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Sample records for assay performance demonstration

  1. Performance in the WIPP nondestructive assay performance demonstration program

    Energy Technology Data Exchange (ETDEWEB)

    Marcinkiewicz, C.J. [Consolidated Technical Services, Inc., Frederick, MD (United States); Connolly, M.J.; Becker, G.K. [Lockheed Martin Idaho Technologies Company, Idaho Falls, ID (United States)

    1997-11-01

    Measurement facilities performing nondestructive assay (NDA) of wastes intended for disposal at the United States Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP) are required to demonstrate their ability to meet specific Quality Assurance Objectives (QAOs). This demonstration is performed, in part, by participation in the NDA Performance Demonstration Program (PDP). The PDP is funded and managed by the Carlsbad Area Office (CAO) of DOE and is conducted by the Idaho National Engineering Laboratory. It tests the characteristics of precision, system bias and/or total uncertainty through the measurement of variable, blind combinations of simulated waste drums and certified radioactive standards. Each facility must successfully participate in the PDP using each different type of measurement system planned for use in waste characterization. The first cycle of the PDP using each different type of measurement system planned for use in waste characterization. The first cycle of the PDP was completed in July 1996 and the second is scheduled for completion by December 1996. Seven sites reported data in cycle 1 for 11 different measurement systems. This paper describes the design and operation of the PDP and provides the performance data from cycle 1. It also describes the preliminary results from cycle 2 and updates the status and future plans for the NDA PDP. 4 refs., 9 figs., 11 tabs.

  2. Performance Demonstration Program Plan for Nondestructive Assay of Boxed Wastes for the TRU Waste Characterization Program

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-10-01

    Each testing and analytical facility performing waste characterization activities for the Waste Isolation Pilot Plant (WIPP) participates in the Performance Demonstration Program (PDP) to comply with the Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (WAC) (DOE/WIPP-02-3122) and the Quality Assurance Program Document (QAPD) (CBFO-94-1012). The PDP serves as a quality control check for data generated in the characterization of waste destined for WIPP. Single-blind audit samples are prepared and distributed to each of the facilities participating in the PDP. Different PDPs evaluate the analyses of simulated headspace gases (HSGs), constituents of the Resource Conservation and Recovery Act (RCRA), and transuranic (TRU) radionuclides using nondestructive assay (NDA) techniques.

  3. Performance Demonstration Program Plan for Nondestructive Assay of Drummed Wastes for the TRU Waste Characterization Program

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    2009-04-01

    Each testing and analytical facility performing waste characterization activities for the Waste Isolation Pilot Plant (WIPP) participates in the Performance Demonstration Program (PDP) to comply with the Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (WAC) (DOE/WIPP-02-3122) and the Quality Assurance Program Document (QAPD) (CBFO-94-1012). The PDP serves as a quality control check for data generated in the characterization of waste destined for WIPP. Single blind audit samples are prepared and distributed to each of the facilities participating in the PDP. The PDP evaluates analyses of simulated headspace gases, constituents of the Resource Conservation and Recovery Act (RCRA), and transuranic (TRU) radionuclides using nondestructive assay (NDA) techniques.

  4. Performance Demonstration Program Plan for Nondestructive Assay of Drummed Wastes for the TRU Waste Characterization Program

    Energy Technology Data Exchange (ETDEWEB)

    Carlsbad Field Office

    2005-08-03

    The Performance Demonstration Program (PDP) for Nondestructive Assay (NDA) is a test program designed to yield data on measurement system capability to characterize drummed transuranic (TRU) waste generated throughout the Department of Energy (DOE) complex. The tests are conducted periodically and provide a mechanism for the independent and objective assessment of NDA system performance and capability relative to the radiological characterization objectives and criteria of the Office of Characterization and Transportation (OCT). The primary documents requiring an NDA PDP are the Waste Acceptance Criteria for the Waste Isolation Pilot Plant (WAC), which requires annual characterization facility participation in the PDP, and the Quality Assurance Program Document (QAPD). This NDA PDP implements the general requirements of the QAPD and applicable requirements of the WAC. Measurement facilities must demonstrate acceptable radiological characterization performance through measurement of test samples comprised of pre-specified PDP matrix drum/radioactive source configurations. Measurement facilities are required to analyze the NDA PDP drum samples using the same procedures approved and implemented for routine operational waste characterization activities. The test samples provide an independent means to assess NDA measurement system performance and compliance per criteria delineated in the NDA PDP Plan. General inter-comparison of NDA measurement system performance among DOE measurement facilities and commercial NDA services can also be evaluated using measurement results on similar NDA PDP test samples. A PDP test sample consists of a 55-gallon matrix drum containing a waste matrix type representative of a particular category of the DOE waste inventory and nuclear material standards of known radionuclide and isotopic composition typical of DOE radioactive material. The PDP sample components are made available to participating measurement facilities as designated by the

  5. Evaluation of the technical performance of novel holotranscobalamin (holoTC) assays in a multicenter European demonstration project.

    Science.gov (United States)

    Morkbak, Anne L; Heimdal, Randi M; Emmens, Kathleen; Molloy, Anne; Hvas, Anne-Mette; Schneede, Joern; Clarke, Robert; Scott, John M; Ueland, Per M; Nexo, Ebba

    2005-01-01

    A commercially available holotranscobalamin (holo-TC) radioimmunoassay (RIA) (Axis-Shield, Dundee, Scotland) was evaluated in four laboratories and compared with a holoTC ELISA run in one laboratory. The performance of the holoTC RIA assay was comparable in three of the four participating laboratories. The results from these three laboratories, involving at least 20 initial runs of "low", "medium" and "high" serum-based controls (mean holoTC concentrations 34, 60 and 110 pmol/L, respectively) yielded an intra-laboratory imprecision of 6-10%. No systematic inter-laboratory deviations were observed on runs involving 72 patient samples (holoTC concentration range 10-160 pmol/L). A fourth laboratory demonstrated higher assay imprecision for control samples and systematic deviation of results for the patient samples. Measurement of holoTC by ELISA showed an imprecision of 4-5%, and slightly higher mean values for the controls (mean holoTC concentrations 40, 70 and 114 pmol/L, respectively). Comparable results were obtained for the patient samples. The long-term intra-laboratory imprecision was 12% for the holoTC RIA and 6% for the ELISA. In conclusion, it would be prudent to check the calibration and precision prior to starting to use these holoTC assays in research or clinical practice. The results obtained using the holoTC RIA were similar to those obtained using the holoTC ELISA assay.

  6. Design of benign matrix drums for the non-destructive assay performance demonstration program for the National TRU Program

    Energy Technology Data Exchange (ETDEWEB)

    Becker, G.K.

    1996-09-01

    Regulatory compliance programs associated with the Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP) Transuranic (TRU) Waste Characterization Program (the Program) require the collection of waste characterization data of known quality to support repository performance assessment, permitting, and associated activities. Blind audit samples, referred to as PDP (performance demonstration program) samples, are devices used in the NDA PDP program to acquire waste NDA system performance data per defined measurement routines. As defined under the current NDA PDP Program Plan, a PDP sample consists of a DOT 17C 55-gallon PDP matrix drum configured with insertable radioactive standards, working reference materials (WRMs). The particular manner in which the matrix drum and PDP standard(s) are combined is a function of the waste NDA system performance test objectives of a given cycle. The scope of this document is confined to the design of the PDP drum radioactive standard internal support structure, the matrix type and the as installed configuration. The term benign is used to designate a matrix possessing properties which are nominally non-interfering to waste NDA measurement techniques. Measurement interference sources are technique specific but include attributes such as: high matrix density, heterogeneous matrix distributions, matrix compositions containing high moderator/high Z element concentrations, etc. To the extent practicable the matrix drum design should not unduly bias one NDA modality over another due to the manner in which the matrix drum configuration manifests itself to the measurement system. To this end the PDP matrix drum configuration and composition detailed below is driven primarily by the intent to minimize the incorporation of matrix attributes known to interfere with fundamental waste NDA modalities, i.e. neutron and gamma based techniques.

  7. Performance of a Multiplex Serological Helicobacter pylori Assay on a Novel Microfluidic Assay Platform

    Directory of Open Access Journals (Sweden)

    Angela Filomena

    2017-10-01

    Full Text Available Infection with Helicobacter pylori (H. pylori occurs in 50% of the world population, and is associated with the development of ulcer and gastric cancer. Serological diagnostic tests indicate an H. pylori infection by detecting antibodies directed against H. pylori proteins. In addition to line blots, multiplex assay platforms provide smart solutions for the simultaneous analysis of antibody responses towards several H. pylori proteins. We used seven H. pylori proteins (FliD, gGT, GroEL, HpaA, CagA, VacA, and HP0231 and an H. pylori lysate for the development of a multiplex serological assay on a novel microfluidic platform. The reaction limited binding regime in the microfluidic channels allows for a short incubation time of 35 min. The developed assay showed very high sensitivity (99% and specificity (100%. Besides sensitivity and specificity, the technical validation (intra-assay CV = 3.7 ± 1.2% and inter-assay CV = 5.5 ± 1.2% demonstrates that our assay is also a robust tool for the analysis of the H. pylori-specific antibody response. The integration of the virulence factors CagA and VacA allow for the assessment of the risk for gastric cancer development. The short assay time and the performance of the platform shows the potential for implementation of such assays in a clinical setting.

  8. Equivalence of ELISpot assays demonstrated between major HIV network laboratories.

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    Dilbinder K Gill

    2010-12-01

    Full Text Available The Comprehensive T Cell Vaccine Immune Monitoring Consortium (CTC-VIMC was created to provide standardized immunogenicity monitoring services for HIV vaccine trials. The ex vivo interferon-gamma (IFN-γ ELISpot is used extensively as a primary immunogenicity assay to assess T cell-based vaccine candidates in trials for infectious diseases and cancer. Two independent, GCLP-accredited central laboratories of CTC-VIMC routinely use their own standard operating procedures (SOPs for ELISpot within two major networks of HIV vaccine trials. Studies are imperatively needed to assess the comparability of ELISpot measurements across laboratories to benefit optimal advancement of vaccine candidates.We describe an equivalence study of the two independently qualified IFN-g ELISpot SOPs. The study design, data collection and subsequent analysis were managed by independent statisticians to avoid subjectivity. The equivalence of both response rates and positivity calls to a given stimulus was assessed based on pre-specified acceptance criteria derived from a separate pilot study.Detection of positive responses was found to be equivalent between both laboratories. The 95% C.I. on the difference in response rates, for CMV (-1.5%, 1.5% and CEF (-0.4%, 7.8% responses, were both contained in the pre-specified equivalence margin of interval [-15%, 15%]. The lower bound of the 95% C.I. on the proportion of concordant positivity calls for CMV (97.2% and CEF (89.5% were both greater than the pre-specified margin of 70%. A third CTC-VIMC central laboratory already using one of the two SOPs also showed comparability when tested in a smaller sub-study.The described study procedure provides a prototypical example for the comparison of bioanalytical methods in HIV vaccine and other disease fields. This study also provides valuable and unprecedented information for future vaccine candidate evaluations on the comparison and pooling of ELISpot results generated by the CTC

  9. Demonstration of DSI-semen--A novel DNA methylation-based forensic semen identification assay.

    Science.gov (United States)

    Wasserstrom, Adam; Frumkin, Dan; Davidson, Ariane; Shpitzen, Moshe; Herman, Yael; Gafny, Ron

    2013-01-01

    Determining whether the source tissue of biological material is semen is important in confirming sexual assaults, which account for a considerable percentage of crime cases. The gold standard for confirming the presence of semen is microscopic identification of sperm cells, however, this method is labor intensive and operator-dependent. Protein-based immunologic assays, such as PSA, are highly sensitive and relatively fast, but suffer from low specificity in some situations. In addition, proteins are less stable than DNA under most environmental insults. Recently, forensic tissue identification advanced with the development of several approaches based on mRNA and miRNA for identification of various body fluids. Herein is described DNA source identifier (DSI)-semen, a DNA-based assay that determines whether the source tissue of a sample is semen based on detection of semen-specific methylation patterns in five genomic loci. The assay is comprised of a simple single tube biochemical procedure, similar to DNA profiling, followed by automatic software analysis, yielding the identification (semen/non-semen) accompanied by a statistical confidence level. Three additional internal control loci are used to ascertain the reliability of the results. The assay, which aims to replace microscopic examination, can easily be integrated by forensic laboratories and is automatable. The kit was tested on 135 samples of semen, saliva, venous blood, menstrual blood, urine, and vaginal swabs and the identification of semen vs. non-semen was correct in all cases. In order to test the assay's applicability in "real-life" situations, 33 actual casework samples from the forensic biological lab of the Israeli police were analyzed, and the results were compared with microscopic examination performed by Israeli police personnel. There was complete concordance between both analyses except for one sample, in which the assay identified semen whereas no sperm was seen in the microscope. This

  10. ACES demonstration: construction, startup, and performance report

    Energy Technology Data Exchange (ETDEWEB)

    Holman, A.S.; Brantley, V.R.

    1978-10-01

    A 2000-ft/sup 2/ single-family residence was constructed during the second quarter of 1976 to demonstrate the energy-conserving features of additional insulation, a ventilation cooling cycle, and the Annual Cycle Energy System (ACES). The ACES is an integrated heating and cooling system that supplies space heating, hot water, and space cooling using a heat pump and low-temperature thermal storage. Included in this report are a discussion of the construction techniques employed and the problems encountered during construction, a description of the ACES concept and the ACES mechanical package, and a discussion of the ACES performance and the experiences obtained during initial operation of the ACES. Continuous operation and data collection were begun in May 1977. Performance data from November 1977 through March 1978 have shown a seasonal heating coefficient of performance of 2.77 for the ACES, giving a 63% energy reduction compared to electric resistance space and water heating.

  11. Contamination control and assay results for the Majorana Demonstrator ultra clean components

    Science.gov (United States)

    Christofferson, C. D.; Abgrall, N.; Alvis, S. I.; Arnquist, I. J.; Avignone, F. T.; Barabash, A. S.; Barton, C. J.; Bertrand, F. E.; Bode, T.; Bradley, A. W.; Brudanin, V.; Busch, M.; Buuck, M.; Caldwell, T. S.; Chan, Y.-D.; Chu, P.-H.; Cuesta, C.; Detwiler, J. A.; Dunagan, C.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Gilliss, T.; Giovanetti, G. K.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Haufe, C. R.; Hehn, L.; Henning, R.; Hoppe, E. W.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; Lopez, A. M.; Martin, R. D.; Massarczyk, R.; Meijer, S. J.; Mertens, S.; Myslik, J.; O'Shaughnessy, C.; Othman, G.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Reine, A. L.; Rielage, K.; Robertson, R. G. H.; Rouf, N. W.; Shanks, B.; Shirchenko, M.; Suriano, A. M.; Tedeschi, D.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C.-H.; Yumatov, V.; Zhitnikov, I.; Zhu, B. X.

    2018-01-01

    The Majorana Demonstrator is a neutrinoless double beta decay experiment utilizing enriched Ge-76 detectors in 2 separate modules inside of a common solid shield at the Sanford Underground Research Facility. The Demonstrator has utilized world leading assay sensitivities to develop clean materials and processes for producing ultra-pure copper and plastic components. This experiment is now operating, and initial data provide new insights into the success of cleaning and processing. Post production copper assays after the completion of Module 1 showed an increase in U and Th contamination in finished parts compared to starting bulk material. A revised cleaning method and additional round of surface contamination studies prior to Module 2 construction have provided evidence that more rigorous process control can reduce surface contamination. This article describes the assay results and discuss further studies to take advantage of assay capabilities for the purpose of maintaining ultra clean fabrication and process design.

  12. Erythrocyte-based Pig-a gene mutation assay: demonstration of cross-species potential.

    Science.gov (United States)

    Phonethepswath, Souk; Bryce, Steven M; Bemis, Jeffrey C; Dertinger, Stephen D

    2008-12-08

    Glycosylphosphatidylinositol (GPI) anchors attach specific proteins to the cell surface of hematopoietic cells. Of the genes required to form GPI anchors, only Pig-a is located on the X-chromosome. Prior work with rats suggests that the GPI anchor deficient phenotype is a reliable indicator of Pig-a mutation [Bryce et al., Environ. Mol. Mutagen., 49 (2008) 256-264]. The current report extends this line of investigation by describing simplified blood handling procedures, and by testing the assay principle in a second species, Mus musculus. With this method, erythrocytes are isolated, incubated with anti-CD24-PE, and stained with SYTO 13. Flow cytometric analyses quantify GPI anchor-deficient erythrocytes and reticulocytes. After reconstruction experiments with mutant-mimicking cells demonstrated that the analytical performance of the method is high, CD-1 mice were treated on three occasions with 7,12-dimethyl-1,2-benz[a]anthracene (DMBA, 75 mg/kg/day) or ethyl-N-nitrosourea (ENU, 40 mg/kg/day). Two weeks after the final treatment, DMBA-treated mice were found to exhibit markedly elevated frequencies of GPI anchor deficient erythrocytes and reticulocytes. For the ENU experiment, blood specimens were collected at weekly intervals over a 5-week period. Whereas the frequencies of mutant reticulocytes were significantly elevated 1 week after the last administration, the erythrocyte population was unchanged until the second week. Thereafter, both populations exhibited persistently elevated frequencies for the duration of the experiment (mean frequency at termination=310x10(-6) and 523x10(-6) for erythrocyte and reticulocyte populations, respectively). These data provide evidence that Pig-a mutation does not convey an appreciable positive or negative cell survival advantage to affected erythroid progenitors, although they do suggest that affected erythrocytes have a reduced lifespan in circulation. Collectively, accumulated data support the hypothesis that flow cytometric

  13. Performance characteristics of the ARCHITECT Galectin-3 assay.

    Science.gov (United States)

    La'ulu, Sonia L; Apple, Fred S; Murakami, Maryann M; Ler, Ranka; Roberts, William L; Straseski, Joely A

    2013-01-01

    Galectin-3 is an emerging biomarker that is commonly increased in patients with heart failure and/or patients at risk for cardiovascular disease. We evaluated the Galectin-3 assay on the Abbott ARCHITECT i1000(SR) and ARCHITECT i2000(SR) at 2 testing sites. Imprecision (%CV), interference, limits of blank (LoB), detection (LoD), and quantitation (LoQ), linearity, method comparison to an ELISA method, comparisons between plasma and serum, and reference intervals were evaluated. Imprecision was performed based on two runs of duplicate testing conducted daily. Verification of LoB, LoD, and LoQ was performed according to Clinical and Laboratory Standards Institute guidelines. Linearity was evaluated by making 5 dilutions of a high patient EDTA plasma pool with a low patient pool. Reference intervals were established using EDTA plasma collected from self-reported healthy volunteers. A second lot of reagent was used at one site for method comparison and imprecision studies. Total CV's were ≤6.0%. A positive interference was observed for hemolyzed samples over 2.0 g/L hemolysate. The LoB ranged from 0.1 to 0.3 ng/mL, the LoD from 1.4 to 2.1 ng/mL and the LoQ from 3.0 to 3.3 ng/mL. Linearity studies had slopes and correlation coefficients equal to 1.0. Comparison of the i1000(SR) and i2000(SR) to the ELISA method demonstrated slopes of 1.0 to 1.2 and correlation coefficients of 0.93 to 0.97. The 97.5th percentile of the reference interval was 18.7 and 17.9 ng/mL for the i1000(SR) and i2000(SR), respectively. The Abbott Galectin-3 assay demonstrated acceptable analytical performance on both the ARCHITECT i1000(SR) and ARCHITECT i2000(SR). Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  14. Clinical performance of a new hepatitis B surface antigen quantitative assay with automatic dilution

    Directory of Open Access Journals (Sweden)

    Ta-Wei Liu

    2015-01-01

    Full Text Available Hepatitis B virus surface antigen (HBsAg levels reflect disease status and can predict the clinical response to antiviral treatment; however, the emergence of HBsAg mutant strains has become a challenge. The Abbott HBsAg quantification assay provides enhanced detection of HBsAg and HBsAg mutants. We aimed to evaluate the performance of the Abbott HBsAg quantification assay with automatic sample dilutions (shortened as automatic Architect assay, compared with the Abbott HBsAg quantification assay with manual sample dilutions (shortened as manual Architect assay and the Roche HBsAg quantification assay with automatic sample dilutions (shortened as Elecsys. A total of 130 sera samples obtained from 87 hepatitis B virus (HBV-infected patients were collected to assess the correlation between the automatic and manual Architect assays. Among the 87 patients, 41 provided 42 sera samples to confirm the linearity and reproducibility of the automatic Architect assay, and find out the correlation among the Elecsys and two Architect assays. The coefficients of variation (0.44–9.53% and R2 = 0.996–1, which were both determined using values obtained from the automatic Architect assay, showed good reproducibility and linearity. Results of the two Architect assays demonstrated a feasible correlation (n = 130 samples; R = 0.898, p  0.93 in all cases. In conclusion, the correlation between the automatic and manual dilution Architect assays was feasible, particularly in the HBeAg-negative and low DNA groups. With lower labor costs and less human error than the manual version, the Abbott automatic dilution Architect assay provided a good clinical performance with regard to the HBsAg levels.

  15. Performance evaluation of a new fourth-generation HIV combination antigen-antibody assay.

    Science.gov (United States)

    Mühlbacher, A; Schennach, H; van Helden, J; Hebell, T; Pantaleo, G; Bürgisser, P; Cellerai, C; Permpikul, P; Rodriguez, M I; Eiras, A; Alborino, F; Cunningham, P; Axelsson, M; Andersson, S; Wetlitzky, O; Kaiser, C; Möller, P; de Sousa, G

    2013-02-01

    Education and diagnostic tests capable of early detection represent our most effective means of preventing transmission of human immunodeficiency virus (HIV). The importance of early detection is underlined by studies demonstrating increased life expectancy following early initiation of antiviral treatment. The Elecsys(®) HIV combi PT assay is a fourth-generation antigen-antibody combination assay developed to allow earlier detection of seroconversion, and to have increased sensitivity and improved specificity. We aimed to determine how early the assay could detect infection compared with existing assays; whether all HIV variants could be detected; and the assay's specificity using samples from blood donors, routine specimens, and patients with potential cross-reacting factors. Samples were identified as positive by the Elecsys(®) assay 4.9 days after a positive polymerase chain reaction result (as determined by the panel supplier), which was earlier than the 5.3-7.1 days observed with comparators. The analytical sensitivity of the Elecsys(®) HIV combi PT assay for the HIV-1 p24 antigen was 1.05 IU/mL, which compares favorably with the comparator assays. In addition, the Elecsys(®) assay identified all screened HIV subtypes and displayed greater sensitivity to HIV-2 homologous antigen and antibodies to HIV-1 E and O and HIV-2 than the other assays. Overall, the specificity of the Elecsys(®) assay was 99.88 % using samples from blood donors and 99.81 % when analyzing unselected samples. Potential cross-reacting factors did not interfere with assay performance. The Elecsys(®) HIV combi PT assay is a sensitive and specific assay that has been granted the CE mark according to Directive 2009/886/EC.

  16. The Abbott RealTime MTB assay and the Cepheid GeneXpert assay show comparable performance for the detection of Mycobacterium tuberculosis in sputum specimens.

    Science.gov (United States)

    Wang, Sheng Fen; Ou, Xi Chao; Li, Qiang; Zheng, Hui Wen; Wang, Yu Feng; Zhao, Yan Lin

    2016-04-01

    To evaluate the performance of the newly developed technology Abbott RealTime MTB assay (RealTime MTB assay) for the detection of Mycobacterium tuberculosis in sputum specimens and to compare its performance with that of the Cepheid GeneXpert assay. Sputum specimens were collected from 270 subjects suspected to have tuberculosis (TB). Smear microscopy, culture, identification, RealTime MTB, and GeneXpert assays were performed according to standard protocols. Accuracy measures of the method evaluated were determined using solid culture as the reference standard. The RealTime MTB assay showed similar positive detection rates as the GeneXpert assay in smear-positive, culture-positive, and smear/culture-negative groups; no significant differences were found in these groups between the two assays. The RealTime MTB assay demonstrated a sensitivity of 100% and a specificity of 84.4%; the GeneXpert assay had a sensitivity of 96.9% and specificity of 89.6%. After the resolution of discordant results by PCR-based molecular method, the sensitivities and specificities of the RealTime MTB and GeneXpert assays were 100% vs. 97% and 90.0% vs. 95.6%, respectively; no significant difference in sensitivity or specificity was found between the RealTime MTB and GeneXpert assays. This study demonstrated that the Abbott RealTime MTB and Cepheid GeneXpert assays have similar sensitivity and specificity. The Abbott RealTime MTB assay is a highly promising method for the diagnosis of TB. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Pu-238 assay performance with the Canberra IQ3 system

    Energy Technology Data Exchange (ETDEWEB)

    Booth, L.; Gillespie, B.; Seaman, G.

    1997-11-01

    Canberra Industries has recently completed a demonstration project at the Westinghouse Savannah River Site (WSRC) to characterize 55-gallon drums containing Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 waste to detection limits of less than 50 nCi/g using gamma assay techniques. This would permit reclassification of these drums from transuranic (TRU) waste to low-level waste (LLW). The instrument used for this assay was a Canberra IQ3 high sensitivity gamma assay system, mounted in a trailer. The results of the measurements demonstrate achievement of detection levels as low as 1 nCi/g for low density waste drums, and good correlation with known concentrations in several test drums. In addition, the data demonstrates significant advantages for using large area low-energy germanium detectors for achieving the lowest possible MDAs for gamma rays in the 80-250 keV range. 1 fig., 2 tabs.

  18. Prop Demonstrations in Biology Lectures Facilitate Student Learning and Performance

    Directory of Open Access Journals (Sweden)

    Farshad Tamari

    2015-02-01

    Full Text Available Science students can benefit from visual aids. In biology lectures, visual aids are usually limited to tables, figures, and PowerPoint presentations. In this IRB-approved study, we examined the effectiveness of the use of five prop demonstrations, three of which are at the intersection of biology and chemistry, in three community college biology courses. We hypothesized that students’ performance on test questions is enhanced by the use of prop demonstrations. Consistent with our hypothesis, we showed that students learn more effectively and perform better on questions that relate to demonstrations than on questions related to lessons that do not have a demonstration component.

  19. Prop demonstrations in biology lectures facilitate student learning and performance.

    Science.gov (United States)

    Tamari, Farshad; Bonney, Kevin M; Polizzotto, Kristin

    2015-05-01

    Science students can benefit from visual aids. In biology lectures, visual aids are usually limited to tables, figures, and PowerPoint presentations. In this IRB-approved study, we examined the effectiveness of the use of five prop demonstrations, three of which are at the intersection of biology and chemistry, in three community college biology courses. We hypothesized that students' performance on test questions is enhanced by the use of prop demonstrations. Consistent with our hypothesis, we showed that students learn more effectively and perform better on questions that relate to demonstrations than on questions related to lessons that do not have a demonstration component.

  20. Evaluation of the Thermo Scientific SureTect Listeria species assay. AOAC Performance Tested Method 071304.

    Science.gov (United States)

    Cloke, Jonathan; Evans, Katharine; Crabtree, David; Hughes, Annette; Simpson, Helen; Holopainen, Jani; Wickstrand, Nina; Kauppinen, Mikko; Leon-Velarde, Carlos; Larson, Nathan; Dave, Keron

    2014-01-01

    The Thermo Scientific SureTect Listeria species Assay is a new real-time PCR assay for the detection of all species of Listeria in food and environmental samples. This validation study was conducted using the AOAC Research Institute (RI) Performance Tested Methods program to validate the SureTect Listeria species Assay in comparison to the reference method detailed in International Organization for Standardization 11290-1:1996 including amendment 1:2004 in a variety of foods plus plastic and stainless steel. The food matrixes validated were smoked salmon, processed cheese, fresh bagged spinach, cantaloupe, cooked prawns, cooked sliced turkey meat, cooked sliced ham, salami, pork frankfurters, and raw ground beef. All matrixes were tested by Thermo Fisher Scientific, Microbiology Division, Basingstoke, UK. In addition, three matrixes (pork frankfurters, fresh bagged spinach, and stainless steel surface samples) were analyzed independently as part of the AOAC-RI-controlled independent laboratory study by the University ofGuelph, Canada. Using probability of detection statistical analysis, a significant difference in favour of the SureTect assay was demonstrated between the SureTect and reference method for high level spiked samples of pork frankfurters, smoked salmon, cooked prawns, stainless steel, and low-spiked samples of salami. For all other matrixes, no significant difference was seen between the two methods during the study. Inclusivity testing was conducted with 68 different isolates of Listeria species, all of which were detected by the SureTect Listeria species Assay. None of the 33 exclusivity isolates were detected by the SureTect Listeria species Assay. Ruggedness testing was conducted to evaluate the performance of the assay with specific method deviations outside of the recommended parameters open to variation, which demonstrated that the assay gave reliable performance. Accelerated stability testing was additionally conducted, validating the assay

  1. Multicenter performance evaluation of a second generation cortisol assay.

    Science.gov (United States)

    Vogeser, Michael; Kratzsch, Jürgen; Ju Bae, Yoon; Bruegel, Mathias; Ceglarek, Uta; Fiers, Tom; Gaudl, Alexander; Kurka, Hedwig; Milczynski, Christoph; Prat Knoll, Cristina; Suhr, Anna C; Teupser, Daniel; Zahn, Ingrid; Ostlund, Richard E

    2017-05-01

    Untreated disorders of the adrenocortical system, such as Cushing's or Addison's disease, can be fatal, and accurate quantification of a patient's cortisol levels is vital for diagnosis. The objective of this study was to assess the analytical performance of a new fully-automated Elecsys® Cortisol II assay (second generation) to measure cortisol levels in serum and saliva. Four European investigational sites assessed the intermediate precision and reproducibility of the Cortisol II assay (Roche Diagnostics) under routine conditions. Method comparisons of the Cortisol II assay vs. liquid chromatography-tandem mass spectrometry (LC-MS/MS), the gold standard for cortisol measurement, were performed. Cortisol reference ranges from three US sites were determined using samples from self-reported healthy individuals. The coefficients of variation (CVs) for repeatability, intermediate precision, and reproducibility for serum samples were ≤2.6%, ≤5.8%, and ≤9.5%, respectively, and for saliva were ≤4.4% and ≤10.9%, and ≤11.4%, respectively. Agreement between the Cortisol II assay and LC-MS/MS in serum samples was close, with a slope of 1.02 and an intercept of 4.473 nmol/L. Reference range samples were collected from healthy individuals (n=300) and serum morning cortisol concentrations (5-95th percentile) were 166.1-507 nmol/L and afternoon concentrations were 73.8-291 nmol/L. Morning, afternoon, and midnight saliva concentrations (95th percentile) were 20.3, 6.94, and 7.56 nmol/L, respectively. The Cortisol II assay had good precision over the entire measuring range and had excellent agreement with LC-MS/MS. This test was found suitable for routine diagnostic application and will be valuable for the diagnosis of adrenocortical diseases.

  2. Evaluation of the Clinical Performance of the HPV-Risk Assay Using the VALGENT-3 Panel.

    Science.gov (United States)

    Polman, N J; Oštrbenk, A; Xu, L; Snijders, P J F; Meijer, C J L M; Poljak, M; Heideman, D A M; Arbyn, M

    2017-12-01

    Human papillomavirus (HPV) testing is increasingly being incorporated into cervical cancer screening. The Validation of HPV Genotyping Tests (VALGENT) is a framework designed to evaluate the clinical performance of various HPV tests relative to that of the validated and accepted comparator test in a formalized and uniform manner. The aim of this study was to evaluate the clinical performance of the HPV-Risk assay with samples from the VALGENT-3 panel and to compare its performance to that of the clinically validated Hybrid Capture 2 assay (HC2). The VALGENT-3 panel comprises 1,300 consecutive samples from women participating in routine cervical cancer screening and is enriched with 300 samples from women with abnormal cytology. DNA was extracted from original ThinPrep PreservCyt medium aliquots, and HPV testing was performed using the HPV-Risk assay by investigators blind to the clinical data. HPV prevalence was analyzed, and the clinical performance of the HPV-Risk assay for the detection of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) and CIN2 or worse (CIN2+) relative to the performance of HC2 was assessed. The sensitivity of the HPV-Risk assay for the detection of CIN3+ was similar to that of HC2 (relative sensitivity, 1.00; 95% confidence interval [CI], 0.95 to 1.05; P = 1.000), but the specificity of the HPV-Risk assay was significantly higher than that of HC2 (relative specificity, 1.02; 95% CI, 1.01 to 1.04; P performance of the HPV-Risk assay for the detection of CIN3+ and CIN2+ was noninferior to that of HC2, with all P values being ≤0.006. In conclusion, the HPV-Risk assay demonstrated noninferiority to the clinically validated HC2 by the use of samples from the VALGENT-3 panel for test validation and comparison. Copyright © 2017 Polman et al.

  3. A supplemented soft agar chemotaxis assay demonstrates the Helicobacter pylori chemotactic response to zinc and nickel

    Science.gov (United States)

    Sanders, Lisa; Andermann, Tessa M.

    2013-01-01

    Directed motility, or chemotaxis, is required for Helicobacter pylori to establish infection in the stomach, although the full repertoire of this bacterium’s chemotactic responses is not yet known. Here we report that H. pylori responds to zinc as an attractant and nickel as a repellent. To reach this conclusion, we employed both a temporal chemotaxis assay based on bacterial reversals and a supplemented soft agar spatial assay. We refined the temporal assay using a previously described chemorepellent, acid, and found that H. pylori requires rich media with serum to maintain optimal swimming motility. Surprisingly, we found that some strains respond to acid as an attractant, and that the TlpC chemoreceptor correlated with whether acid was sensed as an attractant or repellent. Using this same assay, we detected weak repellent responses to nickel and copper, and a varied response to zinc. We thus developed an alternative spatial chemotactic assay called the supplemented soft agar assay, which utilizes soft agar medium supplemented with the test compound. With Escherichia coli, the attractant serine slowed overall bacterial migration, while the repellent nickel increased the speed of overall migration. In H. pylori we detected slowed migration with doubled tryptone media, as well as zinc, consistent with an attractant response. In contrast, nickel increased migration, consistent with repulsion. PMID:23139399

  4. RNA-based Assay Demonstrated Enterococcus faecalis Metabolic Activity after Chemomechanical Procedures.

    Science.gov (United States)

    Pinheiro, Ericka T; Candeiro, George T; Teixeira, Sílvia R; Shin, Regina C; Prado, Laís C; Gavini, Giulio; Mayer, Márcia P A

    2015-09-01

    Because ribosomal RNA (rRNA) indicates metabolic cell activity, this study aimed to evaluate the sensitivity of rRNA-based quantitative polymerase chain reaction (RT-qPCR) for the identification of active Enterococcus faecalis in root canals samples compared with a method based on ribosomal DNA (rDNA) (rRNA genes). Samples were taken from 18 teeth with persistent/secondary intraradicular infection before (S1) and after (S2) chemomechanical preparation. RNA and DNA were extracted, and complementary DNA was synthesized from RNA using RT-PCR. Complementary DNA and genomic DNA were subjected to quantitative polymerase chain reaction with primers complementary for E. faecalis 16S rRNA sequence. E. faecalis was detected in 77.8% and 72.2% of S1 samples using rRNA- and rDNA-based assays, respectively. In contrast, E. faecalis was detected in only 33.3% of S2 samples using rDNA as the template compared with 61.1% using the rRNA-based method. The median concentration of rRNA copies of E. faecalis was significantly higher than rDNA copies, indicating a higher sensitivity for the method targeting rRNA in both S1 (P faecalis persisted in root canals after chemomechanical preparation. The RT-qPCR assay provides a sensitive method for the identification of active E. faecalis from endodontic samples. Furthermore, the rRNA-based assay indicated that E. faecalis viable cells persisted in treated root canals, suggesting that it may be a useful tool for monitoring microbial load during endodontic treatment. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. The Beckman DxI 800 prolactin assay demonstrates superior specificity for monomeric prolactin.

