The Influence of the Antecedent Variable on the Teachers' Performance through Achievement Motivation in Senior High School

ERIC Educational Resources Information Center

Dewi, Erni R.; Bundu, Patta; Tahmir, Suradi

2016-01-01

This study aims at analysing whether the antecedent variable directly affects the performance of the high school teachers or not. In addition, this research strives to find out whether the antecedent variable indirectly affects the teachers' performance through the achievement motivation of the high school teachers. It was a quantitative research…

Simultaneous determination of niacin and pyridoxine at trace levels by using diode array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry.

PubMed

Sel, Sabriye; Öztürk Er, Elif; Bakırdere, Sezgin

2017-12-01

A highly sensitive and simple diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method was developed for the simultaneous determination of niacin and pyridoxine in pharmaceutical drugs, tap water, and wastewater samples. To determine the in vivo behavior of niacin and pyridoxine, analytes were subjected to simulated gastric conditions. The calibration plots of the diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method showed good linearity over a wide concentration range with close to 1.0 correlation coefficients for both analytes. The limit of detection/limit of quantitation values for liquid chromatography quadrupole time-of-flight tandem mass spectrometry analysis were 1.98/6.59 and 1.3/4.4 μg/L for niacin and pyridoxine, respectively, while limit of detection/limit of quantitation values for niacin and pyridoxine in high-performance liquid chromatography analysis were 3.7/12.3 and 5.7/18.9 μg/L, respectively. Recovery studies were also performed to show the applicability of the developed methods, and percentage recovery values were found to be 90-105% in tap water and 94-97% in wastewater for both analytes. The method was also successfully applied for the qualitative and quantitative determination of niacin and pyridoxine in drug samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Two-way and three-way approaches to ultra high performance liquid chromatography-photodiode array dataset for the quantitative resolution of a two-component mixture containing ciprofloxacin and ornidazole.

PubMed

Dinç, Erdal; Ertekin, Zehra Ceren; Büker, Eda

2016-09-01

Two-way and three-way calibration models were applied to ultra high performance liquid chromatography with photodiode array data with coeluted peaks in the same wavelength and time regions for the simultaneous quantitation of ciprofloxacin and ornidazole in tablets. The chromatographic data cube (tensor) was obtained by recording chromatographic spectra of the standard and sample solutions containing ciprofloxacin and ornidazole with sulfadiazine as an internal standard as a function of time and wavelength. Parallel factor analysis and trilinear partial least squares were used as three-way calibrations for the decomposition of the tensor, whereas three-way unfolded partial least squares was applied as a two-way calibration to the unfolded dataset obtained from the data array of ultra high performance liquid chromatography with photodiode array detection. The validity and ability of two-way and three-way analysis methods were tested by analyzing validation samples: synthetic mixture, interday and intraday samples, and standard addition samples. Results obtained from two-way and three-way calibrations were compared to those provided by traditional ultra high performance liquid chromatography. The proposed methods, parallel factor analysis, trilinear partial least squares, unfolded partial least squares, and traditional ultra high performance liquid chromatography were successfully applied to the quantitative estimation of the solid dosage form containing ciprofloxacin and ornidazole. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical Carcinogen-Induced Changes in tRNA Metabolism in Human Cells.

DTIC Science & Technology

1983-11-30

expression of carcinogenesis is postulated. MATERIALS AND METHODS Nucleosldem In urine were resolved and quantitated using reversed-phase high performance...liquid chromatography 8 following clarification on a boronate colun 5 . Quantitation was relative to the creatinine content in random urine specimens 7...Patients Urinary nucleoside excretion has been quantitated for patients with nasopharyngeal carcinoma (NPC) and leukemia, and the results nLn m l

ICSH recommendations for assessing automated high-performance liquid chromatography and capillary electrophoresis equipment for the quantitation of HbA2.

PubMed

Stephens, A D; Colah, R; Fucharoen, S; Hoyer, J; Keren, D; McFarlane, A; Perrett, D; Wild, B J

2015-10-01

Automated high performance liquid chromatography and Capillary electrophoresis are used to quantitate the proportion of Hemoglobin A2 (HbA2 ) in blood samples order to enable screening and diagnosis of carriers of β-thalassemia. Since there is only a very small difference in HbA2 levels between people who are carriers and people who are not carriers such analyses need to be both precise and accurate. This paper examines the different parameters of such equipment and discusses how they should be assessed. © 2015 John Wiley & Sons Ltd.

Quality evaluation of moluodan concentrated pill using high-performance liquid chromatography fingerprinting coupled with chemometrics.

PubMed

Tao, Lingyan; Zhang, Qing; Wu, Yongjiang; Liu, Xuesong

2016-12-01

In this study, a fast and effective high-performance liquid chromatography method was developed to obtain a fingerprint chromatogram and quantitative analysis simultaneously of four indexes including gallic acid, chlorogenic acid, albiflorin and paeoniflorin of the traditional Chinese medicine Moluodan Concentrated Pill. The method was performed by using a Waters X-bridge C 18 reversed phase column on an Agilent 1200S high-performance liquid chromatography system coupled with diode array detection. The mobile phase of the high-performance liquid chromatography method was composed of 20 mmol/L phosphate solution and acetonitrile with a 1 mL/min eluent velocity, under a detection temperature of 30°C and a UV detection wavelength of 254 nm. After the methodology validation, 16 batches of Moluodan Concentrated Pill were analyzed by this high-performance liquid chromatography method and both qualitative and quantitative evaluation results were achieved by similarity analysis, principal component analysis and hierarchical cluster analysis. The results of these three chemometrics were in good agreement and all indicated that batch 10 and batch 16 showed significant differences with the other 14 batches. This suggested that the developed high-performance liquid chromatography method could be applied in the quality evaluation of Moluodan Concentrated Pill. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantitative analysis of benzodiazepines in vitreous humor by high-performance liquid chromatography

PubMed Central

Bazmi, Elham; Behnoush, Behnam; Akhgari, Maryam; Bahmanabadi, Leila

2016-01-01

Objective: Benzodiazepines are frequently screened drugs in emergency toxicology, drugs of abuse testing, and in forensic cases. As the variations of benzodiazepines concentrations in biological samples during bleeding, postmortem changes, and redistribution could be biasing forensic medicine examinations, hence selecting a suitable sample and a validated accurate method is essential for the quantitative analysis of these main drug categories. The aim of this study was to develop a valid method for the determination of four benzodiazepines (flurazepam, lorazepam, alprazolam, and diazepam) in vitreous humor using liquid–liquid extraction and high-performance liquid chromatography. Methods: Sample preparation was carried out using liquid–liquid extraction with n-hexane: ethyl acetate and subsequent detection by high-performance liquid chromatography method coupled to diode array detector. This method was applied to quantify benzodiazepines in 21 authentic vitreous humor samples. Linear curve for each drug was obtained within the range of 30–3000 ng/mL with coefficient of correlation higher than 0.99. Results: The limit of detection and quantitation were 30 and 100 ng/mL respectively for four drugs. The method showed an appropriate intra- and inter-day precision (coefficient of variation < 10%). Benzodiazepines recoveries were estimated to be over 80%. The method showed high selectivity; no additional peak due to interfering substances in samples was observed. Conclusion: The present method was selective, sensitive, accurate, and precise for the quantitative analysis of benzodiazepines in vitreous humor samples in forensic toxicology laboratory. PMID:27635251

Quantitative description on structure-property relationships of Li-ion battery materials for high-throughput computations

NASA Astrophysics Data System (ADS)

Wang, Youwei; Zhang, Wenqing; Chen, Lidong; Shi, Siqi; Liu, Jianjun

2017-12-01

Li-ion batteries are a key technology for addressing the global challenge of clean renewable energy and environment pollution. Their contemporary applications, for portable electronic devices, electric vehicles, and large-scale power grids, stimulate the development of high-performance battery materials with high energy density, high power, good safety, and long lifetime. High-throughput calculations provide a practical strategy to discover new battery materials and optimize currently known material performances. Most cathode materials screened by the previous high-throughput calculations cannot meet the requirement of practical applications because only capacity, voltage and volume change of bulk were considered. It is important to include more structure-property relationships, such as point defects, surface and interface, doping and metal-mixture and nanosize effects, in high-throughput calculations. In this review, we established quantitative description of structure-property relationships in Li-ion battery materials by the intrinsic bulk parameters, which can be applied in future high-throughput calculations to screen Li-ion battery materials. Based on these parameterized structure-property relationships, a possible high-throughput computational screening flow path is proposed to obtain high-performance battery materials.

Quantitative description on structure-property relationships of Li-ion battery materials for high-throughput computations.

PubMed

Wang, Youwei; Zhang, Wenqing; Chen, Lidong; Shi, Siqi; Liu, Jianjun

2017-01-01

Li-ion batteries are a key technology for addressing the global challenge of clean renewable energy and environment pollution. Their contemporary applications, for portable electronic devices, electric vehicles, and large-scale power grids, stimulate the development of high-performance battery materials with high energy density, high power, good safety, and long lifetime. High-throughput calculations provide a practical strategy to discover new battery materials and optimize currently known material performances. Most cathode materials screened by the previous high-throughput calculations cannot meet the requirement of practical applications because only capacity, voltage and volume change of bulk were considered. It is important to include more structure-property relationships, such as point defects, surface and interface, doping and metal-mixture and nanosize effects, in high-throughput calculations. In this review, we established quantitative description of structure-property relationships in Li-ion battery materials by the intrinsic bulk parameters, which can be applied in future high-throughput calculations to screen Li-ion battery materials. Based on these parameterized structure-property relationships, a possible high-throughput computational screening flow path is proposed to obtain high-performance battery materials.

A multi-center study benchmarks software tools for label-free proteome quantification

PubMed Central

Gillet, Ludovic C; Bernhardt, Oliver M.; MacLean, Brendan; Röst, Hannes L.; Tate, Stephen A.; Tsou, Chih-Chiang; Reiter, Lukas; Distler, Ute; Rosenberger, George; Perez-Riverol, Yasset; Nesvizhskii, Alexey I.; Aebersold, Ruedi; Tenzer, Stefan

2016-01-01

The consistent and accurate quantification of proteins by mass spectrometry (MS)-based proteomics depends on the performance of instruments, acquisition methods and data analysis software. In collaboration with the software developers, we evaluated OpenSWATH, SWATH2.0, Skyline, Spectronaut and DIA-Umpire, five of the most widely used software methods for processing data from SWATH-MS (sequential window acquisition of all theoretical fragment ion spectra), a method that uses data-independent acquisition (DIA) for label-free protein quantification. We analyzed high-complexity test datasets from hybrid proteome samples of defined quantitative composition acquired on two different MS instruments using different SWATH isolation windows setups. For consistent evaluation we developed LFQbench, an R-package to calculate metrics of precision and accuracy in label-free quantitative MS, and report the identification performance, robustness and specificity of each software tool. Our reference datasets enabled developers to improve their software tools. After optimization, all tools provided highly convergent identification and reliable quantification performance, underscoring their robustness for label-free quantitative proteomics. PMID:27701404

A multicenter study benchmarks software tools for label-free proteome quantification.

PubMed

Navarro, Pedro; Kuharev, Jörg; Gillet, Ludovic C; Bernhardt, Oliver M; MacLean, Brendan; Röst, Hannes L; Tate, Stephen A; Tsou, Chih-Chiang; Reiter, Lukas; Distler, Ute; Rosenberger, George; Perez-Riverol, Yasset; Nesvizhskii, Alexey I; Aebersold, Ruedi; Tenzer, Stefan

2016-11-01

Consistent and accurate quantification of proteins by mass spectrometry (MS)-based proteomics depends on the performance of instruments, acquisition methods and data analysis software. In collaboration with the software developers, we evaluated OpenSWATH, SWATH 2.0, Skyline, Spectronaut and DIA-Umpire, five of the most widely used software methods for processing data from sequential window acquisition of all theoretical fragment-ion spectra (SWATH)-MS, which uses data-independent acquisition (DIA) for label-free protein quantification. We analyzed high-complexity test data sets from hybrid proteome samples of defined quantitative composition acquired on two different MS instruments using different SWATH isolation-window setups. For consistent evaluation, we developed LFQbench, an R package, to calculate metrics of precision and accuracy in label-free quantitative MS and report the identification performance, robustness and specificity of each software tool. Our reference data sets enabled developers to improve their software tools. After optimization, all tools provided highly convergent identification and reliable quantification performance, underscoring their robustness for label-free quantitative proteomics.

A Quantitative Causal-Comparative Study Examining the Effect of Block and Traditional Bell Schedules on Cognitive Load and Mathematics Academic Performance in High School Freshmen of the Southwestern USA

ERIC Educational Resources Information Center

Nogler, Tracey A.

2017-01-01

The purpose of this quantitative causal-comparative research was to examine if and to what extent there were differences in students' cognitive load and the subsequent academic performance based on block bell schedule and traditional bell schedule for freshmen in Algebra 1 in the Southwestern United States. This study included students from two…

Simultaneous qualitative and quantitative analysis of flavonoids and alkaloids from the leaves of Nelumbo nucifera Gaertn. using high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry.

PubMed

Guo, Yujie; Chen, Xi; Qi, Jin; Yu, Boyang

2016-07-01

A reliable method, combining qualitative analysis by high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and quantitative assessment by high-performance liquid chromatography with photodiode array detection, has been developed to simultaneously analyze flavonoids and alkaloids in lotus leaf extracts. In the qualitative analysis, a total of 30 compounds, including 12 flavonoids, 16 alkaloids, and two proanthocyanidins, were identified. The fragmentation behaviors of four types of flavone glycoside and three types of alkaloid are summarized. The mass spectra of four representative components, quercetin 3-O-glucuronide, norcoclaurine, nuciferine, and neferine, are shown to illustrate their fragmentation pathways. Five pairs of isomers were detected and three of them were distinguished by comparing the elution order with reference substances and the mass spectrometry data with reported data. In the quantitative analysis, 30 lotus leaf samples from different regions were analyzed to investigate the proportion of eight representative compounds. Quercetin 3-O-glucuronide was found to be the predominant constituent of lotus leaf extracts. For further discrimination among the samples, hierarchical cluster analysis, and principal component analysis, based on the areas of the eight quantitative peaks, were carried out. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mallow carotenoids determined by high-performance liquid chromatography

USDA-ARS?s Scientific Manuscript database

Mallow (corchorus olitorius) is a green vegetable, which is widely consumed either fresh or dry by Middle East population. This study was carried out to determine the contents of major carotenoids quantitatively in mallow, by using a High Performance Liquid Chromatography (HPLC) equipped with a Bis...

Evaluation of quantitative image analysis criteria for the high-resolution microendoscopic detection of neoplasia in Barrett's esophagus

NASA Astrophysics Data System (ADS)

Muldoon, Timothy J.; Thekkek, Nadhi; Roblyer, Darren; Maru, Dipen; Harpaz, Noam; Potack, Jonathan; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca

2010-03-01

Early detection of neoplasia in patients with Barrett's esophagus is essential to improve outcomes. The aim of this ex vivo study was to evaluate the ability of high-resolution microendoscopic imaging and quantitative image analysis to identify neoplastic lesions in patients with Barrett's esophagus. Nine patients with pathologically confirmed Barrett's esophagus underwent endoscopic examination with biopsies or endoscopic mucosal resection. Resected fresh tissue was imaged with fiber bundle microendoscopy; images were analyzed by visual interpretation or by quantitative image analysis to predict whether the imaged sites were non-neoplastic or neoplastic. The best performing pair of quantitative features were chosen based on their ability to correctly classify the data into the two groups. Predictions were compared to the gold standard of histopathology. Subjective analysis of the images by expert clinicians achieved average sensitivity and specificity of 87% and 61%, respectively. The best performing quantitative classification algorithm relied on two image textural features and achieved a sensitivity and specificity of 87% and 85%, respectively. This ex vivo pilot trial demonstrates that quantitative analysis of images obtained with a simple microendoscope system can distinguish neoplasia in Barrett's esophagus with good sensitivity and specificity when compared to histopathology and to subjective image interpretation.

Fast and simultaneous determination of 12 polyphenols in apple peel and pulp by using chemometrics-assisted high-performance liquid chromatography with diode array detection.

PubMed

Wang, Tong; Wu, Hai-Long; Xie, Li-Xia; Zhu, Li; Liu, Zhi; Sun, Xiao-Dong; Xiao, Rong; Yu, Ru-Qin

2017-04-01

In this work, a smart chemometrics-enhanced strategy, high-performance liquid chromatography, and diode array detection coupled with second-order calibration method based on alternating trilinear decomposition algorithm was proposed to simultaneously quantify 12 polyphenols in different kinds of apple peel and pulp samples. The proposed strategy proved to be a powerful tool to solve the problems of coelution, unknown interferences, and chromatographic shifts in the process of high-performance liquid chromatography analysis, making it possible for the determination of 12 polyphenols in complex apple matrices within 10 min under simple conditions of elution. The average recoveries with standard deviations, and figures of merit including sensitivity, selectivity, limit of detection, and limit of quantitation were calculated to validate the accuracy of the proposed method. Compared to the quantitative analysis results from the classic high-performance liquid chromatography method, the statistical and graphical analysis showed that our proposed strategy obtained more reliable results. All results indicated that our proposed method used in the quantitative analysis of apple polyphenols was an accurate, fast, universal, simple, and green one, and it was expected to be developed as an attractive alternative method for simultaneous determination of multitargeted analytes in complex matrices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Smile line assessment comparing quantitative measurement and visual estimation.

PubMed

Van der Geld, Pieter; Oosterveld, Paul; Schols, Jan; Kuijpers-Jagtman, Anne Marie

2011-02-01

Esthetic analysis of dynamic functions such as spontaneous smiling is feasible by using digital videography and computer measurement for lip line height and tooth display. Because quantitative measurements are time-consuming, digital videography and semiquantitative (visual) estimation according to a standard categorization are more practical for regular diagnostics. Our objective in this study was to compare 2 semiquantitative methods with quantitative measurements for reliability and agreement. The faces of 122 male participants were individually registered by using digital videography. Spontaneous and posed smiles were captured. On the records, maxillary lip line heights and tooth display were digitally measured on each tooth and also visually estimated according to 3-grade and 4-grade scales. Two raters were involved. An error analysis was performed. Reliability was established with kappa statistics. Interexaminer and intraexaminer reliability values were high, with median kappa values from 0.79 to 0.88. Agreement of the 3-grade scale estimation with quantitative measurement showed higher median kappa values (0.76) than the 4-grade scale estimation (0.66). Differentiating high and gummy smile lines (4-grade scale) resulted in greater inaccuracies. The estimation of a high, average, or low smile line for each tooth showed high reliability close to quantitative measurements. Smile line analysis can be performed reliably with a 3-grade scale (visual) semiquantitative estimation. For a more comprehensive diagnosis, additional measuring is proposed, especially in patients with disproportional gingival display. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

High performance liquid chromatographic assay for the quantitation of total glutathione in plasma

NASA Technical Reports Server (NTRS)

Abukhalaf, Imad K.; Silvestrov, Natalia A.; Menter, Julian M.; von Deutsch, Daniel A.; Bayorh, Mohamed A.; Socci, Robin R.; Ganafa, Agaba A.

2002-01-01

A simple and widely used homocysteine HPLC procedure was applied for the HPLC identification and quantitation of glutathione in plasma. The method, which utilizes SBDF as a derivatizing agent utilizes only 50 microl of sample volume. Linear quantitative response curve was generated for glutathione over a concentration range of 0.3125-62.50 micromol/l. Linear regression analysis of the standard curve exhibited correlation coefficient of 0.999. Limit of detection (LOD) and limit of quantitation (LOQ) values were 5.0 and 15 pmol, respectively. Glutathione recovery using this method was nearly complete (above 96%). Intra-assay and inter-assay precision studies reflected a high level of reliability and reproducibility of the method. The applicability of the method for the quantitation of glutathione was demonstrated successfully using human and rat plasma samples.

DETERMINATION OF CHLOROPHEONIS, NITROPHENOIS AND METHYLPHENOIS IN GROUND-WATER SAMPLES USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

EPA Science Inventory

A high performance liquid chromatography (HPLC) method was developed to quantitatively determine phenolic compounds and their isomers in aqueous samples. The HPLC method can analyze a mixture of 15 contaminants in the same analytical run with an analysis time of 25 minutes. The...

Quantitative determination of seven chemical constituents and chemo-type differentiation of chamomiles using high-performance thin-layer chromatography

USDA-ARS?s Scientific Manuscript database

Matricaria recutita L. (German Chamomile), Anthemis nobilis L. (Roman Chamomile) and Chrysanthemum morifolium Ramat are commonly used chamomiles. High performance thin layer chromatographic (HPTLC) method was developed for estimation of six flavonoids (rutin, luteolin-7-O-ß-glucoside, chamaemeloside...

Going Beyond, Going Further: An Inexpensive Experiment for the Introduction of High Performance Liquid Chromatography.

ERIC Educational Resources Information Center

Bidlingmeyer, Brian A.; Warren, F. Vincent, Jr.

1984-01-01

Background information, materials needed, laboratory procedures, and typical results are provided for five high performance liquid chromatography experiments (three isocratic and two step gradient separations). Suggestions for further experimentation are also provided, including quantitative determinations and separation of charged solutes. (JN)

DETERMINATION OF CHLOROPHENOLS, NITROPHENOLS, AND METHYLPHENOLS IN GROUND-WATER SAMPLES USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

EPA Science Inventory

A high performance liquid chromatography (HPLC) method was developed to quantitatively determine phenolic compounds and their isomers in aqueous samples. The HPLC method can analyze a mixture of 15 contaminants in the same analytical run with an analysis time of 25 minutes. The...

Recommendations for Quantitative Analysis of Small Molecules by Matrix-assisted laser desorption ionization mass spectrometry

PubMed Central

Wang, Poguang; Giese, Roger W.

2017-01-01

Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) has been used for quantitative analysis of small molecules for many years. It is usually preceded by an LC separation step when complex samples are tested. With the development several years ago of “modern MALDI” (automation, high repetition laser, high resolution peaks), the ease of use and performance of MALDI as a quantitative technique greatly increased. This review focuses on practical aspects of modern MALDI for quantitation of small molecules conducted in an ordinary way (no special reagents, devices or techniques for the spotting step of MALDI), and includes our ordinary, preferred Methods The review is organized as 18 recommendations with accompanying explanations, criticisms and exceptions. PMID:28118972

High performance thin layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) for the qualitative and quantitative analysis of Calendula officinalis-advantages and limitations.

PubMed

Loescher, Christine M; Morton, David W; Razic, Slavica; Agatonovic-Kustrin, Snezana

2014-09-01

Chromatography techniques such as HPTLC and HPLC are commonly used to produce a chemical fingerprint of a plant to allow identification and quantify the main constituents within the plant. The aims of this study were to compare HPTLC and HPLC, for qualitative and quantitative analysis of the major constituents of Calendula officinalis and to investigate the effect of different extraction techniques on the C. officinalis extract composition from different parts of the plant. The results found HPTLC to be effective for qualitative analysis, however, HPLC was found to be more accurate for quantitative analysis. A combination of the two methods may be useful in a quality control setting as it would allow rapid qualitative analysis of herbal material while maintaining accurate quantification of extract composition. Copyright © 2014 Elsevier B.V. All rights reserved.

Quantitation of sugar content in pyrolysis liquids after acid hydrolysis using high-performance liquid chromatography without neutralization.

PubMed

Johnston, Patrick A; Brown, Robert C

2014-08-13

A rapid method for the quantitation of total sugars in pyrolysis liquids using high-performance liquid chromatography (HPLC) was developed. The method avoids the tedious and time-consuming sample preparation required by current analytical methods. It is possible to directly analyze hydrolyzed pyrolysis liquids, bypassing the neutralization step usually required in determination of total sugars. A comparison with traditional methods was used to determine the validity of the results. The calibration curve coefficient of determination on all standard compounds was >0.999 using a refractive index detector. The relative standard deviation for the new method was 1.13%. The spiked sugar recoveries on the pyrolysis liquid samples were between 104 and 105%. The research demonstrates that it is possible to obtain excellent accuracy and efficiency using HPLC to quantitate glucose after acid hydrolysis of polymeric and oligomeric sugars found in fast pyrolysis bio-oils without neutralization.

Qualitative and Quantitative Analyses of Glycogen in Human Milk.

PubMed

Matsui-Yatsuhashi, Hiroko; Furuyashiki, Takashi; Takata, Hiroki; Ishida, Miyuki; Takumi, Hiroko; Kakutani, Ryo; Kamasaka, Hiroshi; Nagao, Saeko; Hirose, Junko; Kuriki, Takashi

2017-02-22

Identification as well as a detailed analysis of glycogen in human milk has not been shown yet. The present study confirmed that glycogen is contained in human milk by qualitative and quantitative analyses. High-performance anion exchange chromatography (HPAEC) and high-performance size exclusion chromatography with a multiangle laser light scattering detector (HPSEC-MALLS) were used for qualitative analysis of glycogen in human milk. Quantitative analysis was carried out by using samples obtained from the individual milks. The result revealed that the concentration of human milk glycogen varied depending on the mother's condition-such as the period postpartum and inflammation. The amounts of glycogen in human milk collected at 0 and 1-2 months postpartum were higher than in milk collected at 3-14 months postpartum. In the milk from mothers with severe mastitis, the concentration of glycogen was about 40 times higher than that in normal milk.

Simultaneous determination of the HIV nucleoside analogue reverse transcriptase inhibitors lamivudine, didanosine, stavudine, zidovudine and abacavir in human plasma by reversed phase high performance liquid chromatography.

PubMed

Verweij-van Wissen, C P W G M; Aarnoutse, R E; Burger, D M

2005-02-25

A reversed phase high performance liquid chromatography method was developed for the simultaneous quantitative determination of the nucleoside reverse transcriptase inhibitors (NRTIs) lamivudine, didanosine, stavudine, zidovudine and abacavir in plasma. The method involved solid-phase extraction with Oasis MAX cartridges from plasma, followed by high performance liquid chromatography with a SymmetryShield RP 18 column and ultraviolet detection set at a wavelength of 260 nm. The assay was validated over the concentration range of 0.015-5 mg/l for all five NRTIs. The average accuracies for the assay were 92-102%, inter- and intra-day coefficients of variation (CV) were <2.5% and extraction recoveries were higher than 97%. This method proved to be simple, accurate and precise, and is currently in use in our laboratory for the quantitative analysis of NRTIs in plasma.

Quantitative analysis of oxyresveratrol in different plant parts of Morus species and related Genera by HPTLC

USDA-ARS?s Scientific Manuscript database

Four aromatic compounds; oxyresveratrol (1), mulberroside A (2), cudraflavone C (3) and kuwanone J (4) were isolated from the stems of Morus rubra L. The quantitative determination of oxyresveratrol from M. rubra L., M. alba L. and related genera by high performance thin layer chromatography (HPTLC)...

Initial Teacher Education: Does Self-Efficacy Influence Candidate Teacher Academic Achievement and Future Career Performance?

ERIC Educational Resources Information Center

Shawer, Saad F.

2013-01-01

This quantitative investigation examined the influence of low and high self-efficacy on candidate teacher academic performance in a foreign language teaching methodology course through testing the speculation that high self-efficacy levels would improve pedagogical-content knowledge (PCK). Positivism guided the research design at the levels of…

Quantitative description on structure–property relationships of Li-ion battery materials for high-throughput computations

PubMed Central

Wang, Youwei; Zhang, Wenqing; Chen, Lidong; Shi, Siqi; Liu, Jianjun

2017-01-01

Abstract Li-ion batteries are a key technology for addressing the global challenge of clean renewable energy and environment pollution. Their contemporary applications, for portable electronic devices, electric vehicles, and large-scale power grids, stimulate the development of high-performance battery materials with high energy density, high power, good safety, and long lifetime. High-throughput calculations provide a practical strategy to discover new battery materials and optimize currently known material performances. Most cathode materials screened by the previous high-throughput calculations cannot meet the requirement of practical applications because only capacity, voltage and volume change of bulk were considered. It is important to include more structure–property relationships, such as point defects, surface and interface, doping and metal-mixture and nanosize effects, in high-throughput calculations. In this review, we established quantitative description of structure–property relationships in Li-ion battery materials by the intrinsic bulk parameters, which can be applied in future high-throughput calculations to screen Li-ion battery materials. Based on these parameterized structure–property relationships, a possible high-throughput computational screening flow path is proposed to obtain high-performance battery materials. PMID:28458737

Analysis of metalaxyl racemate using high performance liquid chromatography coupled with four kinds of detectors.

PubMed

Chen, Tao; Fan, Jun; Gao, Ruiqi; Wang, Tai; Yu, Ying; Zhang, Weiguang

2016-10-07

Chiral stationary phase-high performance liquid chromatography coupled with various detectors has been one of most commonly used methods for analysis and separation of chiral compounds over the past decades. Various detectors exhibit different characteristics in qualitative and quantitative studies under different chromatographic conditions. Herein, a comparative evaluation of HPLC coupled with ultraviolet, optical rotation, refractive index, and evaporative light scattering detectors has been conducted for qualitative and quantitative analyses of metalaxyl racemate. Effects of separation conditions on the peak area ratio between two enantiomers, including sample concentration, column temperature, mobile phase composition, as well as flow rate, have been investigated in detail. In addition, the limits of detection, the limits of quantitation, quantitative range and precision for these two enantiomers by using four detectors have been also studied. As indicated, the chromatographic separation conditions have been slight effects on ultraviolet and refractive index detections and the peak area ratio between two enantiomers remains almost unchanged, but the evaporative light scattering detection has been significantly affected by the above-mentioned chromatographic conditions and the corresponding peak area ratios varied greatly. Moreover, the limits of detection, the limits of quantitation, and the quantitative ranges of two enantiomers with UV detection were remarkably lower by 1-2 magnitudes than the others. Copyright © 2016 Elsevier B.V. All rights reserved.

A Microfluidic Platform for High-Throughput Multiplexed Protein Quantitation

PubMed Central

Volpetti, Francesca; Garcia-Cordero, Jose; Maerkl, Sebastian J.

2015-01-01

We present a high-throughput microfluidic platform capable of quantitating up to 384 biomarkers in 4 distinct samples by immunoassay. The microfluidic device contains 384 unit cells, which can be individually programmed with pairs of capture and detection antibody. Samples are quantitated in each unit cell by four independent MITOMI detection areas, allowing four samples to be analyzed in parallel for a total of 1,536 assays per device. We show that the device can be pre-assembled and stored for weeks at elevated temperature and we performed proof-of-concept experiments simultaneously quantitating IL-6, IL-1β, TNF-α, PSA, and GFP. Finally, we show that the platform can be used to identify functional antibody combinations by screening 64 antibody combinations requiring up to 384 unique assays per device. PMID:25680117

Application of Genome Wide Association and Genomic Prediction for Improvement of Cacao Productivity and Resistance to Black and Frosty Pod Diseases

PubMed Central

Romero Navarro, J. Alberto; Phillips-Mora, Wilbert; Arciniegas-Leal, Adriana; Mata-Quirós, Allan; Haiminen, Niina; Mustiga, Guiliana; Livingstone III, Donald; van Bakel, Harm; Kuhn, David N.; Parida, Laxmi; Kasarskis, Andrew; Motamayor, Juan C.

2017-01-01

Chocolate is a highly valued and palatable confectionery product. Chocolate is primarily made from the processed seeds of the tree species Theobroma cacao. Cacao cultivation is highly relevant for small-holder farmers throughout the tropics, yet its productivity remains limited by low yields and widespread pathogens. A panel of 148 improved cacao clones was assembled based on productivity and disease resistance, and phenotypic single-tree replicated clonal evaluation was performed for 8 years. Using high-density markers, the diversity of clones was expressed relative to 10 known ancestral cacao populations, and significant effects of ancestry were observed in productivity and disease resistance. Genome-wide association (GWA) was performed, and six markers were significantly associated with frosty pod disease resistance. In addition, genomic selection was performed, and consistent with the observed extensive linkage disequilibrium, high predictive ability was observed at low marker densities for all traits. Finally, quantitative trait locus mapping and differential expression analysis of two cultivars with contrasting disease phenotypes were performed to identify genes underlying frosty pod disease resistance, identifying a significant quantitative trait locus and 35 differentially expressed genes using two independent differential expression analyses. These results indicate that in breeding populations of heterozygous and recently admixed individuals, mapping approaches can be used for low complexity traits like pod color cacao, or in other species single gene disease resistance, however genomic selection for quantitative traits remains highly effective relative to mapping. Our results can help guide the breeding process for sustainable improved cacao productivity. PMID:29184558

49 CFR 19.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... projects can be readily quantified, such quantitative data should be related to cost data for computation... information including, when appropriate, analysis and explanation of cost overruns or high unit costs. (e... performance data from recipients. ...

43 CFR 12.951 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... readily quantified, such quantitative data should be related to cost data for computation of unit costs... including, when appropriate, analysis and explanation of cost overruns or high unit costs. (e) Recipients... performance data from recipients. ...

41 CFR 105-72.601 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... readily quantified, such quantitative data should be related to cost data for computation of unit costs... including, when appropriate, analysis and explanation of cost overruns or high unit costs. (e) Recipients... performance data from recipients. ...

22 CFR 518.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-04-01

... projects can be readily quantified, such quantitative data should be related to cost data for computation... information including, when appropriate, analysis and explanation of cost overruns or high unit costs. (e... performance data from recipients. ...

7 CFR 3019.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... readily quantified, such quantitative data should be related to cost data for computation of unit costs... including, when appropriate, analysis and explanation of cost overruns or high unit costs. (e) Recipients... performance data from recipients. ...

PET Imaging Stability Measurements During Simultaneous Pulsing of Aggressive MR Sequences on the SIGNA PET/MR System.

PubMed

Deller, Timothy W; Khalighi, Mohammad Mehdi; Jansen, Floris P; Glover, Gary H

2018-01-01

The recent introduction of simultaneous whole-body PET/MR scanners has enabled new research taking advantage of the complementary information obtainable with PET and MRI. One such application is kinetic modeling, which requires high levels of PET quantitative stability. To accomplish the required PET stability levels, the PET subsystem must be sufficiently isolated from the effects of MR activity. Performance measurements have previously been published, demonstrating sufficient PET stability in the presence of MR pulsing for typical clinical use; however, PET stability during radiofrequency (RF)-intensive and gradient-intensive sequences has not previously been evaluated for a clinical whole-body scanner. In this work, PET stability of the GE SIGNA PET/MR was examined during simultaneous scanning of aggressive MR pulse sequences. Methods: PET performance tests were acquired with MR idle and during simultaneous MR pulsing. Recent system improvements mitigating RF interference and gain variation were used. A fast recovery fast spin echo MR sequence was selected for high RF power, and an echo planar imaging sequence was selected for its high heat-inducing gradients. Measurements were performed to determine PET stability under varying MR conditions using the following metrics: sensitivity, scatter fraction, contrast recovery, uniformity, count rate performance, and image quantitation. A final PET quantitative stability assessment for simultaneous PET scanning during functional MRI studies was performed with a spiral in-and-out gradient echo sequence. Results: Quantitation stability of a 68 Ge flood phantom was demonstrated within 0.34%. Normalized sensitivity was stable during simultaneous scanning within 0.3%. Scatter fraction measured with a 68 Ge line source in the scatter phantom was stable within the range of 40.4%-40.6%. Contrast recovery and uniformity were comparable for PET images acquired simultaneously with multiple MR conditions. Peak noise equivalent count rate was 224 kcps at an effective activity concentration of 18.6 kBq/mL, and the count rate curves and scatter fraction curve were consistent for the alternating MR pulsing states. A final test demonstrated quantitative stability during a spiral functional MRI sequence. Conclusion: PET stability metrics demonstrated that PET quantitation was not affected during simultaneous aggressive MRI. This stability enables demanding applications such as kinetic modeling. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Systematic assessment of survey scan and MS2-based abundance strategies for label-free quantitative proteomics using high-resolution MS data.

PubMed

Tu, Chengjian; Li, Jun; Sheng, Quanhu; Zhang, Ming; Qu, Jun

2014-04-04

Survey-scan-based label-free method have shown no compelling benefit over fragment ion (MS2)-based approaches when low-resolution mass spectrometry (MS) was used, the growing prevalence of high-resolution analyzers may have changed the game. This necessitates an updated, comparative investigation of these approaches for data acquired by high-resolution MS. Here, we compared survey scan-based (ion current, IC) and MS2-based abundance features including spectral-count (SpC) and MS2 total-ion-current (MS2-TIC), for quantitative analysis using various high-resolution LC/MS data sets. Key discoveries include: (i) study with seven different biological data sets revealed only IC achieved high reproducibility for lower-abundance proteins; (ii) evaluation with 5-replicate analyses of a yeast sample showed IC provided much higher quantitative precision and lower missing data; (iii) IC, SpC, and MS2-TIC all showed good quantitative linearity (R(2) > 0.99) over a >1000-fold concentration range; (iv) both MS2-TIC and IC showed good linear response to various protein loading amounts but not SpC; (v) quantification using a well-characterized CPTAC data set showed that IC exhibited markedly higher quantitative accuracy, higher sensitivity, and lower false-positives/false-negatives than both SpC and MS2-TIC. Therefore, IC achieved an overall superior performance than the MS2-based strategies in terms of reproducibility, missing data, quantitative dynamic range, quantitative accuracy, and biomarker discovery.

Systematic Assessment of Survey Scan and MS2-Based Abundance Strategies for Label-Free Quantitative Proteomics Using High-Resolution MS Data

PubMed Central

2015-01-01

Survey-scan-based label-free method have shown no compelling benefit over fragment ion (MS2)-based approaches when low-resolution mass spectrometry (MS) was used, the growing prevalence of high-resolution analyzers may have changed the game. This necessitates an updated, comparative investigation of these approaches for data acquired by high-resolution MS. Here, we compared survey scan-based (ion current, IC) and MS2-based abundance features including spectral-count (SpC) and MS2 total-ion-current (MS2-TIC), for quantitative analysis using various high-resolution LC/MS data sets. Key discoveries include: (i) study with seven different biological data sets revealed only IC achieved high reproducibility for lower-abundance proteins; (ii) evaluation with 5-replicate analyses of a yeast sample showed IC provided much higher quantitative precision and lower missing data; (iii) IC, SpC, and MS2-TIC all showed good quantitative linearity (R2 > 0.99) over a >1000-fold concentration range; (iv) both MS2-TIC and IC showed good linear response to various protein loading amounts but not SpC; (v) quantification using a well-characterized CPTAC data set showed that IC exhibited markedly higher quantitative accuracy, higher sensitivity, and lower false-positives/false-negatives than both SpC and MS2-TIC. Therefore, IC achieved an overall superior performance than the MS2-based strategies in terms of reproducibility, missing data, quantitative dynamic range, quantitative accuracy, and biomarker discovery. PMID:24635752

Stereotype Threat? Male and Female Students in Advanced High School Courses

NASA Astrophysics Data System (ADS)

Corra, Mamadi

Propositions of stereotype threat theory imply that the social consequences of academic distinction in advanced quantitative areas (such as math and the physical sciences) for women may promote the under representation of female students in advanced quantitative academic courses. The hypothesis that female students will be underrepresented in advanced quantitative (honors and advanced placement math and physical science) courses is tested using academic performance and enrollment data for high school students in a "Student/Parent Informed Choice" (open registration) school district in North Carolina. Results show female students to be overrepresented in both advanced verbal/writing intensive (honors and advanced placement English, foreign language, and social science) and advanced quantitative (honors and advanced placement math and physical science) courses compared to their proportion of the student body. More surprisingly, results also indicate female students (compared to male students) to be overrepresented in advanced courses compared to their proportion of high-performing students. Furthermore, as with patterns observed at the district level, additional analysis of enrollment data for the entire state reveals similar results. Taken together, the findings call into question the prevailing presumption that female students continue to be underrepresented in math and physical science courses. Instead, the changing social context within which females and males experience schooling may provide an explanation for the findings.

Determination of alpha-hydroxy acids in cosmetic products by high-performance liquid chromatography with a narrow-bore column.

PubMed

Nicoletti, I; Corradini, C; Cogliandro, E; Cavazza, A

1999-08-01

This paper reports the results of a study carried out to develop a simple, rapid and sensitive method for the separation, identification and quantitative measurement of alpha-hydroxy acids in commercial cosmetics using high-performance liquid chromatography (HPLC). This method is successfully applied to the simultaneous identification and quantitative determination of glycolic, lactic, malic, tartaric and citric acids employing a reversed phase narrow-bore column under isocratic condition and UV detection. The method is validated by determining the precision of replicate analyses and accuracy by analyzing samples with and without adding know amount of the alpha-hydroxy acids. The procedure is suitable for routine analyses of commercial cosmetics.

Development of a Liquid Chromatography High Resolution Mass Spectrometry (LC-HRMS) Method for the Quantitation of Viral Envelope Glycoprotein in Ebola Virus-Like Particle Vaccine Preparations

DTIC Science & Technology

2016-09-05

46 was performed on an LTQ-Orbitrap Elite MS and the final quantitation was derived by 47 comparing the relative response of the 200 fmol AQUA...shown in Figure 3B, the final quantitation is derived by comparing the 527 relative response of the 200 fmol AQUA standards (SEE and IRSEE: Set 1) to...measure of eVLP quality, the western blot 553 and LC-HRMS quantitation results were compared to survival data in mice for each of these 554 eVLP vaccine

Assessing deep and shallow learning methods for quantitative prediction of acute chemical toxicity.

PubMed

Liu, Ruifeng; Madore, Michael; Glover, Kyle P; Feasel, Michael G; Wallqvist, Anders

2018-05-02

Animal-based methods for assessing chemical toxicity are struggling to meet testing demands. In silico approaches, including machine-learning methods, are promising alternatives. Recently, deep neural networks (DNNs) were evaluated and reported to outperform other machine-learning methods for quantitative structure-activity relationship modeling of molecular properties. However, most of the reported performance evaluations relied on global performance metrics, such as the root mean squared error (RMSE) between the predicted and experimental values of all samples, without considering the impact of sample distribution across the activity spectrum. Here, we carried out an in-depth analysis of DNN performance for quantitative prediction of acute chemical toxicity using several datasets. We found that the overall performance of DNN models on datasets of up to 30,000 compounds was similar to that of random forest (RF) models, as measured by the RMSE and correlation coefficients between the predicted and experimental results. However, our detailed analyses demonstrated that global performance metrics are inappropriate for datasets with a highly uneven sample distribution, because they show a strong bias for the most populous compounds along the toxicity spectrum. For highly toxic compounds, DNN and RF models trained on all samples performed much worse than the global performance metrics indicated. Surprisingly, our variable nearest neighbor method, which utilizes only structurally similar compounds to make predictions, performed reasonably well, suggesting that information of close near neighbors in the training sets is a key determinant of acute toxicity predictions.

Assessing the performance of quantitative image features on early stage prediction of treatment effectiveness for ovary cancer patients: a preliminary investigation

NASA Astrophysics Data System (ADS)

Zargari, Abolfazl; Du, Yue; Thai, Theresa C.; Gunderson, Camille C.; Moore, Kathleen; Mannel, Robert S.; Liu, Hong; Zheng, Bin; Qiu, Yuchen

2018-02-01

The objective of this study is to investigate the performance of global and local features to better estimate the characteristics of highly heterogeneous metastatic tumours, for accurately predicting the treatment effectiveness of the advanced stage ovarian cancer patients. In order to achieve this , a quantitative image analysis scheme was developed to estimate a total of 103 features from three different groups including shape and density, Wavelet, and Gray Level Difference Method (GLDM) features. Shape and density features are global features, which are directly applied on the entire target image; wavelet and GLDM features are local features, which are applied on the divided blocks of the target image. To assess the performance, the new scheme was applied on a retrospective dataset containing 120 recurrent and high grade ovary cancer patients. The results indicate that the three best performed features are skewness, root-mean-square (rms) and mean of local GLDM texture, indicating the importance of integrating local features. In addition, the averaged predicting performance are comparable among the three different categories. This investigation concluded that the local features contains at least as copious tumour heterogeneity information as the global features, which may be meaningful on improving the predicting performance of the quantitative image markers for the diagnosis and prognosis of ovary cancer patients.

Contextualising Mathematics Self-Efficacy and Performance among Rural High School Students in the Philippines

ERIC Educational Resources Information Center

Causapin, Mark

2016-01-01

This paper expands the scope of typical quantitative studies on mathematics self-efficacy by including a short ethnography of the students' daily classroom experiences. It attempts to provide a "thicker description" and a context in which these beliefs could be interpreted. Using both qualitative and quantitative sets of data, it is…

Determination of Niacinamide in Lotions and Creams Using Liquid-Liquid Extraction and High-Performance Liquid Chromatography

ERIC Educational Resources Information Center

Usher, Karyn M.; Simmons, Carolyn R.; Keating, Daniel W.; Rossi, Henry F., III

2015-01-01

Chemical separations are an important part of an undergraduate chemistry curriculum. Sophomore students often get experience with liquid-liquid extraction in organic chemistry classes, but liquid-liquid extraction is not as often introduced as a quantitative sample preparation method in honors general chemistry or quantitative analysis classes.…

Two-Photon Flow Cytometry

NASA Technical Reports Server (NTRS)

Zhog, Cheng Frank; Ye, Jing Yong; Norris, Theodore B.; Myc, Andrzej; Cao, Zhengyl; Bielinska, Anna; Thomas, Thommey; Baker, James R., Jr.

2004-01-01

Flow cytometry is a powerful technique for obtaining quantitative information from fluorescence in cells. Quantitation is achieved by assuring a high degree of uniformity in the optical excitation and detection, generally by using a highly controlled flow such as is obtained via hydrodynamic focusing. In this work, we demonstrate a two-beam, two- channel detection and two-photon excitation flow cytometry (T(sup 3)FC) system that enables multi-dye analysis to be performed very simply, with greatly relaxed requirements on the fluid flow. Two-photon excitation using a femtosecond near-infrared (NIR) laser has the advantages that it enables simultaneous excitation of multiple dyes and achieves very high signal-to-noise ratio through simplified filtering and fluorescence background reduction. By matching the excitation volume to the size of a cell, single-cell detection is ensured. Labeling of cells by targeted nanoparticles with multiple fluorophores enables normalization of the fluorescence signal and thus ratiometric measurements under nonuniform excitation. Quantitative size measurements can also be done even under conditions of nonuniform flow via a two-beam layout. This innovative detection scheme not only considerably simplifies the fluid flow system and the excitation and collection optics, it opens the way to quantitative cytometry in simple and compact microfluidics systems, or in vivo. Real-time detection of fluorescent microbeads in the vasculature of mouse ear demonstrates the ability to do flow cytometry in vivo. The conditions required to perform quantitative in vivo cytometry on labeled cells will be presented.

14 CFR 1260.151 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... quantitative data should be related to cost data for computation of unit costs. (2) Reasons why established..., analysis and explanation of cost overruns or high unit costs. (e) Recipients shall not be required to... performance data from recipients. ...

24 CFR 84.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-04-01

... programs or projects can be readily quantified, such quantitative data should be related to cost data for... information including, when appropriate, analysis and explanation of cost overruns or high unit costs. (e... when requesting performance data from recipients. ...

The Effect of Studying Tech Prep in High School and College Academic Performance

ERIC Educational Resources Information Center

Ray, Larry A.

2011-01-01

This study examined the academic performance of Tech Prep students (referred to as participants) in comparison to non-Tech Prep students (referred to as non-participants) entering a two-year community college from sixteen different high schools in Stark County, Ohio. This study provided a quantitative analysis of students' academic experiences to…

The Impact of Various Quizzing Patterns on the Test Performance of High School Economics Students

ERIC Educational Resources Information Center

Robertson, William L.

2010-01-01

Presenting college students, in a wide variety of content areas, with frequent announced and unannounced quizzes appears to correlate positively with enhanced test performance. The purpose of this quantitative study was to examine if similar results can be achieved with high school students in a standard economics class. Based on a theoretical…

Validation of HPLC and UV spectrophotometric methods for the determination of meropenem in pharmaceutical dosage form.

PubMed

Mendez, Andreas S L; Steppe, Martin; Schapoval, Elfrides E S

2003-12-04

A high-performance liquid chromatographic method and a UV spectrophotometric method for the quantitative determination of meropenem, a highly active carbapenem antibiotic, in powder for injection were developed in present work. The parameters linearity, precision, accuracy, specificity, robustness, limit of detection and limit of quantitation were studied according to International Conference on Harmonization guidelines. Chromatography was carried out by reversed-phase technique on an RP-18 column with a mobile phase composed of 30 mM monobasic phosphate buffer and acetonitrile (90:10; v/v), adjusted to pH 3.0 with orthophosphoric acid. The UV spectrophotometric method was performed at 298 nm. The samples were prepared in water and the stability of meropenem in aqueous solution at 4 and 25 degrees C was studied. The results were satisfactory with good stability after 24 h at 4 degrees C. Statistical analysis by Student's t-test showed no significant difference between the results obtained by the two methods. The proposed methods are highly sensitive, precise and accurate and can be used for the reliable quantitation of meropenem in pharmaceutical dosage form.

Ultra-high-performance supercritical fluid chromatography with quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) for analysis of lignin-derived monomeric compounds in processed lignin samples.

PubMed

Prothmann, Jens; Sun, Mingzhe; Spégel, Peter; Sandahl, Margareta; Turner, Charlotta

2017-12-01

The conversion of lignin to potentially high-value low molecular weight compounds often results in complex mixtures of monomeric and oligomeric compounds. In this study, a method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) has been developed. Seven different columns were explored for maximum selectivity. Makeup solvent composition and ion source settings were optimised using a D-optimal design of experiment (DoE). Differently processed lignin samples were analysed and used for the method validation. The new UHPSFC/QTOF-MS method showed good separation of the 40 compounds within only 6-min retention time, and out of these, 36 showed high ionisation efficiency in negative electrospray ionisation mode. Graphical abstract A rapid and selective method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS).

Determination of alkylphenols and alkylphenol mono- and diethoxylates in environmental samples by high-performance liquid chromatography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahel, M.; Giger, W.

1985-07-01

A routine method is described for the quantitative determination of 4-nonylphenol (NP) and 4-nonylphenol mono-(NP1EO) and diethoxylate (NP2EO) in samples from wastewater and sludge treatment and from the aquatic environment. An exhaustive steam-distillation/solvent-extraction procedure was employed to enrich the analytes from aqueous and solid samples. Quantitative determinations were performed by normal-phase high-performance liquid chromatography (HP-LC) using aminosilica columns. Relative standard deviations were 3.0-4.4% in a river water containing 3.9 ..mu..g/L NP, 23.4 ..mu..g/L NP1EO, and 9.4 ..mu..g/L NP2EO. A digested sewage sludge with 1.6 g of NP/kg of dry matter was analyzed with a relative standard deviation of 3.7%. Recoveriesmore » were higher than 80%, and the estimated detection limit in water samples was 0.5 ..mu..g/L. Reversed-phase HPLC on octylsilica provided complementary qualitative data, particularly on homologous alkylphenolic compounds. Good agreement was found between quantitative determinations by HPLC and by high-resolution gas chromatography with flame ionization detection and directly coupled mass spectrometry. Municipal wastewater effluents, sewage sludges, and natural waters were analyzed to demonstrate the method's broad applicability. 19 references, 4 tables, 4 figures.« less

Quantitative Analysis of Scattering Mechanisms in Highly Crystalline CVD MoS2 through a Self-Limited Growth Strategy by Interface Engineering.

PubMed

Wan, Xi; Chen, Kun; Xie, Weiguang; Wen, Jinxiu; Chen, Huanjun; Xu, Jian-Bin

2016-01-27

The electrical performance of highly crystalline monolayer MoS2 is remarkably enhanced by a self-limited growth strategy on octadecyltrimethoxysilane self-assembled monolayer modified SiO2 /Si substrates. The scattering mechanisms in low-κ dielectric, including the dominant charged impurities, acoustic deformation potentials, optical deformation potentials), Fröhlich interaction, and the remote interface phonon interaction in dielectrics, are quantitatively analyzed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reproducibility in light microscopy: Maintenance, standards and SOPs.

PubMed

Deagle, Rebecca C; Wee, Tse-Luen Erika; Brown, Claire M

2017-08-01

Light microscopy has grown to be a valuable asset in both the physical and life sciences. It is a highly quantitative method available in individual research laboratories and often centralized in core facilities. However, although quantitative microscopy is becoming a customary tool in research, it is rarely standardized. To achieve accurate quantitative microscopy data and reproducible results, three levels of standardization must be considered: (1) aspects of the microscope, (2) the sample, and (3) the detector. The accuracy of the data is only as reliable as the imaging system itself, thereby imposing the need for routine standard performance testing. Depending on the task some maintenance procedures should be performed once a month, some before each imaging session, while others conducted annually. This text should be implemented as a resource for researchers to integrate with their own standard operating procedures to ensure the highest quality quantitative microscopy data. Copyright © 2017. Published by Elsevier Ltd.

Versatile quantitative phase imaging system applied to high-speed, low noise and multimodal imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Federici, Antoine; Aknoun, Sherazade; Savatier, Julien; Wattellier, Benoit F.

2017-02-01

Quadriwave lateral shearing interferometry (QWLSI) is a well-established quantitative phase imaging (QPI) technique based on the analysis of interference patterns of four diffraction orders by an optical grating set in front of an array detector [1]. As a QPI modality, this is a non-invasive imaging technique which allow to measure the optical path difference (OPD) of semi-transparent samples. We present a system enabling QWLSI with high-performance sCMOS cameras [2] and apply it to perform high-speed imaging, low noise as well as multimodal imaging. This modified QWLSI system contains a versatile optomechanical device which images the optical grating near the detector plane. Such a device is coupled with any kind of camera by varying its magnification. In this paper, we study the use of a sCMOS Zyla5.5 camera from Andor along with our modified QWLSI system. We will present high-speed live cell imaging, up to 200Hz frame rate, in order to follow intracellular fast motions while measuring the quantitative phase information. The structural and density information extracted from the OPD signal is complementary to the specific and localized fluorescence signal [2]. In addition, QPI detects cells even when the fluorophore is not expressed. This is very useful to follow a protein expression with time. The 10 µm spatial pixel resolution of our modified QWLSI associated to the high sensitivity of the Zyla5.5 enabling to perform high quality fluorescence imaging, we have carried out multimodal imaging revealing fine structures cells, like actin filaments, merged with the morphological information of the phase. References [1]. P. Bon, G. Maucort, B. Wattellier, and S. Monneret, "Quadriwave lateral shearing interferometry for quantitative phase microscopy of living cells," Opt. Express, vol. 17, pp. 13080-13094, 2009. [2] P. Bon, S. Lécart, E. Fort and S. Lévêque-Fort, "Fast label-free cytoskeletal network imaging in living mammalian cells," Biophysical journal, 106(8), pp. 1588-1595, 2014

Quantitative capillary electrophoresis and its application in analysis of alkaloids in tea, coffee, coca cola, and theophylline tablets.

PubMed

Li, Mengjia; Zhou, Junyi; Gu, Xue; Wang, Yan; Huang, Xiaojing; Yan, Chao

2009-01-01

A quantitative CE (qCE) system with high precision has been developed, in which a 4-port nano-valve was isolated from the electric field and served as sample injector. The accurate amount of sample was introduced into the CE system with high reproducibility. Based on this system, consecutive injections and separations were performed without voltage interruption. Reproducibilities in terms of RSD lower than 0.8% for retention time and 1.7% for peak area were achieved. The effectiveness of the system was demonstrated by the quantitative analysis of caffeine, theobromine, and theophylline in real samples, such as tea leaf, roasted coffee, coca cola, and theophylline tablets.

Validation of HPLC method for the simultaneous and quantitative determination of 12 UV-filters in cosmetics.

PubMed

Nyeborg, M; Pissavini, M; Lemasson, Y; Doucet, O

2010-02-01

The aim of the study was the validation of a high-performance liquid chromatography (HPLC) method for the simultaneous and quantitative determination of twelve commonly used organic UV-filters (phenylbenzimidazole sulfonic acid, benzophenone-3, isoamyl p-methoxycinnamate, diethylamino hydroxybenzoyl hexyl benzoate, octocrylene, ethylhexyl methoxycinnamate, ethylhexyl salicylate, butyl methoxydibenzoylmethane, diethylhexyl butamido triazone, ethylhexyl triazone, methylene bis-benzotriazolyl tetramethylbutylphenol and bis-ethylhexyloxyphenol methoxyphenyl triazine) contained in suncare products. The separation and quantitative determination was performed in <30 min, using a Symmetry Shield(R) C18 (5 microm) column from Waters and a mobile phase (gradient mode) consisting of ethanol and acidified water. UV measurements were carried out at multi-wavelengths, according to the absorption of the analytes.

36 CFR 1210.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... quantitative data should be related to cost data for computation of unit costs. (2) Reasons why established..., analysis and explanation of cost overruns or high unit costs. (e) Recipients shall not be required to... requesting performance data from recipients. ...

Quantitative analysis of three chiral pesticide enantiomers by high-performance column liquid chromatography.

PubMed

Wang, Peng; Liu, Donghui; Gu, Xu; Jiang, Shuren; Zhou, Zhiqiang

2008-01-01

Methods for the enantiomeric quantitative determination of 3 chiral pesticides, paclobutrazol, myclobutanil, and uniconazole, and their residues in soil and water are reported. An effective chiral high-performance liquid chromatographic (HPLC)-UV method using an amylose-tris(3,5-dimethylphenylcarbamate; AD) column was developed for resolving the enantiomers and quantitative determination. The enantiomers were identified by a circular dichroism detector. Validation involved complete resolution of each of the 2 enantiomers, plus determination of linearity, precision, and limit of detection (LOD). The pesticide enantiomers were isolated by solvent extraction from soil and C18 solid-phase extraction from water. The 2 enantiomers of the 3 pesticides could be completely separated on the AD column using n-hexane isopropanol mobile phase. The linearity and precision results indicated that the method was reliable for the quantitative analysis of the enantiomers. LODs were 0.025, 0.05, and 0.05 mg/kg for each enantiomer of paclobutrazol, myclobutanil, and uniconazole, respectively. Recovery and precision data showed that the pretreatment procedures were satisfactory for enantiomer extraction and cleanup. This method can be used for optical purity determination of technical material and analysis of environmental residues.

Quantitative two-dimensional HSQC experiment for high magnetic field NMR spectrometers

NASA Astrophysics Data System (ADS)

Koskela, Harri; Heikkilä, Outi; Kilpeläinen, Ilkka; Heikkinen, Sami

2010-01-01

The finite RF power available on carbon channel in proton-carbon correlation experiments leads to non-uniform cross peak intensity response across carbon chemical shift range. Several classes of broadband pulses are available that alleviate this problem. Adiabatic pulses provide an excellent magnetization inversion over a large bandwidth, and very recently, novel phase-modulated pulses have been proposed that perform 90° and 180° magnetization rotations with good offset tolerance. Here, we present a study how these broadband pulses (adiabatic and phase-modulated) can improve quantitative application of the heteronuclear single quantum coherence (HSQC) experiment on high magnetic field strength NMR spectrometers. Theoretical and experimental examinations of the quantitative, offset-compensated, CPMG-adjusted HSQC (Q-OCCAHSQC) experiment are presented. The proposed experiment offers a formidable improvement to the offset performance; 13C offset-dependent standard deviation of the peak intensity was below 6% in range of ±20 kHz. This covers the carbon chemical shift range of 150 ppm, which contains the protonated carbons excluding the aldehydes, for 22.3 T NMR magnets. A demonstration of the quantitative analysis of a fasting blood plasma sample obtained from a healthy volunteer is given.

Quantitation of polymethoxylated flavones in orange juice by high-performance liquid chromatography.

PubMed

Rouseff, R L; Ting, S V

1979-08-01

A quantitative high-performance liquid chromatographic (HPLC) procedure for the determination of the five major polymethoxylated flavones (PMFs) in orange juice has been developed. It employs a unique ternary solvent system with coupled UV-fluorescence detection. The dual detectors were employed to determine the presence of interfering substances and served as a cross check on quantitation. Stop flow UV and fluorescence scanning was used to identify peaks and determine the presence of impurities. Although all five citrus PMFs fluoresce, some HPLC fluorescence peaks were too small to be of much practical use. All five citrus PMFs could be quantitated satisfactorily with the fixed wavelength UV (313 nm) detector. The HPLC procedure has been used to evaluate each step in the preparation. The optimum extracting solvent was selected and one time consuming step was eliminated, as it was found to be unnecessary. HPLC values for nobiletin and sinensetin are in good agreement with the thin-layer chromatographic (TLC) values in the literature. HPLC values for the other three flavones were considerably lower than those reported in the literature. The HPLC procedure is considerably faster than the TLC procedure with equal or superior precision and accuracy.

Smartphone based hand-held quantitative phase microscope using the transport of intensity equation method.

PubMed

Meng, Xin; Huang, Huachuan; Yan, Keding; Tian, Xiaolin; Yu, Wei; Cui, Haoyang; Kong, Yan; Xue, Liang; Liu, Cheng; Wang, Shouyu

2016-12-20

In order to realize high contrast imaging with portable devices for potential mobile healthcare, we demonstrate a hand-held smartphone based quantitative phase microscope using the transport of intensity equation method. With a cost-effective illumination source and compact microscope system, multi-focal images of samples can be captured by the smartphone's camera via manual focusing. Phase retrieval is performed using a self-developed Android application, which calculates sample phases from multi-plane intensities via solving the Poisson equation. We test the portable microscope using a random phase plate with known phases, and to further demonstrate its performance, a red blood cell smear, a Pap smear and monocot root and broad bean epidermis sections are also successfully imaged. Considering its advantages as an accurate, high-contrast, cost-effective and field-portable device, the smartphone based hand-held quantitative phase microscope is a promising tool which can be adopted in the future in remote healthcare and medical diagnosis.

Qualitative and quantitative analysis of branches in dextran using high-performance anion exchange chromatography coupled to quadrupole time-of-flight mass spectrometry.

PubMed

Yi, Lin; Ouyang, Yilan; Sun, Xue; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

2015-12-04

Dextran, a family of natural polysaccharides, consists of an α (1→6) linked-glucose main (backbone) chain having a number of branches. The determination of the types and the quantities of branches in dextran is important in understanding its various biological roles. In this study, a hyphenated method using high-performance anion exchange chromatography (HPAEC) in parallel with pulsed amperometric detection (PAD) and mass spectrometry (MS) was applied to qualitative and quantitative analysis of dextran branches. A rotary cation-exchange cartridge array desalter was used for removal of salt from the HPAEC eluent making it MS compatible. MS and MS/MS were used to provide structural information on the enzymatically prepared dextran oligosaccharides. PAD provides quantitative data on the ratio of enzyme-resistant, branched dextran oligosaccharides. Both the types and degree of branching found in a variety of dextrans could be simultaneously determined online using this method. Copyright © 2015 Elsevier B.V. All rights reserved.

Separation and quantitation of polyethylene glycols 400 and 3350 from human urine by high-performance liquid chromatography.

PubMed

Ryan, C M; Yarmush, M L; Tompkins, R G

1992-04-01

Polyethylene glycol 3350 (PEG 3350) is useful as an orally administered probe to measure in vivo intestinal permeability to macromolecules. Previous methods to detect polyethylene glycol (PEG) excreted in the urine have been hampered by inherent inaccuracies associated with liquid-liquid extraction and turbidimetric analysis. For accurate quantitation by previous methods, radioactive labels were required. This paper describes a method to separate and quantitate PEG 3350 and PEG 400 in human urine that is independent of radioactive labels and is accurate in clinical practice. The method uses sized regenerated cellulose membranes and mixed ion-exchange resin for sample preparation and high-performance liquid chromatography with refractive index detection for analysis. The 24-h excretion for normal individuals after an oral dose of 40 g of PEG 3350 and 5 g of PEG 400 was 0.12 +/- 0.04% of the original dose of PEG 3350 and 26.3 +/- 5.1% of the original dose of PEG 400.

Comparison of high-performance liquid chromatography and supercritical fluid chromatography using evaporative light scattering detection for the determination of plasticizers in medical devices.

PubMed

Lecoeur, Marie; Decaudin, Bertrand; Guillotin, Yoann; Sautou, Valérie; Vaccher, Claude

2015-10-23

Recently, interest in supercritical fluid chromatography (SFC) has increased due to its high throughput and the development of new system improving chromatographic performances. However, most papers dealt with fundamental studies and chiral applications and only few works described validation process of SFC method. Likewise, evaporative light scattering detection (ELSD) has been widely employed in liquid chromatography but only a few recent works presented its quantitative performances hyphenated with SFC apparatus. The present paper discusses about the quantitative performances of SFC-ELSD compared to HPLC-ELSD, for the determination of plasticizers (ATBC, DEHA, DEHT and TOTM) in PVC tubing used as medical devices. After the development of HPLC-ELSD, both methods were evaluated based on the total error approach using accuracy profile. The results show that HPLC-ELSD was more precise than SFC-ELSD but lower limits of quantitation were obtained by SFC. Hence, HPLC was validated in the ± 10% acceptance limits whereas SFC lacks of accuracy to quantify plasticizers. Finally, both methods were used to determine the composition of plasticized-PVC medical devices. Results demonstrated that SFC and HPLC both hyphenated with ELSD provided similar results. Copyright © 2015 Elsevier B.V. All rights reserved.

[Determination of sugars, organic acids and alcohols in microbial consortium fermentation broth from cellulose using high performance liquid chromatography].

PubMed

Jiang, Yan; Fan, Guifang; Du, Ran; Li, Peipei; Jiang, Li

2015-08-01

A high performance liquid chromatographic method was established for the determination of metabolites (sugars, organic acids and alcohols) in microbial consortium fermentation broth from cellulose. Sulfate was first added in the samples to precipitate calcium ions in microbial consortium culture medium and lower the pH of the solution to avoid the dissociation of organic acids, then the filtrates were effectively separated using high performance liquid chromatography. Cellobiose, glucose, ethanol, butanol, glycerol, acetic acid and butyric acid were quantitatively analyzed. The detection limits were in the range of 0.10-2.00 mg/L. The linear correlation coefficients were greater than 0.999 6 in the range of 0.020 to 1.000 g/L. The recoveries were in the range of 85.41%-115.60% with the relative standard deviations of 0.22% -4.62% (n = 6). This method is accurate for the quantitative analysis of the alcohols, organic acids and saccharides in microbial consortium fermentation broth from cellulose.

Standardisation of Gymnema sylvestre R.Br. by high-performance thin-layer chromatography: an improved method.

PubMed

Raju, Valivarthi S R; Kannababu, S; Subbaraju, Gottumukkala V

2006-01-01

An improved high-performance thin-layer chromatographic (HPTLC) method for the standardisation of Gymnema sylvestre is reported. The method involves the initial hydrolysis of gymnemic acids, the active ingredients, to a common aglycone followed by the quantitative estimation of gymnemagenin. The present method rectifies an error found in an HPTLC method reported recently.

Quantitative Comparison of Minimum Inductance and Minimum Power Algorithms for the Design of Shim Coils for Small Animal Imaging

PubMed Central

HUDSON, PARISA; HUDSON, STEPHEN D.; HANDLER, WILLIAM B.; SCHOLL, TIMOTHY J.; CHRONIK, BLAINE A.

2010-01-01

High-performance shim coils are required for high-field magnetic resonance imaging and spectroscopy. Complete sets of high-power and high-performance shim coils were designed using two different methods: the minimum inductance and the minimum power target field methods. A quantitative comparison of shim performance in terms of merit of inductance (ML) and merit of resistance (MR) was made for shim coils designed using the minimum inductance and the minimum power design algorithms. In each design case, the difference in ML and the difference in MR given by the two design methods was <15%. Comparison of wire patterns obtained using the two design algorithms show that minimum inductance designs tend to feature oscillations within the current density; while minimum power designs tend to feature less rapidly varying current densities and lower power dissipation. Overall, the differences in coil performance obtained by the two methods are relatively small. For the specific case of shim systems customized for small animal imaging, the reduced power dissipation obtained when using the minimum power method is judged to be more significant than the improvements in switching speed obtained from the minimum inductance method. PMID:20411157

Large-Scale Interlaboratory Study to Develop, Analytically Validate and Apply Highly Multiplexed, Quantitative Peptide Assays to Measure Cancer-Relevant Proteins in Plasma*

PubMed Central

Abbatiello, Susan E.; Schilling, Birgit; Mani, D. R.; Zimmerman, Lisa J.; Hall, Steven C.; MacLean, Brendan; Albertolle, Matthew; Allen, Simon; Burgess, Michael; Cusack, Michael P.; Gosh, Mousumi; Hedrick, Victoria; Held, Jason M.; Inerowicz, H. Dorota; Jackson, Angela; Keshishian, Hasmik; Kinsinger, Christopher R.; Lyssand, John; Makowski, Lee; Mesri, Mehdi; Rodriguez, Henry; Rudnick, Paul; Sadowski, Pawel; Sedransk, Nell; Shaddox, Kent; Skates, Stephen J.; Kuhn, Eric; Smith, Derek; Whiteaker, Jeffery R.; Whitwell, Corbin; Zhang, Shucha; Borchers, Christoph H.; Fisher, Susan J.; Gibson, Bradford W.; Liebler, Daniel C.; MacCoss, Michael J.; Neubert, Thomas A.; Paulovich, Amanda G.; Regnier, Fred E.; Tempst, Paul; Carr, Steven A.

