the ceramic implant is estimated on a scale of 0-4 based on the degree of bone fill (0=no bone, 1=up to 25%, 2=25 to 75%, 4=75 to 100% fill); and (2) Percentage Bone: the amount of bone is estimated by determining the percentage of ceramic pores which contain bone. Every tenth section of serially sectioned cubes was scored by each of these methods under double-blind conditions, and the Bone Scale and Percentage Bone results were directly compared to image analysis measurements from identical samples. Correlation coefficients indicate that the Percentage Bone method was more accurate than the Bone Scale scoring method. The Bone Scale

  10. QUANTITATIVE MASS SPECTROMETRIC ANALYSIS OF GLYCOPROTEINS COMBINED WITH ENRICHMENT METHODS

    PubMed Central

    Ahn, Yeong Hee; Kim, Jin Young; Yoo, Jong Shin

    2015-01-01

    Mass spectrometry (MS) has been a core technology for high sensitive and high-throughput analysis of the enriched glycoproteome in aspects of quantitative assays as well as qualitative profiling of glycoproteins. Because it has been widely recognized that aberrant glycosylation in a glycoprotein may involve in progression of a certain disease, the development of efficient analysis tool for the aberrant glycoproteins is very important for deep understanding about pathological function of the glycoprotein and new biomarker development. This review first describes the protein glycosylation-targeting enrichment technologies mainly employing solid-phase extraction methods such as hydrizide-capturing, lectin-specific capturing, and affinity separation techniques based on porous graphitized carbon, hydrophilic interaction chromatography, or immobilized boronic acid. Second, MS-based quantitative analysis strategies coupled with the protein glycosylation-targeting enrichment technologies, by using a label-free MS, stable isotope-labeling, or targeted multiple reaction monitoring (MRM) MS, are summarized with recent published studies. © 2014 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc. Rapid Commun. Mass Spec Rev 34:148–165, 2015. PMID:24889823

  11. A new quantitative method for gunshot residue analysis by ion beam analysis.

    PubMed

    Christopher, Matthew E; Warmenhoeven, John-William; Romolo, Francesco S; Donghi, Matteo; Webb, Roger P; Jeynes, Christopher; Ward, Neil I; Kirkby, Karen J; Bailey, Melanie J

    2013-08-21

    Imaging and analyzing gunshot residue (GSR) particles using the scanning electron microscope equipped with an energy dispersive X-ray spectrometer (SEM-EDS) is a standard technique that can provide important forensic evidence, but the discrimination power of this technique is limited due to low sensitivity to trace elements and difficulties in obtaining quantitative results from small particles. A new, faster method using a scanning proton microbeam and Particle Induced X-ray Emission (μ-PIXE), together with Elastic Backscattering Spectrometry (EBS) is presented for the non-destructive, quantitative analysis of the elemental composition of single GSR particles. In this study, the GSR particles were all Pb, Ba, Sb. The precision of the method is assessed. The grouping behaviour of different makes of ammunition is determined using multivariate analysis. The protocol correctly groups the cartridges studied here, with a confidence >99%, irrespective of the firearm or population of particles selected.

  12. Computer Image Analysis Method for Rapid Quantitation of Macrophage Phagocytosis

    DTIC Science & Technology

    1990-01-01

    None- Methods of Enzymology, ( Sabato , D.G., and Everse, J.. Eds.) theless, occasionally an excessive number of micro- New York: Academic Press, vol...heterogeneity in neonates mology ( Sabato , G.D., and Everse, J., Eds.) New York: Aca- and adults. Blood 68,200, 1986. demic Press. Vol. 132, p. 3, 1986. 21

  13. Mixing Qualitative and Quantitative Methods: Insights into Design and Analysis Issues

    ERIC Educational Resources Information Center

    Lieber, Eli

    2009-01-01

    This article describes and discusses issues related to research design and data analysis in the mixing of qualitative and quantitative methods. It is increasingly desirable to use multiple methods in research, but questions arise as to how best to design and analyze the data generated by mixed methods projects. I offer a conceptualization for such…

  14. Quantitative interpretation of mineral hyperspectral images based on principal component analysis and independent component analysis methods.

    PubMed

    Jiang, Xiping; Jiang, Yu; Wu, Fang; Wu, Fenghuang

    2014-01-01

    Interpretation of mineral hyperspectral images provides large amounts of high-dimensional data, which is often complicated by mixed pixels. The quantitative interpretation of hyperspectral images is known to be extremely difficult when three types of information are unknown, namely, the number of pure pixels, the spectrum of pure pixels, and the mixing matrix. The problem is made even more complex by the disturbance of noise. The key to interpreting abstract mineral component information, i.e., pixel unmixing and abundance inversion, is how to effectively reduce noise, dimension, and redundancy. A three-step procedure is developed in this study for quantitative interpretation of hyperspectral images. First, the principal component analysis (PCA) method can be used to process the pixel spectrum matrix and keep characteristic vectors with larger eigenvalues. This can effectively reduce the noise and redundancy, which facilitates the abstraction of major component information. Second, the independent component analysis (ICA) method can be used to identify and unmix the pixels based on the linear mixed model. Third, the pure-pixel spectrums can be normalized for abundance inversion, which gives the abundance of each pure pixel. In numerical experiments, both simulation data and actual data were used to demonstrate the performance of our three-step procedure. Under simulation data, the results of our procedure were compared with theoretical values. Under the actual data measured from core hyperspectral images, the results obtained through our algorithm are compared with those of similar software (Mineral Spectral Analysis 1.0, Nanjing Institute of Geology and Mineral Resources). The comparisons show that our method is effective and can provide reference for quantitative interpretation of hyperspectral images.

  15. [Study on the multivariate quantitative analysis method for steel alloy elements using LIBS].

    PubMed

    Gu, Yan-hong; Li, Ying; Tian, Ye; Lu, Yuan

    2014-08-01

    Quantitative analysis of steel alloys was carried out using laser induced breakdown spectroscopy (LIBS) taking into account the complex matrix effects in steel alloy samples. The laser induced plasma was generated by a Q-switched Nd:YAG laser operating at 1064 nm with pulse width of 10 ns and repeated frequency of 10 Hz. The LIBS signal was coupled to the echelle spectrometer and recorded by a high sensitive ICCD detector. To get the best experimental conditions, some parameters, such as the detection delay, the CCDs integral gate width and the detecting position from the sample surface, were optimized. The experimental results showed that the optimum detection delay time was 1.5 micros, the optimal CCDs integral gate width was 2 micros and the best detecting position was 1.5 mm below the alloy sample's surface. The samples used in the experiments are ten standard steel alloy samples and two unknown steel alloy samples. The quantitative analysis was investigated with the optimum experimental parameters. Elements Cr and Ni in steel alloy samples were taken as the detection targets. The analysis was carried out with the methods based on conditional univariate quantitative analysis, multiple linear regression and partial least squares (PLS) respectively. It turned out that the correlation coefficients of calibration curves are not very high in the conditional univariate calibration method. The analysis results were obtained with the unsatisfied relative errors for the two predicted samples. So the con- ditional univariate quantitative analysis method can't effectively serve the quantitative analysis purpose for multi-components and complex matrix steel alloy samples. And with multiple linear regression method, the analysis accuracy was improved effectively. The method based on partial least squares (PLS) turned out to be the best method among all the three quantitative analysis methods applied. Based on PLS, the correlation coefficient of calibration curve for Cr is 0

  16. Quantitative interferometric microscopic flow cytometer with expanded principal component analysis method

    NASA Astrophysics Data System (ADS)

    Wang, Shouyu; Jin, Ying; Yan, Keding; Xue, Liang; Liu, Fei; Li, Zhenhua

    2014-11-01

    Quantitative interferometric microscopy is used in biological and medical fields and a wealth of applications are proposed in order to detect different kinds of biological samples. Here, we develop a phase detecting cytometer based on quantitative interferometric microscopy with expanded principal component analysis phase retrieval method to obtain phase distributions of red blood cells with a spatial resolution ~1.5 μm. Since expanded principal component analysis method is a time-domain phase retrieval algorithm, it could avoid disadvantages of traditional frequency-domain algorithms. Additionally, the phase retrieval method realizes high-speed phase imaging from multiple microscopic interferograms captured by CCD camera when the biological cells are scanned in the field of view. We believe this method can be a powerful tool to quantitatively measure the phase distributions of different biological samples in biological and medical fields.

  17. Microchromatography of hemoglobins. VIII. A general qualitative and quantitative method in plastic drinking straws and the quantitative analysis of Hb-F.

    PubMed

    Schroeder, W A; Pace, L A

    1978-03-01

    The microchromatographic procedure for the quantitative analysis of the hemoglobin components in a hemolysate uses columns of DEAE-cellulose in a plastic drinking straw with a glycine-KCN-NaCl developer. Not only may the method be used for the quantitative analysis of Hb-F but also for the analysis of the varied components in mixtures of hemoglobins.

  18. Method of fault-tree quantitative analysis for solid rocket motor

    NASA Astrophysics Data System (ADS)

    Hu, Baochao; Yang, Yicai; Xie, Weimin

    1993-08-01

    Based on the existing problem in determining the failure probabilities of base events in solid rocket motor fault-tree quantitative analysis, an engineering method of 'Solicitation Opinions to Give Marks' was put forward to determine the failure probability. A satisfactory result was obtained by analyzing the practical example of structure reliability for some solid rocket motors at the test sample stage.

  19. Method of fault-tree quantitative analysis for solid rocket motor

    NASA Astrophysics Data System (ADS)

    Hu, Baochao; Yang, Yicai; Xie, Weimin

    1993-08-01

    Based on the existing problem of determining the failure probabilities of base events in solid rocket motor fault tree quantitative analysis, an engineering method of Solicitation Opinions to Give Marks is put forward to determine failure probability. A more satisfactory result is obtained by analyzing the actual example of the structural reliability of solid rocket motors at the test sample stage.

  20. A GC-FID method for quantitative analysis of N,N-carbonyldiimidazole.

    PubMed

    Lee, Claire; Mangion, Ian

    2016-03-20

    N,N-Carbonyldiimidazole (CDI), a common synthetic reagent used in commercial scale pharmaceutical synthesis, is known to be sensitive to hydrolysis from ambient moisture. This liability demands a simple, robust analytical method to quantitatively determine reagent quality to ensure reproducible performance in chemical reactions. This work describes a protocol for a rapid GC-FID based analysis of CDI.

  1. [Study of infrared spectroscopy quantitative analysis method for methane gas based on data mining].

    PubMed

    Zhang, Ai-Ju

    2013-10-01

    Monitoring of methane gas is one of the important factors affecting the coal mine safety. The online real-time monitoring of the methane gas is used for the mine safety protection. To improve the accuracy of model analysis, in the present paper, the author uses the technology of infrared spectroscopy to study the gas infrared quantitative analysis algorithm. By data mining technology application in multi-component infrared spectroscopy quantitative analysis algorithm, it was found that cluster analysis partial least squares algorithm is obviously superior to simply using partial least squares algorithm in terms of accuracy. In addition, to reduce the influence of the error on the accuracy of model individual calibration samples, the clustering analysis was used for the data preprocessing, and such denoising method was found to improve the analysis accuracy.

  2. Visual and Quantitative Analysis Methods of Respiratory Patterns for Respiratory Gated PET/CT

    PubMed Central

    Yoon, Hyun Jin

    2016-01-01

    We integrated visual and quantitative methods for analyzing the stability of respiration using four methods: phase space diagrams, Fourier spectra, Poincaré maps, and Lyapunov exponents. Respiratory patterns of 139 patients were grouped based on the combination of the regularity of amplitude, period, and baseline positions. Visual grading was done by inspecting the shape of diagram and classified into two states: regular and irregular. Quantitation was done by measuring standard deviation of x and v coordinates of Poincaré map (SDx, SDv) or the height of the fundamental peak (A1) in Fourier spectrum or calculating the difference between maximal upward and downward drift. Each group showed characteristic pattern on visual analysis. There was difference of quantitative parameters (SDx, SDv, A1, and MUD-MDD) among four groups (one way ANOVA, p = 0.0001 for MUD-MDD, SDx, and SDv, p = 0.0002 for A1). In ROC analysis, the cutoff values were 0.11 for SDx (AUC: 0.982, p < 0.0001), 0.062 for SDv (AUC: 0.847, p < 0.0001), 0.117 for A1 (AUC: 0.876, p < 0.0001), and 0.349 for MUD-MDD (AUC: 0.948, p < 0.0001). This is the first study to analyze multiple aspects of respiration using various mathematical constructs and provides quantitative indices of respiratory stability and determining quantitative cutoff value for differentiating regular and irregular respiration. PMID:27872857

  3. Quantitative determination of sibutramine in adulterated herbal slimming formulations by TLC-image analysis method.

    PubMed

    Phattanawasin, Panadda; Sotanaphun, Uthai; Sukwattanasinit, Tasamaporn; Akkarawaranthorn, Jariya; Kitchaiya, Sarunyaporn

    2012-06-10

    A simple thin layer chromatographic (TLC)-image analysis method was developed for rapid determination and quantitation of sibutramine hydrochloride (SH) adulterated in herbal slimming products. Chromatographic separation of SH was achieved on a silica gel 60 F(254) TLC plate, using toluene-n-hexane-diethylamine (9:1:0.3, v/v/v) as the mobile phase and Dragendorff reagent as spot detection. Image analysis of the scanned TLC plate was performed to quantify the amount of SH. The polynomial regression data for the calibration plots showed good linear relationship in the concentration range of 1-6 μg/spot. The limits of detection and quantitation were 190 and 634 ng/spot, respectively. The method gave satisfactory specificity, precision, accuracy, robustness and was applied for determination of SH in herbal formulations. The contents of SH in adulterated samples determined by the TLC-image analysis and TLC-densitometry were also compared.

  4. A thioacidolysis method tailored for higher-throughput quantitative analysis of lignin monomers

    DOE PAGES

    Harman-Ware, Anne E.; Foster, Cliff; Happs, Renee M.; ...

    2016-09-14

    Thioacidolysis is a method used to measure the relative content of lignin monomers bound by β-O-4 linkages. Current thioacidolysis methods are low-throughput as they require tedious steps for reaction product concentration prior to analysis using standard GC methods. A quantitative thioacidolysis method that is accessible with general laboratory equipment and uses a non-chlorinated organic solvent and is tailored for higher-throughput analysis is reported. The method utilizes lignin arylglycerol monomer standards for calibration, requires 1-2 mg of biomass per assay and has been quantified using fast-GC techniques including a Low Thermal Mass Modular Accelerated Column Heater (LTM MACH). Cumbersome steps, includingmore » standard purification, sample concentrating and drying have been eliminated to help aid in consecutive day-to-day analyses needed to sustain a high sample throughput for large screening experiments without the loss of quantitation accuracy. As a result, the method reported in this manuscript has been quantitatively validated against a commonly used thioacidolysis method and across two different research sites with three common biomass varieties to represent hardwoods, softwoods, and grasses.« less

  5. A thioacidolysis method tailored for higher-throughput quantitative analysis of lignin monomers

    SciTech Connect

    Harman-Ware, Anne E.; Foster, Cliff; Happs, Renee M.; Doeppke, Crissa; Meunier, Kristoffer; Gehan, Jackson; Yue, Fengxia; Lu, Fachuang; Davis, Mark F.

    2016-09-14

    Thioacidolysis is a method used to measure the relative content of lignin monomers bound by β-O-4 linkages. Current thioacidolysis methods are low-throughput as they require tedious steps for reaction product concentration prior to analysis using standard GC methods. A quantitative thioacidolysis method that is accessible with general laboratory equipment and uses a non-chlorinated organic solvent and is tailored for higher-throughput analysis is reported. The method utilizes lignin arylglycerol monomer standards for calibration, requires 1-2 mg of biomass per assay and has been quantified using fast-GC techniques including a Low Thermal Mass Modular Accelerated Column Heater (LTM MACH). Cumbersome steps, including standard purification, sample concentrating and drying have been eliminated to help aid in consecutive day-to-day analyses needed to sustain a high sample throughput for large screening experiments without the loss of quantitation accuracy. As a result, the method reported in this manuscript has been quantitatively validated against a commonly used thioacidolysis method and across two different research sites with three common biomass varieties to represent hardwoods, softwoods, and grasses.

  6. A thioacidolysis method tailored for higher-throughput quantitative analysis of lignin monomers.

    PubMed

    Harman-Ware, Anne E; Foster, Cliff; Happs, Renee M; Doeppke, Crissa; Meunier, Kristoffer; Gehan, Jackson; Yue, Fengxia; Lu, Fachuang; Davis, Mark F

    2016-10-01

    Thioacidolysis is a method used to measure the relative content of lignin monomers bound by β-O-4 linkages. Current thioacidolysis methods are low-throughput as they require tedious steps for reaction product concentration prior to analysis using standard GC methods. A quantitative thioacidolysis method that is accessible with general laboratory equipment and uses a non-chlorinated organic solvent and is tailored for higher-throughput analysis is reported. The method utilizes lignin arylglycerol monomer standards for calibration, requires 1-2 mg of biomass per assay and has been quantified using fast-GC techniques including a Low Thermal Mass Modular Accelerated Column Heater (LTM MACH). Cumbersome steps, including standard purification, sample concentrating and drying have been eliminated to help aid in consecutive day-to-day analyses needed to sustain a high sample throughput for large screening experiments without the loss of quantitation accuracy. The method reported in this manuscript has been quantitatively validated against a commonly used thioacidolysis method and across two different research sites with three common biomass varieties to represent hardwoods, softwoods, and grasses.

  7. Models and methods for quantitative analysis of surface-enhanced Raman spectra.

    PubMed

    Li, Shuo; Nyagilo, James O; Dave, Digant P; Gao, Jean

    2014-03-01

    The quantitative analysis of surface-enhanced Raman spectra using scattering nanoparticles has shown the potential and promising applications in in vivo molecular imaging. The diverse approaches have been used for quantitative analysis of Raman pectra information, which can be categorized as direct classical least squares models, full spectrum multivariate calibration models, selected multivariate calibration models, and latent variable regression (LVR) models. However, the working principle of these methods in the Raman spectra application remains poorly understood and a clear picture of the overall performance of each model is missing. Based on the characteristics of the Raman spectra, in this paper, we first provide the theoretical foundation of the aforementioned commonly used models and show why the LVR models are more suitable for quantitative analysis of the Raman spectra. Then, we demonstrate the fundamental connections and differences between different LVR methods, such as principal component regression, reduced-rank regression, partial least square regression (PLSR), canonical correlation regression, and robust canonical analysis, by comparing their objective functions and constraints.We further prove that PLSR is literally a blend of multivariate calibration and feature extraction model that relates concentrations of nanotags to spectrum intensity. These features (a.k.a. latent variables) satisfy two purposes: the best representation of the predictor matrix and correlation with the response matrix. These illustrations give a new understanding of the traditional PLSR and explain why PLSR exceeds other methods in quantitative analysis of the Raman spectra problem. In the end, all the methods are tested on the Raman spectra datasets with different evaluation criteria to evaluate their performance.

  8. Emerging flow injection mass spectrometry methods for high-throughput quantitative analysis.

    PubMed

    Nanita, Sergio C; Kaldon, Laura G

    2016-01-01

    Where does flow injection analysis mass spectrometry (FIA-MS) stand relative to ambient mass spectrometry (MS) and chromatography-MS? Improvements in FIA-MS methods have resulted in fast-expanding uses of this technique. Key advantages of FIA-MS over chromatography-MS are fast analysis (typical run time <60 s) and method simplicity, and FIA-MS offers high-throughput without compromising sensitivity, precision and accuracy as much as ambient MS techniques. Consequently, FIA-MS is increasingly becoming recognized as a suitable technique for applications where quantitative screening of chemicals needs to be performed rapidly and reliably. The FIA-MS methods discussed herein have demonstrated quantitation of diverse analytes, including pharmaceuticals, pesticides, environmental contaminants, and endogenous compounds, at levels ranging from parts-per-billion (ppb) to parts-per-million (ppm) in very complex matrices (such as blood, urine, and a variety of foods of plant and animal origin), allowing successful applications of the technique in clinical diagnostics, metabolomics, environmental sciences, toxicology, and detection of adulterated/counterfeited goods. The recent boom in applications of FIA-MS for high-throughput quantitative analysis has been driven in part by (1) the continuous improvements in sensitivity and selectivity of MS instrumentation, (2) the introduction of novel sample preparation procedures compatible with standalone mass spectrometric analysis such as salting out assisted liquid-liquid extraction (SALLE) with volatile solutes and NH4(+) QuEChERS, and (3) the need to improve efficiency of laboratories to satisfy increasing analytical demand while lowering operational cost. The advantages and drawbacks of quantitative analysis by FIA-MS are discussed in comparison to chromatography-MS and ambient MS (e.g., DESI, LAESI, DART). Generally, FIA-MS sits 'in the middle' between ambient MS and chromatography-MS, offering a balance between analytical

  9. Chemical comparison of Tripterygium wilfordii and Tripterygium hypoglaucum based on quantitative analysis and chemometrics methods.

    PubMed

    Guo, Long; Duan, Li; Liu, Ke; Liu, E-Hu; Li, Ping

    2014-07-01

    Tripterygium wilfordii (T. wilfordii) and Tripterygium hypoglaucum (T. hypoglaucum), two commonly used Chinese herbal medicines derived from Tripterygium genus, have been widely used for the treatment of rheumatoid arthritis and other related inflammatory diseases in clinical therapy. In the present study, a rapid resolution liquid chromatography/electrospray ionization tandem mass spectrometry (RRLC-ESI-MS(n)) method has been developed and validated for simultaneous determination of 19 bioactive compounds including four catechins, three sesquiterpene alkaloids, four diterpenoids, and eight triterpenoids in these two similar herbs. The method validation results indicated that the developed method had desirable specificity, linearity, precision and accuracy. Quantitative analysis results showed that there were significant differences in the content of different types of compounds in T. wilfordii and T. hypoglaucum. Moreover, chemometrics methods such as one-way ANOVA, principal component analysis (PCA) and hierarchical clustering analysis (HCA) were performed to compare and discriminate the two Tripterygium herbs based on the quantitative data of analytes, and it was proven straightforward and reliable to differentiate T. wilfordii and T. hypoglaucum samples from different origins. In conclusion, simultaneous quantification of multiple-active component by RRLC-ESI-MS(n) coupled with chemometrics analysis could be a well-acceptable strategy to compare and evaluate the quality of T. wilfordii and T. hypoglaucum.

  10. Method for collecting and immobilizing individual cumulus cells enabling quantitative immunofluorescence analysis of proteins.

    PubMed

    Appeltant, R; Maes, D; Van Soom, A

    2015-07-01

    Most immunofluorescence methods rely on techniques dealing with a very large number of cells. However, when the number of cells in a sample is low (e.g., when cumulus cells must be analyzed from individual cumulus-oocyte complexes), specific techniques are required to conserve, fix, and analyze cells individually. We established and validated a simple and effective method for collecting and immobilizing low numbers of cumulus cells that enables easy and quick quantitative immunofluorescence analysis of proteins from individual cells. To illustrate this technique, we stained proprotein of a disintegrin and metalloproteinase with thrombospondin-like repeats-1 (proADAMTS-1) and analyzed its levels in individual porcine cumulus cells.

  11. A method for quantitative analysis of aquatic humic substances in clear water based on carbon concentration.

    PubMed

    Tsuda, Kumiko; Takata, Akihiro; Shirai, Hidekado; Kozaki, Katsutoshi; Fujitake, Nobuhide

    2012-01-01

    Aquatic humic substances (AHSs) are major constituents of dissolved organic matter (DOM) in freshwater, where they perform a number of important ecological and geochemical functions, yet no method exists for quantifying all AHSs. We have developed a method for the quantitative analysis of AHSs based on their carbon concentration. Our approach includes: (1) the development of techniques for clear-water samples with low AHS concentrations, which normally complicate quantification; (2) avoiding carbon contamination in the laboratory; and (3) optimizing the AHS adsorption conditions.

  12. A fluorescence-quenching method for quantitative analysis of Ponceau 4R in beverage.

    PubMed

    Zhang, Jianpo; Na, Lihua; Jiang, Yunxia; Han, Dandan; Lou, Dawei; Jin, Li

    2017-04-15

    CdTe quantum dots was synthesized and used to quantitative analysis of Ponceau 4R in solution. With the excitation wavelength of 380nm the emission of CdTe quantum dots was quenched obviously by Ponceau 4R. In order to detect Ponceau 4R in mild condition the influences of fluorescence emission wavelength of CdTe quantum dots, pH value, temperature and reaction time were examined to establish the experimental condition. The linear response of the fluorescence intensity of CdTe quantum dots to Ponceau 4R allowed the quantitative analysis of Ponceau 4R in a range of 2.5-25μg/mL, and the limit of detection for Ponceau 4R was 0.025μg/mL. In addition, the responsive mechanism of this reaction system was investigated in detail by using the modified Stern-Volmer equation and thermodynamic calculation. Particularly, this method was used to quantitatively analyze the real sample, which indicated that this method could be more widely applied in similar samples.

  13. Enantiomer labelling, a method for the quantitative analysis of amino acids.

    PubMed

    Frank, H; Nicholson, G J; Bayer, E

    1978-12-21

    Enantiomer labelling a method for the quntitative analysis of optically active natural compounds by gas chromatography, involves the use of the unnatural enantiomer as an internal standard. With Chirasil-Val, a chiral stationary phase that is thermally stable up to up to 240 degrees, the enantiomers of amino acids and a variety of other compounds can be separated and quantitated. Incomplete recovery from the sample, incomplete derivatization, hydrolysis and thermal decomposition of the derivative and shifting response factors can be compensated for by adding the unnatural enantiomer. The accuracy of amino acid analysis by enantiomer labelling is equal or superior to that of hitherto known methods. The procedure affords a complete analysis of peptides with respect to both amino acid composition and the optical purity of each amino acid.

  14. Solution identification and quantitative analysis of fiber-capacitive drop analyzer based on multivariate statistical methods

    NASA Astrophysics Data System (ADS)

    Chen, Zhe; Qiu, Zurong; Huo, Xinming; Fan, Yuming; Li, Xinghua

    2017-03-01

    A fiber-capacitive drop analyzer is an instrument which monitors a growing droplet to produce a capacitive opto-tensiotrace (COT). Each COT is an integration of fiber light intensity signals and capacitance signals and can reflect the unique physicochemical property of a liquid. In this study, we propose a solution analytical and concentration quantitative method based on multivariate statistical methods. Eight characteristic values are extracted from each COT. A series of COT characteristic values of training solutions at different concentrations compose a data library of this kind of solution. A two-stage linear discriminant analysis is applied to analyze different solution libraries and establish discriminant functions. Test solutions can be discriminated by these functions. After determining the variety of test solutions, Spearman correlation test and principal components analysis are used to filter and reduce dimensions of eight characteristic values, producing a new representative parameter. A cubic spline interpolation function is built between the parameters and concentrations, based on which we can calculate the concentration of the test solution. Methanol, ethanol, n-propanol, and saline solutions are taken as experimental subjects in this paper. For each solution, nine or ten different concentrations are chosen to be the standard library, and the other two concentrations compose the test group. By using the methods mentioned above, all eight test solutions are correctly identified and the average relative error of quantitative analysis is 1.11%. The method proposed is feasible which enlarges the applicable scope of recognizing liquids based on the COT and improves the concentration quantitative precision, as well.

  15. On the quantitative method for measurement and analysis of the fine structure of Fraunhofer line profiles

    NASA Astrophysics Data System (ADS)

    Kuli-Zade, D. M.

    The methods of measurement and analysis of the fine structure of weak and moderate Fraunhofer line profiles are considered. The digital spectral materials were obtained using rapid scanning high dispersion and high resolution double monochromators. The methods of asymmetry coefficient, bisector method and new quantitative method pro- posed by the author are discussed. The new physical values of differential, integral, residual and relative asymmetries are first introduced. These quantitative values permit us to investigate the dependence of asymmetry on microscopic (atomic) and macro- scopic (photospheric) values. It is shown that the integral profile asymmetries grow appreciably with increase in line equivalent width. The average effective depths of the formation of used Fraunhofer lines in the photosphere of the Sun are determined. It is shown that with the increasing of the effective formation depths of the lines integral and residual asymmetries of the lines profiles noticeably decrease. It is in fine agree- ment with the results of intensity dependence of asymmetry. The above-mentioned methods are critically compared and the advantages of author's method are shown. The computer program of calculation of the line-profile asymmetry parameters has been worked out.

  16. Selective Weighted Least Squares Method for Fourier Transform Infrared Quantitative Analysis.

    PubMed

    Wang, Xin; Li, Yan; Wei, Haoyun; Chen, Xia

    2016-10-26

    Classical least squares (CLS) regression is a popular multivariate statistical method used frequently for quantitative analysis using Fourier transform infrared (FT-IR) spectrometry. Classical least squares provides the best unbiased estimator for uncorrelated residual errors with zero mean and equal variance. However, the noise in FT-IR spectra, which accounts for a large portion of the residual errors, is heteroscedastic. Thus, if this noise with zero mean dominates in the residual errors, the weighted least squares (WLS) regression method described in this paper is a better estimator than CLS. However, if bias errors, such as the residual baseline error, are significant, WLS may perform worse than CLS. In this paper, we compare the effect of noise and bias error in using CLS and WLS in quantitative analysis. Results indicated that for wavenumbers with low absorbance, the bias error significantly affected the error, such that the performance of CLS is better than that of WLS. However, for wavenumbers with high absorbance, the noise significantly affected the error, and WLS proves to be better than CLS. Thus, we propose a selective weighted least squares (SWLS) regression that processes data with different wavenumbers using either CLS or WLS based on a selection criterion, i.e., lower or higher than an absorbance threshold. The effects of various factors on the optimal threshold value (OTV) for SWLS have been studied through numerical simulations. These studies reported that: (1) the concentration and the analyte type had minimal effect on OTV; and (2) the major factor that influences OTV is the ratio between the bias error and the standard deviation of the noise. The last part of this paper is dedicated to quantitative analysis of methane gas spectra, and methane/toluene mixtures gas spectra as measured using FT-IR spectrometry and CLS, WLS, and SWLS. The standard error of prediction (SEP), bias of prediction (bias), and the residual sum of squares of the errors

  17. A new method for quantitative real-time polymerase chain reaction data analysis.

    PubMed

    Rao, Xiayu; Lai, Dejian; Huang, Xuelin

    2013-09-01

    Quantitative real-time polymerase chain reaction (qPCR) is a sensitive gene quantification method that has been extensively used in biological and biomedical fields. The currently used methods for PCR data analysis, including the threshold cycle method and linear and nonlinear model-fitting methods, all require subtracting background fluorescence. However, the removal of background fluorescence can hardly be accurate and therefore can distort results. We propose a new method, the taking-difference linear regression method, to overcome this limitation. Briefly, for each two consecutive PCR cycles, we subtract the fluorescence in the former cycle from that in the latter cycle, transforming the n cycle raw data into n-1 cycle data. Then, linear regression is applied to the natural logarithm of the transformed data. Finally, PCR amplification efficiencies and the initial DNA molecular numbers are calculated for each reaction. This taking-difference method avoids the error in subtracting an unknown background, and thus it is more accurate and reliable. This method is easy to perform, and this strategy can be extended to all current methods for PCR data analysis.

  18. A Method for Quantitative Phase Analysis of Nanocrystalline Zirconium Dioxide Polymorphs.

    PubMed

    Zhou, Zhiqiang; Guo, Li

    2015-04-01

    A method based on X-ray diffractometry was developed for quantitative phase analysis of nanocrystalline zirconium dioxide polymorphs. Corresponding formulas were derived. The key factors therein were evaluated by rigorous theoretical calculation and fully verified by experimentation. A process of iteration was raised to make the experimental verification proceed in the case of lack of pure ZrO2 crystal polymorphs. By this method, the weight ratios of tetragonal ZrO2 (t-ZrO2) to monoclinic ZrO2 (m-ZrO2) in any a mixture that contains nanocrystalline t-ZrO2 and m-ZrO2 or their weight fractions in a mixture that is composed of nanocrystalline t-ZrO2 and m-ZrO2 can be determined only upon an XRD test. It is proved by both theoretical calculation and experimental test that mutual substitutions of t-ZrO2 and cubic ZrO2 (c-ZrO2) in a wide range show almost no impact on the XRD patterns of their mixtures. And plus the similarity in property of t-ZrO2 and c-ZrO2, they can be treated as one whole phase. The high agreement of the theoretical and experimental results in this work also proves the validity and reliability of the theoretical calculation based on X-ray diffractometry theory for such quantitative phase analysis. This method has the potential to be popularized to other materials.

  19. Quantitative analysis of uranium in aqueous solutions using a semiconductor laser-based spectroscopic method.

    PubMed

    Cho, Hye-Ryun; Jung, Euo Chang; Cha, Wansik; Song, Kyuseok

    2013-05-07

    A simple analytical method based on the simultaneous measurement of the luminescence of hexavalent uranium ions (U(VI)) and the Raman scattering of water, was investigated for determining the concentration of U(VI) in aqueous solutions. Both spectra were measured using a cw semiconductor laser beam at a center wavelength of 405 nm. The empirical calibration curve for the quantitative analysis of U(VI) was obtained by measuring the ratio of the luminescence intensity of U(VI) at 519 nm to the Raman scattering intensity of water at 469 nm. The limit of detection (LOD) in the parts per billion range and a dynamic range from the LOD up to several hundred parts per million were achieved. The concentration of uranium in groundwater determined by this method is in good agreement with the results determined by kinetic phosphorescence analysis and inductively coupled plasma mass spectrometry.

  20. Genetic programming:  a novel method for the quantitative analysis of pyrolysis mass spectral data.

    PubMed

    Gilbert, R J; Goodacre, R; Woodward, A M; Kell, D B

    1997-11-01

    A technique for the analysis of multivariate data by genetic programming (GP) is described, with particular reference to the quantitative analysis of orange juice adulteration data collected by pyrolysis mass spectrometry (PyMS). The dimensionality of the input space was reduced by ranking variables according to product moment correlation or mutual information with the outputs. The GP technique as described gives predictive errors equivalent to, if not better than, more widespread methods such as partial least squares and artificial neural networks but additionally can provide a means for easing the interpretation of the correlation between input and output variables. The described application demonstrates that by using the GP method for analyzing PyMS data the adulteration of orange juice with 10% sucrose solution can be quantified reliably over a 0-20% range with an RMS error in the estimate of ∼1%.

  1. Evaluate the Impact of your Education and Outreach Program Using the Quantitative Collaborative Impact Analysis Method

    NASA Astrophysics Data System (ADS)

    Scalice, D.; Davis, H. B.

    2015-12-01

    The AGU scientific community has a strong motivation to improve the STEM knowledge and skills of today's youth, and we are dedicating increasing amounts of our time and energy to education and outreach work. Scientists and educational project leads can benefit from a deeper connection to the value of evaluation, how to work with an evaluator, and how to effectively integrate evaluation into projects to increase their impact. This talk will introduce a method for evaluating educational activities, including public talks, professional development workshops for educators, youth engagement programs, and more. We will discuss the impetus for developing this method--the Quantitative Collaborative Impact Analysis Method--how it works, and the successes we've had with it in the NASA Astrobiology education community.

  2. Quantitative Analysis of Single Amino Acid Variant Peptides Associated with Pancreatic Cancer in Serum by an Isobaric Labeling Quantitative Method

    PubMed Central

    2015-01-01

    Single amino acid variations are highly associated with many human diseases. The direct detection of peptides containing single amino acid variants (SAAVs) derived from nonsynonymous single nucleotide polymorphisms (SNPs) in serum can provide unique opportunities for SAAV associated biomarker discovery. In the present study, an isobaric labeling quantitative strategy was applied to identify and quantify variant peptides in serum samples of pancreatic cancer patients and other benign controls. The largest number of SAAV peptides to date in serum including 96 unique variant peptides were quantified in this quantitative analysis, of which five variant peptides showed a statistically significant difference between pancreatic cancer and other controls (p-value < 0.05). Significant differences in the variant peptide SDNCEDTPEAGYFAVAVVK from serotransferrin were detected between pancreatic cancer and controls, which was further validated by selected reaction monitoring (SRM) analysis. The novel biomarker panel obtained by combining α-1-antichymotrypsin (AACT), Thrombospondin-1 (THBS1) and this variant peptide showed an excellent diagnostic performance in discriminating pancreatic cancer from healthy controls (AUC = 0.98) and chronic pancreatitis (AUC = 0.90). These results suggest that large-scale analysis of SAAV peptides in serum may provide a new direction for biomarker discovery research. PMID:25393578

  3. A method for rapid quantitative assessment of biofilms with biomolecular staining and image analysis

    DOE PAGES

    Larimer, Curtis J.; Winder, Eric M.; Jeters, Robert T.; ...

    2015-12-07

    Here, the accumulation of bacteria in surface attached biofilms, or biofouling, can be detrimental to human health, dental hygiene, and many industrial processes. A critical need in identifying and preventing the deleterious effects of biofilms is the ability to observe and quantify their development. Analytical methods capable of assessing early stage fouling are cumbersome or lab-confined, subjective, and qualitative. Herein, a novel photographic method is described that uses biomolecular staining and image analysis to enhance contrast of early stage biofouling. A robust algorithm was developed to objectively and quantitatively measure surface accumulation of Pseudomonas putida from photographs and results weremore » compared to independent measurements of cell density. Results from image analysis quantified biofilm growth intensity accurately and with approximately the same precision of the more laborious cell counting method. This simple method for early stage biofilm detection enables quantifiable measurement of surface fouling and is flexible enough to be applied from the laboratory to the field. Broad spectrum staining highlights fouling biomass, photography quickly captures a large area of interest, and image analysis rapidly quantifies fouling in the image.« less

  4. A method for rapid quantitative assessment of biofilms with biomolecular staining and image analysis

    SciTech Connect

    Larimer, Curtis J.; Winder, Eric M.; Jeters, Robert T.; Prowant, Matthew S.; Nettleship, Ian; Addleman, Raymond S.; Bonheyo, George T.

    2015-12-07

    Here, the accumulation of bacteria in surface attached biofilms, or biofouling, can be detrimental to human health, dental hygiene, and many industrial processes. A critical need in identifying and preventing the deleterious effects of biofilms is the ability to observe and quantify their development. Analytical methods capable of assessing early stage fouling are cumbersome or lab-confined, subjective, and qualitative. Herein, a novel photographic method is described that uses biomolecular staining and image analysis to enhance contrast of early stage biofouling. A robust algorithm was developed to objectively and quantitatively measure surface accumulation of Pseudomonas putida from photographs and results were compared to independent measurements of cell density. Results from image analysis quantified biofilm growth intensity accurately and with approximately the same precision of the more laborious cell counting method. This simple method for early stage biofilm detection enables quantifiable measurement of surface fouling and is flexible enough to be applied from the laboratory to the field. Broad spectrum staining highlights fouling biomass, photography quickly captures a large area of interest, and image analysis rapidly quantifies fouling in the image.

  5. Quantitative Analysis of Intra-chromosomal Contacts: The 3C-qPCR Method.

    PubMed

    Ea, Vuthy; Court, Franck; Forné, Thierry

    2017-01-01

    The chromosome conformation capture (3C) technique is fundamental to many population-based methods investigating chromatin dynamics and organization in eukaryotes. Here, we provide a modified quantitative 3C (3C-qPCR) protocol for improved quantitative analyses of intra-chromosomal contacts. We also describe an algorithm for data normalization which allows more accurate comparisons between contact profiles.

  6. Quantitative Analysis of Differential Proteome Expression in Bladder Cancer vs. Normal Bladder Cells Using SILAC Method

    PubMed Central

    Yang, Ganglong; Xu, Zhipeng; Lu, Wei; Li, Xiang; Sun, Chengwen; Guo, Jia; Xue, Peng; Guan, Feng

    2015-01-01

    The best way to increase patient survival rate is to identify patients who are likely to progress to muscle-invasive or metastatic disease upfront and treat them more aggressively. The human cell lines HCV29 (normal bladder epithelia), KK47 (low grade nonmuscle invasive bladder cancer, NMIBC), and YTS1 (metastatic bladder cancer) have been widely used in studies of molecular mechanisms and cell signaling during bladder cancer (BC) progression. However, little attention has been paid to global quantitative proteome analysis of these three cell lines. We labeled HCV29, KK47, and YTS1 cells by the SILAC method using three stable isotopes each of arginine and lysine. Labeled proteins were analyzed by 2D ultrahigh-resolution liquid chromatography LTQ Orbitrap mass spectrometry. Among 3721 unique identified and annotated proteins in KK47 and YTS1 cells, 36 were significantly upregulated and 74 were significantly downregulated with >95% confidence. Differential expression of these proteins was confirmed by western blotting, quantitative RT-PCR, and cell staining with specific antibodies. Gene ontology (GO) term and pathway analysis indicated that the differentially regulated proteins were involved in DNA replication and molecular transport, cell growth and proliferation, cellular movement, immune cell trafficking, and cell death and survival. These proteins and the advanced proteome techniques described here will be useful for further elucidation of molecular mechanisms in BC and other types of cancer. PMID:26230496

  7. Radioisotopic neutron transmission spectrometry: Quantitative analysis by using partial least-squares method.

    PubMed

    Kim, Jong-Yun; Choi, Yong Suk; Park, Yong Joon; Jung, Sung-Hee

    2009-01-01

    Neutron spectrometry, based on the scattering of high energy fast neutrons from a radioisotope and slowing-down by the light hydrogen atoms, is a useful technique for non-destructive, quantitative measurement of hydrogen content because it has a large measuring volume, and is not affected by temperature, pressure, pH value and color. The most common choice for radioisotope neutron source is (252)Cf or (241)Am-Be. In this study, (252)Cf with a neutron flux of 6.3x10(6)n/s has been used as an attractive neutron source because of its high flux neutron and weak radioactivity. Pulse-height neutron spectra have been obtained by using in-house built radioisotopic neutron spectrometric system equipped with (3)He detector and multi-channel analyzer, including a neutron shield. As a preliminary study, polyethylene block (density of approximately 0.947g/cc and area of 40cmx25cm) was used for the determination of hydrogen content by using multivariate calibration models, depending on the thickness of the block. Compared with the results obtained from a simple linear calibration model, partial least-squares regression (PLSR) method offered a better performance in a quantitative data analysis. It also revealed that the PLSR method in a neutron spectrometric system can be promising in the real-time, online monitoring of the powder process to determine the content of any type of molecules containing hydrogen nuclei.

  8. A method for rapid quantitative assessment of biofilms with biomolecular staining and image analysis.

    PubMed

    Larimer, Curtis; Winder, Eric; Jeters, Robert; Prowant, Matthew; Nettleship, Ian; Addleman, Raymond Shane; Bonheyo, George T

    2016-01-01

    The accumulation of bacteria in surface-attached biofilms can be detrimental to human health, dental hygiene, and many industrial processes. Natural biofilms are soft and often transparent, and they have heterogeneous biological composition and structure over micro- and macroscales. As a result, it is challenging to quantify the spatial distribution and overall intensity of biofilms. In this work, a new method was developed to enhance the visibility and quantification of bacterial biofilms. First, broad-spectrum biomolecular staining was used to enhance the visibility of the cells, nucleic acids, and proteins that make up biofilms. Then, an image analysis algorithm was developed to objectively and quantitatively measure biofilm accumulation from digital photographs and results were compared to independent measurements of cell density. This new method was used to quantify the growth intensity of Pseudomonas putida biofilms as they grew over time. This method is simple and fast, and can quantify biofilm growth over a large area with approximately the same precision as the more laborious cell counting method. Stained and processed images facilitate assessment of spatial heterogeneity of a biofilm across a surface. This new approach to biofilm analysis could be applied in studies of natural, industrial, and environmental biofilms.

  9. Quantitative analysis of eugenol in clove extract by a validated HPLC method.

    PubMed

    Yun, So-Mi; Lee, Myoung-Heon; Lee, Kwang-Jick; Ku, Hyun-Ok; Son, Seong-Wan; Joo, Yi-Seok

    2010-01-01

    Clove (Eugenia caryophyllata) is a well-known medicinal plant used for diarrhea, digestive disorders, or in antiseptics in Korea. Eugenol is the main active ingredient of clove and has been chosen as a marker compound for the chemical evaluation or QC of clove. This paper reports the development and validation of an HPLC-diode array detection (DAD) method for the determination of eugenol in clove. HPLC separation was accomplished on an XTerra RP18 column (250 x 4.6 mm id, 5 microm) with an isocratic mobile phase of 60% methanol and DAD at 280 nm. Calibration graphs were linear with very good correlation coefficients (r2 > 0.9999) from 12.5 to 1000 ng/mL. The LOD was 0.81 and the LOQ was 2.47 ng/mL. The method showed good intraday precision (%RSD 0.08-0.27%) and interday precision (%RSD 0.32-1.19%). The method was applied to the analysis of eugenol from clove cultivated in various countries (Indonesia, Singapore, and China). Quantitative analysis of the 15 clove samples showed that the content of eugenol varied significantly, ranging from 163 to 1049 ppb. The method of determination of eugenol by HPLC is accurate to evaluate the quality and safety assurance of clove, based on the results of this study.

  10. Rapid quantitative analysis of lipids using a colorimetric method in a microplate format.

    PubMed

    Cheng, Yu-Shen; Zheng, Yi; VanderGheynst, Jean S

    2011-01-01

    A colorimetric sulfo-phospho-vanillin (SPV) method was developed for high throughput analysis of total lipids. The developed method uses a reaction mixture that is maintained in a 96-well microplate throughout the entire assay. The new assay provides the following advantages over other methods of lipid measurement: (1) background absorbance can be easily corrected for each well, (2) there is less risk of handling and transferring sulfuric acid contained in reaction mixtures, (3) color develops more consistently providing more accurate measurement of absorbance, and (4) the assay can be used for quantitative measurement of lipids extracted from a wide variety of sources. Unlike other spectrophotometric approaches that use fluorescent dyes, the optimal spectra and reaction conditions for the developed assay do not vary with the sample source. The developed method was used to measure lipids in extracts from four strains of microalgae. No significant difference was found in lipid determination when lipid content was measured using the new method and compared to results obtained using a macro-gravimetric method.

  11. Membrane chromatographic immunoassay method for rapid quantitative analysis of specific serum antibodies.

    PubMed

    Ghosh, Raja

    2006-02-05

    This paper discusses a membrane chromatographic immunoassay method for rapid detection and quantitative analysis of specific serum antibodies. A type of polyvinylidine fluoride (PVDF) microfiltration membrane was used in the method for its ability to reversibly and specifically bind IgG antibodies from antiserum samples by hydrophobic interaction. Using this form of selective antibody binding and enrichment an affinity membrane with antigen binding ability was obtained in-situ. This was done by passing a pulse of diluted antiserum sample through a stack of microporous PVDF membranes. The affinity membrane thus formed was challenged with a pulse of antigen solution and the amount of antigen bound was accurately determined using chromatographic methods. The antigen binding correlated well with the antibody loading on the membrane. This method is direct, rapid and accurate, does not involve any chemical reaction, and uses very few reagents. Moreover, the same membrane could be repeatedly used for sequential immunoassays on account of the reversible nature of the antibody binding. Proof of concept of this method is provided using human hemoglobin as model antigen and rabbit antiserum against human hemoglobin as the antibody source.

  12. Quantitatively estimating defects in graphene devices using discharge current analysis method

    PubMed Central

    Jung, Ukjin; Lee, Young Gon; Kang, Chang Goo; Lee, Sangchul; Kim, Jin Ju; Hwang, Hyeon June; Lim, Sung Kwan; Ham, Moon-Ho; Lee, Byoung Hun

    2014-01-01

    Defects of graphene are the most important concern for the successful applications of graphene since they affect device performance significantly. However, once the graphene is integrated in the device structures, the quality of graphene and surrounding environment could only be assessed using indirect information such as hysteresis, mobility and drive current. Here we develop a discharge current analysis method to measure the quality of graphene integrated in a field effect transistor structure by analyzing the discharge current and examine its validity using various device structures. The density of charging sites affecting the performance of graphene field effect transistor obtained using the discharge current analysis method was on the order of 1014/cm2, which closely correlates with the intensity ratio of the D to G bands in Raman spectroscopy. The graphene FETs fabricated on poly(ethylene naphthalate) (PEN) are found to have a lower density of charging sites than those on SiO2/Si substrate, mainly due to reduced interfacial interaction between the graphene and the PEN. This method can be an indispensable means to improve the stability of devices using a graphene as it provides an accurate and quantitative way to define the quality of graphene after the device fabrication. PMID:24811431

  13. Quantitatively estimating defects in graphene devices using discharge current analysis method.

    PubMed

    Jung, Ukjin; Lee, Young Gon; Kang, Chang Goo; Lee, Sangchul; Kim, Jin Ju; Hwang, Hyeon June; Lim, Sung Kwan; Ham, Moon-Ho; Lee, Byoung Hun

    2014-05-08

    Defects of graphene are the most important concern for the successful applications of graphene since they affect device performance significantly. However, once the graphene is integrated in the device structures, the quality of graphene and surrounding environment could only be assessed using indirect information such as hysteresis, mobility and drive current. Here we develop a discharge current analysis method to measure the quality of graphene integrated in a field effect transistor structure by analyzing the discharge current and examine its validity using various device structures. The density of charging sites affecting the performance of graphene field effect transistor obtained using the discharge current analysis method was on the order of 10(14)/cm(2), which closely correlates with the intensity ratio of the D to G bands in Raman spectroscopy. The graphene FETs fabricated on poly(ethylene naphthalate) (PEN) are found to have a lower density of charging sites than those on SiO2/Si substrate, mainly due to reduced interfacial interaction between the graphene and the PEN. This method can be an indispensable means to improve the stability of devices using a graphene as it provides an accurate and quantitative way to define the quality of graphene after the device fabrication.

  14. Quantitatively estimating defects in graphene devices using discharge current analysis method

    NASA Astrophysics Data System (ADS)

    Jung, Ukjin; Lee, Young Gon; Kang, Chang Goo; Lee, Sangchul; Kim, Jin Ju; Hwang, Hyeon June; Lim, Sung Kwan; Ham, Moon-Ho; Lee, Byoung Hun

    2014-05-01

    Defects of graphene are the most important concern for the successful applications of graphene since they affect device performance significantly. However, once the graphene is integrated in the device structures, the quality of graphene and surrounding environment could only be assessed using indirect information such as hysteresis, mobility and drive current. Here we develop a discharge current analysis method to measure the quality of graphene integrated in a field effect transistor structure by analyzing the discharge current and examine its validity using various device structures. The density of charging sites affecting the performance of graphene field effect transistor obtained using the discharge current analysis method was on the order of 1014/cm2, which closely correlates with the intensity ratio of the D to G bands in Raman spectroscopy. The graphene FETs fabricated on poly(ethylene naphthalate) (PEN) are found to have a lower density of charging sites than those on SiO2/Si substrate, mainly due to reduced interfacial interaction between the graphene and the PEN. This method can be an indispensable means to improve the stability of devices using a graphene as it provides an accurate and quantitative way to define the quality of graphene after the device fabrication.

  15. [Quantitative analysis method of natural gas combustion process combining wavelength selection and outlier spectra detection].

    PubMed

    Cao, Hui; Hu, Luo-Na; Zhou, Yan

    2012-10-01

    The present paper uses a combination method of wavelength selection and outlier spectra detection for quantitative analysis of nature gas combustion process based on its near infrared spectra. According to the statistical distribution of partial least squares (PLS) model coefficients and prediction errors, the method realized wavelength selection and outlier spectra detection, respectively. In contrast with PLS, PLS after leave-one-out for outlier detection (LOO-PLS), uninformative variable elimination by PLS (UVE-PLS) and UVE-PLS after leave-one-out for outlier detection (LOO-UVE-PLS), the root-mean-squared error of prediction (RMSEP) based on the method for CH4 prediction model is reduced by 14.33%, 14.33%, 10.96% and 12.21%; the RMSEP value for CO prediction model is reduced by 67.26%, 72.58%, 11.32% and 4.52%; the RMSEP value for CO2 prediction model is reduced by 5.95%, 19.7%, 36.71% and 4.04% respectively. Experimental results demonstrate that the method can significantly decrease the number of selected wavelengths, reduce model complexity and effectively detect outlier spectra. The established prediction model of analytes is more accurate as well as robust.

  16. Nanoparticle-mediated photothermal effect enables a new method for quantitative biochemical analysis using a thermometer.

    PubMed

    Fu, Guanglei; Sanjay, Sharma T; Dou, Maowei; Li, XiuJun

    2016-03-14

    A new biomolecular quantitation method, nanoparticle-mediated photothermal bioassay, using a common thermometer as the signal reader was developed. Using an immunoassay as a proof of concept, iron oxide nanoparticles (NPs) captured in the sandwich-type assay system were transformed into a near-infrared (NIR) laser-driven photothermal agent, Prussian blue (PB) NPs, which acted as a photothermal probe to convert the assay signal into heat through the photothermal effect, thus allowing sensitive biomolecular quantitation using a thermometer. This is the first report of biomolecular quantitation using a thermometer and also serves as the first attempt to introduce the nanoparticle-mediated photothermal effect for bioassays.

  17. Quantitative analysis of collagen change between normal and cancerous thyroid tissues based on SHG method

    NASA Astrophysics Data System (ADS)

    Chen, Xiwen; Huang, Zufang; Xi, Gangqin; Chen, Yongjian; Lin, Duo; Wang, Jing; Li, Zuanfang; Sun, Liqing; Chen, Jianxin; Chen, Rong

    2012-03-01

    Second-harmonic generation (SHG) is proved to be a high spatial resolution, large penetration depth and non-photobleaching method. In our study, SHG method was used to investigate the normal and cancerous thyroid tissue. For SHG imaging performance, system parameters were adjusted for high-contrast images acquisition. Each x-y image was recorded in pseudo-color, which matches the wavelength range in the visible spectrum. The acquisition time for a 512×512-pixels image was 1.57 sec; each acquired image was averaged four frames to improve the signal-to-noise ratio. Our results indicated that collagen presence as determined by counting the ratio of the SHG pixels over the whole pixels for normal and cancerous thyroid tissues were 0.48+/-0.05, 0.33+/-0.06 respectively. In addition, to quantitatively assess collagen-related changes, we employed GLCM texture analysis to the SHG images. Corresponding results showed that the correlation both fell off with distance in normal and cancerous group. Calculated value of Corr50 (the distance where the correlation crossed 50% of the initial correlation) indicated significant difference. This study demonstrates that SHG method can be used as a complementary tool in thyroid histopathology.

  18. Quantitative analysis of collagen change between normal and cancerous thyroid tissues based on SHG method

    NASA Astrophysics Data System (ADS)

    Chen, Xiwen; Huang, Zufang; Xi, Gangqin; Chen, Yongjian; Lin, Duo; Wang, Jing; Li, Zuanfang; Sun, Liqing; Chen, Jianxin; Chen, Rong

    2011-11-01

    Second-harmonic generation (SHG) is proved to be a high spatial resolution, large penetration depth and non-photobleaching method. In our study, SHG method was used to investigate the normal and cancerous thyroid tissue. For SHG imaging performance, system parameters were adjusted for high-contrast images acquisition. Each x-y image was recorded in pseudo-color, which matches the wavelength range in the visible spectrum. The acquisition time for a 512×512-pixels image was 1.57 sec; each acquired image was averaged four frames to improve the signal-to-noise ratio. Our results indicated that collagen presence as determined by counting the ratio of the SHG pixels over the whole pixels for normal and cancerous thyroid tissues were 0.48+/-0.05, 0.33+/-0.06 respectively. In addition, to quantitatively assess collagen-related changes, we employed GLCM texture analysis to the SHG images. Corresponding results showed that the correlation both fell off with distance in normal and cancerous group. Calculated value of Corr50 (the distance where the correlation crossed 50% of the initial correlation) indicated significant difference. This study demonstrates that SHG method can be used as a complementary tool in thyroid histopathology.

  19. A method for quantitative analysis of spatially variable physiological processes across leaf surfaces.

    PubMed

    Aldea, Mihai; Frank, Thomas D; DeLucia, Evan H

    2006-11-01

    Many physiological processes are spatially variable across leaf surfaces. While maps of photosynthesis, stomatal conductance, gene expression, water transport, and the production of reactive oxygen species (ROS) for individual leaves are readily obtained, analytical methods for quantifying spatial heterogeneity and combining information gathered from the same leaf but with different instruments are not widely used. We present a novel application of tools from the field of geographical imaging to the multivariate analysis of physiological images. Procedures for registration and resampling, cluster analysis, and classification provide a general framework for the analysis of spatially resolved physiological data. Two experiments were conducted to illustrate the utility of this approach. Quantitative analysis of images of chlorophyll fluorescence and the production of ROS following simultaneous exposure of soybean leaves to atmospheric O3 and soybean mosaic virus revealed that areas of the leaf where the operating quantum efficiency of PSII was depressed also experienced an accumulation of ROS. This correlation suggests a causal relationship between oxidative stress and inhibition of photosynthesis. Overlaying maps of leaf surface temperature and chlorophyll fluorescence following a photoinhibition treatment indicated that areas with low operating quantum efficiency of PSII also experienced reduced stomatal conductance (high temperature). While each of these experiments explored the covariance of two processes by overlaying independent images gathered with different instruments, the same procedures can be used to analyze the covariance of information from multiple images. The application of tools from geographic image analysis to physiological processes occurring over small spatial scales will help reveal the mechanisms generating spatial variation across leaves.

  20. Quantitative GSL-glycome analysis of human whole serum based on an EGCase digestion and glycoblotting method[S

    PubMed Central

    Furukawa, Jun-ichi; Sakai, Shota; Yokota, Ikuko; Okada, Kazue; Hanamatsu, Hisatoshi; Kobayashi, Takashi; Yoshida, Yasunobu; Higashino, Kenichi; Tamura, Tomohiro; Igarashi, Yasuyuki; Shinohara, Yasuro

    2015-01-01

    Glycosphingolipids (GSLs) are lipid molecules linked to carbohydrate units that form the plasma membrane lipid raft, which is clustered with sphingolipids, sterols, and specific proteins, and thereby contributes to membrane physical properties and specific recognition sites for various biological events. These bioactive GSL molecules consequently affect the pathophysiology and pathogenesis of various diseases. Thus, altered expression of GSLs in various diseases may be of importance for disease-related biomarker discovery. However, analysis of GSLs in blood is particularly challenging because GSLs are present at extremely low concentrations in serum/plasma. In this study, we established absolute GSL-glycan analysis of human serum based on endoglycoceramidase digestion and glycoblotting purification. We established two sample preparation protocols, one with and the other without GSL extraction using chloroform/methanol. Similar amounts of GSL-glycans were recovered with the two protocols. Both protocols permitted absolute quantitation of GSL-glycans using as little as 20 μl of serum. Using 10 healthy human serum samples, up to 42 signals corresponding to GSL-glycan compositions could be quantitatively detected, and the total serum GSL-glycan concentration was calculated to be 12.1–21.4 μM. We further applied this method to TLC-prefractionated serum samples. These findings will assist the discovery of disease-related biomarkers by serum GSL-glycomics. PMID:26420879

  1. Quantitative Techniques in Volumetric Analysis

    NASA Astrophysics Data System (ADS)

    Zimmerman, John; Jacobsen, Jerrold J.

    1996-12-01

    Quantitative Techniques in Volumetric Analysis is a visual library of techniques used in making volumetric measurements. This 40-minute VHS videotape is designed as a resource for introducing students to proper volumetric methods and procedures. The entire tape, or relevant segments of the tape, can also be used to review procedures used in subsequent experiments that rely on the traditional art of quantitative analysis laboratory practice. The techniques included are: Quantitative transfer of a solid with a weighing spoon Quantitative transfer of a solid with a finger held weighing bottle Quantitative transfer of a solid with a paper strap held bottle Quantitative transfer of a solid with a spatula Examples of common quantitative weighing errors Quantitative transfer of a solid from dish to beaker to volumetric flask Quantitative transfer of a solid from dish to volumetric flask Volumetric transfer pipet A complete acid-base titration Hand technique variations The conventional view of contemporary quantitative chemical measurement tends to focus on instrumental systems, computers, and robotics. In this view, the analyst is relegated to placing standards and samples on a tray. A robotic arm delivers a sample to the analysis center, while a computer controls the analysis conditions and records the results. In spite of this, it is rare to find an analysis process that does not rely on some aspect of more traditional quantitative analysis techniques, such as careful dilution to the mark of a volumetric flask. Figure 2. Transfer of a solid with a spatula. Clearly, errors in a classical step will affect the quality of the final analysis. Because of this, it is still important for students to master the key elements of the traditional art of quantitative chemical analysis laboratory practice. Some aspects of chemical analysis, like careful rinsing to insure quantitative transfer, are often an automated part of an instrumental process that must be understood by the

  2. Recommended Methods for Brain Processing and Quantitative Analysis in Rodent Developmental Neurotoxicity Studies.

    PubMed

    Garman, Robert H; Li, Abby A; Kaufmann, Wolfgang; Auer, Roland N; Bolon, Brad

    2016-01-01

    Neuropathology methods in rodent developmental neurotoxicity (DNT) studies have evolved with experience and changing regulatory guidance. This article emphasizes principles and methods to promote more standardized DNT neuropathology evaluation, particularly procurement of highly homologous brain sections and collection of the most reproducible morphometric measurements. To minimize bias, brains from all animals at all dose levels should be processed from brain weighing through paraffin embedding at one time using a counterbalanced design. Morphometric measurements should be anchored by distinct neuroanatomic landmarks that can be identified reliably on the faced block or in unstained sections and which address the region-specific circuitry of the measured area. Common test article-related qualitative changes in the developing brain include abnormal cell numbers (yielding altered regional size), displaced cells (ectopia and heterotopia), and/or aberrant differentiation (indicated by defective myelination or synaptogenesis), but rarely glial or inflammatory reactions. Inclusion of digital images in the DNT pathology raw data provides confidence that the quantitative analysis was done on anatomically matched (i.e., highly homologous) sections. Interpreting DNT neuropathology data and their presumptive correlation with neurobehavioral data requires an integrative weight-of-evidence approach including consideration of maternal toxicity, body weight, brain weight, and the pattern of findings across brain regions, doses, sexes, and ages.

  3. Quantitative environmental risk analysis

    SciTech Connect

    Klovning, J.; Nilsen, E.F.

    1995-12-31

    According to regulations relating to implementation and rise of risk analysis in the petroleum activities issued by the Norwegian Petroleum Directorate, it is mandatory for an operator on the Norwegian Continental Shelf to establish acceptance criteria for environmental risk in the activities and carry out environmental risk analysis. This paper presents a {open_quotes}new{close_quotes} method for environmental risk analysis developed by the company. The objective has been to assist the company to meet rules and regulations and to assess and describe the environmental risk in a systematic manner. In the environmental risk analysis the most sensitive biological resource in the affected area is used to assess the environmental damage. The analytical method is based on the methodology for quantitative risk analysis related to loss of life. In addition it incorporates the effect of seasonal fluctuations in the environmental risk evaluations. The paper is describing the function of the main analytical sequences exemplified through an analysis of environmental risk related to exploration drilling in an environmental sensitive area on the Norwegian Continental Shelf.

  4. Quantitative Analysis of Organic Compounds: A Simple and Rapid Method for Use in Schools

    ERIC Educational Resources Information Center

    Schmidt, Hans-Jurgen

    1973-01-01

    Describes the procedure for making a quantitative analysis of organic compounds suitable for secondary school chemistry classes. Using the Schoniger procedure, the organic compound, such as PVC, is decomposed in a conical flask with oxygen. The products are absorbed in a suitable liquid and analyzed by titration. (JR)

  5. A method for the rapid qualitative and quantitative analysis of 4,4-dimethyl sterols.

    PubMed

    Gibbons, G F; Mitropoulos, K A; Ramananda, K

    1973-09-01

    A simple and relatively rapid technique has been developed for the separation of several 4,4-dimethyl steryl acetates, some of which contain sterically hindered nuclear double bonds. The method involves thin-layer chromatography on silver nitrate-impregnated silica gel and silver nitrate-impregnated alumina. The separated steryl acetates may then be analyzed quantitatively by gas-liquid chromatography.

  6. Quantitative and chemical fingerprint analysis for quality control of rhizoma Coptidischinensis based on UPLC-PAD combined with chemometrics methods.

    PubMed

    Kong, Wei-Jun; Zhao, Yan-Ling; Xiao, Xiao-He; Jin, Cheng; Li, Zu-Lun

    2009-10-01

    To control the quality of rhizoma Coptidis, a method based on ultra performance liquid chromatography with photodiode array detector (UPLC-PAD) was developed for quantitative analysis of five active alkaloids and chemical fingerprint analysis. In quantitative analysis, the five alkaloids showed good regression (R > 0.9992) within test ranges and the recovery of the method was in the range of 98.4-100.8%. The limit of detections and quantifications for five alkaloids in PAD were less than 0.07 and 0.22 microg/ml, respectively. In order to compare the UPLC fingerprints between rhizoma Coptidis from different origins, the chemometrics procedures, including similarity analysis (SA), hierarchical clustering analysis (HCA), principal component analysis (PCA) were applied to classify the rhizoma Coptidis samples according to their cultivated origins. Consistent results were obtained to show that rhizoma Coptidis samples could be successfully grouped in accordance with the province of origin. Furthermore, five marker constituents were screened out to be the main chemical marker, which could be applied to accurate discrimination and quality control for rhizoma Coptidis by quantitative analysis. This study revealed that UPLC-PAD method was simple, sensitive and reliable for quantitative and chemical fingerprint analysis, moreover, for the quality evaluation and control of rhizoma Coptidis.

  7. Analytical methods in sphingolipidomics: Quantitative and profiling approaches in food analysis.

    PubMed

    Canela, Núria; Herrero, Pol; Mariné, Sílvia; Nadal, Pedro; Ras, Maria Rosa; Rodríguez, Miguel Ángel; Arola, Lluís

    2016-01-08

    In recent years, sphingolipidomics has emerged as an interesting omic science that encompasses the study of the full sphingolipidome characterization, content, structure and activity in cells, tissues or organisms. Like other omics, it has the potential to impact biomarker discovery, drug development and systems biology knowledge. Concretely, dietary food sphingolipids have gained considerable importance due to their extensively reported bioactivity. Because of the complexity of this lipid family and their diversity among foods, powerful analytical methodologies are needed for their study. The analytical tools developed in the past have been improved with the enormous advances made in recent years in mass spectrometry (MS) and chromatography, which allow the convenient and sensitive identification and quantitation of sphingolipid classes and form the basis of current sphingolipidomics methodologies. In addition, novel hyphenated nuclear magnetic resonance (NMR) strategies, new ionization strategies, and MS imaging are outlined as promising technologies to shape the future of sphingolipid analyses. This review traces the analytical methods of sphingolipidomics in food analysis concerning sample extraction, chromatographic separation, the identification and quantification of sphingolipids by MS and their structural elucidation by NMR.

  8. Nanoparticle-mediated photothermal effect enables a new method for quantitative biochemical analysis using a thermometer

    NASA Astrophysics Data System (ADS)

    Fu, Guanglei; Sanjay, Sharma T.; Dou, Maowei; Li, Xiujun

    2016-03-01

    A new biomolecular quantitation method, nanoparticle-mediated photothermal bioassay, using a common thermometer as the signal reader was developed. Using an immunoassay as a proof of concept, iron oxide nanoparticles (NPs) captured in the sandwich-type assay system were transformed into a near-infrared (NIR) laser-driven photothermal agent, Prussian blue (PB) NPs, which acted as a photothermal probe to convert the assay signal into heat through the photothermal effect, thus allowing sensitive biomolecular quantitation using a thermometer. This is the first report of biomolecular quantitation using a thermometer and also serves as the first attempt to introduce the nanoparticle-mediated photothermal effect for bioassays.A new biomolecular quantitation method, nanoparticle-mediated photothermal bioassay, using a common thermometer as the signal reader was developed. Using an immunoassay as a proof of concept, iron oxide nanoparticles (NPs) captured in the sandwich-type assay system were transformed into a near-infrared (NIR) laser-driven photothermal agent, Prussian blue (PB) NPs, which acted as a photothermal probe to convert the assay signal into heat through the photothermal effect, thus allowing sensitive biomolecular quantitation using a thermometer. This is the first report of biomolecular quantitation using a thermometer and also serves as the first attempt to introduce the nanoparticle-mediated photothermal effect for bioassays. Electronic supplementary information (ESI) available: Additional information on FTIR characterization (Fig. S1), photothermal immunoassay of PSA in human serum samples (Table S1), and the Experimental section, including preparation of antibody-conjugated iron oxide NPs, sandwich-type immunoassay, characterization, and photothermal detection protocol. See DOI: 10.1039/c5nr09051b

  9. Integrated Geophysical Methods Applied to Geotechnical and Geohazard Engineering: From Qualitative to Quantitative Analysis and Interpretation

    NASA Astrophysics Data System (ADS)

    Hayashi, K.

    2014-12-01

    The Near-Surface is a region of day-to-day human activity on the earth. It is exposed to the natural phenomena which sometimes cause disasters. This presentation covers a broad spectrum of the geotechnical and geohazard ways of mitigating disaster and conserving the natural environment using geophysical methods and emphasizes the contribution of geophysics to such issues. The presentation focusses on the usefulness of geophysical surveys in providing information to mitigate disasters, rather than the theoretical details of a particular technique. Several techniques are introduced at the level of concept and application. Topics include various geohazard and geoenvironmental applications, such as for earthquake disaster mitigation, preventing floods triggered by tremendous rain, for environmental conservation and studying the effect of global warming. Among the geophysical techniques, the active and passive surface wave, refraction and resistivity methods are mainly highlighted. Together with the geophysical techniques, several related issues, such as performance-based design, standardization or regularization, internet access and databases are also discussed. The presentation discusses the application of geophysical methods to engineering investigations from non-uniqueness point of view and introduces the concepts of integrated and quantitative. Most geophysical analyses are essentially non-unique and it is very difficult to obtain unique and reliable engineering solutions from only one geophysical method (Fig. 1). The only practical way to improve the reliability of investigation is the joint use of several geophysical and geotechnical investigation methods, an integrated approach to geophysics. The result of a geophysical method is generally vague, here is a high-velocity layer, it may be bed rock, this low resistivity section may contain clayey soils. Such vague, qualitative and subjective interpretation is not worthwhile on general engineering design works

  10. Defining the knee joint flexion-extension axis for purposes of quantitative gait analysis: an evaluation of methods.

    PubMed

    Schache, Anthony G; Baker, Richard; Lamoreux, Larry W

    2006-08-01

    Minimising measurement variability associated with hip axial rotation and avoiding knee joint angle cross-talk are two fundamental objectives of any method used to define the knee joint flexion-extension axis for purposes of quantitative gait analysis. The aim of this experiment was to compare three different methods of defining this axis: the knee alignment device (KAD) method, a method based on the transepicondylar axis (TEA) and an alternative numerical method (Dynamic). The former two methods are common approaches that have been applied clinically in many quantitative gait analysis laboratories; the latter is an optimisation procedure. A cohort of 20 subjects performed three different functional tasks (normal gait; squat; non-weight bearing knee flexion) on repeated occasions. Three-dimensional hip and knee angles were computed using the three alternative methods of defining the knee joint flexion-extension axis. The repeatability of hip axial rotation measurements during normal gait was found to be significantly better for the Dynamic method (p<0.01). Furthermore, both the variance in the knee varus-valgus kinematic profile and the degree of knee joint angle cross-talk were smallest for the Dynamic method across all functional tasks. The Dynamic method therefore provided superior results in comparison to the KAD and TEA-based methods and thus represents an attractive solution for orientating the knee joint flexion-extension axis for purposes of quantitative gait analysis.