    LENUS (Irish Health Repository)

    Byrne, Brendan

    2010-02-01

    Commercially available prolactin immunoassays detect macroprolactin to variable degrees. Best practice requires laboratories to assess the cross-reactivity of their prolactin assay with macroprolactin, and where appropriate, introduce a screen for the presence of macroprolactin. Our policy has been to reanalyse hyperprolactinaemic samples following polyethylene glycol (PEG) precipitation and to report the resultant value as the monomeric prolactin content of the sample. The goal of this study was to determine the need to continue PEG precipitation when prolactin measurements with the Wallac AutoDELFIA were replaced by the Beckman DxI 800.

  6. Spent nuclear fuel storage -- Performance tests and demonstrations

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, M.A.; DeLoach, V.A.

    1993-04-01

    This report summarizes the results of heat transfer and shielding performance tests and demonstrations conducted from 1983 through 1992 by or in cooperation with the US Department of Energy (DOE), Office of Commercial Radioactive Waste Management (OCRWM). The performance tests consisted of 6 to 14 runs involving one or two loadings, usually three backfill environments (helium, nitrogen, and vacuum backfills), and one or two storage system orientations. A description of the test plan, spent fuel load patterns, results from temperature and dose rate measurements, and fuel integrity evaluations are contained within the report.

  7. GeneQuence" Salmonella assay. Performance Tested Method 030201.

    Science.gov (United States)

    Alles, Susan; Mozola, Mark

    2009-01-01

    A study was conducted to validate the GeneQuence Salmonella DNA hybridization assay, Performance Tested Method 030201, for detection of Salmonella spp. in peanut butter. The study was organized by the AOAC Research Institute under its Emergency Response Validation program. Peanut butter samples inoculated with S. Typhimurium were prepared by an independent laboratory and shipped to study participants for testing. The set of blind-coded test samples consisted of five uninoculated controls, 20 portions inoculated with S. Typhimurium at a low level [determined by most probable number (MPN) analysis to contain 1.1 CFU/25 g portion], and 20 portions inoculated with S. Typhimurium at a higher level (11 CFU/25 g portion by MPN analysis). Samples were tested in parallel by the GeneQuence method and by the U.S. Food and Drug Administration's Bacteriological Analytical Manual reference culture procedure. All five control samples were negative by both methods. For the low-level samples, the same two samples were positive by both the GeneQuence and reference methods. For the high-level samples, the same 19 samples were positive by both methods. All positive GeneQuence assays were confirmed by plating from associated broth cultures. Agreement between the GeneQuence and reference methods was 100%. Sensitivity and specificity of the GeneQuence method were both 100%. Because neither the low- nor the high-level samples yielded the desired fractional positive results (5-15 positives out of 20 samples), a second trial was conducted. Samples in the second trial contained 0.1 and 0.5 CFU/25 g portion for the low and high levels, respectively. All five control samples were negative by both methods. For the low-level samples, the same two samples were positive by both the GeneQuence and reference methods. For the high-level samples, the same three samples were positive by both methods. All positive GeneQuence assays were confirmed by plating from associated broth cultures. Sensitivity

  8. Progress Toward Demonstrating a High Performance Optical Tape Recording Technology

    Science.gov (United States)

    Oakley, W. S.

    1996-01-01

    This paper discusses the technology developments achieved during the first year of a program to develop a high performance digital optical tape recording device using a solid state, diode pumped, frequency doubled green laser source. The goal is to demonstrate, within two years, useful read/write data transfer rates to at least 100 megabytes per second and a user capacity of up to one terabyte per cartridge implemented in a system using a '3480' style mono-reel tape cartridge.

  9. Performance Demonstration Program Plan for Analysis of Simulated Headspace Gases

    Energy Technology Data Exchange (ETDEWEB)

    Carlsbad Field Office

    2006-04-01

    The Performance Demonstration Program (PDP) for headspace gases distributes sample gases of volatile organic compounds (VOCs) for analysis. Participating measurement facilities (i.e., fixed laboratories, mobile analysis systems, and on-line analytical systems) are located across the United States. Each sample distribution is termed a PDP cycle. These evaluation cycles provide an objective measure of the reliability of measurements performed for transuranic (TRU) waste characterization. The primary documents governing the conduct of the PDP are the Quality Assurance Program Document (QAPD) (DOE/CBFO-94-1012) and the Waste Isolation Pilot Plant (WIPP) Waste Analysis Plan (WAP) contained in the Hazardous Waste Facility Permit (NM4890139088-TSDF) issued by the New Mexico Environment Department (NMED). The WAP requires participation in the PDP; the PDP must comply with the QAPD and the WAP. This plan implements the general requirements of the QAPD and the applicable requirements of the WAP for the Headspace Gas (HSG) PDP. Participating measurement facilities analyze blind audit samples of simulated TRU waste package headspace gases according to the criteria set by this PDP Plan. Blind audit samples (hereafter referred to as PDP samples) are used as an independent means to assess each measurement facility’s compliance with the WAP quality assurance objectives (QAOs). To the extent possible, the concentrations of VOC analytes in the PDP samples encompass the range of concentrations anticipated in actual TRU waste package headspace gas samples. Analyses of headspace gases are required by the WIPP to demonstrate compliance with regulatory requirements. These analyses must be performed by measurement facilities that have demonstrated acceptable performance in this PDP. These analyses are referred to as WIPP analyses and the TRU waste package headspace gas samples on which they are performed are referred to as WIPP samples in this document. Participating measurement

  10. Performance Demonstration Program Plan for Analysis of Simulated Headspace Gases

    Energy Technology Data Exchange (ETDEWEB)

    Carlsbad Field Office

    2007-11-13

    The Performance Demonstration Program (PDP) for headspace gases distributes blind audit samples in a gas matrix for analysis of volatile organic compounds (VOCs). Participating measurement facilities (i.e., fixed laboratories, mobile analysis systems, and on-line analytical systems) are located across the United States. Each sample distribution is termed a PDP cycle. These evaluation cycles provide an objective measure of the reliability of measurements performed for transuranic (TRU) waste characterization. The primary documents governing the conduct of the PDP are the Quality Assurance Program Document (QAPD) (DOE/CBFO-94-1012) and the Waste Isolation Pilot Plant (WIPP) Waste Analysis Plan (WAP) contained in the Hazardous Waste Facility Permit (NM4890139088-TSDF) issued by the New Mexico Environment Department (NMED). The WAP requires participation in the PDP; the PDP must comply with the QAPD and the WAP. This plan implements the general requirements of the QAPD and the applicable requirements of the WAP for the Headspace Gas (HSG) PDP. Participating measurement facilities analyze blind audit samples of simulated TRU waste package headspace gases according to the criteria set by this PDP Plan. Blind audit samples (hereafter referred to as PDP samples) are used as an independent means to assess each measurement facility’s compliance with the WAP quality assurance objectives (QAOs). To the extent possible, the concentrations of VOC analytes in the PDP samples encompass the range of concentrations anticipated in actual TRU waste package headspace gas samples. Analyses of headspace gases are required by the WIPP to demonstrate compliance with regulatory requirements. These analyses must be performed by measurement facilities that have demonstrated acceptable performance in this PDP. These analyses are referred to as WIPP analyses and the TRU waste package headspace gas samples on which they are performed are referred to as WIPP samples in this document

  11. Performance Demonstration Program Plan for Analysis of Simulated Headspace Gases

    Energy Technology Data Exchange (ETDEWEB)

    Carlsbad Field Office

    2007-11-19

    The Performance Demonstration Program (PDP) for headspace gases distributes blind audit samples in a gas matrix for analysis of volatile organic compounds (VOCs). Participating measurement facilities (i.e., fixed laboratories, mobile analysis systems, and on-line analytical systems) are located across the United States. Each sample distribution is termed a PDP cycle. These evaluation cycles provide an objective measure of the reliability of measurements performed for transuranic (TRU) waste characterization. The primary documents governing the conduct of the PDP are the Quality Assurance Program Document (QAPD) (DOE/CBFO-94-1012) and the Waste Isolation Pilot Plant (WIPP) Waste Analysis Plan (WAP) contained in the Hazardous Waste Facility Permit (NM4890139088-TSDF) issued by the New Mexico Environment Department (NMED). The WAP requires participation in the PDP; the PDP must comply with the QAPD and the WAP. This plan implements the general requirements of the QAPD and the applicable requirements of the WAP for the Headspace Gas (HSG) PDP. Participating measurement facilities analyze blind audit samples of simulated TRU waste package headspace gases according to the criteria set by this PDP Plan. Blind audit samples (hereafter referred to as PDP samples) are used as an independent means to assess each measurement facility’s compliance with the WAP quality assurance objectives (QAOs). To the extent possible, the concentrations of VOC analytes in the PDP samples encompass the range of concentrations anticipated in actual TRU waste package headspace gas samples. Analyses of headspace gases are required by the WIPP to demonstrate compliance with regulatory requirements. These analyses must be performed by measurement facilities that have demonstrated acceptable performance in this PDP. These analyses are referred to as WIPP analyses and the TRU waste package headspace gas samples on which they are performed are referred to as WIPP samples in this document

  12. Performance of fluorescent europium(III) nanoparticles and colloidal gold reporters in lateral flow bioaffinity assay.

    Science.gov (United States)

    Juntunen, Etvi; Myyryläinen, Tiina; Salminen, Teppo; Soukka, Tero; Pettersson, Kim

    2012-09-01

    Lateral flow (LF) immunoassays (i.e., immunochromatographic assays) have traditionally been applied to analytes that do not require very high analytical sensitivity or quantitative results. The selection of potential analytes is often limited by the performance characteristics of the assay technology. Analytes with more demanding sensitivity requirements call for reporter systems enabling high analytical sensitivity. In this study, we systematically compared the performance of fluorescent europium(III) [Eu(III)] chelate dyed polystyrene nanoparticles and colloidal gold particles in lateral flow assays. The effect of time-resolved measurement mode was also studied. Because binder molecules used in immunoassays might not behave similarly when conjugated to different reporter particles, two model assays were constructed to provide reliable technical comparison of the two reporter systems. The comparative experiment demonstrated that the fluorescent nanoparticles yielded 7- and 300-fold better sensitivity compared with colloidal gold in the two test systems, respectively. Although the two reporter particles may induce variable effects using individual binders, overall the high specific activity of Eu(III) nanoparticles has superior potential over colloidal gold particles for the development of robust high-sensitivity bioaffinity assays. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. A targeted metabolomics assay for cardiac metabolism and demonstration using a mouse model of dilated cardiomyopathy

    NARCIS (Netherlands)

    West, James A.; Beqqali, Abdelaziz; Ament, Zsuzsanna; Elliott, Perry; Pinto, Yigal M.; Arbustini, Eloisa; Griffin, Julian L.

    2016-01-01

    Metabolomics can be performed either as an 'open profiling' tool where the aim is to measure, usually in a semi-quantitative manner, as many metabolites as possible or perform 'closed' or 'targeted' analyses where instead a pre-defined set of metabolites are measured. Targeted methods can be

  14. Repeated Assessment by High-Throughput Assay Demonstrates that Sperm DNA Methylation Levels Are Highly Reproducible

    Science.gov (United States)

    Cortessis, Victoria K.; Siegmund, Kimberly; Houshdaran, Sahar; Laird, Peter W.; Sokol, Rebecca Z.

    2011-01-01

    Objective To assess reliability of high-throughput assay of sperm DNA methylation. Design Observational study comparing DNA methylation of sperm isolated from three divided and twelve longitudinally collected semen samples. Setting Academic Medical Center Patients One man undergoing screening semen analysis during evaluation of the infertile couple and two healthy fertile male volunteers. Interventions Spermatozoa were separated from seminal plasma and somatic cells using gradient separation. DNA was extracted from spermatozoa, and DNA methylation was assessed at 1,505 DNA-sequence specific sites. Main Outcome Measures Repeatability of sperm DNA methylation measures, estimated by correlation coefficients. Results DNA methylation levels were highly correlated within matched sets of divided samples (all r≥0.97) and longitudinal samples (average r=0.97). Conclusions The described methodology reliably assesses methylation of sperm DNA at large numbers of sites. Methylation profiles were consistent over time. High-throughput assessment of sperm DNA methylation is a promising tool for studying the role of epigenetic state in male fertility. PMID:22035967

  15. Low cut-off values increase diagnostic performance of protein S assays

    NARCIS (Netherlands)

    Mulder, Rene; ten Kate, Min Ki; Kluin-Nelemans, Hanneke C.; Mulder, Andre B.

    Conflicting data have been reported on the accuracy of protein S (PS) assays for detection of hereditary PS deficiency. In this study we assessed the diagnostic performance of two total PS antigen assays, four free PS assays and three PS activity assays in a group of 28 heterozygous carriers of

  16. Evaluation of the Thermo Scientific SureTect Salmonella species assay. AOAC Performance Tested Method 051303.

    Science.gov (United States)

    Cloke, Jonathan; Clark, Dorn; Radcliff, Roy; Leon-Velarde, Carlos; Larson, Nathan; Dave, Keron; Evans, Katharine; Crabtree, David; Hughes, Annette; Simpson, Helen; Holopainen, Jani; Wickstrand, Nina; Kauppinen, Mikko

    2014-01-01

    The Thermo Scientific SureTect Salmonella species Assay is a new real-time PCR assay for the detection of Salmonellae in food and environmental samples. This validation study was conducted using the AOAC Research Institute (RI) Performance Tested Methods program to validate the SureTect Salmonella species Assay in comparison to the reference method detailed in International Organization for Standardization 6579:2002 in a variety of food matrixes, namely, raw ground beef, raw chicken breast, raw ground pork, fresh bagged lettuce, pork frankfurters, nonfat dried milk powder, cooked peeled shrimp, pasteurized liquid whole egg, ready-to-eat meal containing beef, and stainless steel surface samples. With the exception of liquid whole egg and fresh bagged lettuce, which were tested in-house, all matrixes were tested by Marshfield Food Safety, Marshfield, WI, on behalf of Thermo Fisher Scientific. In addition, three matrixes (pork frankfurters, lettuce, and stainless steel surface samples) were analyzed independently as part of the AOAC-RI-controlled laboratory study by the University of Guelph, Canada. No significant difference by probability of detection or McNemars Chi-squared statistical analysis was found between the candidate or reference methods for any of the food matrixes or environmental surface samples tested during the validation study. Inclusivity and exclusivity testing was conducted with 117 and 36 isolates, respectively, which demonstrated that the SureTect Salmonella species Assay was able to detect all the major groups of Salmonella enterica subspecies enterica (e.g., Typhimurium) and the less common subspecies of S. enterica (e.g., arizoniae) and the rarely encountered S. bongori. None of the exclusivity isolates analyzed were detected by the SureTect Salmonella species Assay. Ruggedness testing was conducted to evaluate the performance of the assay with specific method deviations outside of the recommended parameters open to variation (enrichment time

  17. Performance Assessment of a Trypanosoma cruzi Chimeric Antigen in Multiplex Liquid Microarray Assays.

    Science.gov (United States)

    Santos, Fred Luciano Neves; Celedon, Paola Alejandra Fiorani; Zanchin, Nilson Ivo Tonin; Leitolis, Amanda; Crestani, Sandra; Foti, Leonardo; de Souza, Wayner Vieira; Gomes, Yara de Miranda; Krieger, Marco Aurélio

    2017-10-01

    Diagnosing chronic Chagas disease (CD) requires antibody-antigen detection methods, which are traditionally based on enzymatic assay techniques whose performance depend on the type and quality of antigen used. Previously, 4 recombinant chimeric proteins from the Instituto de Biologia Molecular do Paraná (IBMP-8.1 to 8.4) comprising immuno-dominant regions of diverse Trypanosoma cruzi antigens showed excellent diagnostic performance in enzyme-linked immunosorbent assays. Considering that next-generation platforms offer improved CD diagnostic accuracy with different T. cruzi -specific recombinant antigens, we assessed the performance of these chimeras in liquid microarrays (LMAs). The chimeric proteins were expressed in Escherichia coli and purified by chromatography. Sera from 653 chagasic and 680 healthy individuals were used to assess the performance of these chimeras in detecting specific anti- T. cruzi antibodies. Accuracies ranged from 98.1 to 99.3%, and diagnostic odds ratio values were 3,548 for IBMP-8.3, 4,826 for IBMP-8.1, 7,882 for IBMP-8.2, and 25,000 for IBMP-8.4. A separate sera bank (851 samples) was employed to assess cross-reactivity with other tropical diseases. Leishmania , a pathogen with high similarity to T. cruzi , showed cross-reactivity rates ranging from 0 to 2.17%. Inconclusive results were negligible (0 to 0.71%). Bland-Altman and Deming regression analysis based on 200 randomly selected CD-positive and negative samples demonstrated interchangeability with respect to CD diagnostic performance in both singleplex and multiplex assays. Our results suggested that these chimeras can potentially replace antigens currently used in commercially available assay kits. Moreover, the use of multiplex platforms, such as LMA assays employing 2 or more IBMP antigens, would abrogate the need for 2 different testing techniques when diagnosing CD. Copyright © 2017 American Society for Microbiology.

  18. Demonstration of nitric oxide on asbestos and silicon carbide fibers with a new ultraviolet spectrophotometric assay.

    Science.gov (United States)

    Leanderson, P; Lagesson, V; Tagesson, C

    1997-09-01

    Nitric oxide (NO) has a number of important functions in biological systems and may play a role in the toxicity of mineral fibers. We investigated whether NO might be present on the surface of mineral fibers and if crocidolite could adsorb NO from NO gas or cigarette smoke. NO was determined with a new gas chromatography-ultraviolet spectrophotometric technique after thermal desorption from the fiber surface and injection in a gas flow cell. NO was found in different amounts on chrysotile B, crocidolite, amosite, and silicon carbide whiskers. There was a strong correlation between the amount of NO and the specific surface area of these fibers (r = 0.98). NO could not be demonstrated on rockwool fibers [man-made vitreous fiber(s) (MMVF)21 and MMVF22] or silicon nitride whiskers. NO on crocidolite, amosite, and silicon carbide whiskers was readily desorbed from the fibers at increased temperature, while NO on chrysotile B seemed to be more firmly adsorbed to the fiber and required a longer period of time to be desorbed. The amount of NO bound to crocidolite increased from 34 micrograms/g fiber to 85 and 474 micrograms/g after exposing the fibers to cigarette smoke and NO gas, respectively. These findings indicate that a) NO adsorbs to fiber surfaces, b) some fibers adsorb more NO than others, c) some fibers adsorb NO more strongly than others, and d) the amounts of NO on fibers may be increased after exposure of the fiber to cigarette smoke or other sources of NO. The biological significance of NO on mineral fibers remains to be investigated.

  19. Demonstration of nitric oxide on asbestos and silicon carbide fibers with a new ultraviolet spectrophotometric assay.

    Science.gov (United States)

    Leanderson, P; Lagesson, V; Tagesson, C

    1997-01-01

    Nitric oxide (NO) has a number of important functions in biological systems and may play a role in the toxicity of mineral fibers. We investigated whether NO might be present on the surface of mineral fibers and if crocidolite could adsorb NO from NO gas or cigarette smoke. NO was determined with a new gas chromatography-ultraviolet spectrophotometric technique after thermal desorption from the fiber surface and injection in a gas flow cell. NO was found in different amounts on chrysotile B, crocidolite, amosite, and silicon carbide whiskers. There was a strong correlation between the amount of NO and the specific surface area of these fibers (r = 0.98). NO could not be demonstrated on rockwool fibers [man-made vitreous fiber(s) (MMVF)21 and MMVF22] or silicon nitride whiskers. NO on crocidolite, amosite, and silicon carbide whiskers was readily desorbed from the fibers at increased temperature, while NO on chrysotile B seemed to be more firmly adsorbed to the fiber and required a longer period of time to be desorbed. The amount of NO bound to crocidolite increased from 34 micrograms/g fiber to 85 and 474 micrograms/g after exposing the fibers to cigarette smoke and NO gas, respectively. These findings indicate that a) NO adsorbs to fiber surfaces, b) some fibers adsorb more NO than others, c) some fibers adsorb NO more strongly than others, and d) the amounts of NO on fibers may be increased after exposure of the fiber to cigarette smoke or other sources of NO. The biological significance of NO on mineral fibers remains to be investigated. Images Figure 3. PMID:9400696

  20. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    Science.gov (United States)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources: a nominal 300 Volt high voltage input bus and a nominal 28 Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power auxiliary supplies, and two parallel 7.5 kilowatt (kW) discharge power supplies that are capable of providing up to 15 kilowatts of total power at 300 to 500 Volts (V) to the thruster. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall effect thruster. The performance of the unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate exceptional performance with full power efficiencies exceeding 97%. The unit was also tested with a 12.5kW Hall effect thruster to verify compatibility and output filter specifications. With space-qualified silicon carbide or similar high voltage, high efficiency power devices, this would provide a design solution to address the need for high power electric propulsion systems.

  1. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    Science.gov (United States)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources - a nominal 300-Volt high voltage input bus and a nominal 28-Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power supplies that provide power to the thruster auxiliary supplies, and two parallel 7.5 kilowatt power supplies that are capable of providing up to 15 kilowatts of total power at 300-Volts to 500-Volts to the thruster discharge supply. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall Effect Thruster. The performance of unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate the exceptional performance with full power efficiencies exceeding 97. With a space-qualified silicon carbide or similar high voltage, high efficiency power device, this design could evolve into a flight design for future missions that require high power electric propulsion systems.

  2. Pecan Street Grid Demonstration Program. Final technology performance report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-02-10

    This document represents the final Regional Demonstration Project Technical Performance Report (TPR) for Pecan Street Inc.’s (Pecan Street) Smart Grid Demonstration Program, DE-OE-0000219. Pecan Street is a 501(c)(3) smart grid/clean energy research and development organization headquartered at The University of Texas at Austin (UT). Pecan Street worked in collaboration with Austin Energy, UT, Environmental Defense Fund (EDF), the City of Austin, the Austin Chamber of Commerce and selected consultants, contractors, and vendors to take a more detailed look at the energy load of residential and small commercial properties while the power industry is undergoing modernization. The Pecan Street Smart Grid Demonstration Program signed-up over 1,000 participants who are sharing their home or businesses’s electricity consumption data with the project via green button protocols, smart meters, and/or a home energy monitoring system (HEMS). Pecan Street completed the installation of HEMS in 750 homes and 25 commercial properties. The program provided incentives to increase the installed base of roof-top solar photovoltaic (PV) systems, plug-in electric vehicles with Level 2 charging, and smart appliances. Over 200 participants within a one square mile area took advantage of Austin Energy and Pecan Street’s joint PV incentive program and installed roof-top PV as part of this project. Of these homes, 69 purchased or leased an electric vehicle through Pecan Street’s PV rebate program and received a Level 2 charger from Pecan Street. Pecan Street studied the impacts of these technologies along with a variety of consumer behavior interventions, including pricing models, real-time feedback on energy use, incentive programs, and messaging, as well as the corresponding impacts on Austin Energy’s distribution assets.The primary demonstration site was the Mueller community in Austin, Texas. The Mueller development, located less than three miles from the Texas State Capitol

  3. 2011-2012 ESTCP Live Site Demonstrations, ESTCP MR-201165, Cost and Performance Report TEMTADS Demonstration

    Science.gov (United States)

    2014-05-30

    FORMER MARE ISLAND NAVAL SHIPYARD 4.2.1 Site Selection The former Mare Island Naval Shipyard (fMINSY) in Vallejo , CA, was selected because of an...DC, October 20, 2011. 8. “2011 ESTCP UXO Live Site Demonstrations, Vallejo , CA, ESTCP MR-1165, Demonstration Data Report, Former Mare Island Naval

  4. Prospective and Retrospective Evaluation of the Performance of the FDA-Approved Cepheid Xpert Flu/RSV XC Assay.

    Science.gov (United States)

    Arbefeville, Sophie; Thonen-Kerr, Elizabeth; Ferrieri, Patricia

    2017-11-08

    Rapid and accurate detection of respiratory viruses is important in patient care and in guiding therapy and infection prevention policy. Rapid viral antigen assays are simple to perform and provide results within 15 to 30 minutes but are limited by their modest-to-moderate sensitivity. Molecular assays are more sensitive and specific but require more technical time and expertise and are more expensive. We verified the performance of the Xpert Flu/RSV XC assay prospectively, using patient respiratory samples from the 2014-2015 respiratory season, and, retrospectively, with frozen patient samples from the previous respiratory season. A total of 60 specimens were assayed on the Xpert Flu/RSV XC assay and by the GenMark Diagnostics eSensor Respiratory Viral Panel. The sensitivity of the Xpert Flu/RSV XC for Flu A was 100% (23/23), for Flu B, 80% (8/10), and for respiratory syncytial virus (RSV), 94.1% (16/17), compared to the reference assay (GenMark). The specificity was 100%. Eight specimens were positive for viruses other than Flu A/B or RSV, and this did not interfere with detection of targets in the Xpert assay. We demonstrated that the performance of the Xpert Flu/RSV XC was comparable to the more comprehensive molecular respiratory assay. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Creatinine Assay Attainment of Analytical Performance Goals Following Implementation of IDMS Standardization

    OpenAIRE

    Elizabeth Sunmin Lee; Christine P Collier; White, Christine A.

    2017-01-01

    Background: The international initiative to standardize creatinine (Cr) assays by tracing reference materials to Isotope Dilution Mass Spectrometry (IDMS) assigned values was implemented to reduce interlaboratory variability and improve assay accuracy. Objective: The aims of this study were to examine whether IDMS standardization has improved Cr assay accuracy (bias), interlaboratory variability (precision), total error (TE), and attainment of recommended analytical performance goals. Methods...

  6. Technology Performance Report: Duke Energy Notrees Wind Storage Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Wehner, Jeff [Duke Energy Renewables, Charlotte, NC (United States); Mohler, David [Duke Energy Renewables, Charlotte, NC (United States); Gibson, Stuart [Duke Energy Renewables, Charlotte, NC (United States); Clanin, Jason [Duke Energy Renewables, Charlotte, NC (United States); Faris, Don [Duke Energy Renewables, Charlotte, NC (United States); Hooker, Kevin [Duke Energy Renewables, Charlotte, NC (United States); Rowand, Michael [Duke Energy Renewables, Charlotte, NC (United States)

    2015-11-01

    Duke Energy Renewables owns and operates the Notrees Wind Farm in west Texas’s Ector and Winkler counties. The wind farm, which was commissioned in April 2009, has a total capacity of 152.6 MW generated by 55 Vestas V82 turbines, one Vestas 1-V90 experimental turbine, and 40 GE 1.5-MW turbines. The Vestas V82 turbines have a generating capacity of 1.65 MW each, the Vestas V90 turbine has a generating capacity of 1.86 MW, and the GE turbines have a generating capacity of 1.5 MW each. The objective of the Notrees Wind Storage Demonstration Project is to validate that energy storage increases the value and practical application of intermittent wind generation and is commercially viable at utility scale. The project incorporates both new and existing technologies and techniques to evaluate the performance and potential of wind energy storage. In addition, it could serve as a model for others to adopt and replicate. Wind power resources are expected to play a significant part in reducing greenhouse gas emissions from electric power generation by 2030. However, the large variability and intermittent nature of wind presents a barrier to integrating it within electric markets, particularly when competing against conventional generation that is more reliable. In addition, wind power production often peaks at night or other times when demand and electricity prices are lowest. Energy storage systems can overcome those barriers and enable wind to become a valuable asset and equal competitor to conventional fossil fuel generation.

  7. PERFORMANCE DEMONSTRATIONS OF ALTERNATIVE SCREEN RECLAMATION PRODUCTS FOR SCREEN PRINTING

    Science.gov (United States)

    This project evaluated environmentally-preferable products for the screen reclamation process In screen printing during month-long demonstrations at 23 printing facilities nationwide. hrough the Environmental Protection Agency (EPA) Design for the Environment Printing Project, pr...

  8. Trueness investigation of routine creatinine assays on nine homogeneous systems in Beijing demonstrates an encouraging outcome that meets clinical requirements.

    Science.gov (United States)

    Liu, Yan; Xu, Guo-bin

    2010-09-01

    criteria. The other five systems met the desirable criteria. Compared with the second criterion, all the results met the requirement of CLIA' 88. Trueness evaluation showed: the MEeGFR of Dade Behring exceeded 10% while the MEeGFRs of Beckman (traceable to rate Jaffe), Beckman (traceable to IDMS) and Ortho (traceable to Jaffe/High Performance Liquid Chromatography) exceeded 20% at level I. At level II the MEeGFRs of Dade Behring, Ortho (traceable to GC/IDMS) and Beckman (traceable to rate Jaffe) exceeded 10%. None of the nine systems got a MEeGFR higher than 20%. The conclusions of NIST SRM 967 agreed with those of LN 24 except for the Beckman measurement system. Trueness investigation of routine creatinine assays on nine homogeneous systems demonstrates an encouraging outcome that meets clinical requirements. Among the nine homogeneous routine systems, Roche and Daiichi produce the most accurate results. The implementation of traceability is effective.

  9. Demonstration and testing of high performance slot furnace. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bjerklie, J.W.; LaHaye, P.G.

    1978-04-01

    A demonstration and test program was conducted on a high temperature, 108'' slot, forge furnace. The efficacy of slot closures, medium weight insulation, massive-recirculation burners, temperature and O/sub 2/ controls, and ceramic recuperators was determined and compared to an unimproved furnace. Fired with No. 2 fuel oil at a maximum rate of 35 gph at start-up, the furnace was loaded manually employing 2/sup 1///sub 2/'' dia by 24'' long, round stock to simulate a typical forge shop load. Under these conditions, the furnace, with all improvements operative, achieved a steady state specific heat consumption (SHC) value of 850 Btu/lb of steel processed at an operating set point of 2400/sup 0/F and a steel processing rate of 3000 lbs/h. The value of each energy conserving improvement individually was determined and demonstrated. The largest single improvement was due to the ceramic recuperator (38%), followed by the door closures (11%), the massive-recirculation burners (10 to 20%), and improved wall thermal insulation (4%). The controls with the burner allowed essentially smoke-free operation to excess air levels of less than 5%. The economic impact of incorporating the energy-conserving recommendations of this study, using the industry ''norms'' for a conventionally equipped forge shop, was determined. Referred to the financial ''operating statement'', the improvement realized in the before-tax income of the forge shop would be increased approximately 20% assuming a current level of 10% profit before taxes.

  10. Comparison of the technical and clinical performance of the Elecsys HBsAg II assay with the Architect, AxSym, and Advia Centaur HBsAg screening assays.

    Science.gov (United States)

    Louisirirotchanakul, S; Khupulsup, K; Akraekthalin, S; Chan, K P; Saw, S; Aw, T C; Cho, D-H; Shin, M-G; Lim, J

    2010-05-01

    South East Asia has some of the highest prevalence rates of hepatitis B virus (HBV) infection (>or=8%) in the world, and the emergence of hepatitis B surface antigen (HBsAg) mutant strains is a growing problem. Assays with the highest levels of sensitivity, including mutant detection, should be used for routine HBsAg screening. In this large multicenter study, the clinical and technical performance of the fully automated Elecsys HBsAg II assay was compared with the Architect, AxSYM, and Advia Centaur HBsAg assays for HBsAg screening. Nine laboratories (three each from Thailand, Korea, and Singapore) compared the Elecsys HBsAg II assay with their routine HBsAg screening assay against a range of stored and routine clinical samples, including recombinant mutants. The Elecsys HBsAg II assay demonstrated equivalent sensitivity and specificity to the Architect HBsAg assay. However, the Elecsys HBsAg II assay recognized a native mutant sample (L94S, L97V, L98V, T123A) that the Architect HBsAg assay failed to detect. The AxSYM and Advia Centaur HBsAg assays appeared less sensitive for the detection of early HBV infection and also failed to detect some of the recombinant mutant strains. There was almost complete agreement between the Elecsys HBsAg II assay and comparator assays with respect to routine serum samples. The results of this study demonstrate that the Elecsys HBsAg II assay is a highly sensitive and specific screening assay for HBsAg and detects reliably the most important and clinically relevant HBV mutants and genotypes. It is suitable for routine HBsAg screening in Asia. (c) 2010 Wiley-Liss, Inc.

  11. Creatinine Assay Attainment of Analytical Performance Goals Following Implementation of IDMS Standardization

    Directory of Open Access Journals (Sweden)

    Elizabeth Sunmin Lee

    2017-02-01

    Full Text Available Background: The international initiative to standardize creatinine (Cr assays by tracing reference materials to Isotope Dilution Mass Spectrometry (IDMS assigned values was implemented to reduce interlaboratory variability and improve assay accuracy. Objective: The aims of this study were to examine whether IDMS standardization has improved Cr assay accuracy (bias, interlaboratory variability (precision, total error (TE, and attainment of recommended analytical performance goals. Methods: External Quality Assessment (EQA data (n = 66 challenge vials from Ontario, Canada, were analyzed. The bias, precision, TE, and the number of EQA challenge vials meeting performance goals were determined by assay manufacturer before (n = 32 and after (n = 34 IDMS implementation. Results: The challenge vials with the worst bias and precision were spiked with known common interfering substances (glucose and bilirubin. IDMS standardization improved assay bias (10.4%-1.6%, P < .001, but precision remained unchanged (5.0%-4.7%, P = .5 with performance goals not consistently being met. Precision and TE goals based on biologic variation were attained by only 29% to 69% and 32% to 62% of challenge vials. Conclusions: While IDMS standardization has improved Cr assay accuracy and thus reduced TE, significant interlaboratory variability remains. Contemporary Cr assays do not currently meet the standards required to allow for accurate and consistent estimated glomerular filtration rate assessment and chronic kidney disease diagnosis across laboratories. Further improvements in Cr assay performance are needed.

  12. Performance validation of commercially available mobile waste-assay systems: Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Schanfein, M.; Bonner, C.; Maez, R. [Los Alamos National Lab., NM (United States)] [and others

    1997-11-01

    Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content to reduce the radioactive hazard to the public. Validation of the waste-assay systems` performance is critical for establishing the credibility of the assay results for storage and disposal purposes. Canberra Nuclear has evaluated regulations worldwide and identified standard, modular, neutron- and gamma-waste-assay systems that can be used to characterize a large portion of existing and newly generated transuranic (TRU) and low-level waste. Before making claims of guaranteeing any system`s performance for specific waste types, the standardized systems` performance be evaluated. 7 figs., 11 tabs.

  13. Development and performance of a microwell-plate-based polymerase chain reaction assay for Mycoplasma genitalium.

    Science.gov (United States)

    Dutro, Susan M; Hebb, Jennifer K; Garin, Cresley A; Hughes, James P; Kenny, George E; Totten, Patricia A

    2003-10-01

    Mycoplasma genitalium is associated with, and could be the cause of, idiopathic cases of urethritis, endometritis, and cervicitis. Further epidemiologic studies on this organism are needed, but currently used polymerase chain reaction (PCR) assays are labor-intensive and culture is insensitive. The goal was to develop and evaluate a microwell-plate-based PCR assay for M. genitalium. We adapted an M. genitalium PCR assay targeting the MgPa gene to a 96-microwell plate format with colorimetric detection of PCR products and incorporation of an internal inhibition control to determine the limit of detection of this assay (termed MgPa-IMW) for M. genitalium DNA and evaluate its performance on cervical and male urine specimens. The MgPa-IMW PCR assay detected 1 and 17 genome copies of M. genitalium (with 27% and 95% confidence) and was able to detect specimens inhibited for amplification. This assay was 100% concordant (50 positive and 50 negative) with the Southern-blot-based PCR assay with cervical specimens. Similarly, this test was 89% concordant with the Southern-blot-based assay for 64 male urine specimens (25 positive, 32 negative, 7 discordant), 97% concordant after correcting for specimens no longer positive by the Southern blot-based assay after freezer storage. The MgPa-IMW assay is sensitive and specific for the detection of M. genitalium in patient specimens and should facilitate large-scale screening for this organism.