2015-01-01

There is an increasing need in biology and clinical medicine to robustly and reliably measure tens to hundreds of peptides and proteins in clinical and biological samples with high sensitivity, specificity, reproducibility, and repeatability. Previously, we demonstrated that LC-MRM-MS with isotope dilution has suitable performance for quantitative measurements of small numbers of relatively abundant proteins in human plasma and that the resulting assays can be transferred across laboratories while maintaining high reproducibility and quantitative precision. Here, we significantly extend that earlier work, demonstrating that 11 laboratories using 14 LC-MS systems can develop, determine analytical figures of merit, and apply highly multiplexed MRM-MS assays targeting 125 peptides derived from 27 cancer-relevant proteins and seven control proteins to precisely and reproducibly measure the analytes in human plasma. To ensure consistent generation of high quality data, we incorporated a system suitability protocol (SSP) into our experimental design. The SSP enabled real-time monitoring of LC-MRM-MS performance during assay development and implementation, facilitating early detection and correction of chromatographic and instrumental problems. Low to subnanogram/ml sensitivity for proteins in plasma was achieved by one-step immunoaffinity depletion of 14 abundant plasma proteins prior to analysis. Median intra- and interlaboratory reproducibility was <20%, sufficient for most biological studies and candidate protein biomarker verification. Digestion recovery of peptides was assessed and quantitative accuracy improved using heavy-isotope-labeled versions of the proteins as internal standards. Using the highly multiplexed assay, participating laboratories were able to precisely and reproducibly determine the levels of a series of analytes in blinded samples used to simulate an interlaboratory clinical study of patient samples. Our study further establishes that LC-MRM-MS using stable isotope dilution, with appropriate attention to analytical validation and appropriate quality control measures, enables sensitive, specific, reproducible, and quantitative measurements of proteins and peptides in complex biological matrices such as plasma. PMID:25693799

Impact of high 131I-activities on quantitative 124I-PET

NASA Astrophysics Data System (ADS)

Braad, P. E. N.; Hansen, S. B.; Høilund-Carlsen, P. F.

2015-07-01

Peri-therapeutic 124 I-PET/CT is of interest as guidance for radioiodine therapy. Unfortunately, image quality is complicated by dead time effects and increased random coincidence rates from high 131 I-activities. A series of phantom experiments with clinically relevant 124 I/131 I-activities were performed on a clinical PET/CT-system. Noise equivalent count rate (NECR) curves and quantitation accuracy were determined from repeated scans performed over several weeks on a decaying NEMA NU-2 1994 cylinder phantom initially filled with 25 MBq 124 I and 1250 MBq 131 I. Six spherical inserts with diameters 10-37 mm were filled with 124 I (0.45 MBq ml-1 ) and 131 I (22 MBq ml-1 ) and placed inside the background of the NEMA/IEC torso phantom. Contrast recovery, background variability and the accuracy of scatter and attenuation corrections were assessed at sphere-to-background activity ratios of 20, 10 and 5. Results were compared to pure 124 I-acquisitions. The quality of 124 I-PET images in the presence of high 131 I-activities was good and image quantification unaffected except at very high count rates. Quantitation accuracy and contrast recovery were uninfluenced at 131 I-activities below 1000 MBq, whereas image noise was slightly increased. The NECR peaked at 550 MBq of 131 I, where it was 2.8 times lower than without 131 I in the phantom. Quantitative peri-therapeutic 124 I-PET is feasible.

Imaging Performance of Quantitative Transmission Ultrasound

PubMed Central

Lenox, Mark W.; Wiskin, James; Lewis, Matthew A.; Darrouzet, Stephen; Borup, David; Hsieh, Scott

2015-01-01

Quantitative Transmission Ultrasound (QTUS) is a tomographic transmission ultrasound modality that is capable of generating 3D speed-of-sound maps of objects in the field of view. It performs this measurement by propagating a plane wave through the medium from a transmitter on one side of a water tank to a high resolution receiver on the opposite side. This information is then used via inverse scattering to compute a speed map. In addition, the presence of reflection transducers allows the creation of a high resolution, spatially compounded reflection map that is natively coregistered to the speed map. A prototype QTUS system was evaluated for measurement and geometric accuracy as well as for the ability to correctly determine speed of sound. PMID:26604918

Qualitative Differences in Real-Time Solution of Standardized Figural Analogies.

ERIC Educational Resources Information Center

Schiano, Diane J.; And Others

Performance on standardized figural analogy tests is considered highly predictive of academic success. While information-processing models of analogy solution attribute performance differences to quantitative differences in processing parameters, the problem-solving literature suggests that qualitative differences in problem representation and…

Differences between genders in colorectal morphology on CT colonography using a quantitative approach: a pilot study.

PubMed

Weber, Charles N; Poff, Jason A; Lev-Toaff, Anna S; Levine, Marc S; Zafar, Hanna M

To explore quantitative differences between genders in morphologic colonic metrics and determine metric reproducibility. Quantitative colonic metrics from 20 male and 20 female CTC datasets were evaluated twice by two readers; all exams were performed after incomplete optical colonoscopy. Intra-/inter-reader reliability was measured with intraclass correlation coefficient (ICC) and concordance correlation coefficient (CCC). Women had overall decreased colonic volume, increased tortuosity and compactness and lower sigmoid apex height on CTC compared to men (p<0.0001,all). Quantitative measurements in colonic metrics were highly reproducible (ICC=0.9989 and 0.9970; CCC=0.9945). Quantitative morphologic differences between genders can be reproducibility measured. Copyright © 2017 Elsevier Inc. All rights reserved.

MR morphology of triangular fibrocartilage complex: correlation with quantitative MR and biomechanical properties.

PubMed

Bae, Won C; Ruangchaijatuporn, Thumanoon; Chang, Eric Y; Biswas, Reni; Du, Jiang; Statum, Sheronda; Chung, Christine B

2016-04-01

To evaluate pathology of the triangular fibrocartilage complex (TFCC) using high-resolution morphologic magnetic resonance (MR) imaging, and compare with quantitative MR and biomechanical properties. Five cadaveric wrists (22-70 years) were imaged at 3 T using morphologic (proton density weighted spin echo, PD FS, and 3D spoiled gradient echo, 3D SPGR) and quantitative MR sequences to determine T2 and T1rho properties. In eight geographic regions, morphology of TFC disc and laminae were evaluated for pathology and quantitative MR values. Samples were disarticulated and biomechanical indentation testing was performed on the distal surface of the TFC disc. On morphologic PD SE images, TFC disc pathology included degeneration and tears, while that of the laminae included degeneration, degeneration with superimposed tear, mucinous transformation, and globular calcification. Punctate calcifications were highly visible on 3D SPGR images and found only in pathologic regions. Disc pathology occurred more frequently in proximal regions of the disc than distal regions. Quantitative MR values were lowest in normal samples, and generally higher in pathologic regions. Biomechanical testing demonstrated an inverse relationship, with indentation modulus being high in normal regions with low MR values. The laminae studied were mostly pathologic, and additional normal samples are needed to discern quantitative changes. These results show technical feasibility of morphologic MR, quantitative MR, and biomechanical techniques to characterize pathology of the TFCC. Quantitative MRI may be a suitable surrogate marker of soft tissue mechanical properties, and a useful adjunct to conventional morphologic MR techniques.

A high throughput geocomputing system for remote sensing quantitative retrieval and a case study

NASA Astrophysics Data System (ADS)

Xue, Yong; Chen, Ziqiang; Xu, Hui; Ai, Jianwen; Jiang, Shuzheng; Li, Yingjie; Wang, Ying; Guang, Jie; Mei, Linlu; Jiao, Xijuan; He, Xingwei; Hou, Tingting

2011-12-01

The quality and accuracy of remote sensing instruments have been improved significantly, however, rapid processing of large-scale remote sensing data becomes the bottleneck for remote sensing quantitative retrieval applications. The remote sensing quantitative retrieval is a data-intensive computation application, which is one of the research issues of high throughput computation. The remote sensing quantitative retrieval Grid workflow is a high-level core component of remote sensing Grid, which is used to support the modeling, reconstruction and implementation of large-scale complex applications of remote sensing science. In this paper, we intend to study middleware components of the remote sensing Grid - the dynamic Grid workflow based on the remote sensing quantitative retrieval application on Grid platform. We designed a novel architecture for the remote sensing Grid workflow. According to this architecture, we constructed the Remote Sensing Information Service Grid Node (RSSN) with Condor. We developed a graphic user interface (GUI) tools to compose remote sensing processing Grid workflows, and took the aerosol optical depth (AOD) retrieval as an example. The case study showed that significant improvement in the system performance could be achieved with this implementation. The results also give a perspective on the potential of applying Grid workflow practices to remote sensing quantitative retrieval problems using commodity class PCs.

A micromethod for the determination of the new antiepileptic drug levetiracetam (ucb LO59) in serum or plasma by high performance liquid chromatography.

PubMed

Ratnaraj, N; Doheny, H C; Patsalos, P N

1996-04-01

An isocratic high performance liquid chromatographic micromethod is described for the quantitation of levetiracetam (ucb L059) in plasma or serum of patients. The chromatography is performed on a 250 x 4 mm I.D. LiChrospher 60 RP-select B, 5-micron column, eluted with an acetonitrile/50 mM phosphate buffer (15:85 vol/vol, pH 5.6) mobile phase, and levetiracetam detected using ultraviolet absorbance at 220 nm. The limit of quantitation was 5 mumol/L and the within-batch and between-batch coefficients of variation were < 7%. No interference from commonly prescribed antiepileptic drugs (carbamazepine and its metabolite carbamazepine epoxide, ethosuximide, gabapentin, lamotrigine, phenobarbitone, phenytoin, primidone, valproic acid, and vigabatrin) was observed, and thus the method can be used to monitor levetiracetam in patients on polytherapy antiepileptic drug regimens.

Development of combinatorial chemistry methods for coatings: high-throughput adhesion evaluation and scale-up of combinatorial leads.

PubMed

Potyrailo, Radislav A; Chisholm, Bret J; Morris, William G; Cawse, James N; Flanagan, William P; Hassib, Lamyaa; Molaison, Chris A; Ezbiansky, Karin; Medford, George; Reitz, Hariklia

2003-01-01

Coupling of combinatorial chemistry methods with high-throughput (HT) performance testing and measurements of resulting properties has provided a powerful set of tools for the 10-fold accelerated discovery of new high-performance coating materials for automotive applications. Our approach replaces labor-intensive steps with automated systems for evaluation of adhesion of 8 x 6 arrays of coating elements that are discretely deposited on a single 9 x 12 cm plastic substrate. Performance of coatings is evaluated with respect to their resistance to adhesion loss, because this parameter is one of the primary considerations in end-use automotive applications. Our HT adhesion evaluation provides previously unavailable capabilities of high speed and reproducibility of testing by using a robotic automation, an expanded range of types of tested coatings by using the coating tagging strategy, and an improved quantitation by using high signal-to-noise automatic imaging. Upon testing, the coatings undergo changes that are impossible to quantitatively predict using existing knowledge. Using our HT methodology, we have developed several coatings leads. These HT screening results for the best coating compositions have been validated on the traditional scales of coating formulation and adhesion loss testing. These validation results have confirmed the superb performance of combinatorially developed coatings over conventional coatings on the traditional scale.

Quantitative and Qualitative Differences in Morphological Traits Revealed between Diploid Fragaria Species

PubMed Central

SARGENT, DANIEL J.; GEIBEL, M.; HAWKINS, J. A.; WILKINSON, M. J.; BATTEY, N. H.; SIMPSON, D. W.

2004-01-01

• Background and Aims The aims of this investigation were to highlight the qualitative and quantitative diversity apparent between nine diploid Fragaria species and produce interspecific populations segregating for a large number of morphological characters suitable for quantitative trait loci analysis. • Methods A qualitative comparison of eight described diploid Fragaria species was performed and measurements were taken of 23 morphological traits from 19 accessions including eight described species and one previously undescribed species. A principal components analysis was performed on 14 mathematically unrelated traits from these accessions, which partitioned the species accessions into distinct morphological groups. Interspecific crosses were performed with accessions of species that displayed significant quantitative divergence and, from these, populations that should segregate for a range of quantitative traits were raised. • Key Results Significant differences between species were observed for all 23 morphological traits quantified and three distinct groups of species accessions were observed after the principal components analysis. Interspecific crosses were performed between these groups, and F2 and backcross populations were raised that should segregate for a range of morphological characters. In addition, the study highlighted a number of distinctive morphological characters in many of the species studied. • Conclusions Diploid Fragaria species are morphologically diverse, yet remain highly interfertile, making the group an ideal model for the study of the genetic basis of phenotypic differences between species through map-based investigation using quantitative trait loci. The segregating interspecific populations raised will be ideal for such investigations and could also provide insights into the nature and extent of genome evolution within this group. PMID:15469944

38 CFR 49.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... readily quantified, such quantitative data should be related to cost data for computation of unit costs... including, when appropriate, analysis and explanation of cost overruns or high unit costs. (e) Recipients... performance data from recipients. (Authority: Pub. L. 104-156; 110 Stat. 1396) ...

Quantitative chest computed tomography as a means of predicting exercise performance in severe emphysema.

PubMed

Crausman, R S; Ferguson, G; Irvin, C G; Make, B; Newell, J D

1995-06-01

We assessed the value of quantitative high-resolution computed tomography (CT) as a diagnostic and prognostic tool in smoking-related emphysema. We performed an inception cohort study of 14 patients referred with emphysema. The diagnosis of emphysema was based on a compatible history, physical examination, chest radiograph, CT scan of the lung, and pulmonary physiologic evaluation. As a group, those who underwent exercise testing were hyperinflated (percentage predicted total lung capacity +/- standard error of the mean = 133 +/- 9%), and there was evidence of air trapping (percentage predicted respiratory volume = 318 +/- 31%) and airflow limitation (forced expiratory volume in 1 sec [FEV1] = 40 +/- 7%). The exercise performance of the group was severely limited (maximum achievable workload = 43 +/- 6%) and was characterized by prominent ventilatory, gas exchange, and pulmonary vascular abnormalities. The quantitative CT index was markedly elevated in all patients (76 +/- 9; n = 14; normal < 4). There were correlations between this quantitative CT index and measures of airflow limitation (FEV1 r2 = .34, p = 09; FEV1/forced vital capacity r2 = .46, p = .04) and between maximum workload achieved (r2 = .93, p = .0001) and maximum oxygen utilization (r2 = .83, p = .0007). Quantitative chest CT assessment of disease severity is correlated with the degree of airflow limitation and exercise impairment in pulmonary emphysema.

Quantitative and Qualitative Determination of Polysulfide Species in the Electrolyte of a Lithium-Sulfur Battery using HPLC ESI/MS with One-Step Derivatization

DOE PAGES

Zheng, Dong; Qu, Deyu; Yang, Xiao-Qing; ...

2015-01-29

The polysulfide species dissolved in aprotic solvents can be separated and analyzed by reverse phase (RP) high performance liquid chromatography (HPLC) in tandem with electrospray-mass spectroscopy. The relative distribution of polysulfide species in the electrolyte recovered from Li-S batteries is quantitatively and reliably determined for the first time.

Quantitative and Qualitative Determination of Polysulfide Species in the Electrolyte of a Lithium-Sulfur Battery using HPLC ESI/MS with One-Step Derivatization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Dong; Qu, Deyu; Yang, Xiao-Qing

The polysulfide species dissolved in aprotic solvents can be separated and analyzed by reverse phase (RP) high performance liquid chromatography (HPLC) in tandem with electrospray-mass spectroscopy. The relative distribution of polysulfide species in the electrolyte recovered from Li-S batteries is quantitatively and reliably determined for the first time.

Assessment of calcium scoring performance in cardiac computed tomography.

PubMed

Ulzheimer, Stefan; Kalender, Willi A

2003-03-01

Electron beam tomography (EBT) has been used for cardiac diagnosis and the quantitative assessment of coronary calcium since the late 1980s. The introduction of mechanical multi-slice spiral CT (MSCT) scanners with shorter rotation times opened new possibilities of cardiac imaging with conventional CT scanners. The purpose of this work was to qualitatively and quantitatively evaluate the performance for EBT and MSCT for the task of coronary artery calcium imaging as a function of acquisition protocol, heart rate, spiral reconstruction algorithm (where applicable) and calcium scoring method. A cardiac CT semi-anthropomorphic phantom was designed and manufactured for the investigation of all relevant image quality parameters in cardiac CT. This phantom includes various test objects, some of which can be moved within the anthropomorphic phantom in a manner that mimics realistic heart motion. These tools were used to qualitatively and quantitatively demonstrate the accuracy of coronary calcium imaging using typical protocols for an electron beam (Evolution C-150XP, Imatron, South San Francisco, Calif.) and a 0.5-s four-slice spiral CT scanner (Sensation 4, Siemens, Erlangen, Germany). A special focus was put on the method of quantifying coronary calcium, and three scoring systems were evaluated (Agatston, volume, and mass scoring). Good reproducibility in coronary calcium scoring is always the result of a combination of high temporal and spatial resolution; consequently, thin-slice protocols in combination with retrospective gating on MSCT scanners yielded the best results. The Agatston score was found to be the least reproducible scoring method. The hydroxyapatite mass, being better reproducible and comparable on different scanners and being a physical quantitative measure, appears to be the method of choice for future clinical studies. The hydroxyapatite mass is highly correlated to the Agatston score. The introduced phantoms can be used to quantitatively assess the performance characteristics of, for example, different scanners, reconstruction algorithms, and quantification methods in cardiac CT. This is especially important for quantitative tasks, such as the determination of the amount of calcium in the coronary arteries, to achieve high and constant quality in this field.

Is quantitative PCR for the pneumolysin (ply) gene useful for detection of pneumococcal lower respiratory tract infection?

PubMed

Abdeldaim, G; Herrmann, B; Korsgaard, J; Olcén, P; Blomberg, J; Strålin, K

2009-06-01

The pneumolysin (ply) gene is widely used as a target in PCR assays for Streptococcus pneumoniae in respiratory secretions. However, false-positive results with conventional ply-based PCR have been reported. The aim here was to study the performance of a quantitative ply-based PCR for the identification of pneumococcal lower respiratory tract infection (LRTI). In a prospective study, fibreoptic bronchoscopy was performed in 156 hospitalized adult patients with LRTI and 31 controls who underwent bronchoscopy because of suspicion of malignancy. Among the LRTI patients and controls, the quantitative ply-based PCR applied to bronchoalveolar lavage (BAL) fluid was positive at >or=10(3) genome copies/mL in 61% and 71% of the subjects, at >or=10(5) genome copies/mL in 40% and 58% of the subjects, and at >or=10(7) genome copies/mL in 15% and 3.2% of the subjects, respectively. Using BAL fluid culture, blood culture, and/or a urinary antigen test, S. pneumoniae was identified in 19 LRTI patients. As compared with these diagnostic methods used in combination, quantitative ply-based PCR showed sensitivities and specificities of 89% and 43% at a cut-off of 10(3) genome copies/mL, of 84% and 66% at a cut-off of 10(5) genome copies/mL, and of 53% and 90% at a cut-off of 10(7) genome copies/mL, respectively. In conclusion, a high cut-off with the quantitative ply-based PCR was required to reach acceptable specificity. However, as a high cut-off resulted in low sensitivity, quantitative ply-based PCR does not appear to be clinically useful. Quantitative PCR methods for S. pneumoniae using alternative gene targets should be evaluated.

Relationships among Testing Medium, Test Performance, and Testing Time of High School Students Who Are Visually Impaired

ERIC Educational Resources Information Center

Erin, Jane N.; Hong, Sunggye; Schoch, Christina; Kuo, YaJu

2006-01-01

This study compared the test scores and time required by high school students who are blind, sighted, or have low vision to complete tests administered in written and oral formats. The quantitative results showed that the blind students performed better on multiple-choice tests in braille and needed more time while taking tests in braille. The…

Quantitative analysis of psilocybin and psilocin in psilocybe baeocystis (Singer and Smith) by high-performance liquid chromatography and by thin-layer chromatography.

PubMed

Beug, M W; Bigwood, J

1981-03-27

Rapid quantification of psilocybin and psilocin in extracts of wild mushrooms is accomplished by reversed-phase high-performance liquid chromatography with paired-ion reagents. Nine solvent systems and three solid supports are evaluated for their efficiency in separating psilocybin, psilocin and other components of crude mushroom extracts by thin-layer chromatography.

The Effects of Servant Leader and Integrity of Principal Performance in Catholic Senior High Schools in North Sulawesi, Indonesia

ERIC Educational Resources Information Center

Malingkas, Melky; Senduk, Johanis Frans; Simandjuntak, Suddin; Binilang, Benny Blemy

2018-01-01

The aim of this research was to examine the effects of servant leader and integrity on principal performance in Catholic senior high schools in North Sulawesi, Indonesia. This quantitative research used questionnaire-gathered data from 75 teachers at 11 schools. The results of research show that the servant leader approach has significant positive…

School Improvement Grants in Georgia: A Quantitative Analysis of the Relationship between the College and Career Ready Performance Index, Students' Proficiency, and Graduation Rates

ERIC Educational Resources Information Center

Covington, Char-Shenda D.

2016-01-01

There are a myriad of factors that contribute to the lowest performing schools in Georgia that School Improvement Grants (SIGs) are designed to ameliorate. Declining graduation rates, dwindling student achievement, high teacher turnover rates, and students leaving high school at an alarming rate ill-prepared for college and/or the workforce…

An Analysis of Final Course Grades in Two Different Entry Level Mathematics Courses between and among First Year College Students with Different Levels of High School Mathematics Preparation

ERIC Educational Resources Information Center

Muir, Carrie

2012-01-01

The purpose of this study was to compare the performance of first year college students with similar high school mathematics backgrounds in two introductory level college mathematics courses, "Fundamentals and Techniques of College Algebra and Quantitative Reasoning and Mathematical Skills," and to compare the performance of students…

Diagnostic performance of semi-quantitative and quantitative stress CMR perfusion analysis: a meta-analysis.

PubMed

van Dijk, R; van Assen, M; Vliegenthart, R; de Bock, G H; van der Harst, P; Oudkerk, M

2017-11-27

Stress cardiovascular magnetic resonance (CMR) perfusion imaging is a promising modality for the evaluation of coronary artery disease (CAD) due to high spatial resolution and absence of radiation. Semi-quantitative and quantitative analysis of CMR perfusion are based on signal-intensity curves produced during the first-pass of gadolinium contrast. Multiple semi-quantitative and quantitative parameters have been introduced. Diagnostic performance of these parameters varies extensively among studies and standardized protocols are lacking. This study aims to determine the diagnostic accuracy of semi- quantitative and quantitative CMR perfusion parameters, compared to multiple reference standards. Pubmed, WebOfScience, and Embase were systematically searched using predefined criteria (3272 articles). A check for duplicates was performed (1967 articles). Eligibility and relevance of the articles was determined by two reviewers using pre-defined criteria. The primary data extraction was performed independently by two researchers with the use of a predefined template. Differences in extracted data were resolved by discussion between the two researchers. The quality of the included studies was assessed using the 'Quality Assessment of Diagnostic Accuracy Studies Tool' (QUADAS-2). True positives, false positives, true negatives, and false negatives were subtracted/calculated from the articles. The principal summary measures used to assess diagnostic accuracy were sensitivity, specificity, andarea under the receiver operating curve (AUC). Data was pooled according to analysis territory, reference standard and perfusion parameter. Twenty-two articles were eligible based on the predefined study eligibility criteria. The pooled diagnostic accuracy for segment-, territory- and patient-based analyses showed good diagnostic performance with sensitivity of 0.88, 0.82, and 0.83, specificity of 0.72, 0.83, and 0.76 and AUC of 0.90, 0.84, and 0.87, respectively. In per territory analysis our results show similar diagnostic accuracy comparing anatomical (AUC 0.86(0.83-0.89)) and functional reference standards (AUC 0.88(0.84-0.90)). Only the per territory analysis sensitivity did not show significant heterogeneity. None of the groups showed signs of publication bias. The clinical value of semi-quantitative and quantitative CMR perfusion analysis remains uncertain due to extensive inter-study heterogeneity and large differences in CMR perfusion acquisition protocols, reference standards, and methods of assessment of myocardial perfusion parameters. For wide spread implementation, standardization of CMR perfusion techniques is essential. CRD42016040176 .

Quantitative determination of tilmicosin in canine serum by high performance liquid chromatography-tandem mass spectrometry.

PubMed

Herrera, Michael; Ding, Haiqing; McClanahan, Robert; Owens, Jane G; Hunter, Robert P

2007-09-15

A highly sensitive and quantitative LC/MS/MS assay for the determination of tilmicosin in serum has been developed and validated. For sample preparation, 0.2 mL of canine serum was extracted with 3 mL of methyl tert-butyl ether. The organic layer was transferred to a new vessel and dried under nitrogen. The sample was then reconstituted for analysis by high performance liquid chromatography-tandem mass spectrometry. A Phenomenex Luna C8(2) analytical column was used for the chromatographic separation. The eluent was subsequently introduced to the mass spectrometer by electrospray ionization. A single range was validated for 50-5000 ng/mL for support of toxicokinetic studies. The inter-day relative error (inaccuracy) for the LLOQ samples ranged from -5.5% to 0.3%. The inter-day relative standard deviations (imprecision) at the respective LLOQ levels were < or =10.1%.

High-performance liquid chromatographic separation of human haemoglobins. Simultaneous quantitation of foetal and glycated haemoglobins.

PubMed

Bisse, E; Wieland, H

1988-12-29

A high-performance liquid chromatographic system, which uses a weak cation exchanger (PolyCATA) together with Bis-Tris buffer (pH 6.47-7.0) and sodium acetate gradients, is described. Samples from adults and newborns were analysed and a clean separation of many minor and major normal and abnormal haemoglobin (Hb) variants was greatly improved. The method allows the separation of minor foetal haemoglobin (HbF) variants and the simultaneous quantitation of HbF and glycated HbA. HbF values correlated well with those obtained by the alkali denaturation method (r = 0.997). The glycated haemoglobin (HbAIc) levels measured in patients with high HbF concentrations correlated with the total glycated haemoglobin determined by bioaffinity chromatography (r = 0.973). The procedure is useful for diagnostic applications and affords an effective and sensitive way of examining blood samples for haemoglobin abnormalities.

Three-phase bone scintigraphy for diagnosis of Charcot neuropathic osteoarthropathy in the diabetic foot - does quantitative data improve diagnostic value?

PubMed

Fosbøl, M; Reving, S; Petersen, E H; Rossing, P; Lajer, M; Zerahn, B

2017-01-01

To investigate whether inclusion of quantitative data on blood flow distribution compared with visual qualitative evaluation improve the reliability and diagnostic performance of 99 m Tc-hydroxymethylene diphosphate three-phase bone scintigraphy (TPBS) in patients suspected for charcot neuropathic osteoarthropathy (CNO) of the foot. A retrospective cohort study of TPBS performed on 148 patients with suspected acute CNO referred from a single specialized diabetes care centre. The quantitative blood flow distribution was calculated based on the method described by Deutsch et al. All scintigraphies were re-evaluated by independent, blinded observers twice with and without quantitative data on blood flow distribution at ankle and focus level, respectively. The diagnostic validity of TPBS was determined by subsequent review of clinical data and radiological examinations. A total of 90 patients (61%) had confirmed diagnosis of CNO. The sensitivity, specificity and accuracy of three-phase bone scintigraphy without/with quantitative data were 89%/88%, 58%/62% and 77%/78%, respectively. The intra-observer agreement improved significantly by adding quantitative data in the evaluation (Kappa value 0·79/0·94). The interobserver agreement was not significantly improved. Adding quantitative data on blood flow distribution in the interpretation of TBPS improves intra-observer variation, whereas no difference in interobserver variation was observed. The sensitivity of TPBS in the diagnosis of CNO is high, but holds limited specificity. Diagnostic performance does not improve using quantitative data in the evaluation. This may be due to the reference intervals applied in the study or the absence of a proper gold standard diagnostic procedure for comparison. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

15 CFR 14.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-01-01

... readily quantified, such quantitative data should be related to cost data for computation of unit costs... including, when appropriate, analysis and explanation of cost overruns or high unit costs. (e) Recipients... comply with clearance requirements of 5 CFR part 1320 when requesting performance data from recipients. ...

Appraising Teacher Performance: A Quantitative Approach.

ERIC Educational Resources Information Center

Wingate, James G.; Bowers, Fred

Following a brief research review regarding the relationship between teacher behavior and student outcomes, a model is proposed for identifying those teaching behaviors that are significantly related to high-quality student performance. The model's stages include: (1) delineation of questions; (2) establishment of a framework; (3) selection of an…

Quantitative evaluation of the risk induced by dominant geomorphological processes on different land uses, based on GIS spatial analysis models

NASA Astrophysics Data System (ADS)

Ştefan, Bilaşco; Sanda, Roşca; Ioan, Fodorean; Iuliu, Vescan; Sorin, Filip; Dănuţ, Petrea

2017-12-01

Maramureş Land is mostly characterized by agricultural and forestry land use due to its specific configuration of topography and its specific pedoclimatic conditions. Taking into consideration the trend of the last century from the perspective of land management, a decrease in the surface of agricultural lands to the advantage of built-up and grass lands, as well as an accelerated decrease in the forest cover due to uncontrolled and irrational forest exploitation, has become obvious. The field analysis performed on the territory of Maramureş Land has highlighted a high frequency of two geomorphologic processes — landslides and soil erosion — which have a major negative impact on land use due to their rate of occurrence. The main aim of the present study is the GIS modeling of the two geomorphologic processes, determining a state of vulnerability (the USLE model for soil erosion and a quantitative model based on the morphometric characteristics of the territory, derived from the HG. 447/2003) and their integration in a complex model of cumulated vulnerability identification. The modeling of the risk exposure was performed using a quantitative approach based on models and equations of spatial analysis, which were developed with modeled raster data structures and primary vector data, through a matrix highlighting the correspondence between vulnerability and land use classes. The quantitative analysis of the risk was performed by taking into consideration the exposure classes as modeled databases and the land price as a primary alphanumeric database using spatial analysis techniques for each class by means of the attribute table. The spatial results highlight the territories with a high risk to present geomorphologic processes that have a high degree of occurrence and represent a useful tool in the process of spatial planning.

Quantitative evaluation of the risk induced by dominant geomorphological processes on different land uses, based on GIS spatial analysis models

NASA Astrophysics Data System (ADS)

Ştefan, Bilaşco; Sanda, Roşca; Ioan, Fodorean; Iuliu, Vescan; Sorin, Filip; Dănuţ, Petrea

2018-06-01

Maramureş Land is mostly characterized by agricultural and forestry land use due to its specific configuration of topography and its specific pedoclimatic conditions. Taking into consideration the trend of the last century from the perspective of land management, a decrease in the surface of agricultural lands to the advantage of built-up and grass lands, as well as an accelerated decrease in the forest cover due to uncontrolled and irrational forest exploitation, has become obvious. The field analysis performed on the territory of Maramureş Land has highlighted a high frequency of two geomorphologic processes — landslides and soil erosion — which have a major negative impact on land use due to their rate of occurrence. The main aim of the present study is the GIS modeling of the two geomorphologic processes, determining a state of vulnerability (the USLE model for soil erosion and a quantitative model based on the morphometric characteristics of the territory, derived from the HG. 447/2003) and their integration in a complex model of cumulated vulnerability identification. The modeling of the risk exposure was performed using a quantitative approach based on models and equations of spatial analysis, which were developed with modeled raster data structures and primary vector data, through a matrix highlighting the correspondence between vulnerability and land use classes. The quantitative analysis of the risk was performed by taking into consideration the exposure classes as modeled databases and the land price as a primary alphanumeric database using spatial analysis techniques for each class by means of the attribute table. The spatial results highlight the territories with a high risk to present geomorphologic processes that have a high degree of occurrence and represent a useful tool in the process of spatial planning.

Quantitative effects of cyanogenesis on an adapted herbivore.

PubMed

Ballhorn, D J; Heil, M; Pietrowski, A; Lieberei, R

2007-12-01

Plant cyanogenesis means the release of gaseous hydrogen cyanide (HCN) in response to cell damage and is considered as an effective defense against generalist herbivores. In contrast, specialists are generally believed not to be affected negatively by this trait. However, quantitative data on long-term effects of cyanogenesis on specialists are rare. In this study, we used lima bean accessions (Fabaceae: Phaseolus lunatus L.) with high quantitative variability of cyanogenic features comprising cyanogenic potential (HCNp; concentration of cyanogenic precursors) and cyanogenic capacities (HCNc; release of gaseous HCN per unit time). In feeding trials, we analyzed performance of herbivorous Mexican bean beetle (Coleoptera: Coccinellidae: Epilachna varivestis Mulsant) on selected lines characterized by high (HC-plants) and low HCNp (LC-plants). Larval and adult stages of this herbivore feed on a narrow range of legumes and prefer cyanogenic lima bean as host plant. Nevertheless, we found that performance of beetles (larval weight gain per time and body mass of adult beetles) was significantly affected by lima bean HCNp: Body weight decreased and developmental period of larvae and pupae increased on HC-plants during the first generation of beetles and then remained constant for four consecutive generations. In addition, we found continuously decreasing numbers of eggs and larval hatching as inter-generational effects on HC-plants. In contrast to HC-plants, constantly high performance was observed among four generations on LC-plants. Our results demonstrate that Mexican bean beetle, although preferentially feeding on lima bean, is quantitatively affected by the HCNp of its host plant. Effects can only be detected when considering more than one generation. Thus, cyanide-containing precursors can have negative effects even on herbivores adapted to feed on cyanogenic plants.

Quantitative aspects of inductively coupled plasma mass spectrometry

NASA Astrophysics Data System (ADS)

Bulska, Ewa; Wagner, Barbara

2016-10-01

Accurate determination of elements in various kinds of samples is essential for many areas, including environmental science, medicine, as well as industry. Inductively coupled plasma mass spectrometry (ICP-MS) is a powerful tool enabling multi-elemental analysis of numerous matrices with high sensitivity and good precision. Various calibration approaches can be used to perform accurate quantitative measurements by ICP-MS. They include the use of pure standards, matrix-matched standards, or relevant certified reference materials, assuring traceability of the reported results. This review critically evaluates the advantages and limitations of different calibration approaches, which are used in quantitative analyses by ICP-MS. Examples of such analyses are provided. This article is part of the themed issue 'Quantitative mass spectrometry'.

[Bioactive saponins and glycosides. XIII. Horse chestnut. (3): Quantitative analysis of escins Ia, Ib, IIa, and IIb by means of high performance liquid chromatography].

PubMed

Yoshikawa, M; Murakami, T; Otuki, K; Yamahara, J; Matsuda, H

1999-01-01

As a part of our studies on the characterization of bioactive saponin constituents of horse chestnut trees, a quantitative method using high performance liquid chromatography (HPLC) has been developed for four principle saponin constituents, such as escins Ia, Ib, IIa, and IIb, isolated from the seeds of European horse chestnut trees (Aesculus hippocastanum L., Hippocastanaceae). As an application of this HPLC method, we examined the contents and compositions of these escins in the seeds of Japanese horse chestnut trees (A. turbinata BLUME) and in several commercial materials named as "beta-escin". Additionally, the distribution of escins in the Japanese horse chestnut trees was examined, and escins were found to be contained only in the seeds.

The use of digital PCR to improve the application of quantitative molecular diagnostic methods for tuberculosis.

PubMed

Devonshire, Alison S; O'Sullivan, Denise M; Honeyborne, Isobella; Jones, Gerwyn; Karczmarczyk, Maria; Pavšič, Jernej; Gutteridge, Alice; Milavec, Mojca; Mendoza, Pablo; Schimmel, Heinz; Van Heuverswyn, Fran; Gorton, Rebecca; Cirillo, Daniela Maria; Borroni, Emanuele; Harris, Kathryn; Barnard, Marinus; Heydenrych, Anthenette; Ndusilo, Norah; Wallis, Carole L; Pillay, Keshree; Barry, Thomas; Reddington, Kate; Richter, Elvira; Mozioğlu, Erkan; Akyürek, Sema; Yalçınkaya, Burhanettin; Akgoz, Muslum; Žel, Jana; Foy, Carole A; McHugh, Timothy D; Huggett, Jim F

2016-08-03

Real-time PCR (qPCR) based methods, such as the Xpert MTB/RIF, are increasingly being used to diagnose tuberculosis (TB). While qualitative methods are adequate for diagnosis, the therapeutic monitoring of TB patients requires quantitative methods currently performed using smear microscopy. The potential use of quantitative molecular measurements for therapeutic monitoring has been investigated but findings have been variable and inconclusive. The lack of an adequate reference method and reference materials is a barrier to understanding the source of such disagreement. Digital PCR (dPCR) offers the potential for an accurate method for quantification of specific DNA sequences in reference materials which can be used to evaluate quantitative molecular methods for TB treatment monitoring. To assess a novel approach for the development of quality assurance materials we used dPCR to quantify specific DNA sequences in a range of prototype reference materials and evaluated accuracy between different laboratories and instruments. The materials were then also used to evaluate the quantitative performance of qPCR and Xpert MTB/RIF in eight clinical testing laboratories. dPCR was found to provide results in good agreement with the other methods tested and to be highly reproducible between laboratories without calibration even when using different instruments. When the reference materials were analysed with qPCR and Xpert MTB/RIF by clinical laboratories, all laboratories were able to correctly rank the reference materials according to concentration, however there was a marked difference in the measured magnitude. TB is a disease where the quantification of the pathogen could lead to better patient management and qPCR methods offer the potential to rapidly perform such analysis. However, our findings suggest that when precisely characterised materials are used to evaluate qPCR methods, the measurement result variation is too high to determine whether molecular quantification of Mycobacterium tuberculosis would provide a clinically useful readout. The methods described in this study provide a means by which the technical performance of quantitative molecular methods can be evaluated independently of clinical variability to improve accuracy of measurement results. These will assist in ultimately increasing the likelihood that such approaches could be used to improve patient management of TB.

Prediction of high-stage liver fibrosis using ADC value on diffusion-weighted imaging and quantitative enhancement ratio at the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI at 1.5 T.

PubMed

Harada, Taiyo L; Saito, Kazuhiro; Araki, Yoichi; Matsubayashi, Jun; Nagao, Toshitaka; Sugimoto, Katsutoshi; Tokuuye, Koichi

2018-05-01

Background Recently, diffusion-weighted imaging (DWI) and quantitative enhancement ratio measured at the hepatobiliary phase (HBP) of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) has been established as an effective method for evaluating liver fibrosis. Purpose To evaluate which is a more favorable surrogate marker in predicting high-stage liver fibrosis, apparently diffusion coefficient (ADC) value or quantitative enhancement ratio measured on HBP. Material and Methods Eighty-three patients with 99 surgically resected hepatic lesions were enrolled in this study. DWI was performed with b-values of 100 and 800 s/mm 2 . Regions of interest were set on ADC map, and the HBP of Gd-EOB-DTPA-enhanced MRI, to calculate ADC value, liver-to-muscle ratio (LMR), liver-to-spleen ratio (LSR), and contrast enhancement index (CEI) of liver. We compared these parameters between low-stage fibrosis (F0, F1, and F2) and high-stage fibrosis (F3 and F4). Receiver operating characteristic analysis was performed to compare the diagnostic performance when distinguishing low-stage fibrosis from high-stage fibrosis. Results LMR and CEI were significantly lower at high-stage fibrosis than at the low stage ( P < 0.01 and P = 0.04, respectively), whereas LSR did not show a significant difference ( P = 0.053). No significant difference was observed in diagnostic performance between LMR and CEI ( P = 0.185). The best sensitivity and specificity, when an LMR of 2.80 or higher was considered to be low-stage fibrosis, were 82.4% and 75.6%, respectively. ADC value showed no significant differences among fibrosis grades ( P = 0.320). Conclusion LMR and CEI were both adequate surrogate parameters to distinguish high-stage fibrosis from low-stage fibrosis.

Electron Energy Distribution and Transfer Phenomena in Non-Equilibrium Gases

DTIC Science & Technology

2016-09-01

and quantitative determination of species difficult. In a mass spectrometry study on boron chemistry a few decade ago, a technique of isotopic...In this FTMS study on TEB, by means of the high-mass-resolution spectrum to distinguish the isobaric ions, we have identified and quantitatively ...reproduce, release, perform, display, or disclose the work. 14. ABSTRACT During this 3-year in-house experimental research task, researchers in the

Quantitative laser diagnostic and modeling study of C2 and CH chemistry in combustion.

PubMed

Köhler, Markus; Brockhinke, Andreas; Braun-Unkhoff, Marina; Kohse-Höinghaus, Katharina

2010-04-15

Quantitative concentration measurements of CH and C(2) have been performed in laminar, premixed, flat flames of propene and cyclopentene with varying stoichiometry. A combination of cavity ring-down (CRD) spectroscopy and laser-induced fluorescence (LIF) was used to enable sensitive detection of these species with high spatial resolution. Previously, CH and C(2) chemistry had been studied, predominantly in methane flames, to understand potential correlations of their formation and consumption. For flames of larger hydrocarbon fuels, however, quantitative information on these small intermediates is scarce, especially under fuel-rich conditions. Also, the combustion chemistry of C(2) in particular has not been studied in detail, and although it has often been observed, its role in potential build-up reactions of higher hydrocarbon species is not well understood. The quantitative measurements performed here are the first to detect both species with good spatial resolution and high sensitivity in the same experiment in flames of C(3) and C(5) fuels. The experimental profiles were compared with results of combustion modeling to reveal details of the formation and consumption of these important combustion molecules, and the investigation was devoted to assist the further understanding of the role of C(2) and of its potential chemical interdependences with CH and other small radicals.

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.

TECHNOLOGICAL INNOVATION IN NEUROSURGERY: A QUANTITATIVE STUDY

PubMed Central

Marcus, Hani J; Hughes-Hallett, Archie; Kwasnicki, Richard M; Darzi, Ara; Yang, Guang-Zhong; Nandi, Dipankar

2015-01-01

Object Technological innovation within healthcare may be defined as the introduction of a new technology that initiates a change in clinical practice. Neurosurgery is a particularly technologically intensive surgical discipline, and new technologies have preceded many of the major advances in operative neurosurgical technique. The aim of the present study was to quantitatively evaluate technological innovation in neurosurgery using patents and peer-reviewed publications as metrics of technology development and clinical translation respectively. Methods A patent database was searched between 1960 and 2010 using the search terms “neurosurgeon” OR “neurosurgical” OR “neurosurgery”. The top 50 performing patent codes were then grouped into technology clusters. Patent and publication growth curves were then generated for these technology clusters. A top performing technology cluster was then selected as an exemplar for more detailed analysis of individual patents. Results In all, 11,672 patents and 208,203 publications relating to neurosurgery were identified. The top performing technology clusters over the 50 years were: image guidance devices, clinical neurophysiology devices, neuromodulation devices, operating microscopes and endoscopes. Image guidance and neuromodulation devices demonstrated a highly correlated rapid rise in patents and publications, suggesting they are areas of technology expansion. In-depth analysis of neuromodulation patents revealed that the majority of high performing patents were related to Deep Brain Stimulation (DBS). Conclusions Patent and publication data may be used to quantitatively evaluate technological innovation in neurosurgery. PMID:25699414

The Effects of Humor on Test Anxiety and Test Performance

ERIC Educational Resources Information Center

Tali, Glenda

2017-01-01

Testing in an academic setting provokes anxiety in all students in higher education, particularly nursing students. When students experience high levels of anxiety, the resulting decline in test performance often does not represent an accurate assessment of students' academic achievement. This quantitative, experimental study examined the effects…

29 CFR 95.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... quantitative data should be related to cost data for computation of unit costs. (2) Reasons why established..., analysis and explanation of cost overruns or high unit costs. (e) Recipients shall not be required to... performance data from recipients. (Approved by the Office of Management and Budget, Approval Number 1225-0017) ...

45 CFR 74.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... quantitative data should be related to cost data for computation of unit costs. (2) Reasons why established..., analysis and explanation of cost overruns or high unit costs. (e) Recipients shall submit the original and..., “Controlling Paperwork Burdens on the Public,” when requesting performance data from recipients. ...

2 CFR 215.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., such quantitative data should be related to cost data for computation of unit costs. (2) Reasons why..., analysis and explanation of cost overruns or high unit costs. (e) Recipients shall not be required to... clearance requirements of 5 CFR part 1320 when requesting performance data from recipients. ...

34 CFR 74.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... programs or projects can be readily quantified, this quantitative data should be related to cost data for... information including, when appropriate, analysis, and explanation of cost overruns or high unit costs. (e... requirements of 5 CFR part 1320 when requesting performance data from recipients. (Approved by the Office of...

MR Morphology of Triangular Fibrocartilage Complex: Correlation with Quantitative MR and Biomechanical Properties

PubMed Central

Bae, Won C.; Ruangchaijatuporn, Thumanoon; Chang, Eric Y; Biswas, Reni; Du, Jiang; Statum, Sheronda

2016-01-01

Objective To evaluate pathology of the triangular fibrocartilage complex (TFCC) using high resolution morphologic magnetic resonance (MR) imaging, and compare with quantitative MR and biomechanical properties. Materials and Methods Five cadaveric wrists (22 to 70 yrs) were imaged at 3T using morphologic (proton density weighted spin echo, PD FS, and 3D spoiled gradient echo, 3D SPGR) and quantitative MR sequences to determine T2 and T1rho properties. In eight geographic regions, morphology of TFC disc and laminae were evaluated for pathology and quantitative MR values. Samples were disarticulated and biomechanical indentation testing was performed on the distal surface of the TFC disc. Results On morphologic PD SE images, TFC disc pathology included degeneration and tears, while that of the laminae included degeneration, degeneration with superimposed tear, mucinous transformation, and globular calcification. Punctate calcifications were highly visible on 3D SPGR images and found only in pathologic regions. Disc pathology occurred more frequently in proximal regions of the disc than distal regions. Quantitative MR values were lowest in normal samples, and generally higher in pathologic regions. Biomechanical testing demonstrated an inverse relationship, with indentation modulus being high in normal regions with low MR values. The laminae studied were mostly pathologic, and additional normal samples are needed to discern quantitative changes. Conclusion These results show technical feasibility of morphologic MR, quantitative MR, and biomechanical techniques to characterize pathology of the TFCC. Quantitative MRI may be a suitable surrogate marker of soft tissue mechanical properties, and a useful adjunct to conventional morphologic MR techniques. PMID:26691643

Variable selection based near infrared spectroscopy quantitative and qualitative analysis on wheat wet gluten

NASA Astrophysics Data System (ADS)

Lü, Chengxu; Jiang, Xunpeng; Zhou, Xingfan; Zhang, Yinqiao; Zhang, Naiqian; Wei, Chongfeng; Mao, Wenhua

2017-10-01

Wet gluten is a useful quality indicator for wheat, and short wave near infrared spectroscopy (NIRS) is a high performance technique with the advantage of economic rapid and nondestructive test. To study the feasibility of short wave NIRS analyzing wet gluten directly from wheat seed, 54 representative wheat seed samples were collected and scanned by spectrometer. 8 spectral pretreatment method and genetic algorithm (GA) variable selection method were used to optimize analysis. Both quantitative and qualitative model of wet gluten were built by partial least squares regression and discriminate analysis. For quantitative analysis, normalization is the optimized pretreatment method, 17 wet gluten sensitive variables are selected by GA, and GA model performs a better result than that of all variable model, with R2V=0.88, and RMSEV=1.47. For qualitative analysis, automatic weighted least squares baseline is the optimized pretreatment method, all variable models perform better results than those of GA models. The correct classification rates of 3 class of <24%, 24-30%, >30% wet gluten content are 95.45, 84.52, and 90.00%, respectively. The short wave NIRS technique shows potential for both quantitative and qualitative analysis of wet gluten for wheat seed.

Quantitative computed tomography assessment of transfusional iron overload.

PubMed

Wood, John C; Mo, Ashley; Gera, Aakansha; Koh, Montre; Coates, Thomas; Gilsanz, Vicente

2011-06-01

Quantitative computed tomography (QCT) has been proposed for iron quantification for more than 30 years, however there has been little clinical validation. We compared liver attenuation by QCT with magnetic resonance imaging (MRI)-derived estimates of liver iron concentration (LIC) in 37 patients with transfusional siderosis. MRI and QCT measurements were performed as clinically indicated monitoring of LIC and vertebral bone-density respectively, over a 6-year period. Mean time difference between QCT and MRI studies was 14 d, with 25 studies performed on the same day. For liver attenuation outside the normal range, attenuation values rose linearly with LIC (r(2) = 0·94). However, intersubject variability in intrinsic liver attenuation prevented quantitation of LIC <8 mg/g dry weight of liver, and was the dominant source of measurement uncertainty. Calculated QCT and MRI accuracies were equivalent for LIC values approaching 22 mg/g dry weight, with QCT having superior performance at higher LIC's. Although not suitable for monitoring patients with good iron control, QCT may nonetheless represent a viable technique for liver iron quantitation in patients with moderate to severe iron in regions where MRI resources are limited because of its low cost, availability, and high throughput. © 2011 Blackwell Publishing Ltd.

Systematic Comparison of Label-Free, Metabolic Labeling, and Isobaric Chemical Labeling for Quantitative Proteomics on LTQ Orbitrap Velos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zhou; Adams, Rachel M; Chourey, Karuna

2012-01-01

A variety of quantitative proteomics methods have been developed, including label-free, metabolic labeling, and isobaric chemical labeling using iTRAQ or TMT. Here, these methods were compared in terms of the depth of proteome coverage, quantification accuracy, precision, and reproducibility using a high-performance hybrid mass spectrometer, LTQ Orbitrap Velos. Our results show that (1) the spectral counting method provides the deepest proteome coverage for identification, but its quantification performance is worse than labeling-based approaches, especially the quantification reproducibility; (2) metabolic labeling and isobaric chemical labeling are capable of accurate, precise, and reproducible quantification and provide deep proteome coverage for quantification. Isobaricmore » chemical labeling surpasses metabolic labeling in terms of quantification precision and reproducibility; (3) iTRAQ and TMT perform similarly in all aspects compared in the current study using a CID-HCD dual scan configuration. Based on the unique advantages of each method, we provide guidance for selection of the appropriate method for a quantitative proteomics study.« less

Comparison of quantitative and qualitative tests for glucose-6-phosphate dehydrogenase deficiency.

PubMed

LaRue, Nicole; Kahn, Maria; Murray, Marjorie; Leader, Brandon T; Bansil, Pooja; McGray, Sarah; Kalnoky, Michael; Zhang, Hao; Huang, Huiqiang; Jiang, Hui; Domingo, Gonzalo J

2014-10-01

A barrier to eliminating Plasmodium vivax malaria is inadequate treatment of infected patients. 8-Aminoquinoline-based drugs clear the parasite; however, people with glucose-6-phosphate dehydrogenase (G6PD) deficiency are at risk for hemolysis from these drugs. Understanding the performance of G6PD deficiency tests is critical for patient safety. Two quantitative assays and two qualitative tests were evaluated. The comparison of quantitative assays gave a Pearson correlation coefficient of 0.7585 with significant difference in mean G6PD activity, highlighting the need to adhere to a single reference assay. Both qualitative tests had high sensitivity and negative predictive value at a cutoff G6PD value of 40% of normal activity if interpreted conservatively and performed under laboratory conditions. The performance of both tests dropped at a cutoff level of 45%. Cytochemical staining of specimens confirmed that heterozygous females with > 50% G6PD-deficient cells can seem normal by phenotypic tests. © The American Society of Tropical Medicine and Hygiene.

Improved Quantitation of Gluten in Wheat Starch for Celiac Disease Patients by Gel-Permeation High-Performance Liquid Chromatography with Fluorescence Detection (GP-HPLC-FLD).

PubMed

Scherf, Katharina Anne; Wieser, Herbert; Koehler, Peter

2016-10-12

Purified wheat starch (WSt) is commonly used in gluten-free products for celiac disease (CD) patients. It is mostly well-tolerated, but doubts about its safety for CD patients persist. One reason may be that most ELISA kits primarily recognize the alcohol-soluble gliadin fraction of gluten, but insufficiently target the alcohol-insoluble glutenin fraction. To address this problem, a new sensitive method based on the sequential extraction of gliadins, glutenins, and gluten from WSt followed by gel-permeation high-performance liquid chromatography with fluorescence detection (GP-HPLC-FLD) was developed. It revealed that considerable amounts of glutenins were present in most WSt. The gluten contents quantitated by GP-HPLC-FLD as sum of gliadins and glutenins were higher than those by R5 ELISA (gluten as gliadin content multiplied by a factor of 2) in 19 out of 26 WSt. Despite its limited selectivity, GP-HPLC-FLD may be applied as confirmatory method to ELISA to quantitate gluten in WSt.

A simple quantitative approach for the determination of long and medium chain lipids in bio-relevant matrices by high performance liquid chromatography with refractive index detection.

PubMed

Lee, Kathy Wai Yu; Porter, Christopher J H; Boyd, Ben J

2013-09-01

There is increasing attention in the literature towards understanding the behaviour of lipid-based drug formulations under digestion conditions using in vitro and in vivo methods. This necessitates a convenient method for quantitation of lipids and lipid digestion products. In this study, a simple and accessible method for the separation and quantitative determination of typical formulation and digested lipids using high performance liquid chromatography coupled to refractive index detection (HPLC-RI) is described. Long and medium chain lipids were separated and quantified in a biological matrix (gastrointestinal content) without derivatisation using HPLC-RI on C18 and C8 columns, respectively. The intra- and inter-assay accuracy was between 92% and 106%, and the assays were precise to within a coefficient of variation of less than 10% over the range of 0.1-2 mg/mL for both long and medium chain lipids. This method is also shown to be suitable for quantifying the lipolysis products collected from the gastrointestinal tract in the course of in vivo lipid digestion studies.

HPAEC-PAD quantification of Haemophilus influenzae type b polysaccharide in upstream and downstream samples.

PubMed

van der Put, Robert M F; de Haan, Alex; van den IJssel, Jan G M; Hamidi, Ahd; Beurret, Michel

2015-11-27

Due to the rapidly increasing introduction of Haemophilus influenzae type b (Hib) and other conjugate vaccines worldwide during the last decade, reliable and robust analytical methods are needed for the quantitative monitoring of intermediate samples generated during fermentation (upstream processing, USP) and purification (downstream processing, DSP) of polysaccharide vaccine components. This study describes the quantitative characterization of in-process control (IPC) samples generated during the fermentation and purification of the capsular polysaccharide (CPS), polyribosyl-ribitol-phosphate (PRP), derived from Hib. Reliable quantitative methods are necessary for all stages of production; otherwise accurate process monitoring and validation is not possible. Prior to the availability of high performance anion exchange chromatography methods, this polysaccharide was predominantly quantified either with immunochemical methods, or with the colorimetric orcinol method, which shows interference from fermentation medium components and reagents used during purification. Next to an improved high performance anion exchange chromatography-pulsed amperometric detection (HPAEC-PAD) method, using a modified gradient elution, both the orcinol assay and high performance size exclusion chromatography (HPSEC) analyses were evaluated. For DSP samples, it was found that the correlation between the results obtained by HPAEC-PAD specific quantification of the PRP monomeric repeat unit released by alkaline hydrolysis, and those from the orcinol method was high (R(2)=0.8762), and that it was lower between HPAEC-PAD and HPSEC results. Additionally, HPSEC analysis of USP samples yielded surprisingly comparable results to those obtained by HPAEC-PAD. In the early part of the fermentation, medium components interfered with the different types of analysis, but quantitative HPSEC data could still be obtained, although lacking the specificity of the HPAEC-PAD method. Thus, the HPAEC-PAD method has the advantage of giving a specific response compared to the orcinol assay and HPSEC, and does not show interference from various components that can be present in intermediate and purified PRP samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Relative Performance of High Resolution Quantitative Precipitation Estimates in the Russian River Basin

NASA Astrophysics Data System (ADS)

Bytheway, J. L.; Biswas, S.; Cifelli, R.; Hughes, M.

2017-12-01

The Russian River carves a 110 mile path through Mendocino and Sonoma counties in western California, providing water for thousands of residents and acres of agriculture as well as a home for several species of endangered fish. The Russian River basin receives almost all of its precipitation during the October through March wet season, and the systems bringing this precipitation are often impacted by atmospheric river events as well as the complex topography of the region. This study will examine the performance of several high resolution (hourly, < 5km) estimates of precipitation from observational products and forecasts over the 2015-2016 and 2016-2017 wet seasons. Comparisons of event total rainfall as well as hourly rainfall will be performed using 1) rain gauges operated by the National Oceanic and Atmospheric Administration (NOAA) Physical Sciences Division (PSD), 2) products from the Multi-Radar/Multi-Sensor (MRMS) QPE dataset, and 3) quantitative precipitation forecasts from the High Resolution Rapid Refresh (HRRR) model at 1, 3, 6, and 12 hour lead times. Further attention will be given to cases or locations representing large disparities between the estimates.

High Thermoelectric Performance by Convergence of Bands in IV-VI Semiconductors, Heavily Doped PbTe, and Alloys/Nanocomposites

NASA Technical Reports Server (NTRS)

Snyder, G. Jeffrey (Inventor); Pei, Yanzhong (Inventor)

2015-01-01

The present invention teaches an effective mechanism for enhancing thermoelectric performance through additional conductive bands. Using heavily doped p-PbTe materials as an example, a quantitative explanation is disclosed, as to why and how these additional bands affect the figure of merit. A high zT of approaching 2 at high temperatures makes these simple, likely more stable (than nanostructured materials) and Tl-free materials excellent for thermoelectric applications.

A New Algorithm Using Cross-Assignment for Label-Free Quantitation with LC/LTQ-FT MS

PubMed Central

Andreev, Victor P.; Li, Lingyun; Cao, Lei; Gu, Ye; Rejtar, Tomas; Wu, Shiaw-Lin; Karger, Barry L.

2008-01-01

A new algorithm is described for label-free quantitation of relative protein abundances across multiple complex proteomic samples. Q-MEND is based on the denoising and peak picking algorithm, MEND, previously developed in our laboratory. Q-MEND takes advantage of the high resolution and mass accuracy of the hybrid LTQFT MS mass spectrometer (or other high resolution mass spectrometers, such as a Q-TOF MS). The strategy, termed “cross-assignment”, is introduced to increase substantially the number of quantitated proteins. In this approach, all MS/MS identifications for the set of analyzed samples are combined into a master ID list, and then each LC/MS run is searched for the features that can be assigned to a specific identification from that master list. The reliability of quantitation is enhanced by quantitating separately all peptide charge states, along with a scoring procedure to filter out less reliable peptide abundance measurements. The effectiveness of Q-MEND is illustrated in the relative quantitative analysis of E.coli samples spiked with known amounts of non-E.coli protein digests. A mean quantitation accuracy of 7% and mean precision of 15% is demonstrated. Q-MEND can perform relative quantitation of a set of LC/MS datasets without manual intervention and can generate files compatible with the Guidelines for Proteomic Data Publication. PMID:17441747

A new algorithm using cross-assignment for label-free quantitation with LC-LTQ-FT MS.

PubMed

Andreev, Victor P; Li, Lingyun; Cao, Lei; Gu, Ye; Rejtar, Tomas; Wu, Shiaw-Lin; Karger, Barry L

2007-06-01

A new algorithm is described for label-free quantitation of relative protein abundances across multiple complex proteomic samples. Q-MEND is based on the denoising and peak picking algorithm, MEND, previously developed in our laboratory. Q-MEND takes advantage of the high resolution and mass accuracy of the hybrid LTQ-FT MS mass spectrometer (or other high-resolution mass spectrometers, such as a Q-TOF MS). The strategy, termed "cross-assignment", is introduced to increase substantially the number of quantitated proteins. In this approach, all MS/MS identifications for the set of analyzed samples are combined into a master ID list, and then each LC-MS run is searched for the features that can be assigned to a specific identification from that master list. The reliability of quantitation is enhanced by quantitating separately all peptide charge states, along with a scoring procedure to filter out less reliable peptide abundance measurements. The effectiveness of Q-MEND is illustrated in the relative quantitative analysis of Escherichia coli samples spiked with known amounts of non-E. coli protein digests. A mean quantitation accuracy of 7% and mean precision of 15% is demonstrated. Q-MEND can perform relative quantitation of a set of LC-MS data sets without manual intervention and can generate files compatible with the Guidelines for Proteomic Data Publication.

Understanding Eating Disorders in Elite Gymnastics: Ethical and Conceptual Challenges.

PubMed

Tan, Jacinta Oon Ai; Calitri, Raff; Bloodworth, Andrew; McNamee, Michael J

2016-04-01

Eating disorders and disordered eating are more common in high performance sports than the general population, and particularly so in high performance aesthetic sports. This paper presents some of the conceptual difficulties in understanding and diagnosing eating disorders in high performance gymnasts. It presents qualitative and quantitative data from a study designed to ascertain the pattern of eating disorder symptoms, depressive symptoms and levels of self-esteem among national and international level gymnasts from the UK in the gymnastic disciplines of sport acrobatics, tumbling, and rhythmic gymnastics. Copyright © 2016 Elsevier Inc. All rights reserved.

Pentobarbital quantitation using EMIT serum barbiturate assay reagents: application to monitoring of high-dose pentobarbital therapy.

PubMed

Pape, B E; Cary, P L; Clay, L C; Godolphin, W

1983-01-01

Pentobarbital serum concentrations associated with a high-dose therapeutic regimen were determined using EMIT immunoassay reagents. Replicate analyses of serum controls resulted in a within-assay coefficient of variation of 5.0% and a between-assay coefficient of variation of 10%. Regression analysis of 44 serum samples analyzed by this technique (y) and a reference procedure (x) were y = 0.98x + 3.6 (r = 0.98; x = ultraviolet spectroscopy) and y = 1.04x + 2.4 (r = 0.96; x = high-performance liquid chromatography). Clinical evaluation of the results indicates the immunoassay is sufficiently sensitive and selective for pentobarbital to allow accurate quantitation within the therapeutic range associated with high-dose therapy.

Association Mapping of the High-Grade Myopia MYP3 Locus Reveals Novel Candidates UHRF1BP1L, PTPRR, and PPFIA2

PubMed Central

Hawthorne, Felicia; Feng, Sheng; Metlapally, Ravikanth; Li, Yi-Ju; Tran-Viet, Khanh-Nhat; Guggenheim, Jeremy A.; Malecaze, Francois; Calvas, Patrick; Rosenberg, Thomas; Mackey, David A.; Venturini, Cristina; Hysi, Pirro G.; Hammond, Christopher J.; Young, Terri L.

2013-01-01

Purpose. Myopia, or nearsightedness, is a common ocular genetic disease for which over 20 candidate genomic loci have been identified. The high-grade myopia locus, MYP3, has been reported on chromosome 12q21–23 by four independent linkage studies. Methods. We performed a genetic association study of the MYP3 locus in a family-based high-grade myopia cohort (n = 82) by genotyping 768 single-nucleotide polymorphisms (SNPs) within the linkage region. Qualitative testing for high-grade myopia (sphere ≤ −5 D affected, > −0.5 D unaffected) and quantitative testing on the average dioptric sphere were performed. Results. Several genetic markers were nominally significantly associated with high-grade myopia in qualitative testing, including rs3803036, a missense mutation in PTPRR (P = 9.1 × 10−4) and rs4764971, an intronic SNP in UHRF1BP1L (P = 6.1 × 10−4). Quantitative testing determined statistically significant SNPs rs4764971, also found by qualitative testing (P = 3.1 × 10−6); rs7134216, in the 3′ untranslated region (UTR) of DEPDC4 (P = 5.4 × 10−7); and rs17306116, an intronic SNP within PPFIA2 (P < 9 × 10−4). Independently conducted whole genome expression array analyses identified protein tyrosine phosphatase genes PTPRR and PPFIA2, which are in the same gene family, as differentially expressed in normal rapidly growing fetal relative to normal adult ocular tissue (confirmed by RT-qPCR). Conclusions. In an independent high-grade myopia cohort, an intronic SNP in UHRF1BP1L, rs4764971, was validated for quantitative association, and SNPs within PTPRR (quantitative) and PPFIA2 (qualitative and quantitative) approached significance. Three genes identified by our association study and supported by ocular expression and/or replication, UHRF1BP1L, PTPRR, and PPFIA2, are novel candidates for myopic development within the MYP3 locus that should be further studied. PMID:23422819

Conceptual versus Algorithmic Learning in High School Chemistry: The Case of Basic Quantum Chemical Concepts--Part 1. Statistical Analysis of a Quantitative Study

ERIC Educational Resources Information Center

Papaphotis, Georgios; Tsaparlis, Georgios

2008-01-01

Part 1 of the findings are presented of a quantitative study (n = 125) on basic quantum chemical concepts taught in the twelfth grade (age 17-18 years) in Greece. A paper-and-pencil test of fourteen questions was used. The study compared performance in five questions that tested recall of knowledge or application of algorithmic procedures (type-A…

Simultaneous separation and quantitation of amino acids and polyamines of forest tree tissues and cell cultures within a single high-performance liquid chromatography run using dansyl derivatization

Treesearch

Rakesh Minocha; Stephanie Long

2004-01-01

The objective of the present study was to develop a rapid HPLC method for simultaneous separation and quantitation of dansylated amino acids and common polyamines in the same matrix for analyzing forest tree tissues and cell cultures. The major modifications incorporated into this method as compared to previously published HPLC methods for separation of only dansyl...

Quantitative aspects of inductively coupled plasma mass spectrometry

PubMed Central

Wagner, Barbara

2016-01-01

Accurate determination of elements in various kinds of samples is essential for many areas, including environmental science, medicine, as well as industry. Inductively coupled plasma mass spectrometry (ICP-MS) is a powerful tool enabling multi-elemental analysis of numerous matrices with high sensitivity and good precision. Various calibration approaches can be used to perform accurate quantitative measurements by ICP-MS. They include the use of pure standards, matrix-matched standards, or relevant certified reference materials, assuring traceability of the reported results. This review critically evaluates the advantages and limitations of different calibration approaches, which are used in quantitative analyses by ICP-MS. Examples of such analyses are provided. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644971

Pump-probe Kelvin-probe force microscopy: Principle of operation and resolution limits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murawski, J.; Graupner, T.; Milde, P., E-mail: peter.milde@tu-dresden.de

Knowledge on surface potential dynamics is crucial for understanding the performance of modern-type nanoscale devices. We describe an electrical pump-probe approach in Kelvin-probe force microscopy that enables a quantitative measurement of dynamic surface potentials at nanosecond-time and nanometer-length scales. Also, we investigate the performance of pump-probe Kelvin-probe force microscopy with respect to the relevant experimental parameters. We exemplify a measurement on an organic field effect transistor that verifies the undisturbed functionality of our pump-probe approach in terms of simultaneous and quantitative mapping of topographic and electronic information at a high lateral and temporal resolution.

Automated classification of cell morphology by coherence-controlled holographic microscopy

NASA Astrophysics Data System (ADS)

Strbkova, Lenka; Zicha, Daniel; Vesely, Pavel; Chmelik, Radim

2017-08-01

In the last few years, classification of cells by machine learning has become frequently used in biology. However, most of the approaches are based on morphometric (MO) features, which are not quantitative in terms of cell mass. This may result in poor classification accuracy. Here, we study the potential contribution of coherence-controlled holographic microscopy enabling quantitative phase imaging for the classification of cell morphologies. We compare our approach with the commonly used method based on MO features. We tested both classification approaches in an experiment with nutritionally deprived cancer tissue cells, while employing several supervised machine learning algorithms. Most of the classifiers provided higher performance when quantitative phase features were employed. Based on the results, it can be concluded that the quantitative phase features played an important role in improving the performance of the classification. The methodology could be valuable help in refining the monitoring of live cells in an automated fashion. We believe that coherence-controlled holographic microscopy, as a tool for quantitative phase imaging, offers all preconditions for the accurate automated analysis of live cell behavior while enabling noninvasive label-free imaging with sufficient contrast and high-spatiotemporal phase sensitivity.

Automated classification of cell morphology by coherence-controlled holographic microscopy.

