Science.gov

Sample records for high performance analysis

  1. System analysis of high performance MHD systems

    SciTech Connect

    Chang, S.L.; Berry, G.F.; Hu, N.

    1988-01-01

    This paper presents the results of an investigation on the upper ranges of performance that an MHD power plant using advanced technology assumptions might achieve and a parametric study on the key variables affecting this high performance. To simulate a high performance MHD power plant and conduct a parametric study, the Systems Analysis Language Translator (SALT) code developed at Argonne National Laboratory was used. The parametric study results indicate that the overall efficiency of an MHD power plant can be further increased subject to the improvement of some key variables such as, the MHD generator inverter efficiency, channel electrical loading factor, magnetic field strength, preheated air temperature, and combustor heat loss. In an optimization calculation, the simulated high performance MHD power plant using advanced technology assumptions can attain an ultra high overall efficiency, exceeding 62%. 12 refs., 5 figs., 4 tabs.

  2. Performance analysis of memory hierachies in high performance systems

    SciTech Connect

    Yogesh, A.

    1993-07-01

    This thesis studies memory bandwidth as a performance predictor of programs. The focus of this work is on computationally intensive programs. These programs are the most likely to access large amounts of data, stressing the memory system. Computationally intensive programs are also likely to use highly optimizing compilers to produce the fastest executables possible. Methods to reduce the amount of data traffic by increasing the average number of references to each item while it resides in the cache are explored. Increasing the average number of references to each cache item reduces the number of memory requests. Chapter 2 describes the DLX architecture. This is the architecture on which all the experiments were performed. Chapter 3 studies memory moves as a performance predictor for a group of application programs. Chapter 4 introduces a model to study the performance of programs in the presence of memory hierarchies. Chapter 5 explores some compiler optimizations that can help increase the references to each item while it resides in the cache.

  3. SIMS analysis of high-performance accelerator niobium

    SciTech Connect

    Maheshwari, P.; Stevie, F. A.; Myneni, Ganapati Rao; Rigsbee, J, M.; Dhakal, Pashupati; Ciovati, Gianluigi; Griffis, D. P.

    2014-11-01

    Niobium is used to fabricate superconducting radio frequency accelerator modules because of its high critical temperature, high critical magnetic field, and easy formability. Recent experiments have shown a very significant improvement in performance (over 100%) after a high-temperature bake at 1400 degrees C for 3h. SIMS analysis of this material showed the oxygen profile was significantly deeper than the native oxide with a shape that is indicative of diffusion. Positive secondary ion mass spectra showed the presence of Ti with a depth profile similar to that of O. It is suspected that Ti is associated with the performance improvement. The source of Ti contamination in the anneal furnace has been identified, and a new furnace was constructed without Ti. Initial results from the new furnace do not show the yield improvement. Further analyses should determine the relationship of Ti to cavity performance.

  4. High Performance Descriptive Semantic Analysis of Semantic Graph Databases

    SciTech Connect

    Joslyn, Cliff A.; Adolf, Robert D.; al-Saffar, Sinan; Feo, John T.; Haglin, David J.; Mackey, Greg E.; Mizell, David W.

    2011-06-02

    As semantic graph database technology grows to address components ranging from extant large triple stores to SPARQL endpoints over SQL-structured relational databases, it will become increasingly important to be able to understand their inherent semantic structure, whether codified in explicit ontologies or not. Our group is researching novel methods for what we call descriptive semantic analysis of RDF triplestores, to serve purposes of analysis, interpretation, visualization, and optimization. But data size and computational complexity makes it increasingly necessary to bring high performance computational resources to bear on this task. Our research group built a novel high performance hybrid system comprising computational capability for semantic graph database processing utilizing the large multi-threaded architecture of the Cray XMT platform, conventional servers, and large data stores. In this paper we describe that architecture and our methods, and present the results of our analyses of basic properties, connected components, namespace interaction, and typed paths such for the Billion Triple Challenge 2010 dataset.

  5. [An analysis of maicaodi by high performance liquid chromatography].

    PubMed

    Yang, H; Chen, R; Jiang, M

    1997-05-01

    Maicaodi has recently been developed and produced by the pesticide plant of Nanjing Agricultural University. The quantitative analysis of the effective components--tribenuron methyl and R (-)napropamide in wettable powder of Maicaode, by a high performance liquid chromatographic method was carried out with a Lichrosorb Si-60 20cm x 0.46cm i.d. column, mobile phase of petroleum ether/isopropanol/methanol/acetonitrile/chloroform mixture solvent (80:5:5:5:5) and internal standard of diisooctyl phthalate. The sample was detected by ultraviolet absorption at 254 nm. The retention times of tribenuron methyl and R (-)napropamide were 10-11min and 6-7min respectively. The coefficient of variation of this analysis was 0.34% with a recovery of 99.51%-100.32%. The coefficient of linear correlation was 0.9999. PMID:15739379

  6. An Analysis of a High Performing School District's Culture

    ERIC Educational Resources Information Center

    Corum, Kenneth D.; Schuetz, Todd B.

    2012-01-01

    This report describes a problem based learning project focusing on the cultural elements of a high performing school district. Current literature on school district culture provides numerous cultural elements that are present in high performing school districts. With the current climate in education placing pressure on school districts to perform…

  7. Total systems design analysis of high performance structures

    NASA Technical Reports Server (NTRS)

    Verderaime, V.

    1993-01-01

    Designer-control parameters were identified at interdiscipline interfaces to optimize structural systems performance and downstream development and operations with reliability and least life-cycle cost. Interface tasks and iterations are tracked through a matrix of performance disciplines integration versus manufacturing, verification, and operations interactions for a total system design analysis. Performance integration tasks include shapes, sizes, environments, and materials. Integrity integrating tasks are reliability and recurring structural costs. Significant interface designer control parameters were noted as shapes, dimensions, probability range factors, and cost. Structural failure concept is presented, and first-order reliability and deterministic methods, benefits, and limitations are discussed. A deterministic reliability technique combining benefits of both is proposed for static structures which is also timely and economically verifiable. Though launch vehicle environments were primarily considered, the system design process is applicable to any surface system using its own unique filed environments.

  8. Thermal Performance Analysis of a High-Mass Residential Building

    SciTech Connect

    Smith, M.W.; Torcellini, P.A., Hayter, S.J.; Judkoff, R.

    2001-01-30

    Minimizing energy consumption in residential buildings using passive solar strategies almost always calls for the efficient use of massive building materials combined with solar gain control and adequate insulation. Using computerized simulation tools to understand the interactions among all the elements facilitates designing low-energy houses. Finally, the design team must feel confident that these tools are providing realistic results. The design team for the residential building described in this paper relied on computerized design tools to determine building envelope features that would maximize the energy performance [1]. Orientation, overhang dimensions, insulation amounts, window characteristics and other strategies were analyzed to optimize performance in the Pueblo, Colorado, climate. After construction, the actual performance of the house was monitored using both short-term and long-term monitoring approaches to verify the simulation results and document performance. Calibrated computer simulations showed that this house consumes 56% less energy than would a similar theoretical house constructed to meet the minimum residential energy code requirements. This paper discusses this high-mass house and compares the expected energy performance, based on the computer simulations, versus actual energy performance.

  9. [High-performance liquid-liquid chromatography in beverage analysis].

    PubMed

    Bricout, J; Koziet, Y; de Carpentrie, B

    1978-01-01

    Liquid liquid chromatography was performed with columns packed with stationary phases chemically bonded to silica microparticules. These columns show a high efficiency and are used very easily. Flavouring compounds like aromatic aldehydes which have a low volatility were analyzed in brandy using a polar phase alkylnitrile. Sapid substances like amarogentin in Gentiana lutea or glyryrrhizin in Glycyrrhiza glabra were determined by reversed phase chromatography. Finally ionizable substances like synthetic dyes can be analyzed by paired ion chromatography witha non polar stationary phase.

  10. High performance computing environment for multidimensional image analysis

    PubMed Central

    Rao, A Ravishankar; Cecchi, Guillermo A; Magnasco, Marcelo

    2007-01-01

    Background The processing of images acquired through microscopy is a challenging task due to the large size of datasets (several gigabytes) and the fast turnaround time required. If the throughput of the image processing stage is significantly increased, it can have a major impact in microscopy applications. Results We present a high performance computing (HPC) solution to this problem. This involves decomposing the spatial 3D image into segments that are assigned to unique processors, and matched to the 3D torus architecture of the IBM Blue Gene/L machine. Communication between segments is restricted to the nearest neighbors. When running on a 2 Ghz Intel CPU, the task of 3D median filtering on a typical 256 megabyte dataset takes two and a half hours, whereas by using 1024 nodes of Blue Gene, this task can be performed in 18.8 seconds, a 478× speedup. Conclusion Our parallel solution dramatically improves the performance of image processing, feature extraction and 3D reconstruction tasks. This increased throughput permits biologists to conduct unprecedented large scale experiments with massive datasets. PMID:17634099

  11. Structural analysis of amorphous phosphates using high performance liquid chromatography

    SciTech Connect

    Sales, B.C.; Boatner, L.A.; Chakoumakos, B.C.; McCallum, J.C.; Ramey, J.O.; Zuhr, R.A.

    1993-12-31

    Determining the atomic-scale structure of amorphous solids has proven to be a formidable scientific and technological problem for the past 100 years. The technique of high-performance liquid chromatography (HPLC) provides unique detailed information regarding the structure of partially disordered or amorphous phosphate solids. Applications of the experimental technique of HPLC to phosphate solids are reviewed, and examples of the type of information that can be obtained with HPLC are presented. Inorganic phosphates encompass a large class of important materials whose applications include: catalysts, ion-exchange media, solid electrolytes for batteries, linear and nonlinear optical components, chelating agents, synthetic replacements for bone and teeth, phosphors, detergents, and fertilizers. Phosphate ions also represent a unique link between living systems and the inorganic world.

  12. Analysis of a high-performance tubular solar collector

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.; Yung, C. S.

    1981-01-01

    This article analyzes the thermal performance of a new vacuum tube solar collector. The assumptions and mathematical modeling are presented. The problem is reduced to the formulation of two simultaneous linear differential equations characterizing the collector thermal behavior. After applying the boundary conditions, a general solution is obtained which is found similar to the general Hottel, Whillier and Bliss form, but with a complex flow factor. The details of the two-dimensional thermal model of the solar collector at steady state is also presented to include the computer simulation and the performance parameterization. Comparison of the simulated performance with the manufacturer's test data showed good agreement at wide ranges of operating conditions.

  13. Moisture and Structural Analysis for High Performance Hybrid Wall Assemblies

    SciTech Connect

    Grin, A.; Lstiburek, J.

    2012-09-01

    This report describes the work conducted by the Building Science Corporation (BSC) Building America Research Team's 'Energy Efficient Housing Research Partnerships' project. Based on past experience in the Building America program, they have found that combinations of materials and approaches---in other words, systems--usually provide optimum performance. No single manufacturer typically provides all of the components for an assembly, nor has the specific understanding of all the individual components necessary for optimum performance.

  14. Transmission System Performance Analysis for High-Penetration Photovoltaics

    SciTech Connect

    Achilles, S.; Schramm, S.; Bebic, J.

    2008-02-01

    This study is an assessment of the potential impact of high levels of penetration of photovoltaic (PV) generation on transmission systems. The effort used stability simulations of a transmission system with different levels of PV generation and load.

  15. Scattering analysis of high performance large sandwich radomes

    NASA Astrophysics Data System (ADS)

    Shavit, Reuven; Smolski, Adam P.; Michielssen, Eric; Mittra, Raj

    1992-02-01

    Large radomes are assembled from many panels connected together forming joints or seams. When the panels are type A sandwiches that are optimized for minimum transmission loss over moderately narrow bandwidths, the seams and joints introduce scattering effects that can degrade the overall electromagnetic performance. Tuning the dielectric seams with conductive wires and optimizing their geometry is, therefore, crucial to enhancing the electromagnetic performance of the radome. The authors address the problem of systematically tuning the dielectric seams and present both numerical and experimental results to illustrate the tuning procedure. Included are results showing the effect of the tuning of the radome on the radiation of an enclosed aperture of circular or elliptic shape.

  16. Moisture and Structural Analysis for High Performance Hybrid Wall Assemblies

    SciTech Connect

    Grin, A.; Lstiburek, J.

    2012-09-01

    Based on past experience in the Building America program, BSC has found that combinations of materials and approaches—in other words, systems—usually provide optimum performance. Integration is necessary, as described in this research project. The hybrid walls analyzed utilize a combination of exterior insulation, diagonal metal strapping, and spray polyurethane foam and leave room for cavity-fill insulation. These systems can provide effective thermal, air, moisture, and water barrier systems in one assembly and provide structure.

  17. Analysis of Cereal Starches by High Performance Size Exclusion Chromatography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch has unique physicochemical characteristics among carbohydrates. Most starch granules are a mixture of two sugar polymers: a highly branched polysaccharide named amylopectin, and a basically linear polysaccharide named amylose. The objective of this study was to develop a simple, one-step and ...

  18. Algorithms and architectures for high performance analysis of semantic graphs.

    SciTech Connect

    Hendrickson, Bruce Alan

    2005-09-01

    Semantic graphs offer one promising avenue for intelligence analysis in homeland security. They provide a mechanism for describing a wide variety of relationships between entities of potential interest. The vertices are nouns of various types, e.g. people, organizations, events, etc. Edges in the graph represent different types of relationships between entities, e.g. 'is friends with', 'belongs-to', etc. Semantic graphs offer a number of potential advantages as a knowledge representation system. They allow information of different kinds, and collected in differing ways, to be combined in a seamless manner. A semantic graph is a very compressed representation of some of relationship information. It has been reported that the semantic graph can be two orders of magnitude smaller than the processed intelligence data. This allows for much larger portions of the data universe to be resident in computer memory. Many intelligence queries that are relevant to the terrorist threat are naturally expressed in the language of semantic graphs. One example is the search for 'interesting' relationships between two individuals or between an individual and an event, which can be phrased as a search for short paths in the graph. Another example is the search for an analyst-specified threat pattern, which can be cast as an instance of subgraph isomorphism. It is important to note than many kinds of analysis are not relationship based, so these are not good candidates for semantic graphs. Thus, a semantic graph should always be used in conjunction with traditional knowledge representation and interface methods. Operations that involve looking for chains of relationships (e.g. friend of a friend) are not efficiently executable in a traditional relational database. However, the semantic graph can be thought of as a pre-join of the database, and it is ideally suited for these kinds of operations. Researchers at Sandia National Laboratories are working to facilitate semantic graph

  19. High Performance Parallel Analysis of Coupled Problems for Aircraft Propulsion

    NASA Technical Reports Server (NTRS)

    Felippa, C. A.; Farhat, C.; Lanteri, S.; Maman, N.; Piperno, S.; Gumaste, U.

    1994-01-01

    In order to predict the dynamic response of a flexible structure in a fluid flow, the equations of motion of the structure and the fluid must be solved simultaneously. In this paper, we present several partitioned procedures for time-integrating this focus coupled problem and discuss their merits in terms of accuracy, stability, heterogeneous computing, I/O transfers, subcycling, and parallel processing. All theoretical results are derived for a one-dimensional piston model problem with a compressible flow, because the complete three-dimensional aeroelastic problem is difficult to analyze mathematically. However, the insight gained from the analysis of the coupled piston problem and the conclusions drawn from its numerical investigation are confirmed with the numerical simulation of the two-dimensional transient aeroelastic response of a flexible panel in a transonic nonlinear Euler flow regime.

  20. Similarity spectra analysis of high-performance jet aircraft noise.

    PubMed

    Neilsen, Tracianne B; Gee, Kent L; Wall, Alan T; James, Michael M

    2013-04-01

    Noise measured in the vicinity of an F-22A Raptor has been compared to similarity spectra found previously to represent mixing noise from large-scale and fine-scale turbulent structures in laboratory-scale jet plumes. Comparisons have been made for three engine conditions using ground-based sideline microphones, which covered a large angular aperture. Even though the nozzle geometry is complex and the jet is nonideally expanded, the similarity spectra do agree with large portions of the measured spectra. Toward the sideline, the fine-scale similarity spectrum is used, while the large-scale similarity spectrum provides a good fit to the area of maximum radiation. Combinations of the two similarity spectra are shown to match the data in between those regions. Surprisingly, a combination of the two is also shown to match the data at the farthest aft angle. However, at high frequencies the degree of congruity between the similarity and the measured spectra changes with engine condition and angle. At the higher engine conditions, there is a systematically shallower measured high-frequency slope, with the largest discrepancy occurring in the regions of maximum radiation.

  1. Similarity spectra analysis of high-performance jet aircraft noise.

    PubMed

    Neilsen, Tracianne B; Gee, Kent L; Wall, Alan T; James, Michael M

    2013-04-01

    Noise measured in the vicinity of an F-22A Raptor has been compared to similarity spectra found previously to represent mixing noise from large-scale and fine-scale turbulent structures in laboratory-scale jet plumes. Comparisons have been made for three engine conditions using ground-based sideline microphones, which covered a large angular aperture. Even though the nozzle geometry is complex and the jet is nonideally expanded, the similarity spectra do agree with large portions of the measured spectra. Toward the sideline, the fine-scale similarity spectrum is used, while the large-scale similarity spectrum provides a good fit to the area of maximum radiation. Combinations of the two similarity spectra are shown to match the data in between those regions. Surprisingly, a combination of the two is also shown to match the data at the farthest aft angle. However, at high frequencies the degree of congruity between the similarity and the measured spectra changes with engine condition and angle. At the higher engine conditions, there is a systematically shallower measured high-frequency slope, with the largest discrepancy occurring in the regions of maximum radiation. PMID:23556581

  2. Performance analysis of high quality parallel preconditioners applied to 3D finite element structural analysis

    SciTech Connect

    Kolotilina, L.; Nikishin, A.; Yeremin, A.

    1994-12-31

    The solution of large systems of linear equations is a crucial bottleneck when performing 3D finite element analysis of structures. Also, in many cases the reliability and robustness of iterative solution strategies, and their efficiency when exploiting hardware resources, fully determine the scope of industrial applications which can be solved on a particular computer platform. This is especially true for modern vector/parallel supercomputers with large vector length and for modern massively parallel supercomputers. Preconditioned iterative methods have been successfully applied to industrial class finite element analysis of structures. The construction and application of high quality preconditioners constitutes a high percentage of the total solution time. Parallel implementation of high quality preconditioners on such architectures is a formidable challenge. Two common types of existing preconditioners are the implicit preconditioners and the explicit preconditioners. The implicit preconditioners (e.g. incomplete factorizations of several types) are generally high quality but require solution of lower and upper triangular systems of equations per iteration which are difficult to parallelize without deteriorating the convergence rate. The explicit type of preconditionings (e.g. polynomial preconditioners or Jacobi-like preconditioners) require sparse matrix-vector multiplications and can be parallelized but their preconditioning qualities are less than desirable. The authors present results of numerical experiments with Factorized Sparse Approximate Inverses (FSAI) for symmetric positive definite linear systems. These are high quality preconditioners that possess a large resource of parallelism by construction without increasing the serial complexity.

  3. ANALYSIS OF DRUG INTERACTIONS WITH HIGH DENSITY LIPOPROTEIN BY HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY

    PubMed Central

    Chen, Sike; Sobansky, Matthew R.; Hage, David S.

    2009-01-01

    Columns containing immobilized lipoproteins were prepared for the analysis of drug interactions with these particles by high-performance affinity chromatography. This approach was evaluated by using it to examine the binding of high density lipoprotein (HDL) to the drugs propranolol or verapamil. HDL was immobilized by the Schiff base method onto silica and gave HPLC columns with reproducible binding to propranolol over four to five days of continuous operation at pH 7.4. Frontal analysis experiments indicated that two types of interactions were occurring between R/S-propranolol and HDL at 37°C: saturable binding with an association equilibrium constant (Ka) of 1.1–1.9 × 105 M−1, and non-saturable binding with an overall affinity constant (n Ka) of 3.7–4.1 × 104 M−1. Similar results were found at 4 and 27°C. Verapamil also gave similar behavior, with a Ka of 6.0 × 104 M−1 at 37°C for the saturable sites and a n Ka value for the non-saturable sites of 2.5 × 104 M−1. These measured affinities gave good agreement with solution-phase values. The results indicated HPAC can be used to study drug interactions with HDL, providing information that should be valuable in obtaining a better description of how drugs are transported within the body. PMID:19833090

  4. The NetLogger Methodology for High Performance Distributed Systems Performance Analysis

    SciTech Connect

    Tierney, Brian; Johnston, William; Crowley, Brian; Hoo, Gary; Brooks, Chris; Gunter, Dan

    1999-12-23

    The authors describe a methodology that enables the real-time diagnosis of performance problems in complex high-performance distributed systems. The methodology includes tools for generating precision event logs that can be used to provide detailed end-to-end application and system level monitoring; a Java agent-based system for managing the large amount of logging data; and tools for visualizing the log data and real-time state of the distributed system. The authors developed these tools for analyzing a high-performance distributed system centered around the transfer of large amounts of data at high speeds from a distributed storage server to a remote visualization client. However, this methodology should be generally applicable to any distributed system. This methodology, called NetLogger, has proven invaluable for diagnosing problems in networks and in distributed systems code. This approach is novel in that it combines network, host, and application-level monitoring, providing a complete view of the entire system.

  5. BioGraphE: high-performance bionetwork analysis using the Biological Graph Environment

    PubMed Central

    Chin, George; Chavarria, Daniel G; Nakamura, Grant C; Sofia, Heidi J

    2008-01-01

    Background Graphs and networks are common analysis representations for biological systems. Many traditional graph algorithms such as k-clique, k-coloring, and subgraph matching have great potential as analysis techniques for newly available data in biology. Yet, as the amount of genomic and bionetwork information rapidly grows, scientists need advanced new computational strategies and tools for dealing with the complexities of the bionetwork analysis and the volume of the data. Results We introduce a computational framework for graph analysis called the Biological Graph Environment (BioGraphE), which provides a general, scalable integration platform for connecting graph problems in biology to optimized computational solvers and high-performance systems. This framework enables biology researchers and computational scientists to identify and deploy network analysis applications and to easily connect them to efficient and powerful computational software and hardware that are specifically designed and tuned to solve complex graph problems. In our particular application of BioGraphE to support network analysis in genome biology, we investigate the use of a Boolean satisfiability solver known as Survey Propagation as a core computational solver executing on standard high-performance parallel systems, as well as multi-threaded architectures. Conclusion In our application of BioGraphE to conduct bionetwork analysis of homology networks, we found that BioGraphE and a custom, parallel implementation of the Survey Propagation SAT solver were capable of solving very large bionetwork problems at high rates of execution on different high-performance computing platforms. PMID:18541059

  6. Analysis of hydrocortisone acetate ointments and creams by high-performance liquid chromatography.

    PubMed

    Lea, A R; Kennedy, J M; Low, G K

    1980-09-26

    High-performance liquid chromatographic (HPLC) methods for the analysis of hydrocortisone containing ointments and creams have been investigated. A method which uses a silica column and involves a minimum of sample pre-treatment has been shown to compare favourably with the triphenyltetrazolim chloride method of the British Pharmacopoeia. For hydrocortisone ointments the HPLC procedure provides results of equivalent precision and has advantages with respect to the time taken for each analysis and specificity. Application of the method to the analysis of hydrocortisone creams has been explored and the deviation between the HPLC and colorimetric method requires further investigation.

  7. Analysis of scalability of high-performance 3D image processing platform for virtual colonoscopy

    NASA Astrophysics Data System (ADS)

    Yoshida, Hiroyuki; Wu, Yin; Cai, Wenli

    2014-03-01

    One of the key challenges in three-dimensional (3D) medical imaging is to enable the fast turn-around time, which is often required for interactive or real-time response. This inevitably requires not only high computational power but also high memory bandwidth due to the massive amount of data that need to be processed. For this purpose, we previously developed a software platform for high-performance 3D medical image processing, called HPC 3D-MIP platform, which employs increasingly available and affordable commodity computing systems such as the multicore, cluster, and cloud computing systems. To achieve scalable high-performance computing, the platform employed size-adaptive, distributable block volumes as a core data structure for efficient parallelization of a wide range of 3D-MIP algorithms, supported task scheduling for efficient load distribution and balancing, and consisted of a layered parallel software libraries that allow image processing applications to share the common functionalities. We evaluated the performance of the HPC 3D-MIP platform by applying it to computationally intensive processes in virtual colonoscopy. Experimental results showed a 12-fold performance improvement on a workstation with 12-core CPUs over the original sequential implementation of the processes, indicating the efficiency of the platform. Analysis of performance scalability based on the Amdahl's law for symmetric multicore chips showed the potential of a high performance scalability of the HPC 3DMIP platform when a larger number of cores is available.

  8. High-performance equation solvers and their impact on finite element analysis

    NASA Technical Reports Server (NTRS)

    Poole, Eugene L.; Knight, Norman F., Jr.; Davis, D. Dale, Jr.

    1990-01-01

    The role of equation solvers in modern structural analysis software is described. Direct and iterative equation solvers which exploit vectorization on modern high-performance computer systems are described and compared. The direct solvers are two Cholesky factorization methods. The first method utilizes a novel variable-band data storage format to achieve very high computation rates and the second method uses a sparse data storage format designed to reduce the number of operations. The iterative solvers are preconditioned conjugate gradient methods. Two different preconditioners are included; the first uses a diagonal matrix storage scheme to achieve high computation rates and the second requires a sparse data storage scheme and converges to the solution in fewer iterations that the first. The impact of using all of the equation solvers in a common structural analysis software system is demonstrated by solving several representative structural analysis problems.

  9. Performance, Performance System, and High Performance System

    ERIC Educational Resources Information Center

    Jang, Hwan Young

    2009-01-01

    This article proposes needed transitions in the field of human performance technology. The following three transitions are discussed: transitioning from training to performance, transitioning from performance to performance system, and transitioning from learning organization to high performance system. A proposed framework that comprises…

  10. Viewpoints: A High-Performance High-Dimensional Exploratory Data Analysis Tool

    NASA Astrophysics Data System (ADS)

    Gazis, P. R.; Levit, C.; Way, M. J.

    2010-12-01

    Scientific data sets continue to increase in both size and complexity. In the past, dedicated graphics systems at supercomputing centers were required to visualize large data sets, but as the price of commodity graphics hardware has dropped and its capability has increased, it is now possible, in principle, to view large complex data sets on a single workstation. To do this in practice, an investigator will need software that is written to take advantage of the relevant graphics hardware. The Viewpoints visualization package described herein is an example of such software. Viewpoints is an interactive tool for exploratory visual analysis of large high-dimensional (multivariate) data. It leverages the capabilities of modern graphics boards (GPUs) to run on a single workstation or laptop. Viewpoints is minimalist: it attempts to do a small set of useful things very well (or at least very quickly) in comparison with similar packages today. Its basic feature set includes linked scatter plots with brushing, dynamic histograms, normalization, and outlier detection/removal. Viewpoints was originally designed for astrophysicists, but it has since been used in a variety of fields that range from astronomy, quantum chemistry, fluid dynamics, machine learning, bioinformatics, and finance to information technology server log mining. In this article, we describe the Viewpoints package and show examples of its usage.

  11. An analysis for high speed propeller-nacelle aerodynamic performance prediction. Volume 1: Theory and application

    NASA Technical Reports Server (NTRS)

    Egolf, T. Alan; Anderson, Olof L.; Edwards, David E.; Landgrebe, Anton J.

    1988-01-01

    A computer program, the Propeller Nacelle Aerodynamic Performance Prediction Analysis (PANPER), was developed for the prediction and analysis of the performance and airflow of propeller-nacelle configurations operating over a forward speed range inclusive of high speed flight typical of recent propfan designs. A propeller lifting line, wake program was combined with a compressible, viscous center body interaction program, originally developed for diffusers, to compute the propeller-nacelle flow field, blade loading distribution, propeller performance, and the nacelle forebody pressure and viscous drag distributions. The computer analysis is applicable to single and coaxial counterrotating propellers. The blade geometries can include spanwise variations in sweep, droop, taper, thickness, and airfoil section type. In the coaxial mode of operation the analysis can treat both equal and unequal blade number and rotational speeds on the propeller disks. The nacelle portion of the analysis can treat both free air and tunnel wall configurations including wall bleed. The analysis was applied to many different sets of flight conditions using selected aerodynamic modeling options. The influence of different propeller nacelle-tunnel wall configurations was studied. Comparisons with available test data for both single and coaxial propeller configurations are presented along with a discussion of the results.

  12. RECENT ADVANCES IN ULTRA-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY FOR THE ANALYSIS OF TRADITIONAL CHINESE MEDICINE.

    PubMed

    Huang, Huilian; Liu, Min; Chen, Pei

    2014-01-01

    Traditional Chinese medicine has been widely used for the prevention and treatment of various diseases for thousands of years in China. Ultra-high performance liquid chromatography (UHPLC) is a relatively new technique offering new possibilities. This paper reviews recent developments in UHPLC in the separation and identification, fingerprinting, quantification, and metabolism of traditional Chinese medicine. Recently, the combination of UHPLC with MS has improved the efficiency of the analysis of these materials.

  13. RECENT ADVANCES IN ULTRA-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY FOR THE ANALYSIS OF TRADITIONAL CHINESE MEDICINE

    PubMed Central

    Huang, Huilian; Liu, Min; Chen, Pei

    2014-01-01

    Traditional Chinese medicine has been widely used for the prevention and treatment of various diseases for thousands of years in China. Ultra-high performance liquid chromatography (UHPLC) is a relatively new technique offering new possibilities. This paper reviews recent developments in UHPLC in the separation and identification, fingerprinting, quantification, and metabolism of traditional Chinese medicine. Recently, the combination of UHPLC with MS has improved the efficiency of the analysis of these materials. PMID:25045170

  14. An analysis for high speed propeller-nacelle aerodynamic performance prediction. Volume 2: User's manual

    NASA Technical Reports Server (NTRS)

    Egolf, T. Alan; Anderson, Olof L.; Edwards, David E.; Landgrebe, Anton J.

    1988-01-01

    A user's manual for the computer program developed for the prediction of propeller-nacelle aerodynamic performance reported in, An Analysis for High Speed Propeller-Nacelle Aerodynamic Performance Prediction: Volume 1 -- Theory and Application, is presented. The manual describes the computer program mode of operation requirements, input structure, input data requirements and the program output. In addition, it provides the user with documentation of the internal program structure and the software used in the computer program as it relates to the theory presented in Volume 1. Sample input data setups are provided along with selected printout of the program output for one of the sample setups.

  15. Development and performance analysis of a metallic micro-direct methanol fuel cell for high-performance applications

    NASA Astrophysics Data System (ADS)

    Zhang, Bo; Zhang, Yufeng; He, Hong; Li, Jianmin; Yuan, Zhenyu; Na, Chaoran; Liu, Xiaowei

    As a promising candidate for conventional micro-power sources, the micro-direct methanol fuel cell (μDMFC) is currently attracting increased attention due to its various advantages and prospective suitability for portable applications. This paper reports the design, fabrication and analysis of a high-performance μDMFC with two metal current collectors. Employing micro-stamping technology, the current collectors are fabricated on 300-μm-thick stainless steel plates. The flow fields for both cathode and anode are uniform in shape and size. Two sheets of stainless steel mesh are added between the membrane electrode assembly (MEA) and current collectors in order to improve cell performance. To avoid electrochemical corrosion, titanium nitride (TiN) layers with thickness of 500 nm are deposited onto the surface of current collectors and stainless steel mesh. The performance of this metallic μDMFC is thoroughly studied by both simulation and experimental methods. The results show that all the parameters investigated, including current collector material, stainless steel mesh, anode feeding mode, methanol concentration, anode flow rate, and operating temperature have significant effects on cell performance. Moreover, the results show that under optimal operating conditions, the metallic μDMFC exhibits promising performance, yielding a maximum power density of 65.66 mW cm -2 at 40 °C and 115.0 mW cm -2 at 80 °C.

  16. The High Performance and Wide Area Analysis and Mining of Scientific & Engineering Data

    SciTech Connect

    Grossman, R.

    2002-12-01

    This final report summarizes our accomplishments and findings and includes recent publications occurring in the final period of this award. One of our research goals was to develop algorithms and services for remote data analysis and distributed data mining which scaled from the commodity internet to high performance networks. When we began the project there was no effective mechanisms to achieve high end to end performance for data intensive applications over wide area, high bandwidth networks. For this reason, we developed algorithms and services for Layers 2,3, and 4 in the simple data web application stack below. We describe our research accomplishments for each of these layers in turn: Layer 4--Data Web Applications; Layer 3--Data Web Services; Layer 2--Network Protocol Services; Layer 1--IP.

  17. Fingerprint chromatogram analysis of Pseudostellaria heterophylla (Miq.) Pax root by high performance liquid chromatography.

    PubMed

    Han, Chao; Chen, Junhui; Chen, Bo; Lee, Frank Sen-Chun; Wang, Xiaoru

    2006-09-01

    A simple and reliable high performance liquid chromatographic (HPLC) method has been developed and validated for the fingerprinting of extracts from the root of Pseudostellaria heterophylla (Miq.) Pax. HPLC with gradient elution was performed on an authentic reference standard of powdered P. heterophylla (Miq.) Pax root and 11 plant samples of the root were collected from different geographic locations. The HPLC chromatograms have been standardized through the selection and identification of reference peaks and the normalization of retention times and peak intensities of all the common peaks. The standardized HPLC fingerprints show high stability and reproducibility, and thus can be used effectively for the screening analysis or quality assessment of the root or its derived products. Similarity index calculations based on cosine angle values or correlation methods have been performed on the HPLC fingerprints. As a group, the fingerprints of the P. heterophylla (Miq.) Pax samples studied are highly correlated with closely similar fingerprints. Within the group, the samples can be further divided into subgroups based on hierarchical clustering analysis (HCA). Sample grouping based on HCA coincides nicely with those based on the geographical origins of the samples. The HPLC fingerprinting techniques thus have high potential in authentication or source-tracing types of applications.

  18. Integrated State Estimation and Contingency Analysis Software Implementation using High Performance Computing Techniques

    SciTech Connect

    Chen, Yousu; Glaesemann, Kurt R.; Rice, Mark J.; Huang, Zhenyu

    2015-12-31

    Power system simulation tools are traditionally developed in sequential mode and codes are optimized for single core computing only. However, the increasing complexity in the power grid models requires more intensive computation. The traditional simulation tools will soon not be able to meet the grid operation requirements. Therefore, power system simulation tools need to evolve accordingly to provide faster and better results for grid operations. This paper presents an integrated state estimation and contingency analysis software implementation using high performance computing techniques. The software is able to solve large size state estimation problems within one second and achieve a near-linear speedup of 9,800 with 10,000 cores for contingency analysis application. The performance evaluation is presented to show its effectiveness.

  19. Core-Shell Columns in High-Performance Liquid Chromatography: Food Analysis Applications

    PubMed Central

    Preti, Raffaella

    2016-01-01

    The increased separation efficiency provided by the new technology of column packed with core-shell particles in high-performance liquid chromatography (HPLC) has resulted in their widespread diffusion in several analytical fields: from pharmaceutical, biological, environmental, and toxicological. The present paper presents their most recent applications in food analysis. Their use has proved to be particularly advantageous for the determination of compounds at trace levels or when a large amount of samples must be analyzed fast using reliable and solvent-saving apparatus. The literature hereby described shows how the outstanding performances provided by core-shell particles column on a traditional HPLC instruments are comparable to those obtained with a costly UHPLC instrumentation, making this novel column a promising key tool in food analysis. PMID:27143972

  20. High-Performance Single Cell Genetic Analysis Using Microfluidic Emulsion Generator Arrays

    PubMed Central

    Zeng, Yong; Novak, Richard; Shuga, Joe; Smith, Martyn T.; Mathies, Richard A.

    2010-01-01

    High-throughput genetic and phenotypic analysis at the single cell level is critical to advance our understanding of the molecular mechanisms underlying cellular function and dysfunction. Here we describe a high-performance single cell genetic analysis (SCGA) technique that combines high-throughput microfluidic emulsion generation with single cell multiplex PCR. Microfabricated emulsion generator array (MEGA) devices containing 4, 32 and 96 channels are developed to confer a flexible capability of generating up to 3.4 × 106 nanoliter-volume droplets per hour. Hybrid glass-polydimethylsiloxane diaphragm micropumps integrated into the MEGA chips afford uniform droplet formation, controlled generation frequency, and effective transportation and encapsulation of primer functionalized microbeads and cells. A multiplex single cell PCR method is developed to detect and quantify both wild type and mutant/pathogenic cells. In this method, microbeads functionalized with multiple forward primers targeting specific genes from different cell types are used for solid-phase PCR in droplets. Following PCR, the droplets are lysed, the beads are pooled and rapidly analyzed by multi-color flow cytometry. Using E. coli bacterial cells as a model, we show that this technique enables digital detection of pathogenic E. coli O157 cells in a high background of normal K12 cells, with a detection limit on the order of 1:105. This result demonstrates that multiplex SCGA is a promising tool for high-throughput quantitative digital analysis of genetic variation in complex populations. PMID:20192178

  1. Linear static structural and vibration analysis on high-performance computers

    NASA Technical Reports Server (NTRS)

    Baddourah, M. A.; Storaasli, O. O.; Bostic, S. W.

    1993-01-01

    Parallel computers offer the oppurtunity to significantly reduce the computation time necessary to analyze large-scale aerospace structures. This paper presents algorithms developed for and implemented on massively-parallel computers hereafter referred to as Scalable High-Performance Computers (SHPC), for the most computationally intensive tasks involved in structural analysis, namely, generation and assembly of system matrices, solution of systems of equations and calculation of the eigenvalues and eigenvectors. Results on SHPC are presented for large-scale structural problems (i.e. models for High-Speed Civil Transport). The goal of this research is to develop a new, efficient technique which extends structural analysis to SHPC and makes large-scale structural analyses tractable.

  2. Linear Static Structural and Vibration Analysis on High-Performance Computers

    NASA Technical Reports Server (NTRS)

    Baddourah, Majdi; Storaasli, Olaf O.; Bostic, Susan

    1993-01-01

    Parallel computers offer the opportunity to significantly reduce the computation time necessary to analyze large-scale aerospace structures. This paper presents algorithms developed for and implemented on a massively-parallel computers hereafter referred to as Scalable High Performance Computers (SHPC) for the most computationally intensive tasks involved in structural analysis, namely, generation and assembly of system matrices, solution of systems of equations and calculation of the eigenvalues and eigenvectors. Results on SHPC are presented for large-scale structural problems (i.e. Models of high speed civil transport). The goal of this research is to develop new efficient technique which extend structural analysis to SHPC and make large-scale structural analyses tractable.

  3. High-performance parallel analysis of coupled problems for aircraft propulsion

    NASA Technical Reports Server (NTRS)

    Felippa, C. A.; Farhat, C.; Lanteri, S.; Maman, N.; Piperno, S.; Gumaste, U.

    1994-01-01

    This research program deals with the application of high-performance computing methods for the analysis of complete jet engines. We have entitled this program by applying the two dimensional parallel aeroelastic codes to the interior gas flow problem of a bypass jet engine. The fluid mesh generation, domain decomposition, and solution capabilities were successfully tested. We then focused attention on methodology for the partitioned analysis of the interaction of the gas flow with a flexible structure and with the fluid mesh motion that results from these structural displacements. This is treated by a new arbitrary Lagrangian-Eulerian (ALE) technique that models the fluid mesh motion as that of a fictitious mass-spring network. New partitioned analysis procedures to treat this coupled three-component problem are developed. These procedures involved delayed corrections and subcycling. Preliminary results on the stability, accuracy, and MPP computational efficiency are reported.

  4. Performance Analysis of Two Early NACA High Speed Propellers with Application to Civil Tiltrotor Configurations

    NASA Technical Reports Server (NTRS)

    Harris, Franklin D.

    1996-01-01

    The helicopter industry is vigorously pursuing development of civil tiltrotors. One key to efficient high speed performance of this rotorcraft is prop-rotor performance. Of equal, if not greater, importance is assurance that the flight envelope is free of aeroelastic instabilities well beyond currently envisioned cuise speeds. This later condition requires study at helical tip Match numbers well in excess of 1.0. Two 1940's 'supersonic' propeller experiments conducted by NACA have provided an immensely valuable data bank with which to study prop-rotor behavior at transonic and supersonic helical tip Mach numbers. Very accurate 'blades alone' data were obtained by using nearly an infinite hub. Tabulated data were recreated from the many thrust and power figures and are included in two Appendices to this report. This data set is exceptionally well suited to re-evaluating classical blade element theories as well as evolving computational fluid dynamic (CFD) analyses. A limited comparison of one propeller's experimental results to a modem rotorcraft CFD code is made. This code, referred to as TURNS, gives very encouraging results. Detailed analysis of the performance data from both propellers is provided in Appendix A. This appendix quantifies the minimum power required to produce usable prop-rotor thrust. The dependence of minimum profile power on Reynolds number is quantified. First order compressibility power losses are quantified as well and a first approximation to design air-foil thickness ratio to avoid compressibility losses is provided. Appendix A's results are applied to study high speed civil tiltrotor cruise performance. Predicted tiltrotor performance is compared to two turboprop commercial transports. The comparison shows that there is no fundamental aerodynamic reason why the rotorcraft industry could not develop civil tiltrotor aircraft which have competitive cruise performance with today's regional, turboprop airlines. Recommendations for future study

  5. 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

  6. 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.

  7. High-Performance Integrated Virtual Environment (HIVE) Tools and Applications for Big Data Analysis.

    PubMed

    Simonyan, Vahan; Mazumder, Raja

    2014-01-01

    The High-performance Integrated Virtual Environment (HIVE) is a high-throughput cloud-based infrastructure developed for the storage and analysis of genomic and associated biological data. HIVE consists of a web-accessible interface for authorized users to deposit, retrieve, share, annotate, compute and visualize Next-generation Sequencing (NGS) data in a scalable and highly efficient fashion. The platform contains a distributed storage library and a distributed computational powerhouse linked seamlessly. Resources available through the interface include algorithms, tools and applications developed exclusively for the HIVE platform, as well as commonly used external tools adapted to operate within the parallel architecture of the system. HIVE is composed of a flexible infrastructure, which allows for simple implementation of new algorithms and tools. Currently, available HIVE tools include sequence alignment and nucleotide variation profiling tools, metagenomic analyzers, phylogenetic tree-building tools using NGS data, clone discovery algorithms, and recombination analysis algorithms. In addition to tools, HIVE also provides knowledgebases that can be used in conjunction with the tools for NGS sequence and metadata analysis. PMID:25271953

  8. High-Performance Integrated Virtual Environment (HIVE) Tools and Applications for Big Data Analysis.

    PubMed

    Simonyan, Vahan; Mazumder, Raja

    2014-09-30

    The High-performance Integrated Virtual Environment (HIVE) is a high-throughput cloud-based infrastructure developed for the storage and analysis of genomic and associated biological data. HIVE consists of a web-accessible interface for authorized users to deposit, retrieve, share, annotate, compute and visualize Next-generation Sequencing (NGS) data in a scalable and highly efficient fashion. The platform contains a distributed storage library and a distributed computational powerhouse linked seamlessly. Resources available through the interface include algorithms, tools and applications developed exclusively for the HIVE platform, as well as commonly used external tools adapted to operate within the parallel architecture of the system. HIVE is composed of a flexible infrastructure, which allows for simple implementation of new algorithms and tools. Currently, available HIVE tools include sequence alignment and nucleotide variation profiling tools, metagenomic analyzers, phylogenetic tree-building tools using NGS data, clone discovery algorithms, and recombination analysis algorithms. In addition to tools, HIVE also provides knowledgebases that can be used in conjunction with the tools for NGS sequence and metadata analysis.

  9. High-Performance Integrated Virtual Environment (HIVE) Tools and Applications for Big Data Analysis

    PubMed Central

    Simonyan, Vahan; Mazumder, Raja

    2014-01-01

    The High-performance Integrated Virtual Environment (HIVE) is a high-throughput cloud-based infrastructure developed for the storage and analysis of genomic and associated biological data. HIVE consists of a web-accessible interface for authorized users to deposit, retrieve, share, annotate, compute and visualize Next-generation Sequencing (NGS) data in a scalable and highly efficient fashion. The platform contains a distributed storage library and a distributed computational powerhouse linked seamlessly. Resources available through the interface include algorithms, tools and applications developed exclusively for the HIVE platform, as well as commonly used external tools adapted to operate within the parallel architecture of the system. HIVE is composed of a flexible infrastructure, which allows for simple implementation of new algorithms and tools. Currently, available HIVE tools include sequence alignment and nucleotide variation profiling tools, metagenomic analyzers, phylogenetic tree-building tools using NGS data, clone discovery algorithms, and recombination analysis algorithms. In addition to tools, HIVE also provides knowledgebases that can be used in conjunction with the tools for NGS sequence and metadata analysis. PMID:25271953

  10. Performance Analysis of Cooperative Wireless Backhaul Networks Operating at Extremely High Frequencies

    NASA Astrophysics Data System (ADS)

    Sakarellos, Vasileios K.; Chortatou, Maria; Skraparlis, Dimitrios; Panagopoulos, Athanasios D.; Kanellopoulos, John D.

    2011-04-01

    Extremely high frequency (EHF) bands above 50 GHz have been proposed to be used as backhaul links of modern cellular mobile networks. They provide interconnectivity between the base stations and the core network. In this paper, we propose the employment of cooperative techniques in backhaul networks. More specifically, the outage performance analysis of a simple cooperative diversity system operating at EHF bands is presented. The destination node combines the direct link with the signal received through a regenerative relay using selection combining. A combined statiform and convective model of rainfall rate for the rain attenuation prediction is considered. The correlation properties and the joint statistics among the microwave paths are also calculated. Numerical results present the impact of the geometrical parameters and the climatic conditions on the outage performance.

  11. Preliminary Evaluation of MapReduce for High-Performance Climate Data Analysis

    NASA Technical Reports Server (NTRS)

    Duffy, Daniel Q.; Schnase, John L.; Thompson, John H.; Freeman, Shawn M.; Clune, Thomas L.

    2012-01-01

    MapReduce is an approach to high-performance analytics that may be useful to data intensive problems in climate research. It offers an analysis paradigm that uses clusters of computers and combines distributed storage of large data sets with parallel computation. We are particularly interested in the potential of MapReduce to speed up basic operations common to a wide range of analyses. In order to evaluate this potential, we are prototyping a series of canonical MapReduce operations over a test suite of observational and climate simulation datasets. Our initial focus has been on averaging operations over arbitrary spatial and temporal extents within Modern Era Retrospective- Analysis for Research and Applications (MERRA) data. Preliminary results suggest this approach can improve efficiencies within data intensive analytic workflows.

  12. Design and performance analysis of high-order optical temporal differentiator with twin-core fiber

    NASA Astrophysics Data System (ADS)

    You, Haidong; Ning, Tigang; Li, Jing; Jian, Wei; Wen, Xiaodong; Pei, Li

    2013-08-01

    A simple and general approach for implementing all-fiber high-order optical temporal differentiator based on twin-core fiber (TCF) is presented and demonstrated. Specifically, the core 2 (or core 1) of the TCF should be cut in N sections with the same length for achieving N'th-order optical temporal differentiator, which can be considered to consist of N cascaded first-order optical temporal differentiators based on TCF. Our simulations show that the proposed approach can provide optical operation bandwidths in the several THz regime, which is capable of accurately processing time features as short as subpicoseconds. Performance analysis results show a good accuracy calculating the high-order time differentiation of the optical signal launched at core 2 (or core 1).

  13. BIOINTERACTION ANALYSIS BY HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY: KINETIC STUDIES OF IMMOBILIZED ANTIBODIES

    PubMed Central

    Nelson, Mary Anne; Moser, Annette; Hage, David S.

    2009-01-01

    A system based on high-performance affinity chromatography was developed for characterizing the binding, elution and regeneration kinetics of immobilized antibodies and immunoaffinity supports. This information was provided by using a combination of frontal analysis, split-peak analysis and peak decay analysis to determine the rate constants for antibody-antigen interactions under typical sample application and elution conditions. This technique was tested using immunoaffinity supports that contained monoclonal antibodies for 2,4-dichlorophenoxyacetic acid (2,4-D). Association equilibrium constants measured by frontal analysis for 2,4-D and related compounds with the immobilized antibodies were 1.7–12 × 106 M−1 at pH 7.0 and 25°C. Split-peak analysis gave association rate constants of 1.4–12 × 105 M−1s−1 and calculated dissociation rate constants of 0.01–0.4 s−1 under the application conditions. Elution at pH 2.5 for the analytes from the antibodies was examined by peak decay analysis and gave dissociation rate constants of 0.056–0.17 s−1. A comparison of frontal analysis results after various periods of column regeneration allowed the rate of antibody regeneration to be examined, with the results giving a first-order regeneration rate constant of 2.4 × 10−4 s−1. This combined approach and the information it provides should be useful in the design and optimization of immunoaffinity chromatography and other analytical methods that employ immobilized antibodies. The methods described are not limited to the particular analytes and antibodies employed in this study but should be useful in characterizing other targets, ligands and supports. PMID:19394281

  14. National cyber defense high performance computing and analysis : concepts, planning and roadmap.

    SciTech Connect

    Hamlet, Jason R.; Keliiaa, Curtis M.

    2010-09-01

    There is a national cyber dilemma that threatens the very fabric of government, commercial and private use operations worldwide. Much is written about 'what' the problem is, and though the basis for this paper is an assessment of the problem space, we target the 'how' solution space of the wide-area national information infrastructure through the advancement of science, technology, evaluation and analysis with actionable results intended to produce a more secure national information infrastructure and a comprehensive national cyber defense capability. This cybersecurity High Performance Computing (HPC) analysis concepts, planning and roadmap activity was conducted as an assessment of cybersecurity analysis as a fertile area of research and investment for high value cybersecurity wide-area solutions. This report and a related SAND2010-4765 Assessment of Current Cybersecurity Practices in the Public Domain: Cyber Indications and Warnings Domain report are intended to provoke discussion throughout a broad audience about developing a cohesive HPC centric solution to wide-area cybersecurity problems.

  15. High-performance parallel analysis of coupled problems for aircraft propulsion

    NASA Technical Reports Server (NTRS)

    Felippa, C. A.; Farhat, C.; Chen, P.-S.; Gumaste, U.; Leoinne, M.; Stern, P.

    1995-01-01

    This research program deals with the application of high-performance computing methods to the numerical simulation of complete jet engines. The program was initiated in 1993 by applying two-dimensional parallel aeroelastic codes to the interior gas flow problem of a by-pass jet engine. The fluid mesh generation, domain decomposition and solution capabilities were successfully tested. Attention was then focused on methodology for the partitioned analysis of the interaction of the gas flow with a flexible structure and with the fluid mesh motion driven by these structural displacements. The latter is treated by an ALE technique that models the fluid mesh motion as that of a fictitious mechanical network laid along the edges of near-field fluid elements. New partitioned analysis procedures to treat this coupled 3-component problem were developed in 1994. These procedures involved delayed corrections and subcycling, and have been successfully tested on several massively parallel computers. For the global steady-state axisymmetric analysis of a complete engine we have decided to use the NASA-sponsored ENG10 program, which uses a regular FV-multiblock-grid discretization in conjunction with circumferential averaging to include effects of blade forces, loss, combustor heat addition, blockage, bleeds and convective mixing. A load-balancing preprocessor for parallel versions of ENG10 has been developed. It is planned to use the steady-state global solution provided by ENG10 as input to a localized three-dimensional FSI analysis for engine regions where aeroelastic effects may be important.

  16. Group-type hydrocarbon standards for high-performance liquid chromatographic analysis of middistillate fuels

    NASA Technical Reports Server (NTRS)

    Otterson, D. A.; Seng, G. T.

    1984-01-01

    A new high-performance liquid chromatographic (HPLC) method for group-type analysis of middistillate fuels is described. It uses a refractive index detector and standards that are prepared by reacting a portion of the fuel sample with sulfuric acid. A complete analysis of a middistillate fuel for saturates and aromatics (including the preparation of the standard) requires about 15 min if standards for several fuels are prepared simultaneously. From model fuel studies, the method was found to be accurate to within 0.4 vol% saturates or aromatics, and provides a precision of + or - 0.4 vol%. Olefin determinations require an additional 15 min of analysis time. However, this determination is needed only for those fuels displaying a significant olefin response at 200 nm (obtained routinely during the saturated/aromatics analysis procedure). The olefin determination uses the responses of the olefins and the corresponding saturates, as well as the average value of their refractive index sensitivity ratios (1.1). Studied indicated that, although the relative error in the olefins result could reach 10 percent by using this average sensitivity ratio, it was 5 percent for the fuels used in this study. Olefin concentrations as low as 0.1 vol% have been determined using this method.

  17. An Analysis of Factors Affecting Teacher Attrition in High Performing and Low Performing Elementary Rural Schools in South Carolina

    ERIC Educational Resources Information Center

    Carter-Blocker, Vickie R.

    2012-01-01

    The purpose of this study was to examine the factors impacting teacher attrition in high-performing and low-performing elementary rural schools in South Carolina. Several factors were identified that interfered with teachers returning to the teaching profession. School districts in rural areas need to be better informed of the factors that affect…

  18. High-performance thin-layer chromatographic analysis of selected organophosphorous pesticide residues in tea.

    PubMed

    Yue, Yongde; Zhang, Rong; Fan, Wei; Tang, Feng

    2008-01-01

    The separation of 9 organophosphates (monocrotophos, quinalphos, triazophos, parathion-methyl, isofenphos-methyl, temephos, parathion, phoxim-ethyl, and chlorpyrifos) by high-performance thin-layer chromatography (HPTLC) with automated multiple development was studied. The HPTLC method was developed and validated for analysis of residues of phoxim-ethyl and chlorpyrifos in tea. The sample was extracted with acetonitrile and cleaned up by ENVI-CARB solid-phase extraction. The extract was directly applied as bands to glass-backed silica gel 60F254 HPTLC plates. The plates were developed with dichloromethane-hexane (1 + 1, v/v) in a glass twin-trough chamber. Evaluation of the developed HPTLC plates was performed densitometrically. The results indicated that the detection limits of phoxim and chlorpyrifos were 5.0 x 10(-9) and 1.0 x 10(-8) g, respectively. Recoveries of the pesticides from tea by this analytical method were 90.7-105.5%, and relative standard deviations were 7.3-13.5%. The precision and accuracy of the method were generally satisfactory for analysis of pesticide residues in tea.

  19. Quantitative analysis of mitragynine in human urine by high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Lu, Shijun; Tran, Buu N; Nelsen, Jamie L; Aldous, Kenneth M

    2009-08-15

    Mitragynine is the primary active alkaloid extracted from the leaves of Mitragyna speciosa Korth, a plant that originates in South-East Asia and is commonly known as kratom in Thailand. Kratom has been used for many centuries for their medicinal and psychoactive qualities, which are comparable to that of opiate-based drugs. Kratom abuse can lead to a detectable content of mitragynine residue in urine. Ultra trace amount of mitragynine in human urine was determined by a high performance liquid chromatography coupled to an electrospray tandem mass spectrometry (HPLC-ESI/MS/MS). Mitragynine was extracted by methyl t-butyl ether (MTBE) and separated on a HILIC column. The ESI/MS/MS was accomplished using a triple quadrupole mass spectrometer in positive ion detection and multiple reactions monitoring (MRM) mode. Ajmalicine, a mitragynine's structure analog was selected as internal standard (IS) for method development. Quality control (QC) performed at three levels 0.1, 1 and 5 ng/ml of mitragynine in urine gave mean recoveries of 90, 109, and 98% with average relative standard deviation of 22, 12 and 16%, respectively. The regression linearity of mitragynine calibration ranged from 0.01 to 5.0 ng/ml was achieved with correlation coefficient greater than 0.995. A detection limit of 0.02 ng/ml and high precision data within-day and between days analysis were obtained. PMID:19577523

  20. Analysis of starch in food systems by high-performance size exclusion chromatography.

    PubMed

    Ovando-Martínez, Maribel; Whitney, Kristin; Simsek, Senay

    2013-02-01

    Starch has unique physicochemical characteristics among food carbohydrates. Starch contributes to the physicochemical attributes of food products made from roots, legumes, cereals, and fruits. It occurs naturally as distinct particles, called granules. Most starch granules are a mixture of 2 sugar polymers: a highly branched polysaccharide named amylopectin and a basically linear polysaccharide named amylose. The starch contained in food products undergoes changes during processing, which causes changes in the starch molecular weight and amylose to amylopectin ratio. The objective of this study was to develop a new, simple, 1-step, and accurate method for simultaneous determination of amylose and amylopectin ratio as well as weight-averaged molecular weights of starch in food products. Starch from bread flour, canned peas, corn flake cereal, snack crackers, canned kidney beans, pasta, potato chips, and white bread was extracted by dissolving in KOH, urea, and precipitation with ethanol. Starch samples were solubilized and analyzed on a high-performance size exclusion chromatography (HPSEC) system. To verify the identity of the peaks, fractions were collected and soluble starch and beta-glucan assays were performed additional to gas chromatography analysis. We found that all the fractions contain only glucose and soluble starch assay is correlated to the HPSEC fractionation. This new method can be used to determine amylose amylopectin ratio and weight-averaged molecular weight of starch from various food products using as low as 25 mg dry samples. PMID:23330715

  1. [Trace analysis of biological substances by high-performance liquid chromatography with electrochemical detection].

    PubMed

    Shimada, K; Oe, T

    1991-01-01

    High-performance liquid chromatography (HPLC) with electrochemical detection has been developed for the trace analysis of electrochemically active substances in biological fluids such as catecholamines. The recent development of this system, both instruments and application, has been reviewed. The principle of instrument and newly developed electrode for electrochemical detector have been described at the first section. Series electrodes, especially with coulometric detection, gave much higher selectivity to the analysis of biological substances. The application of HPLC with electrochemical detection to the determination of estrogens in biological fluids clarified the metabolic pathway of catechol estrogens. The applicability to the determination of vitamin D3 and related compounds has been also suggested. For the purpose of extending the applicability of HPLC with electrochemical detection to electro-inactive compounds, pre- and post-column labeling methods have been developed. Pre-column derivatization reagents possessing ferrocene as an electrophore provided a selective and sensitive response to the detector, because of their high-reversibility and low applied potential in the redox reaction. Post-column reaction by using immobilized enzyme reactor has been widely used for the determination of acetylcholine and choline in biological fluids.

  2. High-Performance Parallel Analysis of Coupled Problems for Aircraft Propulsion

    NASA Technical Reports Server (NTRS)

    Felippa, C. A.; Farhat, C.; Park, K. C.; Gumaste, U.; Chen, P.-S.; Lesoinne, M.; Stern, P.

    1997-01-01

    Applications are described of high-performance computing methods to the numerical simulation of complete jet engines. The methodology focuses on the partitioned analysis of the interaction of the gas flow with a flexible structure and with the fluid mesh motion driven by structural displacements. The latter is treated by a ALE technique that models the fluid mesh motion as that of a fictitious mechanical network laid along the edges of near-field elements. New partitioned analysis procedures to treat this coupled three-component problem were developed. These procedures involved delayed corrections and subcycling, and have been successfully tested on several massively parallel computers, including the iPSC-860, Paragon XP/S and the IBM SP2. The NASA-sponsored ENG10 program was used for the global steady state analysis of the whole engine. This program uses a regular FV-multiblock-grid discretization in conjunction with circumferential averaging to include effects of blade forces, loss, combustor heat addition, blockage, bleeds and convective mixing. A load-balancing preprocessor for parallel versions of ENG10 was developed as well as the capability for the first full 3D aeroelastic simulation of a multirow engine stage. This capability was tested on the IBM SP2 parallel supercomputer at NASA Ames.

  3. Identification of Dactylopius cochineal species with high-performance liquid chromatography and multivariate data analysis.

    PubMed

    Serrano, Ana; Sousa, Micaela; Hallett, Jessica; Simmonds, Monique S J; Nesbitt, Mark; Lopes, João A

    2013-10-21

    Identification of American cochineal species (Dactylopius genus) can provide important information for the study of historical works of art, entomology, cosmetics, pharmaceuticals and foods. In this study, validated species of Dactylopius, including the domesticated cochineal D. coccus, were analysed by high-performance liquid chromatography with a diode array detector (HPLC-DAD) and submitted to multivariate data analysis, in order to discriminate the species and hence construct a reference library for a wide range of applications. Principal components analysis (PCA) and partial least squares discriminant analysis (PLSDA) models successfully provided accurate species classifications. This library was then applied to the identification of 72 historical insect specimens of unidentified species, mostly dating from the 19th century, and belonging to the Economic Botany Collection, Royal Botanic Gardens, Kew, England. With this approach it was possible to identify anomalies in how insects were labelled historically, as several of them were revealed not to be cochineal. Nevertheless, more than 85% of the collection was determined to be species of Dactylopius and the majority of the specimens were identified as D. coccus. These results have shown that HPLC-DAD, in combination with suitable chemometric methods, is a powerful approach for discriminating related cochineal species.

  4. Identification of Dactylopius cochineal species with high-performance liquid chromatography and multivariate data analysis.

    PubMed

    Serrano, Ana; Sousa, Micaela; Hallett, Jessica; Simmonds, Monique S J; Nesbitt, Mark; Lopes, João A

    2013-10-21

    Identification of American cochineal species (Dactylopius genus) can provide important information for the study of historical works of art, entomology, cosmetics, pharmaceuticals and foods. In this study, validated species of Dactylopius, including the domesticated cochineal D. coccus, were analysed by high-performance liquid chromatography with a diode array detector (HPLC-DAD) and submitted to multivariate data analysis, in order to discriminate the species and hence construct a reference library for a wide range of applications. Principal components analysis (PCA) and partial least squares discriminant analysis (PLSDA) models successfully provided accurate species classifications. This library was then applied to the identification of 72 historical insect specimens of unidentified species, mostly dating from the 19th century, and belonging to the Economic Botany Collection, Royal Botanic Gardens, Kew, England. With this approach it was possible to identify anomalies in how insects were labelled historically, as several of them were revealed not to be cochineal. Nevertheless, more than 85% of the collection was determined to be species of Dactylopius and the majority of the specimens were identified as D. coccus. These results have shown that HPLC-DAD, in combination with suitable chemometric methods, is a powerful approach for discriminating related cochineal species. PMID:23961534

  5. HIVE-Hexagon: High-Performance, Parallelized Sequence Alignment for Next-Generation Sequencing Data Analysis

    PubMed Central

    Santana-Quintero, Luis; Dingerdissen, Hayley; Thierry-Mieg, Jean; Mazumder, Raja; Simonyan, Vahan

    2014-01-01

    Due to the size of Next-Generation Sequencing data, the computational challenge of sequence alignment has been vast. Inexact alignments can take up to 90% of total CPU time in bioinformatics pipelines. High-performance Integrated Virtual Environment (HIVE), a cloud-based environment optimized for storage and analysis of extra-large data, presents an algorithmic solution: the HIVE-hexagon DNA sequence aligner. HIVE-hexagon implements novel approaches to exploit both characteristics of sequence space and CPU, RAM and Input/Output (I/O) architecture to quickly compute accurate alignments. Key components of HIVE-hexagon include non-redundification and sorting of sequences; floating diagonals of linearized dynamic programming matrices; and consideration of cross-similarity to minimize computations. Availability https://hive.biochemistry.gwu.edu/hive/ PMID:24918764

  6. High-performance parallel analysis of coupled problems for aircraft propulsion

    NASA Technical Reports Server (NTRS)

    Felippa, C. A.; Farhat, C.; Lanteri, S.; Gumaste, U.; Ronaghi, M.

    1994-01-01

    Applications are described of high-performance parallel, computation for the analysis of complete jet engines, considering its multi-discipline coupled problem. The coupled problem involves interaction of structures with gas dynamics, heat conduction and heat transfer in aircraft engines. The methodology issues addressed include: consistent discrete formulation of coupled problems with emphasis on coupling phenomena; effect of partitioning strategies, augmentation and temporal solution procedures; sensitivity of response to problem parameters; and methods for interfacing multiscale discretizations in different single fields. The computer implementation issues addressed include: parallel treatment of coupled systems; domain decomposition and mesh partitioning strategies; data representation in object-oriented form and mapping to hardware driven representation, and tradeoff studies between partitioning schemes and fully coupled treatment.

  7. High Performance Liquid Chromatography

    NASA Astrophysics Data System (ADS)

    Talcott, Stephen

    High performance liquid chromatography (HPLC) has many applications in food chemistry. Food components that have been analyzed with HPLC include organic acids, vitamins, amino acids, sugars, nitrosamines, certain pesticides, metabolites, fatty acids, aflatoxins, pigments, and certain food additives. Unlike gas chromatography, it is not necessary for the compound being analyzed to be volatile. It is necessary, however, for the compounds to have some solubility in the mobile phase. It is important that the solubilized samples for injection be free from all particulate matter, so centrifugation and filtration are common procedures. Also, solid-phase extraction is used commonly in sample preparation to remove interfering compounds from the sample matrix prior to HPLC analysis.

  8. An Analysis of High School Students' Performance on Five Integrated Science Process Skills.

    ERIC Educational Resources Information Center

    Beaumont-Walters, Yvonne; Soyibo, Kola

    2001-01-01

    This study determined Jamaican high school students' (n=305) level of performance on five integrated science process skills with performance linked to gender, grade level, school location, school type, student type, and socio-economic background (SEB). Statistically significant differences in performance based on grade level, school type, student…

  9. High Performance Liquid Chromatography-mass Spectrometry Analysis of High Antioxidant Australian Fruits with Antiproliferative Activity Against Cancer Cells

    PubMed Central

    Sirdaarta, Joseph; Maen, Anton; Rayan, Paran; Matthews, Ben; Cock, Ian Edwin

    2016-01-01

    g/mL). All other extracts were nontoxic. A total of 145 unique mass signals were detected in the lemon aspen methanolic and aqueous extracts by nonbiased high-performance liquid chromatography-mass spectrometry analysis. Of these, 20 compounds were identified as being of particular interest due to their reported antioxidant and/or anticancer activities. Conclusions: The lack of toxicity and antiproliferative activity of the high antioxidant plant extracts against HeLa and CaCo2 cancer cell lines indicates their potential in the treatment and prevention of some cancers. SUMMARY Australian fruit extracts with high antioxidant contents were potent inhibitors of CaCo2 and HeLa carcinoma cell proliferationMethanolic lemon aspen extract was particularly potent, with IC50 values of 480 μg/mL (HeLa) and 769 μg/mL (CaCo2)High-performance liquid chromatography-mass spectrometry-quadrupole time-of-flight analysis highlighted and putatively identified 20 compounds in the antiproliferative lemon aspen extractsIn contrast, lower antioxidant content extracts stimulated carcinoma cell proliferationAll extracts with antiproliferative activity were nontoxic in the Artemia nauplii assay. Abbreviations used: DPPH: di (phenyl)- (2,4,6-trinitrophenyl) iminoazanium, HPLC: High-performance liquid chromatography, IC50: The concentration required to inhibit by 50%, LC50: The concentration required to achieve 50% mortality, MS: Mass spectrometry. PMID:27279705

  10. libRoadRunner: a high performance SBML simulation and analysis library

    PubMed Central

    Somogyi, Endre T.; Bouteiller, Jean-Marie; Glazier, James A.; König, Matthias; Medley, J. Kyle; Swat, Maciej H.; Sauro, Herbert M.

    2015-01-01

    Motivation: This article presents libRoadRunner, an extensible, high-performance, cross-platform, open-source software library for the simulation and analysis of models expressed using Systems Biology Markup Language (SBML). SBML is the most widely used standard for representing dynamic networks, especially biochemical networks. libRoadRunner is fast enough to support large-scale problems such as tissue models, studies that require large numbers of repeated runs and interactive simulations. Results: libRoadRunner is a self-contained library, able to run both as a component inside other tools via its C++ and C bindings, and interactively through its Python interface. Its Python Application Programming Interface (API) is similar to the APIs of MATLAB (www.mathworks.com) and SciPy (http://www.scipy.org/), making it fast and easy to learn. libRoadRunner uses a custom Just-In-Time (JIT) compiler built on the widely used LLVM JIT compiler framework. It compiles SBML-specified models directly into native machine code for a variety of processors, making it appropriate for solving extremely large models or repeated runs. libRoadRunner is flexible, supporting the bulk of the SBML specification (except for delay and non-linear algebraic equations) including several SBML extensions (composition and distributions). It offers multiple deterministic and stochastic integrators, as well as tools for steady-state analysis, stability analysis and structural analysis of the stoichiometric matrix. Availability and implementation: libRoadRunner binary distributions are available for Mac OS X, Linux and Windows. The library is licensed under Apache License Version 2.0. libRoadRunner is also available for ARM-based computers such as the Raspberry Pi. http://www.libroadrunner.org provides online documentation, full build instructions, binaries and a git source repository. Contacts: hsauro@u.washington.edu or somogyie@indiana.edu Supplementary information: Supplementary data are available

  11. High-Performance Computing for Real-Time Grid Analysis and Operation

    SciTech Connect

    Huang, Zhenyu; Chen, Yousu; Chavarría-Miranda, Daniel

    2013-10-31

    Power grids worldwide are undergoing an unprecedented transition as a result of grid evolution meeting information revolution. The grid evolution is largely driven by the desire for green energy. Emerging grid technologies such as renewable generation, smart loads, plug-in hybrid vehicles, and distributed generation provide opportunities to generate energy from green sources and to manage energy use for better system efficiency. With utility companies actively deploying these technologies, a high level of penetration of these new technologies is expected in the next 5-10 years, bringing in a level of intermittency, uncertainties, and complexity that the grid did not see nor design for. On the other hand, the information infrastructure in the power grid is being revolutionized with large-scale deployment of sensors and meters in both the transmission and distribution networks. The future grid will have two-way flows of both electrons and information. The challenge is how to take advantage of the information revolution: pull the large amount of data in, process it in real time, and put information out to manage grid evolution. Without addressing this challenge, the opportunities in grid evolution will remain unfulfilled. This transition poses grand challenges in grid modeling, simulation, and information presentation. The computational complexity of underlying power grid modeling and simulation will significantly increase in the next decade due to an increased model size and a decreased time window allowed to compute model solutions. High-performance computing is essential to enable this transition. The essential technical barrier is to vastly increase the computational speed so operation response time can be reduced from minutes to seconds and sub-seconds. The speed at which key functions such as state estimation and contingency analysis are conducted (typically every 3-5 minutes) needs to be dramatically increased so that the analysis of contingencies is both

  12. Sources of Variability in Chlorophyll Analysis by Fluorometry and by High Performance Liquid Chromatography. Chapter 22

    NASA Technical Reports Server (NTRS)

    VanHeukelem, Laurie; Thomas, Crystal S.; Glibert, Patricia M.

    2001-01-01

    The need for accurate determination of chlorophyll a (chl a) is of interest for numerous reasons. From the need for ground-truth data for remote sensing to pigment detection for laboratory experimentation, it is essential to know the accuracy of the analyses and the factors potentially contributing to variability and error. Numerous methods and instrument techniques are currently employed in the analyses of chl a. These methods range from spectrophotometric quantification, to fluorometric analysis and determination by high performance liquid chromatography. Even within the application of HPLC techniques, methods vary. Here we provide the results of a comparison among methods and provide some guidance for improving the accuracy of these analyses. These results are based on a round-robin conducted among numerous investigators, including several in the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) and HyCODE Programs. Our purpose here is not to present the full results of the laboratory intercalibration; those results will be presented elsewhere. Rather, here we highlight some of the major factors that may contribute to the variability observed. Specifically, we aim to assess the comparability of chl a analyses performed by fluorometry and HPLC, and we identify several factors in the analyses which may contribute disproportionately to this variability.

  13. Analysis of creams. IV. Application of high performance liquid chromatography. Part I.

    PubMed

    Lake, O A; Hulshoff, A; Van De Vaart, F J; Indemans, A W

    1983-02-25

    The possibilities of applying reversed-phase high performance liquid chromatography to the analysis of o/w emulsion type creams without preceding sample clean-up were investigated. The chromatographic behaviour of cream base components and active compounds in reversed phase systems consisting of methanol-water mixtures as the mobile phase and a chemically bonded octadecyl stationary phase, was studied. A number of active compounds and the preservative (sorbic acid) could be determined--often in one chromatographic run--without complications, by simply dissolving the sample in a suitable solvent mixture and injecting an aliquot of the solution into the chromatograph. Separation was achieved by the proper choice of methanol content, pH and ionic strength of the eluent. The compounds were detected by UV absorption. Some of the lipophilic cream base components could easily be determined in the same manner, with methanol as the eluent and with refraction index detection. The developed procedure was applied to the analysis of a number of creams. Some of the results are presented as examples, demonstrating the suitability of the method for quality control purposes. PMID:6844121

  14. 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.