  14. Performance evaluation of the ADVIA Centaur(®) HIV Ag/Ab Combo assay.

    Science.gov (United States)

    Pumarola, Tomàs; Freeman, James; Saxton, Emeline; Dillon, Paul; Bal, Tricia; van Helden, Josef

    2010-12-01

    Early diagnosis of HIV infection and appropriate care reduces morbidity and mortality. As a result, recent guidelines recommend that HIV screening be routinely included in patient care. Routine screening will likely result in more patients being tested prior to seroconversion; fourth-generation assays can facilitate diagnosis in these patients. This study evaluated the performance of the automated fourth-generation ADVIA Centaur(®) HIV Ag/Ab Combo assay. Samples from three sites were tested using the HIV Ag/Ab Combo assay and a CE-marked predicate assay. The HIV Ag/Ab Combo assay's relative sensitivity was 98.36% (599/609; 95% confidence interval: 97.00-99.21%), and the relative specificity was 99.74% (7743/7763; 95% confidence interval: 99.60-99.84%). The HIV Ag/Ab Combo assay detected seroconversion at the same bleed or at least one bleed earlier in 34/37 panels compared to the CE-marked predicate assay. Compared to the final result, the HIV Ag/Ab Combo assay's sensitivity was 100% (598/598; 95% confidence interval: 99.39-100.00%), and the specificity was 99.74% (7753/7773; 95% confidence interval: 99.60-99.84%). Sensitivity was 100% for the HIV genotypes tested. The HIV Ag/Ab Combo assay is a sensitive and specific assay that can assist clinicians in the early diagnosis of HIV infection. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Performance of the Dimension TAC assay and comparison of multiple platforms for the measurement of tacrolimus.

    Science.gov (United States)

    Cho, Eun-Jung; Ko, Dae-Hyun; Lee, Woochang; Chun, Sail; Lee, Hae-Kyung; Min, Won-Ki

    2017-11-17

    Therapeutic monitoring of tacrolimus is essential for reducing organ rejection and adverse effects. The measurement of tacrolimus in whole blood is taken by many automated platforms. We evaluated the analytical performance of the Dimension TAC assay, which is an upgraded reagent from the previous Dimension TACR assay. The evaluations involved determination of precision, linearity, detection capability, and reagent lot-to-lot variability between three lot numbers. Correlation studies were conducted using the Dimension TACR assay, Architect, Elecsys assay, and MassTrak LC-MS/MS. The total coefficient of variation was below 10%. Acceptable linearity was observed in their respective reportable ranges. The limit of blank, limit of detection, and limit of quantification were 0.29, 0.47, and 0.81 ng/mL, respectively. Correlation analysis indicated that the Dimension TAC assay results were comparable to that of the Dimension TACR assay, Architect, and Elecsys results in liver and heart transplant patients. In kidney transplant patients, the Dimension TAC assay showed the poor correlation with Architect and Elecsys. The results from these assays were slightly higher than that of MassTrak. We found little lot-to-lot reagent variation among the reagents evaluated. The overall analytical performance of the Dimension TAC assay is acceptable for therapeutic monitoring in clinical practice. Our study that compared different platforms may provide some useful information regarding which test method to use. © 2017 Wiley Periodicals, Inc.

  16. Creatinine Assay Attainment of Analytical Performance Goals Following Implementation of IDMS Standardization: Further Improvements Required.

    Science.gov (United States)

    Lee, Elizabeth Sunmin; Collier, Christine P; White, Christine A

    2017-01-01

    The international initiative to standardize creatinine (Cr) assays by tracing reference materials to Isotope Dilution Mass Spectrometry (IDMS) assigned values was implemented to reduce interlaboratory variability and improve assay accuracy. The aims of this study were to examine whether IDMS standardization has improved Cr assay accuracy (bias), interlaboratory variability (precision), total error (TE), and attainment of recommended analytical performance goals. External Quality Assessment (EQA) data (n = 66 challenge vials) from Ontario, Canada, were analyzed. The bias, precision, TE, and the number of EQA challenge vials meeting performance goals were determined by assay manufacturer before (n = 32) and after (n = 34) IDMS implementation. The challenge vials with the worst bias and precision were spiked with known common interfering substances (glucose and bilirubin). IDMS standardization improved assay bias (10.4%-1.6%, P IDMS standardization has improved Cr assay accuracy and thus reduced TE, significant interlaboratory variability remains. Contemporary Cr assays do not currently meet the standards required to allow for accurate and consistent estimated glomerular filtration rate assessment and chronic kidney disease diagnosis across laboratories. Further improvements in Cr assay performance are needed.

  17. Creatinine Assay Attainment of Analytical Performance Goals Following Implementation of IDMS Standardization

    Science.gov (United States)

    Lee, Elizabeth Sunmin; Collier, Christine P.; White, Christine A.

    2017-01-01

    Background: The international initiative to standardize creatinine (Cr) assays by tracing reference materials to Isotope Dilution Mass Spectrometry (IDMS) assigned values was implemented to reduce interlaboratory variability and improve assay accuracy. Objective: The aims of this study were to examine whether IDMS standardization has improved Cr assay accuracy (bias), interlaboratory variability (precision), total error (TE), and attainment of recommended analytical performance goals. Methods: External Quality Assessment (EQA) data (n = 66 challenge vials) from Ontario, Canada, were analyzed. The bias, precision, TE, and the number of EQA challenge vials meeting performance goals were determined by assay manufacturer before (n = 32) and after (n = 34) IDMS implementation. Results: The challenge vials with the worst bias and precision were spiked with known common interfering substances (glucose and bilirubin). IDMS standardization improved assay bias (10.4%-1.6%, P IDMS standardization has improved Cr assay accuracy and thus reduced TE, significant interlaboratory variability remains. Contemporary Cr assays do not currently meet the standards required to allow for accurate and consistent estimated glomerular filtration rate assessment and chronic kidney disease diagnosis across laboratories. Further improvements in Cr assay performance are needed. PMID:28321322

  18. Performance Assessment of Human and Cattle Associated Quantitative Real-time PCR Assays - slides

    Science.gov (United States)

    The presentation overview is (1) Single laboratory performance assessment of human- and cattle associated PCR assays and (2) A Field Study: Evaluation of two human fecal waste management practices in Ohio watershed.

  19. A high-performance, non-radioactive potency assay for measuring cytotoxicity: A full substitute of the chromium-release assay targeting the regulatory-compliance objective.

    Science.gov (United States)

    Rossignol, Alexis; Bonnaudet, Véronique; Clémenceau, Béatrice; Vié, Henri; Bretaudeau, Laurent

    2017-04-01

    Standardized and biologically relevant potency assays are required by the regulatory authorities for the characterization and quality control of therapeutic antibodies. As critical mechanisms of action (MoA) of antibodies, the antibody-dependent cell-meditated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) must be characterized by appropriate potency assays. The current reference method for measuring cytotoxicity is the 51Cr-release method. However, radioactivity handling is difficult to implement in an industrial context because of environmental and operator protection constraints. Alternative non-radioactive methods suffer from poor validation performances and surrogate assays that measure FcγR-dependent functions do not comply with the regulatory requirement of biological relevance. Starting from these observations, we developed a non-radioactive luminescent method that is specific for target cell cytolysis. In adherent and non-adherent target cell models, the ADCC (using standardized effector cells) or CDC activities of rituximab, trastuzumab and adalimumab were compared in parallel using the 51Cr or luminescent methods. We demonstrated that the latter method is highly sensitive, with validation performances similar or better than the 51Cr method. This method also detected apoptosis following induction by a chemical agent or exposure to ultraviolet light. Moreover, it is more accurate, precise and specific than the concurrent non-radioactive calcein- and TR-FRET-based methods. The method is easy to use, versatile, standardized, biologically relevant and cost effective for measuring cytotoxicity. It is an ideal candidate for developing regulatory-compliant cytotoxicity assays for the characterization of the ADCC, CDC or apoptosis activities from the early stages of development to lot release.

  20. Data quality in drug discovery: the role of analytical performance in ligand binding assays.

    Science.gov (United States)

    Wätzig, Hermann; Oltmann-Norden, Imke; Steinicke, Franziska; Alhazmi, Hassan A; Nachbar, Markus; El-Hady, Deia Abd; Albishri, Hassan M; Baumann, Knut; Exner, Thomas; Böckler, Frank M; El Deeb, Sami

    2015-09-01

    Despite its importance and all the considerable efforts made, the progress in drug discovery is limited. One main reason for this is the partly questionable data quality. Models relating biological activity and structures and in silico predictions rely on precisely and accurately measured binding data. However, these data vary so strongly, such that only variations by orders of magnitude are considered as unreliable. This can certainly be improved considering the high analytical performance in pharmaceutical quality control. Thus the principles, properties and performances of biochemical and cell-based assays are revisited and evaluated. In the part of biochemical assays immunoassays, fluorescence assays, surface plasmon resonance, isothermal calorimetry, nuclear magnetic resonance and affinity capillary electrophoresis are discussed in details, in addition radiation-based ligand binding assays, mass spectrometry, atomic force microscopy and microscale thermophoresis are briefly evaluated. In addition, general sources of error, such as solvent, dilution, sample pretreatment and the quality of reagents and reference materials are discussed. Biochemical assays can be optimized to provide good accuracy and precision (e.g. percental relative standard deviation superior related to the biological significance, however, typically they cannot still be considered as really quantitative, in particular when results are compared over longer periods of time or between laboratories. A very careful choice of assays is therefore recommended. Strategies to further optimize assays are outlined, considering the evaluation and the decrease of the relevant error sources. Analytical performance and data quality are still advancing and will further advance the progress in drug development.

  1. Evaluation of performance of human immunodeficiency virus antigen/antibody combination assays in Taiwan.

    Science.gov (United States)

    Chang, Chun-Kai; Kao, Cheng-Feng; Lin, Pi-Han; Huang, Hui-Lin; Ho, Shu-Yuan; Wong, Kuo-Chen; Lin, Bo-Chang; Yeh, Chang-Ching; Lee, Chia-Yeh; Kao, Chuan-Liang; Lee, Chun-Nan; Chang, Sui-Yuan; Yang, Jyh-Yuan

    2017-08-01

    The fourth-generation human immunodeficiency virus (HIV) combination assay, which can simultaneously detect the presence of anti-HIV antibody and HIV antigen, has been shown to shorten the window period in HIV diagnosis compared with the third-generation HIV antibody immunoassay. This study was aimed to determine the performance of HIV combination assays in Taiwan, where the HIV-1 seroprevalence is 0.007% and HIV-2 infection has never been reported. Performance of three fourth-generation HIV Ag/Ab combination assays (Dia.Pro, Wantai, and Bio-Rad) and one third-generation HIV Ab immunoassay (AxSYM HIV 1/2 gO) was assessed. A total of 152 specimens, including 86 confirmed HIV-seropositive and 66 HIV-seronegative samples, were used in the study. The sensitivity of four assays varied from 98.8% to 100%, and specificity varied from 98.5% to 100%. Performance of the 75 equivocal samples, the HIV status of which was confirmed later, in terms of negative prediction varied from 81.8% to 87.5%. The Bio-Rad and Dia.Pro assays exhibited higher sensitivity for the detection of p24 antigen among the three fourth-generation HIV combination assays. The three fourth-generation HIV Ag/Ab combination assays exhibited better sensitivity, specificity, and negative prediction than the third-generation HIV Ab immunoassay. Copyright © 2015. Published by Elsevier B.V.

  2. Performance characteristics of the Architect brain natriuretic peptide (BNP) assay: a two site study.

    Science.gov (United States)

    Mongia, Shella K; La'ulu, Sonia L; Apple, Fred S; Ler, Ranka; Murakami, MaryAnn M; Roberts, William L

    2008-05-01

    Brain natriuretic peptide (BNP) is produced by the ventricles of the heart and is a biomarker for heart failure. Several commercial assays are now available. We evaluated the performance characteristics of the ARCHITECT BNP assay. We evaluated the limit of blank, limit of detection, linearity and imprecision. Method comparison studies were performed with 3 other automated BNP assays including the ADVIA Centaur, AxSYM, and UniCel DxI 800 methods. The mean LOB and LOD of the Architect assay were 3.5 and 5.8 ng/L, respectively. Imprecision studies yielded within run CVs of 1.1 to 5.1% and total CVs of 2.3 to 5.3% using human plasma based multi-constituent controls at concentrations of 92, 500, and 3500 ng/L. The maximum deviation from the target recovery for dilution linearity was 9.6%. Concordance with other BNP assays at a 100 ng/l cutoff was 91 to 98% and kappa statistics were 0.78 to 0.96. The mean difference between the Architect and Advia Centaur methods was positive. For the other methods, the mean difference with the Architect was negative. The Architect BNP assay shows good performance characteristics with total imprecision UniCel DxI BNP assays.

  3. Multicentric performance analysis of HCV quantification assays and its potential relevance for HCV treatment.

    Science.gov (United States)

    Wiesmann, F; Naeth, G; Berger, A; Hirsch, H H; Regenass, S; Ross, R S; Sarrazin, C; Wedemeyer, H; Knechten, H; Braun, P

    2016-06-01

    An accurate quantification of low viremic HCV RNA plasma samples has gained importance since the approval of direct acting antivirals and since only one single measurement predicts the necessity of a prolonged or shortened therapy. As reported previously, HCV quantification assays such as Abbott RealTime HCV and Roche COBAS AmpliPrep/COBAS TaqMan HCV version 2 (CTM v2) may vary in sensitivity and precision particularly in low-level viremia. Importantly, substantial variations were previously demonstrated between some of these assays compared to the Roche High Pure System/COBAS TaqMan assay (HPS) reference assay, which was used to establish the clinical decision points in clinical studies. In this study, the reproducibility of assay performances across several laboratories was assessed by analysing quantification results generated by six independent laboratories (3× RealTime, 3× CTM v2) in comparison with one HPS reference laboratory. The 4th WHO Standard was diluted to 100, 25 and 10 IU/ml, and aliquots were tested in triplicates in 5 independent runs by each assay in the different laboratories to assess assay precision and detection rates. In a second approach, 2 clinical samples (GT 1a & GT 1b) were diluted to 100 and 25 IU/ml and tested as described above. While the result range for WHO 100 IU/ml replicates across all laboratories was similar in this analysis, the CVs of each laboratory ranged from 19.3 to 25.6 % for RealTime laboratories and were lower than CVs of CTM v2 laboratories with a range of 26.1-47.3 %, respectively, and also in comparison with the CV of the HPS reference laboratory (34.9 %). At WHO standard dilution of 25 IU/ml, 24 replicates were quantified by RealTime compared to 8 replicates with CTM v2. Results of clinical samples again revealed a higher variation of CTM v2 results as compared to RealTime values. (CVs at 100 IU/ml: RealTime: 13.1-21.0 % and CTM v2: 15.0-32.3 %; CVs at 25 IU/ml: RealTime 17.6-34.9 % and CTM v2 28

  4. Performance of a next generation sequencing SNP assay on degraded DNA.

    Science.gov (United States)

    Gettings, Katherine Butler; Kiesler, Kevin M; Vallone, Peter M

    2015-11-01

    Forensic DNA casework samples are often of insufficient quantity or quality to generate full profiles by conventional DNA typing methods. Polymerase chain reaction (PCR) amplification of short tandem repeat (STR) loci is inherently limited in samples containing degraded DNA, as the cumulative size of repeat regions, primer binding regions, and flanking sequence is necessarily larger than the PCR template. Additionally, traditional capillary electrophoresis (CE) assay design further inherently limits shortening amplicons because the markers must be separated by size. Non-traditional markers, such as single nucleotide polymorphisms (SNPs) and insertion deletion polymorphisms (InDels), may yield more information from challenging samples due to their smaller amplicon size. In this study, the performance of a next generation sequencing (NGS) SNP assay and CE-based STR, mini-STR, and InDel assays was evaluated with a series of fragmented, size-selected samples. Information obtained from the NGS SNP assay exhibited higher overall inverse random match probability (1/RMP) values compared to the CE-based typing assays, with particular benefit for fragment sizes ≤ 150 base pairs (bp). The InDel, mini-STR, and NGS SNP assays all had similar percentages of loci with reportable alleles at this level of degradation; however, the relatively fewer number of loci in the InDel and mini-STR assays results in the NGS SNP assay having at least nine orders of magnitude higher 1/RMP values. In addition, the NGS SNP assay and three CE-based assays (two STR and one InDel assay) were tested using a dilution series consisting of 0.5 ng, 0.1 ng, and 0.05 ng non-degraded DNA. All tested assays showed similar percentages of loci with reportable alleles at these levels of input DNA; however, due to the larger number of loci, the NGS SNP assay and the larger of the two tested CE-based STR assays both resulted in considerably higher 1/RMP values than the other assays. These results indicate the

  5. Performance Evaluation of Siemens ADVIA Centaur and Roche MODULAR Analytics E170 Total 25-OH Vitamin D Assays

    Science.gov (United States)

    Chen, Yu; Kinney, Lois; Božović, Andrea; Smith, Hilary; Tarr, Heather; Diamandis, Eleftherios P.; LeBlanc, Adrien

    2014-01-01

    Objectives To evaluate the newly developed Roche MODULAR Analytics E170 Total Vitamin D and the Siemens ADVIA Centaur® Vitamin D Total assays. Materials and Methods Assays were evaluated using the Clinical and Laboratory Standards Institute protocols. Split patient samples were compared with LC-MS/MS and DiaSorin LIAISON assays (n=79 including 15 specimens with detectable endogenous 25-OH vitamin D2). Assay accuracy was also evaluated using the Vitamin D External Quality Assessment Scheme samples. Results The ADVIA Centaur and E170 assays demonstrated maximum total CVs of 14.1% and 5.9%, respectively. Both showed excellent linearity (R2 >0.99). The ADVIA Centaur assay demonstrated interference with bilirubin at 800 μmol/L, hemolysis at 1.25 g/L, and triglycerides at 2.8 mmol/L. Compared to LC-MS/MS, the ADVIA Centaur assay demonstrated a R2 value of 0.893, average bias of −8.8%; the E170 assay an R2 value of 0.872, average bias of 14.3% with underestimation of 25-OH vitamin D2. Compared to the LIAISON assay, the ADVIA Centaur assay demonstrated an R2 value of 0.781, average bias of −17.3%; the E170 assay an R2 value of 0.823, average bias of 11.4%. The ADVIA Centaur and E170 assays demonstrated a biases of <20% in 10/10 and 8/10 samples, respectively. Conclusions The ADVIA Centaur and E170 vitamin D assays demonstrated acceptable linearity, imprecision, and accuracy. The E170 assay demonstrated consistent underestimation of 25-OH vitamin D2 levels. Compared with LC-MS/MS, the ADVIA Centaur assay demonstrated a higher R2 value and a smaller average bias than the E170 assay. PMID:22705028

  6. Data quality in drug discovery: the role of analytical performance in ligand binding assays

    Science.gov (United States)

    Wätzig, Hermann; Oltmann-Norden, Imke; Steinicke, Franziska; Alhazmi, Hassan A.; Nachbar, Markus; El-Hady, Deia Abd; Albishri, Hassan M.; Baumann, Knut; Exner, Thomas; Böckler, Frank M.; El Deeb, Sami

    2015-09-01

    Despite its importance and all the considerable efforts made, the progress in drug discovery is limited. One main reason for this is the partly questionable data quality. Models relating biological activity and structures and in silico predictions rely on precisely and accurately measured binding data. However, these data vary so strongly, such that only variations by orders of magnitude are considered as unreliable. This can certainly be improved considering the high analytical performance in pharmaceutical quality control. Thus the principles, properties and performances of biochemical and cell-based assays are revisited and evaluated. In the part of biochemical assays immunoassays, fluorescence assays, surface plasmon resonance, isothermal calorimetry, nuclear magnetic resonance and affinity capillary electrophoresis are discussed in details, in addition radiation-based ligand binding assays, mass spectrometry, atomic force microscopy and microscale thermophoresis are briefly evaluated. In addition, general sources of error, such as solvent, dilution, sample pretreatment and the quality of reagents and reference materials are discussed. Biochemical assays can be optimized to provide good accuracy and precision (e.g. percental relative standard deviation <10 %). Cell-based assays are often considered superior related to the biological significance, however, typically they cannot still be considered as really quantitative, in particular when results are compared over longer periods of time or between laboratories. A very careful choice of assays is therefore recommended. Strategies to further optimize assays are outlined, considering the evaluation and the decrease of the relevant error sources. Analytical performance and data quality are still advancing and will further advance the progress in drug development.

  7. Low cut-off values increase diagnostic performance of protein S assays.

    Science.gov (United States)

    Mulder, René; Ten Kate, Min Ki; Kluin-Nelemans, Hanneke C; Mulder, André B

    2010-09-01

    Conflicting data have been reported on the accuracy of protein S (PS) assays for detection of hereditary PS deficiency. In this study we assessed the diagnostic performance of two total PS antigen assays, four free PS assays and three PS activity assays in a group of 28 heterozygous carriers of mutations in PROS1 and 165 control subjects. Several control groups were formed, one of healthy volunteers and - because PS levels are influenced by oral contraception and pregnancy, and assays measuring PS activity may be influenced by the presence of the factor V Leiden mutation -, we also investigated the influences of these factors. All nine PS assays detected significantly reduced PS levels in subjects with a PROS1 mutation. Eight out of nine PS assays showed a 100% sensitivity and 100% specificity to detect heterozygous carriers of mutations in PROS1 with values far below the lower limit of the reference values obtained from healthy volunteers. Low specificities were found in subjects with a factor V Leiden mutation and in pregnant women. At lower cut-off levels, equal to the highest PS value found in heterozygous carriers of mutations in PROS1, the specificity considerably increased in these subjects. When using low cut-off levels equal to the highest PS value found in heterozygous carriers of mutations in PROS1, ensuring 100% sensitivity, the specificity in all study groups increases considerably, by which misclassification can be maximally avoided.

  8. Implementation and application of moving average as continuous analytical quality control instrument demonstrated for 24 routine chemistry assays.

    Science.gov (United States)

    Rossum, Huub H van; Kemperman, Hans

    2017-07-26

    General application of a moving average (MA) as continuous analytical quality control (QC) for routine chemistry assays has failed due to lack of a simple method that allows optimization of MAs. A new method was applied to optimize the MA for routine chemistry and was evaluated in daily practice as continuous analytical QC instrument. MA procedures were optimized using an MA bias detection simulation procedure. Optimization was graphically supported by bias detection curves. Next, all optimal MA procedures that contributed to the quality assurance were run for 100 consecutive days and MA alarms generated during working hours were investigated. Optimized MA procedures were applied for 24 chemistry assays. During this evaluation, 303,871 MA values and 76 MA alarms were generated. Of all alarms, 54 (71%) were generated during office hours. Of these, 41 were further investigated and were caused by ion selective electrode (ISE) failure (1), calibration failure not detected by QC due to improper QC settings (1), possible bias (significant difference with the other analyzer) (10), non-human materials analyzed (2), extreme result(s) of a single patient (2), pre-analytical error (1), no cause identified (20), and no conclusion possible (4). MA was implemented in daily practice as a continuous QC instrument for 24 routine chemistry assays. In our setup when an MA alarm required follow-up, a manageable number of MA alarms was generated that resulted in valuable MA alarms. For the management of MA alarms, several applications/requirements in the MA management software will simplify the use of MA procedures.

  9. An improved behavioural assay demonstrates that ultrasound vocalizations constitute a reliable indicator of chronic cancer pain and neuropathic pain

    Directory of Open Access Journals (Sweden)

    Selvaraj Deepitha

    2010-03-01

    Full Text Available Abstract Background On-going pain is one of the most debilitating symptoms associated with a variety of chronic pain disorders. An understanding of mechanisms underlying on-going pain, i.e. stimulus-independent pain has been hampered so far by a lack of behavioural parameters which enable studying it in experimental animals. Ultrasound vocalizations (USVs have been proposed to correlate with pain evoked by an acute activation of nociceptors. However, literature on the utility of USVs as an indicator of chronic pain is very controversial. A majority of these inconsistencies arise from parameters confounding behavioural experiments, which include novelty, fear and stress due to restrain, amongst others. Results We have developed an improved assay which overcomes these confounding factors and enables studying USVs in freely moving mice repetitively over several weeks. Using this improved assay, we report here that USVs increase significantly in mice with bone metastases-induced cancer pain or neuropathic pain for several weeks, in comparison to sham-treated mice. Importantly, analgesic drugs which are known to alleviate tumour pain or neuropathic pain in human patients significantly reduce USVs as well as mechanical allodynia in corresponding mouse models. Conclusions We show that studying USVs and mechanical allodynia in the same cohort of mice enables comparing the temporal progression of on-going pain (i.e. stimulus-independent pain and stimulus-evoked pain in these clinically highly-relevant forms of chronic pain.

  10. Analytical performance of the Abbott Architect i2000 tacrolimus assay in Chinese patients after renal transplantation.

    Science.gov (United States)

    Li, Z Y; Yan, C L; Yan, R; Feng, Z R

    2010-12-01

    Monitoring of tacrolimus concentrations has played a crucial role to control the efficacy versus adverse effects of treatment, because of the drug's narrow therapeutic range, inter- and intraindividual variabilities, and drug interactions mediated by hepatic cytochrome P450. Therefore, the stability of methods to monitor tacrolimus is of major importance. This study evaluated the analytical performance of the Abbott Architect i2000 tacrolimus assay, which was recently released in China to monitor tacrolimus therapy. We compared the results using the Abbott Architect i2000 Tacrolimus assay with the traditional Abbott IMx method. We measured concentrations of tacrolimus in 100 samples from renal transplant patients by Architect i2000 and the commonly used Abbott IMx. We observed that the total %CV of the Architect i2000 assay was Architect i2000 assay was linear over the reportable range with recoveries ranging from 90.6% to 106.7%. In addition, this assay was not affected by high concentrations of hemoglobin, lipids, or bilirubin in the samples. The 2 assays yielded similar results. The regression equation obtained from the Passing Bablok analysis was: y = 0.8788x - 0.3485 with a Spearman correlation coefficient (r) of 0.9922. The bias plot between the Architect i2000 and Abbott IMx assay yielded an average negative bias (-1.4 ng/mL). We concluded that, because of its high precision and sensitivity, low cross-reactivity, and acceptable accuracy, the Architect i2000 assay is a suitable alternative to monitor tacrolimus concentrations in renal transplant recipients. Copyright © 2010 Elsevier Inc. All rights reserved.

  11. Evaluation of the performance of the Abbott ARCHITECT HIV Ag/Ab Combo Assay.

    Science.gov (United States)

    Chavez, Pollyanna; Wesolowski, Laura; Patel, Pragna; Delaney, Kevin; Owen, S Michele

    2011-12-01

    Worldwide, many countries test for HIV infection using combination assays that simultaneously detect p24 antigen and HIV antibodies. One such assay, the ARCHITECT(®) HIV Ag/Ab Combo Assay (ARCHITECT), has recently been approved by the Food and Drug Administration (FDA) for use in the United States. To evaluate the performance of ARCHITECT on well-characterized specimens from four CDC-funded studies. We evaluated 3386 HIV-infected, 7551 HIV-uninfected, and 58 acute HIV infection (AHI) specimens. HIV-infected specimens were repeatedly reactive by enzyme immunoassay (EIA) and Western blot (WB) or positive by nucleic acid amplification testing (NAAT). HIV-uninfected specimens were EIA- and NAAT-negative. AHI specimens were seronegative or indeterminate (using antibody-based EIAs, rapid tests or WB) and NAAT-positive. All specimens were de-identified and sent to Abbott Diagnostics for testing with ARCHITECT. ARCHITECT test results were compared to original study characterizations and were used to assess overall sensitivity and specificity and also sensitivity for AHI. ARCHITECT false-positive specimens with sufficient quantity were retested. Based on results from the initial ARCHITECT test, sensitivity was 99.94% (95% confidence interval [CI]: 99.79, 99.99) and specificity was 98.78% (95% CI: 98.51-99.01). Repeat testing resulted in corrected specificity of 99.50% (95% CI: 99.31, 99.64). Also, 48 AHI specimens (83%) were detected by this screening assay. The sensitivity and specificity of the ARCHITECT combination assay are very high and most AHIs were detected by the assay. Use of Ag/Ab combination assays may improve the number of AHIs identified relative to existing FDA-approved HIV-antibody only based serologic assays, particularly in high incidence populations. Published by Elsevier B.V.

  12. Evaluation of Xpert MTB/RIF assay performance in the diagnosis of abdominal tuberculosis.

    Science.gov (United States)

    Kumar, Suraj; Bopanna, Sawan; Kedia, Saurabh; Mouli, Pratap; Dhingra, Rajan; Padhan, Rajesh; Kohli, Mikashmi; Chaubey, Jigyasa; Sharma, Rohini; Das, Prasenjit; Dattagupta, S; Makharia, Govind; Sharma, S K; Ahuja, Vineet

    2017-04-01

    The use of genetic probes for the diagnosis of pulmonary tuberculosis (TB) has been well described. However, the role of these assays in the diagnosis of intestinal tuberculosis is unclear. We therefore assessed the diagnostic utility of the Xpert Mycobacterium tuberculosis /rifampicin (MTB/RIF) assay, and estimated the prevalence of multidrug-resistant (MDR) TB in the Indian population. Of 99 patients recruited, 37 had intestinal TB; two control groups comprised 43 with Crohn's disease (CD) and 19 with irritable bowel syndrome. Colonoscopy was performed before starting any therapy; mucosal biopsies were subjected to histopathology, acid-fast bacilli staining, Lowenstein-Jensen culture, and nucleic acid amplification testing using the Xpert MTB/RIF assay. Patients were followed up for 6 months to confirm the diagnosis and response to therapy. A composite reference standard was used for diagnosis of TB and assessment of the diagnostic utility of the Xpert MTB/RIF assay. Of 37 intestinal TB patients, the Xpert MTB/RIF assay was positive in three of 37 (8.1%), but none had MDR-TB. The sensitivity, specificity, positive predictive value, and negative predictive value of the Xpert MTB/RIF assay was 8.1%, 100%, 100%, and, 64.2%, respectively. The Xpert MTB/RIF assay has low sensitivity but high specificity for intestinal TB, and may be helpful in endemic tuberculosis areas, when clinicians are faced with difficulty differentiating TB and CD. Based on the Xpert MTB/RIF assay, the prevalence of intestinal MDR-TB is low in the Indian population.

  13. Performances of four fourth-generation human immunodeficiency virus-1 screening assays.

    Science.gov (United States)

    Song, Eun Young; Hur, Mina; Roh, Eun Youn; Park, Myoung Hee; Moon, Hee-Won; Yun, Yeo Min

    2012-12-01

    Fourth-generation human immunodeficiency virus-1 (HIV-1) screening assays have improved sensitivity, but vary in performance characteristics. The purpose of this study was to evaluate four different fourth-generation HIV-1 assays. These assays included the AxSYM HIV Ag/Ab Combo (Abbott diagnostics, Delkenheim, Germany), ARCHITECT HIV Ag/Ab Combo (Abbott), Elecsys 2010 HIV Combi (Roche Diagnostics GmbH, Mannheim, Germany), and Elecsys HIV Combi PT (Roche). A total of 1,306 samples that included 1,225 clinical samples and 81 samples consisting of seroconversion panels, an HIV-1 p24 antigen sensitivity panel, and dilution series of HIV-1 lysates and HIV-1 antibodies were tested. All of the assays had sensitivities of 100% on clinical samples. The specificities of the AxSYM, ARCHITECT, Elecsys 2010 HIV Combi, and Elecsys HIV Combi PT were 99.6, 99.6, 99.0, and 99.5%, respectively. Of the 81 samples with different levels of HIV antigen or antibody and/or subtypes, Elecsys HIV Combi PT and ARCHITECT HIV Ag/Ab Combo showed better analytical sensitivities than the other two assays. In summary, the performance characteristics of AxSYM, ARCHITECT, and Elecsys HIV Combi PT were comparable and satisfactory for clinical samples. ARCHITECT HIV Ag/Ab Combo and Elecsys HIV Combi PT have the higher analytical sensitivities, and would be preferable for reducing the window period. Copyright © 2012 Wiley Periodicals, Inc.

  14. How to best freeze liver samples to perform the in vivo mammalian alkaline comet assay

    Directory of Open Access Journals (Sweden)

    José Manuel Enciso Gadea

    2015-06-01

    None of the different methods used was capable of giving good results, except immersing the liver samples in liquid nitrogen, followed by Jackson’s et al. (2013 thawing protocol, suggesting that the thawing process may be as critical as the freezing process. To sum up, these results highlight the importance of deepening the possibility to perform the comet assay with frozen tissue.

  15. The performance of quantitative D-dimer assays in laboratory routine.

    Science.gov (United States)

    Spannagl, Michael; Haverkate, Frits; Reinauer, Hans; Meijer, Piet

    2005-09-01

    Assessment of D-dimer in plasma is routinely used for the exclusion of venous thrombosis and the monitoring of hypercoagulability. Little information is available about the performance of D-dimer assays in clinical laboratories examined by external quality assessment schemes. We obtained results from 423 laboratories measuring plasma pools from patients with elevated D-dimer levels mixed with human normal plasma. The results from five samples were reported containing D-dimer from the lower normal range up to a 20-fold increased level. In addition, information about the assignment of a cut-off point and the medical need to apply these assays was obtained by standardized questionnaire. Participants reported results and additional information from 20 different assays. Lack of standardization regarding the calibration concepts obstructs comparability of results. Results in one sample varied up to 20-fold between the assays applied. In addition, a high variability was reported around the cut-off values introduced for the exclusion of venous thrombosis and pulmonary embolism. As a consequence, generally accepted cut-off values cannot be established. For cut-off assignment, 62% of participants used the kit insert but also 14% used local validation. In conclusion, standardization or at least harmonization of D-dimer assays is necessary to ensure comparability of D-dimer plasma levels measured in clinical routine.

  16. 40 CFR 450.24 - New source performance standards reflecting the best available demonstrated control technology...

    Science.gov (United States)

    2010-07-01

    ... performance standards reflecting the best available demonstrated control technology (NSPS). Any new source... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards reflecting the best available demonstrated control technology (NSPS). 450.24 Section 450.24 Protection of...

  17. Analytical performance and clinical decision limit of a new release for cardiac troponin I assay.

    Science.gov (United States)

    Moretti, M; Pieretti, B; Sisti, D; Rocchi, Mb; Gasperoni, S

    2015-01-01

    Cardiac troponins (cTns) are the 'gold standard' biomarker for the diagnosis and prognosis of acute coronary syndrome. Analytical performance is critical at low concentrations of cTn, and many of the current assays do not meet the guideline requirement of a 10% coefficient of variation (CV) at the 99th percentile concentrations. The aim of the study was to establish if the newly released Access® AccuTnI®+3 (AccuTnI+3) cardiac troponin I assay (Beckman Coulter Inc., Brea, CA, USA) reached this objective. All AccuTnI+3 assays were performed on UniCel® DxI800 analyzer (Beckman Coulter Inc). Limit of Blank (LoB), Limit of Detection (LoD) and Limit of Quantitation (LoQ) were determined according to Clinical Laboratory Standard Institute EP17-A and EP5-A2 protocols. The 99th percentile upper reference limit (URL) was determined by analysing serum samples from 330 apparently healthy blood donors (260 men, 70 women, age range 18-70 years, median age 36 years). LoB and LoD values were 2.6 and 12 ng/L, respectively. The 10% CV was at 18 ng/L (95% confidence interval [CI] 8-25). The 99th percentile URL was 22 ng/L (95% CI 11-34). The newly released assay has improved low-end analytical performance and reaches the goal of having a total imprecision ≤ 10% at 99th percentile of a healthy reference population (guideline acceptable). With this assay, it is now possible to utilize the 99th percentile as decision level for myocardial injury detection. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  18. Pacific Northwest Smart Grid Demonstration Project Technology Performance Report Volume 1: Technology Performance

    Energy Technology Data Exchange (ETDEWEB)

    Melton, Ron [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-01

    The Pacific Northwest Smart Grid Demonstration (PNWSGD), a $179 million project that was co-funded by the U.S. Department of Energy (DOE) in late 2009, was one of the largest and most comprehensive demonstrations of electricity grid modernization ever completed. The project was one of 16 regional smart grid demonstrations funded by the American Recovery and Reinvestment Act. It was the only demonstration that included multiple states and cooperation from multiple electric utilities, including rural electric co-ops, investor-owned, municipal, and other public utilities. No fewer than 55 unique instantiations of distinct smart grid systems were demonstrated at the projects’ sites. The local objectives for these systems included improved reliability, energy conservation, improved efficiency, and demand responsiveness. The demonstration developed and deployed an innovative transactive system, unique in the world, that coordinated many of the project’s distributed energy resources and demand-responsive components. With the transactive system, additional regional objectives were also addressed, including the mitigation of renewable energy intermittency and the flattening of system load. Using the transactive system, the project coordinated a regional response across the 11 utilities. This region-wide connection from the transmission system down to individual premises equipment was one of the major successes of the project. The project showed that this can be done and assets at the end points can respond dynamically on a wide scale. In principle, a transactive system of this type might eventually help coordinate electricity supply, transmission, distribution, and end uses by distributing mostly automated control responsibilities among the many distributed smart grid domain members and their smart devices.