PubMed

Strbkova, Lenka; Zicha, Daniel; Vesely, Pavel; Chmelik, Radim

2017-08-01

In the last few years, classification of cells by machine learning has become frequently used in biology. However, most of the approaches are based on morphometric (MO) features, which are not quantitative in terms of cell mass. This may result in poor classification accuracy. Here, we study the potential contribution of coherence-controlled holographic microscopy enabling quantitative phase imaging for the classification of cell morphologies. We compare our approach with the commonly used method based on MO features. We tested both classification approaches in an experiment with nutritionally deprived cancer tissue cells, while employing several supervised machine learning algorithms. Most of the classifiers provided higher performance when quantitative phase features were employed. Based on the results, it can be concluded that the quantitative phase features played an important role in improving the performance of the classification. The methodology could be valuable help in refining the monitoring of live cells in an automated fashion. We believe that coherence-controlled holographic microscopy, as a tool for quantitative phase imaging, offers all preconditions for the accurate automated analysis of live cell behavior while enabling noninvasive label-free imaging with sufficient contrast and high-spatiotemporal phase sensitivity. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Development and validation of a generic high-performance liquid chromatography for the simultaneous separation and determination of six cough ingredients: Robustness study on core-shell particles.

PubMed

Yehia, Ali Mohamed; Essam, Hebatallah Mohamed

2016-09-01

A generally applicable high-performance liquid chromatographic method for the qualitative and quantitative determination of pharmaceutical preparations containing phenylephrine hydrochloride, paracetamol, ephedrine hydrochloride, guaifenesin, doxylamine succinate, and dextromethorphan hydrobromide is developed. Optimization of chromatographic conditions was performed for the gradient elution using different buffer pH values, flow rates and two C18 stationary phases. The method was developed using a Kinetex® C18 column as a core-shell stationary phase with a gradient profile using buffer pH 5.0 and acetonitrile at 2.0 mL/min flow rate. Detection was carried out at 220 nm and linear calibrations were obtained for all components within the studied ranges. The method was fully validated in agreement with ICH guidelines. The proposed method is specific, accurate and precise (RSD% < 3%). Limits of detection are lower than 2.0 μg/mL. Qualitative and quantitative responses were evaluated using experimental design to assist the method robustness. The method was proved to be highly robust against 10% change in buffer pH and flow rate (RSD% < 10%), however, the flow rate may significantly influence the quantitative responses of phenylephrine, paracetamol, and doxylamine (RSD% > 10%). Satisfactory results were obtained for commercial combinations analyses. Statistical comparison between the proposed chromatographic and official methods revealed no significant difference. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of the Antibiotic Oxytetracycline in Commercial Milk by Solid-Phase Extraction: A High-Performance Liquid Chromatography (HPLC) Experiment for Quantitative Instrumental Analysis

ERIC Educational Resources Information Center

Mei-Ratliff, Yuan

2012-01-01

Trace levels of oxytetracylcine spiked into commercial milk samples are extracted, cleaned up, and preconcentrated using a C[subscript 18] solid-phase extraction column. The extract is then analyzed by a high-performance liquid chromatography (HPLC) instrument equipped with a UV detector and a C[subscript 18] column (150 mm x 4.6 mm x 3.5 [mu]m).…

The Effect of School Supervisors Competence and School Principals Competence on Work Motivation and Performance of Junior High School Teachers in Maros Regency, Indonesia

ERIC Educational Resources Information Center

Arman; Thalib, Syamsul Bachri; Manda, Darman

2016-01-01

This study aims at analyzing the effect of the competence of school supervisors and school principals on work motivation and performance of Junior High School teachers in Maros Regency. This research was a quantitative research by using survey approach. This approach was used because it is adjusted to the nature and assumptions of the study in…

Validity and sensitivity to change of the semi-quantitative OMERACT ultrasound scoring system for tenosynovitis in patients with rheumatoid arthritis.

PubMed

Ammitzbøll-Danielsen, Mads; Østergaard, Mikkel; Naredo, Esperanza; Terslev, Lene

2016-12-01

The aim was to evaluate the metric properties of the semi-quantitative OMERACT US scoring system vs a novel quantitative US scoring system for tenosynovitis, by testing its intra- and inter-reader reliability, sensitivity to change and comparison with clinical tenosynovitis scoring in a 6-month follow-up study. US and clinical assessments of the tendon sheaths of the clinically most affected hand and foot were performed at baseline, 3 and 6 months in 51 patients with RA. Tenosynovitis was assessed using the semi-quantitative scoring system (0-3) proposed by the OMERACT US group and a new quantitative US evaluation (0-100). A sum for US grey scale (GS), colour Doppler (CD) and pixel index (PI), respectively, was calculated for each patient. In 20 patients, intra- and inter-observer agreement was established between two independent investigators. A binary clinical tenosynovitis score was performed, calculating a sum score per patient. The intra- and inter-observer agreements for US tenosynovitis assessments were very good at baseline and for change for GS and CD, but less good for PI. The smallest detectable change was 0.97 for GS, 0.93 for CD and 30.1 for PI. The sensitivity to change from month 0 to 6 was high for GS and CD, and slightly higher than for clinical tenosynovitis score and PI. This study demonstrated an excellent intra- and inter-reader agreement between two investigators for the OMERACT US scoring system for tenosynovitis and a high ability to detect changes over time. Quantitative assessment by PI did not add further information. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Shaping Performance: Do International Accreditations and Quality Management Really Help?

ERIC Educational Resources Information Center

Nigsch, Stefano; Schenker-Wicki, Andrea

2013-01-01

In recent years, international accreditations have become an important form of quality management for business schools all over the world. However, given their high costs and the risk of increasing bureaucratisation and control, accreditations remain highly disputed in academia. This paper uses quantitative data to assess whether accreditations…

An Investigation of Basic Design Capacity Performance in Different Background Students

ERIC Educational Resources Information Center

Cheng, Chu-Yu; Ou, Yang-Kun

2017-01-01

The technological and vocational higher education system in Taiwan is offering an undergraduate degree for design-based vocational high school students and general high school students whose qualitative and quantitative abilities are evaluated through a student selection examination. This study focused on the conceptual understandings of 64…

Relationship between Success in Extracurricular Programs and Student Academic Performance in Economically Disadvantaged High Schools

ERIC Educational Resources Information Center

Killgo, Jay

2010-01-01

The purpose of this study was to determine the common characteristics of economically disadvantaged schools that demonstrate success in academics and extracurricular activities. Mixed-method design was used for this study. The quantitative portion of the study determined the correlation between a school's performance in extracurricular activities,…

Large size crystalline vs. co-sintered ceramic Yb(3+):YAG disk performance in diode pumped amplifiers.

PubMed

Albach, Daniel; Chanteloup, Jean-Christophe

2015-01-12

A comprehensive experimental benchmarking of Yb(3+):YAG crystalline and co-sintered ceramic disks of similar thickness and doping level is presented in the context of high average power laser amplifier operation. Comparison is performed considering gain, depolarization and wave front deformation quantitative measurements and analysis.

Modelling Transposition Latencies: Constraints for Theories of Serial Order Memory

ERIC Educational Resources Information Center

Farrell, Simon; Lewandowsky, Stephan

2004-01-01

Several competing theories of short-term memory can explain serial recall performance at a quantitative level. However, most theories to date have not been applied to the accompanying pattern of response latencies, thus ignoring a rich and highly diagnostic aspect of performance. This article explores and tests the error latency predictions of…

Aural Dictation Affects High Achievement in Sight Singing, Performance and Composition Skills

ERIC Educational Resources Information Center

Rogers, Melissa

2013-01-01

The nature of skill acquisition has long been of interest to music educators. This study considers the research context for relationships between aural dictation, sight singing, performance and composition skills. Then, relationships between these skill areas are quantitatively investigated using data from the Australian New South Wales Music 2…

Safeguards Technology Development Program 1st Quarter FY 2018 Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prasad, Manoj K.

LLNL will evaluate the performance of a stilbene-based scintillation detector array for IAEA neutron multiplicity counting (NMC) applications. This effort will combine newly developed modeling methodologies and recently acquired high-efficiency stilbene detector units to quantitatively compare the prototype system performance with the conventional He-3 counters and liquid scintillator alternatives.

28 CFR 70.51 - Monitoring and reporting program performance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... quantitative data should be related to cost data for computation of unit costs. (2) Reasons why established..., analysis and explanation of cost overruns or high unit costs. (d) Recipients are required to submit the... when requesting performance data from recipients. [Order No. 1980-95, 60 FR 38242, July 26, 1995; Order...

A high-performance liquid chromatography micromethod for the simultaneous determination of vigabatrin and gabapentin in serum.

PubMed

Ratnaraj, N; Patsalos, P N

1998-08-01

A gradient high-performance liquid chromatography micromethod is described for the simultaneous quantitation of vigabatrin and gabapentin in human serum. Chromatography was performed using a 125- x 3-mm ID Hypersil BDS C-18 column with a 3-microm mini-bore, eluted with a gradient system comprised of phosphate buffer (pH 6.5)-acetonitrile-methanol-water at a flow rate of 0.45 ml/minute. The column eluent was monitored on a fluorescence detector using excitation and emission wavelengths of 340 and 440 nm, respectively. The lower limit of quantitation for vigabatrin and for gabapentin was 5 micromol/l, and the within-batch and between-batch coefficients of variation were <5%. No interference from commonly prescribed antiepileptic drugs (carbamazepine and its metabolite carbamazepine epoxide, oxcarbazepine and its metabolite 10-hydroxycarbazepine, ethosuximide, lamotrigine, phenobarbitone, phenytoin, primidone, and valproic acid) was observed; thus, the method can be used to monitor vigabatrin and gabapentin in patients on polytherapy antiepileptic drug regimens.

High-Resolution 3-T Magnetic Resonance Imaging of the Shoulder in Nonsymptomatic Professional Baseball Pitcher Draft Picks.

PubMed

Del Grande, Filippo; Aro, Michael; Jalali Farahani, Sahar; Cosgarea, Andrew; Wilckens, John; Carrino, John A

2016-01-01

To retrospectively assess the qualitative and quantitative high-resolution 3-T magnetic resonance imaging (MRI) findings in nonsymptomatic baseball pitcher draft picks. Institutional review board-approved and HIPAA compliant study. Three-Tesla MRI of the dominant shoulder of 19 asymptomatic baseball pitcher draft picks and detailed clinical examination was performed before contract signing. Two radiologists performed independently qualitative and quantitative evaluation of shoulder structures. Descriptive statistics were performed. Sixty-eight percent (13/19), 32% (6/19), and 21% (4/19) of the baseball pitcher draft picks showed tendinopathy, partial thickness tendon tear of the supraspinatus, and acromioclavicular joint osteoarthritis, respectively. Glenohumeral subluxation, glenoid remodeling, and Bennett lesion were present in 53% (10/19), 79% (15/19), and 21% (4/19) of the subjects, respectively. Interclass coefficient was 0.633 to 0.863 and κ was 0.27 to 1. In asymptomatic baseball pitcher draft picks, 3-T MRI frequently shows abnormalities involving rotator cuff tendons, the coracohumeral, inferior glenohumeral, labrum, and osseous structures.

High-Affinity Recombinant Antibody Fragments (Fabs) Can Be Applied in Peptide Enrichment Immuno-MRM Assays

PubMed Central

2015-01-01

High-affinity antibodies binding to linear peptides in solution are a prerequisite for performing immuno-MRM, an emerging technology for protein quantitation with high precision and specificity using peptide immunoaffinity enrichment coupled to stable isotope dilution and targeted mass spectrometry. Recombinant antibodies can be generated from appropriate libraries in high-throughput in an automated laboratory and thus may offer advantages over conventional monoclonal antibodies. However, recombinant antibodies are typically obtained as fragments (Fab or scFv) expressed from E. coli, and it is not known whether these antibody formats are compatible with the established protocols and whether the affinities necessary for immunocapture of small linear peptides can be achieved with this technology. Hence, we performed a feasibility study to ask: (a) whether it is feasible to isolate high-affinity Fabs to small linear antigens and (b) whether it is feasible to incorporate antibody fragments into robust, quantitative immuno-MRM assays. We describe successful isolation of high-affinity Fab fragments against short (tryptic) peptides from a human combinatorial Fab library. We analytically characterize three immuno-MRM assays using recombinant Fabs, full-length IgGs constructed from these Fabs, or traditional monoclonals. We show that the antibody fragments show similar performance compared with traditional mouse- or rabbit-derived monoclonal antibodies. The data establish feasibility of isolating and incorporating high-affinity Fabs into peptide immuno-MRM assays. PMID:24568200

High-affinity recombinant antibody fragments (Fabs) can be applied in peptide enrichment immuno-MRM assays.

PubMed

Whiteaker, Jeffrey R; Zhao, Lei; Frisch, Christian; Ylera, Francisco; Harth, Stefan; Knappik, Achim; Paulovich, Amanda G

2014-04-04

High-affinity antibodies binding to linear peptides in solution are a prerequisite for performing immuno-MRM, an emerging technology for protein quantitation with high precision and specificity using peptide immunoaffinity enrichment coupled to stable isotope dilution and targeted mass spectrometry. Recombinant antibodies can be generated from appropriate libraries in high-throughput in an automated laboratory and thus may offer advantages over conventional monoclonal antibodies. However, recombinant antibodies are typically obtained as fragments (Fab or scFv) expressed from E. coli, and it is not known whether these antibody formats are compatible with the established protocols and whether the affinities necessary for immunocapture of small linear peptides can be achieved with this technology. Hence, we performed a feasibility study to ask: (a) whether it is feasible to isolate high-affinity Fabs to small linear antigens and (b) whether it is feasible to incorporate antibody fragments into robust, quantitative immuno-MRM assays. We describe successful isolation of high-affinity Fab fragments against short (tryptic) peptides from a human combinatorial Fab library. We analytically characterize three immuno-MRM assays using recombinant Fabs, full-length IgGs constructed from these Fabs, or traditional monoclonals. We show that the antibody fragments show similar performance compared with traditional mouse- or rabbit-derived monoclonal antibodies. The data establish feasibility of isolating and incorporating high-affinity Fabs into peptide immuno-MRM assays.

A Standard Psychophysiological Preparation for Evaluating the Effects of Environmental Vibration Stress. Phase I. Development.

DTIC Science & Technology

A Standard Psychophysiological Preparation (SPP) for the evaluation of the physiological and biomechanical mechanisms responsible for performance...consumption, biomechanical parameters and performance level. The results of pilot tests (including 6-hours exposure to vibration while performing a...tracking task) verify the applicability and utility of the SPP and demonstrate that high quality, quantitative physiological and biomechanical data can

Quantitative comparison of tumor delivery for multiple targeted nanoparticles simultaneously by multiplex ICP-MS.

PubMed

Elias, Andrew; Crayton, Samuel H; Warden-Rothman, Robert; Tsourkas, Andrew

2014-07-28

Given the rapidly expanding library of disease biomarkers and targeting agents, the number of unique targeted nanoparticles is growing exponentially. The high variability and expense of animal testing often makes it unfeasible to examine this large number of nanoparticles in vivo. This often leads to the investigation of a single formulation that performed best in vitro. However, nanoparticle performance in vivo depends on many variables, many of which cannot be adequately assessed with cell-based assays. To address this issue, we developed a lanthanide-doped nanoparticle method that allows quantitative comparison of multiple targeted nanoparticles simultaneously. Specifically, superparamagnetic iron oxide (SPIO) nanoparticles with different targeting ligands were created, each with a unique lanthanide dopant. Following the simultaneous injection of the various SPIO compositions into tumor-bearing mice, inductively coupled plasma mass spectroscopy was used to quantitatively and orthogonally assess the concentration of each SPIO composition in serial blood and resected tumor samples.

A qualitative and quantitative assessment for a bone marrow harvest simulator.

PubMed

Machado, Liliane S; Moraes, Ronei M

2009-01-01

Several approaches to perform assessment in training simulators based on virtual reality have been proposed. There are two kinds of assessment methods: offline and online. The main requirements related to online training assessment methodologies applied to virtual reality systems are the low computational complexity and the high accuracy. In the literature it can be found several approaches for general cases which can satisfy such requirements. An inconvenient about those approaches is related to an unsatisfactory solution for specific cases, as in some medical procedures, where there are quantitative and qualitative information available to perform the assessment. In this paper, we present an approach to online training assessment based on a Modified Naive Bayes which can manipulate qualitative and quantitative variables simultaneously. A special medical case was simulated in a bone marrow harvest simulator. The results obtained were satisfactory and evidenced the applicability of the method.

Sensitive method for the quantitation of droloxifene in plasma and serum by high-performance liquid chromatography employing fluorimetric detection.

PubMed

Tess, D A; Cole, R O; Toler, S M

1995-12-15

A simple and highly sensitive reversed-phase fluorimetric HPLC method for the quantitation of droloxifene from rat, monkey, and human plasma as well as human serum is described. This assay employs solid-phase extraction and has a dynamic range of 25 to 10,000 pg/ml. Sample extraction (efficiencies > 86%) was accomplished using a benzenesulfonic acid (SCX) column with water and methanol rinses. Droloxifene and internal standard were eluted with 1 ml of 3.5% (v/v) ammonium hydroxide (30%) in methanol. Samples were quantitated using post-column UV-photochemical cyclization coupled with fluorimetric detection with excitation and emission wavelengths of 260 nm and 375 nm, respectively. Relative ease of sample extraction and short run times allow for the analysis of approximately 100 samples per day.

Quantitative Myocardial Perfusion Imaging Versus Visual Analysis in Diagnosing Myocardial Ischemia: A CE-MARC Substudy.

PubMed

Biglands, John D; Ibraheem, Montasir; Magee, Derek R; Radjenovic, Aleksandra; Plein, Sven; Greenwood, John P

2018-05-01

This study sought to compare the diagnostic accuracy of visual and quantitative analyses of myocardial perfusion cardiovascular magnetic resonance against a reference standard of quantitative coronary angiography. Visual analysis of perfusion cardiovascular magnetic resonance studies for assessing myocardial perfusion has been shown to have high diagnostic accuracy for coronary artery disease. However, only a few small studies have assessed the diagnostic accuracy of quantitative myocardial perfusion. This retrospective study included 128 patients randomly selected from the CE-MARC (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease) study population such that the distribution of risk factors and disease status was proportionate to the full population. Visual analysis results of cardiovascular magnetic resonance perfusion images, by consensus of 2 expert readers, were taken from the original study reports. Quantitative myocardial blood flow estimates were obtained using Fermi-constrained deconvolution. The reference standard for myocardial ischemia was a quantitative coronary x-ray angiogram stenosis severity of ≥70% diameter in any coronary artery of >2 mm diameter, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver-operating characteristic curve analysis. The area under the curve for visual analysis was 0.88 (95% confidence interval: 0.81 to 0.95) with a sensitivity of 81.0% (95% confidence interval: 69.1% to 92.8%) and specificity of 86.0% (95% confidence interval: 78.7% to 93.4%). For quantitative stress myocardial blood flow the area under the curve was 0.89 (95% confidence interval: 0.83 to 0.96) with a sensitivity of 87.5% (95% confidence interval: 77.3% to 97.7%) and specificity of 84.5% (95% confidence interval: 76.8% to 92.3%). There was no statistically significant difference between the diagnostic performance of quantitative and visual analyses (p = 0.72). Incorporating rest myocardial blood flow values to generate a myocardial perfusion reserve did not significantly increase the quantitative analysis area under the curve (p = 0.79). Quantitative perfusion has a high diagnostic accuracy for detecting coronary artery disease but is not superior to visual analysis. The incorporation of rest perfusion imaging does not improve diagnostic accuracy in quantitative perfusion analysis. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

A quantitative evaluation of the high elbow technique in front crawl.

PubMed

Suito, Hiroshi; Nunome, Hiroyuki; Ikegami, Yasuo

2017-07-01

Many coaches often instruct swimmers to keep the elbow in a high position (high elbow position) during early phase of the underwater stroke motion (pull phase) in front crawl, however, the high elbow position has never been quantitatively evaluated. The aims of this study were (1) to quantitatively evaluate the "high elbow" position, (2) to clarify the relationship between the high elbow position and required upper limb configuration and (3) to examine the efficacy of high elbow position on the resultant swimming velocity. Sixteen highly skilled and 6 novice male swimmers performed 25 m front crawl with maximal effort and their 3-dimensional arm stroke motion was captured at 60 Hz. An attempt was made to develop a new index to evaluate the high elbow position (I he : high elbow index) using 3-dimensional coordinates of the shoulder, elbow and wrist joints. I he of skilled swimmers moderately correlated with the average shoulder internal rotation angle (r = -0.652, P < 0.01) and swimming velocity (r = -0.683, P < 0.01) during the pull phase. These results indicate that I he is a useful index for evaluating high elbow arm stroke technique during the pull phase in front crawl.

Characterization of E 471 food emulsifiers by high-performance thin-layer chromatography-fluorescence detection.

PubMed

Oellig, Claudia; Brändle, Klara; Schwack, Wolfgang

2018-07-13

Mono- and diacylglycerol (MAG and DAG) emulsifiers, also known as food additive E 471, are widely used to adjust techno-functional properties in various foods. Besides MAGs and DAGs, E 471 emulsifiers additionally comprise different amounts of triacylglycerols (TAGs) and free fatty acids (FFAs). MAGs, DAGs, TAGs and FFAs are generally determined by high-performance liquid chromatography (HPLC) or gas chromatography (GC) coupled to mass selective detection, analyzing the individual representatives of the lipid classes. In this work we present a rapid and sensitive method for the determination of MAGs, DAGs, TAGs and FFAs in E 471 emulsifiers by high-performance thin-layer chromatography with fluorescence detection (HPTLC-FLD), including a response factor system for quantitation. Samples were simply dissolved and diluted with t-butyl methyl ether before a two-fold development was performed on primuline pre-impregnated LiChrospher silica gel plates with diethyl ether and n-pentane/n-hexane/diethyl ether (52:20:28, v/v/v) as the mobile phases to 18 and 75 mm, respectively. For quantitation, the plate was scanned in the fluorescence mode at UV 366/>400 nm, when the cumulative signal for each lipid class was used. Calibration was done with 1,2-distearin and amounts of lipid classes were calculated with response factors and expressed as monostearin, distearin, tristearin and stearic acid. Limits of detection and quantitation were 1 and 4 ng/zone, respectively, for 1,2-distearin. Thus, the HPTLC-FLD approach represents a simple, rapid and convenient screening alternative to HPLC and GC analysis of the individual compounds. Visual detection additionally enables an easy characterization and the direct comparison of emulsifiers through the lipid class pattern, when utilized as a fingerprint. Copyright © 2018 Elsevier B.V. All rights reserved.

Quantitative Chemical-Genetic Interaction Map Connects Gene Alterations to Drug Responses | Office of Cancer Genomics

Cancer.gov

In a recent Cancer Discovery report, CTD2 researchers at the University of California in San Francisco developed a new quantitative chemical-genetic interaction mapping approach to evaluate drug sensitivity or resistance in isogenic cell lines. Performing a high-throughput screen with isogenic cell lines allowed the researchers to explore the impact of a panel of emerging and established drugs on cells overexpressing a single cancer-associated gene in isolation.

Experiences of Latina/o Students in "Large Schools in Drag": A Critical Analysis of an Urban Alternative High School

ERIC Educational Resources Information Center

Vélez, William; Antrop-González, René

2007-01-01

This study uses mixed methods to identify the factors linked to varying levels of academic performance among Latina/o students enrolled in an alternative high school. Results from the quantitative analyses suggest students who had highly educated fathers and who reported high levels of English literacy are very likely to be classified as academic…

Chemotyping the distribution of vitamin D metabolites in human serum

NASA Astrophysics Data System (ADS)

Müller, Miriam J.; Stokes, Caroline S.; Lammert, Frank; Volmer, Dietrich A.

2016-02-01

Most studies examining the relationships between vitamin D and disease or health focus on the main 25-hydroxyvitamin D3 (25(OH)D3) metabolite, thus potentially overlooking contributions and dynamic effects of other vitamin D metabolites, the crucial roles of several of which have been previously demonstrated. The ideal assay would determine all relevant high and low-abundant vitamin D species simultaneously. We describe a sensitive quantitative assay for determining the chemotypes of vitamin D metabolites from serum after derivatisation and ultra-high performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (UHPLC-ESI-MS/MS). We performed a validation according to the ‘FDA Guidance for Industry Bioanalytical Method Validation’. The proof-of-concept of the method was then demonstrated by following the metabolite concentrations in patients with chronic liver diseases (CLD) during the course of a vitamin D supplementation study. The new quantitative profiling assay provided highly sensitive, precise and accurate chemotypes of the vitamin D metabolic process rather than the usually determined 25(OH)D3 concentrations.

Qualitative and quantitative analyses of flavonoids in Spirodela polyrrhiza by high-performance liquid chromatography coupled with mass spectrometry.

PubMed

Qiao, Xue; He, Wen-ni; Xiang, Cheng; Han, Jian; Wu, Li-jun; Guo, De-an; Ye, Min

2011-01-01

Spirodela polyrrhiza (L.) Schleid. is a traditional Chinese herbal medicine for the treatment of influenza. Despite its wide use in Chinese medicine, no report on quality control of this herb is available so far. To establish qualitative and quantitative analytical methods by high-performance liquid chromatography (HPLC) coupled with mass spectrometry (MS) for the quality control of S. polyrrhiza. The methanol extract of S. polyrrhiza was analysed by HPLC/ESI-MS(n). Flavonoids were identified by comparing with reference standards or according to their MS(n) (n = 2-4) fragmentation behaviours. Based on LC/MS data, a standardised HPLC fingerprint was established by analysing 15 batches of commercial herbal samples. Furthermore, quantitative analysis was conducted by determining five major flavonoids, namely luteolin 8-C-glucoside, apigenin 8-C-glucoside, luteolin 7-O-glucoside, apigenin 7-O-glucoside and luteolin. A total of 18 flavonoids were identified by LC/MS, and 14 of them were reported from this herb for the first time. The HPLC fingerprints contained 10 common peaks, and could differentiate good quality batches from counterfeits. The total contents of five major flavonoids in S. polyrrhiza varied significantly from 4.28 to 19.87 mg/g. Qualitative LC/MS and quantitative HPLC analytical methods were established for the comprehensive quality control of S. polyrrhiza. Copyright © 2011 John Wiley & Sons, Ltd.

A simultaneous screening and quantitative method for the multiresidue analysis of pesticides in spices using ultra-high performance liquid chromatography-high resolution (Orbitrap) mass spectrometry.

PubMed

Goon, Arnab; Khan, Zareen; Oulkar, Dasharath; Shinde, Raviraj; Gaikwad, Suresh; Banerjee, Kaushik

2018-01-12

A novel screening and quantitation method is reported for non-target multiresidue analysis of pesticides using ultra-HPLC-quadrupole-Orbitrap mass spectrometry in spice matrices, including black pepper, cardamom, chili, coriander, cumin, and turmeric. The method involved sequential full-scan (resolution = 70,000), and variable data independent acquisition (vDIA) with nine consecutive fragmentation events (resolution = 17,500). Samples were extracted by the QuEChERS method. The introduction of an SPE-based clean-up step through hydrophilic-lipophilic-balance (HLB) cartridges proved advantageous in minimizing the false negatives. For coriander, cumin, chili, and cardamom, the screening detection limit was largely at 2 ng/g, while it was 5 ng/g for black pepper, and turmeric. When the method was quantitatively validated for 199 pesticides, the limit of quantification (LOQ) was mostly at 10 ng/g (excluding black pepper, and turmeric with LOQ = 20 ng/g) with recoveries within 70-120%, and precision-RSDs <20%. Furthermore, the method allowed the identification of suspected non-target analytes through retrospective search of the accurate mass of the compound-specific precursor and product ions. Compared to LC-MS/MS, the quantitative performance of this Orbitrap-MS method had agreements in residue values between 78-100%. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantitative Large-Scale Three-Dimensional Imaging of Human Kidney Biopsies: A Bridge to Precision Medicine in Kidney Disease.

PubMed

Winfree, Seth; Dagher, Pierre C; Dunn, Kenneth W; Eadon, Michael T; Ferkowicz, Michael; Barwinska, Daria; Kelly, Katherine J; Sutton, Timothy A; El-Achkar, Tarek M

2018-06-05

Kidney biopsy remains the gold standard for uncovering the pathogenesis of acute and chronic kidney diseases. However, the ability to perform high resolution, quantitative, molecular and cellular interrogation of this precious tissue is still at a developing stage compared to other fields such as oncology. Here, we discuss recent advances in performing large-scale, three-dimensional (3D), multi-fluorescence imaging of kidney biopsies and quantitative analysis referred to as 3D tissue cytometry. This approach allows the accurate measurement of specific cell types and their spatial distribution in a thick section spanning the entire length of the biopsy. By uncovering specific disease signatures, including rare occurrences, and linking them to the biology in situ, this approach will enhance our understanding of disease pathogenesis. Furthermore, by providing accurate quantitation of cellular events, 3D cytometry may improve the accuracy of prognosticating the clinical course and response to therapy. Therefore, large-scale 3D imaging and cytometry of kidney biopsy is poised to become a bridge towards personalized medicine for patients with kidney disease. © 2018 S. Karger AG, Basel.

Putting tools in the toolbox: Development of a free, open-source toolbox for quantitative image analysis of porous media.

NASA Astrophysics Data System (ADS)

Iltis, G.; Caswell, T. A.; Dill, E.; Wilkins, S.; Lee, W. K.

2014-12-01

X-ray tomographic imaging of porous media has proven to be a valuable tool for investigating and characterizing the physical structure and state of both natural and synthetic porous materials, including glass bead packs, ceramics, soil and rock. Given that most synchrotron facilities have user programs which grant academic researchers access to facilities and x-ray imaging equipment free of charge, a key limitation or hindrance for small research groups interested in conducting x-ray imaging experiments is the financial cost associated with post-experiment data analysis. While the cost of high performance computing hardware continues to decrease, expenses associated with licensing commercial software packages for quantitative image analysis continue to increase, with current prices being as high as $24,000 USD, for a single user license. As construction of the Nation's newest synchrotron accelerator nears completion, a significant effort is being made here at the National Synchrotron Light Source II (NSLS-II), Brookhaven National Laboratory (BNL), to provide an open-source, experiment-to-publication toolbox that reduces the financial and technical 'activation energy' required for performing sophisticated quantitative analysis of multidimensional porous media data sets, collected using cutting-edge x-ray imaging techniques. Implementation focuses on leveraging existing open-source projects and developing additional tools for quantitative analysis. We will present an overview of the software suite that is in development here at BNL including major design decisions, a demonstration of several test cases illustrating currently available quantitative tools for analysis and characterization of multidimensional porous media image data sets and plans for their future development.

Facile quantitation of free thiols in a recombinant monoclonal antibody by reversed-phase high performance liquid chromatography with hydrophobicity-tailored thiol derivatization.

PubMed

Welch, Leslie; Dong, Xiao; Hewitt, Daniel; Irwin, Michelle; McCarty, Luke; Tsai, Christina; Baginski, Tomasz

2018-06-02

Free thiol content, and its consistency, is one of the product quality attributes of interest during technical development of manufactured recombinant monoclonal antibodies (mAbs). We describe a new, mid/high-throughput reversed-phase-high performance liquid chromatography (RP-HPLC) method coupled with derivatization of free thiols, for the determination of total free thiol content in an E. coli-expressed therapeutic monovalent monoclonal antibody mAb1. Initial selection of the derivatization reagent used an hydrophobicity-tailored approach. Maleimide-based thiol-reactive reagents with varying degrees of hydrophobicity were assessed to identify and select one that provided adequate chromatographic resolution and robust quantitation of free thiol-containing mAb1 forms. The method relies on covalent derivatization of free thiols in denatured mAb1 with N-tert-butylmaleimide (NtBM) label, followed by RP-HPLC separation with UV-based quantitation of native (disulfide containing) and labeled (free thiol containing) forms. The method demonstrated good specificity, precision, linearity, accuracy and robustness. Accuracy of the method, for samples with a wide range of free thiol content, was demonstrated using admixtures as well as by comparison to an orthogonal LC-MS peptide mapping method with isotope tagging of free thiols. The developed method has a facile workflow which fits well into both R&D characterization and quality control (QC) testing environments. The hydrophobicity-tailored approach to the selection of free thiol derivatization reagent is easily applied to the rapid development of free thiol quantitation methods for full-length recombinant antibodies. Copyright © 2018 Elsevier B.V. All rights reserved.

Transitioning from Targeted to Comprehensive Mass Spectrometry Using Genetic Algorithms.

PubMed

Jaffe, Jacob D; Feeney, Caitlin M; Patel, Jinal; Lu, Xiaodong; Mani, D R

2016-11-01

Targeted proteomic assays are becoming increasingly popular because of their robust quantitative applications enabled by internal standardization, and they can be routinely executed on high performance mass spectrometry instrumentation. However, these assays are typically limited to 100s of analytes per experiment. Considerable time and effort are often expended in obtaining and preparing samples prior to targeted analyses. It would be highly desirable to detect and quantify 1000s of analytes in such samples using comprehensive mass spectrometry techniques (e.g., SWATH and DIA) while retaining a high degree of quantitative rigor for analytes with matched internal standards. Experimentally, it is facile to port a targeted assay to a comprehensive data acquisition technique. However, data analysis challenges arise from this strategy concerning agreement of results from the targeted and comprehensive approaches. Here, we present the use of genetic algorithms to overcome these challenges in order to configure hybrid targeted/comprehensive MS assays. The genetic algorithms are used to select precursor-to-fragment transitions that maximize the agreement in quantification between the targeted and the comprehensive methods. We find that the algorithm we used provided across-the-board improvement in the quantitative agreement between the targeted assay data and the hybrid comprehensive/targeted assay that we developed, as measured by parameters of linear models fitted to the results. We also found that the algorithm could perform at least as well as an independently-trained mass spectrometrist in accomplishing this task. We hope that this approach will be a useful tool in the development of quantitative approaches for comprehensive proteomics techniques. Graphical Abstract ᅟ.

Transitioning from Targeted to Comprehensive Mass Spectrometry Using Genetic Algorithms

NASA Astrophysics Data System (ADS)

Jaffe, Jacob D.; Feeney, Caitlin M.; Patel, Jinal; Lu, Xiaodong; Mani, D. R.

2016-11-01

Targeted proteomic assays are becoming increasingly popular because of their robust quantitative applications enabled by internal standardization, and they can be routinely executed on high performance mass spectrometry instrumentation. However, these assays are typically limited to 100s of analytes per experiment. Considerable time and effort are often expended in obtaining and preparing samples prior to targeted analyses. It would be highly desirable to detect and quantify 1000s of analytes in such samples using comprehensive mass spectrometry techniques (e.g., SWATH and DIA) while retaining a high degree of quantitative rigor for analytes with matched internal standards. Experimentally, it is facile to port a targeted assay to a comprehensive data acquisition technique. However, data analysis challenges arise from this strategy concerning agreement of results from the targeted and comprehensive approaches. Here, we present the use of genetic algorithms to overcome these challenges in order to configure hybrid targeted/comprehensive MS assays. The genetic algorithms are used to select precursor-to-fragment transitions that maximize the agreement in quantification between the targeted and the comprehensive methods. We find that the algorithm we used provided across-the-board improvement in the quantitative agreement between the targeted assay data and the hybrid comprehensive/targeted assay that we developed, as measured by parameters of linear models fitted to the results. We also found that the algorithm could perform at least as well as an independently-trained mass spectrometrist in accomplishing this task. We hope that this approach will be a useful tool in the development of quantitative approaches for comprehensive proteomics techniques.

A Quantitative Research Investigation into High School Design and Art Education in a Local High School in Texas

ERIC Educational Resources Information Center

Lin, Yi-Hsien

2013-01-01

This study was designed to explore the differences between high school teachers with art and science backgrounds in terms of curriculum and student performance in art and design education, federal educational policy, and financial support. The study took place in a local independent school district in Texarkana, Texas. The independent school…

The Influence of Instructional Minutes on Grade 11 Language Arts and Mathematics High School Proficiency Assessment Performance

ERIC Educational Resources Information Center

Welcome, Simone E.

2017-01-01

The purpose for this cross-sectional, non-experimental explanatory quantitative research study was to explain the amount of variance in the High School Proficiency Assessment-11 Language Arts and Mathematics scores accounted for by the amount of instructional minutes at high schools in New Jersey. A proportional, stratified random sample which…

The Effects of Two Scheduling Formats on Student Achievement in a Suburban High School Setting

ERIC Educational Resources Information Center

Jackson, Kenyada Morton

2013-01-01

Limited studies have been conducted on the relationship between scheduling formats and academic performance of high school students. At the target high school, students underperform on standardized tests in English language arts (ELA) and math. The purpose of this causal comparative quantitative study was to compare the means of ELA and math test…

Academic Rigor and Economic Value: GED[R] and High School Students' Perceptions and Misperceptions of the GED[R] vs. the High School Diploma

ERIC Educational Resources Information Center

Horne, Lela M.; Rachal, John R.; Shelley, Kyna

2012-01-01

A mixed methods framework utilized quantitative and qualitative data to determine whether statistically significant differences existed between high school and GED[R] student perceptions of credential value. An exploratory factor analysis (n=326) extracted four factors and then a MANOVA procedure was performed with a stratified quota sample…

High speed all optical shear wave imaging optical coherence elastography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Song, Shaozhen; Hsieh, Bao-Yu; Wei, Wei; Shen, Tueng; O'Donnell, Matthew; Wang, Ruikang K.

2016-03-01

Optical Coherence Elastography (OCE) is a non-invasive testing modality that maps the mechanical property of soft tissues with high sensitivity and spatial resolution using phase-sensitive optical coherence tomography (PhS-OCT). Shear wave OCE (SW-OCE) is a leading technique that relies on the speed of propagating shear waves to provide a quantitative elastography. Previous shear wave imaging OCT techniques are based on repeated M-B scans, which have several drawbacks such as long acquisition time and repeated wave stimulations. Recent developments of Fourier domain mode-locked high-speed swept-source OCT system has enabled enough speed to perform KHz B-scan rate OCT imaging. Here we propose ultra-high speed, single shot shear wave imaging to capture single-shot transient shear wave propagation to perform SW-OCE. The frame rate of shear wave imaging is 16 kHz, at A-line rate of ~1.62 MHz, which allows the detection of high-frequency shear wave of up to 8 kHz. The shear wave is generated photothermal-acoustically, by ultra-violet pulsed laser, which requires no contact to OCE subjects, while launching high frequency shear waves that carries rich localized elasticity information. The image acquisition and processing can be performed at video-rate, which enables real-time 3D elastography. SW-OCE measurements are demonstrated on tissue-mimicking phantoms and porcine ocular tissue. This approach opens up the feasibility to perform real-time 3D SW-OCE in clinical applications, to obtain high-resolution localized quantitative measurement of tissue biomechanical property.

Multiplex, quantitative cellular analysis in large tissue volumes with clearing-enhanced 3D microscopy (Ce3D)

PubMed Central

Li, Weizhe; Germain, Ronald N.

2017-01-01

Organ homeostasis, cellular differentiation, signal relay, and in situ function all depend on the spatial organization of cells in complex tissues. For this reason, comprehensive, high-resolution mapping of cell positioning, phenotypic identity, and functional state in the context of macroscale tissue structure is critical to a deeper understanding of diverse biological processes. Here we report an easy to use method, clearing-enhanced 3D (Ce3D), which generates excellent tissue transparency for most organs, preserves cellular morphology and protein fluorescence, and is robustly compatible with antibody-based immunolabeling. This enhanced signal quality and capacity for extensive probe multiplexing permits quantitative analysis of distinct, highly intermixed cell populations in intact Ce3D-treated tissues via 3D histo-cytometry. We use this technology to demonstrate large-volume, high-resolution microscopy of diverse cell types in lymphoid and nonlymphoid organs, as well as to perform quantitative analysis of the composition and tissue distribution of multiple cell populations in lymphoid tissues. Combined with histo-cytometry, Ce3D provides a comprehensive strategy for volumetric quantitative imaging and analysis that bridges the gap between conventional section imaging and disassociation-based techniques. PMID:28808033

The Effects of Diversity Management on Job Satisfaction and Individual Performance of Teachers

ERIC Educational Resources Information Center

Ordu, Aydan

2016-01-01

In this research, the effects of teachers' perceptions of the diversity management on their job satisfaction and individual performance were examined. Teachers who are working in public high schools during 2014 to 2015 academic year constituted the study group of the research. The data of the research in which quantitative method used were…

Student Learning Motivation as a Mediator of the Relationship between Service Quality and Student Performance

ERIC Educational Resources Information Center

Ibrahim, Hamdi H. M.

2016-01-01

Students look for evidence of service quality when selecting a university to attend. Student dissatisfaction with the quality of service may reduce student motivation in online higher-education settings, and low levels of motivation may lead to inferior student performance and a persistently high dropout rate. The purpose of this quantitative,…

Making Mathematics Matter: Professional Development Improving Outcomes in High-Poverty Environments

ERIC Educational Resources Information Center

Siebers, Carolyn A.

2012-01-01

This research study is a mixed-methods quantitative and qualitative study that analyzed data from an intensive, long-term professional development project named, "Project: Making Mathematics Matter. (PM[superscript 3])" carried out in two low-performing, high-poverty districts. Two of the districts served as treatment districts and ALL…

The Practice of Co-Creating Leadership in High- and Low-Performing High Schools

ERIC Educational Resources Information Center

Jarrett, Ehren; Wasonga, Teresa; Murphy, John

2010-01-01

Purpose: The purpose of this paper is to examine teacher perceptions of the practice of co-creating leadership and its potential impacts on student achievement. Design/methodology/approach: Using a quantitative approach, the study compared the levels of the practice of co-creating leadership dispositional values and institutional conditions that…

Quantitative criteria for assessment of gamma-ray imager performance

NASA Astrophysics Data System (ADS)

Gottesman, Steve; Keller, Kristi; Malik, Hans

2015-08-01

In recent years gamma ray imagers such as the GammaCamTM and Polaris have demonstrated good imaging performance in the field. Imager performance is often summarized as "resolution", either angular, or spatial at some distance from the imager, however the definition of resolution is not always related to the ability to image an object. It is difficult to quantitatively compare imagers without a common definition of image quality. This paper examines three categories of definition: point source; line source; and area source. It discusses the details of those definitions and which ones are more relevant for different situations. Metrics such as Full Width Half Maximum (FWHM), variations on the Rayleigh criterion, and some analogous to National Imagery Interpretability Rating Scale (NIIRS) are discussed. The performance against these metrics is evaluated for a high resolution coded aperture imager modeled using Monte Carlo N-Particle (MCNP), and for a medium resolution imager measured in the lab.

The effect of authentic leadership, organizational justice, and achievement motivation on teachers' performance in vocational high school seventeen Temanggung

NASA Astrophysics Data System (ADS)

Sugi, Slamet, Achmad; Martono, S.

2018-03-01

Teachers' performance in Temanggung in 2016 did not show maximal result. It was shown from many indicators. The low score of UN, UKG and PKB result. Individual performance was different. Achievement motivation could be seen through their attitude and behavior performances. The purpose of this research is to know the effect of authentic leadership, organizational justice, and achievement motivation on teachers' performance. The objects of this research are authentic leadership, organizational justice, achievement motivation and teachers' performance in Vocational High School Seventeen in Temanggung. The research method used is quantitative. Data collection was done by questioners. Then, the data were analyzed by using Path SPSS 16. The result of this research showed that authentic leadership, organizational justice, achievement motivation had significant effect on teachers' performance in Vocational High School Seventeen in Temanggung.

Affordable, automatic quantitative fall risk assessment based on clinical balance scales and Kinect data.

PubMed

Colagiorgio, P; Romano, F; Sardi, F; Moraschini, M; Sozzi, A; Bejor, M; Ricevuti, G; Buizza, A; Ramat, S

2014-01-01

The problem of a correct fall risk assessment is becoming more and more critical with the ageing of the population. In spite of the available approaches allowing a quantitative analysis of the human movement control system's performance, the clinical assessment and diagnostic approach to fall risk assessment still relies mostly on non-quantitative exams, such as clinical scales. This work documents our current effort to develop a novel method to assess balance control abilities through a system implementing an automatic evaluation of exercises drawn from balance assessment scales. Our aim is to overcome the classical limits characterizing these scales i.e. limited granularity and inter-/intra-examiner reliability, to obtain objective scores and more detailed information allowing to predict fall risk. We used Microsoft Kinect to record subjects' movements while performing challenging exercises drawn from clinical balance scales. We then computed a set of parameters quantifying the execution of the exercises and fed them to a supervised classifier to perform a classification based on the clinical score. We obtained a good accuracy (~82%) and especially a high sensitivity (~83%).

Quantitative determination of reserpine, ajmaline, and ajmalicine in Rauvolfia serpentina by reversed-phase high-performance liquid chromatography.

PubMed

Srivastava, A; Tripathi, A K; Pandey, R; Verma, R K; Gupta, M M

2006-10-01

A sensitive and reproducible reversed-phase high-performance liquid chromatography (HPLC) method using photodiode array detection is established for the simultaneous quantitation of important root alkaloids of Rauvolfia serpentina, namely, reserpine, ajmaline, and ajmalicine. A Chromolith Performance RP-18e column (100 x 4.6-mm i.d.) and a binary gradient mobile phase composed of 0.01 M (pH 3.5) phosphate buffer (NaH(2)PO(4)) containing 0.5% glacial acetic acid and acetonitrile are used. Analysis is run at a flow rate of 1.0 mL/min with the detector operated at a wavelength of 254 nm. The calibration curves are linear over a concentration range of 1-20 microg/mL (r = 1.000) for all the alkaloids. The various other aspects of analysis (i.e., peak purity, similarity, recovery, and repeatability) are also validated. For the three components, the recoveries are found to be 98.27%, 97.03%, and 98.38%, respectively. The limits of detection are 6, 4, and 8 microg/mL for ajmaline, ajmalicine, and reserpine, respectively, and the limits of quantitation are 19, 12, and 23 microg/mL for ajmaline, ajmalicine, and reserpine, respectively. The developed method is simple, reproducible, and easy to operate. It is useful for the evaluation of R. serpentina.

Development and validation of stability indicating method for the quantitative determination of venlafaxine hydrochloride in extended release formulation using high performance liquid chromatography

PubMed Central

Kaur, Jaspreet; Srinivasan, K. K.; Joseph, Alex; Gupta, Abhishek; Singh, Yogendra; Srinivas, Kona S.; Jain, Garima

2010-01-01

Objective: Venlafaxine,hydrochloride is a structurally novel phenethyl bicyclic antidepressant, and is usually categorized as a serotonin–norepinephrine reuptake inhibitor (SNRI) but it has been referred to as a serotonin–norepinephrine–dopamine reuptake inhibitor. It inhibits the reuptake of dopamine. Venlafaxine HCL is widely prescribed in the form of sustained release formulations. In the current article we are reporting the development and validation of a fast and simple stability indicating, isocratic high performance liquid chromatographic (HPLC) method for the determination of venlafaxine hydrochloride in sustained release formulations. Materials and Methods: The quantitative determination of venlafaxine hydrochloride was performed on a Kromasil C18 analytical column (250 × 4.6 mm i.d., 5 μm particle size) with 0.01 M phosphate buffer (pH 4.5): methanol (40: 60) as a mobile phase, at a flow rate of 1.0 ml/min. For HPLC methods, UV detection was made at 225 nm. Results: During method validation, parameters such as precision, linearity, accuracy, stability, limit of quantification and detection and specificity were evaluated, which remained within acceptable limits. Conclusions: The method has been successfully applied for the quantification and dissolution profiling of Venlafaxine HCL in sustained release formulation. The method presents a simple and reliable solution for the routine quantitative analysis of Venlafaxine HCL. PMID:21814426

Determination of quantitative retention-activity relationships between pharmacokinetic parameters and biological effectiveness fingerprints of Salvia miltiorrhiza constituents using biopartitioning and microemulsion high-performance liquid chromatography.

PubMed

Gao, Haoshi; Huang, Hongzhang; Zheng, Aini; Yu, Nuojun; Li, Ning

2017-11-01

In this study, we analyzed danshen (Salvia miltiorrhiza) constituents using biopartitioning and microemulsion high-performance liquid chromatography (MELC). The quantitative retention-activity relationships (QRARs) of the constituents were established to model their pharmacokinetic (PK) parameters and chromatographic retention data, and generate their biological effectiveness fingerprints. A high-performance liquid chromatography (HPLC) method was established to determine the abundance of the extracted danshen constituents, such as sodium danshensu, rosmarinic acid, salvianolic acid B, protocatechuic aldehyde, cryptotanshinone, and tanshinone IIA. And another HPLC protocol was established to determine the abundance of those constituents in rat plasma samples. An experimental model was built in Sprague Dawley (SD) rats, and calculated the corresponding PK parameterst with 3P97 software package. Thirty-five model drugs were selected to test the PK parameter prediction capacities of the various MELC systems and to optimize the chromatographic protocols. QRARs and generated PK fingerprints were established. The test included water/oil-soluble danshen constituents and the prediction capacity of the regression model was validated. The results showed that the model had good predictability. Copyright © 2017. Published by Elsevier B.V.

High-Content Microscopy Analysis of Subcellular Structures: Assay Development and Application to Focal Adhesion Quantification.

PubMed

Kroll, Torsten; Schmidt, David; Schwanitz, Georg; Ahmad, Mubashir; Hamann, Jana; Schlosser, Corinne; Lin, Yu-Chieh; Böhm, Konrad J; Tuckermann, Jan; Ploubidou, Aspasia

2016-07-01

High-content analysis (HCA) converts raw light microscopy images to quantitative data through the automated extraction, multiparametric analysis, and classification of the relevant information content. Combined with automated high-throughput image acquisition, HCA applied to the screening of chemicals or RNAi-reagents is termed high-content screening (HCS). Its power in quantifying cell phenotypes makes HCA applicable also to routine microscopy. However, developing effective HCA and bioinformatic analysis pipelines for acquisition of biologically meaningful data in HCS is challenging. Here, the step-by-step development of an HCA assay protocol and an HCS bioinformatics analysis pipeline are described. The protocol's power is demonstrated by application to focal adhesion (FA) detection, quantitative analysis of multiple FA features, and functional annotation of signaling pathways regulating FA size, using primary data of a published RNAi screen. The assay and the underlying strategy are aimed at researchers performing microscopy-based quantitative analysis of subcellular features, on a small scale or in large HCS experiments. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

Three dimensional motion capture applied to violin playing: A study on feasibility and characterization of the motor strategy.

PubMed

Ancillao, Andrea; Savastano, Bernardo; Galli, Manuela; Albertini, Giorgio

2017-10-01

Playing string instruments requires advanced motor skills and a long training that is often spent in uncomfortable postures that may lead to injuries or musculoskeletal disorders. Thus, it is interesting to objectively characterize the motor strategy adopted by the players. In this work, we implemented a method for the quantitative analysis of the motor performance of a violin player. The proposed protocol takes advantage of an optoelectronic system and some infra-red reflecting markers in order to track player's motion. The method was tested on a professional violin player performing a legato bowing task. The biomechanical strategy of the upper limb and bow positioning were described by means of quantitative parameters and motion profiles. Measured quantities were: bow trajectory, angles, tracks, velocity, acceleration and jerk. A good repeatability of the bowing motion (CV < 2%) and high smoothness (jerk < 5 m/s 3 ) were observed. Motion profiles of shoulder, elbow and wrist were repeatable (CV < 7%) and comparable to the curves observed in other studies. Jerk and acceleration profiles demonstrated high smoothness in the ascending and descending phases of bowing. High variability was instead observed for the neck angle (CV ∼56%). "Quantitative" measurements, instead of "qualitative" observation, can support the diagnosis of motor disorders and the accurate evaluation of musicians' skills. The proposed protocol is a powerful tool for the description of musician's performance, that may be useful to document improvements in playing abilities and to adjust training strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

Performance Evaluation of the Bioneer AccuPower® HIV-1 Quantitative RT-PCR kit: Comparison with the Roche COBAS® AmpliPrep/COBAS TaqMan® HIV-1 Test Ver.2.0 for Quantification of HIV-1 Viral Load in Indonesia.

PubMed

Kosasih, Agus Susanto; Sugiarto, Christine; Hayuanta, Hubertus Hosti; Juhaendi, Runingsih; Setiawan, Lyana

2017-08-08

Measurement of viral load in human immunodeficiency virus type 1 (HIV-1) infected patients is essential for the establishment of a therapeutic strategy. Several assays based on qPCR are available for the measurement of viral load; they differ in sample volume, technology applied, target gene, sensitivity and dynamic range. The Bioneer AccuPower® HIV-1 Quantitative RT-PCR is a novel commercial kit that has not been evaluated for its performance. This study aimed to evaluate the performance of the Bioneer AccuPower® HIV-1 Quantitative RT-PCR kit. In total, 288 EDTA plasma samples from the Dharmais Cancer Hospital were analyzed with the Bioneer AccuPower® HIV-1 Quantitative RT-PCR kit and the Roche COBAS? AmpliPrep/COBAS® TaqMan® HIV-1 version 2.0 (CAP/CTM v2.0). The performance of the Bioneer assay was then evaluated against the Roche CAP/CTM v2.0. Overall, there was good agreement between the two assays. The Bioneer assay showed significant linear correlation with CAP/CTM v2.0 (R2=0.963, p<0.001) for all samples (N=118) which were quantified by both assays, with high agreement (94.9%, 112/118) according to the Bland-Altman model. The mean difference between the quantitative values measured by Bioneer assay and CAP/CTM v2.0 was 0.11 Log10 IU/mL (SD=0.26). Based on these results, the Bioneer assay can be used to quantify HIV-1 RNA in clinical laboratories.

Quantitative profiling of immune repertoires for minor lymphocyte counts using unique molecular identifiers.

PubMed

Egorov, Evgeny S; Merzlyak, Ekaterina M; Shelenkov, Andrew A; Britanova, Olga V; Sharonov, George V; Staroverov, Dmitriy B; Bolotin, Dmitriy A; Davydov, Alexey N; Barsova, Ekaterina; Lebedev, Yuriy B; Shugay, Mikhail; Chudakov, Dmitriy M

2015-06-15

Emerging high-throughput sequencing methods for the analyses of complex structure of TCR and BCR repertoires give a powerful impulse to adaptive immunity studies. However, there are still essential technical obstacles for performing a truly quantitative analysis. Specifically, it remains challenging to obtain comprehensive information on the clonal composition of small lymphocyte populations, such as Ag-specific, functional, or tissue-resident cell subsets isolated by sorting, microdissection, or fine needle aspirates. In this study, we report a robust approach based on unique molecular identifiers that allows profiling Ag receptors for several hundred to thousand lymphocytes while preserving qualitative and quantitative information on clonal composition of the sample. We also describe several general features regarding the data analysis with unique molecular identifiers that are critical for accurate counting of starting molecules in high-throughput sequencing applications. Copyright © 2015 by The American Association of Immunologists, Inc.

Portable smartphone based quantitative phase microscope

NASA Astrophysics Data System (ADS)

Meng, Xin; Tian, Xiaolin; Yu, Wei; Kong, Yan; Jiang, Zhilong; Liu, Fei; Xue, Liang; Liu, Cheng; Wang, Shouyu

2018-01-01

To realize portable device with high contrast imaging capability, we designed a quantitative phase microscope using transport of intensity equation method based on a smartphone. The whole system employs an objective and an eyepiece as imaging system and a cost-effective LED as illumination source. A 3-D printed cradle is used to align these components. Images of different focal planes are captured by manual focusing, followed by calculation of sample phase via a self-developed Android application. To validate its accuracy, we first tested the device by measuring a random phase plate with known phases, and then red blood cell smear, Pap smear, broad bean epidermis sections and monocot root were also measured to show its performance. Owing to its advantages as accuracy, high-contrast, cost-effective and portability, the portable smartphone based quantitative phase microscope is a promising tool which can be future adopted in remote healthcare and medical diagnosis.

Mass Spectral Characterization and UPLC Quantitation of 3-Deoxyanthocyanidins in Sorghum bicolor Varietals.

PubMed

Stern, Nathan P; Rana, Jatinder; Chandra, Amitabh; Balles, John

2018-01-01

A quantitative ultra-performance LC (UPLC) method was developed and validated to successfully separate, identify, and quantitate the major polyphenolic compounds present in different varieties of sorghum (Sorghum bicolor) feedstock. The method was linear from 3.2 to 320 ppm, with an r2 of 0.99999 when using luteolinidin chloride as the external standard. Method accuracy was determined to be 99.5%, and precision of replicate preparations was less than 1% RSD. Characterization by UPLC-MS determined that the predominant polyphenolic components of the sorghum varietals were 3-deoxyanthocyanidins (3-DXAs). High-throughput screening for 3-DXA identified four unique classes within the sorghum varieties. Certain feedstock varieties have been found to have a high potential to not only be plant-based colorants, but also provide significant amounts of bioactive 3-DXAs, making them of unique interest to the dietary supplement industry.

Instantaneous Assessment Of Athletic Performance Using High Speed Video

NASA Astrophysics Data System (ADS)

Hubbard, Mont; Alaways, LeRoy W.

1988-02-01

We describe the use of high speed video to provide quantitative assessment of motion in athletic performance. Besides the normal requirement for accuracy, an essential feature is that the information be provided rapidly enough so that it my serve as valuable feedback in the learning process. The general considerations which must be addressed in the development of such a computer based system are discussed. These ideas are illustrated specifically through the description of a prototype system which has been designed for the javelin throw.

Early prediction of coma recovery after cardiac arrest with blinded pupillometry.

PubMed

Solari, Daria; Rossetti, Andrea O; Carteron, Laurent; Miroz, John-Paul; Novy, Jan; Eckert, Philippe; Oddo, Mauro

2017-06-01

Prognostication studies on comatose cardiac arrest (CA) patients are limited by lack of blinding, potentially causing overestimation of outcome predictors and self-fulfilling prophecy. Using a blinded approach, we analyzed the value of quantitative automated pupillometry to predict neurological recovery after CA. We examined a prospective cohort of 103 comatose adult patients who were unconscious 48 hours after CA and underwent repeated measurements of quantitative pupillary light reflex (PLR) using the Neurolight-Algiscan device. Clinical examination, electroencephalography (EEG), somatosensory evoked potentials (SSEP), and serum neuron-specific enolase were performed in parallel, as part of standard multimodal assessment. Automated pupillometry results were blinded to clinicians involved in patient care. Cerebral Performance Categories (CPC) at 1 year was the outcome endpoint. Survivors (n = 50 patients; 32 CPC 1, 16 CPC 2, 2 CPC 3) had higher quantitative PLR (median = 20 [range = 13-41] vs 11 [0-55] %, p < 0.0001) and constriction velocity (1.46 [0.85-4.63] vs 0.94 [0.16-4.97] mm/s, p < 0.0001) than nonsurvivors. At 48 hours, a quantitative PLR < 13% had 100% specificity and positive predictive value to predict poor recovery (0% false-positive rate), and provided equal performance to that of EEG and SSEP. Reduced quantitative PLR correlated with higher serum neuron-specific enolase (Spearman r = -0.52, p < 0.0001). Reduced quantitative PLR correlates with postanoxic brain injury and, when compared to standard multimodal assessment, is highly accurate in predicting long-term prognosis after CA. This is the first prognostication study to show the value of automated pupillometry using a blinded approach to minimize self-fulfilling prophecy. Ann Neurol 2017;81:804-810. © 2017 American Neurological Association.

Predicting epidermal growth factor receptor gene amplification status in glioblastoma multiforme by quantitative enhancement and necrosis features deriving from conventional magnetic resonance imaging.

PubMed

Dong, Fei; Zeng, Qiang; Jiang, Biao; Yu, Xinfeng; Wang, Weiwei; Xu, Jingjing; Yu, Jinna; Li, Qian; Zhang, Minming

2018-05-01

To study whether some of the quantitative enhancement and necrosis features in preoperative conventional MRI (cMRI) had a predictive value for epidermal growth factor receptor (EGFR) gene amplification status in glioblastoma multiforme (GBM).Fifty-five patients with pathologically determined GBMs who underwent cMRI were retrospectively reviewed. The following cMRI features were quantitatively measured and recorded: long and short diameters of the enhanced portion (LDE and SDE), maximum and minimum thickness of the enhanced portion (MaxTE and MinTE), and long and short diameters of the necrotic portion (LDN and SDN). Univariate analysis of each feature and a decision tree model fed with all the features were performed. Area under the receiver operating characteristic (ROC) curve (AUC) was used to assess the performance of features, and predictive accuracy was used to assess the performance of the model.For single feature, MinTE showed the best performance in differentiating EGFR gene amplification negative (wild-type) (nEGFR) GBM from EGFR gene amplification positive (pEGFR) GBM, and it got an AUC of 0.68 with a cut-off value of 2.6 mm. The decision tree model included 2 features MinTE and SDN, and got an accuracy of 0.83 in validation dataset.Our results suggest that quantitative measurement of the features MinTE and SDN in preoperative cMRI had a high accuracy for predicting EGFR gene amplification status in GBM.

Evaluation of Aution Max AX-4030 and 9UB Uriflet, 10PA Aution Sticks urine dipsticks in the automated urine test strip analysis.

PubMed

Rota, Cristina; Biondi, Marco; Trenti, Tommaso

2011-09-26

Aution Max AX-4030, a test strip analyzer recently introduced to the market, represents an upgrade of the Aution Max AX-4280 widely employed for urinalysis. This new instrument model can allocate two different test strips at the same time. In the present study the two instruments have been compared together with the usage of Uriflet 9UB and the recently produced Aution Sticks 10PA urine strips, the latter presenting an additional test area for the measurement of urinary creatinine. Imprecision and correlation between instruments and strips have been evaluated for chemical-physical parameters. Accuracy was evaluated for protein, glucose and creatinine by comparing the semi-quantitative results to those obtained by quantitative methods. The well-known interference effect of high ascorbic acid levels on urine glucose test strip determination was evaluated, ascorbic acid influence was also evaluated on protein and creatinine determination. The two instruments have demonstrated comparable performances: precision and correlation between instruments and strips, evaluated for chemical-physical parameters, were always good. Furthermore, accuracy was always very good: results of protein and glucose semi-quantitative measurements resulted to be highly correlated with those obtained by quantitative methods. Moreover, the semi-quantitative measurements of creatinine, employing Aution Sticks 10PA urine strips, were highly comparable with quantitative results. 10PA urine strips are eligible for urine creatinine determination with the possibility of correcting urinalysis results for urinary creatinine concentration, whenever necessary and calculating the protein creatinine ratio. Further studies should be carried out to evaluate effectiveness and appropriateness of the usage of creatinine semi-quantitative analysis.

The Effects of a Consumer Chemistry Intervention on Urban At-Risk High School Students' Performance, Utility Value, and Intentions to Pursue STEM

ERIC Educational Resources Information Center

Duffin, Lisa C.; Starling, Michael P.; Day, Martha M.; Cribbs, Jennifer D.

2016-01-01

The main purpose of this quantitative study was to examine the degree to which a three-week intervention in an urban high-needs high school science classroom would influence students' (n = 51) interest, utility value, content knowledge, and intentions for future study in chemistry. The intervention consisted of an authentic, inquiry-based…

Optimized slice-selective 1H NMR experiments combined with highly accurate quantitative 13C NMR using an internal reference method

NASA Astrophysics Data System (ADS)

Jézéquel, Tangi; Silvestre, Virginie; Dinis, Katy; Giraudeau, Patrick; Akoka, Serge

2018-04-01

Isotope ratio monitoring by 13C NMR spectrometry (irm-13C NMR) provides the complete 13C intramolecular position-specific composition at natural abundance. It represents a powerful tool to track the (bio)chemical pathway which has led to the synthesis of targeted molecules, since it allows Position-specific Isotope Analysis (PSIA). Due to the very small composition range (which represents the range of variation of the isotopic composition of a given nuclei) of 13C natural abundance values (50‰), irm-13C NMR requires a 1‰ accuracy and thus highly quantitative analysis by 13C NMR. Until now, the conventional strategy to determine the position-specific abundance xi relies on the combination of irm-MS (isotopic ratio monitoring Mass Spectrometry) and 13C quantitative NMR. However this approach presents a serious drawback since it relies on two different techniques and requires to measure separately the signal of all the carbons of the analyzed compound, which is not always possible. To circumvent this constraint, we recently proposed a new methodology to perform 13C isotopic analysis using an internal reference method and relying on NMR only. The method combines a highly quantitative 1H NMR pulse sequence (named DWET) with a 13C isotopic NMR measurement. However, the recently published DWET sequence is unsuited for samples with short T1, which forms a serious limitation for irm-13C NMR experiments where a relaxing agent is added. In this context, we suggest two variants of the DWET called Multi-WET and Profiled-WET, developed and optimized to reach the same accuracy of 1‰ with a better immunity towards T1 variations. Their performance is evaluated on the determination of the 13C isotopic profile of vanillin. Both pulse sequences show a 1‰ accuracy with an increased robustness to pulse miscalibrations compared to the initial DWET method. This constitutes a major advance in the context of irm-13C NMR since it is now possible to perform isotopic analysis with high relaxing agent concentrations, leading to a strong reduction of the overall experiment time.

MR-ARFI-based method for the quantitative measurement of tissue elasticity: application for monitoring HIFU therapy

NASA Astrophysics Data System (ADS)

Vappou, Jonathan; Bour, Pierre; Marquet, Fabrice; Ozenne, Valery; Quesson, Bruno

2018-05-01

Monitoring thermal therapies through medical imaging is essential in order to ensure that they are safe, efficient and reliable. In this paper, we propose a new approach, halfway between MR acoustic radiation force imaging (MR-ARFI) and MR elastography (MRE), allowing for the quantitative measurement of the elastic modulus of tissue in a highly localized manner. It relies on the simulation of the MR-ARFI profile, which depends on tissue biomechanical properties, and on the identification of tissue elasticity through the fitting of experimental displacement images measured using rapid MR-ARFI. This method was specifically developed to monitor MR-guided high intensity focused ultrasound (MRgHIFU) therapy. Elasticity changes were followed during HIFU ablations (N  =  6) performed ex vivo in porcine muscle samples, and were compared to temperature changes measured by MR-thermometry. Shear modulus was found to increase consistently and steadily a few seconds after the heating started, and such changes were found to be irreversible. The shear modulus was found to increase from 1.49  ±  0.48 kPa (before ablation) to 3.69  ±  0.93 kPa (after ablation and cooling). Thanks to its ability to perform quantitative elasticity measurements in a highly localized manner around the focal spot, this method proved to be particularly attractive for monitoring HIFU ablations.

Time-Resolved Fluorescent Immunochromatography of Aflatoxin B1 in Soybean Sauce: A Rapid and Sensitive Quantitative Analysis.

PubMed

Wang, Du; Zhang, Zhaowei; Li, Peiwu; Zhang, Qi; Zhang, Wen

2016-07-14

Rapid and quantitative sensing of aflatoxin B1 with high sensitivity and specificity has drawn increased attention of studies investigating soybean sauce. A sensitive and rapid quantitative immunochromatographic sensing method was developed for the detection of aflatoxin B1 based on time-resolved fluorescence. It combines the advantages of time-resolved fluorescent sensing and immunochromatography. The dynamic range of a competitive and portable immunoassay was 0.3-10.0 µg·kg(-1), with a limit of detection (LOD) of 0.1 µg·kg(-1) and recoveries of 87.2%-114.3%, within 10 min. The results showed good correlation (R² > 0.99) between time-resolved fluorescent immunochromatographic strip test and high performance liquid chromatography (HPLC). Soybean sauce samples analyzed using time-resolved fluorescent immunochromatographic strip test revealed that 64.2% of samples contained aflatoxin B1 at levels ranging from 0.31 to 12.5 µg·kg(-1). The strip test is a rapid, sensitive, quantitative, and cost-effective on-site screening technique in food safety analysis.

Quantitative and Sensitive Detection of Chloramphenicol by Surface-Enhanced Raman Scattering

PubMed Central

Ding, Yufeng; Yin, Hongjun; Meng, Qingyun; Zhao, Yongmei; Liu, Luo; Wu, Zhenglong; Xu, Haijun

2017-01-01

We used surface-enhanced Raman scattering (SERS) for the quantitative and sensitive detection of chloramphenicol (CAP). Using 30 nm colloidal Au nanoparticles (NPs), a low detection limit for CAP of 10−8 M was obtained. The characteristic Raman peak of CAP centered at 1344 cm−1 was used for the rapid quantitative detection of CAP in three different types of CAP eye drops, and the accuracy of the measurement result was verified by high-performance liquid chromatography (HPLC). The experimental results reveal that the SERS technique based on colloidal Au NPs is accurate and sensitive, and can be used for the rapid detection of various antibiotics. PMID:29261161

Method performance and multi-laboratory assessment of a normal phase high pressure liquid chromatography-fluorescence detection method for the quantitation of flavanols and procyanidins in cocoa and chocolate containing samples.