  11. Quantitative methods for genome-scale analysis of in situ hybridization and correlation with microarray data

    PubMed Central

    Lee, Chang-Kyu; Sunkin, Susan M; Kuan, Chihchau; Thompson, Carol L; Pathak, Sayan; Ng, Lydia; Lau, Chris; Fischer, Shanna; Mortrud, Marty; Slaughterbeck, Cliff; Jones, Allan; Lein, Ed; Hawrylycz, Michael

    2008-01-01

    With the emergence of genome-wide colorimetric in situ hybridization (ISH) data sets such as the Allen Brain Atlas, it is important to understand the relationship between this gene expression modality and those derived from more quantitative based technologies. This study introduces a novel method for standardized relative quantification of colorimetric ISH signal that enables a large-scale cross-platform expression level comparison of ISH with two publicly available microarray brain data sources. PMID:18234097

  12. Multivariate Quantitative Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Kinchen, David G.; Capezza, Mary

    1995-01-01

    Technique of multivariate quantitative chemical analysis devised for use in determining relative proportions of two components mixed and sprayed together onto object to form thermally insulating foam. Potentially adaptable to other materials, especially in process-monitoring applications in which necessary to know and control critical properties of products via quantitative chemical analyses of products. In addition to chemical composition, also used to determine such physical properties as densities and strengths.

  13. Quantitative Hydrocarbon Surface Analysis

    NASA Technical Reports Server (NTRS)

    Douglas, Vonnie M.

    2000-01-01

    The elimination of ozone depleting substances, such as carbon tetrachloride, has resulted in the use of new analytical techniques for cleanliness verification and contamination sampling. The last remaining application at Rocketdyne which required a replacement technique was the quantitative analysis of hydrocarbons by infrared spectrometry. This application, which previously utilized carbon tetrachloride, was successfully modified using the SOC-400, a compact portable FTIR manufactured by Surface Optics Corporation. This instrument can quantitatively measure and identify hydrocarbons from solvent flush of hardware as well as directly analyze the surface of metallic components without the use of ozone depleting chemicals. Several sampling accessories are utilized to perform analysis for various applications.

  14. A quantitative cell modeling and wound-healing analysis based on the Electric Cell-substrate Impedance Sensing (ECIS) method.

    PubMed

    Yang, Jen Ming; Chen, Szi-Wen; Yang, Jhe-Hao; Hsu, Chih-Chin; Wang, Jong-Shyan

    2016-02-01

    In this paper, a quantitative modeling and wound-healing analysis of fibroblast and human keratinocyte cells is presented. Our study was conducted using a continuous cellular impedance monitoring technique, dubbed Electric Cell-substrate Impedance Sensing (ECIS). In fact, we have constructed a mathematical model for quantitatively analyzing the cultured cell growth using the time series data directly derived by ECIS in a previous work. In this study, the applicability of our model into the keratinocyte cell growth modeling analysis was assessed first. In addition, an electrical "wound-healing" assay was used as a means to evaluate the healing process of keratinocyte cells at a variety of pressures. Two innovative and new-defined indicators, dubbed cell power and cell electroactivity, respectively, were developed for quantitatively characterizing the biophysical behavior of cells. We then employed the wavelet transform method to perform a multi-scale analysis so the cell power and cell electroactivity across multiple observational time scales may be captured. Numerical results indicated that our model can well fit the data measured from the keratinocyte cell culture for cell growth modeling analysis. Also, the results produced by our quantitative analysis showed that the wound healing process was the fastest at the negative pressure of 125mmHg, which consistently agreed with the qualitative analysis results reported in previous works.

  15. Quantitative method to assess caries via fluorescence imaging from the perspective of autofluorescence spectral analysis

    NASA Astrophysics Data System (ADS)

    Chen, Q. G.; Zhu, H. H.; Xu, Y.; Lin, B.; Chen, H.

    2015-08-01

    A quantitative method to discriminate caries lesions for a fluorescence imaging system is proposed in this paper. The autofluorescence spectral investigation of 39 teeth samples classified by the International Caries Detection and Assessment System levels was performed at 405 nm excitation. The major differences in the different caries lesions focused on the relative spectral intensity range of 565-750 nm. The spectral parameter, defined as the ratio of wavebands at 565-750 nm to the whole spectral range, was calculated. The image component ratio R/(G + B) of color components was statistically computed by considering the spectral parameters (e.g. autofluorescence, optical filter, and spectral sensitivity) in our fluorescence color imaging system. Results showed that the spectral parameter and image component ratio presented a linear relation. Therefore, the image component ratio was graded as <0.66, 0.66-1.06, 1.06-1.62, and >1.62 to quantitatively classify sound, early decay, established decay, and severe decay tissues, respectively. Finally, the fluorescence images of caries were experimentally obtained, and the corresponding image component ratio distribution was compared with the classification result. A method to determine the numerical grades of caries using a fluorescence imaging system was proposed. This method can be applied to similar imaging systems.

  16. A Rapid and Quantitative Flow Cytometry Method for the Analysis of Membrane Disruptive Antimicrobial Activity

    PubMed Central

    O’Brien-Simpson, Neil M.; Pantarat, Namfon; Attard, Troy J.; Walsh, Katrina A.; Reynolds, Eric C.

    2016-01-01

    We describe a microbial flow cytometry method that quantifies within 3 hours antimicrobial peptide (AMP) activity, termed Minimum Membrane Disruptive Concentration (MDC). Increasing peptide concentration positively correlates with the extent of bacterial membrane disruption and the calculated MDC is equivalent to its MBC. The activity of AMPs representing three different membranolytic modes of action could be determined for a range of Gram positive and negative bacteria, including the ESKAPE pathogens, E. coli and MRSA. By using the MDC50 concentration of the parent AMP, the method provides high-throughput, quantitative screening of AMP analogues. A unique feature of the MDC assay is that it directly measures peptide/bacteria interactions and lysed cell numbers rather than bacteria survival as with MIC and MBC assays. With the threat of multi-drug resistant bacteria, this high-throughput MDC assay has the potential to aid in the development of novel antimicrobials that target bacteria with improved efficacy. PMID:26986223

  17. A robust multiple-locus method for quantitative trait locus analysis of non-normally distributed multiple traits.

    PubMed

    Li, Z; Möttönen, J; Sillanpää, M J

    2015-12-01

    Linear regression-based quantitative trait loci/association mapping methods such as least squares commonly assume normality of residuals. In genetics studies of plants or animals, some quantitative traits may not follow normal distribution because the data include outlying observations or data that are collected from multiple sources, and in such cases the normal regression methods may lose some statistical power to detect quantitative trait loci. In this work, we propose a robust multiple-locus regression approach for analyzing multiple quantitative traits without normality assumption. In our method, the objective function is least absolute deviation (LAD), which corresponds to the assumption of multivariate Laplace distributed residual errors. This distribution has heavier tails than the normal distribution. In addition, we adopt a group LASSO penalty to produce shrinkage estimation of the marker effects and to describe the genetic correlation among phenotypes. Our LAD-LASSO approach is less sensitive to the outliers and is more appropriate for the analysis of data with skewedly distributed phenotypes. Another application of our robust approach is on missing phenotype problem in multiple-trait analysis, where the missing phenotype items can simply be filled with some extreme values, and be treated as outliers. The efficiency of the LAD-LASSO approach is illustrated on both simulated and real data sets.

  18. A self-referential outlier detection method for quantitative motor unit action potential analysis.

    PubMed

    Sheean, Geoffrey L

    2012-04-01

    Quantitative MUAP analysis is often based on outlier detection, in the case of neurogenic conditions, the finding of MUAPs that are larger than the limit determined from a reference normal population. Such reference data is available from only a few sources and for only a few muscles. It would be desirable if muscles could serve as their own controls. The Henneman size principle determines the order of recruitment, following an exponential distribution of twitch force, motor neurone, motor unit, and MUAP size. Therefore, an outlier could be detected by being too large for the level of recruitment, as judged by its size relative to the other MUAPs. This would improve the sensitivity of detecting neurogenic muscles and obviate the need for external reference data.

  19. Quantitative Analysis of Single and Mix Food Antiseptics Basing on SERS Spectra with PLSR Method

    NASA Astrophysics Data System (ADS)

    Hou, Mengjing; Huang, Yu; Ma, Lingwei; Zhang, Zhengjun

    2016-06-01

    Usage and dosage of food antiseptics are very concerned due to their decisive influence in food safety. Surface-enhanced Raman scattering (SERS) effect was employed in this research to realize trace potassium sorbate (PS) and sodium benzoate (SB) detection. HfO2 ultrathin film-coated Ag NR array was fabricated as SERS substrate. Protected by HfO2 film, the SERS substrate possesses good acid resistance, which enables it to be applicable in acidic environment where PS and SB work. Regression relationship between SERS spectra of 0.3~10 mg/L PS solution and their concentration was calibrated by partial least squares regression (PLSR) method, and the concentration prediction performance was quite satisfactory. Furthermore, mixture solution of PS and SB was also quantitatively analyzed by PLSR method. Spectrum data of characteristic peak sections corresponding to PS and SB was used to establish the regression models of these two solutes, respectively, and their concentrations were determined accurately despite their characteristic peak sections overlapping. It is possible that the unique modeling process of PLSR method prevented the overlapped Raman signal from reducing the model accuracy.

  20. Measurement and Meaning: Combining Quantitative and Qualitative Methods for the Analysis of Poverty and Social Exclusion in Latin America. World Bank Technical Paper.

    ERIC Educational Resources Information Center

    Gacitua-Mario, Estanislao, Ed.; Wodon, Quentin, Ed.

    This report consists of a collection of case studies from Latin America combining qualitative and quantitative research methods for the analysis of poverty within a social exclusion framework. The first chapter provides an overview of the differences between quantitative and qualitative methods, and the gains from using both types of methods in…

  1. [Quantitative analysis method based on fractal theory for medical imaging of normal brain development in infants].

    PubMed

    Li, Heheng; Luo, Liangping; Huang, Li

    2011-02-01

    The present paper is aimed to study the fractal spectrum of the cerebral computerized tomography in 158 normal infants of different age groups, based on the calculation of chaotic theory. The distribution range of neonatal period was 1.88-1.90 (mean = 1.8913 +/- 0.0064); It reached a stable condition at the level of 1.89-1.90 during 1-12 months old (mean = 1.8927 +/- 0.0045); The normal range of 1-2 years old infants was 1.86-1.90 (mean = 1.8863 +/- 4 0.0085); It kept the invariance of the quantitative value among 1.88-1.91(mean = 1.8958 +/- 0.0083) during 2-3 years of age. ANOVA indicated there's no significant difference between boys and girls (F = 0.243, P > 0.05), but the difference of age groups was significant (F = 8.947, P < 0.001). The fractal dimension of cerebral computerized tomography in normal infants computed by box methods was maintained at an efficient stability from 1.86 to 1.91. It indicated that there exit some attractor modes in pediatric brain development.

  2. Quantitative phase analysis of Mg:ZrO{sub 2} nanoparticles by Rietveld refinement method

    SciTech Connect

    Balaji, V. Senthilkumaran, S. Thangadurai, P.

    2014-04-24

    To quantify the structural phases of nanocrystalline ZrO{sub 2} doped with Mg ions of varying concentrations (3, 5, 10, 15 and 20%) and annealed at different temperatures. Magnesia doped zirconia was prepared by chemical co-precipitation method and annealed up to 1000°C. The monoclinic and tetragonal phases present in Mg:ZrO{sub 2} were quantified using Rietveld refinement analysis of the X-ray diffraction data and compared with the Direct method based on peak intensity calculations. Tetragonal phase was dominant in the 600°C annealed Mg:ZrO{sub 2} for all Mg concentrations.

  3. A simple method for using silicone elastomer masks for quantitative analysis of cell migration without cellular damage or substrate disruption

    PubMed Central

    Sherry, David M; Parks, Eileen E; Bullen, Elizabeth C; Updike, Dawn L; Howard, Eric W

    2013-01-01

    Cell migration is fundamental to many biological processes, including development, normal tissue remodeling, wound healing, and many pathologies. However, cell migration is a complex process, and understanding its regulation in health and disease requires the ability to manipulate and measure this process quantitatively under controlled conditions. This report describes a simple in vitro assay for quantitative analysis of cell migration in two-dimensional cultures that is an inexpensive alternative to the classic “scratch” assay. The method described utilizes flexible silicone masks fabricated in the lab according to the research demands of the specific experiment to create a cell-free area for cells to invade, followed by quantitative analysis based on widely available microscopic imaging tools. This experimental approach has the important advantage of visualizing cell migration in the absence of the cellular damage and disruption of the substrate that occurs when the “wound” is created in the scratch assay. This approach allows the researcher to study the intrinsic migratory characteristics of cells in the absence of potentially confounding contributions from cellular responses to injury and disruption of cell–substrate interactions. This assay has been used with vascular smooth muscle cells, fibroblasts, and epithelial cell types, but should be applicable to the study of practically any type of cultured cell. Furthermore, this method can be easily adapted for use with fluorescence microscopy, molecular biological, or pharmacological manipulations to explore the molecular mechanisms of cell migration, live cell imaging, fluorescence microscopy, and correlative immunolabeling. PMID:24430202

  4. Establishment of quantitative analysis method for genetically modified maize using a reference plasmid and novel primers.

    PubMed

    Moon, Gi-Seong; Shin, Weon-Sun

    2012-12-01

    For the quantitative analysis of genetically modified (GM) maize in processed foods, primer sets and probes based on the 35S promoter (p35S), nopaline synthase terminator (tNOS), p35S-hsp70 intron, and zSSIIb gene encoding starch synthase II for intrinsic control were designed. Polymerase chain reaction (PCR) products (80~101 bp) were specifically amplified and the primer sets targeting the smaller regions (80 or 81 bp) were more sensitive than those targeting the larger regions (94 or 101 bp). Particularly, the primer set 35F1-R1 for p35S targeting 81 bp of sequence was even more sensitive than that targeting 101 bp of sequence by a 3-log scale. The target DNA fragments were also specifically amplified from all GM labeled food samples except for one item we tested when 35F1-R1 primer set was applied. A reference plasmid pGMmaize (3 kb) including the smaller PCR products for p35S, tNOS, p35S-hsp70 intron, and the zSSIIb gene was constructed for real-time PCR (RT-PCR). The linearity of standard curves was confirmed by using diluents ranging from 2×10(1)~10(5) copies of pGMmaize and the R(2) values ranged from 0.999~1.000. In the RT-PCR, the detection limit using the novel primer/probe sets was 5 pg of genomic DNA from MON810 line indicating that the primer sets targeting the smaller regions (80 or 81 bp) could be used for highly sensitive detection of foreign DNA fragments from GM maize in processed foods.

  5. A novel quantitative analysis method of three-dimensional fluorescence spectra for vegetable oils contents in edible blend oil

    NASA Astrophysics Data System (ADS)

    Xu, Jing; Wang, Yu-Tian; Liu, Xiao-Fei

    2015-04-01

    Edible blend oil is a mixture of vegetable oils. Eligible blend oil can meet the daily need of two essential fatty acids for human to achieve the balanced nutrition. Each vegetable oil has its different composition, so vegetable oils contents in edible blend oil determine nutritional components in blend oil. A high-precision quantitative analysis method to detect the vegetable oils contents in blend oil is necessary to ensure balanced nutrition for human being. Three-dimensional fluorescence technique is high selectivity, high sensitivity, and high-efficiency. Efficiency extraction and full use of information in tree-dimensional fluorescence spectra will improve the accuracy of the measurement. A novel quantitative analysis is proposed based on Quasi-Monte-Carlo integral to improve the measurement sensitivity and reduce the random error. Partial least squares method is used to solve nonlinear equations to avoid the effect of multicollinearity. The recovery rates of blend oil mixed by peanut oil, soybean oil and sunflower are calculated to verify the accuracy of the method, which are increased, compared the linear method used commonly for component concentration measurement.

  6. A Computer-Aided Analysis Method of SPECT Brain Images for Quantitative Treatment Monitoring: Performance Evaluations and Clinical Applications

    PubMed Central

    Wei, Wentao; Huang, Qiu; Wan, Jieqing; Huang, Gang

    2017-01-01

    The objective and quantitative analysis of longitudinal single photon emission computed tomography (SPECT) images are significant for the treatment monitoring of brain disorders. Therefore, a computer aided analysis (CAA) method is introduced to extract a change-rate map (CRM) as a parametric image for quantifying the changes of regional cerebral blood flow (rCBF) in longitudinal SPECT brain images. The performances of the CAA-CRM approach in treatment monitoring are evaluated by the computer simulations and clinical applications. The results of computer simulations show that the derived CRMs have high similarities with their ground truths when the lesion size is larger than system spatial resolution and the change rate is higher than 20%. In clinical applications, the CAA-CRM approach is used to assess the treatment of 50 patients with brain ischemia. The results demonstrate that CAA-CRM approach has a 93.4% accuracy of recovered region's localization. Moreover, the quantitative indexes of recovered regions derived from CRM are all significantly different among the groups and highly correlated with the experienced clinical diagnosis. In conclusion, the proposed CAA-CRM approach provides a convenient solution to generate a parametric image and derive the quantitative indexes from the longitudinal SPECT brain images for treatment monitoring. PMID:28251150

  7. A Computer-Aided Analysis Method of SPECT Brain Images for Quantitative Treatment Monitoring: Performance Evaluations and Clinical Applications.

    PubMed

    Zheng, Xiujuan; Wei, Wentao; Huang, Qiu; Song, Shaoli; Wan, Jieqing; Huang, Gang

    2017-01-01

    The objective and quantitative analysis of longitudinal single photon emission computed tomography (SPECT) images are significant for the treatment monitoring of brain disorders. Therefore, a computer aided analysis (CAA) method is introduced to extract a change-rate map (CRM) as a parametric image for quantifying the changes of regional cerebral blood flow (rCBF) in longitudinal SPECT brain images. The performances of the CAA-CRM approach in treatment monitoring are evaluated by the computer simulations and clinical applications. The results of computer simulations show that the derived CRMs have high similarities with their ground truths when the lesion size is larger than system spatial resolution and the change rate is higher than 20%. In clinical applications, the CAA-CRM approach is used to assess the treatment of 50 patients with brain ischemia. The results demonstrate that CAA-CRM approach has a 93.4% accuracy of recovered region's localization. Moreover, the quantitative indexes of recovered regions derived from CRM are all significantly different among the groups and highly correlated with the experienced clinical diagnosis. In conclusion, the proposed CAA-CRM approach provides a convenient solution to generate a parametric image and derive the quantitative indexes from the longitudinal SPECT brain images for treatment monitoring.

  8. Quantitative validation of different protein precipitation methods in proteome analysis of blood platelets.

    PubMed

    Zellner, Maria; Winkler, Wolfgang; Hayden, Hubert; Diestinger, Michael; Eliasen, Maja; Gesslbauer, Bernd; Miller, Ingrid; Chang, Martina; Kungl, Andreas; Roth, Erich; Oehler, Rudolf

    2005-06-01

    For the preparation of proteins for proteome analysis, precipitation is frequently used to concentrate proteins and to remove interfering compounds. Various methods for protein precipitation are applied, which rely on different chemical principles. This study compares the changes in the protein composition of human blood platelet extracts after precipitation with ethanol (EtOH) or trichloroacetic acid (TCA). Both methods yielded the same amount of proteins from the platelet preparations. However, the EtOH-precipitated samples had to be dialyzed because of the considerable salt content. To characterize single platelet proteins, samples were analyzed by two-dimensional fluorescence differential gel electrophoresis. More than 90% of all the spots were equally present in the EtOH- and TCA-precipitated samples. However, both precipitation methods showed a smaller correlation with nonprecipitated samples (EtOH 74.9%, TCA 79.2%). Several proteins were either reduced or relatively enriched in the precipitated samples. The proteins varied randomly in molecular weight and isoelectric point. This study shows that protein precipitation leads to specific changes in the protein composition of proteomics samples. This depends more on the specific structure of the protein than on the precipitating agent used in the experiment.

  9. Interlaboratory validation of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.

    PubMed

    Takabatake, Reona; Koiwa, Tomohiro; Kasahara, Masaki; Takashima, Kaori; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Oguchi, Taichi; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi

    2011-01-01

    To reduce the cost and time required to routinely perform the genetically modified organism (GMO) test, we developed a duplex quantitative real-time PCR method for a screening analysis simultaneously targeting an event-specific segment for GA21 and Cauliflower Mosaic Virus 35S promoter (P35S) segment [Oguchi et al., J. Food Hyg. Soc. Japan, 50, 117-125 (2009)]. To confirm the validity of the method, an interlaboratory collaborative study was conducted. In the collaborative study, conversion factors (Cfs), which are required to calculate the GMO amount (%), were first determined for two real-time PCR instruments, the ABI PRISM 7900HT and the ABI PRISM 7500. A blind test was then conducted. The limit of quantitation for both GA21 and P35S was estimated to be 0.5% or less. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSD(R)). The determined bias and RSD(R) were each less than 25%. We believe the developed method would be useful for the practical screening analysis of GM maize.

  10. Quantitative imaging methods in osteoporosis

    PubMed Central

    Oei, Ling; Koromani, Fjorda; Rivadeneira, Fernando; Zillikens, M. Carola

    2016-01-01

    Osteoporosis is characterized by a decreased bone mass and quality resulting in an increased fracture risk. Quantitative imaging methods are critical in the diagnosis and follow-up of treatment effects in osteoporosis. Prior radiographic vertebral fractures and bone mineral density (BMD) as a quantitative parameter derived from dual-energy X-ray absorptiometry (DXA) are among the strongest known predictors of future osteoporotic fractures. Therefore, current clinical decision making relies heavily on accurate assessment of these imaging features. Further, novel quantitative techniques are being developed to appraise additional characteristics of osteoporosis including three-dimensional bone architecture with quantitative computed tomography (QCT). Dedicated high-resolution (HR) CT equipment is available to enhance image quality. At the other end of the spectrum, by utilizing post-processing techniques such as the trabecular bone score (TBS) information on three-dimensional architecture can be derived from DXA images. Further developments in magnetic resonance imaging (MRI) seem promising to not only capture bone micro-architecture but also characterize processes at the molecular level. This review provides an overview of various quantitative imaging techniques based on different radiological modalities utilized in clinical osteoporosis care and research. PMID:28090446

  11. Quantitative imaging methods in osteoporosis.

    PubMed

    Oei, Ling; Koromani, Fjorda; Rivadeneira, Fernando; Zillikens, M Carola; Oei, Edwin H G

    2016-12-01

    Osteoporosis is characterized by a decreased bone mass and quality resulting in an increased fracture risk. Quantitative imaging methods are critical in the diagnosis and follow-up of treatment effects in osteoporosis. Prior radiographic vertebral fractures and bone mineral density (BMD) as a quantitative parameter derived from dual-energy X-ray absorptiometry (DXA) are among the strongest known predictors of future osteoporotic fractures. Therefore, current clinical decision making relies heavily on accurate assessment of these imaging features. Further, novel quantitative techniques are being developed to appraise additional characteristics of osteoporosis including three-dimensional bone architecture with quantitative computed tomography (QCT). Dedicated high-resolution (HR) CT equipment is available to enhance image quality. At the other end of the spectrum, by utilizing post-processing techniques such as the trabecular bone score (TBS) information on three-dimensional architecture can be derived from DXA images. Further developments in magnetic resonance imaging (MRI) seem promising to not only capture bone micro-architecture but also characterize processes at the molecular level. This review provides an overview of various quantitative imaging techniques based on different radiological modalities utilized in clinical osteoporosis care and research.

  12. Method Development and Validation of a Stability-Indicating RP-HPLC Method for the Quantitative Analysis of Dronedarone Hydrochloride in Pharmaceutical Tablets

    PubMed Central

    Dabhi, Batuk; Jadeja, Yashwantsinh; Patel, Madhavi; Jebaliya, Hetal; Karia, Denish; Shah, Anamik

    2013-01-01

    A simple, precise, and accurate HPLC method has been developed and validated for the quantitative analysis of Dronedarone Hydrochloride in tablet form. An isocratic separation was achieved using a Waters Symmetry C8 (100 × 4.6 mm), 5 μm particle size column with a flow rate of 1 ml/min and UV detector at 290 nm. The mobile phase consisted of buffer: methanol (40:60 v/v) (buffer: 50 mM KH2PO4 + 1 ml triethylamine in 1 liter water, pH=2.5 adjusted with ortho-phosphoric acid). The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The specificity of the method was determined by assessing interference from the placebo and by stress testing the drug (forced degradation). The method was linear over the concentration range 20–80 μg/ml (r2 = 0.999) with a Limit of Detection (LOD) and Limit of Quantitation (LOQ) of 0.1 and 0.3 μg/ml respectively. The accuracy of the method was between 99.2–100.5%. The method was found to be robust and suitable for the quantitative analysis of Dronedarone Hydrochloride in a tablet formulation. Degradation products resulting from the stress studies did not interfere with the detection of Dronedarone Hydrochloride so the assay is thus stability-indicating. PMID:23641332

  13. Quantitative Methods for Software Selection and Evaluation

    DTIC Science & Technology

    2006-09-01

    Quantitative Methods for Software Selection and Evaluation Michael S. Bandor September 2006 Acquisition Support Program...5 2 Evaluation Methods ...Abstract When performing a “buy” analysis and selecting a product as part of a software acquisition strategy , most organizations will consider primarily

  14. The Use of Quantitative and Qualitative Methods in the Analysis of Academic Achievement among Undergraduates in Jamaica

    ERIC Educational Resources Information Center

    McLaren, Ingrid Ann Marie

    2012-01-01

    This paper describes a study which uses quantitative and qualitative methods in determining the relationship between academic, institutional and psychological variables and degree performance for a sample of Jamaican undergraduate students. Quantitative methods, traditionally associated with the positivist paradigm, and involving the counting and…

  15. Enantiomeric separation of the antiuremic drug colchicine by electrokinetic chromatography. Method development and quantitative analysis.

    PubMed

    Menéndez-López, Nuria; Valimaña-Traverso, Jesús; Castro-Puyana, María; Salgado, Antonio; García, María Ángeles; Marina, María Luisa

    2017-05-10

    Two analytical methodologies were developed by CE enabling the enantiomeric separation of colchicine, an antiuremic drug commercialized as pure enantiomer. Succinyl-γ-CD and Sulfated-γ-CD were selected as chiral selectors after a screening with different anionic CDs. Under the optimized conditions, chiral resolutions of 5.6 in 12min and 3.2 in 8min were obtained for colchicine with Succinyl-γ-CD and Sulfated-γ-CD, respectively. An opposite enantiomeric migration order was observed with these two CDs being S-colchicine the first-migrating enantiomer with Succinyl-γ-CD and the second-migrating enantiomer with Sulfated-γ-CD. H NMR experiments showed a 1:1 stoichiometry for the enantiomer-CD complexes in both cases. However, the apparent and averaged equilibrium constants for the enantiomer-CD complexes could be calculated only for Succinyl-γ-CD. The developed methods were applied to the analysis of pharmaceutical formulations but only the use of Succinyl-γ-CD enabled to detect a 0.1% of enantiomeric impurity in colchicine formulations.

  16. A convenient method for the quantitative determination of elemental sulfur in coal by HPLC analysis of perchloroethylene extracts

    USGS Publications Warehouse

    Buchanan, D.H.; Coombs, K.J.; Murphy, P.M.; Chaven, C.

    1993-01-01

    A convenient method for the quantitative determination of elemental sulfur in coal is described. Elemental sulfur is extracted from the coal with hot perchloroethylene (PCE) (tetrachloroethene, C2Cl4) and quantitatively determined by HPLC analysis on a C18 reverse-phase column using UV detection. Calibration solutions were prepared from sublimed sulfur. Results of quantitative HPLC analyses agreed with those of a chemical/spectroscopic analysis. The HPLC method was found to be linear over the concentration range of 6 ?? 10-4 to 2 ?? 10-2 g/L. The lower detection limit was 4 ?? 10-4 g/L, which for a coal sample of 20 g is equivalent to 0.0006% by weight of coal. Since elemental sulfur is known to react slowly with hydrocarbons at the temperature of boiling PCE, standard solutions of sulfur in PCE were heated with coals from the Argonne Premium Coal Sample program. Pseudo-first-order uptake of sulfur by the coals was observed over several weeks of heating. For the Illinois No. 6 premium coal, the rate constant for sulfur uptake was 9.7 ?? 10-7 s-1, too small for retrograde reactions between solubilized sulfur and coal to cause a significant loss in elemental sulfur isolated during the analytical extraction. No elemental sulfur was produced when the following pure compounds were heated to reflux in PCE for up to 1 week: benzyl sulfide, octyl sulfide, thiane, thiophene, benzothiophene, dibenzothiophene, sulfuric acid, or ferrous sulfate. A sluury of mineral pyrite in PCE contained elemental sulfur which increased in concentration with heating time. ?? 1993 American Chemical Society.

  17. A SILAC-Based Method for Quantitative Proteomic Analysis of Intestinal Organoids

    PubMed Central

    Gonneaud, Alexis; Jones, Christine; Turgeon, Naomie; Lévesque, Dominique; Asselin, Claude; Boudreau, François; Boisvert, François-Michel

    2016-01-01

    Organoids have the potential to bridge 3D cell culture to tissue physiology by providing a model resembling in vivo organs. Long-term growing organoids were first isolated from intestinal crypt cells and recreated the renewing intestinal epithelial niche. Since then, this technical breakthrough was applied to many other organs, including prostate, liver, kidney and pancreas. We describe here how to apply a SILAC-based quantitative proteomic approach to measure protein expression changes in intestinal organoids under different experimental conditions. We generated SILAC organoid media that allow organoids to grow and differentiate normally, and confirmed the incorporation of isotopically labelled amino acids. Furthermore, we used a treatment reported to affect organoid differentiation to demonstrate the reproducibility of the quantification using this approach and to validate the identification of proteins that correlate with the inhibition of cellular growth and development. With the combined use of quantitative mass spectrometry, SILAC and organoid culture, we validated this approach and showed that large-scale proteome variations can be measured in an “organ-like” system. PMID:27901089

  18. A SILAC-Based Method for Quantitative Proteomic Analysis of Intestinal Organoids.

    PubMed

    Gonneaud, Alexis; Jones, Christine; Turgeon, Naomie; Lévesque, Dominique; Asselin, Claude; Boudreau, François; Boisvert, François-Michel

    2016-11-30

    Organoids have the potential to bridge 3D cell culture to tissue physiology by providing a model resembling in vivo organs. Long-term growing organoids were first isolated from intestinal crypt cells and recreated the renewing intestinal epithelial niche. Since then, this technical breakthrough was applied to many other organs, including prostate, liver, kidney and pancreas. We describe here how to apply a SILAC-based quantitative proteomic approach to measure protein expression changes in intestinal organoids under different experimental conditions. We generated SILAC organoid media that allow organoids to grow and differentiate normally, and confirmed the incorporation of isotopically labelled amino acids. Furthermore, we used a treatment reported to affect organoid differentiation to demonstrate the reproducibility of the quantification using this approach and to validate the identification of proteins that correlate with the inhibition of cellular growth and development. With the combined use of quantitative mass spectrometry, SILAC and organoid culture, we validated this approach and showed that large-scale proteome variations can be measured in an "organ-like" system.

  19. New Method for the Quantitative Analysis of Smear Slides in Pelagic and Hemi-Pelagic Sediments of the Bering Sea

    NASA Astrophysics Data System (ADS)

    Drake, M. K.; Aiello, I. W.; Ravelo, A. C.

    2014-12-01

    Petrographic microscopy of smear slides is the standard method to initially investigate marine sediments in core sediment studies (e.g. IODP expeditions). The technique is not commonly used in more complex analysis due to concerns over the subjectivity of the method and variability in operator training and experience. Two initiatives sponsored by Ocean Leadership, a sedimentology training workshop and a digital reference of smear slide components (Marsaglia et al., 2013) have been implemented to address the need for advanced training. While the influence of subjectivity on the quality of data has yet to be rigorously tested, the lack of standardization in the current method of smear slide analysis (SSA) remains a concern. The relative abundance of the three main components, (total diatoms, silt-to-sand sized siliciclastics, and clay minerals) of high and low density Bering Sea hemi-pelagic sediments from the ocean margin (Site U144; Site U1339) and pelagic sediments from the open-ocean (Site U1340) were analyzed. Our analyses show visual estimation is a reproducible method to quantify the relative abundance of the main sediment components. Furthermore, we present a modified method for SSA, with procedural changes objectively guided by statistical analyses, including constraints to increase randomness and precision in both the preparation and analysis of the smear slide. For example, repeated measure ANOVAs found a smear slide could be accurately quantified by counting three fields of view. Similarly, the use of replicate smear slides to quantify a sample was analyzed. Finally, the data produced from this modified SSA shows a strong correlation to continuously logged physical parameters of sediment such as gamma ray attenuation (Site U1339 r2= 0.41; Site U1340 r2= 0.36). Therefore, the modified SSA combined with other independent methods (e.g. laser particle size analysis, scanning electron microscopy, and physical properties) can be a very effective tool for the

  20. A Novel Method for Quantitative Serial Autofluorescence Analysis in Retinitis Pigmentosa Using Image Characteristics

    PubMed Central

    Jolly, Jasleen K.; Wagner, Siegfried K.; Moules, Jonathan; Gekeler, Florian; Webster, Andrew R.; Downes, Susan M.; MacLaren, Robert E.

    2016-01-01

    Purpose Identifying potential biomarkers for disease progression in retinitis pigmentosa (RP) is highly relevant now that gene therapy and other treatments are in clinical trial. Here we report a novel technique for analysis of short-wavelength autofluorescence (AF) imaging to quantify defined regions of AF in RP patients. Methods Fifty-five–degree AF images were acquired from 12 participants with RP over a 12-month period. Of these, five were identified as having a hyperfluorescent annulus. A standard Cartesian coordinate system was superimposed on images with the fovea as the origin and eight bisecting lines traversing the center at 45 degrees to each other. Spatial extraction software was programmed to highlight pixels corresponding to varying degrees of percentile fluorescence such that the parafoveal AF ring was mapped. Distance between the fovea and midpoint of the AF ring was measured. Percentage of low luminance areas was utilized as a measure of atrophy. Results The hyperfluorescent ring was most accurately mapped using the 70th percentile of fluorescence. Both the AF ring and peripheral hypofluorescence showed robust repeatability at all time points noted (P = 0.93). Conclusions Both a hypofluorescent ring and retinal pigment epithelium atrophy were present on a significant proportion of RP patients and were consistently mapped over a 12-month period. There is potential extrapolation of this methodology to wide-field imaging as well as other retinal dystrophies. This anatomical change may provide a useful anatomical biomarker for assessing treatment end points in RP. Translational Relevance Spatial extraction software can be a valuable tool in the assessment of ophthalmic imaging data. PMID:27933220

  1. A fast and reliable readout method for quantitative analysis of surface-enhanced Raman scattering nanoprobes on chip surface

    NASA Astrophysics Data System (ADS)

    Chang, Hyejin; Kang, Homan; Jeong, Sinyoung; Ko, Eunbyeol; Lee, Yoon-Sik; Lee, Ho-Young; Jeong, Dae Hong

    2015-05-01

    Surface-enhanced Raman scattering techniques have been widely used for bioanalysis due to its high sensitivity and multiplex capacity. However, the point-scanning method using a micro-Raman system, which is the most common method in the literature, has a disadvantage of extremely long measurement time for on-chip immunoassay adopting a large chip area of approximately 1-mm scale and confocal beam point of ca. 1-μm size. Alternative methods such as sampled spot scan with high confocality and large-area scan method with enlarged field of view and low confocality have been utilized in order to minimize the measurement time practically. In this study, we analyzed the two methods in respect of signal-to-noise ratio and sampling-led signal fluctuations to obtain insights into a fast and reliable readout strategy. On this basis, we proposed a methodology for fast and reliable quantitative measurement of the whole chip area. The proposed method adopted a raster scan covering a full area of 100 μm × 100 μm region as a proof-of-concept experiment while accumulating signals in the CCD detector for single spectrum per frame. One single scan with 10 s over 100 μm × 100 μm area yielded much higher sensitivity compared to sampled spot scanning measurements and no signal fluctuations attributed to sampled spot scan. This readout method is able to serve as one of key technologies that will bring quantitative multiplexed detection and analysis into practice.

  2. A fast and reliable readout method for quantitative analysis of surface-enhanced Raman scattering nanoprobes on chip surface

    SciTech Connect

    Chang, Hyejin; Jeong, Sinyoung; Ko, Eunbyeol; Jeong, Dae Hong E-mail: debobkr@gmail.com; Kang, Homan; Lee, Yoon-Sik E-mail: debobkr@gmail.com; Lee, Ho-Young E-mail: debobkr@gmail.com

    2015-05-15

    Surface-enhanced Raman scattering techniques have been widely used for bioanalysis due to its high sensitivity and multiplex capacity. However, the point-scanning method using a micro-Raman system, which is the most common method in the literature, has a disadvantage of extremely long measurement time for on-chip immunoassay adopting a large chip area of approximately 1-mm scale and confocal beam point of ca. 1-μm size. Alternative methods such as sampled spot scan with high confocality and large-area scan method with enlarged field of view and low confocality have been utilized in order to minimize the measurement time practically. In this study, we analyzed the two methods in respect of signal-to-noise ratio and sampling-led signal fluctuations to obtain insights into a fast and reliable readout strategy. On this basis, we proposed a methodology for fast and reliable quantitative measurement of the whole chip area. The proposed method adopted a raster scan covering a full area of 100 μm × 100 μm region as a proof-of-concept experiment while accumulating signals in the CCD detector for single spectrum per frame. One single scan with 10 s over 100 μm × 100 μm area yielded much higher sensitivity compared to sampled spot scanning measurements and no signal fluctuations attributed to sampled spot scan. This readout method is able to serve as one of key technologies that will bring quantitative multiplexed detection and analysis into practice.

  3. IMAGE-WARP: a real-space restoration method for high-resolution STEM images using quantitative HRTEM analysis.

    PubMed

    Recnik, Aleksander; Möbus, Günter; Sturm, Saso

    2005-07-01

    We have developed a new method for processing distorted high-resolution scanning transmission electron microscopy (STEM) images. The method is based on finding the displaced vertices in the experimental STEM image and warping to geometrically correct reference grid of the object. As a reference grid for warping a structural model obtained using a high-resolution transmission electron microscopy (HRTEM) analysis of the area of interest is utilised. Combined with quantitative HRTEM analysis the IMAGE-WARP method provides a real-space restoration of high-resolution high-angle annular dark-field (HAADF) STEM images without affecting the original Z-contrast information. The method can be applied to extract valuable compositional atomic-column data from any HAADF-STEM image of any kind of bulk crystals with local occupancy or chemistry fluctuations, stacking faults, special grain boundaries or interfaces, for which we have an available structural model. After the warping, distortion-corrected images can be further enhanced using conventional image-filtering techniques, and finally quantified with HAADF-STEM image simulations. The applicability of the IMAGE-WARP method was illustrated using experimental HAADF-STEM images of a strontium titanate crystal disrupted with a Ruddlesden-Popper-type antiphase boundary.

  4. A biphasic parameter estimation method for quantitative analysis of dynamic renal scintigraphic data

    NASA Astrophysics Data System (ADS)

    Koh, T. S.; Zhang, Jeff L.; Ong, C. K.; Shuter, B.

    2006-06-01

    Dynamic renal scintigraphy is an established method in nuclear medicine, commonly used for the assessment of renal function. In this paper, a biphasic model fitting method is proposed for simultaneous estimation of both vascular and parenchymal parameters from renal scintigraphic data. These parameters include the renal plasma flow, vascular and parenchymal mean transit times, and the glomerular extraction rate. Monte Carlo simulation was used to evaluate the stability and confidence of the parameter estimates obtained by the proposed biphasic method, before applying the method on actual patient study cases to compare with the conventional fitting approach and other established renal indices. The various parameter estimates obtained using the proposed method were found to be consistent with the respective pathologies of the study cases. The renal plasma flow and extraction rate estimated by the proposed method were in good agreement with those previously obtained using dynamic computed tomography and magnetic resonance imaging.

  5. Quantitative analysis of glycated proteins.

    PubMed

    Priego-Capote, Feliciano; Ramírez-Boo, María; Finamore, Francesco; Gluck, Florent; Sanchez, Jean-Charles

    2014-02-07

    The proposed protocol presents a comprehensive approach for large-scale qualitative and quantitative analysis of glycated proteins (GP) in complex biological samples including biological fluids and cell lysates such as plasma and red blood cells. The method, named glycation isotopic labeling (GIL), is based on the differential labeling of proteins with isotopic [(13)C6]-glucose, which supports quantitation of the resulting glycated peptides after enzymatic digestion with endoproteinase Glu-C. The key principle of the GIL approach is the detection of doublet signals for each glycated peptide in MS precursor scanning (glycated peptide with in vivo [(12)C6]- and in vitro [(13)C6]-glucose). The mass shift of the doublet signals is +6, +3 or +2 Da depending on the peptide charge state and the number of glycation sites. The intensity ratio between doublet signals generates quantitative information of glycated proteins that can be related to the glycemic state of the studied samples. Tandem mass spectrometry with high-energy collisional dissociation (HCD-MS2) and data-dependent methods with collision-induced dissociation (CID-MS3 neutral loss scan) are used for qualitative analysis.

  6. An improved method for quantitative analysis of total fructans in plant tissues.

    PubMed

    Liu, Zhiqian; Mouradov, Aidyn; Smith, Kevin F; Spangenberg, German

    2011-11-15

    Current methods for measuring fructan levels in plant tissues are time-consuming and costly. They often involve multiple or sequential extractions, enzymatic or acid hydrolysis of fructan polymers, and multiple HPLC runs to quantify fructan-derived hexoses. Here we describe a new method that requires a single extraction step, followed by selective precipitation of fructans by acetone, acid hydrolysis of the precipitate, and a short (10 min) HPLC run to complete the procedure. We used perennial ryegrass samples to show that the new method has similar sensitivity, but better reproducibility, than a more complex method that is widely used. We have used the new method to study developmentally related changes in fructan levels in glasshouse-grown perennial ryegrass plants.

  7. Automated Quantitative Nuclear Cardiology Methods

    PubMed Central

    Motwani, Manish; Berman, Daniel S.; Germano, Guido; Slomka, Piotr J.

    2016-01-01

    Quantitative analysis of SPECT and PET has become a major part of nuclear cardiology practice. Current software tools can automatically segment the left ventricle, quantify function, establish myocardial perfusion maps and estimate global and local measures of stress/rest perfusion – all with minimal user input. State-of-the-art automated techniques have been shown to offer high diagnostic accuracy for detecting coronary artery disease, as well as predict prognostic outcomes. This chapter briefly reviews these techniques, highlights several challenges and discusses the latest developments. PMID:26590779

  8. Methods of quantitative and qualitative analysis of bird migration with a tracking radar

    NASA Technical Reports Server (NTRS)

    Bruderer, B.; Steidinger, P.

    1972-01-01

    Methods of analyzing bird migration by using tracking radar are discussed. The procedure for assessing the rate of bird passage is described. Three topics are presented concerning the grouping of nocturnal migrants, the velocity of migratory flight, and identification of species by radar echoes. The height and volume of migration under different weather conditions are examined. The methods for studying the directions of migration and the correlation between winds and the height and direction of migrating birds are presented.

  9. Improved method for quantitative analysis of the cyclotide kalata B1 in plasma and brain homogenate.

    PubMed

    Melander, Erik; Eriksson, Camilla; Jansson, Britt; Göransson, Ulf; Hammarlund-Udenaes, Margareta

    2016-11-01

    This study provides a new method for quantifying the cyclotide kalata B1 in both plasma and brain homogenate. Cyclotides are ultra-stable peptides with three disulfide bonds that are interesting from a drug development perspective as they can be used as scaffolds. In this study we describe a new validated LC-MS/MS method with high sensitivity and specificity for kalata B1. The limit of quantification was 2 ng/mL in plasma and 5 ng/gmL in brain homogenate. The method was linear in the range 2-10,000 ng/mL for plasma and 5-2000 ng/g for brain. Liquid Chromatographic separation was performed on a HyPurity C18 column, 50 × 4.6 mm, 3 µm particle size. The method had inter- and intra-day precision and accuracy levels <15% and 12% respectively. Applying the method to in vivo plasma samples and brain homogenate samples from equilibrium dialysis yielded satisfying results and was able to describe the plasma pharmacokinetics and brain tissue binding of kalata B1. The described method is quick, reproducible and well suited to quantifying kalata B1 in biological matrices.

  10. Improved method for quantitative analysis of the cyclotide kalata B1 in plasma and brain homogenate

    PubMed Central

    Eriksson, Camilla; Jansson, Britt; Göransson, Ulf; Hammarlund‐Udenaes, Margareta

    2016-01-01

    Abstract This study provides a new method for quantifying the cyclotide kalata B1 in both plasma and brain homogenate. Cyclotides are ultra‐stable peptides with three disulfide bonds that are interesting from a drug development perspective as they can be used as scaffolds. In this study we describe a new validated LC‐MS/MS method with high sensitivity and specificity for kalata B1. The limit of quantification was 2 ng/mL in plasma and 5 ng/gmL in brain homogenate. The method was linear in the range 2–10,000 ng/mL for plasma and 5–2000 ng/g for brain. Liquid Chromatographic separation was performed on a HyPurity C18 column, 50 × 4.6 mm, 3 µm particle size. The method had inter‐ and intra‐day precision and accuracy levels <15% and 12% respectively. Applying the method to in vivo plasma samples and brain homogenate samples from equilibrium dialysis yielded satisfying results and was able to describe the plasma pharmacokinetics and brain tissue binding of kalata B1. The described method is quick, reproducible and well suited to quantifying kalata B1 in biological matrices. PMID:27603276

  11. Structural Analysis and Quantitative Determination of Clevidipine Butyrate Impurities Using an Advanced RP-HPLC Method.

    PubMed

    Zhou, Yuxia; Zhou, Fan; Yan, Fei; Yang, Feng; Yao, Yuxian; Zou, Qiaogen

    2016-03-01

    Eleven potential impurities, including process-related compounds and degradation products, have been analyzed by comprehensive studies on the manufacturing process of clevidipine butyrate. Possible formation mechanisms could also be devised. MS and NMR techniques have been used for the structural characterization of three previously unreported impurities (Imp-3, Imp-5 and Imp-11). To separate and quantify the potential impurities in a simultaneous fashion, an efficient and advanced RP-HPLC method has been developed. In doing so, four major degradation products (Imp-2, Imp-4, Imp-8 and Imp-10) can be observed under varying stress conditions. This analytical method has been validated according to ICH guidelines with respect to specificity, accuracy, linearity, robustness and stability. The method described has been demonstrated to be applicable in routine quality control processes and stability evaluation studies of clevidipine butyrate.

  12. Simulation of evaporation by an extension of the pseudopotential lattice Boltzmann method: a quantitative analysis.

    PubMed

    Márkus, Attila; Házi, Gábor

    2011-04-01

    An extension of the pseudopotential lattice Boltzmann method is introduced to simulate heat transfer problems involving phase transition. Using this model, evaporation through a plane interface and two-phase Poiseuille flow were simulated and the macroscopic jump conditions were utilized to evaluate the accuracy of the method. We have found that the simulation results are in very good agreement with the analytical solutions as far as we take into account the extent of the interface during the evaluation. Using the same model heterogeneous boiling was simulated taking into account the geometry of a cavity and the important features of the boiling process could be observed in the simulation results.

  13. Infrared contrast data analysis method for quantitative measurement and monitoring in flash infrared thermography

    NASA Astrophysics Data System (ADS)

    Koshti, Ajay M.

    2015-04-01

    The paper provides information on a new infrared (IR) image contrast data post-processing method that involves converting raw data to normalized contrast versus time evolutions from the flash infrared thermography inspection video data. Thermal measurement features such as peak contrast, peak contrast time, persistence time, and persistence energy are calculated from the contrast evolutions. In addition, simulation of the contrast evolution is achieved through calibration on measured contrast evolutions from many flat bottom holes in a test plate of the subject material. The measurement features are used to monitor growth of anomalies and to characterize the void-like anomalies. The method was developed to monitor and analyze void-like anomalies in reinforced carbon-carbon (RCC) materials used on the wing leading edge of the NASA Space Shuttle Orbiters, but the method is equally applicable to other materials. The thermal measurement features relate to the anomaly characteristics such as depth and size. Calibration of the contrast is used to provide an assessment of the anomaly depth and width which correspond to the depth and diameter of the equivalent flat bottom hole (EFBH) from the calibration data. An edge detection technique called the half-max is used to measure width and length of the anomaly. Results of the half-max width and the EFBH diameter are compared with actual widths to evaluate utility of IR Contrast method. Some thermal measurements relate to gap thickness of the delaminations. Results of IR Contrast method on RCC hardware are provided. Keywords: normalized contrast, flash infrared thermography.

  14. A quantitative method to measure biofilm removal efficiency from complex biomaterial surfaces using SEM and image analysis

    PubMed Central

    Vyas, N.; Sammons, R. L.; Addison, O.; Dehghani, H.; Walmsley, A. D.

    2016-01-01

    Biofilm accumulation on biomaterial surfaces is a major health concern and significant research efforts are directed towards producing biofilm resistant surfaces and developing biofilm removal techniques. To accurately evaluate biofilm growth and disruption on surfaces, accurate methods which give quantitative information on biofilm area are needed, as current methods are indirect and inaccurate. We demonstrate the use of machine learning algorithms to segment biofilm from scanning electron microscopy images. A case study showing disruption of biofilm from rough dental implant surfaces using cavitation bubbles from an ultrasonic scaler is used to validate the imaging and analysis protocol developed. Streptococcus mutans biofilm was disrupted from sandblasted, acid etched (SLA) Ti discs and polished Ti discs. Significant biofilm removal occurred due to cavitation from ultrasonic scaling (p < 0.001). The mean sensitivity and specificity values for segmentation of the SLA surface images were 0.80 ± 0.18 and 0.62 ± 0.20 respectively and 0.74 ± 0.13 and 0.86 ± 0.09 respectively for polished surfaces. Cavitation has potential to be used as a novel way to clean dental implants. This imaging and analysis method will be of value to other researchers and manufacturers wishing to study biofilm growth and removal. PMID:27601281

  15. A quantitative method to measure biofilm removal efficiency from complex biomaterial surfaces using SEM and image analysis

    NASA Astrophysics Data System (ADS)

    Vyas, N.; Sammons, R. L.; Addison, O.; Dehghani, H.; Walmsley, A. D.

    2016-09-01

    Biofilm accumulation on biomaterial surfaces is a major health concern and significant research efforts are directed towards producing biofilm resistant surfaces and developing biofilm removal techniques. To accurately evaluate biofilm growth and disruption on surfaces, accurate methods which give quantitative information on biofilm area are needed, as current methods are indirect and inaccurate. We demonstrate the use of machine learning algorithms to segment biofilm from scanning electron microscopy images. A case study showing disruption of biofilm from rough dental implant surfaces using cavitation bubbles from an ultrasonic scaler is used to validate the imaging and analysis protocol developed. Streptococcus mutans biofilm was disrupted from sandblasted, acid etched (SLA) Ti discs and polished Ti discs. Significant biofilm removal occurred due to cavitation from ultrasonic scaling (p < 0.001). The mean sensitivity and specificity values for segmentation of the SLA surface images were 0.80 ± 0.18 and 0.62 ± 0.20 respectively and 0.74 ± 0.13 and 0.86 ± 0.09 respectively for polished surfaces. Cavitation has potential to be used as a novel way to clean dental implants. This imaging and analysis method will be of value to other researchers and manufacturers wishing to study biofilm growth and removal.

  16. Quantitative and chemical fingerprint analysis for the quality evaluation of Isatis indigotica based on ultra-performance liquid chromatography with photodiode array detector combined with chemometric methods.

    PubMed

    Shi, Yan-Hong; Xie, Zhi-Yong; Wang, Rui; Huang, Shan-Jun; Li, Yi-Ming; Wang, Zheng-Tao

    2012-01-01

    A simple and reliable method of ultra-performance liquid chromatography with photodiode array detector (UPLC-PDA) was developed to control the quality of Radix Isatidis (dried root of Isatis indigotica) for chemical fingerprint analysis and quantitative analysis of eight bioactive constituents, including R,S-goitrin, progoitrin, epiprogoitrin, gluconapin, adenosine, uridine, guanosine, and hypoxanthine. In quantitative analysis, the eight components showed good regression (R > 0.9997) within test ranges, and the recovery method ranged from 99.5% to 103.0%. The UPLC fingerprints of the Radix Isatidis samples were compared by performing chemometric procedures, including similarity analysis, hierarchical clustering analysis, and principal component analysis. The chemometric procedures classified Radix Isatidis and its finished products such that all samples could be successfully grouped according to crude herbs, prepared slices, and adulterant Baphicacanthis cusiae Rhizoma et Radix. The combination of quantitative and chromatographic fingerprint analysis can be used for the quality assessment of Radix Isatidis and its finished products.

  17. Quantitative analysis of trace bulk oxygen in silicon wafers using an inert gas fusion method.

    PubMed

    Uchihara, Hiroshi; Ikeda, Masahiko; Nakahara, Taketoshi

    2003-11-01

    This paper describes a method for removing oxide film from the surface of silicon wafers using an inert gas fusion impulse furnace and precise determination of bulk oxygen within the wafer. A silicon wafer was cut to about 0.35 g (6 x 13 x 2 mm) and dropped into a graphite crucible. The sample was then heated for 40 s at 1300 degrees C. The wafer's oxide film was reduced by carbon and removed as carbon monoxide. The treated silicon sample was taken out of the graphite crucible and maintained again with the holder of the oxygen analyzer. The graphite crucible was then heated to 2100 degrees C. The treated silicon sample was dropped into the heated graphite crucible and the trace bulk oxygen in the wafer was measured using the inert gas fusion infrared absorption method. The relative standard deviations of the oxygen in silicon wafer samples with the removed surface oxide film were determined to be 0.8% for 9.8 x 10(17) atoms/cm3, and 2.7% for 13.0 x 10(17) atoms/cm3.

  18. Quantitative analysis of bacterial communities from Mediterranean sapropels based on cultivation-dependent methods.

    PubMed

    Süss, Jacqueline; Engelen, Bert; Cypionka, Heribert; Sass, Henrik

    2004-12-27

    Microbial communities of ancient Mediterranean sapropels, buried sediment layers of high organic matter, were analyzed by most probable number (MPN) approaches. Mineral media containing different carbon sources in sub-millimolar concentrations were used. MPN numbers were elevated in sapropels and at the sediment surface, which mirrored total cell count distributions. Highest MPN counts were obtained with a mixture of different monomeric and polymeric substrates, with amino acids or with long-chain fatty acids as sole carbon sources. These values reached up to 2 x 10(7) cm(-3), representing 3.3% of the total cell count. A total of 98 pure cultures were isolated from the highest positive dilutions of the MPN series, representing the most abundant microorganisms culturable by the methods used. The strains were identified by molecular biological methods and could be grouped into 19 different phylotypes. They belonged to the alpha-, beta-, gamma-, and delta-Proteobacteria, to the Actinobacteria and the Firmicutes. However, about half of the number of isolates was closely related to the genera Photobacterium and Agrobacterium. Regarding the high cultivation success, these organisms can be assumed to be typical sapropel bacteria, representing a substantial part of the culturable indigenous microbial community.

  19. Hybrid random walk-linear discriminant analysis method for unwrapping quantitative phase microscopy images of biological samples

    PubMed Central

    Kim, Diane N. H.; Teitell, Michael A.; Reed, Jason; Zangle, Thomas A.

    2015-01-01

    Abstract. Standard algorithms for phase unwrapping often fail for interferometric quantitative phase imaging (QPI) of biological samples due to the variable morphology of these samples and the requirement to image at low light intensities to avoid phototoxicity. We describe a new algorithm combining random walk-based image segmentation with linear discriminant analysis (LDA)-based feature detection, using assumptions about the morphology of biological samples to account for phase ambiguities when standard methods have failed. We present three versions of our method: first, a method for LDA image segmentation based on a manually compiled training dataset; second, a method using a random walker (RW) algorithm informed by the assumed properties of a biological phase image; and third, an algorithm which combines LDA-based edge detection with an efficient RW algorithm. We show that the combination of LDA plus the RW algorithm gives the best overall performance with little speed penalty compared to LDA alone, and that this algorithm can be further optimized using a genetic algorithm to yield superior performance for phase unwrapping of QPI data from biological samples. PMID:26305212

  20. Quantitative and discriminative analysis of nucleic acid samples using luminometric nonspecific nanoparticle methods

    NASA Astrophysics Data System (ADS)

    Pihlasalo, S.; Mariani, L.; Härmä, H.

    2016-03-01

    Homogeneous simple assays utilizing luminescence quenching and time-resolved luminescence resonance energy transfer (TR-LRET) were developed for the quantification of nucleic acids without sequence information. Nucleic acids prevent the adsorption of a protein to europium nanoparticles which is detected as a luminescence quenching of europium nanoparticles with a soluble quencher or as a decrease of TR-LRET from europium nanoparticles to the acceptor dye. Contrary to the existing methods based on fluorescent dye binding to nucleic acids, equal sensitivities for both single- (ssDNA) and double-stranded DNA (dsDNA) were measured and a detection limit of 60 pg was calculated for the quenching assay. The average coefficient of variation was 5% for the quenching assay and 8% for the TR-LRET assay. The TR-LRET assay was also combined with a nucleic acid dye selective to dsDNA in a single tube assay to measure the total concentration of DNA and the ratio of ssDNA and dsDNA in the mixture. To our knowledge, such a multiplexed assay is not accomplished with commercially available assays.Homogeneous simple assays utilizing luminescence quenching and time-resolved luminescence resonance energy transfer (TR-LRET) were developed for the quantification of nucleic acids without sequence information. Nucleic acids prevent the adsorption of a protein to europium nanoparticles which is detected as a luminescence quenching of europium nanoparticles with a soluble quencher or as a decrease of TR-LRET from europium nanoparticles to the acceptor dye. Contrary to the existing methods based on fluorescent dye binding to nucleic acids, equal sensitivities for both single- (ssDNA) and double-stranded DNA (dsDNA) were measured and a detection limit of 60 pg was calculated for the quenching assay. The average coefficient of variation was 5% for the quenching assay and 8% for the TR-LRET assay. The TR-LRET assay was also combined with a nucleic acid dye selective to dsDNA in a single tube

  1. A method for the quantitative gamma spectroscopic analysis of an unusually shaped unknown source.

    PubMed

    Kearfott, Kimberlee J; Dewey, Steven C

    2009-02-01

    An unmarked cylindrical device, identified as a ceramic high voltage capacitor, needed its radioactivity assessed so that proper disposal and shipping requirements could be met. Using a high purity germanium detector, naturally occurring 232Th was identified as the source of radioactivity. A series of point source measurements was made along the length of the item's axis using 60Co, having a gamma ray of nearly the same energy as one of the primary 232Th progeny photopeaks. These measurements were then numerically integrated to determine the response of the detector to a line source. A correction for the self shielding of the item was estimated using Monte Carlo simulations. The item was found to contain approximately 1.85 x 10(5) Bq of uniformly distributed 232Th. The overall method has application to any unusually shaped source, with point source measurements performed using an appropriate radionuclide used to establish an overall sensitivity of the detector, including its dead layer, to the radioactivity in a simple geometric representation of the object. An estimation of self shielding from Monte Carlo is then applied to that result.

  2. Quantitative Laser Biospeckle Method for the Evaluation of the Activity of Trypanosoma cruzi Using VDRL Plates and Digital Analysis

    PubMed Central

    Grassi, Hilda Cristina; García, Lisbette C.; Lobo-Sulbarán, María Lorena; Velásquez, Ana; Andrades-Grassi, Francisco A.; Cabrera, Humberto; Andrades-Grassi, Jesús E.; Andrades, Efrén D. J.

    2016-01-01

    In this paper we report a quantitative laser Biospeckle method using VDRL plates to monitor the activity of Trypanosoma cruzi and the calibration conditions including three image processing algorithms and three programs (ImageJ and two programs designed in this work). Benznidazole was used as a test drug. Variable volume (constant density) and variable density (constant volume) were used for the quantitative evaluation of parasite activity in calibrated wells of the VDRL plate. The desiccation process within the well was monitored as a function of volume and of the activity of the Biospeckle pattern of the parasites as well as the quantitative effect of the surface parasite quantity (proportion of the object’s plane). A statistical analysis was performed with ANOVA, Tukey post hoc and Descriptive Statistics using R and R Commander. Conditions of volume (100μl) and parasite density (2-4x104 parasites/well, in exponential growth phase), assay time (up to 204min), frame number (11 frames), algorithm and program (RCommander/SAGA) for image processing were selected to test the effect of variable concentrations of benznidazole (0.0195 to 20μg/mL / 0.075 to 76.8μM) at various times (1, 61, 128 and 204min) on the activity of the Biospeckle pattern. The flat wells of the VDRL plate were found to be suitable for the quantitative calibration of the activity of Trypanosoma cruzi using the appropriate algorithm and program. Under these conditions, benznidazole produces at 1min an instantaneous effect on the activity of the Biospeckle pattern of T. cruzi, which remains with a similar profile up to 1 hour. A second effect which is dependent on concentrations above 1.25μg/mL and is statistically different from the effect at lower concentrations causes a decrease in the activity of the Biospeckle pattern. This effect is better detected after 1 hour of drug action. This behavior may be explained by an instantaneous effect on a membrane protein of Trypanosoma cruzi that could

  3. Determination of Calcium in Cereal with Flame Atomic Absorption Spectroscopy: An Experiment for a Quantitative Methods of Analysis Course

    ERIC Educational Resources Information Center

    Bazzi, Ali; Kreuz, Bette; Fischer, Jeffrey

    2004-01-01

    An experiment for determination of calcium in cereal using two-increment standard addition method in conjunction with flame atomic absorption spectroscopy (FAAS) is demonstrated. The experiment is intended to introduce students to the principles of atomic absorption spectroscopy giving them hands on experience using quantitative methods of…

  4. Quantitative analysis of PET studies.

    PubMed

    Weber, Wolfgang A

    2010-09-01

    Quantitative analysis can be included relatively easily in clinical PET-imaging protocols, but in order to obtain meaningful quantitative results one needs to follow a standardized protocol for image acquisition and data analysis. Important factors to consider are the calibration of the PET scanner, the radiotracer uptake time and the approach for definition of regions of interests. Using such standardized acquisition protocols quantitative parameters of tumor metabolism or receptor status can be derived from tracer kinetic analysis and simplified approaches such as calculation of standardized uptake values (SUVs).

  5. A Robust Plant RNA Isolation Method for Affymetrix Genechip® Analysis and Quantitative Real-Time RT-PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microarray analysis and quantitative real-time RT-PCR are the major high-throughput techniques that are used to study transcript profiles. One of the major limitations in these technologies is the isolation maximum yield of highly-pure RNA from plant tissues rich in complex polysaccharides, polyphen...

  6. High-resolution gas chromatography/mas spectrometry method for characterization and quantitative analysis of ginkgolic acids in ginkgo biloba plants, extracts, and dietary supplements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A high resolution GC/MS with Selected Ion Monitor (SIM) method focusing on the characterization and quantitative analysis of ginkgolic acids (GAs) in Ginkgo biloba L. plant materials, extracts and commercial products was developed and validated. The method involved sample extraction with (1:1) meth...

  7. Quantitative Method of Measuring Metastatic Activity

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R. (Inventor)

    1999-01-01

    The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated uroldnase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

  8. Quantitative analysis in megageomorphology

    NASA Technical Reports Server (NTRS)

    Mayer, L.

    1985-01-01

    Megageomorphology is the study of regional topographic features and their relations to independent geomorphic variables that operate at the regional scale. These independent variables can be classified as either tectonic or climatic in nature. Quantitative megageomorphology stresses the causal relations between plate tectonic factors and landscape features or correlations between climatic factors and geomorphic processes. In addition, the cumulative effects of tectonics and climate on landscape evolution that simultaneously operate in a complex system of energy transfer is of interst. Regional topographic differentiation, say between continents and ocean floors, is largely the result of the different densities and density contrasts within the oceanic and continental lithosphere and their isostatic consequences. Regional tectonic processes that alter these lithospheric characteristics include rifting, collision, subduction, transpression and transtension.

  9. Effects of DNA extraction and purification methods on real-time quantitative PCR analysis of Roundup Ready soybean.

    PubMed

    Demeke, Tigst; Ratnayaka, Indira; Phan, Anh

    2009-01-01

    The quality of DNA affects the accuracy and repeatability of quantitative PCR results. Different DNA extraction and purification methods were compared for quantification of Roundup Ready (RR) soybean (event 40-3-2) by real-time PCR. DNA was extracted using cetylmethylammonium bromide (CTAB), DNeasy Plant Mini Kit, and Wizard Magnetic DNA purification system for food. CTAB-extracted DNA was also purified using the Zymo (DNA Clean & Concentrator 25 kit), Qtip 100 (Qiagen Genomic-Tip 100/G), and QIAEX II Gel Extraction Kit. The CTAB extraction method provided the largest amount of DNA, and the Zymo purification kit resulted in the highest percentage of DNA recovery. The Abs260/280 and Abs260/230 ratios were less than the expected values for some of the DNA extraction and purification methods used, indicating the presence of substances that could inhibit PCR reactions. Real-time quantitative PCR results were affected by the DNA extraction and purification methods used. Further purification or dilution of the CTAB DNA was required for successful quantification of RR soybean. Less variability of quantitative PCR results was observed among experiments and replications for DNA extracted and/or purified by CTAB, CTAB+Zymo, CTAB+Qtip 100, and DNeasy methods. Correct and repeatable results for real-time PCR quantification of RR soybean were achieved using CTAB DNA purified with Zymo and Qtip 100 methods.

  10. Optimization of an Optical Inspection System Based on the Taguchi Method for Quantitative Analysis of Point-of-Care Testing

    PubMed Central

    Yeh, Chia-Hsien; Zhao, Zi-Qi; Shen, Pi-Lan; Lin, Yu-Cheng

    2014-01-01

    This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS) sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP). PMID:25256108

  11. Optimization of an optical inspection system based on the Taguchi method for quantitative analysis of point-of-care testing.

    PubMed

    Yeh, Chia-Hsien; Zhao, Zi-Qi; Shen, Pi-Lan; Lin, Yu-Cheng

    2014-09-01

    This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS) sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP).

  12. Quantitative analysis of endogenous compounds.

    PubMed

    Thakare, Rhishikesh; Chhonker, Yashpal S; Gautam, Nagsen; Alamoudi, Jawaher Abdullah; Alnouti, Yazen

    2016-09-05

    Accurate quantitative analysis of endogenous analytes is essential for several clinical and non-clinical applications. LC-MS/MS is the technique of choice for quantitative analyses. Absolute quantification by LC/MS requires preparing standard curves in the same matrix as the study samples so that the matrix effect and the extraction efficiency for analytes are the same in both the standard and study samples. However, by definition, analyte-free biological matrices do not exist for endogenous compounds. To address the lack of blank matrices for the quantification of endogenous compounds by LC-MS/MS, four approaches are used including the standard addition, the background subtraction, the surrogate matrix, and the surrogate analyte methods. This review article presents an overview these approaches, cite and summarize their applications, and compare their advantages and disadvantages. In addition, we discuss in details, validation requirements and compatibility with FDA guidelines to ensure method reliability in quantifying endogenous compounds. The standard addition, background subtraction, and the surrogate analyte approaches allow the use of the same matrix for the calibration curve as the one to be analyzed in the test samples. However, in the surrogate matrix approach, various matrices such as artificial, stripped, and neat matrices are used as surrogate matrices for the actual matrix of study samples. For the surrogate analyte approach, it is required to demonstrate similarity in matrix effect and recovery between surrogate and authentic endogenous analytes. Similarly, for the surrogate matrix approach, it is required to demonstrate similar matrix effect and extraction recovery in both the surrogate and original matrices. All these methods represent indirect approaches to quantify endogenous compounds and regardless of what approach is followed, it has to be shown that none of the validation criteria have been compromised due to the indirect analyses.

  13. Real-time elastography in the assessment of liver fibrosis: a review of qualitative and semi-quantitative methods for elastogram analysis.

    PubMed

    Paparo, Francesco; Corradi, Francesco; Cevasco, Luca; Revelli, Matteo; Marziano, Andrea; Molini, Lucio; Cenderello, Giovanni; Cassola, Giovanni; Rollandi, Gian Andrea

    2014-09-01

    Despite its invasiveness, liver biopsy is still considered the gold standard for the assessment of hepatic fibrosis. Non-invasive ultrasound-based techniques are increasingly employed to assess parenchymal stiffness and the progression of chronic diffuse liver diseases. Real-time elastography is a rapidly evolving technique that can reveal the elastic properties of tissues. This review examines qualitative and semi-quantitative methods developed for analysis of real-time liver elastograms, to estimate parenchymal stiffness and, indirectly, the stage of fibrosis. Qualitative analysis is the most immediate approach for elastogram analysis, but this method increases intra- and inter-observer variability, which is seen as a major limitation of real-time elastography. Semi-quantitative methods include analysis of the histogram derived from color-coded maps, as well as calculation of the elastic ratio and fibrosis index.