  15. Geometrically nonlinear design sensitivity analysis on parallel-vector high-performance computers

    NASA Technical Reports Server (NTRS)

    Baddourah, Majdi A.; Nguyen, Duc T.

    1993-01-01

    Parallel-vector solution strategies for generation and assembly of element matrices, solution of the resulted system of linear equations, calculations of the unbalanced loads, displacements, stresses, and design sensitivity analysis (DSA) are all incorporated into the Newton Raphson (NR) procedure for nonlinear finite element analysis and DSA. Numerical results are included to show the performance of the proposed method for structural analysis and DSA in a parallel-vector computer environment.

  16. WEP: a high-performance analysis pipeline for whole-exome data

    PubMed Central

    2013-01-01

    Background The advent of massively parallel sequencing technologies (Next Generation Sequencing, NGS) profoundly modified the landscape of human genetics. In particular, Whole Exome Sequencing (WES) is the NGS branch that focuses on the exonic regions of the eukaryotic genomes; exomes are ideal to help us understanding high-penetrance allelic variation and its relationship to phenotype. A complete WES analysis involves several steps which need to be suitably designed and arranged into an efficient pipeline. Managing a NGS analysis pipeline and its huge amount of produced data requires non trivial IT skills and computational power. Results Our web resource WEP (Whole-Exome sequencing Pipeline web tool) performs a complete WES pipeline and provides easy access through interface to intermediate and final results. The WEP pipeline is composed of several steps: 1) verification of input integrity and quality checks, read trimming and filtering; 2) gapped alignment; 3) BAM conversion, sorting and indexing; 4) duplicates removal; 5) alignment optimization around insertion/deletion (indel) positions; 6) recalibration of quality scores; 7) single nucleotide and deletion/insertion polymorphism (SNP and DIP) variant calling; 8) variant annotation; 9) result storage into custom databases to allow cross-linking and intersections, statistics and much more. In order to overcome the challenge of managing large amount of data and maximize the biological information extracted from them, our tool restricts the number of final results filtering data by customizable thresholds, facilitating the identification of functionally significant variants. Default threshold values are also provided at the analysis computation completion, tuned with the most common literature work published in recent years. Conclusions Through our tool a user can perform the whole analysis without knowing the underlying hardware and software architecture, dealing with both paired and single end data. The interface

  17. High resolution and high precision on line isotopic analysis of Holocene and glacial ice performed in the field

    NASA Astrophysics Data System (ADS)

    Gkinis, V.; Popp, T. J.; Johnsen, S. J.; Blunier, T.; Bigler, M.; Stowasser, C.; Schüpbach, S.; Leuenberger, D.

    2010-12-01

    Ice core records as obtained from polar ice caps provide a wealth of paleoclimatic information. One of the main features of ice cores is their potential for high temporal resolution. The isotopic signature of the ice, expressed through the relative abundances of the two heavy isotopologues H218O and HD16O, is a widely used proxy for the reconstruction of past temperature and accumulation. One step further the combined information obtained from these two isotopologues, commonly referred to as the deuterium excess, can be utilized to infer additional information about the source of the precipitated moisture. Until very recently isotopic analysis of polar ice was performed with isotope Ratio Mass Spectrometry (IRMS) in a discrete fashion resulting in a high workload related to the preparation of samples. Most important though the available temporal resolution of the ice core was in many cases not fully exploited. In order to overcome these limitations we have developed a system that interfaces a commercially available IR laser cavity ring-down spectrometer tailored for water isotope analysis to a stream of liquid water as extracted from a continuously melted ice rod. The system offers the possibility for simultaneous δ18O and δD analysis with a sample requirement of approximately 0.1 ml/min. The system has been deployed in the field during the NEEM ice core drilling project on 2009 and 2010. In this study we present actual on line measurements of Holocene and glacial ice. We also discuss how parameters as the melt rate, acquisition rate and integration time affect the obtained precision and resolution and we describe data analysis techniques that can improve these last two parameters. By applying spectral methods we are able to quantify the smoothing effects imposed by diffusion of the sample in the sample transfer lines and the optical cavity of the instrument. We demonstrate that with an acquisition rate of 0.2 Hz we are able to obtain a precision of 0.5‰ and 0

  18. Analysis of Drug Interactions with Lipoproteins by High-Performance Affinity Chromatography

    PubMed Central

    Sobansky, Matthew R.; Hage, David S.

    2013-01-01

    Lipoproteins such as high-density lipoprotein (HDL) and low-density lipoprotein (LDL) are known to interact with drugs and other solutes in blood. These interactions have been examined in the past by methods such as equilibrium dialysis and capillary electrophoresis. This chapter describes an alternative approach that has recently been developed for examining these interactions by using high-performance affinity chromatography. In this method, lipoproteins are covalently immobilized to a solid support and used within a column as a stationary phase for binding studies. This approach allows the same lipoprotein preparation to be used for a large number of binding studies, leading to precise estimates of binding parameters. This chapter will discuss how this technique can be applied to the identification of interaction models and be used to differentiate between systems that have interactions based on partitioning, adsorption or mixed-mode interactions. It is also shown how this approach can then be used for the measurement of binding parameters for HDL and LDL with drugs. Examples of these studies are provided, with particular attention being given to the use of frontal analysis to examine the interactions of R- and S-propranolol with HDL and LDL. The advantages and possible limitations of this method are described. The extension of this approach to other types of drug-lipoprotein interactions is also considered. PMID:25392741

  19. 13CFLUX2—high-performance software suite for 13C-metabolic flux analysis

    PubMed Central

    Weitzel, Michael; Nöh, Katharina; Dalman, Tolga; Niedenführ, Sebastian; Stute, Birgit; Wiechert, Wolfgang

    2013-01-01

    Summary: 13C-based metabolic flux analysis (13C-MFA) is the state-of-the-art method to quantitatively determine in vivo metabolic reaction rates in microorganisms. 13CFLUX2 contains all tools for composing flexible computational 13C-MFA workflows to design and evaluate carbon labeling experiments. A specially developed XML language, FluxML, highly efficient data structures and simulation algorithms achieve a maximum of performance and effectiveness. Support of multicore CPUs, as well as compute clusters, enables scalable investigations. 13CFLUX2 outperforms existing tools in terms of universality, flexibility and built-in features. Therewith, 13CFLUX2 paves the way for next-generation high-resolution 13C-MFA applications on the large scale. Availability and implementation: 13CFLUX2 is implemented in C++ (ISO/IEC 14882 standard) with Java and Python add-ons to run under Linux/Unix. A demo version and binaries are available at www.13cflux.net. Contact: info@13cflux.net or k.noeh@fz-juelich.de Supplementary information: Supplementary data are available at Bioinformatics online. PMID:23110970

  20. High performance polymer development

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M.

    1991-01-01

    The term high performance as applied to polymers is generally associated with polymers that operate at high temperatures. High performance is used to describe polymers that perform at temperatures of 177 C or higher. In addition to temperature, other factors obviously influence the performance of polymers such as thermal cycling, stress level, and environmental effects. Some recent developments at NASA Langley in polyimides, poly(arylene ethers), and acetylenic terminated materials are discussed. The high performance/high temperature polymers discussed are representative of the type of work underway at NASA Langley Research Center. Further improvement in these materials as well as the development of new polymers will provide technology to help meet NASA future needs in high performance/high temperature applications. In addition, because of the combination of properties offered by many of these polymers, they should find use in many other applications.

  1. Determination of plasma protein binding of positron emission tomography radioligands by high-performance frontal analysis.

    PubMed

    Amini, Nahid; Nakao, Ryuji; Schou, Magnus; Halldin, Christer

    2014-09-01

    Positron emission tomography (PET) is an imaging technique based on the use of radioligands labeled with short lived radionuclides, such as (11)C (t½=20.4min) and (18)F (t½=109.8min), which as a consequence often requires rapid plasma protein binding analysis methods. In addition, PET radioligands can suffer from non-specific binding to the membrane when ultrafiltraion, which is the most commonly used method for measuring protein binding in PET, is employed. In this study a high-performance frontal analysis (HPFA) method based on incorporation of a gel filtration column (discovery(®) BIO GFC 100, 50mm×4.6mm, 5μm, 100Å) into a radio-LC system with phosphate buffered saline (PBS, pH 7.4) at a flow rate of 3ml/min as mobile phase was developed and investigated for four PET radioligands. The minimum injection volume (MIV) of plasma, which is a crucial factor in HPFA, was determined to be 200μl (human), 500μl (monkey), 700μl (human) and 1000μl (monkey) for these four radioligands. The MIV values increased as a higher fraction of the radioligand was present in the protein-free form. The protein binding results obtained were in good agreement with ultrafiltration and the method did not suffer from non-specific binding. The short analysis time (<12min) allowed multiple protein binding measurements during time course of a human [(11)C]PBR28 PET study. PMID:24922085

  2. High-Performance Parallel Analysis of Coupled Problems for Aircraft Propulsion

    NASA Technical Reports Server (NTRS)

    Felippa, C. A.; Farhat, C.; Park, K. C.; Gumaste, U.; Chen, P.-S.; Lesoinne, M.; Stern, P.

    1996-01-01

    This research program dealt with the application of high-performance computing methods to the numerical simulation of complete jet engines. The program was initiated in January 1993 by applying two-dimensional parallel aeroelastic codes to the interior gas flow problem of a bypass jet engine. The fluid mesh generation, domain decomposition and solution capabilities were successfully tested. Attention was then focused on methodology for the partitioned analysis of the interaction of the gas flow with a flexible structure and with the fluid mesh motion driven by these structural displacements. The latter is treated by a ALE technique that models the fluid mesh motion as that of a fictitious mechanical network laid along the edges of near-field fluid elements. New partitioned analysis procedures to treat this coupled three-component problem were developed during 1994 and 1995. These procedures involved delayed corrections and subcycling, and have been successfully tested on several massively parallel computers, including the iPSC-860, Paragon XP/S and the IBM SP2. For the global steady-state axisymmetric analysis of a complete engine we have decided to use the NASA-sponsored ENG10 program, which uses a regular FV-multiblock-grid discretization in conjunction with circumferential averaging to include effects of blade forces, loss, combustor heat addition, blockage, bleeds and convective mixing. A load-balancing preprocessor tor parallel versions of ENG10 was developed. During 1995 and 1996 we developed the capability tor the first full 3D aeroelastic simulation of a multirow engine stage. This capability was tested on the IBM SP2 parallel supercomputer at NASA Ames. Benchmark results were presented at the 1196 Computational Aeroscience meeting.

  3. An Analysis of Jamaican High School Students' Integrated Science Process Skills Performance.

    ERIC Educational Resources Information Center

    Soyibo, Kola; Beaumont-Walters, Yvonne

    This study determined Jamaican high school students' level of performance on five integrated science process skills and if there were significant differences in their performance linked to their gender, grade level, school location, school-type, student-type, and socioeconomic background (SEB). The 305 subjects comprised 133 males, 172 females,…

  4. Analysis of some selected catechins and caffeine in green tea by high performance liquid chromatography.

    PubMed

    El-Shahawi, M S; Hamza, A; Bahaffi, S O; Al-Sibaai, A A; Abduljabbar, T N

    2012-10-15

    Green tea seems to have a positive impact on health due to the catechins-found as flavanols. Thus, the present study was aimed to develop a low cost reversed phase high performance liquid chromatographic (HPLC) method for simultaneous determination of flavanol contents, namely catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin 3-gallate (ECG) and epigallocatechin 3-gallate (EGCG) and caffeine in 29 commercial green tea samples available in a Saudi Arabian local market. A C-18 reversed-phase column, acetonitrile-trifluoroacetic acid as a mobile phase, coupled with UV detector at 205 nm, was successfully used for precise analysis of the tested analytes in boiled water of digested tea leaves. The average values of N (No. of theoretical plates), HETP (height equivalent of theoretical plates) and R(s) (separation factor) (at 10 μg ml(-1) of the catechins EC, EGC, EGCG and ECG) were 2.6×10(3)±1.2×10(3), 1.7×10(-3)±4.7×10(-4) cm and 1.7±5.53×10(-2), respectively. The developed HPLC method demonstrated excellent performance, with low limits of detection (LOD) and quantification (LOQ) of the tested catechins of 0.004-0.05 μg ml(-1) and 0.01-0.17 μg ml(-1), respectively, and recovery percentages of 96-101%. The influence of infusion time (5-30 min) and temperature on the content of the flavanols was investigated by HPLC. After a 5 min infusion of the tea leaves, the average concentrations of caffeine, catechin, EC, EGC, ECG and EGCG were found to be in the ranges 0.086-2.23, 0.113-2.94, 0.58-10.22, 0.19-24.9, 0.22-13.9 and 1.01-43.3 mg g(-1), respectively. The contents of caffeine and catechins followed the sequence: EGCG>EGC>ECG>EC>C>caffeine. The method was applied satisfactorily for the analysis of (+)-catechin, even at trace and ultra trace concentrations of catechins. The method was rapid, accurate, reproducible and ideal for routine analysis.

  5. Analysis of some selected catechins and caffeine in green tea by high performance liquid chromatography.

    PubMed

    El-Shahawi, M S; Hamza, A; Bahaffi, S O; Al-Sibaai, A A; Abduljabbar, T N

    2012-10-15

    Green tea seems to have a positive impact on health due to the catechins-found as flavanols. Thus, the present study was aimed to develop a low cost reversed phase high performance liquid chromatographic (HPLC) method for simultaneous determination of flavanol contents, namely catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin 3-gallate (ECG) and epigallocatechin 3-gallate (EGCG) and caffeine in 29 commercial green tea samples available in a Saudi Arabian local market. A C-18 reversed-phase column, acetonitrile-trifluoroacetic acid as a mobile phase, coupled with UV detector at 205 nm, was successfully used for precise analysis of the tested analytes in boiled water of digested tea leaves. The average values of N (No. of theoretical plates), HETP (height equivalent of theoretical plates) and R(s) (separation factor) (at 10 μg ml(-1) of the catechins EC, EGC, EGCG and ECG) were 2.6×10(3)±1.2×10(3), 1.7×10(-3)±4.7×10(-4) cm and 1.7±5.53×10(-2), respectively. The developed HPLC method demonstrated excellent performance, with low limits of detection (LOD) and quantification (LOQ) of the tested catechins of 0.004-0.05 μg ml(-1) and 0.01-0.17 μg ml(-1), respectively, and recovery percentages of 96-101%. The influence of infusion time (5-30 min) and temperature on the content of the flavanols was investigated by HPLC. After a 5 min infusion of the tea leaves, the average concentrations of caffeine, catechin, EC, EGC, ECG and EGCG were found to be in the ranges 0.086-2.23, 0.113-2.94, 0.58-10.22, 0.19-24.9, 0.22-13.9 and 1.01-43.3 mg g(-1), respectively. The contents of caffeine and catechins followed the sequence: EGCG>EGC>ECG>EC>C>caffeine. The method was applied satisfactorily for the analysis of (+)-catechin, even at trace and ultra trace concentrations of catechins. The method was rapid, accurate, reproducible and ideal for routine analysis. PMID:23442685

  6. The Analysis of Social Teachers' Performance in the Senior High Schools of Ciamis Regency

    ERIC Educational Resources Information Center

    Mulyadi, Endang; Yuniarsih, Tjutju; Disman; Supardan, Dadang

    2016-01-01

    This research is intended to analyze the principal's leadership, school cultures, teachers' welfare, achievement motivation and the competence of social teachers at Senior High Schools in Ciamis regency and their effects towards the teachers' performance. Population of this research are Social teachers at Senior High Schools in Ciamis regency,…

  7. High Performance Parallel Architectures

    NASA Technical Reports Server (NTRS)

    El-Ghazawi, Tarek; Kaewpijit, Sinthop

    1998-01-01

    Traditional remote sensing instruments are multispectral, where observations are collected at a few different spectral bands. Recently, many hyperspectral instruments, that can collect observations at hundreds of bands, have been operational. Furthermore, there have been ongoing research efforts on ultraspectral instruments that can produce observations at thousands of spectral bands. While these remote sensing technology developments hold great promise for new findings in the area of Earth and space science, they present many challenges. These include the need for faster processing of such increased data volumes, and methods for data reduction. Dimension Reduction is a spectral transformation, aimed at concentrating the vital information and discarding redundant data. One such transformation, which is widely used in remote sensing, is the Principal Components Analysis (PCA). This report summarizes our progress on the development of a parallel PCA and its implementation on two Beowulf cluster configuration; one with fast Ethernet switch and the other with a Myrinet interconnection. Details of the implementation and performance results, for typical sets of multispectral and hyperspectral NASA remote sensing data, are presented and analyzed based on the algorithm requirements and the underlying machine configuration. It will be shown that the PCA application is quite challenging and hard to scale on Ethernet-based clusters. However, the measurements also show that a high- performance interconnection network, such as Myrinet, better matches the high communication demand of PCA and can lead to a more efficient PCA execution.

  8. High-Performance Mixed Models Based Genome-Wide Association Analysis with omicABEL software.

    PubMed

    Fabregat-Traver, Diego; Sharapov, Sodbo Zh; Hayward, Caroline; Rudan, Igor; Campbell, Harry; Aulchenko, Yurii; Bientinesi, Paolo

    2014-01-01

    To raise the power of genome-wide association studies (GWAS) and avoid false-positive results in structured populations, one can rely on mixed model based tests. When large samples are used, and when multiple traits are to be studied in the 'omics' context, this approach becomes computationally challenging. Here we consider the problem of mixed-model based GWAS for arbitrary number of traits, and demonstrate that for the analysis of single-trait and multiple-trait scenarios different computational algorithms are optimal. We implement these optimal algorithms in a high-performance computing framework that uses state-of-the-art linear algebra kernels, incorporates optimizations, and avoids redundant computations, increasing throughput while reducing memory usage and energy consumption. We show that, compared to existing libraries, our algorithms and software achieve considerable speed-ups. The OmicABEL software described in this manuscript is available under the GNU GPL v. 3 license as part of the GenABEL project for statistical genomics at http: //www.genabel.org/packages/OmicABEL. PMID:25717363

  9. High-Performance Mixed Models Based Genome-Wide Association Analysis with omicABEL software

    PubMed Central

    Fabregat-Traver, Diego; Sharapov, Sodbo Zh.; Hayward, Caroline; Rudan, Igor; Campbell, Harry; Aulchenko, Yurii; Bientinesi, Paolo

    2014-01-01

    To raise the power of genome-wide association studies (GWAS) and avoid false-positive results in structured populations, one can rely on mixed model based tests. When large samples are used, and when multiple traits are to be studied in the ’omics’ context, this approach becomes computationally challenging. Here we consider the problem of mixed-model based GWAS for arbitrary number of traits, and demonstrate that for the analysis of single-trait and multiple-trait scenarios different computational algorithms are optimal. We implement these optimal algorithms in a high-performance computing framework that uses state-of-the-art linear algebra kernels, incorporates optimizations, and avoids redundant computations, increasing throughput while reducing memory usage and energy consumption. We show that, compared to existing libraries, our algorithms and software achieve considerable speed-ups. The OmicABEL software described in this manuscript is available under the GNU GPL v. 3 license as part of the GenABEL project for statistical genomics at http: //www.genabel.org/packages/OmicABEL. PMID:25717363

  10. A validated method for analysis of Swerchirin in Swertia longifolia Boiss. by high performance liquid chromatography

    PubMed Central

    Shekarchi, M.; Hajimehdipoor, H.; Khanavi, M.; Adib, N.; Bozorgi, M.; Akbari-Adergani, B.

    2010-01-01

    Swertia spp. (Gentianaceae) grow widely in the eastern and southern Asian countries and are used as traditional medicine for gastrointestinal disorders. Swerchirin, one of the xanthones in Swertia spp., has many pharmacological properties, such as, antimalarial, antihepatotoxic, and hypoglycemic effects. Because of the pharmacological importance of Swerchirin in this investigation, it was purified from Swertia longifolia Boiss. as one of the main components and quantified by means of a validated high performance liquid chromatography (HPLC) technique. Aerial parts of the plant were extracted with acetone 80%. Phenolic and non-phenolic constituents of the extract were separated from each other during several processes. The phenolic fraction was injected into the semi-preparative HPLC system, which consisted of a C18 column and a gradient methanol: 0.1% formic acid mode. Using this method, we were able to purify six xanthones from the plant, in order to use them as standard materials. The analytical method was validated for Swerchirin as one of the most important components of the plant, with more pharmacological activities according to the validation parameters, such as, selectivity, linearity (r2 > 0.9998), precision (≤3.3), and accuracy, which were measured by the determination of recovery (98-107%). The limits of detection and quantization were found to be 2.1 and 6.3 μg/mL, respectively. On account of the speed and accuracy, the UV-HPLC method may be used for quantitative analysis of Swerchirin. PMID:20548931

  11. PetIGA: A framework for high-performance isogeometric analysis

    DOE PAGES

    Dalcin, Lisandro; Collier, Nathaniel; Vignal, Philippe; Cortes, Adriano M. A.; Calo, Victor M.

    2016-05-25

    We present PetIGA, a code framework to approximate the solution of partial differential equations using isogeometric analysis. PetIGA can be used to assemble matrices and vectors which come from a Galerkin weak form, discretized with Non-Uniform Rational B-spline basis functions. We base our framework on PETSc, a high-performance library for the scalable solution of partial differential equations, which simplifies the development of large-scale scientific codes, provides a rich environment for prototyping, and separates parallelism from algorithm choice. We describe the implementation of PetIGA, and exemplify its use by solving a model nonlinear problem. To illustrate the robustness and flexibility ofmore » PetIGA, we solve some challenging nonlinear partial differential equations that include problems in both solid and fluid mechanics. Lastly, we show strong scaling results on up to 4096 cores, which confirm the suitability of PetIGA for large scale simulations.« less

  12. Analysis of Fluconazole in Human Urine Sample by High Performance Liquid Chromatography Method

    NASA Astrophysics Data System (ADS)

    Hermawan, D.; Ali, N. A. Md; Ibrahim, W. A. Wan; Sanagi, M. M.

    2013-04-01

    A method for determination of fluconazole, antifungal drug in human urine by using reversed-phased high performance liquid chromatography (RP-HPLC) with ultraviolet (UV) detector was developed. Optimization HPLC conditions were carried out by changing the flow rate and composition of mobile phase. The optimum separation conditions at a flow rate 0.85 mL/min with a composition of mobile phase containing methanol:water (70:30, v/v) with UV detection at a wavelength 254 nm was able to analyze fluconazole within 3 min. The excellent linearity was obtained in the range of concentration 1 to 10 μg/mL with r2 = 0.998. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.39 μg/mL and 1.28 μg/mL, respectively. Solid phase extraction (SPE) method using octadecylsilane (C18) as a sorbent was used to clean-up and pre-concentrated of the urine sample prior to HPLC analysis. The average recoveries of fluconazole in spiked urine sample was 72.4% with RSD of 3.21% (n=3).

  13. DETECTION OF HETEROGENEOUS DRUG-PROTEIN BINDING BY FRONTAL ANALYSIS AND HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY

    PubMed Central

    Tong, Zenghan; Joseph, K.S.; Hage, David S.

    2011-01-01

    This study examined the use of frontal analysis and high-performance affinity chromatography for detecting heterogeneous binding in biomolecular interactions, using the binding of acetohexamide with human serum albumin (HSA) as a model. It was found through the use of this model system and chromatographic theory that double-reciprocal plots could be used more easily than traditional isotherms for the initial detection of binding site heterogeneity. The deviations from linearity that were seen in double-reciprocal plots as a result of heterogeneity were a function of the analyte concentration, the relative affinities of the binding sites in the system and the amount of each type of site that was present. The size of these deviations was determined and compared under various conditions. Plots were also generated to show what experimental conditions would be needed to observe these deviations for general heterogeneous systems or for cases in which some preliminary information was available on the extent of binding heterogeneity. The methods developed in this work for the detection of binding heterogeneity are not limited to drug interactions with HSA but could be applied to other types of drug-protein binding or to additional biological systems with heterogeneous binding. PMID:21612784

  14. High Performance for Labeling, Separation and Detection Methods for Genome Analysis 12

    SciTech Connect

    Richard A. Mathies

    2003-11-24

    OAK-B135 Our research efforts over the past year have focused on the development of advanced integrated PCR reactors on chips, the development of robust integrated valves, the development of integrated optical detectors, and the development of microdevices for performing integrated genetic analysis. The details of all the projects will be found in the listed papers.

  15. College Performance and Retention: A Meta-Analysis of the Predictive Validities of ACT® Scores, High School Grades, and SES

    ERIC Educational Resources Information Center

    Westrick, Paul A.; Le, Huy; Robbins, Steven B.; Radunzel, Justine M. R.; Schmidt, Frank L.

    2015-01-01

    This meta-analysis examines the strength of the relationships of ACT® Composite scores, high school grades, and socioeconomic status (SES) with academic performance and persistence into the 2nd and 3rd years at 4-year colleges and universities. Based upon a sample of 189,612 students at 50 institutions, ACT Composite scores and high school grade…

  16. High Performance Data Clustering: A Comparative Analysis of Performance for GPU, RASC, MPI, and OpenMP Implementations.

    PubMed

    Yang, Luobin; Chiu, Steve C; Liao, Wei-Keng; Thomas, Michael A

    2014-10-01

    Compared to Beowulf clusters and shared-memory machines, GPU and FPGA are emerging alternative architectures that provide massive parallelism and great computational capabilities. These architectures can be utilized to run compute-intensive algorithms to analyze ever-enlarging datasets and provide scalability. In this paper, we present four implementations of K-means data clustering algorithm for different high performance computing platforms. These four implementations include a CUDA implementation for GPUs, a Mitrion C implementation for FPGAs, an MPI implementation for Beowulf compute clusters, and an OpenMP implementation for shared-memory machines. The comparative analyses of the cost of each platform, difficulty level of programming for each platform, and the performance of each implementation are presented.

  17. High Performance Data Clustering: A Comparative Analysis of Performance for GPU, RASC, MPI, and OpenMP Implementations*

    PubMed Central

    Yang, Luobin; Chiu, Steve C.; Liao, Wei-Keng; Thomas, Michael A.

    2013-01-01

    Compared to Beowulf clusters and shared-memory machines, GPU and FPGA are emerging alternative architectures that provide massive parallelism and great computational capabilities. These architectures can be utilized to run compute-intensive algorithms to analyze ever-enlarging datasets and provide scalability. In this paper, we present four implementations of K-means data clustering algorithm for different high performance computing platforms. These four implementations include a CUDA implementation for GPUs, a Mitrion C implementation for FPGAs, an MPI implementation for Beowulf compute clusters, and an OpenMP implementation for shared-memory machines. The comparative analyses of the cost of each platform, difficulty level of programming for each platform, and the performance of each implementation are presented. PMID:25309040

  18. High performance systems

    SciTech Connect

    Vigil, M.B.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  19. The NCI High Performance Computing (HPC) and High Performance Data (HPD) Platform to Support the Analysis of Petascale Environmental Data Collections

    NASA Astrophysics Data System (ADS)

    Evans, B. J. K.; Pugh, T.; Wyborn, L. A.; Porter, D.; Allen, C.; Smillie, J.; Antony, J.; Trenham, C.; Evans, B. J.; Beckett, D.; Erwin, T.; King, E.; Hodge, J.; Woodcock, R.; Fraser, R.; Lescinsky, D. T.

    2014-12-01

    The National Computational Infrastructure (NCI) has co-located a priority set of national data assets within a HPC research platform. This powerful in-situ computational platform has been created to help serve and analyse the massive amounts of data across the spectrum of environmental collections - in particular the climate, observational data and geoscientific domains. This paper examines the infrastructure, innovation and opportunity for this significant research platform. NCI currently manages nationally significant data collections (10+ PB) categorised as 1) earth system sciences, climate and weather model data assets and products, 2) earth and marine observations and products, 3) geosciences, 4) terrestrial ecosystem, 5) water management and hydrology, and 6) astronomy, social science and biosciences. The data is largely sourced from the NCI partners (who include the custodians of many of the national scientific records), major research communities, and collaborating overseas organisations. By co-locating these large valuable data assets, new opportunities have arisen by harmonising the data collections, making a powerful transdisciplinary research platformThe data is accessible within an integrated HPC-HPD environment - a 1.2 PFlop supercomputer (Raijin), a HPC class 3000 core OpenStack cloud system and several highly connected large scale and high-bandwidth Lustre filesystems. New scientific software, cloud-scale techniques, server-side visualisation and data services have been harnessed and integrated into the platform, so that analysis is performed seamlessly across the traditional boundaries of the underlying data domains. Characterisation of the techniques along with performance profiling ensures scalability of each software component, all of which can either be enhanced or replaced through future improvements. A Development-to-Operations (DevOps) framework has also been implemented to manage the scale of the software complexity alone. This ensures that

  20. High Performance Computing for probabilistic distributed slope stability analysis, an early example

    NASA Astrophysics Data System (ADS)

    Rossi, Guglielmo; Catani, Filippo

    2010-05-01

    The term shallow landslides is widely used in literature to describe a slope movement of limited size that mainly develops in soils up to a maximum of a few meters thick. Shallow landslides are usually triggered by heavy rainfall because, as the water starts to infiltrate into the soil, the pore-water pressure increases so that the shear strength of the soil is reduced leading to slope failure. We have developed a distributed hydrological-geotechnical model for forecasting the temporal and spatial distribution of shallow landslides to be used as a real time warning system for civil protection purposes. The stability simulator is developed to use High Performance Computing (HPC) resources and in this way can manage large areas, with high spatial and temporal resolution, at useful computational time for a warning system . The output of the model is a probabilistic value of slope instability. In its current stage the model applied for predicting the expected location of shallow landslides involves several stand-alone components. The base solution suggested by Iverson for the Richards equation is adapted to be used in a real time simulator to estimate the probabilistic distribution of the transient groundwater pressure head according to radar detected rainfall intensity. The use of radar detected rainfall intensity as the input for the hydrological simulation of the infiltration allows a more accurate computation of the redistribution of the groundwater pressure associated with transient infiltration of rain. A soil depth prediction scheme and a limit-equilibrium infinite slope stability algorithm are used to calculate the distributed factor of safety (FS) at different depths and to record the probability distribution of slope instability in the final output file. The additional ancillary data required have been collected during fieldwork and with laboratory standard tests. The model deals with both saturated and unsaturated conditions taking into account the effect of

  1. High Performance Liquid Chromatographic Analysis of Phytoplankton Pigments Using a C16-Amide Column

    EPA Science Inventory

    A reverse-phase high performance liquid chromatographic (RP-HPLC) method was developed to analyze in a single run, most polar and non-polar chlorophylls and carotenoids from marine phytoplankton. The method is based on a RP-C16-Amide column and a ternary gradient system consistin...

  2. Factors Affecting University Entrants' Performance in High-Stakes Tests: A Multiple Regression Analysis

    ERIC Educational Resources Information Center

    Uy, Chin; Manalo, Ronaldo A.; Cabauatan, Ronaldo R.

    2015-01-01

    In the Philippines, students seeking admission to a university are usually required to meet certain entrance requirements, including passing the entrance examinations with questions on IQ and English, mathematics, and science. This paper aims to determine the factors that affect the performance of entrants into business programmes in high-stakes…

  3. Ion-pair high-performance liquid chromatographic analysis of aspartame and related products.

    PubMed

    Verzella, G; Bagnasco, G; Mangia, A

    1985-12-01

    A simple and accurate quantitative determination of aspartame (L-alpha-aspartyl-L-phenylalanine methyl ester), a new artificial sweetener, is described. The method, which is based on ion-pair high-performance liquid chromatography, allows the determination of aspartame in finished bulk and dosage forms, and the detection of a few related products at levels down to 0.1%.

  4. Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration Data

    SciTech Connect

    Rubel, Oliver; Prabhat, Mr.; Wu, Kesheng; Childs, Hank; Meredith, Jeremy; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Ahern, Sean; Weber, Gunther H.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

    2008-08-28

    Our work combines and extends techniques from high-performance scientific data management and visualization to enable scientific researchers to gain insight from extremely large, complex, time-varying laser wakefield particle accelerator simulation data. We extend histogram-based parallel coordinates for use in visual information display as well as an interface for guiding and performing data mining operations, which are based upon multi-dimensional and temporal thresholding and data subsetting operations. To achieve very high performance on parallel computing platforms, we leverage FastBit, a state-of-the-art index/query technology, to accelerate data mining and multi-dimensional histogram computation. We show how these techniques are used in practice by scientific researchers to identify, visualize and analyze a particle beam in a large, time-varying dataset.

  5. Ultra-high performance, solid-state, autoradiographic image digitization and analysis system.

    PubMed

    Lear, J L; Pratt, J P; Ackermann, R F; Plotnick, J; Rumley, S

    1990-06-01

    We developed a Macintosh II-based, charge-coupled device (CCD), image digitization and analysis system for high-speed, high-resolution quantification of autoradiographic image data. A linear CCD array with 3,500 elements was attached to a precision drive assembly and mounted behind a high-uniformity lens. The drive assembly was used to sweep the array perpendicularly to its axis so that an entire 20 x 25-cm autoradiographic image-containing film could be digitized into 256 gray levels at 50-microns resolution in less than 30 sec. The scanner was interfaced to a Macintosh II computer through a specially constructed NuBus circuit board and software was developed for autoradiographic data analysis. The system was evaluated by scanning individual films multiple times, then measuring the variability of the digital data between the different scans. Image data were found to be virtually noise free. The coefficient of variation averaged less than 1%, a value significantly exceeding the accuracy of both high-speed, low-resolution, video camera (VC) systems and low-speed, high-resolution, rotating drum densitometers (RDD). Thus, the CCD scanner-Macintosh computer analysis system offers the advantage over VC systems of the ability to digitize entire films containing many autoradiograms, but with much greater speed and accuracy than achievable with RDD scanners. PMID:2385214

  6. High Performance Polymers

    NASA Technical Reports Server (NTRS)

    Venumbaka, Sreenivasulu R.; Cassidy, Patrick E.

    2003-01-01

    This report summarizes results from research on high performance polymers. The research areas proposed in this report include: 1) Effort to improve the synthesis and to understand and replicate the dielectric behavior of 6HC17-PEK; 2) Continue preparation and evaluation of flexible, low dielectric silicon- and fluorine- containing polymers with improved toughness; and 3) Synthesis and characterization of high performance polymers containing the spirodilactam moiety.

  7. Solar Total Energy Project (STEP) Performance Analysis of High Temperature Energy Storage Subsystem

    NASA Technical Reports Server (NTRS)

    Moore, D. M.

    1984-01-01

    The 1982 milestones and lessons learned; performance in 1983; a typical day's operation; collector field performance and thermal losses; and formal testing are highlighted. An initial test that involves characterizing the high temperature storage (hts) subsystem is emphasized. The primary element is on 11,000 gallon storage tank that provides energy to the steam generator during transient solar conditions or extends operating time. Overnight, thermal losses were analyzed. The length of time the system is operated at various levels of cogeneration using stored energy is reviewed.

  8. Comparative analysis of steroidal saponins in four Dioscoreae herbs by high performance liquid chromatography coupled with mass spectrometry.

    PubMed

    Guo, Long; Zeng, Su-Ling; Zhang, Yu; Li, Ping; Liu, E-Hu

    2016-01-01

    Steroidal saponins, which exhibit multiple pharmacological effects, are the major bioactive constituents in herbal medicines from Dioscoreae species. In this study, a sensitive method based on high performance liquid chromatography-mass spectrometry (HPLC-MS) was established and validated for qualitative and quantitative analysis of steroidal saponins in four Dioscoreae herbs including Dioscoreae Nipponica Rhizome (DNR) and Dioscoreae Hypoglaucae Rhizome (DHR), Dioscoreae Spongiosae Rhizome (DSR) and Dioscoreae Rhizome (DR). A total of eleven steroidal saponins were identified by high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF/MS). Furthermore, seven major steroidal saponins was simultaneous quantified using a high performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-QQQ/MS). The qualitative and quantitative analysis results indicated that the chemical composition of DNR, DHR and DSR samples exhibited a high level of global similarity, while the ingredients in DR varied greatly from the other three herbs. Moreover, principal component analysis (PCA) and hierarchical clustering analysis (HCA) were performed to compare and discriminate the Dioscoreae herbs based on the quantitative data. The results demonstrated the qualitative and quantitative analysis of steroidal saponins based on HPLC-MS is a feasible method for quality control of Dioscoreae herbs.

  9. High performance dash on warning air mobile, missile system. [intercontinental ballistic missiles - systems analysis

    NASA Technical Reports Server (NTRS)

    Levin, A. D.; Castellano, C. R.; Hague, D. S.

    1975-01-01

    An aircraft-missile system which performs a high acceleration takeoff followed by a supersonic dash to a 'safe' distance from the launch site is presented. Topics considered are: (1) technological feasibility to the dash on warning concept; (2) aircraft and boost trajectory requirements; and (3) partial cost estimates for a fleet of aircraft which provide 200 missiles on airborne alert. Various aircraft boost propulsion systems were studied such as an unstaged cryogenic rocket, an unstaged storable liquid, and a solid rocket staged system. Various wing planforms were also studied. Vehicle gross weights are given. The results indicate that the dash on warning concept will meet expected performance criteria, and can be implemented using existing technology, such as all-aluminum aircraft and existing high-bypass-ratio turbofan engines.

  10. Modeling and analysis of high-performance, multicolored anti-reflection coatings for solar cells.

    PubMed

    Lumb, Matthew P; Yoon, Woojun; Bailey, Christopher G; Scheiman, David; Tischler, Joseph G; Walters, Robert J

    2013-07-01

    In this work solar cell anti-reflection coatings tuned to give a specific hue under solar illumination are investigated. We demonstrate that it is possible to form patterned coatings with large color contrast and high transmittance. We use colorimetric and thin film optics models to explore the relationship between the color and performance of bilayer anti-reflection coatings on Si, and predict the photocurrent generation from an example Si solar cell. The colorimetric predictions were verified by measuring a series of coatings deposited on Si substrates. Finally, a patterned Si sample was produced using a simple, low-cost photolithography procedure to selectively etch only the top layer of a bilayer coating to demonstrate a high-performance anti-reflection coating with strong color contrast.

  11. High-performance liquid chromatography analysis of plant saponins: An update 2005-2010

    PubMed Central

    Negi, Jagmohan S.; Singh, Pramod; Pant, Geeta Joshi Nee; Rawat, M. S. M.

    2011-01-01

    Saponins are widely distributed in plant kingdom. In view of their wide range of biological activities and occurrence as complex mixtures, saponins have been purified and separated by high-performance liquid chromatography using reverse-phase columns at lower wavelength. Mostly, saponins are not detected by ultraviolet detector due to lack of chromophores. Electrospray ionization mass spectrometry, diode array detector , evaporative light scattering detection, and charged aerosols have been used for overcoming the detection problem of saponins. PMID:22303089

  12. Stability-indicating sulfa drug analysis using high-performance liquid chromatography.

    PubMed

    Umagat, H; McGarry, P F; Tscherne, R J

    1979-07-01

    Sensitive and efficient methods for sulfonamide determination as single entities and in combination with other drug substances in pharmaceutical dosage formulations were developed using high-performance liquid chromatography. These stability-indicating procedures involved a nitrile bonded phase column and nonaqueous mobile phases having diverse polarities. Sample potency was determined using peak height measurements. The methods may be used to determine trace sulfonamide quantities because detection limits are in the nanogram range.

  13. Analysis of high performance conjugate heat transfer with the OpenPALM coupler

    NASA Astrophysics Data System (ADS)

    Duchaine, Florent; Jauré, Stéphan; Poitou, Damien; Quémerais, Eric; Staffelbach, Gabriel; Morel, Thierry; Gicquel, Laurent

    2015-01-01

    In many communities such as climate science or industrial design, to solve complex coupled problems with high fidelity external coupling of legacy solvers puts a lot of pressure on the tool used for the coupling. The precision of such predictions not only largely depends on simulation resolutions and the use of huge meshes but also on high performance computing to reduce restitution times. In this context, the current work aims at studying the scalability of code coupling on high performance computing architectures for a conjugate heat transfer problem. The flow solver is a Large Eddy Simulation code that has been already ported on massively parallel architectures. The conduction solver is based on the same data structure and thus shares the flow solver scalability properties. Accurately coupling solvers on massively parallel architectures while maintaining their scalability is challenging. It requires exchanging and treating information based on two different computational grids that are partitioned differently on a different number of cores. Such transfers have to be thought to maintain code scalabilities while maintaining numerical accuracy. This raises communication and high performance computing issues: transferring data from a distributed interface to another distributed interface in a parallel way and on a very large number of processors is not straightforward and solutions are not clear. Performance tests have been carried out up to 12 288 cores on the CURIE supercomputer (TGCC/CEA). Results show a good behavior of the coupled model when increasing the number of cores thanks to the fully distributed exchange process implemented in the coupler. Advanced analyses are carried out to draw new paths for future developments for coupled simulations: i.e. optimization of the data transfer protocols through asynchronous communications or coupling-aware preprocessing of the coupled models (mesh partitioning phase).

  14. Simultaneous Analysis and Quantification of Markers of Manjisthadi Churna Using High Performance Thin Layer Chromatography

    PubMed Central

    Patel, V. R.; Patel, R. K.

    2013-01-01

    Manjisthadi churna has been traditionally used in the Ayurvedic system of medicine and by traditional medical practices of India to treat hyperlipidemia. A rapid, simple and accurate method with high performance thin layer chromatography has been developed to standardised Manjisthadi churna using rubiadin, sennoside and ellagic acid as markers. Methanol extract of Manjisthadi churna were used for high performance thin layer chromatography on silica gel plates. The Rf of rubiadin, sennoside-A and ellagic acid were found to 0.48, 0.23 and 0.72, respectively with densitometric scanning at 280 nm and the calibration plot were linear in the range of 100-600 ng of markers. The correlation coefficients were higher than 0.99 were indicative of good linear dependence of peaks area on concentration. The rubiadin, sennoside-A and ellagic acid contents in Manjisthadi churna were found to be 0.014, 0.038 and 0.534% w/w, respectively. This method permits reliable quantification of rubiadin, sennoside-A and ellagic acid with good resolution and separation of the same from other constitutes of the extract of Manjisthadi churna. Recovery value from 95.66-102.33% showed the reliability and reproducibility of the method. The proposed high performance thin layer chromatography method for simultaneous quantification of markers in Manjisthadi churna can be used for routine quality testing. PMID:23901170

  15. High-Throughput and Comprehensive Lipidomic Analysis Using Ultrahigh-Performance Supercritical Fluid Chromatography-Mass Spectrometry.

    PubMed

    Lísa, Miroslav; Holčapek, Michal

    2015-07-21

    New analytical approach for high-throughput and comprehensive lipidomic analysis of biological samples using ultrahigh-performance supercritical fluid chromatography (UHPSFC) with electrospray ionization-mass spectrometry (ESI-MS) is presented in this work as an alternative approach to established shotgun MS or high-performance liquid chromatography-MS. The lipid class separation is performed by UHPSFC method based on 1.7 μm particle-bridged ethylene hybrid silica column with a gradient of methanol-water-ammonium acetate mixture as a modifier. All parameters of UHPSFC conditions are carefully optimized and their influence on the chromatographic behavior of lipids is discussed. The final UHPSFC/ESI-MS method enables a fast separation of 30 nonpolar and polar lipid classes within 6 min analysis covering 6 main lipid categories including fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, and prenols. Individual lipid species within lipid classes are identified based on positive and negative-ion full-scan and tandem mass spectra measured with high mass accuracy and high resolving power. Developed UHPSFC/ESI-MS method is applied for the analysis of porcine brain extract as a complex lipidomic sample, where 24 lipid classes containing 436 lipid species are identified. The method is validated for the quantitative analysis of lipid species in biological tissues using internal standards for each lipid class. This high-throughput, comprehensive and accurate UHPSFC/ESI-MS method is suitable for the lipidomic analysis of large sample sets in the clinical research. PMID:26095628

  16. High Performance Network Monitoring

    SciTech Connect

    Martinez, Jesse E

    2012-08-10

    Network Monitoring requires a substantial use of data and error analysis to overcome issues with clusters. Zenoss and Splunk help to monitor system log messages that are reporting issues about the clusters to monitoring services. Infiniband infrastructure on a number of clusters upgraded to ibmon2. ibmon2 requires different filters to report errors to system administrators. Focus for this summer is to: (1) Implement ibmon2 filters on monitoring boxes to report system errors to system administrators using Zenoss and Splunk; (2) Modify and improve scripts for monitoring and administrative usage; (3) Learn more about networks including services and maintenance for high performance computing systems; and (4) Gain a life experience working with professionals under real world situations. Filters were created to account for clusters running ibmon2 v1.0.0-1 10 Filters currently implemented for ibmon2 using Python. Filters look for threshold of port counters. Over certain counts, filters report errors to on-call system administrators and modifies grid to show local host with issue.

  17. Optimal design analysis for thermal performance of high power 2.5D package

    NASA Astrophysics Data System (ADS)

    Xiaoyang, Liu; He, Ma; Daquan, Yu; Wenlu, Chen; Xiaolong, Wu

    2016-03-01

    Based on ANSYS and Icepak softwares, the numerical analysis method is used to build up the thermal analysis model of the 2.5D package, which contains a high power CPU chip. The focus of the research is on the determination of the contributing factors and their effects on the thermal resistance and heat distribution of the package. The parametric analysis illustrates that the substrate conductivity, TIM conductivity and fin height are more crucial for heat conduction in the package. Furthermore, these major parameters are compared and analyzed by orthogonal tests, and the optimal solution for 2.5D integration is proposed. The factors' influence patterns on thermal resistance, obtained in this article, could be utilized as a thermal design reference. Project supported by the National S & T Major Projects (No. 2011ZX02709-2) and the China National Science Foundation (No. 61176098).

  18. High performance N204/amine elements: Blowapart. [test, and analysis of single element injectors

    NASA Technical Reports Server (NTRS)

    Lawver, B. R.

    1974-01-01

    The work is reported which was conducted to define the mechanisms governing blowapart of hypergolic propellant through the design, fabrication, test, and analysis of single element injectors. Data were developed that show the parameters exhibiting a controlling influence over blowapart are the chamber pressure, orifice diameter, and propellant temperature. Mixing, popping (cyclic blowapart), low pressure separation, and high pressure separation were identified as modes of reactive impingement.

  19. High performance single step co-fired solid oxide fuel cells (SOFC): Polarization measurements and analysis

    NASA Astrophysics Data System (ADS)

    Yoon, Kyung Joong

    At present, one of the major obstacles for the commercialization of solid oxide fuel cell (SOFC) power systems is their high manufacturing costs expressed in terms of SOFC system cost per unit power ($/kW). In this work, anode-supported planar SOFCs were fabricated by a cost-competitive single step co-firing process. The cells were comprised of a porous Ni + yittria-stabilized zirconia (YSZ) anode support, a porous-fine-grained Ni + YSZ anode active layer for some experiments, a dense YSZ electrolyte, a porous-fine-grained Ca-doped LaMnO3 (LCM) + YSZ cathode active layer, and a porous LCM cathode current collector layer. The fabrication process involved tape casting or high shear compaction (HSC) of the anode support followed by screen printing of the remaining component layers. The cells were then co-fired at 1300˜1340°C for 2 hours. The performance of the cell fabricated with the tape casting anode was improved by minimizing various polarization losses through experimental and theoretical modeling approaches, and the maximum power density of 1.5 W/cm 2 was obtained at 800°C with humidified hydrogen (3% H2O) and air. The cells were also tested with various compositions of humidified hydrogen (3˜70% H2O) to simulate the effect of practical fuel utilization on the cell performance. Based on these measurements, an analytical model describing anodic reactions was developed to understand reaction kinetics and rate limiting steps. The cell performance at high fuel utilization was significantly improved by increasing the number of the reaction sites near the anode-electrolyte interface. For anode substrate fabrication, the HSC process offers many advantages such as low fabrication costs, high production throughput, and good control of shrinkage and thickness over the conventional tape casting process. HSC process was successfully employed in single step co-firing process, and SOFCs fabricated with HSC anodes showed adequate performance both at low and high fuel

  20. Discrimination of Semen cassiae from two related species based on the multivariate analysis of high-performance liquid chromatography fingerprints.

    PubMed

    Tang, Liying; Wu, Hongwei; Zhou, Xidan; Xu, Yilong; Zhou, Guohong; Wang, Ting; Kou, Zhenzhen; Wang, Zhuju

    2015-07-01

    A simple and efficient high-performance liquid chromatography fingerprint method was developed to discriminate Semen cassiae from two related species: Cassia obtusifolia L. (CO) and Cassia tora L. (CT), the seeds of which are abbreviated as COS and CTS, respectively. 22 major bioactive ingredients in 42 samples (20 COS and 22 CTS) collected from different provinces of China were identified. The statistical methods included similarity analysis and partial least-squares discriminant analysis. The pattern analysis method was specific and could be readily used for the comprehensive evaluation of Semen cassiae samples. Therefore, high-performance liquid chromatography fingerprint in combination with pattern analysis provided a simple and reliable method for discriminating between COS and CTS.

  1. RAPID ANALYSIS OF CYNANURIC ACID IN SWIMMING POOL WATERS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY USING POROUS GRAPHITIC CARBON COLUMN

    EPA Science Inventory

    An innovative approach is presented for reducing analysis times of cyanuric acid in swimming pool waters by high performance liquid chromatography (HPLC). The HPLC method exploits the unique selectivity of porous graphitic carbon (PGC) to fully resolve cyanuric acid from other p...

  2. RAPID ANALYSIS OF CYANURIC ACID IN SWIMMING POOL WATERS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY USING POROUS GRAPHITIC CARBON

    EPA Science Inventory

    An innovative approach is presented for reducing analysis times of cynuric acid in swimming pool waters by high performance liquid chromatography (HPLC). The HPLC method exploits the unique selectivity of porous graphitic carbon (PGC) to fully resolve within 10 minutes cyanuric ...

  3. Purification of dinosterol for hydrogen isotopic analysis using high-performance liquid chromatography-mass spectrometry.

    PubMed

    Smittenberg, Rienk H; Sachs, Julian P

    2007-10-26

    A semi-preparative normal-phase high-performance liquid chromatography-mass spectrometry (HPLC-MS) method is presented for the purification of various alcohol fractions from total lipid extracts derived from sediments, for the purpose of hydrogen isotopic measurement by gas chromatography-isotope ratio mass spectrometry (GC-IRMS). 4-methylsterols, including the dinoflagellate-specific marker dinosterol (4,23,24-trimethylcholestan-22-en-3beta-ol), were successfully separated from notoriously co-eluting plant-derived pentacyclic triterpenoid alcohols and alkyl alcohols. We find that substantial hydrogen isotope fractionation occurs during chromatographic separation, demonstrating the importance of recovering the entire peak when subsequent hydrogen isotope analyses are to be performed. This is the first report of such hydrogen isotopic fractionation for a natural unlabelled compound.

  4. MIR Performance Analysis

    SciTech Connect

    Hazen, Damian; Hick, Jason

    2012-06-12

    We provide analysis of Oracle StorageTek T10000 Generation B (T10KB) Media Information Record (MIR) Performance Data gathered over the course of a year from our production High Performance Storage System (HPSS). The analysis shows information in the MIR may be used to improve tape subsystem operations. Most notably, we found the MIR information to be helpful in determining whether the drive or tape was most suspect given a read or write error, and for helping identify which tapes should not be reused given their history of read or write errors. We also explored using the MIR Assisted Search to order file retrieval requests. We found that MIR Assisted Search may be used to reduce the time needed to retrieve collections of files from a tape volume.

  5. A rapid and sensitive high performance liquid chromatographic analysis of clofazimine in plasma.

    PubMed

    Krishnan, T R; Abraham, I

    1992-12-01

    The high performance liquid chromatographic (HPLC) method of Gidoh, et al. has been modified substantially to provide a simple, rapid, and relatively inexpensive procedure for measuring clofazimine in plasma. The modification involves the use of commonly available laboratory reagents instead of custom-made ones. It also employs a solid phase system for efficient extraction instead of the conventional, less efficient and more labor intensive, liquid-liquid extraction. The inclusion of an internal standard (salicylic acid) improves the precision and reproducibility. It is demonstrated that the method can be used to monitor in vivo clofazimine levels as may be required in formal pharmacokinetic studies or therapeutic drug monitoring. PMID:1299710

  6. Phytochemical analysis of Hibiscus caesius using high performance liquid chromatography coupled with mass spectrometry.

    PubMed

    Ain, Quratul; Naveed, Muhammad Na; Mumtaz, Abdul Samad; Farman, Muhammad; Ahmed, Iftikhar; Khalid, Nauman

    2015-09-01

    Various species in genus Hibiscus are traditionally known for their therapeutic attributes. The present study focused on the phytochemical analysis of a rather unexplored species Hibiscus caesius (H. caesius), using high-pressure liquid chromatography coupled with mass spectrometry (HPLC-MS). The analysis revealed five major compounds in the aqueous extract, viz. vanillic acid, protocatechoic acid, quercetin, quercetin glucoside and apigenin, being reported for the first time in H. caesius. Literature suggests that these compounds have important pharmacological traits such as anti-cancer, anti-inflammatory, anti-bacterial and hepatoprotective etc. however, this requires further pharmacological investigations at in vitro and in vivo scale. The above study concluded the medicinal potential of H. caesius.

  7. Phytochemical analysis of Hibiscus caesius using high performance liquid chromatography coupled with mass spectrometry.

    PubMed

    Ain, Quratul; Naveed, Muhammad Na; Mumtaz, Abdul Samad; Farman, Muhammad; Ahmed, Iftikhar; Khalid, Nauman

    2015-09-01

    Various species in genus Hibiscus are traditionally known for their therapeutic attributes. The present study focused on the phytochemical analysis of a rather unexplored species Hibiscus caesius (H. caesius), using high-pressure liquid chromatography coupled with mass spectrometry (HPLC-MS). The analysis revealed five major compounds in the aqueous extract, viz. vanillic acid, protocatechoic acid, quercetin, quercetin glucoside and apigenin, being reported for the first time in H. caesius. Literature suggests that these compounds have important pharmacological traits such as anti-cancer, anti-inflammatory, anti-bacterial and hepatoprotective etc. however, this requires further pharmacological investigations at in vitro and in vivo scale. The above study concluded the medicinal potential of H. caesius. PMID:26408882

  8. Extending PowerPack for Profiling and Analysis of High Performance Accelerator-Based Systems

    SciTech Connect

    Li, Bo; Chang, Hung-Ching; Song, Shuaiwen; Su, Chun-Yi; Meyer, Timmy; Mooring, John; Cameron, Kirk

    2014-12-01

    Accelerators offer a substantial increase in efficiency for high-performance systems offering speedups for computational applications that leverage hardware support for highly-parallel codes. However, the power use of some accelerators exceeds 200 watts at idle which means use at exascale comes at a significant increase in power at a time when we face a power ceiling of about 20 megawatts. Despite the growing domination of accelerator-based systems in the Top500 and Green500 lists of fastest and most efficient supercomputers, there are few detailed studies comparing the power and energy use of common accelerators. In this work, we conduct detailed experimental studies of the power usage and distribution of Xeon-Phi-based systems in comparison to the NVIDIA Tesla and at SandyBridge.

  9. High performance polymeric foams

    SciTech Connect

    Gargiulo, M.; Sorrentino, L.; Iannace, S.

    2008-08-28

    The aim of this work was to investigate the foamability of high-performance polymers (polyethersulfone, polyphenylsulfone, polyetherimide and polyethylenenaphtalate). Two different methods have been used to prepare the foam samples: high temperature expansion and two-stage batch process. The effects of processing parameters (saturation time and pressure, foaming temperature) on the densities and microcellular structures of these foams were analyzed by using scanning electron microscopy.

  10. Performance Analysis of high-order remap-type advection scheme on icosahedral-hexagonal grid

    NASA Astrophysics Data System (ADS)

    Mittal, Rashmi; Dubey, Sarvesh; Saxena, Vaibhav; Meurdesoif, Yann

    2014-05-01

    A comparative performance analysis on computational cost of second order advection schemes FF-CSLAM (Flux form conservative semi-Lagrangian multi-tracer transport scheme) and it's two simplifications on Icosahedral grid has been presented. Tracer transport is one of the main building blocks in atmospheric models and hence their performance greatly determines the overall performance of the model. FF-CSLAM falls in the category of arbitrary Lagrangian Eulerian (ALE) scheme. It exploits the finite volume formulation and therefore it is inherently conservative. Flux-area through edges are approximated with great circle arcs in an upwind fashion. Bi-quadratic sub-grid scale reconstructions using weighted least-squares method is employed to approximate trace field. Area integrals on the overlapped region of flux-area and static Eulerian meshes are evaluated via line-integrals. A brief description of implementation of FF-CSLAM on icosahedral -hexagonal meshes along with and its numerical accuracy in terms of standard test cases will be presented. A comparative analysis of the computational overhead is necessary to assess the suitability of FF-CSLAM for massively parallel and multi-threading computer architectures in comparison to other advection schemes implemented on icosahedral grids. The main focus of this work is to present the implementation of the shared memory parallelization and to describe the memory access pattern of the numerical scheme. FF-CSLAM is a remap-type advection scheme, thus extra calculation are done in comparison to the other advection schemes. The additional computations are associated with the search required to find the overlap area between the area swept through the edge and the underlining grid. But the experiments shows that the associated computational overhead is minimal for multi-tracer transport. It will be shown that for the Courant Number less than one, FF-CSLAM, the computations are not expensive. Since the grid cells are arranged in

  11. Fully automated high-performance liquid chromatographic assay for the analysis of free catecholamines in urine.

    PubMed

    Said, R; Robinet, D; Barbier, C; Sartre, J; Huguet, C

    1990-08-24

    A totally automated and reliable high-performance liquid chromatographic method is described for the routine determination of free catecholamines (norepinephrine, epinephrine and dopamine) in urine. The catecholamines were isolated from urine samples using small alumina columns. A standard automated method for pH adjustment of urine before the extraction step has been developed. The extraction was performed on an ASPEC (Automatic Sample Preparation with Extraction Columns, Gilson). The eluate was collected in a separate tube and then automatically injected into the chromatographic column. The catecholamines were separated by reversed-phase ion-pair liquid chromatography and quantified by fluorescence detection. No manual intervention was required during the extraction and separation procedure. One sample may be run every 15 min, ca. 96 samples in 24 h. Analytical recoveries for all three catecholamines are 63-87%, and the detection limits are 0.01, 0.01, and 0.03 microM for norepinephrine, epinephrine and dopamine, respectively, which is highly satisfactory for urine. Day-to-day coefficients of variation were less than 10%.

  12. Modeling and analysis of a high-performance midwave infrared panoramic periscope

    NASA Astrophysics Data System (ADS)

    Nichols, Jonathan M.; Waterman, James R.; Menon, Raghu; Devitt, John

    2010-11-01

    A high-resolution midwave infrared panoramic periscope sensor system has been developed. The sensor includes an f/2.5 catadioptric optical system that provides a field of view with 360-deg horizontal azimuth and -10- to +30-deg elevation without requiring moving components (e.g., rotating mirrors). The focal plane is a 2048×2048, 15-μm-pitch InSb detector operating at 80 K. An onboard thermoelectric reference source allows for real-time nonuniformity correction using the two-point correction method. The entire system (detector-Dewar assembly, cooler, electronics, and optics) is packaged to fit in an 8-in.-high, 6.5-in.-diameter volume. This work describes both the system optics and the electronics and presents sample imagery. We model both the sensor's radiometric performance, quantified by the noise-equivalent temperature difference, and its resolution performance. Model predictions are then compared with estimates obtained from experimental data. The ability of the system to resolve targets as a function of imaged spatial frequency is also presented.

  13. High performance parallel architectures

    SciTech Connect

    Anderson, R.E. )

    1989-09-01

    In this paper the author describes current high performance parallel computer architectures. A taxonomy is presented to show computer architecture from the user programmer's point-of-view. The effects of the taxonomy upon the programming model are described. Some current architectures are described with respect to the taxonomy. Finally, some predictions about future systems are presented. 5 refs., 1 fig.

  14. High-Performance Happy

    ERIC Educational Resources Information Center

    O'Hanlon, Charlene

    2007-01-01

    Traditionally, the high-performance computing (HPC) systems used to conduct research at universities have amounted to silos of technology scattered across the campus and falling under the purview of the researchers themselves. This article reports that a growing number of universities are now taking over the management of those systems and…

  15. High-Performance Liquid Chromatography

    NASA Astrophysics Data System (ADS)

    Reuhs, Bradley L.; Rounds, Mary Ann

    High-performance liquid chromatography (HPLC) developed during the 1960s as a direct offshoot of classic column liquid chromatography through improvements in the technology of columns and instrumental components (pumps, injection valves, and detectors). Originally, HPLC was the acronym for high-pressure liquid chromatography, reflecting the high operating pressures generated by early columns. By the late 1970s, however, high-performance liquid chromatography had become the preferred term, emphasizing the effective separations achieved. In fact, newer columns and packing materials offer high performance at moderate pressure (although still high pressure relative to gravity-flow liquid chromatography). HPLC can be applied to the analysis of any compound with solubility in a liquid that can be used as the mobile phase. Although most frequently employed as an analytical technique, HPLC also may be used in the preparative mode.

  16. High-Performance Computational Analysis of Glioblastoma Pathology Images with Database Support Identifies Molecular and Survival Correlates.

    PubMed

    Kong, Jun; Wang, Fusheng; Teodoro, George; Cooper, Lee; Moreno, Carlos S; Kurc, Tahsin; Pan, Tony; Saltz, Joel; Brat, Daniel

    2013-12-01

    In this paper, we present a novel framework for microscopic image analysis of nuclei, data management, and high performance computation to support translational research involving nuclear morphometry features, molecular data, and clinical outcomes. Our image analysis pipeline consists of nuclei segmentation and feature computation facilitated by high performance computing with coordinated execution in multi-core CPUs and Graphical Processor Units (GPUs). All data derived from image analysis are managed in a spatial relational database supporting highly efficient scientific queries. We applied our image analysis workflow to 159 glioblastomas (GBM) from The Cancer Genome Atlas dataset. With integrative studies, we found statistics of four specific nuclear features were significantly associated with patient survival. Additionally, we correlated nuclear features with molecular data and found interesting results that support pathologic domain knowledge. We found that Proneural subtype GBMs had the smallest mean of nuclear Eccentricity and the largest mean of nuclear Extent, and MinorAxisLength. We also found gene expressions of stem cell marker MYC and cell proliferation maker MKI67 were correlated with nuclear features. To complement and inform pathologists of relevant diagnostic features, we queried the most representative nuclear instances from each patient population based on genetic and transcriptional classes. Our results demonstrate that specific nuclear features carry prognostic significance and associations with transcriptional and genetic classes, highlighting the potential of high throughput pathology image analysis as a complementary approach to human-based review and translational research.

  17. High performance computing methods for the integration and analysis of biomedical data using SAS.

    PubMed

    Brown, Justin R; Dinu, Valentin

    2013-12-01

    From microarrays and next generation sequencing to clinical records, the amount of biomedical data is growing at an exponential rate. Handling and analyzing these large amounts of data demands that computing power and methodologies keep pace. The goal of this paper is to illustrate how high performance computing methods in SAS can be easily implemented without the need of extensive computer programming knowledge or access to supercomputing clusters to help address the challenges posed by large biomedical datasets. We illustrate the utility of database connectivity, pipeline parallelism, multi-core parallel process and distributed processing across multiple machines. Simulation results are presented for parallel and distributed processing. Finally, a discussion of the costs and benefits of such methods compared to traditional HPC supercomputing clusters is given.

  18. High-performance liquid chromatographic analysis of chemical stability of 5-aza-2'-deoxycytidine.

    PubMed

    Lin, K T; Momparler, R L; Rivard, G E

    1981-11-01

    The chemical stability of 5-aza-2'-deoxycytidine (I) in acidic, neutral, and alkaline solutions was analyzed by high-performance liquid chromatography. In alkaline solution, I underwent rapid reversible decomposition to N-(formylamidino)-N'-beta-D-2-deoxyribofuranosylurea (II), which decomposed irreversibly to form 1-beta-D-2'-deoxyribofuranosyl-3-guanylurea (III). The pseudo-first-order rate constants for this reaction were determined. The decomposition of I in alkaline solution was identical to that reported previously for the related analog, 5-aza-cytidine. However, in neutral solution (or water), there was a marked difference in the decomposition of I and 5-azacytidine. The same decomposition products were formed from 5-azacytidine in neutral solution as in alkaline solution. However, in neutral solution, I decomposed to II and three unknown compounds that were chromophoric at 254 nm. Compound I was most stable when stored in neutral solution at low temperature.

  19. [Simultaneous analysis of ten anabolic steroids in blood plasma using high performance liquid chromatography].

    PubMed

    Zhang, Lan; Chen, Jinfeng; Tong, Ping; Li, Tianlin

    2008-07-01

    A method for the simultaneous separation and determination of ten anabolic steroids in blood plasma using high performance liquid chromatography (HPLC) was established. An RP-C18 column was used as the analytical column, and the mixture of acetonitrile and water was used as the mobile phase with gradient elution according to the characteristics of the analytes. The analytes were detected at the adjustable wavelengths ranging from 194 to 290 nm. Under the optimal conditions, ten compounds were separated within 10 min. The detection limits were in the range of 0.01 - 0.10 microg/mL. The spiked recoveries of standards in a rabbit plasma sample were from 70.3% to 120%. Methandriol was injected into the ear meridian of a rabbit, and then the anabolic steroid methandriol in the plasma was successfully detected with the established method. The results show that the method is feasible, rapid, simple and accurate.

  20. Multiresidue analysis of seven anticoagulant rodenticides by high-performance liquid chromatography/electrospray/mass spectrometry.

    PubMed

    Marek, LeEtta J; Koskinen, William C

    2007-02-01

    Mice and rat populations are commonly controlled by two classes of rodenticide anticoagulants, coumarins and indandiones. However, poisoning of nontarget animals also often occurs. For cases such as these, a rapid, multiresidue method, which provides positive confirmation for both classes of anticoagulant rodenticides, is needed by diagnostic laboratories. A method was developed for the determination of seven anticoagulant rodenticides, coumafuryl, pindone, warfarin, diphacinone, chlorophacinone, bromadiolone, and brodifacoum, in diverse matrices, animal feed, cooked beef, and fruit-flavored beverages using high-performance liquid chromatography/electrospray/mass spectrometry. Detection was by MS/MS with electrospray ionization in negative mode. Confirmation was by retention time, m/z of molecular ion, and two parent-daughter transitions. Recoveries from selected the matrices ranged from 61 to 117%. Limits of quantitation were as low as 1.5-4.5 ng g-1. The developed method was rapid and provided the simultaneous confirmation and quantification of the seven anticoagulant rodenticides. PMID:17263443

  1. Analysis of lipophilic pigments from a phototrophic microbial mat community by high performance liquid chromatography

    NASA Technical Reports Server (NTRS)

    Palmisano, A. C.; Cronin, S. E.; Des Marais, D. J.

    1988-01-01

    As assay for lipophilic pigments in phototrophic microbial mat communities using reverse phase-high performance liquid chromatography was developed which allows the separation of 15 carotenoids and chloropigments in a single 30 min program. Lipophilic pigments in a laminated mat from a commercial salina near Laguna Guerrero Negro, Baja California Sur, Mexico reflected their source organisms. Myxoxanthophyll, echinenone, canthaxanthin, and zeaxanthin were derived from cyanobacteria; chlorophyll c, and fucoxanthin from diatoms; chlorophyll a from cyanobacteria and diatoms; bacteriochlorophylls a and c, bacteriophaeophytin a, and gamma-carotene from Chloroflexus spp.; and beta-carotene from a variety of phototrophs. Sensitivity of detection was 0.6-6.1 ng for carotenoids and 1.7-12 ng for most chloropigments. This assay represents a significant improvement over previous analyses of lipophilic pigments in microbial mats and promises to have a wider application to other types of phototrophic communities.

  2. Geostatistical analysis of Landsat-TM lossy compression images in a high-performance computing environment

    NASA Astrophysics Data System (ADS)

    Pesquer, Lluís; Cortés, Ana; Serral, Ivette; Pons, Xavier

    2011-11-01

    The main goal of this study is to characterize the effects of lossy image compression procedures on the spatial patterns of remotely sensed images, as well as to test the performance of job distribution tools specifically designed for obtaining geostatistical parameters (variogram) in a High Performance Computing (HPC) environment. To this purpose, radiometrically and geometrically corrected Landsat-5 TM images from April, July, August and September 2006 were compressed using two different methods: Band-Independent Fixed-Rate (BIFR) and three-dimensional Discrete Wavelet Transform (3d-DWT) applied to the JPEG 2000 standard. For both methods, a wide range of compression ratios (2.5:1, 5:1, 10:1, 50:1, 100:1, 200:1 and 400:1, from soft to hard compression) were compared. Variogram analyses conclude that all compression ratios maintain the variogram shapes and that the higher ratios (more than 100:1) reduce variance in the sill parameter of about 5%. Moreover, the parallel solution in a distributed environment demonstrates that HPC offers a suitable scientific test bed for time demanding execution processes, as in geostatistical analyses of remote sensing images.

  3. Towards Real-Time High Performance Computing For Power Grid Analysis

    SciTech Connect

    Hui, Peter SY; Lee, Barry; Chikkagoudar, Satish

    2012-11-16

    Real-time computing has traditionally been considered largely in the context of single-processor and embedded systems, and indeed, the terms real-time computing, embedded systems, and control systems are often mentioned in closely related contexts. However, real-time computing in the context of multinode systems, specifically high-performance, cluster-computing systems, remains relatively unexplored. Imposing real-time constraints on a parallel (cluster) computing environment introduces a variety of challenges with respect to the formal verification of the system's timing properties. In this paper, we give a motivating example to demonstrate the need for such a system--- an application to estimate the electromechanical states of the power grid--- and we introduce a formal method for performing verification of certain temporal properties within a system of parallel processes. We describe our work towards a full real-time implementation of the target application--- namely, our progress towards extracting a key mathematical kernel from the application, the formal process by which we analyze the intricate timing behavior of the processes on the cluster, as well as timing measurements taken on our test cluster to demonstrate use of these concepts.

  4. Analysis of Metabolomics Datasets with High-Performance Computing and Metabolite Atlases.

    PubMed

    Yao, Yushu; Sun, Terence; Wang, Tony; Ruebel, Oliver; Northen, Trent; Bowen, Benjamin P

    2015-01-01

    Even with the widespread use of liquid chromatography mass spectrometry (LC/MS) based metabolomics, there are still a number of challenges facing this promising technique. Many, diverse experimental workflows exist; yet there is a lack of infrastructure and systems for tracking and sharing of information. Here, we describe the Metabolite Atlas framework and interface that provides highly-efficient, web-based access to raw mass spectrometry data in concert with assertions about chemicals detected to help address some of these challenges. This integration, by design, enables experimentalists to explore their raw data, specify and refine features annotations such that they can be leveraged for future experiments. Fast queries of the data through the web using SciDB, a parallelized database for high performance computing, make this process operate quickly. By using scripting containers, such as IPython or Jupyter, to analyze the data, scientists can utilize a wide variety of freely available graphing, statistics, and information management resources. In addition, the interfaces facilitate integration with systems biology tools to ultimately link metabolomics data with biological models.

  5. Analysis of Metabolomics Datasets with High-Performance Computing and Metabolite Atlases

    PubMed Central

    Yao, Yushu; Sun, Terence; Wang, Tony; Ruebel, Oliver; Northen, Trent; Bowen, Benjamin P.

    2015-01-01

    Even with the widespread use of liquid chromatography mass spectrometry (LC/MS) based metabolomics, there are still a number of challenges facing this promising technique. Many, diverse experimental workflows exist; yet there is a lack of infrastructure and systems for tracking and sharing of information. Here, we describe the Metabolite Atlas framework and interface that provides highly-efficient, web-based access to raw mass spectrometry data in concert with assertions about chemicals detected to help address some of these challenges. This integration, by design, enables experimentalists to explore their raw data, specify and refine features annotations such that they can be leveraged for future experiments. Fast queries of the data through the web using SciDB, a parallelized database for high performance computing, make this process operate quickly. By using scripting containers, such as IPython or Jupyter, to analyze the data, scientists can utilize a wide variety of freely available graphing, statistics, and information management resources. In addition, the interfaces facilitate integration with systems biology tools to ultimately link metabolomics data with biological models. PMID:26287255

  6. High Performance FORTRAN

    NASA Technical Reports Server (NTRS)

    Mehrotra, Piyush

    1994-01-01

    High performance FORTRAN is a set of extensions for FORTRAN 90 designed to allow specification of data parallel algorithms. The programmer annotates the program with distribution directives to specify the desired layout of data. The underlying programming model provides a global name space and a single thread of control. Explicitly parallel constructs allow the expression of fairly controlled forms of parallelism in particular data parallelism. Thus the code is specified in a high level portable manner with no explicit tasking or communication statements. The goal is to allow architecture specific compilers to generate efficient code for a wide variety of architectures including SIMD, MIMD shared and distributed memory machines.