PubMed

Robbins, Rebecca J; Leonczak, Jadwiga; Johnson, J Christopher; Li, Julia; Kwik-Uribe, Catherine; Prior, Ronald L; Gu, Liwei

2009-06-12

The quantitative parameters and method performance for a normal-phase HPLC separation of flavanols and procyanidins in chocolate and cocoa-containing food products were optimized and assessed. Single laboratory method performance was examined over three months using three separate secondary standards. RSD(r) ranged from 1.9%, 4.5% to 9.0% for cocoa powder, liquor and chocolate samples containing 74.39, 15.47 and 1.87 mg/g flavanols and procyanidins, respectively. Accuracy was determined by comparison to the NIST Standard Reference Material 2384. Inter-lab assessment indicated that variability was quite low for seven different cocoa-containing samples, with a RSD(R) of less than 10% for the range of samples analyzed.

An importance-performance analysis of hospital information system attributes: A nurses' perspective.

PubMed

Cohen, Jason F; Coleman, Emma; Kangethe, Matheri J

2016-02-01

Health workers have numerous concerns about hospital IS (HIS) usage. Addressing these concerns requires understanding the system attributes most important to their satisfaction and productivity. Following a recent HIS implementation, our objective was to identify priorities for managerial intervention based on user evaluations of the performance of the HIS attributes as well as the relative importance of these attributes to user satisfaction and productivity outcomes. We collected data along a set of attributes representing system quality, data quality, information quality, and service quality from 154 nurse users. Their quantitative responses were analysed using the partial least squares approach followed by an importance-performance analysis. Qualitative responses were analysed using thematic analysis to triangulate and supplement the quantitative findings. Two system quality attributes (responsiveness and ease of learning), one information quality attribute (detail), one service quality attribute (sufficient support), and three data quality attributes (records complete, accurate and never missing) were identified as high priorities for intervention. Our application of importance-performance analysis is unique in HIS evaluation and we have illustrated its utility for identifying those system attributes for which underperformance is not acceptable to users and therefore should be high priorities for intervention. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A Comparative Study of Academic Achievement and Participation in a High School Freshman Academy

ERIC Educational Resources Information Center

Seng, Mark Patrick

2014-01-01

The transition to high school can be problematic for many ninth graders. Researchers and administrators have sought ways to improve academic performance and promotion rates while reducing dropout rates. A quantitative causal-comparative (ex post facto) and correlation study using a two-group design compared two freshman classes at separate…

Characterization of Vocal Fold Vibration in Sulcus Vocalis Using High-Speed Digital Imaging

ERIC Educational Resources Information Center

Yamauchi, Akihito; Yokonishi, Hisayuki; Imagawa, Hiroshi; Sakakibara, Ken-Ichi; Nito, Takaharu; Tayama, Niro; Yamasoba, Tatsuya

2017-01-01

Purpose: The aim of the present study was to qualitatively and quantitatively characterize vocal fold vibrations in sulcus vocalis by high-speed digital imaging (HSDI) and to clarify the correlations between HSDI-derived parameters and traditional vocal parameters. Method: HSDI was performed in 20 vocally healthy subjects (8 men and 12 women) and…

Quantitative separation of tetralin hydroperoxide from its decomposition products by high performance liquid chromatography

NASA Technical Reports Server (NTRS)

Worstell, J. H.; Daniel, S. R.

1981-01-01

A method for the separation and analysis of tetralin hydroperoxide and its decomposition products by high pressure liquid chromatography has been developed. Elution with a single, mixed solvent from a micron-Porasil column was employed. Constant response factors (internal standard method) over large concentration ranges and reproducible retention parameters are reported.

Frontally eluted components procedure with thin layer chromatography as a mode of sample preparation for high performance liquid chromatography quantitation of acetaminophen in biological matrix.

PubMed

Klimek-Turek, A; Sikora, M; Rybicki, M; Dzido, T H

2016-03-04

A new concept of using thin-layer chromatography to sample preparation for the quantitative determination of solute/s followed by instrumental techniques is presented Thin-layer chromatography (TLC) is used to completely separate acetaminophen and its internal standard from other components (matrix) and to form a single spot/zone containing them at the solvent front position (after the final stage of the thin-layer chromatogram development). The location of the analytes and internal standard in the solvent front zone allows their easy extraction followed by quantitation by HPLC. The exctraction procedure of the solute/s and internal standard can proceed from whole solute frontal zone or its part without lowering in accuracy of quantitative analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Chromatographic and Spectrophotometric Analysis of Phenolic Compounds from Fruits of Libidibia ferrea Martius

PubMed Central

Ferreira, Magda R. A.; Fernandes, Mônica T. M.; da Silva, Wliana A. V.; Bezerra, Isabelle C. F.; de Souza, Tatiane P.; Pimentel, Maria F.; Soares, Luiz A. L.

2016-01-01

Background: Libidibia ferrea (Mart. ex Tul.) L.P. Queiroz (Fabaceae) is a tree which is native to Brazil, widely known as “Jucá,” where its herbal derivatives are used in folk medicine with several therapeutic properties. The constituents, which have already been described in the fruit, are mainly hydrolysable tannins (gallic acid [GA] and ellagic acid [EA]). Objective: The aim of this study was to investigate the phenolic variability in the fruit of L. ferrea by ultraviolet/visible (UV/VIS) and chromatographic methods (high-performance liquid chromatography [HPLC]/high-performance thin layer chromatography [HPTLC]). Materials and Methods: Several samples were collected from different regions of Brazil and the qualitative (fingerprints by HPTLC and HPLC) and quantitative analysis (UV/VIS and HPLC) of polyphenols were performed. Results: The HPTLC and HPLC profiles allowed separation and identification of both major analytical markers: EA and GA. The chemical profiles were similar in a number of spots or peaks for the samples, but some differences could be observed in the intensity or area of the analytical markers for HPTLC or HPLC, respectively. Regarding the quantitative analysis, the polyphenolic content by UV/VIS ranged from 13.99 to 37.86 g% expressed as GA or from 10.75 to 29.09 g% expressed as EA. The contents of EA and GA by liquid chromatography-reversed phase (LC-RP) method ranged from 0.57 to 2.68 g% and from 0.54 to 3.23 g%, respectively. Conclusion: The chemical profiles obtained by HPTLC or HPLC, as well as the quantitative analysis by spectrophotometry or LC-RP method, were suitable for discrimination of each herbal sample and can be used as tools for the comparative analysis of the fruits from L. ferrea. SUMMARY The polyphenols of fruits of Libidibia ferrea can be quantified by UV/VIS and HPLCThe HPLC method was able to detect the gallic and ellagic acids in several samples of fruits of Libidibia ferreaThe phenolic profiles of fruits from Libidibia ferrea by HPTLC and HPLC were reproductible. Abbreviations used: HPTLC: high performance thin layer chromatography, HPLC: high performance liquid chromatography, UV-Vis: spectrophotometry PMID:27279721

Diamond X-ray Photodiode for White and Monochromatic SR beams

PubMed Central

Keister, Jeffrey W.; Smedley, John; Muller, Erik M.; Bohon, Jen; Héroux, Annie

2011-01-01

High purity, single crystal CVD diamond plates are screened for quality and instrumented into a sensor assembly for quantitative characterization of flux and position sensitivity. Initial investigations have yielded encouraging results and have led to further development. Several limiting complications are observed and discussed, as well as mitigations thereof. For example, diamond quality requirements for x-ray diodes include low nitrogen impurity and crystallographic defectivity. Thin electrode windows and electronic readout performance are ultimately also critical to device performance. Promising features observed so far from prototype devices include calculable responsivity, flux linearity, position sensitivity and timing performance. Recent results from testing in high flux and high speed applications are described. PMID:21822344

iMet-Q: A User-Friendly Tool for Label-Free Metabolomics Quantitation Using Dynamic Peak-Width Determination

PubMed Central

Chang, Hui-Yin; Chen, Ching-Tai; Lih, T. Mamie; Lynn, Ke-Shiuan; Juo, Chiun-Gung; Hsu, Wen-Lian; Sung, Ting-Yi

2016-01-01

Efficient and accurate quantitation of metabolites from LC-MS data has become an important topic. Here we present an automated tool, called iMet-Q (intelligent Metabolomic Quantitation), for label-free metabolomics quantitation from high-throughput MS1 data. By performing peak detection and peak alignment, iMet-Q provides a summary of quantitation results and reports ion abundance at both replicate level and sample level. Furthermore, it gives the charge states and isotope ratios of detected metabolite peaks to facilitate metabolite identification. An in-house standard mixture and a public Arabidopsis metabolome data set were analyzed by iMet-Q. Three public quantitation tools, including XCMS, MetAlign, and MZmine 2, were used for performance comparison. From the mixture data set, seven standard metabolites were detected by the four quantitation tools, for which iMet-Q had a smaller quantitation error of 12% in both profile and centroid data sets. Our tool also correctly determined the charge states of seven standard metabolites. By searching the mass values for those standard metabolites against Human Metabolome Database, we obtained a total of 183 metabolite candidates. With the isotope ratios calculated by iMet-Q, 49% (89 out of 183) metabolite candidates were filtered out. From the public Arabidopsis data set reported with two internal standards and 167 elucidated metabolites, iMet-Q detected all of the peaks corresponding to the internal standards and 167 metabolites. Meanwhile, our tool had small abundance variation (≤0.19) when quantifying the two internal standards and had higher abundance correlation (≥0.92) when quantifying the 167 metabolites. iMet-Q provides user-friendly interfaces and is publicly available for download at http://ms.iis.sinica.edu.tw/comics/Software_iMet-Q.html. PMID:26784691

Determination of Aspartame, Caffeine, Saccharin, and Benzoic Acid in Beverages by High Performance Liquid Chromatography.

ERIC Educational Resources Information Center

Delaney, Michael F.; And Others

1985-01-01

Describes a simple and reliable new quantitative analysis experiment using liquid chromatography for the determinaiton of caffeine, saccharin, and sodium benzoate in beverages. Background information, procedures used, and typical results obtained are provided. (JN)

A clustering approach to segmenting users of internet-based risk calculators.

PubMed

Harle, C A; Downs, J S; Padman, R

2011-01-01

Risk calculators are widely available Internet applications that deliver quantitative health risk estimates to consumers. Although these tools are known to have varying effects on risk perceptions, little is known about who will be more likely to accept objective risk estimates. To identify clusters of online health consumers that help explain variation in individual improvement in risk perceptions from web-based quantitative disease risk information. A secondary analysis was performed on data collected in a field experiment that measured people's pre-diabetes risk perceptions before and after visiting a realistic health promotion website that provided quantitative risk information. K-means clustering was performed on numerous candidate variable sets, and the different segmentations were evaluated based on between-cluster variation in risk perception improvement. Variation in responses to risk information was best explained by clustering on pre-intervention absolute pre-diabetes risk perceptions and an objective estimate of personal risk. Members of a high-risk overestimater cluster showed large improvements in their risk perceptions, but clusters of both moderate-risk and high-risk underestimaters were much more muted in improving their optimistically biased perceptions. Cluster analysis provided a unique approach for segmenting health consumers and predicting their acceptance of quantitative disease risk information. These clusters suggest that health consumers were very responsive to good news, but tended not to incorporate bad news into their self-perceptions much. These findings help to quantify variation among online health consumers and may inform the targeted marketing of and improvements to risk communication tools on the Internet.

Qualitative and quantitative analysis of the diuretic component ergone in Polyporus umbellatus by HPLC with fluorescence detection and HPLC-APCI-MS/MS.

PubMed

Zhao, Ying-Yong; Zhao, Ye; Zhang, Yong-Min; Lin, Rui-Chao; Sun, Wen-Ji

2009-06-01

Polyporus umbellatus is a widely used anti-aldosteronic diuretic in Traditional Chinese medicine (TCM). A new, sensitive and selective high-performance liquid chromatography-fluorescence detector (HPLC-FLD) and high-performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS/MS) method for quantitative and qualitative determination of ergosta-4,6,8(14),22-tetraen-3-one(ergone), which is the main diuretic component, was provided for quality control of P. umbellatus crude drug. The ergone in the ethanolic extract of P. umbellatus was unambiguously characterized by HPLC-APCI, and further confirmed by comparing with a standard compound. The trace ergone was detected by the sensitive and selective HPLC-FLD. Linearity (r2 > 0.9998) and recoveries of low, medium and high concentration (100.5%, 100.2% and 100.4%) were consistent with the experimental criteria. The limit of detection (LOD) of ergone was around 0.2 microg/mL. Our results indicated that the content of ergone in P. umbellatus varied significantly from habitat to habitat with contents ranging from 2.13 +/- 0.02 to 59.17 +/- 0.05 microg/g. Comparison among HPLC-FLD and HPLC-UV or HPLC-APCI-MS/MS demonstrated that the HPLC-FLD and HPLC-APCI-MS/MS methods gave similar quantitative results for the selected herb samples, the HPLC-UV methods gave lower quantitative results than HPLC-FLD and HPLC-APCI-MS/MS methods. The established new HPLC-FLD method has the advantages of being rapid, simple, selective and sensitive, and could be used for the routine analysis of P. umbellatus crude drug.

A comparative study of quantitative immunohistochemistry and quantum dot immunohistochemistry for mutation carrier identification in Lynch syndrome.

PubMed

Barrow, Emma; Evans, D Gareth; McMahon, Ray; Hill, James; Byers, Richard

2011-03-01

Lynch Syndrome is caused by mutations in DNA mismatch repair (MMR) genes. Mutation carrier identification is facilitated by immunohistochemical detection of the MMR proteins MHL1 and MSH2 in tumour tissue and is desirable as colonoscopic screening reduces mortality. However, protein detection by conventional immunohistochemistry (IHC) is subjective, and quantitative techniques are required. Quantum dots (QDs) are novel fluorescent labels that enable quantitative multiplex staining. This study compared their use with quantitative 3,3'-diaminobenzidine (DAB) IHC for the diagnosis of Lynch Syndrome. Tumour sections from 36 mutation carriers and six controls were obtained. These were stained with DAB on an automated platform using antibodies against MLH1 and MSH2. Multiplex QD immunofluorescent staining of the sections was performed using antibodies against MLH1, MSH2 and smooth muscle actin (SMA). Multispectral analysis of the slides was performed. The staining intensity of DAB and QDs was measured in multiple colonic crypts, and the mean intensity scores calculated. Receiver operating characteristic (ROC) curves of staining performance for the identification of mutation carriers were evaluated. For quantitative DAB IHC, the area under the MLH1 ROC curve was 0.872 (95% CI 0.763 to 0.981), and the area under the MSH2 ROC curve was 0.832 (95% CI 0.704 to 0.960). For quantitative QD IHC, the area under the MLH1 ROC curve was 0.812 (95% CI 0.681 to 0.943), and the area under the MSH2 ROC curve was 0.598 (95% CI 0.418 to 0.777). Despite the advantage of QD staining to enable several markers to be measured simultaneously, it is of lower utility than DAB IHC for the identification of MMR mutation carriers. Automated DAB IHC staining and quantitative slide analysis may enable high-throughput IHC.

Isotonic Regression Based-Method in Quantitative High-Throughput Screenings for Genotoxicity

PubMed Central

Fujii, Yosuke; Narita, Takeo; Tice, Raymond Richard; Takeda, Shunich

2015-01-01

Quantitative high-throughput screenings (qHTSs) for genotoxicity are conducted as part of comprehensive toxicology screening projects. The most widely used method is to compare the dose-response data of a wild-type and DNA repair gene knockout mutants, using model-fitting to the Hill equation (HE). However, this method performs poorly when the observed viability does not fit the equation well, as frequently happens in qHTS. More capable methods must be developed for qHTS where large data variations are unavoidable. In this study, we applied an isotonic regression (IR) method and compared its performance with HE under multiple data conditions. When dose-response data were suitable to draw HE curves with upper and lower asymptotes and experimental random errors were small, HE was better than IR, but when random errors were big, there was no difference between HE and IR. However, when the drawn curves did not have two asymptotes, IR showed better performance (p < 0.05, exact paired Wilcoxon test) with higher specificity (65% in HE vs. 96% in IR). In summary, IR performed similarly to HE when dose-response data were optimal, whereas IR clearly performed better in suboptimal conditions. These findings indicate that IR would be useful in qHTS for comparing dose-response data. PMID:26673567

Quantitative Determination of Bioactive Constituents in Noni Juice by High-performance Liquid Chromatography with Electrospray Ionization Triple Quadrupole Mass Spectrometry.

PubMed

Yan, Yongqiu; Lu, Yu; Jiang, Shiping; Jiang, Yu; Tong, Yingpeng; Zuo, Limin; Yang, Jun; Gong, Feng; Zhang, Ling; Wang, Ping

2018-01-01

Noni juice has been extensively used as folk medicine for the treatment of arthritis, infections, analgesic, colds, cancers, and diabetes by Polynesians for many years. Due to the lack of standard scientific evaluation methods, various kinds of commercial Noni juice with different quality and price were available on the market. To establish a sensitive, reliable, and accurate high-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometry (HPLC-ESI-MS/MS) method for separation, identification, and simultaneous quantitative analysis of bioactive constituents in Noni juice. The analytes and eight batches of commercially available samples from different origins were separated and analyzed by the HPLC-ESI-MS/MS method on an Agilent ZORBAX SB-C 18 (150 mm × 4.6 mm i.d., 5 μm) column using a gradient elution of acetonitrile-methanol-0.05% glacial acetic acid in water (v/v) at a constant flow rate of 0.5 mL/min. Seven components were identification and all of the assay parameters were within the required limits. Components were within the correlation coefficient values ( R 2 ≥ 0.9993) at the concentration ranges tested. The precision of the assay method was <0.91% and the repeatability between 1.36% and 3.31%. The accuracy varied from 96.40% to 103.02% and the relative standard deviations of stability were <3.91%. Samples from the same origin showed similar content while different origins showed significant different result. The developed methods would provide a reliable basis and be useful in the establishment of a rational quality control standard of Noni juice. Separation, identification, and simultaneous quantitative analysis method of seven bioactive constituents in Noni juice is originally developed by high-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometryThe presented method was successfully applied to the quality control of eight batches of commercially available samples of Noni juiceThis method is simple, sensitive, reliable, accurate, and efficient method with strong specificity, good precision, and high recovery rate and provides a reliable basis for quality control of Noni juice. Abbreviations used: HPLC-ESI-MS/MS: High-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometry, LOD: Limit of detection, LOQ: Limit of quantitation, S/N: Signal-to-noise ratio, RSD: Relative standard deviations, DP: Declustering potential, CE: Collision energy, MRM: Multiple reaction monitoring, RT: Retention time.

Quantitative Determination of Bioactive Constituents in Noni Juice by High-performance Liquid Chromatography with Electrospray Ionization Triple Quadrupole Mass Spectrometry

PubMed Central

Yan, Yongqiu; Lu, Yu; Jiang, Shiping; Jiang, Yu; Tong, Yingpeng; Zuo, Limin; Yang, Jun; Gong, Feng; Zhang, Ling; Wang, Ping

2018-01-01

Background: Noni juice has been extensively used as folk medicine for the treatment of arthritis, infections, analgesic, colds, cancers, and diabetes by Polynesians for many years. Due to the lack of standard scientific evaluation methods, various kinds of commercial Noni juice with different quality and price were available on the market. Objective: To establish a sensitive, reliable, and accurate high-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometry (HPLC-ESI-MS/MS) method for separation, identification, and simultaneous quantitative analysis of bioactive constituents in Noni juice. Materials and Methods: The analytes and eight batches of commercially available samples from different origins were separated and analyzed by the HPLC-ESI-MS/MS method on an Agilent ZORBAX SB-C18 (150 mm × 4.6 mm i.d., 5 μm) column using a gradient elution of acetonitrile-methanol-0.05% glacial acetic acid in water (v/v) at a constant flow rate of 0.5 mL/min. Results: Seven components were identification and all of the assay parameters were within the required limits. Components were within the correlation coefficient values (R2 ≥ 0.9993) at the concentration ranges tested. The precision of the assay method was <0.91% and the repeatability between 1.36% and 3.31%. The accuracy varied from 96.40% to 103.02% and the relative standard deviations of stability were <3.91%. Samples from the same origin showed similar content while different origins showed significant different result. Conclusions: The developed methods would provide a reliable basis and be useful in the establishment of a rational quality control standard of Noni juice. SUMMARY Separation, identification, and simultaneous quantitative analysis method of seven bioactive constituents in Noni juice is originally developed by high-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometryThe presented method was successfully applied to the quality control of eight batches of commercially available samples of Noni juiceThis method is simple, sensitive, reliable, accurate, and efficient method with strong specificity, good precision, and high recovery rate and provides a reliable basis for quality control of Noni juice. Abbreviations used: HPLC-ESI-MS/MS: High-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometry, LOD: Limit of detection, LOQ: Limit of quantitation, S/N: Signal-to-noise ratio, RSD: Relative standard deviations, DP: Declustering potential, CE: Collision energy, MRM: Multiple reaction monitoring, RT: Retention time. PMID:29576704

Evaluation of Effective Factors on the Clinical Performance of General Surgeons in Tehran University of Medical Science, 2015.

PubMed

Farzianpour, Fereshteh; Mohamadi, Efat; Najafpour, Zhila; Yousefinezhadi, Taraneh; Forootan, Sara; Foroushani, Abbas Rahimi

2016-09-01

Existence of doctors with high performance is one of the necessary conditions to provide high quality services. There are different motivations, which could affect their performance. Recognizing Factors which effect the performance of doctors as an effective force in health care centers is necessary. The aim of this article was evaluate the effective factors which influence on clinical performance of general surgery of Tehran University of Medical Sciences in 2015. This is a cross-sectional qualitative-quantitative study. This research conducted in 3 phases-phases I: (use of library studies and databases to collect data), phase II: localization of detected factors in first phase by using the Delphi technique and phase III: prioritizing the affecting factors on performance of doctors by using qualitative interviews. 12 articles were analyzed from 300 abstracts during the evaluation process. The output of assessment identified 23 factors was sent to surgeons and their assistants for obtaining their opinions. Quantitative analysis of the findings showed that "work qualification" (86.1%) and "managers and supervisors style" (50%) have respectively the most and the least impact on the performance of doctors. Finally 18 effective factors were identified and prioritized in the performance of general surgeons. The results showed that motivation and performance is not a single operating parameter and it depends on several factors according to cultural background. Therefore it is necessary to design, implementation and monitoring based on key determinants of effective interventions due to cultural background.

High resolution quantitative phase imaging of live cells with constrained optimization approach

NASA Astrophysics Data System (ADS)

Pandiyan, Vimal Prabhu; Khare, Kedar; John, Renu

2016-03-01

Quantitative phase imaging (QPI) aims at studying weakly scattering and absorbing biological specimens with subwavelength accuracy without any external staining mechanisms. Use of a reference beam at an angle is one of the necessary criteria for recording of high resolution holograms in most of the interferometric methods used for quantitative phase imaging. The spatial separation of the dc and twin images is decided by the reference beam angle and Fourier-filtered reconstructed image will have a very poor resolution if hologram is recorded below a minimum reference angle condition. However, it is always inconvenient to have a large reference beam angle while performing high resolution microscopy of live cells and biological specimens with nanometric features. In this paper, we treat reconstruction of digital holographic microscopy images as a constrained optimization problem with smoothness constraint in order to recover only complex object field in hologram plane even with overlapping dc and twin image terms. We solve this optimization problem by gradient descent approach iteratively and the smoothness constraint is implemented by spatial averaging with appropriate size. This approach will give excellent high resolution image recovery compared to Fourier filtering while keeping a very small reference angle. We demonstrate this approach on digital holographic microscopy of live cells by recovering the quantitative phase of live cells from a hologram recorded with nearly zero reference angle.

High-Throughput Quantitative Lipidomics Analysis of Nonesterified Fatty Acids in Plasma by LC-MS.

PubMed

Christinat, Nicolas; Morin-Rivron, Delphine; Masoodi, Mojgan

2017-01-01

Nonesterified fatty acids are important biological molecules which have multiple functions such as energy storage, gene regulation, or cell signaling. Comprehensive profiling of nonesterified fatty acids in biofluids can facilitate studying and understanding their roles in biological systems. For these reasons, we have developed and validated a high-throughput, nontargeted lipidomics method coupling liquid chromatography to high-resolution mass spectrometry for quantitative analysis of nonesterified fatty acids. Sufficient chromatographic separation is achieved to separate positional isomers such as polyunsaturated and branched-chain species and quantify a wide range of nonesterified fatty acids in human plasma samples. However, this method is not limited only to these fatty acid species and offers the possibility to perform untargeted screening of additional nonesterified fatty acid species.

High Performance Liquid Chromatography-Diode Array Detector Method for the Simultaneous Determination of Five Compounds in the Pulp and Seed of Sea Buckthorn.

PubMed

Zhao, Lu; Wen, E; Upur, Halmuart; Tian, Shuge

2017-01-01

Sea buckthorn ( Hippophae rhamnoides L.) as a traditional Chinese medicinal plant has various uses in Xinjiang. A reversed-phase rapid-resolution liquid-chromatography method with diode array detector was developed for simultaneous determination of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the pulp and seed of sea buckthorn, a widely used traditional Chinese medicine for promoting metabolism and treating scurvy and other diseases. Compounds were separated on an Agilent ZORBAX SB-C18 column (4.6 mm × 250 mm, 5 μm; USA) with gradient elution using methanol and 0.4% phosphoric acid (v/v) at 1.0 mL/min. Detection wavelength was set at 280 nm. The fruits of wild sea buckthorn were collected from Wushi County in Aksu, Xinjiang Province. The RSD of precision test of the five compounds were in the range of 0.60-2.22%, and the average recoveries ranged from 97.36% to 101.19%. Good linearity between specific chromatographic peak and component qualities were observed in the investigated ranges for all the analytes ( R 2 > 0.9997). The proposed method was successfully applied to determine the levels of five active components in sea buckthorn samples from Aksu in Xinjiang. The proposed method is simple, fast, sensitive, accurate, and suitable for quantitative assessment of the pulp and seed of sea buckthorn. Quantitative analysis method of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the extract of sea buckthorn pulp and seed is developed by high-performance liquid chromatography (HPLC) diode array detection.This method is simple and accurate; has strong specificity, good precision, and high recovery rate; and provides a reliable basis for further development of the substances in the pulp and seed of sea buckthorn.The method is widely used for content determination of active ingredients or physiologically active components in traditional Chinese medicine and its preparation Abbreviation used: PR: protocatechuic acid, RU: rutin, QU: quercetin, KA: kaempferol, IS: isorhamnetin, HPLC: high-performance liquid chromatography, HPLC-DAD: high performance liquid chromatographydiode array detector, LOD: linearity and limit of detection, LOQ: limit of quantitation, RSD: relative standard deviation.

Effects of normalization on quantitative traits in association test

PubMed Central

2009-01-01

Background Quantitative trait loci analysis assumes that the trait is normally distributed. In reality, this is often not observed and one strategy is to transform the trait. However, it is not clear how much normality is required and which transformation works best in association studies. Results We performed simulations on four types of common quantitative traits to evaluate the effects of normalization using the logarithm, Box-Cox, and rank-based transformations. The impact of sample size and genetic effects on normalization is also investigated. Our results show that rank-based transformation gives generally the best and consistent performance in identifying the causal polymorphism and ranking it highly in association tests, with a slight increase in false positive rate. Conclusion For small sample size or genetic effects, the improvement in sensitivity for rank transformation outweighs the slight increase in false positive rate. However, for large sample size and genetic effects, normalization may not be necessary since the increase in sensitivity is relatively modest. PMID:20003414

Quantitative Comparison of Tumor Delivery for Multiple Targeted Nanoparticles Simultaneously by Multiplex ICP-MS

PubMed Central

Elias, Andrew; Crayton, Samuel H.; Warden-Rothman, Robert; Tsourkas, Andrew

2014-01-01

Given the rapidly expanding library of disease biomarkers and targeting agents, the number of unique targeted nanoparticles is growing exponentially. The high variability and expense of animal testing often makes it unfeasible to examine this large number of nanoparticles in vivo. This often leads to the investigation of a single formulation that performed best in vitro. However, nanoparticle performance in vivo depends on many variables, many of which cannot be adequately assessed with cell-based assays. To address this issue, we developed a lanthanide-doped nanoparticle method that allows quantitative comparison of multiple targeted nanoparticles simultaneously. Specifically, superparamagnetic iron oxide (SPIO) nanoparticles with different targeting ligands were created, each with a unique lanthanide dopant. Following the simultaneous injection of the various SPIO compositions into tumor-bearing mice, inductively coupled plasma mass spectroscopy was used to quantitatively and orthogonally assess the concentration of each SPIO composition in serial blood and resected tumor samples. PMID:25068300

Development of quantitative laser ionization mass spectrometry (LIMS). Final report, 1 Aug 87-1 Jan 90

DOE Office of Scientific and Technical Information (OSTI.GOV)

Odom, R.W.

1991-06-04

The objective of the research was to develop quantitative microanalysis methods for dielectric thin films using the laser ionization mass spectrometry (LIMS) technique. The research involved preparation of thin (5,000 A) films of SiO2, Al2O3, MgF2, TiO2, Cr2O3, Ta2O5, Si3N4, and ZrO2, and doping these films with ion implant impurities of 11B, 40Ca, 56Fe, 68Zn, 81Br, and 121Sb. Laser ionization mass spectrometry (LIMS), secondary ion mass spectrometry (SIMS) and Rutherford backscattering spectrometry (RBS) were performed on these films. The research demonstrated quantitative LIMS analysis down to detection levels of 10-100 ppm, and led to the development of (1) a compoundmore » thin film standards product line for the performing organization, (2) routine LIMS analytical methods, and (3) the manufacture of high speed preamplifiers for time-of-flight mass spectrometry (TOF-MS) techniques.« less

Qualitative pattern classification of shear wave elastography for breast masses: how it correlates to quantitative measurements.

PubMed

Yoon, Jung Hyun; Ko, Kyung Hee; Jung, Hae Kyoung; Lee, Jong Tae

2013-12-01

To determine the correlation of qualitative shear wave elastography (SWE) pattern classification to quantitative SWE measurements and whether it is representative of quantitative SWE values with similar performances. From October 2012 to January 2013, 267 breast masses of 236 women (mean age: 45.12 ± 10.54 years, range: 21-88 years) who had undergone ultrasonography (US), SWE, and subsequent biopsy were included. US BI-RADS final assessment and qualitative and quantitative SWE measurements were recorded. Correlation between pattern classification and mean elasticity, maximum elasticity, elasticity ratio and standard deviation were evaluated. Diagnostic performances of grayscale US, SWE parameters, and US combined to SWE values were calculated and compared. Of the 267 breast masses, 208 (77.9%) were benign and 59 (22.1%) were malignant. Pattern classifications significantly correlated with all quantitative SWE measurements, showing highest correlation with maximum elasticity, r = 0.721 (P<0.001). Sensitivity was significantly decreased in US combined to SWE measurements to grayscale US: 69.5-89.8% to 100.0%, while specificity was significantly improved: 62.5-81.7% to 13.9% (P<0.001). Area under the ROC curve (Az) did not show significant differences between grayscale US to US combined to SWE (P>0.05). Pattern classification shows high correlation to maximum stiffness and may be representative of quantitative SWE values. When combined to grayscale US, SWE improves specificity of US. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Quantitative determination of a chemically modified hammerhead ribozyme in blood plasma using 96-well solid-phase extraction coupled with high-performance liquid chromatography or capillary gel electrophoresis.

PubMed

Bellon, L; Maloney, L; Zinnen, S P; Sandberg, J A; Johnson, K E

2000-08-01

Versatile bioanalytical assays to detect chemically stabilized hammerhead ribozyme and putative ribozyme metabolites from plasma are described. The extraction protocols presented are based on serial solid-phase extractions performed on a 96-well plate format and are compatible with either IEX-HPLC or CGE back-end analysis. A validation of both assays confirmed that both the HPLC and the CGE methods possess the required linearity, accuracy, and precision to accurately measure concentrations of hammerhead ribozyme extracted from plasma. These methods should be of general use to detect and quantitate ribozymes from other biological fluids such as serum and urine. Copyright 2000 Academic Press.

Clinical Rating of Movement-Pattern Quality in Patients With Femoroacetabular Impingement Syndrome: A Methodological Study.

PubMed

Casartelli, Nicola C; Maffiuletti, Nicola A; Brunner, Romana; Büchi, Marcel; Sutter, Reto; Pfirrmann, Christian W; Naal, Florian D; Leunig, Michael; Bizzini, Mario

2018-04-01

Study Design Cross-sectional study. Objectives To evaluate intrarater and interrater agreement among physical therapists with different clinical experience in performing a visual rating of movement-pattern quality of patients with femoroacetabular impingement (FAI) syndrome using a semi-quantitative scale. Background Visual rating of movement patterns in patients with FAI syndrome is of interest, because poor control of dynamic hip motion is frequently noted. Methods A video camera was used to record the performance of 34 patients with FAI syndrome performing single-limb standing, squat, frontal lunge, hop lunge, bridge, and plank. Visual rating of movement, as recorded on video, was performed by a highly experienced, a moderately experienced, and a novice physical therapist on 2 occasions using a semi-quantitative scale. Hip abductor strength was assessed using dynamometry, and hip pain and function were assessed with a patient-reported questionnaire. Intrarater and interrater agreement among physical therapists was evaluated using Gwet's agreement coefficient 1. Construct validity was evaluated as the association between physical therapists' rating and patients' hip abductor strength, pain, and function. Results Good intrarater and interrater agreement was observed in the highly experienced and moderately experienced physical therapists when rating single-limb standing, bridge, and plank. Poor to moderate intrarater and interrater agreement was found when they rated squat, frontal lunge, and hop lunge. Poor performers, as rated by the highly experienced physical therapist only, demonstrated lower hip abductor strength (P<.05), and similar hip pain and hip function compared to those of good performers. Conclusion Movement-pattern quality of patients with FAI syndrome should be rated by a highly experienced physical therapist. J Orthop Sports Phys Ther 2018;48(4):260-269. doi:10.2519/jospt.2018.7840.

Qualitative and quantitative analysis of hyaluronan oligosaccharides with high performance thin layer chromatography using reagent-free derivatization on amino-modified silica and electrospray ionization-quadrupole time-of-flight mass spectrometry coupling on normal phase.

PubMed

Rothenhöfer, Martin; Scherübl, Rosmarie; Bernhardt, Günther; Heilmann, Jörg; Buschauer, Armin

2012-07-27

Purified oligomers of hyalobiuronic acid are indispensable tools to elucidate the physiological and pathophysiological role of hyaluronan degradation by various hyaluronidase isoenzymes. Therefore, we established and validated a novel sensitive, convenient, rapid, and cost-effective high performance thin layer chromatography (HPTLC) method for the qualitative and quantitative analysis of small saturated hyaluronan oligosaccharides consisting of 2-4 hyalobiuronic acid moieties. The use of amino-modified silica as stationary phase allows a simple reagent-free in situ derivatization by heating, resulting in a very low limit of detection (7-19 pmol per band, depending on the analyzed saturated oligosaccharide). By this derivatization procedure for the first time densitometric quantification of the analytes could be performed by HPTLC. The validated method showed a quantification limit of 37-71 pmol per band and was proven to be superior in comparison to conventional detection of hyaluronan oligosaccharides. The analytes were identified by hyphenation of normal phase planar chromatography to mass spectrometry (TLC-MS) using electrospray ionization. As an alternative to sequential techniques such as high performance liquid chromatography (HPLC) and capillary electrophoresis (CE), the validated HPTLC quantification method can easily be automated and is applicable to the analysis of multiple samples in parallel. Copyright © 2012 Elsevier B.V. All rights reserved.

Characterization of shape and deformation of MEMS by quantitative optoelectronic metrology techniques

NASA Astrophysics Data System (ADS)

Furlong, Cosme; Pryputniewicz, Ryszard J.

2002-06-01

Recent technological trends based on miniaturization of mechanical, electro-mechanical, and photonic devices to the microscopic scale, have led to the development of microelectromechanical systems (MEMS). Effective development of MEMS components requires the synergism of advanced design, analysis, and fabrication methodologies, and also of quantitative metrology techniques for characterizing their performance, reliability, and integrity during the electronic packaging cycle. In this paper, we describe opto-electronic techniques for measuring, with sub-micrometer accuracy, shape and changes in states of deformation of MEMS strictures. With the described opto-electronic techniques, it is possible to characterize MEMS components using the display and data modes. In the display mode, interferometric information related to shape and deformation is displayed at video frame rates, providing the capability for adjusting and setting experimental conditions. In the data mode, interferometric information related to shape and deformation is recorded as high-spatial and high-digital resolution images, which are further processed to provide quantitative 3D information. Furthermore, the quantitative 3D data are exported to computer-aided design (CAD) environments and utilized for analysis and optimization of MEMS devices. Capabilities of opto- electronic techniques are illustrated with representative applications demonstrating their applicability to provide indispensable quantitative information for the effective development and optimization of MEMS devices.

Quantitative Determination of Levonorgestrel in Fish Plasma using UPLC-MS/MS

EPA Science Inventory

In this study, a sensitive high-performance liquid chromatography electrospray tandem mass spectrometric method was developed for the determination of levonorgestrel in fish plasma using levonorgestrel-d6 as an internal standard (IS). In the laboratory, the fish cunner, (Tautogol...

Single-Cell Based Quantitative Assay of Chromosome Transmission Fidelity

PubMed Central

Zhu, Jin; Heinecke, Dominic; Mulla, Wahid A.; Bradford, William D.; Rubinstein, Boris; Box, Andrew; Haug, Jeffrey S.; Li, Rong

2015-01-01

Errors in mitosis are a primary cause of chromosome instability (CIN), generating aneuploid progeny cells. Whereas a variety of factors can influence CIN, under most conditions mitotic errors are rare events that have been difficult to measure accurately. Here we report a green fluorescent protein−based quantitative chromosome transmission fidelity (qCTF) assay in budding yeast that allows sensitive and quantitative detection of CIN and can be easily adapted to high-throughput analysis. Using the qCTF assay, we performed genome-wide quantitative profiling of genes that affect CIN in a dosage-dependent manner and identified genes that elevate CIN when either increased (icCIN) or decreased in copy number (dcCIN). Unexpectedly, qCTF screening also revealed genes whose change in copy number quantitatively suppress CIN, suggesting that the basal error rate of the wild-type genome is not minimized, but rather, may have evolved toward an optimal level that balances both stability and low-level karyotype variation for evolutionary adaptation. PMID:25823586

Single-Cell Based Quantitative Assay of Chromosome Transmission Fidelity.

PubMed

Zhu, Jin; Heinecke, Dominic; Mulla, Wahid A; Bradford, William D; Rubinstein, Boris; Box, Andrew; Haug, Jeffrey S; Li, Rong

2015-03-30

Errors in mitosis are a primary cause of chromosome instability (CIN), generating aneuploid progeny cells. Whereas a variety of factors can influence CIN, under most conditions mitotic errors are rare events that have been difficult to measure accurately. Here we report a green fluorescent protein-based quantitative chromosome transmission fidelity (qCTF) assay in budding yeast that allows sensitive and quantitative detection of CIN and can be easily adapted to high-throughput analysis. Using the qCTF assay, we performed genome-wide quantitative profiling of genes that affect CIN in a dosage-dependent manner and identified genes that elevate CIN when either increased (icCIN) or decreased in copy number (dcCIN). Unexpectedly, qCTF screening also revealed genes whose change in copy number quantitatively suppress CIN, suggesting that the basal error rate of the wild-type genome is not minimized, but rather, may have evolved toward an optimal level that balances both stability and low-level karyotype variation for evolutionary adaptation. Copyright © 2015 Zhu et al.

Comparison of the COBAS TAQMAN HIV-1 HPS with VERSANT HIV-1 RNA 3.0 assay (bDNA) for plasma RNA quantitation in different HIV-1 subtypes.

PubMed

Gomes, Perpétua; Palma, Ana Carolina; Cabanas, Joaquim; Abecasis, Ana; Carvalho, Ana Patrícia; Ziermann, Rainer; Diogo, Isabel; Gonçalves, Fátima; Lobo, Céu Sousa; Camacho, Ricardo

2006-08-01

Quantitation of HIV-1 RNA levels in plasma has an undisputed prognostic value and is extremely important for evaluating response to antiretroviral therapy. The purpose of this study was to evaluate the performance of the real-time PCR COBAS TaqMan 48 analyser, comparing it to the existing VERSANT 3.0 (bDNA) for HIV-1 RNA quantitation in plasma of individuals infected with different HIV-1 subtypes (104 blood samples). A positive linear correlation between the two tests (r2 = 0.88) was found. Quantitation by the COBAS TaqMan assay was approximately 0.32log10 higher than by bDNA. The relationship between the two assays was similar within all subtypes with a Deming regression of <1 and <0 for the Bland-Altman plots. Overall, no significant differences were found in plasma viral load quantitation in different HIV-1 subtypes between both assays; therefore these assays are suitable for viral load quantitation of highly genetically diverse HIV-1 plasma samples.

A simple approach to quantitative analysis using three-dimensional spectra based on selected Zernike moments.

PubMed

Zhai, Hong Lin; Zhai, Yue Yuan; Li, Pei Zhen; Tian, Yue Li

2013-01-21

A very simple approach to quantitative analysis is proposed based on the technology of digital image processing using three-dimensional (3D) spectra obtained by high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). As the region-based shape features of a grayscale image, Zernike moments with inherently invariance property were employed to establish the linear quantitative models. This approach was applied to the quantitative analysis of three compounds in mixed samples using 3D HPLC-DAD spectra, and three linear models were obtained, respectively. The correlation coefficients (R(2)) for training and test sets were more than 0.999, and the statistical parameters and strict validation supported the reliability of established models. The analytical results suggest that the Zernike moment selected by stepwise regression can be used in the quantitative analysis of target compounds. Our study provides a new idea for quantitative analysis using 3D spectra, which can be extended to the analysis of other 3D spectra obtained by different methods or instruments.

Breast cancer Ki67 expression preoperative discrimination by DCE-MRI radiomics features

NASA Astrophysics Data System (ADS)

Ma, Wenjuan; Ji, Yu; Qin, Zhuanping; Guo, Xinpeng; Jian, Xiqi; Liu, Peifang

2018-02-01

To investigate whether quantitative radiomics features extracted from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are associated with Ki67 expression of breast cancer. In this institutional review board approved retrospective study, we collected 377 cases Chinese women who were diagnosed with invasive breast cancer in 2015. This cohort included 53 low-Ki67 expression (Ki67 proliferation index less than 14%) and 324 cases with high-Ki67 expression (Ki67 proliferation index more than 14%). A binary-classification of low- vs. high- Ki67 expression was performed. A set of 52 quantitative radiomics features, including morphological, gray scale statistic, and texture features, were extracted from the segmented lesion area. Three most common machine learning classification methods, including Naive Bayes, k-Nearest Neighbor and support vector machine with Gaussian kernel, were employed for the classification and the least absolute shrink age and selection operator (LASSO) method was used to select most predictive features set for the classifiers. Classification performance was evaluated by the area under receiver operating characteristic curve (AUC), accuracy, sensitivity and specificity. The model that used Naive Bayes classification method achieved the best performance than the other two methods, yielding 0.773 AUC value, 0.757 accuracy, 0.777 sensitivity and 0.769 specificity. Our study showed that quantitative radiomics imaging features of breast tumor extracted from DCE-MRI are associated with breast cancer Ki67 expression. Future larger studies are needed in order to further evaluate the findings.

Use of the MagNA Pure LC Automated Nucleic Acid Extraction System followed by Real-Time Reverse Transcription-PCR for Ultrasensitive Quantitation of Hepatitis C Virus RNA

PubMed Central

Cook, Linda; Ng, Ka-Wing; Bagabag, Arthur; Corey, Lawrence; Jerome, Keith R.

2004-01-01

Hepatitis C virus (HCV) infection is an increasing health problem worldwide. Quantitative assays for HCV viral load are valuable in predicting response to therapy and for following treatment efficacy. Unfortunately, most quantitative tests for HCV RNA are limited by poor sensitivity. We have developed a convenient, highly sensitive real-time reverse transcription-PCR assay for HCV RNA. The assay amplifies a portion of the 5′ untranslated region of HCV, which is then quantitated using the TaqMan 7700 detection system. Extraction of viral RNA for our assay is fully automated with the MagNA Pure LC extraction system (Roche). Our assay has a 100% detection rate for samples containing 50 IU of HCV RNA/ml and is linear up to viral loads of at least 109 IU/ml. The assay detects genotypes 1a, 2a, and 3a with equal efficiency. Quantitative results by our assay correlate well with HCV viral load as determined by the Bayer VERSANT HCV RNA 3.0 bDNA assay. In clinical use, our assay is highly reproducible, with high and low control specimens showing a coefficient of variation for the logarithmic result of 2.8 and 7.0%, respectively. The combination of reproducibility, extreme sensitivity, and ease of performance makes this assay an attractive option for routine HCV viral load testing. PMID:15365000

A quantitative swab is a good non-invasive alternative to a quantitative biopsy for quantifying bacterial load in wounds healing by second intention in horses.

PubMed

Van Hecke, L L; Hermans, K; Haspeslagh, M; Chiers, K; Pint, E; Boyen, F; Martens, A M

2017-07-01

The aim of this study was to evaluate different techniques for diagnosing wound infection in wounds healing by second intention in horses and to assess the effect of a vortex and sonication protocol on quantitative bacteriology in specimens with a histologically confirmed biofilm. In 50 wounds healing by second intention, a clinical assessment, a quantitative swab, a semi-quantitative swab, and a swab for cytology were compared to a quantitative tissue biopsy (reference standard). Part of the biopsy specimen was examined histologically for evidence of a biofilm. There was a significant, high correlation (P<0.001; r=0.747) between the outcome of the quantitative swabs and the quantitative biopsies. The semi-quantitative swabs showed a significant, moderate correlation with the quantitative biopsies (P<0.001; ρ=0.524). Higher white blood cell counts for cytology were significantly associated with lower log 10 colony-forming units (CFU) in the wounds (P=0.02). Wounds with black granulation tissue showed significantly higher log 10 CFU (P=0.003). Specimens with biofilms did not yield higher bacteriological counts after a vortex and sonication protocol was performed to release bacteria from the biofilm. Based on these findings, a quantitative swab is an acceptable non-invasive alternative to a quantitative biopsy for quantifying bacterial load in equine wounds healing by second intention. Copyright © 2017 Elsevier Ltd. All rights reserved.

School Factors Related to Reading Achievement in Rural Schools with and without High Poverty

ERIC Educational Resources Information Center

Miller, Seth W.

2013-01-01

This quantitative study identified how rural schools differ on five school-level factors related to student achievement according to their performance on Grade 3 reading. Through use of a MANOVA test, it was shown that principals of high-poverty rural schools that made AYP in Grade 3 reading reported significantly higher levels of guaranteed and…

Neurobiological findings associated with high cognitive performance in older adults: a systematic review.

PubMed

Borelli, Wyllians Vendramini; Schilling, Lucas Porcello; Radaelli, Graciane; Ferreira, Luciana Borges; Pisani, Leonardo; Portuguez, Mirna Wetters; da Costa, Jaderson Costa

2018-04-18

ABSTRACTObjectives:to perform a comprehensive literature review of studies on older adults with exceptional cognitive performance. We performed a systematic review using two major databases (MEDLINE and Web of Science) from January 2002 to November 2017. Quantitative analysis included nine of 4,457 studies and revealed that high-performing older adults have global preservation of the cortex, especially the anterior cingulate region, and hippocampal volumes larger than normal agers. Histological analysis of this group also exhibited decreased amyloid burden and neurofibrillary tangles compared to cognitively normal older controls. High performers that maintained memory ability after three years showed reduced amyloid positron emission tomography at baseline compared with high performers that declined. A single study on blood plasma found a set of 12 metabolites predicting memory maintenance of this group. Structural and molecular brain preservation of older adults with high cognitive performance may be associated with brain maintenance. The operationalized definition of high-performing older adults must be carefully addressed using appropriate age cut-off and cognitive evaluation, including memory and non-memory tests. Further studies with a longitudinal approach that include a younger control group are essential.

A reversed-phase high-performance liquid chromatography method for bovine serum albumin assay in pharmaceutical dosage forms and protein/antigen delivery systems.

PubMed

Hamidi, Mehrdad; Zarei, Najmeh

2009-05-01

Bovine serum albumin (BSA) is among the most widely used proteins in protein formulations as well as in the development of novel delivery systems as a typical model for therapeutic/diagnostic proteins and the new versions of vaccines. The development of reliable and easily available assay methods for quantitation of this protein would therefore play a crucial role in these types of studies. A simple gradient reversed-phase high-performance liquid chromatography with ultra-violet detection (HPLC-UV) method has been developed for quantitation of BSA in dosage forms and protein delivery systems. The method produced linear responses throughout the wide BSA concentration range of 1 to 100 micro g/mL. The average within-run and between-run variations of the method within the linear concentration range of BSA were 2.46% and 2.20%, respectively, with accuracies of 104.49% and 104.58% for within-run and between-run samples, respectively. The limits of detection (LOD) and quantitation (LOQ) of the method were 0.5 and 1 microg/mL, respectively. The method showed acceptable system suitability indices, which enabled us to use it successfully during our particulate vaccine delivery research project. Copyright 2009 John Wiley & Sons, Ltd.

Constellation Ground Systems Launch Availability Analysis: Enhancing Highly Reliable Launch Systems Design

NASA Technical Reports Server (NTRS)

Gernand, Jeffrey L.; Gillespie, Amanda M.; Monaghan, Mark W.; Cummings, Nicholas H.

2010-01-01

Success of the Constellation Program's lunar architecture requires successfully launching two vehicles, Ares I/Orion and Ares V/Altair, in a very limited time period. The reliability and maintainability of flight vehicles and ground systems must deliver a high probability of successfully launching the second vehicle in order to avoid wasting the on-orbit asset launched by the first vehicle. The Ground Operations Project determined which ground subsystems had the potential to affect the probability of the second launch and allocated quantitative availability requirements to these subsystems. The Ground Operations Project also developed a methodology to estimate subsystem reliability, availability and maintainability to ensure that ground subsystems complied with allocated launch availability and maintainability requirements. The verification analysis developed quantitative estimates of subsystem availability based on design documentation; testing results, and other information. Where appropriate, actual performance history was used for legacy subsystems or comparative components that will support Constellation. The results of the verification analysis will be used to verify compliance with requirements and to highlight design or performance shortcomings for further decision-making. This case study will discuss the subsystem requirements allocation process, describe the ground systems methodology for completing quantitative reliability, availability and maintainability analysis, and present findings and observation based on analysis leading to the Ground Systems Preliminary Design Review milestone.

Simultaneous determination of eight major steroids from Polyporus umbellatus by high-performance liquid chromatography coupled with mass spectrometry detections.

PubMed

Zhao, Ying-yong; Cheng, Xian-long; Zhang, Yongmin; Zhao, Ye; Lin, Rui-chao; Sun, Wen-ji

2010-02-01

Polyporus umbellatus is a widely used diuretic herbal medicine. In this study, a high-performance liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometric detection (HPLC-APCI-MS) method was developed for qualitative and quantitative analysis of steroids, as well as for the quality control of Polyporus umbellatus. The selectivity, reproducibility and sensitivity were compared with HPLC with photodiode array detection and evaporative light scattering detection (ELSD). Selective ion monitoring in positive mode was used for qualitative and quantitative analysis of eight major components and beta-ecdysterone was used as the internal standard. Limits of detection and quantification fell in the ranges 7-21 and 18-63 ng/mL for the eight analytes with an injection of 10 microL samples, and all calibration curves showed good linear regression (r(2) > 0.9919) within the test range. The quantitative results demonstrated that samples from different localities showed different qualities. Advantages, in comparison with conventional HPLC-diode array detection and HPLC-ELSD, are that reliable identification of target compounds could be achieved by accurate mass measurements along with characteristic retention time, and the great enhancement in selectivity and sensitivity allows identification and quantification of low levels of constituents in complex Polyporus umbellatus matrixes. (c) 2009 John Wiley & Sons, Ltd.

Identification and Quantitation of Asparagine and Citrulline Using High-Performance Liquid Chromatography (HPLC)

PubMed Central

Bai, Cheng; Reilly, Charles C.; Wood, Bruce W.

2007-01-01

High-performance liquid chromatography (HPLC) analysis was used for identification of two problematic ureides, asparagine and citrulline. We report here a technique that takes advantage of the predictable delay in retention time of the co-asparagine/citrulline peak to enable both qualitative and quantitative analysis of asparagine and citrulline using the Platinum EPS reverse-phase C18 column (Alltech Associates). Asparagine alone is eluted earlier than citrulline alone, but when both of them are present in biological samples they may co-elute. HPLC retention times for asparagine and citrulline were influenced by other ureides in the mixture. We found that at various asparagines and citrulline ratios [= 3:1, 1:1, and 1:3; corresponding to 75:25, 50:50, and 25:75 (μMol ml−1/μMol ml−1)], the resulting peak exhibited different retention times. Adjustment of ureide ratios as internal standards enables peak identification and quantification. Both chemicals were quantified in xylem sap samples of pecan [Carya illinoinensis (Wangenh.) K. Koch] trees. Analysis revealed that tree nickel nutrition status affects relative concentrations of Urea Cycle intermediates, asparagine and citrulline, present in sap. Consequently, we concluded that the HPLC methods are presented to enable qualitative and quantitative analysis of these metabolically important ureides. PMID:19662174

Identification and quantitation of asparagine and citrulline using high-performance liquid chromatography (HPLC).

PubMed

Bai, Cheng; Reilly, Charles C; Wood, Bruce W

2007-03-28

High-performance liquid chromatography (HPLC) analysis was used for identification of two problematic ureides, asparagine and citrulline. We report here a technique that takes advantage of the predictable delay in retention time of the co-asparagine/citrulline peak to enable both qualitative and quantitative analysis of asparagine and citrulline using the Platinum EPS reverse-phase C18 column (Alltech Associates). Asparagine alone is eluted earlier than citrulline alone, but when both of them are present in biological samples they may co-elute. HPLC retention times for asparagine and citrulline were influenced by other ureides in the mixture. We found that at various asparagines and citrulline ratios [= 3:1, 1:1, and 1:3; corresponding to 75:25, 50:50, and 25:75 (microMol ml(-1)/microMol ml(-1))], the resulting peak exhibited different retention times. Adjustment of ureide ratios as internal standards enables peak identification and quantification. Both chemicals were quantified in xylem sap samples of pecan [Carya illinoinensis (Wangenh.) K. Koch] trees. Analysis revealed that tree nickel nutrition status affects relative concentrations of Urea Cycle intermediates, asparagine and citrulline, present in sap. Consequently, we concluded that the HPLC methods are presented to enable qualitative and quantitative analysis of these metabolically important ureides.

Estrogens in seminal plasma of human and animal species: identification and quantitative estimation by gas chromatography-mass spectrometry associated with stable isotope dilution.

PubMed

Reiffsteck, A; Dehennin, L; Scholler, R

1982-11-01

Estrone, 2-methoxyestrone and estradiol-17 beta have been definitely identified in seminal plasma of man, bull, boar and stallion by high resolution gas chromatography associated with selective monitoring of characteristic ions of suitable derivatives. Quantitative estimations were performed by isotope dilution with deuterated analogues and by monitoring molecular ions of trimethylsilyl ethers of labelled and unlabelled compounds. Concentrations of unconjugated and total estrogens are reported together with the statistical evaluation of accuracy and precision.

Quantitative determination and validation of octreotide acetate using 1 H-NMR spectroscopy with internal standard method.

PubMed

Yu, Chen; Zhang, Qian; Xu, Peng-Yao; Bai, Yin; Shen, Wen-Bin; Di, Bin; Su, Meng-Xiang

2018-01-01

Quantitative nuclear magnetic resonance (qNMR) is a well-established technique in quantitative analysis. We presented a validated 1 H-qNMR method for assay of octreotide acetate, a kind of cyclic octopeptide. Deuterium oxide was used to remove the undesired exchangeable peaks, which was referred to as proton exchange, in order to make the quantitative signals isolated in the crowded spectrum of the peptide and ensure precise quantitative analysis. Gemcitabine hydrochloride was chosen as the suitable internal standard. Experimental conditions, including relaxation delay time, the numbers of scans, and pulse angle, were optimized first. Then method validation was carried out in terms of selectivity, stability, linearity, precision, and robustness. The assay result was compared with that by means of high performance liquid chromatography, which is provided by Chinese Pharmacopoeia. The statistical F test, Student's t test, and nonparametric test at 95% confidence level indicate that there was no significant difference between these two methods. qNMR is a simple and accurate quantitative tool with no need for specific corresponding reference standards. It has the potential of the quantitative analysis of other peptide drugs and standardization of the corresponding reference standards. Copyright © 2017 John Wiley & Sons, Ltd.

Simultaneous quantification of eight organic acid components in Artemisia capillaris Thunb (Yinchen) extract using high-performance liquid chromatography coupled with diode array detection and high-resolution mass spectrometry.

PubMed

Yu, Fangjun; Qian, Hao; Zhang, Jiayu; Sun, Jie; Ma, Zhiguo

2018-04-01

We aim to determine the chemical constituents of Yinchen extract and Yinchen herbs using high-performance liquid chromatography coupled with diode array detection and high-resolution mass spectrometry. The method was developed to analyze of eight organic acid components of Yinchen extract (including neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, caffeic acid, 1,3-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid). The separation was conducted using an Agilent TC-C18 column with acetonitrile - 0.2% formic acid solution as the mobile phases under gradient elution. The analytical method was fully validated in terms of linearity, sensitivity, precision, repeatability as well as recovery, and subsequently the method was performed for the quantitative assessment of Yinchen extracts and Yinchen herbs. In addition, the changes of selected markers were studied when Yinchen herbs decocting in water and isomerization occurred between the chlorogenic acids. The proposed method enables both qualitative and quantitative analyses and could be developed as a new tool for the quality evaluation of Yinchen extract and Yinchen herbs. The changes of selected markers in water decoction process could give us some novel idea when studying the link between substances and drug efficacy. Copyright © 2017. Published by Elsevier B.V.

High Performance Liquid Chromatography-Diode Array Detector Method for the Simultaneous Determination of Five Compounds in the Pulp and Seed of Sea Buckthorn

PubMed Central

Zhao, Lu; Wen, E; Upur, Halmuart; Tian, Shuge

2017-01-01

Context: Sea buckthorn (Hippophae rhamnoides L.) as a traditional Chinese medicinal plant has various uses in Xinjiang. Objective: A reversed-phase rapid-resolution liquid-chromatography method with diode array detector was developed for simultaneous determination of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the pulp and seed of sea buckthorn, a widely used traditional Chinese medicine for promoting metabolism and treating scurvy and other diseases. Settings and design: Compounds were separated on an Agilent ZORBAX SB-C18 column (4.6 mm × 250 mm, 5 μm; USA) with gradient elution using methanol and 0.4% phosphoric acid (v/v) at 1.0 mL/min. Detection wavelength was set at 280 nm. Materials and Methods: The fruits of wild sea buckthorn were collected from Wushi County in Aksu, Xinjiang Province. Statistical performances: The RSD of precision test of the five compounds were in the range of 0.60-2.22%, and the average recoveries ranged from 97.36% to 101.19%. Good linearity between specific chromatographic peak and component qualities were observed in the investigated ranges for all the analytes (R2 > 0.9997). Results: The proposed method was successfully applied to determine the levels of five active components in sea buckthorn samples from Aksu in Xinjiang. Conclusions: The proposed method is simple, fast, sensitive, accurate, and suitable for quantitative assessment of the pulp and seed of sea buckthorn. SUMMARY Quantitative analysis method of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the extract of sea buckthorn pulp and seed is developed by high-performance liquid chromatography (HPLC) diode array detection.This method is simple and accurate; has strong specificity, good precision, and high recovery rate; and provides a reliable basis for further development of the substances in the pulp and seed of sea buckthorn.The method is widely used for content determination of active ingredients or physiologically active components in traditional Chinese medicine and its preparation Abbreviation used: PR: protocatechuic acid, RU: rutin, QU: quercetin, KA: kaempferol, IS: isorhamnetin, HPLC: high-performance liquid chromatography, HPLC-DAD: high performance liquid chromatographydiode array detector, LOD: linearity and limit of detection, LOQ: limit of quantitation, RSD: relative standard deviation PMID:28216897

Chronic obstructive pulmonary disease: quantitative and visual ventilation pattern analysis at xenon ventilation CT performed by using a dual-energy technique.

PubMed

Park, Eun-Ah; Goo, Jin Mo; Park, Sang Joon; Lee, Hyun Ju; Lee, Chang Hyun; Park, Chang Min; Yoo, Chul-Gyu; Kim, Jong Hyo

2010-09-01

To evaluate the potential of xenon ventilation computed tomography (CT) in the quantitative and visual analysis of chronic obstructive pulmonary disease (COPD). This study was approved by the institutional review board. After informed consent was obtained, 32 patients with COPD underwent CT performed before the administration of xenon, two-phase xenon ventilation CT with wash-in (WI) and wash-out (WO) periods, and pulmonary function testing (PFT). For quantitative analysis, results of PFT were compared with attenuation parameters from prexenon images and xenon parameters from xenon-enhanced images in the following three areas at each phase: whole lung, lung with normal attenuation, and low-attenuating lung (LAL). For visual analysis, ventilation patterns were categorized according to the pattern of xenon attenuation in the area of structural abnormalities compared with that in the normal-looking background on a per-lobe basis: pattern A consisted of isoattenuation or high attenuation in the WI period and isoattenuation in the WO period; pattern B, isoattenuation or high attenuation in the WI period and high attenuation in the WO period; pattern C, low attenuation in both the WI and WO periods; and pattern D, low attenuation in the WI period and isoattenuation or high attenuation in the WO period. Among various attenuation and xenon parameters, xenon parameters of the LAL in the WO period showed the best inverse correlation with results of PFT (P < .0001). At visual analysis, while emphysema (which affected 99 lobes) commonly showed pattern A or B, airway diseases such as obstructive bronchiolitis (n = 5) and bronchiectasis (n = 2) and areas with a mucus plug (n = 1) or centrilobular nodules (n = 5) showed pattern D or C. WI and WO xenon ventilation CT is feasible for the simultaneous regional evaluation of structural and ventilation abnormalities both quantitatively and qualitatively in patients with COPD. (c) RSNA, 2010.

Major advances in testing of dairy products: milk component and dairy product attribute testing.

PubMed

Barbano, D M; Lynch, J M

2006-04-01

Milk component analysis is relatively unusual in the field of quantitative analytical chemistry because an analytical test result determines the allocation of very large amounts of money between buyers and sellers of milk. Therefore, there is high incentive to develop and refine these methods to achieve a level of analytical performance rarely demanded of most methods or laboratory staff working in analytical chemistry. In the last 25 yr, well-defined statistical methods to characterize and validate analytical method performance combined with significant improvements in both the chemical and instrumental methods have allowed achievement of improved analytical performance for payment testing. A shift from marketing commodity dairy products to the development, manufacture, and marketing of value added dairy foods for specific market segments has created a need for instrumental and sensory approaches and quantitative data to support product development and marketing. Bringing together sensory data from quantitative descriptive analysis and analytical data from gas chromatography olfactometry for identification of odor-active compounds in complex natural dairy foods has enabled the sensory scientist and analytical chemist to work together to improve the consistency and quality of dairy food flavors.

Quantitative performance characterization of three-dimensional noncontact fluorescence molecular tomography

NASA Astrophysics Data System (ADS)

Favicchio, Rosy; Psycharakis, Stylianos; Schönig, Kai; Bartsch, Dusan; Mamalaki, Clio; Papamatheakis, Joseph; Ripoll, Jorge; Zacharakis, Giannis

2016-02-01

Fluorescent proteins and dyes are routine tools for biological research to describe the behavior of genes, proteins, and cells, as well as more complex physiological dynamics such as vessel permeability and pharmacokinetics. The use of these probes in whole body in vivo imaging would allow extending the range and scope of current biomedical applications and would be of great interest. In order to comply with a wide variety of application demands, in vivo imaging platform requirements span from wide spectral coverage to precise quantification capabilities. Fluorescence molecular tomography (FMT) detects and reconstructs in three dimensions the distribution of a fluorophore in vivo. Noncontact FMT allows fast scanning of an excitation source and noninvasive measurement of emitted fluorescent light using a virtual array detector operating in free space. Here, a rigorous process is defined that fully characterizes the performance of a custom-built horizontal noncontact FMT setup. Dynamic range, sensitivity, and quantitative accuracy across the visible spectrum were evaluated using fluorophores with emissions between 520 and 660 nm. These results demonstrate that high-performance quantitative three-dimensional visible light FMT allowed the detection of challenging mesenteric lymph nodes in vivo and the comparison of spectrally distinct fluorescent reporters in cell culture.

Photon-counting-based diffraction phase microscopy combined with single-pixel imaging

NASA Astrophysics Data System (ADS)

Shibuya, Kyuki; Araki, Hiroyuki; Iwata, Tetsuo

2018-04-01

We propose a photon-counting (PC)-based quantitative-phase imaging (QPI) method for use in diffraction phase microscopy (DPM) that is combined with a single-pixel imaging (SPI) scheme (PC-SPI-DPM). This combination of DPM with the SPI scheme overcomes a low optical throughput problem that has occasionally prevented us from obtaining quantitative-phase images in DPM through use of a high-sensitivity single-channel photodetector such as a photomultiplier tube (PMT). The introduction of a PMT allowed us to perform PC with ease and thus solved a dynamic range problem that was inherent to SPI. As a proof-of-principle experiment, we performed a comparison study of analogue-based SPI-DPM and PC-SPI-DPM for a 125-nm-thick indium tin oxide (ITO) layer coated on a silica glass substrate. We discuss the basic performance of the method and potential future modifications of the proposed system.

A multi-method exploratory study of stress, coping, and substance use among high school youth in private schools

PubMed Central

Leonard, Noelle R.; Gwadz, Marya V.; Ritchie, Amanda; Linick, Jessica L.; Cleland, Charles M.; Elliott, Luther; Grethel, Michele

2015-01-01

There is growing awareness that students’ experiences of stress may impede academic success, compromise mental health, and promote substance use. We examined these factors in an under-studied population, private/independent high school students, using a multi-method (qualitative and quantitative), iterative data collection and analytic process. We first conducted qualitative interviews with faculty and staff at a number of highly competitive private schools, followed by an anonymous quantitative survey with 128 11th grade students from two of these settings. We then conducted a qualitative exploration of the quantitative results with a subset of students. Next, a set of Expert Panel members participated in qualitative interviews to reflect on and interpret study findings. Overall, we found students experienced high levels of chronic stress, particularly in relation to academic performance and the college admissions process. While students described a range of effective, adaptive coping strategies, they also commonly internalized these serious pressures and turned to alcohol and drugs to cope with chronic stress, although not typically at problematic levels. We discuss study implications for both schools and families derived from the Expert Panel. PMID:26257685

A multi-method exploratory study of stress, coping, and substance use among high school youth in private schools.

PubMed

Leonard, Noelle R; Gwadz, Marya V; Ritchie, Amanda; Linick, Jessica L; Cleland, Charles M; Elliott, Luther; Grethel, Michele

2015-01-01

There is growing awareness that students' experiences of stress may impede academic success, compromise mental health, and promote substance use. We examined these factors in an under-studied population, private/independent high school students, using a multi-method (qualitative and quantitative), iterative data collection and analytic process. We first conducted qualitative interviews with faculty and staff at a number of highly competitive private schools, followed by an anonymous quantitative survey with 128 11th grade students from two of these settings. We then conducted a qualitative exploration of the quantitative results with a subset of students. Next, a set of Expert Panel members participated in qualitative interviews to reflect on and interpret study findings. Overall, we found students experienced high levels of chronic stress, particularly in relation to academic performance and the college admissions process. While students described a range of effective, adaptive coping strategies, they also commonly internalized these serious pressures and turned to alcohol and drugs to cope with chronic stress, although not typically at problematic levels. We discuss study implications for both schools and families derived from the Expert Panel.

Targeted proteomics reveals strain-specific changes in the mouse insulin and central metabolic pathways after a sustained high-fat diet.

PubMed

Sabidó, Eduard; Wu, Yibo; Bautista, Lucia; Porstmann, Thomas; Chang, Ching-Yun; Vitek, Olga; Stoffel, Markus; Aebersold, Ruedi

2013-07-16

The metabolic syndrome is a collection of risk factors including obesity, insulin resistance and hepatic steatosis, which occur together and increase the risk of diseases such as diabetes, cardiovascular disease and cancer. In spite of intense research, the complex etiology of insulin resistance and its association with the accumulation of triacylglycerides in the liver and with hepatic steatosis remains not completely understood. Here, we performed quantitative measurements of 144 proteins involved in the insulin-signaling pathway and central metabolism in liver homogenates of two genetically well-defined mouse strains C57BL/6J and 129Sv that were subjected to a sustained high-fat diet. We used targeted mass spectrometry by selected reaction monitoring (SRM) to generate accurate and reproducible quantitation of the targeted proteins across 36 different samples (12 conditions and 3 biological replicates), generating one of the largest quantitative targeted proteomics data sets in mammalian tissues. Our results revealed rapid response to high-fat diet that diverged early in the feeding regimen, and evidenced a response to high-fat diet dominated by the activation of peroxisomal β-oxidation in C57BL/6J and by lipogenesis in 129Sv mice.