  14. LC-MS/MS method development for quantitative analysis of acetaminophen uptake by the aquatic fungus Mucor hiemalis.

    PubMed

    Esterhuizen-Londt, Maranda; Schwartz, Katrin; Balsano, Evelyn; Kühn, Sandra; Pflugmacher, Stephan

    2016-06-01

    Acetaminophen is a pharmaceutical, frequently found in surface water as a contaminant. Bioremediation, in particular, mycoremediation of acetaminophen is a method to remove this compound from waters. Owing to the lack of quantitative analytical method for acetaminophen in aquatic organisms, the present study aimed to develop a method for the determination of acetaminophen using LC-MS/MS in the aquatic fungus Mucor hiemalis. The method was then applied to evaluate the uptake of acetaminophen by M. hiemalis, cultured in pellet morphology. The method was robust, sensitive and reproducible with a lower limit of quantification of 5 pg acetaminophen on column. It was found that M. hiemalis internalize the pharmaceutical, and bioaccumulate it with time. Therefore, M. hiemalis was deemed a suitable candidate for further studies to elucidate its pharmaceutical tolerance and the longevity in mycoremediation applications.

  15. Development and interlaboratory validation of quantitative polymerase chain reaction method for screening analysis of genetically modified soybeans.

    PubMed

    Takabatake, Reona; Onishi, Mari; Koiwa, Tomohiro; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi

    2013-01-01

    A novel real-time polymerase chain reaction (PCR)-based quantitative screening method was developed for three genetically modified soybeans: RRS, A2704-12, and MON89788. The 35S promoter (P35S) of cauliflower mosaic virus is introduced into RRS and A2704-12 but not MON89788. We then designed a screening method comprised of the combination of the quantification of P35S and the event-specific quantification of MON89788. The conversion factor (Cf) required to convert the amount of a genetically modified organism (GMO) from a copy number ratio to a weight ratio was determined experimentally. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSDR), respectively. The determined RSDR values for the method were less than 25% for both targets. We consider that the developed method would be suitable for the simple detection and approximate quantification of GMO.

  16. A systematic study on the influencing parameters and improvement of quantitative analysis of multi-component with single marker method using notoginseng as research subject.

    PubMed

    Wang, Chao-Qun; Jia, Xiu-Hong; Zhu, Shu; Komatsu, Katsuko; Wang, Xuan; Cai, Shao-Qing

    2015-03-01

    A new quantitative analysis of multi-component with single marker (QAMS) method for 11 saponins (ginsenosides Rg1, Rb1, Rg2, Rh1, Rf, Re and Rd; notoginsenosides R1, R4, Fa and K) in notoginseng was established, when 6 of these saponins were individually used as internal referring substances to investigate the influences of chemical structure, concentrations of quantitative components, and purities of the standard substances on the accuracy of the QAMS method. The results showed that the concentration of the analyte in sample solution was the major influencing parameter, whereas the other parameters had minimal influence on the accuracy of the QAMS method. A new method for calculating the relative correction factors by linear regression was established (linear regression method), which demonstrated to decrease standard method differences of the QAMS method from 1.20%±0.02% - 23.29%±3.23% to 0.10%±0.09% - 8.84%±2.85% in comparison with the previous method. And the differences between external standard method and the QAMS method using relative correction factors calculated by linear regression method were below 5% in the quantitative determination of Rg1, Re, R1, Rd and Fa in 24 notoginseng samples and Rb1 in 21 notoginseng samples. And the differences were mostly below 10% in the quantitative determination of Rf, Rg2, R4 and N-K (the differences of these 4 constituents bigger because their contents lower) in all the 24 notoginseng samples. The results indicated that the contents assayed by the new QAMS method could be considered as accurate as those assayed by external standard method. In addition, a method for determining applicable concentration ranges of the quantitative components assayed by QAMS method was established for the first time, which could ensure its high accuracy and could be applied to QAMS methods of other TCMs. The present study demonstrated the practicability of the application of the QAMS method for the quantitative analysis of multi

  17. Analysis of the interferences in quantitation of a site-specifically PEGylated exendin-4 analog by the Bradford method.

    PubMed

    Qian, Xiaowei; Dong, Hongxia; Hu, Xiaojing; Tian, Hong; Guo, Linfeng; Shen, Qingliang; Gao, Xiangdong; Yao, Wenbing

    2014-11-15

    Protein modification has been found to affect the estimation of protein concentration in some of the traditional dye-based absorbance measurements. In this work, a distinct reduction in A595 was observed during the quantitation of a PEGylated exendin-4 analogue (Ex4C) by the Bradford method and the PEGylation process was found to interfere with the measurement. Lys(12), Arg(20), and Lys(27) were further proved to be the major amino acids that functioned as dye-binding sites. The shielding effect produced by the large polymer was demonstrated to depend on the length of PEG that was used for modification.

  18. Software for quantitative trait analysis.

    PubMed

    Almasy, Laura; Warren, Diane M

    2005-09-01

    This paper provides a brief overview of software currently available for the genetic analysis of quantitative traits in humans. Programs that implement variance components, Markov Chain Monte Carlo (MCMC), Haseman-Elston (H-E) and penetrance model-based linkage analyses are discussed, as are programs for measured genotype association analyses and quantitative trait transmission disequilibrium tests. The software compared includes LINKAGE, FASTLINK, PAP, SOLAR, SEGPATH, ACT, Mx, MERLIN, GENEHUNTER, Loki, Mendel, SAGE, QTDT and FBAT. Where possible, the paper provides URLs for acquiring these programs through the internet, details of the platforms for which the software is available and the types of analyses performed.

  19. Three-dimensional Analysis of Normal Facial Morphologies of Asians and Whites: A Novel Method of Quantitative Analysis

    PubMed Central

    Kim, Jamie Y.; Christou, Terpsithea; Ovsenik, Maja; Guk Park, Young

    2016-01-01

    Background: The purpose of this study is to compare 3-dimensional facial averages of Asians (Koreans and Chinese) and Houstonian white faces using a (3-dimensional) surface imaging system. Methods: Three-dimensional images of Korean adults (Seoul, Korea) with class I malocclusion captured using the 3dMDface. The images of 138 Koreans were processed to generate average male and female facial shells using Rapidform 2006 plus pack 2 software and then superimposed and compared with the average shells of Chinese adults (Xi’ An, China) and white adults (Houston, Tex.). Results: The average Korean male and female faces were wider with prominent malar and zygomatic areas when compared with the white faces. The average white male and female faces showed more protrusion in the glabella, nasion, rhinion, and the soft-tissue pogonion than the Korean faces. The average Korean male face was retrusive at masseteric region while having more prominent lips, nasal tip, and supraglabella than the Chinese counterpart. The average Korean female face was narrower than the average Chinese female face, but there was more protrusion in the periorbital, nasal tip, and malar region seen in the Korean female face. Conclusions: Although the average faces of Chinese and Korean populations in this study showed remarkable similarities, there were distinct differences seen in the facial morphology of the 2 Asian groups. Three-dimensional imaging can be effectively used to establish population facial norms and to quantify the variations seen between different ethnicities. This information may be used in the clinical environment for plastic, oral, and maxillofacial surgery and orthodontics. PMID:27757330

  20. Quantitative methods in assessment of neurologic function.

    PubMed

    Potvin, A R; Tourtellotte, W W; Syndulko, K; Potvin, J

    1981-01-01

    Traditionally, neurologists have emphasized qualitative techniques for assessing results of clinical trials. However, in recent years qualitative evaluations have been increasingly augmented by quantitative tests for measuring neurologic functions pertaining to mental state, strength, steadiness, reactions, speed, coordination, sensation, fatigue, gait, station, and simulated activities of daily living. Quantitative tests have long been used by psychologists for evaluating asymptomatic function, assessing human information processing, and predicting proficiency in skilled tasks; however, their methodology has never been directly assessed for validity in a clinical environment. In this report, relevant contributions from the literature on asymptomatic human performance and that on clinical quantitative neurologic function are reviewed and assessed. While emphasis is focused on tests appropriate for evaluating clinical neurologic trials, evaluations of tests for reproducibility, reliability, validity, and examiner training procedures, and for effects of motivation, learning, handedness, age, and sex are also reported and interpreted. Examples of statistical strategies for data analysis, scoring systems, data reduction methods, and data display concepts are presented. Although investigative work still remains to be done, it appears that carefully selected and evaluated tests of sensory and motor function should be an essential factor for evaluating clinical trials in an objective manner.

  1. Development and comparison of the methods for quantitative electron probe X-ray microanalysis analysis of thin specimens and their application to biological material.

    PubMed

    Warley, A

    2016-02-01

    In recent years, there has been a return to the use of electron probe X-ray microanalysis for biological studies but this has occurred at a time when the Hall programme which acted as the mainstay for biological microanalysis is no longer easily available. Commercial quantitative routines rely on the Cliff-Lorimer method that was originally developed for materials science applications. Here, the development of these two main routines for obtaining quantitative data from thin specimens is outlined and the limitations that are likely to be met when the Cliff-Lorimer routine is applied to biological specimens is discussed. The effects of specimen preparation on element content is briefly summarized and the problems encountered when using quantitative analysis on resin-embedded materials emphasized.

  2. Seniors' Online Communities: A Quantitative Content Analysis

    ERIC Educational Resources Information Center

    Nimrod, Galit

    2010-01-01

    Purpose: To examine the contents and characteristics of seniors' online communities and to explore their potential benefits to older adults. Design and Methods: Quantitative content analysis of a full year's data from 14 leading online communities using a novel computerized system. The overall database included 686,283 messages. Results: There was…

  3. Qualitative versus quantitative methods in psychiatric research.

    PubMed

    Razafsha, Mahdi; Behforuzi, Hura; Azari, Hassan; Zhang, Zhiqun; Wang, Kevin K; Kobeissy, Firas H; Gold, Mark S

    2012-01-01

    Qualitative studies are gaining their credibility after a period of being misinterpreted as "not being quantitative." Qualitative method is a broad umbrella term for research methodologies that describe and explain individuals' experiences, behaviors, interactions, and social contexts. In-depth interview, focus groups, and participant observation are among the qualitative methods of inquiry commonly used in psychiatry. Researchers measure the frequency of occurring events using quantitative methods; however, qualitative methods provide a broader understanding and a more thorough reasoning behind the event. Hence, it is considered to be of special importance in psychiatry. Besides hypothesis generation in earlier phases of the research, qualitative methods can be employed in questionnaire design, diagnostic criteria establishment, feasibility studies, as well as studies of attitude and beliefs. Animal models are another area that qualitative methods can be employed, especially when naturalistic observation of animal behavior is important. However, since qualitative results can be researcher's own view, they need to be statistically confirmed, quantitative methods. The tendency to combine both qualitative and quantitative methods as complementary methods has emerged over recent years. By applying both methods of research, scientists can take advantage of interpretative characteristics of qualitative methods as well as experimental dimensions of quantitative methods.

  4. Influence analysis in quantitative trait loci detection

    PubMed Central

    Dou, Xiaoling; Kuriki, Satoshi; Maeno, Akiteru; Takada, Toyoyuki; Shiroishi, Toshihiko

    2014-01-01

    This paper presents systematic methods for the detection of influential individuals that affect the log odds (LOD) score curve. We derive general formulas of influence functions for profile likelihoods and introduce them into two standard quantitative trait locus detection methods—the interval mapping method and single marker analysis. Besides influence analysis on specific LOD scores, we also develop influence analysis methods on the shape of the LOD score curves. A simulation-based method is proposed to assess the significance of the influence of the individuals. These methods are shown useful in the influence analysis of a real dataset of an experimental population from an F2 mouse cross. By receiver operating characteristic analysis, we confirm that the proposed methods show better performance than existing diagnostics. PMID:24740424

  5. Bioimaging for quantitative phenotype analysis.

    PubMed

    Chen, Weiyang; Xia, Xian; Huang, Yi; Chen, Xingwei; Han, Jing-Dong J

    2016-06-01

    With the development of bio-imaging techniques, an increasing number of studies apply these techniques to generate a myriad of image data. Its applications range from quantification of cellular, tissue, organismal and behavioral phenotypes of model organisms, to human facial phenotypes. The bio-imaging approaches to automatically detect, quantify, and profile phenotypic changes related to specific biological questions open new doors to studying phenotype-genotype associations and to precisely evaluating molecular changes associated with quantitative phenotypes. Here, we review major applications of bioimage-based quantitative phenotype analysis. Specifically, we describe the biological questions and experimental needs addressable by these analyses, computational techniques and tools that are available in these contexts, and the new perspectives on phenotype-genotype association uncovered by such analyses.

  6. Quantitative analysis of lipids: a higher-throughput LC–MS/MS-based method and its comparison to ELISA

    PubMed Central

    Gandhi, Adarsh S; Budac, David; Khayrullina, Tanzilya; Staal, Roland; Chandrasena, Gamini

    2017-01-01

    Aim: Lipids such as prostaglandins, leukotrienes and thromboxanes are released as a result of an inflammatory episode in pain (central and peripheral). Methodology & results: To measure these lipids as potential mechanistic biomarkers in neuropathic pain models, we developed a higher-throughput LC–MS/MS-based method with simultaneous detection of PGE2, PGD2, PGF2α, LTB4, TXB2 and 2-arachidonoyl glycerol in brain and spinal cord tissues. We also demonstrate that the LC–MS/MS method was more sensitive and specific in differentiating PGE2 levels in CNS tissues compared with ELISA. Conclusion: The ability to modify the LC–MS/MS method to accommodate numerous other lipids in one analysis, demonstrates that the presented method offers a cost–effective and more sensitive alternative to ELISA method useful in drug discovery settings. PMID:28344822

  7. Quantitative WDS analysis using electron probe microanalyzer

    SciTech Connect

    Ul-Hamid, Anwar . E-mail: anwar@kfupm.edu.sa; Tawancy, Hani M.; Mohammed, Abdul-Rashid I.; Al-Jaroudi, Said S.; Abbas, Nureddin M.

    2006-04-15

    In this paper, the procedure for conducting quantitative elemental analysis by ZAF correction method using wavelength dispersive X-ray spectroscopy (WDS) in an electron probe microanalyzer (EPMA) is elaborated. Analysis of a thermal barrier coating (TBC) system formed on a Ni-based single crystal superalloy is presented as an example to illustrate the analysis of samples consisting of a large number of major and minor elements. The analysis was performed by known standards and measured peak-to-background intensity ratios. The procedure for using separate set of acquisition conditions for major and minor element analysis is explained and its importance is stressed.

  8. Simultaneous quantitative analysis of olmesartan, amlodipine and hydrochlorothiazide in their combined dosage form utilizing classical and alternating least squares based chemometric methods.

    PubMed

    Darwish, Hany W; Bakheit, Ahmed H; Abdelhameed, Ali S

    2016-03-01

    Simultaneous spectrophotometric analysis of a multi-component dosage form of olmesartan, amlodipine and hydrochlorothiazide used for the treatment of hypertension has been carried out using various chemometric methods. Multivariate calibration methods include classical least squares (CLS) executed by net analyte processing (NAP-CLS), orthogonal signal correction (OSC-CLS) and direct orthogonal signal correction (DOSC-CLS) in addition to multivariate curve resolution-alternating least squares (MCR-ALS). Results demonstrated the efficiency of the proposed methods as quantitative tools of analysis as well as their qualitative capability. The three analytes were determined precisely using the aforementioned methods in an external data set and in a dosage form after optimization of experimental conditions. Finally, the efficiency of the models was validated via comparison with the partial least squares (PLS) method in terms of accuracy and precision.

  9. A fast and efficient LC-MS/MS method for detection, identification and quantitative analysis of bioactive sesterterpenes in Salvia dominica crude extracts.

    PubMed

    Dal Piaz, Fabrizio; Imparato, Salvatore; Lepore, Laura; Bader, Ammar; De Tommasi, Nunziatina

    2010-01-05

    Sesterterpenes are a small group of terpenoids showing a number of interesting pharmacological properties, including cytotoxicity, anti-inflammatory, anti-microbial and anti-angiogenic activities and platelet aggregation inhibition. Recently, some sesterterpene lactones isolated from Salvia dominica have been shown to modulate enzymatic activity of tubulin tyrosine ligase (TTL), a promising target for new anticancer therapeutic strategies. However, to allow a direct use of S. dominica extracts as a source of TTL inhibitors, analytical method aimed to their fast qualitative and quantitative characterization is required. Despite the structural features and diverse biological activities of sesterterpenoids, actually no analytical method for their quantization into complex mixtures has been published. Here we describe an LC-MS/MS method aimed to qualitative and quantitative analysis of sesterterpenes lactones in the crude extracts obtained from different parts of S. dominica. This approach allowed us to characterize all the sesterterpenes by a single step analysis and also to identify two unknown compounds. Moreover, a quantitative comparison of the composition in sesterterpenes of extracts obtained from S. dominica leaves, roots and leaf galls was performed, leading to the definition of both leaves and leaf galls as suitable sources of TTL inhibitors.

  10. A rapid, sensitive method for quantitative analysis of underivatized amino acids by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

    PubMed

    Le, Anthony; Ng, Angelina; Kwan, Tony; Cusmano-Ozog, Kristina; Cowan, Tina M

    2014-01-01

    The quantitation of free amino acids from physiologic samples is essential for diagnosing and monitoring patients with inherited metabolic disorders. Current methods are hindered by long preparative and/or analysis times, expensive reagents, and often suboptimal performance characteristics. To overcome these challenges, a improved method for amino acid analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed and validated. Samples were deproteinized with sulfosalicylic acid and supernatants diluted with tridecafluoroheptanoic acid. Chromatographic separation of amino acids occurred using two columns, with conditions favoring resolution of isobaric compounds and minimizing ion suppression. Eluted compounds were detected by selective reaction monitoring, and quantitated by relating peak areas of amino acids to externally run standards. Validation studies evaluated linearity, within- and between-run imprecision, lower limits of detection and quantification for 33 amino acids, and correlation with the Biochrom 30 Amino Acid Analyzer. Total run time including re-equilibration was 15min per sample. Within-run precision averaged 2.8% for all compounds, with an average linear correlation coefficient of 0.995. The majority of compounds were reliably quantitated at ≤0.1μM. Between-run precision averaged 4.0%. Results showed excellent correlation with the Biochrom 30 amino acid analyzer with an average overall correlation of 0.908. We conclude that our method is extremely sensitive, specific and reproducible and represents an improvement over other currently available technologies.

  11. Chemoenzymatic method for glycomics: isolation, identification, and quantitation

    PubMed Central

    Yang, Shuang; Rubin, Abigail; Eshghi, Shadi Toghi; Zhang, Hui

    2015-01-01

    Over the past decade, considerable progress has been made with respect to the analytical methods for analysis of glycans from biological sources. Regardless of the specific methods that are used, glycan analysis includes isolation, identification, and quantitation. Derivatization is indispensable to increase their identification. Derivatization of glycans can be performed by permethylation or carbodiimide coupling / esterification. By introducing a fluorophore or chromophore at their reducing end, glycans can be separated by electrophoresis or chromatography. The fluorogenically labeled glycans can be quantitated using fluorescent detection. The recently developed approaches using solid-phase such as glycoprotein immobilization for glycan extraction and on-tissue glycan mass spectrometry imaging demonstrate advantages over methods performed in solution. Derivatization of sialic acids is favorably implemented on the solid support using carbodiimide coupling, and the released glycans can be further modified at the reducing end or permethylated for quantitative analysis. In this review, methods for glycan isolation, identification, and quantitation are discussed. PMID:26390280

  12. A simple ERP method for quantitative analysis of cognitive workload in myoelectric prosthesis control and human-machine interaction.

    PubMed

    Deeny, Sean; Chicoine, Caitlin; Hargrove, Levi; Parrish, Todd; Jayaraman, Arun

    2014-01-01

    Common goals in the development of human-machine interface (HMI) technology are to reduce cognitive workload and increase function. However, objective and quantitative outcome measures assessing cognitive workload have not been standardized for HMI research. The present study examines the efficacy of a simple event-related potential (ERP) measure of cortical effort during myoelectric control of a virtual limb for use as an outcome tool. Participants trained and tested on two methods of control, direct control (DC) and pattern recognition control (PRC), while electroencephalographic (EEG) activity was recorded. Eighteen healthy participants with intact limbs were tested using DC and PRC under three conditions: passive viewing, easy, and hard. Novel auditory probes were presented at random intervals during testing, and significant task-difficulty effects were observed in the P200, P300, and a late positive potential (LPP), supporting the efficacy of ERPs as a cognitive workload measure in HMI tasks. LPP amplitude distinguished DC from PRC in the hard condition with higher amplitude in PRC, consistent with lower cognitive workload in PRC relative to DC for complex movements. Participants completed trials faster in the easy condition using DC relative to PRC, but completed trials more slowly using DC relative to PRC in the hard condition. The results provide promising support for ERPs as an outcome measure for cognitive workload in HMI research such as prosthetics, exoskeletons, and other assistive devices, and can be used to evaluate and guide new technologies for more intuitive HMI control.

  13. A Simple ERP Method for Quantitative Analysis of Cognitive Workload in Myoelectric Prosthesis Control and Human-Machine Interaction

    PubMed Central

    Deeny, Sean; Chicoine, Caitlin; Hargrove, Levi; Parrish, Todd; Jayaraman, Arun

    2014-01-01

    Common goals in the development of human-machine interface (HMI) technology are to reduce cognitive workload and increase function. However, objective and quantitative outcome measures assessing cognitive workload have not been standardized for HMI research. The present study examines the efficacy of a simple event-related potential (ERP) measure of cortical effort during myoelectric control of a virtual limb for use as an outcome tool. Participants trained and tested on two methods of control, direct control (DC) and pattern recognition control (PRC), while electroencephalographic (EEG) activity was recorded. Eighteen healthy participants with intact limbs were tested using DC and PRC under three conditions: passive viewing, easy, and hard. Novel auditory probes were presented at random intervals during testing, and significant task-difficulty effects were observed in the P200, P300, and a late positive potential (LPP), supporting the efficacy of ERPs as a cognitive workload measure in HMI tasks. LPP amplitude distinguished DC from PRC in the hard condition with higher amplitude in PRC, consistent with lower cognitive workload in PRC relative to DC for complex movements. Participants completed trials faster in the easy condition using DC relative to PRC, but completed trials more slowly using DC relative to PRC in the hard condition. The results provide promising support for ERPs as an outcome measure for cognitive workload in HMI research such as prosthetics, exoskeletons, and other assistive devices, and can be used to evaluate and guide new technologies for more intuitive HMI control. PMID:25402345

  14. Advanced time average holographic method for measurement in extensive vibration amplitude range with quantitative single-pixel analysis

    NASA Astrophysics Data System (ADS)

    Psota, Pavel; Lédl, Vít.; Vojtíšek, Petr; Václavík, Jan; Doleček, Roman; Mokrý, Pavel

    2015-05-01

    In this paper we propose a time average digital holographical arrangement employing frequency shift of reference wave and its phase modulation. It results in Phase Modulated Frequency Shifted Time Average Digital Holography PMFSTADH method. This method has a potential to extend currently using frequency shifted time average digital holography to possibility of numerical analysis. It is primarily useful for measurement of great or very small amplitudes of vibration. Moreover we use acusto-optical modulators to realize frequency as well as phase modulation so we need no additional hardware in our experimental setup.

  15. Development of a quantitative LC-MS/MS method for the analysis of common propellant powder stabilizers in gunshot residue.

    PubMed

    Laza, Désiré; Nys, Bart; Kinder, Jan De; Kirsch-De Mesmaeker, Andrée; Moucheron, Cécile

    2007-07-01

    In traditional scanning electron microscopy/energy dispersive X-ray analysis of gunshot residue (GSR), one has to cope more and more frequently with limitations of this technique due to the use of lead-free ammunition or ammunition lacking heavy metals. New methods for the analysis of the organic components of common propellant powder stabilizers were developed based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). A multiple reactions monitoring scanning method was created for the screening of akardite II, ethylcentralite, diphenylamine, methylcentralite, N-nitrosodiphenylamine, 2-nitrodiphenylamine, and 4-nitrodiphenylamine, present in standards mixtures. Five out of seven of these target compounds can be selectively identified and distinguished from the two others with a high accuracy. Samples from the hands of a shooter were collected by swabbing and underwent solid phase extraction prior to analysis. Detection limits ranging from 5 to 115 mug injected were achieved. Results from several firing trials show that the LC-MS/MS method is suitable for the detection of stabilizers in samples collected following the firing of 9 mm Para ammunitions.

  16. Good practices for quantitative bias analysis.

    PubMed

    Lash, Timothy L; Fox, Matthew P; MacLehose, Richard F; Maldonado, George; McCandless, Lawrence C; Greenland, Sander

    2014-12-01

    Quantitative bias analysis serves several objectives in epidemiological research. First, it provides a quantitative estimate of the direction, magnitude and uncertainty arising from systematic errors. Second, the acts of identifying sources of systematic error, writing down models to quantify them, assigning values to the bias parameters and interpreting the results combat the human tendency towards overconfidence in research results, syntheses and critiques and the inferences that rest upon them. Finally, by suggesting aspects that dominate uncertainty in a particular research result or topic area, bias analysis can guide efficient allocation of sparse research resources. The fundamental methods of bias analyses have been known for decades, and there have been calls for more widespread use for nearly as long. There was a time when some believed that bias analyses were rarely undertaken because the methods were not widely known and because automated computing tools were not readily available to implement the methods. These shortcomings have been largely resolved. We must, therefore, contemplate other barriers to implementation. One possibility is that practitioners avoid the analyses because they lack confidence in the practice of bias analysis. The purpose of this paper is therefore to describe what we view as good practices for applying quantitative bias analysis to epidemiological data, directed towards those familiar with the methods. We focus on answering questions often posed to those of us who advocate incorporation of bias analysis methods into teaching and research. These include the following. When is bias analysis practical and productive? How does one select the biases that ought to be addressed? How does one select a method to model biases? How does one assign values to the parameters of a bias model? How does one present and interpret a bias analysis?. We hope that our guide to good practices for conducting and presenting bias analyses will encourage

  17. Micellar electrokinetic capillary chromatographic method for the quantitative analysis of uricosuric and antigout drugs in pharmaceutical preparations.

    PubMed

    Kou, Hwang-Shang; Lin, Tsai-Pei; Chung, Tang-Chia; Wu, Hsin-Lung

    2006-06-01

    A simple MEKC method is described for the separation and quantification of seven widely used uricosuric and antigout drugs, including allopurinol (AP), benzbromarone (BZB), colchicine (COL), orotic acid (OA), oxypurinol (OP), probenecid (PB), and sulfinpyrazone (SPZ). The drugs were separated in a BGE of borate buffer (45 mM; pH 9.00) with SDS (20 mM) as the micellar source and the separated drugs were directly monitored with a UV detector (214 nm). Several parameters affecting the separation and analysis of the drugs were studied. Based on the normalized peak-area ratios of the drugs to an internal standard versus the concentration of the drugs, the method is applicable to quantify BZB, COL, and SPZ (each 5-200 microM), AP, OA, OP, and PB (each 10-200 microM) with detection limits (S/N = 3, 0.5 psi, 5 s injection) in the range of 0.6-4.0 microM. The precision (RSD; n = 5) and accuracy (relative error; n = 5) of the method for intraday and interday analyses of the analytes at three levels (30, 120, and 180 microM) are below 4% (n = 3). The method was demonstrated to be suitable for the analysis of AP and COL in commercial tablets with speed and simplicity.

  18. Using Qualitative Hazard Analysis to Guide Quantitative Safety Analysis

    NASA Technical Reports Server (NTRS)

    Shortle, J. F.; Allocco, M.

    2005-01-01

    Quantitative methods can be beneficial in many types of safety investigations. However, there are many difficulties in using quantitative m ethods. Far example, there may be little relevant data available. This paper proposes a framework for using quantitative hazard analysis to prioritize hazard scenarios most suitable for quantitative mziysis. The framework first categorizes hazard scenarios by severity and likelihood. We then propose another metric "modeling difficulty" that desc ribes the complexity in modeling a given hazard scenario quantitatively. The combined metrics of severity, likelihood, and modeling difficu lty help to prioritize hazard scenarios for which quantitative analys is should be applied. We have applied this methodology to proposed concepts of operations for reduced wake separation for airplane operatio ns at closely spaced parallel runways.

  19. Modified methods for defining the chlorophyll concentration in the sea using submersible fluorimeters - Theoretical and quantitative analysis

    NASA Astrophysics Data System (ADS)

    Ostrowska, Mirosława; Stoń-Egiert, Joanna; Woźniak, Bogdan

    2015-10-01

    The paper analyses the reliability of fluorimetric methods for determining chlorophyll concentrations in the sea using a submersible fluorimeter. To this end, such concentrations were measured with a bbe FluoroProbe spectrofluorimeter as well as standard methods in a range of Baltic basins of different trophic index. This analysis shows that fluorimetrically determined chlorophyll concentrations are usually slightly lower than those obtained with standard methods and that the error increases with rising trophic index. Similar tendencies are observed in relation to measurements carried out with different types of fluorimeters and in different waters. Probably due to the nonlinearity of the relationship between the concentration of chlorophyll a and the intensity of its fluorescence, this can be explained by the changes in the fluorescence quantum yield and package effect function with trophic index. It is therefore recommended that the internal algorithms of fluorimeters be recalibrated in the manner suggested.

  20. A Robust and Fully-Automated Chromatographic Method for the Quantitative Purification of Ca and Sr for Isotopic Analysis

    NASA Astrophysics Data System (ADS)

    Smith, H. B.; Kim, H.; Romaniello, S. J.; Field, P.; Anbar, A. D.

    2014-12-01

    High throughput methods for sample purification are required to effectively exploit new opportunities in the study of non-traditional stable isotopes. Many geochemical isotopic studies would benefit from larger data sets, but these are often impractical with manual drip chromatography techniques, which can be time-consuming and demand the attention of skilled laboratory staff. Here we present a new, fully-automated single-column method suitable for the purification of both Ca and Sr for stable and radiogenic isotopic analysis. The method can accommodate a wide variety of sample types, including carbonates, bones, and teeth; silicate rocks and sediments; fresh and marine waters; and biological samples such as blood and urine. Protocols for these isotopic analyses are being developed for use on the new prepFAST-MCTM system from Elemental Scientific (ESI). The system is highly adaptable and processes up to 24-60 samples per day by reusing a single chromatographic column. Efficient column cleaning between samples and an all Teflon flow path ensures that sample carryover is maintained at the level of background laboratory blanks typical for manual drip chromatography. This method is part of a family of new fully-automated chromatographic methods being developed to address many different isotopic systems including B, Ca, Fe, Cu, Zn, Sr, Cd, Pb, and U. These methods are designed to be rugged and transferrable, and to allow the preparation of large, diverse sample sets via a highly repeatable process with minimal effort.

  1. RNA Enrichment Method for Quantitative Transcriptional Analysis of Pathogens In Vivo Applied to the Fungus Candida albicans

    PubMed Central

    Amorim-Vaz, Sara; Tran, Van Du T.; Pradervand, Sylvain; Pagni, Marco; Coste, Alix T.

    2015-01-01

    ABSTRACT In vivo transcriptional analyses of microbial pathogens are often hampered by low proportions of pathogen biomass in host organs, hindering the coverage of full pathogen transcriptome. We aimed to address the transcriptome profiles of Candida albicans, the most prevalent fungal pathogen in systemically infected immunocompromised patients, during systemic infection in different hosts. We developed a strategy for high-resolution quantitative analysis of the C. albicans transcriptome directly from early and late stages of systemic infection in two different host models, mouse and the insect Galleria mellonella. Our results show that transcriptome sequencing (RNA-seq) libraries were enriched for fungal transcripts up to 1,600-fold using biotinylated bait probes to capture C. albicans sequences. This enrichment biased the read counts of only ~3% of the genes, which can be identified and removed based on a priori criteria. This allowed an unprecedented resolution of C. albicans transcriptome in vivo, with detection of over 86% of its genes. The transcriptional response of the fungus was surprisingly similar during infection of the two hosts and at the two time points, although some host- and time point-specific genes could be identified. Genes that were highly induced during infection were involved, for instance, in stress response, adhesion, iron acquisition, and biofilm formation. Of the in vivo-regulated genes, 10% are still of unknown function, and their future study will be of great interest. The fungal RNA enrichment procedure used here will help a better characterization of the C. albicans response in infected hosts and may be applied to other microbial pathogens. PMID:26396240

  2. The RAMANITA method for non-destructive and in situ semi-quantitative chemical analysis of mineral solid-solutions by multidimensional calibration of Raman wavenumber shifts.

    PubMed

    Smith, David C

    2005-08-01

    The "RAMANITA" method, for semi-quantitative chemical analysis of mineral solid-solutions by multidimensional calibration of Raman wavenumber shifts and mathematical calculation by simultaneous equations, is published here in detail in English for the first time. It was conceived by the present writer 20 years ago for binary and ternary pyroxene and garnet systems. The mathematical description was set out in 1989, but in an abstract in an obscure French special publication. Detailed "step-by-step" calibration of two garnet ternaries, followed by their linking, in the early 1990s provided a hexary garnet database. Much later, using this garnet database, which forms part of his personal database called RAMANITA, the present writer began to develop the method by improving the terminology, automating the calculations, discussing problems and experimenting with different real chemical problems in archaeometry. Although this RAMANITA method has been very briefly mentioned in two recent books, the necessary full mathematical explanation is given only here. The method will find application in any study which requires obtaining a non-destructive semi-quantitative chemical analysis from mineral solid solutions that cannot be analysed by any destructive analytical method, in particular for archaeological, geological or extraterrestrial research projects, e.g. Recently some other workers have begun deducing chemical compositions from Raman wavenumber shifts in multivariate chemical space, but the philosophical approach is quite different.

  3. Quantitative Methods in Psychology: Inevitable and Useless

    PubMed Central

    Toomela, Aaro

    2010-01-01

    Science begins with the question, what do I want to know? Science becomes science, however, only when this question is justified and the appropriate methodology is chosen for answering the research question. Research question should precede the other questions; methods should be chosen according to the research question and not vice versa. Modern quantitative psychology has accepted method as primary; research questions are adjusted to the methods. For understanding thinking in modern quantitative psychology, two epistemologies should be distinguished: structural-systemic that is based on Aristotelian thinking, and associative-quantitative that is based on Cartesian–Humean thinking. The first aims at understanding the structure that underlies the studied processes; the second looks for identification of cause–effect relationships between the events with no possible access to the understanding of the structures that underlie the processes. Quantitative methodology in particular as well as mathematical psychology in general, is useless for answering questions about structures and processes that underlie observed behaviors. Nevertheless, quantitative science is almost inevitable in a situation where the systemic-structural basis of behavior is not well understood; all sorts of applied decisions can be made on the basis of quantitative studies. In order to proceed, psychology should study structures; methodologically, constructive experiments should be added to observations and analytic experiments. PMID:21833199

  4. Multianalytical Method Validation for Qualitative and Quantitative Analysis of Solvents of Abuse in Oral Fluid by HS-GC/MS.

    PubMed

    Coppe, Bruna Claudia; Borille, Bruna Tassi; Fiorentin, Taís Regina; Jacques, Ana Laura Bemvenuti; Fagundes, Ana Claudia; Castro, Stela Maris de Jezus; Remy, Lysa Silveira; Pechansky, Flavio; Limberger, Renata Pereira

    2016-01-01

    The use of oral fluid as a biological matrix to monitor the use of drugs of abuse is a global trend because it presents several advantages and good correlation to the blood level. Thus, the present work aimed to develop and validate an analytical method for quantification and detection of solvents used as inhalants of abuse in oral fluid (OF), using Quantisal™ as collector device by headspace and gas chromatography coupled with a mass detector (HS-GC/MS). Chromatographic separation was performed with a ZB-BAC1 column and the total time of analysis was 11.8 min. The method showed good linearity (correlation coefficient higher than 0.99 for all solvents). The limits of detection ranged from 0.05 to 5 mg/L, while the lower limits of quantification ranged from 2.5 to 12.5 mg/L. Accuracy, precision, matrix effect, and residual effect presented satisfactory results, meeting the criteria accepted for the validation of bioanalytical methods. The method showed good selectivity considering that, for solvents coeluting at the same retention time, resolution was performed by the mass detector. The method developed proved to be adequate when applied in OF samples from users of drugs and may be used to monitor the abuse of inhalants in routine forensic analyses.

  5. Multianalytical Method Validation for Qualitative and Quantitative Analysis of Solvents of Abuse in Oral Fluid by HS-GC/MS

    PubMed Central

    Coppe, Bruna Claudia; Borille, Bruna Tassi; Fiorentin, Taís Regina; Jacques, Ana Laura Bemvenuti; Fagundes, Ana Claudia; Castro, Stela Maris de Jezus; Remy, Lysa Silveira; Pechansky, Flavio; Limberger, Renata Pereira

    2016-01-01

    The use of oral fluid as a biological matrix to monitor the use of drugs of abuse is a global trend because it presents several advantages and good correlation to the blood level. Thus, the present work aimed to develop and validate an analytical method for quantification and detection of solvents used as inhalants of abuse in oral fluid (OF), using Quantisal™ as collector device by headspace and gas chromatography coupled with a mass detector (HS-GC/MS). Chromatographic separation was performed with a ZB-BAC1 column and the total time of analysis was 11.8 min. The method showed good linearity (correlation coefficient higher than 0.99 for all solvents). The limits of detection ranged from 0.05 to 5 mg/L, while the lower limits of quantification ranged from 2.5 to 12.5 mg/L. Accuracy, precision, matrix effect, and residual effect presented satisfactory results, meeting the criteria accepted for the validation of bioanalytical methods. The method showed good selectivity considering that, for solvents coeluting at the same retention time, resolution was performed by the mass detector. The method developed proved to be adequate when applied in OF samples from users of drugs and may be used to monitor the abuse of inhalants in routine forensic analyses. PMID:27274728

  6. Novel automated extraction method for quantitative analysis of urinary 11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH).

    PubMed

    Fu, Shanlin; Lewis, John

    2008-05-01

    An automated extraction method for extracting the major urinary metabolite of cannabis, 11-nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) was developed on the four-probe Gilson ASPEC XL4trade mark solid-phase extraction (SPE) system. The method works on liquid-liquid extraction principles but does not require the use of SPE cartridges. The limits of detection and quantitation and the upper limit of linearity (ULOL) of the developed method were found to be 1, 2, and 1,500 ng/mL, respectively. There was no detectable carry over after 10,000 ng/mL analyte. For a batch of 76 samples, the process uses less than 100 mL methanol, 450 mL extracting solvent hexane/ethyl acetate (5:1, v/v) and 1 L rinsing solvent, 30% methanol in water. The automated extraction process takes 5 h to complete. Precision and accuracy of the method are comparable to both manual liquid-liquid extraction and automated SPE methods. The method has proven to be a simple, speedy, and economical alternative to the currently popular automated SPE method for the quantitative analysis of urinary THC-COOH.

  7. Quantitative resilience analysis through control design.

    SciTech Connect

    Sunderland, Daniel; Vugrin, Eric D.; Camphouse, Russell Chris

    2009-09-01

    Critical infrastructure resilience has become a national priority for the U. S. Department of Homeland Security. System resilience has been studied for several decades in many different disciplines, but no standards or unifying methods exist for critical infrastructure resilience analysis. Few quantitative resilience methods exist, and those existing approaches tend to be rather simplistic and, hence, not capable of sufficiently assessing all aspects of critical infrastructure resilience. This report documents the results of a late-start Laboratory Directed Research and Development (LDRD) project that investigated the development of quantitative resilience through application of control design methods. Specifically, we conducted a survey of infrastructure models to assess what types of control design might be applicable for critical infrastructure resilience assessment. As a result of this survey, we developed a decision process that directs the resilience analyst to the control method that is most likely applicable to the system under consideration. Furthermore, we developed optimal control strategies for two sets of representative infrastructure systems to demonstrate how control methods could be used to assess the resilience of the systems to catastrophic disruptions. We present recommendations for future work to continue the development of quantitative resilience analysis methods.

  8. A new HPLC method for azithromycin quantitation.

    PubMed

    Zubata, Patricia; Ceresole, Rita; Rosasco, Maria Ana; Pizzorno, Maria Teresa

    2002-02-01

    A simple liquid chromatographic method was developed for the estimation of azithromycin raw material and in pharmaceutical forms. The sample was chromatographed on a reverse phase C18 column and eluants monitored at a wavelength of 215 nm. The method was accurate, precise and sufficiently selective. It is applicable for its quantitation, stability and dissolution tests.

  9. Development of a liquid chromatography-tandem mass spectrometry method for quantitative analysis of trace d-amino acids.

    PubMed

    Nakano, Yosuke; Konya, Yutaka; Taniguchi, Moyu; Fukusaki, Eiichiro

    2017-01-01

    d-Amino acids have recently attracted much attention in various research fields including medical, clinical and food industry due to their important biological functions that differ from l-amino acid. Most chiral amino acid separation techniques require complicated derivatization procedures in order to achieve the desirable chromatographic behavior and detectability. Thus, the aim of this research is to develop a highly sensitive analytical method for the enantioseparation of chiral amino acids without any derivatization process using liquid chromatography-tandem mass spectrometry (LC-MS/MS). By optimizing MS/MS parameters, we established a quantification method that allowed the simultaneous analysis of 18 d-amino acids with high sensitivity and reproducibility. Additionally, we applied the method to food sample (vinegar) for the validation, and successfully quantified trace levels of d-amino acids in samples. These results demonstrated the applicability and feasibility of the LC-MS/MS method as a novel, effective tool for d-amino acid measurement in various biological samples.

  10. A comprehensive method for extraction and quantitative analysis of sterols and secosteroids from human plasma[S

    PubMed Central

    McDonald, Jeffrey G.; Smith, Daniel D.; Stiles, Ashlee R.; Russell, David W.

    2012-01-01

    We describe the development of a method for the extraction and analysis of 62 sterols, oxysterols, and secosteroids from human plasma using a combination of HPLC-MS and GC-MS. Deuterated standards are added to 200 μl of human plasma. Bulk lipids are extracted with methanol:dichloromethane, the sample is hydrolyzed using a novel procedure, and sterols and secosteroids are isolated using solid-phase extraction (SPE). Compounds are resolved on C18 core-shell HPLC columns and by GC. Sterols and oxysterols are measured using triple quadrupole mass spectrometers, and lathosterol is measured using GC-MS. Detection for each compound measured by HPLC-MS was ∪ 1 ng/ml of plasma. Extraction efficiency was between 85 and 110%; day-to-day variability showed a relative standard error of <10%. Numerous oxysterols were detected, including the side chain oxysterols 22-, 24-, 25-, and 27-hydroxycholesterol, as well as ring-structure oxysterols 7α- and 4β-hydroxycholesterol. Intermediates from the cholesterol biosynthetic pathway were also detected, including zymosterol, desmosterol, and lanosterol. This method also allowed the quantification of six secosteroids, including the 25-hydroxylated species of vitamins D2 and D3. Application of this method to plasma samples revealed that at least 50 samples could be extracted in a routine day. PMID:22517925

  11. Quantitative analysis of retinal OCT.

    PubMed

    Sonka, Milan; Abràmoff, Michael D

    2016-10-01

    Clinical acceptance of 3-D OCT retinal imaging brought rapid development of quantitative 3-D analysis of retinal layers, vasculature, retinal lesions as well as facilitated new research in retinal diseases. One of the cornerstones of many such analyses is segmentation and thickness quantification of retinal layers and the choroid, with an inherently 3-D simultaneous multi-layer LOGISMOS (Layered Optimal Graph Image Segmentation for Multiple Objects and Surfaces) segmentation approach being extremely well suited for the task. Once retinal layers are segmented, regional thickness, brightness, or texture-based indices of individual layers can be easily determined and thus contribute to our understanding of retinal or optic nerve head (ONH) disease processes and can be employed for determination of disease status, treatment responses, visual function, etc. Out of many applications, examples provided in this paper focus on image-guided therapy and outcome prediction in age-related macular degeneration and on assessing visual function from retinal layer structure in glaucoma.

  12. A non-derivative method for the quantitative analysis of isosteroidal alkaloids from Fritillaria by high performance liquid chromatography combined with charged aerosol detection.

    PubMed

    Long, Zhen; Guo, Zhimou; Acworth, Ian N; Liu, Xiaoda; Jin, Yan; Liu, Xingguo; Liu, Lvye; Liang, Lina

    2016-05-01

    A non-derivative method was developed for the qualitative and quantitative analysis of isosteroidal alkaloids from Fritillaria thunbergii. During method development the performance of two universal detectors, the charged aerosol detector (CAD) and evaporative light scattering detector (ELSD), were evaluated. The CAD was found to be 30 to 55 times more sensitive than ELSD enabling the measurement of low levels of reference compound impurities that could not be detected by ELSD. The peak area percent of the reference compound, peimisine, obtained by CAD was 50.10%, but 91.66% by ELSD showing that CAD is suitable to estimate the presence of impurities. The CAD showed good reproducibility with overall intra- and inter-day peak area RSD values of less than 1.8% and 2.7%, respectively and had a linear dynamic range of up to 4 orders of magnitude (0.06-44mg/L) for peimine and peiminine. The optimized method was used for the quantitative analysis of peimine and peiminine from F. thunbergii.

  13. An integrated platform for directly widely-targeted quantitative analysis of feces part I: Platform configuration and method validation.

    PubMed

    Song, Yuelin; Song, Qingqing; Li, Jun; Zheng, Jiao; Li, Chun; Zhang, Yuan; Zhang, Lingling; Jiang, Yong; Tu, Pengfei

    2016-07-08

    Direct analysis is of great importance to understand the real chemical profile of a given sample, notably biological materials, because either chemical degradation or diverse errors and uncertainties might be resulted from sophisticated protocols. In comparison with biofluids, it is still challenging for direct analysis of solid biological samples using high performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Herein, a new analytical platform was configured by online hyphenating pressurized liquid extraction (PLE), turbulent flow chromatography (TFC), and LC-MS/MS. A facile, but robust PLE module was constructed based on the phenomenon that noticeable back-pressure can be generated during rapid fluid passing through a narrow tube. TFC column that is advantageous at extracting low molecular analytes from rushing fluid was employed to link at the outlet of the PLE module to capture constituents-of-interest. An electronic 6-port/2-position valve was introduced between TFC column and LC-MS/MS to fragment each measurement into extraction and elution phases, whereas LC-MS/MS took the charge of analyte separation and monitoring. As a proof of concept, simultaneous determination of 24 endogenous substances including eighteen steroids, five eicosanoids, and one porphyrin in feces was carried out in this paper. Method validation assays demonstrated the analytical platform to be qualified for directly simultaneous measurement of diverse endogenous analytes in fecal matrices. Application of this integrated platform on homolog-focused profiling of feces is discussed in a companion paper.

  14. High-resolution gas chromatography/mass spectrometry method for characterization and quantitative analysis of ginkgolic acids in Ginkgo biloba plants, extracts, and dietary supplements.

    PubMed

    Wang, Mei; Zhao, Jianping; Avula, Bharathi; Wang, Yan-Hong; Avonto, Cristina; Chittiboyina, Amar G; Wylie, Philip L; Parcher, Jon F; Khan, Ikhlas A

    2014-12-17

    A high-resolution gas chromatography/mass spectrometry (GC/MS) with selected ion monitor method focusing on the characterization and quantitative analysis of ginkgolic acids (GAs) in Ginkgo biloba L. plant materials, extracts, and commercial products was developed and validated. The method involved sample extraction with (1:1) methanol and 10% formic acid, liquid-liquid extraction with n-hexane, and derivatization with trimethylsulfonium hydroxide (TMSH). Separation of two saturated (C13:0 and C15:0) and six unsaturated ginkgolic acid methyl esters with different positional double bonds (C15:1 Δ8 and Δ10, C17:1 Δ8, Δ10, and Δ12, and C17:2) was achieved on a very polar (88% cyanopropyl) aryl-polysiloxane HP-88 capillary GC column. The double bond positions in the GAs were determined by ozonolysis. The developed GC/MS method was validated according to ICH guidelines, and the quantitation results were verified by comparison with a standard high-performance liquid chromatography method. Nineteen G. biloba authenticated and commercial plant samples and 21 dietary supplements purported to contain G. biloba leaf extracts were analyzed. Finally, the presence of the marker compounds, terpene trilactones and flavonol glycosides for Ginkgo biloba in the dietary supplements was determined by UHPLC/MS and used to confirm the presence of G. biloba leaf extracts in all of the botanical dietary supplements.

  15. Densitometric HPTLC method for qualitative, quantitative analysis and stability study of Coenzyme Q10 in pharmaceutical formulations utilizing normal and reversed-phase silica gel plates.

    PubMed

    Abdel-Kader, Maged Saad; Alam, Prawez; Alqasoumi, Saleh Ibrahim

    2016-03-01

    Two simple, precise and stability-indicating densitometric HPTLC method were developed and validated for qualitative and quantitative analysis of Coenzyme Q10 in pharmaceutical formulations using normal-phase (Method I) and reversed phase (Method II) silica gel TLC plates. Both methods were developed and validated with 10×20 cm glass-backed plates coated with 0.2 mm layers of either silica gel 60 F254 (E-Merck, Germany) using hexane-ethyl acetate (8.5:1.5 v/v) as developing system (Method I) or RP-18 silica gel 60 F254 (E-Merck, Germany) using methanol-acetone (4:6 v/v) as mobile phase (Method II). Both analyses were scanned with a densitometer at 282 nm. Linearity was found in the ranges 50-800 ng/spot (r(2)=0.9989) and 50-800 ng/spot (r(2)=0.9987) for Method I and Method II respectively. Stability of Coenzyme Q10 was explored by the two methods using acid, base, hydrogen peroxide, temperature and different solvents. Due to the efficiency of the method in separating Coenzyme Q10 from other ingredients including its degradation products, it can be applied for quality control, standardization of different pharmaceutical formulations and stability study.

  16. Electric Field Quantitative Measurement System and Method

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R. (Inventor)

    2016-01-01

    A method and system are provided for making a quantitative measurement of an electric field. A plurality of antennas separated from one another by known distances are arrayed in a region that extends in at least one dimension. A voltage difference between at least one selected pair of antennas is measured. Each voltage difference is divided by the known distance associated with the selected pair of antennas corresponding thereto to generate a resulting quantity. The plurality of resulting quantities defined over the region quantitatively describe an electric field therein.

  17. D-glucose, D-galactose, and D-lactose non-enzyme quantitative and qualitative analysis method based on Cu foam electrode.

    PubMed

    Jiaojiao, Jin; Yangyang, Ge; Gangying, Zheng; Yanping, Cai; Wei, Liu; Guohua, Hui

    2015-05-15

    Here, D-glucose, D-galactose, and D-lactose non-enzyme quantitative and qualitative analysis method using Cu foam electrode had been investigated. Porous Cu foam material was prepared by electrodeposition strategy, and used as working electrode. Cyclic voltammetry (CV) explained sweetener electro-oxidation process occurring on Cu foam electrode. Amperometric i-t scanning results demonstrated that Cu foam electrode fast responded to D-glucose, D-galactose, and D-lactose in linear concentration range between 0.18 mM and 3.47 mM with significant sensitivity of 1.79 mA cm(-2)mM(-1), 0.57 mA cm(-2)mM(-1), and 0.64 mA cm(-2)mM(-1), respectively. Limit of detection (LOD) was 9.30 μM, 29.40 μM, and 26 μM respectively (S/N=3). Sweetener species was decided by stochastic resonance (SR) signal-to-noise ratio (SNR) eigen peak located noise intensities. Interference experiment results demonstrated that Cu foam electrode selectively responded to sweeteners against interference chemicals. The proposed method provides a promising way for sweetener non-enzyme quantitative and qualitative analysis.

  18. Rapid quantitative analysis of individual anthocyanin content based on high-performance liquid chromatography with diode array detection with the pH differential method.

    PubMed

    Wang, Huayin

    2014-09-01

    A new quantitative technique for the simultaneous quantification of the individual anthocyanins based on the pH differential method and high-performance liquid chromatography with diode array detection is proposed in this paper. The six individual anthocyanins (cyanidin 3-glucoside, cyanidin 3-rutinoside, petunidin 3-glucoside, petunidin 3-rutinoside, and malvidin 3-rutinoside) from mulberry (Morus rubra) and Liriope platyphylla were used for demonstration and validation. The elution of anthocyanins was performed using a C18 column with stepwise gradient elution and individual anthocyanins were identified by high-performance liquid chromatography with tandem mass spectrometry. Based on the pH differential method, the high-performance liquid chromatography peak areas of maximum and reference absorption wavelengths of anthocyanin extracts were conducted to quantify individual anthocyanins. The calibration curves for these anthocyanins were linear within the range of 10-5500 mg/L. The correlation coefficients (r(2)) all exceeded 0.9972, and the limits of detection were in the range of 1-4 mg/L at a signal-to-noise ratio ≥5 for these anthocyanins. The proposed quantitative analysis was reproducible with good accuracy of all individual anthocyanins ranging from 96.3 to 104.2% and relative recoveries were in the range 98.4-103.2%. The proposed technique is performed without anthocyanin standards and is a simple, rapid, accurate, and economical method to determine individual anthocyanin contents.

  19. The RAMANITA © method for non-destructive and in situ semi-quantitative chemical analysis of mineral solid-solutions by multidimensional calibration of Raman wavenumber shifts

    NASA Astrophysics Data System (ADS)

    Smith, David C.

    2005-08-01

    The "RAMANITA ©" method, for semi-quantitative chemical analysis of mineral solid-solutions by multidimensional calibration of Raman wavenumber shifts and mathematical calculation by simultaneous equations, is published here in detail in English for the first time. It was conceived by the present writer 20 years ago for binary and ternary pyroxene and garnet systems. The mathematical description was set out in 1989, but in an abstract in an obscure French special publication. Detailed "step-by-step" calibration of two garnet ternaries, followed by their linking, by M. Pinet and D.C. Smith in the early 1990s provided a hexary garnet database. Much later, using this garnet database, which forms part of his personal database called RAMANITA ©, the present writer began to develop the method by improving the terminology, automating the calculations, discussing problems and experimenting with different real chemical problems in archaeometry. Although this RAMANITA © method has been very briefly mentioned in two recent books, the necessary full mathematical explanation is given only here. The method will find application in any study which requires obtaining a non-destructive semi-quantitative chemical analysis from mineral solid solutions that cannot be analysed by any destructive analytical method, in particular for archaeological, geological or extraterrestrial research projects, e.g. from gemstones or other crystalline artworks of the cultural heritage (especially by Mobile Raman Microscopy (MRM)) in situ in museums or at archaeological sites, including under water for subaquatic archaeometry; from scientifically precious mineral microinclusions (such as garnet or pyroxene within diamond); from minerals in rocks analysed in situ on planetary bodies by a rover (especially "at distance" by telescopy). Recently some other workers have begun deducing chemical compositions from Raman wavenumber shifts in multivariate chemical space, but the philosophical approach is

  20. Quantitative analysis of unconjugated and total bisphenol A in human urine using solid-phase extraction and UPLC-MS/MS: method implementation, method qualification and troubleshooting.

    PubMed

    Buscher, Brigitte; van de Lagemaat, Dick; Gries, Wolfgang; Beyer, Dieter; Markham, Dan A; Budinsky, Robert A; Dimond, Stephen S; Nath, Rajesh V; Snyder, Stephanie A; Hentges, Steven G

    2015-11-15

    The aim of the presented investigation was to document challenges encountered during implementation and qualification of a method for bisphenol A (BPA) analysis and to develop and discuss precautions taken to avoid and to monitor contamination with BPA during sample handling and analysis. Previously developed and published HPLC-MS/MS methods for the determination of unconjugated BPA (Markham et al. Journal of Analytical Toxicology, 34 (2010) 293-303) [17] and total BPA (Markham et al. Journal of Analytical Toxicology, 38 (2014) 194-203) [20] in human urine were combined and transferred into another laboratory. The initial method for unconjugated BPA was developed and evaluated in two independent laboratories simultaneously. The second method for total BPA was developed and evaluated in one of these laboratories to conserve resources. Accurate analysis of BPA at sub-ppb levels is a challenging task as BPA is a widely used material and is ubiquitous in the environment at trace concentrations. Propensity for contamination of biological samples with BPA is reported in the literature during sample collection, storage, and/or analysis. Contamination by trace levels of BPA is so pervasive that even with extraordinary care, it is difficult to completely exclude the introduction of BPA into biological samples and, consequently, contamination might have an impact on BPA biomonitoring data. The applied UPLC-MS/MS method was calibrated from 0.05 to 25ng/ml. The limit of quantification was 0.1ng/ml for unconjugated BPA and 0.2ng/ml for total BPA, respectively, in human urine. Finally, the method was applied to urine samples derived from 20 volunteers. Overall, BPA can be analyzed in human urine with acceptable recovery and repeatability if sufficient measures are taken to avoid contamination throughout the procedure from sample collection until UPLC-MS/MS analysis.

  1. An image analysis method for the precise selection and quantitation of fluorescently labeled cellular constituents: application to the measurement of human muscle cells in culture.

    PubMed

    Agley, Chibeza C; Velloso, Cristiana P; Lazarus, Norman R; Harridge, Stephen D R

    2012-06-01

    The accurate measurement of the morphological characteristics of cells with nonuniform conformations presents difficulties. We report here a straightforward method using immunofluorescent staining and the commercially available imaging program Adobe Photoshop, which allows objective and precise information to be gathered on irregularly shaped cells. We have applied this measurement technique to the analysis of human muscle cells and their immunologically marked intracellular constituents, as these cells are prone to adopting a highly branched phenotype in culture. Use of this method can be used to overcome many of the long-standing limitations of conventional approaches for quantifying muscle cell size in vitro. In addition, wider applications of Photoshop as a quantitative and semiquantitative tool in immunocytochemistry are explored.

  2. A proposal for comparing methods of quantitative analysis of endogenous compounds in biological systems by using the relative lower limit of quantification (rLLOQ).

    PubMed

    Tsikas, Dimitrios

    2009-08-01

    Accuracy, precision and lower limit of quantification (LLOQ) are experimentally achievable key analytical factors by which the quality of analytical methods can be ascribed and objectively evaluated. Endogenous substances (endobiotica) are physiologically present in biological fluids and tissues at varying basal concentration (C(0,Ln)). Formally, the definition of accuracy and LLOQ is same for xenobiotica and endobiotica. However, these analytical factors must be determined differently, notably by considering the C(0,Ln) value of endobiotica. Often, the impact of the endogeneity on the analytical method is underestimated. This especially applies to the LLOQ, because the LLOQ values for endobiotica are regularly not fixed measures due to the varying C(0,Ln) value in biological samples. In order to circumvent these difficulties and for a more reliable and objective evaluation and comparison of analytical methods for endobiotica, this work proposes the use of the relative lower limit of quantification, i.e., rLLOQ. The rLLOQ is defined as the percentage ratio of the LLOQ value, i.e., C(LLOQ) to C(0,Ln): rLLOQ = (C(LLOQ):C(0,Ln))x100. Thus, the rLLOQ describes that fraction of C(0,Ln) that can be still determined with acceptable values for accuracy (e.g., recovery of 100+/-20%) and precision (e.g., RSD < or = 20%) or with a total error (i.e., recovery+precision) of < or = 30%. Examples from the quantitative analysis of selected endogenous compounds by previously validated GC-MS, GC-MS/MS and LC-MS/MS methods support the appropriateness and expressiveness of the rLLOQ in the quantitative analysis of endobiotica.

  3. Quantitative Auger analysis of Nb-Ge superconducting alloys

    SciTech Connect

    Buitrago, R.H.

    1980-01-01

    The feasibility of using Auger electron analysis for quantitative analysis was investigated by studying Nb/sub 3/Ge thin-film Auger data with different approaches. A method base on elemental standards gave consistent quantitative values with reported Nb-Ge data. Alloy sputter yields were also calculated and results were consistent with those for pure elements.

  4. [Reconstituting evaluation methods based on both qualitative and quantitative paradigms].

    PubMed

    Miyata, Hiroaki; Okubo, Suguru; Yoshie, Satoru; Kai, Ichiro

    2011-01-01

    Debate about the relationship between quantitative and qualitative paradigms is often muddled and confusing and the clutter of terms and arguments has resulted in the concepts becoming obscure and unrecognizable. In this study we conducted content analysis regarding evaluation methods of qualitative healthcare research. We extracted descriptions on four types of evaluation paradigm (validity/credibility, reliability/credibility, objectivity/confirmability, and generalizability/transferability), and classified them into subcategories. In quantitative research, there has been many evaluation methods based on qualitative paradigms, and vice versa. Thus, it might not be useful to consider evaluation methods of qualitative paradigm are isolated from those of quantitative methods. Choosing practical evaluation methods based on the situation and prior conditions of each study is an important approach for researchers.

  5. Application of a rapid and efficient quantitative analysis method for traditional Chinese medicines: the case study of quality assessment of Salvia miltiorrhiza Bunge.

    PubMed

    Jing, Wen-Guang; Zhang, Jun; Zhang, Li-Yan; Wang, Dong-Zhe; Wang, Yue-Sheng; Liu, An

    2013-06-13

    A reference extractive, containing multiple active known compounds, has been considered to be an alternative to individual reference standards. However, in the Chinese Pharmacopoeia (ChP) the great majority of reference extractives have been primarily used for qualitative identification by thin-layer chromatography (TLC) and few studies on the applicability of reference extractives for quantitative analysis have been presented. Using Salvia miltiorrhiza Bunge as an example in this paper, we first present a preliminary discussion on the feasibility and applicability of reference extractives for the quantitative analysis of TCMs. The reference extractive of S. miltiorrhiza Bunge, comprised of three pharmacological marker compounds, namely cryptotanshinone, tanshinone I and tanshinone IIA, was prepared from purchased Salvia miltiorrhiza Bunge by extraction with acetone under reflux, followed by silica gel column chromatography with stepwise elution with petroleum ether-ethyl acetate (25:1, v/v, 4.5 BV) to remove the non-target components and chloroform-methanol (10:1, v/v; 3 BV) to yield a crude reference extractive solution. After concentration, the solution was further purified by preparative reversed-phase HPLC on a C18 column with isocratic elution with 77% methanol aqueous solution to yield the total reference extractive of S. miltiorrhiza Bunge. Thereafter, the reference extractive was applied to the quality assessment of S. miltiorrhiza Bunge using high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD). The validation of the method, including linearity, sensitivity, repeatability, stability and recovery testing, indicated that this method was valid, reliable and sensitive, with good reproducibility. The developed method was successfully applied to quantify seven batches of samples collected from different regions in China and the results were also similar to those obtained using reference standards, with relative standard

  6. A RAPID METHOD FOR THE EXTRACTION OF FUNGAL DNA FROM ENVIRONMENTAL SAMPLES: EVALUATION IN THE QUANTITATIVE ANALYSIS OF MEMNONIELLA ECHINATA CONIDIA USING REAL TIME DETECTION OF PCR PRODUCTS

    EPA Science Inventory

    New technologies are creating the potential for using nucleic acid sequence detection to perform routine microbiological analyses of environmental samples. Our laboratory has recently reported on the development of a method for the quantitative detection of Stachybotrys chartarum...

  7. EVALUATION OF DIFFERENT METHODS FOR THE EXTRACTION OF DNA FROM FUNGAL CONIDIA BY QUANTITATIVE COMPETITIVE PCR ANALYSIS

    EPA Science Inventory

    Five different DNA extraction methods were evaluated for their effectiveness in recovering PCR templates from the conidia of a series of fungal species often encountered in indoor air. The test organisms were Aspergillus versicolor, Penicillium chrysogenum, Stachybotrys chartaru...

  8. A method for direct, semi-quantitative analysis of gas phase samples using gas chromatography-inductively coupled plasma-mass spectrometry

    SciTech Connect

    Carter, Kimberly E; Gerdes, Kirk

    2013-07-01

    A new and complete GC–ICP-MS method is described for direct analysis of trace metals in a gas phase process stream. The proposed method is derived from standard analytical procedures developed for ICP-MS, which are regularly exercised in standard ICP-MS laboratories. In order to implement the method, a series of empirical factors were generated to calibrate detector response with respect to a known concentration of an internal standard analyte. Calibrated responses are ultimately used to determine the concentration of metal analytes in a gas stream using a semi-quantitative algorithm. The method was verified using a traditional gas injection from a GC sampling valve and a standard gas mixture containing either a 1 ppm Xe + Kr mix with helium balance or 100 ppm Xe with helium balance. Data collected for Xe and Kr gas analytes revealed that agreement of 6–20% with the actual concentration can be expected for various experimental conditions. To demonstrate the method using a relevant “unknown” gas mixture, experiments were performed for continuous 4 and 7 hour periods using a Hg-containing sample gas that was co-introduced into the GC sample loop with the xenon gas standard. System performance and detector response to the dilute concentration of the internal standard were pre-determined, which allowed semi-quantitative evaluation of the analyte. The calculated analyte concentrations varied during the course of the 4 hour experiment, particularly during the first hour of the analysis where the actual Hg concentration was under predicted by up to 72%. Calculated concentration improved to within 30–60% for data collected after the first hour of the experiment. Similar results were seen during the 7 hour test with the deviation from the actual concentration being 11–81% during the first hour and then decreasing for the remaining period. The method detection limit (MDL) was determined for the mercury by injecting the sample gas into the system following a

  9. [Haemolysis and turbidity influence on three analysis methods of quantitative determination of total and conjugated bilirubin on ADVIA 1650].

    PubMed

    Gobert De Paepe, E; Munteanu, G; Schischmanoff, P O; Porquet, D

    2008-01-01

    Plasma bilirubin testing is crucial to prevent the occurrence of neonatal kernicterus. Haemolysis may occur during sampling and interfere with bilirubin determination. Moreover, lipidic infusions may induce plasma lipemia and also interfere with bilirubin measurement. We evaluated the interference of haemolysis and lipemia with three methods of total and direct bilirubin measurement adaptated on an Advia 1650 analyser (Siemens Medical Solutions Diagnostics) : Synermed (Sofibel), Bilirubin 2 (Siemens) and Bilirubin Auto FS (Diasys). The measurement of total bilirubin was little affected by haemolysis with all three methods. The Bilirubin 2 (Siemens) method was the less sensitive to haemolysis even at low bilirubin levels. The measurement of conjugated bilirubin was significantly altered by low heamoglobin concentrations for Bilirubin Auto FS(R) (30 microM or 0,192 g/100 mL haemoglobin) and for Synermed (60 microM or 0,484 g/100 mL haemoglobin). In marked contrast, we found no haemoglobin interference with the Direct Bilirubin 2 reagent which complied with the method validation criteria from the French Society for Biological Chemistry. The lipemia up to 2 g/L of Ivelip did not affect neither the measurement of total bilirubin for all three methods nor the measurement of conjugated bilirubin with the Diasys and Siemens reagents. However, we observed a strong interference starting at 0,5 g/L of Ivelip with the Synermed reagent. Our data suggest that both Siemens and Diasys methods allow to measure accurately total and conjugated bilirubin in hemolytic and lipemic samples, nevertheless, the Siemens methodology is less affected by these interferences.

  10. Quantitative phase analysis from powder diffraction using de Rietveld method in hydrogen storage alloys based on TiCr

    NASA Astrophysics Data System (ADS)

    Martinez, A.; Bellon, D.; Reina, L.

    2016-08-01

    Hydrogen storage is one of the important steps in the implementation of the hydrogen economy; metal hydrides are a promising way to achieve this goal. We present in this work the use of Rietveld analysis to characterize structurally TiCr-based alloys that are able to store hydrogen. TiCruV09, TiCrL1V0.45Nb0.45, TiCr1.1V0.2 Nb0.8, TiCr1.1Nb0.9 alloys were synthesized in an arc furnace under argon atmosphere. The analysis of phases was developed by X-Ray Diffraction (XRD) for further refinement of both the two lattice parameters and the percentage of the phases. Our results confirmed that a structure bcc, mostly combined with a small percentage of Laves phases, leads to obtain important properties in this area. Rietveld analysis was performed by the Fullprof program and this program allows us to obtain the different structural parameters.

  11. Liquid chromatography tandem mass spectrometry method for the quantitative analysis of ceritinib in human plasma and its application to pharmacokinetic studies.

    PubMed

    Heudi, Olivier; Vogel, Denise; Lau, Yvonne Y; Picard, Franck; Kretz, Olivier

    2014-11-01

    Ceritinib is a highly selective inhibitor of an important cancer target, anaplastic lymphoma kinase (ALK). Because it is an investigational compound, there is a need to develop a robust and reliable analytical method for its quantitative determination in human plasma. Here, we report the validation of a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the rapid quantification of ceritinib in human plasma. The method consists of protein precipitation with acetonitrile, and salting-out assisted liquid-liquid extraction (SALLE) using a saturated solution of sodium chloride prior to analysis by LC-MS/MS with electrospray ionization (ESI) technique in positive mode. Samples were eluted at 0.800 mL min(-1) on Ascentis Express® C18 column (50 mm × 2.1 mm, 2.7 μm) with a mobile phase made of 0.1 % formic acid in water (A) and 0.1 % formic acid in acetonitrile (B). The method run time was 3.6 min and the low limit of quantification (LLOQ) was estimated at 1.00 ng mL(-1) when using 0.100 mL of human plasma. The assay was fully validated and the method exhibited sufficient specificity, accuracy, precision, and sensitivity. In addition, recovery data and matrix factor (MF) in normal and in hemolyzed plasmas were assessed, while incurred samples stability (ISS) for ceritinib was demonstrated for at least 21 months at a storage temperature of -65 °C or below. The method was successfully applied to the measurement of ceritinib in clinical samples and the data obtained on incurred samples reanalysis (ISR) showed that our method was reliable and suitable to support the analysis of samples from the clinical studies.

  12. Development and Validation of a Rapid RP-HPLC-DAD Analysis Method for the Simultaneous Quantitation of Paclitaxel and Lapatinib in a Polymeric Micelle Formulation.