  7. High Performance Window Retrofit

    SciTech Connect

    Shrestha, Som S; Hun, Diana E; Desjarlais, Andre Omer

    2013-12-01

    The US Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) and Traco partnered to develop high-performance windows for commercial building that are cost-effective. The main performance requirement for these windows was that they needed to have an R-value of at least 5 ft2 F h/Btu. This project seeks to quantify the potential energy savings from installing these windows in commercial buildings that are at least 20 years old. To this end, we are conducting evaluations at a two-story test facility that is representative of a commercial building from the 1980s, and are gathering measurements on the performance of its windows before and after double-pane, clear-glazed units are upgraded with R5 windows. Additionally, we will use these data to calibrate EnergyPlus models that we will allow us to extrapolate results to other climates. Findings from this project will provide empirical data on the benefits from high-performance windows, which will help promote their adoption in new and existing commercial buildings. This report describes the experimental setup, and includes some of the field and simulation results.

  8. A Comparative Analysis of Teacher Perceptions of School Culture in High-Performing and Low-Performing Iowa Schools

    ERIC Educational Resources Information Center

    Ahart, Thomas M.

    2014-01-01

    The challenge of improving the performance of public schools has been given attention from a variety of advocacy groups, researchers, government agencies, education organizations and schools. Since the reauthorization of the Elementary and Secondary Education Act in 2002, titled No Child Left Behind, the stakes for public schools are higher.…

  9. High-performance liquid chromatography-mass spectrometry analysis of plant metabolites in brassicaceae.

    PubMed

    De Vos, Ric C H; Schipper, Bert; Hall, Robert D

    2012-01-01

    The Brassicaceae family comprises a variety of plant species that are of high economic importance as -vegetables or industrial crops. This includes crops such as Brassica rapa (turnip, Bok Choi), B. oleracea (cabbages, broccoli, cauliflower, etc.), and B. napus (oil seed rape), and also includes the famous genetic model of plant research, Arabidopsis thaliana (thale cress). Brassicaceae plants contain a large variety of interesting secondary metabolites, including glucosinolates, hydroxycinnamic acids, and flavonoids. These metabolites are also of particular importance due to their proposed positive effects on human health. Next to these well-known groups of phytochemicals, many more metabolites are of course also present in crude extracts prepared from Brassica and Arabidopsis plant material.High-pressure liquid chromatography coupled to mass spectrometry (HPLC-MS), especially if combined with a high mass resolution instrument such as a QTOF MS, is a powerful approach to separate, detect, and annotate metabolites present in crude aqueous-alcohol plant extracts. Using an essentially unbiased procedure that takes into account all metabolite mass signals from the raw data files, detailed information on the relative abundance of hundreds of both known and, as yet, unknown semipolar metabolites can be obtained. These comprehensive metabolomics data can then be used to, for instance, identify genetic markers regulating metabolic composition, determine effects of (a)biotic stress or specific growth conditions, or establish metabolite changes occurring upon food processing or storage.This chapter describes in detail a procedure for preparing crude extracts and performing comprehensive HPLC-QTOF MS-based profiling of semi-polar metabolites in Brassicaceae plant material. Compounds present in the extract can be (partially or completely) annotated based on their accurate mass, their MS/MS fragments and on other specific chemical characteristics such as retention time and UV

  10. High-Performance Data Analysis Tools for Sun-Earth Connection Missions

    NASA Technical Reports Server (NTRS)

    Messmer, Peter

    2011-01-01

    The data analysis tool of choice for many Sun-Earth Connection missions is the Interactive Data Language (IDL) by ITT VIS. The increasing amount of data produced by these missions and the increasing complexity of image processing algorithms requires access to higher computing power. Parallel computing is a cost-effective way to increase the speed of computation, but algorithms oftentimes have to be modified to take advantage of parallel systems. Enhancing IDL to work on clusters gives scientists access to increased performance in a familiar programming environment. The goal of this project was to enable IDL applications to benefit from both computing clusters as well as graphics processing units (GPUs) for accelerating data analysis tasks. The tool suite developed in this project enables scientists now to solve demanding data analysis problems in IDL that previously required specialized software, and it allows them to be solved orders of magnitude faster than on conventional PCs. The tool suite consists of three components: (1) TaskDL, a software tool that simplifies the creation and management of task farms, collections of tasks that can be processed independently and require only small amounts of data communication; (2) mpiDL, a tool that allows IDL developers to use the Message Passing Interface (MPI) inside IDL for problems that require large amounts of data to be exchanged among multiple processors; and (3) GPULib, a tool that simplifies the use of GPUs as mathematical coprocessors from within IDL. mpiDL is unique in its support for the full MPI standard and its support of a broad range of MPI implementations. GPULib is unique in enabling users to take advantage of an inexpensive piece of hardware, possibly already installed in their computer, and achieve orders of magnitude faster execution time for numerically complex algorithms. TaskDL enables the simple setup and management of task farms on compute clusters. The products developed in this project have the

  11. New trend in the LC separation analysis of pharmaceuticals--high performance separation by ultra high-performance liquid chromatography (UHPLC) with core-shell particle C18 columns--.

    PubMed

    Nishi, Hiroyuki; Nagamatsu, Kumi

    2014-01-01

    This article presents a mini-review of the recent results in the ultra high-performance liquid chromatography (UHPLC) separation of pharmaceuticals by our group. High performance UHPLC separation employing core-shell particle C18 columns was demonstrated. High performance (high theoretical plate number of approximately 20000/10 cm, low theoretical plate height of 5 μm) was obtained without any specific devices in the conventional HPLC apparatus, only through changing detector sampling times and the inner diameter of the connecting tube. High theoretical plate numbers with low column back pressure obtained by the core-shell particle columns enabled fast separation of the analytes. Methanol, which gives high column pressure drops in the reversed-phase mode HPLC compared with acetonitrile, can be used without any trouble. One analysis of the purity testing of diltiazem hydrochloride was performed within 100 s. One analysis in the photostability testing of mecobalamin (vitamin B12 analogue) was successful within 180 s.

  12. High performance cyclone development

    SciTech Connect

    Giles, W.B.

    1981-01-01

    The results of cold flow experiments at atmospheric conditions of an air-shielded 18 in-dia electrocyclone with a central cusped electrode are reported using fine test dusts of both flyash and nickel powder. These results are found to confirm expectations of enhanced performance, similar to earlier work on a 12 in-dia model. An analysis of the combined inertial-electrostatic force field is also presented which identifies general design goals and scaling laws. From this, it is found that electrostatic enhancement will be particularly beneficial for fine dusts in large cyclones. Recommendations for further improvement in cyclone collection efficiency are proposed.

  13. Osiris: A Modern, High-Performance, Coupled, Multi-Physics Code For Nuclear Reactor Core Analysis

    SciTech Connect

    Procassini, R J; Chand, K K; Clouse, C J; Ferencz, R M; Grandy, J M; Henshaw, W D; Kramer, K J; Parsons, I D

    2007-02-26

    To meet the simulation needs of the GNEP program, LLNL is leveraging a suite of high-performance codes to be used in the development of a multi-physics tool for modeling nuclear reactor cores. The Osiris code project, which began last summer, is employing modern computational science techniques in the development of the individual physics modules and the coupling framework. Initial development is focused on coupling thermal-hydraulics and neutral-particle transport, while later phases of the project will add thermal-structural mechanics and isotope depletion. Osiris will be applicable to the design of existing and future reactor systems through the use of first-principles, coupled physics models with fine-scale spatial resolution in three dimensions and fine-scale particle-energy resolution. Our intent is to replace an existing set of legacy, serial codes which require significant approximations and assumptions, with an integrated, coupled code that permits the design of a reactor core using a first-principles physics approach on a wide range of computing platforms, including the world's most powerful parallel computers. A key research activity of this effort deals with the efficient and scalable coupling of physics modules which utilize rather disparate mesh topologies. Our approach allows each code module to use a mesh topology and resolution that is optimal for the physics being solved, and employs a mesh-mapping and data-transfer module to effect the coupling. Additional research is planned in the area of scalable, parallel thermal-hydraulics, high-spatial-accuracy depletion and coupled-physics simulation using Monte Carlo transport.

  14. Cloud CPFP: a shotgun proteomics data analysis pipeline using cloud and high performance computing.

    PubMed

    Trudgian, David C; Mirzaei, Hamid

    2012-12-01

    We have extended the functionality of the Central Proteomics Facilities Pipeline (CPFP) to allow use of remote cloud and high performance computing (HPC) resources for shotgun proteomics data processing. CPFP has been modified to include modular local and remote scheduling for data processing jobs. The pipeline can now be run on a single PC or server, a local cluster, a remote HPC cluster, and/or the Amazon Web Services (AWS) cloud. We provide public images that allow easy deployment of CPFP in its entirety in the AWS cloud. This significantly reduces the effort necessary to use the software, and allows proteomics laboratories to pay for compute time ad hoc, rather than obtaining and maintaining expensive local server clusters. Alternatively the Amazon cloud can be used to increase the throughput of a local installation of CPFP as necessary. We demonstrate that cloud CPFP allows users to process data at higher speed than local installations but with similar cost and lower staff requirements. In addition to the computational improvements, the web interface to CPFP is simplified, and other functionalities are enhanced. The software is under active development at two leading institutions and continues to be released under an open-source license at http://cpfp.sourceforge.net. PMID:23088505

  15. High Performance Analysis of CDS Delta-Sigma ADC in 45-Nanometer Regime

    NASA Astrophysics Data System (ADS)

    Bhargava, Bhanupriya; Sharma, Pradeep Kumar; Akashe, Shyam

    2014-03-01

    In this paper, a correlated double sampling (CDS) technique is proposed in the design of a delta sigma analog-to-digital converter (ADC). These CDS techniques are very effective for the compensation of the nonidealities in switched-capacitor (SC) circuits, such as charge injection, clock feed-through, operational amplifier (op-amp) input-referred offset and finite op-amp gain. An improved compensation scheme is proposed to attain continuous compensation of clock feed-through and offset in SC integrators. Both high-speed and low-power operation is achieved without compromising the accuracy requirement. Also this CDS delta sigma ADC is the most promising circuit for analog to digital converter because this circuit reduces noise due to drift and low frequency noise such as flicker noise and offset voltage and also boosts the gain performance of the amplifier. Further, the simulation results of this circuit are verified on using a "cadence virtuoso tool" using spectre at 45 nm technology with supply voltage 0.7 V.

  16. Performance analysis of a new biolistic gun using high power laser irradiation

    NASA Astrophysics Data System (ADS)

    Han, Tae-Hee; Lee, Hyunhee; Choi, Soojin; Gojani, Ardian B.; Yoh, Jack J.

    2010-11-01

    Impingement of a high power laser pulse (above 109 W/cm2) on a metal foil causes ablation, which is characterized by a rapid expulsion of matter and initiation of a strong shock wave inside the solid metal. The shock propagates through the foil and reverberates on the rear side causing instant deformation of the foil, whose surface is treated with micro particles prior to ablation. Based on this principle of micro particle ejection, we develop a new biolistic gun with improved controllability, stability, efficiency of our previous system, and perform characterization of the penetration shapes at varying confinements and energy levels. The confinement media include BK7 glass, water, and succulent jelly (ultrasound gel). Biological tissue was replicated by a gelatin-water solution at a 3% weight ratio. Present data show that confinement effect results in a conspicuous enhancement of penetration reached by 5 μm cobalt micro particles. Also, there exists an optimal thickness at each energy level when using liquid confinement for enhanced particle delivery.

  17. Cloud CPFP: a shotgun proteomics data analysis pipeline using cloud and high performance computing.

    PubMed

    Trudgian, David C; Mirzaei, Hamid

    2012-12-01

    We have extended the functionality of the Central Proteomics Facilities Pipeline (CPFP) to allow use of remote cloud and high performance computing (HPC) resources for shotgun proteomics data processing. CPFP has been modified to include modular local and remote scheduling for data processing jobs. The pipeline can now be run on a single PC or server, a local cluster, a remote HPC cluster, and/or the Amazon Web Services (AWS) cloud. We provide public images that allow easy deployment of CPFP in its entirety in the AWS cloud. This significantly reduces the effort necessary to use the software, and allows proteomics laboratories to pay for compute time ad hoc, rather than obtaining and maintaining expensive local server clusters. Alternatively the Amazon cloud can be used to increase the throughput of a local installation of CPFP as necessary. We demonstrate that cloud CPFP allows users to process data at higher speed than local installations but with similar cost and lower staff requirements. In addition to the computational improvements, the web interface to CPFP is simplified, and other functionalities are enhanced. The software is under active development at two leading institutions and continues to be released under an open-source license at http://cpfp.sourceforge.net.

  18. ANALYSIS OF DRUG INTERACTIONS WITH VERY LOW DENSITY LIPOPROTEIN BY HIGH PERFORMANCE AFFINITY CHROMATOGRAPHY

    PubMed Central

    Sobansky, Matthew R.; Hage, David S.

    2014-01-01

    High-performance affinity chromatography (HPAC) was utilized to examine the binding of very low density lipoprotein (VLDL) with drugs, using R/S-propranolol as a model. These studies indicated that two mechanisms existed for the binding of R- and S-propranolol with VLDL. The first mechanism involved non-saturable partitioning of these drugs with VLDL, which probably occurred with the lipoprotein's non-polar core. This partitioning was described by overall affinity constants of 1.2 (± 0.3) × 106 M-1 for R-propranolol and 2.4 (± 0.6) × 106 M-1 for S-propranolol at pH 7.4 and 37 °C. The second mechanism occurred through saturable binding by these drugs at fixed sites on VLDL, such as represented by apolipoproteins on the surface of the lipoprotein. The association equilibrium constants for this saturable binding at 37 °C were 7.0 (± 2.3) × 104 M-1 for R-propranolol and 9.6 (± 2.2) × 104 M-1 for S-propranolol. Comparable results were obtained at 20 °C and 27 °C for the propranolol enantiomers. This work provided fundamental information on the processes involved in the binding of R- and S-propranolol to VLDL, while also illustrating how HPAC can be used to evaluate relatively complex interactions between agents such as VLDL and drugs or other solutes. PMID:25103529

  19. Analysis of Lidocaine Interactions with Serum Proteins Using High-Performance Affinity Chromatography

    PubMed Central

    Soman, Sony; Yoo, Michelle J.; Jang, Yoon Jeong; Hage, David S.

    2010-01-01

    High-performance affinity chromatography was used to study binding by the drug lidocaine to human serum albumin (HSA) and α1–acid glycoprotein (AGP). AGP had strong binding to lidocaine, with an association equilibrium constant (Ka) of 1.1-1.7 × 105 M-1 at 37 °C and pH 7.4. Lidocaine had weak-to-moderate binding to HSA, with a Ka in the range of 103 to 104 M-1. Competitive experiments with site selective probes showed that lidocaine was interacting with Sudlow site II of HSA and the propranolol site of AGP. These results agree with previous observations in the literature and provide a better quantitative understanding of how lidocaine binds to these serum proteins and is transported in the circulation. This study also demonstrates how HPAC can be used to examine the binding of a drug with multiple serum proteins and provide detailed information on the interaction sites and equilibrium constants that are involved in such processes. PMID:20138813

  20. Analysis of Phase Separation in High Performance PbTe–PbS Thermoelectric Materials

    SciTech Connect

    Girard, Steven N.; Schmidt-Rohr, Klaus; Chasapis, Thomas C.; Hatzikraniotis, Euripides; Njegic, B.; Levin, E. M.; Rawal, A.; Paraskevopoulos, Konstantios M.; Kanatzidis, Mercouri G.

    2013-02-11

    Phase immiscibility in PbTe–based thermoelectric materials is an effective means of top-down synthesis of nanostructured composites exhibiting low lattice thermal conductivities. PbTe1-x Sx thermoelectric materials can be synthesized as metastable solid solution alloys through rapid quenching. Subsequent post-annealing induces phase separation at the nanometer scale, producing nanostructures that increase phonon scattering and reduce lattice thermal conductivity. However, there has yet to be any study investigating in detail the local chemical structure of both the solid solution and nanostructured variants of this material system. Herein, quenched and annealed (i.e., solid solution and phase-separated) samples of PbTe–PbS are analyzed by in situ high-resolution synchrotron powder X-ray diffraction, solid-state 125Te nuclear magnetic resonance (NMR), and infrared (IR) spectroscopy analysis. For high concentrations of PbS in PbTe, e.g., x >16%, NMR and IR analyses reveal that rapidly quenched samples exhibit incipient phase separation that is not detected by state-of-the-art synchrotron X-ray diffraction, providing an example of a PbTe thermoelectric “alloy” that is in fact phase inhomogeneous. Thermally-induced PbS phase separation in PbTe–PbS occurs close to 200 °C for all compositions studied, and the solubility of the PbS phase in PbTe at elevated temperatures >500 °C is reported. The findings of this study suggest that there may be a large number of thermoelectric alloy systems that are phase inhomogeneous or nanostructured despite adherence to Vegard's Law of alloys, highlighting the importance of careful chemical characterization to differentiate between thermoelectric alloys and composites.

  1. High performance satellite networks

    NASA Astrophysics Data System (ADS)

    Helm, Neil R.; Edelson, Burton I.

    1997-06-01

    The high performance satellite communications networks of the future will have to be interoperable with terrestrial fiber cables. These satellite networks will evolve from narrowband analogue formats to broadband digital transmission schemes, with protocols, algorithms and transmission architectures that will segment the data into uniform cells and frames, and then transmit these data via larger and more efficient synchronous optional (SONET) and asynchronous transfer mode (ATM) networks that are being developed for the information "superhighway". These high performance satellite communications and information networks are required for modern applications, such as electronic commerce, digital libraries, medical imaging, distance learning, and the distribution of science data. In order for satellites to participate in these information superhighway networks, it is essential that they demonstrate their ability to: (1) operate seamlessly with heterogeneous architectures and applications, (2) carry data at SONET rates with the same quality of service as optical fibers, (3) qualify transmission delay as a parameter not a problem, and (4) show that satellites have several performance and economic advantages over fiber cable networks.

  2. High Performance Buildings Database

    DOE Data Explorer

    The High Performance Buildings Database is a shared resource for the building industry, a unique central repository of in-depth information and data on high-performance, green building projects across the United States and abroad. The database includes information on the energy use, environmental performance, design process, finances, and other aspects of each project. Members of the design and construction teams are listed, as are sources for additional information. In total, up to twelve screens of detailed information are provided for each project profile. Projects range in size from small single-family homes or tenant fit-outs within buildings to large commercial and institutional buildings and even entire campuses. The database is a data repository as well. A series of Web-based data-entry templates allows anyone to enter information about a building project into the database. Once a project has been submitted, each of the partner organizations can review the entry and choose whether or not to publish that particular project on its own Web site.

  3. Rapid high performance liquid chromatography-high resolution mass spectrometry methodology for multiple prenol lipids analysis in zebrafish embryos.

    PubMed

    Martano, Chiara; Mugoni, Vera; Dal Bello, Federica; Santoro, Massimo M; Medana, Claudio

    2015-09-18

    The analysis of lipid molecules in living organism is an important step in deciphering metabolic pathways. Recently, the zebrafish has been adopted as a valuable animal model system to perform in vivo metabolomics studies, however limited methodologies and protocols are currently available to investigate zebrafish lipidome and even fewer to analyze specific classes of lipids. Here we present an HPLC-HRMS based method to rapidly measure multiple prenol lipid molecules from zebrafish tissues. In particular, we have optimized our method for concurrent detection of ubiquinones (Coenzyme Q6, Coenzyme Q9, Coenzyme Q10), cholesterol, vitamin E (α-tocopherol), vitamin K1 and vitamin K2. The purpose of this study was to compare different ionization modes, mobile phases and stationary phases in order to optimize lipid molecules separation. After HPLC-HRMS parameters selection, several extraction conditions from zebrafish embryos were evaluated. We assessed our methodology by quantitation of analytical recovery on zebrafish extracts from wild-type or zebrafish mutants (barolo) affected by impaired biosynthesis of ubiquinones.

  4. Performance Measurement Analysis System

    1989-06-01

    The PMAS4.0 (Performance Measurement Analysis System) is a user-oriented system designed to track the cost and schedule performance of Department of Energy (DOE) major projects (MPs) and major system acquisitions (MSAs) reporting under DOE Order 5700.4A, Project Management System. PMAS4.0 provides for the analysis of performance measurement data produced from management control systems complying with the Federal Government''s Cost and Schedule Control Systems Criteria.

  5. The Application of Chemical Derivatization in Forensic Drug Chemistry for Gas and High-Performance Liquid Chromatographic Methods of Analysis.

    PubMed

    Moore, J M

    1990-12-01

    The analyses of solid-dosage forensic drug samples can be enhanced by chemical derivatization followed by gas chromatography or high-performance liquid chromatography. Using these techniques permits improved detection and chromatography of some illicit drugs and their manufacturing by-products. This review focuses on the use of chemical derivatization in conjunction with gas chromatography-flame ionization detection, gas chromatography-electron capture detection, gas chromatography-mass spectrometry, high-performance liquid chromatography-ultraviolet detection and high-performance liquid chromatography-fluorescence detection in the analysis of illicit drug samples. These drugs include the amphetamines, barbiturates, cannabis, fentanyls, opium, and hallucinogens. Discussion on sensitivity enhancement and determination of enantiomeric composition using gas chromatography and high-performance liquid chromatography is included. An entire section is devoted to the chemical derivatization and chromatographic analyses of manufacturing by-products found in illicit amphetamine and methamphetamine, heroin, and cocaine samples. This review also includes a section that describes practical elements and experimental design associated with chemical derivatization-chromatographic analyses..

  6. Analysis of therapeutic proteins and peptides using multiangle light scattering coupled to ultra high performance liquid chromatography.

    PubMed

    Espinosa-de la Garza, Carlos E; Miranda-Hernández, Mariana P; Acosta-Flores, Lilia; Pérez, Néstor O; Flores-Ortiz, Luis F; Medina-Rivero, Emilio

    2015-05-01

    Analysis of the physical properties of biotherapeutic proteins is crucial throughout all the stages of their lifecycle. Herein, we used size-exclusion ultra high performance liquid chromatography coupled to multiangle light scattering and refractive index detection systems to determine the molar mass, mass-average molar mass, molar-mass dispersity and hydrodynamic radius of two monoclonal antibodies (rituximab and trastuzumab), a fusion protein (etanercept), and a synthetic copolymer (glatiramer acetate) employed as models. A customized instrument configuration was set to diminish band-broadening effects and enhance sensitivity throughout detectors. The customized configuration showed a performance improvement with respect to the high-performance liquid chromatography standard configuration, as observed by a 3 h column conditioning and a higher resolution analysis in 20 min. Analysis of the two monoclonal antibodies showed averaged values of 148.0 kDa for mass-average molar mass and 5.4 nm for hydrodynamic radius, whereas for etanercept these values were 124.2 kDa and 6.9 nm, respectively. Molar-mass dispersity was 1.000 on average for these proteins. Regarding glatiramer acetate, a molar mass range from 3 to 45 kDa and a molar-mass dispersity of 1.304 were consistent with its intrinsic peptide diversity, and its mass-average molar mass was 10.4 kDa. Overall, this method demonstrated an accurate determination of molar mass, overcoming the difficulties of size-exclusion chromatography.

  7. High-performance liquid chromatography with fluorescence detection for the rapid analysis of pheophytins and pyropheophytins in virgin olive oil.

    PubMed

    Li, Xueqi; Woodman, Michael; Wang, Selina C

    2015-08-01

    Pheophytins and pyropheophytin are degradation products of chlorophyll pigments, and their ratios can be used as a sensitive indicator of stress during the manufacturing and storage of olive oil. They increase over time depending on the storage condition and if the oil is exposed to heat treatments during the refining process. The traditional analysis method includes solvent- and time-consuming steps of solid-phase extraction followed by analysis by high-performance liquid chromatography with ultraviolet detection. We developed an improved dilute/fluorescence method where multi-step sample preparation was replaced by a simple isopropanol dilution before the high-performance liquid chromatography injection. A quaternary solvent gradient method was used to include a fourth strong solvent wash on a quaternary gradient pump, which avoided the need to premix any solvents and greatly reduced the oil residues on the column from previous analysis. This new method not only reduces analysis cost and time but shows reliability, repeatability, and improved sensitivity, especially important for low-level samples. PMID:26047465

  8. High-performance liquid chromatography with fluorescence detection for the rapid analysis of pheophytins and pyropheophytins in virgin olive oil.

    PubMed

    Li, Xueqi; Woodman, Michael; Wang, Selina C

    2015-08-01

    Pheophytins and pyropheophytin are degradation products of chlorophyll pigments, and their ratios can be used as a sensitive indicator of stress during the manufacturing and storage of olive oil. They increase over time depending on the storage condition and if the oil is exposed to heat treatments during the refining process. The traditional analysis method includes solvent- and time-consuming steps of solid-phase extraction followed by analysis by high-performance liquid chromatography with ultraviolet detection. We developed an improved dilute/fluorescence method where multi-step sample preparation was replaced by a simple isopropanol dilution before the high-performance liquid chromatography injection. A quaternary solvent gradient method was used to include a fourth strong solvent wash on a quaternary gradient pump, which avoided the need to premix any solvents and greatly reduced the oil residues on the column from previous analysis. This new method not only reduces analysis cost and time but shows reliability, repeatability, and improved sensitivity, especially important for low-level samples.

  9. Analysis of dynamic interaction between catenary and pantograph with experimental verification and performance evaluation in new high-speed line

    NASA Astrophysics Data System (ADS)

    Lee, Jin Hee; Park, Tae Won; Oh, Hyuck Keun; Kim, Young Guk

    2015-08-01

    Understanding the dynamic interaction between the catenary and pantograph of a high-speed train is the one of the most important technical issues in the railway industry. This is because the catenary-pantograph system plays a crucial role in providing electric power to the railway vehicle for stable operation. The aim of the present paper is to estimate the current-collection performance of this system by using numerical analysis, in particular, the flexible multibody dynamic analysis technique. To implement large deformable catenary wires, an absolute nodal coordinate formulation is used for the cable element. Additionally, an efficient contact element and an interactive model for the catenary-pantograph system are introduced. Each developed model is then used for analytical and experimental verification. Actual on-line test results of existing high-speed railway vehicles are presented and used to verify the analysis model. Finally, the performance characteristics of a new 400 km/h-class high-speed line are estimated and evaluated on the basis of international standards.

  10. High performance sapphire windows

    NASA Technical Reports Server (NTRS)

    Bates, Stephen C.; Liou, Larry

    1993-01-01

    High-quality, wide-aperture optical access is usually required for the advanced laser diagnostics that can now make a wide variety of non-intrusive measurements of combustion processes. Specially processed and mounted sapphire windows are proposed to provide this optical access to extreme environment. Through surface treatments and proper thermal stress design, single crystal sapphire can be a mechanically equivalent replacement for high strength steel. A prototype sapphire window and mounting system have been developed in a successful NASA SBIR Phase 1 project. A large and reliable increase in sapphire design strength (as much as 10x) has been achieved, and the initial specifications necessary for these gains have been defined. Failure testing of small windows has conclusively demonstrated the increased sapphire strength, indicating that a nearly flawless surface polish is the primary cause of strengthening, while an unusual mounting arrangement also significantly contributes to a larger effective strength. Phase 2 work will complete specification and demonstration of these windows, and will fabricate a set for use at NASA. The enhanced capabilities of these high performance sapphire windows will lead to many diagnostic capabilities not previously possible, as well as new applications for sapphire.

  11. [Qualitative and quantitative analysis of the amino acids in Rhizoma Arisaematis by ultra high performance liquid chromatography-tandem mass spectrometry and high performance liquid chromatography].

    PubMed

    Wang, Xing; Chi, Yumei; Kang, An

    2014-12-01

    A method for the identification and determination of the polar amino components without ultraviolet activity in traditional Chinese medicines was developed. With Rhizoma Arisaematis as the object of this study, using pre-column derivatization with phenyl isothiocyanate (PITC) as the derivatization reagent, compounds were separated and identified on a C18 column (100 mm x 2.1 mm, 3.5 µm) by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A total of 20 components, including 18 amino acids and 2 amine compounds were identified. Furthermore, after the optimization of the derivatization conditions, 15 amino acids were determined by high performance liquid chromatography (HPLC) on Diamonsil C18 column (250 mm x 4.6 mm, 5 µm), detected at 254 nm and gradiently eluted by acetonitrile and 0. 05 mol/L ammonium acetate-acetic acid (pH 6. 5) as the mobile phases. The results of methodological study demonstrated that the method can meet the requirements of the determination. All calibration curves expressed good linearity: Glu, Try in the range of 2-100 mg/L, Arg in the range of 6-300 mg/L, others in the range of 0. 8-40 µg/L, with the correlation coefficients ≥ 0. 999 5. The average recovery of this method was among 95%-105% and the RSD was less than 3%. The developed method was successfully applied to quantitative determination of amino compounds in 12 batches of Rhizoma Arisaematis samples. The method is simple, sensitive, accurate, and can be used for rapid identification and determination of amino components in traditional Chinese medicines.

  12. Fractionation of polyphenols in hawthorn into polymeric procyanidins, phenolic acids and flavonoids prior to high-performance liquid chromatographic analysis.

    PubMed

    Svedström, Ulla; Vuorela, Heikki; Kostiainen, Risto; Laakso, Into; Hiltunen, Raimo

    2006-04-21

    Polymeric procyanidins, phenolic carboxylic acids and flavonoids of hawthorn (Crataegus laevigata) were fractionated prior to HPLC analysis using column chromatography and solid-phase extraction (SPE). The flavonoid fraction also contained (-)-epicatechin. The three groups of phenolics, each with clearly different UV spectra, were examined by means of high-performance liquid chromatography-diode array detection (HPLC-DAD) analysis. The average repeatability of the method (RSD) was in the range of 8-13% for chlorogenic acid, (-)-epicatechin and hyperoside. The polymeric procyanidins of hawthorn flowers consisted mainly of (-)-epicatechin subunits, and their mean degree of polymerization (DP) was 22.2. The HPLC methods developed can be used for the qualitative and quantitative analysis of different phenolic compounds in hawthorn plant material and their extracts.

  13. A meta-analysis of country differences in the high-performance work system-business performance relationship: the roles of national culture and managerial discretion.

    PubMed

    Rabl, Tanja; Jayasinghe, Mevan; Gerhart, Barry; Kühlmann, Torsten M

    2014-11-01

    Our article develops a conceptual framework based primarily on national culture perspectives but also incorporating the role of managerial discretion (cultural tightness-looseness, institutional flexibility), which is aimed at achieving a better understanding of how the effectiveness of high-performance work systems (HPWSs) may vary across countries. Based on a meta-analysis of 156 HPWS-business performance effect sizes from 35,767 firms and establishments in 29 countries, we found that the mean HPWS-business performance effect size was positive overall (corrected r = .28) and positive in each country, regardless of its national culture or degree of institutional flexibility. In the case of national culture, the HPWS-business performance relationship was, on average, actually more strongly positive in countries where the degree of a priori hypothesized consistency or fit between an HPWS and national culture (according to national culture perspectives) was lower, except in the case of tight national cultures, where greater a priori fit of an HPWS with national culture was associated with a more positive HPWS-business performance effect size. However, in loose cultures (and in cultures that were neither tight nor loose), less a priori hypothesized consistency between an HPWS and national culture was associated with higher HPWS effectiveness. As such, our findings suggest the importance of not only national culture but also managerial discretion in understanding the HPWS-business performance relationship. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  14. A high performance cloud computing platform for mRNA analysis.

    PubMed

    Lin, Feng-Seng; Shen, Chia-Ping; Sung, Hsiao-Ya; Lam, Yan-Yu; Lin, Jeng-Wei; Lai, Feipei

    2013-01-01

    Multiclass classification is an important technique to many complex bioinformatics problems. However, their performance is limited by the computation power. Based on the Apache Hadoop design framework, this study proposes a two layer architecture that exploits the inherent parallelism of GA-SVM classification to speed up the work. The performance evaluations on an mRNA benchmark cancer dataset have reduced 86.55% features and raised accuracy from 97.53% to 98.03%. With a user-friendly web interface, the system provides researchers an easy way to investigate the unrevealed secrets in the fast-growing repository of bioinformatics data. PMID:24109986

  15. Parallel-META: efficient metagenomic data analysis based on high-performance computation

    PubMed Central

    2012-01-01

    Background Metagenomics method directly sequences and analyses genome information from microbial communities. There are usually more than hundreds of genomes from different microbial species in the same community, and the main computational tasks for metagenomic data analyses include taxonomical and functional component examination of all genomes in the microbial community. Metagenomic data analysis is both data- and computation- intensive, which requires extensive computational power. Most of the current metagenomic data analysis softwares were designed to be used on a single computer or single computer clusters, which could not match with the fast increasing number of large metagenomic projects' computational requirements. Therefore, advanced computational methods and pipelines have to be developed to cope with such need for efficient analyses. Result In this paper, we proposed Parallel-META, a GPU- and multi-core-CPU-based open-source pipeline for metagenomic data analysis, which enabled the efficient and parallel analysis of multiple metagenomic datasets and the visualization of the results for multiple samples. In Parallel-META, the similarity-based database search was parallelized based on GPU computing and multi-core CPU computing optimization. Experiments have shown that Parallel-META has at least 15 times speed-up compared to traditional metagenomic data analysis method, with the same accuracy of the results http://www.computationalbioenergy.org/parallel-meta.html. Conclusion The parallel processing of current metagenomic data would be very promising: with current speed up of 15 times and above, binning would not be a very time-consuming process any more. Therefore, some deeper analysis of the metagenomic data, such as the comparison of different samples, would be feasible in the pipeline, and some of these functionalities have been included into the Parallel-META pipeline. PMID:23046922

  16. An Analysis of High School Students' Perceptions and Academic Performance in Laboratory Experiences

    ERIC Educational Resources Information Center

    Mirchin, Robert Douglas

    2012-01-01

    This research study is an investigation of student-laboratory (i.e., lab) learning based on students' perceptions of experiences using questionnaire data and evidence of their science-laboratory performance based on paper-and-pencil assessments using Maryland-mandated criteria, Montgomery County Public Schools (MCPS) criteria, and published…

  17. Recent advances in ultra-high performance liquid chromatography for the analysis of traditional chinese medicine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditional Chinese medicines (TCMs) have been widely used for the prevention and treatment of various diseases for thousands of years in China. Ultra Performance Liquid Chromatography (UHPLC) is a relatively new technique offering new possibilities in liquid chromatography. This paper reviews recen...

  18. AVES: A high performance computer cluster array for the INTEGRAL satellite scientific data analysis

    NASA Astrophysics Data System (ADS)

    Federici, Memmo; Martino, Bruno Luigi; Ubertini, Pietro

    2012-07-01

    In this paper we describe a new computing system array, designed, built and now used at the Space Astrophysics and Planetary Institute (IAPS) in Rome, Italy, for the INTEGRAL Space Observatory scientific data analysis. This new system has become necessary in order to reduce the processing time of the INTEGRAL data accumulated during the more than 9 years of in-orbit operation. In order to fulfill the scientific data analysis requirements with a moderately limited investment the starting approach has been to use a `cluster' array of commercial quad-CPU computers, featuring the extremely large scientific and calibration data archive on line.

  19. Analysis of anabolic androgenic steroids as sulfate conjugates using high performance liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Rzeppa, S; Heinrich, G; Hemmersbach, P

    2015-01-01

    Improvements in doping analysis can be effected by speeding up analysis time and extending the detection time. Therefore, direct detection of phase II conjugates of doping agents, especially anabolic androgenic steroids (AAS), is proposed. Besides direct detection of conjugates with glucuronic acid, the analysis of sulfate conjugates, which are usually not part of the routine doping control analysis, can be of high interest. Sulfate conjugates of methandienone and methyltestosterone metabolites have already been identified as long-term metabolites. This study presents the synthesis of sulfate conjugates of six commonly used AAS and their metabolites: trenbolone, nandrolone, boldenone, methenolone, mesterolone, and drostanolone. In the following these sulfate conjugates were used for development of a fast and easy analysis method based on sample preparation using solid phase extraction with a mixed-mode sorbent and detection by high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Validation demonstrated the suitability of the method with regard to the criteria given by the technical documents of the World Anti-Doping Agency (WADA). In addition, suitability has been proven by successful detection of the synthesized sulfate conjugates in excretion urines and routine doping control samples.

  20. Analysis of anabolic androgenic steroids as sulfate conjugates using high performance liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Rzeppa, S; Heinrich, G; Hemmersbach, P

    2015-01-01

    Improvements in doping analysis can be effected by speeding up analysis time and extending the detection time. Therefore, direct detection of phase II conjugates of doping agents, especially anabolic androgenic steroids (AAS), is proposed. Besides direct detection of conjugates with glucuronic acid, the analysis of sulfate conjugates, which are usually not part of the routine doping control analysis, can be of high interest. Sulfate conjugates of methandienone and methyltestosterone metabolites have already been identified as long-term metabolites. This study presents the synthesis of sulfate conjugates of six commonly used AAS and their metabolites: trenbolone, nandrolone, boldenone, methenolone, mesterolone, and drostanolone. In the following these sulfate conjugates were used for development of a fast and easy analysis method based on sample preparation using solid phase extraction with a mixed-mode sorbent and detection by high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Validation demonstrated the suitability of the method with regard to the criteria given by the technical documents of the World Anti-Doping Agency (WADA). In addition, suitability has been proven by successful detection of the synthesized sulfate conjugates in excretion urines and routine doping control samples. PMID:26472592

  1. High Performance Liquid Chromatography of Some Analgesic Compounds: An Instrumental Analysis Experiment.

    ERIC Educational Resources Information Center

    Haddad, Paul; And Others

    1983-01-01

    Background information, procedures, and results are provided for an experiment demonstrating techniques of solvent selection, gradient elution, pH control, and ion-pairing in the analysis of an analgesic mixture using reversed-phase liquid chromatography on an octadecylsilane column. Although developed using sophisticated/expensive equipment, less…

  2. Visiting Science Museums during Middle and High School: A Longitudinal Analysis of Student Performance in Science

    ERIC Educational Resources Information Center

    Suter, Larry E.

    2014-01-01

    This exploratory analysis of student attendance at science museums finds that student achievement in science and mathematics is somewhat higher for those students who visited science museums frequently during the school year or summer. The strength of the association with cognitive achievement is sufficiently noteworthy to encourage further…

  3. A two-dimensional thermal analysis of a new high-performance tubular solar collector

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.; Yung, C. S.

    1979-01-01

    The first of two articles are presented which describe and analyze the thermal performance of a vacuum tube solar collector. The assumptions and mathematical modeling are presented. The problem is reduced to the formulation of two simultaneous linear differential equations characterizing the collector thermal behavior. After applying the boundary conditions, a general solution is obtained which is found similar to the general Hottel, Whillier and Bliss form but with a complex flow factor.

  4. Quality Assessment of Ojeok-San, a Traditional Herbal Formula, Using High-Performance Liquid Chromatography Combined with Chemometric Analysis

    PubMed Central

    Kim, Jung-Hoon; Seo, Chang-Seob; Kim, Seong-Sil; Shin, Hyeun-Kyoo

    2015-01-01

    Ojeok-san (OJS) is a traditional herbal formula consisting of 17 herbal medicines that has been used to treat various disorders. In this study, quantitative analytical methods were developed using high-performance liquid chromatography equipped with a photodiode array detector to determine 19 marker compounds in OJS preparations, which was then combined with chemometric analysis. The method developed was validated in terms of its precision and accuracy. The intra- and interday precision of the marker compounds were <3.0% of the relative standard deviation (RSD) and the recovery of the marker compounds was 92.74%–104.16% with RSD values <3.0%. The results of our quantitative analysis show that the quantities of the 19 marker compounds varied between a laboratory water extract and commercial OJS granules. The chemometric analysis used, principal component analysis (PCA) and hierarchical clustering analysis (HCA), also showed that the OJS water extract produced using a laboratory method clearly differed from the commercial OJS granules; therefore, an equalized production process is required for quality control of OJS preparations. Our results suggest that the HPLC analytical methods developed are suitable for the quantification and quality assessment of OJS preparations when combined with chemometric analysis involving PCA and HCA. PMID:26539304

  5. Comprehensive analysis of chemical constituents in Xingxiong injection by high performance liquid chromatography coupled with mass spectrometry.

    PubMed

    Guo, Long; Dou, Li-Li; Duan, Li; Liu, Ke; Bi, Zhi-Ming; Li, Ping; Liu, E-Hu

    2015-09-01

    Xingxiong injection (XXI) is a widely used Chinese herbal formula prepared by the folium ginkgo extract and ligustrazine for the treatment of cardiovascular and cerebrovascular diseases. Compared with the pharmacological studies, chemical analysis and quality control studies on this formula are relatively limited. In the present study, a high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF MS) method was applied to comprehensive analysis of constituents in XXI. According to the fragmentation rules and previous reports, thirty ginkgo flavonoids, four ginkgo terpene lactones, and one alkaloid were identified. A high performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-QQQ MS) method was then applied to quantify ten major constituents in XXI. The method validation results indicated that the developed method had desirable specificity, linearity, precision and accuracy. The total contents of ginkgo flavonoids were about 22.05-25.51 μg·mL(-1) and the ginkgo terpene lactones amounts were about 4.41-8.70 μg·mL(-1) in six batches of XXI samples, respectively. Furthermore, cosine ratio algorithm and distance measurements were employed to evaluate the similarity of XXI samples, and the results demonstrated a high-quality consistency. This work could provide comprehensive information on the quality control of Xingxiong injection, which be helpful in the establishment of a rational quality control standard.

  6. High-performance hybrid Orbitrap mass spectrometers for quantitative proteome analysis: Observations and implications.

    PubMed

    Williamson, James C; Edwards, Alistair V G; Verano-Braga, Thiago; Schwämmle, Veit; Kjeldsen, Frank; Jensen, Ole N; Larsen, Martin R

    2016-03-01

    We present basic workups and quantitative comparisons for two current generation Orbitrap mass spectrometers, the Q Exactive Plus and Orbitrap Fusion Tribrid, which are widely considered two of the highest performing instruments on the market. We assessed the performance of two quantitative methods on both instruments, namely label-free quantitation and stable isotope labeling using isobaric tags, for studying the heat shock response in Escherichia coli. We investigated the recently reported MS3 method on the Fusion instrument and the potential of MS3-based reporter ion isolation Synchronous Precursor Selection (SPS) and its impact on quantitative accuracy. We confirm that the label-free approach offers a more linear response with a wider dynamic range than MS/MS-based isobaric tag quantitation and that the MS3/SPS approach alleviates but does not eliminate dynamic range compression. We observed, however, that the choice of quantitative approach had little impact on the ability to statistically evaluate the E. coli heat shock response. We conclude that in the experimental conditions tested, MS/MS-based reporter ion quantitation provides reliable biological insight despite the issue of compressed dynamic range, an observation that significantly impacts the choice of instrument.

  7. Analysis of 26-hydroxycholesterol in plasma by high performance liquid chromatography

    SciTech Connect

    Kou, I.L.; Holmes, R.P.

    1986-03-01

    A method utilizing HPLC has been developed for the analysis of 26-hydroxycholesterol in plasma. The method involves initially saponifying samples for estimation of the total sterol or extracting samples with acetonitrile to estimate the free sterol. This is followed by a C-18 Sep Pak fractionation of the extracts, further purification on a Nova Pak C-18 HPLC column, and finally by quantitation on a silicic acid HPLC column by measuring the absorbance at 210 nm. Losses of sterol during this multi-step procedure were determined by estimating the recovery of /sup 3/H-26-hydroxycholesterol added to samples before extraction or saponification. The reproducibility of the method was evaluated by repetitive analysis of one plasma sample. The coefficient of variation was 6.8% for six analyses. In agreement with the mass spectrometric determinations of Javitt et al. The authors observed total plasma levels in the range of 140-260 ng/ml in young adult humans, rats, and rabbits. In the plasma of older human patients undergoing coronary by-pass surgery levels ranged from 335-950 ng/ml, suggesting that an increase in the level of 26-hydroxycholesterol is either age-related or related to the development of acute atherosclerosis.

  8. Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC) : gap analysis for high fidelity and performance assessment code development.

    SciTech Connect

    Lee, Joon H.; Siegel, Malcolm Dean; Arguello, Jose Guadalupe, Jr.; Webb, Stephen Walter; Dewers, Thomas A.; Mariner, Paul E.; Edwards, Harold Carter; Fuller, Timothy J.; Freeze, Geoffrey A.; Jove-Colon, Carlos F.; Wang, Yifeng

    2011-03-01

    This report describes a gap analysis performed in the process of developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with rigorous verification, validation, and software quality requirements. The gap analyses documented in this report were are performed during an initial gap analysis to identify candidate codes and tools to support the development and integration of the Waste IPSC, and during follow-on activities that delved into more detailed assessments of the various codes that were acquired, studied, and tested. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. The gap analysis indicates that significant capabilities may already exist in the existing THC codes although there is no single code able to fully account for all physical and chemical processes involved in a waste disposal system. Large gaps exist in modeling chemical processes and their couplings with other processes. The coupling of chemical processes with flow transport and mechanical deformation remains challenging. The data for extreme environments (e.g., for elevated temperature and high ionic strength media) that are

  9. A parallel-vector algorithm for rapid structural analysis on high-performance computers

    NASA Technical Reports Server (NTRS)

    Storaasli, Olaf O.; Nguyen, Duc T.; Agarwal, Tarun K.

    1990-01-01

    A fast, accurate Choleski method for the solution of symmetric systems of linear equations is presented. This direct method is based on a variable-band storage scheme and takes advantage of column heights to reduce the number of operations in the Choleski factorization. The method employs parallel computation in the outermost DO-loop and vector computation via the loop unrolling technique in the innermost DO-loop. The method avoids computations with zeros outside the column heights, and as an option, zeros inside the band. The close relationship between Choleski and Gauss elimination methods is examined. The minor changes required to convert the Choleski code to a Gauss code to solve non-positive-definite symmetric systems of equations are identified. The results for two large scale structural analyses performed on supercomputers, demonstrate the accuracy and speed of the method.

  10. High-performance analysis of single interphase cells with custom DNA probes spanning translocation break points

    NASA Astrophysics Data System (ADS)

    Weier, Heinz-Ulli G.; Munne, S.; Lersch, Robert A.; Marquez, C.; Wu, J.; Pedersen, Roger A.; Fung, Jingly

    1999-06-01

    The chromatin organization of interphase cell nuclei, albeit an object of intense investigation, is only poorly understood. In the past, this has hampered the cytogenetic analysis of tissues derived from specimens where only few cells were actively proliferating or a significant number of metaphase cells could be obtained by induction of growth. Typical examples of such hard to analyze cell systems are solid tumors, germ cells and, to a certain extent, fetal cells such as amniocytes, blastomeres or cytotrophoblasts. Balanced reciprocal translocations that do not disrupt essential genes and thus do not led to disease symptoms exit in less than one percent of the general population. Since the presence of translocations interferes with homologue pairing in meiosis, many of these individuals experience problems in their reproduction, such as reduced fertility, infertility or a history of spontaneous abortions. The majority of translocation carriers enrolled in our in vitro fertilization (IVF) programs carry simple translocations involving only two autosomes. While most translocations are relatively easy to spot in metaphase cells, the majority of cells biopsied from embryos produced by IVF are in interphase and thus unsuitable for analysis by chromosome banding or FISH-painting. We therefore set out to analyze single interphase cells for presence or absence of specific translocations. Our assay, based on fluorescence in situ hybridization (FISH) of breakpoint-spanning DNA probes, detects translocations in interphase by visual microscopic inspection of hybridization domains. Probes are prepared so that they span a breakpoint and cover several hundred kb of DNA adjacent to the breakpoint. On normal chromosomes, such probes label a contiguous stretch of DNA and produce a single hybridization domain per chromosome in interphase cells. The translocation disrupts the hybridization domain and the resulting two fragments appear as physically separated hybridization domains in

  11. An application of high performance liquid chromatographic assay for the kinetic analysis of degradation of faropenem.

    PubMed

    Cielecka-Piontek, J; Krause, A; Paczkowska, M

    2012-11-01

    An isocratic RP-HPLC-DAD procedure was developed and validated for kinetic analysis of degradation of faropenem in bulk drug substance and in tablets. It involved the use of a C-18 analytical column (5 microm particle size, 250 mm x 4.6 mm), flow rate 1.3 ml/min and 50 microl injection volume. The mobile phase consisted of acetate buffer (pH 3.5) - acetonitrile (70:30 v/v). The determination was carried out at the wavelength of 323 nm. Kinetic studies of faropenem degradation in aqueous solutions included hydrolysis, oxidation, photolysis and thermal degradation. A derivative spectrophotometry was used as an alternative method to compare the observed rate constants. PMID:23210240

  12. Multicriteria Decision Analysis of Material Selection of High Energy Performance Residential Building

    NASA Astrophysics Data System (ADS)

    Čuláková, Monika; Vilčeková, Silvia; Katunská, Jana; Krídlová Burdová, Eva

    2013-11-01

    In world with limited amount of energy sources and with serious environmental pollution, interest in comparing the environmental embodied impacts of buildings using different structure systems and alternative building materials will be increased. This paper shows the significance of life cycle energy and carbon perspective and the material selection in reducing energy consumption and emissions production in the built environment. The study evaluates embodied environmental impacts of nearly zero energy residential structures. The environmental assessment uses framework of LCA within boundary: cradle to gate. Designed alternative scenarios of material compositions are also assessed in terms of energy effectiveness through selected thermal-physical parameters. This study uses multi-criteria decision analysis for making clearer selection between alternative scenarios. The results of MCDA show that alternative E from materials on nature plant base (wood, straw bales, massive wood panel) present possible way to sustainable perspective of nearly zero energy houses in Slovak republic

  13. High-resolution ISAR imaging of maneuvering targets by means of the range instantaneous Doppler technique: modeling and performance analysis.

    PubMed

    Berizzi, F; Mese, E D; Diani, M; Martorella, M

    2001-01-01

    Very high resolution inverse synthetic aperture radar (ISAR) imaging of maneuvering targets is a complicated task. In fact, the conventional range Doppler (RD) ISAR technique does not work properly when target motions generate terms higher than the first order in the phase of the received signal relative to each scatterer. This effect typically happens when at least one of these situations occur: (1) very high resolution images are required; (2) the target maneuvers; and (3) the target undergoes significant angular motions (roll, pitch, and yaw). A novel ISAR technique, named range instantaneous Doppler (RID), has been proposed for the reconstruction of very high resolution images of maneuvering targets. In this paper, we analytically show that the RID technique works properly when high-resolution ISAR images are required of maneuvering and/or rolling, pitching, and yawing targets; we also quantify the performance improvement of the RID technique with respect to the RD technique. The problem is tackled from an analytical point of view. First, we define a new model of the ISAR received signal that is valid for maneuvering targets, then we derive and compare the analytical expression of the point spread function (PSF) for the two techniques. Furthermore, we perform a statistical analysis to evaluate the improvement of the RID technique versus the RD technique in terms of spatial resolution. Finally, we prove the effectiveness of the RID technique by simulating the imaging process for two different targets: (1) a ship that undergoes roll, pitch and yaw motions and (2) a fast maneuvering airplane.

  14. Quantitative analysis of triglyceride species of vegetable oils by high performance liquid chromatography via a flame ionization detector.

    PubMed

    Phillips, F C; Erdahl, W L; Schmit, J A; Privett, O S

    1984-11-01

    A method for the quantitative analysis of triglyceride species composition of vegetable oils by reversed-phase high performance liquid chromatography (RP-HPLC) via a flame ionization detector (FID) is described. Triglycerides are separated into molecular species via Zorbax chemically bonded octadecylsilane (ODS) columns using gradient elution with methylene chloride in acetonitrile. Identification of species is made by matching the retention times of the peaks in the chromatogram with the order of elution of all of the species that could be present in the sample on the basis of a random distribution of the fatty acids and comparison of experimental and calculated theoretical carbon numbers (TCN). Quantitative analysis is based on a direct proportionality of peak areas. Differences in the response of individual species were small and did not dictate the use of response factors. The method is applied to cocoa butter before and after randomization, soybean oil and pure olive oil.

  15. Practice on high performance liquid chromatography. Applications, equipment, and quantitative analysis

    SciTech Connect

    Engelhardt, H.

    1986-01-01

    The title of this book suggests yet another general text on the principles and practice of HPLC-of which there are at least a dozen currently available. This is not the case, however. Instead, the editor has assembled a series of more specialized chapters addressed to the experienced chromatographer. That is, it is assumed that the reader has already been exposed to a more general and basic book on HPLC. Thus, there is no general discussion of the principles of separation, extracolumn effects, how an HPLC procedure is developed, column packings and techniques for reversed-phase HPLC, etc. The first five chapters of the book deal with equipment, quantitative analysis, preparative HPLC, column switching, and sample pretreatment. This paper of the book contains useful material not often seen in other books or review articles. The next two chapters deal with liquid-liquid and ion pair chromatography but ignore reversed-phase, normal-phase, and ion exchange chromatography. The final eight chapters deal with applications in different areas: inorganic samples, forensic chemistry, lipids, nucleic acid metabolites, drugs of pharmaceutical interest, amino acids, proteins, and coal and oil products. To summarize, this book is something between a basic text on HPLC and a review series such as Giddings's Advances in Chromatography. Whereas every practicing chromatographer should have a book of the first kind, libraries are the usual customers for the second kind. The author found this book useful in a variety of ways and so should many other reader.

  16. Beyond the CM-5: A case study in performance analysis for the CM-5, T3D, and high performance RISC workstations

    SciTech Connect

    Beazley, D.M.; Lomdahl, P.S.

    1995-03-22

    We present a comprehensive performance evaluation of our molecular dynamics code SPaSM on the CM-5 in order to devise optimization strategies for the CM-5, T3D, and RISC workstations. In this analysis, we focus on the effective use of the SPARC microprocessor by performing measurements of instruction set utilization, cache effects, memory access patterns, and pipeline stall cycles. We then show that we can account for more than 99% of observed execution time of our program. Optimization strategies are devised and we show that our highly optimized ANSI C program running only on the SPARC microprocessor of the CM-5 is only twice as slow as our Gordon-Bell prize winning code that utilized the CM-5 vector units. On the CM-5E, we show that this optimized code run faster than the vector unit version. We then apply these techniques to the Cray T3D and measure resulting speedups. Finally, we show that simple optimization strategies are effective on a wide variety of high performance RISC workstations.

  17. Analysis of histidine and urocanic acid isomers by reversed-phase high-performance liquid chromatography.

    PubMed

    Hermann, K; Abeck, D

    2001-01-01

    The qualitative separation performance of a C18, C8 and C4 reversed-phase column was investigated for the separation of histidine and its metabolites histamine, 1-methyihistamine and trans- and cis-urocanic acid. Trans- and cis-urocanic acid were baseline separated from their precursor histidine on all three columns using isocratic elution with a mobile phase composed of 0.01 M aqueous TEAP pH 3.0 and acetonitrile at a ratio of 98:2 (v/v). However, histidine was not separated from histamine and 1-methyihistamine. Selecting the C8 column and introducing 0.005 M of the ion pairing reagent 1-octanesulfonic acid sodium salt into the aqueous solution and acetonitrile at a ratio of 90:10 (v/v), significantly improved the separation. The separation was also followed by a change in the retention times and the order of elution. The sequence of elution was histidine, cis-urocanic acid, trans-urocanic acid, histamine and 1-methylhistamine with retention times of 5.58 +/- 0.07, 7.03 +/- 0.15, 7.92 +/- 0.18, 18.77 +/- 0.24 and 20.79 +/- 0.21 min (mean +/- SD; n=5). The separation on the C8 column in the presence of the ion-pairing reagent was further improved with gradient elution that resulted in a reduction in the retention times and elution volumes of histamine and 1-methylhistamine. The detection limits of histidine and trans-urocanic acid at a wavelength of 210 nm and an injection volume of 0.05 ml were 5 x 10(-8) mol l(-1) (n=3). The kinetic of the in-vitro conversion of trans- into the cis-isomer after UV irradiation was depending on the time of exposure and the energy of the light source. UVB light induced a significantly faster conversion than UVA light. TUCA and cUCA samples kept at -25 degrees C were stable for up to 50 weeks. Samples, eluted from human skin showed various concentrations of histidine and trans- and cis-urocanic acid with an average of 1.69 +/- 0.33 x 10(-5) mol l(-1), 1.17 +/- 0.43 x 10(-5) mol l(-1) and 1.67 +/- 0.33 x 10(-5) mol l(-1), respectively

  18. Performance analysis of high frequency single-site-location antenna arrays using numerical electromagnetic modeling

    NASA Astrophysics Data System (ADS)

    Schiantarelli, Harry T.

    1990-09-01

    Electronic support measures (ESM) systems play an increasingly important role in modern warfare and can influence the outcome of a military engagement. The application of ESM can be extended to anti-guerrilla and anti-drug operations where law enforcement agencies can exploit the fact that their presence is inducing the outlaw to depend more on radio communications to coordinate their activities. When a propagation path of no more than one reflection at the ionosphere (1-hop) can be assumed, position of an HF emitter can be determined by a single observing site using vertical triangulation, provided that the height of the ionosphere at the point where the radio wave is reflected, can be determined. This technique is known as high frequency direction finding single-site-location (HFDF SSL). This thesis analyzes the HFDF SSL error in measuring the direction of arrival of the signal, how this error is generated by the antenna array and its effect on emitter location. The characteristics of the two antenna arrays used by a specific HFDF SSL system that implements the phase-interferometer techniques were studied using electromagnetic modeling.

  19. Wheat gluten amino acid analysis by high-performance anion-exchange chromatography with integrated pulsed amperometric detection.

    PubMed

    Rombouts, Ine; Lagrain, Bert; Lamberts, Lieve; Celus, Inge; Brijs, Kristof; Delcour, Jan A

    2012-01-01

    This chapter describes an accurate and user-friendly method for determining amino acid composition of wheat gluten proteins and their gliadin and glutenin fractions. The method consists of hydrolysis of the peptide bonds in 6.0 M hydrochloric acid solution at 110°C for 24 h, followed by evaporation of the acid and separation of the free amino acids by high-performance anion-exchange chromatography with integrated pulsed amperometric detection. In contrast to conventional methods, the analysis requires neither pre- or postcolumn derivatization, nor a time-consuming oxidation or derivatization step prior to hydrolysis. Correction factors account for incomplete release of Val and Ile even after hydrolysis for 24 h, and for losses of Ser during evaporation. Gradient conditions including an extra eluent allow multiple sequential sample analyses without risk of Glu accumulation on the anion-exchange column which otherwise would result from high Gln levels in gluten proteins.

  20. Commoditization of High Performance Storage

    SciTech Connect

    Studham, Scott S.

    2004-04-01

    The commoditization of high performance computers started in the late 80s with the attack of the killer micros. Previously, high performance computers were exotic vector systems that could only be afforded by an illustrious few. Now everyone has a supercomputer composed of clusters of commodity processors. A similar commoditization of high performance storage has begun. Commodity disks are being used for high performance storage, enabling a paradigm change in storage and significantly changing the price point of high volume storage.

  1. High Performance Computing Today

    SciTech Connect

    Dongarra, Jack; Meuer,Hans; Simon,Horst D.; Strohmaier,Erich

    2000-04-01

    In last 50 years, the field of scientific computing has seen a rapid change of vendors, architectures, technologies and the usage of systems. Despite all these changes the evolution of performance on a large scale however seems to be a very steady and continuous process. Moore's Law is often cited in this context. If the authors plot the peak performance of various computers of the last 5 decades in Figure 1 that could have been called the supercomputers of their time they indeed see how well this law holds for almost the complete lifespan of modern computing. On average they see an increase in performance of two magnitudes of order every decade.

  2. A Policy Analysis: State Teacher Evaluations Policies and Practices in Comparison to Evidenced Based Characteristics of High Performing Teachers

    ERIC Educational Resources Information Center

    Janson, Karl E.; Martin, Patrick N.; Sutton, Marica K.

    2011-01-01

    This policy analysis of teacher evaluations focuses specifically on teacher practices related to student performance. Due to the relationship between teacher practices and student performance, and the need for evaluation policy to include these practices, the policy analysis of teacher evaluation policies was conducted. The focus of the project…

  3. 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.

  4. [Preparation of flavonoid reference standards from Scutellariae Radix under the guidance of high performance liquid chromatography-mass spectrometry analysis].

    PubMed

    Guo, Henan; Yang, Xuedong; Liu, Jun; Zheng, Wenfeng

    2012-07-01

    Flavonoid reference standards were targeted-prepared from Scutellariae Radix under the guidance of high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. With HPLC-MS analysis of Scutellariae Radix, 19 flavonoid components were identified by analyzing and comparing their retention times, ultraviolet spectra, and mass spectrometry data with literature. The separation and purification protocols of all targeted flavonoid reference standards were optimally designed according to the results of HPLC-MS analysis and related literature. The ethanol extract of Scutellariae Radix was suspended in water and extracted with petroleum ether, ethyl acetate, and n-butanol successively. The ethyl acetate extract and n-butanol extract were separately subjected to primary separation by low pressure reverse phase preparative chromatography. Then the fractions containing targeted compounds were further purified by low pressure reverse and normal phases preparative chromatography. Finally, baicalin and wogonoside reference standards were obtained from n-butanol extract; baicaelin, wogonin, and oroxylin A reference standards were obtained from ethyl acetate extract. The structures of the 5 reference standards were identified by mass spectrometry (MS) and 1H nuclear magnetic resonance (1H NMR) spectroscopy. The HPLC analytical results showed that the purities of the 5 reference standards were all above 98%. It is demonstrated that the rapid targeted-preparation method under the guidance of the HPLC-MS analysis is applicable for the isolation and preparation of chemical components in traditional Chinese medicines.

  5. High Performance Tools And Technologies

    SciTech Connect

    Collette, M R; Corey, I R; Johnson, J R

    2005-01-24

    This goal of this project was to evaluate the capability and limits of current scientific simulation development tools and technologies with specific focus on their suitability for use with the next generation of scientific parallel applications and High Performance Computing (HPC) platforms. The opinions expressed in this document are those of the authors, and reflect the authors' current understanding and functionality of the many tools investigated. As a deliverable for this effort, we are presenting this report describing our findings along with an associated spreadsheet outlining current capabilities and characteristics of leading and emerging tools in the high performance computing arena. This first chapter summarizes our findings (which are detailed in the other chapters) and presents our conclusions, remarks, and anticipations for the future. In the second chapter, we detail how various teams in our local high performance community utilize HPC tools and technologies, and mention some common concerns they have about them. In the third chapter, we review the platforms currently or potentially available to utilize these tools and technologies on to help in software development. Subsequent chapters attempt to provide an exhaustive overview of the available parallel software development tools and technologies, including their strong and weak points and future concerns. We categorize them as debuggers, memory checkers, performance analysis tools, communication libraries, data visualization programs, and other parallel development aides. The last chapter contains our closing information. Included with this paper at the end is a table of the discussed development tools and their operational environment.

  6. Effects of high power ultrasound on all-E-β-carotene, newly formed compounds analysis by ultra-high-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Carail, Michel; Fabiano-Tixier, Anne-Sylvie; Meullemiestre, Alice; Chemat, Farid; Caris-Veyrat, Catherine

    2015-09-01

    To study effects of high power ultrasound treatment (20 kHz) on β-carotene degradation, a second-order central composite design (CCD) was performed to investigate maximum β-carotene loss with three independent factors (ultrasonic intensity, sonication time, and temperature). Results based on variance analysis and Pareto chart have shown that sonication time is the most important factor, followed by ultrasonic intensity level. The evolved degradation products have been tentatively identified using ultra high performance liquid chromatography coupled to both diode array detector and a mass spectrometer (UHPLC-DAD-MS). The main degradation products, tentatively identified, are three Z-isomers of β-carotene and seven β-apo-carotenals/ones. Hypothesis on the degradation mechanism of carotenoids are presented.

  7. A meta-analysis of the effects of high ambient temperature on growth performance of growing-finishing pigs.

    PubMed

    Renaudeau, D; Gourdine, J L; St-Pierre, N R

    2011-07-01

    High ambient temperature (T) is one of the most important climatic factors influencing pig performance. Increased T occurs sporadically during summer heat waves in temperate climates and year round in tropical climates. Results of published experiments assessing the effects of high T on pig performance are surprisingly variable. Thus, a meta-analysis was performed to aggregate our knowledge and attempt to explain differences in the results across studies on the effect of increased T on ADFI and ADG in growing-finishing pigs. Data for ADFI and ADG were extracted from 86 and 80 trials, respectively, from articles published in scientific journals indexed in PubMed, Science Direct, and from proceedings of scientific meetings through November 2009. Data on ADFI and ADG were analyzed using a linear mixed model that included the linear and the quadratic effects of T and BW, and their interactions as continuous, fixed effects variables, and the trial as a random effect factor (i.e., block). In addition, the effects of housing type (2 levels: individual and group housing) and the year of publication (3 levels: 1970 to 1989, 1990 to 1999, and 2000 to 2009) on the intercept and the linear regression term for T (i.e., the slope) were also tested. Results showed that high T had a curvilinear effect on ADFI and ADG and that this effect was more pronounced in heavier pigs. Across T, ADFI was less when pigs were group-housed. The intercept and the regression coefficient (slope) for T were significantly affected by the year of publication. The effect of increased T was greater in more contemporary works, suggesting that modern genotypes could be more sensitive to heat stress than older genotypes of lesser growth potential. In conclusion, pig performance decreases at an accelerating rate as T is increased. The large between-study variability on the effects of high T on pig performance is partially explained by differences in pig BW and to a lesser extent by the year the study was

  8. New trend in the LC separation analysis of pharmaceuticals--high performance separation by ultra high-performance liquid chromatography (UHPLC) with core-shell particle C18 columns--.

    PubMed

    Nishi, Hiroyuki; Nagamatsu, Kumi

    2014-01-01

    This article presents a mini-review of the recent results in the ultra high-performance liquid chromatography (UHPLC) separation of pharmaceuticals by our group. High performance UHPLC separation employing core-shell particle C18 columns was demonstrated. High performance (high theoretical plate number of approximately 20000/10 cm, low theoretical plate height of 5 μm) was obtained without any specific devices in the conventional HPLC apparatus, only through changing detector sampling times and the inner diameter of the connecting tube. High theoretical plate numbers with low column back pressure obtained by the core-shell particle columns enabled fast separation of the analytes. Methanol, which gives high column pressure drops in the reversed-phase mode HPLC compared with acetonitrile, can be used without any trouble. One analysis of the purity testing of diltiazem hydrochloride was performed within 100 s. One analysis in the photostability testing of mecobalamin (vitamin B12 analogue) was successful within 180 s. PMID:24521905

  9. [Analysis of chlorogenic acids in Helianthus tuberosus Linn leaves using high performance liquid chromatography-mass spectrometry].

    PubMed

    Yuan, Xiaoyan; Gao, Mingzhe; Wang, Kai; Xiao, Hongbin; Tan, Chengyu; Du, Yuguang

    2008-05-01

    To identify chlorogenic acids in Helianthus tuberosus Linn leaves, a method of high performance liquid chromatography-ultraviolet-mass spectrometry (HPLC-UV-MS) was developed. HPLC analysis was performed on an Inertsil ODS-3 column (250 mm x 4.6 mm, 5 microm). The mobile phase consisted of 1% acetic acid (A) and methanol (B). A gradient program was adopted as follows: 0 - 10 min, 20% B to 35% B; 10 - 25 min, 35% B to 50% B; 25 - 35 min, 50% B to 80% B. The flow rate was set at 1.0 mL/min and the column temperature was 35 degrees C. HPLC chromatogram was extracted at 327 nm. The mass spectrometer used was a TSQ triple quadrupole MS equipped with an electrospray ionization (ESI) interface. Initially, the mass spectrometer was programmed to perform full scan ranging from m/z 250 - 1 200. For MS/MS, negative ion monitoring mode was used and the collision energy was set at 10 - 45 eV. By analyzing UV characteristics and MS fragmentation patterns, 7 chlorogenic acids were assigned to be three categories, i. e., three caffeoylquinic acids, one feruloylquinic acid and three dicaffeoylquinic acids. As the results of the method development efforts, an effective and fast method for the qualitative identification of the chlorogenic acids in Helianthus tuberosus Linn leaves was established.

  10. Seismic Assessment of R/C Building Structure through Nonlinear Probabilistic Analysis with High-performance Computing

    SciTech Connect

    Faggella, M.; Barbosa, A.; Conte, J. P.; Restrepo, J. I.; Spacone, E.

    2008-07-08

    This paper presents a probabilistic seismic demand analysis of a three dimensional R/C building model subjected to tri-axial earthquake excitation. Realistic probability distributions are assumed for the main structural and material properties and for the ground motion Intensity Measure (IM) Sa(T1. Natural ground motions are used in the analyses to represent the inherent randomness in the earthquake ground motion time histories. Monte Carlo simulations are performed to account for the record-to-record variability and Tornado diagrams are used to represent the uncertainty induced in the response by the basic uncertainties in the structural properties. In order to perform a probabilistic study on three-dimensional engineering demand parameters (EDPs), a large number of ensemble time history analyses were carried out using the TeraGrid high-performance computing resources available at the San Diego Supercomputer Center. Early results show that for the testbed building used in this study, uncertainty in the structural parameters contribute little to the uncertainty of the EDPs, while large variations in the EDPs are due to the variability of the ground motion intensity measure and the record-to-record variability.

  11. High Performance Arcjet Engines

    NASA Technical Reports Server (NTRS)

    Kennel, Elliot B.; Ivanov, Alexey Nikolayevich; Nikolayev, Yuri Vyacheslavovich

    1994-01-01

    This effort sought to exploit advanced single crystal tungsten-tantalum alloy material for fabrication of a high strength, high temperature arcjet anode. The use of this material is expected to result in improved strength, temperature resistance, and lifetime compared to state of the art polycrystalline alloys. In addition, the use of high electrical and thermal conductivity carbon-carbon composites was considered, and is believed to be a feasible approach. Highly conductive carbon-carbon composite anode capability represents enabling technology for rotating-arc designs derived from the Russian Scientific Research Institute of Thermal Processes (NIITP) because of high heat fluxes at the anode surface. However, for US designs the anode heat flux is much smaller, and thus the benefits are not as great as in the case of NIITP-derived designs. Still, it does appear that the tensile properties of carbon-carbon can be even better than those of single crystal tungsten alloys, especially when nearly-single-crystal fibers such as vapor grown carbon fiber (VGCF) are used. Composites fabricated from such materials must be coated with a refractory carbide coating in order to ensure compatibility with high temperature hydrogen. Fabrication of tungsten alloy single crystals in the sizes required for fabrication of an arcjet anode has been shown to be feasible. Test data indicate that the material can be expected to be at least the equal of W-Re-HfC polycrystalline alloy in terms of its tensile properties, and possibly superior. We are also informed by our colleagues at Scientific Production Association Luch (NP0 Luch) that it is possible to use Russian technology to fabricate polycrystalline W-Re-HfC or other high strength alloys if desired. This is important because existing engines must rely on previously accumulated stocks of these materials, and a fabrication capability for future requirements is not assured.

  12. Chemical fingerprint and quantitative analysis of Salvia plebeia R.Br. by high-performance liquid chromatography.

    PubMed

    Jin, Xiao-feng; Lu, Yan-hua; Wei, Dong-zhi; Wang, Zheng-tao

    2008-09-10

    To control the quality of Salvia plebeia R.Br., a simple and reliable method of high-performance liquid chromatography coupled with photodiode array detector (HPLC-DAD) was developed both for fingerprint analysis and quantitative determination of seven bioactive compounds, namely caffeic acid, luteolin-7-glucoside, nepetin-7-glucoside, homoplantaginin, luteolin, nepetin and hispidulin. In fingerprint analysis, twelve peaks were selected as characteristic peaks. In quantitative analysis, seven compounds showed good regression (R2>0.9995) within test ranges and the recovery of the method was in the range of 91.7-103.2%. The content ranges (mg/g) of seven compounds in the collected samples of S. plebeia were 0.80-1.67 (hispidulin), 2.18-5.75 (homoplantaginin), 0.52-1.22 (nepetin), 1.56-3.48 (nepetin-7-glucoside), 0.12-0.24 (luteolin), 0.97-2.22 (luteolin-7-glucoside) and 0.21-0.44 (caffeic acid), respectively. From the results obtained, the content of homoplantaginin was the highest. In addition, luteolin and luteolin-7-glucoside were isolated for the first time from S. plebeia.

  13. Simultaneous analysis of guaiacol and vanillin in a vanilla extract by using high-performance liquid chromatography with electrochemical detection.