  19. Performance of cryptococcal antigen lateral flow assay using saliva in Ugandans with CD4 <100.

    Directory of Open Access Journals (Sweden)

    Richard Kwizera

    Full Text Available Cryptococcal meningitis can best be diagnosed by cerebrospinal fluid India ink microscopy, cryptococcal antigen detection, or culture. These require invasive lumbar punctures. The utility of cryptococcal antigen detection in saliva is unknown. We evaluated the diagnostic performance of the point-of-care cryptococcal antigen lateral flow assay (CrAg LFA in saliva.We screened HIV-infected, antiretroviral therapy naïve persons with symptomatic meningitis (n = 130 and asymptomatic persons with CD4+<100 cells/µL entering into HIV care (n = 399 in Kampala, Uganda. The diagnostic performance of testing saliva was compared to serum/plasma cryptococcal antigen as the reference standard.The saliva lateral flow assay performance was overall more sensitive in symptomatic patients (88% than in asymptomatic patients (27%. The specificity of saliva lateral flow assay was excellent at 97.8% in the symptomatic patients and 100% in asymptomatic patients. The degree of accuracy of saliva in diagnosing cryptococcosis and the level of agreement between the two sample types was better in symptomatic patients (C-statistic 92.9, κ-0.82 than in asymptomatic patients (C-statistic 63.5, κ-0.41. Persons with false negative salvia CrAg tests had lower levels of peripheral blood CrAg titers (P<0.001.There was poor diagnostic performance in testing saliva for cryptococcal antigen, particularly among asymptomatic persons screened for preemptive treatment of cryptococcosis.

  20. Performance of cryptococcal antigen lateral flow assay using saliva in Ugandans with CD4 <100.

    Science.gov (United States)

    Kwizera, Richard; Nguna, Joyce; Kiragga, Agnes; Nakavuma, Jesca; Rajasingham, Radha; Boulware, David R; Meya, David B

    2014-01-01

    Cryptococcal meningitis can best be diagnosed by cerebrospinal fluid India ink microscopy, cryptococcal antigen detection, or culture. These require invasive lumbar punctures. The utility of cryptococcal antigen detection in saliva is unknown. We evaluated the diagnostic performance of the point-of-care cryptococcal antigen lateral flow assay (CrAg LFA) in saliva. We screened HIV-infected, antiretroviral therapy naïve persons with symptomatic meningitis (n = 130) and asymptomatic persons with CD4+diagnostic performance of testing saliva was compared to serum/plasma cryptococcal antigen as the reference standard. The saliva lateral flow assay performance was overall more sensitive in symptomatic patients (88%) than in asymptomatic patients (27%). The specificity of saliva lateral flow assay was excellent at 97.8% in the symptomatic patients and 100% in asymptomatic patients. The degree of accuracy of saliva in diagnosing cryptococcosis and the level of agreement between the two sample types was better in symptomatic patients (C-statistic 92.9, κ-0.82) than in asymptomatic patients (C-statistic 63.5, κ-0.41). Persons with false negative salvia CrAg tests had lower levels of peripheral blood CrAg titers (Pdiagnostic performance in testing saliva for cryptococcal antigen, particularly among asymptomatic persons screened for preemptive treatment of cryptococcosis.

  1. Performance characteristics of the ARCHITECT Active-B12 (Holotranscobalamin) assay.

    Science.gov (United States)

    Merrigan, Stephen D; Owen, William E; Straseski, Joely A

    2015-01-01

    Vitamin B12 (cobalamin) is a necessary cofactor in methionine and succinyl-CoA metabolism. Studies estimate the deficiency prevalence as high as 30% in the elderly population. Ten to thirty percent of circulating cobalamin is bound to transcobalamin (holotranscobalamin, holoTC) which can readily enter cells and is therefore considered the bioactive form. The objective of our study was to evaluate the analytical performance of a high-throughput, automated holoTC assay (ARCHITECT i2000(SR) Active-B12 (Holotranscobalamin)) and compare it to other available methods. Manufacturer-specified limits of blank (LoB), detection (LoD), and quantitation (LoQ), imprecision, interference, and linearity were evaluated for the ARCHITECT HoloTC assay. Residual de-identified serum samples were used to compare the ARCHITECT HoloTC assay with the automated AxSYM Active-B12 (Holotranscobalamin) assay (Abbott Diagnostics) and the manual Active-B12 (Holotranscobalamin) Enzyme Immunoassay (EIA) (Axis-Shield Diagnostics, Dundee, Scotland, UK). Manufacturer's claims of LoB, LoD, LoQ, imprecision, interference, and linearity to the highest point tested (113.4 pmol/L) were verified for the ARCHITECT HoloTC assay. Method comparison of the ARCHITECT HoloTC to the AxSYM HoloTC produced the following Deming regression statistics: (ARCHITECT(HoloTc)) = 0.941 (AxSYM(HoloTC)) + 1.2 pmol/L, S(y/x) = 6.4, r = 0.947 (n = 98). Comparison to the Active-B12 EIA produced: (ARCHITECT(HoloTC)) = 1.105 (EIA(Active-B12)) - 6.8 pmol/L, S(y/x) = 11.0, r = 0.950 (n = 221). This assay performed acceptably for LoB, LoD, LoQ, imprecision, interference, linearity and method comparison to the predicate device (AxSYM). An additional comparison to a manual Active-B12 EIA method performed similarly, with minor exceptions. This study determined that the ARCHITECT HoloTC assay is suitable for routine clinical use, which provides a high-throughput alternative for automated testing of this emerging marker of cobalamin

  2. Development of an in vitro assay and demonstration of Plasmodium berghei liver-stage inhibition by TRAP-specific CD8+ T cells.

    Directory of Open Access Journals (Sweden)

    Rhea J Longley

    Full Text Available The development of an efficacious vaccine against the Plasmodium parasite remains a top priority. Previous research has demonstrated the ability of a prime-boost virally vectored sub-unit vaccination regimen, delivering the liver-stage expressed malaria antigen TRAP, to produce high levels of antigen-specific T cells. The liver-stage of malaria is the main target of T cell-mediated immunity, yet a major challenge in assessing new T cell inducing vaccines has been the lack of a suitable pre-clinical assay. We have developed a flow-cytometry based in vitro T cell killing assay using a mouse hepatoma cell line, Hepa1-6, and Plasmodium berghei GFP expressing sporozoites. Using this assay, P. berghei TRAP-specific CD8+ T cell enriched splenocytes were shown to inhibit liver-stage parasites in an effector-to-target ratio dependent manner. Further development of this assay using human hepatocytes and P. falciparum would provide a new method to pre-clinically screen vaccine candidates and to elucidate mechanisms of protection in vitro.

  3. Cost and Performance Report for Bioavailable Ferric Iron (BAFeIII) Assay

    Science.gov (United States)

    2005-06-01

    Printed on recycled paper CONTRACT REPORT CR 05-005-ENV COST AND PERFORMANCE REPORT FOR BIOAVAILABLE FERRIC IRON (BAFeIII) ASSAY by...ORGANIZATION REPORT NUMBER Commanding Officer Naval Facilities Engineering Service Center 1100 23rd Ave Port Hueneme, CA 93043- CR -05-005-ENV 9...Emmett-Teller bgs Below ground surface BTEX Benzene-toluene-ethylbenzene-xylenes BrY Shewanella alga BrY CDB Citrate dithionite bicarbonate

  4. High-performance liquid chromatography for assaying NAD glycohydrolase from Neurospora crassa conidia.

    Science.gov (United States)

    Pietta, P; Pace, M; Menegus, F

    1983-06-01

    A rapid and sensitive high-performance liquid chromatographic technique was developed to determinate NAD glycohydrolase (EC 3.2.2.5.) activity from Neurospora crassa conidia. The separation of the assay substrate and products was achieved by isocratic reverse-phase chromatography and the peaks were detected by the absorbance at 259 nm. Quantities of NAD+ and nicotinamide as small as 10 pmol could be measured.

  5. Repeat testing of low-level HIV-1 RNA: assay performance and implementation in clinical trials.

    Science.gov (United States)

    White, Kirsten; Garner, Will; Wei, Lilian; Eron, Joseph J; Zhong, Lijie; Miller, Michael D; Martin, Hal; Plummer, Andrew; Tran-Muchowski, Cecilia; Lindstrom, Kim; Porter, James; Piontkowsky, David; Light, Angela; Reiske, Heinz; Quirk, Erin

    2018-02-08

    Assess the performance of HIV-1 RNA repeat testing of stored samples in cases of low-level viremia during clinical trials. Prospective and retrospective analysis of randomized clinical trial samples and reference standards. To evaluate assay variability of the Cobas AmpliPrep/Cobas TaqMan HIV-1 Test, v2.0, three separate sources of samples were utilized: the World Health Organization (WHO) HIV reference standard (assayed using 50 independent measurements at six viral loads <200 copies/ml), retrospective analysis of four to six aliquots of plasma samples from four clinical trial participants, and prospective repeat testing of 120 samples from participants in randomized trials with low-level viremia. The TaqMan assay on the WHO HIV-1 RNA standards at viral loads <200 copies/ml performed within the expected variability according to assay specifications. However, standards with low viral loads of 36 and 18 copies/ml reported values of at least 50 copies/ml in 66 and 18% of tests, respectively. In participants treated with antiretrovirals who had unexpected viremia of 50-200 copies/ml after achieving <50 copies/ml, retesting of multiple aliquots of stored plasma found <50 copies/ml in nearly all cases upon retesting (14/15; 93%). Repeat testing was prospectively implemented in four clinical trials for all samples with virologic rebound of 50-200 copies/ml (n = 120 samples from 92 participants) from which 42% (50/120) had a retest result of less than 50 copies/ml and 58% (70/120) retested at least 50 copies/ml. The TaqMan HIV-1 RNA assay shows variability around 50 copies/ml that affects clinical trial results and may impact clinical practice. In participants with a history of viral load suppression, unexpected low-level viremia may be because of assay variability rather than low-drug adherence or true virologic failure. Retesting a stored aliquot of the same sample may differentiate between assay variability and virologic failure as the source

  6. Performance of the Xpert HPV assay in women attending for cervical screening

    Directory of Open Access Journals (Sweden)

    Jack Cuzick

    2015-12-01

    Full Text Available Objectives: This study evaluated the Xpert HPV Assay in women attending screening in general practice by comparing Xpert with two established HPV tests, cytology and histology. Methods: A prospective study in women aged 20–60 years attending screening in Bristol, Edinburgh and London using residual Preservcyt cytology samples. Sample order was randomised between Roche cobas4800 and Cepheid Xpert assays with Qiagen hc2 third. Results: 3408 cases were included in the primary analysis. Positivity for Xpert was 19.6%, cobas 19.2% and hc2 19.9% with high concordance (kappa=86.8% vs cobas, 81.55 vs hc2. Xpert, cobas and hc2 showed similar sensitivity (98.7%, 97.5%, 98.7% for CIN2+. All pairwise comparisons had high concordance (Kappa ≥0.78 with any abnormal cytology. Xpert and hc2 were positive for all cases of ≥moderate dyskaryosis (N=63, cobas was negative in two. Histology was available for 172 participants. 79 reported CIN2+, 47 CIN3+. All CIN3+ was positive on Xpert and hc2 and one case negative for cobas. One case of CIN2 was negative for all assays. Conclusions: The performance of Xpert HPV Assay in a general screening population is comparable to established HPV tests. It offers simplicity of testing, flexibility with non-batching of individual samples and rapid turnaround time. Keywords: Human papillomavirus, Xpert, Cervical screening, HPV testing

  7. Evaluation of a BED-SIDE Platelet Function Assay : Performance and Clinical Utility.

    Directory of Open Access Journals (Sweden)

    Lau Wei

    2002-01-01

    Full Text Available Platelets have a pivotal role in the initial defense against insult to the vasculature and are also recognized of critical importance in the acute care settings of percutaneous coronary intervention and cardiopulmonary bypass. In these environments both platelet count and function may be markedly compromised. Unfortunately, current assays to evaluate the parameters of platelet count and function are of limited utility for bed-side testing. Moreover, it is suggested that there may be significant inter patient variation in response to antiplatelet therapy that may be exacerbated by other agents (e.g. heparin that are routinely administered during cardiac intervention. Here we describe a practical, rapid and user-friendly whole blood platelet function assay that has been developed for use in bed-side settings. Platelet agonists were formulated with an anticoagulant and lyophilized in blood collection tubes standardised to receive a l mL fresh whole blood sample. In the presence of an agonist, platelets are activated and interact (aggregate. Using traditional cell counting principles, non-aggregated platelets are counted whereas aggregated platelets are not. The percentage (% of functional platelets in reference to a baseline tube may then be determined. Results are available within four minutes. Platelet aggregation in whole blood demonstrated good correlation with turbidometric aggregometry for both ADP (r=0.91 and collagen (r=0.88. Moreover, in clinical settings where antiplatelet agents were administered, this rapid, bed-side, platelet function assay demonstrated utility in monitoring patient response to these therapies. This novel bed-side assay of platelet function is extremely suitable for the clinical environment with a rapid turn-around time. In addition, it provides a full haematology profile, including platelet count, and should permit enhancement of transfusion and interventional decisions.

  8. Performance characteristics of six automated 25-hydroxyvitamin D assays: Mind your 3s and 2s.

    Science.gov (United States)

    Wyness, Sara P; Straseski, Joely A

    2015-11-01

    Measurement of 25(OH)D has evolved rapidly, with an increased number of high-throughput automated immunoassays becoming available in recent years. The aim of this study was to fully evaluate six commercially available automated 25(OH)D immunoassays, including 2 newly available (Beckman Coulter) and one recalibrated (Siemens) assay. Comparisons were made to specifically identify the effect of the absence or presence of 25(OH)D2 on these assays. Access2 and UniCel DxI 800 (Beckman Coulter), ARCHITECT i2000SR (Abbott Diagnostics), ADVIA Centaur XP (Siemens), Liaison XL (DiaSorin) and MODULAR E170 (Roche Diagnostics) assays were assessed for accuracy, imprecision, interference, limit of blank, and linearity. All were compared to an in-house LC-MS/MS method (traceable to NIST SRM 972) using Passing-Bablok regression and Bland-Altman bias plots. Method comparisons used residual serum samples with both endogenous 25(OH)D2 and 25(OH)D3 (n=50) or 25(OH)D3 only (n=86). Comparisons with all 136 samples were intended to simulate real-world laboratory testing. The majority of assays under-recovered 25(OH)D in comparison to LC-MS/MS, with three of six immunoassays affected by the presence of 25(OH)D2. Imprecision was greatest at 25(OH)D concentrations near the decision limits used to assess deficiency. Only two of six immunoassays would meet the recommended bias criteria of <5%. Although standardization efforts continue, these differences in performance remain a concern. Clinicians should be aware when comparing results among assays and using them to determine adequacy of 25(OH)D stores in various patient populations. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  9. Simultaneous assay for amatoxins and phallotoxins in Amanita phalloides Fr. by high-performance liquid chromatography.

    Science.gov (United States)

    Enjalbert, F; Gallion, C; Jehl, F; Monteil, H; Faulstich, H

    1992-05-15

    A reversed-phase high-performance liquid chromatographic method is described that allows the simultaneous determination of up to eight amatoxins and phallotoxins. The method identifies both neutral toxins (alpha- and gamma-amanitin, phalloidin, phallisin and phalloin) and acidic toxins (beta-amanitin, phallacidin and phallisacin). Toxins were separated, identified and determined by gradient elution with 0.02 M aqueous ammonium acetate-acetonitrile and simultaneous monitoring of the absorbances at 214 and 295 nm. The assay was successfully applied to the analysis of the toxins in a crude extract of Amanita phalloides. The limit of detection for each toxin was 10 ng/ml of extraction medium. The assay was further validated by analysing the toxin content in Galerina marginata, a species containing only amatoxins. This relatively simple method should be suitable for the detection of amatoxins and phallotoxins in almost any species of mushrooms.

  10. Designing Scholarships to Improve College Success: Final Report on the Performance-Based Scholarship Demonstration

    Science.gov (United States)

    Mayer, Alexander K.; Patel, Reshma; Rudd, Timothy; Ratledge, Alyssa

    2015-01-01

    Performance-based scholarships have two main goals: (1) to give students more money for college; and (2) to provide incentives for academic progress. MDRC launched the Performance-Based Scholarship (PBS) Demonstration in 2008 to evaluate the effectiveness of these scholarships in a diverse set of states, institutions, and low-income student…

  11. Environmental assessment for the electric and hybrid vehicle demonstration project, performance standards and financial incentives

    Energy Technology Data Exchange (ETDEWEB)

    LaBelle, S. J.

    1978-10-01

    The assessment is concerned with the impacts of the demonstration of electric and hybrid vehicles acquired to fulfill certain requirements of the Electric and Hybrid Vehicle Research, Development, and Demonstration Act, PL 94-413 as amended. The financial incentives programs and vehicle performance standards associated with the demonstration are also covered. Not included is an assessment of the long term effects of EHV commercialization and of the research and development program being carried out simultaneously with the demonstration, also in response to PL 94-413. These federal actions will be included in a programmatic environmental assessment scheduled for completion in FY 79.

  12. Association of Biotin Ingestion With Performance of Hormone and Nonhormone Assays in Healthy Adults.

    Science.gov (United States)

    Li, Danni; Radulescu, Angela; Shrestha, Rupendra T; Root, Matthew; Karger, Amy B; Killeen, Anthony A; Hodges, James S; Fan, Shu-Ling; Ferguson, Angela; Garg, Uttam; Sokoll, Lori J; Burmeister, Lynn A

    2017-09-26

    Biotinylated antibodies and analogues, with their strong binding to streptavidin, are used in many clinical laboratory tests. Excess biotin in blood due to supplemental biotin ingestion may affect biotin-streptavidin binding, leading to potential clinical misinterpretation. However, the degree of interference remains undefined in healthy adults. To assess performance of specific biotinylated immunoassays after 7 days of ingesting 10 mg/d of biotin, a dose common in over-the-counter supplements for healthy adults. Nonrandomized crossover trial involving 6 healthy adults who were treated at an academic medical center research laboratory. Administration of 10 mg/d of biotin supplementation for 7 days. Analyte concentrations were compared with baseline (day 0) measures on the seventh day of biotin treatment and 7 days after treatment had stopped (day 14). The 11 analytes included 9 hormones (ie, thyroid-stimulating hormone, total thyroxine, total triiodothyronine, free thyroxine, free triiodothyronine, parathyroid hormone, prolactin, N-terminal pro-brain natriuretic peptide, 25-hydroxyvitamin D) and 2 nonhormones (prostate-specific antigen and ferritin). A total of 37 immunoassays for the 11 analytes were evaluated on 4 diagnostic systems, including 23 assays that incorporated biotin and streptavidin components and 14 assays that did not include biotin and streptavidin components and served as negative controls. Among the 2 women and 4 men (mean age, 38 years [range, 31-45 years]) who took 10 mg/d of biotin for 7 days, biotin ingestion-associated interference was found in 9 of the 23 (39%) biotinylated assays compared with none of the 14 nonbiotinylated assays (P = .007). Results from 5 of 8 biotinylated (63%) competitive immunoassays tested falsely high and results from 4 out of 15 (27%) biotinylated sandwich immunoassays tested falsely low. In this preliminary study of 6 healthy adult participants and 11 hormone and nonhormone analytes measured by 37 immunoassays

  13. Performance of the Tile PreProcessor Demonstrator for the ATLAS Tile Calorimeter Phase II Upgrade

    CERN Document Server

    Carrio Argos, Fernando; The ATLAS collaboration

    2015-01-01

    The Tile Calorimeter PreProcessor (TilePPr) demonstrator is a high performance double AMC board based on FPGA resources and QSFP modules. This board has been designed in the framework of the ATLAS Tile Calorimeter (TileCal) Demonstrator Project for the Phase II Upgrade as the first stage of the back-end electronics. The TilePPr demonstrator has been conceived for receiving and processing the data coming from the front-end electronics of the TileCal Demonstrator module, as well as for configuring it. Moreover, the TilePPr demonstrator handles the communication with the Detector Control System to monitor and control the front-end electronics. The TilePPr demonstrator represents 1/8 of the final TilePPr that will be designed and installed into the detector for the ATLAS Phase II Upgrade.

  14. Clinical performance of a multivariate index assay for detecting early-stage ovarian cancer.

    Science.gov (United States)

    Longoria, Teresa C; Ueland, Frederick R; Zhang, Zhen; Chan, Daniel W; Smith, Alan; Fung, Eric T; Munroe, Donald G; Bristow, Robert E

    2014-01-01

    We sought to analyze the effectiveness of a multivariate index assay (MIA) in identifying early-stage ovarian malignancy compared to clinical assessment, CA 125-II, and modified American Congress of Obstetricians and Gynecologists (ACOG) guidelines among women undergoing surgery for an adnexal mass. Patients were recruited in 2 related prospective, multi-institutional trials involving 44 sites. All women had preoperative imaging and biomarker analysis. Preoperative biomarker values, physician assessment of ovarian cancer risk, and modified ACOG guideline risk stratification were correlated with surgical pathology. A total of 1016 patients were evaluable for MIA, CA 125-II, and clinical assessment. Overall, 86 patients (8.5%) had primary-stage I/II primary ovarian malignancy, with 70.9% having stage I disease and 29.1% having stage II disease. For all early-stage ovarian malignancies, MIA combined with clinical assessment had significantly higher sensitivity (95.3%; 95% confidence interval [CI], 88.6-98.2) compared to clinical assessment alone (68.6%; 95% CI, 58.2-77.4), CA 125-II (62.8%; 95% CI, 52.2-72.3), and modified ACOG guidelines (76.7%; 95% CI, 66.8-84.4) (P early-stage ovarian cancer was 89.3% (95% CI, 72.8-96.3) for MIA combined with clinical assessment, 60.7% (95% CI, 42.4-76.4) for clinical assessment alone, 35.7% (95% CI, 20.7-54.2) for CA 125-II, and 78.6% (95% CI, 60.5-89.8) for modified ACOG guidelines. Early-stage ovarian cancer in postmenopausal patients was correctly detected in 98.3% (95% CI, 90.9-99.7) of cases by MIA combined with clinical assessment, compared to 72.4% (95% CI, 59.8-82.2) for clinical assessment alone, 75.9% (95% CI, 63.5-85.0) for CA 125-II, and 75.9% (95% CI, 63.5-85.0) for modified ACOG guidelines. MIA combined with clinical assessment demonstrated higher sensitivity for early-stage ovarian malignancy compared to clinical assessment alone, CA 125-II, and modified ACOG guidelines with consistent performance across menopausal

  15. Performance of three microimmunofluorescence assays for detection of Chlamydia pneumoniae immunoglobulin M, G, and A antibodies

    DEFF Research Database (Denmark)

    Bennedsen, Mette; Berthelsen, Lene; Lind, Inga

    2002-01-01

    The microimmunofluorescence (MIF) test is considered the "gold standard" for laboratory diagnosis of acute and chronic Chlamydia pneumoniae infection. The performance of a MIF test based on C. pneumoniae antigen from Washington Research Foundation (WRF) was compared with those of assays from...... Labsystems (LAB) and MRL Diagnostics (MRL) by investigation of sera from three groups of patients: group I, 83 sera from 28 patients with atypical pneumonia; group II, 37 sera from 16 patients with acute C. pneumoniae or Chlamydia psittaci respiratory tract infection confirmed by PCR or culture; group III...

  16. Construction and performance measurement of a portable thermoacoustic refrigerator demonstration apparatus

    OpenAIRE

    Berhow, Todd J.

    1994-01-01

    Approved for public release; distribution is unlimited This thesis documents the construction and performance measurement of a portable thermoacoustic refrigerator demonstration apparatus. The objective of the portable refrigerator is to graphically display, as a demonstration during lectures, a substantial thermoacoustic cooling power. Within minutes of start up, the apparatus develops frost on a small metal portion of the device. The refrigerator is small and compact and fits into a port...

  17. Key learnings from performance of the U.S. EPA Endocrine Disruptor Screening Program (EDSP) Tier 1 in vitro assays.

    Science.gov (United States)

    LeBaron, Matthew J; Coady, Katie K; O'Connor, John C; Nabb, Diane L; Markell, Lauren K; Snajdr, Suzanne; Sue Marty, M

    2014-02-01

    Tier 1 of the U.S. EPA Endocrine Disruptor Screening Program comprises 11 studies: five in vitro assays, four in vivo mammalian assays, and two in vivo nonmammalian assays. The battery is designed to detect compounds with the potential to interact with the estrogen, androgen, or thyroid signaling pathways. This article examines the procedures, results, and data interpretation for the five Tier 1 in vitro assays: estrogen receptor (ER) and androgen receptor binding assays, an ER transactivation assay, an aromatase assay, and a steroidogenesis assay. Data are presented from two laboratories that have evaluated approximately 11 compounds in the Tier 1 in vitro assays. Generally, the ER and androgen receptor binding assays and the aromatase assay showed good specificity and reproducibility. As described in the guideline for the ER transactivation assay, a result is considered positive when the test compound induces a reporter gene signal that reaches 10% of the response seen with 1 nM 17β-estradiol (positive control). In the experience of these laboratories, this cutoff criterion may result in false-positive responses. For the steroidogenesis assay, there is variability in the basal and stimulated production of testosterone and estradiol by the H295R cells. This variability in responsiveness, coupled with potential cell stress at high concentrations of test compound, may make it difficult to discern whether hormone alterations are specific steroidogenesis alterations (i.e., endocrine active). Lastly, both laboratories had difficulty meeting some recommended performance criteria for each Tier 1 in vitro assay. Data with only minor deviations were deemed valid. © 2014 Wiley Periodicals, Inc.

  18. Performance of the TilePPr demonstrator for the ATLAS Tile Calorimeter Phase II Upgrade

    CERN Document Server

    Carrio Argos, Fernando; The ATLAS collaboration

    2015-01-01

    The Tile Calorimeter Pre-processor (TilePPr) demonstrator is a high performance double AMC board based on FPGA resources and QSFP modules. This board has been designed in the framework of the ATLAS Tile Calorimeter (TileCal) Demonstrator Project for the Phase II Upgrade as the first stage of the off-detector electronics. The TilePPr demonstrator has been conceived for receiving and processing the data coming from the on-detector electronics of the TileCal Demonstrator module, as well as for configuring it. Moreover, the TilePPr demonstrator handles the communication with the Detector Control System to monitor and control the on-detector electronics.

  19. Performance of a daylight redirecting glass shading system demonstration in an office building

    DEFF Research Database (Denmark)

    Appelfeld, David; Svendsen, Svend; Traberg-Borup, Steen

    2011-01-01

    This paper evaluates the daylighting performance of a prototype external dynamic integrated shading and light redirecting system. The demonstration project was carried out on a building with an open-plan office. The prototype and original façades were placed on the same floor with the same...

  20. Control of airborne radioactive emissions for frequently performed TWRS work activities (ALARACT demonstrations)

    Energy Technology Data Exchange (ETDEWEB)

    CLARK, D.E.

    1999-06-23

    This document contains ALARACT Demonstrations identifying agreements made between LMHC, FDH, DOE-RL, and the Washington State Department of Health for frequently performed work activities in TWRS. These ALARACTs do not cover new activities, modifications, construction, or decontamination and decommissioning activities.

  1. Impact of immunization technology and assay application on antibody performance--a systematic comparative evaluation.

    Directory of Open Access Journals (Sweden)

    Michael C Brown

    Full Text Available Antibodies are quintessential affinity reagents for the investigation and determination of a protein's expression patterns, localization, quantitation, modifications, purification, and functional understanding. Antibodies are typically used in techniques such as Western blot, immunohistochemistry (IHC, and enzyme-linked immunosorbent assays (ELISA, among others. The methods employed to generate antibodies can have a profound impact on their success in any of these applications. We raised antibodies against 10 serum proteins using 3 immunization methods: peptide antigens (3 per protein, DNA prime/protein fragment-boost ("DNA immunization"; 3 per protein, and full length protein. Antibodies thus generated were systematically evaluated using several different assay technologies (ELISA, IHC, and Western blot. Antibodies raised against peptides worked predominantly in applications where the target protein was denatured (57% success in Western blot, 66% success in immunohistochemistry, although 37% of the antibodies thus generated did not work in any of these applications. In contrast, antibodies produced by DNA immunization performed well against both denatured and native targets with a high level of success: 93% success in Western blots, 100% success in immunohistochemistry, and 79% success in ELISA. Importantly, success in one assay method was not predictive of success in another. Immunization with full length protein consistently yielded the best results; however, this method is not typically available for new targets, due to the difficulty of generating full length protein. We conclude that DNA immunization strategies which are not encumbered by the limitations of efficacy (peptides or requirements for full length proteins can be quite successful, particularly when multiple constructs for each protein are used.

  2. Learning to perform a new movement with robotic assistance: comparison of haptic guidance and visual demonstration

    Directory of Open Access Journals (Sweden)

    Reinkensmeyer DJ

    2006-08-01

    Full Text Available Abstract Background Mechanical guidance with a robotic device is a candidate technique for teaching people desired movement patterns during motor rehabilitation, surgery, and sports training, but it is unclear how effective this approach is as compared to visual demonstration alone. Further, little is known about motor learning and retention involved with either robot-mediated mechanical guidance or visual demonstration alone. Methods Healthy subjects (n = 20 attempted to reproduce a novel three-dimensional path after practicing it with mechanical guidance from a robot. Subjects viewed their arm as the robot guided it, so this "haptic guidance" training condition provided both somatosensory and visual input. Learning was compared to reproducing the movement following only visual observation of the robot moving along the path, with the hand in the lap (the "visual demonstration" training condition. Retention was assessed periodically by instructing the subjects to reproduce the path without robotic demonstration. Results Subjects improved in ability to reproduce the path following practice in the haptic guidance or visual demonstration training conditions, as evidenced by a 30–40% decrease in spatial error across 126 movement attempts in each condition. Performance gains were not significantly different between the two techniques, but there was a nearly significant trend for the visual demonstration condition to be better than the haptic guidance condition (p = 0.09. The 95% confidence interval of the mean difference between the techniques was at most 25% of the absolute error in the last cycle. When asked to reproduce the path repeatedly following either training condition, the subjects' performance degraded significantly over the course of a few trials. The tracing errors were not random, but instead were consistent with a systematic evolution toward another path, as if being drawn to an "attractor path". Conclusion These results indicate

  3. Stability-indicating high-performance liquid chromatographic assay method and photostability of carprofen.

    Science.gov (United States)

    Wu, A B; Chen, C Y; Chu, S D; Tsai, Y C; Chen, F A

    2001-01-01

    A rapid, sensitive, and accurate stability-indicating high-performance liquid chromatographic assay method for determining the degradation of carprofen (CPF) is developed and validated under acidic, basic, or photo-irradiated conditions. The analysis is monitored with a Cosmosil 5C18-AR column using a mobile phase of CH3CN-H2O-AcOH (50:49:1, v/v/v) at 260 nm. The developed method satisfies the system suitability criteria, peak integrity, and resolution among the parent drug and its degradation products. The results indicate that the established assay method shows good selectivity and specificity suitable for stability measurements of CPF. CPF is found to be more sensitive to exposure to light and in acidic conditions, but it is stable in a basic medium. The kinetic study of the photodegradation of CPF follows an apparent first-order reaction in a variety of solvents. The solvent effects on the rates of degradation are in the decreasing order of chloroform > dichloromethane > methanol > ethanol > 2-propanol, which is irrelevant to the dielectric constant epsilon. However, the hydrogen-donating ability of the solvents is essential to the photochemical decomposition of CPF. A plot of log k versus the Kirkwood function exhibits a linear relationship in aqueous ethanolic solutions, which implies that degradation proceeds via an ionic mechanism.

  4. Clinical performance of the Solana® Point-of-Care Trichomonas Assay from clinician-collected vaginal swabs and urine specimens from symptomatic and asymptomatic women.

    Science.gov (United States)

    Gaydos, C A; Schwebke, J; Dombrowski, J; Marrazzo, J; Coleman, J; Silver, B; Barnes, M; Crane, L; Fine, P

    2017-03-01

    Solana® (Quidel) is a new rapid (Trichomonas vaginalis (TV) DNA. The assay has two steps: 1) specimen preparation, and 2) amplification and detection using isothermal Helicase-Dependent Amplification (HDA). The objective was to demonstrate the performance of Solana for vaginal swabs and female urines based on comparison to wet mount and TV culture. Performance was also compared to the Aptima-TV assay. Urine and four clinician-collected vaginal swabs were collected. The first two were used for FDA composite reference (wet mount; InPouch TV Culture). The third swab was used for Solana. Sensitivity/specificity were based on the reference method. A specimen was considered positive if either test was positive. The fourth swab was for Aptima-TV. Vaginal swabs and urines were obtained from 501 asymptomatic and 543 symptomatic women. Prevalence of TV by was 11.5%. For swabs, Solana® demonstrated high sensitivity and specificity from asymptomatic (100%/98.9%) and symptomatic (98.6%/98.5%) women, as well as for urines from asymptomatic (98.0%/98.4%) and symptomatic (92.9%/97.9%) women, compared to the reference method. Compared to Aptima-TV, the sensitivity/specificity was 89.7%/99.0% for swabs and 100%/98.9% for urines. The Solana® assay performed well compared to the reference assays.

  5. Summary of WPT FOA phase II demonstration performed on July 21, 2015

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Perry T. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Onar, Omer C. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

    2015-08-01

    This summary provides details of the activities, presentations and hardware demonstrations performed at the International Transportation Innovation Center (iTiC) in Greenville, South Carolina as deliverables for the wireless power transfer (WPT) FOA #000667 phase II gateway. This report does not attempt to identify all encompassing efforts from each of the partners leading up to the demonstration, but will attempt to provide a record which briefly describes the project deliverables met and expectations from the Department of Energy (DOE) as action items agreed to during the wrap-up session on July 21, 2015.

  6. An interferon-gamma release assay test performs well in routine screening for tuberculosis

    DEFF Research Database (Denmark)

    Vestergaard Danielsen, Allan; Fløe, Andreas; Lillebæk, Troels

    2014-01-01

    and sensitivity. Material and methods: Data from T-SPOT.TB testing together with age and test indications (anti-tumour necrosis factor alpha (TNFα) candidate, contact investigation or suspicion of tuberculosis (TB)) were combined with mycobac­teria culture results. Results: A total of 1,809 patients were tested......, 41 of 43 culture-verified M. tuberculosis infections tested positive with one false negative. Conclusion: During routine testing, inconclusive tests were rare, but more frequent during autumn/winter periods and for patients 75 years of age. The T-SPOT.TB showed a high sensitivity in culture......Introduction: A positive interferon-gamma release assay (IGRA) is regarded as proof of latent Mycobacterium tuberculosis infection. We conducted an evaluation of the IGRA test “T-SPOT.TB” to test its performance during clinical routine use by analysing the positivity rate and odds, effect of season...