    PubMed

    Saadat, Ebrahim; Ravar, Fatemeh; Dehghankelishadi, Pouya; Dorkoosh, Farid A

    2016-01-01

    A robust and rapid analysis method was developed and validated for the simultaneous assay of paclitaxel (PTX) and lapatinib (LPT) in a polymeric micelle formulation as a novel drug delivery system using high-performance liquid chromatography (HPLC). The assay was performed using the C18 MZ-Analytical Column (5 μm, 150 × 4.6 mm, OSD-3) which was protected with the C18 pre-column (5 μm, 4.0 × 4.6 mm, OSD-3). The mobile phase was composed of acetonitrile and water (70/30; V/V) with a flow rate of 0.5 mL/min and detection wavelength of 227 nm. Accuracy was reported as the relative error and was found to be less than 6.8%. The interday assay was evaluated to be 3.22% and 5.76% RSD for PTX and LPT, respectively. The intraday precision was found to be at its maximum value of 5.83% RSD. The limit of detection for both PTX and LPT was found to be 1 µg/mL by means of the newly developed method. The limit of quantitation for PTX and LPT was found to be 5 µg/mL. The calibration curves for both drugs were linear in the concentration range of 5 to 80 μg/mL. In vitro release for both drugs from the polymeric micelle was evaluated using the newly developed analysis method.

  13. Development and Validation of a Rapid RP-HPLC-DAD Analysis Method for the Simultaneous Quantitation of Paclitaxel and Lapatinib in a Polymeric Micelle Formulation

    PubMed Central

    Saadat, Ebrahim; Ravar, Fatemeh; Dehghankelishadi, Pouya; Dorkoosh, Farid A.

    2016-01-01

    A robust and rapid analysis method was developed and validated for the simultaneous assay of paclitaxel (PTX) and lapatinib (LPT) in a polymeric micelle formulation as a novel drug delivery system using high-performance liquid chromatography (HPLC). The assay was performed using the C18 MZ-Analytical Column (5 μm, 150 × 4.6 mm, OSD-3) which was protected with the C18 pre-column (5 μm, 4.0 × 4.6 mm, OSD-3). The mobile phase was composed of acetonitrile and water (70/30; V/V) with a flow rate of 0.5 mL/min and detection wavelength of 227 nm. Accuracy was reported as the relative error and was found to be less than 6.8%. The interday assay was evaluated to be 3.22% and 5.76% RSD for PTX and LPT, respectively. The intraday precision was found to be at its maximum value of 5.83% RSD. The limit of detection for both PTX and LPT was found to be 1 µg/mL by means of the newly developed method. The limit of quantitation for PTX and LPT was found to be 5 µg/mL. The calibration curves for both drugs were linear in the concentration range of 5 to 80 μg/mL. In vitro release for both drugs from the polymeric micelle was evaluated using the newly developed analysis method. PMID:27222608

  14. Applying Quantitative Genetic Methods to Primate Social Behavior

    PubMed Central

    Brent, Lauren J. N.

    2013-01-01

    Increasingly, behavioral ecologists have applied quantitative genetic methods to investigate the evolution of behaviors in wild animal populations. The promise of quantitative genetics in unmanaged populations opens the door for simultaneous analysis of inheritance, phenotypic plasticity, and patterns of selection on behavioral phenotypes all within the same study. In this article, we describe how quantitative genetic techniques provide studies of the evolution of behavior with information that is unique and valuable. We outline technical obstacles for applying quantitative genetic techniques that are of particular relevance to studies of behavior in primates, especially those living in noncaptive populations, e.g., the need for pedigree information, non-Gaussian phenotypes, and demonstrate how many of these barriers are now surmountable. We illustrate this by applying recent quantitative genetic methods to spatial proximity data, a simple and widely collected primate social behavior, from adult rhesus macaques on Cayo Santiago. Our analysis shows that proximity measures are consistent across repeated measurements on individuals (repeatable) and that kin have similar mean measurements (heritable). Quantitative genetics may hold lessons of considerable importance for studies of primate behavior, even those without a specific genetic focus. PMID:24659839

  15. Quantitative mass spectrometric analysis of dipeptides in protein hydrolysate by a TNBS derivatization-aided standard addition method.

    PubMed

    Hanh, Vu Thi; Kobayashi, Yutaro; Maebuchi, Motohiro; Nakamori, Toshihiro; Tanaka, Mitsuru; Matsui, Toshiro

    2016-01-01

    The aim of this study was to establish, through a standard addition method, a convenient quantification assay for dipeptides (GY, YG, SY, YS, and IY) in soybean hydrolysate using 2,4,6-trinitrobenzene sulfonate (TNBS) derivatization-aided LC-TOF-MS. Soybean hydrolysate samples (25.0 mg mL(-1)) spiked with target standards were subjected to TNBS derivatization. Under the optimal LC-MS conditions, five target dipeptides derivatized with TNBS were successfully detected. Examination of the standard addition curves, with a correlation coefficient of r(2) > 0.979, provided a reliable quantification of the target dipeptides, GY, YG, SY, YS, and IY, in soybean hydrolysate to be 424 ± 20, 184 ± 9, 2188 ± 199, 327 ± 16, and 2211 ± 133 μg g(-1) of hydrolysate, respectively. The proposed LC-MS assay is a reliable and convenient assay method, with no interference from matrix effects in hydrolysate, and with no requirement for the use of an isotope labeled internal standard.

  16. A comparison of sorptive extraction techniques coupled to a new quantitative, sensitive, high throughput GC-MS/MS method for methoxypyrazine analysis in wine.

    PubMed

    Hjelmeland, Anna K; Wylie, Philip L; Ebeler, Susan E

    2016-02-01

    Methoxypyrazines are volatile compounds found in plants, microbes, and insects that have potent vegetal and earthy aromas. With sensory detection thresholds in the low ng L(-1) range, modest concentrations of these compounds can profoundly impact the aroma quality of foods and beverages, and high levels can lead to consumer rejection. The wine industry routinely analyzes the most prevalent methoxypyrazine, 2-isobutyl-3-methoxypyrazine (IBMP), to aid in harvest decisions, since concentrations decrease during berry ripening. In addition to IBMP, three other methoxypyrazines IPMP (2-isopropyl-3-methoxypyrazine), SBMP (2-sec-butyl-3-methoxypyrazine), and EMP (2-ethyl-3-methoxypyrazine) have been identified in grapes and/or wine and can impact aroma quality. Despite their routine analysis in the wine industry (mostly IBMP), accurate methoxypyrazine quantitation is hindered by two major challenges: sensitivity and resolution. With extremely low sensory detection thresholds (~8-15 ng L(-1) in wine for IBMP), highly sensitive analytical methods to quantify methoxypyrazines at trace levels are necessary. Here we were able to achieve resolution of IBMP as well as IPMP, EMP, and SBMP from co-eluting compounds using one-dimensional chromatography coupled to positive chemical ionization tandem mass spectrometry. Three extraction techniques HS-SPME (headspace-solid phase microextraction), SBSE (stirbar sorptive extraction), and HSSE (headspace sorptive extraction) were validated and compared. A 30 min extraction time was used for HS-SPME and SBSE extraction techniques, while 120 min was necessary to achieve sufficient sensitivity for HSSE extractions. All extraction methods have limits of quantitation (LOQ) at or below 1 ng L(-1) for all four methoxypyrazines analyzed, i.e., LOQ's at or below reported sensory detection limits in wine. The method is high throughput, with resolution of all compounds possible with a relatively rapid 27 min GC oven program.

  17. Defining, Enhancing, and Documenting Impact of STEM Education and Public Outreach Projects Through a Quantitative Collaborative Impact Analysis Evaluation Method

    NASA Astrophysics Data System (ADS)

    Davis, H. B.; Scalice, D.

    2015-11-01

    Evaluation of the impact of STEM EPO efforts has now been recognized by policy makers and funders as critical for demonstrating their effects. While this is important and long overdue, it overlooks an equally important function of evaluation—informing the needs assessment, objectives, design, and implementation of a project. As more evaluation is required, there is an opportunity to move from an external evaluation of a project performed by a third party to embedding evaluation in both the work and cognitive framework of the STEM EPO professional. This paper describes the development and use of a collaborative evaluation method with the NASA Astrobiology Institute's (NAI) STEM EPO projects to both enhance and document their impact.

  18. The quantitation of nuclear Overhauser effect methods for total conformational analysis of peptides in solution. Application to gramicidin S.

    PubMed Central

    Jones, C R; Sikakana, C T; Hehir, S; Kuo, M C; Gibbons, W A

    1978-01-01

    The [1H:1H] nuclear Overhauser effects (NOE's) and spin-lattice relaxation times (T1's) are reported for the backbone protons of the decapeptide gramicidin S. Several methods for calculating interproton distances from these measurements are presented. Ratios of interproton distances were obtained from [1H:1H] NOE's and from the combination of [1H:1H]NOE'S and T1 values. Actual proton-proton distances were calculated from these ratios either by using the known distance between two geminal protons or distances derived from scalar coupling constants. The interproton distances calculated for gramicidin S are consistent with a II' beta-turn/antiparallel beta-sheet conformation. PMID:83886

  19. Quantitation of acrylamide (and polyacrylamide): critical review of methods for trace determination/formulation analysis and future-research recommendations. Final report

    SciTech Connect

    Daughton, C.G.

    1988-01-01

    Polyacrylamides (esp. polyelectrolytes) have gained wide usage in water treatment (as flocculants/coagulants), tertiary oil recovery, and various other applications such as sewer grouts. Unreacted, residual acrylamide monomer (2-propenamide: CH2=CH-C(=O)-NH2) is usually present in the various bulk commercial formulations at low fractional percentages. Although the polymers are relatively nontoxic, acrylamide can elicit severe neurotoxicity and genotoxicity. For health concerns, use of polyacrylamides in drinking water has been subjected to closer evaluation during the last decade. Currently, dosage standards are indirectly based on the maximum concentration of acrylamide that would result from use of a commercial formulation of known acrylamide content. Although numerous methods of chemical analysis exist for determining the acrylamide content of a polyacrylamide formulation, no standardized method has been adopted for directly determining trace concentrations of acrylamide in water (e.g., at the sub-parts-per-billion level, ng-micrograms/L). This report represents the first in-depth literature review of methods for determining acrylamide monomer. Over 100 references were reviewed, and those that deal specifically with acrylamide determination are annotated in detail. The approach was to unify the general chemistry of acrylamide (and amides) with the published methods for quantitation.

  20. Quantitative methods in classical perturbation theory.

    NASA Astrophysics Data System (ADS)

    Giorgilli, A.

    Poincaré proved that the series commonly used in Celestial mechanics are typically non convergent, although their usefulness is generally evident. Recent work in perturbation theory has enlightened this conjecture of Poincaré, bringing into evidence that the series of perturbation theory, although non convergent in general, furnish nevertheless valuable approximations to the true orbits for a very large time, which in some practical cases could be comparable with the age of the universe. The aim of the author's paper is to introduce the quantitative methods of perturbation theory which allow to obtain such powerful results.

  1. Comparison of Enterococcus quantitative polymerase chain reaction analysis results from midwest U.S. river samples using EPA Method 1611 and Method 1609 PCR reagents

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has provided recommended beach advisory values in its 2012 recreational water quality criteria (RWQC) for states wishing to use quantitative polymerase chain reaction (qPCR) for the monitoring of Enterococcus fecal indicator bacteria...

  2. Quantitative analysis of glycoprotein glycans.

    PubMed

    Orlando, Ron

    2013-01-01

    The ability to quantitatively determine changes in the N- and O-linked glycans is an essential component of comparative glycomics. Multiple strategies are available to by which this can be accomplished, including; both label free approaches and isotopic labeling strategies. The focus of this chapter is to describe each of these approaches while providing insight into their strengths and weaknesses, so that glycomic investigators can make an educated choice of the strategy that is best suited for their particular application.

  3. Quantitative histogram analysis of images

    NASA Astrophysics Data System (ADS)

    Holub, Oliver; Ferreira, Sérgio T.

    2006-11-01

    loading of an image No. of bits in a word: 32 No. of processors used: 1 Has the code been vectorized or parallelized?: No No of lines in distributed program, including test data, etc.:138 946 No. of bytes in distributed program, including test data, etc.:15 166 675 Distribution format: tar.gz Nature of physical problem: Quantification of image data (e.g., for discrimination of molecular species in gels or fluorescent molecular probes in cell cultures) requires proprietary or complex software packages, which might not include the relevant statistical parameters or make the analysis of multiple images a tedious procedure for the general user. Method of solution: Tool for conversion of RGB bitmap image into luminance-linear image and extraction of luminance histogram, probability distribution, and statistical parameters (average brightness, standard deviation, variance, minimal and maximal brightness, mode, skewness and kurtosis of histogram and median of probability distribution) with possible selection of region of interest (ROI) and lower and upper threshold levels. Restrictions on the complexity of the problem: Does not incorporate application-specific functions (e.g., morphometric analysis) Typical running time: Seconds (depending on image size and processor speed) Unusual features of the program: None

  4. A novel closed-tube method based on high resolution melting (HRM) analysis for authenticity testing and quantitative detection in Greek PDO Feta cheese.

    PubMed

    Ganopoulos, Ioannis; Sakaridis, Ioannis; Argiriou, Anagnostis; Madesis, Panagiotis; Tsaftaris, Athanasios

    2013-11-15

    Animal species identification of milk and dairy products has received increasing attention concerning food composition, traceability, allergic pathologies and accurate consumer information. Here we sought to develop an easy to use and robust method for species identification in cheese with emphasis on an authenticity control of PDO Feta cheese products. We used specific mitochondrial DNA regions coupled with high resolution melting (HRM) a closed-tube method allowing us to detect bovine, ovine and caprine species and authenticate Greek PDO Feta cheese. The primers successfully amplified DNA isolated from milk and cheese and showed a high degree of specificity. HRM was proven capable of accurately identifying the presence of bovine milk (not allowed in Feta) down to 0.1% and also of quantifying the ratio of sheep to goat milk mixture in different Feta cheese commercial products. In conclusion, HRM analysis can be a faster, with higher resolution and a more cost effective alternative method to authenticate milk and dairy products including PDO Feta cheese and to quantitatively detect its sheep milk adulterations.

  5. Quantitative structure-activity relationship study of P2X7 receptor inhibitors using combination of principal component analysis and artificial intelligence methods.

    PubMed

    Ahmadi, Mehdi; Shahlaei, Mohsen

    2015-01-01

    P2X7 antagonist activity for a set of 49 molecules of the P2X7 receptor antagonists, derivatives of purine, was modeled with the aid of chemometric and artificial intelligence techniques. The activity of these compounds was estimated by means of combination of principal component analysis (PCA), as a well-known data reduction method, genetic algorithm (GA), as a variable selection technique, and artificial neural network (ANN), as a non-linear modeling method. First, a linear regression, combined with PCA, (principal component regression) was operated to model the structure-activity relationships, and afterwards a combination of PCA and ANN algorithm was employed to accurately predict the biological activity of the P2X7 antagonist. PCA preserves as much of the information as possible contained in the original data set. Seven most important PC's to the studied activity were selected as the inputs of ANN box by an efficient variable selection method, GA. The best computational neural network model was a fully-connected, feed-forward model with 7-7-1 architecture. The developed ANN model was fully evaluated by different validation techniques, including internal and external validation, and chemical applicability domain. All validations showed that the constructed quantitative structure-activity relationship model suggested is robust and satisfactory.

  6. Hydrophilic interaction liquid chromatography-tandem mass spectrometry quantitative method for the cellular analysis of varying structures of gemini surfactants designed as nanomaterial drug carriers.

    PubMed

    Donkuru, McDonald; Michel, Deborah; Awad, Hanan; Katselis, George; El-Aneed, Anas

    2016-05-13

    Diquaternary gemini surfactants have successfully been used to form lipid-based nanoparticles that are able to compact, protect, and deliver genetic materials into cells. However, what happens to the gemini surfactants after they have released their therapeutic cargo is unknown. Such knowledge is critical to assess the quality, safety, and efficacy of gemini surfactant nanoparticles. We have developed a simple and rapid liquid chromatography electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the quantitative determination of various structures of gemini surfactants in cells. Hydrophilic interaction liquid chromatography (HILIC) was employed allowing for a short simple isocratic run of only 4min. The lower limit of detection (LLOD) was 3ng/mL. The method was valid to 18 structures of gemini surfactants belonging to two different structural families. A full method validation was performed for two lead compounds according to USFDA guidelines. The HILIC-MS/MS method was compatible with the physicochemical properties of gemini surfactants that bear a permanent positive charge with both hydrophilic and hydrophobic elements within their molecular structure. In addition, an effective liquid-liquid extraction method (98% recovery) was employed surpassing previously used extraction methods. The analysis of nanoparticle-treated cells showed an initial rise in the analyte intracellular concentration followed by a maximum and a somewhat more gradual decrease of the intracellular concentration. The observed intracellular depletion of the gemini surfactants may be attributable to their bio-transformation into metabolites and exocytosis from the host cells. Obtained cellular data showed a pattern that grants additional investigations, evaluating metabolite formation and assessing the subcellular distribution of tested compounds.

  7. Applying Knowledge of Quantitative Design and Analysis

    ERIC Educational Resources Information Center

    Baskas, Richard S.

    2011-01-01

    This study compared and contrasted two quantitative scholarly articles in relation to their research designs. Their designs were analyzed by the comparison of research references and research specific vocabulary to describe how various research methods were used. When researching and analyzing quantitative scholarly articles, it is imperative to…

  8. Simultaneous determination of linagliptin and metformin by reverse phase-high performance liquid chromatography method: An application in quantitative analysis of pharmaceutical dosage forms.

    PubMed

    Vemula, Prathyusha; Dodda, Dilip; Balekari, Umamahesh; Panga, Shyam; Veeresham, Ciddi

    2015-01-01

    To enhance patient compliance toward treatment in diseases like diabetes, usually a combination of drugs is prescribed. Therefore, an anti-diabetic fixed-dose combination of 2.5 mg of linagliptin 500 mg of metformin was taken for simultaneous estimation of both the drugs by reverse phase-high performance liquid chromatography (RP-HPLC) method. The present study aimed to develop a simple and sensitive RP-HPLC method for the simultaneous determination of linagliptin and metformin in pharmaceutical dosage forms. The chromatographic separation was designed and evaluated by using linagliptin and metformin working standard and sample solutions in the linearity range. Chromatographic separation was performed on a C18 column using a mobile phase of 70:30 (v/v) mixture of methanol and 0.05 M potassium dihydrogen orthophosphate (pH adjusted to 4.6 with orthophosphoric acid) delivered at a flow rate of 0.6 mL/min and UV detection at 267 nm. Linagliptin and metformin shown linearity in the range of 2-12 μg/mL and 400-2400 μg/mL respectively with correlation co-efficient of 0.9996 and 0.9989. The resultant findings analyzed for standard deviation (SD) and relative standard deviation to validate the developed method. The retention time of linagliptin and metformin was found to be 6.3 and 4.6 min and separation was complete in <10 min. The method was validated for linearity, accuracy and precision were found to be acceptable over the linearity range of the linagliptin and metformin. The method was found suitable for the routine quantitative analysis of linagliptin and metformin in pharmaceutical dosage forms.

  9. Three-dimensional Imaging Methods for Quantitative Analysis of Facial Soft Tissues and Skeletal Morphology in Patients with Orofacial Clefts: A Systematic Review

    PubMed Central

    Kuijpers, Mette A. R.; Chiu, Yu-Ting; Nada, Rania M.; Carels, Carine E. L.; Fudalej, Piotr S.

    2014-01-01

    Background Current guidelines for evaluating cleft palate treatments are mostly based on two-dimensional (2D) evaluation, but three-dimensional (3D) imaging methods to assess treatment outcome are steadily rising. Objective To identify 3D imaging methods for quantitative assessment of soft tissue and skeletal morphology in patients with cleft lip and palate. Data sources Literature was searched using PubMed (1948–2012), EMBASE (1980–2012), Scopus (2004–2012), Web of Science (1945–2012), and the Cochrane Library. The last search was performed September 30, 2012. Reference lists were hand searched for potentially eligible studies. There was no language restriction. Study selection We included publications using 3D imaging techniques to assess facial soft tissue or skeletal morphology in patients older than 5 years with a cleft lip with/or without cleft palate. We reviewed studies involving the facial region when at least 10 subjects in the sample size had at least one cleft type. Only primary publications were included. Data extraction Independent extraction of data and quality assessments were performed by two observers. Results Five hundred full text publications were retrieved, 144 met the inclusion criteria, with 63 high quality studies. There were differences in study designs, topics studied, patient characteristics, and success measurements; therefore, only a systematic review could be conducted. Main 3D-techniques that are used in cleft lip and palate patients are CT, CBCT, MRI, stereophotogrammetry, and laser surface scanning. These techniques are mainly used for soft tissue analysis, evaluation of bone grafting, and changes in the craniofacial skeleton. Digital dental casts are used to evaluate treatment and changes over time. Conclusion Available evidence implies that 3D imaging methods can be used for documentation of CLP patients. No data are available yet showing that 3D methods are more informative than conventional 2D methods. Further research

  10. Foucault test: a quantitative evaluation method.

    PubMed

    Rodríguez, Gustavo; Villa, Jesús; Ivanov, Rumen; González, Efrén; Martínez, Geminiano

    2016-08-01

    Reliable and accurate testing methods are essential to guiding the polishing process during the figuring of optical telescope mirrors. With the natural advancement of technology, the procedures and instruments used to carry out this delicate task have consistently increased in sensitivity, but also in complexity and cost. Fortunately, throughout history, the Foucault knife-edge test has shown the potential to measure transverse aberrations in the order of the wavelength, mainly when described in terms of physical theory, which allows a quantitative interpretation of its characteristic shadowmaps. Our previous publication on this topic derived a closed mathematical formulation that directly relates the knife-edge position with the observed irradiance pattern. The present work addresses the quite unexplored problem of the wavefront's gradient estimation from experimental captures of the test, which is achieved by means of an optimization algorithm featuring a proposed ad hoc cost function. The partial derivatives thereby calculated are then integrated by means of a Fourier-based algorithm to retrieve the mirror's actual surface profile. To date and to the best of our knowledge, this is the very first time that a complete mathematical-grounded treatment of this optical phenomenon is presented, complemented by an image-processing algorithm which allows a quantitative calculation of the corresponding slope at any given point of the mirror's surface, so that it becomes possible to accurately estimate the aberrations present in the analyzed concave device just through its associated foucaultgrams.

  11. Quantitative 31P NMR for Simultaneous Trace Analysis of Organophosphorus Pesticides in Aqueous Media Using the Stir Bar Sorptive Extraction Method

    NASA Astrophysics Data System (ADS)

    Ansari, S.; Talebpour, Z.; Molaabasi, F.; Bijanzadeh, H. R.; Khazaeli, S.

    2016-09-01

    The analysis of pesticides in water samples is of primary concern for quality control laboratories due to the toxicity of these compounds and their associated public health risk. A novel analytical method based on stir bar sorptive extraction (SBSE), followed by 31P quantitative nuclear magnetic resonance (31P QNMR), has been developed for simultaneously monitoring and determining four organophosphorus pesticides (OPPs) in aqueous media. The effects of factors on the extraction efficiency of OPPs were investigated using a Draper-Lin small composite design. An optimal sample volume of 4.2 mL, extraction time of 96 min, extraction temperature of 42°C, and desorption time of 11 min were obtained. The results showed reasonable linearity ranges for all pesticides with correlation coefficients greater than 0.9920. The limit of quantification (LOQ) ranged from 0.1 to 2.60 mg/L, and the recoveries of spiked river water samples were from 82 to 94% with relative standard deviation (RSD) values less than 4%. The results show that this method is simple, selective, rapid, and can be applied to other sample matrices.

  12. Quantitative analysis of qualitative images

    NASA Astrophysics Data System (ADS)

    Hockney, David; Falco, Charles M.

    2005-03-01

    We show optical evidence that demonstrates artists as early as Jan van Eyck and Robert Campin (c1425) used optical projections as aids for producing their paintings. We also have found optical evidence within works by later artists, including Bermejo (c1475), Lotto (c1525), Caravaggio (c1600), de la Tour (c1650), Chardin (c1750) and Ingres (c1825), demonstrating a continuum in the use of optical projections by artists, along with an evolution in the sophistication of that use. However, even for paintings where we have been able to extract unambiguous, quantitative evidence of the direct use of optical projections for producing certain of the features, this does not mean that paintings are effectively photographs. Because the hand and mind of the artist are intimately involved in the creation process, understanding these complex images requires more than can be obtained from only applying the equations of geometrical optics.

  13. A quantitative method for acylcarnitines and amino acids using high resolution chromatography and tandem mass spectrometry in newborn screening dried blood spot analysis.

    PubMed

    Miller, John H; Poston, Philip A; Karnes, H Thomas

    2012-08-15

    We have developed a high resolution liquid chromatographic separation with electrospray ionization (ESI) mass spectrometry detection for the combined analysis of twelve acylcarnitines and seven amino acids commonly measured in newborn screening heritable metabolic disorders. Samples were prepared by punching 3.2 mm disks out of dried blood spots and extracting with a mixture of methanol and 0.1% formic acid containing stable isotopically labeled internal standards. Analysis was performed on an UHPLC system using a HILIC amide, 2.1 mm × 50 mm, 1.7 μm column. A normal phase gradient, employing 10mM ammonium acetate in 90:10 acetonitrile/water for mobile phase B and 0.1% formic acid in water for mobile phase A, was used. Optimized multiple reaction monitoring (MRM) was used for detection of amino acids and acylcarnitines on a Waters Premier mass spectrometer. Quantification of analytes was performed using internal calibration by fortification of sodium heparin whole blood with analytes at appropriate levels to encompass the range around the reported cut-off values. The method was fully validated with respect to precision, accuracy, recovery, linearity, matrix suppression and extraction robustness. Precision and accuracy were evaluated over 3 days and determined to be acceptable with an overall precision within 10% and accuracy within 15% of theoretical for all analytes except for acetylcarnitne at one fortified level, which quantitated 21.8% lower than the expected value. This method is suitable as a second-tier test for newborn screening of specific disorders associated with abnormal levels of acylcarnitines and amino acids, potentially reducing false positive cases and shortening the time to diagnosis.

  14. Traceable Quantitative Raman Microscopy and X-ray Fluorescence Analysis as Nondestructive Methods for the Characterization of Cu(In,Ga)Se2 Absorber Films.

    PubMed

    Zakel, Sabine; Pollakowski, Beatrix; Streeck, Cornelia; Wundrack, Stefan; Weber, Alfons; Brunken, Stefan; Mainz, Roland; Beckhoff, Burckhardt; Stosch, Rainer

    2016-02-01

    The traceability of measured quantities is an essential condition when linking process control parameters to guaranteed physical properties of a product. Using Raman spectroscopy as an analytical tool for monitoring the production of Cu(In1-xGax)Se2 thin-film solar cells, proper calibration with regard to chemical composition and lateral dimensions is a key prerequisite. This study shows how the multiple requirements of calibration in Raman microscopy might be addressed. The surface elemental composition as well as the integral elemental composition of the samples is traced back by reference-free X-ray fluorescence analysis. Reference Raman spectra are then generated for the relevant Cu(In1-xGax)Se2 related compounds. The lateral dimensions are calibrated with the help of a novel dimensional standard whose regular structures have been traced back to the International System of Units by metrological scanning force microscopy. On this basis, an approach for the quantitative determination of surface coverage values from lateral Raman mappings is developed together with a complete uncertainty budget. Raman and X-ray spectrometry have here been proven as complementary nondestructive methods combining surface sensitivity and in-depth information on elemental and species distribution for the reliable quality control of Cu(In1-xGax)Se2 absorbers and Cu(In1-xGax)3Se5 surface layer formation.

  15. Comparison of Enterococcus quantitative polymerase chain reaction analysis results from Midwest U.S. river samples using EPA Method 1611 and Method 1609 PCR reagents.

    PubMed

    Sivaganesan, Mano; Sivaganensan, Mano; Siefring, Shawn; Varma, Manju; Haugland, Richard A

    2014-06-01

    Enterococci target sequence density estimates from analyses of diluted river water DNA extracts by EPA Methods 1611 and 1609 and estimates with lower detection limits from undiluted DNA extracts by Method 1609 were indistinguishable. These methods should be equally suitable for comparison with U.S. EPA 2012 Recreational Water Quality Criteria values.

  16. Quantitative method of measuring cancer cell urokinase and metastatic potential

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R. (Inventor)

    1993-01-01

    The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated urokinase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

  17. Quantitative Methods in the Study of Local History

    ERIC Educational Resources Information Center

    Davey, Pene

    1974-01-01

    The author suggests how the quantitative analysis of data from census records, assessment roles, and newspapers may be integrated into the classroom. Suggestions for obtaining quantitative data are provided. (DE)

  18. Advancing the study of violence against women using mixed methods: integrating qualitative methods into a quantitative research program.

    PubMed

    Testa, Maria; Livingston, Jennifer A; VanZile-Tamsen, Carol

    2011-02-01

    A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women's sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided.

  19. ADVANCING THE STUDY OF VIOLENCE AGAINST WOMEN USING MIXED METHODS: INTEGRATING QUALITATIVE METHODS INTO A QUANTITATIVE RESEARCH PROGRAM

    PubMed Central

    Testa, Maria; Livingston, Jennifer A.; VanZile-Tamsen, Carol

    2011-01-01

    A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women’s sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided. PMID:21307032

  20. [Progress in stable isotope labeled quantitative proteomics methods].

    PubMed

    Zhou, Yuan; Shan, Yichu; Zhang, Lihua; Zhang, Yukui

    2013-06-01

    Quantitative proteomics is an important research field in post-genomics era. There are two strategies for proteome quantification: label-free methods and stable isotope labeling methods which have become the most important strategy for quantitative proteomics at present. In the past few years, a number of quantitative methods have been developed, which support the fast development in biology research. In this work, we discuss the progress in the stable isotope labeling methods for quantitative proteomics including relative and absolute quantitative proteomics, and then give our opinions on the outlook of proteome quantification methods.

  1. Parallel development of chromatographic and mass-spectrometric methods for quantitative analysis of glycation on an IgG1 monoclonal antibody.

    PubMed

    Viski, Kornél; Gengeliczki, Zsolt; Lenkey, Krisztián; Baranyáné Ganzler, Katalin

    2016-10-01

    Monitoring post-translational modifications (PTMs) in biotherapeutics is of paramount importance. In pharmaceutical industry, chromatography with optical detection is the standard choice of quantitation of product related impurities; and mass spectrometry is used only for characterization. Parallel development of a boronate affinity chromatographic (BAC) and a mass spectrometric methods for quantitative measurement of glycation on a monoclonal antibody (mAb) shed light on the importance of certain characteristics of the individual methods. Non-specific interactions in BAC has to be suppressed with the so-called shielding reagent. We have found that excessive amount of shielding reagents in the chromatographic solvents may cause significant underestimation of glycation. Although contamination of the retained peak with the non-glycated isoforms in BAC is unavoidable, our work shows that it can be characterized and quantitated by mass spectrometry. It has been demonstrated that glycation can be measured by mass spectrometry at the intact protein level with an LOQ value of 3.0% and error bar of ±0.5%. The BAC and MS methods have been found to provide equivalent results. These methods have not been compared from these points of view before.

  2. Nonlinear dynamics and quantitative EEG analysis.

    PubMed

    Jansen, B H

    1996-01-01

    Quantitative, computerized electroencephalogram (EEG) analysis appears to be based on a phenomenological approach to EEG interpretation, and is primarily rooted in linear systems theory. A fundamentally different approach to computerized EEG analysis, however, is making its way into the laboratories. The basic idea, inspired by recent advances in the area of nonlinear dynamics and chaos theory, is to view an EEG as the output of a deterministic system of relatively simple complexity, but containing nonlinearities. This suggests that studying the geometrical dynamics of EEGs, and the development of neurophysiologically realistic models of EEG generation may produce more successful automated EEG analysis techniques than the classical, stochastic methods. A review of the fundamentals of chaos theory is provided. Evidence supporting the nonlinear dynamics paradigm to EEG interpretation is presented, and the kind of new information that can be extracted from the EEG is discussed. A case is made that a nonlinear dynamic systems viewpoint to EEG generation will profoundly affect the way EEG interpretation is currently done.

  3. Machine Learning methods for Quantitative Radiomic Biomarkers

    PubMed Central

    Parmar, Chintan; Grossmann, Patrick; Bussink, Johan; Lambin, Philippe; Aerts, Hugo J. W. L.

    2015-01-01

    Radiomics extracts and mines large number of medical imaging features quantifying tumor phenotypic characteristics. Highly accurate and reliable machine-learning approaches can drive the success of radiomic applications in clinical care. In this radiomic study, fourteen feature selection methods and twelve classification methods were examined in terms of their performance and stability for predicting overall survival. A total of 440 radiomic features were extracted from pre-treatment computed tomography (CT) images of 464 lung cancer patients. To ensure the unbiased evaluation of different machine-learning methods, publicly available implementations along with reported parameter configurations were used. Furthermore, we used two independent radiomic cohorts for training (n = 310 patients) and validation (n = 154 patients). We identified that Wilcoxon test based feature selection method WLCX (stability = 0.84 ± 0.05, AUC = 0.65 ± 0.02) and a classification method random forest RF (RSD = 3.52%, AUC = 0.66 ± 0.03) had highest prognostic performance with high stability against data perturbation. Our variability analysis indicated that the choice of classification method is the most dominant source of performance variation (34.21% of total variance). Identification of optimal machine-learning methods for radiomic applications is a crucial step towards stable and clinically relevant radiomic biomarkers, providing a non-invasive way of quantifying and monitoring tumor-phenotypic characteristics in clinical practice. PMID:26278466

  4. Machine Learning methods for Quantitative Radiomic Biomarkers.

    PubMed

    Parmar, Chintan; Grossmann, Patrick; Bussink, Johan; Lambin, Philippe; Aerts, Hugo J W L

    2015-08-17

    Radiomics extracts and mines large number of medical imaging features quantifying tumor phenotypic characteristics. Highly accurate and reliable machine-learning approaches can drive the success of radiomic applications in clinical care. In this radiomic study, fourteen feature selection methods and twelve classification methods were examined in terms of their performance and stability for predicting overall survival. A total of 440 radiomic features were extracted from pre-treatment computed tomography (CT) images of 464 lung cancer patients. To ensure the unbiased evaluation of different machine-learning methods, publicly available implementations along with reported parameter configurations were used. Furthermore, we used two independent radiomic cohorts for training (n = 310 patients) and validation (n = 154 patients). We identified that Wilcoxon test based feature selection method WLCX (stability = 0.84 ± 0.05, AUC = 0.65 ± 0.02) and a classification method random forest RF (RSD = 3.52%, AUC = 0.66 ± 0.03) had highest prognostic performance with high stability against data perturbation. Our variability analysis indicated that the choice of classification method is the most dominant source of performance variation (34.21% of total variance). Identification of optimal machine-learning methods for radiomic applications is a crucial step towards stable and clinically relevant radiomic biomarkers, providing a non-invasive way of quantifying and monitoring tumor-phenotypic characteristics in clinical practice.

  5. Quantitative analytical method to evaluate the metabolism of vitamin D.

    PubMed

    Mena-Bravo, A; Ferreiro-Vera, C; Priego-Capote, F; Maestro, M A; Mouriño, A; Quesada-Gómez, J M; Luque de Castro, M D

    2015-03-10

    A method for quantitative analysis of vitamin D (both D2 and D3) and its main metabolites - monohydroxylated vitamin D (25-hydroxyvitamin D2 and 25-hydroxyvitamin D3) and dihydroxylated metabolites (1,25-dihydroxyvitamin D2, 1,25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3) in human serum is here reported. The method is based on direct analysis of serum by an automated platform involving on-line coupling of a solid-phase extraction workstation to a liquid chromatograph-tandem mass spectrometer. Detection of the seven analytes was carried out by the selected reaction monitoring (SRM) mode, and quantitative analysis was supported on the use of stable isotopic labeled internal standards (SIL-ISs). The detection limits were between 0.3-75pg/mL for the target compounds, while precision (expressed as relative standard deviation) was below 13.0% for between-day variability. The method was externally validated according to the vitamin D External Quality Assurance Scheme (DEQAS) through the analysis of ten serum samples provided by this organism. The analytical features of the method support its applicability in nutritional and clinical studies targeted at elucidating the role of vitamin D metabolism.

  6. [Quantitative method of representative contaminants in groundwater pollution risk assessment].

    PubMed

    Wang, Jun-Jie; He, Jiang-Tao; Lu, Yan; Liu, Li-Ya; Zhang, Xiao-Liang

    2012-03-01

    In the light of the problem that stress vulnerability assessment in groundwater pollution risk assessment is lack of an effective quantitative system, a new system was proposed based on representative contaminants and corresponding emission quantities through the analysis of groundwater pollution sources. And quantitative method of the representative contaminants in this system was established by analyzing the three properties of representative contaminants and determining the research emphasis using analytic hierarchy process. The method had been applied to the assessment of Beijing groundwater pollution risk. The results demonstrated that the representative contaminants hazards greatly depended on different research emphasizes. There were also differences between the sequence of three representative contaminants hazards and their corresponding properties. It suggested that subjective tendency of the research emphasis had a decisive impact on calculation results. In addition, by the means of sequence to normalize the three properties and to unify the quantified properties results would zoom in or out of the relative properties characteristic of different representative contaminants.

  7. Method of quantitating dsDNA

    DOEpatents

    Stark, Peter C.; Kuske, Cheryl R.; Mullen, Kenneth I.

    2002-01-01

    A method for quantitating dsDNA in an aqueous sample solution containing an unknown amount of dsDNA. A first aqueous test solution containing a known amount of a fluorescent dye-dsDNA complex and at least one fluorescence-attenutating contaminant is prepared. The fluorescence intensity of the test solution is measured. The first test solution is diluted by a known amount to provide a second test solution having a known concentration of dsDNA. The fluorescence intensity of the second test solution is measured. Additional diluted test solutions are similarly prepared until a sufficiently dilute test solution having a known amount of dsDNA is prepared that has a fluorescence intensity that is not attenuated upon further dilution. The value of the maximum absorbance of this solution between 200-900 nanometers (nm), referred to herein as the threshold absorbance, is measured. A sample solution having an unknown amount of dsDNA and an absorbance identical to that of the sufficiently dilute test solution at the same chosen wavelength is prepared. Dye is then added to the sample solution to form the fluorescent dye-dsDNA-complex, after which the fluorescence intensity of the sample solution is measured and the quantity of dsDNA in the sample solution is determined. Once the threshold absorbance of a sample solution obtained from a particular environment has been determined, any similarly prepared sample solution taken from a similar environment and having the same value for the threshold absorbance can be quantified for dsDNA by adding a large excess of dye to the sample solution and measuring its fluorescence intensity.

  8. Joint association analysis of bivariate quantitative and qualitative traits.

    PubMed

    Yuan, Mengdie; Diao, Guoqing

    2011-11-29

    Univariate genome-wide association analysis of quantitative and qualitative traits has been investigated extensively in the literature. In the presence of correlated phenotypes, it is more intuitive to analyze all phenotypes simultaneously. We describe an efficient likelihood-based approach for the joint association analysis of quantitative and qualitative traits in unrelated individuals. We assume a probit model for the qualitative trait, under which an unobserved latent variable and a prespecified threshold determine the value of the qualitative trait. To jointly model the quantitative and qualitative traits, we assume that the quantitative trait and the latent variable follow a bivariate normal distribution. The latent variable is allowed to be correlated with the quantitative phenotype. Simultaneous modeling of the quantitative and qualitative traits allows us to make more precise inference on the pleiotropic genetic effects. We derive likelihood ratio tests for the testing of genetic effects. An application to the Genetic Analysis Workshop 17 data is provided. The new method yields reasonable power and meaningful results for the joint association analysis of the quantitative trait Q1 and the qualitative trait disease status at SNPs with not too small MAF.

  9. Mobile app-based quantitative scanometric analysis.

    PubMed

    Wong, Jessica X H; Liu, Frank S F; Yu, Hua-Zhong

    2014-12-16

    The feasibility of using smartphones and other mobile devices as the detection platform for quantitative scanometric assays is demonstrated. The different scanning modes (color, grayscale, black/white) and grayscale converting protocols (average, weighted average/luminosity, and software specific) have been compared in determining the optical darkness ratio (ODR) values, a conventional quantitation measure for scanometric assays. A mobile app was developed to image and analyze scanometric assays, as demonstrated by paper-printed tests and a biotin-streptavidin assay on a plastic substrate. Primarily for ODR analysis, the app has been shown to perform as well as a traditional desktop scanner, augmenting that smartphones (and other mobile devices) promise to be a practical platform for accurate, quantitative chemical analysis and medical diagnostics.

  10. A quantitative approach to scar analysis.

    PubMed

    Khorasani, Hooman; Zheng, Zhong; Nguyen, Calvin; Zara, Janette; Zhang, Xinli; Wang, Joyce; Ting, Kang; Soo, Chia

    2011-02-01

    Analysis of collagen architecture is essential to wound healing research. However, to date no consistent methodologies exist for quantitatively assessing dermal collagen architecture in scars. In this study, we developed a standardized approach for quantitative analysis of scar collagen morphology by confocal microscopy using fractal dimension and lacunarity analysis. Full-thickness wounds were created on adult mice, closed by primary intention, and harvested at 14 days after wounding for morphometrics and standard Fourier transform-based scar analysis as well as fractal dimension and lacunarity analysis. In addition, transmission electron microscopy was used to evaluate collagen ultrastructure. We demonstrated that fractal dimension and lacunarity analysis were superior to Fourier transform analysis in discriminating scar versus unwounded tissue in a wild-type mouse model. To fully test the robustness of this scar analysis approach, a fibromodulin-null mouse model that heals with increased scar was also used. Fractal dimension and lacunarity analysis effectively discriminated unwounded fibromodulin-null versus wild-type skin as well as healing fibromodulin-null versus wild-type wounds, whereas Fourier transform analysis failed to do so. Furthermore, fractal dimension and lacunarity data also correlated well with transmission electron microscopy collagen ultrastructure analysis, adding to their validity. These results demonstrate that fractal dimension and lacunarity are more sensitive than Fourier transform analysis for quantification of scar morphology.

  11. Analytical methods for quantitation of prenylated flavonoids from hops.

    PubMed

    Nikolić, Dejan; van Breemen, Richard B

    2013-01-01

    The female flowers of hops (Humulus lupulus L.) are used as a flavoring agent in the brewing industry. There is growing interest in possible health benefits of hops, particularly as estrogenic and chemopreventive agents. Among the possible active constituents, most of the attention has focused on prenylated flavonoids, which can chemically be classified as prenylated chalcones and prenylated flavanones. Among chalcones, xanthohumol (XN) and desmethylxanthohumol (DMX) have been the most studied, while among flavanones, 8-prenylnaringenin (8-PN) and 6-prenylnaringenin (6-PN) have received the most attention. Because of the interest in medicinal properties of prenylated flavonoids, there is demand for accurate, reproducible and sensitive analytical methods to quantify these compounds in various matrices. Such methods are needed, for example, for quality control and standardization of hop extracts, measurement of the content of prenylated flavonoids in beer, and to determine pharmacokinetic properties of prenylated flavonoids in animals and humans. This review summarizes currently available analytical methods for quantitative analysis of the major prenylated flavonoids, with an emphasis on the LC-MS and LC-MS-MS methods and their recent applications to biomedical research on hops. This review covers all methods in which prenylated flavonoids have been measured, either as the primary analytes or as a part of a larger group of analytes. The review also discusses methodological issues relating to the quantitative analysis of these compounds regardless of the chosen analytical approach.

  12. Analytical methods for quantitation of prenylated flavonoids from hops

    PubMed Central

    Nikolić, Dejan; van Breemen, Richard B.

    2013-01-01

    The female flowers of hops (Humulus lupulus L.) are used as a flavoring agent in the brewing industry. There is growing interest in possible health benefits of hops, particularly as estrogenic and chemopreventive agents. Among the possible active constituents, most of the attention has focused on prenylated flavonoids, which can chemically be classified as prenylated chalcones and prenylated flavanones. Among chalcones, xanthohumol (XN) and desmethylxanthohumol (DMX) have been the most studied, while among flavanones, 8-prenylnaringenin (8-PN) and 6-prenylnaringenin (6-PN) have received the most attention. Because of the interest in medicinal properties of prenylated flavonoids, there is demand for accurate, reproducible and sensitive analytical methods to quantify these compounds in various matrices. Such methods are needed, for example, for quality control and standardization of hop extracts, measurement of the content of prenylated flavonoids in beer, and to determine pharmacokinetic properties of prenylated flavonoids in animals and humans. This review summarizes currently available analytical methods for quantitative analysis of the major prenylated flavonoids, with an emphasis on the LC-MS and LC-MS-MS methods and their recent applications to biomedical research on hops. This review covers all methods in which prenylated flavonoids have been measured, either as the primary analytes or as a part of a larger group of analytes. The review also discusses methodological issues relating to the quantitative analysis of these compounds regardless of the chosen analytical approach. PMID:24077106

  13. Informatics Methods to Enable Sharing of Quantitative Imaging Research Data

    PubMed Central

    Levy, Mia A.; Freymann, John B.; Kirby, Justin S.; Fedorov, Andriy; Fennessy, Fiona M.; Eschrich, Steven A.; Berglund, Anders E.; Fenstermacher, David A.; Tan, Yongqiang; Guo, Xiaotao; Casavant, Thomas L.; Brown, Bartley J.; Braun, Terry A.; Dekker, Andre; Roelofs, Erik; Mountz, James M.; Boada, Fernando; Laymon, Charles; Oborski, Matt; Rubin, Daniel L

    2012-01-01

    Introduction The National Cancer Institute (NCI) Quantitative Research Network (QIN) is a collaborative research network whose goal is to share data, algorithms and research tools to accelerate quantitative imaging research. A challenge is the variability in tools and analysis platforms used in quantitative imaging. Our goal was to understand the extent of this variation and to develop an approach to enable sharing data and to promote reuse of quantitative imaging data in the community. Methods We performed a survey of the current tools in use by the QIN member sites for representation and storage of their QIN research data including images, image meta-data and clinical data. We identified existing systems and standards for data sharing and their gaps for the QIN use case. We then proposed a system architecture to enable data sharing and collaborative experimentation within the QIN. Results There area variety of tools currently used by each QIN institution. We developed a general information system architecture to support the QIN goals. We also describe the remaining architecture gaps we are developing to enable members to share research images and image meta-data across the network. Conclusions As a research network, the QIN will stimulate quantitative imaging research by pooling data, algorithms and research tools. However, there are gaps in current functional requirements that will need to be met by future informatics development. Special attention must be given to the technical requirements needed to translate these methods into the clinical research workflow to enable validation and qualification of these novel imaging biomarkers. PMID:22770688

  14. Quantitative ADF STEM: acquisition, analysis and interpretation

    NASA Astrophysics Data System (ADS)

    Jones, L.

    2016-01-01

    Quantitative annular dark-field in the scanning transmission electron microscope (ADF STEM), where image intensities are used to provide composition and thickness measurements, has enjoyed a renaissance during the last decade. Now in a post aberration-correction era many aspects of the technique are being revisited. Here the recent progress and emerging best-practice for such aberration corrected quantitative ADF STEM is discussed including issues relating to proper acquisition of experimental data and its calibration, approaches for data analysis, the utility of such data, its interpretation and limitations.

  15. Quantitative analysis of blood vessel geometry

    NASA Astrophysics Data System (ADS)

    Fuhrman, Michael G.; Abdul-Karim, Othman; Shah, Sujal; Gilbert, Steven G.; Van Bibber, Richard

    2001-07-01

    Re-narrowing or restenosis of a human coronary artery occurs within six months in one third of balloon angioplasty procedures. Accurate and repeatable quantitative analysis of vessel shape is important to characterize the progression and type of restenosis, and to evaluate effects new therapies might have. A combination of complicated geometry and image variability, and the need for high resolution and large image size makes visual/manual analysis slow, difficult, and prone to error. The image processing and analysis described here was developed to automate feature extraction of the lumen, internal elastic lamina, neointima, external elastic lamina, and tunica adventitia and to enable an objective, quantitative definition of blood vessel geometry. The quantitative geometrical analysis enables the measurement of several features including perimeter, area, and other metrics of vessel damage. Automation of feature extraction creates a high throughput capability that enables analysis of serial sections for more accurate measurement of restenosis dimensions. Measurement results are input into a relational database where they can be statistically analyzed compared across studies. As part of the integrated process, results are also imprinted on the images themselves to facilitate auditing of the results. The analysis is fast, repeatable and accurate while allowing the pathologist to control the measurement process.

  16. Novel method for ANA quantitation using IIF imaging system.

    PubMed

    Peng, Xiaodong; Tang, Jiangtao; Wu, Yongkang; Yang, Bin; Hu, Jing

    2014-02-01

    A variety of antinuclear antibodies (ANAs) are found in the serum of patients with autoimmune diseases. The detection of abnormal ANA titers is a critical criterion for diagnosis of systemic lupus erythematosus (SLE) and other connective tissue diseases. Indirect immunofluorescence assay (IIF) on HEp-2 cells is the gold standard method to determine the presence of ANA and therefore provides information about the localization of autoantigens that are useful for diagnosis. However, its utility was limited in prognosing and monitoring of disease activity due to the lack of standardization in performing the technique, subjectivity in interpreting the results and the fact that it is only semi-quantitative. On the other hand, ELISA for the detection of ANA can quantitate ANA but could not provide further information about the localization of the autoantigens. It would be ideal to integrate both of the quantitative and qualitative methods. To address this issue, this study was conducted to quantitatively detect ANAs by using IIF imaging analysis system. Serum samples from patients with ANA positive (including speckled, homogeneous, nuclear mixture and cytoplasmic mixture patterns) and negative were detected for ANA titers by the classical IIF and analyzed by an image system, the image of each sample was acquired by the digital imaging system and the green fluorescence intensity was quantified by the Image-Pro plus software. A good correlation was found in between two methods and the correlation coefficients (R(2)) of various ANA patterns were 0.942 (speckled), 0.942 (homogeneous), 0.923 (nuclear mixture) and 0.760 (cytoplasmic mixture), respectively. The fluorescence density was linearly correlated with the log of ANA titers in various ANA patterns (R(2)>0.95). Moreover, the novel ANA quantitation method showed good reproducibility (F=0.091, p>0.05) with mean±SD and CV% of positive, and negative quality controls were equal to 126.4±9.6 and 7.6%, 10.4±1.25 and 12

  17. Quantitative Analysis of Radar Returns from Insects

    NASA Technical Reports Server (NTRS)

    Riley, J. R.

    1979-01-01

    When a number of flying insects is low enough to permit their resolution as individual radar targets, quantitative estimates of their aerial density are developed. Accurate measurements of heading distribution using a rotating polarization radar to enhance the wingbeat frequency method of identification are presented.

  18. Some Epistemological Considerations Concerning Quantitative Analysis

    ERIC Educational Resources Information Center

    Dobrescu, Emilian

    2008-01-01

    This article presents the author's address at the 2007 "Journal of Applied Quantitative Methods" ("JAQM") prize awarding festivity. The festivity was included in the opening of the 4th International Conference on Applied Statistics, November 22, 2008, Bucharest, Romania. In the address, the author reflects on three theses that…

  19. Comprehensive quantitative analysis on privacy leak behavior.

    PubMed

    Fan, Lejun; Wang, Yuanzhuo; Jin, Xiaolong; Li, Jingyuan; Cheng, Xueqi; Jin, Shuyuan

    2013-01-01

    Privacy information is prone to be leaked by illegal software providers with various motivations. Privacy leak behavior has thus become an important research issue of cyber security. However, existing approaches can only qualitatively analyze privacy leak behavior of software applications. No quantitative approach, to the best of our knowledge, has been developed in the open literature. To fill this gap, in this paper we propose for the first time four quantitative metrics, namely, possibility, severity, crypticity, and manipulability, for privacy leak behavior analysis based on Privacy Petri Net (PPN). In order to compare the privacy leak behavior among different software, we further propose a comprehensive metric, namely, overall leak degree, based on these four metrics. Finally, we validate the effectiveness of the proposed approach using real-world software applications. The experimental results demonstrate that our approach can quantitatively analyze the privacy leak behaviors of various software types and reveal their characteristics from different aspects.

  20. Comprehensive Quantitative Analysis on Privacy Leak Behavior

    PubMed Central

    Fan, Lejun; Wang, Yuanzhuo; Jin, Xiaolong; Li, Jingyuan; Cheng, Xueqi; Jin, Shuyuan

    2013-01-01

    Privacy information is prone to be leaked by illegal software providers with various motivations. Privacy leak behavior has thus become an important research issue of cyber security. However, existing approaches can only qualitatively analyze privacy leak behavior of software applications. No quantitative approach, to the best of our knowledge, has been developed in the open literature. To fill this gap, in this paper we propose for the first time four quantitative metrics, namely, possibility, severity, crypticity, and manipulability, for privacy leak behavior analysis based on Privacy Petri Net (PPN). In order to compare the privacy leak behavior among different software, we further propose a comprehensive metric, namely, overall leak degree, based on these four metrics. Finally, we validate the effectiveness of the proposed approach using real-world software applications. The experimental results demonstrate that our approach can quantitatively analyze the privacy leak behaviors of various software types and reveal their characteristics from different aspects. PMID:24066046

  1. Review of Quantitative Software Reliability Methods

    SciTech Connect

    Chu, T.L.; Yue, M.; Martinez-Guridi, M.; Lehner, J.

    2010-09-17

    The current U.S. Nuclear Regulatory Commission (NRC) licensing process for digital systems rests on deterministic engineering criteria. In its 1995 probabilistic risk assessment (PRA) policy statement, the Commission encouraged the use of PRA technology in all regulatory matters to the extent supported by the state-of-the-art in PRA methods and data. Although many activities have been completed in the area of risk-informed regulation, the risk-informed analysis process for digital systems has not yet been satisfactorily developed. Since digital instrumentation and control (I&C) systems are expected to play an increasingly important role in nuclear power plant (NPP) safety, the NRC established a digital system research plan that defines a coherent set of research programs to support its regulatory needs. One of the research programs included in the NRC's digital system research plan addresses risk assessment methods and data for digital systems. Digital I&C systems have some unique characteristics, such as using software, and may have different failure causes and/or modes than analog I&C systems; hence, their incorporation into NPP PRAs entails special challenges. The objective of the NRC's digital system risk research is to identify and develop methods, analytical tools, and regulatory guidance for (1) including models of digital systems into NPP PRAs, and (2) using information on the risks of digital systems to support the NRC's risk-informed licensing and oversight activities. For several years, Brookhaven National Laboratory (BNL) has worked on NRC projects to investigate methods and tools for the probabilistic modeling of digital systems, as documented mainly in NUREG/CR-6962 and NUREG/CR-6997. However, the scope of this research principally focused on hardware failures, with limited reviews of software failure experience and software reliability methods. NRC also sponsored research at the Ohio State University investigating the modeling of digital systems

  2. A rapid chemiluminescent method for quantitation of human DNA.

    PubMed Central

    Walsh, P S; Varlaro, J; Reynolds, R

    1992-01-01

    A sensitive and simple method for the quantitation of human DNA is described. This method is based on probe hybridization to a human alpha satellite locus, D17Z1. The biotinylated probe is hybridized to sample DNA immobilized on nylon membrane. The subsequent binding of streptavidin-horseradish peroxidase to the bound probe allows for chemiluminescent detection using a luminol-based reagent and X-ray film. Less than 150 pg of human DNA can easily be detected with a 15 minute exposure. The entire procedure can be performed in 1.5 hours. Microgram quantities of nonhuman DNA have been tested and the results indicate very high specificity for human DNA. The data on film can be scanned into a computer and a commercially available program can be used to create a standard curve where DNA quantity is plotted against the mean density of each slot blot signal. The methods described can also be applied to the very sensitive determination of quantity and quality (size) of DNA on Southern blots. The high sensitivity of this quantitation method requires the consumption of only a fraction of sample for analysis. Determination of DNA quantity is necessary for RFLP and many PCR-based tests where optimal results are obtained only with a relatively narrow range of DNA quantities. The specificity of this quantitation method for human DNA will be useful for the analysis of samples that may also contain bacterial or other non-human DNA, for example forensic evidence samples, ancient DNA samples, or clinical samples. Images PMID:1408822

  3. A rapid chemiluminescent method for quantitation of human DNA.

    PubMed

    Walsh, P S; Varlaro, J; Reynolds, R

    1992-10-11

    A sensitive and simple method for the quantitation of human DNA is described. This method is based on probe hybridization to a human alpha satellite locus, D17Z1. The biotinylated probe is hybridized to sample DNA immobilized on nylon membrane. The subsequent binding of streptavidin-horseradish peroxidase to the bound probe allows for chemiluminescent detection using a luminol-based reagent and X-ray film. Less than 150 pg of human DNA can easily be detected with a 15 minute exposure. The entire procedure can be performed in 1.5 hours. Microgram quantities of nonhuman DNA have been tested and the results indicate very high specificity for human DNA. The data on film can be scanned into a computer and a commercially available program can be used to create a standard curve where DNA quantity is plotted against the mean density of each slot blot signal. The methods described can also be applied to the very sensitive determination of quantity and quality (size) of DNA on Southern blots. The high sensitivity of this quantitation method requires the consumption of only a fraction of sample for analysis. Determination of DNA quantity is necessary for RFLP and many PCR-based tests where optimal results are obtained only with a relatively narrow range of DNA quantities. The specificity of this quantitation method for human DNA will be useful for the analysis of samples that may also contain bacterial or other non-human DNA, for example forensic evidence samples, ancient DNA samples, or clinical samples.

  4. Quantitative analysis of regional myocardial performance in coronary artery disease

    NASA Technical Reports Server (NTRS)

    Stewart, D. K.; Dodge, H. T.; Frimer, M.

    1975-01-01

    Findings from a group of subjects with significant coronary artery stenosis are given. A group of controls determined by use of a quantitative method for the study of regional myocardial performance based on the frame-by-frame analysis of biplane left ventricular angiograms are presented. Particular emphasis was placed upon the analysis of wall motion in terms of normalized segment dimensions, timing and velocity of contraction. The results were compared with the method of subjective assessment used clinically.

  5. Quantitative image analysis of celiac disease.

    PubMed

    Ciaccio, Edward J; Bhagat, Govind; Lewis, Suzanne K; Green, Peter H

    2015-03-07

    We outline the use of quantitative techniques that are currently used for analysis of celiac disease. Image processing techniques can be useful to statistically analyze the pixular data of endoscopic images that is acquired with standard or videocapsule endoscopy. It is shown how current techniques have evolved to become more useful for gastroenterologists who seek to understand celiac disease and to screen for it in suspected patients. New directions for focus in the development of methodology for diagnosis and treatment of this disease are suggested. It is evident that there are yet broad areas where there is potential to expand the use of quantitative techniques for improved analysis in suspected or known celiac disease patients.

  6. Quantitative Analysis of Hypoperfusion in Acute Stroke

    PubMed Central

    Nael, Kambiz; Meshksar, Arash; Liebeskind, David S.; Coull, Bruce M.; Krupinski, Elizabeth A.; Villablanca, J. Pablo

    2014-01-01

    Background and Purpose This study compares the concordance between arterial spin labeling (ASL) and dynamic susceptibility contrast (DSC) for the identification of regional hypoperfusion and diffusion-perfusion mismatch tissue classification using a quantitative method. Methods The inclusion criteria for this retrospective study were as follows: patients with acute ischemic syndrome with symptom onset <24 hours and acquisition of both ASL and DSC MR perfusion. The volumes of infarction and hypoperfused lesions were calculated on ASL and DSC multi-parametric maps. Patients were classified into reperfused, matched, or mismatch groups using time to maximum >6 sec as the reference. In a subset of patients who were successfully recanalized, the identical analysis was performed and the infarction and hypoperfused lesion volumes were used for paired pre- and posttreatment comparisons. Results Forty-one patients met our inclusion criteria. Twenty patients underwent successful endovascular revascularization (TICI>2a), resulting in a total of 61 ASL-DSC data pairs for comparison. The hypoperfusion volume on ASL-cerebral blood flow best approximated the DSC-time to peak volume (r=0.83) in pretreatment group and time to maximum (r=0.46) after recanalization. Both ASL-cerebral blood flow and DSC-TTP overestimated the hypoperfusion volume compared with time to maximum volume in pretreatment (F=27.41, P<0.0001) and recanalized patients (F=8.78, P<0.0001). Conclusions ASL-cerebral blood flow overestimates the DSC time to maximum hypoperfusion volume and mismatch classification in patients with acute ischemic syndrome. Continued overestimation of hypoperfused volume after recanalization suggests flow pattern and velocity changes in addition to arterial transit delay can affects the performance of ASL. PMID:23988646

  7. Quantitative analysis to guide orphan drug development.

    PubMed

    Lesko, L J

    2012-08-01

    The development of orphan drugs for rare diseases has made impressive strides in the past 10 years. There has been a surge in orphan drug designations, but new drug approvals have not kept up. This article presents a three-pronged hierarchical strategy for quantitative analysis of data at the descriptive, mechanistic, and systems levels of the biological system that could represent a standardized and rational approach to orphan drug development. Examples are provided to illustrate the concept.

  8. Quantitative flow cytometric analysis of membrane antigen expression.

    PubMed

    D'hautcourt, Jean-Luc

    2002-11-01

    Immunological analysis for cell antigens has been performed by flow cytometry in a qualitative fashion for over thirty years. During that time it has become increasingly apparent that quantitative measurements such as number of antigens per cell provide unique and useful information. This unit on quantitative flow cytometry (QFCM) describes the most commonly used protocols, both direct and indirect, and the major methods of analysis for the number of antibody binding sites on a cell or particle. Practical applications include detection of antigen under- or overexpression in hematological malignancies, distinguishing between B cell lymphoproliferative disorders, and precise diagnosis of certain rare diseases.

  9. Quantitative O-glycomics based on improvement of the one-pot method for nonreductive O-glycan release and simultaneous stable isotope labeling with 1-(d0/d5)phenyl-3-methyl-5-pyrazolone followed by mass spectrometric analysis.

    PubMed

    Wang, Chengjian; Zhang, Ping; Jin, Wanjun; Li, Lingmei; Qiang, Shan; Zhang, Ying; Huang, Linjuan; Wang, Zhongfu

    2017-01-06

    Rapid, simple and versatile methods for quantitative analysis of glycoprotein O-glycans are urgently required for current studies on protein O-glycosylation patterns and the search for disease O-glycan biomarkers. Relative quantitation of O-glycans using stable isotope labeling followed by mass spectrometric analysis represents an ideal and promising technique. However, it is hindered by the shortage of reliable nonreductive O-glycan release methods as well as the too large or too small inconstant mass difference between the light and heavy isotope form derivatives of O-glycans, which results in difficulties during the recognition and quantitative analysis of O-glycans by mass spectrometry. Herein we report a facile and versatile O-glycan relative quantification strategy, based on an improved one-pot method that can quantitatively achieve nonreductive release and in situ chromophoric labeling of intact mucin-type O-glycans in one step. In this study, the one-pot method is optimized and applied for quantitative O-glycan release and tagging with either non-deuterated (d0-) or deuterated (d5-) 1-phenyl-3-methyl-5-pyrazolone (PMP). The obtained O-glycan derivatives feature a permanent 10-Da mass difference between the d0- and d5-PMP forms, allowing complete discrimination and comparative quantification of these isotopically labeled O-glycans by mass spectrometric techniques. Moreover, the d0- and d5-PMP derivatives of O-glycans also have a relatively high hydrophobicity as well as a strong UV adsorption, especially suitable for high-resolution separation and high-sensitivity detection by RP-HPLC-UV. We have refined the conditions for the one-pot reaction as well as the corresponding sample purification approach. The good quantitation feasibility, reliability and linearity of this strategy have been verified using bovine fetuin and porcine stomach mucin as model O-glycoproteins. Additionally, we have also successfully applied this method to the quantitative O

  10. [Cloning and sequence analysis of the DHBV genome of the brown ducks in Guilin region and establishment of the quantitative method for detecting DHBV].

    PubMed

    Su, He-Ling; Huang, Ri-Dong; He, Song-Qing; Xu, Qing; Zhu, Hua; Mo, Zhi-Jing; Liu, Qing-Bo; Liu, Yong-Ming

    2013-03-01

    Brown ducks carrying DHBV were widely used as hepatitis B animal model in the research of the activity and toxicity of anti-HBV dugs. Studies showed that the ratio of DHBV carriers in the brown ducks in Guilin region was relatively high. Nevertheless, the characters of the DHBV genome of Guilin brown duck remain unknown. Here we report the cloning of the genome of Guilin brown duck DHBV and the sequence analysis of the genome. The full length of the DHBV genome of Guilin brown duck was 3 027bp. Analysis using ORF finder found that there was an ORF for an unknown peptide other than S-ORF, PORF and C-ORF in the genome of the DHBV. Vector NTI 8. 0 analysis revealed that the unknown peptide contained a motif which binded to HLA * 0201. Aligning with the DHBV sequences from different countries and regions indicated that there were no obvious differences of regional distribution among the sequences. A fluorescence quantitative PCR for detecting DHBV was establishment based on the recombinant plasmid pGEM-DHBV-S constructed. This study laid the groundwork for using Guilin brown duck as a hepatitis B animal model.

  11. From themes to hypotheses: following up with quantitative methods.

    PubMed

    Morgan, David L

    2015-06-01

    One important category of mixed-methods research designs consists of quantitative studies that follow up on qualitative research. In this case, the themes that serve as the results from the qualitative methods generate hypotheses for testing through the quantitative methods. That process requires operationalization to translate the concepts from the qualitative themes into quantitative variables. This article illustrates these procedures with examples that range from simple operationalization to the evaluation of complex models. It concludes with an argument for not only following up qualitative work with quantitative studies but also the reverse, and doing so by going beyond integrating methods within single projects to include broader mutual attention from qualitative and quantitative researchers who work in the same field.

  12. Inverse PCR and Quantitative PCR as Alternative Methods to Southern Blotting Analysis to Assess Transgene Copy Number and Characterize the Integration Site in Transgenic Woody Plants.

    PubMed

    Stefano, Biricolti; Patrizia, Bogani; Matteo, Cerboneschi; Massimo, Gori

    2016-06-01

    One of the major unanswered questions with respect to the commercial use of genetic transformation in woody plants is the stability of the transgene expression over several decades within the same individual. Gene expression is strongly affected by the copy number which has been integrated into the plant genome and by the local DNA features close to the integration sites. Because woody plants cannot be subjected to selfing or backcrossing to modify the transgenic allelic structure without affecting the valuable traits of the cultivar, molecular characterization of the transformation event is therefore crucial. After assessing the transgene copy number of a set of apple transgenic clones with Southern blotting, we describe two alternative methods: the first is based on inverse PCR (i-PCR) and the second on the quantitative PCR (q-PCR). The methods produced comparable results with the exception of the data regarding a high copy number clone, but while the q-PCR-based system is rapid and easily adaptable to high throughput systems, the i-PCR-based method can provide information regarding the transformation event and the characteristics of the sequences flanking the transgenic construct.

  13. A quantitative method to track protein translocation between intracellular compartments in real-time in live cells using weighted local variance image analysis.

    PubMed

    Calmettes, Guillaume; Weiss, James N

    2013-01-01

    The genetic expression of cloned fluorescent proteins coupled to time-lapse fluorescence microscopy has opened the door to the direct visualization of a wide range of molecular interactions in living cells. In particular, the dynamic translocation of proteins can now be explored in real time at the single-cell level. Here we propose a reliable, easy-to-implement, quantitative image processing method to assess protein translocation in living cells based on the computation of spatial variance maps of time-lapse images. The method is first illustrated and validated on simulated images of a fluorescently-labeled protein translocating from mitochondria to cytoplasm, and then applied to experimental data obtained with fluorescently-labeled hexokinase 2 in different cell types imaged by regular or confocal microscopy. The method was found to be robust with respect to cell morphology changes and mitochondrial dynamics (fusion, fission, movement) during the time-lapse imaging. Its ease of implementation should facilitate its application to a broad spectrum of time-lapse imaging studies.

  14. Validation of a quantitative and confirmatory method for residue analysis of aminoglycoside antibiotics in poultry, bovine, equine and swine kidney through liquid chromatography-tandem mass spectrometry.

    PubMed

    Almeida, M P; Rezende, C P; Souza, L F; Brito, R B

    2012-01-01

    The use of aminoglycoside antibiotics in food animals is approved in Brazil. Accordingly, Brazilian food safety legislation sets maximum levels for these drugs in tissues from these animals in an effort to guarantee that food safety is not compromised. Aiming to monitor the levels of these drugs in tissues from food animals, the validation of a quantitative, confirmatory method for the detection of residues of 10 aminoglycosides antibiotics in poultry, swine, equine and bovine kidney, with extraction using a solid phase and detection and quantification by LC-MS/MS was performed. The procedure is an adaptation of the US Department of Agriculture, Food Safety and Inspection Service (USDA-FSIS) qualitative method, with the inclusion of additional clean-up and quantification at lower levels, which proved more efficient. Extraction was performed using a phosphate buffer containing trifluoroacetic acid followed by neutralization, purification on a cationic exchange SPE cartridge, with elution with methanol/acetic acid, evaporation, and dilution in ion-pair solvent. The method was validated according to the criteria and requirements of the European Commission Decision 2002/657/EC, showing selectivity with no matrix interference. Linearity was established for all analytes using the method of weighted minimum squares. CCα and CCβ varied between 1036 and 12,293 µg kg(-1), and between 1073 and 14,588 µg kg(-1), respectively. The limits of quantification varied between 27 and 688 µg kg(-1). The values of recovery for all analytes in poultry kidney, fortified in the range of 500-1500 µg kg(-1), were higher than 90%, and the relative standard deviations were lower than 15%, except spectinomycin (21.8%). Uncertainty was estimated using a simplified methodology of 'bottom-up' and 'top-down' strategies. The results showed that this method is effective for the quantification and confirmation of aminoglycoside residues and could be used by the Brazilian programme of residue

  15. A quantitative analysis of the F18 flight control system

    NASA Technical Reports Server (NTRS)

    Doyle, Stacy A.; Dugan, Joanne B.; Patterson-Hine, Ann

    1993-01-01

    This paper presents an informal quantitative analysis of the F18 flight control system (FCS). The analysis technique combines a coverage model with a fault tree model. To demonstrate the method's extensive capabilities, we replace the fault tree with a digraph model of the F18 FCS, the only model available to us. The substitution shows that while digraphs have primarily been used for qualitative analysis, they can also be used for quantitative analysis. Based on our assumptions and the particular failure rates assigned to the F18 FCS components, we show that coverage does have a significant effect on the system's reliability and thus it is important to include coverage in the reliability analysis.

  16. Quantitative Hydrocarbon Energies from the PMO Method.

    ERIC Educational Resources Information Center

    Cooper, Charles F.