    PubMed

    Takahashi, Makoto; Sakamaki, Shizuka; Fujita, Akira

    2013-01-01

    We developed and validated a new high-performance liquid chromatographic analysis for electrochemically detecting guaiacol and vanillin as important components in vanilla extract. Separation was achieved with Capcell Pak C-18 MG, the potential of the working electrode being set at +1000 mV. The respective calibration curves for guaiacol and vanillin were linear in the range of 1.60-460 µg/L and 5.90-1180 µg/L. The respective limits for the quantities of guaiacol and vanillin were 1.60 µg/L and 2.36 µg/L. The related standard deviations of the intra- and inter-day precision of the retention time and peak area were all less than 4%. The recovery of guaiacol and vanillin was both more than 97%, all of the validation data being within an acceptable range. This analysis method is well suited for the simultaneous and convenient analysis of guaiacol and vanillin in a vanilla extract to evaluate the quality of the vanilla extract.

  14. Chemical fingerprint and quantitative analysis of Salvia plebeia R.Br. by high-performance liquid chromatography.

    PubMed

    Jin, Xiao-feng; Lu, Yan-hua; Wei, Dong-zhi; Wang, Zheng-tao

    2008-09-10

    To control the quality of Salvia plebeia R.Br., a simple and reliable method of high-performance liquid chromatography coupled with photodiode array detector (HPLC-DAD) was developed both for fingerprint analysis and quantitative determination of seven bioactive compounds, namely caffeic acid, luteolin-7-glucoside, nepetin-7-glucoside, homoplantaginin, luteolin, nepetin and hispidulin. In fingerprint analysis, twelve peaks were selected as characteristic peaks. In quantitative analysis, seven compounds showed good regression (R2>0.9995) within test ranges and the recovery of the method was in the range of 91.7-103.2%. The content ranges (mg/g) of seven compounds in the collected samples of S. plebeia were 0.80-1.67 (hispidulin), 2.18-5.75 (homoplantaginin), 0.52-1.22 (nepetin), 1.56-3.48 (nepetin-7-glucoside), 0.12-0.24 (luteolin), 0.97-2.22 (luteolin-7-glucoside) and 0.21-0.44 (caffeic acid), respectively. From the results obtained, the content of homoplantaginin was the highest. In addition, luteolin and luteolin-7-glucoside were isolated for the first time from S. plebeia. PMID:18678457

  15. Assessment of repeatability of composition of perfumed waters by high-performance liquid chromatography combined with numerical data analysis based on cluster analysis (HPLC UV/VIS - CA).

    PubMed

    Ruzik, L; Obarski, N; Papierz, A; Mojski, M

    2015-06-01

    High-performance liquid chromatography (HPLC) with UV/VIS spectrophotometric detection combined with the chemometric method of cluster analysis (CA) was used for the assessment of repeatability of composition of nine types of perfumed waters. In addition, the chromatographic method of separating components of the perfume waters under analysis was subjected to an optimization procedure. The chromatograms thus obtained were used as sources of data for the chemometric method of cluster analysis (CA). The result was a classification of a set comprising 39 perfumed water samples with a similar composition at a specified level of probability (level of agglomeration). A comparison of the classification with the manufacturer's declarations reveals a good degree of consistency and demonstrates similarity between samples in different classes. A combination of the chromatographic method with cluster analysis (HPLC UV/VIS - CA) makes it possible to quickly assess the repeatability of composition of perfumed waters at selected levels of probability.

  16. Comparative analysis of different plant oils by high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

    PubMed

    Jakab, Annamaria; Héberger, Károly; Forgács, Esther

    2002-11-01

    Different vegetable oil samples (almond, avocado, corngerm, grapeseed, linseed, olive, peanut, pumpkin seed, soybean, sunflower, walnut, wheatgerm) were analyzed using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. A gradient elution technique was applied using acetone-acetonitrile eluent systems on an ODS column (Purospher, RP-18e, 125 x 4 mm, 5 microm). Identification of triacylglycerols (TAGs) was based on the pseudomolecular ion [M+1]+ and the diacylglycerol fragments. The positional isomers of triacylglycerol were identified from the relative intensities of the [M-RCO2]+ fragments. Linear discriminant analysis (LDA) as a common multivariate mathematical-statistical calculation was successfully used to distinguish the oils based on their TAG composition. LDA showed that 97.6% of the samples were classified correctly.

  17. New High-Performance Droplet Freezing Assay (HP-DFA) for the Analysis of Ice Nuclei with Complex Composition

    NASA Astrophysics Data System (ADS)

    Kunert, Anna Theresa; Scheel, Jan Frederik; Helleis, Frank; Klimach, Thomas; Pöschl, Ulrich; Fröhlich-Nowoisky, Janine

    2016-04-01

    Freezing of water above homogeneous freezing is catalyzed by ice nucleation active (INA) particles called ice nuclei (IN), which can be of various inorganic or biological origin. The freezing temperatures reach up to -1 °C for some biological samples and are dependent on the chemical composition of the IN. The standard method to analyze IN in solution is the droplet freezing assay (DFA) established by Gabor Vali in 1970. Several modifications and improvements were already made within the last decades, but they are still limited by either small droplet numbers, large droplet volumes or inadequate separation of the single droplets resulting in mutual interferences and therefore improper measurements. The probability that miscellaneous IN are concentrated together in one droplet increases with the volume of the droplet, which can be described by the Poisson distribution. At a given concentration, the partition of a droplet into several smaller droplets leads to finely dispersed IN resulting in better statistics and therefore in a better resolution of the nucleation spectrum. We designed a new customized high-performance droplet freezing assay (HP-DFA), which represents an upgrade of the previously existing DFAs in terms of temperature range and statistics. The necessity of observing freezing events at temperatures lower than homogeneous freezing due to freezing point depression, requires high-performance thermostats combined with an optimal insulation. Furthermore, we developed a cooling setup, which allows both huge and tiny temperature changes within a very short period of time. Besides that, the new DFA provides the analysis of more than 750 droplets per run with a small droplet volume of 5 μL. This enables a fast and more precise analysis of biological samples with complex IN composition as well as better statistics for every sample at the same time.

  18. Ultra-high performance supercritical fluid chromatography coupled with quadrupole-time-of-flight mass spectrometry as a performing tool for bioactive analysis.

    PubMed

    Grand-Guillaume Perrenoud, Alexandre; Guillarme, Davy; Boccard, Julien; Veuthey, Jean-Luc; Barron, Denis; Moco, Sofia

    2016-06-10

    Secondary metabolites are an almost unlimited reservoir of potential bioactive compounds. In view of the wide chemical space covered by natural compounds, their comprehensive analysis requires multiple cutting-edge approaches. This study evaluates the applicability of ultra-high performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC-QqToF-MS) as an analytical strategy for plant metabolites profiling. Versatility of this analytical platform was first assessed using 120 highly diverse natural compounds (according to lipophilicity, hydrogen bond capability, acid-base properties, molecular mass and chemical structure) that were screened on a set of 15 rationally chosen stationary phase chemistries. UHPSFC-QqToF-MS provides a suitable analytical solution for 88% of the tested compounds. Three stationary phases (Diol, not endcapped C18 and 2-EP) were highlighted as particularly polyvalent, since they allow suitable elution of 101 out of 120 natural compounds. The systematic evaluation of retention and selectivity of natural compounds further underlined the suitability of these three columns for the separation of natural compounds. This reduced set of key stationary phases constitutes a basis for untargeted scouting analysis and method development. Even if they were less versatile, stationary phases such as endcapped T3C18, polar P-PFP, were nevertheless found to provide extended selectivity for specific natural molecules sub-classes. Finally, the identified polyvalent conditions were successfully applied for the analysis of complex polar and non-polar plant extracts. These first experimental hits demonstrate the full applicability and potential of UHPSFC-QqToF-MS for plant metabolite profiling. PMID:27156735

  19. High Performance Proactive Digital Forensics

    NASA Astrophysics Data System (ADS)

    Alharbi, Soltan; Moa, Belaid; Weber-Jahnke, Jens; Traore, Issa

    2012-10-01

    With the increase in the number of digital crimes and in their sophistication, High Performance Computing (HPC) is becoming a must in Digital Forensics (DF). According to the FBI annual report, the size of data processed during the 2010 fiscal year reached 3,086 TB (compared to 2,334 TB in 2009) and the number of agencies that requested Regional Computer Forensics Laboratory assistance increasing from 689 in 2009 to 722 in 2010. Since most investigation tools are both I/O and CPU bound, the next-generation DF tools are required to be distributed and offer HPC capabilities. The need for HPC is even more evident in investigating crimes on clouds or when proactive DF analysis and on-site investigation, requiring semi-real time processing, are performed. Although overcoming the performance challenge is a major goal in DF, as far as we know, there is almost no research on HPC-DF except for few papers. As such, in this work, we extend our work on the need of a proactive system and present a high performance automated proactive digital forensic system. The most expensive phase of the system, namely proactive analysis and detection, uses a parallel extension of the iterative z algorithm. It also implements new parallel information-based outlier detection algorithms to proactively and forensically handle suspicious activities. To analyse a large number of targets and events and continuously do so (to capture the dynamics of the system), we rely on a multi-resolution approach to explore the digital forensic space. Data set from the Honeynet Forensic Challenge in 2001 is used to evaluate the system from DF and HPC perspectives.

  20. Fingerprint analysis and multi-ingredient quantitative analysis for quality evaluation of Xiaoyanlidan tablets by ultra high performance liquid chromatography with diode array detection.

    PubMed

    Tang, Dao-quan; Li, Zheng; Jiang, Xiang-lan; Li, Yin-jie; Du, Qian; Yang, Dong-zhi

    2014-08-01

    A rapid and sensitive ultra high performance liquid chromatography method with diode array detection was developed for the fingerprint analysis and simultaneous determination of seven active compounds in Xiaoyanlidan (XYLD) tablets. The chromatographic separations were obtained on an Agilent Eclipse plus C18 column (50 × 2.1 mm id, 1.8 μm) using gradient elution with water/formic acid (1%) and acetonitrile at a flow rate of 0.4 mL/min. Within 63 min, 36 peaks could be selected as the common peaks for fingerprint analysis to evaluate the similarities among several samples of XYLD tablets collected from different manufacturers. In quantitative analysis, seven compounds showed good regression (R > 0.9990) within test ranges and the recovery of the method was within the range of 95.9-104.3%. The method was successfully applied to the simultaneous determination of seven compounds in six batches of XYLD tablets. These results demonstrate that the combination of chromatographic fingerprint analysis and simultaneous multi-ingredient quantification using the ultra high performance liquid chromatography method with diode array detection offers a rapid, efficient, and reliable approach for quality evaluation of XYLD tablets.

  1. High Voltage SPT Performance

    NASA Technical Reports Server (NTRS)

    Manzella, David; Jacobson, David; Jankovsky, Robert

    2001-01-01

    A 2.3 kW stationary plasma thruster designed to operate at high voltage was tested at discharge voltages between 300 and 1250 V. Discharge specific impulses between 1600 and 3700 sec were demonstrated with thrust between 40 and 145 mN. Test data indicated that discharge voltage can be optimized for maximum discharge efficiency. The optimum discharge voltage was between 500 and 700 V for the various anode mass flow rates considered. The effect of operating voltage on optimal magnet field strength was investigated. The effect of cathode flow rate on thruster efficiency was considered for an 800 V discharge.

  2. High performance steam development

    SciTech Connect

    Duffy, T.; Schneider, P.

    1995-10-01

    Over 30 years ago U.S. industry introduced the world`s highest temperature (1200{degrees}F at 5000 psig) and most efficient power plant, the Eddystone coal-burning steam plant. The highest alloy material used in the plant was 316 stainless steel. Problems during the first few years of operation caused a reduction in operating temperature to 1100{degrees}F which has generally become the highest temperature used in plants around the world. Leadership in high temperature steam has moved to Japan and Europe over the last 30 years.

  3. Diagnosis of Russell-Silver syndrome by the combined bisulfite restriction analysis-denaturing high-performance liquid chromatography assay.

    PubMed

    Hattori, Mitsu; Torii, Chiharu; Yagihashi, Tatsuhiko; Izumi, Kosuke; Suda, Naoto; Ohyama, Kimie; Takahashi, Takao; Moriyama, Keiji; Kosaki, Kenjiro

    2009-10-01

    Russell-Silver syndrome (RSS) is characterized by prenatal and postnatal growth retardation, triangular facies, and fifth-finger clinodactyly. Half of all patients with RSS have hypomethylation of the differentially methylated region of the H19 gene on chromosome 11p15.5. Hence, a quantitative methylation analysis of this region can be useful for the molecular diagnosis of RSS. However, conventional assays based on bisulfite clone sequencing are rather time and labor consuming and are not suitable for clinical use. In the present study, we investigated a possible method of quantitatively determining H19 hypomethylation in RSS patients using a combined bisulfite restriction analysis (COBRA)-denaturing high-performance liquid chromatography (DHPLC) assay; in this combined assay, polymerase chain reaction products amplified from the H19 differentially methylated region of bisulfite-treated genomic DNA were analyzed using a COBRA assay, which detects methylation-dependent sequence differences in the bisulfite-treated genomic DNA using a restriction enzyme analysis. We designed the assay so that a restriction enzyme (HinfI) would cut the methylated, but not the unmethylated, template. The molar ratio between the cut and uncut fragments was measured using DHPLC, and the construction of a calibration curve enabled the methylation index for the original genomic DNA to be estimated. An analysis of seven RSS patients using the COBRA-DHPLC assay demonstrated that three of the seven RSS patients had a low methylation index of around 10%. A comparison of the methylation indices obtained using COBRA-DHPLC and conventional bisulfite clone sequencing revealed an excellent intermethod agreement. In summary, we have developed a robust, rapid, and cost-effective COBRA-DHPLC-based screening system for RSS.

  4. Leveraging the Power of High Performance Computing for Next Generation Sequencing Data Analysis: Tricks and Twists from a High Throughput Exome Workflow

    PubMed Central

    Wonczak, Stephan; Thiele, Holger; Nieroda, Lech; Jabbari, Kamel; Borowski, Stefan; Sinha, Vishal; Gunia, Wilfried; Lang, Ulrich; Achter, Viktor; Nürnberg, Peter

    2015-01-01

    Next generation sequencing (NGS) has been a great success and is now a standard method of research in the life sciences. With this technology, dozens of whole genomes or hundreds of exomes can be sequenced in rather short time, producing huge amounts of data. Complex bioinformatics analyses are required to turn these data into scientific findings. In order to run these analyses fast, automated workflows implemented on high performance computers are state of the art. While providing sufficient compute power and storage to meet the NGS data challenge, high performance computing (HPC) systems require special care when utilized for high throughput processing. This is especially true if the HPC system is shared by different users. Here, stability, robustness and maintainability are as important for automated workflows as speed and throughput. To achieve all of these aims, dedicated solutions have to be developed. In this paper, we present the tricks and twists that we utilized in the implementation of our exome data processing workflow. It may serve as a guideline for other high throughput data analysis projects using a similar infrastructure. The code implementing our solutions is provided in the supporting information files. PMID:25942438

  5. Leveraging the power of high performance computing for next generation sequencing data analysis: tricks and twists from a high throughput exome workflow.

    PubMed

    Kawalia, Amit; Motameny, Susanne; Wonczak, Stephan; Thiele, Holger; Nieroda, Lech; Jabbari, Kamel; Borowski, Stefan; Sinha, Vishal; Gunia, Wilfried; Lang, Ulrich; Achter, Viktor; Nürnberg, Peter

    2015-01-01

    Next generation sequencing (NGS) has been a great success and is now a standard method of research in the life sciences. With this technology, dozens of whole genomes or hundreds of exomes can be sequenced in rather short time, producing huge amounts of data. Complex bioinformatics analyses are required to turn these data into scientific findings. In order to run these analyses fast, automated workflows implemented on high performance computers are state of the art. While providing sufficient compute power and storage to meet the NGS data challenge, high performance computing (HPC) systems require special care when utilized for high throughput processing. This is especially true if the HPC system is shared by different users. Here, stability, robustness and maintainability are as important for automated workflows as speed and throughput. To achieve all of these aims, dedicated solutions have to be developed. In this paper, we present the tricks and twists that we utilized in the implementation of our exome data processing workflow. It may serve as a guideline for other high throughput data analysis projects using a similar infrastructure. The code implementing our solutions is provided in the supporting information files.

  6. Leveraging the power of high performance computing for next generation sequencing data analysis: tricks and twists from a high throughput exome workflow.

    PubMed

    Kawalia, Amit; Motameny, Susanne; Wonczak, Stephan; Thiele, Holger; Nieroda, Lech; Jabbari, Kamel; Borowski, Stefan; Sinha, Vishal; Gunia, Wilfried; Lang, Ulrich; Achter, Viktor; Nürnberg, Peter

    2015-01-01

    Next generation sequencing (NGS) has been a great success and is now a standard method of research in the life sciences. With this technology, dozens of whole genomes or hundreds of exomes can be sequenced in rather short time, producing huge amounts of data. Complex bioinformatics analyses are required to turn these data into scientific findings. In order to run these analyses fast, automated workflows implemented on high performance computers are state of the art. While providing sufficient compute power and storage to meet the NGS data challenge, high performance computing (HPC) systems require special care when utilized for high throughput processing. This is especially true if the HPC system is shared by different users. Here, stability, robustness and maintainability are as important for automated workflows as speed and throughput. To achieve all of these aims, dedicated solutions have to be developed. In this paper, we present the tricks and twists that we utilized in the implementation of our exome data processing workflow. It may serve as a guideline for other high throughput data analysis projects using a similar infrastructure. The code implementing our solutions is provided in the supporting information files. PMID:25942438

  7. [A method for the analysis of overlapped peaks in the high performance liquid chromatogram based on spectrum analysis].

    PubMed

    Liu, Bao; Fan, Xiaoming; Huo, Shengnan; Zhou, Lili; Wang, Jun; Zhang, Hui; Hu, Mei; Zhu, Jianhua

    2011-12-01

    A method was established to analyse the overlapped chromatographic peaks based on the chromatographic-spectra data detected by the diode-array ultraviolet detector. In the method, the three-dimensional data were de-noised and normalized firstly; secondly the differences and clustering analysis of the spectra at different time points were calculated; then the purity of the whole chromatographic peak were analysed and the region were sought out in which the spectra of different time points were stable. The feature spectra were extracted from the spectrum-stable region as the basic foundation. The nonnegative least-square method was chosen to separate the overlapped peaks and get the flow curve which was based on the feature spectrum. The three-dimensional divided chromatographic-spectrum peak could be gained by the matrix operations of the feature spectra with the flow curve. The results displayed that this method could separate the overlapped peaks.

  8. High Performance Astrophysics Computing

    NASA Astrophysics Data System (ADS)

    Capuzzo-Dolcetta, R.; Arca-Sedda, M.; Mastrobuono-Battisti, A.; Punzo, D.; Spera, M.

    2012-07-01

    The application of high end computing to astrophysical problems, mainly in the galactic environment, is developing for many years at the Dep. of Physics of Sapienza Univ. of Roma. The main scientific topic is the physics of self gravitating systems, whose specific subtopics are: i) celestial mechanics and interplanetary probe transfers in the solar system; ii) dynamics of globular clusters and of globular cluster systems in their parent galaxies; iii) nuclear clusters formation and evolution; iv) massive black hole formation and evolution; v) young star cluster early evolution. In this poster we describe the software and hardware computational resources available in our group and how we are developing both software and hardware to reach the scientific aims above itemized.

  9. Multivalent sialylation of β-thio-glycoclusters by Trypanosoma cruzi trans sialidase and analysis by high performance anion exchange chromatography.

    PubMed

    Agustí, Rosalía; Cano, María Emilia; Cagnoni, Alejandro J; Kovensky, José; de Lederkremer, Rosa M; Uhrig, María Laura

    2016-10-01

    The synthesis of multivalent sialylated glycoclusters is herein addressed by a chemoenzymatic approach using the trans-sialidase of Trypanosoma cruzi (TcTS). Multivalent β-thio-galactopyranosides and β-thio-lactosides were used as acceptor substrates and 3'-sialyllactose as the sialic acid donor. High performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was shown to be an excellent technique for the analysis of the reaction products. Different eluting conditions were optimized to allow the simultaneous resolution of the sialylated species, as well as their neutral precursors. The TcTS efficiently transferred sialyl residues to di, tri, tetra and octa β-thiogalactosides. In the case of an octavalent thiolactoside, up to six polysialylated compounds could be resolved. Preparative sialylation reactions were performed using the tetravalent and octavalent acceptor substrates. The main sialylated derivatives could be unequivocally assigned by MALDI mass spectrometry. Inhibition of the transfer to the natural substrate, N-acetyllactosamine, was also studied. The octalactoside caused 82 % inhibition of sialic acid transfer when we used equimolar concentrations of donor, acceptor and inhibitor.

  10. Rapid high-performance liquid chromatography method for the analysis of sodium benzoate and potassium sorbate in foods.

    PubMed

    Pylypiw, H M; Grether, M T

    2000-06-23

    A rapid and reliable method is presented for the determination of the preservatives sodium benzoate and potassium sorbate in fruit juices, sodas, soy sauce, ketchup, peanut butter, cream cheese, and other foods. The procedure utilizes high-performance liquid chromatography (HPLC) followed by UV diode array detection for identification and quantitation of the two preservatives. Liquid samples were prepared by diluting 1 ml of the sample with 10 ml of an acetonitrile/ammonium acetate buffer solution. Samples of viscous or solid foods were prepared by blending the sample with the same buffer solution in a 1:5 ratio followed by a dilution identical to liquid samples. All samples were filtered to remove particulate matter prior to analysis. The HPLC determination of the preservatives was performed using a reversed-phase C18 column and UV detection at 225 nm for sodium benzoate and 255 nm potassium sorbate. The percentage of preservative in the sample was calculated by external standard using authentic sodium benzoate and potassium sorbate. Apple juice, apple sauce, soy sauce, and peanut butter, spiked at 0.10 and 0.050% for both sodium benzoate and potassium sorbate, yielded recoveries ranging from 82 to 96%. The method can detect 0.0010% (10 mg/l) of either preservative in a juice matrix. PMID:10910223

  11. High Performance Parallel Computational Nanotechnology

    NASA Technical Reports Server (NTRS)

    Saini, Subhash; Craw, James M. (Technical Monitor)

    1995-01-01

    At a recent press conference, NASA Administrator Dan Goldin encouraged NASA Ames Research Center to take a lead role in promoting research and development of advanced, high-performance computer technology, including nanotechnology. Manufacturers of leading-edge microprocessors currently perform large-scale simulations in the design and verification of semiconductor devices and microprocessors. Recently, the need for this intensive simulation and modeling analysis has greatly increased, due in part to the ever-increasing complexity of these devices, as well as the lessons of experiences such as the Pentium fiasco. Simulation, modeling, testing, and validation will be even more important for designing molecular computers because of the complex specification of millions of atoms, thousands of assembly steps, as well as the simulation and modeling needed to ensure reliable, robust and efficient fabrication of the molecular devices. The software for this capacity does not exist today, but it can be extrapolated from the software currently used in molecular modeling for other applications: semi-empirical methods, ab initio methods, self-consistent field methods, Hartree-Fock methods, molecular mechanics; and simulation methods for diamondoid structures. In as much as it seems clear that the application of such methods in nanotechnology will require powerful, highly powerful systems, this talk will discuss techniques and issues for performing these types of computations on parallel systems. We will describe system design issues (memory, I/O, mass storage, operating system requirements, special user interface issues, interconnects, bandwidths, and programming languages) involved in parallel methods for scalable classical, semiclassical, quantum, molecular mechanics, and continuum models; molecular nanotechnology computer-aided designs (NanoCAD) techniques; visualization using virtual reality techniques of structural models and assembly sequences; software required to

  12. Metabolite analysis of toosendanin by an ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry technique.

    PubMed

    Wu, Jian-Lin; Leung, Elaine Lai-Han; Zhou, Hua; Liu, Liang; Li, Na

    2013-01-01

    Toosendanin is the major bioactive component of Melia toosendan Sieb. et Zucc., which is traditionally used for treatment of abdominal pain and as an insecticide. Previous studies reported that toosendanin possesses hepatotoxicity, but the mechanism remains unknown. Its bioavailability in rats is low, which indicates the hepatotoxicity might be induced by its metabolites. In this connection, in the current study, we examined the metabolites obtained by incubating toosendanin with human live microsomes, and then six of these metabolites (M1-M6) were identified for the first time by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF/MS). Further analysis on the MS spectra showed M1, M2, and M3 are oxidative products and M6 is a dehydrogenation product, while M4 and M5 are oxidative and dehydrogenation products of toosendanin. Moreover, their possible structures were deduced from the MS/MS spectral features. Quantitative analysis demonstrated that M1-M5 levels rapidly increased and reached a plateau at 30 min, while M6 rapidly reached a maximal level at 20 min and then decreased slowly afterwards. These findings have provided valuable data not only for understanding the metabolic fate of toosendanin in liver microsomes, but also for elucidating the possible molecular mechanism of its hepatotoxicity. PMID:24084018

  13. Investigation of eluted monomers from resin-based root canal sealer by high-performance liquid chromatography analysis

    PubMed Central

    Omurlu, Huma; Arisu, Hacer Deniz; Dalkilic, Evrim Eliguzeloglu; Tamer, Ugur; Torul, Hilal

    2016-01-01

    Objective: The purpose of the current study was to determine the amount of urethane dimethacrylate (UDMA), bisphenol A-glycidyl methacrylate (Bis-GMA), poly (ethylene glycol) dimethacrylate (PEGDMA), bisphenol A ethoxylated dimethacrylate (Bis-EMA), and 2-hydroxyethyl methacrylate (HEMA) eluted from resin-based root canal sealer, epiphany, using high-performance liquid chromatography (HPLC). Materials and Methods: Epiphany was placed into the plastic molds and light-cured with a light emitting diode. After the curing process, each specimen in the first group (n = 12) was immersed in Eppendorf tubes containing a phosphate-buffered saline solution (PBS) and incubated for 45 s. In the second group, each specimen (n = 12) was immersed in Eppendorf tubes containing PBS and incubated for 24 h. Of the specimen extracts, 100 μL were subjected to HPLC. Analysis of data was accomplished with one-way analysis of variance (P < 0.05). Results: All of the samples eluted HEMA, UDMA, Bis-GMA, PEGDMA, and Bis-EMA. A significant difference was determined between the time periods of HEMA, UDMA, PEGDMA, and Bis-EMA (P < 0.05). Conclusion: The results of the current study showed that Epiphany releases HEMA, UDMA, Bis-GMA, PEGDMA, and Bis-EMA in both time periods. PMID:27011746

  14. High performance alloy electroforming

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Winkelman, D. M.

    1989-01-01

    Electroformed copper and nickel are used in structural applications for advanced propellant combustion chambers. An improved process has been developed by Bell Aerospace Textron, Inc. wherein electroformed nickel-manganese alloy has demonstrated superior mechanical and thermal stability when compared to previously reported deposits from known nickel plating processes. Solution chemistry and parametric operating procedures are now established and material property data is established for deposition of thick, large complex shapes such as the Space Shuttle Main Engine. The critical operating variables are those governing the ratio of codeposited nickel and manganese. The deposition uniformity which in turn affects the manganese concentration distribution is affected by solution resistance and geometric effects as well as solution agitation. The manganese concentration in the deposit must be between 2000 and 3000 ppm for optimum physical properties to be realized. The study also includes data regarding deposition procedures for achieving excellent bond strength at an interface with copper, nickel-manganese or INCONEL 718. Applications for this electroformed material include fabrication of complex or re-entry shapes which would be difficult or impossible to form from high strength alloys such as INCONEL 718.

  15. Two-step microextraction combined with high performance liquid chromatographic analysis of pyrethroids in water and vegetable samples.

    PubMed

    Mukdasai, Siriboon; Thomas, Chunpen; Srijaranai, Supalax

    2014-03-01

    Dispersive liquid microextraction (DLME) combined with dispersive µ-solid phase extraction (D-µ-SPE) has been developed as a new approach for the extraction of four pyrethroids (tetramethrin, fenpropathrin, deltamethrin and permethrin) prior to the analysis by high performance liquid chromatography (HPLC) with UV detection. 1-Octanol was used as the extraction solvent in DLME. Magnetic nanoparticles (Fe3O4) functionalized with 3-aminopropyl triethoxysilane (APTS) were used as the dispersive in DLME and as the adsorbent in D-µ-SPE. The extracted pyrethroids were separated within 30 min using isocratic elution with acetonitrile:water (72:28). The factors affecting the extraction efficiency were investigated. Under the optimum conditions, the enrichment factors were in the range of 51-108. Linearity was obtained in the range 0.5-400 ng mL(-1) (tetramethrin) and 5-400 ng mL(-1) (fenpropathrin, deltamethrin and permethrin) with the correlation coefficients (R(2)) greater than 0.995. Detection limits were 0.05-2 ng mL(-1) (water samples) and 0.02-2.0 ng g(-1) (vegetable samples). The relative standard deviations of peak area varied from 1.8 to 2.5% (n=10). The extraction recoveries of the four pyrethroids in field water and vegetable samples were 91.7-104.5%. The proposed method has high potential for use as a sensitive method for determination of pyrethroid residues in water and vegetable samples.

  16. High performance liquid chromatography coupled to mass spectrometry for profiling and quantitative analysis of folate monoglutamates in tomato.

    PubMed

    Tyagi, Kamal; Upadhyaya, Pallawi; Sarma, Supriya; Tamboli, Vajir; Sreelakshmi, Yellamaraju; Sharma, Rameshwar

    2015-07-15

    Folates are essential micronutrients for animals as they play a major role in one carbon metabolism. Animals are unable to synthesize folates and obtain them from plant derived food. In the present study, a high performance liquid chromatography coupled to mass spectrometric (HPLC-MS/MS) method was developed for the high throughput screening and quantitative analysis of folate monoglutamates in tomato fruits. For folate extraction, several parameters were optimized including extraction conditions, pH range, amount of tri-enzyme and boiling time. After processing the extract was purified using ultra-filtration with 10 kDa membrane filter. The ultra-filtered extract was chromatographed on a RP Luna C18 column using gradient elution program. The method was validated by determining linearity, sensitivity and recovery. This method was successfully applied to folate estimation in spinach, capsicum, and garden pea and demonstrated that this method offers a versatile approach for accurate and fast determination of different folate monoglutamates in vegetables. PMID:25722141

  17. Ultra-high-performance liquid chromatography/tandem high-resolution mass spectrometry analysis of sixteen red beverages containing carminic acid: identification of degradation products by using principal component analysis/discriminant analysis.

    PubMed

    Gosetti, Fabio; Chiuminatto, Ugo; Mazzucco, Eleonora; Mastroianni, Rita; Marengo, Emilio

    2015-01-15

    The study investigates the sunlight photodegradation process of carminic acid, a natural red colourant used in beverages. For this purpose, both carminic acid aqueous standard solutions and sixteen different commercial beverages, ten containing carminic acid and six containing E120 dye, were subjected to photoirradiation. The results show different patterns of degradation, not only between the standard solutions and the beverages, but also from beverage to beverage. Due to the different beverage recipes, unpredictable reactions take place between the dye and the other ingredients. To identify the dye degradation products in a very complex scenario, a methodology was used, based on the combined use of principal component analysis with discriminant analysis and ultra-high-performance liquid chromatography coupled with tandem high resolution mass spectrometry. The methodology is unaffected by beverage composition and allows the degradation products of carminic acid dye to be identified for each beverage. PMID:25149011

  18. Ultra-high-performance liquid chromatography/tandem high-resolution mass spectrometry analysis of sixteen red beverages containing carminic acid: identification of degradation products by using principal component analysis/discriminant analysis.

    PubMed

    Gosetti, Fabio; Chiuminatto, Ugo; Mazzucco, Eleonora; Mastroianni, Rita; Marengo, Emilio

    2015-01-15

    The study investigates the sunlight photodegradation process of carminic acid, a natural red colourant used in beverages. For this purpose, both carminic acid aqueous standard solutions and sixteen different commercial beverages, ten containing carminic acid and six containing E120 dye, were subjected to photoirradiation. The results show different patterns of degradation, not only between the standard solutions and the beverages, but also from beverage to beverage. Due to the different beverage recipes, unpredictable reactions take place between the dye and the other ingredients. To identify the dye degradation products in a very complex scenario, a methodology was used, based on the combined use of principal component analysis with discriminant analysis and ultra-high-performance liquid chromatography coupled with tandem high resolution mass spectrometry. The methodology is unaffected by beverage composition and allows the degradation products of carminic acid dye to be identified for each beverage.

  19. High-performance integrated virtual environment (HIVE): a robust infrastructure for next-generation sequence data analysis

    PubMed Central

    Simonyan, Vahan; Chumakov, Konstantin; Dingerdissen, Hayley; Faison, William; Goldweber, Scott; Golikov, Anton; Gulzar, Naila; Karagiannis, Konstantinos; Vinh Nguyen Lam, Phuc; Maudru, Thomas; Muravitskaja, Olesja; Osipova, Ekaterina; Pan, Yang; Pschenichnov, Alexey; Rostovtsev, Alexandre; Santana-Quintero, Luis; Smith, Krista; Thompson, Elaine E.; Tkachenko, Valery; Torcivia-Rodriguez, John; Wan, Quan; Wang, Jing; Wu, Tsung-Jung; Wilson, Carolyn; Mazumder, Raja

    2016-01-01

    The High-performance Integrated Virtual Environment (HIVE) is a distributed storage and compute environment designed primarily to handle next-generation sequencing (NGS) data. This multicomponent cloud infrastructure provides secure web access for authorized users to deposit, retrieve, annotate and compute on NGS data, and to analyse the outcomes using web interface visual environments appropriately built in collaboration with research and regulatory scientists and other end users. Unlike many massively parallel computing environments, HIVE uses a cloud control server which virtualizes services, not processes. It is both very robust and flexible due to the abstraction layer introduced between computational requests and operating system processes. The novel paradigm of moving computations to the data, instead of moving data to computational nodes, has proven to be significantly less taxing for both hardware and network infrastructure. The honeycomb data model developed for HIVE integrates metadata into an object-oriented model. Its distinction from other object-oriented databases is in the additional implementation of a unified application program interface to search, view and manipulate data of all types. This model simplifies the introduction of new data types, thereby minimizing the need for database restructuring and streamlining the development of new integrated information systems. The honeycomb model employs a highly secure hierarchical access control and permission system, allowing determination of data access privileges in a finely granular manner without flooding the security subsystem with a multiplicity of rules. HIVE infrastructure will allow engineers and scientists to perform NGS analysis in a manner that is both efficient and secure. HIVE is actively supported in public and private domains, and project collaborations are welcomed. Database URL: https://hive.biochemistry.gwu.edu PMID:26989153

  20. High-performance integrated virtual environment (HIVE): a robust infrastructure for next-generation sequence data analysis.

    PubMed

    Simonyan, Vahan; Chumakov, Konstantin; Dingerdissen, Hayley; Faison, William; Goldweber, Scott; Golikov, Anton; Gulzar, Naila; Karagiannis, Konstantinos; Vinh Nguyen Lam, Phuc; Maudru, Thomas; Muravitskaja, Olesja; Osipova, Ekaterina; Pan, Yang; Pschenichnov, Alexey; Rostovtsev, Alexandre; Santana-Quintero, Luis; Smith, Krista; Thompson, Elaine E; Tkachenko, Valery; Torcivia-Rodriguez, John; Voskanian, Alin; Wan, Quan; Wang, Jing; Wu, Tsung-Jung; Wilson, Carolyn; Mazumder, Raja

    2016-01-01

    The High-performance Integrated Virtual Environment (HIVE) is a distributed storage and compute environment designed primarily to handle next-generation sequencing (NGS) data. This multicomponent cloud infrastructure provides secure web access for authorized users to deposit, retrieve, annotate and compute on NGS data, and to analyse the outcomes using web interface visual environments appropriately built in collaboration with research and regulatory scientists and other end users. Unlike many massively parallel computing environments, HIVE uses a cloud control server which virtualizes services, not processes. It is both very robust and flexible due to the abstraction layer introduced between computational requests and operating system processes. The novel paradigm of moving computations to the data, instead of moving data to computational nodes, has proven to be significantly less taxing for both hardware and network infrastructure.The honeycomb data model developed for HIVE integrates metadata into an object-oriented model. Its distinction from other object-oriented databases is in the additional implementation of a unified application program interface to search, view and manipulate data of all types. This model simplifies the introduction of new data types, thereby minimizing the need for database restructuring and streamlining the development of new integrated information systems. The honeycomb model employs a highly secure hierarchical access control and permission system, allowing determination of data access privileges in a finely granular manner without flooding the security subsystem with a multiplicity of rules. HIVE infrastructure will allow engineers and scientists to perform NGS analysis in a manner that is both efficient and secure. HIVE is actively supported in public and private domains, and project collaborations are welcomed. Database URL: https://hive.biochemistry.gwu.edu.

  1. High-performance integrated virtual environment (HIVE): a robust infrastructure for next-generation sequence data analysis.

    PubMed

    Simonyan, Vahan; Chumakov, Konstantin; Dingerdissen, Hayley; Faison, William; Goldweber, Scott; Golikov, Anton; Gulzar, Naila; Karagiannis, Konstantinos; Vinh Nguyen Lam, Phuc; Maudru, Thomas; Muravitskaja, Olesja; Osipova, Ekaterina; Pan, Yang; Pschenichnov, Alexey; Rostovtsev, Alexandre; Santana-Quintero, Luis; Smith, Krista; Thompson, Elaine E; Tkachenko, Valery; Torcivia-Rodriguez, John; Voskanian, Alin; Wan, Quan; Wang, Jing; Wu, Tsung-Jung; Wilson, Carolyn; Mazumder, Raja

    2016-01-01

    The High-performance Integrated Virtual Environment (HIVE) is a distributed storage and compute environment designed primarily to handle next-generation sequencing (NGS) data. This multicomponent cloud infrastructure provides secure web access for authorized users to deposit, retrieve, annotate and compute on NGS data, and to analyse the outcomes using web interface visual environments appropriately built in collaboration with research and regulatory scientists and other end users. Unlike many massively parallel computing environments, HIVE uses a cloud control server which virtualizes services, not processes. It is both very robust and flexible due to the abstraction layer introduced between computational requests and operating system processes. The novel paradigm of moving computations to the data, instead of moving data to computational nodes, has proven to be significantly less taxing for both hardware and network infrastructure.The honeycomb data model developed for HIVE integrates metadata into an object-oriented model. Its distinction from other object-oriented databases is in the additional implementation of a unified application program interface to search, view and manipulate data of all types. This model simplifies the introduction of new data types, thereby minimizing the need for database restructuring and streamlining the development of new integrated information systems. The honeycomb model employs a highly secure hierarchical access control and permission system, allowing determination of data access privileges in a finely granular manner without flooding the security subsystem with a multiplicity of rules. HIVE infrastructure will allow engineers and scientists to perform NGS analysis in a manner that is both efficient and secure. HIVE is actively supported in public and private domains, and project collaborations are welcomed. Database URL: https://hive.biochemistry.gwu.edu. PMID:26989153

  2. Discrimination of Wild Paris Based on Near Infrared Spectroscopy and High Performance Liquid Chromatography Combined with Multivariate Analysis

    PubMed Central

    Zhao, Yanli; Zhang, Ji; Yuan, Tianjun; Shen, Tao; Li, Wei; Yang, Shihua; Hou, Ying; Wang, Yuanzhong; Jin, Hang

    2014-01-01

    Different geographical origins and species of Paris obtained from southwestern China were discriminated by near infrared (NIR) spectroscopy and high performance liquid chromatography (HPLC) combined with multivariate analysis. The NIR parameter settings were scanning (64 times), resolution (4 cm−1), scanning range (10000 cm−1∼4000 cm−1) and parallel collection (3 times). NIR spectrum was optimized by TQ 8.6 software, and the ranges 7455∼6852 cm−1 and 5973∼4007 cm−1 were selected according to the spectrum standard deviation. The contents of polyphyllin I, polyphyllin II, polyphyllin VI, and polyphyllin VII and total steroid saponins were detected by HPLC. The contents of chemical components data matrix and spectrum data matrix were integrated and analyzed by partial least squares discriminant analysis (PLS-DA). From the PLS-DA model of NIR spectrum, Paris samples were separated into three groups according to the different geographical origins. The R2X and Q2Y described accumulative contribution rates were 99.50% and 94.03% of the total variance, respectively. The PLS-DA model according to 12 species of Paris described 99.62% of the variation in X and predicted 95.23% in Y. The results of the contents of chemical components described differences among collections quantitatively. A multivariate statistical model of PLS-DA showed geographical origins of Paris had a much greater influence on Paris compared with species. NIR and HPLC combined with multivariate analysis could discriminate different geographical origins and different species. The quality of Paris showed regional dependence. PMID:24558477

  3. A Comparative Analysis of Social Media Usage and Academic Performance in Public and Private Senior High Schools

    ERIC Educational Resources Information Center

    Mingle, Jeffrey; Adams, Musah; Adjei, E. A.

    2016-01-01

    The study comparatively analyzed social media usage and academic performance in public and private senior high schools. The issue of social media and academic performance has been a very debatable topic with regard to its effect. This study further explores the relation between private and public schools in relation to social media use and…

  4. Common Factors of High Performance Teams

    ERIC Educational Resources Information Center

    Jackson, Bruce; Madsen, Susan R.

    2005-01-01

    Utilization of work teams is now wide spread in all types of organizations throughout the world. However, an understanding of the important factors common to high performance teams is rare. The purpose of this content analysis is to explore the literature and propose findings related to high performance teams. These include definition and types,…

  5. Analysis of amide compounds in different parts of Piper ovatum Vahl by high-performance liquid chromatographic

    PubMed Central

    Silva, Daniel R.; Brenzan, Mislaine A.; Kambara, Lauro M.; Cortez, Lucia E. R.; Cortez, Diógenes A. G.

    2013-01-01

    Background: Piper ovatum (Piperaceae) has been used in traditional medicine for the treatment of inflammations and as an analgesic. Previous studies have showed important biological activities of the extracts and amides from P. ovatum leaves. Objective: In this study, a high-performance liquid chromatographic (HPLC) method was developed and validated for quantitative determination of the amides in different parts of Piper ovatum. Materials and Methods: The analysis was carried out on a Metasil ODS column (150 × 4.6 mm, 5μm) at room temperature. HPLC conditions were as follows: acetonitrile (A), and water (B), 1.0% acetic acid. The gradient elution used was 0–30 min, 0-60% A; 30–40 min, 60% A. Flow rate used was 1.0mL/min, and detection at 280nm. Results: The validation using piperlonguminine, as the standard, demonstrated that the method shows linearity (linear correlation coefficient = 0.998), precision (relative standard deviation <5%) and accuracy (mean recovery = 103.78%) in the concentration range 31.25 – 500μg/mL. The limit of detection and quantification were 1.21 and 4.03μg/mL, respectively. This method allowed the identification and quantification of piperlonguminine and piperovatine in the hydroethanolic extracts of P. ovatum obtained from the leaves, stems and roots. All the extracts showed the same chromatographic profile. The leaves and roots contained the highest concentrations of piperlonguminine and the stems and leaves showed the most concentrations of piperovatine. Conclusion: This HPLC method is suitable for routine quantitative analysis of amides in extracts of Piper ovatum and phytopharmaceuticals containing this herb. PMID:24174818

  6. Multiresidue analysis of fluoroquinolone antimicrobials in chicken meat by molecularly imprinted solid-phase extraction and high performance liquid chromatography.

    PubMed

    Urraca, J L; Castellari, M; Barrios, C A; Moreno-Bondi, M C

    2014-05-23

    This paper describes the synthesis of novel molecularly imprinted polymer (MIP) micro-beads for the selective extraction (MISPE) of six fluoroquinolone (FQ) antibiotics (enrofloxacin, ciprofloxacin, lomefloxacin, danofloxacin, sarafloxacin and norfloxacin) from chicken muscle samples and further analysis by high-performance liquid chromatography (HPLC) with fluorescence (FLD) or mass spectrometry (MS) detection. A combinatorial screening approach has been applied to select the optimal functional monomer and cross-linker formulation for polymer synthesis. The MIP prepared using enoxacin (ENOX) as the template - a mixture of methacrylic acid (MAA) and trifluoromethacrylic acid (TFMAA) as functional monomers and ethylene glycol dimethacrylate (EDMA) as the cross-linker - showed superior FQ recognition properties than the rest of the materials generated. MIP spherical particles were prepared using silica beads as sacrificial scaffolds. The polymers were packed in solid phase extraction (SPE) cartridges. The optimized MISPE-HPLC method allows the extraction of the antimicrobials from aqueous samples followed by a selective washing with acetonitrile/water (0.005% TFA, pH=3.0), 20:80 (v/v) and elution with 5% trifluoroacetic acid in methanol. Optimum MISPE conditions led to recoveries of the target FQs in chicken muscle samples ranging between 68 and 102% and precisions in the 3-4% range (RSD, n=18). The method has been validated according to European Union Decision 2002/657/EC, in terms of linearity, accuracy, precision, selectivity, decision limit (CCα) and detection capability (CCβ) by HPLC-FLD and HPLC-MS/MS. The limits of detection were improved using HPLC-MS/MS analysis and ranged between 0.2 and 2.7μgkg(-1) (S/N=3) for all the FQs tested.

  7. IDENTIFICATION AND ANALYSIS OF STEREOSELECTIVE DRUG INTERACTIONS WITH LOW DENSITY LIPOPROTEIN BY HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY

    PubMed Central

    Sobansky, Matthew R.; Hage, David S.

    2012-01-01

    Columns containing immobilized low density lipoprotein (LDL) were prepared for the analysis of drug interactions with this agent by high-performance affinity chromatography (HPAC). R/S-Propranolol was used as a model drug for this study. The LDL columns gave reproducible binding to propranolol over 60 h of continuous use in the presence of pH 7.4, 0.067 M potassium phosphate buffer. Experiments conducted with this type of column through frontal analysis indicated that two types of interactions were occurring between R-propranolol and LDL, while only a single type of interaction was observed between S-propranolol and LDL. The first type of interaction, which was seen for both enantiomers, involved non-saturable binding; this interaction had an overall affinity (nKa) of 1.9 (± 0.1) × 105 M-1 for R-propranolol and 2.7 (± 0.2) × 105 M-1 for S-propranolol at 37 °C. The second type of interaction was observed only for R-propranolol and involved saturable binding that had an association equilibrium constant (Ka) of 5.2 (± 2.3) × 105 M-1 at 37 °C. Similar differences in binding behavior were found for the two enantiomers at 20 °C and 27 °C. This is the first known example of stereoselective binding of drugs by LDL or other lipoproteins. This work also illustrates the ability of HPAC to be used as a tool for characterizing mixed-mode interactions that involve LDL and related binding agents. PMID:22354572

  8. Development of an efficient extraction method for oxytetracycline in animal manure for high performance liquid chromatography analysis.

    PubMed

    Yuan, Shoujun; Wang, Qiquan; Yates, Scott R; Peterson, Nyles G

    2010-10-01

    Oxytetracycline (2-(amino-hydroxy-methylidene)-4-dimethylamino-5,6,10,11,12a-pentahydroxy-6-methyl-4,4a,5,5a-tetrahydrotetracene-1,3,12-trione) is a major member of the tetracycline antibiotics family of which are widely administered to animals in concentrated animal feeding operations for purposes of therapeutical treatment and health protection. With the disposal of animal manure as fertilizer into agricultural land, tetracyclines enter the environment. However, tetracyclines chelate with multivalent cations and proteins, resulting in low extraction efficiencies from animal manure for tetracycline residue analysis. In this study an efficient extraction method for oxytetracycline from steer manure using methanol/water solution amended with chelating organic acid was developed for the analysis of high performance liquid chromatography. The effect of species and amount of amendment acids, shaking time, methanol/water ratio, manure weight, and repeated times of extraction was investigated. It was optimized to amend 2.5 g citric acid and 1.1 g oxalic acid with 10.0 g manure sample in a 50-ml centrifuge tube and extract with 15 ml methanol/water (9:1 in volume) by vigorously shaking for 30 min in a reciprocating shaker. After centrifugation at 11,000 rpm, supernatant is collected. Sample was extracted for a total of 3 times. The developed extraction method was further applied to extract oxytetracycline from fresh and aged cow manure, swine and poultry manure, and soil. Satisfactory recoveries ranging from (84.1 +/- 2.4) % to (102.0 +/- 3.1) % were obtained, demonstrating that the optimized extraction method is robust for oxytetracycline from different manure sample matrixes.

  9. Microfluidic aqueous two-phase extraction of bisphenol A using ionic liquid for high-performance liquid chromatography analysis.

    PubMed

    Qi, Linlin; Wang, Yunhua; Li, Yajie; Zheng, Guoxia; Li, Changping; Su, Hongzhen

    2015-05-01

    An aqueous two-phase microfluidics (ATPM) method suitable for selective extraction of bisphenol A (BPA) in aqueous samples was developed, and a functional ionic liquid of N, N, N-trioctyl ammonium propionate (TOAP) was specially employed for the formation of a parallel flow system. Based on the analytical model, we optimized the chip design into branch-connection length pattern to achieve maximum extraction efficiency (φ max) and ensure phase separation. In combining the design flexibility and ideal reaction activity of extractant (TOAP), the developed ATPM enabled a selective and effective extraction of BPA (φ max of 95% within 2 s) from phenol derivatives. Meanwhile, the total operation time and ionic liquid consumption of the microfluidic extraction were only 2.5 min and 5 μl, respectively. The ATPM can be run at normal pH and room temperature and showed no interferences from components found in tap or beach water. To be noted, this specific extraction system was applied in real water samples; the recoveries of standard addition for all water samples spiked with BPA were from 96 to 110%. Finally, successful reuse of the chip was also realized. In all cases, the developed microfluidic chip was proven to be useful as an effective and low consumption approach in extracting BPA and should be expanded as a "green" preparative method for high-performance liquid chromatography (HPLC) analysis. PMID:25796523

  10. Wheat gluten amino acid composition analysis by high-performance anion-exchange chromatography with integrated pulsed amperometric detection.

    PubMed

    Rombouts, Ine; Lamberts, Lieve; Celus, Inge; Lagrain, Bert; Brijs, Kristof; Delcour, Jan A

    2009-07-17

    A simple accurate method for determining amino acid composition of wheat gluten proteins and their gliadin and glutenin fractions using high-performance anion-exchange chromatography with integrated pulsed amperometric detection is described. In contrast to most conventional methods, the analysis requires neither pre- or post-column derivatization, nor oxidation of the sample. It consists of hydrolysis (6.0M hydrochloric acid solution at 110 degrees C for 24h), evaporation of hydrolyzates (110 degrees C), and chromatographic separation of the liberated amino acids. Correction factors (f) accounted for incomplete cleavage of peptide bonds involving Val (f=1.07) and Ile (f=1.13) after hydrolysis for 24h and for Ser (f=1.32) losses during evaporation. Gradient conditions including an extra eluent (0.1M acetic acid solution) allowed multiple sequential sample analyses without risk of Glu contamination on the anion-exchange column. While gluten amino acid compositions by the present method were mostly comparable to those obtained by a conventional method involving oxidation, acid hydrolysis and post-column ninhydrin derivatization, the latter method underestimated Tyr, Val and Ile levels. Results for the other amino acids obtained by the different methods were linearly correlated (r>0.99, slope=1.03).

  11. Simultaneous analysis of ten phytohormones in Sargassum horneri by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry.

    PubMed

    Li, Yan; Zhou, Chengxu; Yan, Xiaojun; Zhang, Jinrong; Xu, Jilin

    2016-05-01

    Phytohormones have attracted wide attention due to their important biological functions. However, their detection is still a challenge because of their complex composition, low abundance and diverse sources. In this study, a novel method of high-performance liquid chromatography with electrospray ionization tandem mass spectrometry was developed and validated for the simultaneous determination of ten phytohormones including indole-3-acetic acid, isopentenyladenine, isopentenyl adenosine, trans-zeatin riboside, zeatin, strigolactones, abscisic acid, salicylic acid, gibberellin A3, and jasmonic acid in Sargassum horneri (S. horneri). The phytohormones were extracted from freeze-dried S. horneri with methanol/water/methanoic acid (15:4:1, v/v/v) analyzed on a Hypersil Gold C18 column and detected by electrospray ionization tandem triple quadrupole mass spectrometry in the multiple reaction monitoring mode. The experimental conditions for the extraction and analysis of phytohormones were optimized and validated in terms of reproducibility, linearity, sensitivity, recovery, accuracy, and stability. Distributions of the phytohormones in the stems, blades, and gas bladder of the S. horneri in drift, fixed, and semi-fixed growing states were investigated for the first time. The observed contents of the phytohormones in S. horneri range from not detected to 5066.67 ng/g (fresh weight). Most phytohormones are distributed mainly in the stems of S. horneri in drift and semi-fixed states. PMID:26990813

  12. High Performance Thin Layer Chromatography.

    ERIC Educational Resources Information Center

    Costanzo, Samuel J.

    1984-01-01

    Clarifies where in the scheme of modern chromatography high performance thin layer chromatography (TLC) fits and why in some situations it is a viable alternative to gas and high performance liquid chromatography. New TLC plates, sample applications, plate development, and instrumental techniques are considered. (JN)

  13. [Direct analysis of 38 polyphenols in wine by ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry].

    PubMed

    Zhang, Xieguang; Zheng, Yanjie; Zeng, Yongting; Liu, Wenli

    2015-06-01

    Wine has been described previously as a rich source of polyphenols. However, an accurate screening of its complete phenolic profile is still lacking. In the present work, the analysis of 38 polyphenols in wine using ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UPLC-LTQ/Orbitrap MS) was explored. Wines were directly detected. The sample was loaded onto a Thermo Hypersil Gold C18 column (100 mmx 2.1 mm, 1.9 µm) using a gradient elution of acetonitrile/water containing 0. 1% (v/v) formic acid for the separation. UPLC-LTQ/Orbitrap mass spectrometer acquired full scan MS date for quantification, and data dependent MS2 product ion spectra for identification and/ or confirmation. The regression coefficients (R2) for the calibration curves (two orders of magnitude up to the lowest calibration level) in the study were ≥ 0.99. The limits of detection for the 38 compounds were 0.002-0.50 mg/kg. The average recoveries at three spiked levels were in the range of 90%-102% with the relative standard deviations (RSDs) of 0.51%-2.56%. Mass errors were always ≤ 5 ppm. This procedure was then successfully applied to the analysis of the polyphenols in wines.

  14. [Qualitative and quantitative analysis of amygdalin and its metabolite prunasin in plasma by ultra-high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry and ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry].

    PubMed

    Gao, Meng; Wang, Yuesheng; Wei, Huizhen; Ouyang, Hui; He, Mingzhen; Zeng, Lianqing; Shen, Fengyun; Guo, Qiang; Rao, Yi

    2014-06-01

    A method was developed for the determination of amygdalin and its metabolite prunasin in rat plasma after intragastric administration of Maxing shigan decoction. The analytes were identified by ultra-high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry and quantitatively determined by ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry. After purified by liquid-liquid extraction, the qualitative analysis of amygdalin and prunasin in the plasma sample was performed on a Shim-pack XR-ODS III HPLC column (75 mm x 2.0 mm, 1.6 microm), using acetonitrile-0.1% (v/v) formic acid aqueous solution. The detection was performed on a Triple TOF 5600 quadrupole time of flight mass spectrometer. The quantitative analysis of amygdalin and prunasin in the plasma sample was performed by separation on an Agilent C18 HPLC column (50 mm x 2.1 mm, 1.7 microm), using acetonitrile-0.1% (v/v) formic acid aqueous solution. The detection was performed on an AB Q-TRAP 4500 triple quadrupole mass spectrometer utilizing electrospray ionization (ESI) interface operated in negative ion mode and multiple-reaction monitoring (MRM) mode. The qualitative analysis results showed that amygdalin and its metabolite prunasin were detected in the plasma sample. The quantitative analysis results showed that the linear range of amygdalin was 1.05-4 200 ng/mL with the correlation coefficient of 0.999 0 and the linear range of prunasin was 1.25-2 490 ng/mL with the correlation coefficient of 0.997 0. The method had a good precision with the relative standard deviations (RSDs) lower than 9.20% and the overall recoveries varied from 82.33% to 95.25%. The limits of detection (LODs) of amygdalin and prunasin were 0.50 ng/mL. With good reproducibility, the method is simple, fast and effective for the qualitative and quantitative analysis of the amygdalin and prunasin in plasma sample of rats which were administered by Maxing shigan decoction.

  15. High performance computing enabling exhaustive analysis of higher order single nucleotide polymorphism interaction in Genome Wide Association Studies

    PubMed Central

    2015-01-01

    Genome-wide association studies (GWAS) are a common approach for systematic discovery of single nucleotide polymorphisms (SNPs) which are associated with a given disease. Univariate analysis approaches commonly employed may miss important SNP associations that only appear through multivariate analysis in complex diseases. However, multivariate SNP analysis is currently limited by its inherent computational complexity. In this work, we present a computational framework that harnesses supercomputers. Based on our results, we estimate a three-way interaction analysis on 1.1 million SNP GWAS data requiring over 5.8 years on the full "Avoca" IBM Blue Gene/Q installation at the Victorian Life Sciences Computation Initiative. This is hundreds of times faster than estimates for other CPU based methods and four times faster than runtimes estimated for GPU methods, indicating how the improvement in the level of hardware applied to interaction analysis may alter the types of analysis that can be performed. Furthermore, the same analysis would take under 3 months on the currently largest IBM Blue Gene/Q supercomputer "Sequoia" at the Lawrence Livermore National Laboratory assuming linear scaling is maintained as our results suggest. Given that the implementation used in this study can be further optimised, this runtime means it is becoming feasible to carry out exhaustive analysis of higher order interaction studies on large modern GWAS. PMID:25870758

  16. High performance computing enabling exhaustive analysis of higher order single nucleotide polymorphism interaction in Genome Wide Association Studies.

    PubMed

    Goudey, Benjamin; Abedini, Mani; Hopper, John L; Inouye, Michael; Makalic, Enes; Schmidt, Daniel F; Wagner, John; Zhou, Zeyu; Zobel, Justin; Reumann, Matthias

    2015-01-01

    Genome-wide association studies (GWAS) are a common approach for systematic discovery of single nucleotide polymorphisms (SNPs) which are associated with a given disease. Univariate analysis approaches commonly employed may miss important SNP associations that only appear through multivariate analysis in complex diseases. However, multivariate SNP analysis is currently limited by its inherent computational complexity. In this work, we present a computational framework that harnesses supercomputers. Based on our results, we estimate a three-way interaction analysis on 1.1 million SNP GWAS data requiring over 5.8 years on the full "Avoca" IBM Blue Gene/Q installation at the Victorian Life Sciences Computation Initiative. This is hundreds of times faster than estimates for other CPU based methods and four times faster than runtimes estimated for GPU methods, indicating how the improvement in the level of hardware applied to interaction analysis may alter the types of analysis that can be performed. Furthermore, the same analysis would take under 3 months on the currently largest IBM Blue Gene/Q supercomputer "Sequoia" at the Lawrence Livermore National Laboratory assuming linear scaling is maintained as our results suggest. Given that the implementation used in this study can be further optimised, this runtime means it is becoming feasible to carry out exhaustive analysis of higher order interaction studies on large modern GWAS. PMID:25870758

  17. High performance computing enabling exhaustive analysis of higher order single nucleotide polymorphism interaction in Genome Wide Association Studies.

    PubMed

    Goudey, Benjamin; Abedini, Mani; Hopper, John L; Inouye, Michael; Makalic, Enes; Schmidt, Daniel F; Wagner, John; Zhou, Zeyu; Zobel, Justin; Reumann, Matthias

    2015-01-01

    Genome-wide association studies (GWAS) are a common approach for systematic discovery of single nucleotide polymorphisms (SNPs) which are associated with a given disease. Univariate analysis approaches commonly employed may miss important SNP associations that only appear through multivariate analysis in complex diseases. However, multivariate SNP analysis is currently limited by its inherent computational complexity. In this work, we present a computational framework that harnesses supercomputers. Based on our results, we estimate a three-way interaction analysis on 1.1 million SNP GWAS data requiring over 5.8 years on the full "Avoca" IBM Blue Gene/Q installation at the Victorian Life Sciences Computation Initiative. This is hundreds of times faster than estimates for other CPU based methods and four times faster than runtimes estimated for GPU methods, indicating how the improvement in the level of hardware applied to interaction analysis may alter the types of analysis that can be performed. Furthermore, the same analysis would take under 3 months on the currently largest IBM Blue Gene/Q supercomputer "Sequoia" at the Lawrence Livermore National Laboratory assuming linear scaling is maintained as our results suggest. Given that the implementation used in this study can be further optimised, this runtime means it is becoming feasible to carry out exhaustive analysis of higher order interaction studies on large modern GWAS.

  18. High Performance Networks for High Impact Science

    SciTech Connect

    Scott, Mary A.; Bair, Raymond A.

    2003-02-13

    This workshop was the first major activity in developing a strategic plan for high-performance networking in the Office of Science. Held August 13 through 15, 2002, it brought together a selection of end users, especially representing the emerging, high-visibility initiatives, and network visionaries to identify opportunities and begin defining the path forward.

  19. High power ion thruster performance

    NASA Technical Reports Server (NTRS)

    Rawlin, Vincent K.; Patterson, Michael J.

    1987-01-01

    The ion thruster is one of several forms of space electric propulsion being considered for use on future SP-100-based missions. One possible major mission ground rule is the use of a single Space Shuttle launch. Thus, the mass in orbit at the reactor activation altitude would be limited by the Shuttle mass constraints. When the spacecraft subsystem masses are subtracted from this available mass limit, a maximum propellant mass may be calculated. Knowing the characteristics of each type of electric thruster allows maximum values of total impulse, mission velocity increment, and thrusting time to be calculated. Because ion thrusters easily operate at high values of efficiency (60 to 70%) and specific impulse (3000 to 5000 sec), they can impart large values of total impulse to a spacecraft. They also can be operated with separate control of the propellant flow rate and exhaust velocity. This paper presents values of demonstrated and projected performance of high power ion thrusters used in an analysis of electric propulsion for an SP-100 based mission.

  20. Speciation analysis of mercury in water samples using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography.

    PubMed

    Gao, Zhongben; Ma, Xiaoguo

    2011-09-19

    A novel approach for preconcentration and speciation analysis of trace amount of mercury from water samples was proposed by dispersive liquid-liquid microextraction (DLLME) coupled to high performance liquid chromatography with diode array detection (HPLC-DAD). Mercury species (Hg(2+), methylmercury (MeHg(+)) and phenylmercury (PhHg(+))) were complexed with dithizone (DZ) to form hydrophobic chelates and then extracted into the fine drops of extraction solvent dispersed in the aqueous sample by dispersive solvent. After extraction, the sedimented phase was analyzed by HPLC-DAD. Some important parameters affecting the DLLME such as extraction solvent and dispersive solvent type and volume, concentration of dithizone solution, sample pH, extraction time and salt effect were investigated. Ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM][PF(6)]) was found to be a suitable extractant for the chelates. Under the optimized conditions (extraction solvent: 70 μL of ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM][PF(6)]); dispersive solvent: 0.75 mL of methanol containing dithizone (0.02%, m/v); pH: 4; extraction time: 5 min; and without salt addition), the limits of detection for Hg(2+), MeHg(+) and PhHg(+) were 0.32, 0.96 and 1.91 μg L(-1) (SN(-1)=3) respectively, and the relative standard deviation (RSD) was between 4.1 and 7.3% (n=5). Three real water samples (tap water, river water and lake water) spiked with mercury species were detected by the developed method, and the relative recoveries obtained for Hg(2+), MeHg(+) and PhHg(+) were 89.6-101.3%, 85.6-102.0% and 81.3-97.6%, respectively. PMID:21819859

  1. Mechanisms for Triceps Surae Injury in High Performance Front Row Rugby Union Players: A Kinematic Analysis of Scrummaging Drills

    PubMed Central

    Flavell, Carol A.; Sayers, Mark G. L.; Gordon, Susan J.; Lee, James B.

    2013-01-01

    The front row of a rugby union scrum consists of three players. The loose head prop, hooker and tight head prop. The objective of this study was to determine if known biomechanical risk factors for triceps surae muscle injury are exhibited in the lower limb of front row players during contested scrummaging. Eleven high performance front row rugby union players were landmarked bilaterally at the posterior superior iliac spine (PSIS), greater trochanter, lateral femoral epicondyle, midline of the calcaneus above the plantar aspect of the heel, midline lower leg 5cm and 20cm proximal to the lateral malleolus, at the axis of subtalar joint, lateral malleolus, and head of the fifth metatarsal. Players were video recorded during a series of 2 on 1 live scrummaging drills. Biomechanical three dimensional analysis identified large angular displacements, and increased peak velocities and accelerations at the ankle joint during attacking scrummaging drill techniques when in the stance phase of gait. This places the triceps surae as increased risk of injury and provides valuable information for training staff regarding injury prevention and scrum training practices for front row players. Key points Front rowers exhibited patterns of single leg weight bearing, in a position of greater ankle plantar flexion and knee extension at toe off during scrummaging, which is a risk position for TS injury. Front rowers also exhibited greater acceleration at the ankle, knee, and hip joints, and greater changes in ankle ROM from toe strike to toe off during attacking scrum drills. These reported accelerations and joint displacements may be risk factors for TS injury, as the ankle is accelerating into plantar flexion at final push off and the muscle is shortening from an elongated state. PMID:24149740

  2. A validated high performance liquid chromatography method for the analysis of thymol and carvacrol in Thymus vulgaris L. volatile oil

    PubMed Central

    Hajimehdipoor, H.; Shekarchi, M.; Khanavi, M.; Adib, N.; Amri, M.

    2010-01-01

    Thymus vulgaris L. (Lamiaceae) is a well-known medicinal plant that contains important compounds such as thymol and carvacrol and it has been used in many pharmaceutical dosage forms. Thymol and carvacrol in essential oils are often quantified by gas chromatography (GC) technique but in this work, a validated and reliable high performance liquid chromatography (HPLC) method has been developed for the analysis of these two components in T. vulgaris essential oil. The essential oil of the plant was analyzed by HPLC and GC techniques. The HPLC system consisted of ACE C18 column and an isocratic acetonitrile:water (50:50) as the mobile phase which was kept at a flow rate of 1 ml/min. The method was validated for selectivity, linearity (r2 > 0.997 for both thymol and carvacrol), precision (intra-day 0.8-1.9, 1.7-2.6; and inter-day 3.5-4.5, 3.6-4.7) and recovery (97.7%, 97.6%) for thymol and carvacrol, respectively. The limits of detection (LODs) and limits of quantization (LOQs) were calculated to be 2.8, 0.6 µg/ml and 8.6, 1.8 µg/ml for thymol and carvacrol, respectively. The GC system consisted of flame ionization detector (FID) and CP-SIL 8 column. The concentrations of thymol and carvacrol in essential oil obtained by HPLC (41.2%, 4.3%) and GC (40.7%, 4.2%) were compared by statistical methods and they showed good agreement. PMID:20931071

  3. Mechanisms for triceps surae injury in high performance front row rugby union players: a kinematic analysis of scrummaging drills.

    PubMed

    Flavell, Carol A; Sayers, Mark G L; Gordon, Susan J; Lee, James B

    2013-01-01

    The front row of a rugby union scrum consists of three players. The loose head prop, hooker and tight head prop. The objective of this study was to determine if known biomechanical risk factors for triceps surae muscle injury are exhibited in the lower limb of front row players during contested scrummaging. Eleven high performance front row rugby union players were landmarked bilaterally at the posterior superior iliac spine (PSIS), greater trochanter, lateral femoral epicondyle, midline of the calcaneus above the plantar aspect of the heel, midline lower leg 5cm and 20cm proximal to the lateral malleolus, at the axis of subtalar joint, lateral malleolus, and head of the fifth metatarsal. Players were video recorded during a series of 2 on 1 live scrummaging drills. Biomechanical three dimensional analysis identified large angular displacements, and increased peak velocities and accelerations at the ankle joint during attacking scrummaging drill techniques when in the stance phase of gait. This places the triceps surae as increased risk of injury and provides valuable information for training staff regarding injury prevention and scrum training practices for front row players. Key pointsFront rowers exhibited patterns of single leg weight bearing, in a position of greater ankle plantar flexion and knee extension at toe off during scrummaging, which is a risk position for TS injury.Front rowers also exhibited greater acceleration at the ankle, knee, and hip joints, and greater changes in ankle ROM from toe strike to toe off during attacking scrum drills.These reported accelerations and joint displacements may be risk factors for TS injury, as the ankle is accelerating into plantar flexion at final push off and the muscle is shortening from an elongated state. PMID:24149740

  4. Analysis of glipizide binding to normal and glycated human serum albumin by high-performance affinity chromatography.

    PubMed

    Matsuda, Ryan; Li, Zhao; Zheng, Xiwei; Hage, David S

    2015-07-01

    In diabetes, the elevated levels of glucose in the bloodstream can result in the nonenzymatic glycation of proteins such as human serum albumin (HSA). This type of modification has been shown to affect the interactions of some drugs with HSA, including several sulfonylurea drugs that are used to treat type II diabetes. This study used high-performance affinity chromatography (HPAC) to examine the interactions of glipizide (i.e., a second-generation sulfonylurea drug) with normal HSA or HSA that contained various levels of in vitro glycation. Frontal analysis indicated that glipizide was interacting with both normal and glycated HSA through two general groups of sites: a set of relatively strong interactions and a set of weaker interactions with average association equilibrium constants at pH 7.4 and 37 °C in the range of 2.4-6.0 × 10(5) and 1.7-3.7 × 10(4) M(-1), respectively. Zonal elution competition studies revealed that glipizide was interacting at both Sudlow sites I and II, which were estimated to have affinities of 3.2-3.9 × 10(5) and 1.1-1.4 × 10(4) M(-1). Allosteric effects were also noted to occur for this drug between the tamoxifen site and the binding of R-warfarin at Sudlow site I. Up to an 18% decrease in the affinity for glipizide was observed at Sudlow site I ongoing from normal HSA to glycated HSA, while up to a 27% increase was noted at Sudlow site II. This information should be useful in indicating how HPAC can be used to investigate other drugs that have complex interactions with proteins. These results should also be valuable in providing a better understanding of how glycation may affect drug-protein interactions and the serum transport of drugs such as glipizide during diabetes. PMID:25912461

  5. A validated high performance liquid chromatography method for the analysis of thymol and carvacrol in Thymus vulgaris L. volatile oil.

    PubMed

    Hajimehdipoor, H; Shekarchi, M; Khanavi, M; Adib, N; Amri, M

    2010-07-01

    Thymus vulgaris L. (Lamiaceae) is a well-known medicinal plant that contains important compounds such as thymol and carvacrol and it has been used in many pharmaceutical dosage forms. Thymol and carvacrol in essential oils are often quantified by gas chromatography (GC) technique but in this work, a validated and reliable high performance liquid chromatography (HPLC) method has been developed for the analysis of these two components in T. vulgaris essential oil. The essential oil of the plant was analyzed by HPLC and GC techniques. The HPLC system consisted of ACE C(18) column and an isocratic acetonitrile:water (50:50) as the mobile phase which was kept at a flow rate of 1 ml/min. The method was validated for selectivity, linearity (r(2) > 0.997 for both thymol and carvacrol), precision (intra-day 0.8-1.9, 1.7-2.6; and inter-day 3.5-4.5, 3.6-4.7) and recovery (97.7%, 97.6%) for thymol and carvacrol, respectively. The limits of detection (LODs) and limits of quantization (LOQs) were calculated to be 2.8, 0.6 µg/ml and 8.6, 1.8 µg/ml for thymol and carvacrol, respectively. The GC system consisted of flame ionization detector (FID) and CP-SIL 8 column. The concentrations of thymol and carvacrol in essential oil obtained by HPLC (41.2%, 4.3%) and GC (40.7%, 4.2%) were compared by statistical methods and they showed good agreement. PMID:20931071

  6. Analysis and determination of oestrogen-active compounds in fructus amomi by the combination of high-speed counter-current chromatography and high performance liquid chromatography.

    PubMed

    Ying, Hao; Liu, Jinpeng; Du, Qizhen

    2014-05-01

    Amomum longiligulare or Amomum villosum showed oestrogenic activity. In the present study, oestrogen-active components in fructus amomi, the seeds of A. longiligulare were separated by high-speed countercurrent chromatography (HSCCC) using stepwise elution of eight mobile phases with gradient polarity and advanced separation by high performance liquid chromatography (HPLC). The results yielded 17 compounds with the amount of 8-138mg and a purity of 94.3-99.8% from a 3g ethanolic extract of fructus amomi. The chemical structures of the compounds were identified by ESI-MS and NMR spectra, in which eight diarylheptanoids were demonstrated as the main oestrogen-active compounds in the fructus amomi. Determination of the diarylheptanoids in fructus amomi from various origins showed that fructus amomi contains more than 0.5% total diarylheptanoids. The results showed that fructus amomi is a diarylheptanoids-rich food resource possessing oestrogen-activity. The combination method of HSCCC and HPLC can be applied for the analysis of bioactive compounds by detecting the corresponding bioactivity in the HSCCC fractions and separating the target compounds with HPLC.