Quantitative Measurements of Nitric Oxide Concentration in High-Pressure, Swirl-Stabilized Spray Flames

NASA Technical Reports Server (NTRS)

Cooper, Clayton S.; Laurendeau, Normand M.; Hicks, Yolanda R. (Technical Monitor)

2000-01-01

Lean direct-injection (LDI) spray flames offer the possibility of reducing NO(sub x) emissions from gas turbines by rapid mixing of the liquid fuel and air so as to drive the flame structure toward partially-premixed conditions. We consider the technical approaches required to utilize laser-induced fluorescence methods for quantitatively measuring NO concentrations in high-pressure LDI spray flames. In the progression from atmospheric to high-pressure measurements, the LIF method requires a shift from the saturated to the linear regime of fluorescence measurements. As such, we discuss quantitative, spatially resolved laser-saturated fluorescence (LSF), linear laser-induced fluorescence (LIF), and planar laser-induced fluorescence (PLIF) measurements of NO concentration in LDI spray flames. Spatially-resolved LIF measurements of NO concentration (ppm) are reported for preheated, LDI spray flames at pressures of two to five atmospheres. The spray is produced by a hollow-cone, pressure-atomized nozzle supplied with liquid heptane. NO is excited via the Q(sub 2)(26.5) transition of the gamma(0,0) band. Detection is performed in a two nanometer region centered on the gamma(0,1) band. A complete scheme is developed by which quantitative NO concentrations in high-pressure LDI spray flames can be measured by applying linear LIF. NO is doped into the reactants and convected through the flame with no apparent destruction, thus allowing a NO fluorescence calibration to be taken inside the flame environment. The in-situ calibration scheme is validated by comparisons to a reference flame. Quantitative NO profiles are presented and analyzed so as to better understand the operation of lean-direct injectors for gas turbine combustors. Moreover, parametric studies are provided for variations in pressure, air-preheat temperature, and equivalence ratio. Similar parametric studies are performed for lean, premixed-prevaporized flames to permit comparisons to those for LDI flames. Finally, PLIF is expanded to high pressure in an effort to quantify the detected fluorescence image for LDI flames. Success is achieved by correcting the PLIF calibration via a single-point LIF measurement. This procedure removes the influence of any preferential background that occurs in the PLIF detection window. In general, both the LIF and PLIF measurements verify that the LDI strategy could be used to reduce NO(sub x) emissions in future gas turbine combustors.

Optimized protocol for quantitative multiple reaction monitoring-based proteomic analysis of formalin-fixed, paraffin embedded tissues

PubMed Central

Kennedy, Jacob J.; Whiteaker, Jeffrey R.; Schoenherr, Regine M.; Yan, Ping; Allison, Kimberly; Shipley, Melissa; Lerch, Melissa; Hoofnagle, Andrew N.; Baird, Geoffrey Stuart; Paulovich, Amanda G.

2016-01-01

Despite a clinical, economic, and regulatory imperative to develop companion diagnostics, precious few new biomarkers have been successfully translated into clinical use, due in part to inadequate protein assay technologies to support large-scale testing of hundreds of candidate biomarkers in formalin-fixed paraffin embedded (FFPE) tissues. While the feasibility of using targeted, multiple reaction monitoring-mass spectrometry (MRM-MS) for quantitative analyses of FFPE tissues has been demonstrated, protocols have not been systematically optimized for robust quantification across a large number of analytes, nor has the performance of peptide immuno-MRM been evaluated. To address this gap, we used a test battery approach coupled to MRM-MS with the addition of stable isotope labeled standard peptides (targeting 512 analytes) to quantitatively evaluate the performance of three extraction protocols in combination with three trypsin digestion protocols (i.e. 9 processes). A process based on RapiGest buffer extraction and urea-based digestion was identified to enable similar quantitation results from FFPE and frozen tissues. Using the optimized protocols for MRM-based analysis of FFPE tissues, median precision was 11.4% (across 249 analytes). There was excellent correlation between measurements made on matched FFPE and frozen tissues, both for direct MRM analysis (R2 = 0.94) and immuno-MRM (R2 = 0.89). The optimized process enables highly reproducible, multiplex, standardizable, quantitative MRM in archival tissue specimens. PMID:27462933

Reversed-phase high-performance liquid chromatography of sulfur mustard in water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raghuveeran, C.D.; Malhotra, R.C.; Dangi, R.S.

1993-01-01

A reversed-phase high-performance liquid chromatography method for the detection and quantitation of sulfur mustard (HD) in water is described with detection at 200 nm. The detection based on the solubility of HD in water revealed that extremely low quantities of HD (4 to 5 mg/L) only are soluble. Experience shows that water is still the medium of choice for the analysis of HD in water and aqueous effluents in spite of the minor handicap of its half-life of ca. 4 minutes, which only calls for speedy analysis.

Determination of nitroaromatic explosives and their degradation products in unsaturated-zone water samples by high-performance liquid chromatography with photodiode-array, mass spectrometric, and tandem mass spectrometric detection

USGS Publications Warehouse

Gates, Paul M.; Furlong, E.T.; Dorsey, T.F.; Burkhardt, M.R.

1996-01-01

Mass spectrometry and tandem mass spectrometry, coupled by a thermospray interface to a high-performance liguid chromatography system and equipped with a photodiode array detector, were used to determine the presence of nitroaromatic explosives and their degradation products in USA unsaturated-zone water samples. Using this approach, the lower limits of quantitation for explosives determined by mass spectrometry in this study typically ranged from 10 to 100 ng/l.

Detection of Free Polyamines in Plants Subjected to Abiotic Stresses by High-Performance Liquid Chromatography (HPLC).

PubMed

Gong, Xiaoqing; Liu, Ji-Hong

2017-01-01

High-performance liquid chromatography (HPLC) is a sensitive, rapid, and accurate technique to detect and characterize various metabolites from plants. The metabolites are extracted with different solvents and eluted with appropriate mobile phases in a designed HPLC program. Polyamines are known to accumulate under abiotic stress conditions in various plant species and thought to provide protection against oxidative stress by scavenging reactive oxygen species. Here, we describe a common method to detect the free polyamines in plant tissues both qualitatively and quantitatively.

TRIC: an automated alignment strategy for reproducible protein quantification in targeted proteomics

PubMed Central

Röst, Hannes L.; Liu, Yansheng; D’Agostino, Giuseppe; Zanella, Matteo; Navarro, Pedro; Rosenberger, George; Collins, Ben C.; Gillet, Ludovic; Testa, Giuseppe; Malmström, Lars; Aebersold, Ruedi

2016-01-01

Large scale, quantitative proteomic studies have become essential for the analysis of clinical cohorts, large perturbation experiments and systems biology studies. While next-generation mass spectrometric techniques such as SWATH-MS have substantially increased throughput and reproducibility, ensuring consistent quantification of thousands of peptide analytes across multiple LC-MS/MS runs remains a challenging and laborious manual process. To produce highly consistent and quantitatively accurate proteomics data matrices in an automated fashion, we have developed the TRIC software which utilizes fragment ion data to perform cross-run alignment, consistent peak-picking and quantification for high throughput targeted proteomics. TRIC uses a graph-based alignment strategy based on non-linear retention time correction to integrate peak elution information from all LC-MS/MS runs acquired in a study. When compared to state-of-the-art SWATH-MS data analysis, the algorithm was able to reduce the identification error by more than 3-fold at constant recall, while correcting for highly non-linear chromatographic effects. On a pulsed-SILAC experiment performed on human induced pluripotent stem (iPS) cells, TRIC was able to automatically align and quantify thousands of light and heavy isotopic peak groups and substantially increased the quantitative completeness and biological information in the data, providing insights into protein dynamics of iPS cells. Overall, this study demonstrates the importance of consistent quantification in highly challenging experimental setups, and proposes an algorithm to automate this task, constituting the last missing piece in a pipeline for automated analysis of massively parallel targeted proteomics datasets. PMID:27479329

75 FR 29763 - Government-Owned Inventions; Availability for Licensing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-27

... commercialization of results of federally-funded research and development. Foreign patent applications are filed on... patent applications. Simple, Quantitative and Highly Specific Antibody Detection of Lyme Disease... markedly out-performed the C6 ELISA test (currently the most sensitive test available, with 76% sensitivity...

HPLC Analysis of Chlorophyll a, Chlorophyll b, and Beta-Carotene in Collard Greens: A Project for a Problem-Oriented Laboratory Course.

ERIC Educational Resources Information Center

Silveira, Augustine, Jr.; And Others

1984-01-01

High performance liquid chromatography (HPLC) is used to separate and quantitate beta-carotene, chlorophyll a, and chlorophyll b originating from collard greens. Experimental procedures used and typical results obtained are discussed. (JN)

Determination of seven flavonoids in Ixeridium gracile (DC.) Shih by high-performance liquid chromatography.

PubMed

Chen, Juan; Ma, Xue-Mei; Shi, Yan-Ping

2009-01-01

A high-performance liquid chromatographic technique coupled with photodiode array detection was proposed for the simultaneous determination of 7 flavonoids, i.e., quercetin, kaempferol, 7-hydroxyflavanone, 7-methoxyflavanone, 2',4'-dihydroxychalcone, 2',4'-dihydroxydihydrochalcone, and 7,2'-dihydroxy-3', 4'-dimethoxyisoflavane, in extracts of the plant Ixeridium gracile. Optimum separation was obtained by using a reversed-phase C18 method. Because of the different UV characteristics of these components, 5 detection wavelengths were used for the quantitative analysis. All of the flavonoids showed good linearity (r > 0.9999). The limit of detection and limit of quantitation values for the analytes ranged from 0.06 to 0.46 microg/mL and from 0.18 to 1.48 microg/mL, respectively. The method was validated by evaluating repeatability, precision, stability, and accuracy. Five different extraction and purification procedures were investigated for preparation of the sample solution. The optimized method was applied to the determination of flavonoids in I. gracile and was found to be efficient.

Digital 3D Microstructure Analysis of Concrete using X-Ray Micro Computed Tomography SkyScan 1173: A Preliminary Study

NASA Astrophysics Data System (ADS)

Latief, F. D. E.; Mohammad, I. H.; Rarasati, A. D.

2017-11-01

Digital imaging of a concrete sample using high resolution tomographic imaging by means of X-Ray Micro Computed Tomography (μ-CT) has been conducted to assess the characteristic of the sample’s structure. A standard procedure of image acquisition, reconstruction, image processing of the method using a particular scanning device i.e., the Bruker SkyScan 1173 High Energy Micro-CT are elaborated. A qualitative and a quantitative analysis were briefly performed on the sample to deliver some basic ideas of the capability of the system and the bundled software package. Calculation of total VOI volume, object volume, percent of object volume, total VOI surface, object surface, object surface/volume ratio, object surface density, structure thickness, structure separation, total porosity were conducted and analysed. This paper should serve as a brief description of how the device can produce the preferred image quality as well as the ability of the bundled software packages to help in performing qualitative and quantitative analysis.

Authentication and Quantitation of Fraud in Extra Virgin Olive Oils Based on HPLC-UV Fingerprinting and Multivariate Calibration

PubMed Central

Carranco, Núria; Farrés-Cebrián, Mireia; Saurina, Javier

2018-01-01

High performance liquid chromatography method with ultra-violet detection (HPLC-UV) fingerprinting was applied for the analysis and characterization of olive oils, and was performed using a Zorbax Eclipse XDB-C8 reversed-phase column under gradient elution, employing 0.1% formic acid aqueous solution and methanol as mobile phase. More than 130 edible oils, including monovarietal extra-virgin olive oils (EVOOs) and other vegetable oils, were analyzed. Principal component analysis results showed a noticeable discrimination between olive oils and other vegetable oils using raw HPLC-UV chromatographic profiles as data descriptors. However, selected HPLC-UV chromatographic time-window segments were necessary to achieve discrimination among monovarietal EVOOs. Partial least square (PLS) regression was employed to tackle olive oil authentication of Arbequina EVOO adulterated with Picual EVOO, a refined olive oil, and sunflower oil. Highly satisfactory results were obtained after PLS analysis, with overall errors in the quantitation of adulteration in the Arbequina EVOO (minimum 2.5% adulterant) below 2.9%. PMID:29561820

Quantitation of silibinin, a putative cancer chemopreventive agent derived from milk thistle (Silybum marianum), in human plasma by high-performance liquid chromatography and identification of possible metabolites.

PubMed

Hoh, Carmen S L; Boocock, David J; Marczylo, Timothy H; Brown, V A; Cai, Hong; Steward, William P; Berry, David P; Gescher, Andreas J

2007-04-04

Silibinin has recently received attention as a potential cancer chemopreventive agent because of its antiproliferative and anticarcinogenic effects. A simple and specific reversed-phase high-performance liquid chromatography method was developed and validated for the quantitation of silibinin in human plasma. Sample preparation involved simple protein precipitation, and separation was achieved on a Waters Atlantis C18 column with flow rate of 1.0 mL/min at 40 degrees C and UV detection at 290 nm. Silibinin was detected as two peaks corresponding to trans-diastereoisomers. The peak area was linear over the investigated concentration range (0-5000 ng/mL). The limits of detection were 2 and 1 ng/mL for the two diastereoisomers (d1 and d2), with a recovery of 53-58%. This method was utilized to detect silibinin in plasma of colorectal patients after 7 days of treatment with silipide (silibinin formulated with phosphatidyl choline).

High energy PIXE: A tool to characterize multi-layer thick samples

NASA Astrophysics Data System (ADS)

Subercaze, A.; Koumeir, C.; Métivier, V.; Servagent, N.; Guertin, A.; Haddad, F.

2018-02-01

High energy PIXE is a useful and non-destructive tool to characterize multi-layer thick samples such as cultural heritage objects. In a previous work, we demonstrated the possibility to perform quantitative analysis of simple multi-layer samples using high energy PIXE, without any assumption on their composition. In this work an in-depth study of the parameters involved in the method previously published is proposed. Its extension to more complex samples with a repeated layer is also presented. Experiments have been performed at the ARRONAX cyclotron using 68 MeV protons. The thicknesses and sequences of a multi-layer sample including two different layers of the same element have been determined. Performances and limits of this method are presented and discussed.

Influence of sample preparation and reliability of automated numerical refocusing in stain-free analysis of dissected tissues with quantitative phase digital holographic microscopy

NASA Astrophysics Data System (ADS)

Kemper, Björn; Lenz, Philipp; Bettenworth, Dominik; Krausewitz, Philipp; Domagk, Dirk; Ketelhut, Steffi

2015-05-01

Digital holographic microscopy (DHM) has been demonstrated to be a versatile tool for high resolution non-destructive quantitative phase imaging of surfaces and multi-modal minimally-invasive monitoring of living cell cultures in-vitro. DHM provides quantitative monitoring of physiological processes through functional imaging and structural analysis which, for example, gives new insight into signalling of cellular water permeability and cell morphology changes due to toxins and infections. Also the analysis of dissected tissues quantitative DHM phase contrast prospects application fields by stain-free imaging and the quantification of tissue density changes. We show that DHM allows imaging of different tissue layers with high contrast in unstained tissue sections. As the investigation of fixed samples represents a very important application field in pathology, we also analyzed the influence of the sample preparation. The retrieved data demonstrate that the quality of quantitative DHM phase images of dissected tissues depends strongly on the fixing method and common staining agents. As in DHM the reconstruction is performed numerically, multi-focus imaging is achieved from a single digital hologram. Thus, we evaluated the automated refocussing feature of DHM for application on different types of dissected tissues and revealed that on moderately stained samples highly reproducible holographic autofocussing can be achieved. Finally, it is demonstrated that alterations of the spatial refractive index distribution in murine and human tissue samples represent a reliable absolute parameter that is related of different degrees of inflammation in experimental colitis and Crohn's disease. This paves the way towards the usage of DHM in digital pathology for automated histological examinations and further studies to elucidate the translational potential of quantitative phase microscopy for the clinical management of patients, e.g., with inflammatory bowel disease.

A new high-performance thin-layer chromatographic method for determining bile salt hydrolase activity.

PubMed

Rohawi, Nur Syakila; Ramasamy, Kalavathy; Agatonovic-Kustrin, Snezana; Lim, Siong Meng

2018-06-05

A quantitative assay using high-performance thin-layer chromatography (HPTLC) was developed to investigate bile salt hydrolase (BSH) activity in Pediococcus pentosaceus LAB6 and Lactobacillus plantarum LAB12 probiotic bacteria isolated from Malaysian fermented food. Lactic acid bacteria (LAB) were cultured in de Man Rogosa and Sharpe (MRS) broth containing 1 mmol/L of sodium-based glyco- and tauro-conjugated bile salts for 24 h. The cultures were centrifuged and the resultant cell free supernatant was subjected to chromatographic separation on a HPTLC plate. Conjugated bile salts were quantified by densitometric scans at 550 nm and results were compared to digital image analysis of chromatographic plates after derivatisation with anisaldehyde/sulfuric acid. Standard curves for bile salts determination with both methods show good linearity with high coefficient of determination (R 2 ) between 0.97 and 0.99. Method validation indicates good sensitivity with low relative standard deviation (RSD) (<10%), low limits of detection (LOD) of 0.4 versus 0.2 μg and limit of quantification (LOQ) of 1.4 versus 0.7 μg, for densitometric vs digital image analysis method, respectively. The bile salt hydrolase activity was found to be higher against glyco- than tauro-conjugated bile salts (LAB6; 100% vs >38%: LAB12; 100% vs >75%). The present findings strongly show that quantitative analysis via digitally-enhanced HPTLC offers a rapid quantitative analysis for deconjugation of bile salts by probiotics. Copyright © 2018. Published by Elsevier B.V.

Corneal topography with high-speed swept source OCT in clinical examination

PubMed Central

Karnowski, Karol; Kaluzny, Bartlomiej J.; Szkulmowski, Maciej; Gora, Michalina; Wojtkowski, Maciej

2011-01-01

We present the applicability of high-speed swept source (SS) optical coherence tomography (OCT) for quantitative evaluation of the corneal topography. A high-speed OCT device of 108,000 lines/s permits dense 3D imaging of the anterior segment within a time period of less than one fourth of second, minimizing the influence of motion artifacts on final images and topographic analysis. The swept laser performance was specially adapted to meet imaging depth requirements. For the first time to our knowledge the results of a quantitative corneal analysis based on SS OCT for clinical pathologies such as keratoconus, a cornea with superficial postinfectious scar, and a cornea 5 months after penetrating keratoplasty are presented. Additionally, a comparison with widely used commercial systems, a Placido-based topographer and a Scheimpflug imaging-based topographer, is demonstrated. PMID:21991558

Surface flow measurements from drones

NASA Astrophysics Data System (ADS)

Tauro, Flavia; Porfiri, Maurizio; Grimaldi, Salvatore

2016-09-01

Drones are transforming the way we sense and interact with the environment. However, despite their increased capabilities, the use of drones in geophysical sciences usually focuses on image acquisition for generating high-resolution maps. Motivated by the increasing demand for innovative and high performance geophysical observational methodologies, we posit the integration of drone technology and optical sensing toward a quantitative characterization of surface flow phenomena. We demonstrate that a recreational drone can be used to yield accurate surface flow maps of sub-meter water bodies. Specifically, drone's vibrations do not hinder surface flow observations, and velocity measurements are in agreement with traditional techniques. This first instance of quantitative water flow sensing from a flying drone paves the way to novel observations of the environment.

Quantitation of low molecular weight sugars by chemical derivatization-liquid chromatography/multiple reaction monitoring/mass spectrometry.

PubMed

Han, Jun; Lin, Karen; Sequria, Carita; Yang, Juncong; Borchers, Christoph H

2016-07-01

A new method for the separation and quantitation of 13 mono- and disaccharides has been developed by chemical derivatization/ultra-HPLC/negative-ion ESI-multiple-reaction monitoring MS. 3-Nitrophenylhydrazine (at 50°C for 60 min) was shown to be able to quantitatively derivatize low-molecular weight (LMW) reducing sugars. The nonreducing sugar, sucrose, was not derivatized. A pentafluorophenyl-bonded phase column was used for the chromatographic separation of the derivatized sugars. This method exhibits femtomole-level sensitivity, high precision (CVs of ≤ 4.6%) and high accuracy for the quantitation of LMW sugars in wine. Excellent linearity (R(2) ≥ 0.9993) and linear ranges of ∼500-fold for disaccharides and ∼1000-4000-fold for monosaccharides were achieved. With internal calibration ((13) C-labeled internal standards), recoveries were between 93.6% ± 1.6% (xylose) and 104.8% ± 5.2% (glucose). With external calibration, recoveries ranged from 82.5% ± 0.8% (ribulose) to 105.2% ± 2.1% (xylulose). Quantitation of sugars in two red wines and two white wines was performed using this method; quantitation of the central carbon metabolism-related carboxylic acids and tartaric acid was carried out using a previously established derivatization procedure with 3-nitrophenylhydrazine as well. The results showed that these two classes of compounds-both of which have important organoleptic properties-had different compositions in red and white wines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantitative Analysis of Tetramethylenedisulfotetramine ("Tetramine") Spiked into Beverages by Liquid Chromatography Tandem Mass Spectrometry with Validation by Gas Chromatography Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owens, J; Hok, S; Alcaraz, A

Tetramethylenedisulfotetramine, commonly known as tetramine, is a highly neurotoxic rodenticide (human oral LD{sub 50} = 0.1 mg/kg) used in hundreds of deliberate food poisoning events in China. Here we describe a method for quantitation of tetramine spiked into beverages, including milk, juice, tea, cola, and water and cleaned up by C8 solid phase extraction and liquid-liquid extraction. Quantitation by high performance liquid chromatography tandem mass spectrometry (LC/MS/MS) was based upon fragmentation of m/z 347 to m/z 268. The method was validated by gas chromatography mass spectrometry (GC/MS) operated in SIM mode for ions m/z 212, 240, and 360. The limitmore » of quantitation was 0.10 {micro}g/mL by LC/MS/MS versus 0.15 {micro}g/mL for GC/MS. Fortifications of the beverages at 2.5 {micro}g/mL and 0.25 {micro}g/mL were recovered ranging from 73-128% by liquid-liquid extraction for GC/MS analysis, 13-96% by SPE and 10-101% by liquid-liquid extraction for LC/MS/MS analysis.« less

Prediction of the retention of s-triazines in reversed-phase high-performance liquid chromatography under linear gradient-elution conditions.

PubMed

D'Archivio, Angelo Antonio; Maggi, Maria Anna; Ruggieri, Fabrizio

2014-08-01

In this paper, a multilayer artificial neural network is used to model simultaneously the effect of solute structure and eluent concentration profile on the retention of s-triazines in reversed-phase high-performance liquid chromatography under linear gradient elution. The retention data of 24 triazines, including common herbicides and their metabolites, are collected under 13 different elution modes, covering the following experimental domain: starting acetonitrile volume fraction ranging between 40 and 60% and gradient slope ranging between 0 and 1% acetonitrile/min. The gradient parameters together with five selected molecular descriptors, identified by quantitative structure-retention relationship modelling applied to individual separation conditions, are the network inputs. Predictive performance of this model is evaluated on six external triazines and four unseen separation conditions. For comparison, retention of triazines is modelled by both quantitative structure-retention relationships and response surface methodology, which describe separately the effect of molecular structure and gradient parameters on the retention. Although applied to a wider variable domain, the network provides a performance comparable to that of the above "local" models and retention times of triazines are modelled with accuracy generally better than 7%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of the Aptima HBV Quant assay vs. the COBAS TaqMan HBV test using the high pure system for the quantitation of HBV DNA in plasma and serum samples.

PubMed

Schalasta, Gunnar; Börner, Anna; Speicher, Andrea; Enders, Martin

2018-03-28

Proper management of patients with chronic hepatitis B virus (HBV) infection requires monitoring of plasma or serum HBV DNA levels using a highly sensitive nucleic acid amplification test. Because commercially available assays differ in performance, we compared herein the performance of the Hologic Aptima HBV Quant assay (Aptima) to that of the Roche Cobas TaqMan HBV test for use with the high pure system (HPS/CTM). Assay performance was assessed using HBV reference panels as well as plasma and serum samples from chronically HBV-infected patients. Method correlation, analytical sensitivity, precision/reproducibility, linearity, bias and influence of genotype were evaluated. Data analysis was performed using linear regression, Deming correlation analysis and Bland-Altman analysis. Agreement between the assays for the two reference panels was good, with a difference in assay values vs. target <0.5 log. Qualitative assay results for 159 clinical samples showed good concordance (88.1%; κ=0.75; 95% confidence interval: 0.651-0.845). For the 106 samples quantitated by both assays, viral load results were highly correlated (R=0.92) and differed on average by 0.09 log, with 95.3% of the samples being within the 95% limit of agreement of the assays. Linearity for viral loads 1-7 log was excellent for both assays (R2>0.98). The two assays had similar bias and precision across the different genotypes tested at low viral loads (25-1000 IU/mL). Aptima has a performance comparable with that of HPS/CTM, making it suitable for use for HBV infection monitoring. Aptima runs on a fully automated platform (the Panther system) and therefore offers a significantly improved workflow compared with HPS/CTM.

Estimating rice yield related traits and quantitative trait loci analysis under different nitrogen treatments using a simple tower-based field phenotyping system with modified single-lens reflex cameras

NASA Astrophysics Data System (ADS)

Naito, Hiroki; Ogawa, Satoshi; Valencia, Milton Orlando; Mohri, Hiroki; Urano, Yutaka; Hosoi, Fumiki; Shimizu, Yo; Chavez, Alba Lucia; Ishitani, Manabu; Selvaraj, Michael Gomez; Omasa, Kenji

2017-03-01

Application of field based high-throughput phenotyping (FB-HTP) methods for monitoring plant performance in real field conditions has a high potential to accelerate the breeding process. In this paper, we discuss the use of a simple tower based remote sensing platform using modified single-lens reflex cameras for phenotyping yield traits in rice under different nitrogen (N) treatments over three years. This tower based phenotyping platform has the advantages of simplicity, ease and stability in terms of introduction, maintenance and continual operation under field conditions. Out of six phenological stages of rice analyzed, the flowering stage was the most useful in the estimation of yield performance under field conditions. We found a high correlation between several vegetation indices (simple ratio (SR), normalized difference vegetation index (NDVI), transformed vegetation index (TVI), corrected transformed vegetation index (CTVI), soil-adjusted vegetation index (SAVI) and modified soil-adjusted vegetation index (MSAVI)) and multiple yield traits (panicle number, grain weight and shoot biomass) across a three trials. Among all of the indices studied, SR exhibited the best performance in regards to the estimation of grain weight (R2 = 0.80). Under our tower-based field phenotyping system (TBFPS), we identified quantitative trait loci (QTL) for yield related traits using a mapping population of chromosome segment substitution lines (CSSLs) and a single nucleotide polymorphism data set. Our findings suggest the TBFPS can be useful for the estimation of yield performance during early crop development. This can be a major opportunity for rice breeders whom desire high throughput phenotypic selection for yield performance traits.

Quantitative skills as a graduate learning outcome of university science degree programmes: student performance explored through theplanned-enacted-experiencedcurriculum model

NASA Astrophysics Data System (ADS)

Matthews, Kelly E.; Adams, Peter; Goos, Merrilyn

2016-07-01

Application of mathematical and statistical thinking and reasoning, typically referred to as quantitative skills, is essential for university bioscience students. First, this study developed an assessment task intended to gauge graduating students' quantitative skills. The Quantitative Skills Assessment of Science Students (QSASS) was the result, which examined 10 mathematical and statistical sub-topics. Second, the study established an evidential baseline of students' quantitative skills performance and confidence levels by piloting the QSASS with 187 final-year biosciences students at a research-intensive university. The study is framed within the planned-enacted-experienced curriculum model and contributes to science reform efforts focused on enhancing the quantitative skills of university graduates, particularly in the biosciences. The results found, on average, weak performance and low confidence on the QSASS, suggesting divergence between academics' intentions and students' experiences of learning quantitative skills. Implications for curriculum design and future studies are discussed.

Determination of salicylic acid by HPLC in plasma and saliva from children with juvenile chronic arthritis.

PubMed

Legaz, M E; Acitores, E; Valverde, F

1992-12-01

A high performance liquid chromatography (HPLC) method has been developed for measuring salicylic acid in the plasma and saliva of children with juvenile chronic arthritis (JCA). Samples were extracted with diethyl ether and, after drying, redissolved in methanol to be chromatographed. Quantitation of salicylic acid was performed by reverse phase HPLC on a spherisorb ODS-2 column, using methanol: water: acetic acid as mobile phase. Phenolic was monitored by absorbance at 237 nm. Linearity between the amount of mass injected and the response in the detector was determined. This method was applied to compare concentrations of salivary and plasma salicylic acid. The method also permitted the quantitation of salivary salicylate as a non-invasive, indirect method for monitoring the concentration of plasma salicylate in patients with JCA.

Quantitative Single-Ion Irradiation by ASIPP Microbeam

NASA Astrophysics Data System (ADS)

Wang, Xu-Fei; Chen, Lian-Yun; Hu, Zhi-Wen; Wang, Xiao-Hua; Zhang, Jun; Li, Jun; Chen, Bin; Hu, Su-Hua; Shi, Zhong-Tao; Wu, Yu; Xu, Ming-Liang; Wu, Li-Jun; Wang, Shao-Hu; Yu, Zeng-Liang

2004-05-01

A single-ion microbeam facility has been constructed by the microbeam research group in ASIPP (Institute of Plasma Physics, Chinese Academy of Science). The system was designed to deliver defined numbers of hydrogen ions produced by a van de Graaff accelerator, covering an energy range from 200 keV to 3 MeV, into living cells (5 mum-20 mum diameter) growing in culture on thin plastic films. The beam is collimated by a 1- mum inner diameter HPLC (high performance liquid chromatography) capillary, which forms the micron-dimensional beam-line exit. A microbeam collimator, a scintillation ion counting system and a fast beam shutter, which constitute a precise dosage measuring and controlling system, jointly perform quantitative single-ion irradiation. With this facility, we can presently acquire ion-hitting efficiency close to 95%.

The Relationship between Barrier Courses and Persistence in Engineering

ERIC Educational Resources Information Center

Suresh, Radhika

2007-01-01

Attrition in engineering programs continues to be an important issue for universities across the country. This study examined the connection between student performance in barrier courses and persistence in engineering. Quantitative results showed that high school academic experience, student behaviors (including study habits, work habits, coping…

A collimator optimization method for quantitative imaging: application to Y-90 bremsstrahlung SPECT.

PubMed

Rong, Xing; Frey, Eric C

2013-08-01

Post-therapy quantitative 90Y bremsstrahlung single photon emission computed tomography (SPECT) has shown great potential to provide reliable activity estimates, which are essential for dose verification. Typically 90Y imaging is performed with high- or medium-energy collimators. However, the energy spectrum of 90Y bremsstrahlung photons is substantially different than typical for these collimators. In addition, dosimetry requires quantitative images, and collimators are not typically optimized for such tasks. Optimizing a collimator for 90Y imaging is both novel and potentially important. Conventional optimization methods are not appropriate for 90Y bremsstrahlung photons, which have a continuous and broad energy distribution. In this work, the authors developed a parallel-hole collimator optimization method for quantitative tasks that is particularly applicable to radionuclides with complex emission energy spectra. The authors applied the proposed method to develop an optimal collimator for quantitative 90Y bremsstrahlung SPECT in the context of microsphere radioembolization. To account for the effects of the collimator on both the bias and the variance of the activity estimates, the authors used the root mean squared error (RMSE) of the volume of interest activity estimates as the figure of merit (FOM). In the FOM, the bias due to the null space of the image formation process was taken in account. The RMSE was weighted by the inverse mass to reflect the application to dosimetry; for a different application, more relevant weighting could easily be adopted. The authors proposed a parameterization for the collimator that facilitates the incorporation of the important factors (geometric sensitivity, geometric resolution, and septal penetration fraction) determining collimator performance, while keeping the number of free parameters describing the collimator small (i.e., two parameters). To make the optimization results for quantitative 90Y bremsstrahlung SPECT more general, the authors simulated multiple tumors of various sizes in the liver. The authors realistically simulated human anatomy using a digital phantom and the image formation process using a previously validated and computationally efficient method for modeling the image-degrading effects including object scatter, attenuation, and the full collimator-detector response (CDR). The scatter kernels and CDR function tables used in the modeling method were generated using a previously validated Monte Carlo simulation code. The hole length, hole diameter, and septal thickness of the obtained optimal collimator were 84, 3.5, and 1.4 mm, respectively. Compared to a commercial high-energy general-purpose collimator, the optimal collimator improved the resolution and FOM by 27% and 18%, respectively. The proposed collimator optimization method may be useful for improving quantitative SPECT imaging for radionuclides with complex energy spectra. The obtained optimal collimator provided a substantial improvement in quantitative performance for the microsphere radioembolization task considered.

Photoelectrochemical detection of benzaldehyde in foodstuffs

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaCourse, W.R.; Krull, I.S.

Photoelectrochemical detection (PED) coupled with high performance liquid chromatography was used to quantitatively determine benzaldehyde in extracts, beverages, and foodstuffs. Photoelectrochemical detection is responsive to alkyl and aryl ketones and aldehydes and offers the advantages of 2-3 orders of magnitude linearity, 5-1-ng limits of detection, and a high degree of selectivity without chemical derivatization. This is the first application of the PED to sample analysis.

Evaluation of background parenchymal enhancement on breast MRI: a systematic review

PubMed Central

Signori, Alessio; Valdora, Francesca; Rossi, Federica; Calabrese, Massimo; Durando, Manuela; Mariscotto, Giovanna; Tagliafico, Alberto

2017-01-01

Objective: To perform a systematic review of the methods used for background parenchymal enhancement (BPE) evaluation on breast MRI. Methods: Studies dealing with BPE assessment on breast MRI were retrieved from major medical libraries independently by four reviewers up to 6 October 2015. The keywords used for database searching are “background parenchymal enhancement”, “parenchymal enhancement”, “MRI” and “breast”. The studies were included if qualitative and/or quantitative methods for BPE assessment were described. Results: Of the 420 studies identified, a total of 52 articles were included in the systematic review. 28 studies performed only a qualitative assessment of BPE, 13 studies performed only a quantitative assessment and 11 studies performed both qualitative and quantitative assessments. A wide heterogeneity was found in the MRI sequences and in the quantitative methods used for BPE assessment. Conclusion: A wide variability exists in the quantitative evaluation of BPE on breast MRI. More studies focused on a reliable and comparable method for quantitative BPE assessment are needed. Advances in knowledge: More studies focused on a quantitative BPE assessment are needed. PMID:27925480

Comparison of high-performance liquid chromatography/tandem mass spectrometry and high-performance liquid chromatography/photo-diode array detection for the quantitation of carotenoids, retinyl esters, α-tocopherol and phylloquinone in chylomicron-rich fractions of human plasma.

PubMed

Kopec, Rachel E; Schweiggert, Ralf M; Riedl, Ken M; Carle, Reinhold; Schwartz, Steven J

2013-06-30

Bioavailability of essential lipophilic micronutrients and carotenoids is of utmost interest for human health, as the consumption of these compounds may help alleviate major nutritional deficiencies, cardiovascular disease, and cancer. High-performance liquid chromatography/photo-diode array detection (HPLC-PDA) and high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) were compared for the quantitative analysis of α- and β-carotene, β-cryptoxanthin, lutein, lycopene, α-tocopherol, phylloquinone, and several retinyl esters from chylomicron-containing triglyceride rich lipoprotein (TRL) fractions of human plasma obtained from two clinical trials. After selecting an efficient extraction method for the analytes, both the HPLC/PDA and the HPLC/MS/MS methods were developed and several parameters validated using an HP 1200 series HPLC system interfaced with a HP 1200 series diode-array detector (Agilent Technologies, Santa Clara, CA, USA) and a QTRAP 5500 (AB Sciex, Foster City, CA, USA) via an atmospheric pressure chemical ionization (APCI) probe operated in positive ion mode. For lycopene, α- and β-carotene, HPLC/MS/MS was up to 37 times more sensitive than HPLC-PDA. PDA detection was shown to be up to 8 times more sensitive for lutein. MS/MS signals were enhanced by matrix components for lutein and β-cryptoxanthin, as determined by referencing to the matrix-independent PDA signal. In contrast, matrix suppression was observed for retinyl palmitate, α-carotene, and β-carotene. Both detectors showed similar suitability for α-tocopherol, lycopene and retinyl palmitate (representing ~73% of total retinyl esters). MS/MS exclusively allowed the quantitation of minor retinyl esters, phylloquinone, and (Z)-lycopene isomers. HPLC/MS/MS was more sensitive than HPLC-PDA for six of the eight analytes and represents a powerful tool for the analysis of chylomicron samples and potentially other biological samples of limited sample size. When internal standards are available for the target carotenoid, employing MS/MS detection may reduce the necessary blood sample volume, which is particularly advantageous for minimizing risk and discomfort to human subjects during clinical studies. Copyright © 2013 John Wiley & Sons, Ltd.

Comparison of high-performance liquid chromatography/tandem mass spectrometry and high-performance liquid chromatography/photo-diode array detection for the quantitation of carotenoids, retinyl esters, α-tocopherol and phylloquinone in chylomicron-rich fractions of human plasma

PubMed Central

Kopec, Rachel E.; Schweiggert, Ralf M.; Riedl, Ken M.; Carle, Reinhold; Schwartz, Steven J.

2013-01-01

Rationale Bioavailability of essential lipophilic micronutrients and carotenoids is of utmost interest for human health, as the consumption of these compounds may help alleviate major nutritional deficiencies, cardiovascular disease, and cancer. High-performance liquid chromatography/photo-diode array detection (HPLC-PDA) and high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) were compared for the quantitative analysis of α- and β-carotene, β-cryptoxanthin, lutein, lycopene, α-tocopherol, phylloquinone, and several retinyl esters from chylomicron-containing triglyceride rich lipoprotein (TRL) fractions of human plasma obtained from two clinical trials. Methods After selecting an efficient extraction method for the analytes, both the HPLC/PDA and the HPLC/MS/MS methods were developed and several parameters validated using an HP 1200 series HPLC system interfaced with a HP 1200 series diode-array detector (Agilent Technologies, Santa Clara, CA, USA) and a QTRAP 5500 (AB Sciex, Foster City, CA, USA) via an atmospheric pressure chemical ionization (APCI) probe operated in positive ion mode. Results For lycopene, α- and β-carotene, HPLC/MS/MS was up to 37 times more sensitive than HPLC-PDA. PDA detection was shown to be up to 8 times more sensitive for lutein. MS/MS signals were enhanced by matrix components for lutein and β-cryptoxanthin, as determined by referencing to the matrix-independent PDA signal. In contrast, matrix suppression was observed for retinyl palmitate, α-carotene, and β-carotene. Both detectors showed similar suitability for α-tocopherol, lycopene and retinyl palmitate (representing ~73% of total retinyl esters). MS/MS exclusively allowed the quantitation of minor retinyl esters, phylloquinone, and (Z)-lycopene isomers. Conclusions HPLC/MS/MS was more sensitive than HPLC-PDA for six of the eight analytes and represents a powerful tool for the analysis of chylomicron samples and potentially other biological samples of limited sample size. When internal standards are available for the target carotenoid, employing MS/MS detection may reduce the necessary blood sample volume, which is particularly advantageous for minimizing risk and discomfort to human subjects during clinical studies. PMID:23681818

A comparison study of image features between FFDM and film mammogram images

PubMed Central

Jing, Hao; Yang, Yongyi; Wernick, Miles N.; Yarusso, Laura M.; Nishikawa, Robert M.

2012-01-01

Purpose: This work is to provide a direct, quantitative comparison of image features measured by film and full-field digital mammography (FFDM). The purpose is to investigate whether there is any systematic difference between film and FFDM in terms of quantitative image features and their influence on the performance of a computer-aided diagnosis (CAD) system. Methods: The authors make use of a set of matched film-FFDM image pairs acquired from cadaver breast specimens with simulated microcalcifications consisting of bone and teeth fragments using both a GE digital mammography system and a screen-film system. To quantify the image features, the authors consider a set of 12 textural features of lesion regions and six image features of individual microcalcifications (MCs). The authors first conduct a direct comparison on these quantitative features extracted from film and FFDM images. The authors then study the performance of a CAD classifier for discriminating between MCs and false positives (FPs) when the classifier is trained on images of different types (film, FFDM, or both). Results: For all the features considered, the quantitative results show a high degree of correlation between features extracted from film and FFDM, with the correlation coefficients ranging from 0.7326 to 0.9602 for the different features. Based on a Fisher sign rank test, there was no significant difference observed between the features extracted from film and those from FFDM. For both MC detection and discrimination of FPs from MCs, FFDM had a slight but statistically significant advantage in performance; however, when the classifiers were trained on different types of images (acquired with FFDM or SFM) for discriminating MCs from FPs, there was little difference. Conclusions: The results indicate good agreement between film and FFDM in quantitative image features. While FFDM images provide better detection performance in MCs, FFDM and film images may be interchangeable for the purposes of training CAD algorithms, and a single CAD algorithm may be applied to either type of images. PMID:22830771

Determination of Flavonoids and Anthocyanins in Nitraria tangutorum by High Performance Liquid Chromatography Coupled with Tandem Mass Spectrometry.

PubMed

Zhe, Gao; Ying-Chun, Wang; Yan-Xu, Chang

2016-01-01

Using high-performance liquid chromatography coupled with diode array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-MSn) method, qualitative and quantitative analysis of flavonoids of stems, leaves, fruits and seeds, and anthocyanidin of fresh fruits in Nitraria tangutorum were performed. A total of 14 flavonoid components were identified from the seeds of N. tangutorum including three quercetin derivatives, three kaempferol derivatives, and eight isorhamnetin derivatives. A total of 12, 10, and 7 flavonoid components were identified from leaves, stems, and fruits of N. tangutorum, respectively; all were present in seeds also. The total content of flavonoids in leaves was the highest, up to 42.43 mg/g·dry weight. A total of 12 anthocyanidin components were identified from the fresh fruits of N. tangutorum, belonging to five anthocyanidin. The total content of anthocyanidin in fresh fruits was up to 45.83 mg/100 g· fresh weight, of which the acylated anthocyanidin accounted for 65.7%. The HPLC-DAD-MS(n) method can be operated easily, rapidly, and accurately, and is feasible for qualitative and quantitative analysis of flavone glycosides in N. tangutorum.

Academic trajectories of newcomer immigrant youth.

PubMed

Suárez-Orozco, Carola; Gaytán, Francisco X; Bang, Hee Jin; Pakes, Juliana; O'Connor, Erin; Rhodes, Jean

2010-05-01

Immigration to the United States presents both challenges and opportunities that affect students' academic achievement. Using a 5-year longitudinal, mixed-methods approach, we identified varying academic trajectories of newcomer immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve analysis revealed that although some newcomer students performed at high or improving levels over time, others showed diminishing performance. Multinomial logistic regressions identified significant group differences in academic trajectories, particularly between the high-achieving youth and the other groups. In keeping with ecological-developmental and stage-environment fit theories, School Characteristics (school segregation rate, school poverty rate, and student perceptions of school violence), Family Characteristics (maternal education, parental employment, and household structure), and Individual Characteristics (academic English proficiency, academic engagement, psychological symptoms, gender, and 2 age-related risk factors, number of school transitions and being overaged for grade placement) were associated with different trajectories of academic performance. A series of case studies triangulate many of the quantitative findings as well as illuminate patterns that were not detected in the quantitative data. Thus, the mixed-methods approach sheds light on the cumulative developmental challenges that immigrant students face as they adjust to their new educational settings. 2010 APA, all rights reserved

Development of a precolumn derivatization HPLC method with diode-array detection for the determination of amino sugars in peat and soil humic acids.

PubMed

Beňo, Erik; Góra, Róbert; Hutta, Milan

2018-02-01

The work is focused on the development of a high-performance liquid chromatography method with diode-array detection for the separation and quantitation of the three most abundant amino sugars; d-glucosamine, d-galactosamine, and d-mannosamine. The high-performance liquid chromatography separation was carried out by reversed-phase chromatography on Chromolith Performance RP-18e monolithic column after acid hydrolysis (5 M HCl) and precolumn derivatization of samples using diethyl ethoxymethylenemalonate. Gradient elution and a mobile phase composed of ammonium formate buffer solution (10 mmol/L, pH 3.60) and methanol with flow rate of 1.0 mL/min were used. The monitoring wavelength was set at 280 nm. The limits of detection and quantitation for analytes ranged from 0.017 to 0.122 mg/L and from 0.057 to 0.407 mg/L, respectively. The proposed method was successfully applied for the determination of amino sugars in samples of humic acids isolated from different soils and peat. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of patients with painful total hip arthroplasty using combined single photon emission tomography and conventional computerized tomography (SPECT/CT) - a comparison of semi-quantitative versus 3D volumetric quantitative measurements.

PubMed

Barthassat, Emilienne; Afifi, Faik; Konala, Praveen; Rasch, Helmut; Hirschmann, Michael T

2017-05-08

It was the primary purpose of our study to evaluate the inter- and intra-observer reliability of a standardized SPECT/CT algorithm for evaluating patients with painful primary total hip arthroplasty (THA). The secondary purpose was a comparison of semi-quantitative and 3D volumetric quantification method for assessment of bone tracer uptake (BTU) in those patients. A novel SPECT/CT localization scheme consisting of 14 femoral and 4 acetabular regions on standardized axial and coronal slices was introduced and evaluated in terms of inter- and intra-observer reliability in 37 consecutive patients with hip pain after THA. BTU for each anatomical region was assessed semi-quantitatively using a color-coded Likert type scale (0-10) and volumetrically quantified using a validated software. Two observers interpreted the SPECT/CT findings in all patients two times with six weeks interval between interpretations in random order. Semi-quantitative and quantitative measurements were compared in terms of reliability. In addition, the values were correlated using Pearson`s correlation. A factorial cluster analysis of BTU was performed to identify clinically relevant regions, which should be grouped and analysed together. The localization scheme showed high inter- and intra-observer reliabilities for all femoral and acetabular regions independent of the measurement method used (semiquantitative versus 3D volumetric quantitative measurements). A high to moderate correlation between both measurement methods was shown for the distal femur, the proximal femur and the acetabular cup. The factorial cluster analysis showed that the anatomical regions might be summarized into three distinct anatomical regions. These were the proximal femur, the distal femur and the acetabular cup region. The SPECT/CT algorithm for assessment of patients with pain after THA is highly reliable independent from the measurement method used. Three clinically relevant anatomical regions (proximal femoral, distal femoral, acetabular) were identified.

Optimized slice-selective 1H NMR experiments combined with highly accurate quantitative 13C NMR using an internal reference method.

PubMed

Jézéquel, Tangi; Silvestre, Virginie; Dinis, Katy; Giraudeau, Patrick; Akoka, Serge

2018-04-01

Isotope ratio monitoring by 13 C NMR spectrometry (irm- 13 C NMR) provides the complete 13 C intramolecular position-specific composition at natural abundance. It represents a powerful tool to track the (bio)chemical pathway which has led to the synthesis of targeted molecules, since it allows Position-specific Isotope Analysis (PSIA). Due to the very small composition range (which represents the range of variation of the isotopic composition of a given nuclei) of 13 C natural abundance values (50‰), irm- 13 C NMR requires a 1‰ accuracy and thus highly quantitative analysis by 13 C NMR. Until now, the conventional strategy to determine the position-specific abundance x i relies on the combination of irm-MS (isotopic ratio monitoring Mass Spectrometry) and 13 C quantitative NMR. However this approach presents a serious drawback since it relies on two different techniques and requires to measure separately the signal of all the carbons of the analyzed compound, which is not always possible. To circumvent this constraint, we recently proposed a new methodology to perform 13 C isotopic analysis using an internal reference method and relying on NMR only. The method combines a highly quantitative 1 H NMR pulse sequence (named DWET) with a 13 C isotopic NMR measurement. However, the recently published DWET sequence is unsuited for samples with short T 1 , which forms a serious limitation for irm- 13 C NMR experiments where a relaxing agent is added. In this context, we suggest two variants of the DWET called Multi-WET and Profiled-WET, developed and optimized to reach the same accuracy of 1‰ with a better immunity towards T 1 variations. Their performance is evaluated on the determination of the 13 C isotopic profile of vanillin. Both pulse sequences show a 1‰ accuracy with an increased robustness to pulse miscalibrations compared to the initial DWET method. This constitutes a major advance in the context of irm- 13 C NMR since it is now possible to perform isotopic analysis with high relaxing agent concentrations, leading to a strong reduction of the overall experiment time. Copyright © 2018 Elsevier Inc. All rights reserved.

Economic injury level for the coffee berry borer (Coleoptera: Curculionidae: Scolytinae) using attractive traps in Brazilian coffee fields.

PubMed

Fernandes, F L; Picanço, M C; Campos, S O; Bastos, C S; Chediak, M; Guedes, R N C; Silva, R S

2011-12-01

The currently existing sample procedures available for decision-making regarding the control of the coffee berry borer Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) are time-consuming, expensive, and difficult to perform, compromising their adoption. In addition, the damage functions incorporated in such decision levels only consider the quantitative losses, while dismissing the qualitative losses. Traps containing ethanol, methanol, and benzaldehyde may allow cheap and easy decision-making. Our objective was to determine the economic injury level (EIL) for the adults of the coffee berry borer by using attractant-baited traps. We considered both qualitative and quantitative losses caused by the coffee borer in estimating the EILs. These EILs were determined for conventional and organic coffee under high and average plant yield. When the quantitative losses caused by H. hampei were considered alone, the EILs ranged from 7.9 to 23.7% of bored berries for high and average-yield conventional crops, respectively. For high and average-yield organic coffee the ELs varied from 24.4 to 47.6% of bored berries, respectively. When qualitative and quantitative losses caused by the pest were considered together, the EIL was 4.3% of bored berries for both conventional and organic coffee. The EILs for H. hampei associated to the coffee plants in the flowering, pinhead fruit, and ripening fruit stages were 426, 85, and 28 adults per attractive trap, respectively.

Employment of High-Performance Thin-Layer Chromatography for the Quantification of Oleuropein in Olive Leaves and the Selection of a Suitable Solvent System for Its Isolation with Centrifugal Partition Chromatography.

PubMed

Boka, Vasiliki-Ioanna; Argyropoulou, Aikaterini; Gikas, Evangelos; Angelis, Apostolis; Aligiannis, Nektarios; Skaltsounis, Alexios-Leandros

2015-11-01

A high-performance thin-layer chromatographic methodology was developed and validated for the isolation and quantitative determination of oleuropein in two extracts of Olea europaea leaves. OLE_A was a crude acetone extract, while OLE_AA was its defatted residue. Initially, high-performance thin-layer chromatography was employed for the purification process of oleuropein with fast centrifugal partition chromatography, replacing high-performance liquid-chromatography, in the stage of the determination of the distribution coefficient and the retention volume. A densitometric method was developed for the determination of the distribution coefficients, KC = CS/CM. The total concentrations of the target compound in the stationary phase (CS) and in the mobile phase (CM) were calculated by the area measured in the high-performance thin-layer chromatogram. The estimated Kc was also used for the calculation of the retention volume, VR, with a chromatographic retention equation. The obtained data were successfully applied for the purification of oleuropein and the experimental results confirmed the theoretical predictions, indicating that high-performance thin-layer chromatography could be an important counterpart in the phytochemical study of natural products. The isolated oleuropein (purity > 95%) was subsequently used for the estimation of its content in each extract with a simple, sensitive and accurate high-performance thin-layer chromatography method. The best fit calibration curve from 1.0 µg/track to 6.0 µg/track of oleuropein was polynomial and the quantification was achieved by UV detection at λ 240 nm. The method was validated giving rise to an efficient and high-throughput procedure, with the relative standard deviation % of repeatability and intermediate precision not exceeding 4.9% and accuracy between 92% and 98% (recovery rates). Moreover, the method was validated for robustness, limit of quantitation, and limit of detection. The amount of oleuropein for OLE_A, OLE_AA, and an aqueous extract of olive leaves was estimated to be 35.5% ± 2.7, 51.5% ± 1.4, and 12.5% ± 0.12, respectively. Statistical analysis proved that the method is repeatable and selective, and can be effectively applied for the estimation of oleuropein in olive leaves' extracts, and could potentially replace high-performance liquid chromatography methodologies developed so far. Thus, the phytochemical investigation of oleuropein could be based on high-performance thin-layer chromatography coupled with separation processes, such as fast centrifugal partition chromatography, showing efficacy and credibility. Georg Thieme Verlag KG Stuttgart · New York.

Classification of the medicinal plants of the genus Atractylodes using high-performance liquid chromatography with diode array and tandem mass spectrometry detection combined with multivariate statistical analysis.

PubMed

Cho, Hyun-Deok; Kim, Unyong; Suh, Joon Hyuk; Eom, Han Young; Kim, Junghyun; Lee, Seul Gi; Choi, Yong Seok; Han, Sang Beom

2016-04-01

Analytical methods using high-performance liquid chromatography with diode array and tandem mass spectrometry detection were developed for the discrimination of the rhizomes of four Atractylodes medicinal plants: A. japonica, A. macrocephala, A. chinensis, and A. lancea. A quantitative study was performed, selecting five bioactive components, including atractylenolide I, II, III, eudesma-4(14),7(11)-dien-8-one and atractylodin, on twenty-six Atractylodes samples of various origins. Sample extraction was optimized to sonication with 80% methanol for 40 min at room temperature. High-performance liquid chromatography with diode array detection was established using a C18 column with a water/acetonitrile gradient system at a flow rate of 1.0 mL/min, and the detection wavelength was set at 236 nm. Liquid chromatography with tandem mass spectrometry was applied to certify the reliability of the quantitative results. The developed methods were validated by ensuring specificity, linearity, limit of quantification, accuracy, precision, recovery, robustness, and stability. Results showed that cangzhu contained higher amounts of atractylenolide I and atractylodin than baizhu, and especially atractylodin contents showed the greatest variation between baizhu and cangzhu. Multivariate statistical analysis, such as principal component analysis and hierarchical cluster analysis, were also employed for further classification of the Atractylodes plants. The established method was suitable for quality control of the Atractylodes plants. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of leadership, organizational culture, and competency on teachers' performance in Ibu Kartini vocational high school Semarang

NASA Astrophysics Data System (ADS)

Toha, Mohamad; Katoningsih, Sri

2018-03-01

The low performance of teachers in organization is influenced many factors. Organizational culture could be the key of organization success; hence many researches were done to identify the value and the attitude norm that gave big contribution for organization success. Competency is a part of employee they perform during work as kind of behavior. Competency depends on the aspects process of teachers' performance. The purpose of this research is to know the effect of leadership, organizational culture and competency on teachers' performance. The objects of this research are leadership, organizational culture, competency and teachers' performance in Ibu Kartini vocational high school. This research is quantitative. To collect the data, questionnaire was used. Then, the data were analyzed by using Path analysis in SPPS 16. The result of this research showed that leadership, organizational culture, competency and performance run well and had significant effect on teachers' performance.

Quantitation of zolpidem in biological fluids by electro-driven microextraction combined with HPLC-UV analysis.

PubMed

Yaripour, Saeid; Mohammadi, Ali; Esfanjani, Isa; Walker, Roderick B; Nojavan, Saeed

2018-01-01

In this study, for the first time, an electro-driven microextraction method named electromembrane extraction combined with a simple high performance liquid chromatography and ultraviolet detection was developed and validated for the quantitation of zolpidem in biological samples. Parameters influencing electromembrane extraction were evaluated and optimized. The membrane consisted of 2-ethylhexanol immobilized in the pores of a hollow fiber. As a driving force, a 150 V electric field was applied to facilitate the analyte migration from the sample matrix to an acceptor solution through a supported liquid membrane. The pHs of donor and acceptor solutions were optimized to 6.0 and 2.0, respectively. The enrichment factor was obtained >75 within 15 minutes. The effect of carbon nanotubes (as solid nano-sorbents) on the membrane performance and EME efficiency was evaluated. The method was linear over the range of 10-1000 ng/mL for zolpidem (R 2 >0.9991) with repeatability ( %RSD) between 0.3 % and 7.3 % ( n = 3). The limits of detection and quantitation were 3 and 10 ng/mL, respectively. The sensitivity of HPLC-UV for the determination of zolpidem was enhanced by electromembrane extraction. Finally, the method was employed for the quantitation of zolpidem in biological samples with relative recoveries in the range of 60-79 %.

Quantitation of zolpidem in biological fluids by electro-driven microextraction combined with HPLC-UV analysis

PubMed Central

Yaripour, Saeid; Mohammadi, Ali; Esfanjani, Isa; Walker, Roderick B.; Nojavan, Saeed

2018-01-01

In this study, for the first time, an electro-driven microextraction method named electromembrane extraction combined with a simple high performance liquid chromatography and ultraviolet detection was developed and validated for the quantitation of zolpidem in biological samples. Parameters influencing electromembrane extraction were evaluated and optimized. The membrane consisted of 2-ethylhexanol immobilized in the pores of a hollow fiber. As a driving force, a 150 V electric field was applied to facilitate the analyte migration from the sample matrix to an acceptor solution through a supported liquid membrane. The pHs of donor and acceptor solutions were optimized to 6.0 and 2.0, respectively. The enrichment factor was obtained >75 within 15 minutes. The effect of carbon nanotubes (as solid nano-sorbents) on the membrane performance and EME efficiency was evaluated. The method was linear over the range of 10-1000 ng/mL for zolpidem (R2 >0.9991) with repeatability ( %RSD) between 0.3 % and 7.3 % (n = 3). The limits of detection and quantitation were 3 and 10 ng/mL, respectively. The sensitivity of HPLC-UV for the determination of zolpidem was enhanced by electromembrane extraction. Finally, the method was employed for the quantitation of zolpidem in biological samples with relative recoveries in the range of 60-79 %. PMID:29805344

Conventional liquid chromatography/triple quadrupole mass spectrometer-based metabolite identification and semi-quantitative estimation approach in the investigation of dabigatran etexilate in vitro metabolism

PubMed Central

Hu, Zhe-Yi; Parker, Robert B.; Herring, Vanessa L.; Laizure, S. Casey

2012-01-01

Dabigatran etexilate (DABE) is an oral prodrug that is rapidly converted by esterases to dabigatran (DAB), a direct inhibitor of thrombin. To elucidate the esterase-mediated metabolic pathway of DABE, a high-performance liquid chromatography/mass spectrometer (LC-MS/MS)-based metabolite identification and semi-quantitative estimation approach was developed. To overcome the poor full-scan sensitivity of conventional triple quadrupole mass spectrometry, precursor-product ion pairs were predicted, to search for the potential in vitro metabolites. The detected metabolites were confirmed by the product ion scan. A dilution method was introduced to evaluate the matrix effects of tentatively identified metabolites without chemical standards. Quantitative information on detected metabolites was obtained using ‘metabolite standards’ generated from incubation samples that contain a high concentration of metabolite in combination with a correction factor for mass spectrometry response. Two in vitro metabolites of DABE (M1 and M2) were identified, and quantified by the semi-quantitative estimation approach. It is noteworthy that CES1 convert DABE to M1 while CES2 mediates the conversion of DABE to M2. M1 (or M2) was further metabolized to DAB by CES2 (or CES1). The approach presented here provides a solution to a bioanalytical need for fast identification and semi-quantitative estimation of CES metabolites in preclinical samples. PMID:23239178

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. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Quantitation of free polyethylene glycol in PEGylated protein conjugate by size exclusion HPLC with refractive index (RI) detection.

PubMed

Li, Ning; Ziegemeier, Daisy; Bass, Laura; Wang, Wei

2008-12-15

In this study, size exclusion high performance liquid chromatography was evaluated for its application in separation and quantitation of free polyethylene glycol (PEG) and its PEGylated-protein-conjugate (PEG-conjugate). Although the large mass of the free PEG (2-fold greater than the protein) made separation difficult, chromatographic conditions were identified enabling resolution and quantitation of the free PEG, PEG-conjugate and non-PEGylated protein with Shodex Protein KW803 and KW804 columns in series and refractive index detection. The optimum resolution of 1.7 and 2.0 was achieved for the free PEG and PEG-conjugate as well as the free PEG and non-PEGylated protein using 20mM HEPES buffer at pH 6.5. Under this condition, the plot of log(10)MW of all the pertinent analytes against retention time showed a linear relationship with a correlation coefficient of 1. Limited assay performance evaluation demonstrated that the method was linear in the concentration range of 10 to 250 microg/mL of free PEG with correlation coefficients of > or = 0.99. When free PEG in this concentration range was spiked into PEG-conjugate samples at 1mg/mL, the recovery was in the range of 78%-120%. Detection and quantitation limits were determined to be, respectively, 10 and 25 microg/mL for free PEG. The R.S.D. for intra- and inter-day precision was 0.09% or less for retention time measurements and 2.9% or less for area count measurements. Robustness testing was performed by deliberately deviating +/-0.2 pH units away from the desired pH as well as by increasing the flow rate. These deviations resulted in no significant impact on area percent distribution of all species. However, separation was found to be sensitive to high ionic strength and buffer species.

Teacher Identity and Reform: Intersections within School Culture

ERIC Educational Resources Information Center

Bower, Heather Ann; Parsons, Eileen R. Carlton

2016-01-01

In the era of school accountability, school reform programs aimed at shifting school culture are often implemented in an attempt to increase student achievement as measured by standardized test scores. This ethnographic case study was conducted in Hawk Elementary, a low-performing, high-poverty school. Quantitative and qualitative data collected…

Protocol Analysis of Aptitude Differences in Figural Analogy Problem Representation.

ERIC Educational Resources Information Center

Schiano, Diane J.

Individual differences in performance on figural analogy tests are usually attributed to quantitative differences in processing parameters rather than to qualitative differences in the formation and use of representations. Yet aptitude-related differences in categorizing standardized figural analogy problems between high and low scorers have been…

Imaging and quantitative methods for studying cytoskeletal rearrangements during root development and gravitropism.

PubMed

Jacques, Eveline; Wells, Darren M; Bennett, Malcolm J; Vissenberg, Kris

2015-01-01

High-resolution imaging of cytoskeletal structures paves the way for standardized methods to quantify cytoskeletal organization. Here we provide a detailed description of the analysis performed to determine the microtubule patterns in gravistimulated roots, using the recently developed software tool MicroFilament Analyzer.

Improving Reading Achievement in High Poverty, Rural Schools

ERIC Educational Resources Information Center

Tufts, Janet

2017-01-01

Purpose: The purpose of this quantitative study was to determine what correlation exists between a student's poverty coefficient and the daily number of minutes provided for independent reading and third grade reading achievement level as measured by California Assessment of Student Performance and Progress (CAASPP) in small, rural school…

Detection of argan oil adulteration with vegetable oils by high-performance liquid chromatography-evaporative light scattering detection.

PubMed

Salghi, Rachid; Armbruster, Wolfgang; Schwack, Wolfgang

2014-06-15

Triacylglycerol profiles were selected as indicator of adulteration of argan oils to carry out a rapid screening of samples for the evaluation of authenticity. Triacylglycerols were separated by high-performance liquid chromatography-evaporative light scattering detection. Different peak area ratios were defined to sensitively detect adulteration of argan oil with vegetable oils such as sunflower, soy bean, and olive oil up to the level of 5%. Based on four reference argan oils, mean limits of detection and quantitation were calculated to approximately 0.4% and 1.3%, respectively. Additionally, 19 more argan oil reference samples were analysed by high-performance liquid chromatography-refractive index detection, resulting in highly comparative results. The overall strategy demonstrated a good applicability in practise, and hence a high potential to be transferred to routine laboratories. Copyright © 2013 Elsevier Ltd. All rights reserved.

Micro liquid chromatography-mass spectrometry with direct liquid introduction used for separation and quantitation of all-trans- and 13-cis-retinoic acids and their 4-oxo metabolites in human plasma.

PubMed

Ranalder, U B; Lausecker, B B; Huselton, C

1993-07-23

The separation and quantitation of the pentafluorobenzyl derivatives of all-trans- and 13-cis-retinoic acids and their 4-oxo metabolites in human plasma on micro high-performance liquid chromatographic columns (0.32 mm I.D.) is described. The column outlet was directly coupled to the source of a quadrupole mass spectrometer via a simple SFC-frit interface. Negative ion chemical ionization conditions were obtained by coaxial introduction of ammonia as a reagent gas. A signal-to-noise ratio well above 3 was obtained for 1 pg of each analyte injected. The limit of quantitation calculated from spiked biological plasma extracts was 0.3 ng/ml.

Students' motivation toward feedback-seeking in the clinical workplace.

PubMed

de Jong, Lubberta H; Favier, Robert P; van der Vleuten, Cees P M; Bok, Harold G J

2017-09-01

In medical education, students are increasingly regarded as active seekers of feedback rather than passive recipients. Previous research showed that in the intentions of students to seek feedback, a learning and performance goal can be distinguished. In this study, we investigated the intentions (defined as level and orientation of motivation) of different performing students (low, average, and high performing students) to seek feedback in the clinical workplace using Self-Determination Theory. We conducted a quantitative study with students in their clinical clerkships and grouped them based on their performance. The level of motivation was measured by the number of Mini-CEXs each student collected. The orientation of motivation was measured by conducting the Academic Self-Regulation Questionnaire. We found that high performing students were more motivated and demonstrated higher self-determination compared to low performing students.

Determination of vitamins D2 and D3 in selected food matrices by online high-performance liquid chromatography-gas chromatography-mass spectrometry (HPLC-GC-MS).

PubMed

Nestola, Marco; Thellmann, Andrea

2015-01-01

An online normal-phase liquid chromatography-gas chromatography-mass spectrometry (HPLC-GC-MS) method was developed for the determination of vitamins D2 and D3 in selected food matrices. Transfer of the sample from HPLC to GC was realized by large volume on-column injection; detection was performed with a time-of-flight mass spectrometer (TOF-MS). Typical GC problems in the determination of vitamin D such as sample degradation or sensitivity issues, previously reported in the literature, were not observed. Determination of total vitamin D content was done by quantitation of its pyro isomer based on an isotopically labelled internal standard (ISTD). Extracted ion traces of analyte and ISTD showed cross-contribution, but non-linearity of the calibration curve was not determined inside the chosen calibration range by selection of appropriate quantifier ions. Absolute limits of detection (LOD) and quantitation (LOQ) for vitamins D2 and D3 were calculated as approximately 50 and 150 pg, respectively. Repeatability with internal standard correction was below 2 %. Good agreement between quantitative results of an established high-performance liquid chromatography with UV detection (HPLC-UV) method and HPLC-GC-MS was found. Sterol-enriched margarine was subjected to HPLC-GC-MS and HPLC-MS/MS for comparison, because HPLC-UV showed strong matrix interferences. HPLC-GC-MS produced comparable results with less manual sample cleanup. In summary, online hyphenation of HPLC and GC allowed a minimization in manual sample preparation with an increase of sample throughput.

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.

Quantitative analysis of thoria phase in Th-U alloys using diffraction studies

NASA Astrophysics Data System (ADS)

Thakur, Shital; Krishna, P. S. R.; Shinde, A. B.; Kumar, Raj; Roy, S. B.

2017-05-01

In the present study the quantitative phase analysis of Th-U alloys in bulk form namely Th-52 wt% U and Th-3wt%U has been performed over the data obtained from both X ray diffraction and neutron diffraction technique using Rietveld method of FULLPROF software. Quantifying thoria (ThO2) phase present in bulk of the sample is limited due to surface oxidation and low penetration of x rays in high Z material. Neutron diffraction study probing bulk of the samples has been presented in comparison with x-ray diffraction study.

Polysaccharide Constituents of Three Types of Sea Urchin Shells and Their Anti-Inflammatory Activities

PubMed Central

Jiao, Heng; Shang, Xiaohui; Dong, Qi; Wang, Shuang; Liu, Xiaoyu; Zheng, Heng; Lu, Xiaoling

2015-01-01

As a source of potent anti-inflammatory traditional medicines, the quantitative chromatographic fingerprints of sea urchin shell polysaccharides were well established via pre-column derivatization high performance liquid chromatography (HPLC) analysis. Based on the quantitative results, the content of fucose and glucose could be used as preliminary distinguishing indicators among three sea urchin shell species. Besides, the anti-inflammatory activities of the polysaccharides from sea urchin shells and their gonads were also determined. The gonad polysaccharide of Anthocidaris crassispina showed the most potent anti-inflammatory activity among all samples tested. PMID:26389925

Polysaccharide Constituents of Three Types of Sea Urchin Shells and Their Anti-Inflammatory Activities.