  7. Performance characteristics of an ELISA screening assay for urinary synthetic cannabinoids.

    Science.gov (United States)

    Spinelli, Eliani; Barnes, Allan J; Young, Sheena; Castaneto, Marisol S; Martin, Thomas M; Klette, Kevin L; Huestis, Marilyn A

    2015-06-01

    Synthetic cannabinoids are marketed as legal alternatives to cannabis, as routine urine cannabinoid immunoassays do not detect synthetic cannabinoids. Laboratories are challenged to identify these new designer drugs that are widely available and represent a major public health and safety problem. Immunoassay testing offers rapid separation of presumptive positive and negative specimens, prior to more costly and time-consuming chromatographic confirmation. The Neogen SPICE ELISA kit targets JWH-018 N-pentanoic acid as a marker for urinary synthetic cannabinoids. Assay performance was evaluated by analyzing 2469 authentic urine samples with the Neogen immunoassay and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two immunoassay cut-off concentrations, 5 and 10 µg/L, classified samples as presumptive positive or negative, followed by qualitative LC-MS/MS confirmation for 29 synthetic cannabinoids markers with limits of detection of 0.5-10 µg/L to determine the assay's sensitivity, specificity and efficacy. Challenges at ±25% of each cut-off also were investigated to determine performance around the cut-off and intra- and inter-plate imprecision. The immunoassay was linear from 1 to 250 µg/L (r(2)  = 0.992) with intra- and inter-plate imprecision of ≤5.3% and cannabinoids markers evaluated. Good sensitivity, specificity, and efficiency, lack of sample preparation requirements, and rapid semi-automation documented that the Neogen SPICE ELISA kit is a viable method for screening synthetic cannabinoids in urine targeting JWH-018 N-pentanoic acid. Copyright © 2014 John Wiley & Sons, Ltd.

  8. Design and Demonstration of Emergency Control Modes for Enhanced Engine Performance

    Science.gov (United States)

    Liu, Yuan; Litt, Jonathan S.; Guo, Ten-Huei

    2013-01-01

    A design concept is presented for developing control modes that enhance aircraft engine performance during emergency flight scenarios. The benefits of increased engine performance to overall vehicle survivability during these situations may outweigh the accompanied elevated risk of engine failure. The objective involves building control logic that can consistently increase engine performance beyond designed maximum levels based on an allowable heightened probability of failure. This concept is applied to two previously developed control modes: an overthrust mode that increases maximum engine thrust output and a faster response mode that improves thrust response to dynamic throttle commands. This paper describes the redesign of these control modes and presents simulation results demonstrating both enhanced engine performance and robust maintenance of the desired elevated risk level.

  9. Performance of a daylight redirecting glass shading system demonstration in an office building

    DEFF Research Database (Denmark)

    Appelfeld, David; Svendsen, Svend; Traberg-Borup, Steen

    2011-01-01

    This paper evaluates the daylighting performance of a prototype external dynamic integrated shading and light redirecting system. The demonstration project was carried out on a building with an open-plan office. The prototype and original façades were placed on the same floor with the same...... orientation and similar surroundings. The existing façade was used as the reference for measurements and simulations. The focus of this research project was to employ available simulation tools for the system performance evaluation. This was accompanied by measurements of the daylight conditions...

  10. Thermo-physical performance prediction of the KSC Ground Operation Demonstration Unit for liquid hydrogen

    Science.gov (United States)

    Baik, J. H.; Notardonato, W. U.; Karng, S. W.; Oh, I.

    2015-12-01

    NASA Kennedy Space Center (KSC) researchers have been working on enhanced and modernized cryogenic liquid propellant handling techniques to reduce life cycle costs of propellant management system for the unique KSC application. The KSC Ground Operation Demonstration Unit (GODU) for liquid hydrogen (LH2) plans to demonstrate integrated refrigeration, zero-loss flexible term storage of LH2, and densified hydrogen handling techniques. The Florida Solar Energy Center (FSEC) has partnered with the KSC researchers to develop thermal performance prediction model of the GODU for LH2. The model includes integrated refrigeration cooling performance, thermal losses in the tank and distribution lines, transient system characteristics during chilling and loading, and long term steady-state propellant storage. This paper will discuss recent experimental data of the GODU for LH2 system and modeling results.

  11. Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide

    Directory of Open Access Journals (Sweden)

    Rodrigo Juliano Oliveira

    2014-01-01

    Full Text Available β-glucan is a well-known polysaccharide for its chemopreventive effect. This study aimed to evaluate the chemopreventive ability of β-glucan in somatic and germ cells through the dominant lethal and micronucleus assays, and its influence on the reproductive performance of male mice exposed to cyclophosphamide. The results indicate that β-glucan is capable of preventing changes in DNA in both germ cells and somatic ones. Changes in germ cells were evaluated by the dominant lethal assay and showed damage reduction percentages of 46.46% and 43.79% for the doses of 100 and 150 mg/kg. For the somatic changes, evaluated by micronucleus assay in peripheral blood cells in the first week of treatment, damage reduction percentages from 80.63-116.32% were found. In the fifth and sixth weeks, the percentage ranged from 10.20-52.54% and -0.95-62.35%, respectively. Besides the chemopreventive efficiency it appears that the β-glucan, when combined with cyclophosphamide, is able to improve the reproductive performance of males verified by the significant reduction in rates of post-implantation losses and reabsorption in the mating of nulliparous females with males treated with cyclophosphamide.

  12. Performance of a daylight redirecting glass shading system demonstration in an office building

    OpenAIRE

    Appelfeld, David; Svendsen, Svend; Traberg-Borup, Steen

    2011-01-01

    This paper evaluates the daylighting performance of a prototype external dynamic integrated shading and light redirecting system. The demonstration project was carried out on a building with an open-plan office. The prototype and original façades were placed on the same floor with the same orientation and similar surroundings. The existing façade was used as the reference for measurements and simulations. The focus of this research project was to employ available simulation tools for the syst...

  13. Demonstrated high performance of gas-filled rugby-shaped hohlraums on Omega

    Science.gov (United States)

    Philippe, F.; Tassin, V.; Depierreux, S.; Gauthier, P.; Masson-Laborde, P. E.; Monteil, M. C.; Seytor, P.; Villette, B.; Lasinski, B.; Park, H. S.; Ross, J. S.; Amendt, P.; Döppner, T.; Hinkel, D. E.; Wallace, R.; Williams, E.; Michel, P.; Frenje, J.; Gatu-Johnson, M.; Li, C. K.; Petrasso, R.; Glebov, V.; Sorce, C.; Stoeckl, C.; Nikroo, A.; Giraldez, E.

    2014-07-01

    A direct experimental comparison of rugby-shaped and cylindrical shaped gas-filled hohlraums on the Omega laser facility demonstrates that higher coupling and minimal backscatter can be achieved in the rugby geometry, leading to significantly enhanced implosion performance. A nearly 50% increase of x-ray drive is associated with earlier bangtime and increase of neutron production. The observed drive enhancement from rugby geometry in this study is almost twice stronger than in previously published results.

  14. Demonstrated high performance of gas-filled rugby-shaped hohlraums on Omega

    Energy Technology Data Exchange (ETDEWEB)

    Philippe, F.; Villette, B. [CEA, DAM, DIF, F-91297 Arpajon (France); Michel, P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Petrasso, R. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Giraldez, E. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Tassin, V.; Depierreux, S.; Gauthier, P.; Masson-Laborde, P. E.; Monteil, M. C.; Seytor, P.; Lasinski, B.; Park, H. S.; Ross, J. S.; Amendt, P.; Döppner, T.; Hinkel, D. E.; Wallace, R.; Williams, E.; and others

    2014-07-15

    A direct experimental comparison of rugby-shaped and cylindrical shaped gas-filled hohlraums on the Omega laser facility demonstrates that higher coupling and minimal backscatter can be achieved in the rugby geometry, leading to significantly enhanced implosion performance. A nearly 50% increase of x-ray drive is associated with earlier bangtime and increase of neutron production. The observed drive enhancement from rugby geometry in this study is almost twice stronger than in previously published results.

  15. Demonstrated high performance of gas-filled rugby-shaped hohlraums on Omega

    Energy Technology Data Exchange (ETDEWEB)

    Philippe, F. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Tassin, V. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Depierreux, S. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Gauthier, P. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Masson-Laborde, P. E. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Monteil, M. C. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Seytor, P. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Villette, B. [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA), Arpajon (France); Lasinski, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Park, H. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ross, J. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Amendt, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Doeppner, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hinkel, D. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wallace, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Williams, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Michel, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Frenje, J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Gatu-Johnson, M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Li, C. K. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Petrasso, R. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Glebov, V. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Sorce, C. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Stoeckl, C. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Nikroo, A. [General Atomics, San Diego, CA (United States); Giraldez, E. [General Atomics, San Diego, CA (United States)

    2014-07-25

    A direct experimental comparison of rugby-shaped and cylindrical shaped gas-filled hohlraums on the Omega laser facility demonstrates that higher coupling and minimal backscatter can be achieved in the rugby geometry, leading to significantly enhanced implosion performance. A nearly 50% increase of x-ray drive is associated with earlier bangtime and increase of neutron production. The observed drive enhancement from rugby geometry in this study is almost twice stronger than in previously published results.

  16. Performance characteristics of the Beckman Coulter UniCel DxI 800 TSH (3rd IS) assay.

    Science.gov (United States)

    Winston-McPherson, Gabrielle N; Samraj, Annie N; Poster, Kristina; Yamaguchi, Diane; Dickerson, Jane A; Drees, Julia C; Holmes, Daniel T; Greene, Dina N

    2018-03-01

    Beckman Coulter recently reformulated their commercial TSH assay with primary calibration to the World Health Organization 3rd TSH international standard. An extensive evaluation of the performance characteristics for this assay was completed. Intra-day and inter-day precision was evaluated using 3 concentrations of commercial quality control material. Linearity, reportable range, stability, sensitivity and susceptibility to common inferences were determined using pooled patient specimens. Inter-assay variability was assessed across 5 different platforms (n=47 patient specimens). Intra-day and inter-day CVs were UniCel DxI 800, is precise, highly sensitive and comparable to the previous generation assay. The assay is acceptable for clinical testing. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Developing performance indicators for cardiac surgery: a demonstration project in Victoria.

    Science.gov (United States)

    Reid, C M; Solterbeck, A; Buxton, B F; Skillington, P D; Shardey, G C; Smith, J A; Rosenfeldt, F L

    2001-01-01

    Six Victorian cardiac surgical units pooled data in order to undertake a demonstration project aimed at developing performance indicators to assess outcomes following cardiac surgery. The outcome of the project was an indicative report for the purpose of monitoring surgical performance indicators in a format suitable for: (i) the general public; (ii) the Victorian State Government; and (iii) the participating units and surgeons. Each participating cardiac surgical unit had an existing database used for recording information from each procedure. A request was made to each unit to extract a subset of data from all cases entered over the past 5 years. The proposed list of performance indicators included surgical mortality (within the period of admission for surgery), complication rates (including sternal infection, postoperative myocardial infarction, postoperative stroke, haemorrhage requiring return to theatre), and length of hospital stay. A model was developed from the data and used to provide risk-adjusted measures of hospital performance. Cases from five cardiac surgical units (n = 10 715) were included in the final analysis. A risk-adjusted model (including age, sex, diabetes, hypertension, smoking, procedure type, urgency of procedure) was developed for surgical mortality. Performance indicators for coronary artery bypass graft surgery, including mortality, sternal infection rate and length of hospital stay are presented. From the available data, performance indicators for cardiac surgery in Victorian hospitals compared favourably with international benchmarks. This project has demonstrated that prospective data collection using a standardised system could readily produce local risk-adjustment models for cardiac surgery to aid in developing appropriate performance indicators.

  18. Report on the MHD performance demonstration experiment, October 1, 1977-September 30, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, H J; Starr, R F; Lineberry, J T; Whitehead, G L; Seiber, B L

    1979-04-01

    The Arnold Engineering Development Center (ALDC) has been under contract since December 1973 to modify existing equipment and to design, fabricate, and install new hardware to perform an MHD Performance Demonstration Experiment. The objective of the experiment is to demonstrate that a generator simulating a commercial-sized device can convert 16 to 18 percent of the available thermal energy into electrical power. This report described fabrication, installation, and testing of hardware for this experiment during the period from October 1, 1977, to September 30, 1978. In the past year, fabrication of the high performance generator channel was completed, and satisfactorily pressure and electrically checked. The coils and approximately 95 percent of the coil force containment structure were installed on the 6 Tesla magnet. Fabrication of the outer insulation panels for the magnet was completed. The magnet is to be cryogenically cooled with liquid nitrogen. During the past year, analytical studies to provide guidance in performing the cooldown were completed and are presented. The preliminary design of the cooling manifold system to provide the required control in accordance with the results of the analytical studies was also completed and is reported. Additional testing of the burner system with the diagnostic section installed was conducted and the results for seeded and unseeded operation are included.

  19. Hybrid Neural-Network: Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics Developed and Demonstrated

    Science.gov (United States)

    Kobayashi, Takahisa; Simon, Donald L.

    2002-01-01

    As part of the NASA Aviation Safety Program, a unique model-based diagnostics method that employs neural networks and genetic algorithms for aircraft engine performance diagnostics has been developed and demonstrated at the NASA Glenn Research Center against a nonlinear gas turbine engine model. Neural networks are applied to estimate the internal health condition of the engine, and genetic algorithms are used for sensor fault detection, isolation, and quantification. This hybrid architecture combines the excellent nonlinear estimation capabilities of neural networks with the capability to rank the likelihood of various faults given a specific sensor suite signature. The method requires a significantly smaller data training set than a neural network approach alone does, and it performs the combined engine health monitoring objectives of performance diagnostics and sensor fault detection and isolation in the presence of nominal and degraded engine health conditions.

  20. Experience with local lymph node assay performance standards using standard radioactivity and nonradioactive cell count measurements.

    Science.gov (United States)

    Basketter, David; Kolle, Susanne N; Schrage, Arnhild; Honarvar, Naveed; Gamer, Armin O; van Ravenzwaay, Bennard; Landsiedel, Robert

    2012-08-01

    The local lymph node assay (LLNA) is the preferred test for identification of skin-sensitizing substances by measuring radioactive thymidine incorporation into the lymph node. To facilitate acceptance of nonradioactive variants, validation authorities have published harmonized minimum performance standards (PS) that the alternative endpoint assay must meet. In the present work, these standards were applied to a variant of the LLNA based on lymph node cell counts (LNCC) run in parallel as a control with the standard LLNA with radioactivity measurements, with threshold concentrations (EC3) being determined for the sensitizers. Of the 22 PS chemicals tested in this study, 21 yielded the same results from standard radioactivity and cell count measurements; only 2-mercaptobenzothiazole was positive by LLNA but negative by LNCC. Of the 16 PS positives, 15 were positive by LLNA and 14 by LNCC; methylmethacrylate was not identified as sensitizer by either of the measurements. Two of the six PS negatives tested negative in our study by both LLNA and LNCC. Of the four PS negatives which were positive in our study, chlorobenzene and methyl salicylate were tested at higher concentrations than the published PS, whereas the corresponding concentrations resulted in consistent negative results. Methylmethacrylate and nickel chloride tested positive within the concentration range used for the published PS. The results indicate cell counts and radioactive measurements are in good accordance within the same LLNA using the 22 PS test substances. Comparisons with the published PS results may, however, require balanced analysis rather than a simple checklist approach. Copyright © 2011 John Wiley & Sons, Ltd.

  1. Assay performance improved, but which "scorecard" designation for Vitros Troponin I?

    Science.gov (United States)

    Zaninotto, M; Vernocchi, A; Di Serio, F; Viloria, M Del Mar; Hurtado, Josè M; Perez-Guerrero, J J; Plebani, M

    2012-04-11

    Since cardiac troponins assay technology should comply with the recommendations of scientific societies (i.e. imprecision (10%) at the 99th percentile value observed in healthy subjects being the analytical qualifying aspect), the aim of the present study was to evaluate whether an improved troponin assay (Vitros Troponin I ES) provides data that meet the "guideline acceptable"criteria recently defined in a proposed scorecard. Vitros Troponin I ES, an enhanced chemiluminescence immunoassay, was evaluated in a multicenter study considering: limit of blank (LOB, 60 replicates of 0 calibrators), limit of detection (LOD, 12 measurements for each of 5 serum pools), precision, linearity using control materials and serum plasma pool; matrix samples study matching serum and lithium-heparin plasma (n=107 hospitalized patients); the 99th percentile limit in serum samples from 500 healthy Caucasian donors. LOB and LOD, 0.0029 μg/L and 0.0030 μg/L respectively; coefficients of variation (total CV%), obtained by running 3 levels of control materials and 10 serum pools, from 15.2% (x(-)=0.014 μg/L) to 2.0% (x(-)=5.324 μg/L); method, linear up to 70 μg/L. No significant differences were found between serum and lithium-heparin matched sample (p=0.48) values; 99th percentile limit of cTnI distribution in healthy donors, 0.021 μg/L. Since its analytical reliability meets the proposed performance and scorecard requirements, the Vitros TropI method can be considered "contemporary" and "guideline acceptable". Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Performance characteristics of the Access AMH assay for the quantitative determination of anti-Müllerian hormone (AMH) levels on the Access* family of automated immunoassay systems.

    Science.gov (United States)

    Demirdjian, Gaiane; Bord, Stephanie; Lejeune, Caroline; Masica, Ryan; Rivière, Dominique; Nicouleau, Lucie; Denizot, Philippe; Marquet, Pierre-Yves

    2016-11-01

    Anti-Müllerian hormone (AMH) measurement is useful as an aid in the evaluation of ovarian reserve. In the past, its conventional use was restricted by the low-throughput and variability of existing manual AMH assays. We developed the automated Access AMH assay for the quantitative determination of AMH levels on the Access family of immunoassay systems. The analytical performance of this new assay was evaluated. Sensitivity, dilution linearity, assay imprecision, AMH sample stability, lot-to-lot comparison and correlation with AMH Gen II assay (Beckman Coulter, Inc.) were evaluated. Reference intervals for Access AMH were established in healthy females, males, newborns (≤60days) and pediatric males classified by Tanner stages. The limit of blank and limit of detection were below 0.0077 and 0.0098ng/mL, respectively. The limit of quantitation was 0.010ng/mL. The total imprecision ranged from 2.4 to 5.2%. Linearity was observed up to 24ng/mL. Sample storage at room temperature up to 48h, at 2-8°C up to 7days and at -20°C up to 15months had no impact on measured AMH. The correlation study gave a coefficient between 0.99 and 1 and a regression slope between 0.89 and 0.92. Excellent lot-to-lot comparability was observed on controls and patient samples with a maximum bias of 3.7% between 2.81 and 15.03ng/mL. The fully automated Access AMH immunoassay demonstrates excellent analytical performance. As a consequence, the availability of this assay will represent a robust, fast and precise alternative to manual AMH assay testing. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Demonstration of Cost-Effective, High-Performance Computing at Performance and Reliability Levels Equivalent to a 1994 Vector Supercomputer

    Science.gov (United States)

    Babrauckas, Theresa

    2000-01-01

    The Affordable High Performance Computing (AHPC) project demonstrated that high-performance computing based on a distributed network of computer workstations is a cost-effective alternative to vector supercomputers for running CPU and memory intensive design and analysis tools. The AHPC project created an integrated system called a Network Supercomputer. By connecting computer work-stations through a network and utilizing the workstations when they are idle, the resulting distributed-workstation environment has the same performance and reliability levels as the Cray C90 vector Supercomputer at less than 25 percent of the C90 cost. In fact, the cost comparison between a Cray C90 Supercomputer and Sun workstations showed that the number of distributed networked workstations equivalent to a C90 costs approximately 8 percent of the C90.

  4. Performance of semiquantitative and quantitative D-dimer assays in the ECAT external quality assessment program.

    Science.gov (United States)

    de Maat, M P; Meijer, P; Nieuwenhuizen, W; Haverkate, F; Kluft, C

    2000-01-01

    D-dimer levels are used in clinical practice as markers for the presence or exclusion of venous thrombosis. Therefore, it is important that the performance of the D-dimer tests is well controlled. One of the components of a laboratory quality program is external quality assessment (EQA). The main aim of EQA is to identify the degree of agreement among laboratories. In addition to identifying the individual laboratory performance, it also identifies the characteristics of the different reagents and methods that are used in different laboratories. Recently, the D-dimer test was included in the ECAT External Quality Assessment program. Eighty-one laboratories in four rounds applied semiquantitative and quantitative D-dimer assays to three samples (concentrations normal, slightly elevated, and elevated). Although the reported values varied widely, the classification of the samples was mostly correct for the normal and the elevated samples. The slightly elevated sample was classified as normal by all laboratories using semiquantitative methods and by 60% of the laboratories using quantitative methods, and this varied between 45% and 86% for the different methods. In conclusion, D-dimer methods show a large variation, and the quality of the D-dimer assessment could be improved by standardization and by using cut-off ranges.

  5. Performance of the SNPforID 52 SNP-plex assay in paternity testing

    DEFF Research Database (Denmark)

    Børsting, Claus; Sanchez, Juan Jose; Hansen, Hanna E

    2008-01-01

    The performance of a multiplex assay with 52 autosomal single nucleotide polymorphisms (SNPs) developed for human identification was tested on 124 mother-child-father trios. The typical paternity indices (PIs) were 10(5)-10(6) for the trios and 10(3)-10(4) for the child-father duos. Using the SNP...... profiles from the randomly selected trios and 700 previously typed individuals, a total of 83,096 comparisons between mother, child and an unrelated man were performed. On average, 9-10 mismatches per comparison were detected. Four mismatches were genetic inconsistencies and 5-6 mismatches were opposite...... homozygosities. In only two of the 83,096 comparisons did an unrelated man match perfectly to a mother-child duo, and in both cases the PI of the true father was much higher than the PI of the unrelated man. The trios were also typed for 15 short tandem repeats (STRs) and seven variable number of tandem repeats...

  6. Diagnostic performance of interferon-γ release assay for lymph node tuberculosis.

    Science.gov (United States)

    Jia, Hongyan; Pan, Liping; Du, Boping; Sun, Qi; Wei, Rongrong; Xing, Aiying; Du, Fengjiao; Sun, Huishan; Zhang, Zongde

    2016-05-01

    The aim of the study was to evaluate the performance of interferon-γ (IFN-γ) release assay (IGRA) (T-SPOT.TB) for patients with suspected lymph node tuberculosis (TB). Of the 405 patients with suspected lymph node TB, enrolled from Beijing Chest Hospital between July 2011 and April 2015, 83 (20.5%) were microbiologically/histopathologically confirmed lymph node TB, and 282 (69.6%) did not have active TB. The remaining 21 inconclusive TB and 19 clinical TB were excluded from the final analysis (9.9%). T-SPOT.TB using peripheral blood mononuclear cells was performed to examine the IFN-γ response to the Mycobacterium tuberculosis-specific antigens early secretory antigenic target 6 and culture filtrate protein 10. The overall sensitivity and specificity for T-SPOT.TB were 90.4% and 70.5%, respectively. Spot-forming cells in the lymph node TB group (184 [48-596/10(6) peripheral blood mononuclear cells {PBMCs}]) were significantly higher than that in the nonactive TB group (0 [0-41]/10(6) PBMCs) (Plymph node TB. Copyright © 2016. Published by Elsevier Inc.

  7. STATISTICAL EVALUATION OF SMALL SCALE MIXING DEMONSTRATION SAMPLING AND BATCH TRANSFER PERFORMANCE - 12093

    Energy Technology Data Exchange (ETDEWEB)

    GREER DA; THIEN MG

    2012-01-12

    The ability to effectively mix, sample, certify, and deliver consistent batches of High Level Waste (HLW) feed from the Hanford Double Shell Tanks (DST) to the Waste Treatment and Immobilization Plant (WTP) presents a significant mission risk with potential to impact mission length and the quantity of HLW glass produced. DOE's Tank Operations Contractor, Washington River Protection Solutions (WRPS) has previously presented the results of mixing performance in two different sizes of small scale DSTs to support scale up estimates of full scale DST mixing performance. Currently, sufficient sampling of DSTs is one of the largest programmatic risks that could prevent timely delivery of high level waste to the WTP. WRPS has performed small scale mixing and sampling demonstrations to study the ability to sufficiently sample the tanks. The statistical evaluation of the demonstration results which lead to the conclusion that the two scales of small DST are behaving similarly and that full scale performance is predictable will be presented. This work is essential to reduce the risk of requiring a new dedicated feed sampling facility and will guide future optimization work to ensure the waste feed delivery mission will be accomplished successfully. This paper will focus on the analytical data collected from mixing, sampling, and batch transfer testing from the small scale mixing demonstration tanks and how those data are being interpreted to begin to understand the relationship between samples taken prior to transfer and samples from the subsequent batches transferred. An overview of the types of data collected and examples of typical raw data will be provided. The paper will then discuss the processing and manipulation of the data which is necessary to begin evaluating sampling and batch transfer performance. This discussion will also include the evaluation of the analytical measurement capability with regard to the simulant material used in the demonstration tests. The

  8. Evaluation of a tissue factor dependent factor V assay to detect factor V Leiden: demonstration of high sensitivity and specificity for a generally applicable assay for activated protein C resistance.

    Science.gov (United States)

    Liebman, H A; Sutherland, D; Bacon, R; McGehee, W

    1996-12-01

    Resistance to the anticoagulant effects of activated protein C (APC) is now considered the most prevalent cause of inherited thrombophilia. The great majority of patients with activated protein C resistance (APCR) have a missense mutation in the factor V molecule (factor V Leiden, FVR506Q) resulting in defective inactivation of factor Va due to a loss of an APC cleavage site. The diagnosis of APCR has been based upon the inability of APC to prolong the activated partial thromboplastin (aPTT) clotting time in subjects with APCR. However, this assay has a number of deficiencies which limit its general use. We have evaluated a newly described one-stage tissue factor dependent factor V coagulation assay for APCR in 117 patients and controls and compared the results of this assay in a blinded manner to a polymerase chain reaction (PCR) based assay for the molecular defect of factor V Leiden. 43% (50/117) of the patients studied were receiving coumadin or heparin, or had a lupus anticoagulant. The tissue factor dependent factor V assay had 100% specificity and sensitivity for factor V Leiden and successfully predicted a homozygous state in the three documented homozygotes. The PCR-based assay for factor V Leiden resulted in a single false positive assay due to a silent A to C transition at nucleotide 1692 resulting in the loss of the Mnl restriction endonuclease cleavage site. The single-stage tissue factor dependent factor V assay is a highly sensitive and generally applicable assay for APCR.

  9. Rapid detection of resistant tuberculosis by nitrate reductase assay performed in three settings in Brazil.

    Science.gov (United States)

    Shikama, Maria de Lourdes; Silva, Regina Ruivo Ferro E; Martins, Maria Conceição; Giampaglia, Carmen Maria Saraiva; Oliveira, Rosângela Siqueira; Silva, Rosmari F A M; Silva, Paula Ferro E; Telles, Maria Alice da Silva; Martin, Anandi; Palomino, Juan Carlos

    2009-10-01

    To evaluate nitrate reductase assay (NRA) efficacy for streptomycin, isoniazid, rifampicin and ethambutol susceptibility testing of Mycobacterium tuberculosis strains. Results were generated by three laboratories: the Instituto Adolfo Lutz (IAL) Mycobacteria Reference Laboratory and two IAL Regional Laboratories in Santo André and Sorocaba, São Paulo State, Brazil. One hundred and twenty M. tuberculosis strains were simultaneously tested using NRA and the proportion method (PM), while 117 strains were tested using both NRA and BACTEC MGIT 960 (M960). Repeatability analysis of NRA results showed rates of 100% for isoniazid and ethambutol and 97% for streptomycin and rifampicin susceptibility detection, representing substantial agreement. McNemar testing of the data also indicates that NRA and PM, as well as NRA and M960, do not differ significantly. On average, NRA results were available after 10 days. The data demonstrate that NRA is reliable for susceptibility testing of isoniazid and rifampicin, the two most important drugs for the treatment of tuberculosis. In addition, the reduction in the time necessary to obtain susceptibility results is of fundamental importance.

  10. The impact of initiation: Early onset marijuana smokers demonstrate altered Stroop performance and brain activation

    Directory of Open Access Journals (Sweden)

    K.A. Sagar

    2015-12-01

    Full Text Available Marijuana (MJ use is on the rise, particularly among teens and emerging adults. This poses serious public health concern, given the potential deleterious effects of MJ on the developing brain. We examined 50 chronic MJ smokers divided into early onset (regular MJ use prior to age 16; n = 24 and late onset (age 16 or later; n = 26, and 34 healthy control participants (HCs. All completed a modified Stroop Color Word Test during fMRI. Results demonstrated that MJ smokers exhibited significantly poorer performance on the Interference subtest of the Stroop, as well as altered patterns of activation in the cingulate cortex relative to HCs. Further, early onset MJ smokers exhibited significantly poorer performance relative to both HCs and late onset smokers. Additionally, earlier age of MJ onset as well as increased frequency and magnitude (grams/week of MJ use were predictive of poorer Stroop performance. fMRI results revealed that while late onset smokers demonstrated a more similar pattern of activation to the control group, a different pattern was evident in the early onset group. These findings underscore the importance of assessing age of onset and patterns of MJ use and support the need for widespread education and intervention efforts among youth.

  11. Performance of Celera RUO integrase resistance assay across multiple HIV-1 subtypes.

    Science.gov (United States)

    Wallis, Carole L; Viana, Raquel V; Saravanan, Shanmugam; Silva de Jesus, Carlos; Zeh, Clement; Halvas, Elias K; Mellors, John W

    2017-03-01

    HIV-1 sequence variation is a major obstacle to developing molecular based assays for multiple subtypes. This study sought to independently assess performance characteristics of the ViroSeq™ HIV-1 Integrase RUO Genotyping Kit (Celera, US) for samples of multiple different HIV-1 subtypes. 264 samples were tested in the validation, 106 from integrase inhibitor naïve patients' sent for routine HIV-1 drug resistance testing after failing a 1st- or 2nd-line regimen, and 158 samples from an external virology quality assurance program (VQA). For the latter, 53 unique VQA samples were tested in two to five different laboratories to assess assay reproducibility. For all assays, viral RNA was extracted using the ViroSeq extraction module, reverse transcribed, and amplified in a one-step reaction. Four sequencing primers were used to span codons 1-288 of integrase. The Rega subtyping tool was used for subtype assignment. Integrase polymorphisms and mutations were determined as differences from the HXB2 sequence and by the Stanford database, respectively. Sequences obtained from the different laboratories were aligned and sequence homology determined. HIV-1 RNA in the 264 samples ranged from 3.15 to 6.74logcopies/ml. Successful amplification was obtained for 97% of samples (n=256). The 8 samples that failed to amplify were subtype D (n=3), subtype C (n=1), CRF01_AE (n=1), subtype A1 (n=2), and an unassigned subtype (n=1). Of the 256 that successfully amplified samples, 203 (79%) were successfully sequenced with bidirectional coverage. Of the 53 unsuccessful samples, 13 (5%) failed sequencing and 40 (16%) did not have full bidirectional sequence, as a result of failure of sequencing primers: Primer A (n=1); Primer B (n=18); Primer C (n=1); Primer D (n=7) or short sequences (n=16). For the 135 VQA samples (30 unique samples) that were assayed by different laboratories, homology of the sequences obtained ranged from 92.1% to 100%. However, Laboratory 2 detected more mixtures

  12. Commercial solar demonstration performance evaluation report: Basking Ridge, New Jersey, Environmental Education Center

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    The Somerset County Park Commission for Somerset County, New Jersey, undertook the project of incorporating a solar heating, cooling, and domestic hot water system as part of its newly-constructed Environmental Education Center (EEC) located in Lord Stirling Park, Basking Ridge, New Jersey. It is the objective of this solar energy project to demonstrate the feasibility and effectiveness of using solar energy collected via 3100 sq.ft. of flat plate solar collectors to space heat, cool, and supply domestic hot water to the 18,000 sq.ft. EEC building. The project is also intended to demonstrate the aesthetics and effectiveness of incorporating an integrated solar collector array onto the roof of the newly constructed EEC facility. The results of the solar system performance for the one-year operational period are presented. (MHR)

  13. Analytical Performance Evaluation of a New Cobas Tacrolimus Assay on Cobas e411 Analyzer: Comparison of Values Obtained by the CMIA Tacrolimus Assay and a Liquid Chromatography Combined with Tandem Mass Spectrometric Method.

    Science.gov (United States)

    Dasgupta, Amitava; Khalil, Samir A; Johnson-Davis, Kamisha L

    2016-01-01

    Recently Roche Diagnostics (Indianapolis, IN) developed Cobas tacrolimus assay (currently for investigational use only in U.S) for application on multiple platforms including Cobas e 411 analyzer. We evaluated analytic performance of this new assay. Within run, between run and linearity of this new assay were evaluated. In addition, tacrolimus values in 40 specimens obtained by using this new method were compared with values obtained by using the CMIA assay (Abbott Laboratories). Moreover, 10 specimens where accurate tacrolimus values were determined by a reference method (LC-MS/MS), were further analyzed using Cobas tacrolimus assay and the CMIA assay. New Cobas tacrolimus assay showed excellent precision and accuracy. Comparing tacrolimus values obtained by using the CMIA tacrolimus assay (x-axis) with corresponding values obtained by using the Cobas tacrolimus assay (y-axis), the following regression equation was observed: y=0.922x+0.512 (n=40, r=0.99). For additional 10 specimens where tacrolimus values were determined by LC-MS/MS, tacrolimus values obtained by the Cobas tacrolimus assay as well as by the CMIA assay were higher than the corresponding LC-MS/MS values. The new Cobas tacrolimus assay is comparable to the FDA approved CMIA tacrolimus assay. Therefore, when this assay is approved by the FDA, it can be used for therapeutic drug monitoring of tacrolimus. © 2016 by the Association of Clinical Scientists, Inc.

  14. Comparison of the performance of IFA, CFA, and ELISA assays for the serodiagnosis of acute Q fever by quality assessment.

    Science.gov (United States)

    Herremans, Tineke; Hogema, Boris M; Nabuurs, Marrigje; Peeters, Marcel; Wegdam-Blans, Marjolijn; Schneeberger, Peter; Nijhuis, Carla; Notermans, Daan W; Galama, Joep; Horrevorts, Anton; van Loo, Inge H M; Vlaminckx, Bart; Zaaijer, Hans L; Koopmans, Marion P; Berkhout, Hanneke; Socolovschi, Cristina; Raoult, Didier; Stenos, John; Nicholson, William; Bijlmer, Henk

    2013-01-01

    The indirect immunofluorescence assay (IFA) is considered the reference method for diagnosing Q fever, but serology is also performed by complement fixation assay (CFA) or enzyme-linked immunosorbent assay (ELISA). However, comparability between these assays is not clear, and therefore a quality assessment was performed. A total of 25 serum samples from negative controls, Q fever patients, and a serial diluted high-positive sample were analyzed in 10 Dutch laboratories. Six laboratories performed CFA, 5 performed IFA, and 5 performed ELISAs. Three international reference laboratories from Australia, France, and the USA also participated in this study. Qualitative values between laboratories using the same methods were within close range, and all 3 methods correctly identified acute Q fever patients. The IFA, ELISA, and CFA are all suitable serodiagnostic assays to diagnose acute Q fever, but the IFA remains an important tool in the follow-up of patients and in identifying patients at risk for developing chronic Q fever. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Advanced Flue Gas Desulfurization (AFGD) demonstration project: Volume 2, Project performance and economics. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-30

    The project objective is to demonstrate removal of 90--95% or more of the SO{sub 2} at approximately one-half the cost of conventional scrubbing technology; and to demonstrate significant reduction of space requirements. In this project, Pure Air has built a single SO{sub 2} absorber for a 528-MWe power plant. The absorber performs three functions in a single vessel: prequencher, absorber, and oxidation of sludge to gypsum. Additionally, the absorber is of a co- current design, in which the flue gas and scrubbing slurry move in the same direction and at a relatively high velocity compared to conventional scrubbers. These features all combine to yield a state- of-the-art SO{sub 2} absorber that is more compact and less expensive than conventional scrubbers. The project incorporated a number of technical features including the injection of pulverized limestone directly into the absorber, a device called an air rotary sparger located within the base of the absorber, and a novel wastewater evaporation system. The air rotary sparger combines the functions of agitation and air distribution into one piece of equipment to facilitate the oxidation of calcium sulfite to gypsum. Additionally, wastewater treatment is being demonstrated to minimize water disposal problems inherent in many high-chloride coals. Bituminous coals primarily from the Indiana, Illinois coal basin containing 2--4.5% sulfur were tested during the demonstration. The Advanced Flue Gas Desulfurization (AFGD) process has demonstrated removal of 95% or more of the SO{sub 2} while providing a commercial gypsum by-product in lieu of solid waste. A portion of the commercial gypsum is being agglomerated into a product known as PowerChip{reg_sign} gypsum which exhibits improved physical properties, easier flowability and more user friendly handling characteristics to enhance its transportation and marketability to gypsum end-users.