  7. Chemical fingerprint and quantitative analysis for the quality evaluation of Vitex negundo seeds by reversed-phase high-performance liquid chromatography coupled with hierarchical clustering analysis.

    PubMed

    Shu, Zhiheng; Li, Xiuqing; Rahman, Khalid; Qin, Luping; Zheng, Chengjian

    2016-01-01

    A simple and efficient method was developed for the chemical fingerprint analysis and simultaneous determination of four phenylnaphthalene-type lignans in Vitex negundo seeds using high-performance liquid chromatography with diode array detection. For fingerprint analysis, 13 V. negundo seed samples were collected from different regions in China, and the fingerprint chromatograms were matched by the computer-aided Similarity Evaluation System for Chromatographic Fingerprint of TCM (Version 2004A). A total of 21 common peaks found in all the chromatograms were used for evaluating the similarity between these samples. Additionally, simultaneous quantification of four major bioactive ingredients was conducted to assess the quality of V. negundo seeds. Our results indicated that the contents of four lignans in V. negundo seeds varied remarkably in herbal samples collected from different regions. Moreover, the hierarchical clustering analysis grouped these 13 samples into three categories, which was consistent with the chemotypes of those chromatograms. The method developed in this study provides a substantial foundation for the establishment of reasonable quality control standards for V. negundo seeds.

  8. High-Performance Ball Bearing

    NASA Technical Reports Server (NTRS)

    Bursey, Roger W., Jr.; Haluck, David A.; Olinger, John B.; Owen, Samuel S.; Poole, William E.

    1995-01-01

    High-performance bearing features strong, lightweight, self-lubricating cage with self-lubricating liners in ball apertures. Designed to operate at high speed (tens of thousands of revolutions per minute) in cryogenic environment like liquid-oxygen or liquid-hydrogen turbopump. Includes inner race, outer race, and cage keeping bearing balls equally spaced.

  9. High performance dielectric materials development

    NASA Technical Reports Server (NTRS)

    Piche, Joe; Kirchner, Ted; Jayaraj, K.

    1994-01-01

    The mission of polymer composites materials technology is to develop materials and processing technology to meet DoD and commercial needs. The following are outlined in this presentation: high performance capacitors, high temperature aerospace insulation, rationale for choosing Foster-Miller (the reporting industry), the approach to the development and evaluation of high temperature insulation materials, and the requirements/evaluation parameters. Supporting tables and diagrams are included.

  10. Design study and performance analysis of a high-speed multistage variable-geometry fan for a variable cycle engine

    NASA Technical Reports Server (NTRS)

    Sullivan, T. J.; Parker, D. E.

    1979-01-01

    A design technology study was performed to identify a high speed, multistage, variable geometry fan configuration capable of achieving wide flow modulation with near optimum efficiency at the important operating condition. A parametric screening study of the front and rear block fans was conducted in which the influence of major fan design features on weight and efficiency was determined. Key design parameters were varied systematically to determine the fan configuration most suited for a double bypass, variable cycle engine. Two and three stage fans were considered for the front block. A single stage, core driven fan was studied for the rear block. Variable geometry concepts were evaluated to provide near optimum off design performance. A detailed aerodynamic design and a preliminary mechanical design were carried out for the selected fan configuration. Performance predictions were made for the front and rear block fans.

  11. Analysis of phytochelatins in plant matrices by pre-column derivatization, high-performance liquid chromatography and fluorescence-detection.

    PubMed

    Döring, S; Korhammer, S; Oetken, M; Markert, B

    2000-02-01

    A sensitive method for the determination of phytochelatins in plant matrices by pre-column derivatization with monobromobimane (mBrB) and high-performance liquid chromatography (HPLC) on reversed phases and fluorescence-detection has been developed and applied to cucumber sprouts (Cucumis sativus) treated with cadmium and to the water moss Fontinalis antipyretica (Cd in environmentally-relevant concentrations). Whereas phytochelatins were found in the Cd-treated sprouts, no phytochelatins were detected in Fontinalis anitipyretica. PMID:11225681

  12. Parallel-META 2.0: Enhanced Metagenomic Data Analysis with Functional Annotation, High Performance Computing and Advanced Visualization

    PubMed Central

    Song, Baoxing; Xu, Jian; Ning, Kang

    2014-01-01

    The metagenomic method directly sequences and analyses genome information from microbial communities. The main computational tasks for metagenomic analyses include taxonomical and functional structure analysis for all genomes in a microbial community (also referred to as a metagenomic sample). With the advancement of Next Generation Sequencing (NGS) techniques, the number of metagenomic samples and the data size for each sample are increasing rapidly. Current metagenomic analysis is both data- and computation- intensive, especially when there are many species in a metagenomic sample, and each has a large number of sequences. As such, metagenomic analyses require extensive computational power. The increasing analytical requirements further augment the challenges for computation analysis. In this work, we have proposed Parallel-META 2.0, a metagenomic analysis software package, to cope with such needs for efficient and fast analyses of taxonomical and functional structures for microbial communities. Parallel-META 2.0 is an extended and improved version of Parallel-META 1.0, which enhances the taxonomical analysis using multiple databases, improves computation efficiency by optimized parallel computing, and supports interactive visualization of results in multiple views. Furthermore, it enables functional analysis for metagenomic samples including short-reads assembly, gene prediction and functional annotation. Therefore, it could provide accurate taxonomical and functional analyses of the metagenomic samples in high-throughput manner and on large scale. PMID:24595159

  13. Parallel-META 2.0: enhanced metagenomic data analysis with functional annotation, high performance computing and advanced visualization.

    PubMed

    Su, Xiaoquan; Pan, Weihua; Song, Baoxing; Xu, Jian; Ning, Kang

    2014-01-01

    The metagenomic method directly sequences and analyses genome information from microbial communities. The main computational tasks for metagenomic analyses include taxonomical and functional structure analysis for all genomes in a microbial community (also referred to as a metagenomic sample). With the advancement of Next Generation Sequencing (NGS) techniques, the number of metagenomic samples and the data size for each sample are increasing rapidly. Current metagenomic analysis is both data- and computation- intensive, especially when there are many species in a metagenomic sample, and each has a large number of sequences. As such, metagenomic analyses require extensive computational power. The increasing analytical requirements further augment the challenges for computation analysis. In this work, we have proposed Parallel-META 2.0, a metagenomic analysis software package, to cope with such needs for efficient and fast analyses of taxonomical and functional structures for microbial communities. Parallel-META 2.0 is an extended and improved version of Parallel-META 1.0, which enhances the taxonomical analysis using multiple databases, improves computation efficiency by optimized parallel computing, and supports interactive visualization of results in multiple views. Furthermore, it enables functional analysis for metagenomic samples including short-reads assembly, gene prediction and functional annotation. Therefore, it could provide accurate taxonomical and functional analyses of the metagenomic samples in high-throughput manner and on large scale.

  14. A moderated mediated path analysis of factors influencing student performance on a standardized high-stakes science test

    NASA Astrophysics Data System (ADS)

    Pelkey, Ramona K.

    Gender, ethnicity, family economic status, reading score, mathematics score, and number of science semesters successfully completed were examined for their contributory role to a student's science score on a high-stakes, high school exit examination. Path analysis and analysis of variance procedures were used to quantify each variable's influence on science score. Gender, ethnicity, and family economic status were found to be moderators while reading proved to mediate within the model. The path model was created using a calibration sample and cross-validated using a hold-out validation sample. Bootstrapping was used to verify the goodness of fit of the model. A predictive equation explained 66% (R2 = .66) of the variance in observed TAKS science score.

  15. High rates of non-adherence to antihypertensive treatment revealed by high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS) urine analysis

    PubMed Central

    Tomaszewski, Maciej; White, Christobelle; Patel, Prashanth; Masca, Nicholas; Damani, Ravi; Hepworth, Joanne; Samani, Nilesh J; Gupta, Pankaj; Madira, Webster; Stanley, Adrian; Williams, Bryan

    2014-01-01

    Objectives Non-adherence to therapy is an important cause of suboptimal blood pressure control but few practical tools exist to accurately and routinely detect it. We used a simple urine-based assay to evaluate the prevalence of antihypertensive treatment non-adherence and its impact on blood pressure in a specialist hypertension centre. Methods 208 hypertensive patients (125 new referrals, 66 follow-up patients with inadequate blood pressure control and 17 renal denervation referrals) underwent assessment of antihypertensive drug intake using high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS) urine analysis at the time of clinical appointment. A total of 40 most commonly prescribed antihypertensive medications (or their metabolites) were screened for in spot urine samples. Results Overall, 25% of patients were totally or partially non-adherent to antihypertensive treatment (total non-adherence 10.1%, partial non-adherence 14.9%). The highest prevalence of partial and total non-adherence was among follow-up patients with inadequate blood pressure control (28.8%) and those referred for consideration of renal denervation (23.5%), respectively. There was a linear relationship between blood pressure and the numerical difference in detected/prescribed antihypertensive medications—every unit increase in this difference was associated with 3.0 (1.1) mm Hg, 3.1 (0.7) mm Hg and 1.9 (0.7) mm Hg increase in adjusted clinic systolic blood pressure, clinic diastolic blood pressure (DBP) and 24 h mean daytime DBP (p=0.0051, p=8.62×10−6, p=0.0057), respectively. Conclusions Non-adherence to blood pressure lowering therapy is common, particularly in patients with suboptimal blood pressure control and those referred for renal denervation. HP LC-MS/MS urine analysis could be used to exclude non-adherence and better stratify further investigations and intervention. PMID:24694797

  16. A multiplexed targeted assay for high-throughput quantitative analysis of serum methylamines by ultra performance liquid chromatography coupled to high resolution mass spectrometry.

    PubMed

    Kadar, Hanane; Dubus, Justine; Dutot, Jérémie; Hedjazi, Lyamine; Srinivasa, Suman; Fitch, Kathleen V; Grinspoon, Steven K; Nicholson, Jeremy K; Dumas, Marc-Emmanuel; Gauguier, Dominique

    2016-05-01

    Methylamines are biologically-active metabolites present in serum and urine samples, which play complex roles in metabolic diseases. Methylamines can be detected by proton nuclear magnetic resonance (NMR), but specific methods remain to be developed for their routine assay in human serum in clinical settings. Here we developed and validated a novel reliable "methylamine panel" method for simultaneous quantitative analysis of trimethylamine (TMA), its major detoxification metabolite trimethylamine-N-oxide (TMAO), and precursors choline, betaine and l-carnitine in human serum using Ultra Performance Liquid Chromatography (UPLC) coupled to High Resolution Mass Spectrometry (HRMS). Metabolite separation was carried out on a HILIC stationary phase. For all metabolites, the assay was linear in the range of 0.25-12.5 μmol/L and enabled to reach limit of detection of about 0.10 μmol/L. Relative standard deviations were below 16% for the three levels of concentrations. We demonstrated the strong reliability and robustness of the method, which was applied to serum samples from healthy individuals to establish the range of concentrations of the metabolites and their correlation relationships and detect gender differences. Our data provide original information for implementing in a clinical environment a MS-based diagnostic method with potential for targeted metabolic screening of patients at risk of cardiometabolic diseases.

  17. A multiplexed targeted assay for high-throughput quantitative analysis of serum methylamines by ultra performance liquid chromatography coupled to high resolution mass spectrometry.

    PubMed

    Kadar, Hanane; Dubus, Justine; Dutot, Jérémie; Hedjazi, Lyamine; Srinivasa, Suman; Fitch, Kathleen V; Grinspoon, Steven K; Nicholson, Jeremy K; Dumas, Marc-Emmanuel; Gauguier, Dominique

    2016-05-01

    Methylamines are biologically-active metabolites present in serum and urine samples, which play complex roles in metabolic diseases. Methylamines can be detected by proton nuclear magnetic resonance (NMR), but specific methods remain to be developed for their routine assay in human serum in clinical settings. Here we developed and validated a novel reliable "methylamine panel" method for simultaneous quantitative analysis of trimethylamine (TMA), its major detoxification metabolite trimethylamine-N-oxide (TMAO), and precursors choline, betaine and l-carnitine in human serum using Ultra Performance Liquid Chromatography (UPLC) coupled to High Resolution Mass Spectrometry (HRMS). Metabolite separation was carried out on a HILIC stationary phase. For all metabolites, the assay was linear in the range of 0.25-12.5 μmol/L and enabled to reach limit of detection of about 0.10 μmol/L. Relative standard deviations were below 16% for the three levels of concentrations. We demonstrated the strong reliability and robustness of the method, which was applied to serum samples from healthy individuals to establish the range of concentrations of the metabolites and their correlation relationships and detect gender differences. Our data provide original information for implementing in a clinical environment a MS-based diagnostic method with potential for targeted metabolic screening of patients at risk of cardiometabolic diseases. PMID:27036856

  18. Performance analysis of communication links based on VCSEL and silicon photonics technology for high-capacity data-intensive scenario.

    PubMed

    Boletti, A; Boffi, P; Martelli, P; Ferrario, M; Martinelli, M

    2015-01-26

    To face the increased demand for bandwidth, cost-effectiveness and simplicity of future Ethernet data communications, a comparison between two different solutions based on directly-modulated VCSEL sources and Silicon Photonics technologies is carried out. Also by exploiting 4-PAM modulation, the transmission of 50-Gb/s and beyond capacity per channel is analyzed by means of BER performance. Applications for optical backplane, very short reach and in case of client-optics networks and intra and inter massive data centers communications (up to 10 km) are taken into account. A comparative analysis based on the power consumption is also proposed.

  19. Analysis Methods for Post Occupancy Evaluation of Energy-Use in High Performance Buildings Using Short-Term Monitoring

    NASA Astrophysics Data System (ADS)

    Singh, Vipul

    2011-12-01

    The green building movement has been an effective catalyst in reducing energy demands of buildings and a large number of 'green' certified buildings have been in operation for several years. Whether these buildings are actually performing as intended, and if not, identifying specific causes for this discrepancy falls into the general realm of post-occupancy evaluation (POE). POE involves evaluating building performance in terms of energy-use, indoor environmental quality, acoustics and water-use; the first aspect i.e. energy-use is addressed in this thesis. Normally, a full year or more of energy-use and weather data is required to determine the actual post-occupancy energy-use of buildings. In many cases, either measured building performance data is not available or the time and cost implications may not make it feasible to invest in monitoring the building for a whole year. Knowledge about the minimum amount of measured data needed to accurately capture the behavior of the building over the entire year can be immensely beneficial. This research identifies simple modeling techniques to determine best time of the year to begin in-situ monitoring of building energy-use, and the least amount of data required for generating acceptable long-term predictions. Four analysis procedures are studied. The short-term monitoring for long-term prediction (SMLP) approach and dry-bulb temperature analysis (DBTA) approach allow determining the best time and duration of the year for in-situ monitoring to be performed based only on the ambient temperature data of the location. Multivariate change-point (MCP) modeling uses simulated/monitored data to determine best monitoring period of the year. This is also used to validate the SMLP and DBTA approaches. The hybrid inverse modeling method-1 predicts energy-use by combining a short dataset of monitored internal loads with a year of utility-bills, and hybrid inverse method-2 predicts long term building performance using utility

  20. INL High Performance Building Strategy

    SciTech Connect

    Jennifer D. Morton

    2010-02-01

    High performance buildings, also known as sustainable buildings and green buildings, are resource efficient structures that minimize the impact on the environment by using less energy and water, reduce solid waste and pollutants, and limit the depletion of natural resources while also providing a thermally and visually comfortable working environment that increases productivity for building occupants. As Idaho National Laboratory (INL) becomes the nation’s premier nuclear energy research laboratory, the physical infrastructure will be established to help accomplish this mission. This infrastructure, particularly the buildings, should incorporate high performance sustainable design features in order to be environmentally responsible and reflect an image of progressiveness and innovation to the public and prospective employees. Additionally, INL is a large consumer of energy that contributes to both carbon emissions and resource inefficiency. In the current climate of rising energy prices and political pressure for carbon reduction, this guide will help new construction project teams to design facilities that are sustainable and reduce energy costs, thereby reducing carbon emissions. With these concerns in mind, the recommendations described in the INL High Performance Building Strategy (previously called the INL Green Building Strategy) are intended to form the INL foundation for high performance building standards. This revised strategy incorporates the latest federal and DOE orders (Executive Order [EO] 13514, “Federal Leadership in Environmental, Energy, and Economic Performance” [2009], EO 13423, “Strengthening Federal Environmental, Energy, and Transportation Management” [2007], and DOE Order 430.2B, “Departmental Energy, Renewable Energy, and Transportation Management” [2008]), the latest guidelines, trends, and observations in high performance building construction, and the latest changes to the Leadership in Energy and Environmental Design

  1. Robust modeling and performance analysis of high-power diode side-pumped solid-state laser systems.

    PubMed

    Kashef, Tamer; Ghoniemy, Samy; Mokhtar, Ayman

    2015-12-20

    In this paper, we present an enhanced high-power extrinsic diode side-pumped solid-state laser (DPSSL) model to accurately predict the dynamic operations and pump distribution under different practical conditions. We introduce a new implementation technique for the proposed model that provides a compelling incentive for the performance assessment and enhancement of high-power diode side-pumped Nd:YAG lasers using cooperative agents and by relying on the MATLAB, GLAD, and Zemax ray tracing software packages. A large-signal laser model that includes thermal effects and a modified laser gain formulation and incorporates the geometrical pump distribution for three radially arranged arrays of laser diodes is presented. The design of a customized prototype diode side-pumped high-power laser head fabricated for the purpose of testing is discussed. A detailed comparative experimental and simulation study of the dynamic operation and the beam characteristics that are used to verify the accuracy of the proposed model for analyzing the performance of high-power DPSSLs under different conditions are discussed. The simulated and measured results of power, pump distribution, beam shape, and slope efficiency are shown under different conditions and for a specific case, where the targeted output power is 140 W, while the input pumping power is 400 W. The 95% output coupler reflectivity showed good agreement with the slope efficiency, which is approximately 35%; this assures the robustness of the proposed model to accurately predict the design parameters of practical, high-power DPSSLs. PMID:26837034

  2. High Performance Torso Cooling Garment

    NASA Technical Reports Server (NTRS)

    Conger, Bruce; Makinen, Janice

    2016-01-01

    The concept proposed in this paper is to improve thermal efficiencies of the liquid cooling and ventilation garment (LCVG) in the torso area, which could facilitate removal of LCVG tubing from the arms and legs, thereby increasing suited crew member mobility. EVA space suit mobility in micro-gravity is challenging, and it becomes even more challenging in the gravity of Mars. By using shaped water tubes that greatly increase the contact area with the skin in the torso region of the body, the heat transfer efficiency can be increased. This increase in efficiency could provide the required liquid cooling via torso tubing only; no arm or leg LCVG tubing would be required. Benefits of this approach include increased crewmember mobility, enhanced evaporation cooling, increased comfort during Mars EVA tasks, and easing of the overly dry condition in the helmet associated with the Advanced Extravehicular Mobility Unit (EMU) ventilation loop currently under development. This report describes analysis and test activities performed to evaluate the potential improvements to the thermal performance of the LCVG. Analyses evaluated potential tube shapes for improving the thermal performance of the LCVG. The analysis results fed into the selection of flat flow strips to improve thermal contact with the skin of the suited test subject. Testing of small segments was performed to compare thermal performance of the tubing approach of the current LCVG to the flat flow strips proposed as the new concept. Results of the testing is presented along with recommendations for future development of this new concept.

  3. A game-based crowdsourcing platform for rapidly training middle and high school students to perform biomedical image analysis

    NASA Astrophysics Data System (ADS)

    Feng, Steve; Woo, Min-jae; Kim, Hannah; Kim, Eunso; Ki, Sojung; Shao, Lei; Ozcan, Aydogan

    2016-03-01

    We developed an easy-to-use and widely accessible crowd-sourcing tool for rapidly training humans to perform biomedical image diagnostic tasks and demonstrated this platform's ability on middle and high school students in South Korea to diagnose malaria infected red-blood-cells (RBCs) using Giemsa-stained thin blood smears imaged under light microscopes. We previously used the same platform (i.e., BioGames) to crowd-source diagnostics of individual RBC images, marking them as malaria positive (infected), negative (uninfected), or questionable (insufficient information for a reliable diagnosis). Using a custom-developed statistical framework, we combined the diagnoses from both expert diagnosticians and the minimally trained human crowd to generate a gold standard library of malaria-infection labels for RBCs. Using this library of labels, we developed a web-based training and educational toolset that provides a quantified score for diagnosticians/users to compare their performance against their peers and view misdiagnosed cells. We have since demonstrated the ability of this platform to quickly train humans without prior training to reach high diagnostic accuracy as compared to expert diagnosticians. Our initial trial group of 55 middle and high school students has collectively played more than 170 hours, each demonstrating significant improvements after only 3 hours of training games, with diagnostic scores that match expert diagnosticians'. Next, through a national-scale educational outreach program in South Korea we recruited >1660 students who demonstrated a similar performance level after 5 hours of training. We plan to further demonstrate this tool's effectiveness for other diagnostic tasks involving image labeling and aim to provide an easily-accessible and quickly adaptable framework for online training of new diagnosticians.

  4. High-performance liquid chromatographic analysis of neomycin in petrolatum-based ointments and in veterinary formulations.

    PubMed

    Binns, R B; Tsuji, K

    1984-01-01

    A high-performance liquid chromatographic (HPLC) method has been developed for the assay of neomycin in petrolatum-based ophthalmic and topical ointments and in veterinary formulations. Neomycin assay interferences from drugs, such as bacitracin and polymyxin B and inactive components, e.g. wax, were eliminated by a methanol wash and/or a partitioning method. The extracted neomycin was derivatized with 2,4-dinitrofluorobenzene followed by normal-phase HPLC with detection at 254 nm. The average recovery of neomycin from spiked samples was approximately 100% with a relative standard deviation of less than 1%.

  5. High Performance Bulk Thermoelectric Materials

    SciTech Connect

    Ren, Zhifeng

    2013-03-31

    Over 13 plus years, we have carried out research on electron pairing symmetry of superconductors, growth and their field emission property studies on carbon nanotubes and semiconducting nanowires, high performance thermoelectric materials and other interesting materials. As a result of the research, we have published 104 papers, have educated six undergraduate students, twenty graduate students, nine postdocs, nine visitors, and one technician.

  6. High performance storable propellant resistojet

    NASA Astrophysics Data System (ADS)

    Vaughan, C. E.

    1992-01-01

    From 1965 until 1985 resistojets were used for a limited number of space missions. Capability increased in stages from an initial application using a 90 W gN2 thruster operating at 123 sec specific impulse (Isp) to a 830 W N2H4 thruster operating at 305 sec Isp. Prior to 1985 fewer than 100 resistojets were known to have been deployed on spacecraft. Building on this base NASA embarked upon the High Performance Storable Propellant Resistojet (HPSPR) program to significantly advance the resistojet state-of-the-art. Higher performance thrusters promised to increase the market demand for resistojets and enable space missions requiring higher performance. During the program three resistojets were fabricated and tested. High temperature wire and coupon materials tests were completed. A life test was conducted on an advanced gas generator.

  7. Analysis of the high Reynolds number 2D tests on a wind turbine airfoil performed at two different wind tunnels

    NASA Astrophysics Data System (ADS)

    Pires, O.; Munduate, X.; Ceyhan, O.; Jacobs, M.; Madsen, J.; Schepers, J. G.

    2016-09-01

    2D wind tunnel tests at high Reynolds numbers have been done within the EU FP7 AVATAR project (Advanced Aerodynamic Tools of lArge Rotors) on the DU00-W-212 airfoil and at two different test facilities: the DNW High Pressure Wind Tunnel in Gottingen (HDG) and the LM Wind Power in-house wind tunnel. Two conditions of Reynolds numbers have been performed in both tests: 3 and 6 million. The Mach number and turbulence intensity values are similar in both wind tunnels at the 3 million Reynolds number test, while they are significantly different at 6 million Reynolds number. The paper presents a comparison of the data obtained from the two wind tunnels, showing good repeatability at 3 million Reynolds number and differences at 6 million Reynolds number that are consistent with the different Mach number and turbulence intensity values.

  8. Methods of analysis by the U.S. Geological Survey Organic Geochemistry Research Group; determination of chloroacetanilide herbicide metabolites in water using high-performance liquid chromatography-diode array detection and high-performance liquid chromatography/mass spectrometry

    USGS Publications Warehouse

    Zimmerman, L.R.; Hostetler, K.A.; Thurman, E.M.

    2000-01-01

    Analytical methods using high-performance liquid chromatography-diode array detection (HPLC-DAD) and high-performance liquid chromatography/mass spectrometry (HPLC/MS) were developed for the analysis of the following chloroacetanilide herbicide metabolites in water: acetochlor ethanesulfonic acid (ESA), acetochlor oxanilic acid (OXA), alachlor ESA, alachlor OXA, metolachlor ESA, and metolachlor OXA. Good precision and accuracy were demonstrated for both the HPLC-DAD and HPLC/MS methods in reagent water, surface water, and ground water. The mean HPLC-DAD recoveries of the chloroacetanilide herbicide metabolites from water samples spiked at 0.25, 0.50, and 2.0 mg/L (micrograms per liter) ranged from 84 to 112 percent, with relative standard deviations of 18 percent or less. The mean HPLC/MS recoveries of the metabolites from water samples spiked at 0.05, 0.20, and 2.0 mg/L ranged from 81 to 125 percent, with relative standard deviations of 20 percent or less. The limit of quantitation (LOQ) for all metabolites using the HPLC-DAD method was 0.20 mg/L, whereas the LOQ using the HPLC/MS method was 0.05 mg/L. These metabolite-determination methods are valuable for acquiring information about water quality and the fate and transport of the parent chloroacetanilide herbicides in water.

  9. Preparative isolation and analysis of alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root using ultrafiltration combined with high-performance liquid chromatography and high-speed countercurrent chromatography.

    PubMed

    Chen, Miao; Liu, Liangliang; Chen, Xiaoqing

    2014-07-01

    A simple, rapid, and effective assay based on ultrafiltration combined with high-performance liquid chromatography and high-speed countercurrent chromatography was developed for screening and purifying alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root extract. Experiments were carried out to optimize binding conditions including alcohol dehydrogenase concentration, incubation time, temperature, and pH. By comparing the chromatograms, three compounds were found possessing alcohol dehydrogenase binding activity in Glycyrrhiza uralensis root. Under the target-guidance of ultrafiltration combined with the high-performance liquid chromatography experiment, liquiritin (1), isoliquiritin (2), and liquiritigenin (3) were separated by high-speed countercurrent chromatography using ethyl acetate/methanol/water (5:1:4) as the solvent system. The alcohol dehydrogenase inhibitory activities of these three isolated compounds were assessed; compound 2 showed strongest inhibitory activity with an IC50 of 8.95 μM. The results of the present study indicated that the combinative method using ultrafiltration, high-performance liquid chromatography and high-speed countercurrent chromatography could be widely applied for the rapid screening and isolation of enzyme inhibitors from complex mixtures.

  10. Cranial performance in the Komodo dragon (Varanus komodoensis) as revealed by high-resolution 3-D finite element analysis.

    PubMed

    Moreno, Karen; Wroe, Stephen; Clausen, Philip; McHenry, Colin; D'Amore, Domenic C; Rayfield, Emily J; Cunningham, Eleanor

    2008-06-01

    The Komodo dragon (Varanus komodoensis) displays a unique hold and pull-feeding technique. Its delicate 'space-frame' skull morphology differs greatly from that apparent in most living large prey specialists and is suggestive of a high degree of optimization, wherein use of materials is minimized. Here, using high-resolution finite element modelling based on dissection and in vivo bite and pull data, we present results detailing the mechanical performance of the giant lizard's skull. Unlike most modern predators, V. komodoensis applies minimal input from the jaw muscles when butchering prey. Instead it uses series of actions controlled by postcranial muscles. A particularly interesting feature of the performance of the skull is that it reveals considerably lower overall stress when these additional extrinsic forces are added to those of the jaw adductors. This remarkable reduction in stress in response to additional force is facilitated by both internal and external bone anatomy. Functional correlations obtained from these analyses also provide a solid basis for the interpretation of feeding ecology in extinct species, including dinosaurs and sabre-tooth cats, with which V. komodoensis shares various cranial and dental characteristics.

  11. Cranial performance in the Komodo dragon (Varanus komodoensis) as revealed by high-resolution 3-D finite element analysis

    PubMed Central

    Moreno, Karen; Wroe, Stephen; Clausen, Philip; McHenry, Colin; D’Amore, Domenic C; Rayfield, Emily J; Cunningham, Eleanor

    2008-01-01

    The Komodo dragon (Varanus komodoensis) displays a unique hold and pull-feeding technique. Its delicate ‘space-frame’ skull morphology differs greatly from that apparent in most living large prey specialists and is suggestive of a high degree of optimization, wherein use of materials is minimized. Here, using high-resolution finite element modelling based on dissection and in vivo bite and pull data, we present results detailing the mechanical performance of the giant lizard's skull. Unlike most modern predators, V. komodoensis applies minimal input from the jaw muscles when butchering prey. Instead it uses series of actions controlled by postcranial muscles. A particularly interesting feature of the performance of the skull is that it reveals considerably lower overall stress when these additional extrinsic forces are added to those of the jaw adductors. This remarkable reduction in stress in response to additional force is facilitated by both internal and external bone anatomy. Functional correlations obtained from these analyses also provide a solid basis for the interpretation of feeding ecology in extinct species, including dinosaurs and sabre-tooth cats, with which V. komodoensis shares various cranial and dental characteristics. PMID:18510503

  12. Analysis of microdialysate monoamines, including noradrenaline, dopamine and serotonin, using capillary ultra-high performance liquid chromatography and electrochemical detection.

    PubMed

    Ferry, Barbara; Gifu, Elena-Patricia; Sandu, Ioana; Denoroy, Luc; Parrot, Sandrine

    2014-03-01

    Electrochemical methods are very often used to detect catecholamine and indolamine neurotransmitters separated by conventional reverse-phase high performance liquid chromatography (HPLC). The present paper presents the development of a chromatographic method to detect monoamines present in low-volume brain dialysis samples using a capillary column filled with sub-2μm particles. Several parameters (repeatability, linearity, accuracy, limit of detection) for this new ultrahigh performance liquid chromatography (UHPLC) method with electrochemical detection were examined after optimization of the analytical conditions. Noradrenaline, adrenaline, serotonin, dopamine and its metabolite 3-methoxytyramine were separated in 1μL of injected sample volume; they were detected above concentrations of 0.5-1nmol/L, with 2.1-9.5% accuracy and intra-assay repeatability equal to or less than 6%. The final method was applied to very low volume dialysates from rat brain containing monoamine traces. The study demonstrates that capillary UHPLC with electrochemical detection is suitable for monitoring dialysate monoamines collected at high sampling rate.

  13. Cranial performance in the Komodo dragon (Varanus komodoensis) as revealed by high-resolution 3-D finite element analysis.

    PubMed

    Moreno, Karen; Wroe, Stephen; Clausen, Philip; McHenry, Colin; D'Amore, Domenic C; Rayfield, Emily J; Cunningham, Eleanor

    2008-06-01

    The Komodo dragon (Varanus komodoensis) displays a unique hold and pull-feeding technique. Its delicate 'space-frame' skull morphology differs greatly from that apparent in most living large prey specialists and is suggestive of a high degree of optimization, wherein use of materials is minimized. Here, using high-resolution finite element modelling based on dissection and in vivo bite and pull data, we present results detailing the mechanical performance of the giant lizard's skull. Unlike most modern predators, V. komodoensis applies minimal input from the jaw muscles when butchering prey. Instead it uses series of actions controlled by postcranial muscles. A particularly interesting feature of the performance of the skull is that it reveals considerably lower overall stress when these additional extrinsic forces are added to those of the jaw adductors. This remarkable reduction in stress in response to additional force is facilitated by both internal and external bone anatomy. Functional correlations obtained from these analyses also provide a solid basis for the interpretation of feeding ecology in extinct species, including dinosaurs and sabre-tooth cats, with which V. komodoensis shares various cranial and dental characteristics. PMID:18510503

  14. Numerical Stability and Control Analysis Towards Falling-Leaf Prediction Capabilities of Splitflow for Two Generic High-Performance Aircraft Models

    NASA Technical Reports Server (NTRS)

    Charlton, Eric F.

    1998-01-01

    Aerodynamic analysis are performed using the Lockheed-Martin Tactical Aircraft Systems (LMTAS) Splitflow computational fluid dynamics code to investigate the computational prediction capabilities for vortex-dominated flow fields of two different tailless aircraft models at large angles of attack and sideslip. These computations are performed with the goal of providing useful stability and control data to designers of high performance aircraft. Appropriate metrics for accuracy, time, and ease of use are determined in consultations with both the LMTAS Advanced Design and Stability and Control groups. Results are obtained and compared to wind-tunnel data for all six components of forces and moments. Moment data is combined to form a "falling leaf" stability analysis. Finally, a handful of viscous simulations were also performed to further investigate nonlinearities and possible viscous effects in the differences between the accumulated inviscid computational and experimental data.

  15. Dependability and performability analysis

    NASA Technical Reports Server (NTRS)

    Trivedi, Kishor S.; Ciardo, Gianfranco; Malhotra, Manish; Sahner, Robin A.

    1993-01-01

    Several practical issues regarding specifications and solution of dependability and performability models are discussed. Model types with and without rewards are compared. Continuous-time Markov chains (CTMC's) are compared with (continuous-time) Markov reward models (MRM's) and generalized stochastic Petri nets (GSPN's) are compared with stochastic reward nets (SRN's). It is shown that reward-based models could lead to more concise model specifications and solution of a variety of new measures. With respect to the solution of dependability and performability models, three practical issues were identified: largeness, stiffness, and non-exponentiality, and a variety of approaches are discussed to deal with them, including some of the latest research efforts.

  16. Analysis of EDP performance

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The objective of this contract was the investigation of the potential performance gains that would result from an upgrade of the Space Station Freedom (SSF) Data Management System (DMS) Embedded Data Processor (EDP) '386' design with the Intel Pentium (registered trade-mark of Intel Corp.) '586' microprocessor. The Pentium ('586') is the latest member of the industry standard Intel X86 family of CISC (Complex Instruction Set Computer) microprocessors. This contract was scheduled to run in parallel with an internal IBM Federal Systems Company (FSC) Internal Research and Development (IR&D) task that had the goal to generate a baseline flight design for an upgraded EDP using the Pentium. This final report summarizes the activities performed in support of Contract NAS2-13758. Our plan was to baseline performance analyses and measurements on the latest state-of-the-art commercially available Pentium processor, representative of the proposed space station design, and then phase to an IBM capital funded breadboard version of the flight design (if available from IR&D and Space Station work) for additional evaluation of results. Unfortunately, the phase-over to the flight design breadboard did not take place, since the IBM Data Management System (DMS) for the Space Station Freedom was terminated by NASA before the referenced capital funded EDP breadboard could be completed. The baseline performance analyses and measurements, however, were successfully completed, as planned, on the commercial Pentium hardware. The results of those analyses, evaluations, and measurements are presented in this final report.

  17. High performance seizure-monitoring system using a vibration sensor and videotape recording: behavioral analysis of genetically epileptic rats.

    PubMed

    Amano, S; Yokoyama, M; Torii, R; Fukuoka, J; Tanaka, K; Ihara, N; Hazama, F

    1997-06-01

    A new seizure-monitoring apparatus containing a piezoceramic vibration sensor combined with videotape recording was developed. Behavioral analysis of Ihara's genetically epileptic rat (IGER), which is a recently developed novel mutant with spontaneously limbic-like seizures, was performed using this new device. Twenty 8-month-old male IGERs were monitored continuously for 72 h. Abnormal behaviors were detected by use of a vibration recorder, and epileptic seizures were confirmed by videotape recordings taken synchronously with vibration recording. Representative forms of seizures were generalized convulsions and circling seizures. Generalized convulsions were found in 13 rats, and circling seizures in 7 of 20 animals. Two rats had generalized and circling seizures, and two rats did not have seizures. Although there was no apparent circadian rhythm to the generalized seizures, circling seizures occurred mostly between 1800 and 0800 h. A correlation between the sleep-wake cycle and the occurrence of circling seizures seems likely. Without exception, all the seizure actions were recorded by the vibration recorder and the videotape recorder. To eliminate the risk of a false-negative result, investigators scrutinized the information obtained from the vibration sensor and the videotape recorder. The newly developed seizure-monitoring system was found to facilitate detailed analysis of epileptic seizures in rats.

  18. Genomic analysis of the aconidial and high-performance protein producer, industrially relevant Aspergillus niger SH2 strain.

    PubMed

    Yin, Chao; Wang, Bin; He, Pan; Lin, Ying; Pan, Li

    2014-05-15

    Aspergillus niger is usually regarded as a beneficial species widely used in biotechnological industry. Obtaining the genome sequence of the widely used aconidial A. niger SH2 strain is of great importance to understand its unusual production capability. In this study we assembled a high-quality genome sequence of A. niger SH2 with approximately 11,517 ORFs. Relatively high proportion of genes enriched for protein expression related FunCat items verify its efficient capacity in protein production. Furthermore, genome-wide comparative analysis between A. niger SH2 and CBS513.88 reveals insights into unique properties of A. niger SH2. A. niger SH2 lacks the gene related with the initiation of asexual sporulation (PrpA), leading to its distinct aconidial phenotype. Frame shift mutations and non-synonymous SNPs in genes of cell wall integrity signaling, β-1,3-glucan synthesis and chitin synthesis influence its cell wall development which is important for its hyphal fragmentation during industrial high-efficiency protein production.

  19. High performance magnetically controllable microturbines.

    PubMed

    Tian, Ye; Zhang, Yong-Lai; Ku, Jin-Feng; He, Yan; Xu, Bin-Bin; Chen, Qi-Dai; Xia, Hong; Sun, Hong-Bo

    2010-11-01

    Reported in this paper is two-photon photopolymerization (TPP) fabrication of magnetic microturbines with high surface smoothness towards microfluids mixing. As the key component of the magnetic photoresist, Fe(3)O(4) nanoparticles were carefully screened for homogeneous doping. In this work, oleic acid stabilized Fe(3)O(4) nanoparticles synthesized via high-temperature induced organic phase decomposition of an iron precursor show evident advantages in particle morphology. After modification with propoxylated trimethylolpropane triacrylate (PO(3)-TMPTA, a kind of cross-linker), the magnetic nanoparticles were homogeneously doped in acrylate-based photoresist for TPP fabrication of microstructures. Finally, a magnetic microturbine was successfully fabricated as an active mixing device for remote control of microfluids blending. The development of high quality magnetic photoresists would lead to high performance magnetically controllable microdevices for lab-on-a-chip (LOC) applications. PMID:20721411

  20. Enantioselective analysis of D- and L-amino acids from mouse macrophages using high performance liquid chromatography.

    PubMed

    Kato, Shiro; Masuda, Yuki; Konishi, Morichika; Oikawa, Tadao

    2015-12-10

    The intrinsic D-amino acid profile of mouse macrophages extracted from the peritoneal cavity was analyzed using high performance liquid chromatography. Six D-amino acids (D-Asp, D-Ser, D-Ala, D-Leu, D-Gln and D-Lys) were detected in cell lysates of mouse macrophages. The content and the D/D+L ratio differed depending on the type of D-amino acid and were approximately 3.5-22 nmol/g cells, and approximately 1-20%, respectively. The D-amino acid composition of RAW 264.7 cells, which is a model macrophage cell line, was similar to that of the mouse macrophage. These results suggest that macrophages and RAW 264.7 cells with macrophage-like functions have a similar D-amino acid profile.

  1. Biocompatible chiral monolithic stationary phase synthesized via atom transfer radical polymerization for high performance liquid chromatographic analysis.

    PubMed

    Wang, Huai-Song; Feng, Xia-Yi; Wei, Ji-Ping

    2015-08-28

    Novel biocompatible chiral monolithic stationary phase was prepared by reverse and direct atom transfer radical polymerization (ATRP) methods. By taking advantages of the controlled/living property of ATRP method, the chiral monolith was prepared by reverse ATRP (RATRP) firstly. An attractive feature of RATRP is the prepared polymer containing a terminal radically transferable atom that can initiate another post-polymerization reaction by direct ATRP. Then, the biocompatible poly(hydroxyethyl methacrylate) (PHEMA) was grafted on the surface of the chiral monolith by direct ATRP as a diffusion barrier for proteins. This biocompatible chiral monolith was successfully used as restricted access stationary phase for determination of enantiomers in biological samples with direct injection by high-performance liquid chromatography (HPLC). PMID:26199103

  2. Analysis of potassium iodate reduction in tissue homogenates using high performance liquid chromatography-inductively coupled plasma-mass spectrometry.

    PubMed

    Cao, Xiaoxiao; Ma, Wei; Liu, Liejun; Xu, Jing; Wang, Haiyan; Li, Xiuwei; Wang, Jiangqing; Zhang, Jianhua; Wang, Zexi; Gu, Yunyou

    2015-10-01

    Potassium iodate (KIO3) and potassium iodide (KI) are the major salt iodization agents used worldwide. Unlike iodide (I(-)), iodate (IO3(-)) should be reduced to I(-) before it can be effectively used by the thyroid. In this study, we developed a new method for analyzing IO3(-) and I(-) in tissue homogenates using high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). We further applied the method to demonstrate the KIO3 reduction process by tissues in vitro. The effects of KIO3 on the total antioxidative activity (TAA) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) were also investigated here. Finally, we found that IO3(-) can be reduced to I(-) by tissue homogenates and IO3(-) irreversibly decreases the antioxidant capability of tissues. Our studies suggest that KIO3 might have a big effect on the redox balance of tissue and would further result in oxidative stress of organisms.

  3. High Efficiency, High Performance Clothes Dryer

    SciTech Connect

    Peter Pescatore; Phil Carbone

    2005-03-31

    This program covered the development of two separate products; an electric heat pump clothes dryer and a modulating gas dryer. These development efforts were independent of one another and are presented in this report in two separate volumes. Volume 1 details the Heat Pump Dryer Development while Volume 2 details the Modulating Gas Dryer Development. In both product development efforts, the intent was to develop high efficiency, high performance designs that would be attractive to US consumers. Working with Whirlpool Corporation as our commercial partner, TIAX applied this approach of satisfying consumer needs throughout the Product Development Process for both dryer designs. Heat pump clothes dryers have been in existence for years, especially in Europe, but have not been able to penetrate the market. This has been especially true in the US market where no volume production heat pump dryers are available. The issue has typically been around two key areas: cost and performance. Cost is a given in that a heat pump clothes dryer has numerous additional components associated with it. While heat pump dryers have been able to achieve significant energy savings compared to standard electric resistance dryers (over 50% in some cases), designs to date have been hampered by excessively long dry times, a major market driver in the US. The development work done on the heat pump dryer over the course of this program led to a demonstration dryer that delivered the following performance characteristics: (1) 40-50% energy savings on large loads with 35 F lower fabric temperatures and similar dry times; (2) 10-30 F reduction in fabric temperature for delicate loads with up to 50% energy savings and 30-40% time savings; (3) Improved fabric temperature uniformity; and (4) Robust performance across a range of vent restrictions. For the gas dryer development, the concept developed was one of modulating the gas flow to the dryer throughout the dry cycle. Through heat modulation in a

  4. Simultaneous Quantitative Analysis of Olmesartan Medoxomil and Amlodipine Besylate in Plasma by High-performance Liquid Chromatography Technique

    PubMed Central

    Shah, SK; Asnani, AJ; Kawade, DP; Dangre, SC; Arora, SK; Yende, SR

    2012-01-01

    A rapid, simple and sensitive high-performance liquid chromatography (HPLC) method has been developed for quantification of olmesartan medoxomil (OLM) and amlodipine besylate (AM) in plasma. The assay enables the measurement of OLM and AM for therapeutic drug monitoring with a minimum detectable limit of 2 ng mL. The method involves a simple, one-step extraction procedure and analytical recovery was above 50%. The separation was performed on an analytical 250 × 4.6 mm Eurospher 100-5 C18 column. The wavelength was set at 239 nm. The mobile phase was a mixture of acetonitrile:0.05 M ammonium acetate buffer: 0.1 mL triethylamine at pH 6.8 was selected at a flow rate of 1.0 mL min. The calibration curve for the determination of OLM and AM in plasma was linear over the range 2–2500 and 8–10,000 ng mL AM and OLM. The coefficients of variation for interday and intraday assay were found to be <15%. The method can be applied to a pharmacokinetic and pharmacodynamic study of OLM and AM in a combined dosage form. PMID:22754260

  5. High performance ammonium nitrate propellant

    NASA Technical Reports Server (NTRS)

    Anderson, F. A. (Inventor)

    1979-01-01

    A high performance propellant having greatly reduced hydrogen chloride emission is presented. It is comprised of: (1) a minor amount of hydrocarbon binder (10-15%), (2) at least 85% solids including ammonium nitrate as the primary oxidizer (about 40% to 70%), (3) a significant amount (5-25%) powdered metal fuel, such as aluminum, (4) a small amount (5-25%) of ammonium perchlorate as a supplementary oxidizer, and (5) optionally a small amount (0-20%) of a nitramine.

  6. New, high performance rotating parachute

    SciTech Connect

    Pepper, W.B. Jr.

    1983-01-01

    A new rotating parachute has been designed primarily for recovery of high performance reentry vehicles. Design and development/testing results are presented from low-speed wind tunnel testing, free-flight deployments at transonic speeds and tests in a supersonic wind tunnel at Mach 2.0. Drag coefficients of 1.15 based on the 2-ft diameter of the rotor have been measured in the wind tunnel. Stability of the rotor is excellent.

  7. High-performance thin-layer chromatography analysis of steviol glycosides in Stevia formulations and sugar-free food products, and benchmarking with (ultra) high-performance liquid chromatography.

    PubMed

    Morlock, Gertrud E; Meyer, Stephanie; Zimmermann, Benno F; Roussel, Jean-Marc

    2014-07-11

    A high-performance TLC (HPTLC) method was newly developed and validated for analysis of 7 steviol glycosides in 6 different types of food and Stevia formulations. After a minimized one-step sample preparation, 21 samples were developed in parallel, allowing an effective food screening. Depending on the sample application volume, the method was suited to analyze food sample concentrations in the mg/kg range. LOQs of stevioside in natural yoghurt matrix spiked at 0.02, 0.13 and 0.2% were determined by the calibration curve method to be 12ng/band (peak height). ANOVA was successfully passed to prove data homogeneity in the working range (30-600ng/band). The accuracy (recovery tolerance limit, 92-120%), repeatability (3.1-5.4%) and intermediate precision (4.0-8.4%) were determined for stevioside in milk-based matrix including sample preparation and recovery rates at 3 different concentration levels. For the first time, the recording of HPTLC-ESI-MS spectra via the TLC-MS Interface was demonstrated for rebaudioside A. HPTLC contents for rebaudioside A were compared with results of two (U)HPLC methods. The running costs and analysis time of the three different methods were discussed in detail with regard to screening of food products.

  8. Analysis of food polyphenols by ultra high-performance liquid chromatography coupled to mass spectrometry: an overview.

    PubMed

    Motilva, Maria-José; Serra, Aida; Macià, Alba

    2013-05-31

    Phenolic compounds, which are widely distributed in plant-derived foods, recently attracted much attention due to their health benefits, so their determination in food samples is a topic of increasing interest. In the last few years, the development of chromatographic columns packed with sub-2μm particles and the modern high resolution mass spectrometry (MS) have opened up new possibilities for improving the analytical methods for complex sample matrices, such as ingredients, foods and biological samples. In addition, they have emerged as an ideal tool for profiling complex samples due to its speed, efficiency, sensitivity and selectivity. The present review addresses the use of the improved liquid chromatography (LC), ultra-high performance LC (UHPLC), coupled to MS or tandem MS (MS/MS) as the detector system for the determination of phenolic compounds in food samples. Additionally, the different strategies to extract, quantify the phenolic compounds and to reduce the matrix effect (%ME) are also reviewed. Finally, a briefly outline future trends of UHPLC-MS methods is commented.

  9. Multiclass analysis of mycotoxins in biscuits by high performance liquid chromatography-tandem mass spectrometry. Comparison of different extraction procedures.

    PubMed

    Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; Samperi, Roberto; Stampachiacchiere, Serena; Ventura, Salvatore; Laganà, Aldo

    2014-05-23

    A sensitive, simple and rapid method for the simultaneous determination of 19 mycotoxins in biscuits (a dry matrix containing cereals and egg) has been developed using high performance liquid chromatography coupled to tandem mass spectrometry with electrospray source working in both positive and negative mode. Due to the matrix complexity and the high amount of contaminants, a solid phase extraction method using graphitized carbon black was optimized for an effective clean-up step. Accuracy was carried out in the selected matrix using blank samples spiked at three analyte concentrations. Recoveries between 63 and 107% and relative standard deviations lower than 12% were obtained. For all considered mycotoxin classes, i.e. thricotecenes A and B, zearalenone and its metabolites, fumonisins, ochratoxin A, enniatins and their structurally related beauvericin, the method was validated in terms of linearity, recovery, matrix effect, precision, limit of detection and limit of quantification. Matrix-matched calibration was used for quantification purposes, in order to compensate for matrix effect. The coefficients of determination obtained were in the range of 0.9927-1. The limits of quantification, ranging from 0.04μgkg(-1) for enniatin B1 to 80.2μgkg(-1) for nivalenol, were always lower than maximum permitted levels for every regulated mycotoxin by the current European legislation.

  10. Modelling and analysis of a high-performance Class D audio amplifier using unipolar pulse-width-modulation

    NASA Astrophysics Data System (ADS)

    Zhou, Zekun; Shi, Yue; Ming, Xin; Zhang, Bo; Li, Zhaoji; Chen, Zao

    2012-02-01

    A high-performance class D audio amplifier using unipolar pulse-width-modulation (PWM) with double-sided natural sampling is presented in this article. In order to comprehend and design the system properly, the class D audio amplifier is modelled and analysed. A wide range triangle-wave signal with good linearity and magnitude proportional to supply voltage is embedded in the proposed class D audio amplifier for maximum output power, high power supply rejection ratio (PSRR) and low total harmonic distortion (THD). Design results based on CSMC 0.5-µm 5-V complementary metal-oxide-semiconductor process demonstrate that the proposed class D audio amplifier can operate with supply voltage in the range 2.4-5.5 V and supports 2.8 W output power from a 5.5 V supply; the maximum efficiency is above 95%, the PSRR is -82 dB, the signal-to-noise ratio (SNR) is 97 dB and the total harmonic distortion plus noise (THD+N) is less than 0.1% between 20 and 20 kHz with output power 0.4 W; the quiescent current without load is 1.8 mA, and the shutdown current is 0.01 µA. The active area of the class-D audio power amplifier is 1.5 mm × 1.5 mm.

  11. MPQC: Performance Analysis and Optimization

    SciTech Connect

    Sarje, Abhinav; Williams, Samuel; Bailey, David

    2012-11-30

    MPQC (Massively Parallel Quantum Chemistry) is a widely used computational quantum chemistry code. It is capable of performing a number of computations commonly occurring in quantum chemistry. In order to achieve better performance of MPQC, in this report we present a detailed performance analysis of this code. We then perform loop and memory access optimizations, and measure performance improvements by comparing the performance of the optimized code with that of the original MPQC code. We observe that the optimized MPQC code achieves a significant improvement in the performance through a better utilization of vector processing and memory hierarchies.

  12. High performance aerated lagoon systems

    SciTech Connect

    Rich, L.

    1999-08-01

    At a time when less money is available for wastewater treatment facilities and there is increased competition for the local tax dollar, regulatory agencies are enforcing stricter effluent limits on treatment discharges. A solution for both municipalities and industry is to use aerated lagoon systems designed to meet these limits. This monograph, prepared by a recognized expert in the field, provides methods for the rational design of a wide variety of high-performance aerated lagoon systems. Such systems range from those that can be depended upon to meet secondary treatment standards alone to those that, with the inclusion of intermittent sand filters or elements of sequenced biological reactor (SBR) technology, can also provide for nitrification and nutrient removal. Considerable emphasis is placed on the use of appropriate performance parameters, and an entire chapter is devoted to diagnosing performance failures. Contents include: principles of microbiological processes, control of algae, benthal stabilization, design for CBOD removal, design for nitrification and denitrification in suspended-growth systems, design for nitrification in attached-growth systems, phosphorus removal, diagnosing performance.

  13. Analysis of glucuronide and sulfate steroids in urine by ultra-high-performance supercritical-fluid chromatography hyphenated tandem mass spectrometry.

    PubMed

    Doué, Mickael; Dervilly-Pinel, Gaud; Pouponneau, Karinne; Monteau, Fabrice; Le Bizec, Bruno

    2015-06-01

    Profiling conjugated urinary steroids to detect anabolic-steroid misuse is recognized as an efficient analytical strategy in both chemical-food-safety and anti-doping fields. The relevance and robustness of such profiling rely on the analysis of glucuronide and sulfate steroids, which is expected to have properties including accuracy, specificity, sensitivity, and, if possible, rapidity. In this context, the ability of ultra-high-performance supercritical-fluid chromatography (UHPSFC) hyphenated tandem mass spectrometry (MS-MS) to provide reliable and accurate phase II analysis of steroids was assessed. Four stationary phases with sub-2 μm particles (BEH, BEH 2-ethyl-pyridine, HSS C18 SB, and CSH fluorophenyl) were screened for their capacity to separate several conjugated steroid isomers. Analytical conditions including stationary phase, modifier composition and percentage, back pressure, column temperature, and composition and flow rate of make-up solvent were investigated to improve the separation and/or the sensitivity. Thus, an analytical procedure enabling the analysis of eight glucuronide and 12 sulfate steroids by two different methods in 12 and 15 min, respectively, was optimized. The two procedures were evaluated, and UHPSFC-MS-MS analysis revealed its ability to provide sensitive (limits of quantification: 0.1 ng mL(-1) and 0.5 ng mL(-1) for sulfate and glucuronide steroids, respectively) and reliable quantitative performance (R(2) > 0.995, RSD < 20%, and bias < 30%) through the use of suitable labeled internal standards. Comparison with UHPLC-MS-MS was performed, and UHPSFC-MS-MS obtained better performance in terms of sensitivity. Finally, as a proof of concept, this so-called green technology was used in a chemical-food-safety context to profile steroid conjugates in urine samples from bovines treated with estradiol. Graphical Abstract Glucuronide and sulfate steroids analysis in urine by ultra-high performance supercritical fluid

  14. Lidar performance analysis

    NASA Technical Reports Server (NTRS)

    Spiers, Gary D.

    1994-01-01

    Section 1 details the theory used to build the lidar model, provides results of using the model to evaluate AEOLUS design instrument designs, and provides snapshots of the visual appearance of the coded model. Appendix A contains a Fortran program to calculate various forms of the refractive index structure function. This program was used to determine the refractive index structure function used in the main lidar simulation code. Appendix B contains a memo on the optimization of the lidar telescope geometry for a line-scan geometry. Appendix C contains the code for the main lidar simulation and brief instruction on running the code. Appendix D contains a Fortran code to calculate the maximum permissible exposure for the eye from the ANSI Z136.1-1992 eye safety standards. Appendix E contains a paper on the eye safety analysis of a space-based coherent lidar presented at the 7th Coherent Laser Radar Applications and Technology Conference, Paris, France, 19-23 July 1993.

  15. Micelle-mediated extraction of dibenzocyclooctadiene lignans from Schisandra chinensis with analysis by high-performance liquid chromatography.

    PubMed

    Lee, Ki Yong; Shin, Yong-Jun; Kim, Dae Hyun; Park, Jin-Ho; Kim, Seung Hyun; Han, Sang Beom; Sung, Sang Hyun

    2014-08-01

    Micelle-mediated extraction offers a convenient alternative to conventional extraction systems. A new method based on micelle-mediated extraction was developed for the separation and determination of dibenzocyclooctadiene lignans from Schisandra chinensis by high-performance liquid chromatography with photodiode array detection. Various experimental conditions using the micelle-mediated method were investigated to evaluate the extraction process. Ethylene glycol monoalkyl ether (Genapol X-080), a non-ionic surfactant oligoethylene glycol monoalkyl ether, was chosen as the extract solvent. The chromatographic separation was accomplished on a Shiseido Capcell Pak C18 analytical column (250 × 4.6mm i.d., 5 µm particle diameter), detected by ultraviolet absorption at 254 nm. The isocratic elution was achieved with a mobile phase composed of water-acetonitrile-formic acid (70:30:0.1) at a flow rate of 0.6 mL/min. The method was optimized and fully validated against dibenzocyclooctadiene lignans (schizandrin, gomisin A and gomisin N). With 15% Genapol X-080, a liquid to solid ratio of 100:1 (mL/g) and ultrasonic-assisted extraction for 60 min, the extraction percentage of total dibenzocyclooctadiene lignans reached the highest value. The non-ionic surfactant Genapol X-080 solution is an effective alternative for the extraction of bioactive lignans from S. chinensis.

  16. Performance analysis of RF-sputtered ZnO/Si heterojunction UV photodetectors with high photo-responsivity

    NASA Astrophysics Data System (ADS)

    Singh, Satyendra Kumar; Hazra, Purnima; Tripathi, Shweta; Chakrabarti, P.

    2016-03-01

    In this paper, structural, electrical and ultraviolet photodetection parameters of RF sputtered-ZnO/Si heterojunction diodes are analyzed. In this work, ZnO thin film was deposited on bare Si substrate as well as Si substrate coated with ultrathin ZnO seed layer to exhibit the effect of seed layer on device performance. AFM image of as-grown ZnO films have exhibited the uniform growth ZnO film over the whole Si substrate with average roughness of 3.2 nm and 2.83 nm for ZnO with and without seed layer respectively. Stronger peak intensity along (002) direction, as shown in XRD spectra confirm that ZnO film grown on ZnO seed layer is having more stable wurtzite structure. Ti/Al point contacts were deposited on top of the ZnO film and a layer of Al was deposited on bottom of Si substrate for using as ohmic contacts for further device characterization at dark and under UV light of 365 nm wavelength. This process is repeated for both the films sequentially. The photo-responsivity of our proposed devices is calculated as 0.34 A/W for seed layer-mediated devices and 0.26 A/W for devices without seed layer. These values are very high as compare to the reported value of photo-responsivity for same kind of ZnO/Si heterojunction device prototypes prepared by other techniques.

  17. Analysis of stereochemistry and biosynthesis of epicatechin in tea plants by chiral phase high performance liquid chromatography.

    PubMed

    Qian, Yumei; Zhao, Xianqian; Zhao, Lei; Cui, Lilan; Liu, Li; Jiang, Xiaolan; Liu, Yajun; Gao, Liping; Xia, Tao

    2015-12-01

    Tea (Camellia sinensis) is rich in flavan-3-ols (catechins), especially epicatechin (EC), which is the predominant extension unit of polymeric proanthocyanidins (PAs). However, studies assessing EC's stereochemistry are scarce. Here, a high performance liquid chromatography column using amylose tris-(3, 5-dimethylphenylcarbamate) immobilized on silica-gel as chiral stationary phases (CSPs) was applied to explore its stereochemistry and biosynthetic pathway in tea plants. The results revealed (-)-epicatechin [(-)-EC] was the predominant di-hyroxy-non-galloylated-catechins, while (+)-epicatechin [(+)-EC] was not detected. Interestingly, (-)-EC was the only product obtained from cyanidin using the partially purified native C. sinensis anthocyanidin reductase (CsANR) in the presence of reduction nicotinamide adenine dinucleotide phosphate (NADPH); meanwhile, (+)-EC was the main product using recombinant CsANR in the same conditions. In addition, (-)-EC could be obtained from (+)-catechin [(+)-C] using recombinant CsANR, which displayed C3-epimerase activity in the presence of oxidation nicotinamide adenine dinucleotide phosphate (NADP(+)). But the partially purified native CsANR did not possess this function. Finally, (-)-EC could result from the de-gallate acid reaction of epicatechin gallate (ECG) catalyzed by a novel partially purified native galloylated catechins hydrolase (GCH) from tea leaves. In summary, (-)-EC is likely the product of native protein from the tea plants, and (+)-EC is only produced in a reaction catalyzed by recombinant CsANR in vitro.

  18. High performance liquid chromatographic analysis and anticancer potential of Oplopanax horridus: Comparison of stem and berry extracts

    PubMed Central

    Wang, Chong-Zhi; Aung, Han H.; Mehendale, Sangeeta R.; Shoyama, Yukihiro; Yuan, Chun-Su

    2009-01-01

    Oplopanax horridus or devil’s club is a herbal medicine distributed in North America. The constituents and pharmacological activities of O. horridus (OPH) are largely unknown. In this study, we assayed OPH stem and berry extracts using high performance liquid chromatography (HPLC). The anticancer potentials of extracts on different human cancer cell lines (SW-480, HCT-116, HT-29, MCF-7 and NSCLC) were determined by MTS method. The effect of stem extract on cancer cell cycle, expression of cyclin A, and apoptosis were assayed using flow cytometry. HPLC data showed that the composition of OPH stem extract is more complicated than the berry extract. The wavelength of maximum absorption of the major constituent in stem and berry is 196.0 nm and 201.9 nm, respectively. Compared to the berry extract, the stem extract showed significant potent antiproliferative effect on all the studied cell lines. The stem extract at 0.1 mg/ml arrested cancer cells in S- and G2/M-phases, and significantly induced expression of cyclin A. After treatment with 0.1 mg/ml of stem extract for 72 h, apoptotic cells were increased to 45.2%, while control was 9.6%. The cell cycle arrest and induction of apoptosis may play a critical role in cancer chemoprevention by Oplopanax horridus stem extract. PMID:19686820

  19. NON-COMPETITIVE PEAK DECAY ANALYSIS OF DRUG-PROTEIN DISSOCIATION BY HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY

    PubMed Central

    Chen, Jianzhong; Schiel, John E.; Hage, David S.

    2009-01-01

    The peak decay method is an affinity chromatographic technique that has been used to examine the dissociation of solutes from immobilized ligands in the presence of excess displacing agent. However, it can be difficult to find a displacing agent that does not interfere with detection of the eluting analyte. In this study, a non-competitive peak decay method was developed in which no displacing agent was required for analyte elution. This method was evaluated for the study of drug-protein interactions by using it along with high-performance affinity chromatography to measure the dissociation rate constants for R- and S-warfarin from columns containing immobilized human serum albumin (HSA). Several factors were considered in the optimization of this method, including the amount of applied analyte, the column size, and the flow rate. The dissociation rate constants for R- and S-warfarin from HSA were measured at several temperatures by this approach, giving values of 0.56 (± 0.01) and 0.66 (± 0.01) s−1 at pH 7.4 and 37°C. These results were in good agreement with previous values obtained by other methods. This approach is not limited to warfarin and HSA but could be employed in studying additional drug-protein interactions or other systems with weak-to-moderate binding. PMID:19472288

  20. Analysis of wax ester molecular species by high performance liquid chromatography/atmospheric pressure chemical ionisation mass spectrometry.

    PubMed

    Vrkoslav, Vladimír; Urbanová, Klára; Cvacka, Josef

    2010-06-18

    High chromatographic resolution of wax esters (WEs) was achieved by non-aqueous reversed-phase liquid chromatography on a Nova-Pak C18 column by optimising the acetonitrile/ethyl acetate mobile phase gradient. The retention behaviour of WEs was studied in this chromatographic system. The WEs eluted according to their equivalent carbon number (ECN) values; within the group of WEs with the identical ECN, the most unsaturated species tended to elute first. The isobaric WEs with different positions of the ester moiety were separated from each other whenever the lengths of the chains were sufficiently different. The methyl-branched esters eluted at shorter retention times than the straight-chained analogues, and the resolution among methyl-branched WEs depended on the position of the branching. The analytes were detected by atmospheric pressure chemical ionisation mass spectrometry (APCI-MS) using data-dependent scanning. WEs provided simple full-scan spectra with abundant protonated molecules and low-intensity fragments. Collision-induced dissociation (CID) promoted identification of the WE molecular species. The responses of WEs were found to be dependent on the number of double bonds and on the alkyl-chain length; the limits of the detection ranged from 20micromol/L to 200nmol/L. The HPLC/APCI-MS was applied for the analysis of the WEs isolated from honeycomb beeswax, jojoba oil and human hair. Good agreement between reported results and the literature data was achieved, with several novel polyunsaturated WEs also being found.

  1. Concepts involved in a proposed application of uncertainty analysis to the performance assessment of high-level nuclear waste isolation systems

    SciTech Connect

    Maerker, R.E.

    1986-03-01

    This report introduces the concepts of a previously developed methodology which could readily be extended to the field of performance assessment for high-level nuclear waste isolation systems. The methodology incorporates sensitivities previously obtained with the GRESS code into an uncertainty analysis, from which propagated uncertainties in calculated responses may be derived from basic data uncertainties. Following a definition of terms, examples are provided illustrating commonly used conventions for describing the concepts of covariance and sensitivity. Examples of solutions to problems previously encountered in related fields involving uncertainty analysis and use of a generalized linear least-squares adjustment procedure are also presented. 5 refs., 14 tabs.

  2. Comparison of extraction methods for the analysis of natural dyes in historical textiles by high-performance liquid chromatography.

    PubMed

    Valianou, Lemonia; Karapanagiotis, Ioannis; Chryssoulakis, Yannis

    2009-12-01

    Different methods for the extraction of Dactylopius coccus Costa, Rubia tinctorum L., Isatis tinctoria L., Reseda luteola L., Curcuma longa L. and Cotinus coggygria Scop. from wool fibres are investigated using high-performance liquid chromatography with diode array detector (HPLC-DAD). The efficiencies of five extraction methods which include the use of HCl (widely used extraction method), citric acid, oxalic acid, TFA and a combination of HCOOH and EDTA are compared on the basis of the (a) number, (b) relative quantities, measured as HPLC peak areas and (c) signal-to-noise ratios (S/N) of the compounds extracted from the wool substrates. Flavonoid glycosides and curcuminoids contained in R. luteola L. and C. longa L., respectively, according to liquid chromatography with mass spectrometry (LC-MS) identifications, are not detected after treating the fibres with HCl. All the other milder methods are successful in extracting these compounds. Experiments are performed using HPLC-DAD to compare the HPLC peak areas and the S/N of the following extracted compounds: indigotin, indirubin, curcumin, demethoxycurcumin, bisdemethoxycurcumin, fisetin, sulfuretin, luteolin, luteolin-7-O-glucoside, apigenin, carminic acid, alizarin, puruprin and rubiadin. It is shown that the TFA method provides overall the best results as it gives elevated extraction yields except for fisetin, luteolin, apigenin and luteolin-7-O-glucoside and highest S/N except for fisetin and luteolin-7-O-glucoside. It is noteworthy that treatment of the fibres with the typical HCl extraction method results overall in very low S/N. The TFA method is selected for further studies, as follows. First, it is applied on silk dyed samples and compared with the HCl method. The same relative differences of the TFA and HCl methods observed for the wool dyed samples are reported for the silk dyed samples too, except for rubiadin, luteolin and apigenin. Thus, in most cases, the nature of the substrate (wool or silk

  3. Analysis of oxysterols and vitamin D metabolites in mouse brain and cell line samples by ultra-high-performance liquid chromatography-atmospheric pressure photoionization-mass spectrometry.

    PubMed

    Ahonen, Linda; Maire, Florian B R; Savolainen, Mari; Kopra, Jaakko; Vreeken, Rob J; Hankemeier, Thomas; Myöhänen, Timo; Kylli, Petri; Kostiainen, Risto

    2014-10-17

    We have developed an ultra-high-performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometric (UHPLC-APPI-MS/MS) method for the simultaneous quantitative analyses of several oxysterols and vitamin D metabolites in mouse brain and cell line samples. An UHPLC-APPI-high resolution mass spectrometric (UHPLC-APPI-HRMS) method that uses a quadrupole-time of flight mass spectrometer was also developed for confirmatory analysis and for the identification of non-targeted oxysterols. Both methods showed good quantitative performance. Furthermore, APPI provides high ionization efficiency for determining oxysterols and vitamin D related compounds without the time consuming derivatization step needed in the conventionally used electrospray ionization method to achieve acceptable sensitivity. Several oxysterols were quantified in mouse brain and cell line samples. Additionally, 25-hydroxyvitamin D3 was detected in mouse brain samples for the first time.

  4. High performance, high density hydrocarbon fuels

    NASA Technical Reports Server (NTRS)

    Frankenfeld, J. W.; Hastings, T. W.; Lieberman, M.; Taylor, W. F.

    1978-01-01

    The fuels were selected from 77 original candidates on the basis of estimated merit index and cost effectiveness. The ten candidates consisted of 3 pure compounds, 4 chemical plant streams and 3 refinery streams. Critical physical and chemical properties of the candidate fuels were measured including heat of combustion, density, and viscosity as a function of temperature, freezing points, vapor pressure, boiling point, thermal stability. The best all around candidate was found to be a chemical plant olefin stream rich in dicyclopentadiene. This material has a high merit index and is available at low cost. Possible problem areas were identified as low temperature flow properties and thermal stability. An economic analysis was carried out to determine the production costs of top candidates. The chemical plant and refinery streams were all less than 44 cent/kg while the pure compounds were greater than 44 cent/kg. A literature survey was conducted on the state of the art of advanced hydrocarbon fuel technology as applied to high energy propellents. Several areas for additional research were identified.

  5. Analysis of drugs of abuse in human plasma by dispersive liquid-liquid microextraction and high-performance liquid chromatography.

    PubMed

    Fernández, P; Regenjo, M; Bermejo, A M; Fernández, A M; Lorenzo, R A; Carro, A M

    2015-04-01

    Opioids and cocaine are widely used at present, both for recreational purposes and as drugs of abuse. This raises the need to develop new analytical methods specifically designed for the simultaneous detection of several drugs of abuse in biological samples. In this work, dispersive liquid-liquid microextraction (DLLME) was assessed as a new sample treatment for the simultaneous extraction of morphine (MOR), 6-acetylmorphine (6AM), cocaine (COC), benzoylecgonine (BZE) and methadone (MET) from human plasma. Preliminary assays were done before developing an experimental design based on a Uniform Network Doehlert which allowed the optimum extraction conditions to be identified, namely: a volume of extractant solvent (chloroform) and dispersant solvent (acetonitrile) of 220 µl and 3.2 ml, respectively; 0.2 g of NaCl as a salting-out additive; pH 10.6 and ultrasound stirring for 3.5 min. The resulting extracts were analyzed by high-performance liquid chromatography with photodiode array detection (HPLC-PDA), using an XBridge® RP18 column (250 × 4.6 mm i.d., 5 µm particle size). Calibration graphs were linear over the concentration range 0.1-10 µg ml⁻¹, and detection limits ranged from 13.9 to 28.5 ng ml⁻¹. Precision calculated at three different concentration levels in plasma was included in the range 0.1-6.8% RSD. Recoveries of the five drugs were all higher than 84% on average. Finally the proposed method was successfully applied to 22 plasma samples from heroin, cocaine and/or methadone users, and the most frequently detected drug was benzoylecgonine, followed by methadone, cocaine and morphine.

  6. Targeted Metabolomic Analysis of Head and Neck Cancer Cells Using High Performance Ion Chromatography Coupled with a Q Exactive HF Mass Spectrometer.

    PubMed

    Hu, Shen; Wang, Junhua; Ji, Eoon Hye; Christison, Terri; Lopez, Linda; Huang, Yingying

    2015-06-16

    In this study, we have demonstrated a targeted metabolomics method for analysis of cancer cells, based on high-performance ion chromatography (IC) separation, Q Exactive HF MS for high-resolution and accurate-mass (HR/AM) measurement and the use of stable isotope-labeled internal standards for absolute quantitation. Our method offers great technical advantages for metabolite analysis, including exquisite sensitivity, high speed and reproducibility, and wide dynamic range. The high-performance IC provided fast separation of cellular metabolites within 20 min and excellent resolving power for polar molecules including many isobaric metabolites. The IC/Q Exactive HF MS achieved wide dynamic ranges of 5 orders of magnitude for six targeted metabolites, pyruvate, succinic acid, malic acid, citric acid, fumaric acid, and alpha-ketoglutaric acid, with R(2) ≈ 0.99. Using this platform, metabolites can be simultaneously quantified from low fmol/μL to nmol/μL levels in cellular samples. The high flow rate IC at 380 μL/min has shown excellent reproducibility for a large set of samples (150 injections), with minimal variations of retention time (SD < ± 0.03 min). In addition, the IC-MS-based approach acquires targeted and global metabolomic data in a same analytical run, and the use of stable isotope-labeled standards facilitates accurate quantitation of targeted metabolites in large-scale metabolomics analysis. This metabolomics approach has been successfully applied to analysis of targeted metabolites in head and neck cancer cells as well as cancer stem-like cells (CSCs), and the findings indicate that the metabolic phenotypes may be distinct between high and low invasive head and neck cancer cells and between CSCs and non-SCCs.