    1979-01-01

    Details a procedure for accurately calculating the quantum mechanical energies of hydrocarbons using the perturbational molecular orbital (PMO) method, which does not require the use of a computer. (BT)

  17. A Quantitative Method for the Analysis of Nomothetic Relationships between Idiographic Structures: Dynamic Patterns Create Attractor States for Sustained Posttreatment Change

    ERIC Educational Resources Information Center

    Fisher, Aaron J.; Newman, Michelle G.; Molenaar, Peter C. M.

    2011-01-01

    Objective: The present article aimed to demonstrate that the establishment of dynamic patterns during the course of psychotherapy can create attractor states for continued adaptive change following the conclusion of treatment. Method: This study is a secondary analysis of T. D. Borkovec and E. Costello (1993). Of the 55 participants in the…

  18. Quantitating the subtleties of microglial morphology with fractal analysis

    PubMed Central

    Karperien, Audrey; Ahammer, Helmut; Jelinek, Herbert F.

    2013-01-01

    It is well established that microglial form and function are inextricably linked. In recent years, the traditional view that microglial form ranges between “ramified resting” and “activated amoeboid” has been emphasized through advancing imaging techniques that point to microglial form being highly dynamic even within the currently accepted morphological categories. Moreover, microglia adopt meaningful intermediate forms between categories, with considerable crossover in function and varying morphologies as they cycle, migrate, wave, phagocytose, and extend and retract fine and gross processes. From a quantitative perspective, it is problematic to measure such variability using traditional methods, but one way of quantitating such detail is through fractal analysis. The techniques of fractal analysis have been used for quantitating microglial morphology, to categorize gross differences but also to differentiate subtle differences (e.g., amongst ramified cells). Multifractal analysis in particular is one technique of fractal analysis that may be useful for identifying intermediate forms. Here we review current trends and methods of fractal analysis, focusing on box counting analysis, including lacunarity and multifractal analysis, as applied to microglial morphology. PMID:23386810

  19. Quantitative analysis of non-Hodgkin's lymphoma.

    PubMed Central

    Abbott, C R; Blewitt, R W; Bird, C C

    1982-01-01

    A preliminary attempt has been made to characterise a small series of non-Hodgkin's lymphomas (NHL) by morphometric means using the Quantimet 720 Kontron MOP/AMO3 image analysis systems. In most cases it was found that the distribution of nuclear area and correlation between mean nuclear area and frequency per unit field, corresponded closely with tumour classification determined by light microscopy. These results suggest that it may be possible to devise an objective and reproducible grading system for NHL using quantitative morphometric techniques. PMID:7040479

  20. Quantitative NIR Raman analysis in liquid mixtures.

    PubMed

    Sato-Berrú, R Ysacc; Medina-Valtierra, Jorge; Medina-Gutiérrez, Cirilo; Frausto-Reyes, Claudio

    2004-08-01

    The capability to obtain quantitative information of a simple way from Raman spectra is a subject of considerable interest. In this work, this is demonstrated for mixtures of ethanol with water and rhodamine-6G (R-6G) with methanol, which were analyzed directly in glass vessel. The Raman intensities and a simple mathematical model have been used and applied for the analysis of liquid samples. It is starting point to generate a general expression, from the experimental spectra, as the sum of the particular expression for each pure compound allow us to obtain an expression for the mixtures which can be used for determining concentrations, from the Raman spectrum, of the mixture.

  1. Quantitative methods to direct exploration based on hydrogeologic information

    USGS Publications Warehouse

    Graettinger, A.J.; Lee, J.; Reeves, H.W.; Dethan, D.

    2006-01-01

    Quantitatively Directed Exploration (QDE) approaches based on information such as model sensitivity, input data covariance and model output covariance are presented. Seven approaches for directing exploration are developed, applied, and evaluated on a synthetic hydrogeologic site. The QDE approaches evaluate input information uncertainty, subsurface model sensitivity and, most importantly, output covariance to identify the next location to sample. Spatial input parameter values and covariances are calculated with the multivariate conditional probability calculation from a limited number of samples. A variogram structure is used during data extrapolation to describe the spatial continuity, or correlation, of subsurface information. Model sensitivity can be determined by perturbing input data and evaluating output response or, as in this work, sensitivities can be programmed directly into an analysis model. Output covariance is calculated by the First-Order Second Moment (FOSM) method, which combines the covariance of input information with model sensitivity. A groundwater flow example, modeled in MODFLOW-2000, is chosen to demonstrate the seven QDE approaches. MODFLOW-2000 is used to obtain the piezometric head and the model sensitivity simultaneously. The seven QDE approaches are evaluated based on the accuracy of the modeled piezometric head after information from a QDE sample is added. For the synthetic site used in this study, the QDE approach that identifies the location of hydraulic conductivity that contributes the most to the overall piezometric head variance proved to be the best method to quantitatively direct exploration. ?? IWA Publishing 2006.

  2. Linear-After-The-Exponential (LATE)–PCR: An advanced method of asymmetric PCR and its uses in quantitative real-time analysis

    PubMed Central

    Sanchez, J. Aquiles; Pierce, Kenneth E.; Rice, John E.; Wangh, Lawrence J.

    2004-01-01

    Conventional asymmetric PCR is inefficient and difficult to optimize because limiting the concentration of one primer lowers its melting temperature below the reaction annealing temperature. Linear-After-The-Exponential (LATE)–PCR describes a new paradigm for primer design that renders assays as efficient as symmetric PCR assays, regardless of primer ratio. LATE-PCR generates single-stranded products with predictable kinetics for many cycles beyond the exponential phase. LATE-PCR also introduces new probe design criteria that uncouple hybridization probe detection from primer annealing and extension, increase probe reliability, improve allele discrimination, and increase signal strength by 80–250% relative to symmetric PCR. These improvements in PCR are particularly useful for real-time quantitative analysis of target numbers in small samples. LATE-PCR is adaptable to high throughput applications in fields such as clinical diagnostics, biodefense, forensics, and DNA sequencing. We showcase LATE-PCR via amplification of the cystic fibrosis CFΔ508 allele and the Tay-Sachs disease TSD 1278 allele from single heterozygous cells. PMID:14769930

  3. Quantitative analysis of the heterogeneous population of endocytic vesicles.

    PubMed

    Kozlov, Konstantin; Kosheverova, Vera; Kamentseva, Rimma; Kharchenko, Marianna; Sokolkova, Alena; Kornilova, Elena; Samsonova, Maria

    2017-03-07

    The quantitative characterization of endocytic vesicles in images acquired with microscope is critically important for deciphering of endocytosis mechanisms. Image segmentation is the most important step of quantitative image analysis. In spite of availability of many segmentation methods, the accurate segmentation is challenging when the images are heterogeneous with respect to object shapes and signal intensities what is typical for images of endocytic vesicles. We present a Morphological reconstruction and Contrast mapping segmentation method (MrComas) for the segmentation of the endocytic vesicle population that copes with the heterogeneity in their shape and intensity. The method uses morphological opening and closing by reconstruction in the vicinity of local minima and maxima respectively thus creating the strong contrast between their basins of attraction. As a consequence, the intensity is flattened within the objects and their edges are enhanced. The method accurately recovered quantitative characteristics of synthetic images that preserve characteristic features of the endocytic vesicle population. In benchmarks and quantitative comparisons with two other popular segmentation methods, namely manual thresholding and Squash plugin, MrComas shows the best segmentation results on real biological images of EGFR (Epidermal Growth Factor Receptor) endocytosis. As a proof of feasibility, the method was applied to quantify the dynamical behavior of Early Endosomal Autoantigen 1 (EEA1)-positive endosome subpopulations during EGF-stimulated endocytosis.

  4. Reversed-phase HPLC/FD method for the quantitative analysis of the neurotoxin BMAA (β-N-methylamino-L-alanine) in cyanobacteria.

    PubMed

    Cianca, R C Cervantes; Baptista, M S; Silva, Luís Pinto da; Lopes, V R; Vasconcelos, V M

    2012-03-01

    A method has been developed and optimized in order to detect and quantify the non-protein amino acid β-N-methylamino-L-alanine(BMAA) in cyanobacteria. The novelty of the method is that we have used methanol instead of acetonitrile as the eluent. The method includes extraction with 0.1 M trichloroacetic acid (free BMAA) or protein hydrolysis with 6 M hydrochloric acid (total BMAA), derivatization with AQC (6-aminoquinolyl-N-hydroxysuccinimidyl carbamate) and reversed-phase high-performance liquid chromatography analysis with fluorescence detection (HPLC/FD). Detection limits ranged from 0.35 to 0.75 pg injected, while quantification limits ranged from 1.10 to 2.55 pg injected for total and free BMAA hydrolysis, respectively. The linear response range was up to 850 pmol in both methods, embracing three orders of magnitude. The method was successfully applied to a lyophilized estuarine species of Nostoc (LEGE 06077). All previous published methods for BMAA quantification, using HPLC/FD, have reported the usage of acetonitrile. This is the first report using methanol as the mobile phase. Although the elution strength differs with both solvents, the final method proved efficient for the quantification of BMAA in this complex sample. The method resulted effective, low-priced, and simple, being suitable for routine monitoring of BMAA in cyanobacteria.

  5. Simultaneous quantitation of 14 active components in Yinchenhao decoction with an ultrahigh performance liquid chromatography-diode array detector: Method development and ingredient analysis of different commonly prepared samples.

    PubMed

    Yi, YaXiong; Zhang, Yong; Ding, Yue; Lu, Lu; Zhang, Tong; Zhao, Yuan; Xu, XiaoJun; Zhang, YuXin

    2016-11-01

    J. Sep. Sci. 2016, 39, 4147-4157 DOI: 10.1002/jssc.201600284 Yinchenhao decoction (YCHD) is a famous Chinese herbal formula recorded in the Shang Han Lun which was prescribed by Zhongjing Zhang during 150-219 AD. A novel quantitative analysis method was developed, based on ultrahigh performance liquid chromatography coupled with a diode array detector for the simultaneous determination of 14 main active components in Yinchenhao decoction. Furthermore, the method has been applied for compositional difference analysis of the 14 components in eight normal extraction samples of Yinchenhao decoction, with the aid of hierarchical clustering analysis and similarity analysis. The present research could help hospital, factory and lab choose the best way to make Yinchenhao decoction with better efficacy.

  6. Markov chain Monte Carlo linkage analysis of complex quantitative phenotypes.

    PubMed

    Hinrichs, A; Reich, T

    2001-01-01

    We report a Markov chain Monte Carlo analysis of the five simulated quantitative traits in Genetic Analysis Workshop 12 using the Loki software. Our objectives were to determine the efficacy of the Markov chain Monte Carlo method and to test a new scoring technique. Our initial blind analysis, on replicate 42 (the "best replicate") successfully detected four out of the five disease loci and found no false positives. A power analysis shows that the software could usually detect 4 of the 10 trait/gene combinations at an empirical point-wise p-value of 1.5 x 10(-4).

  7. A method for the quantitative analysis of Intensity-Modulated Radiation Therapy (IMRT) treatment plan verification with radiographic film and polymer gel dosimeters

    NASA Astrophysics Data System (ADS)

    Witten, Matthew Roy

    The clinical implementation of intensity-modulated radiotherapy has necessitated the development of sophisticated quality assurance techniques to ensure that the radiation dose distribution calculated by the computerized radiotherapy treatment planning system is reproduced with an acceptable degree of fidelity during treatment delivery. The index of agreement is introduced as a quantitative quality assurance tool capable of comparing the planned dose distribution with the dose distribution measured with a radiation dosimeter. The index of agreement method begins with solving a constrained optimization problem for each pixel (or voxel) of the planned dose distribution. Each pixel (or voxel) of the planned distribution is then assigned a score based upon the solution of the constrained optimization problem. The index of agreement is then calculated by dividing the number of pixels (or voxels) that are clinically relevant and for which the score function is equal to zero by the total number of clinically relevant pixels (or voxels). Data acquired with radiographic film and polymer gel indicate that the index of agreement is a stable quality assurance parameter.

  8. Quantitative Structure activity Relationship Analysis of Pyridinone HIV-1 Reverse Transcriptase Inhibitors using the k Nearest Neighbor Method and QSAR-based Database Mining

    NASA Astrophysics Data System (ADS)

    Medina-Franco, Jose Luis; Golbraikh, Alexander; Oloff, Scott; Castillo, Rafael; Tropsha, Alexander

    2005-04-01

    We have developed quantitative structure-activity relationship (QSAR) models for 44 non-nucleoside HIV-1 reverse transcriptase inhibitors (NNRTIs) of the pyridinone derivative type. The k nearest neighbor ( kNN) variable selection approach was used. This method utilizes multiple descriptors such as molecular connectivity indices, which are derived from two-dimensional molecular topology. The modeling process entailed extensive validation including the randomization of the target property (Y-randomization) test and the division of the dataset into multiple training and test sets to establish the external predictive power of the training set models. QSAR models with high internal and external accuracy were generated, with leave-one-out cross-validated R 2 ( q 2) values ranging between 0.5 and 0.8 for the training sets and R 2 values exceeding 0.6 for the test sets. The best models with the highest internal and external predictive power were used to search the National Cancer Institute database. Derivatives of the pyrazolo[3,4- d]pyrimidine and phenothiazine type were identified as promising novel NNRTIs leads. Several candidates were docked into the binding pocket of nevirapine with the AutoDock (version 3.0) software. Docking results suggested that these types of compounds could be binding in the NNRTI binding site in a similar mode to a known non-nucleoside inhibitor nevirapine.

  9. Quantitative analysis of the ribbon synapse number of cochlear inner hair cells in C57BL/6J mice using the three-dimensional modeling method.

    PubMed

    Liu, Ke; Li, ShuNa; Jiang, XueJun

    2009-09-01

    In mammals, the ribbon synapses of cochlear inner hair cells are a synaptic structure of the first sensory nerve in the pathway of acoustical signal transmission to the acoustic center, and it is directly involved in voice coding and neurotransmitter release. It is difficult to quantitatively analyze the ribbon synaptic number only using an electron microscope, because the ribbon synaptic number is relatively limited and their location is deep. In this study, the specific presynaptic structure-RIBEYE, and non-specific postsynaptic structure-GluR 2 & 3 in C57BL/6J mouse basilar membrane samples were treated by immunofluorescent labeling. Serial section was performed on the samples using a laser scanning confocal microscope, and then the serial sections were used to build three-dimensional models using 3DS MAX software. Each fluorescein color pair indicates one synapse, so the number of ribbon synapses of inner hair cells is obtained. The spatial distribution and the number of ribbon synapses of cochlear inner hair cells were clearly shown in this experiment, and the mean number of ribbon synapses per inner hair cell was 16.10+/-1.03. Our results have demonstrated the number of ribbon synapses is accurately calculated by double immunofluorescent labeling to presynaptic and postsynaptic structures, serial sections obtained using a laser scanning confocal microscope, and three-dimensional modeling obtained using 3DS MAX software. The method above is feasible and has important significance for further exploring the mechanism of sensorineural deafness.

  10. [Simultaneous quantitative analysis of four lignanoids in Schisandra chinensis by quantitative analysis of multi-components by single marker].

    PubMed

    He, Feng-Cheng; Li, Shou-Xin; Zhao, Zhi-Quan; Dong, Jin-Ping; Liu, Wu-Zhan; Su, Rui-Qiang

    2012-07-01

    The aim of the study is to establish a new method of quality evaluation and validate its feasibilities by the simultaneous quantitative assay of four lignanoids in Schisandra chinensis. A new quality evaluation method, quantitative analysis of multi-components by single marker (QAMS), was established and validated with Schisandra chinensis. Four main lignanoids, schisandrin, schisantherin A, deoxyschizandrin and gamma-schizandrin, were selected as analytes and schisandrin as internal reference substance to evaluate the quality. Their contents in 13 different batches of samples, collected from different bathes, were determined by both external standard method and QAMS. The method was evaluated by comparison of the quantitative results between external standard method and QAMS. No significant differences were found in the quantitative results of four lignanoids in 13 batches of S. chinensis determined by external standard method and QAMS. QAMS is feasible for determination of four lignanoids simultaneously when some authentic standard substances were unavailable, and the developed method can be used for quality control of S. chinensis.

  11. Method for quantitating sensitivity to a staphylococcal bacteriocin.

    PubMed Central

    Van Norman, G; Groman, N

    1979-01-01

    A convenient method for quantitating the sensitivity of large numbers of bacterial strains (presently Corynebacterium diphtheriae) to a Staphylococcus aureus phage type 71 bacteriocin is described. Images PMID:121117

  12. Fluorometric method of quantitative cell mutagenesis

    DOEpatents

    Dolbeare, Frank A.

    1982-01-01

    A method for assaying a cell culture for mutagenesis is described. A cell culture is stained first with a histochemical stain, and then a fluorescent stain. Normal cells in the culture are stained by both the histochemical and fluorescent stains, while abnormal cells are stained only by the fluorescent stain. The two stains are chosen so that the histochemical stain absorbs the wavelengths that the fluorescent stain emits. After the counterstained culture is subjected to exciting light, the fluorescence from the abnormal cells is detected.

  13. Fluorometric method of quantitative cell mutagenesis

    DOEpatents

    Dolbeare, F.A.

    1980-12-12

    A method for assaying a cell culture for mutagenesis is described. A cell culture is stained first with a histochemical stain, and then a fluorescent stain. Normal cells in the culture are stained by both the histochemical and fluorescent stains, while abnormal cells are stained only by the fluorescent stain. The two stains are chosen so that the histochemical stain absorbs the wavelengths that the fluorescent stain emits. After the counterstained culture is subjected to exciting light, the fluorescence from the abnormal cells is detected.

  14. Quantitative analysis of retinal changes in hypertension

    NASA Astrophysics Data System (ADS)

    Giansanti, Roberto; Boemi, Massimo; Fumelli, Paolo; Passerini, Giorgio; Zingaretti, Primo

    1995-05-01

    Arterial hypertension is a high prevalence disease in Western countries and it is associated with increased risk for cardiovascular accidents. Retinal vessel changes are common findings in patients suffering from long-standing hypertensive disease. Morphological evaluations of the fundus oculi represent a fundamental tool for the clinical approach to the patient with hypertension. A qualitative analysis of the retinal lesions is usually performed and this implies severe limitations both in the classification of the different degrees of the pathology and in the follow-up of the disease. A diagnostic system based on a quantitative analysis of the retinal changes could overcome these problems. Our computerized approach was intended for this scope. The paper concentrates on the results and the implications of a computerized approach to the automatic extraction of numerical indexes describing morphological details of the fundus oculi. A previously developed image processing and recognition system, documented elsewhere and briefly described here, was successfully tested in pre-clinical experiments and applied in the evaluation of normal as well as of pathological fundus. The software system was developed to extract indexes such as caliber and path of vessels, local tortuosity of arteries and arterioles, positions and angles of crossings between two vessels. The reliability of the results, justified by their low variability, makes feasible the standardization of quantitative parameters to be used both in the diagnosis and in the prognosis of hypertension, and also allows prospective studies based upon them.

  15. Quantitative interactome analysis reveals a chemoresistant edgotype

    PubMed Central

    Chavez, Juan D.; Schweppe, Devin K.; Eng, Jimmy K.; Zheng, Chunxiang; Taipale, Alex; Zhang, Yiyi; Takara, Kohji; Bruce, James E.

    2015-01-01

    Chemoresistance is a common mode of therapy failure for many cancers. Tumours develop resistance to chemotherapeutics through a variety of mechanisms, with proteins serving pivotal roles. Changes in protein conformations and interactions affect the cellular response to environmental conditions contributing to the development of new phenotypes. The ability to understand how protein interaction networks adapt to yield new function or alter phenotype is limited by the inability to determine structural and protein interaction changes on a proteomic scale. Here, chemical crosslinking and mass spectrometry were employed to quantify changes in protein structures and interactions in multidrug-resistant human carcinoma cells. Quantitative analysis of the largest crosslinking-derived, protein interaction network comprising 1,391 crosslinked peptides allows for ‘edgotype' analysis in a cell model of chemoresistance. We detect consistent changes to protein interactions and structures, including those involving cytokeratins, topoisomerase-2-alpha, and post-translationally modified histones, which correlate with a chemoresistant phenotype. PMID:26235782

  16. Development of a rapid method for the quantitative analysis of four methoxypyrazines in white and red wine using multi-dimensional Gas Chromatography-Mass Spectrometry.

    PubMed

    Botezatu, Andreea; Pickering, Gary J; Kotseridis, Yorgos

    2014-10-01

    Alkyl-methoxypyrazines (MPs) are important odour-active constituents of many grape cultivars and their wines. Recently, a new MP - 2,5-dimethyl-3-methoxypyrazine (DMMP) - has been reported as a possible constituent of wine. This study sought to develop a rapid and reliable method for quantifying DMMP, isopropyl methoxypyrazine (IPMP), secbutyl methoxypyrazine (SBMP) and isobutyl methoxypyrazine (IBMP) in wine. The proposed method is able to rapidly and accurately resolve all 4 MPs in a range of wine styles, with limits of detection between 1 and 2 ng L(-1) for IPMP, SBMP and IBMP and 5 ng L(-1) for DMMP. Analysis of a set of 11 commercial wines agrees with previously published values for IPMP, SBMP and IBMP, and shows for the first time that DMMP may be an important and somewhat common odorant in red wines. To our knowledge, this is the first analytical method developed for the quantification of DMMP in wine.

  17. Structural and quantitative analysis of Equisetum alkaloids.

    PubMed

    Cramer, Luise; Ernst, Ludger; Lubienski, Marcus; Papke, Uli; Schiebel, Hans-Martin; Jerz, Gerold; Beuerle, Till

    2015-08-01

    Equisetum palustre L. is known for its toxicity for livestock. Several studies in the past addressed the isolation and identification of the responsible alkaloids. So far, palustrine (1) and N(5)-formylpalustrine (2) are known alkaloids of E. palustre. A HPLC-ESI-MS/MS method in combination with simple sample work-up was developed to identify and quantitate Equisetum alkaloids. Besides the two known alkaloids six related alkaloids were detected in different Equisetum samples. The structure of the alkaloid palustridiene (3) was derived by comprehensive 1D and 2D NMR experiments. N(5)-Acetylpalustrine (4) was also thoroughly characterized by NMR for the first time. The structure of N(5)-formylpalustridiene (5) is proposed based on mass spectrometry results. Twenty-two E. palustre samples were screened by a HPLC-ESI-MS/MS method after development of a simple sample work-up and in most cases the set of all eight alkaloids were detected in all parts of the plant. A high variability of the alkaloid content and distribution was found depending on plant organ, plant origin and season ranging from 88 to 597mg/kg dried weight. However, palustrine (1) and the alkaloid palustridiene (3) always represented the main alkaloids. For the first time, a comprehensive identification, quantitation and distribution of Equisetum alkaloids was achieved.

  18. Rapid Method Development in Hydrophilic Interaction Liquid Chromatography for Pharmaceutical Analysis Using a Combination of Quantitative Structure-Retention Relationships and Design of Experiments.

    PubMed

    Taraji, Maryam; Haddad, Paul R; Amos, Ruth I J; Talebi, Mohammad; Szucs, Roman; Dolan, John W; Pohl, Chris A

    2017-02-07

    A design-of-experiment (DoE) model was developed, able to describe the retention times of a mixture of pharmaceutical compounds in hydrophilic interaction liquid chromatography (HILIC) under all possible combinations of acetonitrile content, salt concentration, and mobile-phase pH with R(2) > 0.95. Further, a quantitative structure-retention relationship (QSRR) model was developed to predict retention times for new analytes, based only on their chemical structures, with a root-mean-square error of prediction (RMSEP) as low as 0.81%. A compound classification based on the concept of similarity was applied prior to QSRR modeling. Finally, we utilized a combined QSRR-DoE approach to propose an optimal design space in a quality-by-design (QbD) workflow to facilitate the HILIC method development. The mathematical QSRR-DoE model was shown to be highly predictive when applied to an independent test set of unseen compounds in unseen conditions with a RMSEP value of 5.83%. The QSRR-DoE computed retention time of pharmaceutical test analytes and subsequently calculated separation selectivity was used to optimize the chromatographic conditions for efficient separation of targets. A Monte Carlo simulation was performed to evaluate the risk of uncertainty in the model's prediction, and to define the design space where the desired quality criterion was met. Experimental realization of peak selectivity between targets under the selected optimal working conditions confirmed the theoretical predictions. These results demonstrate how discovery of optimal conditions for the separation of new analytes can be accelerated by the use of appropriate theoretical tools.

  19. Development and validation of a LC-MS/MS method for quantitative analysis of uraemic toxins p-cresol sulphate and indoxyl sulphate in saliva.

    PubMed

    Giebułtowicz, Joanna; Korytowska, Natalia; Sankowski, Bartłomiej; Wroczyński, Piotr

    2016-04-01

    p-Cresol sulphate (pCS) and indoxyl sulphate (IS) are uraemic toxins, the concentration of which in serum correlate with the stage of renal failure. The aim of this study was to develop and validate a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of pCS and IS in saliva. This is the first time, to our knowledge, that such a method has been developed using saliva. Unstimulated, fasting saliva was collected from healthy volunteers in the morning and pooled for validation assay. The method was validated for linearity, precision, accuracy, stability (freeze/thaw stability, stability in autosampler, short- and long-term stability, stock solution stability), dilution integrity and matrix effect. The analysed validation criteria were fulfilled. No influence of salivary flow (pCS: p=0.678; IS: p=0.238) nor type of swab in the Salivette device was detected. Finally, using the novel validated method, the saliva samples of healthy people (n=70) of various ages were analysed. We observed a tendency for an increase of concentration of toxins in saliva in the elderly. This could be a result of age-related diseases, e.g., diabetes and kidney function decline. We can conclude that the novel LC-MS/MS method can be used for the determination of pCS and IS in human saliva. The results encourage the validation of saliva as a clinical sample for monitoring toxin levels in organisms.

  20. Development and validation of a stability-indicating RP-UPLC method for the quantitative analysis of nabumetone in tablet dosage form.

    PubMed

    Sethi, Neha; Anand, Ankit; Chandrul, Kaushal K; Jain, Garima; Srinivas, Kona S

    2012-02-01

    High efficiency and less run time are the basic requirements of high-speed chromatographic separations. To fulfill these requirements, a new separation technique, ultra-performance liquid chromatography (UPLC), has shown promising developments. A rapid, specific, sensitive, and precise reverse-phase UPLC method is developed for the determination of nabumetone in tablet dosage form. In this work, a new isocratic chromatographic method is developed. The newly developed method is applicable for assay determination of the active pharmaceutical ingredient. The chromatographic separation is achieved on a Waters Acquity BEH column (100 mm, i.d., 2.1 mm, 1.7 µm) within a short runtime of 2 min using a mobile phase of 5 mM ammonium acetate-acetonitrile (25:75, v/v), at a flow rate of 0.3 mL/min at an ambient temperature. Quantification is achieved with photodiode array detection at 230 nm, over the concentration range of 0.05-26 µg/mL. Forced degradation studies are also performed for nabumetone bulk drug samples to demonstrate the stability-indicating power of the UPLC method. Comparison of system performance with conventional high-performance liquid chromatography is made with respect to analysis time, efficiency, and sensitivity. The method is validated according to the ICH guidelines and is applied successfully for the determination of nabumetone in tablets.

  1. Automated quantitative image analysis of nanoparticle assembly

    NASA Astrophysics Data System (ADS)

    Murthy, Chaitanya R.; Gao, Bo; Tao, Andrea R.; Arya, Gaurav

    2015-05-01

    The ability to characterize higher-order structures formed by nanoparticle (NP) assembly is critical for predicting and engineering the properties of advanced nanocomposite materials. Here we develop a quantitative image analysis software to characterize key structural properties of NP clusters from experimental images of nanocomposites. This analysis can be carried out on images captured at intermittent times during assembly to monitor the time evolution of NP clusters in a highly automated manner. The software outputs averages and distributions in the size, radius of gyration, fractal dimension, backbone length, end-to-end distance, anisotropic ratio, and aspect ratio of NP clusters as a function of time along with bootstrapped error bounds for all calculated properties. The polydispersity in the NP building blocks and biases in the sampling of NP clusters are accounted for through the use of probabilistic weights. This software, named Particle Image Characterization Tool (PICT), has been made publicly available and could be an invaluable resource for researchers studying NP assembly. To demonstrate its practical utility, we used PICT to analyze scanning electron microscopy images taken during the assembly of surface-functionalized metal NPs of differing shapes and sizes within a polymer matrix. PICT is used to characterize and analyze the morphology of NP clusters, providing quantitative information that can be used to elucidate the physical mechanisms governing NP assembly.The ability to characterize higher-order structures formed by nanoparticle (NP) assembly is critical for predicting and engineering the properties of advanced nanocomposite materials. Here we develop a quantitative image analysis software to characterize key structural properties of NP clusters from experimental images of nanocomposites. This analysis can be carried out on images captured at intermittent times during assembly to monitor the time evolution of NP clusters in a highly automated

  2. Materials characterization through quantitative digital image analysis

    SciTech Connect

    J. Philliber; B. Antoun; B. Somerday; N. Yang

    2000-07-01

    A digital image analysis system has been developed to allow advanced quantitative measurement of microstructural features. This capability is maintained as part of the microscopy facility at Sandia, Livermore. The system records images digitally, eliminating the use of film. Images obtained from other sources may also be imported into the system. Subsequent digital image processing enhances image appearance through the contrast and brightness adjustments. The system measures a variety of user-defined microstructural features--including area fraction, particle size and spatial distributions, grain sizes and orientations of elongated particles. These measurements are made in a semi-automatic mode through the use of macro programs and a computer controlled translation stage. A routine has been developed to create large montages of 50+ separate images. Individual image frames are matched to the nearest pixel to create seamless montages. Results from three different studies are presented to illustrate the capabilities of the system.

  3. Near Real Time Quantitative Gas Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Herget, William F.; Tromp, Marianne L.; Anderson, Charles R.

    1985-12-01

    A Fourier transform infrared (FT-IR) - based system has been developed and is undergoing evaluation for near real time multicomponent quantitative analysis of undiluted gaseous automotive exhaust emissions. The total system includes: (1) a gas conditioning system (GCS) for tracer gas injection, gas mixing, and temperature stabilization; and (2) an exhaust gas analyzer (EGA) consisting of a sample cell, an FT-IR system, and a computerized data processing system. Tests have shown that the system can monitor about 20 individual species (concentrations down to the 1-20 ppm range) with a time resolution of one second. Tests have been conducted on a chassis dynamometer system utilizing different autos, different fuels, and different driving cycles. Results were compared with those obtained using a standard constant volume sampling (CVS) system.

  4. Data from quantitative label free proteomics analysis of rat spleen.

    PubMed

    Dudekula, Khadar; Le Bihan, Thierry

    2016-09-01

    The dataset presented in this work has been obtained using a label-free quantitative proteomic analysis of rat spleen. A robust method for extraction of proteins from rat spleen tissue and LC-MS-MS analysis was developed using a urea and SDS-based buffer. Different fractionation methods were compared. A total of 3484 different proteins were identified from the pool of all experiments run in this study (a total of 2460 proteins with at least two peptides). A total of 1822 proteins were identified from nine non-fractionated pulse gels, 2288 proteins and 2864 proteins were identified by SDS-PAGE fractionation into three and five fractions respectively. The proteomics data are deposited in ProteomeXchange Consortium via PRIDE PXD003520, Progenesis and Maxquant output are presented in the supported information. The generated list of proteins under different regimes of fractionation allow assessing the nature of the identified proteins; variability in the quantitative analysis associated with the different sampling strategy and allow defining a proper number of replicates for future quantitative analysis.

  5. Quantitative methods in electroencephalography to access therapeutic response.

    PubMed

    Diniz, Roseane Costa; Fontenele, Andrea Martins Melo; Carmo, Luiza Helena Araújo do; Ribeiro, Aurea Celeste da Costa; Sales, Fábio Henrique Silva; Monteiro, Sally Cristina Moutinho; Sousa, Ana Karoline Ferreira de Castro

    2016-07-01

    Pharmacometrics or Quantitative Pharmacology aims to quantitatively analyze the interaction between drugs and patients whose tripod: pharmacokinetics, pharmacodynamics and disease monitoring to identify variability in drug response. Being the subject of central interest in the training of pharmacists, this work was out with a view to promoting this idea on methods to access the therapeutic response of drugs with central action. This paper discusses quantitative methods (Fast Fourier Transform, Magnitude Square Coherence, Conditional Entropy, Generalised Linear semi-canonical Correlation Analysis, Statistical Parametric Network and Mutual Information Function) used to evaluate the EEG signals obtained after administration regimen of drugs, the main findings and their clinical relevance, pointing it as a contribution to construction of different pharmaceutical practice. Peter Anderer et. al in 2000 showed the effect of 20mg of buspirone in 20 healthy subjects after 1, 2, 4, 6 and 8h after oral ingestion of the drug. The areas of increased power of the theta frequency occurred mainly in the temporo-occipital - parietal region. It has been shown by Sampaio et al., 2007 that the use of bromazepam, which allows the release of GABA (gamma amino butyric acid), an inhibitory neurotransmitter of the central nervous system could theoretically promote dissociation of cortical functional areas, a decrease of functional connectivity, a decrease of cognitive functions by means of smaller coherence (electrophysiological magnitude measured from the EEG by software) values. Ahmad Khodayari-Rostamabad et al. in 2015 talk that such a measure could be a useful clinical tool potentially to assess adverse effects of opioids and hence give rise to treatment guidelines. There was the relation between changes in pain intensity and brain sources (at maximum activity locations) during remifentanil infusion despite its potent analgesic effect. The statement of mathematical and computational

  6. A method for the quantitative determination of crystalline phases by X-ray

    NASA Technical Reports Server (NTRS)

    Petzenhauser, I.; Jaeger, P.

    1988-01-01

    A mineral analysis method is described for rapid quantitative determination of crystalline substances in those cases in which the sample is present in pure form or in a mixture of known composition. With this method there is no need for prior chemical analysis.

  7. Development and validation of a hydrophilic interaction chromatography method coupled with a charged aerosol detector for quantitative analysis of nonchromophoric α-hydroxyamines, organic impurities of metoprolol.

    PubMed

    Xu, Qun; Tan, Shane; Petrova, Katya

    2016-01-25

    The European Pharmacopeia (EP) metoprolol impurities M and N are polar, nonchromophoric α-hydroxyamines, which are poorly retained in a conventional reversed-phase chromatographic system and are invisible for UV detection. Impurities M and N are currently analyzed by TLC methods in the EP as specified impurities and in the United States Pharmacopeia-National Formulary (USP-NF) as unspecified impurities. In order to modernize the USP monographs of metoprolol drug substances and related drug products, a hydrophilic interaction chromatography (HILIC) method coupled with a charged aerosol detector (CAD) was explored for the analysis of the two impurities. A comprehensive column screening that covers a variety of HILIC stationary phases (underivatized silica, amide, diol, amino, zwitterionic, polysuccinimide, cyclodextrin, and mixed-mode) and optimization of HPLC conditions led to the identification of a Halo Penta HILIC column (4.6 × 150 mm, 5 μm) and a mobile phase comprising 85% acetonitrile and 15% ammonium formate buffer (100 mM, pH 3.2). Efficient separations of metoprolol, succinic acid, and EP metoprolol impurities M and N were achieved within a short time frame (<8 min). The HILIC-CAD method was subsequently validated per USP validation guidelines with respect to specificity, robustness, linearity, accuracy, and precision, and could be incorporated into the current USP-NF monographs to replace the outdated TLC methods. Furthermore, the developed method was successfully applied to determine organic impurities in metoprolol drug substance (metoprolol succinate) and drug products (metoprolol tartrate injection and metoprolol succinate extended release tablets).

  8. Quantitative laser-induced breakdown spectroscopy data using peak area step-wise regression analysis: an alternative method for interpretation of Mars science laboratory results

    SciTech Connect

    Clegg, Samuel M; Barefield, James E; Wiens, Roger C; Dyar, Melinda D; Schafer, Martha W; Tucker, Jonathan M

    2008-01-01

    The ChemCam instrument on the Mars Science Laboratory (MSL) will include a laser-induced breakdown spectrometer (LIBS) to quantify major and minor elemental compositions. The traditional analytical chemistry approach to calibration curves for these data regresses a single diagnostic peak area against concentration for each element. This approach contrasts with a new multivariate method in which elemental concentrations are predicted by step-wise multiple regression analysis based on areas of a specific set of diagnostic peaks for each element. The method is tested on LIBS data from igneous and metamorphosed rocks. Between 4 and 13 partial regression coefficients are needed to describe each elemental abundance accurately (i.e., with a regression line of R{sup 2} > 0.9995 for the relationship between predicted and measured elemental concentration) for all major and minor elements studied. Validation plots suggest that the method is limited at present by the small data set, and will work best for prediction of concentration when a wide variety of compositions and rock types has been analyzed.

  9. A rapid and sensitive LC/ESI-MS/MS method for quantitative analysis of docetaxel in human plasma and its application to a pharmacokinetic study.

    PubMed

    Yamaguchi, Hiroaki; Fujikawa, Asuka; Ito, Hajime; Tanaka, Nobuaki; Furugen, Ayako; Miyamori, Kazuaki; Takahashi, Natsuko; Ogura, Jiro; Kobayashi, Masaki; Yamada, Takehiro; Mano, Nariyasu; Iseki, Ken

    2012-04-15

    Docetaxel is a taxane family antineoplastic agent widely employed in cancer chemotherapy. We developed a liquid chromatography/tandem mass spectrometry method for the determination of docetaxel in human plasma. Plasma samples were deproteinized by acetonitrile containing internal standard paclitaxel. Chromatographic separation was performed on a TSKgel ODS-100 V 3 μm (50 mm × 2.0 mm i.d.) column using a mobile phase composed of acetonitrile-methanol-water-formic acid (50:5:45:0.1, v/v/v/v). Detection was performed on a triple-quadrupole tandem mass spectrometer with multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. This method covered a linearity range of 5-5000 ng/mL with the lower limit of quantification of 5 ng/mL. The intra-day precision and inter-day precision (R.S.D.) of analysis were less than 6.7%, and the accuracy (R.E.) was within ± 9.0% at the concentrations of 5, 20, 200, and 2000 ng/mL. The total run time was 5.0 min. This method was successfully applied for clinical pharmacokinetic investigation.

  10. A quantitative dimming method for LED based on PWM

    NASA Astrophysics Data System (ADS)

    Wang, Jiyong; Mou, Tongsheng; Wang, Jianping; Tian, Xiaoqing

    2012-10-01

    Traditional light sources were required to provide stable and uniform illumination for a living or working environment considering performance of visual function of human being. The requirement was always reasonable until non-visual functions of the ganglion cells in the retina photosensitive layer were found. New generation of lighting technology, however, is emerging based on novel lighting materials such as LED and photobiological effects on human physiology and behavior. To realize dynamic lighting of LED whose intensity and color were adjustable to the need of photobiological effects, a quantitative dimming method based on Pulse Width Modulation (PWM) and light-mixing technology was presented. Beginning with two channels' PWM, this paper demonstrated the determinacy and limitation of PWM dimming for realizing Expected Photometric and Colorimetric Quantities (EPCQ), in accordance with the analysis on geometrical, photometric, colorimetric and electrodynamic constraints. A quantitative model which mapped the EPCQ into duty cycles was finally established. The deduced model suggested that the determinacy was a unique individuality only for two channels' and three channels' PWM, but the limitation was an inevitable commonness for multiple channels'. To examine the model, a light-mixing experiment with two kinds of white LED simulated variations of illuminance and Correlation Color Temperature (CCT) from dawn to midday. Mean deviations between theoretical values and measured values were obtained, which were 15lx and 23K respectively. Result shows that this method can effectively realize the light spectrum which has a specific requirement of EPCQ, and provides a theoretical basis and a practical way for dynamic lighting of LED.

  11. Qualitative and quantitative analysis of multiple components for quality control of Deng-Zhan-Sheng-Mai capsules by ultra high performance liquid chromatography tandem mass spectrometry method coupled with chemometrics.

    PubMed

    Jiang, Pin; Lu, Yan; Chen, Daofeng

    2017-02-01

    Deng-Zhan-Sheng-Mai capsules are a well-known traditional Chinese patent medicine that was developed in China for the treatment of ischemic stroke. Its quality control focuses on Erigerontis Herba but ignores the contributions of Ginseng Radix et Rhizoma, Schisandrae Chinensis Fructus, and Ophiopogonis Radix. To improve the quality standards for this medicine, this work reports the application of a systematic ultra high performance liquid chromatography tandem mass spectrometric method coupled with chemometrics. Three qualitative and quantitative parameters are established for the evaluation of quality: chemical profiling, the relationship between the contents of 18 compounds and the antioxidant activity, and chemometric analysis. A total of 55 compounds, including 20 phenolic acids, 10 flavonoids, 15 saponins, and 10 lignans, were identified. The method for the quantitative determination of the aforementioned 18 compounds was validated. The limit of quantification ranged from 0.13 to 9.60 ng/mL. The overall recoveries ranged from 95.31 to 103.54%. Hierarchical cluster analysis and principal component analysis were applied to the data of 18 components in ten batches of samples. Nine compounds, including scutellarin, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid, ginsenoside Rb1, ginsenoside Re, ginsenoside Rg1, ophiopogonin D, schisandrin, and schisandrol B, are suggested as chemical markers for evaluating the quality.

  12. Validated ultra high performance liquid chromatography-tandem mass spectrometry method for quantitative analysis of total and free thyroid hormones in bovine serum.

    PubMed

    Kiebooms, Julie Anne Lucie; Wauters, Jella; Vanden Bussche, Julie; Vanhaecke, Lynn

    2014-06-06

    Thyroid hormones are essential hormones for regulating growth and development. Methods to accurately monitor low-levels (ppb-ppt) of these hormones in serum are needed to assess overall health, both from a clinical perspective as from environmental contaminant or drug exposures. In general, the separation of the free thyroid hormone fraction from animal sera is performed through labour intensive equilibrium dialysis, while detection of total and free thyroid hormone fractions in animals is done with commercially available radioimmunoassays (RIAs). This study reports newly developed analysis methods for both the total and free fractions of triiodothyronine (T3), reverse-triiodothyronine (rT3) and thyroxin (T4) from bovine serum, with a much higher specificity and selectivity than commercially available RIAs. The bovine serum extraction procedures of total and free T3, rT3, T4 were optimised with fractional factorial designs and consisted of, respectively, deproteinisation followed by liquid-liquid extraction, 30 kDA ultracentrifugation and solid phase extraction. Both free and total thyroid hormone UHPLC-HESI-MS/MS based analysis methods were successfully validated. The limits of quantification for T4, rT3 and T3 amounted respectively 0.04 ng mL(-1), 0.05 ng mL(-1), 0.03 ng mL(-1) for the total fraction, and 6.6 pg mL(-1), 2.6 pg mL(-1) and 2.7 pg mL(-1) for the free fraction. Individual recoveries of total and free thyroid hormone fractions ranged between 95.6 and 106.3% and 92.1 and 106.5%. Good results for repeatability and intra-laboratory reproducibility (RSD%) were observed, i.e. respectively ≤8.0% and ≤7.3% for the total and free fractions. Excellent linearity (R(2)≥0.99) and lack-of-fit was proven for both fractions. In conclusion, these methods show excellent in-house performance and possibilities for elaboration to application in other animal sera (e.g. feline, canine, equine).

  13. Simultaneous quantitation of 14 active components in Yinchenhao decoction by using ultra high performance liquid chromatography with diode array detection: Method development and ingredient analysis of different commonly prepared samples.

    PubMed

    Yi, YaXiong; Zhang, Yong; Ding, Yue; Lu, Lu; Zhang, Tong; Zhao, Yuan; Xu, XiaoJun; Zhang, YuXin

    2016-11-01

    We developed a novel quantitative analysis method based on ultra high performance liquid chromatography coupled with diode array detection for the simultaneous determination of the 14 main active components in Yinchenhao decoction. All components were separated on an Agilent SB-C18 column by using a gradient solvent system of acetonitrile/0.1% phosphoric acid solution at a flow rate of 0.4 mL/min for 35 min. Subsequently, linearity, precision, repeatability, and accuracy tests were implemented to validate the method. Furthermore, the method has been applied for compositional difference analysis of 14 components in eight normal-extraction Yinchenhao decoction samples, accompanied by hierarchical clustering analysis and similarity analysis. The result that all samples were divided into three groups based on different contents of components demonstrated that extraction methods of decocting, refluxing, ultrasonication and extraction solvents of water or ethanol affected component differentiation, and should be related to its clinical applications. The results also indicated that the sample prepared by patients in the family by using water extraction employing a casserole was almost same to that prepared using a stainless-steel kettle, which is mostly used in pharmaceutical factories. This research would help patients to select the best and most convenient method for preparing Yinchenhao decoction.

  14. Quantitative analysis of protein turnover in plants.

    PubMed

    Nelson, Clark J; Li, Lei; Millar, A Harvey

    2014-03-01

    Proteins are constantly being synthesised and degraded as plant cells age and as plants grow, develop and adapt the proteome. Given that plants develop through a series of events from germination to fruiting and even undertake whole organ senescence, an understanding of protein turnover as a fundamental part of this process in plants is essential. Both synthesis and degradation processes are spatially separated in a cell across its compartmented structure. The majority of protein synthesis occurs in the cytosol, while synthesis of specific components occurs inside plastids and mitochondria. Degradation of proteins occurs in both the cytosol, through the action of the plant proteasome, and in organelles and lytic structures through different protease classes. Tracking the specific synthesis and degradation rate of individual proteins can be undertaken using stable isotope feeding and the ability of peptide MS to track labelled peptide fractions over time. Mathematical modelling can be used to follow the isotope signature of newly synthesised protein as it accumulates and natural abundance proteins as they are lost through degradation. Different technical and biological constraints govern the potential for the use of (13)C, (15)N, (2)H and (18)O for these experiments in complete labelling and partial labelling strategies. Future development of quantitative protein turnover analysis will involve analysis of protein populations in complexes and subcellular compartments, assessing the effect of PTMs and integrating turnover studies into wider system biology study of plants.

  15. Quantitative Analysis of Triple Mutant Genetic Interactions

    PubMed Central

    Braberg, Hannes; Alexander, Richard; Shales, Michael; Xu, Jiewei; Franks-Skiba, Kathleen E.; Wu, Qiuqin; Haber, James E.; Krogan, Nevan J.

    2014-01-01

    The quantitative analysis of genetic interactions between pairs of gene mutations has proven effective for characterizing cellular functions but can miss important interactions for functionally redundant genes. To address this limitation, we have developed an approach termed Triple Mutant Analysis (TMA). The procedure relies on a query strain that contains two deletions in a pair of redundant or otherwise related genes, that is crossed against a panel of candidate deletion strains to isolate triple mutants and measure their growth. A central feature of TMA is to interrogate mutants that are synthetically sick when two other genes are deleted but interact minimally with either single deletion. This approach has been valuable for discovering genes that restore critical functions when the principle actors are deleted. TMA has also uncovered double mutant combinations that produce severe defects because a third protein becomes deregulated and acts in a deleterious fashion, and it has revealed functional differences between proteins presumed to act together. The protocol is optimized for Singer ROTOR pinning robots, takes 3 weeks to complete, and measures interactions for up to 30 double mutants against a library of 1536 single mutants. PMID:25010907

  16. Qualitative and quantitative stability analysis of penta-rhythmic circuits

    NASA Astrophysics Data System (ADS)

    Schwabedal, Justus T. C.; Knapper, Drake E.; Shilnikov, Andrey L.

    2016-12-01

    Inhibitory circuits of relaxation oscillators are often-used models for dynamics of biological networks. We present a qualitative and quantitative stability analysis of such a circuit constituted by three generic oscillators (of a Fitzhugh-Nagumo type) as its nodes coupled reciprocally. Depending on inhibitory strengths, and parameters of individual oscillators, the circuit exhibits polyrhythmicity of up to five simultaneously stable rhythms. With methods of bifurcation analysis and phase reduction, we investigate qualitative changes in stability of these circuit rhythms for a wide range of parameters. Furthermore, we quantify robustness of the rhythms maintained under random perturbations by monitoring phase diffusion in the circuit. Our findings allow us to describe how circuit dynamics relate to dynamics of individual nodes. We also find that quantitative and qualitative stability properties of polyrhythmicity do not always align.

  17. Quantitative Analysis by Isotopic Dilution Using Mass Spectroscopy: The Determination of Caffeine by GC-MS.

    ERIC Educational Resources Information Center

    Hill, Devon W.; And Others

    1988-01-01

    Describes a laboratory technique for quantitative analysis of caffeine by an isotopic dilution method for coupled gas chromatography-mass spectroscopy. Discusses caffeine analysis and experimental methodology. Lists sample caffeine concentrations found in common products. (MVL)

  18. Method development towards qualitative and semi-quantitative analysis of multiple pesticides from food surfaces and extracts by desorption electrospray ionization mass spectrometry as a preselective tool for food control.

    PubMed

    Gerbig, Stefanie; Stern, Gerold; Brunn, Hubertus E; Düring, Rolf-Alexander; Spengler, Bernhard; Schulz, Sabine

    2017-03-01

    Direct analysis of fruit and vegetable surfaces is an important tool for in situ detection of food contaminants such as pesticides. We tested three different ways to prepare samples for the qualitative desorption electrospray ionization mass spectrometry (DESI-MS) analysis of 32 pesticides found on nine authentic fruits collected from food control. Best recovery rates for topically applied pesticides (88%) were found by analyzing the surface of a glass slide which had been rubbed against the surface of the food. Pesticide concentration in all samples was at or below the maximum residue level allowed. In addition to the high sensitivity of the method for qualitative analysis, quantitative or, at least, semi-quantitative information is needed in food control. We developed a DESI-MS method for the simultaneous determination of linear calibration curves of multiple pesticides of the same chemical class using normalization to one internal standard (ISTD). The method was first optimized for food extracts and subsequently evaluated for the quantification of pesticides in three authentic food extracts. Next, pesticides and the ISTD were applied directly onto food surfaces, and the corresponding calibration curves were obtained. The determination of linear calibration curves was still feasible, as demonstrated for three different food surfaces. This proof-of-principle method was used to simultaneously quantify two pesticides on an authentic sample, showing that the method developed could serve as a fast and simple preselective tool for disclosure of pesticide regulation violations. Graphical Abstract Multiple pesticide residues were detected and quantified in-situ from an authentic set of food items and extracts in a proof of principle study.

  19. Quantitative infrared analysis of hydrogen fluoride

    SciTech Connect

    Manuta, D.M.

    1997-04-01

    This work was performed at the Portsmouth Gaseous Diffusion Plant where hydrogen fluoride is produced upon the hydrolysis of UF{sub 6}. This poses a problem for in this setting and a method for determining the mole percent concentration was desired. HF has been considered to be a non-ideal gas for many years. D. F. Smith utilized complex equations in his HF studies in the 1950s. We have evaluated HF behavior as a function of pressure from three different perspectives. (1) Absorbance at 3877 cm{sup -1} as a function of pressure for 100% HF. (2) Absorbance at 3877 cm{sup -1} as a function of increasing partial pressure HF. Total pressure = 300 mm HgA maintained with nitrogen. (3) Absorbance at 3877 cm{sup -1} for constant partial pressure HF. Total pressure is increased to greater than 800 mm HgA with nitrogen. These experiments have shown that at partial pressures up to 35mm HgA, HIF follows the ideal gas law. The absorbance at 3877 cm{sup -1} can be quantitatively analyzed via infrared methods.

  20. Wave propagation models for quantitative defect detection by ultrasonic methods

    NASA Astrophysics Data System (ADS)

    Srivastava, Ankit; Bartoli, Ivan; Coccia, Stefano; Lanza di Scalea, Francesco

    2008-03-01

    Ultrasonic guided wave testing necessitates of quantitative, rather than qualitative, information on flaw size, shape and position. This quantitative diagnosis ability can be used to provide meaningful data to a prognosis algorithm for remaining life prediction, or simply to generate data sets for a statistical defect classification algorithm. Quantitative diagnostics needs models able to represent the interaction of guided waves with various defect scenarios. One such model is the Global-Local (GL) method, which uses a full finite element discretization of the region around a flaw to properly represent wave diffraction, and a suitable set of wave functions to simulate regions away from the flaw. Displacement and stress continuity conditions are imposed at the boundary between the global and the local regions. In this paper the GL method is expanded to take advantage of the Semi-Analytical Finite Element (SAFE) method in the global portion of the waveguide. The SAFE method is efficient because it only requires the discretization of the cross-section of the waveguide to obtain the wave dispersion solutions and it can handle complex structures such as multilayered sandwich panels. The GL method is applied to predicting quantitatively the interaction of guided waves with defects in aluminum and composites structural components.

  1. Quantitative analysis of boldine alkaloid in natural extracts by cyclic voltammetry at a liquid-liquid interface and validation of the method by comparison with high performance liquid chromatography.

    PubMed

    Cámara, C I; Bornancini, C A; Cabrera, J L; Ortega, M G; Yudi, L M

    2010-12-15

    The quantitative determination of boldine alkaloid in boldo leaf extracts by employing cyclic voltammetry, at a liquid/liquid interface as well as the validation of this methodology against the reference method, high performance liquid chromatography (HPLC), are reported in the present paper. The voltammetric analysis was performed successfully and economically using two kinds of liquid/liquid interfaces: water/1,2-dicholoroethane and water/PVC (polyvinyl chloride)-gelled 1,2-dichloroethane. Linear calibration curves in the concentration range of 1.04 × 10(-5)mol L(-1) to 5.19 × 10(-4)mol L(-1) were obtained with a detection limit equal to (6.1 ± 0.7) × 10(-5)mol L(-1) and the quantitative determination of this alkaloid, in complex matrixes such as boldo leaf extracts, by the electrochemical technique proposed was found to be equal to the values obtained using the standard HPLC method. The validation analysis of this methodology against HPLC demonstrated that accuracy, linearity, limit of detection (LOD), limit of quantification (LOQ), specificity and precision are acceptable. The electroanalytical technique proposed is economical and selective, involves simple equipment and can be applied for the quantitative determination of boldine alkaloid in complex matrixes such as leaf extracts without special drug separation. Moreover, cyclic voltammetry (CV) experiments applied at the liquid/liquid interface under different experimental conditions allowed us to study the transfer mechanism of boldine, and determine a value of pK(a)(w)=6.90 for protonated boldine, from the variation of voltammetric peak current with pH.

  2. Quantitative Phosphoproteomic Analysis of T-Cell Receptor Signaling.

    PubMed

    Ahsan, Nagib; Salomon, Arthur R

    2017-01-01

    TCR signaling critically depends on protein phosphorylation across many proteins. Localization of each phosphorylation event relative to the T-cell receptor (TCR) and canonical T-cell signaling proteins will provide clues about the structure of TCR signaling networks. Quantitative phosphoproteomic analysis by mass spectrometry provides a wide-scale view of cellular phosphorylation networks. However, analysis of phosphorylation by mass spectrometry is still challenging due to the relative low abundance of phosphorylated proteins relative to all proteins and the extraordinary diversity of phosphorylation sites across the proteome. Highly selective enrichment of phosphorylated peptides is essential to provide the most comprehensive view of the phosphoproteome. Optimization of phosphopeptide enrichment methods coupled with highly sensitive mass spectrometry workflows significantly improves the sequencing depth of the phosphoproteome to over 10,000 unique phosphorylation sites from complex cell lysates. Here we describe a step-by-step method for phosphoproteomic analysis that has achieved widespread success for identification of serine, threonine, and tyrosine phosphorylation. Reproducible quantification of relative phosphopeptide abundance is provided by intensity-based label-free quantitation. An ideal set of mass spectrometry analysis parameters is also provided that optimize the yield of identified sites. We also provide guidelines for the bioinformatic analysis of this type of data to assess the quality of the data and to comply with proteomic data reporting requirements.

  3. Breast tumour visualization using 3D quantitative ultrasound methods

    NASA Astrophysics Data System (ADS)

    Gangeh, Mehrdad J.; Raheem, Abdul; Tadayyon, Hadi; Liu, Simon; Hadizad, Farnoosh; Czarnota, Gregory J.

    2016-04-01

    Breast cancer is one of the most common cancer types accounting for 29% of all cancer cases. Early detection and treatment has a crucial impact on improving the survival of affected patients. Ultrasound (US) is non-ionizing, portable, inexpensive, and real-time imaging modality for screening and quantifying breast cancer. Due to these attractive attributes, the last decade has witnessed many studies on using quantitative ultrasound (QUS) methods in tissue characterization. However, these studies have mainly been limited to 2-D QUS methods using hand-held US (HHUS) scanners. With the availability of automated breast ultrasound (ABUS) technology, this study is the first to develop 3-D QUS methods for the ABUS visualization of breast tumours. Using an ABUS system, unlike the manual 2-D HHUS device, the whole patient's breast was scanned in an automated manner. The acquired frames were subsequently examined and a region of interest (ROI) was selected in each frame where tumour was identified. Standard 2-D QUS methods were used to compute spectral and backscatter coefficient (BSC) parametric maps on the selected ROIs. Next, the computed 2-D parameters were mapped to a Cartesian 3-D space, interpolated, and rendered to provide a transparent color-coded visualization of the entire breast tumour. Such 3-D visualization can potentially be used for further analysis of the breast tumours in terms of their size and extension. Moreover, the 3-D volumetric scans can be used for tissue characterization and the categorization of breast tumours as benign or malignant by quantifying the computed parametric maps over the whole tumour volume.

  4. Quantitative multivariate analysis of dynamic multicellular morphogenic trajectories.

    PubMed

    White, Douglas E; Sylvester, Jonathan B; Levario, Thomas J; Lu, Hang; Streelman, J Todd; McDevitt, Todd C; Kemp, Melissa L

    2015-07-01

    Interrogating fundamental cell biology principles that govern tissue morphogenesis is critical to better understanding of developmental biology and engineering novel multicellular systems. Recently, functional micro-tissues derived from pluripotent embryonic stem cell (ESC) aggregates have provided novel platforms for experimental investigation; however elucidating the factors directing emergent spatial phenotypic patterns remains a significant challenge. Computational modelling techniques offer a unique complementary approach to probe mechanisms regulating morphogenic processes and provide a wealth of spatio-temporal data, but quantitative analysis of simulations and comparison to experimental data is extremely difficult. Quantitative descriptions of spatial phenomena across multiple systems and scales would enable unprecedented comparisons of computational simulations with experimental systems, thereby leveraging the inherent power of computational methods to interrogate the mechanisms governing emergent properties of multicellular biology. To address these challenges, we developed a portable pattern recognition pipeline consisting of: the conversion of cellular images into networks, extraction of novel features via network analysis, and generation of morphogenic trajectories. This novel methodology enabled the quantitative description of morphogenic pattern trajectories that could be compared across diverse systems: computational modelling of multicellular structures, differentiation of stem cell aggregates, and gastrulation of cichlid fish. Moreover, this method identified novel spatio-temporal features associated with different stages of embryo gastrulation, and elucidated a complex paracrine mechanism capable of explaining spatiotemporal pattern kinetic differences in ESC aggregates of different sizes.

  5. Comprehensive Quantitative Analysis of SQ Injection Using Multiple Chromatographic Technologies.

    PubMed

    Chau, Siu-Leung; Huang, Zhi-Bing; Song, Yan-Gang; Yue, Rui-Qi; Ho, Alan; Lin, Chao-Zhan; Huang, Wen-Hua; Han, Quan-Bin

    2016-08-19

    Quality control of Chinese medicine injections remains a challenge due to our poor knowledge of their complex chemical profile. This study aims to investigate the chemical composition of one of the best-selling injections, Shenqi Fuzheng (SQ) injection (SQI), via a full component quantitative analysis. A total of 15 representative small molecular components of SQI were simultaneously determined using ultra-high performance liquid chromatography (UHPLC) coupled with quadrupole tandem time-of-flight mass spectrometry (Q-TOF-MS); saccharide composition of SQI was also quantitatively determined by high performance liquid chromatography (HPLC) with evaporative light scattering detector (ELSD) on an amino column before and after acid hydrolysis. The existence of polysaccharides was also examined on a gel permeation chromatography column. The method was well validated in terms of linearity, sensitivity, precision, accuracy and stability, and was successfully applied to analyze 13 SQI samples. The results demonstrate that up to 94.69% (w/w) of this injection product are quantitatively determined, in which small molecules and monosaccharide/sucrose account for 0.18%-0.21%, and 53.49%-58.2%, respectively. The quantitative information contributes to accumulating scientific evidence to better understand the therapy efficacy and safety of complex Chinese medicine injections.

  6. Quantitative Proteomic Approaches for Analysis of Protein S-Nitrosylation.

    PubMed

    Qu, Zhe; Greenlief, C Michael; Gu, Zezong

    2016-01-04

    S-Nitrosylation is a redox-based post-translational modification of a protein in response to nitric oxide (NO) signaling, and it participates in a variety of processes in diverse biological systems. The significance of this type of protein modification in health and diseases is increasingly recognized. In the central nervous system, aberrant S-nitrosylation, due to excessive NO production, is known to cause protein misfolding, mitochondrial dysfunction, transcriptional dysregulation, and neuronal death. This leads to an altered physiological state and consequently contributes to pathogenesis of neurodegenerative disorders. To date, much effort has been made to understand the mechanisms underlying protein S-nitrosylation, and several approaches have been developed to unveil S-nitrosylated proteins from different organisms. Interest in determining the dynamic changes of protein S-nitrosylation under different physiological and pathophysiological conditions has underscored the need for the development of quantitative proteomic approaches. Currently, both gel-based and gel-free mass spectrometry-based quantitative methods are widely used, and they each have advantages and disadvantages but may also be used together to produce complementary data. This review evaluates current available quantitative proteomic techniques for the analysis of protein S-nitrosylation and highlights recent advances, with emphasis on applications in neurodegenerative diseases. An important goal is to provide a comprehensive guide of feasible quantitative proteomic methodologies for examining protein S-nitrosylation in research to yield insights into disease mechanisms, diagnostic biomarkers, and drug discovery.

  7. Combinative Method Using Multi-components Quantitation and HPLC Fingerprint for Comprehensive Evaluation of Gentiana crassicaulis

    PubMed Central

    Song, Jiuhua; Chen, Fengzheng; Liu, Jiang; Zou, Yuanfeng; Luo, Yun; Yi, Xiaoyan; Meng, Jie; Chen, Xingfu

    2017-01-01

    Background: Gentiana crassicaulis () is an important traditional Chinese herb. Like other herbs, its chemical compounds vary greatly by the environmental and genetic factors, as a result, the quality is always different even from the same region, and therefore, the quality evaluation is necessary for its safety and effective use. In this study, a comprehensive method including HPLC quantitative analysis and fingerprints was developed to evaluate the quality of Cujingqinjiao and to classify the samples collected from Lijiang City of Yunnan province. A total of 30 common peaks including four identified peaks, were found, and were involved for further characterization and quality control of Cujingqinjiao. Twenty-one batches of samples from Lijiang City of Yunnan Province were evaluated by similarity analysis (SA), hierarchical cluster analysis (HCA), principal component analysis (PCA) and factor analysis (FA) according to the characteristic of common peaks. Results: The obtained data showed good stability and repeatability of the chromatographic fingerprint, similarity values were all more than 0.90. This study demonstrated that a combination of the chromatographic quantitative analysis and fingerprint offered an efficient way to quality consistency evaluation of Cujingqinjiao. Consistent results were obtained to show that samples from a same origin could be successfully classified into two groups. Conclusion: This study revealed that the combinative method was reliable, simple and sensitive for fingerprint analysis, moreover, for quality control and pattern recognition of Cujingqinjiao. SUMMARY HPLC quantitative analysis and fingerprints was developed to evaluate the quality of Gentiana crassicaulisSimilarity analysis, hierarchical cluster analysis, principal component analysis and factor analysis were employed to analysis the chromatographic dataset.The results of multi-components quantitation analysis, similarity analysis, hierarchical cluster analysis, principal

  8. The Use of Quantitative Methods as an Aid to Decision Making in Educational Administration.

    ERIC Educational Resources Information Center

    Alkin, Marvin C.

    Three quantitative methods are outlined, with suggestions for application to particular problem areas of educational administration: (1) The Leontief input-output analysis, incorporating a "transaction table" for displaying relationships between economic outputs and inputs, mainly applicable to budget analysis and planning; (2) linear programing,…

  9. Quantitative methods to study epithelial morphogenesis and polarity.

    PubMed

    Aigouy, B; Collinet, C; Merkel, M; Sagner, A

    2017-01-01

    Morphogenesis of an epithelial tissue emerges from the behavior of its constituent cells, including changes in shape, rearrangements, and divisions. In many instances the directionality of these cellular events is controlled by the polarized distribution of specific molecular components. In recent years, our understanding of morphogenesis and polarity highly benefited from advances in genetics, microscopy, and image analysis. They now make it possible to measure cellular dynamics and polarity with unprecedented precision for entire tissues throughout their development. Here we review recent approaches to visualize and measure cell polarity and tissue morphogenesis. The chapter is organized like an experiment. We first discuss the choice of cell and polarity reporters and describe the use of mosaics to reveal hidden cell polarities or local morphogenetic events. Then, we outline application-specific advantages and disadvantages of different microscopy techniques and image projection algorithms. Next, we present methods to extract cell outlines to measure cell polarity and detect cellular events underlying morphogenesis. Finally, we bridge scales by presenting approaches to quantify the specific contribution of each cellular event to global tissue deformation. Taken together, we provide an in-depth description of available tools and theoretical concepts to quantitatively study cell polarity and tissue morphogenesis over multiple scales.

  10. A General Method for Targeted Quantitative Cross-Linking Mass Spectrometry

    PubMed Central

    Chavez, Juan D.; Eng, Jimmy K.; Schweppe, Devin K.; Cilia, Michelle; Rivera, Keith; Zhong, Xuefei; Wu, Xia; Allen, Terrence; Khurgel, Moshe; Kumar, Akhilesh; Lampropoulos, Athanasios; Larsson, Mårten; Maity, Shuvadeep; Morozov, Yaroslav; Pathmasiri, Wimal; Perez-Neut, Mathew; Pineyro-Ruiz, Coriness; Polina, Elizabeth; Post, Stephanie; Rider, Mark; Tokmina-Roszyk, Dorota; Tyson, Katherine; Vieira Parrine Sant'Ana, Debora; Bruce, James E.

    2016-01-01

    Chemical cross-linking mass spectrometry (XL-MS) provides protein structural information by identifying covalently linked proximal amino acid residues on protein surfaces. The information gained by this technique is complementary to other structural biology methods such as x-ray crystallography, NMR and cryo-electron microscopy[1]. The extension of traditional quantitative proteomics methods with chemical cross-linking can provide information on the structural dynamics of protein structures and protein complexes. The identification and quantitation of cross-linked peptides remains challenging for the general community, requiring specialized expertise ultimately limiting more widespread adoption of the technique. We describe a general method for targeted quantitative mass spectrometric analysis of cross-linked peptide pairs. We report the adaptation of the widely used, open source software package Skyline, for the analysis of quantitative XL-MS data as a means for data analysis and sharing of methods. We demonstrate the utility and robustness of the method with a cross-laboratory study and present data that is supported by and validates previously published data on quantified cross-linked peptide pairs. This advance provides an easy to use resource so that any lab with access to a LC-MS system capable of performing targeted quantitative analysis can quickly and accurately measure dynamic changes in protein structure and protein interactions. PMID:27997545

  11. Quantitative analysis of in vivo confocal microscopy images: a review.

    PubMed

    Patel, Dipika V; McGhee, Charles N

    2013-01-01

    In vivo confocal microscopy (IVCM) is a non-invasive method of examining the living human cornea. The recent trend towards quantitative studies using IVCM has led to the development of a variety of methods for quantifying image parameters. When selecting IVCM images for quantitative analysis, it is important to be consistent regarding the location, depth, and quality of images. All images should be de-identified, randomized, and calibrated prior to analysis. Numerous image analysis software are available, each with their own advantages and disadvantages. Criteria for analyzing corneal epithelium, sub-basal nerves, keratocytes, endothelium, and immune/inflammatory cells have been developed, although there is inconsistency among research groups regarding parameter definition. The quantification of stromal nerve parameters, however, remains a challenge. Most studies report lower inter-observer repeatability compared with intra-observer repeatability, and observer experience is known to be an important factor. Standardization of IVCM image analysis through the use of a reading center would be crucial for any future large, multi-centre clinical trials using IVCM.

  12. 3D quantitative analysis of brain SPECT images

    NASA Astrophysics Data System (ADS)

    Loncaric, Sven; Ceskovic, Ivan; Petrovic, Ratimir; Loncaric, Srecko

    2001-07-01

    The main purpose of this work is to develop a computer-based technique for quantitative analysis of 3-D brain images obtained by single photon emission computed tomography (SPECT). In particular, the volume and location of ischemic lesion and penumbra is important for early diagnosis and treatment of infracted regions of the brain. SPECT imaging is typically used as diagnostic tool to assess the size and location of the ischemic lesion. The segmentation method presented in this paper utilizes a 3-D deformable model in order to determine size and location of the regions of interest. The evolution of the model is computed using a level-set implementation of the algorithm. In addition to 3-D deformable model the method utilizes edge detection and region growing for realization of a pre-processing. Initial experimental results have shown that the method is useful for SPECT image analysis.