PubMed

Jiao, Heng; Shang, Xiaohui; Dong, Qi; Wang, Shuang; Liu, Xiaoyu; Zheng, Heng; Lu, Xiaoling

2015-09-16

As a source of potent anti-inflammatory traditional medicines, the quantitative chromatographic fingerprints of sea urchin shell polysaccharides were well established via pre-column derivatization high performance liquid chromatography (HPLC) analysis. Based on the quantitative results, the content of fucose and glucose could be used as preliminary distinguishing indicators among three sea urchin shell species. Besides, the anti-inflammatory activities of the polysaccharides from sea urchin shells and their gonads were also determined. The gonad polysaccharide of Anthocidaris crassispina showed the most potent anti-inflammatory activity among all samples tested.

Comparative evaluation of two quantitative test methods for determining the efficacy of liquid sporicides and sterilants on a hard surface: a precollaborative study.

PubMed

Tomasino, Stephen F; Hamilton, Martin A

2007-01-01

Two quantitative carrier-based test methods for determining the efficacy of liquid sporicides and sterilants on a hard surface, the Standard Quantitative Carrier Test Method-ASTM E 2111-00 and an adaptation of a quantitative micro-method as reported by Sagripanti and Bonifacino, were compared in this study. The methods were selected based on their desirable characteristics (e.g., well-developed protocol, previous use with spores, fully quantitative, and use of readily available equipment) for testing liquid sporicides and sterilants on a hard surface. In this paper, the Sagripanti-Bonifacino procedure is referred to as the Three Step Method (TSM). AOAC Official Method 966.04 was included in this study as a reference method. Three laboratories participated in the evaluation. Three chemical treatments were tested: (1) 3000 ppm sodium hypochlorite with pH adjusted to 7.0, (2) a hydrogen peroxide/peroxyacetic acid product, and (3) 3000 ppm sodium hypochlorite with pH unadjusted (pH of approximately 10.0). A fourth treatment, 6000 ppm sodium hypochlorite solution with pH adjusted to 7.0, was included only for Method 966.04 as a positive control (high level of efficacy). The contact time was 10 min for all chemical treatments except the 6000 ppm sodium hypochlorite treatment which was tested at 30 min. Each chemical treatment was tested 3 times using each of the methods. Only 2 of the laboratories performed the AOAC method. Method performance was assessed by the within-laboratory variance, between-laboratory variance, and total variance associated with the log reduction (LR) estimates generated by each quantitative method. The quantitative methods performed similarly, and the LR values generated by each method were not statistically different for the 3 treatments evaluated. Based on feedback from the participating laboratories, compared to the TSM, ASTM E 2111-00 was more resource demanding and required more set-up time. The logistical and resource concerns identified for ASTM E 2111-00 were largely associated with the filtration process and counting bacterial colonies on filters. Thus, the TSM was determined to be the most suitable method.

GLS-Finder: A Platform for Fast Profiling of Glucosinolates in Brassica Vegetables.

PubMed

Sun, Jianghao; Zhang, Mengliang; Chen, Pei

2016-06-01

Mass spectrometry combined with related tandem techniques has become the most popular method for plant secondary metabolite characterization. We introduce a new strategy based on in-database searching, mass fragmentation behavior study, formula predicting for fast profiling of glucosinolates, a class of important compounds in brassica vegetables. A MATLAB script-based expert system computer program, "GLS-Finder", was developed. It is capable of qualitative and semi-quantitative analyses of glucosinolates in samples using data generated by ultrahigh-performance liquid chromatography-high-resolution accurate mass with multi-stage mass fragmentation (UHPLC-HRAM/MS(n)). A suite of bioinformatic tools was integrated into the "GLS-Finder" to perform raw data deconvolution, peak alignment, glucosinolate putative assignments, semi-quantitation, and unsupervised principal component analysis (PCA). GLS-Finder was successfully applied to identify intact glucosinolates in 49 commonly consumed Brassica vegetable samples in the United States. It is believed that this work introduces a new way of fast data processing and interpretation for qualitative and quantitative analyses of glucosinolates, where great efficacy was improved in comparison to identification manually.

Quantitative determination of major active components in Ginkgo biloba dietary supplements by liquid chromatography/mass spectrometry.

PubMed

Ding, Shujing; Dudley, Ed; Plummer, Sue; Tang, Jiandong; Newton, Russell P; Brenton, A Gareth

2006-01-01

A reversed-phase high-performance liquid chromatography/electrospray ionisation mass spectrometry (RP-HPLC/ESI-MS) method was developed and validated for the simultaneous determination of ten major active components in Ginkgo biloba extract (bilobalide, ginkgolides A, B, C, quercetin, kaempferol, isorhamnetin, rutin hydrate, quercetin-3-beta-D-glucoside and quercitrin hydrate) which have not been previously reported to be quantified in a single analysis. The ten components exhibit baseline separation in 50 min by C18 chromatography using a water/1:1 (v/v) methanol/acetonitrile gradient. Quantitation was performed using negative ESI-MS in selected ion monitoring (SIM) mode. Good reproducibility and recovery were obtained by this method. The sensitivity of both UV and different mass spectrometry modes (full scan, selected ion monitoring (SIM), and selected reaction monitoring (SRM)) were compared and both quantitation with and without internal standard were evaluated. The analysis of Ginkgo biloba commercial products showed remarkable variations in the rutin and quercetin content as well as the terpene lactone contents although all the products satisfy the conventional quality control method. Copyright 2006 John Wiley & Sons, Ltd.

Visual investigation on the heat dissipation process of a heat sink by using digital holographic interferometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Bingjing; Zhao, Jianlin, E-mail: jlzhao@nwpu.edu.cn; Wang, Jun

2013-11-21

We present a method for visually and quantitatively investigating the heat dissipation process of plate-fin heat sinks by using digital holographic interferometry. A series of phase change maps reflecting the temperature distribution and variation trend of the air field surrounding heat sink during the heat dissipation process are numerically reconstructed based on double-exposure holographic interferometry. According to the phase unwrapping algorithm and the derived relationship between temperature and phase change of the detection beam, the full-field temperature distributions are quantitatively obtained with a reasonably high measurement accuracy. And then the impact of heat sink's channel width on the heat dissipationmore » performance in the case of natural convection is analyzed. In addition, a comparison between simulation and experiment results is given to verify the reliability of this method. The experiment results certify the feasibility and validity of the presented method in full-field, dynamical, and quantitative measurement of the air field temperature distribution, which provides a basis for analyzing the heat dissipation performance of plate-fin heat sinks.« less

Comparative Performance of Reagents and Platforms for Quantitation of Cytomegalovirus DNA by Digital PCR

PubMed Central

Gu, Z.; Sam, S. S.; Sun, Y.; Tang, L.; Pounds, S.; Caliendo, A. M.

2016-01-01

A potential benefit of digital PCR is a reduction in result variability across assays and platforms. Three sets of PCR reagents were tested on two digital PCR systems (Bio-Rad and RainDance), using three different sets of PCR reagents for quantitation of cytomegalovirus (CMV). Both commercial quantitative viral standards and 16 patient samples (n = 16) were tested. Quantitative accuracy (compared to nominal values) and variability were determined based on viral standard testing results. Quantitative correlation and variability were assessed with pairwise comparisons across all reagent-platform combinations for clinical plasma sample results. The three reagent sets, when used to assay quantitative standards on the Bio-Rad system, all showed a high degree of accuracy, low variability, and close agreement with one another. When used on the RainDance system, one of the three reagent sets appeared to have a much better correlation to nominal values than did the other two. Quantitative results for patient samples showed good correlation in most pairwise comparisons, with some showing poorer correlations when testing samples with low viral loads. Digital PCR is a robust method for measuring CMV viral load. Some degree of result variation may be seen, depending on platform and reagents used; this variation appears to be greater in samples with low viral load values. PMID:27535685

The Quantitative Reasoning for College Science (QuaRCS) Assessment: Emerging Themes from 5 Years of Data

NASA Astrophysics Data System (ADS)

Follette, Katherine; Dokter, Erin; Buxner, Sanlyn

2018-01-01

The Quantitative Reasoning for College Science (QuaRCS) Assessment is a validated assessment instrument that was designed to measure changes in students' quantitative reasoning skills, attitudes toward mathematics, and ability to accurately assess their own quantitative abilities. It has been administered to more than 5,000 students at a variety of institutions at the start and end of a semester of general education college science instruction. I will begin by briefly summarizing our published work surrounding validation of the instrument and identification of underlying attitudinal factors (composite variables identified via factor analysis) that predict 50% of the variation in students' scores on the assessment. I will then discuss more recent unpublished work, including: (1) Development and validation of an abbreviated version of the assessment (The QuaRCS Light), which results in marked improvements in students' ability to maintain a high effort level throughout the assessment and has broad implications for quantitative reasoning assessments in general, and (2) Our efforts to revise the attitudinal portion of the assessment to better assess math anxiety level, another key factor in student performance on numerical assessments.

The Effect of Leadership Styles on Learners' Performance. The Case of Asonomaso Nkwanta in the Kwabre District Assembly of Ashanti Region in Ghana

ERIC Educational Resources Information Center

Gyasi, Richard Sarfo; Xi, Wang Bao; Owusu-Ampomah, Yvonne

2016-01-01

The purpose of this study was to explore the effect of leadership styles on academic performance in Junior High Schools (JHS) in Asonomaso Nkwanta in the Kwabre District Assembly of Ashanti Region in Ghana. The design for the study was a mixed study using both the qualitative and quantitative analyzes. It was a correlation survey designed to…

Separation and quantitation of colour pigments of chili powder (Capsicum frutescens) by high-performance liquid chromatography-diode array detection.

PubMed

Cserháti, T; Forgács, E; Morais, M H; Mota, T; Ramos, A

2000-10-27

The performance of reversed-phase thin-layer (RP-TLC) and reversed-phase high-performance liquid chromatography (RP-HPLC) was compared for the separation and determination of the colour pigments of chili (Capsicum frutescens) powder using a wide variety of eluent systems. No separation of pigments was achieved in RP-TLC, however, it was established that tetrahydrofuran shows an unusually high solvent strength. RP-HPLC using water-methanol-acetonitrile gradient elution separated the chili pigments in many fractions. Diode array detection (DAD) indicated that yellow pigments are eluted earlier than the red ones and chili powder contains more yellow pigments than common paprika powders. It was established that the very different absorption spectra of pigments make the use of DAD necessary.

Note: Evaluation of microfracture strength of diamond materials using nano-polycrystalline diamond spherical indenter

NASA Astrophysics Data System (ADS)

Sumiya, H.; Hamaki, K.; Harano, K.

2018-05-01

Ultra-hard and high-strength spherical indenters with high precision and sphericity were successfully prepared from nanopolycrystalline diamond (NPD) synthesized by direct conversion sintering from graphite under high pressure and high temperature. It was shown that highly accurate and stable microfracture strength tests can be performed on various super-hard diamond materials by using the NPD spherical indenters. It was also verified that this technique enables quantitative evaluation of the strength characteristics of single crystal diamonds and NPDs which have been quite difficult to evaluate.

[Determination by high performance chromatography, steroid saponins in a biologically active food supplements containing the extract of Tribulus terrestris].

PubMed

Kozlova, O I; Perederiaev, O I; Ramenskaia, G V

2011-01-01

Steroidal saponins are bioactive substances of Tribulus terrestris and can be used to assess the quality of raw materials and processed products from them. For this purpose has been developed the method of qualitative and quantitative determination of steroidal saponins by high performance liquid chromatography with spectrophotometric and mass-selective detection and optimal conditions of sample preparation (70% methanol extraction with sonication and heating); also has been studied steroidal saponins composition of Tribulus terrestris (protodioscin, tribulosaponin B, metilprotodiostsin, terrestrozin H, prototribestin, gracillin and others were found).

A Focused Multiple Reaction Monitoring (MRM) Quantitative Method for Bioactive Grapevine Stilbenes by Ultra-High-Performance Liquid Chromatography Coupled to Triple-Quadrupole Mass Spectrometry (UHPLC-QqQ).

PubMed

Hurtado-Gaitán, Elías; Sellés-Marchart, Susana; Martínez-Márquez, Ascensión; Samper-Herrero, Antonio; Bru-Martínez, Roque

2017-03-07

Grapevine stilbenes are a family of polyphenols which derive from trans -resveratrol having antifungal and antimicrobial properties, thus being considered as phytoalexins. In addition to their diverse bioactive properties in animal models, they highlight a strong potential in human health maintenance and promotion. Due to this relevance, highly-specific qualitative and quantitative methods of analysis are necessary to accurately analyze stilbenes in different matrices derived from grapevine. Here, we developed a rapid, sensitive, and specific analysis method using ultra-high-performance liquid chromatography coupled to triple-quadrupole mass spectrometry (UHPLC-QqQ) in MRM mode to detect and quantify five grapevine stilbenes, trans -resveratrol, trans -piceid, trans -piceatannol, trans -pterostilbene, and trans -ε-viniferin, whose interest in relation to human health is continuously growing. The method was optimized to minimize in-source fragmentation of piceid and to avoid co-elution of cis -piceid and trans -resveratrol, as both are detected with resveratrol transitions. The applicability of the developed method of stilbene analysis was tested successfully in different complex matrices including cellular extracts of Vitis vinifera cell cultures, reaction media of biotransformation assays, and red wine.

Quantitative high-performance liquid chromatography of nucleosides in biological materials.

PubMed

Gehrke, C W; Kuo, K C; Davis, G E; Suits, R D; Waalkes, T P; Borek, E

1978-03-21

A rigorous, comprehensive, and reliable reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the analysis of ribonucleosides in urine (psi, m1A, m1I, m2G, A, m2(2)G). An initial isolation of ribonucleosides with an affinity gel containing an immobilized phenylboronic acid was used to improve selectivity and sensitivity. Response for all nucleosides was linear from 0.1 to 50 nmoles injected and good quantitation was obtained for 25 microliter or less of sample placed on the HPLC column. Excellent precision of analysis for urinary nucleosides was achieved on matrix dependent and independent samples, and the high resolution of the reversed-phase column allowed the complete separation of 9 nucleosides from other unidentified UV absorbing components at the 1-ng level. Supporting experimental data are presented on precision, recovery, chromatographic methods, minimum detection limit, retention time, relative molar response, sample clean-up, stability of nucleosides, boronate gel capacity, and application to analysis of urine from patients with leukemia and breast cancer. This method is now being used routinely for the determination of the concentration and ratios of nucleosides in urine from patients with different types of cancer and in chemotherapy response studies.

Nonesterified fatty acid determination for functional lipidomics: comprehensive ultrahigh performance liquid chromatography-tandem mass spectrometry quantitation, qualification, and parameter prediction.

PubMed

Hellmuth, Christian; Weber, Martina; Koletzko, Berthold; Peissner, Wolfgang

2012-02-07

Despite their central importance for lipid metabolism, straightforward quantitative methods for determination of nonesterified fatty acid (NEFA) species are still missing. The protocol presented here provides unbiased quantitation of plasma NEFA species by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Simple deproteination of plasma in organic solvent solution yields high accuracy, including both the unbound and initially protein-bound fractions, while avoiding interferences from hydrolysis of esterified fatty acids from other lipid classes. Sample preparation is fast and nonexpensive, hence well suited for automation and high-throughput applications. Separation of isotopologic NEFA is achieved using ultrahigh-performance liquid chromatography (UPLC) coupled to triple quadrupole LC-MS/MS detection. In combination with automated liquid handling, total assay time per sample is less than 15 min. The analytical spectrum extends beyond readily available NEFA standard compounds by a regression model predicting all the relevant analytical parameters (retention time, ion path settings, and response factor) of NEFA species based on chain length and number of double bonds. Detection of 50 NEFA species and accurate quantification of 36 NEFA species in human plasma is described, the highest numbers ever reported for a LC-MS application. Accuracy and precision are within widely accepted limits. The use of qualifier ions supports unequivocal analyte verification. © 2012 American Chemical Society

Constellation Ground Systems Launch Availability Analysis: Enhancing Highly Reliable Launch Systems Design

NASA Technical Reports Server (NTRS)

Gernand, Jeffrey L.; Gillespie, Amanda M.; Monaghan, Mark W.; Cummings, Nicholas H.

2010-01-01

Success of the Constellation Program's lunar architecture requires successfully launching two vehicles, Ares I/Orion and Ares V/Altair, within a very limited time period. The reliability and maintainability of flight vehicles and ground systems must deliver a high probability of successfully launching the second vehicle in order to avoid wasting the on-orbit asset launched by the first vehicle. The Ground Operations Project determined which ground subsystems had the potential to affect the probability of the second launch and allocated quantitative availability requirements to these subsystems. The Ground Operations Project also developed a methodology to estimate subsystem reliability, availability, and maintainability to ensure that ground subsystems complied with allocated launch availability and maintainability requirements. The verification analysis developed quantitative estimates of subsystem availability based on design documentation, testing results, and other information. Where appropriate, actual performance history was used to calculate failure rates for legacy subsystems or comparative components that will support Constellation. The results of the verification analysis will be used to assess compliance with requirements and to highlight design or performance shortcomings for further decision making. This case study will discuss the subsystem requirements allocation process, describe the ground systems methodology for completing quantitative reliability, availability, and maintainability analysis, and present findings and observation based on analysis leading to the Ground Operations Project Preliminary Design Review milestone.

Multiplexed MRM-based assays for the quantitation of proteins in mouse plasma and heart tissue.

PubMed

Percy, Andrew J; Michaud, Sarah A; Jardim, Armando; Sinclair, Nicholas J; Zhang, Suping; Mohammed, Yassene; Palmer, Andrea L; Hardie, Darryl B; Yang, Juncong; LeBlanc, Andre M; Borchers, Christoph H

2017-04-01

The mouse is the most commonly used laboratory animal, with more than 14 million mice being used for research each year in North America alone. The number and diversity of mouse models is increasing rapidly through genetic engineering strategies, but detailed characterization of these models is still challenging because most phenotypic information is derived from time-consuming histological and biochemical analyses. To expand the biochemists' toolkit, we generated a set of targeted proteomic assays for mouse plasma and heart tissue, utilizing bottom-up LC/MRM-MS with isotope-labeled peptides as internal standards. Protein quantitation was performed using reverse standard curves, with LC-MS platform and curve performance evaluated by quality control standards. The assays comprising the final panel (101 peptides for 81 proteins in plasma; 227 peptides for 159 proteins in heart tissue) have been rigorously developed under a fit-for-purpose approach and utilize stable-isotope labeled peptides for every analyte to provide high-quality, precise relative quantitation. In addition, the peptides have been tested to be interference-free and the assay is highly multiplexed, with reproducibly determined protein concentrations spanning >4 orders of magnitude. The developed assays have been used in a small pilot study to demonstrate their application to molecular phenotyping or biomarker discovery/verification studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantitative EEG analysis using error reduction ratio-causality test; validation on simulated and real EEG data.

PubMed

Sarrigiannis, Ptolemaios G; Zhao, Yifan; Wei, Hua-Liang; Billings, Stephen A; Fotheringham, Jayne; Hadjivassiliou, Marios

2014-01-01

To introduce a new method of quantitative EEG analysis in the time domain, the error reduction ratio (ERR)-causality test. To compare performance against cross-correlation and coherence with phase measures. A simulation example was used as a gold standard to assess the performance of ERR-causality, against cross-correlation and coherence. The methods were then applied to real EEG data. Analysis of both simulated and real EEG data demonstrates that ERR-causality successfully detects dynamically evolving changes between two signals, with very high time resolution, dependent on the sampling rate of the data. Our method can properly detect both linear and non-linear effects, encountered during analysis of focal and generalised seizures. We introduce a new quantitative EEG method of analysis. It detects real time levels of synchronisation in the linear and non-linear domains. It computes directionality of information flow with corresponding time lags. This novel dynamic real time EEG signal analysis unveils hidden neural network interactions with a very high time resolution. These interactions cannot be adequately resolved by the traditional methods of coherence and cross-correlation, which provide limited results in the presence of non-linear effects and lack fidelity for changes appearing over small periods of time. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

A Quantitative and Qualitative Assessment of Verbal Short-Term Memory and Phonological Processing in 8-Year-Olds with a History of Repetitive Otitis Media

ERIC Educational Resources Information Center

Majerus, Steve; Amand, Pierre; Boniver, Vincent; Demanez, Jean-Pierre; Demanez, Laurent; Van der Linden, Martial

2005-01-01

Language outcome in children experiencing fluctuant hearing loss due to otitis media (OME) remains highly equivocal. In the current study, we assessed performance on highly sensitive verbal short-term memory (STM), new word learning and phonological processing tasks in 8-year-old children who had suffered from recurrent OME before the age of 3.…

Application of High-Performance Liquid Chromatography Coupled with Linear Ion Trap Quadrupole Orbitrap Mass Spectrometry for Qualitative and Quantitative Assessment of Shejin-Liyan Granule Supplements.

PubMed

Gu, Jifeng; Wu, Weijun; Huang, Mengwei; Long, Fen; Liu, Xinhua; Zhu, Yizhun

2018-04-11

A method for high-performance liquid chromatography coupled with linear ion trap quadrupole Orbitrap high-resolution mass spectrometry (HPLC-LTQ-Orbitrap MS) was developed and validated for the qualitative and quantitative assessment of Shejin-liyan Granule. According to the fragmentation mechanism and high-resolution MS data, 54 compounds, including fourteen isoflavones, eleven ligands, eight flavonoids, six physalins, six organic acids, four triterpenoid saponins, two xanthones, two alkaloids, and one licorice coumarin, were identified or tentatively characterized. In addition, ten of the representative compounds (matrine, galuteolin, tectoridin, iridin, arctiin, tectorigenin, glycyrrhizic acid, irigenin, arctigenin, and irisflorentin) were quantified using the validated HPLC-LTQ-Orbitrap MS method. The method validation showed a good linearity with coefficients of determination (r²) above 0.9914 for all analytes. The accuracy of the intra- and inter-day variation of the investigated compounds was 95.0-105.0%, and the precision values were less than 4.89%. The mean recoveries and reproducibilities of each analyte were 95.1-104.8%, with relative standard deviations below 4.91%. The method successfully quantified the ten compounds in Shejin-liyan Granule, and the results show that the method is accurate, sensitive, and reliable.

An optimized method for neurotransmitters and their metabolites analysis in mouse hypothalamus by high performance liquid chromatography-Q Exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry.

PubMed

Yang, Zong-Lin; Li, Hui; Wang, Bing; Liu, Shu-Ying

2016-02-15

Neurotransmitters (NTs) and their metabolites are known to play an essential role in maintaining various physiological functions in nervous system. However, there are many difficulties in the detection of NTs together with their metabolites in biological samples. A new method for NTs and their metabolites detection by high performance liquid chromatography coupled with Q Exactive hybrid quadruple-orbitrap high-resolution accurate mass spectrometry (HPLC-HRMS) was established in this paper. This method was a great development of the applying of Q Exactive MS in the quantitative analysis. This method enabled a rapid quantification of ten compounds within 18min. Good linearity was obtained with a correlation coefficient above 0.99. The concentration range of the limit of detection (LOD) and the limit of quantitation (LOQ) level were 0.0008-0.05nmol/mL and 0.002-25.0nmol/mL respectively. Precisions (relative standard deviation, RSD) of this method were at 0.36-12.70%. Recovery ranges were between 81.83% and 118.04%. Concentrations of these compounds in mouse hypothalamus were detected by Q Exactive LC-MS technology with this method. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantitative High-Throughput Luciferase Screening in Identifying CAR Modulators.

PubMed

Lynch, Caitlin; Zhao, Jinghua; Wang, Hongbing; Xia, Menghang

2016-01-01

The constitutive androstane receptor (CAR, NR1I3) is responsible for the transcription of multiple drug metabolizing enzymes and transporters. There are two possible methods of activation for CAR, direct ligand binding and a ligand-independent method, which makes this a unique nuclear receptor. Both of these mechanisms require translocation of CAR from the cytoplasm into the nucleus. Interestingly, CAR is constitutively active in immortalized cell lines due to the basal nuclear location of this receptor. This creates an important challenge in most in vitro assay models because immortalized cells cannot be used without inhibiting the high basal activity. In this book chapter, we go into detail of how to perform quantitative high-throughput screens to identify hCAR1 modulators through the employment of a double stable cell line. Using this line, we are able to identify activators, as well as deactivators, of the challenging nuclear receptor, CAR.

Cell classification using big data analytics plus time stretch imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Jalali, Bahram; Chen, Claire L.; Mahjoubfar, Ata

2016-09-01

We show that blood cells can be classified with high accuracy and high throughput by combining machine learning with time stretch quantitative phase imaging. Our diagnostic system captures quantitative phase images in a flow microscope at millions of frames per second and extracts multiple biophysical features from individual cells including morphological characteristics, light absorption and scattering parameters, and protein concentration. These parameters form a hyperdimensional feature space in which supervised learning and cell classification is performed. We show binary classification of T-cells against colon cancer cells, as well classification of algae cell strains with high and low lipid content. The label-free screening averts the negative impact of staining reagents on cellular viability or cell signaling. The combination of time stretch machine vision and learning offers unprecedented cell analysis capabilities for cancer diagnostics, drug development and liquid biopsy for personalized genomics.

Demonstration of a diode-laser-based high spectral resolution lidar (HSRL) for quantitative profiling of clouds and aerosols.

PubMed

Hayman, Matthew; Spuler, Scott

2017-11-27

We present a demonstration of a diode-laser-based high spectral resolution lidar. It is capable of performing calibrated retrievals of aerosol and cloud optical properties at a 150 m range resolution with less than 1 minute integration time over an approximate range of 12 km during day and night. This instrument operates at 780 nm, a wavelength that is well established for reliable semiconductor lasers and detectors, and was chosen because it corresponds to the D2 rubidium absorption line. A heated vapor reference cell of isotopic rubidium 87 is used as an effective and reliable aerosol signal blocking filter in the instrument. In principle, the diode-laser-based high spectral resolution lidar can be made cost competitive with elastic backscatter lidar systems, yet delivers a significant improvement in data quality through direct retrieval of quantitative optical properties of clouds and aerosols.

Gender, Math Confidence, and Grit: Relationships with Quantitative Skills and Performance in an Undergraduate Biology Course

PubMed Central

Flanagan, K. M.; Einarson, J.

2017-01-01

In a world filled with big data, mathematical models, and statistics, the development of strong quantitative skills is becoming increasingly critical for modern biologists. Teachers in this field must understand how students acquire quantitative skills and explore barriers experienced by students when developing these skills. In this study, we examine the interrelationships among gender, grit, and math confidence for student performance on a pre–post quantitative skills assessment and overall performance in an undergraduate biology course. Here, we show that females significantly underperformed relative to males on a quantitative skills assessment at the start of term. However, females showed significantly higher gains over the semester, such that the gender gap in performance was nearly eliminated by the end of the semester. Math confidence plays an important role in the performance on both the pre and post quantitative skills assessments and overall performance in the course. The effect of grit on student performance, however, is mediated by a student’s math confidence; as math confidence increases, the positive effect of grit decreases. Consequently, the positive impact of a student’s grittiness is observed most strongly for those students with low math confidence. We also found grit to be positively associated with the midterm score and the final grade in the course. Given the relationships established in this study among gender, grit, and math confidence, we provide “instructor actions” from the literature that can be applied in the classroom to promote the development of quantitative skills in light of our findings. PMID:28798209

Carotid lesion characterization by synthetic-aperture-imaging techniques with multioffset ultrasonic probes

NASA Astrophysics Data System (ADS)

Capineri, Lorenzo; Castellini, Guido; Masotti, Leonardo F.; Rocchi, Santina

1992-06-01

This paper explores the applications of a high-resolution imaging technique to vascular ultrasound diagnosis, with emphasis on investigation of the carotid vessel. With the present diagnostic systems, it is difficult to measure quantitatively the extension of the lesions and to characterize the tissue; quantitative images require enough spatial resolution and dynamic to reveal fine high-risk pathologies. A broadband synthetic aperture technique with multi-offset probes is developed to improve the lesion characterization by the evaluation of local scattering parameters. This technique works with weak scatterers embedded in a constant velocity medium, large aperture, and isotropic sources and receivers. The features of this technique are: axial and lateral spatial resolution of the order of the wavelength, high dynamic range, quantitative measurements of the size and scattering intensity of the inhomogeneities, and capabilities of investigation of inclined layer. The evaluation of the performances in real condition is carried out by a software simulator in which different experimental situations can be reproduced. Images of simulated anatomic test-objects are presented. The images are obtained with an inversion process of the synthesized ultrasonic signals, collected on the linear aperture by a limited number of finite size transducers.

Pushing quantitation limits in micro UHPLC-MS/MS analysis of steroid hormones by sample dilution using high volume injection.

PubMed

Márta, Zoltán; Bobály, Balázs; Fekete, Jenő; Magda, Balázs; Imre, Tímea; Mészáros, Katalin Viola; Szabó, Pál Tamás

2016-09-10

Ultratrace analysis of sample components requires excellent analytical performance in terms of limits of quantitation (LoQ). Micro UHPLC coupling with sensitive tandem mass spectrometry provides state of the art solutions for such analytical problems. Decreased column volume in micro LC limits the injectable sample volume. However, if analyte concentration is extremely low, it might be necessary to inject high sample volumes. This is particularly critical for strong sample solvents and weakly retained analytes, which are often the case when preparing biological samples (protein precipitation, sample extraction, etc.). In that case, high injection volumes may cause band broadening, peak distortion or even elution in dead volume. In this study, we evaluated possibilities of high volume injection onto microbore RP-LC columns, when sample solvent is diluted. The presented micro RP-LC-MS/MS method was optimized for the analysis of steroid hormones from human plasma after protein precipitation with organic solvents. A proper sample dilution procedure helps to increase the injection volume without compromising peak shapes. Finally, due to increased injection volume, the limit of quantitation can be decreased by a factor of 2-5, depending on the analytes and the experimental conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Motivation, Compensation, and Performance for Science and Technological Teachers

NASA Astrophysics Data System (ADS)

Abast, R. M.; Sangi, N. M.; Tumanduk, M. S. S. S.; Roring, R.

2018-02-01

This research is operationally aimed to obtain the result of analysis and interpretation about: relationship of achievement motive, compensation with performance at a junior high school in Manado, Indonesia. This research applies a quantitative approach with correlation analysis method. The research was conducted at one junior high school in Manado, Indonesia. The results showed achievement motive at the school teachers is quite high. This result means that, generally, the teachers of the school have a desire to improve achievement; the performance at the school is good enough. This result means that in general, the performance of teachers at the school is increasing, there is a linkage degree and determinative power between the achievement motive with the performance of teachers at the school amounted 0.773% or 77.3%, compensation for the school teachers in Manado is good enough. This result means that the compensation received is satisfactory, there is a linkage degree and determinative power between compensation and performance of the school teachers in Manado amounted to 0.582 or 58.2%.

High-throughput fabrication and screening improves gold nanoparticle chemiresistor sensor performance.

PubMed

Hubble, Lee J; Cooper, James S; Sosa-Pintos, Andrea; Kiiveri, Harri; Chow, Edith; Webster, Melissa S; Wieczorek, Lech; Raguse, Burkhard

2015-02-09

Chemiresistor sensor arrays are a promising technology to replace current laboratory-based analysis instrumentation, with the advantage of facile integration into portable, low-cost devices for in-field use. To increase the performance of chemiresistor sensor arrays a high-throughput fabrication and screening methodology was developed to assess different organothiol-functionalized gold nanoparticle chemiresistors. This high-throughput fabrication and testing methodology was implemented to screen a library consisting of 132 different organothiol compounds as capping agents for functionalized gold nanoparticle chemiresistor sensors. The methodology utilized an automated liquid handling workstation for the in situ functionalization of gold nanoparticle films and subsequent automated analyte testing of sensor arrays using a flow-injection analysis system. To test the methodology we focused on the discrimination and quantitation of benzene, toluene, ethylbenzene, p-xylene, and naphthalene (BTEXN) mixtures in water at low microgram per liter concentration levels. The high-throughput methodology identified a sensor array configuration consisting of a subset of organothiol-functionalized chemiresistors which in combination with random forests analysis was able to predict individual analyte concentrations with overall root-mean-square errors ranging between 8-17 μg/L for mixtures of BTEXN in water at the 100 μg/L concentration. The ability to use a simple sensor array system to quantitate BTEXN mixtures in water at the low μg/L concentration range has direct and significant implications to future environmental monitoring and reporting strategies. In addition, these results demonstrate the advantages of high-throughput screening to improve the performance of gold nanoparticle based chemiresistors for both new and existing applications.

Metabolite fingerprinting of Camptotheca acuminata and the HPLC-ESI-MS/MS analysis of camptothecin and related alkaloids.

PubMed

Montoro, Paola; Maldini, Mariateresa; Piacente, Sonia; Macchia, Mario; Pizza, Cosimo

2010-01-20

The major phytochemical constituents, namely, alkaloids, flavonoids and ellagic acid derivatives, of leaves of Camptotheca acuminata were identified using high performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry (ESI-MS) in extracts of plants cultivated in Italy and collected at different growth stages. Alkaloids related to camptothecin were identified and quantified by HPLC coupled with ESI-tandem mass spectrometry (MS/MS) employing, respectively, an ion trap and a triple quadrupole mass analyser. The fragmentation patterns of alkaloids related to camptothecin were analysed and a specific Multiple Reaction Monitoring HPLC-MS/MS method was developed for the quantitative determination of these constituents. The described method provides high sensitivity and specificity for the characterisation and quantitative determination of the alkaloids in C. acuminata.

Shape Matters: Intravital Microscopy Reveals Surprising Geometrical Dependence for Nanoparticles in Tumor Models of Extravasation

PubMed Central

Smith, Bryan Ronain; Kempen, Paul; Bouley, Donna; Xu, Alexander; Liu, Zhuang; Melosh, Nicholas; Dai, Hongjie; Sinclair, Robert; Gambhir, Sanjiv Sam

2012-01-01

Delivery is one of the most critical obstacles confronting nanoparticle use in cancer diagnosis and therapy. For most oncological applications, nanoparticles must extravasate in order to reach tumor cells and perform their designated task. However, little understanding exists regarding the effect of nanoparticle shape on extravasation. Herein we use real-time intravital microscopic imaging to meticulously examine how two different nanoparticles behave across three different murine tumor models. The study quantitatively demonstrates that high-aspect ratio single-walled carbon nanotubes (SWNTs) display extravasational behavior surprisingly different from, and counterintuitive to, spherical nanoparticles although the nanoparticles have similar surface coatings, area, and charge. This work quantitatively indicates that nanoscale extravasational competence is highly dependent on nanoparticle geometry and is heterogeneous. PMID:22650417

A fully battery-powered inexpensive spectrophotometric system for high-sensitivity point-of-care analysis on a microfluidic chip

PubMed Central

Dou, Maowei; Lopez, Juan; Rios, Misael; Garcia, Oscar; Xiao, Chuan; Eastman, Michael

2016-01-01

A cost-effective battery-powered spectrophotometric system (BASS) was developed for quantitative point-of-care (POC) analysis on a microfluidic chip. By using methylene blue as a model analyte, we first compared the performance of the BASS with a commercial spectrophotometric system, and further applied the BASS for loop-mediated isothermal amplification (LAMP) detection and subsequent quantitative nucleic acid analysis which exhibited a comparable limit of detection to that of Nanodrop. Compared to the commercial spectrophotometric system, our spectrophotometric system is lower-cost, consumes less reagents, and has a higher detection sensitivity. Most importantly, it does not rely on external power supplies. All these features make our spectrophotometric system highly suitable for a variety of POC analyses, such as field detection. PMID:27143408

Model-Based Linkage Analysis of a Quantitative Trait.

PubMed

Song, Yeunjoo E; Song, Sunah; Schnell, Audrey H

2017-01-01

Linkage Analysis is a family-based method of analysis to examine whether any typed genetic markers cosegregate with a given trait, in this case a quantitative trait. If linkage exists, this is taken as evidence in support of a genetic basis for the trait. Historically, linkage analysis was performed using a binary disease trait, but has been extended to include quantitative disease measures. Quantitative traits are desirable as they provide more information than binary traits. Linkage analysis can be performed using single-marker methods (one marker at a time) or multipoint (using multiple markers simultaneously). In model-based linkage analysis the genetic model for the trait of interest is specified. There are many software options for performing linkage analysis. Here, we use the program package Statistical Analysis for Genetic Epidemiology (S.A.G.E.). S.A.G.E. was chosen because it also includes programs to perform data cleaning procedures and to generate and test genetic models for a quantitative trait, in addition to performing linkage analysis. We demonstrate in detail the process of running the program LODLINK to perform single-marker analysis, and MLOD to perform multipoint analysis using output from SEGREG, where SEGREG was used to determine the best fitting statistical model for the trait.

High-definition optical coherence tomography intrinsic skin ageing assessment in women: a pilot study.

PubMed

Boone, M A L M; Suppa, M; Marneffe, A; Miyamoto, M; Jemec, G B E; Del Marmol, V

2015-10-01

Several non-invasive two-dimensional techniques with different lateral resolution and measurable depth range have proved to be useful in assessing and quantifying morphological changes in skin ageing. Among these, only in vivo microscopy techniques permit histometric measurements in vivo. Qualitative and quantitative assessment of chronological (intrinsic) age-related (IAR) morphological changes of epidermis, dermo-epidermal junction (DEJ), papillary dermis (PD), papillary-reticular dermis junction and reticular dermis (RD) have been performed by high-definition optical coherence tomography in real time 3-D. HD-OCT images were taken at the internal site of the right upper arm. Qualitative HD-OCT IAR descriptors were reported at skin surface, at epidermal layer, DEJ, PD and upper RD. Quantitative evaluation of age-related compaction and backscattered intensity or brightness of different skin layers was performed by using the plugin plot z-axis profile of ImageJ(®) software permitting intensity assessment of HD-OCT (DICOM) images (3-D images). Analysis was in blind from all clinical information. Sixty, fair-skinned (Fitzpatrick types I-III) healthy females were analysed retrospectively in this study. The subjects belonged to three age groups: twenty in group I aged 20-39, twenty in group II aged 40-59 and twenty in group III aged 60-79. Only intrinsic ageing in women has been studied. Significant age-related qualitative and quantitative differences could be noticed. IAR changes in dermal matrix fibers morphology/organisation and in microvasculature were observed. The brightness and compaction of the different skin layers increased significantly with intrinsic skin ageing. The depth of visibility of fibers in RD increased significantly in the older age group. In conclusion, HD-OCT allows 3-D in vivo and real time qualitative and quantitative assessment of chronological (intrinsic) age-related morphological skin changes at high resolution from skin surface to a depth of the superficial reticular dermis.

A new technique for collection, concentration and determination of gaseous tropospheric formaldehyde

NASA Astrophysics Data System (ADS)

Cofer, Wesley R.; Edahl, Robert A.

This article describes an improved technique for making in situ measurements of gaseous tropospheric formaldehyde (CH 2O). The new technique is based on nebulization/reflux principles that have proved very effective in quantitatively scrubbing water soluble trace gases (e.g. CH 2O) into aqueous mediums, which are subsequently analyzed. Atmospheric formaldehyde extractions and analyses have been performed with the nebulization/reflux concentrator using an acidified dinitrophenylhydrazine solution that indicate that quantitative analysis of CH 2O at global background levels (˜ 0.1 ppbv) is feasible with 20-min extractions. Analysis of CH 2O, once concentrated, is accomplished using high performance liquid chromatography (HPLC) with ultraviolet photometric detection. The CH 2O-hydrazone derivative, produced by the reaction of 2,4-dinitrophenylhydrazine in H 2SO 4 acidified aqueous solution, is detected as CH 2O.

A new technique for collection, concentration and determination of gaseous tropospheric formaldehyde

NASA Technical Reports Server (NTRS)

Cofer, W. R., III; Edahl, R. A., Jr.

1986-01-01

This article describes an improved technique for making in situ measurements of gaseous tropospheric formaldehyde (CH2O). The new technique is based on nebulization/reflux principles that have proved very effective in quantitatively scrubbing water soluble trace gases (e.g., CH2O) into aqueous mediums, which are subsequently analyzed. Atmospheric formaldehyde extractions and analyses have been performed with the nebulization/reflux concentrator using an acidified dinitrophenylhydrazine solution that indicate that quantitative analysis of CH2O at global background levels (about 0.1 ppbv) is feasible with 20-min extractions. Analysis of CH2O, once concentrated, is accomplished using high performance liquid chromatography with ultraviolet photometric detection. The CH2O-hydrazone derivative, produced by the reaction of 2,4-dinitrophenylhydrazine in H2SO4 acidified aqueous solution, is detected as CH2O.

A quantitative and high-throughput assay of human papillomavirus DNA replication.

PubMed

Gagnon, David; Fradet-Turcotte, Amélie; Archambault, Jacques

2015-01-01

Replication of the human papillomavirus (HPV) double-stranded DNA genome is accomplished by the two viral proteins E1 and E2 in concert with host DNA replication factors. HPV DNA replication is an established model of eukaryotic DNA replication and a potential target for antiviral therapy. Assays to measure the transient replication of HPV DNA in transfected cells have been developed, which rely on a plasmid carrying the viral origin of DNA replication (ori) together with expression vectors for E1 and E2. Replication of the ori-plasmid is typically measured by Southern blotting or PCR analysis of newly replicated DNA (i.e., DpnI digested DNA) several days post-transfection. Although extremely valuable, these assays have been difficult to perform in a high-throughput and quantitative manner. Here, we describe a modified version of the transient DNA replication assay that circumvents these limitations by incorporating a firefly luciferase expression cassette in cis of the ori. Replication of this ori-plasmid by E1 and E2 results in increased levels of firefly luciferase activity that can be accurately quantified and normalized to those of Renilla luciferase expressed from a control plasmid, thus obviating the need for DNA extraction, digestion, and analysis. We provide a detailed protocol for performing the HPV type 31 DNA replication assay in a 96-well plate format suitable for small-molecule screening and EC50 determinations. The quantitative and high-throughput nature of the assay should greatly facilitate the study of HPV DNA replication and the identification of inhibitors thereof.

Evaluation and utilization of preassembled frozen commercial fast real-time qPCR master mixes for detection of cytomegalovirus and BK virus.

PubMed

Glover, William A; Atienza, Ederlyn E; Nesbitt, Shannon; Kim, Woo J; Castor, Jared; Cook, Linda; Jerome, Keith R

2016-01-01

Quantitative DNA detection of cytomegalovirus (CMV) and BK virus (BKV) is critical in the management of transplant patients. Quantitative laboratory-developed procedures for CMV and BKV have been described in which much of the processing is automated, resulting in rapid, reproducible, and high-throughput testing of transplant patients. To increase the efficiency of such assays, the performance and stability of four commercial preassembled frozen fast qPCR master mixes (Roche FastStart Universal Probe Master Mix with Rox, Bio-Rad SsoFast Probes Supermix with Rox, Life Technologies TaqMan FastAdvanced Master Mix, and Life Technologies Fast Universal PCR Master Mix), in combination with in-house designed primers and probes, was evaluated using controls and standards from standard CMV and BK assays. A subsequent parallel evaluation using patient samples was performed comparing the performance of freshly prepared assay mixes versus aliquoted frozen master mixes made with two of the fast qPCR mixes (Life Technologies TaqMan FastAdvanced Master Mix, and Bio-Rad SsoFast Probes Supermix with Rox), chosen based on their performance and compatibility with existing PCR cycling conditions. The data demonstrate that the frozen master mixes retain excellent performance over a period of at least 10 weeks. During the parallel testing using clinical specimens, no difference in quantitative results was observed between the preassembled frozen master mixes and freshly prepared master mixes. Preassembled fast real-time qPCR frozen master mixes perform well and represent an additional strategy laboratories can implement to reduce assay preparation times, and to minimize technical errors and effort necessary to perform clinical PCR. © 2015 Wiley Periodicals, Inc.

High Resolution Qualitative and Quantitative MR Evaluation of the Glenoid Labrum

PubMed Central

Iwasaki, Kenyu; Tafur, Monica; Chang, Eric Y.; SherondaStatum; Biswas, Reni; Tran, Betty; Bae, Won C.; Du, Jiang; Bydder, Graeme M.; Chung, Christine B.

2015-01-01

Objective To implement qualitative and quantitative MR sequences for the evaluation of labral pathology. Methods Six glenoid labra were dissected and the anterior and posterior portions were divided into normal, mildly degenerated, or severely degenerated groups using gross and MR findings. Qualitative evaluation was performed using T1-weighted, proton density-weighted (PD), spoiled gradient echo (SPGR) and ultra-short echo time (UTE) sequences. Quantitative evaluation included T2 and T1rho measurements as well as T1, T2*, and T1rho measurements acquired with UTE techniques. Results SPGR and UTE sequences best demonstrated labral fiber structure. Degenerated labra had a tendency towards decreased T1 values, increased T2/T2* values and increased T1 rho values. T2* values obtained with the UTE sequence allowed for delineation between normal, mildly degenerated and severely degenerated groups (p<0.001). Conclusion Quantitative T2* measurements acquired with the UTE technique are useful for distinguishing between normal, mildly degenerated and severely degenerated labra. PMID:26359581

Boron concentration measurements by alpha spectrometry and quantitative neutron autoradiography in cells and tissues treated with different boronated formulations and administration protocols.

PubMed

Bortolussi, Silva; Ciani, Laura; Postuma, Ian; Protti, Nicoletta; Luca Reversi; Bruschi, Piero; Ferrari, Cinzia; Cansolino, Laura; Panza, Luigi; Ristori, Sandra; Altieri, Saverio

2014-06-01

The possibility to measure boron concentration with high precision in tissues that will be irradiated represents a fundamental step for a safe and effective BNCT treatment. In Pavia, two techniques have been used for this purpose, a quantitative method based on charged particles spectrometry and a boron biodistribution imaging based on neutron autoradiography. A quantitative method to determine boron concentration by neutron autoradiography has been recently set-up and calibrated for the measurement of biological samples, both solid and liquid, in the frame of the feasibility study of BNCT. This technique was calibrated and the obtained results were cross checked with those of α spectrometry, in order to validate them. The comparisons were performed using tissues taken form animals treated with different boron administration protocols. Subsequently the quantitative neutron autoradiography was employed to measure osteosarcoma cell samples treated with BPA and with new boronated formulations. © 2013 Published by Elsevier Ltd.

Probing myocardium biomechanics using quantitative optical coherence elastography

NASA Astrophysics Data System (ADS)

Wang, Shang; Lopez, Andrew L.; Morikawa, Yuka; Tao, Ge; Li, Jiasong; Larina, Irina V.; Martin, James F.; Larin, Kirill V.

2015-03-01

We present a quantitative optical coherence elastographic method for noncontact assessment of the myocardium elasticity. The method is based on shear wave imaging optical coherence tomography (SWI-OCT), where a focused air-puff system is used to induce localized tissue deformation through a low-pressure short-duration air stream and a phase-sensitive OCT system is utilized to monitor the propagation of the induced tissue displacement with nanoscale sensitivity. The 1-D scanning of M-mode OCT imaging and the application of optical phase retrieval and mapping techniques enable the reconstruction and visualization of 2-D depth-resolved shear wave propagation in tissue with ultra-high frame rate. The feasibility of this method in quantitative elasticity measurement is demonstrated on tissue-mimicking phantoms with the estimated Young's modulus compared with uniaxial compression tests. We also performed pilot experiments on ex vivo mouse cardiac muscle tissues with normal and genetically altered cardiomyocytes. Our results indicate this noncontact quantitative optical coherence elastographic method can be a useful tool for the cardiac muscle research and studies.

A novel high-throughput method for supported liquid extraction of retinol and alpha-tocopherol from human serum and simultaneous quantitation by liquid chromatography tandem mass spectrometry.

PubMed

Hinchliffe, Edward; Rudge, James; Reed, Paul

2016-07-01

Measurement of vitamin A (retinol) and E (alpha-tocopherol) in UK clinical laboratories is currently performed exclusively by high-performance liquid chromatography with ultraviolet detection. We investigated whether retinol and alpha-tocopherol could be measured simultaneously by liquid chromatography tandem mass spectrometry. Serum samples (100 μL) were extracted using Isolute + Supported Liquid Extraction plates. Chromatography was performed on a Phenomenex Kinetex Biphenyl 2.6 μm, 50 × 2.1 mm column, and liquid chromatography tandem mass spectrometry on a Waters Acquity TQD. Injection-to-injection time was 4.3 min. The assay was validated according to published guidelines. Patient samples were used to compare liquid chromatography tandem mass spectrometry and high-performance liquid chromatography with ultraviolet detection methods. For retinol and alpha-tocopherol, respectively, the assay was linear up to 6.0 and 80.0 μmol/L, and lower limit of quantification was 0.07 and 0.26 μmol/L. Intra and interassay imprecision were within desirable analytical specifications. Analysis of quality control material aligned to NIST SRM 968e, and relative spiked recovery from human serum, both yielded results within 15% of target values. Method comparison with high-performance liquid chromatography with ultraviolet detection methodology demonstrated a negative bias for retinol and alpha-tocopherol by the liquid chromatography tandem mass spectrometry method. Analysis of United Kingdom National External Quality Assurance Scheme samples yielded mean bias from the target value of +3.0% for retinol and -11.2% for alpha-tocopherol. We have developed a novel, high-throughput method for extraction of retinol and alpha-tocopherol from human serum followed by simultaneous quantitation by liquid chromatography tandem mass spectrometry. The method offers a rapid, sensitive, specific and cost-effective alternative to high-performance liquid chromatography with ultraviolet detection methodology, and is suitable for routine clinical monitoring of patients predisposed to fat-soluble vitamin malabsorption. © The Author(s) 2015.

Assay of flavonoid aglycones from the species of genus Sideritis (Lamiaceae) from Macedonia with HPLC-UV DAD.

PubMed

Janeska, Bisera; Stefova, Marina; Alipieva, Kalina

2007-09-01

Flavonoids obtained from Sideritis species (Lamiaceae), S. raeseri and S. scardica, grown in Macedonia were studied. Qualitative and quantitative analyses of the flavonoid aglycones were performed using high-performance liquid chromatography (HPLC) with a UV diode array detector. Extracts were prepared by acid hydrolysis in acetone, re-extraction in ethyl acetate and evaporation to dryness; the residue dissolved in methanol was subjected to HPLC analysis.Isoscutellarein, chryseriol and apigenin were identified in the extracts. Also, a 4'-methyl ether derivative of isoscutellarein was found, together with hypolaetin and its methyl ether derivative, which were identified according to previously isolated glycosides and literature data. Quantitation was performed using calibration with apigenin.According to this screening analysis, the samples of the genus Sideritis from Macedonia are rich in polyhydroxy flavones and analogous with the previously studied Mediterranean Sideritis species from the Ibero-North African and Greek Sideritis species with respect to the presence of 8-OH flavones and their derivatives.

Metabolite fingerprinting of Punica granatum L. (pomegranate) polyphenols by means of high-performance liquid chromatography with diode array and electrospray ionization-mass spectrometry detection.

PubMed

Brighenti, Virginia; Groothuis, Sebastiaan Frearick; Prencipe, Francesco Pio; Amir, Rachel; Benvenuti, Stefania; Pellati, Federica

2017-01-13

The present study was aimed at the development of a new analytical method for the comprehensive multi-component analysis of polyphenols in Punica granatum L. (pomegranate) juice and peel. While pomegranate juice was directly analysed after simple centrifugation, different extraction techniques, including maceration, heat reflux extraction, ultrasound-assisted extraction and microwave-assisted extraction, were compared in order to obtain a high yield of the target analytes from pomegranate peel. Dynamic maceration with a mixture of water and ethanol 80:20 (v/v) with 0.1% of hydrochloric acid as the extraction solvent provided the best result in terms of recovery of pomegranate secondary metabolites. The quali- and quantitative analysis of pomegranate polyphenols was performed by high-performance liquid chromatography with diode array and electrospray ionization-mass spectrometry detection. The application of fused-core column technology allowed us to obtain an improvement of the chromatographic performance in comparison with that of conventional particulate stationary phases, thus enabling a good separation of all constituents in a shorter time and with low solvent usage. The analytical method was completely validated to show compliance with the International Conference on Harmonization of Technical Requirements for the Registration of Pharmaceuticals for Human Use guidelines and successfully applied to the characterisation of commercial and experimental pomegranate samples, thus demonstrating its efficiency as a tool for the fingerprinting of this plant material. The quantitative data collected were submitted to principal component analysis, in order to highlight the possible presence of pomegranate samples with high content of secondary metabolites. From the statistical analysis, four experimental samples showed a notable content of bioactive compounds in the peels, while commercial ones still represent the best source of healthy juice. Copyright © 2016 Elsevier B.V. All rights reserved.

GLS-Finder: An Automated Data-Mining System for Fast Profiling Glucosinolates and its Application in Brassica Vegetables

USDA-ARS?s Scientific Manuscript database

A rapid computer-aided program for profiling glucosinolates, “GLS-Finder", was developed. GLS-Finder is a Matlab script based expert system that is capable for qualitative and semi-quantitative analysis of glucosinolates in samples using data generated by ultra-high performance liquid chromatograph...

Students' Achievements and Misunderstandings When Solving Problems Using Electronics Models--A Case Study

ERIC Educational Resources Information Center

Trotskovsky, Elena; Sabag, Nissim; Waks, Shlomo

2015-01-01

This paper examines students' achievements in solving problems and their misunderstandings when using models. A mixed research methodology was applied. Quantitative research investigated how the performance of students with various levels of high school GPAs correlated with their rating of their lecturers' teaching proficiency. Four lecturers and…

Determination of Beet Root Betanin in Dairy Products by High-Performance Liquid Chromatography (HPLC)

ERIC Educational Resources Information Center

Gandia-Herrero, Fernando; Simon-Carrillo, Ana; Escribano, Josefa; Garcia-Carmona, Francisco

2012-01-01

The food industry uses different additives to give foods and beverages the appearance expected by the consumer. Among them, pigments of natural origin are receiving increasing attention due to safety concerns about traditional colorants and the relevance of a healthy diet. This experiment describes the quantitative determination of the…

Evaluating Serious Games through User Experience and Performance Assessment

ERIC Educational Resources Information Center

Barton, Irving Gary, Jr.

2017-01-01

Military education is held to high standards for our servicemen and women. The purpose of this quantitative, comparative study was to determine if significant differences existed in learning styles relative to military experience as determined by learning in a serious game environment. Study results are expected to advance the state of research in…

Matrix effects break the LC behavior rule for analytes in LC-MS/MS analysis of biological samples

USDA-ARS?s Scientific Manuscript database

High-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) are generally accepted as the preferred techniques for detecting and quantitating analytes of interest in biological matrices on the basis of the rule that one chemical compound yields one LC-...

Quantitative relations between interaction parameter, miscibility and function in organic solar cells

NASA Astrophysics Data System (ADS)

Ye, Long; Hu, Huawei; Ghasemi, Masoud; Wang, Tonghui; Collins, Brian A.; Kim, Joo-Hyun; Jiang, Kui; Carpenter, Joshua H.; Li, Hong; Li, Zhengke; McAfee, Terry; Zhao, Jingbo; Chen, Xiankai; Lai, Joshua Lin Yuk; Ma, Tingxuan; Bredas, Jean-Luc; Yan, He; Ade, Harald

2018-03-01

Although it is known that molecular interactions govern morphology formation and purity of mixed domains of conjugated polymer donors and small-molecule acceptors, and thus largely control the achievable performance of organic solar cells, quantifying interaction-function relations has remained elusive. Here, we first determine the temperature-dependent effective amorphous-amorphous interaction parameter, χaa(T), by mapping out the phase diagram of a model amorphous polymer:fullerene material system. We then establish a quantitative `constant-kink-saturation' relation between χaa and the fill factor in organic solar cells that is verified in detail in a model system and delineated across numerous high- and low-performing materials systems, including fullerene and non-fullerene acceptors. Our experimental and computational data reveal that a high fill factor is obtained only when χaa is large enough to lead to strong phase separation. Our work outlines a basis for using various miscibility tests and future simulation methods that will significantly reduce or eliminate trial-and-error approaches to material synthesis and device fabrication of functional semiconducting blends and organic blends in general.

Quantitative Determination of Cannabinoids in Cannabis and Cannabis Products Using Ultra-High-Performance Supercritical Fluid Chromatography and Diode Array/Mass Spectrometric Detection.

PubMed

Wang, Mei; Wang, Yan-Hong; Avula, Bharathi; Radwan, Mohamed M; Wanas, Amira S; Mehmedic, Zlatko; van Antwerp, John; ElSohly, Mahmoud A; Khan, Ikhlas A

2017-05-01

Ultra-high-performance supercritical fluid chromatography (UHPSFC) is an efficient analytical technique and has not been fully employed for the analysis of cannabis. Here, a novel method was developed for the analysis of 30 cannabis plant extracts and preparations using UHPSFC/PDA-MS. Nine of the most abundant cannabinoids, viz. CBD, ∆ 8 -THC, THCV, ∆ 9 -THC, CBN, CBG, THCA-A, CBDA, and CBGA, were quantitatively determined (RSDs < 6.9%). Unlike GC methods, no derivatization or decarboxylation was required prior to UHPSFC analysis. The UHPSFC chromatographic separation of cannabinoids displayed an inverse elution order compared to UHPLC. Combining with PDA-MS, this orthogonality is valuable for discrimination of cannabinoids in complex matrices. The developed method was validated, and the quantification results were compared with a standard UHPLC method. The RSDs of these two methods were within ±13.0%. Finally, chemometric analysis including principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were used to differentiate between cannabis samples. © 2016 American Academy of Forensic Sciences.

Using Reference Quantitative Polymerase Chain Reaction to Assess the Clinical Performance of the Paracheck-Pf® Rapid Diagnostic Test in a Field Setting in Uganda.

PubMed

Mitran, Catherine J; Mbonye, Anthony K; Hawkes, Michael; Yanow, Stephanie K

2018-06-04

Malaria rapid diagnostic tests (RDTs) are widely used in clinical and surveillance settings. However, the performance of most RDTs has not been characterized at parasite densities below detection by microscopy. We present findings from Uganda, where RDT results from 491 participants with suspected malaria were correlated with quantitative polymerase chain reaction (qPCR)-defined parasitemia. Compared with qPCR, the sensitivity and specificity of the RDT for Plasmodium falciparum mono-infections were 76% (95% confidence interval [CI]: 68-83%) and 95% (95% CI: 92-97%), respectively. The sensitivity of the RDT at parasite densities between 0.2 and 200 parasites/μL was surprisingly high (87%, 95% CI: 74-94%). The high sensitivity of the RDT is likely because of histidine-rich protein 2 from submicroscopic infections, gametocytes, or sequestered parasites. These findings underscore the importance of evaluating different RDTs in field studies against qPCR reference testing to better define the sensitivity and specificity, particularly at low parasite densities.

Improved quantitative analysis of spectra using a new method of obtaining derivative spectra based on a singular perturbation technique.

PubMed

Li, Zhigang; Wang, Qiaoyun; Lv, Jiangtao; Ma, Zhenhe; Yang, Linjuan

2015-06-01

Spectroscopy is often applied when a rapid quantitative analysis is required, but one challenge is the translation of raw spectra into a final analysis. Derivative spectra are often used as a preliminary preprocessing step to resolve overlapping signals, enhance signal properties, and suppress unwanted spectral features that arise due to non-ideal instrument and sample properties. In this study, to improve quantitative analysis of near-infrared spectra, derivatives of noisy raw spectral data need to be estimated with high accuracy. A new spectral estimator based on singular perturbation technique, called the singular perturbation spectra estimator (SPSE), is presented, and the stability analysis of the estimator is given. Theoretical analysis and simulation experimental results confirm that the derivatives can be estimated with high accuracy using this estimator. Furthermore, the effectiveness of the estimator for processing noisy infrared spectra is evaluated using the analysis of beer spectra. The derivative spectra of the beer and the marzipan are used to build the calibration model using partial least squares (PLS) modeling. The results show that the PLS based on the new estimator can achieve better performance compared with the Savitzky-Golay algorithm and can serve as an alternative choice for quantitative analytical applications.

Multidisciplinary Biomarkers of Early Mammary Carcinogenesis

DTIC Science & Technology

2011-04-01

cDNA prepared. Quantitative real-time PCR (qRT-PCR) was then performed on the cDNA. All qRT-PCR reactions were performed in triplicate. ESR1 ...in Figure 4, all ER(+) cells express ESR1 at high levels (at least 4 fold higher than ER(-) cell lines). A Pearson correlation coefficient was...calculated to determine the linear relationship between the optical redox ratio and ESR1 expression levels and found to be significant (p = 0.0024, r

Proceedings of the Conference on the Standardization of Safety and Performance Tests for Energetic Materials. Volume 1

DTIC Science & Technology

1977-09-01

EE Dover, NJ 07801 DEXTER, Robert F. Bureau of Alcohol , Tobacco and Firearms 12th and Penna. Ave, N.W. Federal Bldg. RM 8233 Washington, DC...the digestion in alcoholic KOH. This point should be further investigated by developing a quantitative TLC or high performance liquid...the anti- oxydant neutralizes most of the oxidizing gas, then when the antioxydant is completely depleted, all the samples similarly began showing an

Integrating prediction, provenance, and optimization into high energy workflows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schram, M.; Bansal, V.; Friese, R. D.

We propose a novel approach for efficient execution of workflows on distributed resources. The key components of this framework include: performance modeling to quantitatively predict workflow component behavior; optimization-based scheduling such as choosing an optimal subset of resources to meet demand and assignment of tasks to resources; distributed I/O optimizations such as prefetching; and provenance methods for collecting performance data. In preliminary results, these techniques improve throughput on a small Belle II workflow by 20%.

A globotetraosylceramide (Gb₄) receptor-based ELISA for quantitative detection of Shiga toxin 2e.

PubMed

Togashi, Katsuhiro; Sasaki, Shiho; Sato, Wataru

2015-08-01

Currently, no simple assays are available for routine quantitative detection of Escherichia coli-produced Shiga toxin 2e (Stx2e) that causes porcine edema disease. Here, we present a novel quantitative detection method for Stx2e based on the measurement of Stx2e binding to the specific globotetraosylceramide (Gb4) receptor by ELISA (Gb4-ELISA). No cross-reactivity was found with the other Shiga toxins Stx1 and Stx2, indicating high specificity. When the recombinant Stx2e B subunit (Stx2eB) was used, the absorbance measured by Gb4-ELISA increased linearly with Stx2eB concentration in the range of 20-2,500 ng/ml. The Gb4-ELISA method can be easily performed, suggesting that it would be a useful diagnostic tool for porcine edema disease.

Affinity Proteomics for Fast, Sensitive, Quantitative Analysis of Proteins in Plasma.

PubMed

O'Grady, John P; Meyer, Kevin W; Poe, Derrick N

2017-01-01

The improving efficacy of many biological therapeutics and identification of low-level biomarkers are driving the analytical proteomics community to deal with extremely high levels of sample complexity relative to their analytes. Many protein quantitation and biomarker validation procedures utilize an immunoaffinity enrichment step to purify the sample and maximize the sensitivity of the corresponding liquid chromatography tandem mass spectrometry measurements. In order to generate surrogate peptides with better mass spectrometric properties, protein enrichment is followed by a proteolytic cleavage step. This is often a time-consuming multistep process. Presented here is a workflow which enables rapid protein enrichment and proteolytic cleavage to be performed in a single, easy-to-use reactor. Using this strategy Klotho, a low-abundance biomarker found in plasma, can be accurately quantitated using a protocol that takes under 5 h from start to finish.

Improved method for HPLC analysis of polyamines, agmatine and aromatic monoamines in plant tissue

NASA Technical Reports Server (NTRS)

Slocum, R. D.; Flores, H. E.; Galston, A. W.; Weinstein, L. H.

1989-01-01

The high performance liquid chromatographic (HPLC) method of Flores and Galston (1982 Plant Physiol 69: 701) for the separation and quantitation of benzoylated polyamines in plant tissues has been widely adopted by other workers. However, due to previously unrecognized problems associated with the derivatization of agmatine, this important intermediate in plant polyamine metabolism cannot be quantitated using this method. Also, two polyamines, putrescine and diaminopropane, also are not well resolved using this method. A simple modification of the original HPLC procedure greatly improves the separation and quantitation of these amines, and further allows the simulation analysis of phenethylamine and tyramine, which are major monoamine constituents of tobacco and other plant tissues. We have used this modified HPLC method to characterize amine titers in suspension cultured carrot (Daucas carota L.) cells and tobacco (Nicotiana tabacum L.) leaf tissues.

Teacher-student interactions and domain-specific motivation: The relationship between students' perceptions of teacher interpersonal behavior and motivation in middle school science

NASA Astrophysics Data System (ADS)

Smart, Julie Brockman

2009-11-01

This study examined interactions between middle school science students' perceptions of teacher-student interactions and their motivation for learning science. Specifically, in order to better understand factors affecting middle school students' motivation for science, this study investigated the interactions between middle school students' perceptions of teacher interpersonal behavior in their science classroom and their efficacy, task value, mastery orientations, and goal orientation for learning science. This mixed methods study followed a sequential explanatory model (Cresswell & Plano-Clark, 2007). Quantitative and qualitative data were collected in two phases, with quantitative data in the first phase informing the selection of participants for the qualitative phase that followed. The qualitative phase also helped to clarify and explain results from the quantitative phase. Data mixing occurred between Phase One and Phase Two (participant selection) and at the interpretation level (explanatory) after quantitative and qualitative data were analyzed separately. Results from Phase One indicated that students' perceptions of teacher interpersonal behaviors were predictive of their efficacy for learning science, task value for learning science, mastery orientation, and performance orientation. These results were used to create motivation/perception composites, which were used in order to select students for the qualitative interviews. A total of 24 students with high motivation/high perceptions, low motivation/low perceptions, high motivation/low perceptions, and low motivation/high perceptions were selected in order to represent students whose profiles either supported or refuted the quantitative results. Results from Phase Two revealed themes relating to students' construction of their perceptions of teacher interpersonal behavior and dimensions of their efficacy and task value for science. Students who reported high motivation and high perceptions of teacher-student interactions during the quantitative phase described the most instances of teacher cooperative behaviors, such as teacher helpfulness and understanding. Conversely, students reporting low motivation and low perceptions of teacher-student interactions described the most instances of teacher oppositional behavior, such as harsh and impatient behaviors. An in-depth description of categories and subcategories is also provided. This study concludes with an interpretive analysis of quantitative and qualitative results considered both separately and together. Implications for middle grades science education are discussed, including recommendations for behavior management, scaffolding students' transition to middle school, making explicit connections to science careers, and providing opportunities for small successes within the science classroom. Implications for science teacher education, limitations of the study, and future research directions are also discussed.

Diagnostic accuracy of stress perfusion CMR in comparison with quantitative coronary angiography: fully quantitative, semiquantitative, and qualitative assessment.

PubMed

Mordini, Federico E; Haddad, Tariq; Hsu, Li-Yueh; Kellman, Peter; Lowrey, Tracy B; Aletras, Anthony H; Bandettini, W Patricia; Arai, Andrew E

2014-01-01

This study's primary objective was to determine the sensitivity, specificity, and accuracy of fully quantitative stress perfusion cardiac magnetic resonance (CMR) versus a reference standard of quantitative coronary angiography. We hypothesized that fully quantitative analysis of stress perfusion CMR would have high diagnostic accuracy for identifying significant coronary artery stenosis and exceed the accuracy of semiquantitative measures of perfusion and qualitative interpretation. Relatively few studies apply fully quantitative CMR perfusion measures to patients with coronary disease and comparisons to semiquantitative and qualitative methods are limited. Dual bolus dipyridamole stress perfusion CMR exams were performed in 67 patients with clinical indications for assessment of myocardial ischemia. Stress perfusion images alone were analyzed with a fully quantitative perfusion (QP) method and 3 semiquantitative methods including contrast enhancement ratio, upslope index, and upslope integral. Comprehensive exams (cine imaging, stress/rest perfusion, late gadolinium enhancement) were analyzed qualitatively with 2 methods including the Duke algorithm and standard clinical interpretation. A 70% or greater stenosis by quantitative coronary angiography was considered abnormal. The optimum diagnostic threshold for QP determined by receiver-operating characteristic curve occurred when endocardial flow decreased to <50% of mean epicardial flow, which yielded a sensitivity of 87% and specificity of 93%. The area under the curve for QP was 92%, which was superior to semiquantitative methods: contrast enhancement ratio: 78%; upslope index: 82%; and upslope integral: 75% (p = 0.011, p = 0.019, p = 0.004 vs. QP, respectively). Area under the curve for QP was also superior to qualitative methods: Duke algorithm: 70%; and clinical interpretation: 78% (p < 0.001 and p < 0.001 vs. QP, respectively). Fully quantitative stress perfusion CMR has high diagnostic accuracy for detecting obstructive coronary artery disease. QP outperforms semiquantitative measures of perfusion and qualitative methods that incorporate a combination of cine, perfusion, and late gadolinium enhancement imaging. These findings suggest a potential clinical role for quantitative stress perfusion CMR. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Aircraft Carrier Operations at Sea: The Challenges of High Reliability Performance

DTIC Science & Technology

1988-07-29

34 Human Communication Research, 4 (Oct.,1978), 283-293. 3. R. A. Cooke and D . M . Rousseau , "The Organizational Culture Inventory : A Quantitative...from USS Carl Vinson (CVN-70) and Air Wing 15. 31 I Endnotes. Section 3. 1. K.H. Roberts and D . M Rousseau , "Research in Nearly Failure Free, High...Weick, School of Business Administration, University of Texas, Austin, Social Psychology and Organizational Behavior; Denise M . Rousseau , Business

Very High Performance High Nitrogen Energetic Ingredients and Energetic Polymers for Structural Components

DTIC Science & Technology

2011-12-31

have developed a vastly improved procedure for synthesis of the n- propyl ester that gives essentially quantitative yield and uses concentrated... Synthesis of n- propyl 4-aminofurazan-3-carboxylate. We next turned our attention to the synthesis of the amide. Again, the literature procedure is... synthesis and chemistry of 3-hydroxymethyl-4-amino[1,2,5]oxadiazole and 5) work on energetic polymers for structural components. 15. SUBJECT TERMS

Examining Opportunity-to-Learn and Success in High School Mathematics Performance in California under NCLB

ERIC Educational Resources Information Center

Gavrilovic, Daniel Miodrag

2013-01-01

The No Child Left Behind Act of 2001 has put many schools under a lot of pressure to meet its high demands. In this quantitative study, the effects that the NCLB act has had on students' opportunity to learn (OTL) and Subject Level Success (SS) from 2004 to 2012 in 9th, 10th, and 11th grade math coursework (Algebra 1, Geometry, Algebra 2, and…

Accuracy Enhancement of Raman Spectroscopy Using Complementary Laser-Induced Breakdown Spectroscopy (LIBS) with Geologically Mixed Samples.