  7. 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.

  8. High performance electromagnetic simulation tools

    NASA Astrophysics Data System (ADS)

    Gedney, Stephen D.; Whites, Keith W.

    1994-10-01

    Army Research Office Grant #DAAH04-93-G-0453 has supported the purchase of 24 additional compute nodes that were installed in the Intel iPsC/860 hypercube at the Univesity Of Kentucky (UK), rendering a 32-node multiprocessor. This facility has allowed the investigators to explore and extend the boundaries of electromagnetic simulation for important areas of defense concerns including microwave monolithic integrated circuit (MMIC) design/analysis and electromagnetic materials research and development. The iPSC/860 has also provided an ideal platform for MMIC circuit simulations. A number of parallel methods based on direct time-domain solutions of Maxwell's equations have been developed on the iPSC/860, including a parallel finite-difference time-domain (FDTD) algorithm, and a parallel planar generalized Yee-algorithm (PGY). The iPSC/860 has also provided an ideal platform on which to develop a 'virtual laboratory' to numerically analyze, scientifically study and develop new types of materials with beneficial electromagnetic properties. These materials simulations are capable of assembling hundreds of microscopic inclusions from which an electromagnetic full-wave solution will be obtained in toto. This powerful simulation tool has enabled research of the full-wave analysis of complex multicomponent MMIC devices and the electromagnetic properties of many types of materials to be performed numerically rather than strictly in the laboratory.

  9. High Performance Field Reversed Configurations

    NASA Astrophysics Data System (ADS)

    Binderbauer, Michl

    2014-10-01

    The field-reversed configuration (FRC) is a prolate compact toroid with poloidal magnetic fields. FRCs could lead to economic fusion reactors with high power density, simple geometry, natural divertor, ease of translation, and possibly capable of burning aneutronic fuels. However, as in other high-beta plasmas, there are stability and confinement concerns. These concerns can be addressed by introducing and maintaining a significant fast ion population in the system. This is the approach adopted by TAE and implemented for the first time in the C-2 device. Studying the physics of FRCs driven by Neutral Beam (NB) injection, significant improvements were made in confinement and stability. Early C-2 discharges had relatively good confinement, but global power losses exceeded the available NB input power. The addition of axially streaming plasma guns, magnetic end plugs as well as advanced surface conditioning leads to dramatic reductions in turbulence driven losses and greatly improved stability. As a result, fast ion confinement significantly improved and allowed for build-up of a dominant fast particle population. Under such appropriate conditions we achieved highly reproducible, long-lived, macroscopically stable FRCs with record lifetimes. This demonstrated many beneficial effects of large orbit particles and their performance impact on FRCs Together these achievements point to the prospect of beam-driven FRCs as a path toward fusion reactors. This presentation will review and expand on key results and present context for their interpretation.

  10. The High Performance Storage System

    SciTech Connect

    Coyne, R.A.; Hulen, H.; Watson, R.

    1993-09-01

    The National Storage Laboratory (NSL) was organized to develop, demonstrate and commercialize technology for the storage system that will be the future repositories for our national information assets. Within the NSL four Department of Energy laboratories and IBM Federal System Company have pooled their resources to develop an entirely new High Performance Storage System (HPSS). The HPSS project concentrates on scalable parallel storage system for highly parallel computers as well as traditional supercomputers and workstation clusters. Concentrating on meeting the high end of storage system and data management requirements, HPSS is designed using network-connected storage devices to transfer data at rates of 100 million bytes per second and beyond. The resulting products will be portable to many vendor`s platforms. The three year project is targeted to be complete in 1995. This paper provides an overview of the requirements, design issues, and architecture of HPSS, as well as a description of the distributed, multi-organization industry and national laboratory HPSS project.

  11. Fast and comprehensive analysis of secondary metabolites in cocoa products using ultra high-performance liquid chromatography directly after pressurized liquid extraction.

    PubMed

    Damm, Irina; Enger, Eileen; Chrubasik-Hausmann, Sigrun; Schieber, Andreas; Zimmermann, Benno F

    2016-08-01

    Fast methods for the extraction and analysis of various secondary metabolites from cocoa products were developed and optimized regarding speed and separation efficiency. Extraction by pressurized liquid extraction is automated and the extracts are analyzed by rapid reversed-phase ultra high-performance liquid chromatography and normal-phase high-performance liquid chromatography methods. After extraction, no further sample treatment is required before chromatographic analysis. The analytes comprise monomeric and oligomeric flavanols, flavonols, methylxanthins, N-phenylpropenoyl amino acids, and phenolic acids. Polyphenols and N-phenylpropenoyl amino acids are separated in a single run of 33 min, procyanidins are analyzed by normal-phase high-performance liquid chromatography within 16 min, and methylxanthins require only 6 min total run time. A fourth method is suitable for phenolic acids, but only protocatechuic acid was found in relevant quantities. The optimized methods were validated and applied to 27 dark chocolates, one milk chocolate, two cocoa powders and two food supplements based on cocoa extract. PMID:27418182

  12. Fast and comprehensive analysis of secondary metabolites in cocoa products using ultra high-performance liquid chromatography directly after pressurized liquid extraction.

    PubMed

    Damm, Irina; Enger, Eileen; Chrubasik-Hausmann, Sigrun; Schieber, Andreas; Zimmermann, Benno F

    2016-08-01

    Fast methods for the extraction and analysis of various secondary metabolites from cocoa products were developed and optimized regarding speed and separation efficiency. Extraction by pressurized liquid extraction is automated and the extracts are analyzed by rapid reversed-phase ultra high-performance liquid chromatography and normal-phase high-performance liquid chromatography methods. After extraction, no further sample treatment is required before chromatographic analysis. The analytes comprise monomeric and oligomeric flavanols, flavonols, methylxanthins, N-phenylpropenoyl amino acids, and phenolic acids. Polyphenols and N-phenylpropenoyl amino acids are separated in a single run of 33 min, procyanidins are analyzed by normal-phase high-performance liquid chromatography within 16 min, and methylxanthins require only 6 min total run time. A fourth method is suitable for phenolic acids, but only protocatechuic acid was found in relevant quantities. The optimized methods were validated and applied to 27 dark chocolates, one milk chocolate, two cocoa powders and two food supplements based on cocoa extract.

  13. Fingerprint analysis, multi-component quantitation, and antioxidant activity for the quality evaluation of Salvia miltiorrhiza var. alba by high-performance liquid chromatography and chemometrics.

    PubMed

    Zhang, Danlu; Duan, Xiaoju; Deng, Shuhong; Nie, Lei; Zang, Hengchang

    2015-10-01

    Salvia miltiorrhiza Bge. var. alba C.Y. Wu and H.W. Li has wide prospects in clinical practice. A useful comprehensive method was developed for the quality evaluation of S. miltiorrhiza var. alba by three quantitative parameters: high-performance liquid chromatography fingerprint, ten-component contents, and antioxidant activity. The established method was validated for linearity, precision, repeatability, stability, and recovery. Principal components analysis and hierarchical clustering analysis were both used to evaluate the quality of the samples from different origins. The results showed that there were category discrepancies in quality of S. miltiorrhiza var. alba samples according to the three quantitative parameters. Multivariate linear regression was adopted to explore the relationship between components and antioxidant activity. Three constituents, namely, danshensu, rosmarinic acid, and salvianolic acid B, significantly correlated with antioxidant activity, and were successfully elucidated by the optimized multivariate linear regression model. The combined use of high-performance liquid chromatography fingerprint analysis, simultaneous multicomponent quantitative analysis, and antioxidant activity for the quality evaluation of S. miltiorrhiza var. alba is a reliable, comprehensive, and promising approach, which might provide a valuable reference for other herbal products in general to improve their quality control.

  14. High Performance Perovskite Solar Cells

    PubMed Central

    Tong, Xin; Lin, Feng; Wu, Jiang

    2015-01-01

    Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long‐term stable all‐solid‐state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost‐effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole‐transporting materials (HTMs) and electron‐transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction.

  15. Distributed Large Data-Object Environments: End-to-End Performance Analysis of High Speed Distributed Storage Systems in Wide Area ATM Networks

    NASA Technical Reports Server (NTRS)

    Johnston, William; Tierney, Brian; Lee, Jason; Hoo, Gary; Thompson, Mary

    1996-01-01

    We have developed and deployed a distributed-parallel storage system (DPSS) in several high speed asynchronous transfer mode (ATM) wide area networks (WAN) testbeds to support several different types of data-intensive applications. Architecturally, the DPSS is a network striped disk array, but is fairly unique in that its implementation allows applications complete freedom to determine optimal data layout, replication and/or coding redundancy strategy, security policy, and dynamic reconfiguration. In conjunction with the DPSS, we have developed a 'top-to-bottom, end-to-end' performance monitoring and analysis methodology that has allowed us to characterize all aspects of the DPSS operating in high speed ATM networks. In particular, we have run a variety of performance monitoring experiments involving the DPSS in the MAGIC testbed, which is a large scale, high speed, ATM network and we describe our experience using the monitoring methodology to identify and correct problems that limit the performance of high speed distributed applications. Finally, the DPSS is part of an overall architecture for using high speed, WAN's for enabling the routine, location independent use of large data-objects. Since this is part of the motivation for a distributed storage system, we describe this architecture.

  16. Design and performance of a new continuous-flow sample-introduction system for flame infrared-emission spectrometry: Applications in process analysis, flow injection analysis, and ion-exchange high-performance liquid chromatography.

    PubMed

    Lam, C K; Zhang, Y; Busch, M A; Busch, K W

    1993-06-01

    A new sample introduction system for the analysis of continuously flowing liquid streams by flame infrared-emission (FIRE) spectrometry has been developed. The system uses a specially designed purge cell to strip dissolved CO(2) from solution into a hydrogen gas stream that serves as the fuel for a hydrogen/air flame. Vibrationally excited CO(2) molecules present in the flame are monitored with a simple infrared filter (4.4 mum) photometer. The new system can be used to introduce analytes as a continuous liquid stream (process analysis mode) or on a discrete basis by sample injection (flow injection analysis mode). The key to the success of the method is the new purge-cell design. The small internal volume of the cell minimizes problems associated with purge-cell clean-out and produces sharp, reproducible signals. Spent analytical solution is continuously drained from the cell, making cell disconnection and cleaning between samples unnecessary. Under the conditions employed in this study, samples could be analyzed at a maximum rate of approximately 60/h. The new sample introduction system was successfully tested in both a process analysis- and a flow injection analysis mode for the determination of total inorganic carbon in Waco tap water. For the first time, flame infrared-emission spectrometry was successfully extended to non-volatile organic compounds by using chemical pretreatment with peroxydisulfate in the presence of silver ion to convert the analytes into dissolved carbon dioxide, prior to purging and detection by the FIRE radiometer. A test of the peroxydisulfate/Ag(+) reaction using six organic acids and five sugars indicated that all 11 compounds were oxidized to nearly the same extent. Finally, the new sample introduction system was used in conjunction with a simple filter FIRE radiometer as a detection system in ion-exchange high-performance liquid chromatography. Ion-exchange chromatograms are shown for two aqueous mixtures, one containing six organic

  17. Milestones for Selection, Characterization, and Analysis of the Performance of a Repository for Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain.

    SciTech Connect

    Rechard, Robert P.

    2014-02-01

    This report presents a concise history in tabular form of events leading up to site identification in 1978, site selection in 1987, subsequent characterization, and ongoing analysis through 2008 of the performance of a repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain in southern Nevada. The tabulated events generally occurred in five periods: (1) commitment to mined geologic disposal and identification of sites; (2) site selection and analysis, based on regional geologic characterization through literature and analogous data; (3) feasibility analysis demonstrating calculation procedures and importance of system components, based on rough measures of performance using surface exploration, waste process knowledge, and general laboratory experiments; (4) suitability analysis demonstrating viability of disposal system, based on environment-specific laboratory experiments, in-situ experiments, and underground disposal system characterization; and (5) compliance analysis, based on completed site-specific characterization. Because the relationship is important to understanding the evolution of the Yucca Mountain Project, the tabulation also shows the interaction between four broad categories of political bodies and government agencies/institutions: (a) technical milestones of the implementing institutions, (b) development of the regulatory requirements and related federal policy in laws and court decisions, (c) Presidential and agency directives and decisions, and (d) critiques of the Yucca Mountain Project and pertinent national and world events related to nuclear energy and radioactive waste.

  18. Analysis of the 16 Environmental Protection Agency priority polycyclic aromatic hydrocarbons by high performance liquid chromatography-oxidized diamond film electrodes.

    PubMed

    Bouvrette, Pierre; Hrapovic, Sabahudin; Male, Keith B; Luong, John H T

    2006-01-27

    The capabilities of using boron-doped diamond (BDD) thin films as electrode materials for analysis of the 16 US Environmental Protection Agency (EPA) priority polyaromatic hydrocarbons (PAHs) after a liquid chromatographic separation were evaluated. The BDD electrode was able to detect all 16 PAHs with high sensitivity due to the low background current and wide potential window. The method provided detection limits ranging from 12-40 nM (3-10 ppb) and repeatable results over consecutive analysis. Calibration curves were linear up to at least 10 microM for all PAHs. The work shows the promising use of diamond as an amperometric detector in high performance liquid chromatography (HPLC), especially for PAHs and other hydrophobic aromatic compounds.

  19. Direct analysis of six antibiotics in wastewater samples using rapid high-performance liquid chromatography coupled with diode array detector: a chemometric study towards green analytical chemistry.

    PubMed

    Vosough, Maryam; Rashvand, Masoumeh; Esfahani, Hadi M; Kargosha, Kazem; Salemi, Amir

    2015-04-01

    In this work, a rapid HPLC-DAD method has been developed for the analysis of six antibiotics (amoxicillin, metronidazole, sulfamethoxazole, ofloxacine, sulfadiazine and sulfamerazine) in the sewage treatment plant influent and effluent samples. Decreasing the chromatographic run time to less than 4 min as well as lowering the cost per analysis, were achieved through direct injection of the samples into the HPLC system followed by chemometric analysis. The problem of the complete separation of the analytes from each other and/or from the matrix ingredients was resolved as a posteriori. The performance of MCR/ALS and U-PLS/RBL, as second-order algorithms, was studied and comparable results were obtained from implication of these modeling methods. It was demonstrated that the proposed methods could be used promisingly as green analytical strategies for detection and quantification of the targeted pollutants in wastewater samples while avoiding the more complicated high cost instrumentations. PMID:25640119

  20. Analysis of 2,4,6-trinitrotoluene and its transformation products in soils and plant tissues by high-performance liquid chromatography

    SciTech Connect

    Harvey, S.D.; Fellows, R.J.; Cataldo, D.A.; Bean, R.M. )

    1990-01-01

    Previous studies have failed to provide an acceptable mass balance for 2,4,6-trinitrotoluene (TNT) in soils and plants due to deficiencies in analytical methodology. A high-performance liquid chromatographic (HPLC) method for soil analysis is reported which allowed for a mass balance in excess of 88% during a 2-month study. A method for plant analysis was developed which involved fractionation of organic extracts on Florisil adsorbent, to remove interfering pigments, followed by HPLC analysis of TNT and the primary metabolites, 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene. Chromatographic recovery of TNT from spiked tissues was 85{plus minus}6%. The methodology was utilized to investigate TNT uptake and metabolism in plants grown in TNT hydroponic solutions.

  1. Direct analysis of six antibiotics in wastewater samples using rapid high-performance liquid chromatography coupled with diode array detector: a chemometric study towards green analytical chemistry.

    PubMed

    Vosough, Maryam; Rashvand, Masoumeh; Esfahani, Hadi M; Kargosha, Kazem; Salemi, Amir

    2015-04-01

    In this work, a rapid HPLC-DAD method has been developed for the analysis of six antibiotics (amoxicillin, metronidazole, sulfamethoxazole, ofloxacine, sulfadiazine and sulfamerazine) in the sewage treatment plant influent and effluent samples. Decreasing the chromatographic run time to less than 4 min as well as lowering the cost per analysis, were achieved through direct injection of the samples into the HPLC system followed by chemometric analysis. The problem of the complete separation of the analytes from each other and/or from the matrix ingredients was resolved as a posteriori. The performance of MCR/ALS and U-PLS/RBL, as second-order algorithms, was studied and comparable results were obtained from implication of these modeling methods. It was demonstrated that the proposed methods could be used promisingly as green analytical strategies for detection and quantification of the targeted pollutants in wastewater samples while avoiding the more complicated high cost instrumentations.

  2. Retrofit Weight-Loss Outcomes at 6, 12, and 24 Months and Characteristics of 12-Month High Performers: A Retrospective Analysis

    PubMed Central

    Hanson, Nicholas Buck; Kachin, Kevin; Berger, Jan

    2016-01-01

    Background Obesity is the leading cause of preventable death costing the health care system billions of dollars. Combining self-monitoring technology with personalized behavior change strategies results in clinically significant weight loss. However, there is a lack of real-world outcomes in commercial weight-loss program research. Objective Retrofit is a personalized weight management and disease-prevention solution. This study aimed to report Retrofit’s weight-loss outcomes at 6, 12, and 24 months and characterize behaviors, age, and sex of high-performing participants who achieved weight loss of 10% or greater at 12 months. Methods A retrospective analysis was performed from 2011 to 2014 using 2720 participants enrolled in a Retrofit weight-loss program. Participants had a starting body mass index (BMI) of >25 kg/m² and were at least 18 years of age. Weight measurements were assessed at 6, 12, and 24 months in the program to evaluate change in body weight, BMI, and percentage of participants who achieved 5% or greater weight loss. A secondary analysis characterized high-performing participants who lost ≥10% of their starting weight (n=238). Characterized behaviors were evaluated, including self-monitoring through weigh-ins, number of days wearing an activity tracker, daily step count average, and engagement through coaching conversations via Web-based messages, and number of coaching sessions attended. Results Average weight loss at 6 months was −5.55% for male and −4.86% for female participants. Male and female participants had an average weight loss of −6.28% and −5.37% at 12 months, respectively. Average weight loss at 24 months was −5.03% and −3.15% for males and females, respectively. Behaviors of high-performing participants were assessed at 12 months. Number of weigh-ins were greater in high-performing male (197.3 times vs 165.4 times, P=.001) and female participants (222 times vs 167 times, P<.001) compared with remaining participants

  3. A validated ultra-high performance liquid chromatography coupled to high resolution mass spectrometry analysis for the simultaneous quantification of the three known boar taint compounds.

    PubMed

    Bekaert, K M; Vanden Bussche, J; François, S; Tuyttens, F A M; De Brabander, H F; Vandendriessche, F; Vanhaecke, L

    2012-05-25

    Boar taint is an off-odour that can occur when meat or fat from entire male pigs is heated. Most of the currently available analytical methods are not capable of detecting the three known boar taint compounds (indole, skatole and androstenone) simultaneously, which renders their analysis often labour-intensive and time-consuming as separate analyses are required. In this study a validated U-HPLC-HR-Orbitrap-MS analysis method is described for the quantitative determination of the three boar taint compounds in fat. The sample pre-treatment involves a melting step followed by extraction with methanol and clean-up consisting of a freezing step and solid phase extraction (HLB cartridges). The analytes are then chromatographically separated and detected with an Exactive high-resolution mass spectrometer. Due to the absence of guidelines for the analysis of boar taint in fat, the Commission Decision 2002/657/EC [18] and ISO 17025 [19] guidelines were used as guideline for validation of the developed detection method. This resulted in limits of detection and limits of quantification between 2.5 and 7 μg kg(-1) and between 5 and 10 μg kg(-1) for the three compounds, respectively, which is far below the threshold values set at 100 μg L(-1) for indole, 200 μg L(-1) for skatole and 1000 μg L(-1) for androstenone in pig fat samples. The method obtained for the three compounds a repeatability (RSD) lower then 12.7% and a within-laboratory reproducibility (RSD) lower than 16.9%. The recovery of the three compounds ranged between 99 and 112 and an excellent linearity (R(2) ≥ 0.99) was found. In the future, this method may be extended with other compounds that turn out to be correlated with boar taint. PMID:22498353

  4. A high pH based reversed-phase high performance liquid chromatographic method for the analysis of aminoglycoside plazomicin and its impurities.

    PubMed

    Tan, Li; Wlasichuk, Kenneth B; Schmidt, Donald E; Campbell, Robert L; Hirtzer, Pam; Cheng, Lisa; Karr, Dane E

    2012-07-01

    A reversed-phase high performance liquid chromatographic (RP-HPLC) method has been developed for the aminoglycoside (AG) plazomicin (ACHN-490). This method employed a high pH mobile phase (pH>11) with a gradient of 0.25 M ammonium hydroxide in water and acetonitrile, an XBridge C(18) column and UV detection at 210 nm. Although the molar UV absorption of plazomicin is weak, the high pH conditions of this method allow for higher loadings, which compensates for the inherent low UV sensitivity. Under these high pH conditions, impurities and degradants were base line separated from plazomicin. The mobile phases used for this method allowed for on-line mass detection for the impurities and degradants. The RP-HPLC method has been validated in terms of specificity, linearity and range, accuracy, and precision. The analytical method met specificity requirements of a homogenous peak with no interferences from the blank or from the known impurities in plazomicin. The linearity of the method for the plazomicin impurity determination was excellent, with a coefficient of determination (r(2)) of 0.9993, over the freebase (FB) concentration range of 0.0025-3.0 mg/mL. The method is capable of detecting impurities down to 0.1% of the peak area of plazomicin. A single point standard at a concentration of 1.0 mg/mL FB was validated over the range of 50-150% for quantitation of the freebase content (the assay) in bulk drug substance. The mean recoveries of FB are in the range 98.6-102.0% with a mean RSD (relative standard deviation) <1.0%. The study also examined the method precision for purity, impurities and the assay with two instruments on two different days. The method showed adequate accuracy and precision for the intended use. This high pH method was successfully used to determine the impurity and measure the drug content in the final plazomicin drug substance. In addition, the method with an on-line mass spectrometry detector has been used to characterize the structures of the

  5. Application of isoabsorption plots generated by high-performance liquid chromatography with diode array detection to the development of multicomponent quantitative analysis of traditional herbal medicines.

    PubMed

    Fang, Luo; Yang, Guonong; Song, Yu; Li, Fanzhu; Lin, Nengming

    2014-11-01

    Multicomponent quantitative analysis is one of the mainstream quality control methods of traditional herbal medicines. Since the constituents of traditional herbal medicines samples are complex, the development of high-performance liquid chromatography methods is laborious. In this study, an isoabsorption plot, a chromatographic/spectrometric data image plotted by diode array detection was utilized to facilitate the establishment of a high-performance liquid chromatography method by optimizing and validating the detection conditions off-line. Consequently a simple, reliable and accurate method for simultaneous determination of seven active polyphenolic components (protocatechuic acid, chlorogenic acid, caffeic acid, p-coumaric acid, rosmarinic acid, scutellarin, and apigenin) in Qingfei mixture, a long-used Chinese prescription, was developed. The chromatographic separation was performed on a C18 column with gradient elution of phosphoric acid aqueous solution (0.05%, v/v) and acetonitrile, and a wavelength switch program optimized with isoplot was adopted for detection. The method was validated in terms of linearity, sensitivity, precision, repeatability, and accuracy and was successfully applied to the simultaneous determination of the seven polyphenolic components in different production batches of Qingfei Mixture. These results indicated that isoplot is an effective tool to improve the establishment of multicomponent quantitative analysis methods.

  6. High Performance Woven Mesh Heat Exchangers

    NASA Astrophysics Data System (ADS)

    Wirtz, Richard A.; Li, Chen; Park, Ji-Wook; Xu, Jun

    2002-07-01

    Simple-to-fabricate woven mesh structures, consisting of bonded laminates of two-dimensional plain-weave conductive screens, or three-dimensional orthogonal weaves are described. Geometric equations show that these porous matrices can be fabricated to have a wide range of porosity and a highly anisotropic thermal conductivity vector. A mathematical model of the thermal performance of such a mesh, deployed as a heat exchange surface, is developed. Measurements of pressure drop and overall heat transfer rate are reported and used with the performance model to develop correlation equations of mesh friction factor and Colburn j-factor as a function of coolant properties, mesh characteristics and flow rate through the mesh. A heat exchanger performance analysis delineates conditions where the two mesh technologies offer superior performance.

  7. Performance Analysis of GYRO: A Tool Evaluation

    SciTech Connect

    Worley, P.; Roth, P.; Candy, J.; Shan, Hongzhang; Mahinthakumar,G.; Sreepathi, S.; Carrington, L.; Kaiser, T.; Snavely, A.; Reed, D.; Zhang, Y.; Huck, K.; Malony, A.; Shende, S.; Moore, S.; Wolf, F.

    2005-06-26

    The performance of the Eulerian gyrokinetic-Maxwell solver code GYRO is analyzed on five high performance computing systems. First, a manual approach is taken, using custom scripts to analyze the output of embedded wall clock timers, floating point operation counts collected using hardware performance counters, and traces of user and communication events collected using the profiling interface to Message Passing Interface (MPI) libraries. Parts of the analysis are then repeated or extended using a number of sophisticated performance analysis tools: IPM, KOJAK, SvPablo, TAU, and the PMaC modeling tool suite. The paper briefly discusses what has been discovered via this manual analysis process, what performance analyses are inconvenient or infeasible to attempt manually, and to what extent the tools show promise in accelerating or significantly extending the manual performance analyses.

  8. High performance Cu adhesion coating

    SciTech Connect

    Lee, K.W.; Viehbeck, A.; Chen, W.R.; Ree, M.

    1996-12-31

    Poly(arylene ether benzimidazole) (PAEBI) is a high performance thermoplastic polymer with imidazole functional groups forming the polymer backbone structure. It is proposed that upon coating PAEBI onto a copper surface the imidazole groups of PAEBI form a bond with or chelate to the copper surface resulting in strong adhesion between the copper and polymer. Adhesion of PAEBI to other polymers such as poly(biphenyl dianhydride-p-phenylene diamine) (BPDA-PDA) polyimide is also quite good and stable. The resulting locus of failure as studied by XPS and IR indicates that PAEBI gives strong cohesive adhesion to copper. Due to its good adhesion and mechanical properties, PAEBI can be used in fabricating thin film semiconductor packages such as multichip module dielectric (MCM-D) structures. In these applications, a thin PAEBI coating is applied directly to a wiring layer for enhancing adhesion to both the copper wiring and the polymer dielectric surface. In addition, a thin layer of PAEBI can also function as a protection layer for the copper wiring, eliminating the need for Cr or Ni barrier metallurgies and thus significantly reducing the number of process steps.

  9. ALMA high performance nutating subreflector

    NASA Astrophysics Data System (ADS)

    Gasho, Victor L.; Radford, Simon J. E.; Kingsley, Jeffrey S.

    2003-02-01

    For the international ALMA project"s prototype antennas, we have developed a high performance, reactionless nutating subreflector (chopping secondary mirror). This single axis mechanism can switch the antenna"s optical axis by +/-1.5" within 10 ms or +/-5" within 20 ms and maintains pointing stability within the antenna"s 0.6" error budget. The light weight 75 cm diameter subreflector is made of carbon fiber composite to achieve a low moment of inertia, <0.25 kg m2. Its reflecting surface was formed in a compression mold. Carbon fiber is also used together with Invar in the supporting structure for thermal stability. Both the subreflector and the moving coil motors are mounted on flex pivots and the motor magnets counter rotate to absorb the nutation reaction force. Auxiliary motors provide active damping of external disturbances, such as wind gusts. Non contacting optical sensors measure the positions of the subreflector and the motor rocker. The principle mechanical resonance around 20 Hz is compensated with a digital PID servo loop that provides a closed loop bandwidth near 100 Hz. Shaped transitions are used to avoid overstressing mechanical links.

  10. Recent advances in the application of high performance liquid chromatography in the analysis of polyphenols in wine and propolis.

    PubMed

    Medić-Sarić, Marica; Rastija, Vesna; Bojić, Mirza

    2011-01-01

    Wine and propolis are among the richest sources of polyphenolics. Flavonoids and phenolic acids are main pharmacological components whose benefits have been shown in numerous reports. This paper presents a review of the latest applications of HPLC for determination of polyphenolics in propolis and wine. Special attention is focused on sample preparation, chromatographic conditions, and detection of polyphenolics. HPLC will undoubtedly be the most used method that is readily available for analysis, as well as for isolation of polyphenolics in complex mixtures.

  11. Development of a sensitive and reliable high performance liquid chromatography method with fluorescence detection for high-throughput analysis of multi-class mycotoxins in Coix seed.

    PubMed

    Kong, Wei-Jun; Li, Jun-Yuan; Qiu, Feng; Wei, Jian-He; Xiao, Xiao-He; Zheng, Yuguo; Yang, Mei-Hua

    2013-10-17

    As an edible and medicinal plant, Coix seed is readily contaminated by more than one group of mycotoxins resulting in potential risk to human health. A reliable and sensitive method has been developed to determine seven mycotoxins (aflatoxins B1, B2, G1, G2, zearalenone, α-zearalenol, and β-zearalenol) simultaneously in 10 batches of Coix seed marketed in China. The method is based on a rapid ultrasound-assisted solid-liquid extraction (USLE) using methanol/water (80/20) followed by immunoaffinity column (IAC) clean-up, on-line photochemical derivatization (PCD), and high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). Careful optimization of extraction, clean-up, separation and detection conditions was accomplished to increase sample throughput and to attain rapid separation and sensitive detection. Method validation was performed by analyzing samples spiked at three different concentrations for the seven mycotoxins. Recoveries were from 73.5% to 107.3%, with relative standard deviations (RSDs) lower than 7.7%. The intra- and inter-day precisions, expressed as RSDs, were lower than 4% for all studied analytes. Limits of detection and quantification ranged from 0.01 to 50.2 μg kg(-1), and from 0.04 to 125.5 μg kg(-1), respectively, which were below the tolerance levels for mycotoxins set by the European Union. Samples that tested positive were further analyzed by HPLC tandem electrospray ionization mass spectrometry for confirmatory purposes. This is the first application of USLE-IAC-HPLC-PCD-FLD for detecting the occurrence of multi-class mycotoxins in Coix seed.

  12. Simple, high throughput ultra-high performance liquid chromatography/tandem mass spectrometry trace analysis of perfluorinated alkylated substances in food of animal origin: milk and fish.

    PubMed

    Lacina, Ondrej; Hradkova, Petra; Pulkrabova, Jana; Hajslova, Jana

    2011-07-15

    The present study documents development and validation of a novel approach for determination of 23 perfluorinated alkylated substances (PFASs) in food of animal origin represented by milk and fish. The list of target analytes comprises four classes of PFASs, both ionic and non-ionic: 11 perfluorocarboxylic acids (PFCAs), 4 perfluorosulphonic acids (PFSAs), 5 perfluorosulphonamides (FOSAs) and 3 perfluorophosphonic acids (PFPAs). Fast sample preparation procedure is based on an extraction of target analytes with acetonitrile (MeCN) and their transfer (supported by inorganic salts and acidification) into the organic phase. Removing of matrix co-extracts by a simple dispersive solid phase extraction (SPE) employing ENVI-Carb and C18 sorbents is followed by an efficient sample pre-concentration performed by acetonitrile evaporation and subsequent dilution of residue in a small volume of methanol (matrix equivalent in the final extracts was 16 and 8 g mL(-1), for milk and fish respectively). Using modern instrumentation consisting of ultra-high performance liquid chromatography (UHPLC) hyphenated with a tandem mass spectrometer (MS/MS), limits of quantification (LOQs) as low as 0.001-0.006 μg kg(-1) for milk and 0.002-0.013 μg kg(-1) for fish can be achieved. Under these conditions, a wide spectrum of PFASs, including minor representatives, can be determined which enables collecting data required for human exposure studies. The pilot study employing the new method for examination of milk and canned fish samples was realized. Whereas in majority of canned fish products a wide spectrum of PFCAs, perfluorooctanesulphonic acid (PFOS) and perfluoro-1-octanesulphonamide (PFOSA) was detected, only in a few milk samples very low concentrations (LOQ levels) of PFOS and perfluorooctansulphonic acid (PFDS) were found. PMID:21621213

  13. Extraction and analysis of avermectines in agricultural soils by microwave assisted extraction and ultra high performance liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Raich-Montiu, J; Prat, M D; Granados, M

    2011-07-01

    A method for the analysis of avermectines (abamectine, doramectine and ivermectine) in soils has been developed. The analytes are extracted with acetonitrile/water (90:10) by using microwave assisted extraction. The extract is cleaned-up through solid phase extraction with Oasis HLB cartridges and analyzed by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Separation is obtained in 3 min. Extraction of analytes from the soil, that is the most critical point, has been studied in detail, and the effect of soil composition and aging time on the analytes recovery has been investigated. PMID:21641416

  14. SIMPLE SAMPLE CLEAN UP PROCEDURE AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR THE ANALYSIS OF CYANURIC ACID IN HUMAN URINE

    EPA Science Inventory

    Cyanuric acide (CA) is widely used as a chlorine stabilizer in outdoor pools. No simple method exists for CA measurement in the urine of exposed swimmers. The high hydrophilicity of CA makes usage of solid phase sorbents to extract it from urine nearly impossible because of samp...

  15. Analysis of experimental shaft seal data for high-performance turbomachines - As for Space Shuttle main engines

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Mullen, R. L.; Braun, M. J.; Burcham, R. E.; Diamond, W. A.

    1987-01-01

    High-pressure, high-temperature seal flow (leakage) data for nonrotating and rotating Raleigh-step and convergent-tapered-bore seals were characterized in terms of a normalized flow coefficient. The data for normalized Rayleigh-step and nonrotating tapered-bore seals were in reasonable agreement with theory, but data for the rotating tapered-bore seals were not. The tapered-bore-seal operational clearances estimated from the flow data were significantly larger than calculated. Although clearances are influenced by wear from conical to cylindrical geometry and errors in clearance corrections, the problem was isolated to the shaft temperature - rotational speed clearance correction. The geometric changes support the use of some conical convergence in any seal. Under these conditions rotation reduced the normalized flow coefficiently by nearly 10 percent.

  16. Analysis of experimental shaft seal data for high-performance turbomachines, as for Space Shuttle main engines

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Braun, M. J.; Mullen, R. L.; Burcham, R. E.; Diamond, W. A.

    1985-01-01

    High-pressure, high-temperature seal flow (leakage) data for nonrotating and rotating Raleigh-step and convergent-tapered-bore seals were characterized in terms of a normalized flow coefficient. The data for normalized Rayleigh-steip and nonrotating tapered-bore seals were in reasonable agreement with theory, but data for the rotating tapered-bore seals were not. The tapered-bore-seal operational clearances estimated from the flow data were significantly larger than calculated. Although clearances are influenced by wear from conical to cylindrical geometry and errors in clearance corrections, the problem was isolated to the shaft temperature - rotational speed clearance correction. The geometric changes support the use of some conical convergence in any seal. Under these conditions rotation reduced the normalized flow coefficiently by nearly 10 percent.

  17. Software Performs Complex Design Analysis

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Designers use computational fluid dynamics (CFD) to gain greater understanding of the fluid flow phenomena involved in components being designed. They also use finite element analysis (FEA) as a tool to help gain greater understanding of the structural response of components to loads, stresses and strains, and the prediction of failure modes. Automated CFD and FEA engineering design has centered on shape optimization, which has been hindered by two major problems: 1) inadequate shape parameterization algorithms, and 2) inadequate algorithms for CFD and FEA grid modification. Working with software engineers at Stennis Space Center, a NASA commercial partner, Optimal Solutions Software LLC, was able to utilize its revolutionary, one-of-a-kind arbitrary shape deformation (ASD) capability-a major advancement in solving these two aforementioned problems-to optimize the shapes of complex pipe components that transport highly sensitive fluids. The ASD technology solves the problem of inadequate shape parameterization algorithms by allowing the CFD designers to freely create their own shape parameters, therefore eliminating the restriction of only being able to use the computer-aided design (CAD) parameters. The problem of inadequate algorithms for CFD grid modification is solved by the fact that the new software performs a smooth volumetric deformation. This eliminates the extremely costly process of having to remesh the grid for every shape change desired. The program can perform a design change in a markedly reduced amount of time, a process that would traditionally involve the designer returning to the CAD model to reshape and then remesh the shapes, something that has been known to take hours, days-even weeks or months-depending upon the size of the model.

  18. Qualitative and quantitative high performance thin layer chromatography analysis of Calendula officinalis using high resolution plate imaging and artificial neural network data modelling.

    PubMed

    Agatonovic-Kustrin, S; Loescher, Christine M

    2013-10-10

    Calendula officinalis, commonly known Marigold, has been traditionally used for its anti-inflammatory effects. The aim of this study was to investigate the capacity of an artificial neural network (ANN) to analyse thin layer chromatography (TLC) chromatograms as fingerprint patterns for quantitative estimation of chlorogenic acid, caffeic acid and rutin in Calendula plant extracts. By applying samples with different weight ratios of marker compounds to the system, a database of chromatograms was constructed. A hundred and one signal intensities in each of the HPTLC chromatograms were correlated to the amounts of applied chlorogenic acid, caffeic acid, and rutin using an ANN. The developed ANN correlation was used to quantify the amounts of 3 marker compounds in calendula plant extracts. The minimum quantifiable level (MQL) of 610, 190 and 940 ng and the limit of detection (LD) of 183, 57 and 282 ng were established for chlorogenic, caffeic acid and rutin, respectively. A novel method for quality control of herbal products, based on HPTLC separation, high resolution digital plate imaging and ANN data analysis has been developed. The proposed method can be adopted for routine evaluation of the phytochemical variability in calendula extracts.

  19. Assessment of ultra high performance supercritical fluid chromatography as a separation technique for the analysis of seized drugs: Applicability to synthetic cannabinoids.

    PubMed

    Breitenbach, Stephanie; Rowe, Walter F; McCord, Bruce; Lurie, Ira S

    2016-04-01

    The recent development of modern methods for ultra high performance supercritical fluid chromatography (UHPSFC) has great potential for impacting the analysis of seized drugs. In the separation of synthetic cannabinoids the technique has the potential to produce superior resolution of positional isomers and diastereomers. To demonstrate this potential we have examined the capability of UHPSFC for the analysis of two different groups of synthetic cannabinoids. The first group was a mixture of 22 controlled synthetic cannabinoids, and the second group included JWH018 and nine of its non-controlled positional isomers The clear superiority of UHPSFC over other separation techniques was demonstrated, in that it was capable of near baseline separation of all 10 positional isomers using a chiral column. In total we examined four achiral columns, including Acquity UPC(2) Torus 2-PIC, Acquity UPC(2) Torus Diol, Acquity UPC(2) Torus DEA and Acquity UPC(2) Torus 1-AA (1.7μm 3.0×100mm), and three chiral columns, including Acquity UPC(2) Trefoil AMY1, Acquity UPC(2) Trefoil CEL1 and Acquity UPC(2) Trefoil CEL2 (2.5μm 3.0×150mm), using mobile phase compositions that combined carbon dioxide with methanol, acetonitrile, ethanol or isopropanol modifier gradients. Detection was performed using simultaneous PDA UV detection and quadrupole mass spectrometry. The orthogonality of UHPSFC, GC and UHPLC for the analysis of these compounds was demonstrated using principal component analysis. Overall we feel that this new technique should prove useful in the analysis and detection of seized drug samples, and will be a useful addition to the compendium of methods for drug analysis.

  20. Stage Separation Performance Analysis Project

    NASA Technical Reports Server (NTRS)

    Chen, Yen-Sen; Zhang, Sijun; Liu, Jiwen; Wang, Ten-See

    2001-01-01

    Stage separation process is an important phenomenon in multi-stage launch vehicle operation. The transient flowfield coupled with the multi-body systems is a challenging problem in design analysis. The thermodynamics environment with burning propellants during the upper-stage engine start in the separation processes adds to the complexity of the-entire system. Understanding the underlying flow physics and vehicle dynamics during stage separation is required in designing a multi-stage launch vehicle with good flight performance. A computational fluid dynamics model with the capability to coupling transient multi-body dynamics systems will be a useful tool for simulating the effects of transient flowfield, plume/jet heating and vehicle dynamics. A computational model using generalize mesh system will be used as the basis of this development. The multi-body dynamics system will be solved, by integrating a system of six-degree-of-freedom equations of motion with high accuracy. Multi-body mesh system and their interactions will be modeled using parallel computing algorithms. Adaptive mesh refinement method will also be employed to enhance solution accuracy in the transient process.

  1. Method for simultaneous analysis of eight vitamin E isomers in various foods by high performance liquid chromatography and fluorescence detection.

    PubMed

    Pinheiro-Sant'ana, Helena Maria; Guinazi, Michele; Oliveira, Daniela da Silva; Della Lucia, Ceres Mattos; Reis, Bárbara de Lazzari; Brandão, Sebastião César Cardoso

    2011-11-25

    The objective of this study was to optimize a method to investigate the occurrence and to quantify the full isomeric composition of vitamin E (α-, β-, γ- and δ-tocopherols and tocotrienols) in 6 vegetables (raw and cooked), 3 herbs/spices, raw and cooked eggs, vegetable oils (canola, olive and soybean), flaxseed and sorghum (flour and seeds) and soy (flour) by HPLC with fluorescence detection. Different conditions of extraction and analysis were tested. The optimized method consisted of direct extraction with solvent (hexane:ethyl acetate, 85:15, v/v). For analysis normal phase column was used with mobile phase consisting of hexane:isopropanol:acetic acid (98.9:0.6:0.5) with isocratic elution and fluorescence detection. Excellent separation of all isomers was obtained along with adequate quantification in the foods analyzed. Recovery rates of standards ranged from 91.3 to 99.4%. The linearity range for each isomer varied from 2.5 to 137.5 ng/mL (R² greater than 0.995 in all cases). Detection limits ranged from 21.0 to 48.0 ng/mL for tocopherols and from 56.0 to 67.0 ng/mL for tocotrienols, while quantification limits ranged from 105.0 to 240.0 ng/mL for tocopherols and from 280.0 to 335.0 ng/mL for tocotrienols. The optimized method was considered simple, fast and reliable, and also preserved vitamin E isomers when compared to validated methods involving saponification. PMID:22014383

  2. Comprehensive quantitative analysis of Chinese patent drug YinHuang drop pill by ultra high-performance liquid chromatography quadrupole time of flight mass spectrometry.

    PubMed

    Wong, Tin-Long; An, Ya-Qi; Yan, Bing-Chao; Yue, Rui-Qi; Zhang, Tian-Bo; Ho, Hing-Man; Ren, Tian-Jing; Fung, Hau-Yee; Ma, Dik-Lung; Leung, Chung-Hang; Liu, Zhong-Liang; Pu, Jian-Xin; Han, Quan-Bin; Sun, Han-Dong

    2016-06-01

    YinHuang drop pill (YHDP) is a new preparation, derived from the traditional YinHuang (YH) decoction. Since drop pills are one of the newly developed forms of Chinese patent drugs, not much research has been done regarding the quality and efficacy. This study aims to establish a comprehensive quantitative analysis of the chemical profile of YHDP. ultra high-performance liquid chromatography quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS/MS) was used to identify 34 non-sugar small molecules including 15 flavonoids, 9 phenolic acids, 5 saponins, 1 iridoid, and 4 iridoid glycosides in YHDP samples, and 26 of them were quantitatively determined. Sugar composition of YHDP in terms of fructose, glucose and sucrose was examined via a high performance liquid chromatography-evaporative light scattering detector on an amide column (HPLC-NH2P-ELSD). Macromolecules were examined by high performance gel permeation chromatography coupled with ELSD (HPGPC-ELSD). The content of the drop pill's skeleton component PEG-4000 was also quantified via ultra-high performance liquid chromatography coupled with charged aerosol detector (UHPLC-CAD). The results showed that up to 73% (w/w) of YHDP could be quantitatively determined. Small molecules accounted for approximately 5%, PEG-4000 represented 68%, while no sugars or macromolecules were found. Furthermore, YHDP showed no significant differences in terms of daily dosage, compared to YinHuang granules and YinHuang oral liquid; however, it has a higher small molecules content compared to YinHuang lozenge. PMID:27131804

  3. Comprehensive quantitative analysis of Chinese patent drug YinHuang drop pill by ultra high-performance liquid chromatography quadrupole time of flight mass spectrometry.

    PubMed

    Wong, Tin-Long; An, Ya-Qi; Yan, Bing-Chao; Yue, Rui-Qi; Zhang, Tian-Bo; Ho, Hing-Man; Ren, Tian-Jing; Fung, Hau-Yee; Ma, Dik-Lung; Leung, Chung-Hang; Liu, Zhong-Liang; Pu, Jian-Xin; Han, Quan-Bin; Sun, Han-Dong

    2016-06-01

    YinHuang drop pill (YHDP) is a new preparation, derived from the traditional YinHuang (YH) decoction. Since drop pills are one of the newly developed forms of Chinese patent drugs, not much research has been done regarding the quality and efficacy. This study aims to establish a comprehensive quantitative analysis of the chemical profile of YHDP. ultra high-performance liquid chromatography quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS/MS) was used to identify 34 non-sugar small molecules including 15 flavonoids, 9 phenolic acids, 5 saponins, 1 iridoid, and 4 iridoid glycosides in YHDP samples, and 26 of them were quantitatively determined. Sugar composition of YHDP in terms of fructose, glucose and sucrose was examined via a high performance liquid chromatography-evaporative light scattering detector on an amide column (HPLC-NH2P-ELSD). Macromolecules were examined by high performance gel permeation chromatography coupled with ELSD (HPGPC-ELSD). The content of the drop pill's skeleton component PEG-4000 was also quantified via ultra-high performance liquid chromatography coupled with charged aerosol detector (UHPLC-CAD). The results showed that up to 73% (w/w) of YHDP could be quantitatively determined. Small molecules accounted for approximately 5%, PEG-4000 represented 68%, while no sugars or macromolecules were found. Furthermore, YHDP showed no significant differences in terms of daily dosage, compared to YinHuang granules and YinHuang oral liquid; however, it has a higher small molecules content compared to YinHuang lozenge.

  4. Langevin power curve analysis for numerical wind energy converter models with new insights on high frequency power performance

    NASA Astrophysics Data System (ADS)

    Mücke, Tanja A.; Wächter, Matthias; Milan, Patrick; Peinke, Joachim

    2015-11-01

    Based on the Langevin equation it has been proposed to obtain power curves for wind turbines from high frequency data of wind speed measurements u(t) and power output P (t). The two parts of the Langevin approach, power curve and drift field, give a comprehensive description of the conversion dynamic over the whole operating range of the wind turbine. The method deals with high frequent data instead of 10 min means. It is therefore possible to gain a reliable power curve already from a small amount of data per wind speed. Furthermore, the method is able to visualize multiple fixed points, which is e.g. characteristic for the transition from partial to full load or in case the conversion process deviates from the standard procedures. In order to gain a deeper knowledge it is essential that the method works not only for measured data but also for numerical wind turbine models and synthetic wind fields. Here, we characterize the dynamics of a detailed numerical wind turbine model and calculate the Langevin power curve for different data samplings. We show, how to get reliable results from synthetic data and verify the applicability of the method for field measurements with ultra-sonic, cup and Lidar measurements. The independence of the fixed points on site specific turbulence effects is also confirmed with the numerical model. Furthermore, we demonstrate the potential of the Langevin approach to detect failures in the conversion process and thus show the potential of the Langevin approach for a condition monitoring system.

  5. Digitized neutron imaging with high spatial resolution at a low power research reactor: I. Analysis of detector performance

    NASA Astrophysics Data System (ADS)

    Zawisky, M.; Hameed, F.; Dyrnjaja, E.; Springer, J.

    2008-03-01

    Imaging techniques provide an indispensable tool for investigation of materials. Neutrons, due to their specific properties, offer a unique probe for many aspects of condensed matter. Neutron imaging techniques present a challenging experimental task, especially at a low power research reactor. The Atomic Institute with a 250 kW TRIGA MARK II reactor looks back at a long tradition in neutron imaging. Here we report on the advantages gained in a recent upgrade of the imaging instrument including the acquisition of a thin-plate scintillation detector, a single counting micro-channel plate detector, and an imaging plate detector in combination with a high resolution scanner. We analyze the strengths and limitations of each detector in the field of neutron radiography and tomography, and demonstrate that high resolution digitized imaging down to the 50 μm scale can be accomplished with weak beam intensities of 1.3×10 5 n/cm 2 s, if appropriate measures are taken for the inevitable extension of measurement times. In a separate paper we will present some promising first results from the fields of engineering and geology.

  6. Combined column-mobile phase mixture statistical design optimization of high-performance liquid chromatographic analysis of multicomponent systems.

    PubMed

    Breitkreitz, Márcia C; Jardim, Isabel C S F; Bruns, Roy E

    2009-02-27

    A statistical approach for the simultaneous optimization of the mobile and stationary phases used in reversed-phase liquid chromatography is presented. Mixture designs using aqueous mixtures of acetonitrile (ACN), methanol (MeOH) and tetrahydrofuran (THF) organic modifiers were performed simultaneously with column type optimization, according to a split-plot design, to achieve the best separation of compounds in two sample sets: one containing 10 neutral compounds with similar retention factors and another containing 11 pesticides. Combined models were obtained by multiplying a linear model for column type, C8 or C18, by quadratic or special cubic mixture models. Instead of using an objective response function, combined models were built for elementary chromatographic criteria (retention factors, resolution and relative retention) of each solute or pair of solutes and, after their validation, the global separation was accomplished by means of Derringer's desirability functions. For neutral compounds a 37:12:8:43 (v/v/v/v) percentage mixture of ACN:MeOH:THF:H2O with the C18 column and for pesticides a 15:15:70 (v/v/v) ACN:THF:H2O mixture with the C8 column provide excellent resolution of all peaks.

  7. Analysis of wax esters by silver-ion high-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Vrkoslav, Vladimír; Urbanová, Klára; Háková, Matina; Cvačka, Josef

    2013-08-01

    Wax esters (WEs), esters of long-chain fatty acids and long-chain alcohols, were analysed by Ag-HPLC/APCI-MS/MS. Two ChromSpher Lipids columns connected in series (a total length of 50cm) and hexane-2-propanol-acetonitrile mobile phases were used to achieve good separation of the molecular species. The chromatographic behaviour of WEs was studied under optimised conditions: retention increased with the number of double bonds and with the temperature (15-35°C); retention times were affected by the double-bond position, trans isomers eluted earlier than cis isomers, and the WEs were partially separated depending on the aliphatic-chain length. The WEs provided simple APCI spectra with [M+H](+) ions, the MS/MS spectra showed fragments, which allowed their identification. The method was applied for an analysis of the WE mixtures from jojoba oil and human hair and the results were compared with analogous data from an optimised RP-HPLC system.

  8. Development of high-performance X-ray transparent crystallization plates for in situ protein crystal screening and analysis

    PubMed Central

    Soliman, Ahmed S. M.; Warkentin, Matthew; Apker, Benjamin; Thorne, Robert E.

    2011-01-01

    X-ray transparent crystallization plates based upon a novel drop-pinning technology provide a flexible, simple and inexpensive approach to protein crystallization and screening. The plates consist of open cells sealed top and bottom by thin optically, UV and X-ray transparent films. The plates do not need wells or depressions to contain liquids. Instead, protein drops and reservoir solution are held in place by rings with micrometre dimensions that are patterned onto the bottom film. These rings strongly pin the liquid contact lines, thereby improving drop shape and position uniformity, and thus crystallization reproducibility, and simplifying automated image analysis of drop contents. The same rings effectively pin solutions containing salts, proteins, cryoprotectants, oils, alcohols and detergents. Strong pinning by rings allows the plates to be rotated without liquid mixing to 90° for X-ray data collection or to be inverted for hanging-drop crystallization. The plates have the standard SBS format and are compatible with standard liquid-handling robots. PMID:21697603

  9. Analysis of isothiazolinone biocides in paper for food packaging by ultra-high-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Lin, Q-B; Wang, T-J; Song, H; Li, B

    2010-12-01

    A novel and simple method to detect isothiazolinone-type biocides (2-methyl-3-isothiazolinone (MI), 5-chloro-2-methyl-3-isothiazolinone (CMI), 1,2-benzisothiazolinone (BIT) and 2-octyl-3-isothiazolinone (OIT)) in paper used for food packaging by ultrasonic extraction coupled with UPLC-MS/MS was developed. Parameters affecting process efficiency such as extraction solvents, UPLC mobile phase, gradient elution procedure and MS/MS conditions were studied to optimise the operating conditions. Using the optimised gradient elution procedure, the retention time was less than 6 min. The limits of detection (LODs) were found to be between 0.001 and 0.010 mg kg⁻¹, which was validated using actual concentrations. After diluting the standard solution with a blank matrix, the linear calibration curve ranges were 0.002-1.000 mg kg⁻¹ for BIT and OIT, 0.005-1.000 mg kg⁻¹ for MI, and 0.020-1.000 mg kg⁻¹ for CMI, with correlation coefficients higher than 0.9985 (n = 6). A good level of precision with a mean recovery greater than 81.3% and a relative standard deviation (RSD) less than 6.2% were also obtained. A methodology has been proposed for the analysis of isothiazolinones in paper.

  10. Fast and sensitive high performance liquid chromatography analysis of cosmetic creams for hydroquinone, phenol and six preservatives.

    PubMed

    Gao, Wenhui; Legido-Quigley, Cristina

    2011-07-15

    A fast and sensitive HPLC method for analysis of cosmetic creams for hydroquinone, phenol and six preservatives has been developed. The influence of sample preparation conditions and the composition of the mobile phase and elution mode were investigated to optimize the separation of the eight studied components. Final conditions were 60% methanol and 40% water (v/v) extraction of the cosmetic creams. A C18 column (100 mm × 2.1 mm) was used as the separation column and the mobile phase consisted of methanol and 0.05 mol/L ammonium formate in water (pH=3.0) with gradient elution. The results showed that complete separation of the eight studied components was achieved within 10 min, the linear ranges were 1.0-200 μg/mL for phenol, 0.1-150 μg/mL for sorbic acid, 2.0-200 μg/mL for benzoic acid, 0.5-200 μg/mL for hydroquinone, methyl paraben, ethyl paraben and propyl paraben, butyl paraben, and good linear correlation coefficient (≥0.9997) were obtained, the detection limit was in the range of 0.05-1.0 μg/mL, the average recovery was between 86.5% and 116.3%, and the relative standard deviation (RSD) was less than 5.0% (n=6). The method is easy, fast and sensitive, it can be employed to analyze component residues in cosmetic creams especially in a quality control setting.

  11. Ultra high performance liquid chromatography with mass spectrometry for the rapid analysis and global characterization of multiple constituents from Zibu Piyin Recipe.

    PubMed

    Dong, Peipei; Zhang, Lin; Zhan, Libin; Liu, Yanqiu

    2016-02-01

    Zibu Piyin Recipe is a traditional Chinese medicine that has been used for the clinical treatment of memory loss in China. However, the chemical components have not been thoroughly studied so far. To quickly identify the chemical components and understand the chemical profiles related to cognition improvement activity, ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry has been applied. The analysis was performed on an Agilent 1290 ultra-high performance liquid chromatography system with a Poroshell 120 EC-C18 column (3.0 × 150 mm, 2.7 μm) using gradient elution. Using the optimized method, 155 chemical components in Zibu Piyin Recipe were tentatively identified. Among them, 112 components in negative ion mode, 73 constituents in positive ion mode, and 30 compounds in both modes could be detected. The major components were identified from Red Ginseng, Dan shen Root, White Paeony Root, liquorice root, Radix Polygalae, Tangerine Red Epicarp, Grassleaf Sweetflag Rhizome, Indian Buead, and lotus seed. These results suggest that the established rapid and robust method will be useful for identifying multiple constituents of traditional Chinese medicine prescriptions. This method could provide helpful chemical information for further in vivo pharmacological mechanism research of Zibu Piyin Recipe and new drug development for cognition improvement. PMID:26844931

  12. Ultra high performance liquid chromatography with mass spectrometry for the rapid analysis and global characterization of multiple constituents from Zibu Piyin Recipe.

    PubMed

    Dong, Peipei; Zhang, Lin; Zhan, Libin; Liu, Yanqiu

    2016-02-01

    Zibu Piyin Recipe is a traditional Chinese medicine that has been used for the clinical treatment of memory loss in China. However, the chemical components have not been thoroughly studied so far. To quickly identify the chemical components and understand the chemical profiles related to cognition improvement activity, ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry has been applied. The analysis was performed on an Agilent 1290 ultra-high performance liquid chromatography system with a Poroshell 120 EC-C18 column (3.0 × 150 mm, 2.7 μm) using gradient elution. Using the optimized method, 155 chemical components in Zibu Piyin Recipe were tentatively identified. Among them, 112 components in negative ion mode, 73 constituents in positive ion mode, and 30 compounds in both modes could be detected. The major components were identified from Red Ginseng, Dan shen Root, White Paeony Root, liquorice root, Radix Polygalae, Tangerine Red Epicarp, Grassleaf Sweetflag Rhizome, Indian Buead, and lotus seed. These results suggest that the established rapid and robust method will be useful for identifying multiple constituents of traditional Chinese medicine prescriptions. This method could provide helpful chemical information for further in vivo pharmacological mechanism research of Zibu Piyin Recipe and new drug development for cognition improvement.

  13. Optimization of two methods for the analysis of hydrogen peroxide: high performance liquid chromatography with fluorescence detection and high performance liquid chromatography with electrochemical detection in direct current mode.

    PubMed

    Tarvin, Megan; McCord, Bruce; Mount, Kelly; Sherlach, Katy; Miller, Mark L

    2010-11-26

    Two complementary methods were optimized for the separation and detection of trace levels of hydrogen peroxide. The first method utilized reversed-phase high-performance liquid chromatography with fluorescence detection (HPLC-FD). With this approach, hydrogen peroxide was detected based upon its participation in the hemin-catalyzed oxidation of p-hydroxyphenylacetic acid to yield the fluorescent dimer. The second method utilized high performance liquid chromatography with electrochemical detection (HPLC-ED). With this approach, hydrogen peroxide was detected based upon its oxidation at a gold working electrode at an applied potential of 400 mV vs. hydrogen reference electrode (Pd/H(2)). Both methods were linear across the range of 15-300 μM, and the electrochemical method was linear across a wider range of 7.4-15,000 μM. The limit of detection for hydrogen peroxide was 6 μM by HPLC/FD, and 0.6 μM by HPLC/ED. A series of organic peroxides and inorganic ions were evaluated for their potential to interfere with the detection of hydrogen peroxide. Studies investigating the recovery of hydrogen peroxide with three different extraction protocols were also performed. Post-blast debris from the detonation of a mixture of concentrated hydrogen peroxide with nitromethane was analyzed on both systems. Hydrogen peroxide residues were successfully detected on this post-blast debris.

  14. Enantiomeric separation of isochromene derivatives by high-performance liquid chromatography using cyclodextrin based stationary phases and principal component analysis of the separation data.

    PubMed

    Nanayakkara, Yasith S; Woods, Ross M; Breitbach, Zachary S; Handa, Sachin; Slaughter, LeGrande M; Armstrong, Daniel W

    2013-08-30

    Isochromene derivatives are very important precursors in the natural products industry. Hence the enantiomeric separations of chiral isochromenes are important in the pharmaceutical industry and for organic asymmetric synthesis. Here we report enantiomeric separations of 21 different chiral isochromene derivatives, which were synthesized using alkynylbenzaldehyde cyclization catalyzed by chiral gold(I) acyclic diaminocarbene complexes. All separations were achieved by high-performance liquid chromatography with cyclodextrin based (Cyclobond) chiral stationary phases. Retention data of 21 chiral compounds and 14 other previously separated isochromene derivatives were analyzed using principal component analysis. The effect of the structure of the substituents on the isochromene ring on enantiomeric resolution as well as the other separation properties was analyzed in detail. Using principal component analysis it can be shown that the structural features that contribute to increased retention are different from those that enhance enantiomeric resolution. In addition, principal component analysis is useful for eliminating redundant factors from consideration when analyzing the effect of various chromatographic parameters. It was found that the chiral recognition mechanism is different for the larger γ-cyclodextrin as compared to the smaller β-cyclodextrin derivatives. Finally this specific system of chiral analytes and cyclodextrin based chiral selectors provides an effective format to examine the application of principal component analysis to enantiomeric separations using basic retention data and structural features. PMID:23906806

  15. Analysis of sulfate metabolites of the doping agents oxandrolone and danazol using high performance liquid chromatography coupled to tandem mass spectrometry.

    PubMed

    Rzeppa, S; Viet, L

    2016-09-01

    The direct detection of sulfate conjugates of anabolic androgenic steroids (AAS) can be a powerful tool in doping control analysis. By skipping the solvolysis step analysis time can be reduced, and due to long term sulfate metabolites the detection time can be significantly extended as demonstrated for some AAS. This study presents the successful identification of sulfate metabolites of the doping agents oxandrolone and danazol in excretion urines by high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The sulfate conjugate of 17β-hydroxymethyl-17α-methyl-18-nor-2-oxa-5α-androsta-13-en-3-one could be identified as a new metabolite of oxandrolone. Sulfate conjugates of the danazol metabolites ethisterone and 2α-hydroxymethylethisterone were identified in an excretion urine for the first time. In addition, these sulfate conjugates were synthesized successfully. For a confirmation analysis, the number of analytes can be increased by additional sulfate conjugates of danazol metabolites (2-hydroxymethyl-1,2-dehydroethisterone and 6β-hydroxy-2-hydroxymethylethisterone), which were also identified for the first time. The presented validation data underline the suitability of the identified sulfate conjugates for doping analysis with regard to the criteria given by the technical documents of the World Anti-Doping Agency (WADA). PMID:27394004

  16. A high performance thermoacoustic engine

    NASA Astrophysics Data System (ADS)

    Tijani, M. E. H.; Spoelstra, S.

    2011-11-01

    In thermoacoustic systems heat is converted into acoustic energy and vice versa. These systems use inert gases as working medium and have no moving parts which makes the thermoacoustic technology a serious alternative to produce mechanical or electrical power, cooling power, and heating in a sustainable and environmentally friendly way. A thermoacoustic Stirling heat engine is designed and built which achieves a record performance of 49% of the Carnot efficiency. The design and performance of the engine is presented. The engine has no moving parts and is made up of few simple components.

  17. High-performance composite chocolate

    NASA Astrophysics Data System (ADS)

    Dean, Julian; Thomson, Katrin; Hollands, Lisa; Bates, Joanna; Carter, Melvyn; Freeman, Colin; Kapranos, Plato; Goodall, Russell

    2013-07-01

    The performance of any engineering component depends on and is limited by the properties of the material from which it is fabricated. It is crucial for engineering students to understand these material properties, interpret them and select the right material for the right application. In this paper we present a new method to engage students with the material selection process. In a competition-based practical, first-year undergraduate students design, cost and cast composite chocolate samples to maximize a particular performance criterion. The same activity could be adapted for any level of education to introduce the subject of materials properties and their effects on the material chosen for specific applications.

  18. Techniques for Automated Performance Analysis

    SciTech Connect

    Marcus, Ryan C.

    2014-09-02

    The performance of a particular HPC code depends on a multitude of variables, including compiler selection, optimization flags, OpenMP pool size, file system load, memory usage, MPI configuration, etc. As a result of this complexity, current predictive models have limited applicability, especially at scale. We present a formulation of scientific codes, nodes, and clusters that reduces complex performance analysis to well-known mathematical techniques. Building accurate predictive models and enhancing our understanding of scientific codes at scale is an important step towards exascale computing.

  19. Toward High-Performance Organizations.

    ERIC Educational Resources Information Center

    Lawler, Edward E., III

    2002-01-01

    Reviews management changes that companies have made over time in adopting or adapting four approaches to organizational performance: employee involvement, total quality management, re-engineering, and knowledge management. Considers future possibilities and defines a new view of what constitutes effective organizational design in management.…

  20. High-Performance Composite Chocolate

    ERIC Educational Resources Information Center

    Dean, Julian; Thomson, Katrin; Hollands, Lisa; Bates, Joanna; Carter, Melvyn; Freeman, Colin; Kapranos, Plato; Goodall, Russell

    2013-01-01

    The performance of any engineering component depends on and is limited by the properties of the material from which it is fabricated. It is crucial for engineering students to understand these material properties, interpret them and select the right material for the right application. In this paper we present a new method to engage students with…

  1. Carpet Aids Learning in High Performance Schools

    ERIC Educational Resources Information Center

    Hurd, Frank

    2009-01-01

    The Healthy and High Performance Schools Act of 2002 has set specific federal guidelines for school design, and developed a federal/state partnership program to assist local districts in their school planning. According to the Collaborative for High Performance Schools (CHPS), high-performance schools are, among other things, healthy, comfortable,…

  2. Initial performance of the High Speed Photometer

    NASA Technical Reports Server (NTRS)

    Richards, Evan; Percival, Jeff; Nelson, Matt; Hatter, ED; Fitch, John; White, Rick

    1991-01-01

    The Hubble Space Telescope High Speed Photometer has four image dissector tubes, two with UV sensitive photocathodes, two sensitive to the near UV and to visual light, and a single red sensitive photomultiplier tube. The HSP is capable of photometric measurements from 1200 to 7500 A with time resolution of 11 microseconds and has no moving parts. An initial analysis of the on-orbit engineering performance of the HSP is presented with changes in operating procedures resulting from the primary mirror spherical aberration and experience gained during the verification period.

  3. Comparison of two thin-film microextractions for the analysis of estrogens in aqueous tea extract and environmental water samples by high performance liquid chromatography-ultraviolet detection.

    PubMed

    Cai, Pei-Shan; Li, Dan; Chen, Jing; Xiong, Chao-Mei; Ruan, Jin-Lan

    2015-04-15

    Two thin-film microextractions (TFME), octadecylsilane (ODS)-polyacrylonitrile (PAN)-TFME and polar enhanced phase (PEP)-PAN-TFME have been proposed for the analysis of bisphenol-A, diethylstilbestrol and 17β-estradiol in aqueous tea extract and environmental water samples followed by high performance liquid chromatography-ultraviolet detection. Both thin-films were prepared by spraying. The influencing factors including pH, extraction time, desorption solvent, desorption volume, desorption time, ion strength and reusability were investigated. Under the optimal conditions, the two TFME methods are similar in terms of the analytical performance evaluated by standard addition method. The limits of detection for three estrogens in environmental water and aqueous tea extract matrix ranged from 1.3 to 1.6 and 2.8 to 7.1 ng mL(-1) by the two TFME methods, respectively. Both approaches were applied for the analysis of analytes in real aqueous tea extract and environmental water samples, presenting satisfactory recoveries ranged from 87.3% to 109.4% for the spiked samples.

  4. Quantification of allicin by high performance liquid chromatography-ultraviolet analysis with effect of post-ultrasonic sound and microwave radiation on fresh garlic cloves

    PubMed Central

    Bose, Sankhadip; Laha, Bibek; Banerjee, Subhasis

    2014-01-01

    Background: Garlic (Allium sativum L.) has been accepted universally to be applied in food, spice and traditional medicine. The medicinal and other beneficial properties of garlic are attributed to organosulfur compounds. Objective: As of today no simultaneous analysis has been performed; hence the transformation of allicin to its degraded products during cultivation and storage is open into doubt. Materials and Methods: In our present work, we have tried to develop a sensitive and reproducible analytical method to measure allicin by high performance liquid chromatography-ultraviolet analysis with effect of post-acoustic waves and microwave radiation on fresh garlic cloves. Results: The process revealed the effect of different radiation techniques on fresh garlic retains the principle component, allicin in its pure form and generated higher yield than the conventional way of extraction. Conclusion: Therefore, materializing these techniques in the pharmaceutical industry will definitely be proved beneficial in term of time as well as money. Most interestingly, the methods ruled out possibilities of degradation of organosulfur compounds as well. PMID:24991105

  5. Ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry coupled with hierarchical cluster analysis to evaluate Wikstroemia indica (L.) C. A. Mey. from different geographical regions.

    PubMed

    Wei, Lan; Wang, Xiaobo; Mu, Shanxue; Sun, Lixin; Yu, Zhiguo

    2015-06-01

    A sensitive, rapid and simple ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry method was developed to determine seven constituents (umbelliferone, apigenin, triumbelletin, daphnoretin, arctigenin, genkwanin and emodin) in Wikstroemia indica (L.) C. A. Mey. The chromatographic analysis was performed on an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm, 1.7 μm) by gradient elution with the mobile phase of 0.05% formic acid aqueous solution (A) and acetonitrile (B). Multiple reaction monitoring mode with positive and negative electrospray ionization interface was carried out to detect the components. This method was validated in terms of specificity, linearity, accuracy, precision and stability. Excellent linear behavior was observed over the certain concentration ranges with the correlation coefficient values higher than 0.999. The intraday and innerday precisions were within 2.0%. The recoveries of seven analytes were 99.4-101.1% with relative standard deviation less than 1.2%. The 18 Wikstroemia indica samples from different origins were classified by hierarchical clustering analysis according to the contents of seven components. The results demonstrated that the developed method could successfully be used to quantify simultaneously of seven components in Wikstroemia indica and could be a helpful tool for the detection and confirmation of the quality of traditional Chinese medicines.

  6. Hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry for highly rapid and sensitive analysis of underivatized amino acids in functional foods.

    PubMed

    Zhou, Guisheng; Pang, Hanqing; Tang, Yuping; Yao, Xin; Mo, Xuan; Zhu, Shaoqing; Guo, Sheng; Qian, Dawei; Qian, Yefei; Su, Shulan; Zhang, Li; Jin, Chun; Qin, Yong; Duan, Jin-ao

    2013-05-01

    This work presented a new analytical methodology based on hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry in multiple-reaction monitoring mode for analysis of 24 underivatized free amino acids (FAAs) in functional foods. The proposed method was first reported and validated by assessing the matrix effects, linearity, limit of detections and limit of quantifications, precision, repeatability, stability and recovery of all target compounds, and it was used to determine the nutritional substances of FAAs in ginkgo seeds and further elucidate the nutritional value of this functional food. The result showed that ginkgo seed turned out to be a good source of FAAs with high levels of several essential FAAs and to have a good nutritional value. Furthermore, the principal component analysis was performed to classify the ginkgo seed samples on the basis of 24 FAAs. As a result, the samples could be mainly clustered into three groups, which were similar to areas classification. Overall, the presented method would be useful for the investigation of amino acids in edible plants and agricultural products.

  7. Optimisation of high-performance liquid chromatography with diode array detection using an automatic peak tracking procedure based on augmented iterative target transformation factor analysis.

    PubMed

    van Zomeren, P V; Hoogvorst, A; Coenegracht, P M J; de Jong, G J

    2004-03-01

    An automated method for the optimisation of high-performance liquid chromatography is developed. First of all, the sample of interest is analysed with various eluent compositions. All obtained data are combined into one augmented data matrix. Subsequently, augmented iterative target transformation factor analysis performs the integrated tasks of curve resolution and peak tracking. Since this type of curve resolution processes all data at once, it can deal with strong peak overlap and reveal the correspondence of compounds between runs, i.e. peak tracking. The retention time and peak width at half height for each component of the sample are determined for every eluent composition. Next, models are built for the retention time and the peak width at half height. These models are used to predict the resolution and the analysis time for each point in factor space. Finally, a multi-criterion decision-making method, Pareto optimality, is used to find the optimum. The method completes all calculations within a few minutes and without user intervention. By means of this procedure, a mixture of three benzodiazepines is successfully separated using a ternary mobile phase. There are two requirements for the automated optimisation method to work correctly. Firstly, all components of the sample must have sufficiently different spectra. Secondly, each compound should have the same spectrum under all experimental conditions.

  8. Ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry coupled with hierarchical cluster analysis to evaluate Wikstroemia indica (L.) C. A. Mey. from different geographical regions.

    PubMed

    Wei, Lan; Wang, Xiaobo; Mu, Shanxue; Sun, Lixin; Yu, Zhiguo

    2015-06-01

    A sensitive, rapid and simple ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry method was developed to determine seven constituents (umbelliferone, apigenin, triumbelletin, daphnoretin, arctigenin, genkwanin and emodin) in Wikstroemia indica (L.) C. A. Mey. The chromatographic analysis was performed on an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm, 1.7 μm) by gradient elution with the mobile phase of 0.05% formic acid aqueous solution (A) and acetonitrile (B). Multiple reaction monitoring mode with positive and negative electrospray ionization interface was carried out to detect the components. This method was validated in terms of specificity, linearity, accuracy, precision and stability. Excellent linear behavior was observed over the certain concentration ranges with the correlation coefficient values higher than 0.999. The intraday and innerday precisions were within 2.0%. The recoveries of seven analytes were 99.4-101.1% with relative standard deviation less than 1.2%. The 18 Wikstroemia indica samples from different origins were classified by hierarchical clustering analysis according to the contents of seven components. The results demonstrated that the developed method could successfully be used to quantify simultaneously of seven components in Wikstroemia indica and could be a helpful tool for the detection and confirmation of the quality of traditional Chinese medicines. PMID:25866087

  9. Rapid speciation analysis of Cr(VI) and Cr(III) by reversed-phase high-performance liquid chromatography with UV detection.