  13. Quantitative methods for stochastic high frequency spatio-temporal and non-linear analysis: Assessing health effects of exposure to extreme ambient temperature

    NASA Astrophysics Data System (ADS)

    Liss, Alexander

    Extreme weather events, such as heat waves and cold spells, cause substantial excess mortality and morbidity in the vulnerable elderly population, and cost billions of dollars. The accurate and reliable assessment of adverse effects of extreme weather events on human health is crucial for environmental scientists, economists, and public health officials to ensure proper protection of vulnerable populations and efficient allocation of scarce resources. However, the methodology for the analysis of large national databases is yet to be developed. The overarching objective of this dissertation is to examine the effect of extreme weather on the elderly population of the Conterminous US (ConUS) with respect to seasonality in temperature in different climatic regions by utilizing heterogeneous high frequency and spatio-temporal resolution data. To achieve these goals the author: 1) incorporated dissimilar stochastic high frequency big data streams and distinct data types into the integrated data base for use in analytical and decision support frameworks; 2) created an automated climate regionalization system based on remote sensing and machine learning to define climate regions for the Conterminous US; 3) systematically surveyed the current state of the art and identified existing gaps in the scientific knowledge; 4) assessed the dose-response relationship of exposure to temperature extremes on human health in relatively homogeneous climate regions using different statistical models, such as parametric and non-parametric, contemporaneous and asynchronous, applied to the same data; 5) assessed seasonal peak timing and synchronization delay of the exposure and the disease within the framework of contemporaneous high frequency harmonic time series analysis and modification of the effect by the regional climate; 6) modeled using hyperbolic functional form non-linear properties of the effect of exposure to extreme temperature on human health. The proposed climate

  14. A general radiochemical-color method for quantitation of immunoblots.

    PubMed

    Esmaeli-Azad, B; Feinstein, S C

    1991-12-01

    Quantitative interpretation of protein immunoblotting procedures is hampered by a variety of technical liabilities inherent in the use of photographic and densitometric methods. In this paper, we present a novel, simple, and generally applicable alternative procedure to acquire quantitative data from immunoblots. Our strategy employs both the standard alkaline phosphatase color reaction and radiolabelled Protein A. The color reaction is used to localize the polypeptide of interest after transfer to a solid support. The colored bands are then excised and the radioactivity in the colocalized Protein A is quantitated in a gamma counter. In addition to avoiding the problems associated with photographic and densitometric procedures, our assay also overcomes common problems associated with variable gel lane width and individual band distortion. The resulting data is linear over a range of at least 50-fold (10-500 ng of specific protein, for the example used in this study) and is highly reproducible.

  15. A Novel Targeted Learning Method for Quantitative Trait Loci Mapping

    PubMed Central

    Wang, Hui; Zhang, Zhongyang; Rose, Sherri; van der Laan, Mark

    2014-01-01

    We present a novel semiparametric method for quantitative trait loci (QTL) mapping in experimental crosses. Conventional genetic mapping methods typically assume parametric models with Gaussian errors and obtain parameter estimates through maximum-likelihood estimation. In contrast with univariate regression and interval-mapping methods, our model requires fewer assumptions and also accommodates various machine-learning algorithms. Estimation is performed with targeted maximum-likelihood learning methods. We demonstrate our semiparametric targeted learning approach in a simulation study and a well-studied barley data set. PMID:25258376

  16. A novel targeted learning method for quantitative trait loci mapping.

    PubMed

    Wang, Hui; Zhang, Zhongyang; Rose, Sherri; van der Laan, Mark

    2014-12-01

    We present a novel semiparametric method for quantitative trait loci (QTL) mapping in experimental crosses. Conventional genetic mapping methods typically assume parametric models with Gaussian errors and obtain parameter estimates through maximum-likelihood estimation. In contrast with univariate regression and interval-mapping methods, our model requires fewer assumptions and also accommodates various machine-learning algorithms. Estimation is performed with targeted maximum-likelihood learning methods. We demonstrate our semiparametric targeted learning approach in a simulation study and a well-studied barley data set.

  17. Computer compensation for NMR quantitative analysis of trace components

    SciTech Connect

    Nakayama, T.; Fujiwara, Y.

    1981-07-22

    A computer program has been written that determines trace components and separates overlapping components in multicomponent NMR spectra. This program uses the Lorentzian curve as a theoretical curve of NMR spectra. The coefficients of the Lorentzian are determined by the method of least squares. Systematic errors such as baseline/phase distortion are compensated and random errors are smoothed by taking moving averages, so that there processes contribute substantially to decreasing the accumulation time of spectral data. The accuracy of quantitative analysis of trace components has been improved by two significant figures. This program was applied to determining the abundance of 13C and the saponification degree of PVA.

  18. Quantitative analysis of sideband coupling in photoinduced force microscopy

    NASA Astrophysics Data System (ADS)

    Jahng, Junghoon; Kim, Bongsu; Lee, Eun Seong; Potma, Eric Olaf

    2016-11-01

    We present a theoretical and experimental analysis of the cantilever motions detected in photoinduced force microscopy (PiFM) using the sideband coupling detection scheme. In sideband coupling, the cantilever dynamics are probed at a combination frequency of a fundamental mechanical eigenmode and the modulation frequency of the laser beam. Using this detection mode, we develop a method for reconstructing the modulated photoinduced force gradient from experimental parameters in a quantitative manner. We show evidence, both theoretically and experimentally, that the sideband coupling detection mode provides PiFM images with superior contrast compared to images obtained when detecting the cantilever motions directly at the laser modulation frequency.

  19. Validation of an enhanced knowledge-based method for segmentation and quantitative analysis of intrathoracic airway trees from three-dimensional CT images

    SciTech Connect

    Sonka, M.; Park, W.; Hoffman, E.A.

    1995-12-31

    Accurate assessment of airway physiology, evaluated in terms of geometric changes, is critically dependent upon the accurate imaging and image segmentation of the three-dimensional airway tree structure. The authors have previously reported a knowledge-based method for three-dimensional airway tree segmentation from high resolution CT (HRCT) images. Here, they report a substantially improved version of the method. In the current implementation, the method consists of several stages. First, the lung borders are automatically determined in the three-dimensional set of HRCT data. The primary airway tree is semi-automatically identified. In the next stage, potential airways are determined in individual CT slices using a rule-based system that uses contextual information and a priori knowledge about pulmonary anatomy. Using three-dimensional connectivity properties of the pulmonary airway tree, the three-dimensional tree is constructed from the set of adjacent slices. The method`s performance and accuracy were assessed in five 3D HRCT canine images. Computer-identified airways matched 226/258 observer-defined airways (87.6%); the computer method failed to detect the airways in the remaining 32 locations. By visual assessment of rendered airway trees, the experienced observers judged the computer-detected airway trees as highly realistic.

  20. Multivariate calibration applied to the quantitative analysis of infrared spectra

    SciTech Connect

    Haaland, D.M.

    1991-01-01

    Multivariate calibration methods are very useful for improving the precision, accuracy, and reliability of quantitative spectral analyses. Spectroscopists can more effectively use these sophisticated statistical tools if they have a qualitative understanding of the techniques involved. A qualitative picture of the factor analysis multivariate calibration methods of partial least squares (PLS) and principal component regression (PCR) is presented using infrared calibrations based upon spectra of phosphosilicate glass thin films on silicon wafers. Comparisons of the relative prediction abilities of four different multivariate calibration methods are given based on Monte Carlo simulations of spectral calibration and prediction data. The success of multivariate spectral calibrations is demonstrated for several quantitative infrared studies. The infrared absorption and emission spectra of thin-film dielectrics used in the manufacture of microelectronic devices demonstrate rapid, nondestructive at-line and in-situ analyses using PLS calibrations. Finally, the application of multivariate spectral calibrations to reagentless analysis of blood is presented. We have found that the determination of glucose in whole blood taken from diabetics can be precisely monitored from the PLS calibration of either mind- or near-infrared spectra of the blood. Progress toward the non-invasive determination of glucose levels in diabetics is an ultimate goal of this research. 13 refs., 4 figs.

  1. Quantitative analysis of chlorpheniramine maleate and phenylephrine hydrochloride in nasal drops by differential-derivative spectrophotometric, zero-crossing first derivative UV spectrophotometric and absorbance ratio methods.

    PubMed

    Erk, N

    2000-11-01

    Three simple, rapid and accurate methods are described for the simultaneous determination of chlorpheniramine maleate and phenylephrine hydrochloride in two component mixtures. The first method comprised of measurement of difference absorptivities derivatized in first order of a nasal drops in 0.1 N NaOH relative to that of an equimolar solution in methanol at wavelengths of 271.6 and 250.2 nm, respectively. The second method, zero-crossing derivative spectrophotometry, is based on recording the first derivative curves and determining each component using the zero-crossing technique. Using first derivative spectrophotometry, the amplitudes in the first derivative spectra at 246.5 and 238.6 nm were selected to simultaneously determine chlorpheniramine maleate and phenylephrine hydrochloride in the mixture. The presence of identical zero-crossing points for pure drugs and nasal drop solutions established the non-interference of the excipients in the absorption at these wavelengths. Absorbance ratio method was also developed for a comparison method. The proposed procedures were successfully applied to the determination of chlorpheniramine maleate and phenylephrine hydrochloride in nasal drops, with a high percentage of recovery, good accuracy and precision.

  2. Validation of a headspace trap gas chromatography and mass spectrometry method for the quantitative analysis of volatile compounds from degraded rapeseed oil.

    PubMed

    Sghaier, Lilia; Cordella, Christophe B Y; Rutledge, Douglas N; Watiez, Mickaël; Breton, Sylvie; Sassiat, Patrick; Thiebaut, Didier; Vial, Jérôme

    2016-05-01

    Due to lipid oxidation, off-flavors, characterized by a fishy odor, are emitted during the heating of rapeseed oil in a fryer and affect the flavor of rapeseed oil even at low concentrations. Thus, there is a need for analytical methods to identify and quantify these products. To study the headspace composition of degraded rapeseed oil, and more specifically the compounds responsible for the fishy odor, a headspace trap gas chromatography with mass spectrometry method was developed and validated. Six volatile compounds formed during the degradation of rapeseed oil were quantified: 1-penten-3-one, (Z)-4-heptenal, hexanal, nonanal, (E,E)-heptadienal, and (E)-2-heptenal. Validation using accuracy profiles allowed us to determine the valid ranges of concentrations for each compound, with acceptance limits of 40% and tolerance limits of 80%. This method was then successfully applied to real samples of degraded oils.

  3. A validated LC-MS/MS method for quantitative analysis of curcumin in mouse plasma and brain tissue and its application in pharmacokinetic and brain distribution studies.

    PubMed

    Ramalingam, Prakash; Ko, Young Tag

    2014-10-15

    Curcumin is a well-known multitherapeutic agent widely employed in neurodegenerative disorders and cancer. A selective, fast, and sensitive method employing liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed and validated for the simultaneous determination of curcumin in mouse plasma and brain tissue, by using salbutamol as an internal standard. Triple quadrupole mass detection with multiple reaction monitoring (MRM) mode was used to monitor the ion transitions, m/z of 369>285 for curcumin, and m/z of 240>148 for salbutamol. The method was validated for recovery, accuracy, precision, linearity, and applicability. The lower limits of quantification (LLOQ) in both matrices were 2.5ng/mL. The inter-day and intra-day precisions and accuracy values were within the Food and Drug Administration (FDA) acceptance criteria, for both matrixes. The method was successfully applied in pharmacokinetics and brain distribution studies of curcumin after intravenous administration of free curcumin and curcumin-loaded solid lipid nanoparticles to mice. Furthermore, the application of this method along with serial blood sampling in mice has led to significant reduction in animal use and dosage and drastic improvement in speed, throughput, and quality of pharmacokinetic parameters.

  4. Development and validation of an in-house quantitative analysis method for cylindrospermopsin using hydrophilic interaction liquid chromatography-tandem mass spectrometry: Quantification demonstrated in 4 aquatic organisms.

    PubMed

    Esterhuizen-Londt, Maranda; Kühn, Sandra; Pflugmacher, Stephan

    2015-12-01

    The cyanobacterial toxin cylindrospermopsin (CYN) is of great concern in aquatic environments because of its incidence, multiple toxicity endpoints, and, therefore, the severity of health implications. It may bioaccumulate in aquatic food webs, resulting in high exposure concentrations to higher-order trophic levels, particularly humans. Because of accumulation at primary levels resulting from exposure to trace amounts of toxin, a sensitive analytical technique with proven aquatic applications is required. In the present study, a hydrophilic interaction liquid chromatographic-tandem mass spectrometric method with a lower limit of detection of 200 fg on column (signal-to-noise ratio = 3, n = 9) and a lower limit of quantification of 1 pg on column (signal-to-noise ratio = 11, n = 9) with demonstrated application in 4 aquatic organisms is described. The analytical method was optimized and validated with a linear range (r(2) = 0.999) from 0.1 ng mL(-1) to 100 ng mL(-1) CYN. Mean recovery of the extraction method was 98 ± 2%. Application of the method was demonstrated by quantifying CYN uptake in Scenedesmus subspicatus (green algae), Egeria densa (Brazilian waterweed), Daphnia magna (water flea), and Lumbriculus variegatus (blackworm) after 24 h of static exposure to 50 μg L(-1) CYN. Uptake ranged from 0.05% to 0.11% of the nominal CYN exposure amount. This constitutes a sensitive and reproducible method for extraction and quantification of unconjugated CYN with demonstrated application in 4 aquatic organisms, which can be used in further aquatic toxicological investigations.

  5. Testing of flat optical surfaces by the quantitative Foucault method.

    PubMed

    Simon, M C; Simon, J M

    1978-01-01

    The complete theory of measurement of optical flat mirrors of circular or elliptical shape using the quantitative Foucault method is described here. It has been used in Córdoba since 1939 in a partially intuitive but correct form. The surface, not yet flat and, at times, astigmatic, is assimilated to the sum of a spherical plus a cylindrical dome. The errors of the three possible ways of reckoning are calculated.

  6. A simple LC-MS/MS method for quantitative analysis of underivatized neurotransmitters in rats urine: assay development, validation and application in the CUMS rat model.

    PubMed

    Zhai, Xue-jia; Chen, Fen; Zhu, Chao-ran; Lu, Yong-ning

    2015-11-01

    Many amino acid neurotransmitters in urine are associated with chronic stress as well as major depressive disorders. To better understand depression, an analytical LC-MS/MS method for the simultaneous determination of 11 underivatized neurotransmitters (4-aminohippurate, 5-HIAA, glutamate, glutamine, hippurate, pimelate, proline, tryptophan, tyramine, tyrosine and valine) in a single analytical run was developed. The advantage of this method is the simple preparation in that there is no need to deconjugate the urine samples. The quantification range was 25-12,800 ng mL(-1) with >85.8% recovery for all analytes. The nocturnal urine concentrations of the 11 neurotransmitters in chronic unpredictable mild stress (CUMS) model rats and control group (n = 12) were analyzed. A series of significant changes in urinary excretion of neurotransmitters could be detected: the urinary glutamate, glutamine, hippurate and tyramine concentrations were significantly lower in the CUMS group. In addition, the urinary concentrations of tryptophan as well as tyrosine were significantly higher in chronically stressed rats. This method allows the assessment of the neurotransmitters associated with CUMS in rat urine in a single analytical run, making it suitable for implementation as a routine technique in depression research.

  7. Rapid qualitative and quantitative ultra high performance liquid chromatography method for simultaneous analysis of twenty nine common phenolic compounds of various structures.

    PubMed

    Nováková, Lucie; Spácil, Zdenek; Seifrtová, Marcela; Opletal, Lubomír; Solich, Petr

    2010-03-15

    Twenty nine phenolic compounds comprising nine phenolic acids, sixteen flavonoids (including eight tea catechins, glycosides and aglycones), four coumarins plus caffeine were analysed within 20 min using ultra high performance liquid chromatography (UHPLC) with PDA detection. UHPLC system was equipped with C18 analytical column (100 mm x 2.1mm, 1.7 microm), utilising 0.1% formic acid and methanol mobile phase in the gradient elution mode. The developed method was tested for the system suitability: resolution, asymmetry factor, peak capacity, retention time repeatability and peak area repeatability. The method was fully validated in the terms of linearity (r(2)>0.9990 for all 30 compounds), range (typically 1-100 mg L(-1)), LOD, LOQ, inter/intra-day precision (<3% and <9% respectively) and inter/intra-day accuracy (typically 100+/-10%). Subsequently the method was applied to the identification (spectral information and peak purity calculations were profited) and quantification of phenolic compounds and caffeine present in tea infusions and extracts.

  8. A powder X-ray diffraction method for detection of polyprenylated benzophenones in plant extracts associated with HPLC for quantitative analysis.

    PubMed

    Martins, Felipe T; dos Santos, Marcelo H; Coelho, Carla P; Barbosa, Luiz C A; Dias, Gizelly C; Fracca, Mônica P; Neves, Person P; Stringheta, Paulo C; Doriguetto, Antônio C

    2011-02-20

    A robust, direct, rapid and non-destructive X-ray diffraction crystallography method to detect the polyprenylated benzophenones 7-epi-clusianone (1) and guttiferone A (2) in extracts from Garcinia brasiliensis is presented. Powder samples of benzophenones 1 and 2, dried hexane extracts from G. brasiliensis seeds and fruit's pericarp, and the dried ethanolic extract from G. brasiliensis seeds were unambiguously characterized by powder X-ray diffractometry. The calculated X-ray diffraction peaks from crystal structures of analytes 1 and 2, previously determined by single-crystal X-ray diffraction technique, were overlaid to those of the experimental powder diffractograms, providing a practical identification of these compounds in the analyzed material and confirming the pure contents of the powder samples. Using the X-ray diffraction crystallography method, the studied polyprenylated benzophenones were selectively and simultaneously detected in the extracts which were mounted directly on sample holder. In addition, reference materials of the analytes were not required for analyses since the crystal structures of the compounds are known. High performance liquid chromatography analyses also were comparatively carried out to quantify the analytes in the same plant extracts showing to be in agreement with X-ray diffraction crystallography method.

  9. Quantitative analysis of planetary reflectance spectra with principal components analysis

    NASA Technical Reports Server (NTRS)

    Johnson, P. E.; Smith, M. O.; Adams, J. B.

    1985-01-01

    A technique is presented for quantitative analysis of planetary reflectance spectra as mixtures of particles on microscopic and macroscopic scales using principal components analysis. This technique allows for determination of the endmembers being mixed, their abundance, and the scale of mixing, as well as other physical parameters. Eighteen lunar telescopic reflectance spectra of the Copernicus crater region, from 600 nm to 1800 nm in wavelength, are modeled in terms of five likely endmembers: mare basalt, mature mare soil, anorthosite, mature highland soil, and clinopyroxene. These endmembers were chosen from a similar analysis of 92 lunar soil and rock samples. The models fit the data to within 2 percent rms. It is found that the goodness of fit is marginally better for intimate mixing over macroscopic mixing.

  10. Quantitative imaging biomarkers: a review of statistical methods for technical performance assessment.

    PubMed

    Raunig, David L; McShane, Lisa M; Pennello, Gene; Gatsonis, Constantine; Carson, Paul L; Voyvodic, James T; Wahl, Richard L; Kurland, Brenda F; Schwarz, Adam J; Gönen, Mithat; Zahlmann, Gudrun; Kondratovich, Marina V; O'Donnell, Kevin; Petrick, Nicholas; Cole, Patricia E; Garra, Brian; Sullivan, Daniel C

    2015-02-01

    Technological developments and greater rigor in the quantitative measurement of biological features in medical images have given rise to an increased interest in using quantitative imaging biomarkers to measure changes in these features. Critical to the performance of a quantitative imaging biomarker in preclinical or clinical settings are three primary metrology areas of interest: measurement linearity and bias, repeatability, and the ability to consistently reproduce equivalent results when conditions change, as would be expected in any clinical trial. Unfortunately, performance studies to date differ greatly in designs, analysis method, and metrics used to assess a quantitative imaging biomarker for clinical use. It is therefore difficult or not possible to integrate results from different studies or to use reported results to design studies. The Radiological Society of North America and the Quantitative Imaging Biomarker Alliance with technical, radiological, and statistical experts developed a set of technical performance analysis methods, metrics, and study designs that provide terminology, metrics, and methods consistent with widely accepted metrological standards. This document provides a consistent framework for the conduct and evaluation of quantitative imaging biomarker performance studies so that results from multiple studies can be compared, contrasted, or combined.

  11. Quantitative analysis of tumor burden in mouse lung via MRI.

    PubMed

    Tidwell, Vanessa K; Garbow, Joel R; Krupnick, Alexander S; Engelbach, John A; Nehorai, Arye

    2012-02-01

    Lung cancer is the leading cause of cancer death in the United States. Despite recent advances in screening protocols, the majority of patients still present with advanced or disseminated disease. Preclinical rodent models provide a unique opportunity to test novel therapeutic drugs for targeting lung cancer. Respiratory-gated MRI is a key tool for quantitatively measuring lung-tumor burden and monitoring the time-course progression of individual tumors in mouse models of primary and metastatic lung cancer. However, quantitative analysis of lung-tumor burden in mice by MRI presents significant challenges. Herein, a method for measuring tumor burden based upon average lung-image intensity is described and validated. The method requires accurate lung segmentation; its efficiency and throughput would be greatly aided by the ability to automatically segment the lungs. A technique for automated lung segmentation in the presence of varying tumor burden levels is presented. The method includes development of a new, two-dimensional parametric model of the mouse lungs and a multi-faceted cost function to optimally fit the model parameters to each image. Results demonstrate a strong correlation (0.93), comparable with that of fully manual expert segmentation, between the automated method's tumor-burden metric and the tumor burden measured by lung weight.

  12. Optimisation and validation of ultra-high performance liquid chromatographic-tandem mass spectrometry method for qualitative and quantitative analysis of potato steroidal alkaloids.

    PubMed

    Hossain, Mohammad B; Rai, Dilip K; Brunton, Nigel P

    2015-08-01

    An ultra-high performance liquid chromatographic-tandem mass spectrometry (UHPLC-MS/MS) method for quantification of potato steroidal alkaloids, namely α-solanine, α-chaconine, solanidine and demissidine was developed and validated. Three different column chemistries, i.e. ethylene bridged hybrid (BEH) C18, hydrophilic lipophilic interaction and amide columns, were assessed. The BEH C18 column showed best separation and sensitivity for the alkaloids. Validation data (inter-day and intra-day combined) for accuracy and recovery ranged from 94.3 to 107.7% and 97.0 to 103.5%, respectively. The accuracy data were within the acceptable range of 15% as outlined in the United States Food and Drug Administration (USFDA) guidelines. The recovery data were consistent and reproducible with a coefficient of variation (CV) ranging from 6.2 to 9.7%. In addition, precision of the method also met the criteria of the USFDA with CV values lower than 15% even at lower limit of quantification (LLOQ), while the permissible variation is considered acceptable below 20%. The limit of detection and LLOQ of the four alkaloids were in the range of 0.001-0.004μg/mL whereas the linearities of the standard curves were between 0.980 and 0.995.

  13. Validation of an UPLC-MS-MS Method for Quantitative Analysis of Vincristine in Human Urine After Intravenous Administration of Vincristine Sulfate Liposome Injection.

    PubMed

    Yang, Fen; Wang, Hongyun; Hu, Pei; Jiang, Ji

    2015-07-01

    Vincristine sulfate liposome injection (VSLI) is a liposomal formulation of vincristine (VCR) sulfate, being developed for the systemic treatment of cancer. In this paper, we have developed and validated a method to quantify VCR in human urine to obtain the urinary excretion of VCR after intravenous administration of VSLI. The analyte was extracted from urine samples using liquid-liquid extraction after addition of vinblastine (VBL, used as internal standard) and chromatographed on an Acquity UPLC HSS T3 column with a gradient mobile phase at a flow rate of 0.4 mL/min. The multiple reactions monitoring transitions of m/z 413.2 → 353.2 and m/z 406.2 → 271.6 were used to quantify VCR and VBL, respectively. The lower limit of quantification was 0.5 ng/mL with a precision (RSD%) of 5.7% and an accuracy (RE%) of 6.7%. The calibration curve was linear up to 100.0 ng/mL. Intraday precision and accuracy ranged from 0.8 to 11.0% and from -12.4 to 11.3%, respectively. Interassay precision and accuracy ranged from 8.0 to 10.1% and from -7.7 to 3.6%, respectively. No significant matrix effect was observed for VCR. The method was successfully applied for pharmacokinetic study of VSLI to investigate the route and extent of VCR urinary excretion in Chinese subjects with lymphoma.

  14. Simulating realistic predator signatures in quantitative fatty acid signature analysis

    USGS Publications Warehouse

    Bromaghin, Jeffrey F.

    2015-01-01

    Diet estimation is an important field within quantitative ecology, providing critical insights into many aspects of ecology and community dynamics. Quantitative fatty acid signature analysis (QFASA) is a prominent method of diet estimation, particularly for marine mammal and bird species. Investigators using QFASA commonly use computer simulation to evaluate statistical characteristics of diet estimators for the populations they study. Similar computer simulations have been used to explore and compare the performance of different variations of the original QFASA diet estimator. In both cases, computer simulations involve bootstrap sampling prey signature data to construct pseudo-predator signatures with known properties. However, bootstrap sample sizes have been selected arbitrarily and pseudo-predator signatures therefore may not have realistic properties. I develop an algorithm to objectively establish bootstrap sample sizes that generates pseudo-predator signatures with realistic properties, thereby enhancing the utility of computer simulation for assessing QFASA estimator performance. The algorithm also appears to be computationally efficient, resulting in bootstrap sample sizes that are smaller than those commonly used. I illustrate the algorithm with an example using data from Chukchi Sea polar bears (Ursus maritimus) and their marine mammal prey. The concepts underlying the approach may have value in other areas of quantitative ecology in which bootstrap samples are post-processed prior to their use.

  15. Quantitative analysis of Caenorhabditis elegans chemotaxis using a microfluidic device.

    PubMed

    Hu, Liang; Ye, Jinjuan; Tan, Haowei; Ge, Anle; Tang, Lichun; Feng, Xiaojun; Du, Wei; Liu, Bi-Feng

    2015-08-05

    Caenorhabditis elegans, one of the widely studied model organisms, sense external chemical cues and perform relative chemotaxis behaviors through its simple chemosensory neuronal system. To study the mechanism underlying chemosensory behavior, a rapid and reliable method for quantitatively analyzing the worms' behaviors is essential. In this work, we demonstrated a microfluidic approach for investigating chemotaxis responses of worms to chemical gradients. The flow-based microfluidic chip was consisted of circular tree-like microchannels, which was able to generate eight flow streams containing stepwise chemical concentrations without the difference in flow velocity. Worms' upstream swimming into microchannels with various concentrations was monitored for quantitative analysis of the chemotaxis behavior. By using this microfluidic chip, the attractive and repellent responses of C. elegans to NaCl were successfully quantified within several minutes. The results demonstrated the wild type-like repellent responses and severely impaired attractive responses in grk-2 mutant animals with defects in calcium influx. In addition, the chemotaxis analysis of the third stage larvae revealed that its gustatory response was different from that in the adult stage. Thus, our microfluidic method provided a useful platform for studying the chemosensory behaviors of C. elegans and screening of chemosensation-related chemical drugs.

  16. A quantitative method for measuring the quality of history matches

    SciTech Connect

    Shaw, T.S.; Knapp, R.M.

    1997-08-01

    History matching can be an efficient tool for reservoir characterization. A {open_quotes}good{close_quotes} history matching job can generate reliable reservoir parameters. However, reservoir engineers are often frustrated when they try to select a {open_quotes}better{close_quotes} match from a series of history matching runs. Without a quantitative measurement, it is always difficult to tell the difference between a {open_quotes}good{close_quotes} and a {open_quotes}better{close_quotes} matches. For this reason, we need a quantitative method for testing the quality of matches. This paper presents a method for such a purpose. The method uses three statistical indices to (1) test shape conformity, (2) examine bias errors, and (3) measure magnitude of deviation. The shape conformity test insures that the shape of a simulated curve matches that of a historical curve. Examining bias errors assures that model reservoir parameters have been calibrated to that of a real reservoir. Measuring the magnitude of deviation assures that the difference between the model and the real reservoir parameters is minimized. The method was first tested on a hypothetical model and then applied to published field studies. The results showed that the method can efficiently measure the quality of matches. It also showed that the method can serve as a diagnostic tool for calibrating reservoir parameters during history matching.

  17. Quality assessment of the saffron samples using second-order spectrophotometric data assisted by three-way chemometric methods via quantitative analysis of synthetic colorants in adulterated saffron.

    PubMed

    Masoum, Saeed; Gholami, Ali; Hemmesi, Marjan; Abbasi, Saleheh

    2015-09-05

    Saffron is a valuable culinary spice that can be used not only for dyes and cooking, but also for many medical purposes. Due to its high price and restriction of its production, various fraud manners in its production have been growing. Addition of synthetic colorants to saffron is the most common way for adulteration. In this work, chemometric methods are proposed to resolve the three-dimensional absorbance spectra-pH data for simultaneous determination of the two colorants Tartrazin and Sunset yellow, in adulterated saffron. The rank deficiency in the concentration mode impaired the system. Therefore, to extirpate the ambiguity, which results from rank deficiency, three-way variation array V was generated by subtracting the first pH spectrum from each spectrum at each pH. This allows the extraction of extent reaction profile and mixture reaction spectral profiles, as well as the relative concentrations of the analytes.

  18. Quality assessment of the saffron samples using second-order spectrophotometric data assisted by three-way chemometric methods via quantitative analysis of synthetic colorants in adulterated saffron

    NASA Astrophysics Data System (ADS)

    Masoum, Saeed; Gholami, Ali; Hemmesi, Marjan; Abbasi, Saleheh

    2015-09-01

    Saffron is a valuable culinary spice that can be used not only for dyes and cooking, but also for many medical purposes. Due to its high price and restriction of its production, various fraud manners in its production have been growing. Addition of synthetic colorants to saffron is the most common way for adulteration. In this work, chemometric methods are proposed to resolve the three-dimensional absorbance spectra-pH data for simultaneous determination of the two colorants Tartrazin and Sunset yellow, in adulterated saffron. The rank deficiency in the concentration mode impaired the system. Therefore, to extirpate the ambiguity, which results from rank deficiency, three-way variation array V was generated by subtracting the first pH spectrum from each spectrum at each pH. This allows the extraction of extent reaction profile and mixture reaction spectral profiles, as well as the relative concentrations of the analytes.

  19. Quantitative analysis of motion control in long term microgravity.

    PubMed

    Baroni, G; Ferrigno, G; Anolli, A; Andreoni, G; Pedotti, A

    1998-01-01

    In the frame of the 179-days EUROMIR '95 space mission, two in-flight experiments have foreseen quantitative three-dimensional human movement analysis in microgravity. For this aim, a space qualified opto-electronic motion analyser based on passive markers has been installed onboard the Russian Space Station MIR and 8 in flight sessions have been performed. Techhology and method for the collection of kinematics data are described, evaluating the accuracy in three-dimensional marker localisation. Results confirm the suitability of opto-electronic technology for quantitative human motion analysis on orbital modules and raise a set of "lessons learned", leading to the improvement of motion analyser performance with a contemporary swiftness of the on-board operations. Among the experimental program of T4, results of three voluntary posture perturbation protocols are described. The analysis suggests that a short term reinterpretation of proprioceptive information and re-calibration of sensorimotor mechanisms seem to end within the first weeks of flight, while a continuous long term adaptation process allows the refinement of motor performance, in the frame of never abandoned terrestrial strategies.

  20. A quantitative method for optimized placement of continuous air monitors.

    PubMed

    Whicker, Jeffrey J; Rodgers, John C; Moxley, John S

    2003-11-01

    Alarming continuous air monitors (CAMs) are a critical component for worker protection in facilities that handle large amounts of hazardous materials. In nuclear facilities, continuous air monitors alarm when levels of airborne radioactive materials exceed alarm thresholds, thus prompting workers to exit the room to reduce inhalation exposures. To maintain a high level of worker protection, continuous air monitors are required to detect radioactive aerosol clouds quickly and with good sensitivity. This requires that there are sufficient numbers of continuous air monitors in a room and that they are well positioned. Yet there are no published methodologies to quantitatively determine the optimal number and placement of continuous air monitors in a room. The goal of this study was to develop and test an approach to quantitatively determine optimal number and placement of continuous air monitors in a room. The method we have developed uses tracer aerosol releases (to simulate accidental releases) and the measurement of the temporal and spatial aspects of the dispersion of the tracer aerosol through the room. The aerosol dispersion data is then analyzed to optimize continuous air monitor utilization based on simulated worker exposure. This method was tested in a room within a Department of Energy operated plutonium facility at the Savannah River Site in South Carolina, U.S. Results from this study show that the value of quantitative airflow and aerosol dispersion studies is significant and that worker protection can be significantly improved while balancing the costs associated with CAM programs.

  1. Quantitative analysis of aortic regurgitation: real-time 3-dimensional and 2-dimensional color Doppler echocardiographic method--a clinical and a chronic animal study

    NASA Technical Reports Server (NTRS)

    Shiota, Takahiro; Jones, Michael; Tsujino, Hiroyuki; Qin, Jian Xin; Zetts, Arthur D.; Greenberg, Neil L.; Cardon, Lisa A.; Panza, Julio A.; Thomas, James D.

    2002-01-01

    BACKGROUND: For evaluating patients with aortic regurgitation (AR), regurgitant volumes, left ventricular (LV) stroke volumes (SV), and absolute LV volumes are valuable indices. AIM: The aim of this study was to validate the combination of real-time 3-dimensional echocardiography (3DE) and semiautomated digital color Doppler cardiac flow measurement (ACM) for quantifying absolute LV volumes, LVSV, and AR volumes using an animal model of chronic AR and to investigate its clinical applicability. METHODS: In 8 sheep, a total of 26 hemodynamic states were obtained pharmacologically 20 weeks after the aortic valve noncoronary (n = 4) or right coronary (n = 4) leaflet was incised to produce AR. Reference standard LVSV and AR volume were determined using the electromagnetic flow method (EM). Simultaneous epicardial real-time 3DE studies were performed to obtain LV end-diastolic volumes (LVEDV), end-systolic volumes (LVESV), and LVSV by subtracting LVESV from LVEDV. Simultaneous ACM was performed to obtain LVSV and transmitral flows; AR volume was calculated by subtracting transmitral flow volume from LVSV. In a total of 19 patients with AR, real-time 3DE and ACM were used to obtain LVSVs and these were compared with each other. RESULTS: A strong relationship was found between LVSV derived from EM and those from the real-time 3DE (r = 0.93, P <.001, mean difference (3D - EM) = -1.0 +/- 9.8 mL). A good relationship between LVSV and AR volumes derived from EM and those by ACM was found (r = 0.88, P <.001). A good relationship between LVSV derived from real-time 3DE and that from ACM was observed (r = 0.73, P <.01, mean difference = 2.5 +/- 7.9 mL). In patients, a good relationship between LVSV obtained by real-time 3DE and ACM was found (r = 0.90, P <.001, mean difference = 0.6 +/- 9.8 mL). CONCLUSION: The combination of ACM and real-time 3DE for quantifying LV volumes, LVSV, and AR volumes was validated by the chronic animal study and was shown to be clinically applicable.

  2. Morphometric, quantitative, and three-dimensional analysis of the heart muscle fibers of old rats: transmission electron microscopy and high-resolution scanning electron microscopy methods.

    PubMed

    Cury, Diego Pulzatto; Dias, Fernando José; Sosthenes, Marcia Consentino Kronka; Dos Santos Haemmerle, Carlos Alexandre; Ogawa, Koichi; Da Silva, Marcelo Cavenaghi Pereira; Mardegan Issa, João Paulo; Iyomasa, Mamie Mizusaki; Watanabe, Ii-Sei

    2013-02-01

    This research investigated the morphological, morphometric, and ultrastructural cardiomyocyte characteristics of male Wistar rats at 18 months of age. The animals were euthanized using an overdose of anesthesia (ketamine and xylazine, 150/10 mg/kg) and perfused transcardially, after which samples were collected for light microscopy, transmission electron microscopy, and high-resolution scanning electron microscopy. The results showed that cardiomyocyte arrangement was disposed parallel between the mitochondria and the A-, I-, and H-bands and their M- and Z-lines from the sarcomere. The sarcomere junction areas had intercalated disks, a specific structure of heart muscle. The ultrastructural analysis revealed several mitochondria of various sizes and shapes intermingled between the blood capillaries and their endothelial cells; some red cells inside vessels are noted. The muscle cell sarcolemma could be observed associated with the described structures. The cardiomyocytes of old rats presented an average sarcomere length of 2.071 ± 0.09 μm, a mitochondrial volume density (Vv) of 0.3383, a mitochondrial average area of 0.537 ± 0.278 μm(2), a mitochondrial average length of 1.024 ± 0.352 μm, an average mitochondrial cristae thickness of 0.038 ± 0.09 μm and a ratio of mitochondrial greater length/lesser length of 1.929 ± 0.965. Of the observed mitochondrial shapes, 23.4% were rounded, 45.3% were elongated, and 31.1% had irregular profiles. In this study, we analyzed the morphology and morphometry of cardiomyocytes in old rats, focusing on mitochondria. These data are important for researchers who focus the changes in cardiac tissue, especially changes owing to pathologies and drug administration that may or may not be correlated with aging.

  3. Development of pulmonary blood flow evaluation method with a dynamic flat-panel detector: quantitative correlation analysis with findings on perfusion scan.

    PubMed

    Tanaka, Rie; Sanada, Shigeru; Fujimura, Masaki; Yasui, Masahide; Hayashi, Norio; Tsuji, Shiro; Okamoto, Hiroyuki; Nanbu, Yuko; Matsui, Osamu

    2010-01-01

    Pulmonary blood flow is reflected in dynamic chest radiographs as changes in X-ray translucency, i.e., pixel values. Thus, decreased blood flow should be observed as a reduction of the variation of X-ray translucency. We performed the present study to investigate the feasibility of pulmonary blood flow evaluation with a dynamic flat-panel detector (FPD). Sequential chest radiographs of 14 subjects were obtained with a dynamic FPD system. The changes in pixel value in each local area were measured and mapped on the original image by use of a gray scale in which small and large changes were shown in white and black, respectively. The resulting images were compared to the findings in perfusion scans. The cross-correlation coefficients of the changes in pixel value and radioactivity counts in each local area were also computed. In all patients, pulmonary blood flow disorder was indicated as a reduction of changes in pixel values on the mapping image, and a correlation was observed between the distribution of changes in pixel value and those in radioactivity counts (0.7 method is potentially useful for evaluating pulmonary blood flow as an additional examination in conventional chest radiography.

  4. Advance in orientation microscopy: quantitative analysis of nanocrystalline structures.

    PubMed

    Seyring, Martin; Song, Xiaoyan; Rettenmayr, Markus

    2011-04-26

    The special properties of nanocrystalline materials are generally accepted to be a consequence of the high density of planar defects (grain and twin boundaries) and their characteristics. However, until now, nanograin structures have not been characterized with similar detail and statistical relevance as coarse-grained materials, due to the lack of an appropriate method. In the present paper, a novel method based on quantitative nanobeam diffraction in transmission electron microscopy (TEM) is presented to determine the misorientation of adjacent nanograins and subgrains. Spatial resolution of <5 nm can be achieved. This method is applicable to characterize orientation relationships in wire, film, and bulk materials with nanocrystalline structures. As a model material, nanocrystalline Cu is used. Several important features of the nanograin structure are discovered utilizing quantitative analysis: the fraction of twin boundaries is substantially higher than that observed in bright-field images in the TEM; small angle grain boundaries are prominent; there is an obvious dependence of the grain boundary characteristics on grain size distribution and mean grain size.

  5. Quantitative analysis of protein-ligand interactions by NMR.

    PubMed

    Furukawa, Ayako; Konuma, Tsuyoshi; Yanaka, Saeko; Sugase, Kenji

    2016-08-01

    Protein-ligand interactions have been commonly studied through static structures of the protein-ligand complex. Recently, however, there has been increasing interest in investigating the dynamics of protein-ligand interactions both for fundamental understanding of the underlying mechanisms and for drug development. NMR is a versatile and powerful tool, especially because it provides site-specific quantitative information. NMR has widely been used to determine the dissociation constant (KD), in particular, for relatively weak interactions. The simplest NMR method is a chemical-shift titration experiment, in which the chemical-shift changes of a protein in response to ligand titration are measured. There are other quantitative NMR methods, but they mostly apply only to interactions in the fast-exchange regime. These methods derive the dissociation constant from population-averaged NMR quantities of the free and bound states of a protein or ligand. In contrast, the recent advent of new relaxation-based experiments, including R2 relaxation dispersion and ZZ-exchange, has enabled us to obtain kinetic information on protein-ligand interactions in the intermediate- and slow-exchange regimes. Based on R2 dispersion or ZZ-exchange, methods that can determine the association rate, kon, dissociation rate, koff, and KD have been developed. In these approaches, R2 dispersion or ZZ-exchange curves are measured for multiple samples with different protein and/or ligand concentration ratios, and the relaxation data are fitted to theoretical kinetic models. It is critical to choose an appropriate kinetic model, such as the two- or three-state exchange model, to derive the correct kinetic information. The R2 dispersion and ZZ-exchange methods are suitable for the analysis of protein-ligand interactions with a micromolar or sub-micromolar dissociation constant but not for very weak interactions, which are typical in very fast exchange. This contrasts with the NMR methods that are used

  6. Functional Regression Models for Epistasis Analysis of Multiple Quantitative Traits.

    PubMed

    Zhang, Futao; Xie, Dan; Liang, Meimei; Xiong, Momiao

    2016-04-01

    To date, most genetic analyses of phenotypes have focused on analyzing single traits or analyzing each phenotype independently. However, joint epistasis analysis of multiple complementary traits will increase statistical power and improve our understanding of the complicated genetic structure of the complex diseases. Despite their importance in uncovering the genetic structure of complex traits, the statistical methods for identifying epistasis in multiple phenotypes remains fundamentally unexplored. To fill this gap, we formulate a test for interaction between two genes in multiple quantitative trait analysis as a multiple functional regression (MFRG) in which the genotype functions (genetic variant profiles) are defined as a function of the genomic position of the genetic variants. We use large-scale simulations to calculate Type I error rates for testing interaction between two genes with multiple phenotypes and to compare the power with multivariate pairwise interaction analysis and single trait interaction analysis by a single variate functional regression model. To further evaluate performance, the MFRG for epistasis analysis is applied to five phenotypes of exome sequence data from the NHLBI's Exome Sequencing Project (ESP) to detect pleiotropic epistasis. A total of 267 pairs of genes that formed a genetic interaction network showed significant evidence of epistasis influencing five traits. The results demonstrate that the joint interaction analysis of multiple phenotypes has a much higher power to detect interaction than the interaction analysis of a single trait and may open a new direction to fully uncovering the genetic structure of multiple phenotypes.

  7. Multipoint quantitative-trait linkage analysis in general pedigrees.

    PubMed Central

    Almasy, L; Blangero, J

    1998-01-01

    Multipoint linkage analysis of quantitative-trait loci (QTLs) has previously been restricted to sibships and small pedigrees. In this article, we show how variance-component linkage methods can be used in pedigrees of arbitrary size and complexity, and we develop a general framework for multipoint identity-by-descent (IBD) probability calculations. We extend the sib-pair multipoint mapping approach of Fulker et al. to general relative pairs. This multipoint IBD method uses the proportion of alleles shared identical by descent at genotyped loci to estimate IBD sharing at arbitrary points along a chromosome for each relative pair. We have derived correlations in IBD sharing as a function of chromosomal distance for relative pairs in general pedigrees and provide a simple framework whereby these correlations can be easily obtained for any relative pair related by a single line of descent or by multiple independent lines of descent. Once calculated, the multipoint relative-pair IBDs can be utilized in variance-component linkage analysis, which considers the likelihood of the entire pedigree jointly. Examples are given that use simulated data, demonstrating both the accuracy of QTL localization and the increase in power provided by multipoint analysis with 5-, 10-, and 20-cM marker maps. The general pedigree variance component and IBD estimation methods have been implemented in the SOLAR (Sequential Oligogenic Linkage Analysis Routines) computer package. PMID:9545414

  8. EBprot: Statistical analysis of labeling-based quantitative proteomics data.

    PubMed

    Koh, Hiromi W L; Swa, Hannah L F; Fermin, Damian; Ler, Siok Ghee; Gunaratne, Jayantha; Choi, Hyungwon

    2015-08-01

    Labeling-based proteomics is a powerful method for detection of differentially expressed proteins (DEPs). The current data analysis platform typically relies on protein-level ratios, which is obtained by summarizing peptide-level ratios for each protein. In shotgun proteomics, however, some proteins are quantified with more peptides than others, and this reproducibility information is not incorporated into the differential expression (DE) analysis. Here, we propose a novel probabilistic framework EBprot that directly models the peptide-protein hierarchy and rewards the proteins with reproducible evidence of DE over multiple peptides. To evaluate its performance with known DE states, we conducted a simulation study to show that the peptide-level analysis of EBprot provides better receiver-operating characteristic and more accurate estimation of the false discovery rates than the methods based on protein-level ratios. We also demonstrate superior classification performance of peptide-level EBprot analysis in a spike-in dataset. To illustrate the wide applicability of EBprot in different experimental designs, we applied EBprot to a dataset for lung cancer subtype analysis with biological replicates and another dataset for time course phosphoproteome analysis of EGF-stimulated HeLa cells with multiplexed labeling. Through these examples, we show that the peptide-level analysis of EBprot is a robust alternative to the existing statistical methods for the DE analysis of labeling-based quantitative datasets. The software suite is freely available on the Sourceforge website http://ebprot.sourceforge.net/. All MS data have been deposited in the ProteomeXchange with identifier PXD001426 (http://proteomecentral.proteomexchange.org/dataset/PXD001426/).

  9. Traditional Methods for Mineral Analysis

    NASA Astrophysics Data System (ADS)

    Ward, Robert E.; Carpenter, Charles E.

    This chapter describes traditional methods for analysis of minerals involving titrimetric and colorimetric procedures, and the use of ion selective electrodes. Other traditional methods of mineral analysis include gravimetric titration (i.e., insoluble forms of minerals are precipitated, rinse, dried, and weighed) and redox reactions (i.e., mineral is part of an oxidation-reduction reaction, and product is quantitated). However, these latter two methods will not be covered because they currently are used little in the food industry. The traditional methods that will be described have maintained widespread usage in the food industry despite the development of more modern instrumentation such as atomic absorption spectroscopy and inductively coupled plasma-atomic emission spectroscopy (Chap. 24). Traditional methods generally require chemicals and equipment that are routinely available in an analytical laboratory and are within the experience of most laboratory technicians. Additionally, traditional methods often form the basis for rapid analysis kits (e.g., Quantab®; for salt determination) that are increasingly in demand. Procedures for analysis of minerals of major nutritional or food processing concern are used for illustrative purposes. For additional examples of traditional methods refer to references (1-6). Slight modifications of these traditional methods are often needed for specific foodstuffs to minimize interferences or to be in the range of analytical performance. For analytical requirements for specific foods see the Official Methods of Analysis of AOAC International (5) and related official methods (6).

  10. Comparison study on qualitative and quantitative risk assessment methods for urban natural gas pipeline network.

    PubMed

    Han, Z Y; Weng, W G

    2011-05-15

    In this paper, a qualitative and a quantitative risk assessment methods for urban natural gas pipeline network are proposed. The qualitative method is comprised of an index system, which includes a causation index, an inherent risk index, a consequence index and their corresponding weights. The quantitative method consists of a probability assessment, a consequences analysis and a risk evaluation. The outcome of the qualitative method is a qualitative risk value, and for quantitative method the outcomes are individual risk and social risk. In comparison with previous research, the qualitative method proposed in this paper is particularly suitable for urban natural gas pipeline network, and the quantitative method takes different consequences of accidents into consideration, such as toxic gas diffusion, jet flame, fire ball combustion and UVCE. Two sample urban natural gas pipeline networks are used to demonstrate these two methods. It is indicated that both of the two methods can be applied to practical application, and the choice of the methods depends on the actual basic data of the gas pipelines and the precision requirements of risk assessment.

  11. Energy Dispersive Spectrometry and Quantitative Analysis Short Course. Introduction to X-ray Energy Dispersive Spectrometry and Quantitative Analysis

    NASA Technical Reports Server (NTRS)

    Carpenter, Paul; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    This course will cover practical applications of the energy-dispersive spectrometer (EDS) to x-ray microanalysis. Topics covered will include detector technology, advances in pulse processing, resolution and performance monitoring, detector modeling, peak deconvolution and fitting, qualitative and quantitative analysis, compositional mapping, and standards. An emphasis will be placed on use of the EDS for quantitative analysis, with discussion of typical problems encountered in the analysis of a wide range of materials and sample geometries.

  12. Quantitative analysis of dynamic association in live biological fluorescent samples.

    PubMed

    Ruusuvuori, Pekka; Paavolainen, Lassi; Rutanen, Kalle; Mäki, Anita; Huttunen, Heikki; Marjomäki, Varpu

    2014-01-01

    Determining vesicle localization and association in live microscopy may be challenging due to non-simultaneous imaging of rapidly moving objects with two excitation channels. Besides errors due to movement of objects, imaging may also introduce shifting between the image channels, and traditional colocalization methods cannot handle such situations. Our approach to quantifying the association between tagged proteins is to use an object-based method where the exact match of object locations is not assumed. Point-pattern matching provides a measure of correspondence between two point-sets under various changes between the sets. Thus, it can be used for robust quantitative analysis of vesicle association between image channels. Results for a large set of synthetic images shows that the novel association method based on point-pattern matching demonstrates robust capability to detect association of closely located vesicles in live cell-microscopy where traditional colocalization methods fail to produce results. In addition, the method outperforms compared Iterated Closest Points registration method. Results for fixed and live experimental data shows the association method to perform comparably to traditional methods in colocalization studies for fixed cells and to perform favorably in association studies for live cells.

  13. Quantitative, Qualitative and Geospatial Methods to Characterize HIV Risk Environments

    PubMed Central

    Conners, Erin E.; West, Brooke S.; Roth, Alexis M.; Meckel-Parker, Kristen G.; Kwan, Mei-Po; Magis-Rodriguez, Carlos; Staines-Orozco, Hugo; Clapp, John D.; Brouwer, Kimberly C.

    2016-01-01

    Increasingly, ‘place’, including physical and geographical characteristics as well as social meanings, is recognized as an important factor driving individual and community health risks. This is especially true among marginalized populations in low and middle income countries (LMIC), whose environments may also be more difficult to study using traditional methods. In the NIH-funded longitudinal study Mapa de Salud, we employed a novel approach to exploring the risk environment of female sex workers (FSWs) in two Mexico/U.S. border cities, Tijuana and Ciudad Juárez. In this paper we describe the development, implementation, and feasibility of a mix of quantitative and qualitative tools used to capture the HIV risk environments of FSWs in an LMIC setting. The methods were: 1) Participatory mapping; 2) Quantitative interviews; 3) Sex work venue field observation; 4) Time-location-activity diaries; 5) In-depth interviews about daily activity spaces. We found that the mixed-methodology outlined was both feasible to implement and acceptable to participants. These methods can generate geospatial data to assess the role of the environment on drug and sexual risk behaviors among high risk populations. Additionally, the adaptation of existing methods for marginalized populations in resource constrained contexts provides new opportunities for informing public health interventions. PMID:27191846

  14. Quantitative, Qualitative and Geospatial Methods to Characterize HIV Risk Environments.

    PubMed

    Conners, Erin E; West, Brooke S; Roth, Alexis M; Meckel-Parker, Kristen G; Kwan, Mei-Po; Magis-Rodriguez, Carlos; Staines-Orozco, Hugo; Clapp, John D; Brouwer, Kimberly C

    2016-01-01

    Increasingly, 'place', including physical and geographical characteristics as well as social meanings, is recognized as an important factor driving individual and community health risks. This is especially true among marginalized populations in low and middle income countries (LMIC), whose environments may also be more difficult to study using traditional methods. In the NIH-funded longitudinal study Mapa de Salud, we employed a novel approach to exploring the risk environment of female sex workers (FSWs) in two Mexico/U.S. border cities, Tijuana and Ciudad Juárez. In this paper we describe the development, implementation, and feasibility of a mix of quantitative and qualitative tools used to capture the HIV risk environments of FSWs in an LMIC setting. The methods were: 1) Participatory mapping; 2) Quantitative interviews; 3) Sex work venue field observation; 4) Time-location-activity diaries; 5) In-depth interviews about daily activity spaces. We found that the mixed-methodology outlined was both feasible to implement and acceptable to participants. These methods can generate geospatial data to assess the role of the environment on drug and sexual risk behaviors among high risk populations. Additionally, the adaptation of existing methods for marginalized populations in resource constrained contexts provides new opportunities for informing public health interventions.

  15. A New Kinetic Spectrophotometric Method for the Quantitation of Amorolfine.

    PubMed

    Soto, César; Poza, Cristian; Contreras, David; Yáñez, Jorge; Nacaratte, Fallon; Toral, M Inés

    2017-01-01

    Amorolfine (AOF) is a compound with fungicide activity based on the dual inhibition of growth of the fungal cell membrane, the biosynthesis and accumulation of sterols, and the reduction of ergosterol. In this work a sensitive kinetic and spectrophotometric method for the AOF quantitation based on the AOF oxidation by means of KMnO4 at 30 min (fixed time), pH alkaline, and ionic strength controlled was developed. Measurements of changes in absorbance at 610 nm were used as criterion of the oxidation progress. In order to maximize the sensitivity, different experimental reaction parameters were carefully studied via factorial screening and optimized by multivariate method. The linearity, intraday, and interday assay precision and accuracy were determined. The absorbance-concentration plot corresponding to tap water spiked samples was rectilinear, over the range of 7.56 × 10(-6)-3.22 × 10(-5) mol L(-1), with detection and quantitation limits of 2.49 × 10(-6) mol L(-1) and 7.56 × 10(-6) mol L(-1), respectively. The proposed method was successfully validated for the application of the determination of the drug in the spiked tap water samples and the percentage recoveries were 94.0-105.0%. The method is simple and does not require expensive instruments or complicated extraction steps of the reaction product.

  16. A New Kinetic Spectrophotometric Method for the Quantitation of Amorolfine

    PubMed Central

    Poza, Cristian; Contreras, David; Yáñez, Jorge; Nacaratte, Fallon; Toral, M. Inés

    2017-01-01

    Amorolfine (AOF) is a compound with fungicide activity based on the dual inhibition of growth of the fungal cell membrane, the biosynthesis and accumulation of sterols, and the reduction of ergosterol. In this work a sensitive kinetic and spectrophotometric method for the AOF quantitation based on the AOF oxidation by means of KMnO4 at 30 min (fixed time), pH alkaline, and ionic strength controlled was developed. Measurements of changes in absorbance at 610 nm were used as criterion of the oxidation progress. In order to maximize the sensitivity, different experimental reaction parameters were carefully studied via factorial screening and optimized by multivariate method. The linearity, intraday, and interday assay precision and accuracy were determined. The absorbance-concentration plot corresponding to tap water spiked samples was rectilinear, over the range of 7.56 × 10−6–3.22 × 10−5 mol L−1, with detection and quantitation limits of 2.49 × 10−6 mol L−1 and 7.56 × 10−6 mol L−1, respectively. The proposed method was successfully validated for the application of the determination of the drug in the spiked tap water samples and the percentage recoveries were 94.0–105.0%. The method is simple and does not require expensive instruments or complicated extraction steps of the reaction product. PMID:28348920

  17. Validation of PCR methods for quantitation of genetically modified plants in food.

    PubMed

    Hübner, P; Waiblinger, H U; Pietsch, K; Brodmann, P

    2001-01-01

    For enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients, quantitative detection methods such as quantitative competitive (QC-PCR) and real-time PCR are applied by official food control laboratories. The experiences of 3 European food control laboratories in validating such methods were compared to describe realistic performance characteristics of quantitative PCR detection methods. The limit of quantitation (LOQ) of GMO-specific, real-time PCR was experimentally determined to reach 30-50 target molecules, which is close to theoretical prediction. Starting PCR with 200 ng genomic plant DNA, the LOQ depends primarily on the genome size of the target plant and ranges from 0.02% for rice to 0.7% for wheat. The precision of quantitative PCR detection methods, expressed as relative standard deviation (RSD), varied from 10 to 30%. Using Bt176 corn containing test samples and applying Bt176 specific QC-PCR, mean values deviated from true values by -7to 18%, with an average of 2+/-10%. Ruggedness of real-time PCR detection methods was assessed in an interlaboratory study analyzing commercial, homogeneous food samples. Roundup Ready soybean DNA contents were determined in the range of 0.3 to 36%, relative to soybean DNA, with RSDs of about 25%. Taking the precision of quantitative PCR detection methods into account, suitable sample plans and sample sizes for GMO analysis are suggested. Because quantitative GMO detection methods measure GMO contents of samples in relation to reference material (calibrants), high priority must be given to international agreements and standardization on certified reference materials.

  18. Quantitative analysis of gallstones using laser-induced breakdown spectroscopy

    SciTech Connect

    Singh, Vivek K.; Singh, Vinita; Rai, Awadhesh K.; Thakur, Surya N.; Rai, Pradeep K.; Singh, Jagdish P

    2008-11-01

    The utility of laser-induced breakdown spectroscopy (LIBS) for categorizing different types of gallbladder stone has been demonstrated by analyzing their major and minor constituents. LIBS spectra of three types of gallstone have been recorded in the 200-900 nm spectral region. Calcium is found to be the major element in all types of gallbladder stone. The spectrophotometric method has been used to classify the stones. A calibration-free LIBS method has been used for the quantitative analysis of metal elements, and the results have been compared with those obtained from inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurements. The single-shot LIBS spectra from different points on the cross section (in steps of 0.5 mm from one end to the other) of gallstones have also been recorded to study the variation of constituents from the center to the surface. The presence of different metal elements and their possible role in gallstone formation is discussed.

  19. Automatic analysis of quantitative NMR data of pharmaceutical compound libraries.

    PubMed

    Liu, Xuejun; Kolpak, Michael X; Wu, Jiejun; Leo, Gregory C

    2012-08-07

    In drug discovery, chemical library compounds are usually dissolved in DMSO at a certain concentration and then distributed to biologists for target screening. Quantitative (1)H NMR (qNMR) is the preferred method for the determination of the actual concentrations of compounds because the relative single proton peak areas of two chemical species represent the relative molar concentrations of the two compounds, that is, the compound of interest and a calibrant. Thus, an analyte concentration can be determined using a calibration compound at a known concentration. One particularly time-consuming step in the qNMR analysis of compound libraries is the manual integration of peaks. In this report is presented an automated method for performing this task without prior knowledge of compound structures and by using an external calibration spectrum. The script for automated integration is fast and adaptable to large-scale data sets, eliminating the need for manual integration in ~80% of the cases.

  20. Quantitative cell imaging using single beam phase retrieval method

    NASA Astrophysics Data System (ADS)

    Anand, Arun; Chhaniwal, Vani; Javidi, Bahram

    2011-06-01

    Quantitative three-dimensional imaging of cells can provide important information about their morphology as well as their dynamics, which will be useful in studying their behavior under various conditions. There are several microscopic techniques to image unstained, semi-transparent specimens, by converting the phase information into intensity information. But most of the quantitative phase contrast imaging techniques is realized either by using interference of the object wavefront with a known reference beam or using phase shifting interferometry. A two-beam interferometric method is challenging to implement especially with low coherent sources and it also requires a fine adjustment of beams to achieve high contrast fringes. In this letter, the development of a single beam phase retrieval microscopy technique for quantitative phase contrast imaging of cells using multiple intensity samplings of a volume speckle field in the axial direction is described. Single beam illumination with multiple intensity samplings provides fast convergence and a unique solution of the object wavefront. Three-dimensional thickness profiles of different cells such as red blood cells and onion skin cells were reconstructed using this technique with an axial resolution of the order of several nanometers.

  1. Quantitative analysis in outcome assessment of instrumented lumbosacral arthrodesis.

    PubMed

    Champain, Sabina; Mazel, Christian; Mitulescu, Anca; Skalli, Wafa

    2007-08-01

    The outcome assessment in instrumented lumbosacral fusion mostly focuses on clinical criteria, complications and scores, with a high variability of imaging means, methods of fusion grading and parameters describing degenerative changes, making comparisons between studies difficult. The aim of this retrospective evaluation was to evaluate the interest of quantified radiographic analysis of lumbar spine in global outcome assessment and to highlight the key biomechanical factors involved. Clinical data and Beaujon-Lassale scores were collected for 49 patients who underwent lumbosacral arthrodesis after prior lumbar discectomy (mean follow-up: 5 years). Sagittal standing and lumbar flexion-extension X-ray films allowed quantifying vertebral, lumbar, pelvic and kinematic parameters of the lumbar spine, which were compared to reference values. Statistics were performed to assess evolution for all variables. At long-term follow-up, 90% of patients presented satisfactory clinical outcomes, associated to normal sagittal alignment; vertebral parameters objectified adjacent level degeneration in four cases (8%). Clinical outcome was correlated (r = 0.8) with fusion that was confirmed in 80% of cases, doubtful in 16% and pseudarthrosis seemed to occur in 4% (2) of cases. In addition to clinical data (outcomes comparable to the literature), quantitative analysis accurately described lumbar spine geometry and kinematics, highlighting parameters related to adjacent level's degeneration and a significant correlation between clinical outcome and fusion. Furthermore, criteria proposed to quantitatively evaluate fusion from lumbar dynamic radiographs seem to be appropriate and in agreement with surgeon's qualitative grading in 87% of cases.

  2. Quantitative analysis of live cells using digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Lewis, Tan Rongwei; Qu, Weijuan; Chee, Oi Choo; Singh, Vijay Raj; Asundi, Anand

    2010-03-01

    During the life time of a cell, it goes through changes to the plasma membrane as well as its internal structures especially distinctive during processes like cell division and death. Different types of microscope are used to fulfill the observation of the cell's variation. In our experiment, Vero cells have been investigated by using phase contrast microscopy and digital holographic microscopy (DHM). A comparison of the images obtained for cell division is presented here. The conventional phase contrast microscope provided a good imaging method in the real time analysis of cell division. The off-axis digital hologram recorded by the DHM system can be reconstructed to obtain both the intensity image and phase contrast image of the test object. These can be used for live cell imaging to provide multiple results from a single equipment setup. The DHM system, besides being a qualitative tool, is able to provide quantitative results and 3D images of the cell division process. The ability of DHM to provide quantitative analysis makes it an ideal tool for life science applications.

  3. Quantitative analysis of live cells using digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Lewis, Tan Rongwei; Qu, Weijuan; Chee, Oi Choo; Singh, Vijay Raj; Asundi, Anand

    2009-12-01

    During the life time of a cell, it goes through changes to the plasma membrane as well as its internal structures especially distinctive during processes like cell division and death. Different types of microscope are used to fulfill the observation of the cell's variation. In our experiment, Vero cells have been investigated by using phase contrast microscopy and digital holographic microscopy (DHM). A comparison of the images obtained for cell division is presented here. The conventional phase contrast microscope provided a good imaging method in the real time analysis of cell division. The off-axis digital hologram recorded by the DHM system can be reconstructed to obtain both the intensity image and phase contrast image of the test object. These can be used for live cell imaging to provide multiple results from a single equipment setup. The DHM system, besides being a qualitative tool, is able to provide quantitative results and 3D images of the cell division process. The ability of DHM to provide quantitative analysis makes it an ideal tool for life science applications.

  4. Geographical classification of Epimedium based on HPLC fingerprint analysis combined with multi-ingredients quantitative analysis.

    PubMed

    Xu, Ning; Zhou, Guofu; Li, Xiaojuan; Lu, Heng; Meng, Fanyun; Zhai, Huaqiang

    2017-05-01

    A reliable and comprehensive method for identifying the origin and assessing the quality of Epimedium has been developed. The method is based on analysis of HPLC fingerprints, combined with similarity analysis, hierarchical cluster analysis (HCA), principal component analysis (PCA) and multi-ingredient quantitative analysis. Nineteen batches of Epimedium, collected from different areas in the western regions of China, were used to establish the fingerprints and 18 peaks were selected for the analysis. Similarity analysis, HCA and PCA all classified the 19 areas into three groups. Simultaneous quantification of the five major bioactive ingredients in the Epimedium samples was also carried out to confirm the consistency of the quality tests. These methods were successfully used to identify the geographical origin of the Epimedium samples and to evaluate their quality.

  5. Qualitative and quantitative analysis of endocytic recycling.

    PubMed

    Reineke, James B; Xie, Shuwei; Naslavsky, Naava; Caplan, Steve

    2015-01-01

    Endocytosis, which encompasses the internalization and sorting of plasma membrane (PM) lipids and proteins to distinct membrane-bound intracellular compartments, is a highly regulated and fundamental cellular process by which eukaryotic cells dynamically regulate their PM composition. Indeed, endocytosis is implicated in crucial cellular processes that include proliferation, migration, and cell division as well as maintenance of tissue homeostasis such as apical-basal polarity. Once PM constituents have been taken up into the cell, either via clathrin-dependent endocytosis (CDE) or clathrin-independent endocytosis (CIE), they typically have two fates: degradation through the late-endosomal/lysosomal pathway or returning to the PM via endocytic recycling pathways. In this review, we will detail experimental procedures that allow for both qualitative and quantitative assessment of endocytic recycling of transmembrane proteins internalized by CDE and CIE, using the HeLa cervical cancer cell line as a model system.

  6. Automatic quantitative analysis of cardiac MR perfusion images

    NASA Astrophysics Data System (ADS)

    Breeuwer, Marcel M.; Spreeuwers, Luuk J.; Quist, Marcel J.

    2001-07-01

    Magnetic Resonance Imaging (MRI) is a powerful technique for imaging cardiovascular diseases. The introduction of cardiovascular MRI into clinical practice is however hampered by the lack of efficient and accurate image analysis methods. This paper focuses on the evaluation of blood perfusion in the myocardium (the heart muscle) from MR images, using contrast-enhanced ECG-triggered MRI. We have developed an automatic quantitative analysis method, which works as follows. First, image registration is used to compensate for translation and rotation of the myocardium over time. Next, the boundaries of the myocardium are detected and for each position within the myocardium a time-intensity profile is constructed. The time interval during which the contrast agent passes for the first time through the left ventricle and the myocardium is detected and various parameters are measured from the time-intensity profiles in this interval. The measured parameters are visualized as color overlays on the original images. Analysis results are stored, so that they can later on be compared for different stress levels of the heart. The method is described in detail in this paper and preliminary validation results are presented.

  7. Investigating the performance of in situ quantitative nuclear magnetic resonance analysis and applying the method to determine the distribution of saccharides in various parts of carrot roots (Daucus carota L.).

    PubMed

    Bauchard, Elsa; This, Hervé

    2015-01-01

    In order to explore the performance of the analytical method called in situ quantitative nuclear magnetic resonance spectroscopy - is q NMR - the distribution of glucose, fructose and sucrose in various parts of a carrot root (Daucus carota L.) - primary xylem, secondary xylem, phloem, cortex; top part and lower part - was determined. The influence on the quality of spectra of drying samples before analysis was studied, as well as the influence of the length of strips of tissue used in analysis. Finally samples as small as 240 mm(3) could be studied directly, with minimum prior treatment (only drying), along with deuterated water for locking and a sealed capillary tube containing a solution of 0.5% of the sodium salt of (trimethylsilyl)propionic-2,2,3,3-d4 acid, used both as an internal reference and for quantification. With optimized parameters, the coefficients of variation for measurements were observed to have an average value of 0.038, with a standard deviation of 0.047.

  8. Biological characteristics of crucian by quantitative inspection method

    NASA Astrophysics Data System (ADS)

    Chu, Mengqi

    2015-04-01

    Biological characteristics of crucian by quantitative inspection method Through quantitative inspection method , the biological characteristics of crucian was preliminary researched. Crucian , Belongs to Cypriniformes, Cyprinidae, Carassius auratus, is a kind of main plant-eating omnivorous fish,like Gregarious, selection and ranking. Crucian are widely distributed, perennial water all over the country all have production. Determine the indicators of crucian in the experiment, to understand the growth, reproduction situation of crucian in this area . Using the measured data (such as the scale length ,scale size and wheel diameter and so on) and related functional to calculate growth of crucian in any one year.According to the egg shape, color, weight ,etc to determine its maturity, with the mean egg diameter per 20 eggs and the number of eggs per 0.5 grams, to calculate the relative and absolute fecundity of the fish .Measured crucian were female puberty. Based on the relation between the scale diameter and length and the information, linear relationship between crucian scale diameter and length: y=1.530+3.0649. From the data, the fertility and is closely relative to the increase of age. The older, the more mature gonad development. The more amount of eggs. In addition, absolute fecundity increases with the pituitary gland.Through quantitative check crucian bait food intake by the object, reveals the main food, secondary foods, and chance food of crucian ,and understand that crucian degree of be fond of of all kinds of bait organisms.Fish fertility with weight gain, it has the characteristics of species and populations, and at the same tmes influenced by the age of the individual, body length, body weight, environmental conditions (especially the nutrition conditions), and breeding habits, spawning times factors and the size of the egg. After a series of studies of crucian biological character, provide the ecological basis for local crucian's feeding, breeding

  9. [Quantitative and qualitative research methods, can they coexist yet?].

    PubMed

    Hunt, Elena; Lavoie, Anne-Marise

    2011-06-01

    Qualitative design is gaining ground in Nursing research. In spite of a relative progress however, the evidence based practice movement continues to dominate and to underline the exclusive value of quantitative design (particularly that of randomized clinical trials) for clinical decision making. In the actual context convenient to those in power making utilitarian decisions on one hand, and facing nursing criticism of the establishment in favor of qualitative research on the other hand, it is difficult to chose a practical and ethical path that values the nursing role within the health care system, keeping us committed to quality care and maintaining researcher's integrity. Both qualitative and quantitative methods have advantages and disadvantages, and clearly, none of them can, by itself, capture, describe and explain reality adequately. Therefore, a balance between the two methods is needed. Researchers bare responsibility to society and science, and they should opt for the appropriate design susceptible to answering the research question, not promote the design favored by the research funding distributors.

  10. DREAM: a method for semi-quantitative dermal exposure assessment.

    PubMed

    Van-Wendel-de-Joode, Berna; Brouwer, Derk H; Vermeulen, Roel; Van Hemmen, Joop J; Heederik, Dick; Kromhout, Hans

    2003-01-01

    This paper describes a new method (DREAM) for structured, semi-quantitative dermal exposure assessment for chemical or biological agents that can be used in occupational hygiene or epidemiology. It is anticipated that DREAM could serve as an initial assessment of dermal exposure, amongst others, resulting in a ranking of tasks and subsequently jobs. DREAM consists of an inventory and evaluation part. Two examples of dermal exposure of workers of a car-construction company show that DREAM characterizes tasks and gives insight into exposure mechanisms, forming a basis for systematic exposure reduction. DREAM supplies estimates for exposure levels on the outside clothing layer as well as on skin, and provides insight into the distribution of dermal exposure over the body. Together with the ranking of tasks and people, this provides information for measurement strategies and helps to determine who, where and what to measure. In addition to dermal exposure assessment, the systematic description of dermal exposure pathways helps to prioritize and determine most adequate measurement strategies and methods. DREAM could be a promising approach for structured, semi-quantitative, dermal exposure assessment.