  16. Lattice design and expected performance of the Muon Ionization Cooling Experiment demonstration of ionization cooling

    Directory of Open Access Journals (Sweden)

    2017-06-01

    Full Text Available Muon beams of low emittance provide the basis for the intense, well-characterized neutrino beams necessary to elucidate the physics of flavor at a neutrino factory and to provide lepton-antilepton collisions at energies of up to several TeV at a muon collider. The international Muon Ionization Cooling Experiment (MICE aims to demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam passes through a material in which it loses energy. The energy lost is then replaced using rf cavities. The combined effect of energy loss and reacceleration is to reduce the transverse emittance of the beam (transverse cooling. A major revision of the scope of the project was carried out over the summer of 2014. The revised experiment can deliver a demonstration of ionization cooling. The design of the cooling demonstration experiment will be described together with its predicted cooling performance.

  17. Lattice design and expected performance of the Muon Ionization Cooling Experiment demonstration of ionization cooling

    Science.gov (United States)

    Bogomilov, M.; Tsenov, R.; Vankova-Kirilova, G.; Song, Y.; Tang, J.; Li, Z.; Bertoni, R.; Bonesini, M.; Chignoli, F.; Mazza, R.; Palladino, V.; de Bari, A.; Cecchet, G.; Orestano, D.; Tortora, L.; Kuno, Y.; Ishimoto, S.; Filthaut, F.; Jokovic, D.; Maletic, D.; Savic, M.; Hansen, O. M.; Ramberger, S.; Vretenar, M.; Asfandiyarov, R.; Blondel, A.; Drielsma, F.; Karadzhov, Y.; Charnley, G.; Collomb, N.; Dumbell, K.; Gallagher, A.; Grant, A.; Griffiths, S.; Hartnett, T.; Martlew, B.; Moss, A.; Muir, A.; Mullacrane, I.; Oates, A.; Owens, P.; Stokes, G.; Warburton, P.; White, C.; Adams, D.; Anderson, R. J.; Barclay, P.; Bayliss, V.; Boehm, J.; Bradshaw, T. W.; Courthold, M.; Francis, V.; Fry, L.; Hayler, T.; Hills, M.; Lintern, A.; Macwaters, C.; Nichols, A.; Preece, R.; Ricciardi, S.; Rogers, C.; Stanley, T.; Tarrant, J.; Tucker, M.; Wilson, A.; Watson, S.; Bayes, R.; Nugent, J. C.; Soler, F. J. P.; Gamet, R.; Barber, G.; Blackmore, V. J.; Colling, D.; Dobbs, A.; Dornan, P.; Hunt, C.; Kurup, A.; Lagrange, J.-B.; Long, K.; Martyniak, J.; Middleton, S.; Pasternak, J.; Uchida, M. A.; Cobb, J. H.; Lau, W.; Booth, C. N.; Hodgson, P.; Langlands, J.; Overton, E.; Robinson, M.; Smith, P. J.; Wilbur, S.; Dick, A. J.; Ronald, K.; Whyte, C. G.; Young, A. R.; Boyd, S.; Franchini, P.; Greis, J. R.; Pidcott, C.; Taylor, I.; Gardener, R. B. S.; Kyberd, P.; Nebrensky, J. J.; Palmer, M.; Witte, H.; Bross, A. D.; Bowring, D.; Liu, A.; Neuffer, D.; Popovic, M.; Rubinov, P.; DeMello, A.; Gourlay, S.; Li, D.; Prestemon, S.; Virostek, S.; Freemire, B.; Hanlet, P.; Kaplan, D. M.; Mohayai, T. A.; Rajaram, D.; Snopok, P.; Suezaki, V.; Torun, Y.; Onel, Y.; Cremaldi, L. M.; Sanders, D. A.; Summers, D. J.; Hanson, G. G.; Heidt, C.; MICE Collaboration

    2017-06-01

    Muon beams of low emittance provide the basis for the intense, well-characterized neutrino beams necessary to elucidate the physics of flavor at a neutrino factory and to provide lepton-antilepton collisions at energies of up to several TeV at a muon collider. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam passes through a material in which it loses energy. The energy lost is then replaced using rf cavities. The combined effect of energy loss and reacceleration is to reduce the transverse emittance of the beam (transverse cooling). A major revision of the scope of the project was carried out over the summer of 2014. The revised experiment can deliver a demonstration of ionization cooling. The design of the cooling demonstration experiment will be described together with its predicted cooling performance.

  18. LIFAC sorbent injection desulfurization demonstration project. Final report, volume II: Project performance and economics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    This publication discusses the demonstration of the LIFAC sorbent injection technology at Richmond Power and Light`s Whitewater Valley Unit No. 2, performed under the auspices of the U.S. Department of Energy`s (DOE) Clean Coal Technology Program. LIFAC is a sorbent injection technology capable of removing 75 to 85 percent of a power plant`s SO{sub 2} emissions using limestone at calcium to sulfur molar ratios of between 2 and 2.5 to 1. The site of the demonstration is a coal-fired electric utility power plant located in Richmond, Indiana. The project is being conducted by LIFAC North America (LIFAC NA), a joint venture partnership of Tampella Power Corporation and ICF Kaiser Engineers, in cooperation with DOE, RP&L, and Research Institute (EPRI), the State of Indiana, and Black Beauty Coal Company. The purpose of Public Design Report Volume 2: Project Performance and Economics is to consolidate, for public use, the technical efficiency and economy of the LIFAC Process. The report has been prepared pursuant to the Cooperative Agreement No. DE-FC22-90PC90548 between LIFAC NA and the U.S. Department of Energy.

  19. Evaluation of the Diagnostic Performance of Onchocerca volvulus Linear Epitopes in a Peptide Enzyme-Linked Immunosorbent Assay.

    Science.gov (United States)

    Lagatie, Ole; Verheyen, Ann; Nijs, Erik; Van Dorst, Bieke; Batsa Debrah, Linda; Debrah, Alex; Supali, Taniawati; Sartono, Erliyani; Stuyver, Lieven J

    2018-01-08

    Diagnostic tools for the detection of infection with Onchocerca volvulus are presently limited to microfilaria detection in skin biopsies and serological assessment using the Ov16 immunoglobulin G4 (IgG4) rapid test, both of which have limited sensitivity. We have investigated the diagnostic performance of a peptide enzyme-linked immunosorbent assay (ELISA) based on immunodominant linear epitopes previously discovered. Peptides that were used in these assays were designated O. volvulus motif peptides (OvMP): OvMP-1 (VSV-EPVTTQET-VSV), OvMP-2 (VSV-KDGEDK-VSV), OvMP-3 (VSV-QTSNLD-VSV), and the combination of the latter two, OvMP-23 (VSV-KDGEDK-VSV-QTSNLD-VSV). Sensitivity (O. volvulus infection), specificity (non-helminth infections), and cross-reactivity (helminth infections) were determined using several panels of clinical plasma isolates. OvMP-1 was found to be very sensitive (100%) and specific (98.7%), but showed substantial cross-reactivity with other helminths. Of the other peptides, OvMP-23 was the most promising peptide with a sensitivity of 92.7%, a specificity of 100%, and a cross-reactivity of 6%. It was also demonstrated that these peptides were immunoreactive to IgG but not IgG4, and there is no correlation with the Ov16 IgG4 status, making them promising candidates to complement this already available test. Combination of the Ov16 IgG4 rapid test and OvMP-23 peptide ELISA led to a sensitivity of 97.3% for the detection of O. volvulus infection, without compromising specificity and with minimal impact on cross-reactivity. The available results open the opportunity for a "clinical utility use case" discussion for improved O. volvulus epidemiological mapping.

  20. Performance of the Xpert® HIV-1 Viral Load assay: A systematic review and meta-analysis.

    Science.gov (United States)

    Nash, Madlen; Huddart, Sophie; Badar, Sayema; Baliga, Shrikala; Saravu, Kavitha; Pai, Madhukar

    2018-01-31

    Viral load (VL) is the preferred treatment monitoring approach for HIV-positive patients. However, more rapid, near-patient, and low-complexity assays are needed to scale-up VL testing. The Xpert HIV-1 VL assay (Cepheid, Sunnyvale) is a new, automated molecular test, and can leverage the GeneXpert systems that are being used widely for tuberculosis diagnosis. We systematically reviewed the evidence on the performance of this new tool in comparison to established reference standards. A total of twelve articles (thirteen studies) in which HIV patient VLs were compared between Xpert HIV VL assay and a reference standard VL assay were identified. Study quality was generally high but substantial variability was observed in the number and type of agreement measures reported. Correlation coefficients between Xpert and reference assays were high with a pooled Pearson correlation (n=8) of 0.94 [lsqb]0.89,0.97[rsqb] and Spearman correlation (n=3) of 0.96 [lsqb]0.86, 0.99[rsqb]. Bland-Altman metrics (n=11) were all within 0.35 log copies/mL of perfect agreement. Overall, Xpert HIV -1 VL performed well in comparison with current reference tests. The minimal training and infrastructure requirements for the Xpert HIV-1 VL assay make it attractive for use in resource constrained settings, where point-of-care VL testing is most needed. Copyright © 2018 Nash et al.

  1. Comparative Evaluation of the Diagnostic Performance of the Prototype Cepheid GeneXpert Ebola Assay

    Science.gov (United States)

    Jansen van Vuren, Petrus; Grobbelaar, Antoinette; Storm, Nadia; Conteh, Ousman; Konneh, Kelfala; Kamara, Abdul; Sanne, Ian

    2015-01-01

    The Ebola virus disease (EVD) outbreak in West Africa has highlighted an urgent need for point-of-care (POC) assays for the diagnosis of this devastating disease in resource-limited African countries. The diagnostic performance characteristics of a prototype Cepheid GeneXpert Ebola POC used to detect Ebola virus (EBOV) in stored serum and plasma samples collected from suspected EVD cases in Sierra Leone in 2014 and 2015 was evaluated. The GeneXpert Ebola POC is a self-contained single-cartridge automated system that targets the glycoprotein (GP) and nucleoprotein (NP) genes of EBOV and yields results within 90 min. Results from 281 patient samples were compared to the results of a TaqMan real-time reverse transcription-PCR (RT-PCR) targeting the polymerase gene and performed on two real-time PCR machines. Agreement between the three platforms was 100% at cycle threshold (CT) values of ≤34.99, but discordant results were noted between CT values of 35 and 45.The diagnostic sensitivity of the three platforms was 100% in 91 patient samples that were confirmed to be infectious by virus isolation. All three molecular platforms detected viral EBOV RNA in additional samples that did not contain viable EBOV. The analytical sensitivity of the GeneXpert Ebola POC for the detection of NP was higher, and comparable to that of polymerase gene detection, than that for the detection of GP when using a titrated laboratory stock of EBOV. There was no detectable cross-reactivity with other hemorrhagic fever viruses or arboviruses. The GeneXpert Ebola POC offers an easy to operate and sensitive diagnostic tool that can be used for the rapid screening of suspected EVD cases in treatment or in holding centers during EVD outbreaks. PMID:26637383

  2. Performance of the Elecsys Rubella IgG Assay in the Diagnostic Laboratory Setting for Assessment of Immune Status

    Science.gov (United States)

    Bartelt, Uwe; Knotek, Frank; Bunn, Kristina; Strobel, Sirpa; Dietz, Klaus; Enders, Gisela

    2013-01-01

    Rubella in early pregnancy bears a high risk for congenital defects (e.g., cataracts, hearing loss, and heart disease) and for long-term sequelae in the newborn. Despite implementation of vaccination programs in many regions, the threat of devastating consequences from congenital rubella virus infection remains and careful screening of maternal immune status before and during pregnancy helps to reduce the risk. This study compared the performance of the Elecsys Rubella IgG assay with that of other assays routinely used for screening. Samples from 1,090 women undergoing routine antenatal care were tested using the Elecsys and Enzygnost Rubella IgG assays and the hemagglutination inhibition test. Samples with hemagglutination inhibition titers of Rubella IgG assays. Agreement of qualitative results from the Elecsys, Enzygnost, and hemagglutination inhibition assays was good in all samples. All assays showed 100.0% specificity. In samples with hemagglutination inhibition titers of 90.0%) than the other immunoassays (78.6 to 82.4%). The Elecsys assay reported significantly higher rubella virus IgG levels than the other immunoassays across the whole set of 1,090 samples, with the largest bias and deviation from limits of agreement in Bland-Altman analysis. In conclusion, the Elecsys assay is highly sensitive and specific with regard to qualitative results and suitable for routine automated screening. However, given the considerable variation between quantitative results from different immunoassays, testing methods should be documented and the same assay used throughout an individual's antenatal follow-up wherever possible. PMID:23345585

  3. Selecting the correct weighting factors for linear and quadratic calibration curves with least-squares regression algorithm in bioanalytical LC-MS/MS assays and impacts of using incorrect weighting factors on curve stability, data quality, and assay performance.

    Science.gov (United States)

    Gu, Huidong; Liu, Guowen; Wang, Jian; Aubry, Anne-Françoise; Arnold, Mark E

    2014-09-16

    A simple procedure for selecting the correct weighting factors for linear and quadratic calibration curves with least-squares regression algorithm in bioanalytical LC-MS/MS assays is reported. The correct weighting factor is determined by the relationship between the standard deviation of instrument responses (σ) and the concentrations (x). The weighting factor of 1, 1/x, or 1/x(2) should be selected if, over the entire concentration range, σ is a constant, σ(2) is proportional to x, or σ is proportional to x, respectively. For the first time, we demonstrated with detailed scientific reasoning, solid historical data, and convincing justification that 1/x(2) should always be used as the weighting factor for all bioanalytical LC-MS/MS assays. The impacts of using incorrect weighting factors on curve stability, data quality, and assay performance were thoroughly investigated. It was found that the most stable curve could be obtained when the correct weighting factor was used, whereas other curves using incorrect weighting factors were unstable. It was also found that there was a very insignificant impact on the concentrations reported with calibration curves using incorrect weighting factors as the concentrations were always reported with the passing curves which actually overlapped with or were very close to the curves using the correct weighting factor. However, the use of incorrect weighting factors did impact the assay performance significantly. Finally, the difference between the weighting factors of 1/x(2) and 1/y(2) was discussed. All of the findings can be generalized and applied into other quantitative analysis techniques using calibration curves with weighted least-squares regression algorithm.

  4. Demonstration of short-range wind lidar in a high-performance wind tunnel

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Montes, Belen Fernández; Pedersen, Jens Engholm

    A short-range continuous-wave coherent laser radar (lidar) has been tested in a high-performance wind tunnel for possible use as a standard component in wind tunnels. The lidar was tested in a low as well as a high speed regime ranging from 5-35 m/s and 40-75 m/s, respectively. In both low and high......-speed regimes very good correlation with reference measurements was found. Furthermore different staring directions were tested and taking a simple geometrical correction into account very good correlation was again found. These measurements all demonstrate the high accuracy of the lidar and indicate a possible...... future for short range lidars as a complement to LDA and other standard equipment in wind tunnels....

  5. Demonstration of short-range wind lidar in a high-performance wind tunnel

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Montes, Belen Fernández; Pedersen, Jens Engholm

    2012-01-01

    A short-range continuous-wave coherent laser radar (lidar) has been tested in a high-performance wind tunnel for possible use as a standard component in wind tunnels. The lidar was tested in a low as well as a high speed regime ranging from 5-35 m/s and 40-75 m/s, respectively. In both low and high......-speed regimes very good correlation with reference measurements was found. Furthermore different staring directions were tested and taking a simple geometrical correction into account very good correlation was again found. These measurements all demonstrate the high accuracy of the lidar and indicate a possible...... future for short range lidars as a complement to LDA and other standard equipment in wind tunnels....

  6. Normalized performance and load data for the deepwind demonstrator in controlled conditions

    Directory of Open Access Journals (Sweden)

    L. Battisti

    2016-09-01

    Full Text Available Performance and load normalized coefficients, deriving from an experimental campaign of measurements conducted at the large scale wind tunnel of the Politecnico di Milano (Italy, are presented with the aim of providing useful benchmark data for the validation of numerical codes. Rough data, derived from real scale measurements on a three-bladed Troposkien vertical-axis wind turbine, are manipulated in a convenient form to be easily compared with the typical outputs provided by simulation codes. The here proposed data complement and support the measurements already presented in “Wind Tunnel Testing of the DeepWind Demonstrator in Design and Tilted Operating Conditions” (Battisti et al., 2016 [1].

  7. Cyclotron Radiation Emission Spectroscopy: First demonstration and performance benchmarks from the Project 8 experiment

    Science.gov (United States)

    LaRoque, Benjamin Hines

    The Project 8 collaboration is taking a phased approach to developing an experimental search for the absolute neutrino mass scale, based on a novel technique, Cyclotron Radiation Emission Spectroscopy. The first phase was a demonstration of this new spectroscopy technique using a well understood source of narrow conversion electron lines, 83mKr, as a proof of principle. Results from the first successful operation of the detector are presented, demonstrating the viability of the approach. The strong conversion electron lines near 17.8, 30.4, and 32 keV were observed with full width at half maximum between 140 eV and 15 eV depending on the choice of trapping configuration used. Various upgrades were made to the detector prior to its being operated with the specific goal of determining a performance baseline for planning future phases. These included alternative trapping configurations, with which the observed full width at half maximum has been improved to 3.6 eV. Evaluation of the event reconstruction and data quality are presented based on this data collection period. Areas where improvements will be required for phase II, when the approach will be used for the first time to measure a electrons from a continuous spectrum, are identified.

  8. Comparison of Hemoglobin A1c assay performance on two different commercial systems

    Directory of Open Access Journals (Sweden)

    Jozo Ćorić

    2015-04-01

    Full Text Available Introduction: Glycated hemoglobin (HbA1c is formed by non-enzymatic binding of glucose to the free amino group of the N-terminal end of the ß-chain of hemoglobin A. HbA1c is representative of the mean blood glucose level over three months. The aim of the study was to evaluate the Hemoglobin A1c immunoturbidimetric assay performance on two different commercial systems.Methods: We evaluated the precision and trueness for determination of HbA1c in whole blood. Concentrations of total hemoglobin and HbA1c were evaluated on Dimension Xpand (Siemens and Cobas 501 (Roche analyzers. HbA1c was measured in a latex agglutination inhibition test. Commercial controls Liquichek Diabetes Control Level 1 and Liquichek Diabetes Control Level 2 (Bio Rad at two levels were used for quality control. Analytical validation of HbA1c included: within-run imprecision, between-day imprecision, inaccuracy and comparison determination on the human samples on 2 systems: Dimension Xpand and Cobas 501 analyzers. Results: Within-run imprecision on the commercially controls for Level 1 is 4.5% and Level 2 is 3.2% between-day imprecision on commercially controls is 6.1% Level 1 and 5.1% Level 2 for respectively inac- curacy on commercially controls for Level 1 is 1.8% and Level 2 is 4.8%. Method comparison on human samples shows the correlation coefficient of 0.99.Conclusion: The presented results of the analytical evaluation methods for the determination of HbA1c showed an acceptable accuracy and precision.

  9. Performance of a Fourth-Generation HIV Screening Assay and an Alternative HIV Diagnostic Testing Algorithm

    Science.gov (United States)

    Nasrullah, Muazzam; Wesolowski, Laura G.; Meyer, William A.; Owen, S. Michele; Masciotra, Silvina; Vorwald, Craig; Becker, William J.; Branson, Bernard M.

    2015-01-01

    Objective We evaluated the performance of the GS fourth-generation antigen/antibody assay and compared CDC’s proposed alternative algorithm (repeatedly reactive [RR] fourth-generation immunoassay [IA] followed by an HIV-1/HIV-2 differentiation IA and, if needed, nucleic acid testing [NAT]) with the current algorithm (RR third-generation IA followed by HIV-1 Western blot [WB]). Design A convenience sample of the following four specimen sets was acquired: 10,014 from insurance applicants, 493 known WB-positive, 20 known WB-indeterminate specimens, and 230 specimens from 26 HIV-1 seroconverters. Methods Specimens were tested with the GS third- and fourth-generation IAs, the Multispot HIV-1/HIV-2 differentiation IA, NAT, and WB. We applied the two algorithms using these results. Results Among insurance specimens, 13 (0.13%) specimens were IA RR: 2 were HIV-positive (RR by third- and fourth-generation IAs, and WB and Multispot positive); 2 third-generation RR and 9 fourth-generation RR specimens were false-positive. Third- and fourth-generation specificities were 99.98% (95%CI: 99.93%–100%) and 99.91% (95%CI: 99.84%–99.96%) respectively. All HIV-1 WB-positive specimens were RR by third- and fourth-generation IAs. By Multispot, 491 (99.6%) were HIV-1 positive and 2 (0.4%) were HIV-2 positive. Only eight (40%) WB-indeterminate specimens were fourth-generation RR: 6 were Multispot and NAT negative and 2 were Multispot HIV-1 positive but NAT negative. The alternative algorithm correctly classified as positive 102 seroconverter specimens with the third-generation IA and 130 with the fourth-generation IA compared with 56 using the WB with either IA. Conclusions The alternative testing algorithm improved early infection sensitivity and identified HIV-2 infections. Two potential false-positive algorithm results occurred with WB-indeterminate specimens. PMID:23135170

  10. Analytical and clinical performance of Abbott RealTime MTB, an assay for detection of Mycobacterium tuberculosis in pulmonary specimens.

    Science.gov (United States)

    Tang, Ning; Frank, Andrea; Pahalawatta, Vihanga; Lampinen, John; Coblenz-Korte, Anke; Dunn, Chad; Li, Cheng; Cloherty, Gavin; Abravaya, Klara; Leckie, Gregor

    2015-09-01

    Nucleic acid amplification test (NAAT)-based assays provide fast and sensitive results compared to conventional TB tests. The performance of the new Abbott Molecular MTB assay for the qualitative detection of MTB complex using the automated m2000™ system or manual sample preparation is summarized in this paper. The assay detects eight MTB complex subspecies. The observed limit of detection (LOD) when used to test an MTB H37Rv panel was 2.45 colony forming units (cfu)/mL, while the claimed assay LOD with this MTB strain is 17 cfu/mL. No cross reactivity, or carryover were observed in the study. The clinical sensitivity of the assay was 93% overall; 99% in smear positive, culture positive specimens, and 81% in smear negative, culture positive samples. The clinical specificity was 97%. The inhibition rate in the study was 0.34%. The data suggest that Abbott RealTime MTB is a reliable, robust and sensitive assay for the molecular detection of MTB. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. A next generation enzymatic magnesium assay on the Abbott ARCHITECT chemistry system meets performance goals based on biological variation.

    Science.gov (United States)

    Bailey, D; Martens, P; Mah, W; Yip, P M

    2014-01-01

    To evaluate the performance of the Abbott ARCHITECT enzymatic assay for magnesium (3P68) in serum/plasma and urine against analytical goals based on biological variation. Analytical performance was evaluated according to CLSI protocols. Precision was examined using commercial chemistry controls. Accuracy was assessed against NIST SRM 956c, electrolytes in human serum. Correlation with the arsenazo Mg assay (7D70) was completed using patient samples (plasma, N = 101; urine, N = 90). Common interferences were examined in pooled patient specimens with high and low magnesium concentrations. The enzymatic Mg assay displayed imprecision of 1.7% at 0.72 mmol/L and 1.4% at 1.80 mmol/L (20 days, one calibration, one reagent lot). The linear range was verified between 0.18-7.0 mmol/L (plasma) and 0.01-10.69 mmol/L (urine). Results of the enzymatic assay (x) correlated well with the predicate assay (y) with the relationships y = 0.891x + 0.035, R = 0.967 (plasma) and y = 1.181x + 0.086, R = 0.997 (urine). Mean bias of the NIST SRM 956 c samples was -1.4%. This method showed minimal interference by hemoglobin (3g/L as hemolysate), lipemia (20 g/L Intralipid), unconjugated bilirubin (531 μmol/L), and ascorbate (680 μmol/L). The ARCHITECT Magnesium assay 3P68 achieved the desirable analytical quality specification of 4.8% for total allowable error. In comparison to the 7D70 assay, notable improvements are seen in precision, 30-day calibration stability, and minimal interference by hemolyzed and lipemic samples. © 2013.

  12. Performance Evaluation of the Elecsys Syphilis Assay for the Detection of Total Antibodies to Treponema pallidum

    Science.gov (United States)

    Enders, Martin; Hunjet, Andrea; Gleich, Michael; Imdahl, Roland; Mühlbacher, Annelies; Schennach, Harald; Chaiwong, Kriangsak; Sakuldamrongpanich, Tasanee; Turhan, Ajda; Sertöz, Rüchan; Wolf, Eva; Mayer, Wolfgang; Tao, Chuanmin; Wang, Lan Lan; Semprini, Simona

    2014-01-01

    Syphilis is a health problem of increasing incidence in recent years that may have severe complications if not diagnosed and treated at an early stage. There are many diagnostic tests available for syphilis, but there is no gold standard, and diagnosis therefore usually relies upon a combination of tests. In this multicenter study, we evaluated the treponemal Elecsys syphilis assay for use in the diagnosis of syphilis in routine samples, i.e., when syphilis is suspected or during antenatal or blood donation screening. The sensitivity and specificity of the Elecsys syphilis assay were compared head to head with those of other treponemal assays used in routine clinical practice and were assessed in potentially cross-reactive samples from patients with Epstein-Barr virus, HIV, and Lyme disease. In a total of 8,063 syphilis-negative samples collected from routine diagnostic requests and blood donations, the Elecsys syphilis assay had a specificity of 99.88%. In 928 samples previously identified as syphilis positive, the sensitivity was 99.57 to 100% (the result is presented as a range depending on whether four initially indeterminate samples are included in the assessment). The specificity of the Elecsys syphilis assay in patients with other infections was 100%; no false-positive samples were identified. PMID:25355799

  13. Performance of the new Platelia Candida Plus assays for the diagnosis of invasive Candida infection in patients undergoing myeloablative therapy

    NARCIS (Netherlands)

    Lunel, F.M.; Donnelly, J.P.; Lee, H.A.L. van der; Blijlevens, N.M.A.; Verweij, P.E.

    2011-01-01

    The performance of the new Platelia Candida Antigen Plus (Ag Plus) and Antibody Plus (Ab Plus) assays (Biorad Laboratories, France) was evaluated using a collection of serum samples obtained from 21 patients with microbiologically proven invasive candidiasis and 30 control patients who were being

  14. Adaptive use of bubble wrap for storing liquid samples and performing analytical assays.

    Science.gov (United States)

    Bwambok, David K; Christodouleas, Dionysios C; Morin, Stephen A; Lange, Heiko; Phillips, Scott T; Whitesides, George M

    2014-08-05

    This paper demonstrates that the gas-filled compartments in the packing material commonly called "bubble wrap" can be repurposed in resource-limited regions as containers to store liquid samples, and to perform bioanalyses. The bubbles of bubble wrap are easily filled by injecting the samples into them using a syringe with a needle or a pipet tip, and then sealing the hole with nail hardener. The bubbles are transparent in the visible range of the spectrum, and can be used as "cuvettes" for absorbance and fluorescence measurements. The interiors of these bubbles are sterile and allow storage of samples without the need for expensive sterilization equipment. The bubbles are also permeable to gases, and can be used to culture and store micro-organisms. By incorporating carbon electrodes, these bubbles can be used as electrochemical cells. This paper demonstrates the capabilities of the bubbles by culturing E. coli, growing C. elegans, measuring glucose and hemoglobin spectrophotometrically, and measuring ferrocyanide electrochemically, all within the bubbles.

  15. ESPGHAN guidance on coeliac disease 2012: multiples of ULN for decision making do not harmonise assay performance across centres.

    Science.gov (United States)

    Egner, William; Shrimpton, Anna; Sargur, Ravishankar; Patel, Dina; Swallow, Kirsty

    2012-12-01

    The updated ESPGHAN guidance on coeliac disease recommends the use of common multiples of the upper limit of normal (ULN) for IgA tissue transglutaminase antibodies (TG2) when deciding which diagnostic pathway to follow. The current lack of standardisation between assays makes it difficult to harmonise results between centres as different performance characteristics are observed with each assay. This variability is shown in data from external quality assessment distributions. As a result, the updated guidance is too generalised for use with all the commercial TG2 kits and is therefore not translatable for use in all centres.

  16. Adolescents at risk for alcohol abuse demonstrate altered frontal lobe activation during Stroop performance.

    Science.gov (United States)

    Silveri, Marisa M; Rogowska, Jadwiga; McCaffrey, Alexandra; Yurgelun-Todd, Deborah A

    2011-02-01

    Children and adolescents, family history positive (FH+) for alcoholism, exhibit differences in brain structure and functional activation when compared to family history negative (FH-) counterparts. Given that frontal brain regions, and associated reciprocal connections with limbic structures, undergo the most dramatic maturational changes during adolescence, the objective of this study was to compare functional brain activation during a frontally mediated test of response inhibition in 32 adolescents separated into low-risk (FH-) and high-risk (FH+) groups. Functional magnetic resonance (fMRI) blood oxygen level-dependent data were acquired at 1.5 Tesla during performance of Stroop Color Naming, Word Reading, and Interference. Preprocessing and statistical analyses, covaried for age, were conducted in SPM99 using a search territory that included superior, middle, and inferior frontal gyri (trigone region), anterior cingulate gyrus (CG), and left and right amygdala. Significantly greater activation in the fronto-limbic search territory was observed in FH+ relative to FH- subjects during Stroop Interference. In addition, a significant regression between brain activation and family history density was observed, with a greater density being associated with increased activation in regions including middle frontal gyrus (BA9) and CG (BA24). These data demonstrate a significant influence of FH status on brain activation during the performance of a response inhibition task, perhaps reflecting a neurobiological vulnerability associated with FH status that may include reduced neuronal efficiency and/or recruitment of additional neuronal resources. These findings are important given that the adolescent developmental period is already associated with reduced inhibitory capacity, even prior to the onset of alcohol use. Copyright © 2010 by the Research Society on Alcoholism.

  17. Performance of a fourth-generation HIV screening assay and an alternative HIV diagnostic testing algorithm.

    Science.gov (United States)

    Nasrullah, Muazzam; Wesolowski, Laura G; Meyer, William A; Owen, S Michele; Masciotra, Silvina; Vorwald, Craig; Becker, William J; Branson, Bernard M

    2013-03-13

    We evaluated the performance of the GS fourth-generation antigen/antibody assay and compared Centers for Disease Control and Prevention's (CDC's) proposed alternative algorithm [repeatedly reactive fourth-generation immunoassay followed by an HIV-1/HIV-2 differentiation immunoassay and, if needed, nucleic acid test (NAT)] with the current algorithm (repeatedly reactive third-generation immunoassay followed by HIV-1 western blot). A convenience sample of the following four specimen sets was acquired: 10 014 from insurance applicants, 493 known western blot-positive, 20 known western blot-indeterminate specimens, and 230 specimens from 26 HIV-1 seroconverters. Specimens were tested with the GS third-generation and fourth-generation immunoassays, the Multispot HIV-1/HIV-2 differentiation immunoassay, NAT, and western blot. We applied the two algorithms using these results. Among insurance specimens, 13 (0.13%) specimens were immunoassay repeatedly reactive: two were HIV-positive (repeatedly reactive by third-generation and fourth-generation immunoassays, and western blot and Multispot positive); two third-generation repeatedly reactive and nine fourth-generation repeatedly reactive specimens were false-positive. Third-generation and fourth-generation specificities were 99.98% [95% confidence interval (CI) 99.93-100%] and 99.91% (95% CI 99.84-99.96%), respectively.All HIV-1 western blot-positive specimens were repeatedly reactive by third-generation and fourth-generation immunoassays. By Multispot, 491 (99.6%) were HIV-1-positive and two (0.4%) were HIV-2-positive.Only eight (40%) western blot-indeterminate specimens were fourth-generation repeatedly reactive: six were Multispot and NAT-negative and two were Multispot HIV-1-positive but NAT-negative.The alternative algorithm correctly classified as positive 102 seroconverter specimens with the third-generation immunoassay and 130 with the fourth-generation immunoassay compared with 56 using the western blot with

  18. Analytical Performance Characteristics of the Cepheid GeneXpert Ebola Assay for the Detection of Ebola Virus.

    Science.gov (United States)

    Pinsky, Benjamin A; Sahoo, Malaya K; Sandlund, Johanna; Kleman, Marika; Kulkarni, Medha; Grufman, Per; Nygren, Malin; Kwiatkowski, Robert; Baron, Ellen Jo; Tenover, Fred; Denison, Blake; Higuchi, Russell; Van Atta, Reuel; Beer, Neil Reginald; Carrillo, Alda Celena; Naraghi-Arani, Pejman; Mire, Chad E; Ranadheera, Charlene; Grolla, Allen; Lagerqvist, Nina; Persing, David H

    2015-01-01

    The recently developed Xpert® Ebola Assay is a novel nucleic acid amplification test for simplified detection of Ebola virus (EBOV) in whole blood and buccal swab samples. The assay targets sequences in two EBOV genes, lowering the risk for new variants to escape detection in the test. The objective of this report is to present analytical characteristics of the Xpert® Ebola Assay on whole blood samples. This study evaluated the assay's analytical sensitivity, analytical specificity, inclusivity and exclusivity performance in whole blood specimens. EBOV RNA, inactivated EBOV, and infectious EBOV were used as targets. The dynamic range of the assay, the inactivation of virus, and specimen stability were also evaluated. The lower limit of detection (LoD) for the assay using inactivated virus was estimated to be 73 copies/mL (95% CI: 51-97 copies/mL). The LoD for infectious virus was estimated to be 1 plaque-forming unit/mL, and for RNA to be 232 copies/mL (95% CI 163-302 copies/mL). The assay correctly identified five different Ebola viruses, Yambuku-Mayinga, Makona-C07, Yambuku-Ecran, Gabon-Ilembe, and Kikwit-956210, and correctly excluded all non-EBOV isolates tested. The conditions used by Xpert® Ebola for inactivation of infectious virus reduced EBOV titer by ≥6 logs. In summary, we found the Xpert® Ebola Assay to have high analytical sensitivity and specificity for the detection of EBOV in whole blood. It offers ease of use, fast turnaround time, and remote monitoring. The test has an efficient viral inactivation protocol, fulfills inclusivity and exclusivity criteria, and has specimen stability characteristics consistent with the need for decentralized testing. The simplicity of the assay should enable testing in a wide variety of laboratory settings, including remote laboratories that are not capable of performing highly complex nucleic acid amplification tests, and during outbreaks where time to detection is critical.

  19. Detection of aflatoxin B1 in imported food products into Japan by enzyme-linked immunosorbent assay and high performance liquid chromatography.

    Science.gov (United States)

    Adachi, Y; Hara, M; Kumazawa, N H; Hirano, K; Ueno, I; Egawa, K

    1991-02-01

    In order to detect the presence of aflatoxin B1 (AFB1), the use of the enzyme-linked immunosorbent assay (ELISA) and recovery test was evaluated. The detection limit of ELISA for AFB1 was 1 pg/assay and the recovery from maize spiked with AFB1 exceeded 80%. AFB1 was detected by ELISA in seven out of twelve samples of imported food products including peanut, almond, red pepper, cocoa bean, black pepper, buckwheat, walnut, adlay, soybean, popcorn, and pistachio nut, and by high performance liquid chromatography (HPLC) in four of the samples. However, the content of AFB1 in these samples was less than 10 ng/g of the minimum value authorized by the Japanese sanitation law. These results demonstrate that ELISA is more sensitive than HPLC and imported food products are broadly contaminated with AFB1.