    PubMed

    Hossain, Mohammad Abul; Kumita, Mikio; Michigami, Yoshimasa; Islam, Tajmeri S A; Mori, Shigeru

    2005-02-01

    A simple and rapid method is developed for the simultaneous determination of Cr(VI) and Cr(III) based on the formation of their different complexes with ammonium pyrrolidine-dithiocarbamate (APDC). Separation is performed using reversed-phase high-performance liquid chromatography coupled with UV detection. The conditions for complex formation and speciation are determined, such as solution pH, amount of APDC, temperature, and type of mobile phase. In order to substantially reduce the analysis time, the separation is carried out without extraction of chromium-APDC complexes from the mother liquor. Under the optimum analysis conditions, the chromatograms obtained show good peak separation, and the absolute detection limits (3s) are 2.2 microg/L for Cr(VI) and 4.5 microg/L for Cr(III). The calibration curves are linear from 3 to 5000 microg/L for Cr(VI) and 5 to 3000 microg/L for Cr(III). The relative standard deviations of peak areas in five measurements using a sample solution of 200 microg/L are less than 2% for Cr(VI) and 4% for Cr(III), indicating good reproducibility for this analytical method. Furthermore, simultaneous determination of Cr(VI) and Cr(III) is successful with the application of the proposed procedure in the synthetic wastewaters containing common heavy metal ions: Fe(III), Pb(II), Cd(II), Cu(II), and Zn(II). PMID:15826369

  10. Simple quantitative determination of potent thiols at ultratrace levels in wine by derivatization and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis.

    PubMed

    Capone, Dimitra L; Ristic, Renata; Pardon, Kevin H; Jeffery, David W

    2015-01-20

    Volatile sulfur compounds contribute characteristic aromas to foods and beverages and are widely studied, because of their impact on sensory properties. Certain thiols are particularly important to the aromas of roasted coffee, cooked meat, passion fruit, grapefruit, and guava. These same thiols enhance the aroma profiles of different wine styles, imparting pleasant aromas reminiscent of citrus and tropical fruits (due to 3-mercaptohexan-1-ol, 3-mercaptohexyl acetate, 4-mercapto-4-methylpentan-2-one), roasted coffee (2-furfurylthiol), and struck flint (benzyl mercaptan), at nanogram-per-liter levels. In contrast to the usual gas chromatography (GC) approaches, a simple and unique high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for routine analysis of five wine thiols, using 4,4'-dithiodipyridine (DTDP) as a derivatizing agent and polydeuterated internal standards for maximum accuracy and precision. DTDP reacted rapidly with thiols at wine pH and provided stable derivatives, which were enriched by solid-phase extraction (SPE) prior to analysis by HPLC-MS/MS. All steps were optimized and the method was validated in different wine matrices, with method performance being comparable to a well-optimized but more cumbersome gas chromatography-mass spectrometry (GC-MS) method. A range of commercial wines was analyzed with the new method, revealing the distribution of the five thiols in white, red, rosé, and sparkling wine styles.

  11. High-Performance Miniature Hygrometer

    NASA Technical Reports Server (NTRS)

    Van Zandt, Thomas R.; Kaiser, William J.; Kenny, Thomas W.; Crisp, David

    1994-01-01

    Relatively inexpensive hygrometer that occupies volume less than 4 in.(3) measures dewpoints as much as 100 degrees C below ambient temperatures, with accuracy of 0.1 degrees C. Field tests indicate accuracy and repeatability identical to those of state-of-the-art larger dewpoint hygrometers. Operates up to 100 times as fast as older hygrometers, and offers simplicity and small size needed to meet cost and performance requirements of many applications.

  12. Switchable window modeling. Task 12: Building energy analysis and design tools for solar applications, Subtask A.1: High-performance glazing

    SciTech Connect

    Reilly, S.; Selkowitz, S.; Winkelmann, F.

    1992-06-30

    This document presents the work conducted as part of Subtask A.1, High-Performance Glazing, of Task 12 of the IEA Solar Heating and Cooling Program. At the start of the task, the participants agreed that chromogenic technology (switchable glazing) held considerable promise, and that algorithms to accurately model their dynamic behavior were needed. The purpose of this subtask was to develop algorithms that could be incorporated into building energy analysis programs for predicting the thermal and optical performance of switchable windows. The work entailed a review of current techniques for modelling switchable glazing in windows and switchable windows in buildings and methods for improving upon existing modeling approaches. The proposed approaches correct some of the shortcomings in the existing techniques, and could be adapted for use in other similar programs. The proposed approaches generally provide more detailed calculations needed for evaluating the short-term (hourly and daily) impact of switchable windows on the energy and daylighting performance of a building. Examples of the proposed algorithms are included.

  13. Simultaneous analysis of hyoscyamine, scopolamine, 6beta-hydroxyhyoscyamine and apoatropine in Solanaceous hairy roots by reversed-phase high-performance liquid chromatography.

    PubMed

    Kursinszki, László; Hank, Hajnalka; László, Imre; Szoke, Eva

    2005-10-14

    A new high-performance liquid chromatographic method is described for tropane alkaloid analysis in genetically transformed root cultures of Datura innoxia Mill. and Atropa belladonna L. Sample preparation, tropane alkaloid extraction with chloroform-methanol-concentrated ammonia 15:5:1 (v/v/v), was followed by solid-phase extraction on Supelclean LC-18 cartridges. Optimized conditions and careful pH control resulted in high recovery and reproducibility. Simultaneous determination of apoatropine, 6beta-hydroxyhyoscyamine, hyoscyamine and scopolamine was performed by HPLC on C18 (2) reversed-phase column. The application of Luna new-generation silica-based stationary phase resulted in excellent peak shapes using an ion-pair reagent and triethanolamine free mobile phase and allowed to exploit the full power of pH-dependent selectivity. Simplicity and improved selectivity make this method a preferred alternative of published ion-pair chromatographic methods. Validation studies proved that the global method has good repeatability and satisfactory recovery. Absolute limits of detection were 0.6, 0.6, and 0.8 ng for hyoscyamine, 6beta-hydroxyhyoscyamine, and scopolamine respectively.

  14. Analysis of buprenorphine in rat plasma using a solid-phase extraction technique and high-performance liquid chromatography with electrochemical detection.

    PubMed

    Salem, A; Pierce, T L; Hope, W

    1997-03-01

    A solid-phase extraction method and sensitive reversed phase high-performance liquid chromatography analysis with electrochemical detection of buprenorphine and its metabolite, norbuprenorphine, in rat plasma is described. Adequate separation of the compounds of interest was achieved on a Phenomenex C18 reversed-phase column using a mobile phase comprising phosphate buffer: acetonitrile (75:25, pH 3.0) and 0.25 mM 1-octane-sulfonic acid, at a flow rat of 1 ml/min. Electrochemical detection was performed at a potential of 0.75 V and sensitivity of 2 nA. Buprenorphine and norbuprenorphine were extracted from plasma by solid-phase extraction technique using naltrindole as an internal standard (IS). Recoveries of buprenorphine and norbuprenorphine following the extraction method were high (70%-89%) over the concentration range used (25-100 ng/ml) and no endogenous substances in plasma interfered with any of the sample components. The retention times for norbuprenorphine, IS, and buprenorphine were 8, 12.5, and 30.5 min, respectively. The limits of detection of buprenorphine and norbuprenorphine in spiked plasma samples were 25 and 5 ng/ml, respectively. Using this method, buprenorphine was detected in rat plasma in animals acutely treated with the drug (5 mg/kg, s.c.).

  15. Quantitative analysis of ripasudil hydrochloride hydrate and its impurities by reversed-phase high-performance liquid chromatography after precolumn derivatization: Identification of four impurities.

    PubMed

    Hui, Wenkai; Sun, Lili; Zhang, Hui; Zou, Liang; Zou, Qiaogen; Ouyang, Pingkai

    2016-09-01

    We report the development and validation of a stability-indicating reversed-phase high-performance liquid chromatography method with precolumn derivatization for the separation and identification of the impurities of ripasudil hydrochloride hydrate, a novel protein kinase inhibitor. 2,3,4,6-Tetra-O-acetyl-β-d-glucopyranosyl isothiocyanate was chosen as the derivatizing reagent and triethylamine was added as catalyst. 200 μL sample solution (1 mg/mL), 600 μL derivatizing reagent (1 mg/mL), and 200 μL triethylamine solution (1%, v/v) were mixed and reacted at 40°C for 30 min. The separation was achieved on an Inertsil C18 ODS-3 (250 mm × 4.6 mm, 5 μm) column using mobile phases including 10 mmol monopotassium phosphate buffer (pH 3.0) and methanol in gradient mode. The column temperature was adjusted at 25°C and the flow rate at 1 mL/min. The detection was carried out at 220 nm. Different precolumn derivatization conditions as well as the high-performance liquid chromatography conditions were optimized. Ripasudil hydrochloride hydrate and its four impurities were detected and quantitated, among which two new compounds were characterized. The proposed method was validated and proven to be selective, accurate, and precise and suitable for the quantitative analysis of ripasudil hydrochloride hydrate. PMID:27390135

  16. High-performance solar collector

    NASA Technical Reports Server (NTRS)

    Beekley, D. C.; Mather, G. R., Jr.

    1979-01-01

    Evacuated all-glass concentric tube collector using air or liquid transfer mediums is very efficient at high temperatures. Collector can directly drive existing heating systems that are presently driven by fossil fuel with relative ease of conversion and less expense than installation of complete solar heating systems.

  17. Nanofluid of zinc oxide nanoparticles in ionic liquid for single drop liquid microextraction of fungicides in environmental waters prior to high performance liquid chromatographic analysis.

    PubMed

    Amde, Meseret; Tan, Zhi-Qiang; Liu, Rui; Liu, Jing-Fu

    2015-05-22

    Using a nanofluid obtained by dispersing ZnO nanoparticles (ZnO NPs) in 1-hexyl-3-methylimidazolium hexafluorophosphate, new single drop microextraction method was developed for simultaneous extraction of three fungicides (chlorothalonil, kresoxim-methyl and famoxadone) in water samples prior to their analysis by high performance liquid chromatography (HPLC-VWD). The parameters affecting the extraction efficiency such as amount of ZnO NPs in the nanofluid, solvent volume, extraction time, stirring rate, pH and ionic strength of the sample solution were optimized. Under the optimized conditions, the limits of detection were in the range of 0.13-0.19ng/mL, the precision of the method assessed with intra-day and inter-day relative standard deviations were <4.82% and <7.04%, respectively. The proposed method was successfully applied to determine the three fungicides in real water samples including lake water, river water, as well as effluent and influent of wastewater treatment plant, with recoveries in the range of 74.94-96.11% at 5ng/mL spiking level. Besides to being environmental friendly, the high enrichment factor and the data quality obtained with the proposed method demonstrated its potential for application in multi residue analysis of fungicides in actual water samples.

  18. Nanofluid of zinc oxide nanoparticles in ionic liquid for single drop liquid microextraction of fungicides in environmental waters prior to high performance liquid chromatographic analysis.

    PubMed

    Amde, Meseret; Tan, Zhi-Qiang; Liu, Rui; Liu, Jing-Fu

    2015-05-22

    Using a nanofluid obtained by dispersing ZnO nanoparticles (ZnO NPs) in 1-hexyl-3-methylimidazolium hexafluorophosphate, new single drop microextraction method was developed for simultaneous extraction of three fungicides (chlorothalonil, kresoxim-methyl and famoxadone) in water samples prior to their analysis by high performance liquid chromatography (HPLC-VWD). The parameters affecting the extraction efficiency such as amount of ZnO NPs in the nanofluid, solvent volume, extraction time, stirring rate, pH and ionic strength of the sample solution were optimized. Under the optimized conditions, the limits of detection were in the range of 0.13-0.19ng/mL, the precision of the method assessed with intra-day and inter-day relative standard deviations were <4.82% and <7.04%, respectively. The proposed method was successfully applied to determine the three fungicides in real water samples including lake water, river water, as well as effluent and influent of wastewater treatment plant, with recoveries in the range of 74.94-96.11% at 5ng/mL spiking level. Besides to being environmental friendly, the high enrichment factor and the data quality obtained with the proposed method demonstrated its potential for application in multi residue analysis of fungicides in actual water samples. PMID:25857539

  19. Profiling and multivariate statistical analysis of Panax ginseng based on ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry.

    PubMed

    Wu, Wei; Sun, Le; Zhang, Zhe; Guo, Yingying; Liu, Shuying

    2015-03-25

    An ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) method was developed for the detection and structural analysis of ginsenosides in white ginseng and related processed products (red ginseng). Original neutral, malonyl, and chemically transformed ginsenosides were identified in white and red ginseng samples. The aglycone types of ginsenosides were determined by MS/MS as PPD (m/z 459), PPT (m/z 475), C-24, -25 hydrated-PPD or PPT (m/z 477 or m/z 493), and Δ20(21)-or Δ20(22)-dehydrated-PPD or PPT (m/z 441 or m/z 457). Following the structural determination, the UHPLC-Q-TOF-MS-based chemical profiling coupled with multivariate statistical analysis method was applied for global analysis of white and processed ginseng samples. The chemical markers present between the processed products red ginseng and white ginseng could be assigned. Process-mediated chemical changes were recognized as the hydrolysis of ginsenosides with large molecular weight, chemical transformations of ginsenosides, changes in malonyl-ginsenosides, and generation of 20-(R)-ginsenoside enantiomers. The relative contents of compounds classified as PPD, PPT, malonyl, and transformed ginsenosides were calculated based on peak areas in ginseng before and after processing. This study provides possibility to monitor multiple components for the quality control and global evaluation of ginseng products during processing.

  20. Qualitative and quantitative analysis of an alkaloid fraction from Piper longum L. using ultra-high performance liquid chromatography-diode array detector-electrospray ionization mass spectrometry.

    PubMed

    Li, Kuiyong; Fan, Yunpeng; Wang, Hui; Fu, Qing; Jin, Yu; Liang, Xinmiao

    2015-05-10

    In a previous research, an alkaloid fraction and 18 alkaloid compounds were prepared from Piper longum L. by series of purification process. In this paper, a qualitative and quantitative analysis method using ultra-high performance liquid chromatography-diode array detector-mass spectrometry (UHPLC-DAD-MS) was developed to evaluate the alkaloid fraction. Qualitative analysis of the alkaloid fraction was firstly completed by UHPLC-DAD method and 18 amide alkaloid compounds were identified. A further qualitative analysis of the alkaloid fraction was accomplished by UHPLC-MS/MS method. Another 25 amide alkaloids were identified according to their characteristic ions and neutral losses. At last, a quantitative method for the alkaloid fraction was established using four marker compounds including piperine, pipernonatine, guineensine and N-isobutyl-2E,4E-octadecadienamide. After the validation of this method, the contents of above four marker compounds in the alkaloid fraction were 57.5mg/g, 65.6mg/g, 17.7mg/g and 23.9mg/g, respectively. Moreover, the relative response factors of other three compounds to piperine were calculated. A comparative study between external standard quantification and relative response factor quantification proved no remarkable difference. UHPLC-DAD-MS method was demonstrated to be a powerful tool for the characterization of the alkaloid fraction from P. longum L. and the result proved that the quality of alkaloid fraction was efficiently improved after appropriate purification.

  1. Screening for RB1 mutations in tumor tissue using denaturing high performance liquid chromatography, multiplex ligation-dependent probe amplification, and loss of heterozygosity analysis.

    PubMed

    Sellner, Loryn N; Edkins, Edward; Smith, Nicholas

    2006-01-01

    Retinoblastoma is a malignant retinal neoplasm arising in infancy as a result of inactivating mutations in both alleles of the retinoblastoma susceptibility gene, RB1. Identification of the causative RB1 mutations in a patient assists in the clinical management of the affected patient and risk assessment of family members, principally on the basis of whether there is a germline mutation. In this paper, we describe our experience with molecular analysis of RB1 mutations in tumor and nontumor samples from 18 retinoblastoma patients, using multiplex ligation dependent probe amplification (MLPA) to detect large deletions or duplications, microsatellite analysis to detect loss of heterozygosity (LOH), and denaturing high performance liquid chromatography (D-HPLC) analysis to detect point mutations and small insertions or deletions. We found LOH in 71% of all cases, and 83% of these were due to acquired isodisomy rather than chromosomal deletions. Small mutations identified by D-HPLC accounted for 78% of the non-LOH mutations, and large deletions/duplications detected by MLPA accounted for the remaining 22%. We give the first report of a large, multiexon duplication in RB1 of exons 8 to 18. PMID:16808635

  2. Argentation high performance liquid chromatography on-line coupled to gas chromatography for the analysis of monounsaturated polyolefin oligomers in packaging materials and foods.

    PubMed

    Lommatzsch, Martin; Biedermann, Maurus; Simat, Thomas J; Grob, Koni

    2015-07-10

    Multidimensional chromatography based on two-dimensional high performance liquid chromatography on-line coupled to gas chromatography (on-line HPLC-HPLC-GC) enables the separate analysis of saturated, monounsaturated and aromatic hydrocarbons in packaging materials like polyolefins or paperboard and their migrates into foods. Since normal-phase HPLC on silica gel did not preseparate saturated from monounsaturated hydrocarbons, a separation step on a normal-phase HPLC column treated in the laboratory with an optimized amount of silver nitrate was added. The preparation of this HPLC column and the instrumental set-up are described, followed by examples showing the potential of the method. In a preliminary investigation of 11 polyolefin granulates for food contact up to 40% monounsaturated hydrocarbons among the oligomers C16-35 were determined.

  3. Detailed analysis of petroleum hydrocarbon attenuation in biopiles by high-performance liquid chromatography followed by comprehensive two-dimensional gas chromatography.

    PubMed

    Mao, Debin; Lookman, Richard; Van De Weghe, Hendrik; Van Look, Dirk; Vanermen, Guido; De Brucker, Nicole; Diels, Ludo

    2009-02-27

    Enhanced bioremediation of petroleum hydrocarbons in two biopiles was quantified by high-performance liquid chromatography (HPLC) followed by comprehensive two-dimensional gas chromatography (GCXGC). The attenuation of 34 defined hydrocarbon classes was calculated by HPLC-GCXGC analysis of representative biopile samples at start-up and after 18 weeks of biopile operation. In general, a-cyclic alkanes were most efficiently removed from the biopiles, followed by monoaromatic hydrocarbons. Cycloalkanes and polycyclic aromatic hydrocarbons (PAHs) were more resistant to degradation. A-cyclic biomarkers farnesane, trimethyl-C13, norpristane, pristane and phytane dropped to only about 10% of their initial concentrations. On the other hand, C29-C31 hopane concentrations remained almost unaltered after 18 weeks of biopile operation, confirming their resistance to biodegradation. They are thus reliable indicators to estimate attenuation potential of petroleum hydrocarbons in biopile processed soils.

  4. Geographical classification of Italian saffron (Crocus sativus L.) based on chemical constituents determined by high-performance liquid-chromatography and by using linear discriminant analysis.

    PubMed

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

    2016-12-01

    One hundred and forty-four Italian saffron samples produced in the years from 2009 to 2015 in five distinct areas located in four different regions, Abruzzo (L'Aquila), Tuscany (Florence), Umbria (Cascia and Città della Pieve) and Sardinia, have been analysed by high-performance liquid chromatography with diode array detection. Intensities of the chromatographic peaks attributed to crocins, safranal, picrocrocin and its derivatives and flavonoids were considered as variables in linear discriminant analysis to attempt geographical classification. The results revealed that spices produced at different sites of the Italian territory can be discriminated with good accuracy. The differentiation of saffron cultivated in Sardinia from those produced in Central Italy was mainly attributed to different contents of the most abundant crocins. Good differentiation of spices produced in close sites of Central Italy was also observed, 88% of validation samples being correctly classified; some minor crocins are responsible for such discrimination. PMID:27374513

  5. 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

    2015-12-01

    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.

  6. Analysis of drug-protein interactions by high-performance affinity chromatography: interactions of sulfonylurea drugs with normal and glycated human serum albumin.

    PubMed

    Matsuda, Ryan; Anguizola, Jeanethe; Hoy, Krina S; Hage, David S

    2015-01-01

    High-performance affinity chromatography (HPAC) is a type of liquid chromatography that has seen growing use as a tool for the study of drug-protein interactions. This report describes how HPAC can be used to provide information on the number of binding sites, equilibrium constants, and changes in binding that can occur during drug-protein interactions. This approach will be illustrated through recent data that have been obtained by HPAC for the binding of sulfonylurea drugs and other solutes to the protein human serum albumin (HSA), and especially to forms of this protein that have been modified by non-enzymatic glycation. The theory and use of both frontal analysis and zonal elution competition studies in such work will be discussed. Various practical aspects of these experiments will be presented, as well as factors to consider in the extension of these methods to other drugs and proteins or additional types of biological interactions. PMID:25749961

  7. A High-Performance Liquid Chromatography-Based Screening Method for the Analysis of Atrazine, Alachlor, and Ten of Their Transformation Products

    USGS Publications Warehouse

    Schroyer, B.R.; Capel, P.D.

    1996-01-01

    A high-performance liquid Chromatography (HPLC) method is presented for the for the fast, quantitative analysis of the target analytes in water and in low organic-carbon, sandy soils that are known to be contaminated with the parent herbicides. Speed and ease of sample preparation was prioritized above minimizing detection limits. Soil samples were extracted using 80:20 methanol:water (volume:volume). Water samples (50 ??L) were injected directly into the HPLC without prior preparation. Method quantification limits for soil samples (10 g dry weight) and water samples ranged from 20 to 110 ng/g and from 20 to 110 ??g/L for atrazine and its transformation products and from 80 to 320 ng/g and from 80 to 320 ??g/L for alachlor and its transformation products, respectively.

  8. Geographical classification of Italian saffron (Crocus sativus L.) based on chemical constituents determined by high-performance liquid-chromatography and by using linear discriminant analysis.

    PubMed

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

    2016-12-01

    One hundred and forty-four Italian saffron samples produced in the years from 2009 to 2015 in five distinct areas located in four different regions, Abruzzo (L'Aquila), Tuscany (Florence), Umbria (Cascia and Città della Pieve) and Sardinia, have been analysed by high-performance liquid chromatography with diode array detection. Intensities of the chromatographic peaks attributed to crocins, safranal, picrocrocin and its derivatives and flavonoids were considered as variables in linear discriminant analysis to attempt geographical classification. The results revealed that spices produced at different sites of the Italian territory can be discriminated with good accuracy. The differentiation of saffron cultivated in Sardinia from those produced in Central Italy was mainly attributed to different contents of the most abundant crocins. Good differentiation of spices produced in close sites of Central Italy was also observed, 88% of validation samples being correctly classified; some minor crocins are responsible for such discrimination.

  9. Validation and application of multi-residue analysis of eight anticoagulant rodenticides by high-performance liquid chromatography with fluorimetric detection.

    PubMed

    Armentano, Antonio; Iammarino, Marco; Lo Magro, Sonia; Muscarella, Marilena

    2012-03-01

    Poisoning of domestic animals is frequently caused by anticoagulant rodenticides. Validation and applications of a rapid and reliable method for the simultaneous determination of 8 anticoagulant rodenticides (bromadiolone, brodifacoum, coumachlor, coumafuryl, coumatetralyl, difenacoum, flocoumafen, and warfarin) in baits and animal livers using high-performance liquid chromatography with fluorescence detection are reported herein. The methodology was validated by an in-house validation model at 2.5 mg/kg, which is the level commonly found in the tissues of poisoned domestic animals. The 8 anticoagulants can be determined at the concentration range of 1.25-100 mg/kg with determination coefficients higher than 0.992. A recovery value from 70% to 109% was observed for all the studied molecules. The results of the validation process demonstrate suitability for application in official analysis and for monitoring purposes of animal poisoning by anticoagulant rodenticides. PMID:22379046

  10. Novel high performance multispectral photodetector and its performance

    NASA Astrophysics Data System (ADS)

    Mizuno, Genki; Dutta, Jaydeep; Oduor, Patrick; Dutta, Achyut K.; Dhar, Nibir K.

    2016-05-01

    Banpil Photonics has developed a novel high-performance multispectral photodetector array for Short-Wave Infrared (SWIR) imaging. The InGaAs based device uses a unique micro-nano pillar structure that eliminates surface reflection to significantly increase sensitivity and the absorption spectra compared to its macro-scaled thin film pixels counterpart (non-pillar). We discuss the device structure and highlight fabrication of the novel high performance multispectral image sensor. We also present performance results of the device characterization showing low dark current suitable for high performance imaging applications for the most demanding security, defense, and machine vision applications.

  11. Cloud-point extraction and reversed-phase high performance liquid chromatography for analysis of phenolic compounds and their antioxidant activity in Thai local wines.

    PubMed

    Vichapong, Jitlada; Santaladchaiyakit, Yanawath; Burakham, Rodjana; Srijaranai, Supalax

    2014-04-01

    A cloud-point extraction (CPE) was developed for the determination of 12 phenolic compounds (i.e. gallic acid, procatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, guaiacol, p-cresol, o-cresol and 3,5-xylenol) using reversed-phase high performance liquid chromatography (RP-HPLC) with photodiode array (PDA) detection. The optimum CPE conditions were 2.0% (w/v) Triton X-114, 3.0% (w/v) Na2SO4 and 20-min equilibrated at 45 °C. The surfactant-rich phase was then analyzed by HPLC using a Symmetry C18 column, gradient mobile phase of acetonitrile and 1% (v/v) acetic acid, and PDA detection at 280 nm. Under the optimum condition, the target phenolic compounds were separated within 25 min. CPE gave higher enrichment factor up to 15-fold compared to that of direct analysis. The proposed method showed good analytical performances with limits of detection in the range 0.01-0.1 mg L(-1) and precisions with relative standard deviation (RSD) lower than 5% for retention time and 10% for peak area. The method was successfully applied to the analysis of phenolic compounds in Thai local wine samples. Gallic acid, procatechuic acid, and vanillic acid were the highest phenolics found in the studied wines with the contents up to 172.4, 99.1, and 26.6 mg L(-1), respectively. The recovery of the spiked wine samples (0.5, 1.0, and 2.0 mg L(-1)) were obtained in the range of 90.4-110%. High total phenolic content, total flavonoids, and antioxidant activity (DPPH method) in the studied wines were also observed.

  12. High performance rotational vibration isolator.

    PubMed

    Sunderland, Andrew; Blair, David G; Ju, Li; Golden, Howard; Torres, Francis; Chen, Xu; Lockwood, Ray; Wolfgram, Peter

    2013-10-01

    We present a new rotational vibration isolator with an extremely low resonant frequency of 0.055 ± 0.002 Hz. The isolator consists of two concentric spheres separated by a layer of water and joined by very soft silicone springs. The isolator reduces rotation noise at all frequencies above its resonance which is very important for airborne mineral detection. We show that more than 40 dB of isolation is achieved in a helicopter survey for rotations at frequencies between 2 Hz and 20 Hz. Issues affecting performance such as translation to rotation coupling and temperature are discussed. The isolator contains almost no metal, making it particularly suitable for electromagnetic sensors.

  13. Students' Accounts of School-Performance Stress: A Qualitative Analysis of a High-Achieving Setting in Stockholm, Sweden

    ERIC Educational Resources Information Center

    Låftman, Sara Brolin; Almquist, Ylva B.; Östberg, Viveca

    2013-01-01

    The aim of the study is to examine students' experiences of school performance as a stressor. Accounts of school-performance stress at both the individual level and in relation to group mechanisms are studied through qualitative interviews with eighth-grade students in a high-performing school in Stockholm, Sweden (n = 49). Using qualitative…

  14. Analysis of drug-protein binding using on-line immunoextraction and high-performance affinity microcolumns: Studies with normal and glycated human serum albumin.

    PubMed

    Matsuda, Ryan; Jobe, Donald; Beyersdorf, Jared; Hage, David S

    2015-10-16

    A method combining on-line immunoextraction microcolumns with high-performance affinity chromatography (HPAC) was developed and tested for use in examining drug-protein interactions with normal or modified proteins. Normal human serum albumin (HSA) and glycated HSA were used as model proteins for this work. High-performance immunoextraction microcolumns with sizes of 1.0-2.0 cm × 2.1mm i.d. and containing anti-HSA polyclonal antibodies were developed and tested for their ability to bind normal HSA or glycated HSA. These microcolumns were able to extract up to 82-93% for either type of protein at 0.05-0.10 mL/min and had a binding capacity of 0.34-0.42 nmol HSA for a 1.0 cm × 2.1mm i.d. microcolumn. The immunoextraction microcolumns and their adsorbed proteins were tested for use in various approaches for drug binding studies. Frontal analysis was used with the adsorbed HSA/glycated HSA to measure the overall affinities of these proteins for the drugs warfarin and gliclazide, giving comparable values to those obtained previously using similar protein preparations that had been covalently immobilized within HPAC columns. Zonal elution competition studies with gliclazide were next performed to examine the specific interactions of this drug at Sudlow sites I and II of the adsorbed proteins. These results were also comparable to those noted in prior work with covalently immobilized samples of normal HSA or glycated HSA. These experiments indicated that drug-protein binding studies can be carried out by using on-line immunoextraction microcolumns with HPAC. The same method could be used in the future with clinical samples and other drugs or proteins of interest in pharmaceutical studies or biomedical research.

  15. Triacylglycerol analysis of potential margarine base stocks by high-performance liquid chromatography with atmospheric pressure chemical ionization mass spectrometry and flame ionization detection.

    PubMed

    Byrdwell, W C; Neff, W E; List, G R

    2001-01-01

    Several margarine base stock candidates have previously been prepared for the purpose of finding better, more oxidatively stable food components: high-saturate vegetable oils, randomized vegetable oils, vegetable oil-hard stock blends, and interesterified vegetable oil-hard stock blends. Here are reported the triacylglycerol compositions of these products, determined using reverse-phase high-performance liquid chromatography (HPLC) coupled with a flame ionization detector or a quadrupole mass spectrometer with an atmospheric pressure chemical ionization source. Triacylglycerol percent composition results for samples of known composition (randomized and interesterified samples) exhibited less average error by HPLC coupled with a quadrupole mass spectrometer with an atmospheric pressure chemical ionization source, after application of response factors, than the results by HPLC coupled with a flame ionization detector. The fatty acid compositions calculated from the mass spectrometric data exhibited less average error than the fatty acid compositions resulting from the flame ionization detector data. The average error of the fatty acid compositions by the mass spectrometer was lowest for interesterified blend samples, next lowest for randomized samples, then followed by high-saturated fatty acid oils, normal oils, and blends. Analysis of the vegetable oil-hard stock blends by mass spectrometer required special treatment for calculation of response factors.

  16. ANALYSIS OF DRUG INTERACTIONS WITH MODIFIED PROTEINS BY HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY: BINDING OF GLIBENCLAMIDE TO NORMAL AND GLYCATED HUMAN SERUM ALBUMIN

    PubMed Central

    Matsuda, Ryan; Anguizola, Jeanethe; Joseph, K.S.; Hage, David S.

    2012-01-01

    High-performance affinity chromatography (HPAC) was used to examine the changes in binding that occur for the sulfonylurea drug glibenclamide with human serum albumin (HSA) at various stages of glycation for HSA. Frontal analysis on columns containing normal HSA or glycated HSA indicated glibenclamide was interacting through both high affinity sites (association equilibrium constant, Ka, 1.4–1.9 × 106 M−1 at pH 7.4 and 37°C) and lower affinity sites (Ka, 4.4–7.2 × 104 M−1). Competition studies were used to examine the effect of glycation at specific binding sites of HSA. An increase in affinity of 1.7- to 1.9-fold was seen at Sudlow site I with moderate to high levels of glycation. An even larger increase of 4.3- to 6.0-fold in affinity was noted at Sudlow site II for all of the tested samples of glycated HSA. A slight decrease in affinity may have occurred at the digitoxin site, but this change was not significant for any individual glycated HSA sample. These results illustrate how HPAC can be used as tool for examining the interactions of relatively non-polar drugs like glibenclamide with modified proteins and should lead to a more complete understanding of how glycation can alter the binding of drugs in blood. PMID:23092871

  17. Guided wave tomography performance analysis

    NASA Astrophysics Data System (ADS)

    Huthwaite, Peter; Lowe, Michael; Cawley, Peter

    2016-02-01

    Quantifying wall loss caused by corrosion is a significant challenge for the petrochemical industry. Corrosion commonly occurs at pipe supports, where surface access for inspection is limited. Guided wave tomography is pursued as a solution to this: guided waves are transmitted through the region of interest from an array, and tomographic reconstruction techniques are applied to the measured signals in order to produce a map of thickness. There are many parameters in the system which can affect the performance; this paper investigates how the accuracy varies as defect width and depth, operating frequency and guided wave mode are all changed. For the S0 mode, the best performance was seen around 170kHz on the 10mm plate, with poor performance seen at almost all other frequencies. A0 showed better performance across a broad range of frequencies, with resolution improving with frequency as the wavelength reduced. However, it was shown that the resolution limit did drop relative to the wavelength, limiting the performance at high frequencies slightly.

  18. An Associate Degree in High Performance Manufacturing.

    ERIC Educational Resources Information Center

    Packer, Arnold

    In order for more individuals to enter higher paying jobs, employers must create a sufficient number of high-performance positions (the demand side), and workers must acquire the skills needed to perform in these restructured workplaces (the supply side). Creating an associate degree in High Performance Manufacturing (HPM) will help address four…

  19. Scalable Performance Measurement and Analysis

    SciTech Connect

    Gamblin, Todd

    2009-01-01

    Concurrency levels in large-scale, distributed-memory supercomputers are rising exponentially. Modern machines may contain 100,000 or more microprocessor cores, and the largest of these, IBM's Blue Gene/L, contains over 200,000 cores. Future systems are expected to support millions of concurrent tasks. In this dissertation, we focus on efficient techniques for measuring and analyzing the performance of applications running on very large parallel machines. Tuning the performance of large-scale applications can be a subtle and time-consuming task because application developers must measure and interpret data from many independent processes. While the volume of the raw data scales linearly with the number of tasks in the running system, the number of tasks is growing exponentially, and data for even small systems quickly becomes unmanageable. Transporting performance data from so many processes over a network can perturb application performance and make measurements inaccurate, and storing such data would require a prohibitive amount of space. Moreover, even if it were stored, analyzing the data would be extremely time-consuming. In this dissertation, we present novel methods for reducing performance data volume. The first draws on multi-scale wavelet techniques from signal processing to compress systemwide, time-varying load-balance data. The second uses statistical sampling to select a small subset of running processes to generate low-volume traces. A third approach combines sampling and wavelet compression to stratify performance data adaptively at run-time and to reduce further the cost of sampled tracing. We have integrated these approaches into Libra, a toolset for scalable load-balance analysis. We present Libra and show how it can be used to analyze data from large scientific applications scalably.

  20. High-temperature testing of high performance fiber reinforced concrete

    NASA Astrophysics Data System (ADS)

    Fořt, Jan; Vejmelková, Eva; Pavlíková, Milena; Trník, Anton; Čítek, David; Kolísko, Jiří; Černý, Robert; Pavlík, Zbyšek

    2016-06-01

    The effect of high-temperature exposure on properties of High Performance Fiber Reinforced Concrete (HPFRC) is researched in the paper. At first, reference measurements are done on HPFRC samples without high-temperature loading. Then, the HPFRC samples are exposed to the temperatures of 200, 400, 600, 800, and 1000 °C. For the temperature loaded samples, measurement of residual mechanical and basic physical properties is done. Linear thermal expansion coefficient as function of temperature is accessed on the basis of measured thermal strain data. Additionally, simultaneous difference scanning calorimetry (DSC) and thermogravimetry (TG) analysis is performed in order to observe and explain material changes at elevated temperature. It is found that the applied high temperature loading significantly increases material porosity due to the physical, chemical and combined damage of material inner structure, and negatively affects also the mechanical strength. Linear thermal expansion coefficient exhibits significant dependence on temperature and changes of material structure. The obtained data will find use as input material parameters for modelling the damage of HPFRC structures exposed to the fire and high temperature action.

  1. Combination of multivariate curve resolution and multivariate classification techniques for comprehensive high-performance liquid chromatography-diode array absorbance detection fingerprints analysis of Salvia reuterana extracts.

    PubMed

    Hakimzadeh, Neda; Parastar, Hadi; Fattahi, Mohammad

    2014-01-24

    In this study, multivariate curve resolution (MCR) and multivariate classification methods are proposed to develop a new chemometric strategy for comprehensive analysis of high-performance liquid chromatography-diode array absorbance detection (HPLC-DAD) fingerprints of sixty Salvia reuterana samples from five different geographical regions. Different chromatographic problems occurred during HPLC-DAD analysis of S. reuterana samples, such as baseline/background contribution and noise, low signal-to-noise ratio (S/N), asymmetric peaks, elution time shifts, and peak overlap are handled using the proposed strategy. In this way, chromatographic fingerprints of sixty samples are properly segmented to ten common chromatographic regions using local rank analysis and then, the corresponding segments are column-wise augmented for subsequent MCR analysis. Extended multivariate curve resolution-alternating least squares (MCR-ALS) is used to obtain pure component profiles in each segment. In general, thirty-one chemical components were resolved using MCR-ALS in sixty S. reuterana samples and the lack of fit (LOF) values of MCR-ALS models were below 10.0% in all cases. Pure spectral profiles are considered for identification of chemical components by comparing their resolved spectra with the standard ones and twenty-four components out of thirty-one components were identified. Additionally, pure elution profiles are used to obtain relative concentrations of chemical components in different samples for multivariate classification analysis by principal component analysis (PCA) and k-nearest neighbors (kNN). Inspection of the PCA score plot (explaining 76.1% of variance accounted for three PCs) showed that S. reuterana samples belong to four clusters. The degree of class separation (DCS) which quantifies the distance separating clusters in relation to the scatter within each cluster is calculated for four clusters and it was in the range of 1.6-5.8. These results are then

  2. Analysis of cytochrome P450 metabolites of arachidonic acid by stable isotope probe labeling coupled with ultra high-performance liquid chromatography/mass spectrometry.

    PubMed

    Zhu, Quan-Fei; Hao, Yan-Hong; Liu, Ming-Zhou; Yue, Jiang; Ni, Jian; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-09-01

    Cytochrome P450 metabolites of arachidonic acid (AA) belong to eicosanoids and are potent lipid mediators of inflammation. It is well-known that eicosanoids play an important role in numerous pathophysiological processes. Therefore, quantitative analysis of cytochrome P450 metabolites of AA, including hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatreinoic acids (EETs), and dihydroxyeicosatrienoic acids (DHETs) can provide crucial information to uncover underlying mechanisms of cytochrome P450 metabolites of AA related diseases. Herein, we developed a highly sensitive method to identify and quantify HETEs, EETs, and DHETs in lipid extracts of biological samples based on stable isotope probe labeling coupled with ultra high-performance liquid chromatography/mass spectrometry. To this end, a pair of stable isotope probes, 2-dimethylaminoethylamine (DMED) and d4-2-dimethylaminoethylamine (d4-DMED), were utilized to facilely label eicosanoids. The heavy labeled eicosanoid standards were prepared and used as internal standards for quantification to minimize the matrix and ion suppression effects in mass spectrometry analysis. In addition, the detection sensitivities of DMED labeled eicosanoids improved by 3-104 folds in standard solution and 5-138 folds in serum matrix compared with unlabeled analytes. Moreover, a good separation of eicosanoids isomers was achieved upon DMED labeling. The established method provided substantial sensitivity (limit of quantification at sub-picogram), high specificity, and broad linear dynamics range (3 orders of magnitude). We further quantified cytochrome P450 metabolites of AA in rat liver, heart, brain tissues and human serum using the developed method. The results showed that 19 eicosanoids could be distinctly detected and the contents of 11-, 15-, 16-, 20-HETE, 5,6-EET, and 14,15-EET in type 2 diabetes mellitus patients and 5-, 11-, 12-, 15-, 16-, 20-HETE, 8,9-EET, and 5,6-DHET in myeloid leukemia patients had significant changes

  3. Analysis of multi-site drug-protein interactions by high-performance affinity chromatography: Binding by glimepiride to normal or glycated human serum albumin.

    PubMed

    Matsuda, Ryan; Li, Zhao; Zheng, Xiwei; Hage, David S

    2015-08-21

    High-performance affinity chromatography (HPAC) was used in a variety of formats to examine multi-site interactions between glimepiride, a third-generation sulfonylurea drug, and normal or in vitro glycated forms of the transport protein human serum albumin (HSA). Frontal analysis revealed that glimepiride interacts with normal HSA and glycated HSA at a group of high affinity sites (association equilibrium constant, or Ka, 9.2-11.8×10(5)M(-1) at pH 7.4 and 37°C) and a group of lower affinity regions (Ka, 5.9-16×10(3)M(-1)). Zonal elution competition studies were designed and carried out in both normal- and reversed-role formats to investigate the binding by this drug at specific sites. These experiments indicated that glimepiride was interacting at both Sudlow sites I and II. Allosteric effects were also noted with R-warfarin at Sudlow site I and with tamoxifen at the tamoxifen site on HSA. The binding at Sudlow site I had a 2.1- to 2.3-fold increase in affinity in going from normal HSA to the glycated samples of HSA. There was no significant change in the affinity for glimepiride at Sudlow site II in going from normal HSA to a moderately glycated sample of HSA, but a slight decrease in affinity was seen in going to a more highly glycated HSA sample. These results demonstrated how various HPAC-based methods can be used to profile and characterize multi-site binding by a drug such as glimepiride to a protein and its modified forms. The information obtained from this study should be useful in providing a better understanding of how drug-protein binding may be affected by glycation and of how separation and analysis methods based on HPAC can be employed to study systems with complex interactions or that involve modified proteins.

  4. Analysis of multi-site drug-protein interactions by high-performance affinity chromatography: Binding by glimepiride to normal or glycated human serum albumin.

    PubMed

    Matsuda, Ryan; Li, Zhao; Zheng, Xiwei; Hage, David S

    2015-08-21

    High-performance affinity chromatography (HPAC) was used in a variety of formats to examine multi-site interactions between glimepiride, a third-generation sulfonylurea drug, and normal or in vitro glycated forms of the transport protein human serum albumin (HSA). Frontal analysis revealed that glimepiride interacts with normal HSA and glycated HSA at a group of high affinity sites (association equilibrium constant, or Ka, 9.2-11.8×10(5)M(-1) at pH 7.4 and 37°C) and a group of lower affinity regions (Ka, 5.9-16×10(3)M(-1)). Zonal elution competition studies were designed and carried out in both normal- and reversed-role formats to investigate the binding by this drug at specific sites. These experiments indicated that glimepiride was interacting at both Sudlow sites I and II. Allosteric effects were also noted with R-warfarin at Sudlow site I and with tamoxifen at the tamoxifen site on HSA. The binding at Sudlow site I had a 2.1- to 2.3-fold increase in affinity in going from normal HSA to the glycated samples of HSA. There was no significant change in the affinity for glimepiride at Sudlow site II in going from normal HSA to a moderately glycated sample of HSA, but a slight decrease in affinity was seen in going to a more highly glycated HSA sample. These results demonstrated how various HPAC-based methods can be used to profile and characterize multi-site binding by a drug such as glimepiride to a protein and its modified forms. The information obtained from this study should be useful in providing a better understanding of how drug-protein binding may be affected by glycation and of how separation and analysis methods based on HPAC can be employed to study systems with complex interactions or that involve modified proteins. PMID:26189669

  5. Analysis of Multi-Site Drug-Protein Interactions by High-Performance Affinity Chromatography: Binding by Glimepiride to Normal or Glycated Human Serum Albumin

    PubMed Central

    Matsuda, Ryan; Li, Zhao; Zheng, Xiwei; Hage, David S.

    2015-01-01

    High-performance affinity chromatography (HPAC) was used in a variety of formats to examine multi-site interactions between glimepiride, a third-generation sulfonylurea drug, and normal or in vitro glycated forms of the transport protein human serum albumin (HSA). Frontal analysis revealed that glimepiride interacts with normal HSA and glycated HSA at a group of high affinity sites (association equilibrium constant, or Ka, 9.2–11.8 × 105 M−1 at pH 7.4 and 37°C) and a group of lower affinity regions (Ka, 5.9–16.2 × 103 M−1). Zonal elution competition studies were designed and carried out in both normal- and reversed-role formats to investigate the binding by this drug at specific sites. These experiments indicated that glimepiride was interacting at both Sudlow sites I and II. Allosteric effects were also noted with R-warfarin at Sudlow site I and with tamoxifen at the tamoxifen site on HSA. The binding at Sudlow site I had a 2.1- to 2.3-fold increase in affinity in going from normal HSA to the glycated samples of HSA. There was no significant change in the affinity for glimepiride at Sudlow site II in going from normal HSA to a moderately glycated sample of HSA, but a slight decrease in affinity was seen in going to a more highly glycated HSA sample. These results demonstrated how various HPAC-based methods can be used to profile and characterize multi-site binding by a drug such as glimepiride to a protein and its modified forms. The information obtained from this study should be useful in providing a better understanding of how drug-protein binding may be affected by glycation and of how separation and analysis methods based on HPAC can be employed to study systems with complex interactions or that involve modified proteins. PMID:26189669

  6. HIGH-PERFORMANCE COATING MATERIALS

    SciTech Connect

    SUGAMA,T.

    2007-01-01

    Corrosion, erosion, oxidation, and fouling by scale deposits impose critical issues in selecting the metal components used at geothermal power plants operating at brine temperatures up to 300 C. Replacing these components is very costly and time consuming. Currently, components made of titanium alloy and stainless steel commonly are employed for dealing with these problems. However, another major consideration in using these metals is not only that they are considerably more expensive than carbon steel, but also the susceptibility of corrosion-preventing passive oxide layers that develop on their outermost surface sites to reactions with brine-induced scales, such as silicate, silica, and calcite. Such reactions lead to the formation of strong interfacial bonds between the scales and oxide layers, causing the accumulation of multiple layers of scales, and the impairment of the plant component's function and efficacy; furthermore, a substantial amount of time is entailed in removing them. This cleaning operation essential for reusing the components is one of the factors causing the increase in the plant's maintenance costs. If inexpensive carbon steel components could be coated and lined with cost-effective high-hydrothermal temperature stable, anti-corrosion, -oxidation, and -fouling materials, this would improve the power plant's economic factors by engendering a considerable reduction in capital investment, and a decrease in the costs of operations and maintenance through optimized maintenance schedules.

  7. Combination of quantitative analysis and chemometric analysis for the quality evaluation of three different frankincenses by ultra high performance liquid chromatography and quadrupole time of flight mass spectrometry.

    PubMed

    Zhang, Chao; Sun, Lei; Tian, Run-tao; Jin, Hong-yu; Ma, Shuang-Cheng; Gu, Bing-ren

    2015-10-01

    Frankincense has gained increasing attention in the pharmaceutical industry because of its pharmacologically active components such as boswellic acids. However, the identity and overall quality evaluation of three different frankincense species in different Pharmacopeias and the literature have less been reported. In this paper, quantitative analysis and chemometric evaluation were established and applied for the quality control of frankincense. Meanwhile, quantitative and chemometric analysis could be conducted under the same analytical conditions. In total 55 samples from four habitats (three species) of frankincense were collected and six boswellic acids were chosen for quantitative analysis. Chemometric analyses such as similarity analysis, hierarchical cluster analysis, and principal component analysis were used to identify frankincense of three species to reveal the correlation between its components and species. In addition, 12 chromatographic peaks have been tentatively identified explored by reference substances and quadrupole time-of-flight mass spectrometry. The results indicated that the total boswellic acid profiles of three species of frankincense are similar and their fingerprints can be used to differentiate between them. PMID:26228790

  8. Chemometrics-assisted high performance liquid chromatography-diode array detection strategy to solve varying interfering patterns from different chromatographic columns and sample matrices for beverage analysis.

    PubMed

    Yin, Xiao-Li; Wu, Hai-Long; Gu, Hui-Wen; Hu, Yong; Wang, Li; Xia, Hui; Xiang, Shou-Xia; Yu, Ru-Qin

    2016-02-26

    This work reports a chemometrics-assisted high performance liquid chromatography-diode array detection (HPLC-DAD) strategy to solve varying interfering patterns from different chromatographic columns and sample matrices for the rapid simultaneous determination of six synthetic colorants in five kinds of beverages with little sample pretreatment. The investigation was performed using two types of LC columns under the same elution conditions. Although analytes using different columns have different co-elution patterns that appear more seriously in complex backgrounds, all colorants were properly resolved by alternating trilinear decomposition (ATLD) method and accurate chromatographic elution profiles, spectral profiles as well as relative concentrations were obtained. The results were confirmed by those obtained from traditional HPLC-UV method at a particular wavelength and the results of both methods were consistent with each other. All results demonstrated that the proposed chemometrics-assisted HPLC-DAD method is accurate, economical and universal, and can be promisingly applied to solve varying interfering patterns from different chromatographic columns and sample matrices for the analysis of complex food samples.

  9. Ultra performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry for high-sensitivity and high-throughput analysis of U.S. Environmental Protection Agency 16 priority pollutants polynuclear aromatic hydrocarbons.

    PubMed

    Cai, Sheng-Suan; Syage, Jack A; Hanold, Karl A; Balogh, Michael P

    2009-03-15

    In this work, we demonstrate the utility of ultra performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry (UPLC-APPI-MS/MS) for high-sensitivity and high-throughput analysis of United States Environmental Protection Agency (U.S. EPA) 16 priority pollutants polycyclic aromatic hydrocarbons (PAHs). Analyses were performed on a Waters Acquity-TQD equipped with Syagen's PhotoMate APPI source. All 16 PAHs were analyzed on column in approximately 3.5 min with excellent chromatographic separation for all PAH isomers and with low picogram detection limits on column for all analytes using chlorobenzene as a dopant. Dynamic linear ranges were evaluated and found to cover at least 3-4 orders of magnitude. In comparison with the existing U.S. EPA methods, this approach improves instrument sample throughput by at least 10-fold.

  10. Quantitative analysis of phenylalanine, tyrosine, tryptophan and kynurenine in rat model for tauopathies by ultra-high performance liquid chromatography with fluorescence and mass spectrometry detection.

    PubMed

    Galba, Jaroslav; Michalicova, Alena; Parrak, Vojtech; Novak, Michal; Kovac, Andrej

    2016-01-01

    We developed and validated a simple and sensitive ultra-high performance liquid chromatography (UHPLC) method for the analysis of phenylalanine (Phe), tyrosine (Tyr), tryptophan (Trp) and kynurenine (Kyn) in rat plasma. Analytes were separated on Acquity UPLC HSS T3 column (2.1 mm×50 mm, 1.8 μm particle size) using a 4 min ammonium acetate (pH 5) gradient and detected by fluorescence and positive ESI mass spectrometry. Sample preparation involved dilution of plasma, deproteinization by trichloroacetic acid and centrifugation. The procedure was validated in compliance with the FDA guideline. The limits of quantification (LOQ) were 0.3 μM for Kyn and from 1.5 to 3 μM for Phe, Tyr, Trp. The method showed excellent linearity with regression coefficients higher than 0.99. The accuracy was within the range of 86-108%. The inter-day precision (n=5 days), expressed as % RSD, was in the range 1-13%. The benefit of using UHPLC is a short analysis period and thus, a very good sample throughput. Using this method, we analyzed plasma samples and detected significant changes of Kyn and Phe in transgenic rat model for tauopathies.

  11. Comparison of performance of object-based image analysis techniques available in open source software (Spring and Orfeo Toolbox/Monteverdi) considering very high spatial resolution data

    NASA Astrophysics Data System (ADS)

    Teodoro, Ana C.; Araujo, Ricardo

    2016-01-01

    The use of unmanned aerial vehicles (UAVs) for remote sensing applications is becoming more frequent. However, this type of information can result in several software problems related to the huge amount of data available. Object-based image analysis (OBIA) has proven to be superior to pixel-based analysis for very high-resolution images. The main objective of this work was to explore the potentialities of the OBIA methods available in two different open source software applications, Spring and OTB/Monteverdi, in order to generate an urban land cover map. An orthomosaic derived from UAVs was considered, 10 different regions of interest were selected, and two different approaches were followed. The first one (Spring) uses the region growing segmentation algorithm followed by the Bhattacharya classifier. The second approach (OTB/Monteverdi) uses the mean shift segmentation algorithm followed by the support vector machine (SVM) classifier. Two strategies were followed: four classes were considered using Spring and thereafter seven classes were considered for OTB/Monteverdi. The SVM classifier produces slightly better results and presents a shorter processing time. However, the poor spectral resolution of the data (only RGB bands) is an important factor that limits the performance of the classifiers applied.

  12. Analysis of quaternary ammonium and phosphonium ionic liquids by reversed-phase high-performance liquid chromatography with charged aerosol detection and unified calibration.

    PubMed

    Stojanovic, Anja; Lämmerhofer, Michael; Kogelnig, Daniel; Schiesel, Simone; Sturm, Martin; Galanski, Markus; Krachler, Regina; Keppler, Bernhard K; Lindner, Wolfgang

    2008-10-31

    Several hydrophobic ionic liquids (ILs) based on long-chain aliphatic ammonium- and phosphonium cations and selected aromatic anions were analyzed by reversed-phase high-performance liquid chromatography (RP-HPLC) employing trifluoroacetic acid as ion-pairing additive to the acetonitrile-containing mobile phase and adopting a step-gradient elution mode. The coupling of charged aerosol detection (CAD) for the non-chromophoric aliphatic cations with diode array detection (DAD) for the aromatic anions allowed their simultaneous analysis in a set of new ILs derived from either tricaprylmethylammonium chloride (Aliquat 336) and trihexyltetradecylphosphonium chloride as precursors. Aliquat 336 is a mix of ammonium cations with distinct aliphatic chain lengths. In the course of the studies it turned out that CAD generates an identical detection response for all the distinct aliphatic cations. Due to lack of single component standards of the individual Aliquat 336 cation species, a unified calibration function was established for the quantitative analysis of the quaternary ammonium cations of the ILs. The developed method was validated according to ICH guidelines, which confirmed the validity of the unified calibration. The application of the method revealed molar ratios of cation to anion close to 1 indicating a quantitative exchange of the chloride ions of the precursors by the various aromatic anions in the course of the synthesis of new ILs. Anomalies of CAD observed for the detection of some aromatic anions (thiosalicylate and benzoate) are discussed.

  13. Fast analysis of 29 polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs with ultra-high performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry

    PubMed Central

    Lung, Shih-Chun Candice; Liu, Chun-Hu

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs are ubiquitous in the environment. Some of them are probable carcinogens and some are source markers. This work presents an ultra-high performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry (UHPLC-APPI-MS/MS) method for simultaneous analysis of 20 PAHs and nine nitro-PAHs. These compounds are separated in 15 minutes in the positive mode and 11 minutes in the negative mode, one half of GC/MS analysis time. Two pairs of precursor/product ions are offered, which is essential for confirmation. This method separates and quantifies benzo[a]pyrene (the most toxic PAHs) and non-priority benzo[e]pyrene (isomers, little toxicity) to avoid overestimation of toxin levels, demonstrating its importance for health-related researches. With 0.5% 2,4-difluoroanisole in chlorobenzene as the dopant, limits of detection of PAHs except acenaphthylene and those of nitro-PAHs except 2-nitrofluoranthene are below 10 pg and 3 pg, respectively, mostly lower than or comparable to those reported using LC-related systems. The responses were linear over two orders of magnitude with fairly good accuracy and precision. Certified reference materials and real aerosol samples were analyzed to demonstrate its applicability. This fast, sensitive, and reliable method is the first UHPLC-APPI-MS/MS method capable of simultaneously analyzing 29 environmentally and toxicologically important PAHs and nitro-PAHs. PMID:26265155

  14. Analysis of anthelmintics in surface water by ultra high performance liquid chromatography coupled to quadrupole linear ion trap tandem mass spectrometry.

    PubMed

    Zrnčić, Mirta; Gros, Meritxell; Babić, Sandra; Kaštelan-Macan, Marija; Barcelo, Damia; Petrović, Mira

    2014-03-01

    A method based on ultra high performance liquid chromatography coupled to quadrupole linear ion trap mass spectrometry (UHPLC-QqLIT-MS) has been developed to investigate occurrence of 10 anthelmintic drugs from different structural groups (moxidectin, flubendazole, fenbendazole, levamisol, mebendazole, oxibendazole, albendazole, triclabendazole, febantel and praziquantel) in surface water. Analytes were pre-concentrated by solid phase extraction (SPE) using hydrophilic-lipophilic polymeric based sorbent. Quantification of investigated analytes was done using deuterated compounds as internal standards in order to minimize matrix effect. Analyte recoveries from spiked samples at two concentration levels were above 75% for most of the analytes. The main advantages of developed method are fast separation using UHPLC and therefore short analysis time, combined with good sensitivity which is demonstrated by low ngL(-1) detection limits. The developed method was applied for analysis of anthelmintics in the Llobregat River (NE Spain) and its main tributaries (rivers Anoia and Cardener). Eight out of ten anthelmintics were detected in all analyzed samples with the concentrations in low ngL(-1) level. The method fills the gap on analytical methodologies for determination of anthelmintic drugs in the environment.

  15. Rapid analysis of charge variants of monoclonal antibodies using non-linear salt gradient in cation-exchange high performance liquid chromatography.

    PubMed

    Joshi, Varsha; Kumar, Vijesh; Rathore, Anurag S

    2015-08-01

    A method is proposed for rapid development of a short, analytical cation exchange high performance liquid chromatography method for analysis of charge heterogeneity in monoclonal antibody products. The parameters investigated and optimized include pH, shape of elution gradient and length of the column. It is found that the most important parameter for development of a shorter method is the choice of the shape of elution gradient. In this paper, we propose a step by step approach to develop a non-linear sigmoidal shape gradient for analysis of charge heterogeneity for two different monoclonal antibody products. The use of this gradient not only decreases the run time of the method to 4min against the conventional method that takes more than 40min but also the resolution is retained. Superiority of the phosphate gradient over sodium chloride gradient for elution of mAbs is also observed. The method has been successfully evaluated for specificity, sensitivity, linearity, limit of detection, and limit of quantification. Application of this method as a potential at-line process analytical technology tool has been suggested.

  16. High-speed counter-current chromatography coupled online to high performance liquid chromatography-diode array detector-mass spectrometry for purification, analysis and identification of target compounds from natural products.

    PubMed

    Liang, Xuejuan; Zhang, Yuping; Chen, Wei; Cai, Ping; Zhang, Shuihan; Chen, Xiaoqin; Shi, Shuyun

    2015-03-13

    A challenge in coupling high-speed counter-current chromatography (HSCCC) online with high performance liquid chromatography (HPLC) for purity analysis was their time incompatibility. Consequently, HSCCC-HPLC was conducted by either controlling HPLC analysis time and HSCCC flow rate or using stop-and-go scheme. For natural products containing compounds with a wide range of polarities, the former would optimize experimental conditions, while the latter required more time. Here, a novel HSCCC-HPLC-diode array detector-mass spectrometry (HSCCC-HPLC-DAD-MS) was developed for undisrupted purification, analysis and identification of multi-compounds from natural products. Two six-port injection valves and a six-port switching valve were used as interface for collecting key HSCCC effluents alternatively for HPLC-DAD-MS analysis and identification. The ethyl acetate extract of Malus doumeri was performed on the hyphenated system to verify its efficacy. Five main flavonoids, 3-hydroxyphloridzin (1), phloridzin (2), 4',6'-dihydroxyhydrochalcone-2'-O-β-D-glucopyranoside (3, first found in M. doumeri), phloretin (4), and chrysin (5), were purified with purities over 99% by extrusion elution and/or stepwise elution mode in two-step HSCCC, and 25mM ammonium acetate solution was selected instead of water to depress emulsification in the first HSCCC. The online system shortened manipulation time largely compared with off-line analysis procedure and stop-and-go scheme. The results indicated that the present method could serve as a simple, rapid and effective way to achieve target compounds with high purity from natural products.

  17. Statistical properties of high performance cesium standards

    NASA Technical Reports Server (NTRS)

    Percival, D. B.

    1973-01-01

    The intermediate term frequency stability of a group of new high-performance cesium beam tubes at the U.S. Naval Observatory were analyzed from two viewpoints: (1) by comparison of the high-performance standards to the MEAN(USNO) time scale and (2) by intercomparisons among the standards themselves. For sampling times up to 5 days, the frequency stability of the high-performance units shows significant improvement over older commercial cesium beam standards.

  18. On-line desalting and carbohydrate analysis for immobilized enzyme hydrolysis of waste cellulosic biomass by column-switching high-performance liquid chromatography.

    PubMed

    Cheng, Cheanyeh; Chen, Chi-Sung; Hsieh, Pei-Hsin

    2010-04-01

    An innovative green column-switching high-performance liquid chromatographic (HPLC) technique was developed by coupling traditional and Pb(2+) ion-exclusion columns to study enzyme hydrolysis components of waste cellulosic biomass. Pure water was used as the mobile phase to separate neutral polar analytes in high salt content solution. The column-switching HPLC-RI was connected on-line to the immobilized enzyme reactor for successive on-line desalting and simultaneous analysis of six carbohydrates (cellobiose, glucose, xylose, galactose, mannose, and arabinose) in the hydrolysate of waste paper and waste tree branch by incorporating the heart-cut and the elution-time-difference techniques. Six internal standard calibration curves in the linear concentration range of 0-2,000 microg mL(-1) were prepared. Xylitol was used as the internal standard to give excellent linear correlation coefficients (0.9984-0.9999). The limits of detection and quantification for cellobiose, glucose, xylose, galactose, mannose, and arabinose varied between 0.12-4.88 and 0.40-16.3 microg mL(-1), respectively, with an accuracy of 90-102% and a precision of 0.1-7.8%. Cellulose and hemicellulose contents were higher in waste paper than in waste tree branch. PMID:20181346

  19. Porous molecularly imprinted monolithic capillary column for on-line extraction coupled to high-performance liquid chromatography for trace analysis of antimicrobials in food samples.

    PubMed

    Zhang, Qianchun; Xiao, Xiaohua; Li, Gongke

    2014-06-01

    A novel porous molecularly imprinted monolithic capillary column (MIMCC) based on ternary porogen was synthesized by in situ technique with sulfaquinoxaline as the template molecule. The characteristics of the MIMCC were investigated by scanning electron microscopy, infrared spectrum, thermogravimetric analysis and solvent resistance test. The saturated adsorption amount of sulfaquinoxaline on MIMCC was 2.7 times over that on the non-imprinted monolithic capillary column (NIMCC). The MIMCC also exhibited good enrichment ability to its analogs and the enrichment factors were 46-211 for five antimicrobials. High permeability and imprinting factors as well as good stability, reproducibility and long lifetime were obtained. An on-line method based on MIMCC solid-phase microextraction coupled with high-performance liquid chromatography was developed for the determination of trace antimicrobials in complex samples. The good linearity for sulfametoxydiazine, sulamethoxazole and sulfaquinoxaline was 0.05-10 µg/L, the limits of detection (LODs) were 10.0-14.0 ng/L. The linear range for mequindox and quinocetone were 0.10-10.0 µg/L, the LODs were 20.0-27.0 ng/L respectively. The recoveries were 71.0-108.2% with relative standard deviation of 1.6-8.5%, correspondingly. The results showed that MIMCC could effectively enrich antimicrobials from complex matrices. The on-line method based on MIMCC and HPLC was selective, sensitive and convenient for trace determination of antimicrobials in complex samples. PMID:24725865

  20. New strategy for the biosorption of atrazine after magnetic solid-phase extraction from water followed by high-performance liquid chromatography analysis.

    PubMed

    Haeri, Seyed Ammar; Abbasi, Shahryar

    2016-07-01

    We describe a rapid and simple microextraction of atrazine from water samples. This method is based on the use of magnetic nanoparticles as sorbents and bioaggregates that are applied to the extraction and preconcentration of atrazine. The resulting magnetic nanoparticles possess a fast adsorption kinetics and high adsorption capacity. Bioaggregates made up of rhaminolipid biosurfactant were assessed as a new strategy for the sample treatment. The extractant was obtained from magnetic nanoparticles using the magnetic solid-phase extraction method. Then the target analyte was rapidly transferred from the sorbent surface to bioaggregates, which have a low toxicity and are green and ecofriendly. Finally, the extract is centrifuged and transferred to micro-syringe for analysis by high-performance liquid chromatography. Experimental parameters affecting the extraction efficiency were studied and optimized. Under optimum conditions the enrichment factor was 268. The linear dynamic range and limit of detection were 0.1-50 and 0.033 μg/L, respectively. The relative standard deviation for six replicate measurements was 5.3%. The results demonstrate good applicability of biosorption-assisted magnetic solid-phase extraction method for the determination of atrazine from water samples. PMID:27233234

  1. High-temperature EBPR process: the performance, analysis of PAOs and GAOs and the fine-scale population study of Candidatus "Accumulibacter phosphatis".

    PubMed

    Ong, Ying Hui; Chua, Adeline Seak May; Fukushima, Toshikazu; Ngoh, Gek Cheng; Shoji, Tadashi; Michinaka, Atsuko

    2014-11-01

    The applicability of the enhanced biological phosphorus removal (EBPR) process for the removal of phosphorus in warm climates is uncertain due to frequent reports of EBPR deterioration at temperature higher than 25 °C. Nevertheless, a recent report on a stable and efficient EBPR process at 28 °C has inspired the present study to examine the performance of EBPR at 24 °C-32 °C, as well as the PAOs and GAOs involved, in greater detail. Two sequencing batch reactors (SBRs) were operated for EBPR in parallel at different temperatures, i.e., SBR-1 at 28 °C and SBR-2 first at 24 °C and subsequently at 32 °C. Both SBRs exhibited high phosphorus removal efficiencies at all three temperatures and produced effluents with phosphorus concentrations less than 1.0 mg/L during the steady state of reactor operation. Real-time quantitative polymerase chain reaction (qPCR) revealed Accumulibacter-PAOs comprised 64% of the total bacterial population at 24 °C, 43% at 28 °C and 19% at 32 °C. Based on fluorescent in situ hybridisation (FISH), the abundance of Competibacter-GAOs at both 24 °C and 28 °C was rather low (<10%), while it accounted for 40% of the total bacterial population at 32 °C. However, the smaller Accumulibacter population and larger population of Competibacter at 32 °C did not deteriorate the phosphorus removal performance. A polyphosphate kinase 1 (ppk1)-based qPCR analysis on all studied EBPR processes detected only Accumulibacter clade IIF. The Accumulibacter population shown by 16S rRNA and ppk1 was not significantly different. This finding confirmed the existence of single clade IIF in the processes and the specificity of the clade IIF primer sets designed in this study. Habitat filtering related to temperature could have contributed to the presence of a unique clade. The clade IIF was hypothesised to be able to perform the EBPR activity at high temperatures. The clade's robustness most likely helps it to fit the high-temperature EBPR

  2. High-temperature EBPR process: the performance, analysis of PAOs and GAOs and the fine-scale population study of Candidatus "Accumulibacter phosphatis".

    PubMed

    Ong, Ying Hui; Chua, Adeline Seak May; Fukushima, Toshikazu; Ngoh, Gek Cheng; Shoji, Tadashi; Michinaka, Atsuko

    2014-11-01

    The applicability of the enhanced biological phosphorus removal (EBPR) process for the removal of phosphorus in warm climates is uncertain due to frequent reports of EBPR deterioration at temperature higher than 25 °C. Nevertheless, a recent report on a stable and efficient EBPR process at 28 °C has inspired the present study to examine the performance of EBPR at 24 °C-32 °C, as well as the PAOs and GAOs involved, in greater detail. Two sequencing batch reactors (SBRs) were operated for EBPR in parallel at different temperatures, i.e., SBR-1 at 28 °C and SBR-2 first at 24 °C and subsequently at 32 °C. Both SBRs exhibited high phosphorus removal efficiencies at all three temperatures and produced effluents with phosphorus concentrations less than 1.0 mg/L during the steady state of reactor operation. Real-time quantitative polymerase chain reaction (qPCR) revealed Accumulibacter-PAOs comprised 64% of the total bacterial population at 24 °C, 43% at 28 °C and 19% at 32 °C. Based on fluorescent in situ hybridisation (FISH), the abundance of Competibacter-GAOs at both 24 °C and 28 °C was rather low (<10%), while it accounted for 40% of the total bacterial population at 32 °C. However, the smaller Accumulibacter population and larger population of Competibacter at 32 °C did not deteriorate the phosphorus removal performance. A polyphosphate kinase 1 (ppk1)-based qPCR analysis on all studied EBPR processes detected only Accumulibacter clade IIF. The Accumulibacter population shown by 16S rRNA and ppk1 was not significantly different. This finding confirmed the existence of single clade IIF in the processes and the specificity of the clade IIF primer sets designed in this study. Habitat filtering related to temperature could have contributed to the presence of a unique clade. The clade IIF was hypothesised to be able to perform the EBPR activity at high temperatures. The clade's robustness most likely helps it to fit the high-temperature EBPR

  3. High performance carbon nanocomposites for ultracapacitors

    DOEpatents

    Lu, Wen

    2012-10-02

    The present invention relates to composite electrodes for electrochemical devices, particularly to carbon nanotube composite electrodes for high performance electrochemical devices, such as ultracapacitors.

  4. Method of making a high performance ultracapacitor

    DOEpatents

    Farahmandi, C. Joseph; Dispennette, John M.

    2000-07-26

    A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

  5. Acrylamide-functionalized graphene micro-solid-phase extraction coupled to high-performance liquid chromatography for the online analysis of trace monoamine acidic metabolites in biological samples.

    PubMed

    Yang, Xiaoting; Hu, Yufei; Li, Gongke; Zhang, Zhuomin

    2015-05-01

    Monoamine acidic metabolites in biological samples are essential biomarkers for the diagnosis of neurological disorders. In this work, acrylamide-functionalized graphene adsorbent was successfully synthesized by a chemical functionalization method and was packed in a homemade polyether ether ketone micro column as a micro-solid-phase extraction unit. This micro-solid-phase extraction unit was directly coupled to high-performance liquid chromatography to form an online system for the separation and analysis of three monoamine acidic metabolites including homovanillic acid, 5-hydroxyindole-3-acetic acid, and 3,4-dihydroxyphenylacetic acid in human urine and plasma. The online system showed high stability, permeability, and adsorption capacity toward target metabolites. The saturated extraction amount of this online system was 213.1, 107.0, and 153.4 ng for homovanillic acid, 5-hydroxyindole-3-acetic acid, and 3,4-dihydroxyphenylacetic acid, respectively. Excellent detection limits were achieved in the range of 0.08-0.25 μg/L with good linearity and reproducibility. It was interesting that three targets in urine and plasma could be actually quantified to be 0.94-3.93 μg/L in plasma and 7.15-19.38 μg/L in urine. Good recoveries were achieved as 84.8-101.4% for urine and 77.8-95.1% for plasma with the intra- and interday relative standard deviations less than 9.3 and 10.3%, respectively. This method shows great potential for online analysis of trace monoamine acidic metabolites in biological samples.

  6. Fast analysis of curcuminoids from turmeric (Curcuma longa L.) by high-performance liquid chromatography using a fused-core column.

    PubMed

    Osorio-Tobón, J Felipe; Carvalho, Pedro I N; Barbero, Gerardo Fernández; Nogueira, Gislaine Chrystina; Rostagno, Mauricio Ariel; Meireles, Maria Angela de Almeida

    2016-06-01

    The recent development of fused-core technology in HPLC columns is enabling faster and highly efficient separations. This technology was evaluated for the development of a fast method for the analysis of main curcuminoids (curcumin, demethoxycurcumin and bisdemethoxycurcumin) present in extracts of turmeric (Curcuma longa L.). A step-by-step strategy was used to optimize temperature (40-55 °C), flow rate (1.0-2.5 mL min(-1)), mobile phase composition and equilibration time (1-5 min). A gradient method was developed using acidified water and acetonitrile combined with high column temperature (55 °C) and flow rate (2.5 mL min(-1)). Optimized conditions provided a method for the separation of these three curcuminoids in approximately 1.3 min with a total analysis time (sample-to-sample) of 7 min, including the clean-up and the re-equilibration of the column. Evaluation of chromatographic performance revealed excellent intraday and interday reproducibility (>99%), resolution (>2.23), selectivity (>1.12), peak symmetry (1.24-1.42) while presenting low limits of detection (<0.40 mg L(-1)) and quantification (<1.34 mg L(-1)). The robustness of the method was calculated according to the concentration/dilution of the sample and the injection volume. Several combinations of methanol and ethanol with water as sample solvents were evaluated and the best chromatographic results and extraction rate were obtained using 100% methanol. Finally, the developed method was validated with different extracts of turmeric rhizome and products that use turmeric in their formulation.