  11. Quantitative Analysis of HIV-1 Preintegration Complexes

    PubMed Central

    Engelman, Alan; Oztop, Ilker; Vandegraaff, Nick; Raghavendra, Nidhanapati K.

    2009-01-01

    Retroviral replication proceeds through the formation of a provirus, an integrated DNA copy of the viral RNA genome. The linear cDNA product of reverse transcription is the integration substrate and two different integrase activities, 3′ processing and DNA strand transfer, are required for provirus formation. Integrase nicks the cDNA ends adjacent to phylogenetically-conserved CA dinucleotides during 3′ processing. After nuclear entry and locating a suitable chromatin acceptor site, integrase joins the recessed 3′-OHs to the 5′-phosphates of a double-stranded staggered cut in the DNA target. Integrase functions in the context of a large nucleoprotein complex, called the preintegration complex (PIC), and PICs are analyzed to determine levels of integrase 3′ processing and DNA strand transfer activities that occur during acute virus infection. Denatured cDNA end regions are monitored by indirect end-labeling to measure the extent of 3′ processing. Native PICs can efficiently integrate their viral cDNA into exogenously added target DNA in vitro, and Southern blotting or nested PCR assays are used to quantify the resultant DNA strand transfer activity. This study details HIV-1 infection, PIC extraction, partial purification, and quantitative analyses of integrase 3′ processing and DNA strand transfer activities. PMID:19233280

  12. Quantitative multi-modal NDT data analysis

    SciTech Connect

    Heideklang, René; Shokouhi, Parisa

    2014-02-18

    A single NDT technique is often not adequate to provide assessments about the integrity of test objects with the required coverage or accuracy. In such situations, it is often resorted to multi-modal testing, where complementary and overlapping information from different NDT techniques are combined for a more comprehensive evaluation. Multi-modal material and defect characterization is an interesting task which involves several diverse fields of research, including signal and image processing, statistics and data mining. The fusion of different modalities may improve quantitative nondestructive evaluation by effectively exploiting the augmented set of multi-sensor information about the material. It is the redundant information in particular, whose quantification is expected to lead to increased reliability and robustness of the inspection results. There are different systematic approaches to data fusion, each with its specific advantages and drawbacks. In our contribution, these will be discussed in the context of nondestructive materials testing. A practical study adopting a high-level scheme for the fusion of Eddy Current, GMR and Thermography measurements on a reference metallic specimen with built-in grooves will be presented. Results show that fusion is able to outperform the best single sensor regarding detection specificity, while retaining the same level of sensitivity.

  13. Novel method for the quantitative measurement of color vision deficiencies

    NASA Astrophysics Data System (ADS)

    Xiong, Kai; Hou, Minxian; Ye, Guanrong

    2005-01-01

    The method is based on chromatic visual evoked potential (VEP) measurement. The equiluminance of color stimulus in normal subjects is characterized by L-cone and M-cone activation in retina. For the deuteranopes and protanopes, only the activations of one relevant remaining cone type should be considered. The equiluminance turning curve was established for the recorded VEPs of the luminance changes of the red and green color stimulus, and the position of the equiluminance was used to define the kind and degree of color vision deficiencies. In the test of 47 volunteers, we got the VEP traces and the equiluminance turning curves, which was in accordance with the judgment by the pseudoisochromatic plate used in clinic. The method fulfills the impersonal and quantitative requirements in color vision deficiencies test.

  14. Validated LC-MS/MS analysis of immune checkpoint inhibitor Nivolumab in human plasma using a Fab peptide-selective quantitation method: nano-surface and molecular-orientation limited (nSMOL) proteolysis.

    PubMed

    Iwamoto, Noriko; Shimada, Takashi; Terakado, Hiroyuki; Hamada, Akinobu

    2016-06-15

    We previously reported the nano-surface and molecular-orientation limited (nSMOL) proteolysis, which is a novel method for selective quantitation of monoclonal antibody Fab. The nSMOL strategy is a Fab-selective limited proteolysis which utilizes the size difference between the protease nanoparticle (200nm) and the antibody resin pore (100nm). Here, we applied this method to a fully validated LCMS analysis of Nivolumab in human plasma. The immunoglobulin fraction was collected using Protein A resin, which was then followed by nSMOL reaction using the FG nanoparticle surface-immobilized trypsin under a nondenaturing physiological condition at 50°C for 7h. After removal of resin and nanoparticles by filter centrifugation, signature peptides were separated using the ODS column liquid chromatography. The signature peptide ASGITFSNSGMHWVR from Nivolumab complementarity-determining region (CDR) and the P14R internal standard were simultaneously quantified by multiple-reaction monitoring (MRM) LCMS, with parent m/z 550.8>fragment m/z 661.5 (y11 2+). The lower limit of quantification (LLOQ) of Nivolumab using the nSMOL method was 0.977μg/ml, with a linear dynamic range of from 0.977 to 250μg/ml. The intra- and inter-assay precision of LLOQ, low quality control (LQC), middle quality control (MQC), and high quality control (HQC) were 7.56-17.9% and 15.6%, 6.99-9.25% and 7.51%, 2.51-8.85% and 8.01%, and 4.78-7.33% and 6.75%, respectively. Our study demonstrates that the nSMOL bioanalysis can be utilized as a reliable method for clinical pharmacokinetic studies of Nivolumab and other antibody drugs.

  15. Quantitative measurement of speech sound distortions with the aid of minimum variance spectral estimation method for dentistry use.

    PubMed

    Bereteu, L; Drăgănescu, G E; Stănescu, D; Sinescu, C

    2011-12-01

    In this paper, we search an adequate quantitative method based on minimum variance spectral analysis in order to reflect the dependence of the speech quality on the correct positioning of the dental prostheses. We also search some quantitative parameters, which reflect the correct position of dental prostheses in a sensitive manner.

  16. An approach for quantitative image quality analysis for CT

    NASA Astrophysics Data System (ADS)

    Rahimi, Amir; Cochran, Joe; Mooney, Doug; Regensburger, Joe

    2016-03-01

    An objective and standardized approach to assess image quality of Compute Tomography (CT) systems is required in a wide variety of imaging processes to identify CT systems appropriate for a given application. We present an overview of the framework we have developed to help standardize and to objectively assess CT image quality for different models of CT scanners used for security applications. Within this framework, we have developed methods to quantitatively measure metrics that should correlate with feature identification, detection accuracy and precision, and image registration capabilities of CT machines and to identify strengths and weaknesses in different CT imaging technologies in transportation security. To that end we have designed, developed and constructed phantoms that allow for systematic and repeatable measurements of roughly 88 image quality metrics, representing modulation transfer function, noise equivalent quanta, noise power spectra, slice sensitivity profiles, streak artifacts, CT number uniformity, CT number consistency, object length accuracy, CT number path length consistency, and object registration. Furthermore, we have developed a sophisticated MATLAB based image analysis tool kit to analyze CT generated images of phantoms and report these metrics in a format that is standardized across the considered models of CT scanners, allowing for comparative image quality analysis within a CT model or between different CT models. In addition, we have developed a modified sparse principal component analysis (SPCA) method to generate a modified set of PCA components as compared to the standard principal component analysis (PCA) with sparse loadings in conjunction with Hotelling T2 statistical analysis method to compare, qualify, and detect faults in the tested systems.

  17. A quantitative risk analysis approach to port hydrocarbon logistics.

    PubMed

    Ronza, A; Carol, S; Espejo, V; Vílchez, J A; Arnaldos, J

    2006-01-16

    A method is presented that allows quantitative risk analysis to be performed on marine hydrocarbon terminals sited in ports. A significant gap was identified in the technical literature on QRA for the handling of hazardous materials in harbours published prior to this work. The analysis is extended to tanker navigation through port waters and loading and unloading facilities. The steps of the method are discussed, beginning with data collecting. As to accident scenario identification, an approach is proposed that takes into account minor and massive spills due to loading arm failures and tank rupture. Frequency estimation is thoroughly reviewed and a shortcut approach is proposed for frequency calculation. This allows for the two-fold possibility of a tanker colliding/grounding at/near the berth or while navigating to/from the berth. A number of probability data defining the possibility of a cargo spill after an external impact on a tanker are discussed. As to consequence and vulnerability estimates, a scheme is proposed for the use of ratios between the numbers of fatal victims, injured and evacuated people. Finally, an example application is given, based on a pilot study conducted in the Port of Barcelona, where the method was tested.

  18. Quantitative Analysis of Peripheral Tissue Perfusion Using Spatiotemporal Molecular Dynamics

    PubMed Central

    Lee, Jungsul; Koh, Gou Young; Kwon, Kihwan; Choi, Chulhee

    2009-01-01

    Background Accurate measurement of peripheral tissue perfusion is challenging but necessary to diagnose peripheral vascular insufficiency. Because near infrared (NIR) radiation can penetrate relatively deep into tissue, significant attention has been given to intravital NIR fluorescence imaging. Methodology/Principal Findings We developed a new optical imaging-based strategy for quantitative measurement of peripheral tissue perfusion by time-series analysis of local pharmacokinetics of the NIR fluorophore, indocyanine green (ICG). Time-series NIR fluorescence images were obtained after injecting ICG intravenously in a murine hindlimb ischemia model. Mathematical modeling and computational simulations were used for translating time-series ICG images into quantitative pixel perfusion rates and a perfusion map. We could successfully predict the prognosis of ischemic hindlimbs based on the perfusion profiles obtained immediately after surgery, which were dependent on the preexisting collaterals. This method also reflected increases in perfusion and improvements in prognosis of ischemic hindlimbs induced by treatment with vascular endothelial growth factor and COMP-angiopoietin-1. Conclusions/Significance We propose that this novel NIR-imaging-based strategy is a powerful tool for biomedical studies related to the evaluation of therapeutic interventions directed at stimulating angiogenesis. PMID:19169354

  19. The quantitative failure of human reliability analysis

    SciTech Connect

    Bennett, C.T.

    1995-07-01

    This philosophical treatise argues the merits of Human Reliability Analysis (HRA) in the context of the nuclear power industry. Actually, the author attacks historic and current HRA as having failed in informing policy makers who make decisions based on risk that humans contribute to systems performance. He argues for an HRA based on Bayesian (fact-based) inferential statistics, which advocates a systems analysis process that employs cogent heuristics when using opinion, and tempers itself with a rational debate over the weight given subjective and empirical probabilities.

  20. Functional Linear Models for Association Analysis of Quantitative Traits

    PubMed Central

    Fan, Ruzong; Wang, Yifan; Mills, James L.; Wilson, Alexander F.; Bailey-Wilson, Joan E.; Xiong, Momiao

    2014-01-01

    Functional linear models are developed in this paper for testing associations between quantitative traits and genetic variants, which can be rare variants or common variants or the combination of the two. By treating multiple genetic variants of an individual in a human population as a realization of a stochastic process, the genome of an individual in a chromosome region is a continuum of sequence data rather than discrete observations. The genome of an individual is viewed as a stochastic function that contains both linkage and linkage disequilibrium (LD) information of the genetic markers. By using techniques of functional data analysis, both fixed and mixed effect functional linear models are built to test the association between quantitative traits and genetic variants adjusting for covariates. After extensive simulation analysis, it is shown that the F-distributed tests of the proposed fixed effect functional linear models have higher power than that of sequence kernel association test (SKAT) and its optimal unified test (SKAT-O) for three scenarios in most cases: (1) the causal variants are all rare, (2) the causal variants are both rare and common, and (3) the causal variants are common. The superior performance of the fixed effect functional linear models is most likely due to its optimal utilization of both genetic linkage and LD information of multiple genetic variants in a genome and similarity among different individuals, while SKAT and SKAT-O only model the similarities and pairwise LD but do not model linkage and higher order LD information sufficiently. In addition, the proposed fixed effect models generate accurate type I error rates in simulation studies. We also show that the functional kernel score tests of the proposed mixed effect functional linear models are preferable in candidate gene analysis and small sample problems. The methods are applied to analyze three biochemical traits in data from the Trinity Students Study. PMID:24130119

  1. Quantitative Analysis of Single-Molecule RNA-Protein Interaction

    PubMed Central

    Fuhrmann, Alexander; Schoening, Jan C.; Anselmetti, Dario; Staiger, Dorothee; Ros, Robert

    2009-01-01

    Abstract RNA-binding proteins impact gene expression at the posttranscriptional level by interacting with cognate cis elements within the transcripts. Here, we apply dynamic single-molecule force spectroscopy to study the interaction of the Arabidopsis glycine-rich RNA-binding protein AtGRP8 with its RNA target. A dwell-time-dependent analysis of the single-molecule data in combination with competition assays and site-directed mutagenesis of both the RNA target and the RNA-binding domain of the protein allowed us to distinguish and quantify two different binding modes. For dwell times <0.21 s an unspecific complex with a lifetime of 0.56 s is observed, whereas dwell times >0.33 s result in a specific interaction with a lifetime of 208 s. The corresponding reaction lengths are 0.28 nm for the unspecific and 0.55 nm for the specific AtGRP8-RNA interactions, indicating formation of a tighter complex with increasing dwell time. These two binding modes cannot be dissected in ensemble experiments. Quantitative titration in RNA bandshift experiments yields an ensemble-averaged equilibrium constant of dissociation of KD = 2 × 10−7 M. Assuming comparable on-rates for the specific and nonspecific binding modes allows us to estimate their free energies as ΔG0 = −42 kJ/mol and ΔG0 = −28 kJ/mol for the specific and nonspecific binding modes, respectively. Thus, we show that single-molecule force spectroscopy with a refined statistical analysis is a potent tool for the analysis of protein-RNA interactions without the drawback of ensemble averaging. This makes it possible to discriminate between different binding modes or sites and to analyze them quantitatively. We propose that this method could be applied to complex interactions of biomolecules in general, and be of particular interest for the investigation of multivalent binding reactions. PMID:19527663

  2. Functional linear models for association analysis of quantitative traits.

    PubMed

    Fan, Ruzong; Wang, Yifan; Mills, James L; Wilson, Alexander F; Bailey-Wilson, Joan E; Xiong, Momiao

    2013-11-01

    Functional linear models are developed in this paper for testing associations between quantitative traits and genetic variants, which can be rare variants or common variants or the combination of the two. By treating multiple genetic variants of an individual in a human population as a realization of a stochastic process, the genome of an individual in a chromosome region is a continuum of sequence data rather than discrete observations. The genome of an individual is viewed as a stochastic function that contains both linkage and linkage disequilibrium (LD) information of the genetic markers. By using techniques of functional data analysis, both fixed and mixed effect functional linear models are built to test the association between quantitative traits and genetic variants adjusting for covariates. After extensive simulation analysis, it is shown that the F-distributed tests of the proposed fixed effect functional linear models have higher power than that of sequence kernel association test (SKAT) and its optimal unified test (SKAT-O) for three scenarios in most cases: (1) the causal variants are all rare, (2) the causal variants are both rare and common, and (3) the causal variants are common. The superior performance of the fixed effect functional linear models is most likely due to its optimal utilization of both genetic linkage and LD information of multiple genetic variants in a genome and similarity among different individuals, while SKAT and SKAT-O only model the similarities and pairwise LD but do not model linkage and higher order LD information sufficiently. In addition, the proposed fixed effect models generate accurate type I error rates in simulation studies. We also show that the functional kernel score tests of the proposed mixed effect functional linear models are preferable in candidate gene analysis and small sample problems. The methods are applied to analyze three biochemical traits in data from the Trinity Students Study.

  3. Quantitative analysis of the reconstruction performance of interpolants

    NASA Technical Reports Server (NTRS)

    Lansing, Donald L.; Park, Stephen K.

    1987-01-01

    The analysis presented provides a quantitative measure of the reconstruction or interpolation performance of linear, shift-invariant interpolants. The performance criterion is the mean square error of the difference between the sampled and reconstructed functions. The analysis is applicable to reconstruction algorithms used in image processing and to many types of splines used in numerical analysis and computer graphics. When formulated in the frequency domain, the mean square error clearly separates the contribution of the interpolation method from the contribution of the sampled data. The equations provide a rational basis for selecting an optimal interpolant; that is, one which minimizes the mean square error. The analysis has been applied to a selection of frequently used data splines and reconstruction algorithms: parametric cubic and quintic Hermite splines, exponential and nu splines (including the special case of the cubic spline), parametric cubic convolution, Keys' fourth-order cubic, and a cubic with a discontinuous first derivative. The emphasis in this paper is on the image-dependent case in which no a priori knowledge of the frequency spectrum of the sampled function is assumed.

  4. Quantitive and Sociological Analysis of Blog Networks

    NASA Astrophysics Data System (ADS)

    Bachnik, W.; Szymczyk, S.; Leszczynski, S.; Podsiadlo, R.; Rymszewicz, E.; Kurylo, L.; Makowiec, D.; Bykowska, B.

    2005-10-01

    This paper examines the emerging phenomenon of blogging, using three different Polish blogging services as the base of the research. Authors show that blog networks are sharing their characteristics with complex networks (gamma coefficients, small worlds, cliques, etc.). Elements of sociometric analysis were used to prove existence of some social structures in the blog networks.

  5. A novel semi-quantitative method for measuring tissue bleeding.

    PubMed

    Vukcevic, G; Volarevic, V; Raicevic, S; Tanaskovic, I; Milicic, B; Vulovic, T; Arsenijevic, S

    2014-03-01

    In this study, we describe a new semi-quantitative method for measuring the extent of bleeding in pathohistological tissue samples. To test our novel method, we recruited 120 female patients in their first trimester of pregnancy and divided them into three groups of 40. Group I was the control group, in which no dilation was applied. Group II was an experimental group, in which dilation was performed using classical mechanical dilators. Group III was also an experimental group, in which dilation was performed using a hydraulic dilator. Tissue samples were taken from the patients' cervical canals using a Novak's probe via energetic single-step curettage prior to any dilation in Group I and after dilation in Groups II and III. After the tissue samples were prepared, light microscopy was used to obtain microphotographs at 100x magnification. The surfaces affected by bleeding were measured in the microphotographs using the Autodesk AutoCAD 2009 program and its "polylines" function. The lines were used to mark the area around the entire sample (marked A) and to create "polyline" areas around each bleeding area on the sample (marked B). The percentage of the total area affected by bleeding was calculated using the formula: N = Bt x 100 / At where N is the percentage (%) of the tissue sample surface affected by bleeding, At (A total) is the sum of the surfaces of all of the tissue samples and Bt (B total) is the sum of all the surfaces affected by bleeding in all of the tissue samples. This novel semi-quantitative method utilizes the Autodesk AutoCAD 2009 program, which is simple to use and widely available, thereby offering a new, objective and precise approach to estimate the extent of bleeding in tissue samples.

  6. A method for the extraction and quantitation of phycoerythrin from algae

    NASA Technical Reports Server (NTRS)

    Stewart, D. E.

    1982-01-01

    A summary of a new technique for the extraction and quantitation of phycoerythrin (PHE) from algal samples is described. Results of analysis of four extracts representing three PHE types from algae including cryptomonad and cyanophyte types are presented. The method of extraction and an equation for quantitation are given. A graph showing the relationship of concentration and fluorescence units that may be used with samples fluorescing around 575-580 nm (probably dominated by cryptophytes in estuarine waters) and 560 nm (dominated by cyanophytes characteristics of the open ocean) is provided.

  7. Modeling conflict : research methods, quantitative modeling, and lessons learned.

    SciTech Connect

    Rexroth, Paul E.; Malczynski, Leonard A.; Hendrickson, Gerald A.; Kobos, Peter Holmes; McNamara, Laura A.

    2004-09-01

    This study investigates the factors that lead countries into conflict. Specifically, political, social and economic factors may offer insight as to how prone a country (or set of countries) may be for inter-country or intra-country conflict. Largely methodological in scope, this study examines the literature for quantitative models that address or attempt to model conflict both in the past, and for future insight. The analysis concentrates specifically on the system dynamics paradigm, not the political science mainstream approaches of econometrics and game theory. The application of this paradigm builds upon the most sophisticated attempt at modeling conflict as a result of system level interactions. This study presents the modeling efforts built on limited data and working literature paradigms, and recommendations for future attempts at modeling conflict.

  8. Quantitative analysis of airway abnormalities in CT

    NASA Astrophysics Data System (ADS)

    Petersen, Jens; Lo, Pechin; Nielsen, Mads; Edula, Goutham; Ashraf, Haseem; Dirksen, Asger; de Bruijne, Marleen

    2010-03-01

    A coupled surface graph cut algorithm for airway wall segmentation from Computed Tomography (CT) images is presented. Using cost functions that highlight both inner and outer wall borders, the method combines the search for both borders into one graph cut. The proposed method is evaluated on 173 manually segmented images extracted from 15 different subjects and shown to give accurate results, with 37% less errors than the Full Width at Half Maximum (FWHM) algorithm and 62% less than a similar graph cut method without coupled surfaces. Common measures of airway wall thickness such as the Interior Area (IA) and Wall Area percentage (WA%) was measured by the proposed method on a total of 723 CT scans from a lung cancer screening study. These measures were significantly different for participants with Chronic Obstructive Pulmonary Disease (COPD) compared to asymptomatic participants. Furthermore, reproducibility was good as confirmed by repeat scans and the measures correlated well with the outcomes of pulmonary function tests, demonstrating the use of the algorithm as a COPD diagnostic tool. Additionally, a new measure of airway wall thickness is proposed, Normalized Wall Intensity Sum (NWIS). NWIS is shown to correlate better with lung function test values and to be more reproducible than previous measures IA, WA% and airway wall thickness at a lumen perimeter of 10 mm (PI10).

  9. A Comparative Assessment of Greek Universities' Efficiency Using Quantitative Analysis

    ERIC Educational Resources Information Center

    Katharaki, Maria; Katharakis, George

    2010-01-01

    In part due to the increased demand for higher education, typical evaluation frameworks for universities often address the key issue of available resource utilisation. This study seeks to estimate the efficiency of 20 public universities in Greece through quantitative analysis (including performance indicators, data envelopment analysis (DEA) and…

  10. Quantitative impact characterization of aeronautical CFRP materials with non-destructive testing methods

    NASA Astrophysics Data System (ADS)

    Kiefel, Denis; Stoessel, Rainer; Grosse, Christian

    2015-03-01

    In recent years, an increasing number of safety-relevant structures are designed and manufactured from carbon fiber reinforced polymers (CFRP) in order to reduce weight of airplanes by taking the advantage of their specific strength into account. Non-destructive testing (NDT) methods for quantitative defect analysis of damages are liquid- or air-coupled ultrasonic testing (UT), phased array ultrasonic techniques, and active thermography (IR). The advantage of these testing methods is the applicability on large areas. However, their quantitative information is often limited on impact localization and size. In addition to these techniques, Airbus Group Innovations operates a micro x-ray computed tomography (μ-XCT) system, which was developed for CFRP characterization. It is an open system which allows different kinds of acquisition, reconstruction, and data evaluation. One main advantage of this μ-XCT system is its high resolution with 3-dimensional analysis and visualization opportunities, which enables to gain important quantitative information for composite part design and stress analysis. Within this study, different NDT methods will be compared at CFRP samples with specified artificial impact damages. The results can be used to select the most suitable NDT-method for specific application cases. Furthermore, novel evaluation and visualization methods for impact analyzes are developed and will be presented.

  11. Quantitative impact characterization of aeronautical CFRP materials with non-destructive testing methods

    SciTech Connect

    Kiefel, Denis E-mail: Rainer.Stoessel@airbus.com; Stoessel, Rainer E-mail: Rainer.Stoessel@airbus.com; Grosse, Christian

    2015-03-31

    In recent years, an increasing number of safety-relevant structures are designed and manufactured from carbon fiber reinforced polymers (CFRP) in order to reduce weight of airplanes by taking the advantage of their specific strength into account. Non-destructive testing (NDT) methods for quantitative defect analysis of damages are liquid- or air-coupled ultrasonic testing (UT), phased array ultrasonic techniques, and active thermography (IR). The advantage of these testing methods is the applicability on large areas. However, their quantitative information is often limited on impact localization and size. In addition to these techniques, Airbus Group Innovations operates a micro x-ray computed tomography (μ-XCT) system, which was developed for CFRP characterization. It is an open system which allows different kinds of acquisition, reconstruction, and data evaluation. One main advantage of this μ-XCT system is its high resolution with 3-dimensional analysis and visualization opportunities, which enables to gain important quantitative information for composite part design and stress analysis. Within this study, different NDT methods will be compared at CFRP samples with specified artificial impact damages. The results can be used to select the most suitable NDT-method for specific application cases. Furthermore, novel evaluation and visualization methods for impact analyzes are developed and will be presented.

  12. A Quantitative Vainberg Method for Black Box Scattering

    NASA Astrophysics Data System (ADS)

    Galkowski, Jeffrey

    2017-01-01

    We give a quantitative version of Vainberg's method relating pole free regions to propagation of singularities for black box scatterers. In particular, we show that there is a logarithmic resonance free region near the real axis of size {τ} with polynomial bounds on the resolvent if and only if the wave propagator gains derivatives at rate {τ}. Next we show that if there exist singularities in the wave trace at times tending to infinity which smooth at rate {τ}, then there are resonances in logarithmic strips whose width is given by {τ}. As our main application of these results, we give sharp bounds on the size of resonance free regions in scattering on geometrically nontrapping manifolds with conic points. Moreover, these bounds are generically optimal on exteriors of nontrapping polygonal domains.

  13. Methods for Quantitative Interpretation of Retarding Field Analyzer Data

    SciTech Connect

    Calvey, J.R.; Crittenden, J.A.; Dugan, G.F.; Palmer, M.A.; Furman, M.; Harkay, K.

    2011-03-28

    Over the course of the CesrTA program at Cornell, over 30 Retarding Field Analyzers (RFAs) have been installed in the CESR storage ring, and a great deal of data has been taken with them. These devices measure the local electron cloud density and energy distribution, and can be used to evaluate the efficacy of different cloud mitigation techniques. Obtaining a quantitative understanding of RFA data requires use of cloud simulation programs, as well as a detailed model of the detector itself. In a drift region, the RFA can be modeled by postprocessing the output of a simulation code, and one can obtain best fit values for important simulation parameters with a chi-square minimization method.

  14. Influence of corrosion layers on quantitative analysis

    NASA Astrophysics Data System (ADS)

    Denker, A.; Bohne, W.; Opitz-Coutureau, J.; Rauschenberg, J.; Röhrich, J.; Strub, E.

    2005-09-01

    Art historians and restorers in charge of ancient metal objects are often reluctant to remove the corrosion layer evolved over time, as this would change the appearance of the artefact dramatically. Therefore, when an elemental analysis of the objects is required, this has to be done by penetrating the corrosion layer. In this work the influence of corrosion was studied on Chinese and Roman coins, where removal of oxidized material was possible. Measurements on spots with and without corrosion are presented and the results discussed.

  15. Segmentation and Quantitative Analysis of Epithelial Tissues.

    PubMed

    Aigouy, Benoit; Umetsu, Daiki; Eaton, Suzanne

    2016-01-01

    Epithelia are tissues that regulate exchanges with the environment. They are very dynamic and can acquire virtually any shape; at the cellular level, they are composed of cells tightly connected by junctions. Most often epithelia are amenable to live imaging; however, the large number of cells composing an epithelium and the absence of informatics tools dedicated to epithelial analysis largely prevented tissue scale studies. Here we present Tissue Analyzer, a free tool that can be used to segment and analyze epithelial cells and monitor tissue dynamics.

  16. Distance-based microfluidic quantitative detection methods for point-of-care testing.

    PubMed

    Tian, Tian; Li, Jiuxing; Song, Yanling; Zhou, Leiji; Zhu, Zhi; Yang, Chaoyong James

    2016-04-07

    Equipment-free devices with quantitative readout are of great significance to point-of-care testing (POCT), which provides real-time readout to users and is especially important in low-resource settings. Among various equipment-free approaches, distance-based visual quantitative detection methods rely on reading the visual signal length for corresponding target concentrations, thus eliminating the need for sophisticated instruments. The distance-based methods are low-cost, user-friendly and can be integrated into portable analytical devices. Moreover, such methods enable quantitative detection of various targets by the naked eye. In this review, we first introduce the concept and history of distance-based visual quantitative detection methods. Then, we summarize the main methods for translation of molecular signals to distance-based readout and discuss different microfluidic platforms (glass, PDMS, paper and thread) in terms of applications in biomedical diagnostics, food safety monitoring, and environmental analysis. Finally, the potential and future perspectives are discussed.

  17. QUANTITATIVE CT ANALYSIS, AIRFLOW OBSTRUCTION AND LUNG CANCER IN THE PITTSBURGH LUNG SCREENING STUDY

    PubMed Central

    Wilson, David O; Leader, Joseph K; Fuhrman, Carl R; Reilly, John J; Sciurba, Frank C.; Weissfeld, Joel L

    2011-01-01

    Background To study the relationship between emphysema, airflow obstruction and lung cancer in a high risk population we performed quantitative analysis of screening computed tomography (CT) scans. Methods Subjects completed questionnaires, spirometry and low-dose helical chest CT. Analyses compared cases and controls according to automated quantitative analysis of lung parenchyma and airways measures. Results Our case-control study of 117 matched pairs of lung cancer cases and controls did not reveal any airway or lung parenchymal findings on quantitative analysis of screening CT scans that were associated with increased lung cancer risk. Airway measures including wall area %, lumen perimeter, lumen area and average wall HU, and parenchymal measures including lung fraction < −910 Hounsfield Units (HU), were not statistically different between cases and controls. Conclusions The relationship between visual assessment of emphysema and increased lung cancer risk could not be verified by quantitative analysis of low-dose screening CT scans in a high risk tobacco exposed population. PMID:21610523

  18. Linking multidimensional functional diversity to quantitative methods: a graphical hypothesis--evaluation framework.

    PubMed

    Boersma, Kate S; Dee, Laura E; Miller, Steve J; Bogan, Michael T; Lytle, David A; Gitelman, Alix I

    2016-03-01

    Functional trait analysis is an appealing approach to study differences among biological communities because traits determine species' responses to the environment and their impacts on ecosystem functioning. Despite a rapidly expanding quantitative literature, it remains challenging to conceptualize concurrent changes in multiple trait dimensions ("trait space") and select quantitative functional diversity methods to test hypotheses prior to analysis. To address this need, we present a widely applicable framework for visualizing ecological phenomena in trait space to guide the selection, application, and interpretation of quantitative functional diversity methods. We describe five hypotheses that represent general patterns of responses to disturbance in functional community ecology and then apply a formal decision process to determine appropriate quantitative methods to test ecological hypotheses. As a part of this process, we devise a new statistical approach to test for functional turnover among communities. Our combination of hypotheses and metrics can be applied broadly to address ecological questions across a range of systems and study designs. We illustrate the framework with a case study of disturbance in freshwater communities. This hypothesis-driven approach will increase the rigor and transparency of applied functional trait studies.

  19. [Adequate application of quantitative and qualitative statistic analytic methods in acupuncture clinical trials].

    PubMed

    Tan, Ming T; Liu, Jian-ping; Lao, Lixing

    2012-08-01

    Recently, proper use of the statistical methods in traditional Chinese medicine (TCM) randomized controlled trials (RCTs) has received increased attention. Statistical inference based on hypothesis testing is the foundation of clinical trials and evidence-based medicine. In this article, the authors described the methodological differences between literature published in Chinese and Western journals in the design and analysis of acupuncture RCTs and the application of basic statistical principles. In China, qualitative analysis method has been widely used in acupuncture and TCM clinical trials, while the between-group quantitative analysis methods on clinical symptom scores are commonly used in the West. The evidence for and against these analytical differences were discussed based on the data of RCTs assessing acupuncture for pain relief. The authors concluded that although both methods have their unique advantages, quantitative analysis should be used as the primary analysis while qualitative analysis can be a secondary criterion for analysis. The purpose of this paper is to inspire further discussion of such special issues in clinical research design and thus contribute to the increased scientific rigor of TCM research.

  20. Quantitative evaluation of midpalatal suture maturation via fractal analysis

    PubMed Central

    Kwak, Kyoung Ho; Kim, Yong-Il; Kim, Yong-Deok

    2016-01-01

    Objective The purpose of this study was to determine whether the results of fractal analysis can be used as criteria for midpalatal suture maturation evaluation. Methods The study included 131 subjects aged over 18 years of age (range 18.1–53.4 years) who underwent cone-beam computed tomography. Skeletonized images of the midpalatal suture were obtained via image processing software and used to calculate fractal dimensions. Correlations between maturation stage and fractal dimensions were calculated using Spearman's correlation coefficient. Optimal fractal dimension cut-off values were determined using a receiver operating characteristic curve. Results The distribution of maturation stages of the midpalatal suture according to the cervical vertebrae maturation index was highly variable, and there was a strong negative correlation between maturation stage and fractal dimension (−0.623, p < 0.001). Fractal dimension was a statistically significant indicator of dichotomous results with regard to maturation stage (area under curve = 0.794, p < 0.001). A test in which fractal dimension was used to predict the resulting variable that splits maturation stages into ABC and D or E yielded an optimal fractal dimension cut-off value of 1.0235. Conclusions There was a strong negative correlation between fractal dimension and midpalatal suture maturation. Fractal analysis is an objective quantitative method, and therefore we suggest that it may be useful for the evaluation of midpalatal suture maturation. PMID:27668195

  1. Quantitative Analysis of Seismicity in Iran

    NASA Astrophysics Data System (ADS)

    Raeesi, Mohammad; Zarifi, Zoya; Nilfouroushan, Faramarz; Boroujeni, Samar Amini; Tiampo, Kristy

    2017-03-01

    We use historical and recent major earthquakes and GPS geodetic data to compute seismic strain rate, geodetic slip deficit, static stress drop, the parameters of the magnitude-frequency distribution and geodetic strain rate in the Iranian Plateau to identify seismically mature fault segments and regions. Our analysis suggests that 11 fault segments are in the mature stage of the earthquake cycle, with the possibility of generating major earthquakes. These faults primarily are located in the north and the east of Iran. Four seismically mature regions in southern Iran with the potential for damaging strong earthquakes are also identified. We also delineate four additional fault segments in Iran that can generate major earthquakes without robust clues to their maturity.The most important fault segment in this study is the strike-slip system near the capital city of Tehran, with the potential to cause more than one million fatalities.

  2. Quantitative Analysis of Seismicity in Iran

    NASA Astrophysics Data System (ADS)

    Raeesi, Mohammad; Zarifi, Zoya; Nilfouroushan, Faramarz; Boroujeni, Samar Amini; Tiampo, Kristy

    2016-12-01

    We use historical and recent major earthquakes and GPS geodetic data to compute seismic strain rate, geodetic slip deficit, static stress drop, the parameters of the magnitude-frequency distribution and geodetic strain rate in the Iranian Plateau to identify seismically mature fault segments and regions. Our analysis suggests that 11 fault segments are in the mature stage of the earthquake cycle, with the possibility of generating major earthquakes. These faults primarily are located in the north and the east of Iran. Four seismically mature regions in southern Iran with the potential for damaging strong earthquakes are also identified. We also delineate four additional fault segments in Iran that can generate major earthquakes without robust clues to their maturity.The most important fault segment in this study is the strike-slip system near the capital city of Tehran, with the potential to cause more than one million fatalities.

  3. Structural analysis of mylonitic rocks in the Cougar Creek Complex, Oregon-Idaho using the porphyroclast hyperbolic distribution method, and potential use of SC'-type extensional shear bands as quantitative vorticity indicators

    NASA Astrophysics Data System (ADS)

    Kurz, Gene A.; Northrup, Clyde J.

    2008-08-01

    Mylonitic rocks of the Cougar Creek Complex of northeastern Oregon and west-central Idaho provide an opportunity to document the deformational structures produced during general non-coaxial shear within quartz-feldspar mylonites and to explore the potential role of SC'-type extensional shear bands in vorticity analysis. Well-developed feldspar porphyroclasts within six mylonite zones were utilized to estimate bulk kinematic vorticity ( Wk) using the porphyroclast hyperbolic distribution (PHD) method. Wk values for the Cougar Creek mylonites range from Wk = 0.26 to Wk = 0.37. Synthetic and antithetic shear band inclinations were measured relative to observed shear zone boundaries within five mylonite zones with estimated Wk values and compared to the non-coaxial flow field geometries and eigenvector orientations. In each mylonite zone, synthetic SC'-type shear band populations exhibit a range of inclination with maximum inclination lying approximately parallel to the acute bisector (AB) of the eigenvectors. Similarly, antithetic shear band populations show a range of inclination near the obtuse bisector (OB) of the eigenvectors. We infer that SC'-type extensional shear bands form initially parallel to AB and OB and rotate towards the flow plane with progressive deformation, decreasing their inclination relative to the shear zone boundary. AB and OB have significance in the strain field in that they represent orientations of maximum angular strain rate. Thus, planes perpendicular to AB and OB are mechanically favorable for small zones of localized simple shear (shear bands) within the heterogeneous bulk strain of the mylonite. Orientation analysis of populations of SC'-type shear bands may provide a direct, quantitative means of estimating Wk.

  4. QTL analysis for some quantitative traits in bread wheat*

    PubMed Central

    Pushpendra, Kumar Gupta; Harindra, Singh Balyan; Pawan, Laxminarayan Kulwal; Neeraj, Kumar; Ajay, Kumar; Reyazul, Rouf Mir; Amita, Mohan; Jitendra, Kumar

    2007-01-01

    Quantitative trait loci (QTL) analysis was conducted in bread wheat for 14 important traits utilizing data from four different mapping populations involving different approaches of QTL analysis. Analysis for grain protein content (GPC) suggested that the major part of genetic variation for this trait is due to environmental interactions. In contrast, pre-harvest sprouting tolerance (PHST) was controlled mainly by main effect QTL (M-QTL) with very little genetic variation due to environmental interactions; a major QTL for PHST was detected on chromosome arm 3AL. For grain weight, one QTL each was detected on chromosome arms 1AS, 2BS and 7AS. QTL for 4 growth related traits taken together detected by different methods ranged from 37 to 40; nine QTL that were detected by single-locus as well as two-locus analyses were all M-QTL. Similarly, single-locus and two-locus QTL analyses for seven yield and yield contributing traits in two populations respectively allowed detection of 25 and 50 QTL by composite interval mapping (CIM), 16 and 25 QTL by multiple-trait composite interval mapping (MCIM) and 38 and 37 QTL by two-locus analyses. These studies should prove useful in QTL cloning and wheat improvement through marker aided selection. PMID:17973342

  5. A quantitative assessment method for Ascaris eggs on hands.

    PubMed

    Jeandron, Aurelie; Ensink, Jeroen H J; Thamsborg, Stig M; Dalsgaard, Anders; Sengupta, Mita E

    2014-01-01

    The importance of hands in the transmission of soil transmitted helminths, especially Ascaris and Trichuris infections, is under-researched. This is partly because of the absence of a reliable method to quantify the number of eggs on hands. Therefore, the aim of this study was to develop a method to assess the number of Ascaris eggs on hands and determine the egg recovery rate of the method. Under laboratory conditions, hands were seeded with a known number of Ascaris eggs, air dried and washed in a plastic bag retaining the washing water, in order to determine recovery rates of eggs for four different detergents (cationic [benzethonium chloride 0.1% and cetylpyridinium chloride CPC 0.1%], anionic [7X 1% - quadrafos, glycol ether, and dioctyl sulfoccinate sodium salt] and non-ionic [Tween80 0.1% -polyethylene glycol sorbitan monooleate]) and two egg detection methods (McMaster technique and FLOTAC). A modified concentration McMaster technique showed the highest egg recovery rate from bags. Two of the four diluted detergents (benzethonium chloride 0.1% and 7X 1%) also showed a higher egg recovery rate and were then compared with de-ionized water for recovery of helminth eggs from hands. The highest recovery rate (95.6%) was achieved with a hand rinse performed with 7X 1%. Washing hands with de-ionized water resulted in an egg recovery rate of 82.7%. This washing method performed with a low concentration of detergent offers potential for quantitative investigation of contamination of hands with Ascaris eggs and of their role in human infection. Follow-up studies are needed that validate the hand washing method under field conditions, e.g. including people of different age, lower levels of contamination and various levels of hand cleanliness.

  6. Quantitative analysis in outcome assessment of instrumented lumbosacral arthrodesis

    PubMed Central

    Mazel, Christian; Mitulescu, Anca

    2007-01-01

    The outcome assessment in instrumented lumbosacral fusion mostly focuses on clinical criteria, complications and scores, with a high variability of imaging means, methods of fusion grading and parameters describing degenerative changes, making comparisons between studies difficult. The aim of this retrospective evaluation was to evaluate the interest of quantified radiographic analysis of lumbar spine in global outcome assessment and to highlight the key biomechanical factors involved. Clinical data and Beaujon–Lassale scores were collected for 49 patients who underwent lumbosacral arthrodesis after prior lumbar discectomy (mean follow-up: 5 years). Sagittal standing and lumbar flexion-extension X-ray films allowed quantifying vertebral, lumbar, pelvic and kinematic parameters of the lumbar spine, which were compared to reference values. Statistics were performed to assess evolution for all variables. At long-term follow-up, 90% of patients presented satisfactory clinical outcomes, associated to normal sagittal alignment; vertebral parameters objectified adjacent level degeneration in four cases (8%). Clinical outcome was correlated (r = 0.8) with fusion that was confirmed in 80% of cases, doubtful in 16% and pseudarthrosis seemed to occur in 4% (2) of cases. In addition to clinical data (outcomes comparable to the literature), quantitative analysis accurately described lumbar spine geometry and kinematics, highlighting parameters related to adjacent level’s degeneration and a significant correlation between clinical outcome and fusion. Furthermore, criteria proposed to quantitatively evaluate fusion from lumbar dynamic radiographs seem to be appropriate and in agreement with surgeon’s qualitative grading in 87% of cases. PMID:17216227

  7. A method for comprehensive glycosite-mapping and direct quantitation of plasma glycoproteins

    PubMed Central

    Hong, Qiuting; Ruhaak, L. Renee; Stroble, Carol; Parker, Evan; Huang, Jincui; Maverakis, Emanual; Lebrilla, Carlito B.

    2015-01-01

    A comprehensive glycan map was constructed for the top eight abundant plasma glycoproteins using both specific and non-specific enzyme digestions followed by nano LC–Chip/QTOF mass spectrometry (MS) analysis. Glycopeptides were identified using an in-house software tool, GPFinder. A sensitive and reproducible multiple reaction monitoring (MRM) technique on a triple quadrupole MS was developed and applied to quantify immunoglobulins G, A, M, and their site-specific glycans simultaneously and directly from human serum without protein enrichments. A total of 64 glycopeptides and 15 peptides were monitored for IgG, IgA, and IgM in a 20-min UPLC gradient. The absolute protein contents were quantified using peptide calibration curves. The glycopeptide ion abundances were normalized to the respective protein abundances to separate protein glycosylation from protein expression. This technique yields higher method reproducibility and less sample loss when compared to quantitation methods that involve protein enrichments. The absolute protein quantitation has a wide linear range (3-4 orders of magnitude) and low limit of quantitation (femtomole level). This rapid and robust quantitation technique, which provides quantitative information for both proteins and glycosylation, will further facilitate disease biomarker discoveries. PMID:26510530

  8. A Method for Comprehensive Glycosite-Mapping and Direct Quantitation of Serum Glycoproteins.

    PubMed

    Hong, Qiuting; Ruhaak, L Renee; Stroble, Carol; Parker, Evan; Huang, Jincui; Maverakis, Emanual; Lebrilla, Carlito B

    2015-12-04

    A comprehensive glycan map was constructed for the top eight abundant glycoproteins in plasma using both specific and nonspecific enzyme digestions followed by nano liquid chromatography (LC)-chip/quadrupole time-of-flight mass spectrometry (MS) analysis. Glycopeptides were identified using an in-house software tool, GPFinder. A sensitive and reproducible multiple reaction monitoring (MRM) technique on a triple quadrupole MS was developed and applied to quantify immunoglobulins G, A, M, and their site-specific glycans simultaneously and directly from human serum/plasma without protein enrichments. A total of 64 glycopeptides and 15 peptides were monitored for IgG, IgA, and IgM in a 20 min ultra high performance (UP)LC gradient. The absolute protein contents were quantified using peptide calibration curves. The glycopeptide ion abundances were normalized to the respective protein abundances to separate protein glycosylation from protein expression. This technique yields higher method reproducibility and less sample loss when compared with the quantitation method that involves protein enrichments. The absolute protein quantitation has a wide linear range (3-4 orders of magnitude) and low limit of quantitation (femtomole level). This rapid and robust quantitation technique, which provides quantitative information for both proteins and glycosylation, will further facilitate disease biomarker discoveries.

  9. Quantitative analysis of drug-induced tremor in mice.

    PubMed

    Shinozaki, H

    1984-12-01

    A method of analyzing tremor in mice was developed using a power spectral analysis of the random current induced by the movement of a magnet attached to a mouse, on a wire coil. The power spectral density function defined the frequency composition of the tremor, and the mean square value of the data in any frequency range of concern was determined. It was possible to determine qualitative differences in the tremor caused by various tremorgenic agents, and to differentiate the drug-induced tremor from spontaneous motor activity. The power spectral densities of the tremorine- and oxotremorine-induced tremors were tentatively expressed as the sum of 3 main components (Cauchy distribution) with different peak frequencies, consisting of the spontaneous motor activity component and two tremor components. On the other hand, the power spectral densities of the harmaline-induced tremor were expressed as the sum of two components with two peak frequencies, and the plots of the power spectral densities versus frequency, consisting of the spontaneous motor activity component and a tremor component. The frequency of the peak spectral density was almost independent of the dose of tremorgenic agents, but changed slightly with the lapse of time after their injection. The severity of the tremor was determined quantitatively in terms of the sum of the mean square value. The sum of the mean square value for a period of 45 min after the injection of tremorine, changed in a dose-dependent manner. The severity of the tremor was different for each of the mouse strains. The method studied in the present paper is expected to be utilized for the quantitative examination of the fine motor movement of the experimental animal, particularly, for the screening test of new anti-tremor drugs.

  10. Nuclear medicine and imaging research (instrumentation and quantitative methods of evaluation)

    SciTech Connect

    Beck, R.N.; Cooper, M.; Chen, C.T.

    1992-07-01

    This document is the annual progress report for project entitled 'Instrumentation and Quantitative Methods of Evaluation.' Progress is reported in separate sections individually abstracted and indexed for the database. Subject areas reported include theoretical studies of imaging systems and methods, hardware developments, quantitative methods of evaluation, and knowledge transfer: education in quantitative nuclear medicine imaging.

  11. Uncertainty in environmental health impact assessment: quantitative methods and perspectives.

    PubMed

    Mesa-Frias, Marco; Chalabi, Zaid; Vanni, Tazio; Foss, Anna M

    2013-01-01

    Environmental health impact assessment models are subjected to great uncertainty due to the complex associations between environmental exposures and health. Quantifying the impact of uncertainty is important if the models are used to support health policy decisions. We conducted a systematic review to identify and appraise current methods used to quantify the uncertainty in environmental health impact assessment. In the 19 studies meeting the inclusion criteria, several methods were identified. These were grouped into random sampling methods, second-order probability methods, Bayesian methods, fuzzy sets, and deterministic sensitivity analysis methods. All 19 studies addressed the uncertainty in the parameter values but only 5 of the studies also addressed the uncertainty in the structure of the models. None of the articles reviewed considered conceptual sources of uncertainty associated with the framing assumptions or the conceptualisation of the model. Future research should attempt to broaden the way uncertainty is taken into account in environmental health impact assessments.

  12. High throughput, quantitative analysis of human osteoclast differentiation and activity.

    PubMed

    Diepenhorst, Natalie A; Nowell, Cameron J; Rueda, Patricia; Henriksen, Kim; Pierce, Tracie; Cook, Anna E; Pastoureau, Philippe; Sabatini, Massimo; Charman, William N; Christopoulos, Arthur; Summers, Roger J; Sexton, Patrick M; Langmead, Christopher J

    2017-02-15

    Osteoclasts are multinuclear cells that degrade bone under both physiological and pathophysiological conditions. Osteoclasts are therefore a major target of osteoporosis therapeutics aimed at preserving bone. Consequently, analytical methods for osteoclast activity are useful for the development of novel biomarkers and/or pharmacological agents for the treatment of osteoporosis. The nucleation state of an osteoclast is indicative of its maturation and activity. To date, activity is routinely measured at the population level with only approximate consideration of the nucleation state (an 'osteoclast population' is typically defined as cells with ≥3 nuclei). Using a fluorescent substrate for tartrate-resistant acid phosphatase (TRAP), a routinely used marker of osteoclast activity, we developed a multi-labelled imaging method for quantitative measurement of osteoclast TRAP activity at the single cell level. Automated image analysis enables interrogation of large osteoclast populations in a high throughput manner using open source software. Using this methodology, we investigated the effects of receptor activator of nuclear factor kappa-B ligand (RANK-L) on osteoclast maturation and activity and demonstrated that TRAP activity directly correlates with osteoclast maturity (i.e. nuclei number). This method can be applied to high throughput screening of osteoclast-targeting compounds to determine changes in maturation and activity.

  13. Quantitative analysis in medicine using photoacoustic tomography.

    PubMed

    Haisch, Christoph

    2009-01-01

    Photoacoustic imaging, or photoacoustic tomography, is a 2D or 3D optical imaging method based on localized optical absorption of pulsed laser radiation. By a spatially resolved detection of the following thermoelastic expansion, the local distribution of the absorption can be determined. The technique has been proven to have significant potential for the imaging of human and animal organs and single blood vessels, combining high contrast with good spatial resolution. The contrast is based on the specific optical absorption of certain components in the visible and near-infrared spectral range, for most applications of blood. Generally, the images represent the local distribution of blood in a qualitative or semiquantitative way. Although photoacoustic imaging is capable of revealing absolute and spatially resolved concentrations of endogenous (such as oxyhemoglobin and deoxyhemoglobin) or artificial (such as tumor markers) chromophores, only a very limited number of publications have dealt with this demanding task. In this report, the problems involved and possible solutions are reviewed and summarized.

  14. Control of separation and quantitative analysis by GC-FTIR

    NASA Astrophysics Data System (ADS)

    Semmoud, A.; Huvenne, Jean P.; Legrand, P.

    1992-03-01

    Software for 3-D representations of the 'Absorbance-Wavenumber-Retention time' is used to control the quality of the GC separation. Spectral information given by the FTIR detection allows the user to be sure that a chromatographic peak is 'pure.' The analysis of peppermint essential oil is presented as an example. This assurance is absolutely required for quantitative applications. In these conditions, we have worked out a quantitative analysis of caffeine. Correlation coefficients between integrated absorbance measurements and concentration of caffeine are discussed at two steps of the data treatment.

  15. The Quantitative Methods Boot Camp: Teaching Quantitative Thinking and Computing Skills to Graduate Students in the Life Sciences

    PubMed Central

    Stefan, Melanie I.; Gutlerner, Johanna L.; Born, Richard T.; Springer, Michael

    2015-01-01

    The past decade has seen a rapid increase in the ability of biologists to collect large amounts of data. It is therefore vital that research biologists acquire the necessary skills during their training to visualize, analyze, and interpret such data. To begin to meet this need, we have developed a “boot camp” in quantitative methods for biology graduate students at Harvard Medical School. The goal of this short, intensive course is to enable students to use computational tools to visualize and analyze data, to strengthen their computational thinking skills, and to simulate and thus extend their intuition about the behavior of complex biological systems. The boot camp teaches basic programming using biological examples from statistics, image processing, and data analysis. This integrative approach to teaching programming and quantitative reasoning motivates students’ engagement by demonstrating the relevance of these skills to their work in life science laboratories. Students also have the opportunity to analyze their own data or explore a topic of interest in more detail. The class is taught with a mixture of short lectures, Socratic discussion, and in-class exercises. Students spend approximately 40% of their class time working through both short and long problems. A high instructor-to-student ratio allows students to get assistance or additional challenges when needed, thus enhancing the experience for students at all levels of mastery. Data collected from end-of-course surveys from the last five offerings of the course (between 2012 and 2014) show that students report high learning gains and feel that the course prepares them for solving quantitative and computational problems they will encounter in their research. We outline our course here which, together with the course materials freely available online under a Creative Commons License, should help to facilitate similar efforts by others. PMID:25880064

  16. The quantitative methods boot camp: teaching quantitative thinking and computing skills to graduate students in the life sciences.

    PubMed

    Stefan, Melanie I; Gutlerner, Johanna L; Born, Richard T; Springer, Michael

    2015-04-01

    The past decade has seen a rapid increase in the ability of biologists to collect large amounts of data. It is therefore vital that research biologists acquire the necessary skills during their training to visualize, analyze, and interpret such data. To begin to meet this need, we have developed a "boot camp" in quantitative methods for biology graduate students at Harvard Medical School. The goal of this short, intensive course is to enable students to use computational tools to visualize and analyze data, to strengthen their computational thinking skills, and to simulate and thus extend their intuition about the behavior of complex biological systems. The boot camp teaches basic programming using biological examples from statistics, image processing, and data analysis. This integrative approach to teaching programming and quantitative reasoning motivates students' engagement by demonstrating the relevance of these skills to their work in life science laboratories. Students also have the opportunity to analyze their own data or explore a topic of interest in more detail. The class is taught with a mixture of short lectures, Socratic discussion, and in-class exercises. Students spend approximately 40% of their class time working through both short and long problems. A high instructor-to-student ratio allows students to get assistance or additional challenges when needed, thus enhancing the experience for students at all levels of mastery. Data collected from end-of-course surveys from the last five offerings of the course (between 2012 and 2014) show that students report high learning gains and feel that the course prepares them for solving quantitative and computational problems they will encounter in their research. We outline our course here which, together with the course materials freely available online under a Creative Commons License, should help to facilitate similar efforts by others.

  17. Development and validation of an HPLC-MS/MS analytical method for quantitative analysis of TCBA-TPQ, a novel anticancer makaluvamine analog, and application in a pharmacokinetic study in rats.

    PubMed

    Yu, Jun-Xian; Voruganti, Sukesh; Li, Dan-Dan; Qin, Jiang-Jiang; Nag, Subhasree; Xu, Su; Velu, Sadanandan E; Wang, Wei; Zhang, Ruiwen

    2015-07-01

    We have recently designed and synthesized several novel iminoquinone anticancer agents that have entered preclinical development for the treatment of human cancers. Herein we developed and validated a quantitative HPLC-MS/MS analytical method for one of the lead novel anticancer makaluvamine analog, TCBA-TPQ, and conducted a pharmacokinetic study in laboratory rats. Our results indicated that the HPLC-MS/MS method was precise, accurate, and specific. Using this method, we carried out in vitro and in vivo evaluations of the pharmacological properties of TCBA-TPQ and plasma pharmacokinetics in rats. Our results provide a basis for future preclinical and clinical development of this promising anticancer marine analog.

  18. [Quantitative image analysis in pulmonary pathology - digitalization of preneoplastic lesions in human bronchial epithelium (author's transl)].

    PubMed

    Steinbach, T; Müller, K M; Kämper, H

    1979-01-01

    The report concerns the first phase of a quantitative study of normal and abnormal bronchial epithelium with the objective of establishing the digitalization of histologic patterns. Preparative methods, data collecting and handling, and further mathematical analysis are described. In cluster and discriminatory analysis the digitalized histologic features can be used to separate and classify the individual cases into the respective diagnostic groups.

  19. Issues in Quantitative Analysis of Ultraviolet Imager (UV) Data: Airglow

    NASA Technical Reports Server (NTRS)

    Germany, G. A.; Richards, P. G.; Spann, J. F.; Brittnacher, M. J.; Parks, G. K.

    1999-01-01

    The GGS Ultraviolet Imager (UVI) has proven to be especially valuable in correlative substorm, auroral morphology, and extended statistical studies of the auroral regions. Such studies are based on knowledge of the location, spatial, and temporal behavior of auroral emissions. More quantitative studies, based on absolute radiometric intensities from UVI images, require a more intimate knowledge of the instrument behavior and data processing requirements and are inherently more difficult than studies based on relative knowledge of the oval location. In this study, UVI airglow observations are analyzed and compared with model predictions to illustrate issues that arise in quantitative analysis of UVI images. These issues include instrument calibration, long term changes in sensitivity, and imager flat field response as well as proper background correction. Airglow emissions are chosen for this study because of their relatively straightforward modeling requirements and because of their implications for thermospheric compositional studies. The analysis issues discussed here, however, are identical to those faced in quantitative auroral studies.

  20. Inside Single Cells: Quantitative Analysis with Advanced Optics and Nanomaterials

    PubMed Central

    Cui, Yi; Irudayaraj, Joseph

    2014-01-01

    Single cell explorations offer a unique window to inspect molecules and events relevant to mechanisms and heterogeneity constituting the central dogma of biology. A large number of nucleic acids, proteins, metabolites and small molecules are involved in determining and fine-tuning the state and function of a single cell at a given time point. Advanced optical platforms and nanotools provide tremendous opportunities to probe intracellular components with single-molecule accuracy, as well as promising tools to adjust single cell activity. In order to obtain quantitative information (e.g. molecular quantity, kinetics and stoichiometry) within an intact cell, achieving the observation with comparable spatiotemporal resolution is a challenge. For single cell studies both the method of detection and the biocompatibility are critical factors as they determine the feasibility, especially when considering live cell analysis. Although a considerable proportion of single cell methodologies depend on specialized expertise and expensive instruments, it is our expectation that the information content and implication will outweigh the costs given the impact on life science enabled by single cell analysis. PMID:25430077

  1. Chemical Fingerprint Analysis and Quantitative Analysis of Rosa rugosa by UPLC-DAD.

    PubMed

    Mansur, Sanawar; Abdulla, Rahima; Ayupbec, Amatjan; Aisa, Haji Akbar

    2016-12-21

    A method based on ultra performance liquid chromatography with a diode array detector (UPLC-DAD) was developed for quantitative analysis of five active compounds and chemical fingerprint analysis of Rosa rugosa. Ten batches of R. rugosa collected from different plantations in the Xinjiang region of China were used to establish the fingerprint. The feasibility and advantages of the used UPLC fingerprint were verified for its similarity evaluation by systematically comparing chromatograms with professional analytical software recommended by State Food and Drug Administration (SFDA) of China. In quantitative analysis, the five compounds showed good regression (R² = 0.9995) within the test ranges, and the recovery of the method was in the range of 94.2%-103.8%. The similarities of liquid chromatography fingerprints of 10 batches of R. rugosa were more than 0.981. The developed UPLC fingerprint method is simple, reliable, and validated for the quality control and identification of R. rugosa. Additionally, simultaneous quantification of five major bioactive ingredients in the R. rugosa samples was conducted to interpret the consistency of the quality test. The results indicated that the UPLC fingerprint, as a characteristic distinguishing method combining similarity evaluation and quantification analysis, can be successfully used to assess the quality and to identify the authenticity of R. rugosa.

  2. Quantitative analysis of flavanones and chalcones from willow bark.

    PubMed

    Freischmidt, A; Untergehrer, M; Ziegler, J; Knuth, S; Okpanyi, S; Müller, J; Kelber, O; Weiser, D; Jürgenliemk, G

    2015-09-01

    Willow bark extracts are used for the treatment of fever, pain and inflammation. Recent clinical and pharmacological research revealed that not only the salicylic alcohol derivatives, but also the polyphenols significantly contribute to these effects. Quantitative analysis of the European Pharmacopoeia still focuses on the determination of the salicylic alcohol derivatives. The objective of the present study was the development of an effective quantification method for the determination of as many flavanone and chalcone glycosides as possible in Salix purpurea and other Salix species as well as commercial preparations thereof. As Salix species contain a diverse spectrum of the glycosidated flavanones naringenin, eriodictyol, and the chalcone chalconaringenin, a subsequent acidic and enzymatic hydrolysis was developed to yield naringenin and eriodictyol as aglycones, which were quantified by HPLC. The 5-O-glucosides were cleaved with 11.5% TFA before subsequent hydrolysis of the 7-O-glucosides with an almond β-glucosidase at pH 6-7. The method was validated with regard to LOD, LOQ, intraday and interday precision, accuracy, stability, recovery, time of hydrolysis, robustness and applicability to extracts. All 5-O- and 7-O-glucosides of naringenin, eriodictyol and chalconaringenin were completely hydrolysed and converted to naringenin and eriodictyol. The LOD of the HPLC method was 0.77 μM of naringenin and 0.45 μM of eriodictyol. The LOQ was 2.34 μM of naringenin and 1.35 μM for eriodictyol. The method is robust with regard to sample weight, but susceptible concerning enzyme deterioration. The developed method is applicable to the determination of flavanone and chalcone glycosides in willow bark and corresponding preparations.

  3. Method for quantitative proteomics research by using metal element chelated tags coupled with mass spectrometry.

    PubMed

    Liu, Huiling; Zhang, Yangjun; Wang, Jinglan; Wang, Dong; Zhou, Chunxi; Cai, Yun; Qian, Xiaohong

    2006-09-15

    The mass spectrometry-based methods with a stable isotope as the internal standard in quantitative proteomics have been developed quickly in recent years. But the use of some stable isotope reagents is limited by the relative high price and synthetic difficulties. We have developed a new method for quantitative proteomics research by using metal element chelated tags (MECT) coupled with mass spectrometry. The bicyclic anhydride diethylenetriamine-N,N,N',N' ',N' '-pentaacetic acid (DTPA) is covalently coupled to primary amines of peptides, and the ligand is then chelated to the rare earth metals Y and Tb. The tagged peptides are mixed and analyzed by LC-ESI-MS/MS. Peptides are quantified by measuring the relative signal intensities for the Y and Tb tag pairs in MS, which permits the quantitation of the original proteins generating the corresponding peptides. The protein is then identified by the corresponding peptide sequence from its MS/MS spectrum. The MECT method was evaluated by using standard proteins as model sample. The experimental results showed that metal chelate-tagged peptides chromatographically coeluted successfully during the reversed-phase LC analysis. The relative quantitation results were accurate for proteins using MECT. DTPA modification of the N-terminal of peptides promoted cleaner fragmentation (only y-series ions) in mass spectrometry and improved the confidence level of protein identification. The MECT strategy provides a simple, rapid, and economical alternative to current mass tagging technologies available.

  4. Towards quantitative analysis of retinal features in optical coherence tomography.

    PubMed

    Baroni, Maurizio; Fortunato, Pina; La Torre, Agostino

    2007-05-01

    The purpose of this paper was to propose a new computer method for quantitative evaluation of representative features of the retina using optical coherence tomography (OCT). A multi-step approach was devised and positively tested for segmentation of the three main retinal layers: the vitreo-retinal interface and the inner and outer retina. Following a preprocessing step, three regions of interest were delimited. Significant peaks corresponding to high and low intensity strips were located along the OCT A-scan lines and accurate boundaries between different layers were obtained by maximizing an edge likelihood function. For a quantitative description, thickness measurement, densitometry, texture and curvature analyses were performed. As a first application, the effect of intravitreal injection of triamcinolone acetonide (IVTA) for the treatment of vitreo-retinal interface syndrome was evaluated. Almost all the parameters, measured on a set of 16 pathologic OCT images, were statistically different before and after IVTA injection (p<0.05). Shape analysis of the internal limiting membrane confirmed the reduction of the pathological traction state. Other significant parameters, such as reflectivity and texture contrast, exhibited relevant changes both at the vitreo-retinal interface and in the inner retinal layers. Texture parameters in the inner and outer retinal layers significantly correlated with the visual acuity restoration. According to these findings an IVTA injection might be considered a possible alternative to surgery for selected patients. In conclusion, the proposed approach appeared to be a promising tool for the investigation of tissue changes produced by pathology and/or therapy.

  5. Quantitative Analysis Of Acoustic Emission From Rock Fracture Experiments

    NASA Astrophysics Data System (ADS)

    Goodfellow, Sebastian David

    This thesis aims to advance the methods of quantitative acoustic emission (AE) analysis by calibrating sensors, characterizing sources, and applying the results to solve engi- neering problems. In the first part of this thesis, we built a calibration apparatus and successfully calibrated two commercial AE sensors. The ErgoTech sensor was found to have broadband velocity sensitivity and the Panametrics V103 was sensitive to surface normal displacement. These calibration results were applied to two AE data sets from rock fracture experiments in order to characterize the sources of AE events. The first data set was from an in situ rock fracture experiment conducted at the Underground Research Laboratory (URL). The Mine-By experiment was a large scale excavation response test where both AE (10 kHz - 1 MHz) and microseismicity (MS) (1 Hz - 10 kHz) were monitored. Using the calibration information, magnitude, stress drop, dimension and energy were successfully estimated for 21 AE events recorded in the tensile region of the tunnel wall. Magnitudes were in the range -7.5 < Mw < -6.8, which is consistent with other laboratory AE results, and stress drops were within the range commonly observed for induced seismicity in the field (0.1 - 10 MPa). The second data set was AE collected during a true-triaxial deformation experiment, where the objectives were to characterize laboratory AE sources and identify issues related to moving the analysis from ideal in situ conditions to more complex laboratory conditions in terms of the ability to conduct quantitative AE analysis. We found AE magnitudes in the range -7.8 < Mw < -6.7 and as with the in situ data, stress release was within the expected range of 0.1 - 10 MPa. We identified four major challenges to quantitative analysis in the laboratory, which in- hibited our ability to study parameter scaling (M0 ∝ fc -3 scaling). These challenges were 0c (1) limited knowledge of attenuation which we proved was continuously evolving, (2

  6. Quantitative analysis of plasma interleiukin-6 by immunoassay on microchip

    NASA Astrophysics Data System (ADS)

    Abe, K.; Hashimoto, Y.; Yatsushiro, S.; Yamamura, S.; Tanaka, M.; Ooie, T.; Baba, Y.; Kataoka, M.

    2012-03-01

    Sandwich enzyme-linked immunoassay (ELISA) is one of the most frequently employed assays for clinical diagnosis, since this enables the investigator to identify specific protein biomarkers. However, the conventional assay using a 96-well microtitration plate is time- and sample-consuming, and therefore is not suitable for rapid diagnosis. To overcome these drawbacks, we performed a sandwich ELISA on a microchip. We employed the piezoelectric inkjet printing for deposition and fixation of 1st antibody on the microchannnel surface (300 μm width and 100 μm depth). Model analyte was interleukin-6 (IL-6) which was one of the inflammatory cytokine. After blocking the microchannel, antigen, biotin-labeled 2nd antibody, and avidin-labeled peroxidase were infused into the microchannel and incubated for 20 min, 10 min, and 5 min, respectively. This assay could detect 2 pg/ml and quantitatively measure the range of 0-32 pg/ml. Liner regression analysis of plasma IL-6 concentration obtained by microchip and conventional methods exhibited a significant relationship (R2 = 0.9964). This assay reduced the time for the antigen-antibody reaction to 1/6, and the consumption of samples and reagents to 1/50 compared with the conventional method. This assay enables us to determine plasma IL-6 with accuracy, high sensitivity, time saving ability, and low consumption of sample and reagents, and thus will be applicable to clinic diagnosis.

  7. Lipid biomarker analysis for the quantitative analysis of airborne microorganisms

    SciTech Connect

    Macnaughton, S.J.; Jenkins, T.L.; Cormier, M.R.

    1997-08-01

    There is an ever increasing concern regarding the presence of airborne microbial contaminants within indoor air environments. Exposure to such biocontaminants can give rise to large numbers of different health effects including infectious diseases, allergenic responses and respiratory problems, Biocontaminants typically round in indoor air environments include bacteria, fungi, algae, protozoa and dust mites. Mycotoxins, endotoxins, pollens and residues of organisms are also known to cause adverse health effects. A quantitative detection/identification technique independent of culturability that assays both culturable and non culturable biomass including endotoxin is critical in defining risks from indoor air biocontamination. Traditionally, methods employed for the monitoring of microorganism numbers in indoor air environments involve classical culture based techniques and/or direct microscopic counting. It has been repeatedly documented that viable microorganism counts only account for between 0.1-10% of the total community detectable by direct counting. The classic viable microbiologic approach doe`s not provide accurate estimates of microbial fragments or other indoor air components that can act as antigens and induce or potentiate allergic responses. Although bioaerosol samplers are designed to damage the microbes as little as possible, microbial stress has been shown to result from air sampling, aerosolization and microbial collection. Higher collection efficiency results in greater cell damage while less cell damage often results in lower collection efficiency. Filtration can collect particulates at almost 100% efficiency, but captured microorganisms may become dehydrated and damaged resulting in non-culturability, however, the lipid biomarker assays described herein do not rely on cell culture. Lipids are components that are universally distributed throughout cells providing a means to assess independent of culturability.

  8. Methods for analysis of fluoroquinolones in biological fluids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods for analysis of 10 selected fluoroquinolone antibiotics in biological fluids are reviewed. Approaches for sample preparation, detection methods, limits of detection and quantitation and recovery information are provided for both single analyte and multi-analyte fluoroquinolone methods....

  9. CUMULATIVE RISK ASSESSMENT: GETTING FROM TOXICOLOGY TO QUANTITATIVE ANALYSIS

    EPA Science Inventory

    INTRODUCTION: GETTING FROM TOXICOLOGY TO QUANTITATIVE ANALYSIS FOR CUMULATIVE RISK

    Hugh A. Barton1 and Carey N. Pope2
    1US EPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC
    2Department of...

  10. Quantitative Methods for Comparing Different Polyline Stream Network Models

    SciTech Connect

    Danny L. Anderson; Daniel P. Ames; Ping Yang

    2014-04-01

    Two techniques for exploring relative horizontal accuracy of complex linear spatial features are described and sample source code (pseudo code) is presented for this purpose. The first technique, relative sinuosity, is presented as a measure of the complexity or detail of a polyline network in comparison to a reference network. We term the second technique longitudinal root mean squared error (LRMSE) and present it as a means for quantitatively assessing the horizontal variance between two polyline data sets representing digitized (reference) and derived stream and river networks. Both relative sinuosity and LRMSE are shown to be suitable measures of horizontal stream network accuracy for assessing quality and variation in linear features. Both techniques have been used in two recent investigations involving extracting of hydrographic features from LiDAR elevation data. One confirmed that, with the greatly increased resolution of LiDAR data, smaller cell sizes yielded better stream network delineations, based on sinuosity and LRMSE, when using LiDAR-derived DEMs. The other demonstrated a new method of delineating stream channels directly from LiDAR point clouds, without the intermediate step of deriving a DEM, showing that the direct delineation from LiDAR point clouds yielded an excellent and much better match, as indicated by the LRMSE.