PubMed

Choi, Soojin; Kim, Dongyoung; Yang, Junho; Yoh, Jack J

2017-04-01

Quantitative Raman analysis was carried out with geologically mixed samples that have various matrices. In order to compensate the matrix effect in Raman shift, laser-induced breakdown spectroscopy (LIBS) analysis was performed. Raman spectroscopy revealed the geological materials contained in the mixed samples. However, the analysis of a mixture containing different matrices was inaccurate due to the weak signal of the Raman shift, interference, and the strong matrix effect. On the other hand, the LIBS quantitative analysis of atomic carbon and calcium in mixed samples showed high accuracy. In the case of the calcite and gypsum mixture, the coefficient of determination of atomic carbon using LIBS was 0.99, while the signal using Raman was less than 0.9. Therefore, the geological composition of the mixed samples is first obtained using Raman and the LIBS-based quantitative analysis is then applied to the Raman outcome in order to construct highly accurate univariate calibration curves. The study also focuses on a method to overcome matrix effects through the two complementary spectroscopic techniques of Raman spectroscopy and LIBS.

High-resolution dynamic imaging and quantitative analysis of lung cancer xenografts in nude mice using clinical PET/CT

PubMed Central

Wang, Ying Yi; Wang, Kai; Xu, Zuo Yu; Song, Yan; Wang, Chu Nan; Zhang, Chong Qing; Sun, Xi Lin; Shen, Bao Zhong

2017-01-01

Considering the general application of dedicated small-animal positron emission tomography/computed tomography is limited, an acceptable alternative in many situations might be clinical PET/CT. To estimate the feasibility of using clinical PET/CT with [F-18]-fluoro-2-deoxy-D-glucose for high-resolution dynamic imaging and quantitative analysis of cancer xenografts in nude mice. Dynamic clinical PET/CT scans were performed on xenografts for 60 min after injection with [F-18]-fluoro-2-deoxy-D-glucose. Scans were reconstructed with or without SharpIR method in two phases. And mice were sacrificed to extracting major organs and tumors, using ex vivo γ-counting as a reference. Strikingly, we observed that the image quality and the correlation between the all quantitive data from clinical PET/CT and the ex vivo counting was better with the SharpIR reconstructions than without. Our data demonstrate that clinical PET/CT scanner with SharpIR reconstruction is a valuable tool for imaging small animals in preclinical cancer research, offering dynamic imaging parameters, good image quality and accurate data quatification. PMID:28881772

High-resolution dynamic imaging and quantitative analysis of lung cancer xenografts in nude mice using clinical PET/CT.

PubMed

Wang, Ying Yi; Wang, Kai; Xu, Zuo Yu; Song, Yan; Wang, Chu Nan; Zhang, Chong Qing; Sun, Xi Lin; Shen, Bao Zhong

2017-08-08

Considering the general application of dedicated small-animal positron emission tomography/computed tomography is limited, an acceptable alternative in many situations might be clinical PET/CT. To estimate the feasibility of using clinical PET/CT with [F-18]-fluoro-2-deoxy-D-glucose for high-resolution dynamic imaging and quantitative analysis of cancer xenografts in nude mice. Dynamic clinical PET/CT scans were performed on xenografts for 60 min after injection with [F-18]-fluoro-2-deoxy-D-glucose. Scans were reconstructed with or without SharpIR method in two phases. And mice were sacrificed to extracting major organs and tumors, using ex vivo γ-counting as a reference. Strikingly, we observed that the image quality and the correlation between the all quantitive data from clinical PET/CT and the ex vivo counting was better with the SharpIR reconstructions than without. Our data demonstrate that clinical PET/CT scanner with SharpIR reconstruction is a valuable tool for imaging small animals in preclinical cancer research, offering dynamic imaging parameters, good image quality and accurate data quatification.

Quantitative imaging of single-shot liquid distributions in sprays using broadband flash x-ray radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halls, B. R.; Roy, S.; Gord, J. R.

Flash x-ray radiography is used to capture quantitative, two-dimensional line-of-sight averaged, single-shot liquid distribution measurements in impinging jet sprays. The accuracy of utilizing broadband x-ray radiation from compact flash tube sources is investigated for a range of conditions by comparing the data with radiographic high-speed measurements from a narrowband, high-intensity synchrotron x-ray facility at the Advanced Photon Source (APS) of Argonne National Laboratory. The path length of the liquid jets is varied to evaluate the effects of energy dependent x-ray attenuation, also known as spectral beam hardening. The spatial liquid distributions from flash x-ray and synchrotron-based radiography are compared, alongmore » with spectral characteristics using Taylor’s hypothesis. The results indicate that quantitative, single-shot imaging of liquid distributions can be achieved using broadband x-ray sources with nanosecond temporal resolution. Practical considerations for optimizing the imaging system performance are discussed, including the coupled effects of x-ray bandwidth, contrast, sensitivity, spatial resolution, temporal resolution, and spectral beam hardening.« less

Quantitative and Isolated Measurement of Far-Field Light Scattering by a Single Nanostructure

NASA Astrophysics Data System (ADS)

Kim, Donghyeong; Jeong, Kwang-Yong; Kim, Jinhyung; Ee, Ho-Seok; Kang, Ju-Hyung; Park, Hong-Gyu; Seo, Min-Kyo

2017-11-01

Light scattering by nanostructures has facilitated research on various optical phenomena and applications by interfacing the near fields and free-propagating radiation. However, direct quantitative measurement of far-field scattering by a single nanostructure on the wavelength scale or less is highly challenging. Conventional back-focal-plane imaging covers only a limited solid angle determined by the numerical aperture of the objectives and suffers from optical aberration and distortion. Here, we present a quantitative measurement of the differential far-field scattering cross section of a single nanostructure over the full hemisphere. In goniometer-based far-field scanning with a high signal-to-noise ratio of approximately 27.4 dB, weak scattering signals are efficiently isolated and detected under total-internal-reflection illumination. Systematic measurements reveal that the total and differential scattering cross sections of a Au nanorod are determined by the plasmonic Fabry-Perot resonances and the phase-matching conditions to the free-propagating radiation, respectively. We believe that our angle-resolved far-field measurement scheme provides a way to investigate and evaluate the physical properties and performance of nano-optical materials and phenomena.

The predictive value of quantitative fibronectin testing in combination with cervical length measurement in symptomatic women.

PubMed

Bruijn, Merel M C; Kamphuis, Esme I; Hoesli, Irene M; Martinez de Tejada, Begoña; Loccufier, Anne R; Kühnert, Maritta; Helmer, Hanns; Franz, Marie; Porath, Martina M; Oudijk, Martijn A; Jacquemyn, Yves; Schulzke, Sven M; Vetter, Grit; Hoste, Griet; Vis, Jolande Y; Kok, Marjolein; Mol, Ben W J; van Baaren, Gert-Jan

2016-12-01

The combination of the qualitative fetal fibronectin test and cervical length measurement has a high negative predictive value for preterm birth within 7 days; however, positive prediction is poor. A new bedside quantitative fetal fibronectin test showed potential additional value over the conventional qualitative test, but there is limited evidence on the combination with cervical length measurement. The purpose of this study was to compare quantitative fetal fibronectin and qualitative fetal fibronectin testing in the prediction of spontaneous preterm birth within 7 days in symptomatic women who undergo cervical length measurement. We performed a European multicenter cohort study in 10 perinatal centers in 5 countries. Women between 24 and 34 weeks of gestation with signs of active labor and intact membranes underwent quantitative fibronectin testing and cervical length measurement. We assessed the risk of preterm birth within 7 days in predefined strata based on fibronectin concentration and cervical length. Of 455 women who were included in the study, 48 women (11%) delivered within 7 days. A combination of cervical length and qualitative fibronectin resulted in the identification of 246 women who were at low risk: 164 women with a cervix between 15 and 30 mm and a negative fibronectin test (<50 ng/mL; preterm birth rate, 2%) and 82 women with a cervix at >30 mm (preterm birth rate, 2%). Use of quantitative fibronectin alone resulted in a predicted risk of preterm birth within 7 days that ranged from 2% in the group with the lowest fibronectin level (<10 ng/mL) to 38% in the group with the highest fibronectin level (>500 ng/mL), with similar accuracy as that of the combination of cervical length and qualitative fibronectin. Combining cervical length and quantitative fibronectin resulted in the identification of an additional 19 women at low risk (preterm birth rate, 5%), using a threshold of 10 ng/mL in women with a cervix at <15 mm, and 6 women at high risk (preterm birth rate, 33%) using a threshold of >500 ng/mL in women with a cervix at >30 mm. In women with threatened preterm birth, quantitative fibronectin testing alone performs equal to the combination of cervical length and qualitative fibronectin. Possibly, the combination of quantitative fibronectin testing and cervical length increases this predictive capacity. Cost-effectiveness analysis and the availability of these tests in a local setting should determine the final choice. Copyright © 2016 Elsevier Inc. All rights reserved.

Factors Influencing Academic Performance in Quantitative Courses among Undergraduate Business Students of a Public Higher Education Institution

ERIC Educational Resources Information Center

Yousef, Darwish Abdulrahamn

2017-01-01

Purpose: This paper aims to investigate the impacts of teaching style, English language and communication and assessment methods on the academic performance of undergraduate business students in introductory quantitative courses such as Statistics for Business 1 and 2, Quantitative Methods for Business, Operations and Production Management and…

A Text Analysis of the Marine Corps Fitness Report

DTIC Science & Technology

2017-06-01

difficulty in quantitatively analyzing textual. The study pulls 835 anonymous and non-attributable surveys between 2005 and 2009 from the Center for... quantitative assessments of performance. 14. SUBJECT TERMS natural language processing, fitness reports, computational linguistics, manpower 15. NUMBER...Corps provide word-picture guidance to distinguish talented Marines and promote conformity in issuing quantitative assessments of performance. vi

Exploring Systems That Support Good Clinical Care in Indigenous Primary Health-care Services: A Retrospective Analysis of Longitudinal Systems Assessment Tool Data from High-Improving Services.

PubMed

Woods, Cindy; Carlisle, Karen; Larkins, Sarah; Thompson, Sandra Claire; Tsey, Komla; Matthews, Veronica; Bailie, Ross

2017-01-01

Continuous Quality Improvement is a process for raising the quality of primary health care (PHC) across Indigenous PHC services. In addition to clinical auditing using plan, do, study, and act cycles, engaging staff in a process of reflecting on systems to support quality care is vital. The One21seventy Systems Assessment Tool (SAT) supports staff to assess systems performance in terms of five key components. This study examines quantitative and qualitative SAT data from five high-improving Indigenous PHC services in northern Australia to understand the systems used to support quality care. High-improving services selected for the study were determined by calculating quality of care indices for Indigenous health services participating in the Audit and Best Practice in Chronic Disease National Research Partnership. Services that reported continuing high improvement in quality of care delivered across two or more audit tools in three or more audits were selected for the study. Precollected SAT data (from annual team SAT meetings) are presented longitudinally using radar plots for quantitative scores for each component, and content analysis is used to describe strengths and weaknesses of performance in each systems' component. High-improving services were able to demonstrate strong processes for assessing system performance and consistent improvement in systems to support quality care across components. Key strengths in the quality support systems included adequate and orientated workforce, appropriate health system supports, and engagement with other organizations and community, while the weaknesses included lack of service infrastructure, recruitment, retention, and support for staff and additional costs. Qualitative data revealed clear voices from health service staff expressing concerns with performance, and subsequent SAT data provided evidence of changes made to address concerns. Learning from the processes and strengths of high-improving services may be useful as we work with services striving to improve the quality of care provided in other areas.

Wave energy and swimming performance shape coral reef fish assemblages

PubMed Central

Fulton, C.J; Bellwood, D.R; Wainwright, P.C

2005-01-01

Physical factors often have an overriding influence on the distribution patterns of organisms, and can ultimately shape the long-term structure of communities. Although distribution patterns in sessile marine organisms have frequently been attributed to functional characteristics interacting with wave-induced water motion, similar evidence for mobile organisms is lacking. Links between fin morphology and swimming performance were examined in three diverse coral reef fish families from two major evolutionary lineages. Among-habitat variation in morphology and performance was directly compared with quantitative values of wave-induced water motion from seven coral reef habitats of different depth and wave exposure on the Great Barrier Reef. Fin morphology was strongly correlated with both field and experimental swimming speeds in all three families. The range of observed swimming speeds coincided closely with the magnitude of water velocities commonly found on coral reefs. Distribution patterns in all three families displayed highly congruent relationships between fin morphology and wave-induced water motion. Our findings indicate a general functional relationship between fin morphology and swimming performance in labriform-swimming fishes, and provide quantitative evidence that wave energy may directly influence the assemblage structure of coral reef fishes through interactions with morphology and swimming performance. PMID:15888415

Validated semiquantitative/quantitative screening of 51 drugs in whole blood as silylated derivatives by gas chromatography-selected ion monitoring mass spectrometry and gas chromatography electron capture detection.

PubMed

Gunnar, Teemu; Mykkänen, Sirpa; Ariniemi, Kari; Lillsunde, Pirjo

2004-07-05

A comprehensively validated procedure is presented for simultaneous semiquantitative/quantitative screening of 51 drugs of abuse or drugs potentially hazardous for traffic safety in serum, plasma or whole blood. Benzodiazepines (12), cannabinoids (3), opioids (8), cocaine, antidepressants (13), antipsychotics (5) and antiepileptics (2) as well as zolpidem, zaleplon, zopiclone, meprobamate, carisoprodol, tizanidine and orphenadrine and internal standard flurazepam, were isolated by high-yield liquid-liquid extraction (LLE). The dried extracts were derivatized by two-step silylation and analyzed by the combination of two different gas chromatographic (GC) separations with both electron capture detection (ECD) and mass spectrometry (MS) operating in a selected ion-monitoring (SIM) mode. Quantitative or semiquantitative results were obtained for each substance based on four-point calibration. In the validation tests, accuracy, reproducibility, linearity, limit of detection (LOD) and limit of quantitation (LOQ), selectivity, as well as extraction efficiency and stability of standard stock solutions were tested, and derivatization was optimized in detail. Intra- and inter-day precisions were within 2.5-21.8 and 6.0-22.5%, and square of correlation coefficients of linearity ranged from 0.9896 to 0.9999. The limit of quantitation (LOQ) varied from 2 to 2000 ng/ml due to a variety of the relevant concentrations of the analyzed substances in blood. The method is feasible for highly sensitive, reliable and possibly routinely performed clinical and forensic toxicological analyses.

A hybrid approach identifies metabolic signatures of high-producers for chinese hamster ovary clone selection and process optimization.

PubMed

Popp, Oliver; Müller, Dirk; Didzus, Katharina; Paul, Wolfgang; Lipsmeier, Florian; Kirchner, Florian; Niklas, Jens; Mauch, Klaus; Beaucamp, Nicola

2016-09-01

In-depth characterization of high-producer cell lines and bioprocesses is vital to ensure robust and consistent production of recombinant therapeutic proteins in high quantity and quality for clinical applications. This requires applying appropriate methods during bioprocess development to enable meaningful characterization of CHO clones and processes. Here, we present a novel hybrid approach for supporting comprehensive characterization of metabolic clone performance. The approach combines metabolite profiling with multivariate data analysis and fluxomics to enable a data-driven mechanistic analysis of key metabolic traits associated with desired cell phenotypes. We applied the methodology to quantify and compare metabolic performance in a set of 10 recombinant CHO-K1 producer clones and a host cell line. The comprehensive characterization enabled us to derive an extended set of clone performance criteria that not only captured growth and product formation, but also incorporated information on intracellular clone physiology and on metabolic changes during the process. These criteria served to establish a quantitative clone ranking and allowed us to identify metabolic differences between high-producing CHO-K1 clones yielding comparably high product titers. Through multivariate data analysis of the combined metabolite and flux data we uncovered common metabolic traits characteristic of high-producer clones in the screening setup. This included high intracellular rates of glutamine synthesis, low cysteine uptake, reduced excretion of aspartate and glutamate, and low intracellular degradation rates of branched-chain amino acids and of histidine. Finally, the above approach was integrated into a workflow that enables standardized high-content selection of CHO producer clones in a high-throughput fashion. In conclusion, the combination of quantitative metabolite profiling, multivariate data analysis, and mechanistic network model simulations can identify metabolic traits characteristic of high-performance clones and enables informed decisions on which clones provide a good match for a particular process platform. The proposed approach also provides a mechanistic link between observed clone phenotype, process setup, and feeding regimes, and thereby offers concrete starting points for subsequent process optimization. Biotechnol. Bioeng. 2016;113: 2005-2019. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Determination of isoxaflutole (balance) and its metabolites in water using solid phase extraction followed by high-performance liquid chromatography with ultraviolet or mass spectrometry

USGS Publications Warehouse

Lin, Chung-Ho; Lerch, Robert N.; Thurman, E. Michael; Garrett , Harold E.; George, Milon F.

2002-01-01

Balance (isoxaflutole, IXF) belongs to a new family of herbicides referred to as isoxazoles. IXF has a very short soil half-life (<24 h), degrading to a biologically active diketonitrile (DKN) metabolite that is more polar and considerably more stable. Further degradation of the DKN metabolite produces a nonbiologically active benzoic acid (BA) metabolite. Analytical methods using solid phase extraction followed by high-performance liquid chromatography−UV (HPLC-UV) or high-performance liquid chromatography−mass spectrometry (HPLC-MS) were developed for the analysis of IXF and its metabolites in distilled deionized water and ground water samples. To successfully detect and quantify the BA metabolite by HPLC-UV from ground water samples, a sequential elution scheme was necessary. Using HPLC-UV, the mean recoveries from sequential elution of the parent and its two metabolites from fortified ground water samples ranged from 68.6 to 101.4%. For HPLC-MS, solid phase extraction of ground water samples was performed using a polystyrene divinylbenzene polymer resin. The mean HPLC-MS recoveries of the three compounds from ground water samples spiked at 0.05−2 μg/L ranged from 100.9 to 110.3%. The limits of quantitation for HPLC-UV are approximately 150 ng/L for IXF, 100 ng/L for DKN, and 250 ng/L for BA. The limit of quantitation by HPLC-MS is 50 ng/L for each compound. The methods developed in this work can be applied to determine the transport and fate of Balance in the environment.

Determination of isoxaflutole (balance) and its metabolites in water using solid phase extraction followed by high-performance liquid chromatography with ultraviolet or mass spectrometry.

PubMed

Lin, Chung-Ho; Lerch, Robert N; Thurman, E Michael; Garrett, Harold E; George, Milon F

2002-10-09

Balance (isoxaflutole, IXF) belongs to a new family of herbicides referred to as isoxazoles. IXF has a very short soil half-life (<24 h), degrading to a biologically active diketonitrile (DKN) metabolite that is more polar and considerably more stable. Further degradation of the DKN metabolite produces a nonbiologically active benzoic acid (BA) metabolite. Analytical methods using solid phase extraction followed by high-performance liquid chromatography-UV (HPLC-UV) or high-performance liquid chromatography-mass spectrometry (HPLC-MS) were developed for the analysis of IXF and its metabolites in distilled deionized water and ground water samples. To successfully detect and quantify the BA metabolite by HPLC-UV from ground water samples, a sequential elution scheme was necessary. Using HPLC-UV, the mean recoveries from sequential elution of the parent and its two metabolites from fortified ground water samples ranged from 68.6 to 101.4%. For HPLC-MS, solid phase extraction of ground water samples was performed using a polystyrene divinylbenzene polymer resin. The mean HPLC-MS recoveries of the three compounds from ground water samples spiked at 0.05-2 microg/L ranged from 100.9 to 110.3%. The limits of quantitation for HPLC-UV are approximately 150 ng/L for IXF, 100 ng/L for DKN, and 250 ng/L for BA. The limit of quantitation by HPLC-MS is 50 ng/L for each compound. The methods developed in this work can be applied to determine the transport and fate of Balance in the environment.

A rapid and sensitive evaluation of nitrite content in Saudi Arabian processed meat and poultry using a novel ultra performance liquid chromatography-mass spectrometry method.

PubMed

Siddiqui, Masoom Raza; Wabaidur, Saikh Mohammad; Khan, Moonis Ali; ALOthman, Zeid A; Rafiquee, M Z A; Alqadami, Ayoub Abdullah

2018-01-01

Quantitative assessment of nitrite (NO 2 - ) anion was performed using a newly developed high throughput ultra performance liquid chromatography-mass spectrometric (UPLC-MS) method. The nitrite determination with the proposed method using micellar mobile phase was unknown. Selected ion reaction mode using negative electrospray ionization was adopted for the identification and quantitative analysis of nitrite. The chromatographic separation was performed using BEH C-18 column and a micellar mobile phase consisted of sodium dodecyl sulphate and acetonitrile in ratio 30:70 was used. The elution of nitrite anion was accomplished in less than 1 min. Under the optimal analysis conditions, the linearity of the developed method was checked in the concentration range of 0.5-20 mg kg -1 NO 2 - with an excellent correlation coefficient of 0.996. The precisions of the method with relative standard deviation <2% was observed when standard at concentration of 1 mg kg -1 was used. The limit of detection and limit of quantitation of the developed mass spectrometric method was found to be 0.114 and 0.346 mg kg -1 , respectively. The developed UPLC/MS method was applied to quantify this anion in processed meats and poultries from various super market of Saudi Arabia (Riyadh region). The recoveries of the nitrite in the various samples were found in the range of 100.03-103.5%.

Technological innovation in neurosurgery: a quantitative study.

PubMed

Marcus, Hani J; Hughes-Hallett, Archie; Kwasnicki, Richard M; Darzi, Ara; Yang, Guang-Zhong; Nandi, Dipankar

2015-07-01

Technological innovation within health care may be defined as the introduction of a new technology that initiates a change in clinical practice. Neurosurgery is a particularly technology-intensive surgical discipline, and new technologies have preceded many of the major advances in operative neurosurgical techniques. The aim of the present study was to quantitatively evaluate technological innovation in neurosurgery using patents and peer-reviewed publications as metrics of technology development and clinical translation, respectively. The authors searched a patent database for articles published between 1960 and 2010 using the Boolean search term "neurosurgeon OR neurosurgical OR neurosurgery." The top 50 performing patent codes were then grouped into technology clusters. Patent and publication growth curves were then generated for these technology clusters. A top-performing technology cluster was then selected as an exemplar for a more detailed analysis of individual patents. In all, 11,672 patents and 208,203 publications related to neurosurgery were identified. The top-performing technology clusters during these 50 years were image-guidance devices, clinical neurophysiology devices, neuromodulation devices, operating microscopes, and endoscopes. In relation to image-guidance and neuromodulation devices, the authors found a highly correlated rapid rise in the numbers of patents and publications, which suggests that these are areas of technology expansion. An in-depth analysis of neuromodulation-device patents revealed that the majority of well-performing patents were related to deep brain stimulation. Patent and publication data may be used to quantitatively evaluate technological innovation in neurosurgery.

Birds and bats diverge in the qualitative and quantitative components of seed dispersal of a pioneer tree

NASA Astrophysics Data System (ADS)

Jacomassa, Fábio André F.; Pizo, Marco Aurélio

2010-09-01

Although the overlap in fruit diet between birds and bats is low, they sometimes consume and compete for fruits of the same plant species. What is poorly known is how birds and bats compare with each other in relation to the effectiveness of seed dispersal. In this paper we contrasted birds and bats in relation to quantitative (the amount of fruits removed from plants) and qualitative (germination performance of seeds) components of the seed dispersal of Solanum granuloso- leprosum, a pioneer, small-seeded tree of open areas and forest edges in south Brazil. We tagged fruits on the plants and monitored their removal by day and night. We compared the final percent of germination and speed of germination of seeds ingested by birds and bats with non-ingested, control seeds. While bats removed more fruits than birds, performing better in the quantitative component, birds improved the germination performance of seeds, an aspect of the qualitative component of seed dispersal effectiveness. Although bats are more likely to deposit seeds in highly disturbed sites that favor the recruitment of pioneer plant species, birds frequent forest edges, which is also suitable habitat for S. granuloso- leprosum, We concluded that birds and bats are not 'redundant' seed dispersers for S. granuloso- leprosum because in conjunction they may enhance its recruitment by diversifying the microsites where seeds are deposited, performing in addition different ecological functions in terms of quantity and quality of dispersal.

A quantitative link between face discrimination deficits and neuronal selectivity for faces in autism☆

PubMed Central

Jiang, Xiong; Bollich, Angela; Cox, Patrick; Hyder, Eric; James, Joette; Gowani, Saqib Ali; Hadjikhani, Nouchine; Blanz, Volker; Manoach, Dara S.; Barton, Jason J.S.; Gaillard, William D.; Riesenhuber, Maximilian

2013-01-01

Individuals with Autism Spectrum Disorder (ASD) appear to show a general face discrimination deficit across a range of tasks including social–emotional judgments as well as identification and discrimination. However, functional magnetic resonance imaging (fMRI) studies probing the neural bases of these behavioral differences have produced conflicting results: while some studies have reported reduced or no activity to faces in ASD in the Fusiform Face Area (FFA), a key region in human face processing, others have suggested more typical activation levels, possibly reflecting limitations of conventional fMRI techniques to characterize neuron-level processing. Here, we test the hypotheses that face discrimination abilities are highly heterogeneous in ASD and are mediated by FFA neurons, with differences in face discrimination abilities being quantitatively linked to variations in the estimated selectivity of face neurons in the FFA. Behavioral results revealed a wide distribution of face discrimination performance in ASD, ranging from typical performance to chance level performance. Despite this heterogeneity in perceptual abilities, individual face discrimination performance was well predicted by neural selectivity to faces in the FFA, estimated via both a novel analysis of local voxel-wise correlations, and the more commonly used fMRI rapid adaptation technique. Thus, face processing in ASD appears to rely on the FFA as in typical individuals, differing quantitatively but not qualitatively. These results for the first time mechanistically link variations in the ASD phenotype to specific differences in the typical face processing circuit, identifying promising targets for interventions. PMID:24179786

Reactivity to stress and the cognitive components of math disability in grade 1 children.

PubMed

MacKinnon McQuarrie, Maureen A; Siegel, Linda S; Perry, Nancy E; Weinberg, Joanne

2014-01-01

This study investigated the relationship among working memory, processing speed, math performance, and reactivity to stress in 83 Grade 1 children. Specifically, 39 children with math disability (MD) were compared to 44 children who are typically achieving (TA) in mathematics. It is the first study to use a physiological index of stress (salivary cortisol levels) to measure children's reactivity while completing tasks that assess the core components of MD: working memory for numbers, working memory for words, digits backward, letter number sequence, digit span forward, processing speed for numbers and words, block rotation, and math tasks. Grade 1 children with MD obtained significantly lower scores on the letter number sequence and quantitative concepts tasks. Higher levels of reactivity significantly predicted poorer performance on the working memory for numbers, working memory for words, and quantitative concepts tasks for Grade 1 children, regardless of math ability. Grade 1 children with MD and higher reactivity had significantly lower scores on the letter number sequence task than the children with MD and low reactivity. The findings suggest that high reactivity impairs performance in working memory and math tasks in Grade 1 children, and young children with high reactivity may benefit from interventions aimed at lowering anxiety in stressful situations, which may improve learning. © Hammill Institute on Disabilities 2012.

Reactivity to Stress and the Cognitive Components of Math Disability in Grade 1 Children

PubMed Central

MacKinnon McQuarrie, Maureen A.; Siegel, Linda S.; Perry, Nancy E.; Weinberg, Joanne

2016-01-01

This study investigated the relationship among working memory, processing speed, math performance, and reactivity to stress in 83 Grade 1 children. Specifically, 39 children with math disability (MD) were compared to 44 children who are typically achieving (TA) in mathematics. It is the first study to use a physiological index of stress (salivary cortisol levels) to measure children’s reactivity while completing tasks that assess the core components of MD: working memory for numbers, working memory for words, digits backward, letter number sequence, digit span forward, processing speed for numbers and words, block rotation, and math tasks. Grade 1 children with MD obtained significantly lower scores on the letter number sequence and quantitative concepts tasks. Higher levels of reactivity significantly predicted poorer performance on the working memory for numbers, working memory for words, and quantitative concepts tasks for Grade 1 children, regardless of math ability. Grade 1 children with MD and higher reactivity had significantly lower scores on the letter number sequence task than the children with MD and low reactivity. The findings suggest that high reactivity impairs performance in working memory and math tasks in Grade 1 children, and young children with high reactivity may benefit from interventions aimed at lowering anxiety in stressful situations, which may improve learning. PMID:23124381

Qualitative and quantitative analysis of specific polysaccharides in Dendrobium huoshanense by using saccharide mapping and chromatographic methods.

PubMed

Deng, Yong; Chen, Ling-Xiao; Han, Bang-Xing; Wu, Ding-Tao; Cheong, Kit-Leong; Chen, Nai-Fu; Zhao, Jing; Li, Shao-Ping

2016-09-10

Qualitative and quantitative analysis of specific polysaccharides from ten batches of Dendrobium huoshanense were performed using high performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detector (HPSEC-MALLS-RID), gas chromatography-mass spectrometry (GC-MS), nuclear magnetic resonance (NMR) and saccharide mapping based on polysaccharides analysis by using carbohydrate gel electrophoresis (PACE) and high performance thin layer chromatography (HPTLC). Results showed that molecular weights, the radius of gyrations, and contents of specific polysaccharides in D. huoshanense were ranging from 1.16×10(5) to 2.17×10(5)Da, 38.8 to 52.1nm, and 9.9% to 19.9%, respectively. Furthermore, the main monosaccharide compositions were Man and Glc. Indeed, the main glycosidic linkages were β-1,4-Manp and β-1,4-Glcp, and substituted with acetyl groups at O-2 and O-3 of 1,4-linked Manp. Moreover, results showed that PACE and HPTLC fingerprints of partial acidic and enzymatic hydrolysates of specific polysaccharides were similar, which are helpful to better understand the specific polysaccharides in D. huoshanense and beneficial to improve their quality control. These approaches could also be routinely used for quality control of polysaccharides in other medicinal plants. Copyright © 2016 Elsevier B.V. All rights reserved.

Can continuous scans in orthogonal planes improve diagnostic performance of shear wave elastography for breast lesions?

PubMed

Yang, Pan; Peng, Yulan; Zhao, Haina; Luo, Honghao; Jin, Ya; He, Yushuang

2015-01-01

Static shear wave elastography (SWE) is used to detect breast lesions, but slice and plane selections result in discrepancies. To evaluate the intraobserver reproducibility of continuous SWE, and whether quantitative elasticities in orthogonal planes perform better in the differential diagnosis of breast lesions. One hundred and twenty-two breast lesions scheduled for ultrasound-guided biopsy were recruited. Continuous SWE scans were conducted in orthogonal planes separately. Quantitative elasticities and histopathology results were collected. Reproducibility in the same plane and diagnostic performance in different planes were evaluated. The maximum and mean elasticities of the hardest portion, and standard deviation of whole lesion, had high inter-class correlation coefficients (0.87 to 0.95) and large areas under receiver operation characteristic curve (0.887 to 0.899). Without loss of accuracy, sensitivities had increased in orthogonal planes compared with single plane (from 73.17% up to 82.93% at most). Mean elasticity of whole lesion and lesion-to-parenchyma ratio were significantly less reproducible and less accurate. Continuous SWE is highly reproducible for the same observer. The maximum and mean elasticities of the hardest portion and standard deviation of whole lesion are most reliable. Furthermore, the sensitivities of the three parameters are improved in orthogonal planes without loss of accuracies.

Improving quantitative gas chromatography-electron ionization mass spectrometry results using a modified ion source: demonstration for a pharmaceutical application.

PubMed

D'Autry, Ward; Wolfs, Kris; Hoogmartens, Jos; Adams, Erwin; Van Schepdael, Ann

2011-07-01

Gas chromatography-mass spectrometry is a well established analytical technique. However, mass spectrometers with electron ionization sources may suffer from signal drifts, hereby negatively influencing quantitative performance. To demonstrate this phenomenon for a real application, a static headspace-gas chromatography method in combination with electron ionization-quadrupole mass spectrometry was optimized for the determination of residual dichloromethane in coronary stent coatings. Validating the method, the quantitative performance of an original stainless steel ion source was compared to that of a modified ion source. Ion source modification included the application of a gold coating on the repeller and exit plate. Several validation aspects such as limit of detection, limit of quantification, linearity and precision were evaluated using both ion sources. It was found that, as expected, the stainless steel ion source suffered from signal drift. As a consequence, non-linearity and high RSD values for repeated analyses were obtained. An additional experiment was performed to check whether an internal standard compound would lead to better results. It was found that the signal drift patterns of the analyte and internal standard were different, consequently leading to high RSD values for the response factor. With the modified ion source however, a more stable signal was observed resulting in acceptable linearity and precision. Moreover, it was also found that sensitivity improved compared to the stainless steel ion source. Finally, the optimized method with the modified ion source was applied to determine residual dichloromethane in the coating of coronary stents. The solvent was detected but found to be below the limit of quantification. Copyright © 2011 Elsevier B.V. All rights reserved.

Diagnosis of feline leukaemia virus infection by semi-quantitative real-time polymerase chain reaction.

PubMed

Pinches, Mark D G; Helps, Christopher R; Gruffydd-Jones, Tim J; Egan, Kathy; Jarrett, Oswald; Tasker, Séverine

2007-02-01

In this paper the design and use of a semi-quantitative real-time polymerase chain reaction assay (RT-PCR) for feline leukaemia virus (FeLV) provirus is described. Its performance is evaluated against established methods of FeLV diagnosis, including virus isolation and enzyme-linked immunoassay (ELISA) in a population of naturally infected cats. The RT-PCR assay is found to have both a high sensitivity (0.92) and specificity (0.99) when examined by expectation maximisation methods and is also able to detect a large number of cats with low FeLV proviral loads that were negative by other conventional test methods.

QUANTITATIVE PLUTONIUM MICRODISTRIBUTION IN BONE TISSUE OF VERTEBRA FROM A MAYAK WORKER

PubMed Central

Lyovkina, Yekaterina V.; Miller, Scott C.; Romanov, Sergey A.; Krahenbuhl, Melinda P.; Belosokhov, Maxim V.

2010-01-01

The purpose was to obtain quantitative data on plutonium microdistribution in different structural elements of human bone tissue for local dose assessment and dosimetric models validation. A sample of the thoracic vertebra was obtained from a former Mayak worker with a rather high plutonium burden. Additional information was obtained on occupational and exposure history, medical history, and measured plutonium content in organs. Plutonium was detected in bone sections from its fission tracks in polycarbonate film using neutron-induced autoradiography. Quantitative analysis of randomly selected microscopic fields on one of the autoradiographs was performed. Data included fission fragment tracks in different bone tissue and surface areas. Quantitative information on plutonium microdistribution in human bone tissue was obtained for the first time. From these data, quantitative relationship of plutonium decays in bone volume to decays on bone surface in cortical and trabecular fractions were defined as 2.0 and 0.4, correspondingly. The measured quantitative relationship of decays in bone volume to decays on bone surface does not coincide with recommended models for the cortical bone fraction by the International Commission on Radiological Protection. Biokinetic model parameters of extrapulmonary compartments might need to be adjusted after expansion of the data set on quantitative plutonium microdistribution in other bone types in human as well as other cases with different exposure patterns and types of plutonium. PMID:20838087

Application of image analysis in studies of quantitative disease resistance, exemplified using common bacterial blight-common bean pathosystem.

PubMed

Xie, Weilong; Yu, Kangfu; Pauls, K Peter; Navabi, Alireza

2012-04-01

The effectiveness of image analysis (IA) compared with an ordinal visual scale, for quantitative measurement of disease severity, its application in quantitative genetic studies, and its effect on the estimates of genetic parameters were investigated. Studies were performed using eight backcross-derived families of common bean (Phaseolus vulgaris) (n = 172) segregating for the molecular marker SU91, known to be associated with a quantitative trait locus (QTL) for resistance to common bacterial blight (CBB), caused by Xanthomonas campestris pv. phaseoli and X. fuscans subsp. fuscans. Even though both IA and visual assessments were highly repeatable, IA was more sensitive in detecting quantitative differences between bean genotypes. The CBB phenotypic difference between the two SU91 genotypic groups was consistently more than fivefold for IA assessments but generally only two- to threefold for visual assessments. Results suggest that the visual assessment results in overestimation of the effect of QTL in genetic studies. This may have been caused by lack of additivity and uneven intervals of the visual scale. Although visual assessment of disease severity is a useful tool for general selection in breeding programs, assessments using IA may be more suitable for phenotypic evaluations in quantitative genetic studies involving CBB resistance as well as other foliar diseases.

Sequence stratigraphy and high-frequency cycles: New aspects for a quantitative evaluation of the Gulf of Suez basin, Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nio, S.D.; Yang, C.S.; Tewfik, N.

1993-09-01

A new development in the application of sequence stratigraphic concepts in marine as well as continental basins is the recognition of high-frequency cyclic patterns in rock successions in the subsurface. Studies of six wells from the northern, central, and southern parts of the Gulf of Suez show the presence of well-preserved, high-frequency cycles with periodicities similar to the orbitally forced Malankovitch parameters. Subsurface rock successions, third-order sequences, and high-frequency cycles were compared with outcrops. After establishing the biostratigraphic framework for the above-mentioned wells, a sequence analysis was performed. Sequence boundaries and maximum flooding positions in each well were calibrated withmore » the occurrences and evaluation of the high-frequency cycles. It became obvious that there is an intimate relationship between these high-frequency Milankovitch cycles and sequence organization. In addition, a close relationship can be observed in the subsurface as well as in outcrops between high-frequency climatic changes (connected to the Milankovitch cycles) and (litho)facies variability. Quantitative evaluations of each sequence and/or systems tract can be computed with the International Geoservices' cyclicity analysis tool (MILABAR). The results are summarized in a well composite chart, rate (NAR), and ratio of preserved time. In correlations between the wells, an accuracy of 500-100 Ka can be obtained. The quantitative evaluation of the sequence and high-frequency cycle analysis gave some new aspects concerning the (litho)facies and geodynamic development during the pre- as well as the synrift stages of the Gulf of Suez Basin.« less

Performing Repeated Quantitative Small-Animal PET with an Arterial Input Function Is Routinely Feasible in Rats.

PubMed

Huang, Chi-Cheng; Wu, Chun-Hu; Huang, Ya-Yao; Tzen, Kai-Yuan; Chen, Szu-Fu; Tsai, Miao-Ling; Wu, Hsiao-Ming

2017-04-01

Performing quantitative small-animal PET with an arterial input function has been considered technically challenging. Here, we introduce a catheterization procedure that keeps a rat physiologically stable for 1.5 mo. We demonstrated the feasibility of quantitative small-animal 18 F-FDG PET in rats by performing it repeatedly to monitor the time course of variations in the cerebral metabolic rate of glucose (CMR glc ). Methods: Aseptic surgery was performed on 2 rats. Each rat underwent catheterization of the right femoral artery and left femoral vein. The catheters were sealed with microinjection ports and then implanted subcutaneously. Over the next 3 wk, each rat underwent 18 F-FDG quantitative small-animal PET 6 times. The CMR glc of each brain region was calculated using a 3-compartment model and an operational equation that included a k* 4 Results: On 6 mornings, we completed 12 18 F-FDG quantitative small-animal PET studies on 2 rats. The rats grew steadily before and after the 6 quantitative small-animal PET studies. The CMR glc of the conscious brain (e.g., right parietal region, 99.6 ± 10.2 μmol/100 g/min; n = 6) was comparable to that for 14 C-deoxyglucose autoradiographic methods. Conclusion: Maintaining good blood patency in catheterized rats is not difficult. Longitudinal quantitative small-animal PET imaging with an arterial input function can be performed routinely. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Quantitative cultures of bronchoscopically obtained specimens should be performed for optimal management of ventilator-associated pneumonia.

PubMed

Baselski, Vickie; Klutts, J Stacey; Baselski, Vickie; Klutts, J Stacey

2013-03-01

Ventilator-associated pneumonia (VAP) is a leading cause of health care-associated infection. It has a high rate of attributed mortality, and this mortality is increased in patients who do not receive appropriate empirical antimicrobial therapy. As a result of the overuse of broad-spectrum antimicrobials such as the carbapenems, strains of Acinetobacter, Enterobacteriaceae, and Pseudomonas aeruginosa susceptible only to polymyxins and tigecycline have emerged as important causes of VAP. The need to accurately diagnose VAP so that appropriate discontinuation or de-escalation of antimicrobial therapy can be initiated to reduce this antimicrobial pressure is essential. Practice guidelines for the diagnosis of VAP advocate the use of bronchoalveolar lavage (BAL) fluid obtained either bronchoscopically or by the use of a catheter passed through the endotracheal tube. The CDC recommends that quantitative cultures be performed on these specimens, using ≥ 10(4) CFU/ml to designate a positive culture (http://www.cdc.gov/nhsn/TOC_PSCManual.html, accessed 30 October 2012). However, there is no consensus in the clinical microbiology community as to whether these specimens should be cultured quantitatively, using the aforementioned designated bacterial cell count to designate infection, or by a semiquantitative approach. We have asked Vickie Baselski, University of Tennessee Health Science Center, who was the lead author on one of the seminal papers on quantitative BAL fluid culture, to explain why she believes that quantitative BAL fluid cultures are the optimal strategy for VAP diagnosis. We have Stacey Klutts, University of Iowa, to advocate the semiquantitative approach.

Quantitative twoplex glycan analysis using 12C6 and 13C6 stable isotope 2-aminobenzoic acid labelling and capillary electrophoresis mass spectrometry.

PubMed

Váradi, Csaba; Mittermayr, Stefan; Millán-Martín, Silvia; Bones, Jonathan

2016-12-01

Capillary electrophoresis (CE) offers excellent efficiency and orthogonality to liquid chromatographic (LC) separations for oligosaccharide structural analysis. Combination of CE with high resolution mass spectrometry (MS) for glycan analysis remains a challenging task due to the MS incompatibility of background electrolyte buffers and additives commonly used in offline CE separations. Here, a novel method is presented for the analysis of 2-aminobenzoic acid (2-AA) labelled glycans by capillary electrophoresis coupled to mass spectrometry (CE-MS). To ensure maximum resolution and excellent precision without the requirement for excessive analysis times, CE separation conditions including the concentration and pH of the background electrolyte, the effect of applied pressure on the capillary inlet and the capillary length were evaluated. Using readily available 12/13 C 6 stable isotopologues of 2-AA, the developed method can be applied for quantitative glycan profiling in a twoplex manner based on the generation of extracted ion electropherograms (EIE) for 12 C 6 'light' and 13 C 6 'heavy' 2-AA labelled glycan isotope clusters. The twoplex quantitative CE-MS glycan analysis platform is ideally suited for comparability assessment of biopharmaceuticals, such as monoclonal antibodies, for differential glycomic analysis of clinical material for potential biomarker discovery or for quantitative microheterogeneity analysis of different glycosylation sites within a glycoprotein. Additionally, due to the low injection volume requirements of CE, subsequent LC-MS analysis of the same sample can be performed facilitating the use of orthogonal separation techniques for structural elucidation or verification of quantitative performance.

Quantitative and multiplexed detection for blood typing based on quantum dot-magnetic bead assay.

PubMed

Xu, Ting; Zhang, Qiang; Fan, Ya-Han; Li, Ru-Qing; Lu, Hua; Zhao, Shu-Ming; Jiang, Tian-Lun

2017-01-01

Accurate and reliable blood grouping is essential for safe blood transfusion. However, conventional methods are qualitative and use only single-antigen detection. We overcame these limitations by developing a simple, quantitative, and multiplexed detection method for blood grouping using quantum dots (QDs) and magnetic beads. In the QD fluorescence assay (QFA), blood group A and B antigens were quantified using QD labeling and magnetic beads, and the blood groups were identified according to the R value (the value was calculated with the fluorescence intensity from dual QD labeling) of A and B antigens. The optimized performance of QFA was established by blood typing 791 clinical samples. Quantitative and multiplexed detection for blood group antigens can be completed within 35 min with more than 10 5 red blood cells. When conditions are optimized, the assay performance is satisfactory for weak samples. The coefficients of variation between and within days were less than 10% and the reproducibility was good. The ABO blood groups of 791 clinical samples were identified by QFA, and the accuracy obtained was 100% compared with the tube test. Receiver-operating characteristic curves revealed that the QFA has high sensitivity and specificity toward clinical samples, and the cutoff points of the R value of A and B antigens were 1.483 and 1.576, respectively. In this study, we reported a novel quantitative and multiplexed method for the identification of ABO blood groups and presented an effective alternative for quantitative blood typing. This method can be used as an effective tool to improve blood typing and further guarantee clinical transfusion safety.

Comparing Laser Welding Technologies with Friction Stir Welding for Production of Aluminum Tailor-Welded Blanks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hovanski, Yuri; Carsley, John; Carlson, Blair

2014-01-15

A comparison of welding techniques was performed to determine the most effective method for producing aluminum tailor-welded blanks for high volume automotive applications. Aluminum sheet was joined with an emphasis on post weld formability, surface quality and weld speed. Comparative results from several laser based welding techniques along with friction stir welding are presented. The results of this study demonstrate a quantitative comparison of weld methodologies in preparing tailor-welded aluminum stampings for high volume production in the automotive industry. Evaluation of nearly a dozen welding variations ultimately led to down selecting a single process based on post-weld quality and performance.

High-Performance Liquid Chromatography (HPLC)-Based Detection and Quantitation of Cellular c-di-GMP.

PubMed

Petrova, Olga E; Sauer, Karin

2017-01-01

The modulation of c-di-GMP levels plays a vital role in the regulation of various processes in a wide array of bacterial species. Thus, investigation of c-di-GMP regulation requires reliable methods for the assessment of c-di-GMP levels and turnover. Reversed-phase high-performance liquid chromatography (RP-HPLC) analysis has become a commonly used approach to accomplish these goals. The following describes the extraction and HPLC-based detection and quantification of c-di-GMP from Pseudomonas aeruginosa samples, a procedure that is amenable to modifications for the analysis of c-di-GMP in other bacterial species.

Near quantitative agreement of model free DFT- MD predictions with XAFS observations of the hydration structure of highly charged transition metal ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fulton, John L.; Bylaska, Eric J.; Bogatko, Stuart A.

DFT-MD simulations (PBE96 and PBE0) with MD-XAFS scattering calculations (FEFF9) show near quantitative agreement with new and existing XAFS measurements for a comprehensive series of transition metal ions which interact with their hydration shells via complex mechanisms (high spin, covalency, charge transfer, etc.). This work was supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences. Pacific Northwest National Laboratory (PNNL) is operated for the U.S. DOE by Battelle. A portion of the research was performed using EMSL, a national scientific user facility sponsored by the U.S. DOE's Office ofmore » Biological and Environmental Research and located at Pacific Northwest National Laboratory.« less

Association between periodontal condition and subgingival microbiota in women during pregnancy: a longitudinal study.

PubMed

Borgo, Priscila Viola; Rodrigues, Viviane Aparecida Arenas; Feitosa, Alfredo Carlos Rodrigues; Xavier, Karla Correa Barcelos; Avila-Campos, Mario Julio

2014-01-01

In this study, the gingival conditions and the quantitative detection for Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis and Prevotella intermedia in pregnant women were determined. Quantitative determinations of periodontal bacteria by using a SyBr green system in women during pregnancy were performed. Women at the 2nd and 3rd trimesters of pregnancy and non-pregnant women were included in this study. A. actinomycetemcomitans was observed in high numbers in women at the 2nd and 3rd trimesters of pregnancy with a significant difference (p<0.05). F. nucleatum and P. intermedia were also observed in high levels. Our results show that pregnant women are more susceptible to gingivitis, and the presence of A. actinomycetemcomitans in subgingival biofilm might be taken into account for the treatment of periodontal disease.

Quantitative secondary electron imaging for work function extraction at atomic level and layer identification of graphene

PubMed Central

Zhou, Yangbo; Fox, Daniel S; Maguire, Pierce; O’Connell, Robert; Masters, Robert; Rodenburg, Cornelia; Wu, Hanchun; Dapor, Maurizio; Chen, Ying; Zhang, Hongzhou

2016-01-01

Two-dimensional (2D) materials usually have a layer-dependent work function, which require fast and accurate detection for the evaluation of their device performance. A detection technique with high throughput and high spatial resolution has not yet been explored. Using a scanning electron microscope, we have developed and implemented a quantitative analytical technique which allows effective extraction of the work function of graphene. This technique uses the secondary electron contrast and has nanometre-resolved layer information. The measurement of few-layer graphene flakes shows the variation of work function between graphene layers with a precision of less than 10 meV. It is expected that this technique will prove extremely useful for researchers in a broad range of fields due to its revolutionary throughput and accuracy. PMID:26878907

Development and evaluation of a study design typology for human research.

PubMed

Carini, Simona; Pollock, Brad H; Lehmann, Harold P; Bakken, Suzanne; Barbour, Edward M; Gabriel, Davera; Hagler, Herbert K; Harper, Caryn R; Mollah, Shamim A; Nahm, Meredith; Nguyen, Hien H; Scheuermann, Richard H; Sim, Ida

2009-11-14

A systematic classification of study designs would be useful for researchers, systematic reviewers, readers, and research administrators, among others. As part of the Human Studies Database Project, we developed the Study Design Typology to standardize the classification of study designs in human research. We then performed a multiple observer masked evaluation of active research protocols in four institutions according to a standardized protocol. Thirty-five protocols were classified by three reviewers each into one of nine high-level study designs for interventional and observational research (e.g., N-of-1, Parallel Group, Case Crossover). Rater classification agreement was moderately high for the 35 protocols (Fleiss' kappa = 0.442) and higher still for the 23 quantitative studies (Fleiss' kappa = 0.463). We conclude that our typology shows initial promise for reliably distinguishing study design types for quantitative human research.

Quantitative X-ray Differential Interference Contrast Microscopy

NASA Astrophysics Data System (ADS)

Nakamura, Takashi

Full-field soft x-ray microscopes are widely used in many fields of sciences. Advances in nanofabrication technology enabled short wavelength focusing elements with significantly improved spatial resolution. In the soft x-ray spectral region, samples as small as 12 nm can be resolved using micro zone-plates as the objective lens. In addition to conventional x-ray microscopy in which x-ray absorption difference provides the image contrast, phase contrast mechanisms such as differential phase contrast (DIC) and Zernike phase contrast have also been demonstrated These phase contrast imaging mechanisms are especially attractive at the x-ray wavelengths where phase contrast of most materials is typically 10 times stronger than the absorption contrast. With recent progresses in plasma-based x- ray sources and increasing accessibility to synchrotron user facilities, x-ray microscopes are quickly becoming standard measurement equipment in the laboratory. To further the usefulness of x-ray DIC microscopy this thesis explicitly addresses three known issues with this imaging modality by introducing new techniques and devices First, as opposed to its visible-light counterpart, no quantitative phase imaging technique exists for x-ray DIC microscopy. To address this issue, two nanoscale x-ray quantitative phase imaging techniques, using exclusive OR (XOR) patterns and zone-plate doublets, respectively, are proposed. Unlike existing x-ray quantitative phase imaging techniques such as Talbot interferometry and ptychography, no dedicated experimental setups or stringent illumination coherence are needed for quantitative phase retrieval. Second, to the best of our knowledge, no quantitative performance characterization of DIC microscopy exists to date. Therefore the imaging system's response to sample's spatial frequency is not known In order to gain in-depth understanding of this imaging modality, performance of x-ray DIC microscopy is quantified using modulation transfer function. A new illumination apparatus required for the transfer function analysis under partially coherent illumination is also proposed. Such a characterization is essential for a proper selection of DIC optics for various transparent samples under study. Finally, optical elements used for x-ray DIC microscopy are highly absorptive and high brilliance x-ray sources such as synchrotrons are generally needed for image contrast. To extend the use of x-ray DIC microscopy to a wider variety of applications, a high efficiency large numerical aperture optical element consisting of high reflective Bragg reflectors is proposed. Using Bragg reflectors, which have 70% ˜99% reflectivity at extreme ultraviolet and soft x-rays for all angles of glancing incidence, the first order focusing efficiency is expected to increase by ˜ 8 times compared to that of a typical Fresnel zone-plate. This thesis contributes to current nanoscale x-ray phase contrast imaging research and provides new insights for biological, material, and magnetic sciences

Smoothing of the bivariate LOD score for non-normal quantitative traits.

PubMed

Buil, Alfonso; Dyer, Thomas D; Almasy, Laura; Blangero, John

2005-12-30

Variance component analysis provides an efficient method for performing linkage analysis for quantitative traits. However, type I error of variance components-based likelihood ratio testing may be affected when phenotypic data are non-normally distributed (especially with high values of kurtosis). This results in inflated LOD scores when the normality assumption does not hold. Even though different solutions have been proposed to deal with this problem with univariate phenotypes, little work has been done in the multivariate case. We present an empirical approach to adjust the inflated LOD scores obtained from a bivariate phenotype that violates the assumption of normality. Using the Collaborative Study on the Genetics of Alcoholism data available for the Genetic Analysis Workshop 14, we show how bivariate linkage analysis with leptokurtotic traits gives an inflated type I error. We perform a novel correction that achieves acceptable levels of type I error.

Separating DDTs in edible animal fats using matrix solid-phase dispersion extraction with activated carbon filter, Toyobo-KF.

PubMed

Furusawa, Naoto

2006-09-01

A technique is presented for the economical, routine, and quantitative analysis of contamination by dichloro-diphenyl-trichloroethanes (DDTs) [pp'-DDT, pp'-dichlorodiphenyl dichloroethylene, and pp'-dichlorodiphenyl dichloreothane in beef tallow and chicken fat samples, based on their separation using matrix solid-phase dispersion (MSPD) extraction with Toyobo-KF, an activated carbon fiber. Toyobo-KF is a newly applied MSPD sorbent, and it is followed by reversed-phase high-performance liquid chromatography (HPLC) with a photodiode array detector. The resulting analytical performance parameters [recoveries of spiked DDTs (0.1, 0.2, and 0.4 microg/g) > or = 81%, with relative standard deviations of < or = 8% (n = 5), and quantitation limits < or = 0.03 microg/g], with minimal handling and cost-efficiency, indicate that the present MSPD-HPLC method may be a useful tool for routine monitoring of DDT contamination in meat.

Chromatographic background drift correction coupled with parallel factor analysis to resolve coelution problems in three-dimensional chromatographic data: quantification of eleven antibiotics in tap water samples by high-performance liquid chromatography coupled with a diode array detector.

PubMed

Yu, Yong-Jie; Wu, Hai-Long; Fu, Hai-Yan; Zhao, Juan; Li, Yuan-Na; Li, Shu-Fang; Kang, Chao; Yu, Ru-Qin

2013-08-09

Chromatographic background drift correction has been an important field of research in chromatographic analysis. In the present work, orthogonal spectral space projection for background drift correction of three-dimensional chromatographic data was described in detail and combined with parallel factor analysis (PARAFAC) to resolve overlapped chromatographic peaks and obtain the second-order advantage. This strategy was verified by simulated chromatographic data and afforded significant improvement in quantitative results. Finally, this strategy was successfully utilized to quantify eleven antibiotics in tap water samples. Compared with the traditional methodology of introducing excessive factors for the PARAFAC model to eliminate the effect of background drift, clear improvement in the quantitative performance of PARAFAC was observed after background drift correction by orthogonal spectral space projection. Copyright © 2013 Elsevier B.V. All rights reserved.

Performance prediction of electrohydrodynamic thrusters by the perturbation method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shibata, H., E-mail: shibata@daedalus.k.u-tokyo.ac.jp; Watanabe, Y.; Suzuki, K.

2016-05-15

In this paper, we present a novel method for analyzing electrohydrodynamic (EHD) thrusters. The method is based on a perturbation technique applied to a set of drift-diffusion equations, similar to the one introduced in our previous study on estimating breakdown voltage. The thrust-to-current ratio is generalized to represent the performance of EHD thrusters. We have compared the thrust-to-current ratio obtained theoretically with that obtained from the proposed method under atmospheric air conditions, and we have obtained good quantitative agreement. Also, we have conducted a numerical simulation in more complex thruster geometries, such as the dual-stage thruster developed by Masuyama andmore » Barrett [Proc. R. Soc. A 469, 20120623 (2013)]. We quantitatively clarify the fact that if the magnitude of a third electrode voltage is low, the effective gap distance shortens, whereas if the magnitude of the third electrode voltage is sufficiently high, the effective gap distance lengthens.« less

MR Guided Pulsed High Intensity Focused Ultrasound Enhancement of Gene Therapy Combined with Androgen Deprivation and Radiotherapy for Prostate Cancer Treatment

DTIC Science & Technology

2012-09-01

for the treatment of prostate tumor-bearing mice using a clinical MRgHIFU device. We performed animal studies for quantitative measurement of the...by measuring the protein expression level of MDM2, p53 and p21 using immunohistochemical staining and west blotting techniques. We also performed...therapy) in implanted prostate tumors in mice in vivo by measuring the protein expression level of MDM, p53 and p21 with time points after treatment

QFT Multi-Input, Multi-Output Design with Non-Diagonal, Non-Square Compensation Matrices

NASA Technical Reports Server (NTRS)

Hess, R. A.; Henderson, D. K.

1996-01-01

A technique for obtaining a non-diagonal compensator for the control of a multi-input, multi-output plant is presented. The technique, which uses Quantitative Feedback Theory, provides guaranteed stability and performance robustness in the presence of parametric uncertainty. An example is given involving the lateral-directional control of an uncertain model of a high-performance fighter aircraft in which redundant control effectors are in evidence, i.e. more control effectors than output variables are used.

Characteristics of ring-cusp discharge chambers

NASA Technical Reports Server (NTRS)

Matossian, J. N.; Beattie, J. R.

1991-01-01

Measurements have been obtained for the operating characteristics of a 30 cm diameter ring-cusp ion thruster (RCIT), quantitatively comparing its performance parameters to those of a divergent-field J-series cluster of the same size. The high level of performance established for the RCIT is due to its maintenance of both a higher primary-electron population and Maxwellian-electron temperature, as the beam-ion production cost is reduced to its baseline value. Ion losses to the discharge-chamber walls can be reduced by an applied electrostatic field.

Quantitative proteomic analysis of human lung tumor xenografts treated with the ectopic ATP synthase inhibitor citreoviridin.

PubMed

Wu, Yi-Hsuan; Hu, Chia-Wei; Chien, Chih-Wei; Chen, Yu-Ju; Huang, Hsuan-Cheng; Juan, Hsueh-Fen

2013-01-01

ATP synthase is present on the plasma membrane of several types of cancer cells. Citreoviridin, an ATP synthase inhibitor, selectively suppresses the proliferation and growth of lung cancer without affecting normal cells. However, the global effects of targeting ectopic ATP synthase in vivo have not been well defined. In this study, we performed quantitative proteomic analysis using isobaric tags for relative and absolute quantitation (iTRAQ) and provided a comprehensive insight into the complicated regulation by citreoviridin in a lung cancer xenograft model. With high reproducibility of the quantitation, we obtained quantitative proteomic profiling with 2,659 proteins identified. Bioinformatics analysis of the 141 differentially expressed proteins selected by their relative abundance revealed that citreoviridin induces alterations in the expression of glucose metabolism-related enzymes in lung cancer. The up-regulation of enzymes involved in gluconeogenesis and storage of glucose indicated that citreoviridin may reduce the glycolytic intermediates for macromolecule synthesis and inhibit cell proliferation. Using comprehensive proteomics, the results identify metabolic aspects that help explain the antitumorigenic effect of citreoviridin in lung cancer, which may lead to a better understanding of the links between metabolism and tumorigenesis in cancer therapy.

Quantitative Proteomic Analysis of Human Lung Tumor Xenografts Treated with the Ectopic ATP Synthase Inhibitor Citreoviridin

PubMed Central

Wu, Yi-Hsuan; Hu, Chia-Wei; Chien, Chih-Wei; Chen, Yu-Ju; Huang, Hsuan-Cheng; Juan, Hsueh-Fen

2013-01-01

ATP synthase is present on the plasma membrane of several types of cancer cells. Citreoviridin, an ATP synthase inhibitor, selectively suppresses the proliferation and growth of lung cancer without affecting normal cells. However, the global effects of targeting ectopic ATP synthase in vivo have not been well defined. In this study, we performed quantitative proteomic analysis using isobaric tags for relative and absolute quantitation (iTRAQ) and provided a comprehensive insight into the complicated regulation by citreoviridin in a lung cancer xenograft model. With high reproducibility of the quantitation, we obtained quantitative proteomic profiling with 2,659 proteins identified. Bioinformatics analysis of the 141 differentially expressed proteins selected by their relative abundance revealed that citreoviridin induces alterations in the expression of glucose metabolism-related enzymes in lung cancer. The up-regulation of enzymes involved in gluconeogenesis and storage of glucose indicated that citreoviridin may reduce the glycolytic intermediates for macromolecule synthesis and inhibit cell proliferation. Using comprehensive proteomics, the results identify metabolic aspects that help explain the antitumorigenic effect of citreoviridin in lung cancer, which may lead to a better understanding of the links between metabolism and tumorigenesis in cancer therapy. PMID:23990911

Identification and quantitation of semi-crystalline microplastics using image analysis and differential scanning calorimetry.

PubMed

Rodríguez Chialanza, Mauricio; Sierra, Ignacio; Pérez Parada, Andrés; Fornaro, Laura

2018-06-01

There are several techniques used to analyze microplastics. These are often based on a combination of visual and spectroscopic techniques. Here we introduce an alternative workflow for identification and mass quantitation through a combination of optical microscopy with image analysis (IA) and differential scanning calorimetry (DSC). We studied four synthetic polymers with environmental concern: low and high density polyethylene (LDPE and HDPE, respectively), polypropylene (PP), and polyethylene terephthalate (PET). Selected experiments were conducted to investigate (i) particle characterization and counting procedures based on image analysis with open-source software, (ii) chemical identification of microplastics based on DSC signal processing, (iii) dependence of particle size on DSC signal, and (iv) quantitation of microplastics mass based on DSC signal. We describe the potential and limitations of these techniques to increase reliability for microplastic analysis. Particle size demonstrated to have particular incidence in the qualitative and quantitative performance of DSC signals. Both, identification (based on characteristic onset temperature) and mass quantitation (based on heat flow) showed to be affected by particle size. As a result, a proper sample treatment which includes sieving of suspended particles is particularly required for this analytical approach.

An Optimized Method for the Measurement of Acetaldehyde by High-Performance Liquid Chromatography

PubMed Central

Guan, Xiangying; Rubin, Emanuel; Anni, Helen

2011-01-01

Background Acetaldehyde is produced during ethanol metabolism predominantly in the liver by alcohol dehydrogenase, and rapidly eliminated by oxidation to acetate via aldehyde dehydrogenase. Assessment of circulating acetaldehyde levels in biological matrices is performed by headspace gas chromatography and reverse phase high-performance liquid chromatography (RP-HPLC). Methods We have developed an optimized method for the measurement of acetaldehyde by RP-HPLC in hepatoma cell culture medium, blood and plasma. After sample deproteinization, acetaldehyde was derivatized with 2,4-dinitrophenylhydrazine (DNPH). The reaction was optimized for pH, amount of derivatization reagent,, time and temperature. Extraction methods of the acetaldehyde-hydrazone (AcH-DPN) stable derivative and product stability studies were carried out. Acetaldehyde was identified by its retention time in comparison to AcH-DPN standard, using a new chromatography gradient program, and quantitated based on external reference standards and standard addition calibration curves in the presence and absence of ethanol. Results Derivatization of acetaldehyde was performed at pH 4.0 with a 80-fold molar excess of DNPH. The reaction was completed in 40 min at ambient temperature, and the product was stable for 2 days. A clear separation of AcH-DNP from DNPH was obtained with a new 11-min chromatography program. Acetaldehyde detection was linear up to 80 μM. The recovery of acetaldehyde was >88% in culture media, and >78% in plasma. We quantitatively determined the ethanol-derived acetaldehyde in hepatoma cells, rat blood and plasma with a detection limit around 3 μM. The accuracy of the method was <9% for intraday and <15% for interday measurements, in small volume (70 μl) plasma sampling. Conclusions An optimized method for the quantitative determination of acetaldehyde in biological systems was developed using derivatization with DNPH, followed by a short RP-HPLC separation of AcH-DNP. The method has an extended linear range, is reproducible and applicable to small volume sampling of culture media and biological fluids. PMID:21895715

An optimized method for the measurement of acetaldehyde by high-performance liquid chromatography.

PubMed

Guan, Xiangying; Rubin, Emanuel; Anni, Helen

2012-03-01

Acetaldehyde is produced during ethanol metabolism predominantly in the liver by alcohol dehydrogenase and rapidly eliminated by oxidation to acetate via aldehyde dehydrogenase. Assessment of circulating acetaldehyde levels in biological matrices is performed by headspace gas chromatography and reverse phase high-performance liquid chromatography (RP-HPLC). We have developed an optimized method for the measurement of acetaldehyde by RP-HPLC in hepatoma cell culture medium, blood, and plasma. After sample deproteinization, acetaldehyde was derivatized with 2,4-dinitrophenylhydrazine (DNPH). The reaction was optimized for pH, amount of derivatization reagent, time, and temperature. Extraction methods of the acetaldehyde-hydrazone (AcH-DNP) stable derivative and product stability studies were carried out. Acetaldehyde was identified by its retention time in comparison with AcH-DNP standard, using a new chromatography gradient program, and quantitated based on external reference standards and standard addition calibration curves in the presence and absence of ethanol. Derivatization of acetaldehyde was performed at pH 4.0 with an 80-fold molar excess of DNPH. The reaction was completed in 40 minutes at ambient temperature, and the product was stable for 2 days. A clear separation of AcH-DNP from DNPH was obtained with a new 11-minute chromatography program. Acetaldehyde detection was linear up to 80 μM. The recovery of acetaldehyde was >88% in culture media and >78% in plasma. We quantitatively determined the ethanol-derived acetaldehyde in hepatoma cells, rat blood and plasma with a detection limit around 3 μM. The accuracy of the method was <9% for intraday and <15% for interday measurements, in small volume (70 μl) plasma sampling. An optimized method for the quantitative determination of acetaldehyde in biological systems was developed using derivatization with DNPH, followed by a short RP-HPLC separation of AcH-DNP. The method has an extended linear range, is reproducible and applicable to small-volume sampling of culture media and biological fluids. Copyright © 2011 by the Research Society on Alcoholism.

Benchmarking quantitative label-free LC-MS data processing workflows using a complex spiked proteomic standard dataset.