  7. Method optimization and quality assurance in speciation analysis using high performance liquid chromatography with detection by inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Larsen, Erik H.

    1998-02-01

    Achievement of optimum selectivity, sensitivity and robustness in speciation analysis using high performance liquid chromatography (HPLC) with inductively coupled mass spectrometry (ICP-MS) detection requires that each instrumental component is selected and optimized with a view to the ideal operating characteristics of the entire hyphenated system. An isocratic HPLC system, which employs an aqueous mobile phase with organic buffer constituents, is well suited for introduction into the ICP-MS because of the stability of the detector response and high degree of analyte sensitivity attained. Anion and cation exchange HPLC systems, which meet these requirements, were used for the seperation of selenium and arsenic species in crude extracts of biological samples. Furthermore, the signal-to-noise ratios obtained for these incompletely ionized elements in the argon ICP were further enhanced by a factor of four by continously introducing carbon as methanol via the mobile phase into the ICP. Sources of error in the HPLC system (column overload), in the sample introduction system (memory by organic solvents) and in the ICP-MS (spectroscopic interferences) and their prevention are also discussed. The optimized anion and cation exchange HPLC-ICP-MS systems were used for arsenic speciation in contaminated ground water and in an in-house shrimp reference sample. For the purpose of verification, HPLC coupled with tandem mass spectrometry with electrospray ionization was additionally used for arsenic speciation in the shrimp sample. With this analytical technique the HPLC retention time in combination with mass analysis of the molecular ions and their collision-induced fragments provide almost conclusive evidence of the identity of the analyte species. The speciation methods are validated by establishing a mass balance of the analytes in each fraction of the extraction procedure, by recovery of spikes and by employing and comparing independent techniques. The urgent need for

  8. Ultra high-performance liquid chromatography-tandem mass spectrometry for the simultaneous analysis of asparagine, sugars, and acrylamide in Maillard reactions.

    PubMed

    Zhang, Yu; Ren, Yiping; Jiao, Jingjing; Li, Dong; Zhang, Ying

    2011-05-01

    We developed an automated microwave digestion labstation (MDL) combined with ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method under the control of positive-negative ion switching as a robust kinetic study tool for rapid and simultaneous quantification of asparagine, glucose, fructose, and acrylamide in Maillard reaction products. Maillard reactions were conducted in a potato model via MDL. The two-step simple pretreatment procedures included the addition of isotope internal standards (15)N(2)-asparagine, (13)C(6)-glucose, and D(3)-acrylamide, followed by appropriate dilution with the mobile phase and filtration. Analytes were separated on a Hypercarb column and monitored by MS/MS. Study of matrix effects indicated Maillard reaction products induce an ionization suppression of both positive and negative precursor ions, but quantitative results are corrected through the use of isotopically labeled internal standards. Using this method, the limit of detection (LOD) and limit of quantification (LOQ) ranges of all analytes were calculated as 0.04-0.6 and 0.1-1.1 μM, respectively. Excellent repeatability (RSD < 9.6%) and acceptable within-laboratory reproducibility (RSD < 9.2%) substantially supported the use of this method for sample analysis. The present kinetic tools, with 10-50 min mimic of Maillard reactions and short instrumental run time (5.5 min per sample), were successfully validated and applied to simultaneous determination of acrylamide and its precursors and intermediates during Maillard reactions and kinetic elucidation. Furthermore, current tools of MDL combined with simple sample treatment procedures and UHPLC-MS/MS analysis reduce sample analysis time and labor in the kinetic study. PMID:21462916

  9. A Theoretical Structure of High School Concert Band Performance

    ERIC Educational Resources Information Center

    Bergee, Martin J.

    2015-01-01

    This study used exploratory (EFA) and confirmatory factor analysis (CFA) to verify a theoretical structure for high school concert band performance and to test that structure for viability, generality, and invariance. A total of 101 university students enrolled in two different bands rated two high school band performances (a "first"…

  10. Strategy Guideline: High Performance Residential Lighting

    SciTech Connect

    Holton, J.

    2012-02-01

    The Strategy Guideline: High Performance Residential Lighting has been developed to provide a tool for the understanding and application of high performance lighting in the home. The high performance lighting strategies featured in this guide are drawn from recent advances in commercial lighting for application to typical spaces found in residential buildings. This guide offers strategies to greatly reduce lighting energy use through the application of high quality fluorescent and light emitting diode (LED) technologies. It is important to note that these strategies not only save energy in the home but also serve to satisfy the homeowner's expectations for high quality lighting.

  11. Rapid isolation of biomarkers for compound specific radiocarbon dating using high-performance liquid chromatography and flow injection analysis-atmospheric pressure chemical ionisation mass spectrometry.

    PubMed

    Smittenberg, Rienk H; Hopmans, Ellen C; Schouten, Stefan; Sinninghe Damsté, Jaap S

    2002-11-29

    Repeated semi-preparative normal-phase HPLC was performed to isolate selected biomarkers from sediment extracts for radiocarbon analysis. Flow injection analysis-mass spectrometry was used for rapid analysis of collected fractions to evaluate the separation procedure, taking only 1 min per fraction. In this way 100-1000 microg of glycerol dialkyl glycerol tetraethers, sterol fractions and chlorophyll-derived phytol were isolated from typically 100 g of marine sediment, i.e., in sufficient quantities for radiocarbon analysis, without significant carbon isotopic fractionation or contamination.

  12. High-performance capillary electrophoresis of histones

    SciTech Connect

    Gurley, L.R.; London, J.E.; Valdez, J.G.

    1991-01-01

    A high performance capillary electrophoresis (HPCE) system has been developed for the fractionation of histones. This system involves electroinjection of the sample and electrophoresis in a 0.1M phosphate buffer at pH 2.5 in a 50 {mu}m {times} 35 cm coated capillary. Electrophoresis was accomplished in 9 minutes separating a whole histone preparation into its components in the following order of decreasing mobility; (MHP) H3, H1 (major variant), H1 (minor variant), (LHP) H3, (MHP) H2A (major variant), (LHP) H2A, H4, H2B, (MHP) H2A (minor variant) where MHP is the more hydrophobic component and LHP is the less hydrophobic component. This order of separation is very different from that found in acid-urea polyacrylamide gel electrophoresis and in reversed-phase HPLC and, thus, brings the histone biochemist a new dimension for the qualitative analysis of histone samples. 27 refs., 8 figs.

  13. Direct analysis of trace level bisphenol A, octylphenols and nonylphenol in bottled water and leached from bottles by ultra-high-performance liquid chromatography/tandem mass spectrometry.

    PubMed

    Wang, Jinyuan; Schnute, William C

    2010-09-15

    A high-throughput method was developed for the direct analysis of trace level bisphenol A (BPA), 4-n-octylphenol (4-n-OP), 4-tert-octylphenol (4-t-OP) and 4-n-nonylphenol (4-n-NP) in water samples by ultra-high-performance liquid chromatography/tandem mass spectrometry (uHPLC/MS/MS) using an isotope-labeled internal standard. Aliquots of water samples were spiked with the internal standard and analyzed without sample cleanup or enrichment. All target analytes were chromatographically separated within 3 min and detected using the highly selective multiple reaction monitoring (MRM) detection mode. The method detection limits were statistically calculated and ranged from 0.040 ppb (BPA) to 0.057 ppb (4-n-NP). Excellent correlation of determination was achieved for each analyte with r greater than 0.995. Precision was achieved within 8% relative standard deviation (RSD) for all analytes, and recoveries from spiked samples ranged from 97% to 106.2% except for 4-n-OP which may be corrected by using an isotope-labeled analog as internal standard. This method was used for analyzing eight randomly selected bottled water samples and found no detectable target analytes. This method was also used to analyze target analytes leached from bottles (6 low cost bottles and 6 brand-name baby-feeding bottles). Low levels of BPA were found in three bottles after they had been heated in a microwave oven, and a trace amount of 4-n-NP was also found in three bottles. 4-t-OP, which has not been reported as a leachable chemical, was found in two brand name baby-feeding bottles from the same manufacturer, and was confirmed with bottles from different batches.

  14. Monoclonal antibody heterogeneity analysis and deamidation monitoring with high-performance cation-exchange chromatofocusing using simple, two component buffer systems.

    PubMed

    Kang, Xuezhen; Kutzko, Joseph P; Hayes, Michael L; Frey, Douglas D

    2013-03-29

    The use of either a polyampholyte buffer or a simple buffer system for the high-performance cation-exchange chromatofocusing of monoclonal antibodies is demonstrated for the case where the pH gradient is produced entirely inside the column and with no external mixing of buffers. The simple buffer system used was composed of two buffering species, one which becomes adsorbed onto the column packing and one which does not adsorb, together with an adsorbed ion that does not participate in acid-base equilibrium. The method which employs the simple buffer system is capable of producing a gradual pH gradient in the neutral to acidic pH range that can be adjusted by proper selection of the starting and ending pH values for the gradient as well as the buffering species concentration, pKa, and molecular size. By using this approach, variants of representative monoclonal antibodies with isoelectric points of 7.0 or less were separated with high resolution so that the approach can serve as a complementary alternative to isoelectric focusing for characterizing a monoclonal antibody based on differences in the isoelectric points of the variants present. Because the simple buffer system used eliminates the use of polyampholytes, the method is suitable for antibody heterogeneity analysis coupled with mass spectrometry. The method can also be used at the preparative scale to collect highly purified isoelectric variants of an antibody for further study. To illustrate this, a single isoelectric point variant of a monoclonal antibody was collected and used for a stability study under forced deamidation conditions.

  15. Team Development for High Performance Management.

    ERIC Educational Resources Information Center

    Schermerhorn, John R., Jr.

    1986-01-01

    The author examines a team development approach to management that creates shared commitments to performance improvement by focusing the attention of managers on individual workers and their task accomplishments. It uses the "high-performance equation" to help managers confront shared beliefs and concerns about performance and develop realistic…

  16. Properties Of High-Performance Thermoplastics

    NASA Technical Reports Server (NTRS)

    Johnston, Norman J.; Hergenrother, Paul M.

    1992-01-01

    Report presents review of principal thermoplastics (TP's) used to fabricate high-performance composites. Sixteen principal TP's considered as candidates for fabrication of high-performance composites presented along with names of suppliers, Tg, Tm (for semicrystalline polymers), and approximate maximum processing temperatures.

  17. Turning High-Poverty Schools into High-Performing Schools

    ERIC Educational Resources Information Center

    Parrett, William H.; Budge, Kathleen

    2012-01-01

    If some schools can overcome the powerful and pervasive effects of poverty to become high performing, shouldn't any school be able to do the same? Shouldn't we be compelled to learn from those schools? Although schools alone will never systemically eliminate poverty, high-poverty, high-performing (HP/HP) schools take control of what they can to…

  18. High energy beam lifetime analysis

    SciTech Connect

    Howell, R.H.; Sterne, P.A.; Hartley, J.; Cowan, T.E.

    1997-05-01

    We have developed a positron lifetime defect analysis capability based on a 3 MeV electrostatic accelerator. The high energy beam lifetime spectrometer is operational with a 60 mCi {sup 22}Na source providing a current of 7 10{sup 5} positrons per second. Lifetime data are derived from a thin plastic transmission detector providing an implantation time and a BaF{sub 2} detector to determine the annihilation time. Positron lifetime analysis is performed with a 3 MeV positron beam on thick sample specimens at counting rates in excess of 2000 per second. The instrument is being used for bulk sample analysis and analysis of samples encapsulated in controlled environments for in situ measurements.

  19. FRAPTRAN Predictability of High Burnup Advanced Fuel Performance: Analysis of the CABRI CIP0-1 and CIP0-2 Experiments

    SciTech Connect

    Del Barrio, M.T.; Herranz, L.E.

    2007-07-01

    Adequacy of analytical tools to estimate advanced high burnup fuel during a power pulse need to be soundly proven. Most of models in codes dealing with transient are extrapolations of those developed for lower irradiations. In addition, lack of open information prevents often a proper account of mechanical properties of new advanced cladding material. These circumstances make experimental programs on high burnup fuel performance an indispensable tool to enhance safety codes predictability through building up sound databases on which models can be extended or developed and on which suitable code performance can be proven. The experiments CIP0-1 and CIP0-2, carried out on 2002 in the CABRI reactor, can be seen as reference tests to investigate high burnup fuel response to RIA transients. Fuel rods of up to 75 GWd/tU (average rod burnup) encapsulated in advanced cladding materials (ZIRLO and M5) were submitted to power pulses of about 30 ms of half maximum width that injected 90-100 cal/g after 1.2 s. None of the rodlets failed during the experiments, but they underwent deformation that was experimentally determined. The FRAPTRAN code has been used for the analysis of these RIA tests. The fuel rod characterization necessary for FRAPTRAN at the end of the base irradiation, prior to the transient, was provided by FRAPCON-3. An investigation of major deviations of fuel rod characterization at the end of the base irradiation has highlighted that thermal uncertainties could result in outstanding discrepancies in FGR estimates. Transient comparison with the available data shows that FRAPTRAN presents a relatively good agreement in permanent clad hoop strain and overestimates significantly the axial elongation of the cladding. The potential effect of approximations made in describing the cladding mechanical behavior, the fuel-to-clad relative movement and the pre-transient gap width, have been all discussed. Given existing uncertainties, a conclusive statement could not be

  20. Antimicrobial activity of Marcetia DC species (Melastomataceae) and analysis of its flavonoids by reverse phase-high performance liquid chromatography coupled-diode array detector

    PubMed Central

    Leite, Tonny Cley Campos; de Sena, Amanda Reges; dos Santos Silva, Tânia Regina; dos Santos, Andrea Karla Almeida; Uetanabaro, Ana Paula Trovatti; Branco, Alexsandro

    2012-01-01

    Background: Marcetia genera currently comprises 29 species, with approximately 90% inhabiting Bahia (Brazil), and most are endemic to the highlands of the Chapada Diamantina (Bahia). Among the species, only M. taxifolia (A.St.-Hil.) DC. populates Brazil (state of Roraima to Paraná) and also Venezuela, Colombia, and Guyana. Objective: This work evaluated the antimicrobial activity of hexane, ethyl acetate, and methanol extracts of three species of Marcetia (Marcetia canescens Naud., M. macrophylla Wurdack, and M. taxifolia A.StHil) against several microorganism. In addition, the flavonoids were analyzed in extracts by HPLC-DAD. Materials and methods: The tests were made using Gram-positive (three strains of Staphylococcus aureus) and Gram-negative (two strains of Escherichia coli, a strain of Pseudomonas aeruginosa and another of Salmonella choleraesius) bacteria resistant and nonresistant to antibiotics and yeasts (two strains of Candida albicans and one of C. parapsilosis) by the disk diffusion method. Solid-phase extraction (SPE) was performed on the above extracts to isolate flavonoids, which were subsequently analyzed by high performance liquid chromatography coupled diode array detector (HPLC-DAD). Results: Results showed that extracts inhibited the Gram-positive bacteria and yeast. The hexane extracts possessed the lowest activity, while the ethyl acetate and methanolic extracts were more active. Conclusion: Marcetia taxifolia was more effective (active against 10 microorganisms studied), and only its methanol extract inhibited Gram-negative bacteria (P. aeruginosa and S. choleraesius). SPE and HPLC-DAD analysis showed that M. canescens and M. macrophylla contain glycosylated flavonoids, while the majority of extracts from M. taxifolia were aglycone flavonoids. PMID:23060695

  1. Polyaniline/cyclodextrin composite coated stir bar sorptive extraction combined with high performance liquid chromatography-ultraviolet detection for the analysis of trace polychlorinated biphenyls in environmental waters.

    PubMed

    Lei, Yun; He, Man; Chen, Beibei; Hu, Bin

    2016-04-01

    A novel polyaniline/α-cyclodextrin (PANI/α-CD) composite coated stir bar was prepared by sol-gel process for the analysis of polychlorinated biphenyls (PCBs) in this work. The preparation reproducibility of the PANI/α-CD-coated stir bar was good, with relative standard deviations (RSDs) ranging from 2.3% to 3.7% (n=7) and 2.0% to 3.8% (n=7) for bar to bar and batch to batch, respectively. Based on it, a novel method of PANI/α-CD-coated stir bar sorptive extraction (SBSE) followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection was developed for the determination of trace PCBs in environmental waters. To obtain the best extraction performance for target PCBs, several parameters affecting SBSE, such as extraction time, stirring rate, and ionic strength were investigated. Under optimal experimental conditions, the limits of detection (LODs) of the proposed method for seven PCBs were in the range of 0.048-0.22 μg/L, and the RSDs were 5.3-9.8% (n=7, c=1 μg/L). Enrichment factors (EFs) ranging from 39.8 to 68.4-fold (theoretical EF, 83.3-fold) for target analytes were achieved. The proposed method was successfully applied for the determination of seven target PCBs in Yangtze River water and East Lake water, and the recoveries were in the range of 73.0-120% for the spiked East Lake water samples and 82.7-121% for the spiked Yangtze River water samples, respectively. PMID:26838413

  2. Analysis of L-citrulline and L-arginine in Ficus deltoidea leaf extracts by reverse phase high performance liquid chromatography

    PubMed Central

    Shafaei, Armaghan; Aisha, Abdalrahim F. A.; Siddiqui, Mohammad Jamshed Ahmad; Ismail, Zhari

    2015-01-01

    Background: Ficus deltoidea (FD) is one of the native plants widely distributed in several countries in Southeast Asia. Previous studies have shown that FD leaf possess antinociceptive, wound healing and antioxidant properties. These beneficial effects have been attributed to the presence of primary and secondary metabolites such as polyphenols, amino acids and flavonoids. Objective: The aim was to develop a reverse phase high-performance liquid chromatography method with ultraviolet detection that involves precolumn derivatisation with O-phthaladehyde for simultaneous analysis of two amino acids L-citrulline and L-arginine in FD leaf extracts. Materials and Methods: An isocratic elution program consisting of methanol: acetonitrile: Water at 45:45:10 v/v (solvent A) and 0.1 M phosphate buffer pH 7.5 (solvent B) at A: B v/v ratio of 80:20 on Zorbax Eclipse C18 SB-Aq column (250 × 4.6 mm, 5 μm) were used. The flow rate was set at 1 ml/min and detection was carried out at 338 nm with 30 min separation time. Results: Good linearity for L-citrulline and L-arginine was obtained in the range 0.1-1000 μg/ml at R2 ≥ 0.998. The limit of detection and limit of quantification values for both L-citrulline and L-arginine were 1 and 5 μg/ml, respectively. The average of recoveries was in the range 94.94-101.95%, with relative standard deviation (%RSD) less than 3%. Intra- and inter-day precision was in the range 96.36-102.43% with RSD less than 2%. Conclusion: All validation parameters of the developed method indicate the method is reliable and efficient for simultaneous determination of L-citrulline and L-arginine for routine analysis of FD. PMID:25598632

  3. Pre-column dilution large volume injection ultra-high performance liquid chromatography-tandem mass spectrometry for the analysis of multi-class pesticides in cabbages.

    PubMed

    Zhong, Qisheng; Shen, Lingling; Liu, Jiaqi; Yu, Dianbao; Li, Siming; Yao, Jinting; Zhan, Song; Huang, Taohong; Hashi, Yuki; Kawano, Shin-ichi; Liu, Zhaofeng; Zhou, Ting

    2016-04-15

    Pre-column dilution large volume injection (PD-LVI), a novel sample injection technique for reverse phase ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), was developed in this study. The PD-LVI UHPLC-MS/MS system was designed by slightly modifying the commercial UHPLC-MS/MS equipment with a mixer chamber. During the procedure of PD-LVI, sample solution of 200μL was directly carried by the organic mobile phase to the mixer and diluted with the aqueous mobile phase. After the mixture was introduced to the UHPLC column in a mobile phase of acetonitrile-water (15/85, v/v), the target analytes were stacked on the head of the column until following separation. Using QuEChERS extraction, no additional steps such as solvent evaporation or residue redissolution were needed before injection. The features of PD-LVI UHPLC-MS/MS system were systematically investigated, including the injection volume, the mixer volume, the precondition time and the gradient elution. The efficiency of this approach was demonstrated by direct analysis of 24 pesticides in cabbages. Under the optimized conditions, low limits of detection (0.00074-0.8 ng/kg) were obtained. The recoveries were in the range of 63.3-109% with relative standard deviations less than 8.1%. Compared with common UHPLC-MS/MS technique, PD-LVI UHPLC-MS/MS showed significant advantages such as excellent sensitivity and reliability. The mechanism of PD-LVI was demonstrated to be based on the column-head stacking effect with pre-column dilution. Based on the results, PD-LVI as a simple and effective sample injection technique of reverse phase UHPLC-MS/MS for the analysis of trace analytes in complex samples showed a great promising prospect. PMID:26979268

  4. Pre-column dilution large volume injection ultra-high performance liquid chromatography-tandem mass spectrometry for the analysis of multi-class pesticides in cabbages.

    PubMed

    Zhong, Qisheng; Shen, Lingling; Liu, Jiaqi; Yu, Dianbao; Li, Siming; Yao, Jinting; Zhan, Song; Huang, Taohong; Hashi, Yuki; Kawano, Shin-ichi; Liu, Zhaofeng; Zhou, Ting

    2016-04-15

    Pre-column dilution large volume injection (PD-LVI), a novel sample injection technique for reverse phase ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), was developed in this study. The PD-LVI UHPLC-MS/MS system was designed by slightly modifying the commercial UHPLC-MS/MS equipment with a mixer chamber. During the procedure of PD-LVI, sample solution of 200μL was directly carried by the organic mobile phase to the mixer and diluted with the aqueous mobile phase. After the mixture was introduced to the UHPLC column in a mobile phase of acetonitrile-water (15/85, v/v), the target analytes were stacked on the head of the column until following separation. Using QuEChERS extraction, no additional steps such as solvent evaporation or residue redissolution were needed before injection. The features of PD-LVI UHPLC-MS/MS system were systematically investigated, including the injection volume, the mixer volume, the precondition time and the gradient elution. The efficiency of this approach was demonstrated by direct analysis of 24 pesticides in cabbages. Under the optimized conditions, low limits of detection (0.00074-0.8 ng/kg) were obtained. The recoveries were in the range of 63.3-109% with relative standard deviations less than 8.1%. Compared with common UHPLC-MS/MS technique, PD-LVI UHPLC-MS/MS showed significant advantages such as excellent sensitivity and reliability. The mechanism of PD-LVI was demonstrated to be based on the column-head stacking effect with pre-column dilution. Based on the results, PD-LVI as a simple and effective sample injection technique of reverse phase UHPLC-MS/MS for the analysis of trace analytes in complex samples showed a great promising prospect.

  5. Analysis of Cocoa Proanthocyanidins Using Reversed Phase High-Performance Liquid Chromatography and Electrochemical Detection: Application to Studies on the Effect of Alkaline Processing.

    PubMed

    Stanley, Todd H; Smithson, Andrew T; Neilson, Andrew P; Anantheswaran, Ramaswamy C; Lambert, Joshua D

    2015-07-01

    Flavan-3-ols and proanthocyanidins play a key role in the health beneficial effects of cocoa. Here, we developed a new reversed phased high-performance liquid chromatography-electrochemical detection (HPLC-ECD) method for the analysis of flavan-3-ols and proanthocyanidins of degree of polymerization (DP) 2-7. We used this method to examine the effect of alkalization on polyphenol composition of cocoa powder. Treatment of cocoa powder with NaOH (final pH 8.0) at 92 °C for up to 1 h increased catechin content by 40%, but reduced epicatechin and proanthocyanidins by 23-66%. Proanthocyanidin loss could be modeled using a two-phase exponential decay model (R(2) > 0.7 for epicatchin and proanthocyanidins of odd DP). Alkalization resulted in a significant color change and 20% loss of total polyphenols. The present work demonstrates the first use of HPLC-ECD for the detection of proanthocyanidins up to DP 7 and provides an initial predictive model for the effect of alkali treatment on cocoa polyphenols.

  6. Multiresidue analysis of endocrine-disrupting compounds and perfluorinated sulfates and carboxylic acids in sediments by ultra-high-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Cavaliere, Chiara; Capriotti, Anna Laura; Ferraris, Francesca; Foglia, Patrizia; Samperi, Roberto; Ventura, Salvatore; Laganà, Aldo

    2016-03-18

    A multiresidue analytical method for the determination of 11 perfluorinated compounds and 22 endocrine-disrupting compounds (ECDs) including 13 natural and synthetic estrogens (free and conjugated forms), 2 alkylphenols, 1 plasticiser, 2 UV-filters, 1 antimicrobial, and 2 organophosphorus compounds in sediments has been developed. Ultrasound-assisted extraction followed by solid phase extraction (SPE) with graphitized carbon black (GCB) cartridge as clean-up step were used. The extraction process yield was optimized in terms of solvent composition. Then, a 3(2) experimental design was used to optimize solvent volume and sonication time by response surface methodology, which simplifies the optimization procedure. The final extract was analyzed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry. The optimized sample preparation method is simple and robust, and allows recovery of ECDs belonging to different classes in a complex matrix such as sediment. The use of GCB for SPE allowed to obtain with a single clean-up procedure excellent recoveries ranging between 75 and 110% (relative standard deviation <16%). The developed methodology has been successfully applied to the analysis of ECDs in sediments from different rivers and lakes of the Lazio Region (Italy). These analyses have shown the ubiquitous presence of chloro-substituted organophosphorus flame retardants and bisphenol A, while other analyzed compounds were occasionally found at concentration between the limit of detection and quantification.

  7. Analysis of oligomer proanthocyanidins in different barley genotypes using high-performance liquid chromatography-fluorescence detection-mass spectrometry and near-infrared methodologies.

    PubMed

    Verardo, Vito; Cevoli, Chiara; Pasini, Federica; Gómez-Caravaca, Ana María; Marconi, Emanuele; Fabbri, Angelo; Caboni, Maria Fiorenza

    2015-04-29

    Proanthocyanidins are a class of polyphenols present in many foodstuffs (i.e., tea, cocoa, berries, etc.) that may reduce the risk of several chronic diseases. Barley, with sorghum, rice, and wheat, are the only cereals that contain these compounds. Because of that, two barley genotypes, named waxy and non-waxy, were analyzed by normal-phase high-performance liquid chromatography-fluorescence detection-mass spectrometry (NP-HPLC-FLD-MS). Total proanthocyanidin content ranged between 293.2 and 652.6 μg/g of flour. Waxy samples reported the highest content (p < 0.05) of proanthocyanidins. Dimer compounds were the principal proanthocyanidin constituents of barley samples. Moreover, the possibility to use near-infrared (NIR) spectroscopy as a rapid method to discriminate between waxy and non-waxy samples and to predict quantitatively proanthocyanidins in barley samples was evaluated. Partial least squares (PLS) models were built to predict the proanthocyanidin constituent, obtaining determination coefficients (R(2)) ranging from 0.92 to 0.97, in test set validation. Because of that, this study highlights that NIR spectroscopy technology with multivariate calibration analysis could be successfully applied as a rapid method to determine proanthocyanidin content in barley.

  8. Chemical characteristics of different parts of Coreopsis tinctoria in China using microwave-assisted extraction and high-performance liquid chromatography followed by chemometric analysis.

    PubMed

    Lam, Shing-Chung; Liu, Xin; Chen, Xian-Qiang; Hu, De-Jun; Zhao, Jing; Long, Ze-Rong; Fan, Bing; Li, Shao-Ping

    2016-08-01

    Coreopsis tinctoria, also called "snow chrysanthemum" in China, is a flower tea material that has been reported to possess excellent pharmacological properties such as antioxidant and antidiabetic activities. The chemical characteristics of different parts (flowers, buds, seeds, stems, and leaves) of C. tinctoria were investigated based on microwave-assisted extraction and the simultaneous determination of 13 major active compounds by high-performance liquid chromatography, including taxifolin-7-O-glucoside, chlorogenic acid, (R/S)-flavanomarein, isocoreopsin, quercetagetin-7-O-glucoside, isookanin, 5,7,3',5'-tetrahydroxyflavanone-7-O-glucoside, marein, 3,5-dicaffeoylquinic acid, coreopsin, okanin, 5,7,3',5'-tetrahydroxyflavanone, and N(1) ,N(5) ,N(10) ,N(14) -tetra-p-coumaroylspermine. Chemometric analysis based on the contents of investigated compounds from 13 samples showed that C. tinctoria and the related flower tea materials, Chrysanthemum morifolium cv "Hangju" and "Gongju," were in different clusters, and different parts (flowers, buds, seeds, stems, and leaves) of C. tinctoria were obviously different. This study is helpful for the quality control and pharmacological evaluation of different parts from C. tinctoria and its related products. PMID:27291468

  9. Evaluation of a direct injection nebulizer interface for flow injection analysis and high performance liquid chromatography with inductively coupled plasma-atomic emission spectroscopic detection

    SciTech Connect

    LaFreniere, K.E.

    1986-06-01

    A direct injection nebulizer (DIN) was designed, developed, and evaluated to determine its potential utilization as an effective interface for flow injection analysis (FIA) and high performance liquid chromatography (HPLC) coupled with inductively coupled plasma-atomic emission spectroscopic detection. The analytical figures of merit for the DIN when used as an interface for FIA-ICP-AES were found to be comparable to or better than those obtained with conventional pneumatic nebulization in terms of limits of detection (LODs), reproducibility, linearity, and interelement effects. Stable plasma operation was maintained for the DIN sample introduction of a variety of pure organic solvents, including acetonitrile, methanol, methylisobutylketone, and pyridine. The HPLC-DIN-ICP-AES facility was specifically applied for the speciation of inorganic and organometallic species contained in synthetic mixtures, vanilla extracts, and a variety of energy-related materials, such as shale oil process water, coal extracts, shale oil, crude oil, and an SRC II. Suggestions for future research are also considered. 227 refs., 44 figs., 15 tabs.

  10. Evaluation of a direct injection nebulizer interface for flow injection analysis and high performance liquid chromatography with inductively coupled plasma-atomic emission spectroscopic detection

    SciTech Connect

    LaFreniere, K.E.

    1986-01-01

    A direct injection nebulizer (DIN) was designed, developed and evaluated to determine its potential utilization as an effective interface for flow injection analysis (FIA) and high performance liquid chromatography (HPLC) coupled with inductively coupled plasma-atomic emission spectroscopic detection. The analytical figures of merit for the DIN when used as an interface for FIA-ICP-AES were found to be comparable to or better than those obtained with conventional pneumatic nebulization in terms of limits of detection (LODs), reproducibility, linearity, and interelement effects. In the HPLC mode, the LODDs were found to be comparable to those obtained by continuous-flow sample introduction into the ICP, or inferior by up to only a factor of four. Stable plasma operation was maintained for the DIN sample introduction of a variety of pure organic solvents, including acetonitrile, methanol, methyl-isobutylketone, and pyridine. The HPLC-DIN-ICP-AES facility was specifically applied for the speciation of inorganic and organo-metallic species contained in synthetic mixtures, vanilla extracts and a variety of energy-related materials, such as shale oil process water, coal extracts, shale oil, crude oil, and an SRC II. Suggestions for future research are also considered.

  11. Ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry and chemometric analysis of licorice based on the simultaneous determination of saponins and flavonoids.

    PubMed

    Jiang, Zhenzuo; Wang, Yuefei; Zheng, Yunfeng; Yang, Jing; Zhang, Lei

    2016-08-01

    Licorice is among the most popular herbal medicines and frequently used in traditional medicine, food products, and cosmetics. In China, only Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat. and Glycyrrhiza glabra L. are officially used and are usually processed with honey prior to use. To maintain the quality of commercially available herbal products, a simple, rapid, and reliable ultra high performance liquid chromatography with triple quadrupole mass spectrometry was developed to investigate the major active constituents of commercially available licorice products. Nineteen components were accurately determined, including eight triterpenoid saponins, one triterpene, and ten flavonoids. Subsequently, multivariate statistical analysis methods were employed to further explore and interpret the experimental data. The results indicated that liquiritin apioside may be considered as a candidate index for the quality control of licorice as well as 18β-glycyrrhizic acid and liquiritin. In addition, both 18β-glycyrrhizic acid and licorice-saponin G2 can be used for discrimination between crude and honey-processed licorice. Furthermore, using 18β-glycyrrhizic acid and liquiritin as markers, this work revealed that the quality of licorice products may have declined in recent years. This highlights the need for additional effort focused on good agricultural practice during the processing of licorice. In summary, this study provides a valuable reference for the quality assessment of licorice. PMID:27273927

  12. Analysis of caffeine and paraxanthine in human saliva with ultra-high-performance liquid chromatography for CYP1A2 phenotyping.

    PubMed

    Jordan, Nan Yeun; Mimpen, Jolet Y; van den Bogaard, Willie J M; Flesch, Frits M; van de Meent, Michiel H M; Torano, Javier Sastre

    2015-07-15

    Cytochrome P450 1A2 (CYP1A2) plays an important role in drug metabolism. Caffeine (CAF) is converted into paraxanthine (PX) by this enzyme and is used as a xenobiotic substrate to determine the CYP1A2 phenotype in humans. A method for the quantification of CAF and PX in saliva was developed using liquid-liquid extraction with ethyl acetate and analysis with ultra-high-performance liquid chromatography. Peaks from CAF, PX and internal standard were resolved within 6min. The method was validated from 0.05 to 5μgmL(-1) CAF and 0.025-2.5μgmL(-1) PX. Inter- and intra-day accuracies ranged from 91.2 to 107.2% with precisions <13.5%. The limits of detection were 0.16 and 0.63 ngmL(-1) for PX and CAF, respectively. PX/CAF concentration ratios from volunteers were 0.26-1.09 with mean ratios of 0.78±0.26 and 0.38±0.10 for regular and light/non-coffee drinkers, respectively. PMID:26038236

  13. Analysis of oligomer proanthocyanidins in different barley genotypes using high-performance liquid chromatography-fluorescence detection-mass spectrometry and near-infrared methodologies.

    PubMed

    Verardo, Vito; Cevoli, Chiara; Pasini, Federica; Gómez-Caravaca, Ana María; Marconi, Emanuele; Fabbri, Angelo; Caboni, Maria Fiorenza

    2015-04-29

    Proanthocyanidins are a class of polyphenols present in many foodstuffs (i.e., tea, cocoa, berries, etc.) that may reduce the risk of several chronic diseases. Barley, with sorghum, rice, and wheat, are the only cereals that contain these compounds. Because of that, two barley genotypes, named waxy and non-waxy, were analyzed by normal-phase high-performance liquid chromatography-fluorescence detection-mass spectrometry (NP-HPLC-FLD-MS). Total proanthocyanidin content ranged between 293.2 and 652.6 μg/g of flour. Waxy samples reported the highest content (p < 0.05) of proanthocyanidins. Dimer compounds were the principal proanthocyanidin constituents of barley samples. Moreover, the possibility to use near-infrared (NIR) spectroscopy as a rapid method to discriminate between waxy and non-waxy samples and to predict quantitatively proanthocyanidins in barley samples was evaluated. Partial least squares (PLS) models were built to predict the proanthocyanidin constituent, obtaining determination coefficients (R(2)) ranging from 0.92 to 0.97, in test set validation. Because of that, this study highlights that NIR spectroscopy technology with multivariate calibration analysis could be successfully applied as a rapid method to determine proanthocyanidin content in barley. PMID:25803838

  14. Analysis of Cocoa Proanthocyanidins Using Reversed Phase High-Performance Liquid Chromatography and Electrochemical Detection: Application to Studies on the Effect of Alkaline Processing.

    PubMed

    Stanley, Todd H; Smithson, Andrew T; Neilson, Andrew P; Anantheswaran, Ramaswamy C; Lambert, Joshua D

    2015-07-01

    Flavan-3-ols and proanthocyanidins play a key role in the health beneficial effects of cocoa. Here, we developed a new reversed phased high-performance liquid chromatography-electrochemical detection (HPLC-ECD) method for the analysis of flavan-3-ols and proanthocyanidins of degree of polymerization (DP) 2-7. We used this method to examine the effect of alkalization on polyphenol composition of cocoa powder. Treatment of cocoa powder with NaOH (final pH 8.0) at 92 °C for up to 1 h increased catechin content by 40%, but reduced epicatechin and proanthocyanidins by 23-66%. Proanthocyanidin loss could be modeled using a two-phase exponential decay model (R(2) > 0.7 for epicatchin and proanthocyanidins of odd DP). Alkalization resulted in a significant color change and 20% loss of total polyphenols. The present work demonstrates the first use of HPLC-ECD for the detection of proanthocyanidins up to DP 7 and provides an initial predictive model for the effect of alkali treatment on cocoa polyphenols. PMID:26042917

  15. High-performance liquid chromatography analysis of anti-inflammatory pharmaceuticals with ultraviolet and electrospray-mass spectrometry detection in suspected counterfeit homeopathic medicinal products.

    PubMed

    Panusa, Alessia; Multari, Giuseppina; Incarnato, Giampaolo; Gagliardi, Luigi

    2007-03-12

    A simple high-performance liquid chromatography (HPLC) method with both ultraviolet (UV) and electrospray ionisation mass spectrometry (ESI-MS) detection has been developed for the determination of seven pharmaceuticals in counterfeit homeopathic preparations. Naproxen, Ketoprofen, Ibuprofen, Diclofenac, Piroxicam, Nimesulide and Paracetamol were separated by reversed phase chromatography with acetonitrile-water (0.1% acetic acid) mobile phase, and detected by UV at 245 nm and by ESI-MS in negative ionisation mode with the exception of Paracetamol which was detected in positive ionisation mode. Benzoic acid was used as internal standard (IS). This method was successfully applied to the analysis of homeopathic preparations like mother tinctures, solutions, tablets, granules, creams, and suppositories. Linearity was studied with UV detection in the 50-400 microg mL(-1) range and with ESI-MS in the 0.1-50 microg mL(-1) range. Good correlation coefficients were found in both UV and ESI-MS. Detection limits ranged from 0.18 to 41.5 ng in UV and from 0.035 to 1.00 ng in ESI-MS.

  16. A new derivatization approach for the rapid and sensitive analysis of brassinosteroids by using ultra high performance liquid chromatography-electrospray ionization triple quadrupole mass spectrometry.

    PubMed

    Huo, Feifeng; Wang, Xin; Han, Yehua; Bai, Yu; Zhang, Wei; Yuan, Hancheng; Liu, Huwei

    2012-09-15

    In this work, a new labeling reagent, 2-bromopyridine-5-boronic acid (BPBA), was introduced to derivatize brassinosteroids (BRs). The BPBA not only provided a very simple and rapid labeling procedure, but also remarkably increased the detection sensitivity of BRs. Based on this new labeling reaction, a rapid and sensitive method for BRs' analysis in Arabidopsis thaliana was established by using the ultra high performance liquid chromatography-electrospray ionization triple quadrupole mass spectrometry (UHPLC-ESI-QqQ-MS). The extraction and purification procedure of the plant sample was also simplified and improved in this work. Good linearities were obtained for three BRs with the determination coefficients (R(2)) about 0.9999. The limits of detection (S/N=3) for three BRs were found to be 2.00-8.00 ng/L while the limits of quantification (S/N=10) were 6.00-23.0 ng/L. The RSD % for all three samples are lower than 8.67% (n=5). The recoveries of three BRs spiked in A. thaliana samples were from 76.9% to 86.1%. Using this method, the endogenous 0.055 ng/g fresh weight (FW) 24-epiBR and 0.070 ng/g (FW) 28-epihomoBR were successfully detected from only 2g A. thaliana plants.

  17. Global identification and quantitative analysis of chemical constituents in traditional Chinese medicinal formula Qi-Fu-Yin by ultra-high performance liquid chromatography coupled with mass spectrometry.

    PubMed

    Li, Meng-Ning; Dong, Xin; Gao, Wen; Liu, Xin-Guang; Wang, Rui; Li, Ping; Yang, Hua

    2015-10-10

    Qi-Fu-Yin (QFY), a classical traditional Chinese medicine formula, is proven to have significant neuroprotective effects by modern pharmacological studies. However, the chemical constituents of QFY have not been fully explored. In this study, an ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF MS) was developed for comprehensive analysis of chemical constituents in QFY. By using characteristic ions and fragmentation rules, a reliable identification of 156 compounds was described here, including 69 triterpene saponins, 23 oligosaccharide esters, 22 flavanoids, 9 alkaloids, 9 phenolic acids, 8 phthalides, 7 phenylethanoid glycosides, 3 xanthones, 3 sesquiterpene lactones, 2 ionones and 1 iridoid glycoside. Twenty-six major compounds were then determined in a single run by UHPLC coupled with triple quadrupole tandem mass spectrometry (QQQ MS) with fast positive/negative polarity switching. It allows for the acquisition of MS data in both ionization modes from a single run. The proposed method was then validated in terms of linearity, accuracy, precision and recovery. The overall recoveries for 26 analytes ranged from 91.35% to 109.58%, with RSDs ranging from 0.82% to 4.83%. In addition, the content of 26 analytes in QFY prepared by five batches of herbal materials was also analyzed. These results demonstrated that our present method was effective and reliable for comprehensive quality evaluation of QFY. Meanwhile, the study might provide the chemical evidence for revealing the material basis of its therapeutic effects.

  18. Analysis of caffeine and paraxanthine in human saliva with ultra-high-performance liquid chromatography for CYP1A2 phenotyping.

    PubMed

    Jordan, Nan Yeun; Mimpen, Jolet Y; van den Bogaard, Willie J M; Flesch, Frits M; van de Meent, Michiel H M; Torano, Javier Sastre

    2015-07-15

    Cytochrome P450 1A2 (CYP1A2) plays an important role in drug metabolism. Caffeine (CAF) is converted into paraxanthine (PX) by this enzyme and is used as a xenobiotic substrate to determine the CYP1A2 phenotype in humans. A method for the quantification of CAF and PX in saliva was developed using liquid-liquid extraction with ethyl acetate and analysis with ultra-high-performance liquid chromatography. Peaks from CAF, PX and internal standard were resolved within 6min. The method was validated from 0.05 to 5μgmL(-1) CAF and 0.025-2.5μgmL(-1) PX. Inter- and intra-day accuracies ranged from 91.2 to 107.2% with precisions <13.5%. The limits of detection were 0.16 and 0.63 ngmL(-1) for PX and CAF, respectively. PX/CAF concentration ratios from volunteers were 0.26-1.09 with mean ratios of 0.78±0.26 and 0.38±0.10 for regular and light/non-coffee drinkers, respectively.

  19. High Performance Computing CFRD -- Final Technial Report

    SciTech Connect

    Hope Forsmann; Kurt Hamman

    2003-01-01

    The Bechtel Waste Treatment Project (WTP), located in Richland, WA, is comprised of many processes containing complex physics. Accurate analyses of the underlying physics of these processes is needed to reduce the amount of added costs during and after construction that are due to unknown process behavior. The WTP will have tight operating margins in order to complete the treatment of the waste on schedule. The combination of tight operating constraints coupled with complex physical processes requires analysis methods that are more accurate than traditional approaches. This study is focused specifically on multidimensional computer aided solutions. There are many skills and tools required to solve engineering problems. Many physical processes are governed by nonlinear partial differential equations. These governing equations have few, if any, closed form solutions. Past and present solution methods require assumptions to reduce these equations to solvable forms. Computational methods take the governing equations and solve them directly on a computational grid. This ability to approach the equations in their exact form reduces the number of assumptions that must be made. This approach increases the accuracy of the solution and its applicability to the problem at hand. Recent advances in computer technology have allowed computer simulations to become an essential tool for problem solving. In order to perform computer simulations as quickly and accurately as possible, both hardware and software must be evaluated. With regards to hardware, the average consumer personal computers (PCs) are not configured for optimal scientific use. Only a few vendors create high performance computers to satisfy engineering needs. Software must be optimized for quick and accurate execution. Operating systems must utilize the hardware efficiently while supplying the software with seamless access to the computer’s resources. From the perspective of Bechtel Corporation and the Idaho

  20. High resolution analysis

    NASA Technical Reports Server (NTRS)

    Robinove, C. J.

    1982-01-01

    The possibilities for the use of high spectral resolution analysis in the field of hydrology and water resources are examined. Critical gaps in scientific knowledge that must be filled before technology can be evaluated involve the spectral response of water, substances dissolved and suspended in water, and substances floating on water. The most complete mapping of oil slicks can be done in the ultraviolet region. A mean of measuring the ultraviolet reflection at the surface from satellite altitudes needs to be determined. The use of high spectral resolution sensors in a reasonable number of narrow bands may be able to sense the reflectance or emission characteristics of water and its contained materials that can be correlated with commonly used water quality variables. Technological alternative available to experiment with problems of sensing water quality are to use existing remote sensing instrumentation in an empirical mode and to develop instruments for either testing hypoteses or conducting empirical experiments.

  1. HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY AND THE ANALYSIS OF DRUG INTERACTIONS WITH MODIFIED PROTEINS: BINDING OF GLICLAZIDE WITH GLYCATED HUMAN SERUM ALBUMIN

    PubMed Central

    Matsuda, Ryan; Anguizola, Jeanethe; Joseph, K.S.; Hage, David S.

    2011-01-01

    This study used high-performance affinity chromatography (HPAC) to examine the binding of gliclazide (i.e., a sulfonylurea drug used to treat diabetes) with the protein human serum albumin (HSA) at various stages of modification due to glycation. Frontal analysis conducted with small HPAC columns was first used to estimate the number of binding sites and association equilibrium constants (Ka) for gliclazide with normal HSA and glycated HSA. Both normal and glycated HSA interacted with gliclazide according to a two-site model, with a class of high affinity sites (average Ka, 7.1-10 × 104 M−1) and a group of lower affinity sites (average Ka, 5.7-8.9 × 103 M−1) at pH 7.4 and 37°C. Competition experiments indicated that Sudlow sites I and II of HSA were both involved in these interactions, with the Ka values for gliclazide at these sites being 1.9 × 104 M−1 and 6.0 × 104 M−1, respectively, for normal HSA. Two samples of glycated HSA had similar affinities to normal HSA for gliclazide at Sudlow site I, but one sample had a 1.9-fold increase in affinity at this site. All three glycated HSA samples differed from normal HSA in their affinity for gliclazide at Sudlow site II. This work illustrated how HPAC can be used to examine both the overall binding of a drug with normal or modified proteins and the site-specific changes that can occur in these interactions as a result of protein modification. PMID:21922305

  2. Drug quality analysis through high performance liquid chromatography of isometamidium chloride hydrochloride and diminazene diaceturate purchased from official and unofficial sources in Northern Togo.

    PubMed

    Tchamdja, E; Kulo, A E; Akoda, K; Teko-Agbo, A; Assoumy, A M; Niang, E M M; Batawui, K; Adomefa, K; Bankolé, A A; Kombiagou, K; Hoppenheit, A; Clausen, P-H; Mattioli, R C; Peter, R; Napier, G B; De Deken, R; Marcotty, T; Van Den Abbeele, J; Delespaux, V

    2016-04-01

    Trypanocidal drugs remain the most accessible and thus commonly used means of controlling tsetse transmitted animal African trypanosomosis. In Togo, trypanocides are sold on official as well as unofficial markets, but the quality of these trypanocides is undocumented so a drug quality assessment study was conducted from May 2013 to June 2014. Trypanocides supplied by European, Indian and Chinese pharmaceutical companies and sold on official and unofficial markets in Togo were purchased. In total fifty-two trypanocides were obtained, 24 of these samples from official markets and 28 from unofficial markets made up of a total of 36 diminazene diaceturate and 16 isometamidium chloride hydrochloride samples. The samples were analysed in the reference laboratory of the OIE (World Organisation for Animal Health), Laboratory for the Control of Veterinary Medicines (LACOMEV) in Dakar which uses galenic testing and high performance liquid chromatography (HPLC) testing as standard reference analysis methods. The results revealed a high proportion of trypanocides of sub-standard quality on the Togolese market: 40% were non-compliant to these quality reference standards. All of the HPLC non-compliant samples contained lower amounts of active ingredient compared to the concentration specified on the packaging. Non-compliance was higher in samples from the unofficial (53.57%) than from the official markets (25%; p=0.04).The main drug manufacturers, mostly of French origin in the study area, supply quality drugs through the official legal distribution circuit. Products of other origins mostly found on illegal markets present a significantly lower quality. PMID:26907208

  3. Analysis of preservatives with different polarities in beverage samples by dual-phase dual stir bar sorptive extraction combined with high-performance liquid chromatography.

    PubMed

    Xu, Jin; Chen, Beibei; He, Man; Hu, Bin

    2013-02-22

    A new concept of "dual-phase dual stir bar sorptive extraction (SBSE)" was proposed to simultaneously extract six preservatives with different polarities (logKo/w values of 1.27-3.41), namely, benzoic acid (BA), sorbic acid (SA), methyl p-hydroxybenzoate (MP), ethyl p-hydroxybenzoate (EP), propyl p-hydroxybenzoate (PP), and butyl p-hydroxybenzoate (BP). The dual-phase dual SBSE apparatus was consisted of two differently coated stir bars, a 3-aminopropyltriethoxysilane (APTES)-hydroxy-terminated silicone oil (OH-TSO)-coated stir bar that was prepared by sol-gel technique and a C(18) silica (C(18))-polydimethylsiloxane (PDMS)-coated stir bar that was prepared by adhesion. In dual-phase dual SBSE, the two stir bars with different coatings were placed in the same sample solution for the simultaneous extraction of the target analytes with different polarities, and then the bars were desorbed in the same desorption solvent. The extraction performance of the dual-phase dual SBSE for the six preservatives was evaluated by comparing with the conventional SBSE (individual stir bar) with different coatings, including commercial PDMS, homemade PDMS, C(18)-APTES-OH-TSO, APTES-OH-TSO, and C(18)-PDMS. The experimental results showed that the dual-phase dual SBSE had the highest extraction efficiency for the six target preservatives. Based on this fact, a novel method by combining the dual-phase dual SBSE which was consisted of the APTES-OH-TSO-coated and C(18)-PDMS-coated stir bars with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was developed for the simultaneous analysis of six target beverage preservatives in beverages. Under optimal conditions, the limits of detection (LODs) for six target preservatives ranged from 0.6 to 2.7 μgL(-1) with the relative standard deviations (RSDs) of 4.6-9.2% (C(BA,SA)=5 μgL(-1),C(MP)=20 μgL(-1),C(EP,PP,BP)=10 μgL(-1), n=7). The enrichment factors (EFs) were approximately 16-42-fold (theoretical EF was 50-fold

  4. Strategy Guideline. Partnering for High Performance Homes

    SciTech Connect

    Prahl, Duncan

    2013-01-01

    High performance houses require a high degree of coordination and have significant interdependencies between various systems in order to perform properly, meet customer expectations, and minimize risks for the builder. Responsibility for the key performance attributes is shared across the project team and can be well coordinated through advanced partnering strategies. For high performance homes, traditional partnerships need to be matured to the next level and be expanded to all members of the project team including trades, suppliers, manufacturers, HERS raters, designers, architects, and building officials as appropriate. This guide is intended for use by all parties associated in the design and construction of high performance homes. It serves as a starting point and features initial tools and resources for teams to collaborate to continually improve the energy efficiency and durability of new houses.

  5. Determination of Ruscogenin in Ophiopogonis Radix by High-performance Liquid Chromatography-evaporative Light Scattering Detector Coupled with Hierarchical Clustering Analysis

    PubMed Central

    Liu, Chun-Hua; Li, Ming; Feng, Ya-Qian; Hu, Yuan-Jia; Yu, Bo-Yang; Qi, Jin

    2016-01-01

    Background: Ophiopogonis Radix is a famous traditional Chinese medicine. It is necessary to establish a suitable quality control methods of Ophiopogonis Radix. Objective: To investigate the quality control methods of Ophiopogonis Radix by high-performance liquid chromatography (HPLC) coupled with evaporative light scattering detector (ELSD). Materials and Methods: A rapid and simple method, HPLC coupled with ELSD, was applied to determinate ruscogenin in 35 batches of Ophiopogenis Radix samples. Orthogonal tests and single factor explorations were used to optimize the extraction condition of ruscogenin. The content of ruscogenin in different origin was further analyzed by hierarchical clustering analysis (HCA). Results: The ruscogenin was successfully determined by HPLC-ELSD with a two-phase solvent system composed of methanol-water (88:12) at a flow rate 1.0 ml/min, column temperature maintained at 25°C, detector draft tube temperature at 42.2°C, nebulizer gas flow rate at 1.4 L/min, and the gain at 8. The result showed the good linearity of ruscogenin in the range of 40.20–804.00 μg/ml (R2 = 0.9996). Average of recovery was 101.3% (relative standard deviation = 1.59%). A significant difference of ruscogenin content was shown among 35 batches of Ophiopogenis Radix from different origin, varied from 0.0035% to 0.0240%. HCA based on the content of ruscogenin indicated that Ophiopogonis Radix in different origin was mainly divided into two clusters. Conclusion: This simple, rapid, low-cost, and reliable HPLC-ELSD method could be suitable for measurement of ruscogenin content rations and quality control of Ophiopogonis Radix. SUMMARY Ophiopogonis Radix is an important Traditional Chinese Medicine (TCM) to treat and prevent cardiovascular diseases and acute or chronic inflammation for thousands of years. Steroidal saponins were known as the dominant active components for their significant cardiovascular activity, and the most steroid sapogenin of them is

  6. High-performance computers for unmanned vehicles

    NASA Astrophysics Data System (ADS)

    Toms, David; Ettinger, Gil J.

    2005-10-01

    The present trend of increasing functionality onboard unmanned vehicles is made possible by rapid advances in high-performance computers (HPCs). An HPC is characterized by very high computational capability (100s of billions of operations per second) contained in lightweight, rugged, low-power packages. HPCs are critical to the processing of sensor data onboard these vehicles. Operations such as radar image formation, target tracking, target recognition, signal intelligence signature collection and analysis, electro-optic image compression, and onboard data exploitation are provided by these machines. The net effect of an HPC is to minimize communication bandwidth requirements and maximize mission flexibility. This paper focuses on new and emerging technologies in the HPC market. Emerging capabilities include new lightweight, low-power computing systems: multi-mission computing (using a common computer to support several sensors); onboard data exploitation; and large image data storage capacities. These new capabilities will enable an entirely new generation of deployed capabilities at reduced cost. New software tools and architectures available to unmanned vehicle developers will enable them to rapidly develop optimum solutions with maximum productivity and return on investment. These new technologies effectively open the trade space for unmanned vehicle designers.

  7. ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS

    SciTech Connect

    WONG, CPC; MALANG, S; NISHIO, S; RAFFRAY, R; SAGARA, S

    2002-04-01

    OAK A271 ADVANCED HIGH PERFORMANCE SOLID WALL BLANKET CONCEPTS. First wall and blanket (FW/blanket) design is a crucial element in the performance and acceptance of a fusion power plant. High temperature structural and breeding materials are needed for high thermal performance. A suitable combination of structural design with the selected materials is necessary for D-T fuel sufficiency. Whenever possible, low afterheat, low chemical reactivity and low activation materials are desired to achieve passive safety and minimize the amount of high-level waste. Of course the selected fusion FW/blanket design will have to match the operational scenarios of high performance plasma. The key characteristics of eight advanced high performance FW/blanket concepts are presented in this paper. Design configurations, performance characteristics, unique advantages and issues are summarized. All reviewed designs can satisfy most of the necessary design goals. For further development, in concert with the advancement in plasma control and scrape off layer physics, additional emphasis will be needed in the areas of first wall coating material selection, design of plasma stabilization coils, consideration of reactor startup and transient events. To validate the projected performance of the advanced FW/blanket concepts the critical element is the need for 14 MeV neutron irradiation facilities for the generation of necessary engineering design data and the prediction of FW/blanket components lifetime and availability.

  8. Comparative Analysis of Performance and Microbial Characteristics Between High-Solid and Low-Solid Anaerobic Digestion of Sewage Sludge Under Mesophilic Conditions.

    PubMed

    Lu, Qin; Yi, Jing; Yang, Dianhai

    2016-01-01

    High-solid anaerobic digestion of sewage sludge achieves highly efficient volatile solid reduction, and production of volatile fatty acid (VFA) and methane compared with conventional low-solid anaerobic digestion. In this study, the potential mechanisms of the better performance in high-solid anaerobic digestion of sewage sludge were investigated by using 454 high-throughput pyrosequencing and real-time PCR to analyze the microbial characteristics in sewage sludge fermentation reactors. The results obtained by 454 high-throughput pyrosequencing revealed that the phyla Chloroflexi, Bacteroidetes, and Firmicutes were the dominant functional microorganisms in high-solid and low-solid anaerobic systems. Meanwhile, the real-time PCR assays showed that high-solid anaerobic digestion significantly increased the number of total bacteria, which enhanced the hydrolysis and acidification of sewage sludge. Further study indicated that the number of total archaea (dominated by Methanosarcina) in a high-solid anaerobic fermentation reactor was also higher than that in a low-solid reactor, resulting in higher VFA consumption and methane production. Hence, the increased key bacteria and methanogenic archaea involved in sewage sludge hydrolysis, acidification, and methanogenesis resulted in the better performance of high-solid anaerobic sewage sludge fermentation.

  9. Dinosaurs can fly -- High performance refining

    SciTech Connect

    Treat, J.E.

    1995-09-01

    High performance refining requires that one develop a winning strategy based on a clear understanding of one`s position in one`s company`s value chain; one`s competitive position in the products markets one serves; and the most likely drivers and direction of future market forces. The author discussed all three points, then described measuring performance of the company. To become a true high performance refiner often involves redesigning the organization as well as the business processes. The author discusses such redesigning. The paper summarizes ten rules to follow to achieve high performance: listen to the market; optimize; organize around asset or area teams; trust the operators; stay flexible; source strategically; all maintenance is not equal; energy is not free; build project discipline; and measure and reward performance. The paper then discusses the constraints to the implementation of change.

  10. Life-cycle costs of high-performance cells

    NASA Technical Reports Server (NTRS)

    Daniel, R.; Burger, D.; Reiter, L.

    1985-01-01

    A life cycle cost analysis of high efficiency cells was presented. Although high efficiency cells produce more power, they also cost more to make and are more susceptible to array hot-spot heating. Three different computer analysis programs were used: SAMICS (solar array manufacturing industry costing standards), PVARRAY (an array failure mode/degradation simulator), and LCP (lifetime cost and performance). The high efficiency cell modules were found to be more economical in this study, but parallel redundancy is recommended.

  11. High performance pitch-based carbon fiber

    SciTech Connect

    Tadokoro, Hiroyuki; Tsuji, Nobuyuki; Shibata, Hirotaka; Furuyama, Masatoshi

    1996-12-31

    The high performance pitch-based carbon fiber with smaller diameter, six micro in developed by Nippon Graphite Fiber Corporation. This fiber possesses high tensile modulus, high tensile strength, excellent yarn handle ability, low thermal expansion coefficient, and high thermal conductivity which make it an ideal material for space applications such as artificial satellites. Performance of this fiber as a reinforcement of composites was sufficient. With these characteristics, this pitch-based carbon fiber is expected to find wide variety of possible applications in space structures, industrial field, sporting goods and civil infrastructures.

  12. NCI's Transdisciplinary High Performance Scientific Data Platform

    NASA Astrophysics Data System (ADS)

    Evans, Ben; Antony, Joseph; Bastrakova, Irina; Car, Nicholas; Cox, Simon; Druken, Kelsey; Evans, Bradley; Fraser, Ryan; Ip, Alex; Kemp, Carina; King, Edward; Minchin, Stuart; Larraondo, Pablo; Pugh, Tim; Richards, Clare; Santana, Fabiana; Smillie, Jon; Trenham, Claire; Wang, Jingbo; Wyborn, Lesley

    2016-04-01

    The Australian National Computational Infrastructure (NCI) manages Earth Systems data collections sourced from several domains and organisations onto a single High Performance Data (HPD) Node to further Australia's national priority research and innovation agenda. The NCI HPD Node has rapidly established its value, currently managing over 10 PBytes of datasets from collections that span a wide range of disciplines including climate, weather, environment, geoscience, geophysics, water resources and social sciences. Importantly, in order to facilitate broad user uptake, maximise reuse and enable transdisciplinary access through software and standardised interfaces, the datasets, associated information systems and processes have been incorporated into the design and operation of a unified platform that NCI has called, the National Environmental Research Data Interoperability Platform (NERDIP). The key goal of the NERDIP is to regularise data access so that it is easily discoverable, interoperable for different domains and enabled for high performance methods. It adopts and implements international standards and data conventions, and promotes scientific integrity within a high performance computing and data analysis environment. NCI has established a rich and flexible computing environment to access to this data, through the NCI supercomputer; a private cloud that supports both domain focused virtual laboratories and in-common interactive analysis interfaces; as well as remotely through scalable data services. Data collections of this importance must be managed with careful consideration of both their current use and the needs of the end-communities, as well as its future potential use, such as transitioning to more advanced software and improved methods. It is therefore critical that the data platform is both well-managed and trusted for stable production use (including transparency and reproducibility), agile enough to incorporate new technological advances and

  13. Analysis of anthocyanins in commercial fruit juices by using nano-liquid chromatography-electrospray-mass spectrometry and high-performance liquid chromatography with UV-vis detector.

    PubMed

    Fanali, Chiara; Dugo, Laura; D'Orazio, Giovanni; Lirangi, Melania; Dachà, Marina; Dugo, Paola; Mondello, Luigi

    2011-01-01

    Nano-LC and conventional HPLC techniques were applied for the analysis of anthocyanins present in commercial fruit juices using a capillary column of 100 μm id and a 2.1 mm id narrow-bore C(18) column. Analytes were detected by UV-Vis at 518 nm and ESI-ion trap MS with HPLC and nano-LC, respectively. Commercial blueberry juice (14 anthocyanins detected) was used to optimize chromatographic separation of analytes and other analysis parameters. Qualitative identification of anthocyanins was performed by comparing the recorded mass spectral data with those of published papers. The use of the same mobile phase composition in both techniques revealed that the miniaturized method exhibited shorter analysis time and higher sensitivity than narrow-bore chromatography. Good intra-day and day-to-day precision of retention time was obtained in both methods with values of RSD less than 3.4 and 0.8% for nano-LC and HPLC, respectively. Quantitative analysis was performed by external standard curve calibration of cyanidin-3-O-glucoside standard. Calibration curves were linear in the concentration ranges studied, 0.1-50 and 6-50 μg/mL for HPLC-UV/Vis and nano-LC-MS, respectively. LOD and LOQ values were good for both methods. In addition to commercial blueberry juice, qualitative and quantitative analysis of other juices (e.g. raspberry, sweet cherry and pomegranate) was performed. The optimized nano-LC-MS method allowed an easy and selective identification and quantification of anthocyanins in commercial fruit juices; it offered good results, shorter analysis time and reduced mobile phase volume with respect to narrow-bore HPLC. PMID:21246720

  14. Cloud point extraction preconcentration prior to high-performance liquid chromatography coupled with cold vapor generation atomic fluorescence spectrometry for speciation analysis of mercury in fish samples.

    PubMed

    Yu, Li-Ping

    2005-12-14

    A cloud point extraction methodology was developed for simultaneous preconcentration of Hg(II), methylmercury (MeHg), ethylmercury (EtHg), and phenylmercury (PhHg) prior to reversed-phase high-performance liquid chromatography (HPLC) on-line coupled with cold vapor atomic fluorescence spectrometry for speciation analysis of mercury in fish. The four mercury species were taken into complexes with ammonium pyrrolidine dithiocarbamate (APDC) in aqueous nonionic surfactant Triton X-114 medium and concentrated in the surfactant-rich phase by bringing the solution to the temperature of 40 degrees C. Baseline separation of the enriched complexes was achieved on an RP-C(18) column with a mixture of methanol, acetonitrile, and water (65:15:20, v/v) containing 200 mmol L(-1) HAc (pH 3.5) as the mobile phase. An on-line postcolumn oxidation of the effluent from HPLC, in the presence of K2S2O8 in HCl, was applied in the system followed by an optimal cold vapor generation of mercury species. The variables affecting the complexation and extraction steps were examined. The preconcentration of 10 mL of solution with 0.08% w/v Triton X-114 and 0.04% w/v APDC at pH 3.5 gave enrichment factors of 29, 43, 80, and 98 for MeHg, EtHg, PhHg, and Hg(II), respectively. Low detection limits (S/N = 3) were obtained, ranging from 2 to 9 ng L(-1) (as Hg) for all species. The developed method was successfully applied to the speciation of mercury in real fish samples.

  15. [Multiresidue analysis of 63 veterinary drugs in meat by dispersive solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry].

    PubMed

    Luo, Huitai; Xie, Mengting; Huang, Xiaolan; Wu, Huiqin; Zhu, Zhixin; Huang, Fang; Lin, Xiaoshan; Ouyang, Gangfeng

    2015-04-01

    A novel multiresidue analytical method has been developed and validated for the determination of five classes of veterinary drugs including 18 β-lactams, 15 quinolones, 21 sulfonamides, 3 sulfonamide potentiators and 6 antiparasitics in meat using dispersive solid-phase extraction (dispersive-SPE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The analytes were extracted with a vortex mixer by 0.1 mol/L Na2 EDTA solution and acetonitrile containing 1% (v/v) acetic acid, and then the extracts were purified using dispersive-SPE with C18 sorbent. Electrospray ionization mass spectrometry was operated in positive mode using dynamic multiple reaction monitoring (DMRM) for the qualitative and quantitative analysis of the 63 analytes after the separation on a Poroshell EC-C18 column (100 mm x 2.1 mm, 2.4 µm). The correlation coefficients of linear calibration curves were over 0.99 in the corresponding concentration ranges. The average recoveries of the 63 analytes ranged from 62.2% to 112.0%, and the relative standard deviations (RSDs) were 3.1%-16.3% in spiked meat (pork, beef and chicken muscle) at three levels. The limits of detection (LODs, S/N ≥ 3) and the limits of quantification (LOQs, S/N ≥ 10) were 0.1-3.0 µg/kg and 0.5-10.0 µg/kg, respectively. The method is simple, rapid, sensitive, reliable and suitable for the determination of residues in animal products. PMID:26292404

  16. Cloud point extraction preconcentration prior to high-performance liquid chromatography coupled with cold vapor generation atomic fluorescence spectrometry for speciation analysis of mercury in fish samples.

    PubMed

    Yu, Li-Ping

    2005-12-14

    A cloud point extraction methodology was developed for simultaneous preconcentration of Hg(II), methylmercury (MeHg), ethylmercury (EtHg), and phenylmercury (PhHg) prior to reversed-phase high-performance liquid chromatography (HPLC) on-line coupled with cold vapor atomic fluorescence spectrometry for speciation analysis of mercury in fish. The four mercury species were taken into complexes with ammonium pyrrolidine dithiocarbamate (APDC) in aqueous nonionic surfactant Triton X-114 medium and concentrated in the surfactant-rich phase by bringing the solution to the temperature of 40 degrees C. Baseline separation of the enriched complexes was achieved on an RP-C(18) column with a mixture of methanol, acetonitrile, and water (65:15:20, v/v) containing 200 mmol L(-1) HAc (pH 3.5) as the mobile phase. An on-line postcolumn oxidation of the effluent from HPLC, in the presence of K2S2O8 in HCl, was applied in the system followed by an optimal cold vapor generation of mercury species. The variables affecting the complexation and extraction steps were examined. The preconcentration of 10 mL of solution with 0.08% w/v Triton X-114 and 0.04% w/v APDC at pH 3.5 gave enrichment factors of 29, 43, 80, and 98 for MeHg, EtHg, PhHg, and Hg(II), respectively. Low detection limits (S/N = 3) were obtained, ranging from 2 to 9 ng L(-1) (as Hg) for all species. The developed method was successfully applied to the speciation of mercury in real fish samples. PMID:16332112

  17. Quantitative analysis of amino acids and acylcarnitines combined with untargeted metabolomics using ultra-high performance liquid chromatography and quadrupole time-of-flight mass spectrometry.

    PubMed

    Roy, Cynthia; Tremblay, Pierre-Yves; Bienvenu, Jean-François; Ayotte, Pierre

    2016-08-01

    Metabolomics is an "omic" technique being increasingly used in epidemiological and clinical studies. We developed a method combining untargeted metabolomics with the quantitative determination of eight amino acids (AA) and eight acylcarnitines (AC) in plasma using ultra-high pressure liquid chromatography (UHPLC), electrospray ionization (ESI) and quadrupole time-of-flight mass spectrometry (QTOFMS). Separation of metabolites is performed by ion-pair reverse phase UHPLC using a HSS T3 column (2.1×100mm, 100Å, 1.8μm particle size) and formic acid-ammonium acetate-heptafluorobutyric acid in water and formic acid-ammonium acetate in methanol as mobile phases. Metabolite identification and quantification are achieved using a QTOFMS operating in ESI-positive and full-scan mode along with MS(E) acquisition of fragmentation patterns. Targeted metabolites are quantified using the appropriate labeled standards and include branched-chain AA (leucine, isoleucine, valine), aromatic AA (phenylalanine, tyrosine) as well as acetylcarnitine and propionylcarnitine, which have been identified as biomarkers of future cardiometabolic disease risk. The inter-day precision (relative standard deviation) for the targeted method was <15% for all but one metabolite and accuracy (bias) of amino acids ranged from 0.5% to 13.9% using SRM 1950 as the external standard. Untargeted metabolomics in 30 plasma samples from the general Canadian population revealed 5018 features, of which 48 metabolites were identified using the MZmine 2.19 software including 23 by our in-house library that comprises 671 annotated metabolites. SRM 1950 analysis revealed 11,684 features, among which 154 metabolites were identified. Our method is currently applied in several epidemiological studies to better characterize cardiometabolic diseases and identify new biomarkers for disease prevention. PMID:27240302

  18. Comparative oxidation state specific analysis of arsenic species by high-performance liquid chromatography-inductively coupled-mass spectrometry and hydride generation-cryotrapping-atomic absorption spectrometry

    EPA Science Inventory

    The formation of methylarsonous acid (MAsIII) and dimethylarsinous acid (DMAsIII) in the course of inorganic arsenic (iAs) metabolism plays an important role in the adverse effects of chronic exposure to iAs. High-performance liquid chromatography-inductively coupled plasma-mass ...

  19. Highlighting High Performance: Whitman Hanson Regional High School; Whitman, Massachusetts

    SciTech Connect

    Not Available

    2006-06-01

    This brochure describes the key high-performance building features of the Whitman-Hanson Regional High School. The brochure was paid for by the Massachusetts Technology Collaborative as part of their Green Schools Initiative. High-performance features described are daylighting and energy-efficient lighting, indoor air quality, solar and wind energy, building envelope, heating and cooling systems, water conservation, and acoustics. Energy cost savings are also discussed.

  20. Speciation analysis of mercury in sediments using vortex-assisted liquid-liquid microextraction coupled to high-performance liquid chromatography-cold vapor atomic fluorescence spectrometry.

    PubMed

    Leng, Geng; Yin, Hui; Li, Shaobo; Chen, Yong; Dan, Dezhong

    2012-09-15

    A simple and fast solvent microextraction method termed vortex-assisted liquid-liquid microextraction (VALLME) coupled with high-performance liquid chromatography-vapor generation atomic fluorescence spectrometry (HPLC-CVAFS) has been developed for the trace analysis of methylmercury (MeHg(+)), ethylmercury (EtHg(+)) and inorganic mercury (Hg(2+)) in sediment samples. Carbon tetrachloride was used as collecting solvent for the extraction of mercury species from sediment by a vortex-assisted extraction. In VALLME, 100 μL 1% (m/v) l-Cysteine were used as extraction solvent and were injected into 4 mL carbon tetrachloride. The extraction solvent dispersed into carbon tetrachloride under vigorously shaking by a vortex agitator. The fine droplets could extract mercury species within few minutes because of the shorter diffusion distance and larger specific surface area. After centrifugation, the floating extractant phase restored its initial single microdrop shape and was used for HPLC-CVAFS analysis. The parameters affecting the extraction efficiency of the proposed VALLME such as extraction solvent, vortex time, volumes of extraction solvent and salt addition etc. were investigated. Under the optimum conditions, linearity was found in the concentration range from 0.1 to 25 ng g(-1) for MeHg(+), 0.2 to 65 ng g(-1) for EtHg(+), and 0.1 to 30 ng g(-1) for Hg(2+). Coefficients of determination (R(2)) ranged from 0.9938 to 0.9972. The limits of detection (LODs, signal-to-noise ratio (S/N)=3) were 0.028 ng g(-1) for MeHg(+), 0.057 ng g(-1) for EtHg(+), and 0.029 ng g(-1) for Hg(2+). Reproducibility and recoveries were assessed by testing a series of 6 sediment samples, which were spiked with different concentration levels. Finally, the proposed method was successfully applied in analyses of real nature sediment samples. In this work, VALLME was applied to the extraction of mercury species in sediment samples for the first time. Using l-Cys as extraction solvent, the