  11. Structural and Quantitative Analysis of Three C-Glycosylflavones by Variable Temperature Proton Quantitative Nuclear Magnetic Resonance

    PubMed Central

    Liu, Yang; Dai, Zhong

    2017-01-01

    Quantitative nuclear magnetic resonance is a powerful tool in drug analysis because of its speed, precision, and efficiency. In present study, the application of variable temperature proton quantitative nuclear magnetic resonance (VT-1H-qNMR) for the calibration of three C-glycosylflavones including orientin, isoorientin, and schaftoside as reference substances was reported. Since there was conformational equilibrium due to the restricted rotation around the C(sp3)-C(sp2) bond in C-glycosylflavones, the conformational behaviors were investigated by VT-NMR and verified by molecular mechanics (MM) calculation. The VT-1H-qNMR method was validated including the linearity, limit of quantification, precision, and stability. The results were consistent with those obtained from mass balance approach. VT-1H-qNMR can be deployed as an effective tool in analyzing C-glycosylflavones. PMID:28243484

  12. The correlation of contrast-enhanced ultrasound and MRI perfusion quantitative analysis in rabbit VX2 liver cancer.

    PubMed

    Xiang, Zhiming; Liang, Qianwen; Liang, Changhong; Zhong, Guimian

    2014-12-01

    Our objective is to explore the value of liver cancer contrast-enhanced ultrasound (CEUS) and MRI perfusion quantitative analysis in liver cancer and the correlation between these two analysis methods. Rabbit VX2 liver cancer model was established in this study. CEUS was applied. Sono Vue was applied in rabbits by ear vein to dynamically observe and record the blood perfusion and changes in the process of VX2 liver cancer and surrounding tissue. MRI perfusion quantitative analysis was used to analyze the mean enhancement time and change law of maximal slope increasing, which were further compared with the pathological examination results. Quantitative indicators of liver cancer CEUS and MRI perfusion quantitative analysis were compared, and the correlation between them was analyzed by correlation analysis. Rabbit VX2 liver cancer model was successfully established. CEUS showed that time-intensity curve of rabbit VX2 liver cancer showed "fast in, fast out" model while MRI perfusion quantitative analysis showed that quantitative parameter MTE of tumor tissue increased and MSI decreased: the difference was statistically significant (P < 0.01). The diagnostic results of CEUS and MRI perfusion quantitative analysis were not significantly different (P > 0.05). However, the quantitative parameter of them were significantly positively correlated (P < 0.05). CEUS and MRI perfusion quantitative analysis can both dynamically monitor the liver cancer lesion and surrounding liver parenchyma, and the quantitative parameters of them are correlated. The combined application of both is of importance in early diagnosis of liver cancer.

  13. Quantitative x-ray diffraction phase analysis of coarse airborne particulate collected by cascade impactor sampling

    NASA Astrophysics Data System (ADS)

    Esteve, V.; Rius, J.; Ochando, L. E.; Amigó, J. M.

    Mineralogical composition of Castellon (Spanish Mediterranean coast) atmospheric aerosol was studied by X-ray diffraction by sampling with a cascade impactor without filters. Quantitative phase analysis of natural phases present in the atmospheric coarse aerosol was performed using a modified version of the computer program MENGE, that uses the standardless X-ray method developed by Rius for the quantitative analysis of multiphase mixtures, adapted for PC running. Presence of quartz, calcite and gypsum was identified in the atmospheric aerosol and we have quantified their amounts using the standardless method.

  14. Analysis of liver connexin expression using reverse transcription quantitative real-time polymerase chain reaction

    PubMed Central

    Maes, Michaël; Willebrords, Joost; Crespo Yanguas, Sara; Cogliati, Bruno; Vinken, Mathieu

    2016-01-01

    Summary Although connexin production is mainly regulated at the protein level, altered connexin gene expression has been identified as the underlying mechanism of several pathologies. When studying the latter, appropriate methods to quantify connexin mRNA levels are required. The present chapter describes a well-established reverse transcription quantitative real-time polymerase chain reaction procedure optimized for analysis of hepatic connexins. The method includes RNA extraction and subsequent quantification, generation of complementary DNA, quantitative real-time polymerase chain reaction and data analysis. PMID:27207283

  15. Quantitative analysis of culture using millions of digitized books.

    PubMed

    Michel, Jean-Baptiste; Shen, Yuan Kui; Aiden, Aviva Presser; Veres, Adrian; Gray, Matthew K; Pickett, Joseph P; Hoiberg, Dale; Clancy, Dan; Norvig, Peter; Orwant, Jon; Pinker, Steven; Nowak, Martin A; Aiden, Erez Lieberman

    2011-01-14

    We constructed a corpus of digitized texts containing about 4% of all books ever printed. Analysis of this corpus enables us to investigate cultural trends quantitatively. We survey the vast terrain of 'culturomics,' focusing on linguistic and cultural phenomena that were reflected in the English language between 1800 and 2000. We show how this approach can provide insights about fields as diverse as lexicography, the evolution of grammar, collective memory, the adoption of technology, the pursuit of fame, censorship, and historical epidemiology. Culturomics extends the boundaries of rigorous quantitative inquiry to a wide array of new phenomena spanning the social sciences and the humanities.

  16. Quantitative analysis of culture using millions of digitized books

    PubMed Central

    Michel, Jean-Baptiste; Shen, Yuan Kui; Aiden, Aviva P.; Veres, Adrian; Gray, Matthew K.; Pickett, Joseph P.; Hoiberg, Dale; Clancy, Dan; Norvig, Peter; Orwant, Jon; Pinker, Steven; Nowak, Martin A.; Aiden, Erez Lieberman

    2011-01-01

    We constructed a corpus of digitized texts containing about 4% of all books ever printed. Analysis of this corpus enables us to investigate cultural trends quantitatively. We survey the vast terrain of ‘culturomics’, focusing on linguistic and cultural phenomena that were reflected in the English language between 1800 and 2000. We show how this approach can provide insights about fields as diverse as lexicography, the evolution of grammar, collective memory, the adoption of technology, the pursuit of fame, censorship, and historical epidemiology. ‘Culturomics’ extends the boundaries of rigorous quantitative inquiry to a wide array of new phenomena spanning the social sciences and the humanities. PMID:21163965

  17. Quantitative numerical analysis of transient IR-experiments on buildings

    NASA Astrophysics Data System (ADS)

    Maierhofer, Ch.; Wiggenhauser, H.; Brink, A.; Röllig, M.

    2004-12-01

    Impulse-thermography has been established as a fast and reliable tool in many areas of non-destructive testing. In recent years several investigations have been done to apply active thermography to civil engineering. For quantitative investigations in this area of application, finite difference calculations have been performed for systematic studies on the influence of environmental conditions, heating power and time, defect depth and size and thermal properties of the bulk material (concrete). The comparison of simulated and experimental data enables the quantitative analysis of defects.

  18. The Measles Vaccination Narrative in Twitter: A Quantitative Analysis

    PubMed Central

    Radzikowski, Jacek; Jacobsen, Kathryn H; Croitoru, Arie; Crooks, Andrew; Delamater, Paul L

    2016-01-01

    Background The emergence of social media is providing an alternative avenue for information exchange and opinion formation on health-related issues. Collective discourse in such media leads to the formation of a complex narrative, conveying public views and perceptions. Objective This paper presents a study of Twitter narrative regarding vaccination in the aftermath of the 2015 measles outbreak, both in terms of its cyber and physical characteristics. We aimed to contribute to the analysis of the data, as well as presenting a quantitative interdisciplinary approach to analyze such open-source data in the context of health narratives. Methods We collected 669,136 tweets referring to vaccination from February 1 to March 9, 2015. These tweets were analyzed to identify key terms, connections among such terms, retweet patterns, the structure of the narrative, and connections to the geographical space. Results The data analysis captures the anatomy of the themes and relations that make up the discussion about vaccination in Twitter. The results highlight the higher impact of stories contributed by news organizations compared to direct tweets by health organizations in communicating health-related information. They also capture the structure of the antivaccination narrative and its terms of reference. Analysis also revealed the relationship between community engagement in Twitter and state policies regarding child vaccination. Residents of Vermont and Oregon, the two states with the highest rates of non-medical exemption from school-entry vaccines nationwide, are leading the social media discussion in terms of participation. Conclusions The interdisciplinary study of health-related debates in social media across the cyber-physical debate nexus leads to a greater understanding of public concerns, views, and responses to health-related issues. Further coalescing such capabilities shows promise towards advancing health communication, thus supporting the design of more

  19. Spotsizer: High-throughput quantitative analysis of microbial growth

    PubMed Central

    Jeffares, Daniel C.; Arzhaeva, Yulia; Bähler, Jürg

    2017-01-01

    Microbial colony growth can serve as a useful readout in assays for studying complex genetic interactions or the effects of chemical compounds. Although computational tools for acquiring quantitative measurements of microbial colonies have been developed, their utility can be compromised by inflexible input image requirements, non-trivial installation procedures, or complicated operation. Here, we present the Spotsizer software tool for automated colony size measurements in images of robotically arrayed microbial colonies. Spotsizer features a convenient graphical user interface (GUI), has both single-image and batch-processing capabilities, and works with multiple input image formats and different colony grid types. We demonstrate how Spotsizer can be used for high-throughput quantitative analysis of fission yeast growth. The user-friendly Spotsizer tool provides rapid, accurate, and robust quantitative analyses of microbial growth in a high-throughput format. Spotsizer is freely available at https://data.csiro.au/dap/landingpage?pid=csiro:15330 under a proprietary CSIRO license. PMID:27712582

  20. Spotsizer: High-throughput quantitative analysis of microbial growth.

    PubMed

    Bischof, Leanne; Převorovský, Martin; Rallis, Charalampos; Jeffares, Daniel C; Arzhaeva, Yulia; Bähler, Jürg

    2016-10-01

    Microbial colony growth can serve as a useful readout in assays for studying complex genetic interactions or the effects of chemical compounds. Although computational tools for acquiring quantitative measurements of microbial colonies have been developed, their utility can be compromised by inflexible input image requirements, non-trivial installation procedures, or complicated operation. Here, we present the Spotsizer software tool for automated colony size measurements in images of robotically arrayed microbial colonies. Spotsizer features a convenient graphical user interface (GUI), has both single-image and batch-processing capabilities, and works with multiple input image formats and different colony grid types. We demonstrate how Spotsizer can be used for high-throughput quantitative analysis of fission yeast growth. The user-friendly Spotsizer tool provides rapid, accurate, and robust quantitative analyses of microbial growth in a high-throughput format. Spotsizer is freely available at https://data.csiro.au/dap/landingpage?pid=csiro:15330 under a proprietary CSIRO license.

  1. Automatic segmentation method of striatum regions in quantitative susceptibility mapping images

    NASA Astrophysics Data System (ADS)

    Murakawa, Saki; Uchiyama, Yoshikazu; Hirai, Toshinori

    2015-03-01

    Abnormal accumulation of brain iron has been detected in various neurodegenerative diseases. Quantitative susceptibility mapping (QSM) is a novel contrast mechanism in magnetic resonance (MR) imaging and enables the quantitative analysis of local tissue susceptibility property. Therefore, automatic segmentation tools of brain regions on QSM images would be helpful for radiologists' quantitative analysis in various neurodegenerative diseases. The purpose of this study was to develop an automatic segmentation and classification method of striatum regions on QSM images. Our image database consisted of 22 QSM images obtained from healthy volunteers. These images were acquired on a 3.0 T MR scanner. The voxel size was 0.9×0.9×2 mm. The matrix size of each slice image was 256×256 pixels. In our computerized method, a template mating technique was first used for the detection of a slice image containing striatum regions. An image registration technique was subsequently employed for the classification of striatum regions in consideration of the anatomical knowledge. After the image registration, the voxels in the target image which correspond with striatum regions in the reference image were classified into three striatum regions, i.e., head of the caudate nucleus, putamen, and globus pallidus. The experimental results indicated that 100% (21/21) of the slice images containing striatum regions were detected accurately. The subjective evaluation of the classification results indicated that 20 (95.2%) of 21 showed good or adequate quality. Our computerized method would be useful for the quantitative analysis of Parkinson diseases in QSM images.

  2. Enabling Quantitative Analysis in Ambient Ionization Mass Spectrometry: Internal Standard Coated Capillary Samplers

    PubMed Central

    Liu, Jiangjiang; Cooks, R. Graham; Ouyang, Zheng

    2013-01-01

    We describe a sampling method using glass capillaries for quantitative analysis of trace analytes in small volumes of complex mixtures (~1 μL) using ambient ionization mass spectrometry. The internal surface of a sampling glass capillary was coated with internal standard then used to draw liquid sample and so transfer both the analyte and internal standard in a single fixed volume onto a substrate for analysis. The internal standard was automatically mixed into the sample during this process and the volumes of the internal standard solution and sample are both fixed by the capillary volume. Precision in quantitation is insensitive to variations in length of the capillary, making the preparation of the sampling capillary simple and providing a robust sampling protocol. Significant improvements in quantitation accuracy were obtained for analysis of 1 μL samples using various ambient ionization methods. PMID:23731380

  3. Statistical shape analysis using 3D Poisson equation--A quantitatively validated approach.

    PubMed

    Gao, Yi; Bouix, Sylvain

    2016-05-01

    Statistical shape analysis has been an important area of research with applications in biology, anatomy, neuroscience, agriculture, paleontology, etc. Unfortunately, the proposed methods are rarely quantitatively evaluated, and as shown in recent studies, when they are evaluated, significant discrepancies exist in their outputs. In this work, we concentrate on the problem of finding the consistent location of deformation between two population of shapes. We propose a new shape analysis algorithm along with a framework to perform a quantitative evaluation of its performance. Specifically, the algorithm constructs a Signed Poisson Map (SPoM) by solving two Poisson equations on the volumetric shapes of arbitrary topology, and statistical analysis is then carried out on the SPoMs. The method is quantitatively evaluated on synthetic shapes and applied on real shape data sets in brain structures.

  4. Apparatus and method for quantitative determination of materials contained in fluids

    DOEpatents

    Radziemski, Leon J.; Cremers, David A.

    1985-01-01

    Apparatus and method for near real-time in-situ monitoring of particulates and vapors contained in fluids. Initial filtration of a known volume of the fluid sample is combined with laser-induced dielectric breakdown spectroscopy of the filter employed to obtain qualitative and quantitative information with high sensitivity. Application of the invention to monitoring of beryllium, beryllium oxide, or other beryllium-alloy dusts is demonstrated. Significant shortening of analysis time is achieved from those of the usual chemical techniques of analysis.

  5. Apparatus and method for quantitative determination of materials contained in fluids

    DOEpatents

    Radziemski, L.J.; Cremers, D.A.

    1982-09-07

    Apparatus and method for near real-time in-situ monitoring of particulates and vapors contained in fluids are described. Initial filtration of a known volume of the fluid sample is combined with laser-induced dielectric breakdown spectroscopy of the filter employed to obtain qualitative and quantitative information with high sensitivity. Application of the invention to monitoring of beryllium, beryllium oxide, or other beryllium-alloy dusts is shown. Significant shortening of analysis time is achieved from the usual chemical techniques of analysis.

  6. Thermography as a quantitative imaging method for assessing postoperative inflammation

    PubMed Central

    Christensen, J; Matzen, LH; Vaeth, M; Schou, S; Wenzel, A

    2012-01-01

    Objective To assess differences in skin temperature between the operated and control side of the face after mandibular third molar surgery using thermography. Methods 127 patients had 1 mandibular third molar removed. Before the surgery, standardized thermograms were taken of both sides of the patient's face using a Flir ThermaCam™ E320 (Precisions Teknik AB, Halmstad, Sweden). The imaging procedure was repeated 2 days and 7 days after surgery. A region of interest including the third molar region was marked on each image. The mean temperature within each region of interest was calculated. The difference between sides and over time were assessed using paired t-tests. Results No significant difference was found between the operated side and the control side either before or 7 days after surgery (p > 0.3). The temperature of the operated side (mean: 32.39 °C, range: 28.9–35.3 °C) was higher than that of the control side (mean: 32.06 °C, range: 28.5–35.0 °C) 2 days after surgery [0.33 °C, 95% confidence interval (CI): 0.22–0.44 °C, p < 0.001]. No significant difference was found between the pre-operative and the 7-day post-operative temperature (p > 0.1). After 2 days, the operated side was not significantly different from the temperature pre-operatively (p = 0.12), whereas the control side had a lower temperature (0.57 °C, 95% CI: 0.29–0.86 °C, p < 0.001). Conclusions Thermography seems useful for quantitative assessment of inflammation between the intervention side and the control side after surgical removal of mandibular third molars. However, thermography cannot be used to assess absolute temperature changes due to normal variations in skin temperature over time. PMID:22752326

  7. Quantitative SERS sensors for environmental analysis of naphthalene.

    PubMed

    Péron, O; Rinnert, E; Toury, T; Lamy de la Chapelle, M; Compère, C

    2011-03-07

    In the investigation of chemical pollutants, such as PAHs (Polycyclic Aromatic Hydrocarbons) at low concentration in aqueous medium, Surface-Enhanced Raman Scattering (SERS) stands for an alternative to the inherent low cross-section of normal Raman scattering. Indeed, SERS is a very sensitive spectroscopic technique due to the excitation of the surface plasmon modes of the nanostructured metallic film. The surface of quartz substrates was coated with a hydrophobic film obtained by silanization and subsequently reacted with polystyrene (PS) beads coated with gold nanoparticles. The hydrophobic surface of the SERS substrates pre-concentrates non-polar molecules such as naphthalene. Under laser excitation, the SERS-active substrates allow the detection and the identification of the target molecules localized close to the gold nanoparticles. The morphology of the SERS substrates based on polystyrene beads surrounded by gold nanoparticles was characterized by scanning electron microscopy (SEM). Furthermore, the Raman fingerprint of the polystyrene stands for an internal spectral reference. To this extent, an innovative method to detect and to quantify organic molecules, as naphthalene in the range of 1 to 20 ppm, in aqueous media was carried out. Such SERS-active substrates tend towards an application as quantitative SERS sensors for the environmental analysis of naphthalene.

  8. Segmentation of vascular structures and hematopoietic cells in 3D microscopy images and quantitative analysis

    NASA Astrophysics Data System (ADS)

    Mu, Jian; Yang, Lin; Kamocka, Malgorzata M.; Zollman, Amy L.; Carlesso, Nadia; Chen, Danny Z.

    2015-03-01

    In this paper, we present image processing methods for quantitative study of how the bone marrow microenvironment changes (characterized by altered vascular structure and hematopoietic cell distribution) caused by diseases or various factors. We develop algorithms that automatically segment vascular structures and hematopoietic cells in 3-D microscopy images, perform quantitative analysis of the properties of the segmented vascular structures and cells, and examine how such properties change. In processing images, we apply local thresholding to segment vessels, and add post-processing steps to deal with imaging artifacts. We propose an improved watershed algorithm that relies on both intensity and shape information and can separate multiple overlapping cells better than common watershed methods. We then quantitatively compute various features of the vascular structures and hematopoietic cells, such as the branches and sizes of vessels and the distribution of cells. In analyzing vascular properties, we provide algorithms for pruning fake vessel segments and branches based on vessel skeletons. Our algorithms can segment vascular structures and hematopoietic cells with good quality. We use our methods to quantitatively examine the changes in the bone marrow microenvironment caused by the deletion of Notch pathway. Our quantitative analysis reveals property changes in samples with deleted Notch pathway. Our tool is useful for biologists to quantitatively measure changes in the bone marrow microenvironment, for developing possible therapeutic strategies to help the bone marrow microenvironment recovery.

  9. Development and validation of an HPLC-MS/MS analytical method for quantitative analysis of TCBA-TPQ, a novel anticancer makaluvamine analog, and application in a pharmacokinetic study in rats

    PubMed Central

    Jun-Xian, YU; Voruganti, Sukesh; Dan-Dan, LI; Qin, Jiang-Jiang; Nag, Subhasree; Xu, Su; Velu, Sadanandan E.; Wang, Wei; Zhang, Ruiwen

    2016-01-01

    We have recently designed and synthesized several novel iminoquinone anticancer agents that have entered preclinical development for the treatment of human cancers. Herein we developed and validated a quantitative HPLC-MS/MS analytical method for one of the lead novel anticancer makaluvamine analog, TCBA-TPQ, and conducted a pharmacokinetic study in laboratory rats. Our results indicated that the HPLC-MS/MS method was precise, accurate, and specific. Using this method, we carried out in vitro and in vivo evaluations of the pharmacological properties of TCBA-TPQ and plasma pharmacokinetics in rats. Our results provide a basis for future preclinical and clinical development of this promising anticancer marine analog. PMID:26233847

  10. Quantitative Expression Analysis in Brassica napus by Northern Blot Analysis and Reverse Transcription-Quantitative PCR in a Complex Experimental Setting.

    PubMed

    Rumlow, Annekathrin; Keunen, Els; Klein, Jan; Pallmann, Philip; Riemenschneider, Anja; Cuypers, Ann; Papenbrock, Jutta

    Analysis of gene expression is one of the major ways to better understand plant reactions to changes in environmental conditions. The comparison of many different factors influencing plant growth challenges the gene expression analysis for specific gene-targeted experiments, especially with regard to the choice of suitable reference genes. The aim of this study is to compare expression results obtained by Northern blot, semi-quantitative PCR and RT-qPCR, and to identify a reliable set of reference genes for oilseed rape (Brassica napus L.) suitable for comparing gene expression under complex experimental conditions. We investigated the influence of several factors such as sulfur deficiency, different time points during the day, varying light conditions, and their interaction on gene expression in oilseed rape plants. The expression of selected reference genes was indeed influenced under these conditions in different ways. Therefore, a recently developed algorithm, called GrayNorm, was applied to validate a set of reference genes for normalizing results obtained by Northern blot analysis. After careful comparison of the three methods mentioned above, Northern blot analysis seems to be a reliable and cost-effective alternative for gene expression analysis under a complex growth regime. For using this method in a quantitative way a number of references was validated revealing that for our experiment a set of three references provides an appropriate normalization. Semi-quantitative PCR was prone to many handling errors and difficult to control while RT-qPCR was very sensitive to expression fluctuations of the reference genes.

  11. Quantitative risk analysis of oil storage facilities in seismic areas.

    PubMed

    Fabbrocino, Giovanni; Iervolino, Iunio; Orlando, Francesca; Salzano, Ernesto

    2005-08-31

    Quantitative risk analysis (QRA) of industrial facilities has to take into account multiple hazards threatening critical equipment. Nevertheless, engineering procedures able to evaluate quantitatively the effect of seismic action are not well established. Indeed, relevant industrial accidents may be triggered by loss of containment following ground shaking or other relevant natural hazards, either directly or through cascade effects ('domino effects'). The issue of integrating structural seismic risk into quantitative probabilistic seismic risk analysis (QpsRA) is addressed in this paper by a representative study case regarding an oil storage plant with a number of atmospheric steel tanks containing flammable substances. Empirical seismic fragility curves and probit functions, properly defined both for building-like and non building-like industrial components, have been crossed with outcomes of probabilistic seismic hazard analysis (PSHA) for a test site located in south Italy. Once the seismic failure probabilities have been quantified, consequence analysis has been performed for those events which may be triggered by the loss of containment following seismic action. Results are combined by means of a specific developed code in terms of local risk contour plots, i.e. the contour line for the probability of fatal injures at any point (x, y) in the analysed area. Finally, a comparison with QRA obtained by considering only process-related top events is reported for reference.

  12. Sequencing human ribs into anatomical order by quantitative multivariate methods.

    PubMed

    Cirillo, John; Henneberg, Maciej

    2012-06-01

    Little research has focussed on methods to anatomically sequence ribs. Correct anatomical sequencing of ribs assists in determining the location and distribution of regional trauma, age estimation, number of puncture wounds, number of individuals, and personal identification. The aim of the current study is to develop a method for placing fragmented and incomplete rib sets into correct anatomical position. Ribs 2-10 were used from eleven cadavers of an Australian population. Seven variables were measured from anatomical locations on the rib. General descriptive statistics were calculated for each variable along with an analysis of variance (ANOVA) and ANOVA with Bonferroni statistics. Considerable overlap was observed between ribs for univariate methods. Bivariate and multivariate methods were then applied. Results of the ANOVA with post hoc Bonferroni statistics show that ratios of various dimensions of a single rib could be used to sequence it within adjacent ribs. Using multiple regression formulae, the most accurate estimation of the anatomical rib number occurs when the entire rib is found in isolation. This however, is not always possible. Even when only the head and neck of the rib are preserved, a modified multivariate regression formula assigned 91.95% of ribs into correct anatomical position or as an adjacent rib. Using multivariate methods it is possible to sequence a single human rib with a high level of accuracy and they are superior to univariate methods. Left and right ribs were found to be highly symmetrical. Some rib dimensions were greater in males than in females, but overall the level of sexual dimorphism was low.

  13. Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays

    PubMed Central

    Guetterman, Timothy C.; Fetters, Michael D.; Creswell, John W.

    2015-01-01

    PURPOSE Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. METHODS We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. RESULTS The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. CONCLUSIONS Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. PMID:26553895

  14. Evaluation of the quantitative performances of supercritical fluid chromatography: from method development to validation.

    PubMed

    Dispas, Amandine; Lebrun, Pierre; Ziemons, Eric; Marini, Roland; Rozet, Eric; Hubert, Philippe

    2014-08-01

    Recently, the number of papers about SFC increased drastically but scientists did not truly focus their work on quantitative performances of this technique. In order to prove the potential of UHPSFC, the present work discussed about the different steps of the analytical life cycle of a method: from development to validation and application. Moreover, the UHPSFC quantitative performances were evaluated in comparison with UHPLC, which is the main technique used for quality control in the pharmaceutical industry and then could be considered as a reference. The methods were developed using Design Space strategy, leading to the optimization of robust method. In this context, when the Design Space optimization shows guarantee of quality, no more robustness study is required prior to the validation. Then, the methods were geometrically transferred in order to reduce the analysis time. The UHPSFC and UHPLC methods were validated based on the total error approach using accuracy profile. Even if UHPLC showed better precision and sensitivity, UHPSFC method is able to give accurate results in a dosing range larger than the 80-120% range required by the European Medicines Agency. Consequently, UHPSFC results are valid and could be used for the control of active substance in a finished pharmaceutical product. Finally, UHPSFC validated method was used to analyse real samples and gave similar results than the reference method (UHPLC).

  15. Methods and challenges in quantitative imaging biomarker development.

    PubMed

    Abramson, Richard G; Burton, Kirsteen R; Yu, John-Paul J; Scalzetti, Ernest M; Yankeelov, Thomas E; Rosenkrantz, Andrew B; Mendiratta-Lala, Mishal; Bartholmai, Brian J; Ganeshan, Dhakshinamoorthy; Lenchik, Leon; Subramaniam, Rathan M

    2015-01-01

    Academic radiology is poised to play an important role in the development and implementation of quantitative imaging (QI) tools. This article, drafted by the Association of University Radiologists Radiology Research Alliance Quantitative Imaging Task Force, reviews current issues in QI biomarker research. We discuss motivations for advancing QI, define key terms, present a framework for QI biomarker research, and outline challenges in QI biomarker development. We conclude by describing where QI research and development is currently taking place and discussing the paramount role of academic radiology in this rapidly evolving field.

  16. Quantitative Decomposition of Dynamics of Mathematical Cell Models: Method and Application to Ventricular Myocyte Models.

    PubMed

    Shimayoshi, Takao; Cha, Chae Young; Amano, Akira

    2015-01-01

    Mathematical cell models are effective tools to understand cellular physiological functions precisely. For detailed analysis of model dynamics in order to investigate how much each component affects cellular behaviour, mathematical approaches are essential. This article presents a numerical analysis technique, which is applicable to any complicated cell model formulated as a system of ordinary differential equations, to quantitatively evaluate contributions of respective model components to the model dynamics in the intact situation. The present technique employs a novel mathematical index for decomposed dynamics with respect to each differential variable, along with a concept named instantaneous equilibrium point, which represents the trend of a model variable at some instant. This article also illustrates applications of the method to comprehensive myocardial cell models for analysing insights into the mechanisms of action potential generation and calcium transient. The analysis results exhibit quantitative contributions of individual channel gating mechanisms and ion exchanger activities to membrane repolarization and of calcium fluxes and buffers to raising and descending of the cytosolic calcium level. These analyses quantitatively explicate principle of the model, which leads to a better understanding of cellular dynamics.

  17. A Framework for Mixing Methods in Quantitative Measurement Development, Validation, and Revision: A Case Study

    ERIC Educational Resources Information Center

    Luyt, Russell

    2012-01-01

    A framework for quantitative measurement development, validation, and revision that incorporates both qualitative and quantitative methods is introduced. It extends and adapts Adcock and Collier's work, and thus, facilitates understanding of quantitative measurement development, validation, and revision as an integrated and cyclical set of…

  18. Studying learning in the healthcare setting: the potential of quantitative diary methods.

    PubMed

    Ciere, Yvette; Jaarsma, Debbie; Visser, Annemieke; Sanderman, Robbert; Snippe, Evelien; Fleer, Joke

    2015-08-01

    Quantitative diary methods are longitudinal approaches that involve the repeated measurement of aspects of peoples' experience of daily life. In this article, we outline the main characteristics and applications of quantitative diary methods and discuss how their use may further research in the field of medical education. Quantitative diary methods offer several methodological advantages, such as measuring aspects of learning with great detail, accuracy and authenticity. Moreover, they enable researchers to study how and under which conditions learning in the health care setting occurs and in which way learning can be promoted. Hence, quantitative diary methods may contribute to theory development and the optimization of teaching methods in medical education.

  19. Comprehensive rotorcraft analysis methods

    NASA Technical Reports Server (NTRS)

    Stephens, Wendell B.; Austin, Edward E.

    1988-01-01

    The development and application of comprehensive rotorcraft analysis methods in the field of rotorcraft technology are described. These large scale analyses and the resulting computer programs are intended to treat the complex aeromechanical phenomena that describe the behavior of rotorcraft. They may be used to predict rotor aerodynamics, acoustic, performance, stability and control, handling qualities, loads and vibrations, structures, dynamics, and aeroelastic stability characteristics for a variety of applications including research, preliminary and detail design, and evaluation and treatment of field problems. The principal comprehensive methods developed or under development in recent years and generally available to the rotorcraft community because of US Army Aviation Research and Technology Activity (ARTA) sponsorship of all or part of the software systems are the Rotorcraft Flight Simulation (C81), Dynamic System Coupler (DYSCO), Coupled Rotor/Airframe Vibration Analysis Program (SIMVIB), Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD), General Rotorcraft Aeromechanical Stability Program (GRASP), and Second Generation Comprehensive Helicopter Analysis System (2GCHAS).

  20. Implementing a Quantitative Analysis Design Tool for Future Generation Interfaces

    DTIC Science & Technology

    2012-03-01

    future MAC-enabled systems. A human-computer interaction ( HCI ) Index, originally applied to multi-function displays was applied to the prototype Vigilant...Spirit interface. A modified version of the HCI Index was successfully applied to perform a quantitative analysis of the baseline VSCS interface and...two modified interface designs. The modified HCI Index incorporates the Hick-Hyman decision time, Fitts’ Law time, and the physical actions

  1. Quantitative NMR Analysis of Partially Substituted Biodiesel Glycerols

    SciTech Connect

    Nagy, M.; Alleman, T. L.; Dyer, T.; Ragauskas, A. J.

    2009-01-01

    Phosphitylation of hydroxyl groups in biodiesel samples with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane followed by 31P-NMR analysis provides a rapid quantitative analytical technique for the determination of substitution patterns on partially esterified glycerols. The unique 31P-NMR chemical shift data was established with a series mono and di-substituted fatty acid esters of glycerol and then utilized to characterize an industrial sample of partially processed biodiesel.

  2. Quantitative methods to characterize morphological properties of cell lines.

    PubMed

    Mancia, Annalaura; Elliott, John T; Halter, Michael; Bhadriraju, Kiran; Tona, Alessandro; Spurlin, Tighe A; Middlebrooks, Bobby L; Baatz, John E; Warr, Gregory W; Plant, Anne L

    2012-07-01

    Descriptive terms are often used to characterize cells in culture, but the use of nonquantitative and poorly defined terms can lead to ambiguities when comparing data from different laboratories. Although recently there has been a good deal of interest in unambiguous identification of cell lines via their genetic markers, it is also critical to have definitive, quantitative metrics to describe cell phenotypic characteristics. Quantitative metrics of cell phenotype will aid the comparison of data from experiments performed at different times and in different laboratories where influences such as the age of the population and differences in culture conditions or protocols can potentially affect cellular metabolic state and gene expression in the absence of changes in the genetic profile. Here, we present examples of robust methodologies for quantitatively assessing characteristics of cell morphology and cell-cell interactions, and of growth rates of cells within the population. We performed these analyses with endothelial cell lines derived from dolphin, bovine and human, and with a mouse fibroblast cell line. These metrics quantify some characteristics of these cells lines that clearly distinguish them from one another, and provide quantitative information on phenotypic changes in one of the cell lines over large number of passages.

  3. Guidelines for Reporting Quantitative Methods and Results in Primary Research

    ERIC Educational Resources Information Center

    Norris, John M.; Plonsky, Luke; Ross, Steven J.; Schoonen, Rob

    2015-01-01

    Adequate reporting of quantitative research about language learning involves careful consideration of the logic, rationale, and actions underlying both study designs and the ways in which data are analyzed. These guidelines, commissioned and vetted by the board of directors of "Language Learning," outline the basic expectations for…

  4. Quantitative Methods for Administrative Decision Making in Junior Colleges.

    ERIC Educational Resources Information Center

    Gold, Benjamin Knox

    With the rapid increase in number and size of junior colleges, administrators must take advantage of the decision-making tools already used in business and industry. This study investigated how these quantitative techniques could be applied to junior college problems. A survey of 195 California junior college administrators found that the problems…

  5. [The method of quantitative assessment of dentition aesthetic parameters].

    PubMed

    Ryakhovsky, A N; Kalacheva, Ya A

    2016-01-01

    This article describes the formula for calculating the aesthetic index of treatment outcome. The formula was derived on the basis of the obtained regression equations showing the dependence of visual assessment of the value of aesthetic violations. The formula can be used for objective quantitative evaluation of the aesthetics of the teeth when smiling before and after dental treatment.

  6. Quantitative and Qualitative Analysis of Nutrition and Food Safety Information in School Science Textbooks of India

    ERIC Educational Resources Information Center

    Subba Rao, G. M.; Vijayapushapm, T.; Venkaiah, K.; Pavarala, V.

    2012-01-01

    Objective: To assess quantity and quality of nutrition and food safety information in science textbooks prescribed by the Central Board of Secondary Education (CBSE), India for grades I through X. Design: Content analysis. Methods: A coding scheme was developed for quantitative and qualitative analyses. Two investigators independently coded the…

  7. Qualitative and quantitative analysis of mixtures of compounds containing both hydrogen and deuterium

    NASA Technical Reports Server (NTRS)

    Crespi, H. L.; Harkness, L.; Katz, J. J.; Norman, G.; Saur, W.

    1969-01-01

    Method allows qualitative and quantitative analysis of mixtures of partially deuterated compounds. Nuclear magnetic resonance spectroscopy determines location and amount of deuterium in organic compounds but not fully deuterated compounds. Mass spectroscopy can detect fully deuterated species but not the location.

  8. Gas chromatograph-mass spectrometer (GC/MS) system for quantitative analysis of reactive chemical compounds

    DOEpatents

    Grindstaff, Quirinus G.

    1992-01-01

    Described is a new gas chromatograph-mass spectrometer (GC/MS) system and method for quantitative analysis of reactive chemical compounds. All components of such a GC/MS system external to the oven of the gas chromatograph are programmably temperature controlled to operate at a volatilization temperature specific to the compound(s) sought to be separated and measured.

  9. Clinical applications of a quantitative analysis of regional lift ventricular wall motion

    NASA Technical Reports Server (NTRS)

    Leighton, R. F.; Rich, J. M.; Pollack, M. E.; Altieri, P. I.

    1975-01-01

    Observations were summarized which may have clinical application. These were obtained from a quantitative analysis of wall motion that was used to detect both hypokinesis and tardokinesis in left ventricular cineangiograms. The method was based on statistical comparisons with normal values for regional wall motion derived from the cineangiograms of patients who were found not to have heart disease.

  10. Quantitative Evaluation of the Total Magnetic Moments of Colloidal Magnetic Nanoparticles: A Kinetics-based Method.

    PubMed

    Liu, Haiyi; Sun, Jianfei; Wang, Haoyao; Wang, Peng; Song, Lina; Li, Yang; Chen, Bo; Zhang, Yu; Gu, Ning

    2015-06-08

    A kinetics-based method is proposed to quantitatively characterize the collective magnetization of colloidal magnetic nanoparticles. The method is based on the relationship between the magnetic force on a colloidal droplet and the movement of the droplet under a gradient magnetic field. Through computational analysis of the kinetic parameters, such as displacement, velocity, and acceleration, the magnetization of colloidal magnetic nanoparticles can be calculated. In our experiments, the values measured by using our method exhibited a better linear correlation with magnetothermal heating, than those obtained by using a vibrating sample magnetometer and magnetic balance. This finding indicates that this method may be more suitable to evaluate the collective magnetism of colloidal magnetic nanoparticles under low magnetic fields than the commonly used methods. Accurate evaluation of the magnetic properties of colloidal nanoparticles is of great importance for the standardization of magnetic nanomaterials and for their practical application in biomedicine.

  11. [Quantitative surface analysis of Pt-Co, Cu-Au and Cu-Ag alloy films by XPS and AES].

    PubMed

    Li, Lian-Zhong; Zhuo, Shang-Jun; Shen, Ru-Xiang; Qian, Rong; Gao, Jie

    2013-11-01

    In order to improve the quantitative analysis accuracy of AES, We associated XPS with AES and studied the method to reduce the error of AES quantitative analysis, selected Pt-Co, Cu-Au and Cu-Ag binary alloy thin-films as the samples, used XPS to correct AES quantitative analysis results by changing the auger sensitivity factors to make their quantitative analysis results more similar. Then we verified the accuracy of the quantitative analysis of AES when using the revised sensitivity factors by other samples with different composition ratio, and the results showed that the corrected relative sensitivity factors can reduce the error in quantitative analysis of AES to less than 10%. Peak defining is difficult in the form of the integral spectrum of AES analysis since choosing the starting point and ending point when determining the characteristic auger peak intensity area with great uncertainty, and to make analysis easier, we also processed data in the form of the differential spectrum, made quantitative analysis on the basis of peak to peak height instead of peak area, corrected the relative sensitivity factors, and verified the accuracy of quantitative analysis by the other samples with different composition ratio. The result showed that the analytical error in quantitative analysis of AES reduced to less than 9%. It showed that the accuracy of AES quantitative analysis can be highly improved by the way of associating XPS with AES to correct the auger sensitivity factors since the matrix effects are taken into account. Good consistency was presented, proving the feasibility of this method.

  12. Study of proper conditions for quantitative atom-probe analysis

    NASA Astrophysics Data System (ADS)

    Rolander, Ulf; Andrén, Hans-Olof

    1994-03-01

    Atom-probe microanalysis is a truly quantitative method only if certain requirements are fulfilled. Field evaporation must only happen when the detector system is active; ions must travel from specimen to detector without being obstructed; and ions must be detected with the same probability regardless of mass and energy. Designs and methods to achieve these requirements are presented in the paper, such as a controlled high-voltage pulser, a detector with good and variable multi-hit resolution, ion optical alignment procedures, and a method to statistically correct for pile-up in the detector.

  13. Quantitative proton nuclear magnetic resonance for the structural and quantitative analysis of atropine sulfate.

    PubMed

    Shen, Shi; Yao, Jing; Shi, Yaqin

    2014-02-01

    This study assessed a general method of quantitative nuclear magnetic resonance (qNMR) for the calibration of atropine sulfate (Active Pharmaceutical Ingredient, API) as reference standard. The spectra were acquired in D2O using maleic acid as the internal standard. Conformational behaviors of tropane ring were observed and studied by means of NMR and ROESY experiments at different temperature, which showed that the azine methyl group was at equilibrium for axial and equatorial conformations at room temperature. Signal delay and monitor signals of qNMR experimentation were optimized for quantification. The study reported here validated the method's linearity, range, limit of quantification, stability and precision. The results were consistent with the results obtained from mass balance approach.

  14. Reliable Quantitative SERS Analysis Facilitated by Core-Shell Nanoparticles with Embedded Internal Standards.

    PubMed

    Shen, Wei; Lin, Xuan; Jiang, Chaoyang; Li, Chaoyu; Lin, Haixin; Huang, Jingtao; Wang, Shuo; Liu, Guokun; Yan, Xiaomei; Zhong, Qiling; Ren, Bin

    2015-06-15

    Quantitative analysis is a great challenge in surface-enhanced Raman scattering (SERS). Core-molecule-shell nanoparticles with two components in the molecular layer, a framework molecule to form the shell, and a probe molecule as a Raman internal standard, were rationally designed for quantitative SERS analysis. The signal of the embedded Raman probe provides effective feedback to correct the fluctuation of samples and measuring conditions. Meanwhile, target molecules with different affinities can be adsorbed onto the shell. The quantitative analysis of target molecules over a large concentration range has been demonstrated with a linear response of the relative SERS intensity versus the surface coverage, which has not been achieved by conventional SERS methods.

  15. Quantitative analysis of immobilized metalloenzymes by atomic absorption spectroscopy.

    PubMed

    Opwis, Klaus; Knittel, Dierk; Schollmeyer, Eckhard

    2004-12-01

    A new, sensitive assay for the quantitative determination of immobilized metal containing enzymes has been developed using atomic absorption spectroscopy (AAS). In contrast with conventionally used indirect methods the described quantitative AAS assay for metalloenzymes allows more exact analyses, because the carrier material with the enzyme is investigated directly. As an example, the validity and reliability of the method was examined by fixing the iron-containing enzyme catalase on cotton fabrics using different immobilization techniques. Sample preparation was carried out by dissolving the loaded fabrics in sulfuric acid before oxidising the residues with hydrogen peroxide. The iron concentrations were determined by flame atomic absorption spectrometry after calibration of the spectrometer with solutions of the free enzyme at different concentrations.

  16. Quantitative analysis of the mixtures of illicit drugs using terahertz time-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Jiang, Dejun; Zhao, Shusen; Shen, Jingling

    2008-03-01

    A method was proposed to quantitatively inspect the mixtures of illicit drugs with terahertz time-domain spectroscopy technique. The mass percentages of all components in a mixture can be obtained by linear regression analysis, on the assumption that all components in the mixture and their absorption features be known. For illicit drugs were scarce and expensive, firstly we used common chemicals, Benzophenone, Anthraquinone, Pyridoxine hydrochloride and L-Ascorbic acid in the experiment. Then illicit drugs and a common adulterant, methamphetamine and flour, were selected for our experiment. Experimental results were in significant agreement with actual content, which suggested that it could be an effective method for quantitative identification of illicit drugs.

  17. Semi-quantitative spectrographic analysis and rank correlation in geochemistry

    USGS Publications Warehouse

    Flanagan, F.J.

    1957-01-01

    The rank correlation coefficient, rs, which involves less computation than the product-moment correlation coefficient, r, can be used to indicate the degree of relationship between two elements. The method is applicable in situations where the assumptions underlying normal distribution correlation theory may not be satisfied. Semi-quantitative spectrographic analyses which are reported as grouped or partly ranked data can be used to calculate rank correlations between elements. ?? 1957.

  18. Quantitative analysis of Euclidean distance to complement qualitative analysis of facial expression during deception

    PubMed Central

    Mondal, Ananya; Mukhopadhyay, Pritha; Basu, Nabanita; Bandyopadhyay, Samir Kumar; Chatterjee, Tanima

    2016-01-01

    Background: Accurate evaluation of an individuals' veracity is a fundamental aspect of social functioning that allows individuals to act in adaptive ways. The domain of deception detection ability is still young, and many components in this field are yet to be touched which demands more research in this field. Aims: The present study aims at deciphering the structural composition of face during felt, posed, and deceived emotions in facial expression unique to Indian culture, using Facial Action Coding System (FACS). Quantitative analysis of Euclidean distance has been done to complement qualitative FACS analysis. Methods: In this study, thirty female, young adults with age range of 23–27 years were chosen randomly for portraying their (felt, posed, and deceived) facial expression. All facial expressions were captured through instruction, and videos were converted into static images. The static images were coded on the basis of FACS to decipher the felt, posed, and deceived expressions. Quantitative analysis of the data has been done using MATLAB to meet the objectives of the study and to complement the qualitative analysis. Results: Felt and posed emotions differ in terms of intensity of the expression and subjective experience. Posed emotional and deceived expressions differ in intent. Facial asymmetry is an important indicator for detecting deception. PMID:28163412

  19. Quantitative proteomic analysis by accurate mass retention time pairs.

    PubMed

    Silva, Jeffrey C; Denny, Richard; Dorschel, Craig A; Gorenstein, Marc; Kass, Ignatius J; Li, Guo-Zhong; McKenna, Therese; Nold, Michael J; Richardson, Keith; Young, Phillip; Geromanos, Scott

    2005-04-01

    Current methodologies for protein quantitation include 2-dimensional gel electrophoresis techniques, metabolic labeling, and stable isotope labeling methods to name only a few. The current literature illustrates both pros and cons for each of the previously mentioned methodologies. Keeping with the teachings of William of Ockham, "with all things being equal the simplest solution tends to be correct", a simple LC/MS based methodology is presented that allows relative changes in abundance of proteins in highly complex mixtures to be determined. Utilizing a reproducible chromatographic separations system along with the high mass resolution and mass accuracy of an orthogonal time-of-flight mass spectrometer, the quantitative comparison of tens of thousands of ions emanating from identically prepared control and experimental samples can be made. Using this configuration, we can determine the change in relative abundance of a small number of ions between the two conditions solely by accurate mass and retention time. Employing standard operating procedures for both sample preparation and ESI-mass spectrometry, one typically obtains under 5 ppm mass precision and quantitative variations between 10 and 15%. The principal focus of this paper will demonstrate the quantitative aspects of the methodology and continue with a discussion of the associated, complementary qualitative capabilities.

  20. A quantitative method for the evaluation of three-dimensional structure of temporal bone pneumatization

    PubMed Central

    Hill, Cheryl A.; Richtsmeier, Joan T.

    2010-01-01

    Temporal bone pneumatization has been included in lists of characters used in phylogenetic analyses of human evolution. While studies suggest that the extent of pneumatization has decreased over the course of human evolution, little is known about the processes underlying these changes or their significance. In short, reasons for the observed reduction and the potential reorganization within pneumatized spaces are unknown. Technological limitations have limited previous analyses of pneumatization in extant and fossil species to qualitative observations of the extent of temporal bone pneumatization. In this paper, we introduce a novel application of quantitative methods developed for the study of trabecular bone to the analysis of pneumatized spaces of the temporal bone. This method utilizes high-resolution X-ray computed tomography (HRXCT) images and quantitative software to estimate three-dimensional parameters (bone volume fractions, anisotropy, and trabecular thickness) of bone structure within defined units of pneumatized spaces. We apply this approach in an analysis of temporal bones of diverse but related primate species, Gorilla gorilla, Pan troglodytes, Homo sapiens, and Papio hamadryas anubis, to illustrate the potential of these methods. In demonstrating the utility of these methods, we show that there are interspecific differences in the bone structure of pneumatized spaces, perhaps reflecting changes in the localized growth dynamics, location of muscle attachments, encephalization, or basicranial flexion. PMID:18715622

  1. Mini-Column Ion-Exchange Separation and Atomic Absorption Quantitation of Nickel, Cobalt, and Iron: An Undergraduate Quantitative Analysis Experiment.

    ERIC Educational Resources Information Center

    Anderson, James L.; And Others

    1980-01-01

    Presents an undergraduate quantitative analysis experiment, describing an atomic absorption quantitation scheme that is fast, sensitive and comparatively simple relative to other titration experiments. (CS)

  2. Quantitative risk assessment methods for cancer and noncancer effects.

    PubMed

    Baynes, Ronald E

    2012-01-01

    Human health risk assessments have evolved from the more qualitative approaches to more quantitative approaches in the past decade. This has been facilitated by the improvement in computer hardware and software capability and novel computational approaches being slowly recognized by regulatory agencies. These events have helped reduce the reliance on experimental animals as well as better utilization of published animal toxicology data in deriving quantitative toxicity indices that may be useful for risk management purposes. This chapter briefly describes some of the approaches as described in the guidance documents from several of the regulatory agencies as it pertains to hazard identification and dose-response assessment of a chemical. These approaches are contrasted with more novel computational approaches that provide a better grasp of the uncertainty often associated with chemical risk assessments.

  3. Fluorescent microscopy approaches of quantitative soil microbial analysis

    NASA Astrophysics Data System (ADS)

    Ivanov, Konstantin; Polyanskaya, Lubov

    2015-04-01

    Classical fluorescent microscopy method was used during the last decades in various microbiological studies of terrestrial ecosystems. The method provides representative results and simple application which is allow to use it both as routine part of amplitudinous research and in small-scaled laboratories. Furthermore, depending on research targets a lot of modifications of fluorescent microscopy method were established. Combination and comparison of several approaches is an opportunity of quantitative estimation of microbial community in soil. The first analytical part of the study was dedicated to soil bacterial density estimation by fluorescent microscopy in dynamic of several 30-days experiments. The purpose of research was estimation of changes in soil bacterial community on the different soil horizons under aerobic and anaerobic conditions with adding nutrients in two experimental sets: cellulose and chitin. Was modified the nalidixic acid method for inhibition of DNA division of gram-negative bacteria, and the method provides the quantification of this bacterial group by fluorescent microscopy. Established approach allowed to estimate 3-4 times more cells of gram-negative bacteria in soil. The functions of actinomyces in soil polymer destruction are traditionally considered as dominant in comparison to gram-negative bacterial group. However, quantification of gram-negative bacteria in chernozem and peatland provides underestimation of classical notion for this bacterial group. Chitin introduction had no positive effect to gram-negative bacterial population density changes in chernozem but concurrently this nutrient provided the fast growing dynamics at the first 3 days of experiment both under aerobic and anaerobic conditions. This is confirming chitinolytic activity of gram-negative bacteria in soil organic matter decomposition. At the next part of research modified method for soil gram-negative bacteria quantification was compared to fluorescent in situ

  4. A method for normalizing pathology images to improve feature extraction for quantitative pathology

    SciTech Connect

    Tam, Allison; Barker, Jocelyn; Rubin, Daniel

    2016-01-15

    Purpose: With the advent of digital slide scanning technologies and the potential proliferation of large repositories of digital pathology images, many research studies can leverage these data for biomedical discovery and to develop clinical applications. However, quantitative analysis of digital pathology images is impeded by batch effects generated by varied staining protocols and staining conditions of pathological slides. Methods: To overcome this problem, this paper proposes a novel, fully automated stain normalization method to reduce batch effects and thus aid research in digital pathology applications. Their method, intensity centering and histogram equalization (ICHE), normalizes a diverse set of pathology images by first scaling the centroids of the intensity histograms to a common point and then applying a modified version of contrast-limited adaptive histogram equalization. Normalization was performed on two datasets of digitized hematoxylin and eosin (H&E) slides of different tissue slices from the same lung tumor, and one immunohistochemistry dataset of digitized slides created by restaining one of the H&E datasets. Results: The ICHE method was evaluated based on image intensity values, quantitative features, and the effect on downstream applications, such as a computer aided diagnosis. For comparison, three methods from the literature were reimplemented and evaluated using the same criteria. The authors found that ICHE not only improved performance compared with un-normalized images, but in most cases showed improvement compared with previous methods for correcting batch effects in the literature. Conclusions: ICHE may be a useful preprocessing step a digital pathology image processing pipeline.

  5. Quantitative gas chromatographic analysis of volatile fatty acids in spent culture media and body fluids.

    PubMed Central

    van den Bogaard, A E; Hazen, M J; Van Boven, C P

    1986-01-01

    Gas chromatographic analysis of volatile fatty acids for identification of obligately anaerobic bacteria and for presumptive diagnosis of anaerobic infections is now widely practiced. However, it is difficult to compare data because only a qualitative analysis is done or only chromatograms are presented instead of quantitative data on volatile fatty acid production. We compared three stationary phases for volatile fatty acid analysis of aqueous solutions and four methods of pretreating samples for gas chromatography. Quantitative analysis could be done accurately by using Carbowax as the stationary phase after pretreatment of spent culture media with Dowex columns. If only qualitative analysis is required (e.g., for presumptive diagnosis of anaerobic infections), ether extraction and headspace analysis are equally suitable. The overall variation coefficient for volatile fatty acid production by four reference strains of obligately anaerobic bacteria after 24 h of incubation was approximately 10%. PMID:3958144

  6. EXTRACTION AND QUANTITATIVE ANALYSIS OF ELEMENTAL SULFUR FROM SULFIDE MINERAL SURFACES BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY. (R826189)

    EPA Science Inventory

    A simple method for the quantitative determination of elemental sulfur on oxidized sulfide minerals is described. Extraction of elemental sulfur in perchloroethylene and subsequent analysis with high-performance liquid chromatography were used to ascertain the total elemental ...

  7. Quantitative analysis of maytansinoid (DM1) in human serum by on-line solid phase extraction coupled with liquid chromatography tandem mass spectrometry - Method validation and its application to clinical samples.

    PubMed

    Heudi, Olivier; Barteau, Samuel; Picard, Franck; Kretz, Olivier

    2016-02-20

    A sensitive and specific method was developed and validated for the quantitation of maytansinoid (DM1) in human serum using on-line solid phase extraction (SPE)-liquid chromatography-tandem mass spectrometry (LC-MS/MS). Because DM1 contains a free thiol moiety, likely to readily dimerize or react with other thiol-containing molecules in serum, samples were pre-treated with a reducing agent [tris (2-carboxyethyl) phosphine] (TCEP) and further blocked with N-ethylmaleimide (NEM). The resulting samples were diluted with acetonitrile prior to the on-line solid phase extraction (SPE) on a C18 cartridge. A C18 (150×4.6mm ID 3μm particle size) column was used for chromatographic separation with a 10.0min HPLC gradient and DM1-NEM was detected in the selected reaction monitoring mode of a triple quadrupole mass spectrometer. DM1 concentrations were back-calculated from DM1-NEM amount found in the human serum samples. The quantitation range of the method was 0.200-200ng/mL when using 0.25mL serum. Within-run day precisions (n=6) were 0.9-4.4% and between-run day (3 days runs; n=18) precisions 2.5-5.6%. Method biases were between 3.5-14.5% across the whole calibration range. DM1-NEM exhibited sufficiently stability under all relevant analytical conditions and no DM1 losses from the ADC were observed. Finally, the assay was used for DM1 determination in human serum concentration after the intravenous administration of an investigational antibody drug conjugate (ADC) containing DM1 as payload.

  8. Cell poking: quantitative analysis of indentation of thick viscoelastic layers.

    PubMed

    Duszyk, M; Schwab, B; Zahalak, G I; Qian, H; Elson, E L

    1989-04-01

    A recently introduced device, the cell poker, measures the force required to indent the exposed surface of a cell adherent to a rigid substratum. The cell poker has provided phenomenological information about the viscoelastic properties of several different types of cells, about mechanical changes triggered by external stimuli, and about the role of the cytoskeleton in these mechanical functions. Except in special cases, however, it has not been possible to extract quantitative estimates of viscosity and elasticity moduli from cell poker measurements. This paper presents cell poker measurements of well characterized viscoelastic polymeric materials, polydimethylsiloxanes of different degrees of polymerization, in a simple shape, a flat, thick layer, which for our purposes can be treated as a half space. Analysis of the measurements in terms of a linear viscoelasticity theory yields viscosity values for three polymer samples in agreement with those determined by measurements on a macroscopic scale. Theoretical analysis further indicates that the measured limiting static elasticity of the layers may result from the tension generated at the interface between the polymer and water. This work demonstrates the possibility of obtaining quantitative viscoelastic material properties from cell poker measurements and represents the first step in extending these quantitative studies to more complicated structures including cells.

  9. Cell poking: quantitative analysis of indentation of thick viscoelastic layers.

    PubMed Central

    Duszyk, M; Schwab, B; Zahalak, G I; Qian, H; Elson, E L

    1989-01-01

    A recently introduced device, the cell poker, measures the force required to indent the exposed surface of a cell adherent to a rigid substratum. The cell poker has provided phenomenological information about the viscoelastic properties of several different types of cells, about mechanical changes triggered by external stimuli, and about the role of the cytoskeleton in these mechanical functions. Except in special cases, however, it has not been possible to extract quantitative estimates of viscosity and elasticity moduli from cell poker measurements. This paper presents cell poker measurements of well characterized viscoelastic polymeric materials, polydimethylsiloxanes of different degrees of polymerization, in a simple shape, a flat, thick layer, which for our purposes can be treated as a half space. Analysis of the measurements in terms of a linear viscoelasticity theory yields viscosity values for three polymer samples in agreement with those determined by measurements on a macroscopic scale. Theoretical analysis further indicates that the measured limiting static elasticity of the layers may result from the tension generated at the interface between the polymer and water. This work demonstrates the possibility of obtaining quantitative viscoelastic material properties from cell poker measurements and represents the first step in extending these quantitative studies to more complicated structures including cells. PMID:2720066

  10. Quantitative Analysis of the Effective Functional Structure in Yeast Glycolysis

    PubMed Central

    De la Fuente, Ildefonso M.; Cortes, Jesus M.

    2012-01-01

    The understanding of the effective functionality that governs the enzymatic self-organized processes in cellular conditions is a crucial topic in the post-genomic era. In recent studies, Transfer Entropy has been proposed as a rigorous, robust and self-consistent method for the causal quantification of the functional information flow among nonlinear processes. Here, in order to quantify the functional connectivity for the glycolytic enzymes in dissipative conditions we have analyzed different catalytic patterns using the technique of Transfer Entropy. The data were obtained by means of a yeast glycolytic model formed by three delay differential equations where the enzymatic rate equations of the irreversible stages have been explicitly considered. These enzymatic activity functions were previously modeled and tested experimentally by other different groups. The results show the emergence of a new kind of dynamical functional structure, characterized by changing connectivity flows and a metabolic invariant that constrains the activity of the irreversible enzymes. In addition to the classical topological structure characterized by the specific location of enzymes, substrates, products and feedback-regulatory metabolites, an effective functional structure emerges in the modeled glycolytic system, which is dynamical and characterized by notable variations of the functional interactions. The dynamical structure also exhibits a metabolic invariant which constrains the functional attributes of the enzymes. Finally, in accordance with the classical biochemical studies, our numerical analysis reveals in a quantitative manner that the enzyme phosphofructokinase is the key-core of the metabolic system, behaving for all conditions as the main source of the effective causal flows in yeast glycolysis. PMID:22393350

  11. Using qualitative and quantitative methods to evaluate small-scale disease management pilot programs.

    PubMed

    Esposito, Dominick; Taylor, Erin Fries; Gold, Marsha

    2009-02-01

    Interest in disease management programs continues to grow as managed care plans, the federal and state governments, and other organizations consider such efforts as a means to improve health care quality and reduce costs. These efforts vary in size, scope, and target population. While large-scale programs provide the means to measure impacts, evaluation of smaller interventions remains valuable as they often represent the early planning stages of larger initiatives. This paper describes a multi-method approach for evaluating small interventions that sought to improve the quality of care for Medicaid beneficiaries with multiple chronic conditions. Our approach relied on quantitative and qualitative methods to develop a complete understanding of each intervention. Quantitative data in the form of both process measures, such as case manager contacts, and outcome measures, such as hospital use, were reported and analyzed. Qualitative information was collected through interviews and the development of logic models to document the flow of intervention activities and how they were intended to affect outcomes. The logic models helped us to understand the underlying reasons for the success or lack thereof of each intervention. The analysis provides useful information on several fronts. First, qualitative data provided valuable information about implementation. Second, process measures helped determine whether implementation occurred as anticipated. Third, outcome measures indicated the potential for favorable results later, possibly suggesting further study. Finally, the evaluation of qualitative and quantitative data in combination helped us assess the potential promise of each intervention and identify common themes and challenges across all interventions.

  12. Quantitative analysis of endocytosis with cytoplasmic pHluorin chimeras.

    PubMed

    Prosser, Derek C; Whitworth, Karen; Wendland, Beverly

    2010-09-01

    The pH-sensitive green fluorescent protein (GFP) variant pHluorin is typically fused to the extracellular domain of transmembrane proteins to monitor endocytosis. Here, we have turned pHluorin inside-out, and show that cytoplasmic fusions of pHluorin are effective quantitative reporters for endocytosis and multivesicular body (MVB) sorting. In yeast in particular, fusion of GFP and its variants on the extracellular side of transmembrane proteins can result in perturbed trafficking. In contrast, cytoplasmic fusions are well tolerated, allowing for the quantitative assessment of trafficking of virtually any transmembrane protein. Quenching of degradation-resistant pHluorin in the acidic vacuole permits quantification of extravacuolar cargo proteins at steady-state levels and is compatible with kinetic analysis of endocytosis in live cells.

  13. Ammonia quantitative analysis model based on miniaturized Al ionization gas sensor and non-linear bistable dynamic model

    PubMed Central

    Ma, Rongfei

    2015-01-01

    In this paper, ammonia quantitative analysis based on miniaturized Al ionization gas sensor and non-linear bistable dynamic model was proposed. Al plate anodic gas-ionization sensor was used to obtain the current-voltage (I-V) data. Measurement data was processed by non-linear bistable dynamics model. Results showed that the proposed method quantitatively determined ammonia concentrations. PMID:25975362

  14. Rapid determination of lymphogranuloma venereum serovars of Chlamydia trachomatis by quantitative high-resolution melt analysis (HRMA).

    PubMed

    Twin, Jimmy; Stevens, Matthew P; Garland, Suzanne M; Zaia, Angelo M; Tabrizi, Sepehr N

    2012-11-01

    A quantitative high-resolution melt analysis assay was developed to differentiate lymphogranuloma venereum-causing serovars of Chlamydia trachomatis (L1 to L3) from other C. trachomatis serovars (D to K). The detection limit of this assay is approximately 10 copies per reaction, comparable to the limits of other quantitative-PCR-based methods.

  15. Quantitative analysis of somatic mitochondrial DNA mutations by single-cell single-molecule PCR.

    PubMed

    Kraytsberg, Yevgenya; Bodyak, Natalya; Myerow, Susan; Nicholas, Alexander; Ebralidze, Konstantin; Khrapko, Konstantin

    2009-01-01

    Mitochondrial genome integrity is an important issue in somatic mitochondrial genetics. Development of quantitative methods is indispensable to somatic mitochondrial genetics as quantitative studies are required to characterize heteroplasmy and mutation processes, as well as their effects on phenotypic developments. Quantitative studies include the identification and measurement of the load of pathogenic and non-pathogenic clonal mutations, screening mitochondrial genomes for mutations in order to determine the mutation spectra and characterize an ongoing mutation process. Single-molecule PCR (smPCR) has been shown to be an effective method that can be applied to all areas of quantitative studies. It has distinct advantages over conventional vector-based cloning techniques avoiding the well-known PCR-related artifacts such as the introduction of artificial mutations, preferential allelic amplifications, and "jumping" PCR. smPCR is a straightforward and robust method, which can be effectively used for molecule-by-molecule mutational analysis, even when mitochondrial whole genome (mtWG) analysis is involved. This chapter describes the key features of the smPCR method and provides three examples of its applications in single-cell analysis: di-plex smPCR for deletion quantification, smPCR cloning for clonal point mutation quantification, and smPCR cloning for whole genome sequencing (mtWGS).

  16. Identification and quantitative analysis of chemical compounds based on multiscale linear fitting of terahertz spectra

    NASA Astrophysics Data System (ADS)

    Qiao, Lingbo; Wang, Yingxin; Zhao, Ziran; Chen, Zhiqiang

    2014-07-01

    Terahertz (THz) time-domain spectroscopy is considered as an attractive tool for the analysis of chemical composition. The traditional methods for identification and quantitative analysis of chemical compounds by THz spectroscopy are all based on full-spectrum data. However, intrinsic features of the THz spectrum only lie in absorption peaks due to existence of disturbances, such as unexpected components, scattering effects, and barrier materials. We propose a strategy that utilizes Lorentzian parameters of THz absorption peaks, extracted by a multiscale linear fitting method, for both identification of pure chemicals and quantitative analysis of mixtures. The multiscale linear fitting method can automatically remove background content and accurately determine Lorentzian parameters of the absorption peaks. The high recognition rate for 16 pure chemical compounds and the accurate predicted concentrations for theophylline-lactose mixtures demonstrate the practicability of our approach.

  17. MCM - 2 and Ki - 67 as proliferation markers in renal cell carcinoma: A quantitative and semi - quantitative analysis

    PubMed Central

    Mehdi, Muhammad Zain; Nagi, Abdul Hanan; Naseem, Nadia

    2016-01-01

    ABSTRACT Introduction/Background: Fuhrman nuclear grade is the most important histological parameter to predict prognosis in a patient of renal cell carcinoma (RCC). However, it suffers from inter-observer and intra-observer variation giving rise to need of a parameter that not only correlates with nuclear grade but is also objective and reproducible. Proliferation is the measure of aggressiveness of a tumour and it is strongly correlated with Fuhrman nuclear grade, clinical survival and recurrence in RCC. Ki-67 is conventionally used to assess proliferation. Mini-chromosome maintenance 2 (MCM-2) is a lesser known marker of proliferation and identifies a greater proliferation faction. This study was designed to assess the prognostic significance of MCM-2 by comparing it with Fuhrman nuclear grade and Ki-67. Material and Methods: n=50 cases of various ages, stages, histological subtypes and grades of RCC were selected for this study. Immunohistochemical staining using Ki-67(MIB-1, Mouse monoclonal antibody, Dako) and MCM-2 (Mouse monoclonal antibody, Thermo) was performed on the paraffin embedded blocks in the department of Morbid anatomy and Histopathology, University of Health Sciences, Lahore. Labeling indices (LI) were determined by two pathologists independently using quantitative and semi-quantitative analysis. Statistical analysis was carried out using SPSS 20.0. Kruskall-Wallis test was used to determine a correlation of proliferation markers with grade, and Pearson's correlate was used to determine correlation between the two proliferation markers. Results: Labeling index of MCM-2 (median=24.29%) was found to be much higher than Ki-67(median=13.05%). Both markers were significantly related with grade (p=0.00; Kruskall-Wallis test). LI of MCM-2 was found to correlate significantly with LI of Ki-67(r=0.0934;p=0.01 with Pearson's correlate). Results of semi-quantitative analysis correlated well with quantitative analysis. Conclusion: Both Ki-67 and MCM-2 are

  18. Dynamic and Quantitative Method of Analyzing Service Consistency Evolution Based on Extended Hierarchical Finite State Automata

    PubMed Central

    Fan, Linjun; Tang, Jun; Ling, Yunxiang; Li, Benxian

    2014-01-01

    This paper is concerned with the dynamic evolution analysis and quantitative measurement of primary factors that cause service inconsistency in service-oriented distributed simulation applications (SODSA). Traditional methods are mostly qualitative and empirical, and they do not consider the dynamic disturbances among factors in service's evolution behaviors such as producing, publishing, calling, and maintenance. Moreover, SODSA are rapidly evolving in terms of large-scale, reusable, compositional, pervasive, and flexible features, which presents difficulties in the usage of traditional analysis methods. To resolve these problems, a novel dynamic evolution model extended hierarchical service-finite state automata (EHS-FSA) is constructed based on finite state automata (FSA), which formally depict overall changing processes of service consistency states. And also the service consistency evolution algorithms (SCEAs) based on EHS-FSA are developed to quantitatively assess these impact factors. Experimental results show that the bad reusability (17.93% on average) is the biggest influential factor, the noncomposition of atomic services (13.12%) is the second biggest one, and the service version's confusion (1.2%) is the smallest one. Compared with previous qualitative analysis, SCEAs present good effectiveness and feasibility. This research can guide the engineers of service consistency technologies toward obtaining a higher level of consistency in SODSA. PMID:24772033

  19. Quantitative methods in the tuberculosis epidemiology and in the evaluation of BCG vaccination programs.

    PubMed

    Lugosi, L

    1986-01-01

    Controversies concerning the protective efficacy of the BCG vaccination result mostly from the fact that quantitative methods have not been used in the evaluation of the BCG programs. Therefore, to eliminate the current controversy an unconditional requirement is to apply valid biostatistical models to analyse the results of the BCG programs. In order to achieve objective statistical inferences and epidemiological interpretations the following conditions should be fulfilled: data for evaluation have to be taken from epidemiological trials exempt from sampling error, since the morbidity rates are not normally distributed an appropriate normalizing transformation is needed for point and confidence interval estimations, only unbiased point estimates (dependent variables) could be used in valid models for hypothesis tests, in cases of rejected null hypothesis the ranked estimates of the compared groups must be evaluated in a multiple comparison model in order to diminish the Type I error in the decision. The following quantitative methods are presented to evaluate the effectiveness of BCG vaccination in Hungary: linear regression analysis, stepwise regression analysis and log-linear analysis.

  20. Dynamic and quantitative method of analyzing service consistency evolution based on extended hierarchical finite state automata.

    PubMed

    Fan, Linjun; Tang, Jun; Ling, Yunxiang; Li, Benxian

    2014-01-01

    This paper is concerned with the dynamic evolution analysis and quantitative measurement of primary factors that cause service inconsistency in service-oriented distributed simulation applications (SODSA). Traditional methods are mostly qualitative and empirical, and they do not consider the dynamic disturbances among factors in service's evolution behaviors such as producing, publishing, calling, and maintenance. Moreover, SODSA are rapidly evolving in terms of large-scale, reusable, compositional, pervasive, and flexible features, which presents difficulties in the usage of traditional analysis methods. To resolve these problems, a novel dynamic evolution model extended hierarchical service-finite state automata (EHS-FSA) is constructed based on finite state automata (FSA), which formally depict overall changing processes of service consistency states. And also the service consistency evolution algorithms (SCEAs) based on EHS-FSA are developed to quantitatively assess these impact factors. Experimental results show that the bad reusability (17.93% on average) is the biggest influential factor, the noncomposition of atomic services (13.12%) is the second biggest one, and the service version's confusion (1.2%) is the smallest one. Compared with previous qualitative analysis, SCEAs present good effectiveness and feasibility. This research can guide the engineers of service consistency technologies toward obtaining a higher level of consistency in SODSA.