PubMed

Ramus, Claire; Hovasse, Agnès; Marcellin, Marlène; Hesse, Anne-Marie; Mouton-Barbosa, Emmanuelle; Bouyssié, David; Vaca, Sebastian; Carapito, Christine; Chaoui, Karima; Bruley, Christophe; Garin, Jérôme; Cianférani, Sarah; Ferro, Myriam; Van Dorssaeler, Alain; Burlet-Schiltz, Odile; Schaeffer, Christine; Couté, Yohann; Gonzalez de Peredo, Anne

2016-01-30

Proteomic workflows based on nanoLC-MS/MS data-dependent-acquisition analysis have progressed tremendously in recent years. High-resolution and fast sequencing instruments have enabled the use of label-free quantitative methods, based either on spectral counting or on MS signal analysis, which appear as an attractive way to analyze differential protein expression in complex biological samples. However, the computational processing of the data for label-free quantification still remains a challenge. Here, we used a proteomic standard composed of an equimolar mixture of 48 human proteins (Sigma UPS1) spiked at different concentrations into a background of yeast cell lysate to benchmark several label-free quantitative workflows, involving different software packages developed in recent years. This experimental design allowed to finely assess their performances in terms of sensitivity and false discovery rate, by measuring the number of true and false-positive (respectively UPS1 or yeast background proteins found as differential). The spiked standard dataset has been deposited to the ProteomeXchange repository with the identifier PXD001819 and can be used to benchmark other label-free workflows, adjust software parameter settings, improve algorithms for extraction of the quantitative metrics from raw MS data, or evaluate downstream statistical methods. Bioinformatic pipelines for label-free quantitative analysis must be objectively evaluated in their ability to detect variant proteins with good sensitivity and low false discovery rate in large-scale proteomic studies. This can be done through the use of complex spiked samples, for which the "ground truth" of variant proteins is known, allowing a statistical evaluation of the performances of the data processing workflow. We provide here such a controlled standard dataset and used it to evaluate the performances of several label-free bioinformatics tools (including MaxQuant, Skyline, MFPaQ, IRMa-hEIDI and Scaffold) in different workflows, for detection of variant proteins with different absolute expression levels and fold change values. The dataset presented here can be useful for tuning software tool parameters, and also testing new algorithms for label-free quantitative analysis, or for evaluation of downstream statistical methods. Copyright © 2015 Elsevier B.V. All rights reserved.

Simultaneous quantitative determination of 11 sesquiterpene lactones in Jerusalem artichoke (Helianthus tuberosus L.) leaves by ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry.

PubMed

Yuan, Xiaoyan; Yang, Qianxu

2017-04-01

A method of ultra high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was developed for the simultaneous quantification of 11 sesquiterpene lactones in 11 Jerusalem artichoke leaf samples harvested in a number of areas at different periods. The optimal chromatographic conditions were achieved on a ZORBAX Eclipse Plus C 18 column (3.0 × 150 mm, 1.8 μm) with linear gradient elution of methanol and water in 8 min. Quantitative analysis was carried out under selective ion monitoring mode. All of the sesquiterpene lactones showed good linearity (R 2 ≥ 0.9949), repeatability (relative standard deviations < 4.66%), and intra- and interday precisions (relative standard deviations < 4.52%) with an accuracy of 95.24-104.84%. The recoveries measured at three concentration levels varied from 95.07 to 104.87% with relative standard deviations less than 4.9%. The limit of detection and limit of quantitation for this method were 0.89-5.05 and 1.12-44.33 ng/mL, respectively. The results showed that the contents of sesquiterpene lactones varied significantly in the Jerusalem artichoke leaf samples from different areas. Among them, the content of sesquiterpene lactones in the sample collected from Dalian, Liaoning province was the highest and the early flowering period was considered to be the optimal harvest time. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-Resolution C-Arm CT and Metal Artifact Reduction Software: A Novel Imaging Modality for Analyzing Aneurysms Treated with Stent-Assisted Coil Embolization.

PubMed

Yuki, I; Kambayashi, Y; Ikemura, A; Abe, Y; Kan, I; Mohamed, A; Dahmani, C; Suzuki, T; Ishibashi, T; Takao, H; Urashima, M; Murayama, Y

2016-02-01

Combination of high-resolution C-arm CT and novel metal artifact reduction software may contribute to the assessment of aneurysms treated with stent-assisted coil embolization. This study aimed to evaluate the efficacy of a novel Metal Artifact Reduction prototype software combined with the currently available high spatial-resolution C-arm CT prototype implementation by using an experimental aneurysm model treated with stent-assisted coil embolization. Eight experimental aneurysms were created in 6 swine. Coil embolization of each aneurysm was performed by using a stent-assisted technique. High-resolution C-arm CT with intra-arterial contrast injection was performed immediately after the treatment. The obtained images were processed with Metal Artifact Reduction. Five neurointerventional specialists reviewed the image quality before and after Metal Artifact Reduction. Observational and quantitative analyses (via image analysis software) were performed. Every aneurysm was successfully created and treated with stent-assisted coil embolization. Before Metal Artifact Reduction, coil loops protruding through the stent lumen were not visualized due to the prominent metal artifacts produced by the coils. These became visible after Metal Artifact Reduction processing. Contrast filling in the residual aneurysm was also visualized after Metal Artifact Reduction in every aneurysm. Both the observational (P < .0001) and quantitative (P < .001) analyses showed significant reduction of the metal artifacts after application of the Metal Artifact Reduction prototype software. The combination of high-resolution C-arm CT and Metal Artifact Reduction enables differentiation of the coil mass, stent, and contrast material on the same image by significantly reducing the metal artifacts produced by the platinum coils. This novel image technique may improve the assessment of aneurysms treated with stent-assisted coil embolization. © 2016 by American Journal of Neuroradiology.

New Performance Metrics for Quantitative Polymerase Chain Reaction-Based Microbial Source Tracking Methods

EPA Science Inventory

Binary sensitivity and specificity metrics are not adequate to describe the performance of quantitative microbial source tracking methods because the estimates depend on the amount of material tested and limit of detection. We introduce a new framework to compare the performance ...

Sensitive and quantitative measurement of gene expression directly from a small amount of whole blood.

PubMed

Zheng, Zhi; Luo, Yuling; McMaster, Gary K

2006-07-01

Accurate and precise quantification of mRNA in whole blood is made difficult by gene expression changes during blood processing, and by variations and biases introduced by sample preparations. We sought to develop a quantitative whole-blood mRNA assay that eliminates blood purification, RNA isolation, reverse transcription, and target amplification while providing high-quality data in an easy assay format. We performed single- and multiplex gene expression analysis with multiple hybridization probes to capture mRNA directly from blood lysate and used branched DNA to amplify the signal. The 96-well plate singleplex assay uses chemiluminescence detection, and the multiplex assay combines Luminex-encoded beads with fluorescent detection. The single- and multiplex assays could quantitatively measure as few as 6000 and 24,000 mRNA target molecules (0.01 and 0.04 amoles), respectively, in up to 25 microL of whole blood. Both formats had CVs < 10% and dynamic ranges of 3-4 logs. Assay sensitivities allowed quantitative measurement of gene expression in the minority of cells in whole blood. The signals from whole-blood lysate correlated well with signals from purified RNA of the same sample, and absolute mRNA quantification results from the assay were similar to those obtained by quantitative reverse transcription-PCR. Both single- and multiplex assay formats were compatible with common anticoagulants and PAXgene-treated samples; however, PAXgene preparations induced expression of known antiapoptotic genes in whole blood. Both the singleplex and the multiplex branched DNA assays can quantitatively measure mRNA expression directly from small volumes of whole blood. The assay offers an alternative to current technologies that depend on RNA isolation and is amenable to high-throughput gene expression analysis of whole blood.

Quantitative analysis of glycated albumin in serum based on ATR-FTIR spectrum combined with SiPLS and SVM.

PubMed

Li, Yuanpeng; Li, Fucui; Yang, Xinhao; Guo, Liu; Huang, Furong; Chen, Zhenqiang; Chen, Xingdan; Zheng, Shifu

2018-08-05

A rapid quantitative analysis model for determining the glycated albumin (GA) content based on Attenuated total reflectance (ATR)-Fourier transform infrared spectroscopy (FTIR) combining with linear SiPLS and nonlinear SVM has been developed. Firstly, the real GA content in human serum was determined by GA enzymatic method, meanwhile, the ATR-FTIR spectra of serum samples from the population of health examination were obtained. The spectral data of the whole spectra mid-infrared region (4000-600 cm -1 ) and GA's characteristic region (1800-800 cm -1 ) were used as the research object of quantitative analysis. Secondly, several preprocessing steps including first derivative, second derivative, variable standardization and spectral normalization, were performed. Lastly, quantitative analysis regression models were established by using SiPLS and SVM respectively. The SiPLS modeling results are as follows: root mean square error of cross validation (RMSECV T ) = 0.523 g/L, calibration coefficient (R C ) = 0.937, Root Mean Square Error of Prediction (RMSEP T ) = 0.787 g/L, and prediction coefficient (R P ) = 0.938. The SVM modeling results are as follows: RMSECV T  = 0.0048 g/L, R C  = 0.998, RMSEP T  = 0.442 g/L, and R p  = 0.916. The results indicated that the model performance was improved significantly after preprocessing and optimization of characteristic regions. While modeling performance of nonlinear SVM was considerably better than that of linear SiPLS. Hence, the quantitative analysis model for GA in human serum based on ATR-FTIR combined with SiPLS and SVM is effective. And it does not need sample preprocessing while being characterized by simple operations and high time efficiency, providing a rapid and accurate method for GA content determination. Copyright © 2018 Elsevier B.V. All rights reserved.

A direct and fast method to monitor lipid oxidation progress in model fatty acid methyl esters by high-performance size-exclusion chromatography.

PubMed

Márquez-Ruiz, G; Holgado, F; García-Martínez, M C; Dobarganes, M C

2007-09-21

A new method based on high-performance size-exclusion chromatography (HPSEC) is proposed to quantitate primary and secondary oxidation compounds in model fatty acid methyl esters (FAMEs). The method consists on simply injecting an aliquot sample in HPSEC, without preliminary isolation procedures neither addition of standard internal. Four groups of compounds can be quantified, namely, unoxidised FAME, oxidised FAME monomers including hydroperoxides, FAME dimers and FAME polymers. Results showed high repeatability and sensitivity, and substantial advantages versus determination of residual substrate by gas-liquid chromatography. Applicability of the method is shown through selected data obtained by numerous oxidation experiments on pure FAME, mainly methyl linoleate, at ambient and moderate temperatures.

Parental Involvement and Perceived At-Risk Student Performance: Views from Predominantly Hispanic Parents

ERIC Educational Resources Information Center

Braley, Richard; Slate, John R.; Cavazos, Jose

2009-01-01

These researchers analyzed the perceptions of parents of students determined to be at-risk about their involvement with their children. Parents (n = 229), predominantly Hispanic, were surveyed from elementary schools, middle schools, and high schools in a district in South Texas near the Texas-Mexico border. Quantitative data obtained from the…

A Didactic Experiment and Model of a Flat-Plate Solar Collector

ERIC Educational Resources Information Center

Gallitto, Aurelio Agliolo; Fiordilino, Emilio

2011-01-01

We report on an experiment performed with a home-made flat-plate solar collector, carried out together with high-school students. To explain the experimental results, we propose a model that describes the heating process of the solar collector. The model accounts quantitatively for the experimental data. We suggest that solar-energy topics should…

Safety characteristics of the lithium SO2 system

NASA Technical Reports Server (NTRS)

Watson, T.

1978-01-01

Extensive tests were conducted to quantitatively define the safety characteristics of high-rate SO2 multicell batteries under various discharge and temperature profiles, which closely simulated actual field-use conditions. The resulting behavior patters of the multicell batteries and the corrective action which can be implemented to minimize or prevent hazardous battery performance are briefly summarized.

A reliable methodology for quantitative extraction of fruit and vegetable physiological amino acids and their subsequent analysis with commonly available HPLC systems

USDA-ARS?s Scientific Manuscript database

High performance liquid chromatography of dabsyl derivatives of amino acids was employed for quantification of physiological amino acids in selected fruits and vegetables. This method was found to be particularly useful because the dabsyl derivatives of glutamine and citrulline were sufficiently se...

A Lifespan Study of Cooperative Education Graduates: Quantitative Aspects.

ERIC Educational Resources Information Center

Linn, Patricia L.; Ferguson, Jane

1999-01-01

Career histories of 73 graduates of Antioch College's liberal arts co-op program, 1946-55, showed an average of 6.5 jobs before retirement and high rates of self-employment. Those with low performance in cooperative education were much more likely to have earned graduate degrees. Self-employed graduates had more varied jobs and retired later. (SK)

A Quantitative Review of Physical Activity, Health, and Learning Outcomes Associated with Classroom-Based Physical Activity Interventions

ERIC Educational Resources Information Center

Erwin, Heather; Fedewa, Alicia; Beighle, Aaron; Ahn, Soyeon

2012-01-01

Research suggests that physical activity may foster improved academic performance, yet schools are receiving more pressure to achieve high academic standards. It is important for classroom teachers, administrators and school psychologists to understand the benefits of incorporating physical activity into the school day. This article serves as a…

Study of the Relationship between Self-Reported Leadership Styles of Charter School Principals and Their Performance

ERIC Educational Resources Information Center

Alizor, John O.

2012-01-01

The purpose of this quantitative study, using the three-way repeated measures ANOVA, was to identify certain leadership styles used by effective and ineffective charter high school principals that impact the students' academic achievement. Principal ratings and school demographic characteristics were gathered from 19 charter schools. The study's…

Diagnostic performance and color overlay pattern in shear wave elastography (SWE) for palpable breast mass.

PubMed

Park, Jiyoon; Woo, Ok Hee; Shin, Hye Seon; Cho, Kyu Ran; Seo, Bo Kyoung; Kang, Eun Young

2015-10-01

The purpose of this study is to evaluate the diagnostic performance of SWE in palpable breast mass and to compare with color overlay pattern in SWE with conventional US and quantitative SWE for assessing palpable breast mass. SWE and conventional breast US were performed in 133 women with 156 palpable breast lesions (81 benign, 75 malignant) between August 2013 to June 2014. Either pathology or periodic imaging surveillance more than 2 years was a reference standard. Existence of previous image was blinded to performing radiologists. US BI-RADS final assessment, qualitative and quantitative SWE measurements were evaluated. Diagnostic performances of grayscale US, SWE and US combined to SWE were calculated and compared. Correlation between pattern classification and quantitative SWE was evaluated. Both color overlay pattern and quantitative SWE improved the specificity of conventional US, from 81.48% to 96.30% (p=0.0005), without improvement in sensitivity. Color overlay pattern was significantly related to all quantitative SWE parameters and malignancy rate (p<0.0001.). The optimal cutoff of color overlay pattern was between 2 and 3. Emax with optimal cutoff at 45.1 kPa showed the highest Az value, sensitivity, specificity and accuracy among other quantitative SWE parameters (p<0.0001). Echogenic halo on grayscale US showed significant correlation with color overlay pattern and pathology (p<0.0001). In evaluation of palpable breast mass, conventional US combine to SWE improves specificity and reduces the number of biopsies that ultimately yield a benign result. Color overlay pattern classification is more quick and easy and may represent quantitative SWE measurements with similar diagnostic performances. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Adaptability and stability of soybean genotypes in off-season cultivation.

PubMed

Batista, R O; Hamawaki, R L; Sousa, L B; Nogueira, A P O; Hamawaki, O T

2015-08-14

The oil and protein contents of soybean grains are important quantitative traits for use in breeding. However, few breeding programs perform selection based on these traits in different environments. This study assessed the adaptability and stability of 14 elite early soybean breeding lines in off-season cultivation with respect to yield, and oil and protein contents. A range of statistical methods was applied and these analyses indicated that for off-season cultivation, the lines UFUS 5 and UFUS 10 could be recommended due to their superior performance in grain yield, oil content, and specific adaptability to unfavorable environments along with high stability in these characteristics. Also recommended were UFUS 06, which demonstrated superior performance in all three tested characteristics and showed adaptation to favorable environments, and UFUS 13, which showed high adaptability and stability and a superior performance for protein content.

Selective Amperometric Recording of Endogenous Ascorbate Secretion from a Single Rat Adrenal Chromaffin Cell with Pretreated Carbon Fiber Microelectrodes.

PubMed

Wang, Kai; Xiao, Tongfang; Yue, Qingwei; Wu, Fei; Yu, Ping; Mao, Lanqun

2017-09-05

Quantitative description of ascorbate secretion at a single-cell level is of great importance in physiological studies; however, most studies on the ascorbate secretion have so far been performed through analyzing cell extracts with high performance liquid chromatography, which lacks time resolution and analytical performance on a single-cell level. This study demonstrates a single-cell amperometry with carbon fiber microelectrodes (CFEs) to selectively monitor amperometric vesicular secretion of endogenous ascorbate from a single rat adrenal chromaffin cell. The CFEs are electrochemically pretreated in a weakly basic solution (pH 9.5), and such pretreatment essentially enables the oxidation of ascorbate to occur at a relatively low potential (i.e., 0.0 V vs Ag/AgCl), and further a high selectivity for ascorbate measurement over endogenously existing electroactive species such as epinephrine, norepinephrine, and dopamine. The selectivity is ensured by much larger amperometric response at the pretreated CFEs toward ascorbate over those toward other endogenously existing electroactive species added into the solution or ejected to the electrode with a micropuffer pipet, and by the totally suppressed current response by adding ascorbate oxidase into the cell lysate. With the pretreated CFE-based single-cell amperometry developed here, exocytosis of endogenous ascorbate of rat adrenal chromaffin cells is directly observed and ensured with the calcium ion-dependent high K + -induced secretion of endogenous ascorbate from the cells. Moreover, the quantitative information on the exocytosis of endogenous ascorbate is provided.

Ultra-high performance liquid chromatography with tandem mass spectrometry method for the simultaneous quantitation of five phthalides in rat plasma: Application to a comparative pharmacokinetic study of Huo Luo Xiao Ling Dan and herb-pair extract.

PubMed

Ma, Wen; Wang, Weihui; Peng, Yan; Bian, Qiaoxia; Wang, Nannan; Lee, David Y-W; Dai, Ronghua

2016-06-01

A fast, sensitive, and reliable ultra-high performance liquid chromatography with tandem mass spectrometry method has been developed and validated for the simultaneous quantitation and pharmacokinetic study of five phthalides (senkyunolide A, ligustilide, butylidenephthalide, 3-butylphthalide, and levistilide A) in rat plasma after oral administration of Huo Luo Xiao Ling Dan (HLXLD) or Angelica sinensis--Ligusticum chuanxiong herb pair (DG-CX) between normal and arthritis rats. After extraction from blood, the analytes and internal standard were subjected to ultra-high performance liquid chromatography with a Shim-pack XR-ODS column (75 × 3.0 mm(2) , 2.2 μm particles) and mobile phase was composed of methanol and water (containing 0.05% formic acid) under gradient elution conditions, with an electrospray ionization source in the positive ionization and multiple reaction monitoring mode. The lower limits of quantification were 0.192-0.800 ng/mL for all the analytes. Satisfactory linearity, precision, accuracy, mean extraction recovery, and acceptable matrix effect have been achieved. The validated method was successfully applied to a comparative pharmacokinetic study of five bioactive components in rat plasma after oral administration of HLXLD or DG-CX alone, respectively, between normal and arthritic rats. The results showed that there were unlike characters of pharmacokinetics among different groups. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chuang, Chihpin; Singh, Dileep; Kenesei, Peter

The size and morphology of the graphite particles play a crucial role in determining various mechanical and thermal properties of cast iron. In the present study, we utilized high-energy synchrotron X-ray tomography to perform quantitative 3D-characterization of the distribution of graphite particles in high-strength compacted graphite iron (CGI). The size, shape, and spatial connectivity of graphite were examined. The analysis reveals that the compacted graphite can grow with a coral-tree-like morphology and span several hundred microns in the iron matrix.

Image Harvest: an open-source platform for high-throughput plant image processing and analysis

PubMed Central

Knecht, Avi C.; Campbell, Malachy T.; Caprez, Adam; Swanson, David R.; Walia, Harkamal

2016-01-01

High-throughput plant phenotyping is an effective approach to bridge the genotype-to-phenotype gap in crops. Phenomics experiments typically result in large-scale image datasets, which are not amenable for processing on desktop computers, thus creating a bottleneck in the image-analysis pipeline. Here, we present an open-source, flexible image-analysis framework, called Image Harvest (IH), for processing images originating from high-throughput plant phenotyping platforms. Image Harvest is developed to perform parallel processing on computing grids and provides an integrated feature for metadata extraction from large-scale file organization. Moreover, the integration of IH with the Open Science Grid provides academic researchers with the computational resources required for processing large image datasets at no cost. Image Harvest also offers functionalities to extract digital traits from images to interpret plant architecture-related characteristics. To demonstrate the applications of these digital traits, a rice (Oryza sativa) diversity panel was phenotyped and genome-wide association mapping was performed using digital traits that are used to describe different plant ideotypes. Three major quantitative trait loci were identified on rice chromosomes 4 and 6, which co-localize with quantitative trait loci known to regulate agronomically important traits in rice. Image Harvest is an open-source software for high-throughput image processing that requires a minimal learning curve for plant biologists to analyzephenomics datasets. PMID:27141917

Laser induced fluorescence measurements and modeling of nitric oxide in high-pressure premixed flames

NASA Technical Reports Server (NTRS)

Reisel, John R.; Laurendeau, Normand M.

1994-01-01

Laser-induced fluorescence (LIF) has been applied to the quantitative measurement of nitric oxide (NO) in premixed, laminar, high-pressure flames. Their chemistry was also studied using three current kinetics schemes to determine the predictive capabilities of each mechanism with respect to NO concentrations. The flames studied were low-temperature (1600 less than T less than 1850K) C2H6/O2/N2 and C2H6/O2/N2 flames, and high temperature (2100 less than T less than 2300K) C2H6/O2/N2 flames. Laser-saturated fluorescence (LSF) was initially used to measure the NO concentrations. However, while the excitation transition was well saturated at atmospheric pressure, the fluorescence behavior was basically linear with respect to laser power at pressures above 6 atm. Measurements and calculations demonstrated that the fluorescence quenching rate variation is negligible for LIF measurements of NO at a given pressure. Therefore, linear LIF was used to perform quantitative measurements of NO concentration in these high-pressure flames. The transportability of a calibration factor from one set of flame conditions to another also was investigated by considering changes in the absorption and quenching environment for different flame conditions. The feasibility of performing LIF measurements of (NO) in turbulent flames was studied; the single-shot detection limit was determined to be 2 ppm.

Crowdsourcing Assessment of Surgeon Dissection of Renal Artery and Vein During Robotic Partial Nephrectomy: A Novel Approach for Quantitative Assessment of Surgical Performance.

PubMed

Powers, Mary K; Boonjindasup, Aaron; Pinsky, Michael; Dorsey, Philip; Maddox, Michael; Su, Li-Ming; Gettman, Matthew; Sundaram, Chandru P; Castle, Erik P; Lee, Jason Y; Lee, Benjamin R

2016-04-01

We sought to describe a methodology of crowdsourcing for obtaining quantitative performance ratings of surgeons performing renal artery and vein dissection of robotic partial nephrectomy (RPN). We sought to compare assessment of technical performance obtained from the crowdsourcers with that of surgical content experts (CE). Our hypothesis is that the crowd can score performances of renal hilar dissection comparably to surgical CE using the Global Evaluative Assessment of Robotic Skills (GEARS). A group of resident and attending robotic surgeons submitted a total of 14 video clips of RPN during hilar dissection. These videos were rated by both crowd and CE for technical skills performance using GEARS. A minimum of 3 CE and 30 Amazon Mechanical Turk crowdworkers evaluated each video with the GEARS scale. Within 13 days, we received ratings of all videos from all CE, and within 11.5 hours, we received 548 GEARS ratings from crowdworkers. Even though CE were exposed to a training module, internal consistency across videos of CE GEARS ratings remained low (ICC = 0.38). Despite this, we found that crowdworker GEARS ratings of videos were highly correlated with CE ratings at both the video level (R = 0.82, p < 0.001) and surgeon level (R = 0.84, p < 0.001). Similarly, crowdworker ratings of the renal artery dissection were highly correlated with expert assessments (R = 0.83, p < 0.001) for the unique surgery-specific assessment question. We conclude that crowdsourced assessment of qualitative performance ratings may be an alternative and/or adjunct to surgical experts' ratings and would provide a rapid scalable solution to triage technical skills.

Quantitative high dynamic range beam profiling for fluorescence microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell, T. J., E-mail: t.j.mitchell@dur.ac.uk; Saunter, C. D.; O’Nions, W.

2014-10-15

Modern developmental biology relies on optically sectioning fluorescence microscope techniques to produce non-destructive in vivo images of developing specimens at high resolution in three dimensions. As optimal performance of these techniques is reliant on the three-dimensional (3D) intensity profile of the illumination employed, the ability to directly record and analyze these profiles is of great use to the fluorescence microscopist or instrument builder. Though excitation beam profiles can be measured indirectly using a sample of fluorescent beads and recording the emission along the microscope detection path, we demonstrate an alternative approach where a miniature camera sensor is used directly withinmore » the illumination beam. Measurements taken using our approach are solely concerned with the illumination optics as the detection optics are not involved. We present a miniature beam profiling device and high dynamic range flux reconstruction algorithm that together are capable of accurately reproducing quantitative 3D flux maps over a large focal volume. Performance of this beam profiling system is verified within an optical test bench and demonstrated for fluorescence microscopy by profiling the low NA illumination beam of a single plane illumination microscope. The generality and success of this approach showcases a widely flexible beam amplitude diagnostic tool for use within the life sciences.« less

Evolution of enzymes in a series is driven by dissimilar functional demands.

PubMed

Salvador, Armindo; Savageau, Michael A

2006-02-14

That distinct enzyme activities in an unbranched metabolic pathway are evolutionarily tuned to a single functional requirement is a pervasive assumption. Here we test this assumption by examining the activities of two consecutively acting enzymes in human erythrocytes with an approach to quantitative evolutionary design that avoids the above-mentioned assumption. We previously found that avoidance of NADPH depletion during the pulses of oxidative load to which erythrocytes are normally exposed is the main functional requirement mediating selection for high glucose-6-phosphate dehydrogenase activity. In the present study, we find that, in contrast, the maintenance of oxidized glutathione at low concentrations is the main functional requirement mediating selection for high glutathione reductase activity. The results in this case show that, contrary to the assumption of a single functional requirement, natural selection for the normal activities of the distinct enzymes in the pathway is mediated by different requirements. On the other hand, the results agree with the more general principles that underlie our approach. Namely, that (i) the values of biochemical parameters evolve so as to fulfill the various performance requirements that are relevant to achieve high fitness, and (ii) these performance requirements can be inferred from quantitative systems theory considerations, informed by knowledge of specific aspects of the biochemistry, physiology, genetics, and ecology of the organism.

Gender Differences in Motor Skills of the Overarm Throw

PubMed Central

Gromeier, Michael; Koester, Dirk; Schack, Thomas

2017-01-01

In this cross-sectional study, the qualitative and quantitative throwing performance of male and female athletes (6 to 16 years of age) was analyzed. The goal of this study was to assess whether there were gender based qualitative and quantitative differences in throwing performance of young athletes, throughout three different age bands (childhood, pubescence, and adolescence). Furthermore, we explored whether all components of the throwing movement are equally affected by gender differences. Focus was placed on five essential components of action: trunk, forearm, humerus, stepping, and backswing. Therefore, children and adolescents (N = 96) were invited to throw three times from three different distances, while aiming at a target placed at shoulder height. The participants were aspiring athletes, competitive in the sport handball. For analyzing the quality of movement the component approach of Halverson and Roberton (1984) was used. The throwing accuracy was noted and used to evaluate the quantitative performance of the throwing movement. Throughout three different age bands, no statistically significant difference was found between genders in throwing accuracy, i.e., quantitative performance. Regarding the qualitative evaluation of the throwing movement, male and female athletes differed significantly. The component approach yielded higher scores for male than for female participants. As expected, with increasing age qualitative and quantitative performance of male and female athletes improved. These results suggest that there are gender-specific differences in qualitative throwing performance, but not necessarily in quantitative throwing performance. Exploration shows that differences in the qualitative throwing performance were seen in specific components of action. Male and female athletes demonstrated similar movement patterns in humerus and forearm actions, but differed in trunk, stepping, and backswing actions. PMID:28261142

Quantitative Analysis and Comparison of Four Major Flavonol Glycosides in the Leaves of Toona sinensis (A. Juss.) Roemer (Chinese Toon) from Various Origins by High-Performance Liquid Chromatography-Diode Array Detector and Hierarchical Clustering Analysis

PubMed Central

Sun, Xiaoxiang; Zhang, Liting; Cao, Yaqi; Gu, Qinying; Yang, Huan; Tam, James P.

2016-01-01

Background: Toona sinensis (A. Juss.) Roemer is an endemic species of Toona genus native to Asian area. Its dried leaves are applied in the treatment of many diseases; however, few investigations have been reported for the quantitative analysis and comparison of major bioactive flavonol glycosides in the leaves harvested from various origins. Objective: To quantitatively analyze four major flavonol glycosides including rutinoside, quercetin-3-O-β-D-glucoside, quercetin-3-O-α-L-rhamnoside, and kaempferol-3-O-α-L-rhamnoside in the leaves from different production sites and classify them according to the content of these glycosides. Materials and Methods: A high-performance liquid chromatography-diode array detector (HPLC-DAD) method for their simultaneous determination was developed and validated for linearity, precision, accuracy, stability, and repeatability. Moreover, the method established was then employed to explore the difference in the content of these four glycosides in raw materials. Finally, a hierarchical clustering analysis was performed to classify 11 voucher specimens. Results: The separation was performed on a Waters XBridge Shield RP18 column (150 mm × 4.6 mm, 3.5 μm) kept at 35°C, and acetonitrile and H2O containing 0.30% trifluoroacetic acid as mobile phase was driven at 1.0 mL/min during the analysis. Ten microliters of solution were injected and 254 nm was selected to monitor the separation. A strong linear relationship between the peak area and concentration of four analytes was observed. And, the method was also validated to be repeatable, stable, precise, and accurate. Conclusion: An efficient and reliable HPLC-DAD method was established and applied in the assays for the samples from 11 origins successfully. Moreover, the content of those flavonol glycosides varied much among different batches, and the flavonoids could be considered as biomarkers to control the quality of Chinese Toon. SUMMARY Four major flavonol glycosides in the leaves of Toona sinensis were determined by HPLC-DAD and their contents were compared among various origins by HCA. Abbreviations used: HPLC-DAD: High-performance liquid chromatography-diode array detector, HCA: Hierarchical clustering analysis, MS: Mass spectrometry, RSD: Relative standard deviation. PMID:27279719

Stable isotope dilution ultra-high performance liquid chromatography-tandem mass spectrometry quantitative profiling of tryptophan-related neuroactive substances in human serum and cerebrospinal fluid.

PubMed

Hényková, Eva; Vránová, Hana Přikrylová; Amakorová, Petra; Pospíšil, Tomáš; Žukauskaitė, Asta; Vlčková, Magdaléna; Urbánek, Lubor; Novák, Ondřej; Mareš, Jan; Kaňovský, Petr; Strnad, Miroslav

2016-03-11

Many compounds related to L-tryptophan (L-TRP) have interesting biological or pharmacological activity, and their abnormal neurotransmission seems to be linked to a wide range of neurodegenerative and psychiatric diseases. A high-throughput method based on ultra-high performance liquid chromatography connected to electrospray tandem mass spectrometry (UHPLC-ESI-MS/MS) was developed for the quantitative analysis of L-TRP and 16 of its metabolites in human serum and cerebrospinal fluid (CSF), representing both major and minor routes of L-TRP catabolism. The combination of a fast LC gradient with selective tandem mass spectrometry enabled accurate analysis of almost 100 samples in 24h. The standard isotope dilution method was used for quantitative determination. The method's lower limits of quantification for serum and cerebrospinal fluid ranged from 0.05 to 15nmol/L and 0.3 to 45nmol/L, respectively. Analytical recoveries ranged from 10.4 to 218.1% for serum and 22.1 to 370.0% for CSF. The method's accuracy ranged from 82.4 to 128.5% for serum matrix and 90.7 to 127.7% for CSF matrix. All intra- and inter-day coefficients of variation were below 15%. These results demonstrate that the new method is capable of quantifying endogenous serum and CSF levels of a heterogeneous group of compounds spanning a wide range of concentrations. The method was used to determine the physiological levels of target analytes in serum and CSF samples from 18 individuals, demonstrating its reliability and potential usefulness in large-scale epidemiological studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Simultaneous detection and quantitation of organic impurities in methamphetamine by ultra-high-performance liquid chromatography-tandem mass spectrometry, a complementary technique for methamphetamine profiling.

PubMed

Li, Li; Brown, Jaclyn L; Toske, Steven G

2018-04-06

The analysis of organic impurities plays an important role in the impurity profiling of methamphetamine, which in turn provides valuable information about methamphetamine manufacturing, in particular its synthetic route, chemicals, and precursors used. Ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) is ideally suited for this purpose due to its excellent sensitivity, selectivity, and wide linear range in multiple reaction monitoring (MRM) mode. In this study, a dilute-and-shoot UHPLC-MS/MS method was developed for the simultaneous identification and quantitation of 23 organic manufacturing impurities in illicit methamphetamine. The developed method was validated in terms of stability, limit of detection (LOD), lower limit of quantification (LLOQ), accuracy, and precision. More than 100 illicitly prepared methamphetamine samples were analyzed. Due to its ability to detect ephedrine/pseudoephedrine and its high sensitivity for critical target markers (eg, chloro-pseudoephedrine, N-cyclohexylamphetamine, and compounds B and P), more impurities and precursor/pre-precursors were identified and quantified versus the current procedure by gas chromatography-mass spectrometry (GC-MS). Consequently, more samples could be classified by their synthetic routes. However, the UHPLC-MS/MS method has difficulty in detecting neutral and untargeted emerging manufacturing impurities and can therefore only serve as a complement to the current method. Despite this deficiency, the quantitative information acquired by the presented UHPLC-MS/MS methodology increased the sample discrimination power, thereby enhancing the capacity of methamphetamine profiling program (MPP) to conduct sample-sample comparisons. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Assessment of the risk of introducing foot-and-mouth disease into Panama via a ferry operating between Cartagena, Colombia and Colon, Panama.

PubMed

White, W R; Crom, R L; Walker, K D

1996-07-23

It should be emphasized that the proposed ferry hazard categorizations do not represent absolute risks for introducing FMD into Panama, but instead provide a systematic method for comparing and estimating risks in the absence of quantitative data. A hazard rating of high may not necessarily represent a high quantitative risk for the introduction of FMD, but is high when compared to other scenarios. A low hazard rating may estimate a low quantitative risk of importing FMD, but economic consequences of a potential outbreak should also be considered. When further data become available, a more complete assessment of the risks of the Crucero Express compared to airplanes, cargo boats, and small boats can be performed. At present, the risk of the Crucero Express is at least as low as the other transport modes described above. Since vehicles are not presently allowed transport from Colombia to Panama, they present no risk to Panama, but with proper cleaning and disinfection procedures, vehicles can be permitted with low risk. However, the Crucero Express can carry 125 vehicles, and thorough cleaning and disinfection of this many cars will require modern and efficient facilities not yet present at either port.

Quantitation of tamsulosin in human plasma by liquid chromatography-electrospray ionization mass spectrometry.

PubMed

Din, Li; Li, Limin; Tao, Ping; Yang, Jin; Zhang, Zhengxing

2002-02-05

A highly sensitive method for quantitation of tamsulosin in human plasma using 1-(2,6-dimethyl-3-hydroxylphenoxy)-2-(3,4-methoxyphenylethylamino)-propane hydrochloride as the internal standard (I.S.) was established using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). After alkalization with saturated sodium bicarbonate, plasma were extracted by ethyl acetate and separated by HPLC on a C18 reversed-phase column using a mobile phase of methanol-water-acetic acid-triethylamine (620:380:1.5:1.5, v/v). Analytes were quantitated using positive electrospray ionization in a quadrupole spectrometer. LC-ESI-MS was performed in the selected ion monitoring (SIM) mode using target ions at m/z 228 for tamsulosin and m/z 222 for the I.S. Calibration curves, which were linear over the range 0.2-30 ng/ml, were analyzed contemporaneously with each batch of samples, along with low (0.5 ng/ml), medium (3 ng/ml) and high (30 ng/ml) quality control samples. The intra- and inter-assay variability ranged from 2.14 to 8.87% for the low, medium and high quality control samples. The extraction recovery of tamsulosin from plasma was in the range of 84.2-94.5%. The method has been used successfully to study tamsulosin pharmacokinetics in adult humans.

Analysis of Vaginal Microbicide Film Hydration Kinetics by Quantitative Imaging Refractometry

PubMed Central

Rinehart, Matthew; Grab, Sheila; Rohan, Lisa; Katz, David; Wax, Adam

2014-01-01

We have developed a quantitative imaging refractometry technique, based on holographic phase microscopy, as a tool for investigating microscopic structural changes in water-soluble polymeric materials. Here we apply the approach to analyze the structural degradation of vaginal topical microbicide films due to water uptake. We implemented transmission imaging of 1-mm diameter film samples loaded into a flow chamber with a 1.5×2 mm field of view. After water was flooded into the chamber, interference images were captured and analyzed to obtain high resolution maps of the local refractive index and subsequently the volume fraction and mass density of film material at each spatial location. Here, we compare the hydration dynamics of a panel of films with varying thicknesses and polymer compositions, demonstrating that quantitative imaging refractometry can be an effective tool for evaluating and characterizing the performance of candidate microbicide film designs for anti-HIV drug delivery. PMID:24736376

Analysis of vaginal microbicide film hydration kinetics by quantitative imaging refractometry.

PubMed

Rinehart, Matthew; Grab, Sheila; Rohan, Lisa; Katz, David; Wax, Adam

2014-01-01

We have developed a quantitative imaging refractometry technique, based on holographic phase microscopy, as a tool for investigating microscopic structural changes in water-soluble polymeric materials. Here we apply the approach to analyze the structural degradation of vaginal topical microbicide films due to water uptake. We implemented transmission imaging of 1-mm diameter film samples loaded into a flow chamber with a 1.5×2 mm field of view. After water was flooded into the chamber, interference images were captured and analyzed to obtain high resolution maps of the local refractive index and subsequently the volume fraction and mass density of film material at each spatial location. Here, we compare the hydration dynamics of a panel of films with varying thicknesses and polymer compositions, demonstrating that quantitative imaging refractometry can be an effective tool for evaluating and characterizing the performance of candidate microbicide film designs for anti-HIV drug delivery.

How Students Process Equations in Solving Quantitative Synthesis Problems? Role of Mathematical Complexity in Students' Mathematical Performance

ERIC Educational Resources Information Center

Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.; White, Daniel R.; Badeau, Ryan

2017-01-01

We examine students' mathematical performance on quantitative "synthesis problems" with varying mathematical complexity. Synthesis problems are tasks comprising multiple concepts typically taught in different chapters. Mathematical performance refers to the formulation, combination, and simplification of equations. Generally speaking,…

A novel approach for evaluating the performance of real time quantitative loop-mediated isothermal amplification-based methods.

PubMed

Nixon, Gavin J; Svenstrup, Helle F; Donald, Carol E; Carder, Caroline; Stephenson, Judith M; Morris-Jones, Stephen; Huggett, Jim F; Foy, Carole A

2014-12-01

Molecular diagnostic measurements are currently underpinned by the polymerase chain reaction (PCR). There are also a number of alternative nucleic acid amplification technologies, which unlike PCR, work at a single temperature. These 'isothermal' methods, reportedly offer potential advantages over PCR such as simplicity, speed and resistance to inhibitors and could also be used for quantitative molecular analysis. However there are currently limited mechanisms to evaluate their quantitative performance, which would assist assay development and study comparisons. This study uses a sexually transmitted infection diagnostic model in combination with an adapted metric termed isothermal doubling time (IDT), akin to PCR efficiency, to compare quantitative PCR and quantitative loop-mediated isothermal amplification (qLAMP) assays, and to quantify the impact of matrix interference. The performance metric described here facilitates the comparison of qLAMP assays that could assist assay development and validation activities.

Optical Basicity and Nepheline Crystallization in High Alumina Glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodriguez, Carmen P.; McCloy, John S.; Schweiger, M. J.

2011-02-25

The purpose of this study was to find compositions that increase waste loading of high-alumina wastes beyond what is currently acceptable while avoiding crystallization of nepheline (NaAlSiO4) on slow cooling. Nepheline crystallization has been shown to have a large impact on the chemical durability of high-level waste glasses. It was hypothesized that there would be some composition regions where high-alumina would not result in nepheline crystal production, compositions not currently allowed by the nepheline discriminator. Optical basicity (OB) and the nepheline discriminator (ND) are two ways of describing a given complex glass composition. This report presents the theoretical and experimentalmore » basis for these models. They are being studied together in a quadrant system as metrics to explore nepheline crystallization and chemical durability as a function of waste glass composition. These metrics were calculated for glasses with existing data and also for theoretical glasses to explore nepheline formation in Quadrant IV (passes OB metric but fails ND metric), where glasses are presumed to have good chemical durability. Several of these compositions were chosen, and glasses were made to fill poorly represented regions in Quadrant IV. To evaluate nepheline formation and chemical durability of these glasses, quantitative X-ray diffraction (XRD) analysis and the Product Consistency Test were conducted. A large amount of quantitative XRD data is collected here, both from new glasses and from glasses of previous studies that had not previously performed quantitative XRD on the phase assemblage. Appendix A critically discusses a large dataset to be considered for future quantitative studies on nepheline formation in glass. Appendix B provides a theoretical justification for choice of the oxide coefficients used to compute the OB criterion for nepheline formation.« less

Projecting technology change to improve space technology planning and systems management

NASA Astrophysics Data System (ADS)

Walk, Steven Robert

2011-04-01

Projecting technology performance evolution has been improving over the years. Reliable quantitative forecasting methods have been developed that project the growth, diffusion, and performance of technology in time, including projecting technology substitutions, saturation levels, and performance improvements. These forecasts can be applied at the early stages of space technology planning to better predict available future technology performance, assure the successful selection of technology, and improve technology systems management strategy. Often what is published as a technology forecast is simply scenario planning, usually made by extrapolating current trends into the future, with perhaps some subjective insight added. Typically, the accuracy of such predictions falls rapidly with distance in time. Quantitative technology forecasting (QTF), on the other hand, includes the study of historic data to identify one of or a combination of several recognized universal technology diffusion or substitution patterns. In the same manner that quantitative models of physical phenomena provide excellent predictions of system behavior, so do QTF models provide reliable technological performance trajectories. In practice, a quantitative technology forecast is completed to ascertain with confidence when the projected performance of a technology or system of technologies will occur. Such projections provide reliable time-referenced information when considering cost and performance trade-offs in maintaining, replacing, or migrating a technology, component, or system. This paper introduces various quantitative technology forecasting techniques and illustrates their practical application in space technology and technology systems management.

Correlation of admissions statistics to graduate student success in medical physics

PubMed Central

McSpadden, Erin; Rakowski, Joseph; Nalichowski, Adrian; Yudelev, Mark; Snyder, Michael

2014-01-01

The purpose of this work is to develop metrics for evaluation of medical physics graduate student performance, assess relationships between success and other quantifiable factors, and determine whether graduate student performance can be accurately predicted by admissions statistics. A cohort of 108 medical physics graduate students from a single institution were rated for performance after matriculation based on final scores in specific courses, first year graduate Grade Point Average (GPA), performance on the program exit exam, performance in oral review sessions, and faculty rating. Admissions statistics including matriculating program (MS vs. PhD); undergraduate degree type, GPA, and country; graduate degree; general and subject GRE scores; traditional vs. nontraditional status; and ranking by admissions committee were evaluated for potential correlation with the performance metrics. GRE verbal and quantitative scores were correlated with higher scores in the most difficult courses in the program and with the program exit exam; however, the GRE section most correlated with overall faculty rating was the analytical writing section. Students with undergraduate degrees in engineering had a higher faculty rating than those from other disciplines and faculty rating was strongly correlated with undergraduate country. Undergraduate GPA was not statistically correlated with any success metrics investigated in this study. However, the high degree of selection on GPA and quantitative GRE scores during the admissions process results in relatively narrow ranges for these quantities. As such, these results do not necessarily imply that one should not strongly consider traditional metrics, such as undergraduate GPA and quantitative GRE score, during the admissions process. They suggest that once applicants have been initially filtered by these metrics, additional selection should be performed via the other metrics shown here to be correlated with success. The parameters used to make admissions decisions for our program are accurate in predicting student success, as illustrated by the very strong statistical correlation between admissions rank and course average, first year graduate GPA, and faculty rating (p<0.002). Overall, this study indicates that an undergraduate degree in physics should not be considered a fundamental requirement for entry into our program and that within the relatively narrow range of undergraduate GPA and quantitative GRE scores of those admitted into our program, additional variations in these metrics are not important predictors of success. While the high degree of selection on particular statistics involved in the admissions process, along with the relatively small sample size, makes it difficult to draw concrete conclusions about the meaning of correlations here, these results suggest that success in medical physics is based on more than quantitative capabilities. Specifically, they indicate that analytical and communication skills play a major role in student success in our program, as well as predicted future success by program faculty members. Finally, this study confirms that our current admissions process is effective in identifying candidates who will be successful in our program and are expected to be successful after graduation, and provides additional insight useful in improving our admissions selection process. PACS number: 01.40.‐d PMID:24423842

NanoDrop Microvolume Quantitation of Nucleic Acids

PubMed Central

Desjardins, Philippe; Conklin, Deborah

2010-01-01

Biomolecular assays are continually being developed that use progressively smaller amounts of material, often precluding the use of conventional cuvette-based instruments for nucleic acid quantitation for those that can perform microvolume quantitation. The NanoDrop microvolume sample retention system (Thermo Scientific NanoDrop Products) functions by combining fiber optic technology and natural surface tension properties to capture and retain minute amounts of sample independent of traditional containment apparatus such as cuvettes or capillaries. Furthermore, the system employs shorter path lengths, which result in a broad range of nucleic acid concentration measurements, essentially eliminating the need to perform dilutions. Reducing the volume of sample required for spectroscopic analysis also facilitates the inclusion of additional quality control steps throughout many molecular workflows, increasing efficiency and ultimately leading to greater confidence in downstream results. The need for high-sensitivity fluorescent analysis of limited mass has also emerged with recent experimental advances. Using the same microvolume sample retention technology, fluorescent measurements may be performed with 2 μL of material, allowing fluorescent assays volume requirements to be significantly reduced. Such microreactions of 10 μL or less are now possible using a dedicated microvolume fluorospectrometer. Two microvolume nucleic acid quantitation protocols will be demonstrated that use integrated sample retention systems as practical alternatives to traditional cuvette-based protocols. First, a direct A260 absorbance method using a microvolume spectrophotometer is described. This is followed by a demonstration of a fluorescence-based method that enables reduced-volume fluorescence reactions with a microvolume fluorospectrometer. These novel techniques enable the assessment of nucleic acid concentrations ranging from 1 pg/ μL to 15,000 ng/ μL with minimal consumption of sample. PMID:21189466

High-performance liquid chromatographic determination of the beta2-selective adrenergic agonist fenoterol in human plasma after fluorescence derivatization.

PubMed

Kramer, S; Blaschke, G

2001-02-10

A sensitive high-performance liquid chromatographic method has been developed for the determination of the beta2-selective adrenergic agonist fenoterol in human plasma. To improve the sensitivity of the method, fenoterol was derivatized with N-(chloroformyl)-carbazole prior to HPLC analysis yielding highly fluorescent derivatives. The assay involves protein precipitation with acetonitrile, liquid-liquid-extraction of fenoterol from plasma with isobutanol under alkaline conditions followed by derivatization with N-(chloroformyl)-carbazole. Reversed-phase liquid chromatographic determination of the fenoterol derivative was performed using a column-switching system consisting of a LiChrospher 100 RP 18 and a LiChrospher RP-Select B column with acetonitrile, methanol and water as mobile phase. The limit of quantitation in human plasma was 376 pg fenoterol/ml. The method was successfully applied for the assay of fenoterol in patient plasma.

Micro-polarimeter for high performance liquid chromatography

DOEpatents

Yeung, Edward E.; Steenhoek, Larry E.; Woodruff, Steven D.; Kuo, Jeng-Chung

1985-01-01

A micro-polarimeter interfaced with a system for high performance liquid chromatography, for quantitatively analyzing micro and trace amounts of optically active organic molecules, particularly carbohydrates. A flow cell with a narrow bore is connected to a high performance liquid chromatography system. Thin, low birefringence cell windows cover opposite ends of the bore. A focused and polarized laser beam is directed along the longitudinal axis of the bore as an eluent containing the organic molecules is pumped through the cell. The beam is modulated by air gap Faraday rotators for phase sensitive detection to enhance the signal to noise ratio. An analyzer records the beams's direction of polarization after it passes through the cell. Calibration of the liquid chromatography system allows determination of the quantity of organic molecules present from a determination of the degree to which the polarized beam is rotated when it passes through the eluent.

The active learning hypothesis of the job-demand-control model: an experimental examination.

PubMed

Häusser, Jan Alexander; Schulz-Hardt, Stefan; Mojzisch, Andreas

2014-01-01

The active learning hypothesis of the job-demand-control model [Karasek, R. A. 1979. "Job Demands, Job Decision Latitude, and Mental Strain: Implications for Job Redesign." Administration Science Quarterly 24: 285-307] proposes positive effects of high job demands and high job control on performance. We conducted a 2 (demands: high vs. low) × 2 (control: high vs. low) experimental office workplace simulation to examine this hypothesis. Since performance during a work simulation is confounded by the boundaries of the demands and control manipulations (e.g. time limits), we used a post-test, in which participants continued working at their task, but without any manipulation of demands and control. This post-test allowed for examining active learning (transfer) effects in an unconfounded fashion. Our results revealed that high demands had a positive effect on quantitative performance, without affecting task accuracy. In contrast, high control resulted in a speed-accuracy tradeoff, that is participants in the high control conditions worked slower but with greater accuracy than participants in the low control conditions.

Fuzzy method of recognition of high molecular substances in evidence-based biology

NASA Astrophysics Data System (ADS)

Olevskyi, V. I.; Smetanin, V. T.; Olevska, Yu. B.

2017-10-01

Nowadays modern requirements to achieving reliable results along with high quality of researches put mathematical analysis methods of results at the forefront. Because of this, evidence-based methods of processing experimental data have become increasingly popular in the biological sciences and medicine. Their basis is meta-analysis, a method of quantitative generalization of a large number of randomized trails contributing to a same special problem, which are often contradictory and performed by different authors. It allows identifying the most important trends and quantitative indicators of the data, verification of advanced hypotheses and discovering new effects in the population genotype. The existing methods of recognizing high molecular substances by gel electrophoresis of proteins under denaturing conditions are based on approximate methods for comparing the contrast of electrophoregrams with a standard solution of known substances. We propose a fuzzy method for modeling experimental data to increase the accuracy and validity of the findings of the detection of new proteins.

Quantitative x-ray phase imaging at the nanoscale by multilayer Laue lenses

PubMed Central

Yan, Hanfei; Chu, Yong S.; Maser, Jörg; Nazaretski, Evgeny; Kim, Jungdae; Kang, Hyon Chol; Lombardo, Jeffrey J.; Chiu, Wilson K. S.

2013-01-01

For scanning x-ray microscopy, many attempts have been made to image the phase contrast based on a concept of the beam being deflected by a specimen, the so-called differential phase contrast imaging (DPC). Despite the successful demonstration in a number of representative cases at moderate spatial resolutions, these methods suffer from various limitations that preclude applications of DPC for ultra-high spatial resolution imaging, where the emerging wave field from the focusing optic tends to be significantly more complicated. In this work, we propose a highly robust and generic approach based on a Fourier-shift fitting process and demonstrate quantitative phase imaging of a solid oxide fuel cell (SOFC) anode by multilayer Laue lenses (MLLs). The high sensitivity of the phase to structural and compositional variations makes our technique extremely powerful in correlating the electrode performance with its buried nanoscale interfacial structures that may be invisible to the absorption and fluorescence contrasts. PMID:23419650

Gender, Math Confidence, and Grit: Relationships with Quantitative Skills and Performance in an Undergraduate Biology Course.

PubMed

Flanagan, K M; Einarson, J

2017-01-01

In a world filled with big data, mathematical models, and statistics, the development of strong quantitative skills is becoming increasingly critical for modern biologists. Teachers in this field must understand how students acquire quantitative skills and explore barriers experienced by students when developing these skills. In this study, we examine the interrelationships among gender, grit, and math confidence for student performance on a pre-post quantitative skills assessment and overall performance in an undergraduate biology course. Here, we show that females significantly underperformed relative to males on a quantitative skills assessment at the start of term. However, females showed significantly higher gains over the semester, such that the gender gap in performance was nearly eliminated by the end of the semester. Math confidence plays an important role in the performance on both the pre and post quantitative skills assessments and overall performance in the course. The effect of grit on student performance, however, is mediated by a student's math confidence; as math confidence increases, the positive effect of grit decreases. Consequently, the positive impact of a student's grittiness is observed most strongly for those students with low math confidence. We also found grit to be positively associated with the midterm score and the final grade in the course. Given the relationships established in this study among gender, grit, and math confidence, we provide "instructor actions" from the literature that can be applied in the classroom to promote the development of quantitative skills in light of our findings. © 2017 K. M. Flanagan and J. Einarson. CBE—Life Sciences Education © 2017 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

LFQuant: a label-free fast quantitative analysis tool for high-resolution LC-MS/MS proteomics data.

PubMed

Zhang, Wei; Zhang, Jiyang; Xu, Changming; Li, Ning; Liu, Hui; Ma, Jie; Zhu, Yunping; Xie, Hongwei

2012-12-01

Database searching based methods for label-free quantification aim to reconstruct the peptide extracted ion chromatogram based on the identification information, which can limit the search space and thus make the data processing much faster. The random effect of the MS/MS sampling can be remedied by cross-assignment among different runs. Here, we present a new label-free fast quantitative analysis tool, LFQuant, for high-resolution LC-MS/MS proteomics data based on database searching. It is designed to accept raw data in two common formats (mzXML and Thermo RAW), and database search results from mainstream tools (MASCOT, SEQUEST, and X!Tandem), as input data. LFQuant can handle large-scale label-free data with fractionation such as SDS-PAGE and 2D LC. It is easy to use and provides handy user interfaces for data loading, parameter setting, quantitative analysis, and quantitative data visualization. LFQuant was compared with two common quantification software packages, MaxQuant and IDEAL-Q, on the replication data set and the UPS1 standard data set. The results show that LFQuant performs better than them in terms of both precision and accuracy, and consumes significantly less processing time. LFQuant is freely available under the GNU General Public License v3.0 at http://sourceforge.net/projects/lfquant/. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous determination of rhamnose, xylitol, arabitol, fructose, glucose, inositol, sucrose, maltose in jujube (Zizyphus jujube Mill.) extract: comparison of HPLC-ELSD, LC-ESI-MS/MS and GC-MS.

PubMed

Sun, Shihao; Wang, Hui; Xie, Jianping; Su, Yue

2016-01-01

Jujube extract is commonly used as a food additive and flavoring. The sensory properties of the extract, especially sweetness, are a critical factor determining the product quality and therefore affecting consumer acceptability. Small molecular carbohydrates make major contribution to the sweetness of the jujube extract, and their types and contents in the extract have direct influence on quality of the product. So, an appropriate qualitative and quantitative method for determination of the carbohydrates is vitally important for quality control of the product. High performance liquid chromatography-evaporative light scattering detection (HPLC-ELSD), liquid chromatography-electronic spay ionization tandem mass spectrometry (LC-ESI-MS/MS), and gas chromatography-mass spectrometry (GC-MS) methods have been developed and applied to determining small molecular carbohydrates in jujube extract, respectively. Eight sugars and alditols were identified from the extract, including rhamnose, xylitol, arabitol, fructose, glucose, inositol, sucrose, and maltose. Comparisons were carried out to investigate the performance of the methods. Although the methods have been found to perform satisfactorily, only three sugars (fructose, glucose and inositol) could be detected by all these methods. Meanwhile, a similar quantitative result for the three sugars can be obtained by the methods. Eight sugars and alditols in the jujube extract were determined by HPLC-ELSD, LC-ESI-MS/MS and GC-MS, respectively. The LC-ELSD method and the LC-ESI-MS/MS method with good precision and accuracy were suitable for quantitative analysis of carbohydrates in jujube extract; although the performance of the GC-MS method for quantitative analysis was inferior to the other methods, it has a wider scope in qualitative analysis. A multi-analysis technique should be adopted in order to obtain complete constituents of about the carbohydrates in jujube extract, and the methods should be employed according to the purpose of analysis.

Quantitation of repaglinide and metabolites in mouse whole-body thin tissue sections using droplet-based liquid microjunction surface sampling-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry.

PubMed

Chen, Weiqi; Wang, Lifei; Van Berkel, Gary J; Kertesz, Vilmos; Gan, Jinping

2016-03-25

Herein, quantitation aspects of a fully automated autosampler/HPLC-MS/MS system applied for unattended droplet-based surface sampling of repaglinide dosed thin tissue sections with subsequent HPLC separation and mass spectrometric analysis of parent drug and various drug metabolites were studied. Major organs (brain, lung, liver, kidney and muscle) from whole-body thin tissue sections and corresponding organ homogenates prepared from repaglinide dosed mice were sampled by surface sampling and by bulk extraction, respectively, and analyzed by HPLC-MS/MS. A semi-quantitative agreement between data obtained by surface sampling and that by employing organ homogenate extraction was observed. Drug concentrations obtained by the two methods followed the same patterns for post-dose time points (0.25, 0.5, 1 and 2 h). Drug amounts determined in the specific tissues was typically higher when analyzing extracts from the organ homogenates. In addition, relative comparison of the levels of individual metabolites between the two analytical methods also revealed good semi-quantitative agreement. Copyright © 2015 Elsevier B.V. All rights reserved.

Quantitation of repaglinide and metabolites in mouse whole-body thin tissue sections using droplet-based liquid microjunction surface sampling-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

DOE PAGES

Chen, Weiqi; Wang, Lifei; Van Berkel, Gary J.; ...

2015-11-03

Herein, quantitation aspects of a fully automated autosampler/HPLC-MS/MS system applied for unattended droplet-based surface sampling of repaglinide dosed thin tissue sections with subsequent HPLC separation and mass spectrometric analysis of parent drug and various drug metabolites was studied. Major organs (brain, lung, liver, kidney, muscle) from whole-body thin tissue sections and corresponding organ homogenates prepared from repaglinide dosed mice were sampled by surface sampling and by bulk extraction, respectively, and analyzed by HPLC-MS/MS. A semi-quantitative agreement between data obtained by surface sampling and that by employing organ homogenate extraction was observed. Drug concentrations obtained by the two methods followed themore » same patterns for post-dose time points (0.25, 0.5, 1 and 2 h). Drug amounts determined in the specific tissues was typically higher when analyzing extracts from the organ homogenates. Furthermore, relative comparison of the levels of individual metabolites between the two analytical methods also revealed good semi-quantitative agreement.« less

Quantitation of repaglinide and metabolites in mouse whole-body thin tissue sections using droplet-based liquid microjunction surface sampling-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Weiqi; Wang, Lifei; Van Berkel, Gary J.

Herein, quantitation aspects of a fully automated autosampler/HPLC-MS/MS system applied for unattended droplet-based surface sampling of repaglinide dosed thin tissue sections with subsequent HPLC separation and mass spectrometric analysis of parent drug and various drug metabolites was studied. Major organs (brain, lung, liver, kidney, muscle) from whole-body thin tissue sections and corresponding organ homogenates prepared from repaglinide dosed mice were sampled by surface sampling and by bulk extraction, respectively, and analyzed by HPLC-MS/MS. A semi-quantitative agreement between data obtained by surface sampling and that by employing organ homogenate extraction was observed. Drug concentrations obtained by the two methods followed themore » same patterns for post-dose time points (0.25, 0.5, 1 and 2 h). Drug amounts determined in the specific tissues was typically higher when analyzing extracts from the organ homogenates. Furthermore, relative comparison of the levels of individual metabolites between the two analytical methods also revealed good semi-quantitative agreement.« less

Utility of DWI with quantitative ADC values in ovarian tumors: a meta-analysis of diagnostic test performance.

PubMed

Pi, Shan; Cao, Rong; Qiang, Jin Wei; Guo, Yan Hui

2018-01-01

Background Diffusion-weighted imaging (DWI) and quantitative apparent diffusion coefficient (ADC) values are widely used in the differential diagnosis of ovarian tumors. Purpose To assess the diagnostic performance of quantitative ADC values in ovarian tumors. Material and Methods PubMed, Embase, the Cochrane Library, and local databases were searched for studies assessing ovarian tumors using quantitative ADC values. We quantitatively analyzed the diagnostic performances for two clinical problems: benign vs. malignant tumors and borderline vs. malignant tumors. We evaluated diagnostic performances by the pooled sensitivity and specificity values and by summary receiver operating characteristic (SROC) curves. Subgroup analyses were used to analyze study heterogeneity. Results From the 742 studies identified in the search results, 16 studies met our inclusion criteria. A total of ten studies evaluated malignant vs. benign ovarian tumors and six studies assessed malignant vs. borderline ovarian tumors. Regarding the diagnostic accuracy of quantitative ADC values for distinguishing between malignant and benign ovarian tumors, the pooled sensitivity and specificity values were 0.91 and 0.91, respectively. The area under the SROC curve (AUC) was 0.96. For differentiating borderline from malignant tumors, the pooled sensitivity and specificity values were 0.89 and 0.79, and the AUC was 0.91. The methodological quality of the included studies was moderate. Conclusion Quantitative ADC values could serve as useful preoperative markers for predicting the nature of ovarian tumors. Nevertheless, prospective trials focused on standardized imaging parameters are needed to evaluate the clinical value of quantitative ADC values in ovarian tumors.

Comparative Evaluation of Four Real-Time PCR Methods for the Quantitative Detection of Epstein-Barr Virus from Whole Blood Specimens.

PubMed

Buelow, Daelynn; Sun, Yilun; Tang, Li; Gu, Zhengming; Pounds, Stanley; Hayden, Randall

2016-07-01

Monitoring of Epstein-Barr virus (EBV) load in immunocompromised patients has become integral to their care. An increasing number of reagents are available for quantitative detection of EBV; however, there are little published comparative data. Four real-time PCR systems (one using laboratory-developed reagents and three using analyte-specific reagents) were compared with one another for detection of EBV from whole blood. Whole blood specimens seeded with EBV were used to determine quantitative linearity, analytical measurement range, lower limit of detection, and CV for each assay. Retrospective testing of 198 clinical samples was performed in parallel with all methods; results were compared to determine relative quantitative and qualitative performance. All assays showed similar performance. No significant difference was found in limit of detection (3.12-3.49 log10 copies/mL; P = 0.37). A strong qualitative correlation was seen with all assays that used clinical samples (positive detection rates of 89.5%-95.8%). Quantitative correlation of clinical samples across assays was also seen in pairwise regression analysis, with R(2) ranging from 0.83 to 0.95. Normalizing clinical sample results to IU/mL did not alter the quantitative correlation between assays. Quantitative EBV detection by real-time PCR can be performed over a wide linear dynamic range, using three different commercially available reagents and laboratory-developed methods. EBV was detected with comparable sensitivity and quantitative correlation for all assays. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

A Correlational Study of Graphic Organizers and Science Achievement of English Language Learners

NASA Astrophysics Data System (ADS)

Clarke, William Gordon

English language learners (ELLs) demonstrate lower academic performance and have lower graduation and higher dropout rates than their non-ELL peers. The primary purpose of this correlational quantitative study was to investigate the relationship between the use of graphic organizer-infused science instruction and science learning of high school ELLs. Another objective was to determine if the method of instruction, socioeconomic status (SES), gender, and English language proficiency (ELP) were predictors of academic achievement of high school ELLs. Data were gathered from a New York City (NYC) high school fall 2012-2013 archival records of 145 ninth-grade ELLs who had received biology instruction in freestanding English as a second language (ESL) classes, followed by a test of their learning of the material. Fifty-four (37.2%) of these records were of students who had learned science by the conventional textbook method, and 91 (62.8%) by using graphic organizers. Data analysis employed the Statistical Package for the Social Sciences (SPSS) software for multiple regression analysis, which found graphic organizer use to be a significant predictor of New York State Regents Living Environment (NYSRLE) test scores (p < .01). One significant regression model was returned whereby, when combined, the four predictor variables (method of instruction, SES, gender, and ELP) explained 36% of the variance of the NYSRLE score. Implications of the study findings noted graphic organizer use as advantageous for ELL science achievement. Recommendations made for practice were for (a) the adoption of graphic organizer infused-instruction, (b) establishment of a protocol for the implementation of graphic organizer-infused instruction, and (c) increased length of graphic organizer instructional time. Recommendations made for future research were (a) a replication quantitative correlational study in two or more high schools, (b) a quantitative quasi-experimental quantitative study to determine the influence of graphic organizer instructional intervention and ELL science achievement, (c) a quantitative quasi-experimental study to determine the effect of teacher-based factors on graphic organizer-infused instruction, and (c) a causal comparative study to determine the efficacy of graphic organizer use in testing modifications for high school ELL science.

HPLC and LC-MS/MS methods for determination of sodium benzoate and potassium sorbate in food and beverages: performances of local accredited laboratories via proficiency tests in Turkey.

PubMed

Gören, Ahmet C; Bilsel, Gökhan; Şimşek, Adnan; Bilsel, Mine; Akçadağ, Fatma; Topal, Kevser; Ozgen, Hasan

2015-05-15

High Performance Liquid Chromatography LC-UV and LC-MS/MS methods were developed and validated for quantitative analyses of sodium benzoate and potassium sorbate in foods and beverages. HPLC-UV and LC-MS/MS methods were compared for quantitative analyses of sodium benzoate and potassium sorbate in a representative ketchup sample. Optimisation of the methods enabled the chromatographic separation of the analytes in less than 4 min. A correlation coefficient of 0.999 was achieved over the measured calibration range for both compounds and methods (HPLC and LC-MS/MS). The uncertainty values of sodium benzoate and potassium sorbate were found as 0.199 and 0.150 mg/L by HPLC and 0.072 and 0.044 mg/L by LC-MS/MS, respectively. Proficiency testing performance of Turkish accredited laboratories between the years 2005 and 2013 was evaluated and reported herein. The aim of the proficiency testing scheme was to evaluate the performance of the laboratories, analysing benzoate and sorbate in tomato ketchup. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantitative assessment of joint position sense recovery in subacute stroke patients: a pilot study.

PubMed

Kattenstroth, Jan-Christoph; Kalisch, Tobias; Kowalewski, Rebecca; Tegenthoff, Martin; Dinse, Hubert R

2013-11-01

To assess joint position sense performance in subacute stroke patients using a novel quantitative assessment. Proof-of-principle pilot study with a group of subacute stroke patients. Assessment at baseline and after 2 weeks of intervention. Additional data for a healthy age-matched control group. Ten subacute stroke patients (aged 65.41 years (standard deviation 2.5), 4 females, 2.3 weeks (standard deviation 0.2)) post-stroke receiving in-patient standard rehabilitation and repetitive electrical stimulation of the affected hand. Joint position sense was assessed based on the ability of correctly perceiving the opening angles of the finger joints. Patients had to report size differences of polystyrene balls of various sizes, whilst the balls were enclosed simultaneously by the affected and the non-affected hands. A total of 21 pairwise size comparisons was used to quantify joint position performance. After 2 weeks of therapeutic intervention a significant improvement in joint position sense performance was observed; however, the performance level was still below that of a healthy control group. The results indicate high feasibility and sensitivity of the joint position test in subacute stroke patients. Testing allowed quantification of both the deficit and the rehabilitation outcome.

Protocol for Standardizing High-to-Moderate Abundance Protein Biomarker Assessments Through an MRM-with-Standard-Peptides Quantitative Approach.

PubMed

Percy, Andrew J; Yang, Juncong; Chambers, Andrew G; Mohammed, Yassene; Miliotis, Tasso; Borchers, Christoph H

2016-01-01

Quantitative mass spectrometry (MS)-based approaches are emerging as a core technology for addressing health-related queries in systems biology and in the biomedical and clinical fields. In several 'omics disciplines (proteomics included), an approach centered on selected or multiple reaction monitoring (SRM or MRM)-MS with stable isotope-labeled standards (SIS), at the protein or peptide level, has emerged as the most precise technique for quantifying and screening putative analytes in biological samples. To enable the widespread use of MRM-based protein quantitation for disease biomarker assessment studies and its ultimate acceptance for clinical analysis, the technique must be standardized to facilitate precise and accurate protein quantitation. To that end, we have developed a number of kits for assessing method/platform performance, as well as for screening proposed candidate protein biomarkers in various human biofluids. Collectively, these kits utilize a bottom-up LC-MS methodology with SIS peptides as internal standards and quantify proteins using regression analysis of standard curves. This chapter details the methodology used to quantify 192 plasma proteins of high-to-moderate abundance (covers a 6 order of magnitude range from 31 mg/mL for albumin to 18 ng/mL for peroxidredoxin-2), and a 21-protein subset thereof. We also describe the application of this method to patient samples for biomarker discovery and verification studies. Additionally, we introduce our recently developed Qualis-SIS software, which is used to expedite the analysis and assessment of protein quantitation data in control and patient samples.