  20. Radiochemical assay for determination of dihydropyrimidinase activity using reversed-phase high-performance liquid chromatography

    NARCIS (Netherlands)

    van Kuilenburg, A. B.; van Lenthe, H.; van Gennip, A. H.

    1999-01-01

    A radiochemical assay was developed to measure the activity of dihydropyrimidinase (DHP) in human liver homogenates. The method is based on the separation of radiolabeled dihydrouracil from N-carbamyl-beta-alanine by HPLC with on-line detection of radioactivity combined with detection of 14CO2 by

  1. Performance of point-of-care diagnosis of AIDS: label-free one-step-immunoassay vs. lateral flow assay.

    Science.gov (United States)

    Kwon, J-H; Kim, H-T; Sim, S J; Cha, Y J; Lee, J

    2018-02-12

    The objective of this study is to develop an accurate, rapid, simple, and label-free assay technology that enables point-of-care diagnosis of AIDS. For this, 3-dimensional (3D) probes to sensitively detect anti-HIV antibodies were designed and synthesized by genetically presenting a HIV antigen (gp41) on the surface of engineered human ferritin nanoparticles. The 3D probes also present multi-copies of the hexa-histidine peptide (H 6 ) on their surface to chemisorb gold ions (Au 3+ ), which is essential for the generation and self-enhancement of assay signals. The developed new assay technology (named "one-step-immunoassay") quickly produced clear optical signals through a simple and convenient one-step procedure. The diagnostic performance of the one-step-immunoassay was compared with that of the conventional lateral flow assay (LFA) using 30 AIDS patient and 20 healthy sera. The sensitivity of LFA was only 63% when a single antigen (gp41) was used but enhanced to 90% when three different antigens (gp41, p24, and gp120) were used together as the assay probes. In contrast, the one-step-immunoassay using only gp41 produced strong optical signals within 15 min without causing any false negative/positive signals, showing 100% sensitivity and 100% specificity and holding promising potential for clinical point-of-care diagnosis of AIDS.

  2. TINA, a new fully automated high-performance droplet freezing assay coupled to a customized infrared detection system

    Science.gov (United States)

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

    2017-04-01

    Heterogeneous ice nucleation is frequently investigated by simultaneously cooling a defined number of droplets of equal volume in droplet freezing assays. In 1971, Gabor Vali established the quantitative assessment of ice nuclei active at specific temperatures for many droplet freezing assays. Since then, several instruments have been developed, and various modifications and improvements have been made. However, for quantitative analysis of ice nuclei, the current known droplet freezing assays are still limited by either small droplet numbers, large droplet volumes, inadequate separation of the single droplets, which can result in mutual interferences, or imprecise temperature control within the system. Here, we present the Twin Ice Nucleation Assay (TINA), which represents an improvement of the until now existing droplet freezing assays in terms of temperature range and statistics. Above all, we developed a distinct detection system for freezing events in droplet freezing assays, where the temperature gradient of each single droplet is tracked individually by infrared cameras coupled to a self-written software. In the fully automated setup, ice nucleation can be studied in two independently cooled, customized aluminum blocks run by a high-performance thermostat. We developed a cooling setup, which allows both huge and tiny temperature changes within a very short period of time, combined with an optimal insulation. Hence, measurements can be performed at temperatures down to -55 °C (218 K) and at cooling rates up to 3 K min-1. Besides that, TINA provides the analysis of nearly 1000 droplets per run with various droplet volumes between 1 µL and 50 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.

  3. DEMONSTRATION OF CIRCULATING PNEUMOCOCCAL IMMUNOGLOBULIN-G IMMUNE-COMPLEXES IN PATIENTS WITH COMMUNITY-ACQUIRED PNEUMONIA BY MEANS OF AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY

    NARCIS (Netherlands)

    HOLLOWAY, Y; SNIJDER, JAM; BOERSMA, WG

    1993-01-01

    An enzyme-linked immunosorbent assay was developed for quantitation of circulating immune complexes (CICs) containing specific antipneumococcal immunoglobulin G (IgG). These CICs were detected in 17 (85%) of 20 patients with bacteremic pneumococcal pneumonia, 4 (36.4%) of 11 patients with probable

  4. Clinical performance of the (1,3)-β-D-glucan assay in early diagnosis of nosocomial Candida bloodstream infections.

    Science.gov (United States)

    Del Bono, Valerio; Delfino, Emanuele; Furfaro, Elisa; Mikulska, Malgorzata; Nicco, Elena; Bruzzi, Paolo; Mularoni, Alessandra; Bassetti, Matteo; Viscoli, Claudio

    2011-12-01

    Microbiological diagnosis of nosocomial candidemia is negatively affected by suboptimal culture yield. Alternative methods are not fully reliable as an aid in candidemia diagnosis. Recently, the detection of (1,3)-β-D-glucan (BG) has been shown to be very promising in this setting. We carried out a prospective study on the clinical usefulness of BG detection in early diagnosis of candidemia. BG detection was performed in patients with fever unresponsive to antibacterial agents and risk factors for candidemia. BG detection was done with the Fungitell test. A total of 152 patients were included in the study; 53 were proven to have candidemia, while in 52 patients candidemia was excluded on microbiological and clinical bases. The remaining 47 patients were considered to have possible candidemia. In summary, 41 of 53 candidemia patients (77.3%), 9 of 52 patients without candidemia (17.3%), and 38 of 47 patients with possible candidemia (80.8%) were positive in the BG assay. With these results, the sensitivity and the specificity of the assay were 77% and 83%, respectively. BG levels of >160 pg/ml were highly predictive of candidemia. In 36 of 41 patients with candidemia and positive BG testing, the BG assay was performed within 48 h from when the first Candida-positive blood sample for culture was drawn, thus allowing a possible earlier start of antifungal therapy. Based on these results, the BG assay may be used as an aid in the diagnosis of nosocomial candidemia. The timing of assay performance is critical for collecting clinically useful information. However, the test results should be associated with clinical data.

  5. Analytical Performance Characteristics of the Cepheid GeneXpert Ebola Assay for the Detection of Ebola Virus

    Science.gov (United States)

    Pinsky, Benjamin A.; Sahoo, Malaya K.; Sandlund, Johanna; Kleman, Marika; Kulkarni, Medha; Grufman, Per; Nygren, Malin; Kwiatkowski, Robert; Baron, Ellen Jo; Tenover, Fred; Denison, Blake; Higuchi, Russell; Van Atta, Reuel; Beer, Neil Reginald; Carrillo, Alda Celena; Naraghi-Arani, Pejman; Mire, Chad E.; Ranadheera, Charlene; Grolla, Allen; Lagerqvist, Nina; Persing, David H.

    2015-01-01

    Background The recently developed Xpert® Ebola Assay is a novel nucleic acid amplification test for simplified detection of Ebola virus (EBOV) in whole blood and buccal swab samples. The assay targets sequences in two EBOV genes, lowering the risk for new variants to escape detection in the test. The objective of this report is to present analytical characteristics of the Xpert® Ebola Assay on whole blood samples. Methods and Findings This study evaluated the assay’s analytical sensitivity, analytical specificity, inclusivity and exclusivity performance in whole blood specimens. EBOV RNA, inactivated EBOV, and infectious EBOV were used as targets. The dynamic range of the assay, the inactivation of virus, and specimen stability were also evaluated. The lower limit of detection (LoD) for the assay using inactivated virus was estimated to be 73 copies/mL (95% CI: 51–97 copies/mL). The LoD for infectious virus was estimated to be 1 plaque-forming unit/mL, and for RNA to be 232 copies/mL (95% CI 163–302 copies/mL). The assay correctly identified five different Ebola viruses, Yambuku-Mayinga, Makona-C07, Yambuku-Ecran, Gabon-Ilembe, and Kikwit-956210, and correctly excluded all non-EBOV isolates tested. The conditions used by Xpert® Ebola for inactivation of infectious virus reduced EBOV titer by ≥6 logs. Conclusion In summary, we found the Xpert® Ebola Assay to have high analytical sensitivity and specificity for the detection of EBOV in whole blood. It offers ease of use, fast turnaround time, and remote monitoring. The test has an efficient viral inactivation protocol, fulfills inclusivity and exclusivity criteria, and has specimen stability characteristics consistent with the need for decentralized testing. The simplicity of the assay should enable testing in a wide variety of laboratory settings, including remote laboratories that are not capable of performing highly complex nucleic acid amplification tests, and during outbreaks where time to detection

  6. Standardization and performance evaluation of mononuclear cell cytokine secretion assays in a multicenter study

    Directory of Open Access Journals (Sweden)

    Grindle Kristine

    2006-12-01

    Full Text Available Abstract Background Cryopreservation of peripheral blood mononuclear cells has been used to preserve and standardize immunologic measurements for multicenter studies, however, effects of cryopreservation on cytokine responses are incompletely understood. In designing immunologic studies for a new multicenter birth cohort study of childhood asthma, we performed a series of experiments to determine the effects of two different methods of cryopreservation on the cytokine responses of cord and peripheral blood mononuclear cells. Results Paired samples of PBMC were processed freshly, or after cryopreservation in a Nalgene container (NC or a controlled-rate freezer (CRF. Although there were some differences between the methods, cryopreservation inhibited PHA-induced IL-10 secretion and Der f 1-induced IL-2 secretion, and augmented PHA-induced IL-2 secretion and spontaneous secretion of TNF-α. In separate experiments, NC cryopreservation inhibited secretion of several cytokines (IL-13, IL-10, IFN-γ, TNF-α by PHA-stimulated cord blood mononuclear cells. With the exception of PHA-induced IL-13, results from fresh and cryopreserved cord blood samples were not significantly correlated. Finally, in reproducibility studies involving processing of identical cell samples in up to 4 separate laboratories, variances in cytokine responses of fresh cells stimulated at separate sites did not exceed those in cryopreserved cells stimulated at a central site. Conclusion Collectively, these studies indicate that cryopreservation can affect mononuclear cell cytokine response profiles, and that IL-10 secretion and antigen-induced responses may be especially vulnerable. These studies also demonstrate that mononuclear cell responses can be standardized for performance in a small number of laboratories for multicenter studies, and underscore the importance of measuring reproducibility and of testing whether cryopreservation techniques alter specific immunologic outcomes.

  7. On performance experience and measurements with Ningyo Waste Assay System (NWAS)

    OpenAIRE

    在間 直樹; 中島 伸一; 金田 弘司; 門 一実

    2011-01-01

    The uranium mass assay systems for 200-litter wastes drums applied neutron and gamma measurements by NDA method had been developed. The measurement systems and trial data are described in this preliminary report. The systems are composed of the 16 pieces of helium-3 proportional counters for neutron detection and a large sized NaI(Tl) scintillation detector for gamma ray detection. The extensive testing trials using the calibrated uranium sources with different enrichment and some kinds of ma...

  8. Performance of scintillation proximity assay (SPA) to measure the level of VEGFR 1 protein

    Energy Technology Data Exchange (ETDEWEB)

    LEE, So-Young; LIM, Jae-Cheong; KIM, Jin-Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Scintillation proximity assay is a one of radioimmunoassay and can be assayed without the washing or filtration procedures normally used to separate bound from free fractions. Due to its simplicity and high-throughput protocol, it is broadly applicable to immunology, receptor binding, monitoring receptor-ligand interactions and enzyme reactions. Briefly, an antibody or receptor is coated on SPA beads. When a radiolabeled antigen or ligand binds to the beads, the SPA beads stimulate to emit short range electrons. The {sup 3}H and {sup 125}I are commonly used for radiolabeling and the produced photons are detectable with a liquid scintillation counter (LSC). A binding affinity of unlabeled ligands can be determined by competitive reaction of the radiolabeled ligands. Bevacizumab is a recombinant humanized monoclonal antibody, and can stop or delay growth of tumors by inhibiting vascular endothelial growth factor (VEGF). Bevacizumab was approved by FDA for metastatic cancer such as colorectal cancers, ovarian cancers, breast cancers and glioblastoma multiform of the brain. Recently, Dan G. duda et al. was reported that the concentration of vascular endothelial growth factor receptor-1 (VEGFR-1) in plasma may potentially be used as a negative selection biomarker. In this study, we describe a method using scintillation proximity assay to detect the amounts of VEGFR-1 protein. This method is successfully used to measure the concentration of VEGFR-1 protein in human cell extracts. In summary, a simple and sensitive assay is developed for measuring the amount of VEGFR 1 protein in cancer cell lysate using SPA beads. The antibody coating on the beads and antigen binding are achieved in one mixing step.

  9. A Low-Cost, High-Performance System for Fluorescence Lateral Flow Assays

    Science.gov (United States)

    Lee, Linda G.; Nordman, Eric S.; Johnson, Martin D.; Oldham, Mark F.

    2013-01-01

    We demonstrate a fluorescence lateral flow system that has excellent sensitivity and wide dynamic range. The illumination system utilizes an LED, plastic lenses and plastic and colored glass filters for the excitation and emission light. Images are collected on an iPhone 4. Several fluorescent dyes with long Stokes shifts were evaluated for their signal and nonspecific binding in lateral flow. A wide range of values for the ratio of signal to nonspecific binding was found, from 50 for R-phycoerythrin (R-PE) to 0.15 for Brilliant Violet 605. The long Stokes shift of R-PE allowed the use of inexpensive plastic filters rather than costly interference filters to block the LED light. Fluorescence detection with R-PE and absorbance detection with colloidal gold were directly compared in lateral flow using biotinylated bovine serum albumen (BSA) as the analyte. Fluorescence provided linear data over a range of 0.4–4,000 ng/mL with a 1,000-fold signal change while colloidal gold provided non-linear data over a range of 16–4,000 ng/mL with a 10-fold signal change. A comparison using human chorionic gonadotropin (hCG) as the analyte showed a similar advantage in the fluorescent system. We believe our inexpensive yet high-performance platform will be useful for providing quantitative and sensitive detection in a point-of-care setting. PMID:25586412

  10. A Low-Cost, High-Performance System for Fluorescence Lateral Flow Assays

    Directory of Open Access Journals (Sweden)

    Linda G. Lee

    2013-10-01

    Full Text Available We demonstrate a fluorescence lateral flow system that has excellent sensitivity and wide dynamic range. The illumination system utilizes an LED, plastic lenses and plastic and colored glass filters for the excitation and emission light. Images are collected on an iPhone 4. Several fluorescent dyes with long Stokes shifts were evaluated for their signal and nonspecific binding in lateral flow. A wide range of values for the ratio of signal to nonspecific binding was found, from 50 for R-phycoerythrin (R-PE to 0.15 for Brilliant Violet 605. The long Stokes shift of R-PE allowed the use of inexpensive plastic filters rather than costly interference filters to block the LED light. Fluorescence detection with R-PE and absorbance detection with colloidal gold were directly compared in lateral flow using biotinylated bovine serum albumen (BSA as the analyte. Fluorescence provided linear data over a range of 0.4–4,000 ng/mL with a 1,000-fold signal change while colloidal gold provided non-linear data over a range of 16–4,000 ng/mL with a 10-fold signal change. A comparison using human chorionic gonadotropin (hCG as the analyte showed a similar advantage in the fluorescent system. We believe our inexpensive yet high-performance platform will be useful for providing quantitative and sensitive detection in a point-of-care setting.

  11. Performance of Indirect Immunoglobulin M (IgM) Serology Tests and IgM Capture Assays for Laboratory Diagnosis of Measles

    Science.gov (United States)

    Ratnam, Samuel; Tipples, Graham; Head, Carol; Fauvel, Micheline; Fearon, Margaret; Ward, Brian J.

    2000-01-01

    As progress is made toward elimination of measles, the laboratory confirmation of measles becomes increasingly important. However, both false-positive and false-negative results can occur with the routinely used indirect measles immunoglobulin M (IgM) serology tests. The measles IgM capture assay is considered to be more specific, and therefore, its use is indicated for confirmatory testing, but its relative performance has not been fully assessed. Four commercial indirect measles IgM serology test kits (the Behring, Clark, Gull, and PanBio assays) and a commercial IgM capture assay (the Light Diagnostics assay) were evaluated for their abilities to detect measles virus-specific IgM antibody with a total of 308 serum samples from patients involved in a measles outbreak and with confirmed cases of measles and 454 samples from subjects without measles. The Centers for Disease Control and Prevention (CDC) IgM capture assay was also used in a part of the evaluation. Among the indirect assays, the overall sensitivities ranged from 82.8% (Clark assay) to 88.6% (Behring assay) and specificity ranged from 86.6% (PanBio assay) to 99.6% (Gull assay). These rates were 92.2 and 86.6%, respectively, for the Light Diagnostics capture assay and 87.0 and 94.8%, respectively, for the CDC capture assay. While the Light Diagnostics capture assay had the best detection rate (80%) with the acute-phase samples compared with those for the rest of the tests (CDC capture assay, 77%; Behring assay, 70%; Gull assay, 69%; PanBio assay, 58%; and Clark assay, 57%), all tests showed a significantly improved sensitivity in the range of 92% (Clark and PanBio assays) to 97% (Light Diagnostics and CDC capture assays) with the convalescent-phase samples, as expected. The best seropositivity rates (in the range of 92 to 100%) were observed with samples collected 6 to 14 days after the onset of symptoms. The Gull assay showed the highest positive predictive value (99.6%), followed by the Behring assay

  12. Analytical and clinical performance characteristics of the Abbott RealTime MTB RIF/INH Resistance, an assay for the detection of rifampicin and isoniazid resistant Mycobacterium tuberculosis in pulmonary specimens.

    Science.gov (United States)

    Kostera, Joshua; Leckie, Gregor; Tang, Ning; Lampinen, John; Szostak, Magdalena; Abravaya, Klara; Wang, Hong

    2016-12-01

    Clinical management of drug-resistant tuberculosis patients continues to present significant challenges to global health. To tackle these challenges, the Abbott RealTime MTB RIF/INH Resistance assay was developed to accelerate the diagnosis of rifampicin and/or isoniazid resistant tuberculosis to within a day. This article summarizes the performance of the Abbott RealTime MTB RIF/INH Resistance assay; including reliability, analytical sensitivity, and clinical sensitivity/specificity as compared to Cepheid GeneXpert MTB/RIF version 1.0 and Hain MTBDRplus version 2.0. The limit of detection (LOD) of the Abbott RealTime MTB RIF/INH Resistance assay was determined to be 32 colony forming units/milliliter (cfu/mL) using the Mycobacterium tuberculosis (MTB) strain H37Rv cell line. For rifampicin resistance detection, the Abbott RealTime MTB RIF/INH Resistance assay demonstrated statistically equivalent clinical sensitivity and specificity as compared to Cepheid GeneXpert MTB/RIF. For isoniazid resistance detection, the assay demonstrated statistically equivalent clinical sensitivity and specificity as compared to Hain MTBDRplus. The performance data presented herein demonstrate that the Abbott RealTime MTB RIF/INH Resistance assay is a sensitive, robust, and reliable test for realtime simultaneous detection of first line anti-tuberculosis antibiotics rifampicin and isoniazid in patient specimens. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  13. Measurement of dabigatran: previously demonstrated Hemoclot® Thrombin Inhibitor assay reagent instability on Sysmex CS-2100i is no longer an issue

    DEFF Research Database (Denmark)

    Comuth, Willemijn; Faaborg, Louise; Henriksen, Linda Østervig

    2017-01-01

    The Hemoclot® Thrombin Inhibitor (HTI) assay has been recommended for measurement of dabigatran concentrations in specific clinical situations. Traditionally, reagents for biochemical assays are prepared from instructions found in the package insert. For the HTI reagents the manufacturer recommends...... incubating the reagents much longer than indicated in the package insert. These recommendations are added to the application sheets designed for different analyzers. Many clinicians and laboratory personnel may be unaware of the discrepancy between the two instructions, resulting in incorrect handling...... of the reagents. The aim of this study was to investigate the effect of the two different preparation methods on reagent stability and test results. For the standard concentration range, reagent stability on Sysmex CS-2100i was only two hours instead of the eight hours indicated by the producer when following...

  14. Performance of a Branch Chain RNA In Situ Hybridization Assay for the Detection of High-risk Human Papillomavirus in Head and Neck Squamous Cell Carcinoma.

    Science.gov (United States)

    Kerr, Darcy A; Arora, Kshitij S; Mahadevan, Krishnan K; Hornick, Jason L; Krane, Jeffrey F; Rivera, Miguel N; Ting, David T; Deshpande, Vikram; Faquin, William C

    2015-12-01

    High-risk human papillomavirus (HR-HPV) is a major etiologic agent in a subset of head and neck squamous cell carcinomas (HNSCCs), and its recognition has prognostic and predictive implications. The availability of a sensitive and specific test to assess HR-HPV status is limited. We evaluate an RNA in situ hybridization (ISH) method using branch chain technology to detect HR-HPV and compare its results with DNA ISH, p16 immunohistochemistry, and polymerase chain reaction (PCR). Tissue sections from 54 patients were stained with a manual RNA ISH assay (ViewRNA), which detects 14 HR-HPV types, an automated DNA ISH assay, and p16 immunohistochemistry. Most cases (83%, n=45) were also tested on an automated platform for 14 HR-HPV types and 1 limited to HPV 16/18. PCR was performed in all cases and was successful in 93% (n=50). The RNA ISH assay produced results in 96% of the cases with strong signals and was easily interpreted. HR-HPV was detected in more cases (63%, n=34) by RNA ISH than by DNA ISH (39%, n=21). Compared with PCR, both ISH platforms were 94% specific. RNA ISH was more sensitive (91%) than DNA ISH (65%), and RNA ISH correlated more strongly with p16 immunostaining. HPV 16 represented 89% of HR-HPV detected. The cocktail HPV 16/18 platform was concordant with the pooled HR-HPV assay in all expected cases. The automated assay demonstrated high concordance (96%) with the manual version, showed decreased background, and should allow for easy implementation into the workflow of the diagnostic pathology laboratory.

  15. 42 CFR 475.104 - Requirements for demonstrating ability to perform review.

    Science.gov (United States)

    2010-10-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) QUALITY IMPROVEMENT ORGANIZATIONS QUALITY IMPROVEMENT ORGANIZATIONS Utilization and Quality Control Quality Improvement Organizations § 475.104 Requirements for demonstrating... system is adequate; and (2) The organization has available sufficient resources (including access to...

  16. Analytical performance of the Alere™ i Influenza A&B assay for the rapid detection of influenza viruses.

    Science.gov (United States)

    Riazzo, Cristina; Pérez-Ruiz, Mercedes; Sanbonmatsu-Gámez, Sara; Pedrosa-Corral, Irene; Gutiérrez-Fernández, José; Navarro-Marí, José-María

    The analytical performance of the new Alere™ i Influenza A&B kit (AL-Flu) assay, based on isothermal nucleic acids amplification, was evaluated and compared with an antigen detection method, SD Bioline Influenza Virus Antigen Test (SDB), and an automated real-time RT-PCR, Simplexa™ Flu A/B & VRS Direct assay (SPX), for detection of influenza viruses. An "in-house" RT-PCR was used as the reference method. Sensitivity of AL-Flu, SDB, and SPX was 71.7%, 34.8%, and 100%, respectively. Specificity was 100% for all techniques. The turnaround time was 13min for AL-Flu, 15min for SDB, and 75min for SPX. The Alere™ i Influenza A&B assay is an optimal point-of-care assay for influenza diagnosis in clinical emergency settings, and is more sensitive and specific than antigen detection methods. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  17. Identifying top-performing hospitals by algorithm: results from a demonstration project.

    Science.gov (United States)

    Allison, Jeroan J; Weissman, Norman W; Silvey, Andrea B; Chapin, Charlie A; Kiefe, Catarina I

    2008-06-01

    Because of the move toward performance-based reimbursement, identification of top-performing hospitals has acquired new importance. The High Performance Algorithm (HPA) for hospitals was developed on the basis of the following principles: (1) the approach must be data driven and transparent, (2) all hospitals providing the same service are held to the same standard, (3) top-performing hospitals must perform well on easily achieved and difficult quality measures, and (4) high performance demands sustained excellence over time. The HPA algorithm was applied to 16 quality measures from the national Hospital Quality Alliance (July 2003-June 2004) for acute myocardial infarction (AMI), heart failure (HF), and pneumonia. Top-performing hospitals were defined as those with the top 1% of HPA scores (n = 45). From all 3,867 hospitals, median HPA scores (interquartile range) were 17.0 (16.0-19.0) for top-performing hospitals and 3.0 (1.0-6.0) for others (p performance on quality measures was higher for top hospitals on all 16 measures. For example, on administration of angiotensin-converting enzyme inhibitors to patients with HF, the mean score for top-performing hospitals was 93.3%, compared with 76.5% for others (p performance across multiple conditions and time periods was uncommon, with or = 16/36 points on the HPA scale. Using national, publicly reported data, the HPA provided good discrimination between top-performing and other hospitals. This project sets the stage for future comparisons of organizational, leadership, and policy differences between top-performing and other hospitals.

  18. Performance of a Pneumolysin Enzyme-Linked Immunosorbent Assay for Diagnosis of Pneumococcal Infections▿

    Science.gov (United States)

    del Mar García-Suárez, María; Cima-Cabal, María Dolores; Villaverde, Roberto; Espinosa, Emma; Falguera, Miquel; de Los Toyos, Juan R.; Vázquez, Fernando; Méndez, Francisco J.

    2007-01-01

    A pneumolysin-specific enzyme-linked immunosorbent assay (PLY-ELISA) for the detection of pneumolysin in urine was developed and evaluated in comparison with the commercially available Binax Now Streptococcus pneumoniae test (Binax, Portland, ME) for the diagnosis of pneumococcal infections. Assay sensitivity was evaluated using urine from 108 patients with culture-confirmed pneumococcal infections. In adults, the sensitivity and specificity of the PLY-ELISA were 56.6% and 92.2%, respectively. In children with nasopharyngeal pneumococcal carriage, PLY-ELISA and Binax Now S. pneumoniae test sensitivities were 62.5% and 87.5%, respectively, while specificities were 94.4% and 27.8%, respectively. In children with nonnasopharyngeal pneumococcal carriage, PLY-ELISA and Binax Now S. pneumoniae test sensitivities were 68.7% and 93.7%, respectively, and test specificities were 94.1% and 41.2%, respectively. The persistence of pneumolysin in urine of pneumococcal pneumonia patients decreased significantly after 4 to 6 days of treatment. Our data suggest that combining the high specificity of the PLY-ELISA with the high sensitivity of the Binax Now S. pneumoniae test would enable pneumococcal infections to be accurately diagnosed in children. PMID:17728474

  19. Laboratory assessment of Activated Protein C Resistance/Factor V-Leiden and performance characteristics of a new quantitative assay.

    Science.gov (United States)

    Amiral, Jean; Vissac, Anne Marie; Seghatchian, Jerard

    2017-12-01

    Activated Protein C Resistance is mainly associated to a factor V mutation (RQ506), which induces a deficient inactivation of activated factor V by activated protein C, and is associated to an increased risk of venous and arterial thrombosis in affected individuals, caused by the prolonged activated factor V survival. Its prevalence is mainly in Caucasians (about 5%), and this mutation is absent in Africans and Asians. Presence of Factor V-Leiden is usually evidenced with clotting methods, using a two-step APTT assay performed without or with APC: prolongation of blood coagulation time is decreased if this factor is present. The R506Q Factor V-Leiden mutation is now usually characterized using molecular biology, and this technique tends to become the first intention assay for characterization of patients. Both techniques are qualitative, and allow classifying tested individuals as heterozygotes or homozygotes for the mutation, when present. A new quantitative assay for Factor V-Leiden, using a one-step clotting method, has been developed, and designed with highly purified human coagulation proteins. Clotting is triggered with human Factor Xa, in presence of calcium and phospholipids (mixture which favours APC action over clotting process). Diluted tested plasma, is supplemented with a clotting mixture containing human fibrinogen, prothrombin, and protein S at a constant concentration. APC is added, and clotting is initiated with calcium. Calibration is performed with a pool of plasmas from patients carrying the R506Q Factor V mutation, and its mixtures with normal plasma. Homozygous patients have clotting times of about 70sec. Factor V-Leiden concentration is usually >75% in homozygous patients, 30-60% in heterozygous patients and below 5% in normal. The assay is insensitive to clotting factor deficiencies (II, VII, VIII: C, IX, X), dicoumarol or heparin therapies, and has no interference with lupus anticoagulant (LA). This new assay for Factor V-Leiden can be

  20. Development and optical performance tests of the Si immersed grating demonstrator for E-ELT METIS

    Science.gov (United States)

    Navarro, Ramon; Agócs, Tibor; Venema, Lars; van Amerongen, Aaldert H.; Rodenhuis, Michiel; Hoogeveen, Ruud W. M.; Coppens, Tonny; Brandl, Bernhard R.; Vink, Ramon

    2017-09-01

    Immersed gratings offer several advantages over conventional gratings: more compact spectrograph designs, and by using standard semiconductor industry techniques, higher diffraction-efficiency and lower stray-light can be achieved. We present the optical tests of the silicon immersed grating demonstrator for the Mid-infrared E-ELT Imager and Spectrograph, METIS. We detail the interferometric tests that were done to measure the wavefront-error and present the results of the throughput and stray-light measurements. We also elaborate on the challenges encountered and lessons learned during the immersed grating demonstrator test campaign that helped us to improve the fabrication processes of the grating patterning on the wafer.

  1. Hanford Tanks Initiative alternate retrieval system demonstrations - final report of testing performed by Grey Pilgrim LLC

    Energy Technology Data Exchange (ETDEWEB)

    Berglin, E.J.

    1997-07-24

    A waste retrieval system has been defined to provide a safe and cost-effective solution to the Hanford Tanks Initiative. This system consists of the EMMA robotic manipulator (by GreyPilgrim LLC) and the lightweight Scarifier (by Waterjet Technology, Inc.) powered by a 36-kpsi Jet-Edge diesel powered high pressure pumping system. For demonstration and testing purposes, an air conveyance system was utilized to remove the waste from the simulated tank floor. The EMMA long reach manipulator utilized for this demonstration was 33 feet long. It consisted of 4 hydraulically controlled stages of varying lengths and coupling configurations. T

  2. Analytical and clinical performance of the CDC real time RT-PCR assay for detection and typing of dengue virus.

    Directory of Open Access Journals (Sweden)

    Gilberto A Santiago

    Full Text Available Dengue is an acute illness caused by the positive-strand RNA dengue virus (DENV. There are four genetically distinct DENVs (DENV-1-4 that cause disease in tropical and subtropical countries. Most patients are viremic when they present with symptoms; therefore, RT-PCR has been increasingly used in dengue diagnosis. The CDC DENV-1-4 RT-PCR Assay has been developed as an in-vitro diagnostic platform and was recently approved by the US Food and Drug Administration (FDA for detection of dengue in patients with signs or symptoms of mild or severe dengue. The primers and probes of this test have been designed to detect currently circulating strains of DENV-1-4 from around the world at comparable sensitivity. In a retrospective study with 102 dengue cases confirmed by IgM anti-DENV seroconversion in the convalescent sample, the RT-PCR Assay detected DENV RNA in 98.04% of the paired acute samples. Using sequencing as a positive indicator, the RT-PCR Assay had a 97.92% positive agreement in 86 suspected dengue patients with a single acute serum sample. After extensive validations, the RT-PCR Assay performance was highly reproducible when evaluated across three independent testing sites, did not produce false positive results for etiologic agents of other febrile illnesses, and was not affected by pathological levels of potentially interfering biomolecules. These results indicate that the CDC DENV-1-4 RT-PCR Assay provides a reliable diagnostic platform capable for confirming dengue in suspected cases.

  3. Analytical and Clinical Performance of the CDC Real Time RT-PCR Assay for Detection and Typing of Dengue Virus

    Science.gov (United States)

    Santiago, Gilberto A.; Vergne, Edgardo; Quiles, Yashira; Cosme, Joan; Vazquez, Jesus; Medina, Juan F.; Medina, Freddy; Colón, Candimar; Margolis, Harold; Muñoz-Jordán, Jorge L.

    2013-01-01

    Dengue is an acute illness caused by the positive-strand RNA dengue virus (DENV). There are four genetically distinct DENVs (DENV-1–4) that cause disease in tropical and subtropical countries. Most patients are viremic when they present with symptoms; therefore, RT-PCR has been increasingly used in dengue diagnosis. The CDC DENV-1–4 RT-PCR Assay has been developed as an in-vitro diagnostic platform and was recently approved by the US Food and Drug Administration (FDA) for detection of dengue in patients with signs or symptoms of mild or severe dengue. The primers and probes of this test have been designed to detect currently circulating strains of DENV-1–4 from around the world at comparable sensitivity. In a retrospective study with 102 dengue cases confirmed by IgM anti-DENV seroconversion in the convalescent sample, the RT-PCR Assay detected DENV RNA in 98.04% of the paired acute samples. Using sequencing as a positive indicator, the RT-PCR Assay had a 97.92% positive agreement in 86 suspected dengue patients with a single acute serum sample. After extensive validations, the RT-PCR Assay performance was highly reproducible when evaluated across three independent testing sites, did not produce false positive results for etiologic agents of other febrile illnesses, and was not affected by pathological levels of potentially interfering biomolecules. These results indicate that the CDC DENV-1–4 RT-PCR Assay provides a reliable diagnostic platform capable for confirming dengue in suspected cases. PMID:23875046

  4. Performance Evaluation of a Restored Dimension TACR Assay: An Automated Platform for Measuring the Whole Blood Tacrolimus Concentration.

    Science.gov (United States)

    Ko, Dae-hyun; Jeong, Tae-dong; Lee, Woochang; Chun, Sail; Min, Won-Ki

    2016-01-01

    Monitoring tacrolimus levels is essential for successful organ transplantation. The Dimension TACR (Siemens Healthcare Diagnostics, USA) is an automated platform used to measure tacrolimus concentrations. Recently, the manufacturer started shipping an assay reagent with improved functions. We evaluated the analytical performance of the improved Dimension TACR assay. The precision was evaluated according to the CLSI EP5-A2 guideline. Two levels of control materials were analyzed twice a day in duplicate for 20 days in the precision study. The linearity was evaluated using five levels of mixed calibrators based on the CLSI EP6-A guideline. A comparison study was conducted based on the CLSI EP9-A3 guideline using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ) were evaluated using CLSI EP17-A2. In the precision analyses, the within-run, between-run, and total coefficients of variation were 5.8%, 4.6%, and 8.1% for the low level control and 4.2%, 2.8%, and 5.9% for the high level, respectively. A linear range of 1.18-8.32 ng/mL was observed. In the comparison study, the correlation coefficient, slope, and intercept were 0.9768, 1.118, and -0.251, respectively. The results of the Dimension TACR assay were slightly higher than those of LC-MS/MS (mean bias 0.64 ng/mL). The LoB, LoD, and LoQ were 0.063 ng/mL, 0.408 ng/mL, and 1.15 ng/mL, respectively. The Dimension TACR assay showed good precision and linearity. Although the results using the Dimension TACR assay were higher than those using mass spectrometry, the differences were acceptable clinically.

  5. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS: PHASE II. PRETREATMENT SYSTEM PERFORMANCE MEASUREMENT

    Science.gov (United States)

    The report describes Phase II of a demonstration of the utilization of commercial phosphoric acid fuel cells to recover energy from landfill gas. This phase consisted primarily of the construction and testing of a Gas Pretreatment Unit (GPU) whose function is to remove those impu...

  6. Performance of human fecal anaerobe-associated PCR-based assays in a multi-laboratory method evaluation study

    Science.gov (United States)

    Layton, Blythe A.; Cao, Yiping; Ebentier, Darcy L.; Hanley, Kaitlyn; Ballesté, Elisenda; Brandão, João; Byappanahalli, Muruleedhara N.; Converse, Reagan; Farnleitner, Andreas H.; Gentry-Shields, Jennifer; Gourmelon, Michèle; Lee, Chang Soo; Lee, Jiyoung; Lozach, Solen; Madi, Tania; Meijer, Wim G.; Noble, Rachel; Peed, Lindsay; Reischer, Georg H.; Rodrigues, Raquel; Rose, Joan B.; Schriewer, Alexander; Sinigalliano, Chris; Srinivasan, Sangeetha; Stewart, Jill; ,; Laurie, C.; Wang, Dan; Whitman, Richard; Wuertz, Stefan; Jay, Jenny; Holden, Patricia A.; Boehm, Alexandria B.; Shanks, Orin; Griffith, John F.

    2013-01-01

    A number of PCR-based methods for detecting human fecal material in environmental waters have been developed over the past decade, but these methods have rarely received independent comparative testing in large multi-laboratory studies. Here, we evaluated ten of these methods (BacH, BacHum-UCD, Bacteroides thetaiotaomicron (BtH), BsteriF1, gyrB, HF183 endpoint, HF183 SYBR, HF183 Taqman®, HumM2, and Methanobrevibacter smithii nifH (Mnif)) using 64 blind samples prepared in one laboratory. The blind samples contained either one or two fecal sources from human, wastewater or non-human sources. The assay results were assessed for presence/absence of the human markers and also quantitatively while varying the following: 1) classification of samples that were detected but not quantifiable (DNQ) as positive or negative; 2) reference fecal sample concentration unit of measure (such as culturable indicator bacteria, wet mass, total DNA, etc); and 3) human fecal source type (stool, sewage or septage). Assay performance using presence/absence metrics was found to depend on the classification of DNQ samples. The assays that performed best quantitatively varied based on the fecal concentration unit of measure and laboratory protocol. All methods were consistently more sensitive to human stools compared to sewage or septage in both the presence/absence and quantitative analysis. Overall, HF183 Taqman® was found to be the most effective marker of human fecal contamination in this California-based study.

  7. SNOX demonstration project: Volume 2, Project performance and economics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    The SNOX process, developed by Haldor Topsoe A/S and demonstrated and marketed in North America by ABB Environmental Systems (ABBES), is an innovative process which removes both sulfur dioxide and nitrogen oxides from power plant flue gases. Sulfur dioxide is recovered as high purity, concentrated sulfuric acid and nitrogen oxides are converted to nitrogen gas and water vapor; no additional waste streams are produced. As part of the Clean Coal Technology Program, this project was demonstrated under joint sponsorship from the US Department of Energy, Ohio Coal Development Office, ABBES, Snamprogetti, and Ohio Edison. The project objective was to demonstrate the SO{sub 2}/NO{sub x} reduction efficiencies of the SNOX process on an electric power plant firing high-sulfur Ohio Coal. A 35-MWe demonstration has been conducted on a 108-MWe unit, Ohio Edison`s Niles Plant Unit 2, in Trumbull County, Ohio. The $31.4 million project began site preparation in November 1990 and commenced treating flue gas in March of 1992. A parametric test program has been completed. This report presents a description of the technology, results from the 33 month testing and operation phase, and information from a commercial scale economic evaluation. During the demonstration, the process met or exceeded its design goals of 95% SO{sub 2} removal, 90% NO{sub x} removal, and production of commercial grade (>93.2 wt.%) sulfuric acid. The plant was operated for approximately 8000 hours and produced more than 5600 tons of acid, which was purchased and distributed by a local supplier to end users. Projected economics for a 500 MWe commercial SNOX plant indicate a total capital requirement of 305 $/kW, levelized incremental cost of power at 6.1 mills/kWh, 219 $/ton of SO{sub 2} removed, and 198 $/ton of SO{sub 2}+NO{sub x} removed (all at constant dollars).

  8. GATEWAY Report Brief: SSL Demonstration: Long-Term Evaluation of Indoor Field Performance

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-02-28

    Report brief summarizing a GATEWAY program evaluation of the long-term performance characteristics (chromaticity change, maintained illuminance, and operations and maintenance) of LED lighting systems in four field installations previously documented in separate DOE GATEWAY reports.

  9. Evaluation of safe performance secondary school driver education curriculum demonstration project

    Science.gov (United States)

    1983-06-01

    The primary objective of this Project was to determine the crash reduction potential of a quality, competency-based driver training program known as the Safe Performance Curriculum (SPC). The experimental design called for the random assignment of 18...

  10. GATEWAY Demonstrations: Long-Term Evaluation of SSL Field Performance in Select Interior Projects

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Tess E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Davis, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wilkerson, Andrea M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-02-28

    The GATEWAY program evaluated the long-term performance characteristics (chromaticity change, maintained illuminance, and operations and maintenance) of LED lighting systems in four field installations previously documented in separate DOE GATEWAY reports.

  11. Does Replacing Live Demonstration With Instructional Videos Improve Student Satisfaction and Osteopathic Manipulative Treatment Examination Performance?

    Science.gov (United States)

    Seals, Ryan; Gustowski, Sharon M; Kominski, Carol; Li, Feiming

    2016-11-01

    Instructional videos for osteopathic manipulative treatment (OMT) are a potentially valuable resource for novice learners. To evaluate student experiences and the effectiveness of instructional videos in lieu of live faculty demonstration in a second-year osteopathic manipulative medicine course. Faculty created and produced written instructions and videos for selected Still and facilitated positional release techniques. These materials incorporated curricular design principles and psychomotor skills development strategies. During a second-year OMT skills laboratory session, students used the videos as the primary source for technique demonstration and instruction. Table trainers monitored and assisted students per their request or if errors were observed. Students completed surveys regarding their previous experiences in the OMT skills laboratory sessions (presession survey) and the video-based instructional one (postsession survey). One month after the survey, students were also asked to complete a postexamination survey. Student scores on the skills competency examination were compared with scores from the previous year. Of the 230 students, 162 (70%), 135 (59%), and 86 (37%) responded to the presession, postsession, and postexamination surveys, respectively. The majority of students indicated that the OMT videos helped them feel more prepared (98%) and more confident for their examination (78%), were a valuable addition to learning (97%), and would help increase confidence in using osteopathic manipulative medicine on patients (84%). Two-thirds of students indicated that the videos were superior to faculty demonstration from the stage. Compared with students from the previous year, no statistically significant improvement was noted on the total clinical competency examination scores. The faculty-created videos for teaching OMT techniques did not improve scores on the clinical competency examination but had subjective benefits as part of the OMT laboratory

  12. Strong interferon-gamma mediated cellular immunity to scrub typhus demonstrated using a novel whole cell antigen ELISpot assay in rhesus macaques and humans.

    Directory of Open Access Journals (Sweden)

    Manutsanun Sumonwiriya

    2017-09-01

    Full Text Available Scrub typhus is a febrile infection caused by the obligate intracellular bacterium Orientia tsutsugamushi, which causes significant morbidity and mortality across the Asia-Pacific region. The control of this vector-borne disease is challenging due to humans being dead-end hosts, vertical maintenance of the pathogen in the vector itself, and a potentially large rodent reservoir of unclear significance, coupled with a lack of accurate diagnostic tests. Development of an effective vaccine is highly desirable. This however requires better characterization of the natural immune response of this neglected but important disease. Here we implement a novel IFN-γ ELISpot assay as a tool for studying O. tsutsugamushi induced cellular immune responses in an experimental scrub typhus rhesus macaque model and human populations. Whole cell antigen for O. tsutsugamushi (OT-WCA was prepared by heat inactivation of Karp-strain bacteria. Rhesus macaques were infected intradermally with O. tsutsugamushi. Freshly isolated peripheral blood mononuclear cells (PBMC from infected (n = 10 and uninfected animals (n = 5 were stimulated with OT-WCA, and IFN-γ secreting cells quantitated by ELISpot assay at five time points over 28 days. PBMC were then assayed from people in a scrub typhus-endemic region of Thailand (n = 105 and responses compared to those from a partially exposed population in a non-endemic region (n = 14, and to a naïve population in UK (n = 12. Mean results at Day 0 prior to O. tsutsugamushi infection were 12 (95% CI 0-25 and 15 (2-27 spot-forming cells (SFC/106 PBMC for infected and control macaques respectively. Strong O. tsutsugamushi-specific IFN-γ responses were seen post infection, with ELISpot responses 20-fold higher than baseline at Day 7 (mean 235, 95% CI 200-270 SFC/106 PBMC, 105-fold higher at Day 14 (mean 1261, 95% CI 1,097-1,425 SFC/106 PBMC, 125-fold higher at Day 21 (mean 1,498, 95% CI 1,496-1,500 SFC/106 PBMC and 118-fold higher at

  13. Coinfection of human herpesviruses 6A (HHV-6A and HHV-6B as demonstrated by novel digital droplet PCR assay.

    Directory of Open Access Journals (Sweden)

    Emily C Leibovitch

    Full Text Available The human herpesviruses HHV-6A and HHV-6B have been associated with various neurologic disorders partly due to the detection of elevated viral DNA levels in patients compared to controls. However the reported frequency of these viruses varies widely, likely reflecting differences in PCR methodologies used for detection. Digital droplet PCR (ddPCR is a third generation PCR technology that enables the absolute quantification of target DNA molecules. Mounting evidence of the biological differences between HHV-6A and HHV-6B has led to their recent reclassification as separate species. As it is now especially relevant to investigate each virus, our objectives were to first design a multiplex HHV-6A and HHV-6B ddPCR assay and then to investigate the incidence of HHV-6A and HHV-6B coinfection in samples from healthy donors and patients with MS, a disease in which HHV-6 is thought to play a role. In our assessment of healthy donors, we observed a heretofore-underappreciated high frequency of coinfection in PBMC and serum, and found that our assay precisely detects both HHV-6A and HHV-6B chromosomally integrated virus, which has important implications in clinical settings. Interestingly, upon comparing the saliva from MS patients and healthy donors, we detected a significantly elevated frequency of coinfection in MS saliva; increased detection of HHV-6A in MS patients is consistent with other studies suggesting that this viral species (thought to be more neurotropic than HHV-6B is more prevalent among MS patients compared to healthy donors. As the biology and disease associations between these two viral species differ, identifying and quantifying both species of HHV-6 may provide clinically relevant information, as well as enhance our understanding of the roles of each in health and disease.

  14. Demonstration of Uncertainty Quantification and Sensitivity Analysis for PWR Fuel Performance with BISON

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongbin; Ladd, Jacob; Zhao, Haihua; Zou, Ling; Burns, Douglas

    2015-11-01

    BISON is an advanced fuels performance code being developed at Idaho National Laboratory and is the code of choice for fuels performance by the U.S. Department of Energy (DOE)’s Consortium for Advanced Simulation of Light Water Reactors (CASL) Program. An approach to uncertainty quantification and sensitivity analysis with BISON was developed and a new toolkit was created. A PWR fuel rod model was developed and simulated by BISON, and uncertainty quantification and sensitivity analysis were performed with eighteen uncertain input parameters. The maximum fuel temperature and gap conductance were selected as the figures of merit (FOM). Pearson, Spearman, and partial correlation coefficients were considered for all of the figures of merit in sensitivity analysis.

  15. Demonstrate VERA Core Simulator Performance Improvements L2:PHI.P13.03

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Benjamin S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hamilton, Steven P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jarrett, Michael G. [Univ. of Michigan, Ann Arbor, MI (United States); Kim, Kang Seog [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kochunas, Brendan [Univ. of Michigan, Ann Arbor, MI (United States); Liu, Yuxuan [Univ. of Michigan, Ann Arbor, MI (United States); Palmtag, Scott [Core Physics, Inc., Cary, NC (United States); Salko, Robert K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stimpson, Shane G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Toth, Alex [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yee, Ben [Univ. of Michigan, Ann Arbor, MI (United States)

    2016-08-31

    This report describes the performance improvements made to the VERA Core Simulator (VERA-CS) during FY2016. The development of the VERA Core Simulator has focused on the capability needed to deplete physical reactors and help solve various problems; this capability required the accurate simulation of many operating cycles of a nuclear power plant. The first section of this report introduces two test problems used to assess the run-time performance of VERA-CS using a source dated February 2016. The next section provides a brief overview of the major modifications made to decrease the computational cost. Following the descriptions of the major improvements, the run-time for each improvement is shown. Conclusions on the work are presented, and further follow-on performance improvements are suggested.

  16. Performance-Based Scholarships: Emerging Findings from a National Demonstration. Policy Brief

    Science.gov (United States)

    Patel, Reshma; Richburg-Hayes, Lashawn

    2012-01-01

    Low-income students are at particular risk of not persisting to earn a certificate or degree, often because of competing priorities, financial pressures, and inadequate preparation for college. One form of financial assistance designed explicitly to reward students' academic success is a performance-based scholarship, paid contingent on attaining…

  17. The Development of Accepted Performance Items to Demonstrate Competence in Literary Braille

    Science.gov (United States)

    Lewis, Sandra; D'Andrea, Frances Mary; Rosenblum, L. Penny

    2012-01-01

    Introduction: This research attempted to establish the content validity of several performance statements that are associated with basic knowledge, production, and reading of braille by beginning teachers. Methods: University instructors (n = 21) and new teachers of students with visual impairments (n = 20) who had taught at least 2 braille…

  18. Performance Characteristics of Different Anti-Double-Stranded DNA Antibody Assays in the Monitoring of Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Michael Mahler

    2017-01-01

    Full Text Available Objective. We sought to evaluate different anti-double-stranded DNA assays for their performance characteristics in monitoring disease activity fluctuations in systemic lupus erythematosus (SLE. Methods. 36 active SLE patients were followed monthly. At each study visit (total n=371, blood was collected and disease activity was scored using the SELENA-SLEDAI (excluding anti-dsDNA or complement components and by a physician’s global assessment (PGA. Four anti-dsDNA tests were compared. Linear mixed-effects models with random intercept and fixed slopes were used to evaluate the relationship between the longitudinal fluctuations of disease activity and anti-dsDNA titers. Results. At enrollment, positivity for QUANTA Lite and high-avidity anti-dsDNA assay was both 64% and significantly lower than anti-dsDNA positivity by QUANTA Flash (83% and CLIFT (96%. Linear mixed-effects modeling indicated that the change in clinical SELENA-SLEDAI scores was associated with the titers of all anti-dsDNA with QUANTA Flash yielding the highest marginal R2 (0.15; p<0.01. QUANTA Flash was the only anti-dsDNA assay significantly associated with the change in PGA (marginal R2=0.05; p<0.01. Conclusion. These data indicate that anti-dsDNA antibodies determined by QUANTA Flash have a value in monitoring SLE disease activity.

  19. Calculating inspector probability of detection using performance demonstration program pass rates

    Science.gov (United States)

    Cumblidge, Stephen; D'Agostino, Amy

    2016-02-01

    The United States Nuclear Regulatory Commission (NRC) staff has been working since the 1970's to ensure that nondestructive testing performed on nuclear power plants in the United States will provide reasonable assurance of structural integrity of the nuclear power plant components. One tool used by the NRC has been the development and implementation of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section XI Appendix VIII[1] (Appendix VIII) blind testing requirements for ultrasonic procedures, equipment, and personnel. Some concerns have been raised, over the years, by the relatively low pass rates for the Appendix VIII qualification testing. The NRC staff has applied statistical tools and simulations to determine the expected probability of detection (POD) for ultrasonic examinations under ideal conditions based on the pass rates for the Appendix VIII qualification tests for the ultrasonic testing personnel. This work was primarily performed to answer three questions. First, given a test design and pass rate, what is the expected overall POD for inspectors? Second, can we calculate the probability of detection for flaws of different sizes using this information? Finally, if a previously qualified inspector fails a requalification test, does this call their earlier inspections into question? The calculations have shown that one can expect good performance from inspectors who have passed appendix VIII testing in a laboratory-like environment, and the requalification pass rates show that the inspectors have maintained their skills between tests. While these calculations showed that the PODs for the ultrasonic inspections are very good under laboratory conditions, the field inspections are conducted in a very different environment. The NRC staff has initiated a project to systematically analyze the human factors differences between qualification testing and field examinations. This work will be used to evaluate and prioritize

  20. Demonstration and Validation of Two Coat High Performance Coating System for Steel Structures in Corrosive Environments

    Science.gov (United States)

    2016-12-01

    have many steel structures in the base infrastructure that encounter problems with atmospheric corro- sion. Maintenance and repair costs due to the...of Staff for Installation Man - agement (ACSIM), and the stakeholder was the U.S. Army Installation Management Command (IMCOM). The technical monitors...condition were scuff sanded and repaired , then over coated, and the others were abrasive blasted and repainted. The performance of this coating

  1. Diagnostic performance of automated liquid culture and molecular line probe assay in smear-negative pulmonary tuberculosis.

    Science.gov (United States)

    Kotwal, Aarti; Biswas, Debasis; Raghuvanshi, Shailendra; Sindhwani, Girish; Kakati, Barnali; Sharma, Shweta

    2017-04-01

    The diagnosis of smear-negative pulmonary tuberculosis (PTB) is particularly challenging, and automated liquid culture and molecular line probe assays (LPA) may prove particularly useful. The objective of our study was to evaluate the diagnostic potential of automated liquid culture (ALC) technology and commercial LPA in sputum smear-negative PTB suspects. Spot sputum samples were collected from 145 chest-symptomatic smear-negative patients and subjected to ALC, direct drug susceptibility test (DST) testing and LPA, as per manufacturers' instructions. A diagnostic yield of 26.2% was observed among sputum smear-negative TB suspects with 47.4% of the culture isolates being either INH- and/or rifampicin-resistant. Complete agreement was observed between the results of ALC assay and LPA except for two isolates which demonstrated sensitivity to INH and rifampicin at direct DST but were rifampicin-resistant in LPA. Two novel mutations were also detected among the multidrug isolates by LPA. In view of the diagnostic challenges associated with the diagnosis of TB in sputum smear-negative patients, our study demonstrates the applicability of ALC and LPA in establishing diagnostic evidence of TB.

  2. Performance of in situ chemical oxidation field demonstrations at DOE sites

    Energy Technology Data Exchange (ETDEWEB)

    Cline, S.R.; West, O.R.; Siegrist, R.L.; Holden, W.L.

    1997-04-01

    Researchers at the Oak Ridge National Laboratory (ORNL) have been investigating the use of in situ chemical oxidation to remediate organic contaminants (VOCs, SVOCs, and PCBs) in soils and groundwater at the laboratory and field scales. Field scale design parameters (e.g., oxidant loading rates and oxidant delivery techniques) are often dictated by site conditions (e.g., soil properties and initial contaminant concentrations). Chemical destruction of organic compounds can be accomplished using a variety of oxidants. Recent research has involved field scale in situ chemical oxidation demonstrations using H{sub 2}O{sub 2} and KMnO{sub 4} in conjunction with soil mixing as the oxidant delivery mechanism. A description of some of these fields activities and future field-scale work is presented here.

  3. Demonstration of imaging Fourier Transform Spectrometer (FTS) performance for planetary and geostationary Earth observing

    Science.gov (United States)

    Revercomb, Henry E.; Sromovsky, Lawrence A.; Fry, Patrick M.; Best, Fred A.; LaPorte, Daniel D.

    2001-02-01

    The combination of massively parallel spatial sampling and accurate spectral radiometry offered by imaging FTS makes it extremely attractive for earth and planetary remote sensing. We constructed a breadboard instrument to help assess the potential for planetary applications of small imaging FTS instruments in the 1-5 micrometers range. The results also support definition of the NASA Geostationary Imaging FTS instrument that will make key meteorological and climate observations from geostationary earth orbit. The PIFTS pivoting voice- coil delay scan mechanism, and laser diode metrology system. The interferometer optical output is measured by a commercial IR camera procured from Santa Barbara Focal plane. It uses an InSb 128 by 128 detector array that covers the entire FOV of the instrument when coupled with a 25-mm focal length commercial camera lens. With appropriate lenses and cold filters the instrument can be used from the visible to 5 micrometers . The delay scan is continuos, but slow, covering the maximum range of +/- 0.4 cm in 37.56 sec at a rate of 500 image frames per second. Image exposures are timed to be centered around predicted zero crossings. The design allows for prediction algorithms that account for the most recent fringe rate so that timing jitter produced by scan speed variations can be minimized. Response to a fixed source is linear with exposure time nearly to the point of saturation. Linearity with respect to input variations was demonstrated to within 0.16 percent using a 3-point blackbody calibration. Imaging of external complex scenes was carried out at low and high spectral resolution. These require full complex calibration to remove background contributions that vary dramatically over the instrument FOV. Testing is continuing to demonstrate the precise radiometric accuracy and noise characteristics.

  4. Evaluation of analytical and preliminary clinical performance of Myconostica MycAssay Aspergillus when testing serum specimens for diagnosis of invasive Aspergillosis.

    Science.gov (United States)

    White, P Lewis; Perry, Michael D; Moody, Adrian; Follett, Sarah A; Morgan, Gillian; Barnes, Rosemary A

    2011-06-01

    Diagnosis of invasive aspergillosis remains a significant problem. PCR testing may aid diagnosis but is not yet included in disease-defining criteria due to a lack of standardization of assays and methodologies. This study investigated the analytical performance and the clinical sensitivity and specificity of the Myconostica MycAssay Aspergillus PCR (MAP) assay compared to those of a validated in-house Aspergillus PCR (IHP) test when testing serum specimens. Serum specimens spiked with Aspergillus genomic DNA had a limit of detection equivalent to 5 genomes and a linear dynamic range of 5 to >5 × 10(4) genomes for both assays. When testing clinical specimens (n = 170), the MAP assay had a sensitivity of 60 to 70% and a specificity of 90.5 to 100%. The IHP assay had a sensitivity of 50 to 80% and a specificity of 100%. A commercially available Aspergillus PCR assay provides a methodology that is standardized and reagents that are quality controlled. This facilitates multicenter evaluation of the clinical utility of PCR diagnosis. The performance of the MAP assay is comparable to that of the IHP assay and to those in previously reported studies evaluating commercial tests (galactomannan enzyme-linked immunosorbent assay).

  5. Evaluation of Analytical and Preliminary Clinical Performance of Myconostica MycAssay Aspergillus When Testing Serum Specimens for Diagnosis of Invasive Aspergillosis▿†

    Science.gov (United States)

    White, P. Lewis; Perry, Michael D.; Moody, Adrian; Follett, Sarah A.; Morgan, Gillian; Barnes, Rosemary A.

    2011-01-01

    Diagnosis of invasive aspergillosis remains a significant problem. PCR testing may aid diagnosis but is not yet included in disease-defining criteria due to a lack of standardization of assays and methodologies. This study investigated the analytical performance and the clinical sensitivity and specificity of the Myconostica MycAssay Aspergillus PCR (MAP) assay compared to those of a validated in-house Aspergillus PCR (IHP) test when testing serum specimens. Serum specimens spiked with Aspergillus genomic DNA had a limit of detection equivalent to 5 genomes and a linear dynamic range of 5 to >5 × 104 genomes for both assays. When testing clinical specimens (n = 170), the MAP assay had a sensitivity of 60 to 70% and a specificity of 90.5 to 100%. The IHP assay had a sensitivity of 50 to 80% and a specificity of 100%. A commercially available Aspergillus PCR assay provides a methodology that is standardized and reagents that are quality controlled. This facilitates multicenter evaluation of the clinical utility of PCR diagnosis. The performance of the MAP assay is comparable to that of the IHP assay and to those in previously reported studies evaluating commercial tests (galactomannan enzyme-linked immunosorbent assay). PMID:21450965

  6. Normalized performance and load data for the deepwind demonstrator in controlled conditions

    DEFF Research Database (Denmark)

    Battisti, L.; Benini, E.; Brighenti, A.

    2016-01-01

    Performance and load normalized coefficients, deriving from an experimental campaign of measurements conducted at the large scale wind tunnel of the Politecnico di Milano (Italy), are presented with the aim of providing useful benchmark data for the validation of numerical codes. Rough data......, derived from real scale measurements on a three-bladed Troposkien vertical-axis wind turbine, are manipulated in a convenient form to be easily compared with the typical outputs provided by simulation codes. The here proposed data complement and support the measurements already presented in "Wind Tunnel...

  7. Demonstration and Validation of a High-Performance Floor-Sealant System to Reduce Concrete Degradation

    Science.gov (United States)

    2015-05-01

    The A-A-52624 Type 1 Recycled Antifreeze had no effect on the concrete or sealant system. All the other test chemicals penetrated the sealant...System to Reduce Concrete Degradation Final Report on Project F10-AR02 Co ns tr uc tio n En gi ne er in g R es ea rc h La bo ra to ry Clint...of a High-Performance Floor-Sealant System to Reduce Concrete Degradation Final Report on Project F10-AR02 Clint A. Wilson and Susan A. Drozdz

  8. A Low-Cost, High-Performance System for Fluorescence Lateral Flow Assays

    OpenAIRE

    Linda G. Lee; Nordman, Eric S.; Johnson, Martin D.; Mark F. Oldham

    2013-01-01

    We demonstrate a fluorescence lateral flow system that has excellent sensitivity and wide dynamic range. The illumination system utilizes an LED, plastic lenses and plastic and colored glass filters for the excitation and emission light. Images are collected on an iPhone 4. Several fluorescent dyes with long Stokes shifts were evaluated for their signal and nonspecific binding in lateral flow. A wide range of values for the ratio of signal to nonspecific binding was found, from 50 for R-phyco...

  9. Foundation Heat Exchanger Final Report: Demonstration, Measured Performance, and Validated Model and Design Tool

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Patrick [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Im, Piljae [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

    2012-01-01

    (FHX) has been coined to refer exclusively to ground heat exchangers installed in the overcut around the basement walls. The primary technical challenge undertaken by this project was the development and validation of energy performance models and design tools for FHX. In terms of performance modeling and design, ground heat exchangers in other construction excavations (e.g., utility trenches) are no different from conventional HGHX, and models and design tools for HGHX already exist. This project successfully developed and validated energy performance models and design tools so that FHX or hybrid FHX/HGHX systems can be engineered with confidence, enabling this technology to be applied in residential and light commercial buildings. The validated energy performance model also addresses and solves another problem, the longstanding inadequacy in the way ground-building thermal interaction is represented in building energy models, whether or not there is a ground heat exchanger nearby. Two side-by-side, three-level, unoccupied research houses with walkout basements, identical 3,700 ft{sup 2} floor plans, and hybrid FHX/HGHX systems were constructed to provide validation data sets for the energy performance model and design tool. The envelopes of both houses are very energy efficient and airtight, and the HERS ratings of the homes are 44 and 45 respectively. Both houses are mechanically ventilated with energy recovery ventilators, with space conditioning provided by water-to-air heat pumps with 2 ton nominal capacities. Separate water-to-water heat pumps with 1.5 ton nominal capacities were used for water heating. In these unoccupied research houses, human impact on energy use (hot water draw, etc.) is simulated to match the national average. At House 1 the hybrid FHX/HGHX system was installed in 300 linear feet of excavation, and 60% of that was construction excavation (needed to construct the home). At House 2 the hybrid FHX/HGHX system was installed in 360 feet of

  10. Foundation Heat Exchanger Final Report: Demonstration, Measured Performance, and Validated Model and Design Tool

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Patrick [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Im, Piljae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2012-04-01

    (FHX) has been coined to refer exclusively to ground heat exchangers installed in the overcut around the basement walls. The primary technical challenge undertaken by this project was the development and validation of energy performance models and design tools for FHX. In terms of performance modeling and design, ground heat exchangers in other construction excavations (e.g., utility trenches) are no different from conventional HGHX, and models and design tools for HGHX already exist. This project successfully developed and validated energy performance models and design tools so that FHX or hybrid FHX/HGHX systems can be engineered with confidence, enabling this technology to be applied in residential and light commercial buildings. The validated energy performance model also addresses and solves another problem, the longstanding inadequacy in the way ground-building thermal interaction is represented in building energy models, whether or not there is a ground heat exchanger nearby. Two side-by-side, three-level, unoccupied research houses with walkout basements, identical 3,700 ft{sup 2} floor plans, and hybrid FHX/HGHX systems were constructed to provide validation data sets for the energy performance model and design tool. The envelopes of both houses are very energy efficient and airtight, and the HERS ratings of the homes are 44 and 45 respectively. Both houses are mechanically ventilated with energy recovery ventilators, with space conditioning provided by water-to-air heat pumps with 2 ton nominal capacities. Separate water-to-water heat pumps with 1.5 ton nominal capacities were used for water heating. In these unoccupied research houses, human impact on energy use (hot water draw, etc.) is simulated to match the national average. At House 1 the hybrid FHX/HGHX system was installed in 300 linear feet of excavation, and 60% of that was construction excavation (needed to construct the home). At House 2 the hybrid FHX/HGHX system was installed in 360 feet of

  11. Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport- Demonstration of Approach and Results on Used Fuel Performance Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Adkins, Harold [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Geelhood, Ken [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Koeppel, Brian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bignell, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flores, Gregg [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wang, Jy-An [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sanborn, Scott [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Spears, Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States); Klymyshyn, Nick [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-09-30

    This document addresses Oak Ridge National Laboratory milestone M2FT-13OR0822015 Demonstration of Approach and Results on Used Nuclear Fuel Performance Characterization. This report provides results of the initial demonstration of the modeling capability developed to perform preliminary deterministic evaluations of moderate-to-high burnup used nuclear fuel (UNF) mechanical performance under normal conditions of storage (NCS) and normal conditions of transport (NCT) conditions. This report also provides results from the sensitivity studies that have been performed. Finally, discussion on the long-term goals and objectives of this initiative are provided.

  12. Field Evaluation of Performance of Alere and Cepheid Qualitative HIV Assays for Pediatric Point-of-Care Testing in an Academic Hospital in Soweto, South Africa.

    Science.gov (United States)

    Murray, Tanya Y; Sherman, Gayle G; Nakwa, Firdose; MacLeod, William B; Sipambo, Nosisa; Velaphi, Sithembiso; Carmona, Sergio

    2017-11-01

    Point-of-care (POC) technologies for HIV diagnosis in infants have the potential to overcome logistical challenges that delay treatment initiation and prevent improvements in morbidity and mortality. This study aimed to evaluate the performance of two POC technologies against the current standard-of-care (SOC) laboratory-based assay in South Africa, when operated by nurses in a hospital environment. Children <18 months of age who were treatment naive (excluding prophylaxis) and in whom an HIV PCR test was indicated were eligible for the study. To increase the rate of enrollment of HIV PCR-positive children, HIV-exposed neonates at high risk of mother-to-child transmission and children requiring confirmatory HIV testing were preferentially enrolled. The two POC technologies demonstrated excellent concordance, with 315 (97.8%) results consistent with the SOC result. The POC technologies yielded 102 positive and 220 negative tests each. The SOC assay had 101 positive, 214 negative, 4 indeterminate, 1 invalid, and 2 specimen-rejected results. To include the indeterminate results in sensitivity/specificity calculations, a sensitivity analysis was performed, which yielded a simulated sensitivity of 0.9904 (interquartile range [IQR], 0.9808 to 0.9904) and a specificity of 0.9954 (IQR, 0.9954 to 1.0). This study confirmed that both POC technologies can be successfully used outside the laboratory environment to yield precise sensitivity/specificity values for pediatric, including neonatal, HIV testing. Copyright © 2017 American Society for Microbiology.

  13. GATEWAY Demonstrations: LED System Performance in a Trial Installation--Two Years Later, Yuma Border Patrol, Yuma, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Andrea M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sullivan, Gregory P. [Efficiency Solutions, Inc., Richland, WA (United States); Davis, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-04-01

    Along the Yuma Sector Border Patrol Area in Yuma, Arizona, the GATEWAY program conducted a trial demonstration in which the incumbent quartz metal halide area lighting was replaced with LED at three pole locations at the Yuma Sector Border Patrol Area in Yuma, Arizona. The retrofit was documented to better understand LED technology performance in high-temperature environments. This report follows the GATEWAY Yuma Phase 1.1 Report and reflects LED system results documented two years after the demonstration began.

  14. GATEWAY Demonstrations: LED System Performance in a Trial Installation--One Year Later, Yuma Border Patrol, Yuma, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, A. M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Davis, R. G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-04-01

    Along the Yuma Sector Border Patrol Area in Yuma, Arizona, the GATEWAY program conducted a trial demonstration in which the incumbent quartz metal halide area lighting was replaced with LED at three pole locations at the Yuma Sector Border Patrol Area in Yuma, Arizona. The retrofit was documented to better understand LED technology performance in high-temperature environments. This report follows the GATEWAY Yuma Phase 1.0 Report and reflects LED system results documented one year after the demonstration began.

  15. Demonstrating the potential of yttrium-doped barium zirconate electrolyte for high-performance fuel cells.

    Science.gov (United States)

    Bae, Kiho; Jang, Dong Young; Choi, Hyung Jong; Kim, Donghwan; Hong, Jongsup; Kim, Byung-Kook; Lee, Jong-Ho; Son, Ji-Won; Shim, Joon Hyung

    2017-02-23

    In reducing the high operating temperatures (≥800 °C) of solid-oxide fuel cells, use of protonic ceramics as an alternative electrolyte material is attractive due to their high conductivity and low activation energy in a low-temperature regime (≤600 °C). Among many protonic ceramics, yttrium-doped barium zirconate has attracted attention due to its excellent chemical stability, which is the main issue in protonic-ceramic fuel cells. However, poor sinterability of yttrium-doped barium zirconate discourages its fabrication as a thin-film electrolyte and integration on porous anode supports, both of which are essential to achieve high performance. Here we fabricate a protonic-ceramic fuel cell using a thin-film-deposited yttrium-doped barium zirconate electrolyte with no impeding grain boundaries owing to the columnar structure tightly integrated with nanogranular cathode and nanoporous anode supports, which to the best of our knowledge exhibits a record high-power output of up to an order of magnitude higher than those of other reported barium zirconate-based fuel cells.

  16. Medipix3 Demonstration and understanding of near ideal detector performance for 60 & 80 keV electrons

    CERN Document Server

    Mir, J.A.; MacInnes, R.; Gough, C.; Plackett, R.; Shipsey, I.; Sawada, H.; MacLaren, I.; Ballabriga, R.; Maneuski, D.; O'Shea, V.; McGrouther, D.; Kirkland, A.I.

    2016-01-01

    In our article we report first quantitative measurements of imaging performance for the current generation of hybrid pixel detector, Medipix3, as direct electron detector. Utilising beam energies of 60 & 80 keV, measurements of modulation transfer function (MTF) and detective quantum efficiency (DQE) have revealed that, in single pixel mode (SPM), energy threshold values can be chosen to maximize either the MTF or DQE, obtaining values near to, or even exceeding, those for an ideal detector. We have demonstrated that the Medipix3 charge summing mode (CSM) can deliver simultaneous, near ideal values of both MTF and DQE. To understand direct detection performance further we have characterized the detector response to single electron events, building an empirical model which can predict detector MTF and DQE performance based on energy threshold. Exemplifying our findings we demonstrate the Medipix3 imaging performance, recording a fully exposed electron diffraction pattern at 24-bit depth and images in SPM a...

  17. Diagnostic performance of interferon-gamma releasing assay in HIV-infected patients in China.

    Directory of Open Access Journals (Sweden)

    Yanhua Yu

    Full Text Available BACKGROUND: Active tuberculosis infection represents a very common and significant threat to HIV-infected patients. But measures to accurately detect it are limited. OBJECTIVE: To compare and analyze the diagnostic efficacy of T-SPOT.TB alone and in combination with TST in HIV-infected patients in China. METHOD: TST (tuberculin skin test and T-SPOT.TB were performed on 131 HIV-infected patients admitted in Beijing You'an Hospital and Beijing Ditan Hospital between Oct, 2010 and Jul, 2012, who were initially diagnosed as suspected ATB (active TB. The patients were further categorized into ATB and Not ATB based on clinical and cultural evidences. The performance of TST and T-SPOT.TB were analyzed and compared. RESULTS: The sensitivity and specificity of T-SPOT.TB were 41.3% and 94.6%, respectively, both higher than TST (12.9% and 91.8%. By combining T-SPOT.TB and TST, the sensitivity did not increase, but specificity was elevated to 100%. TST, T-SPOT.TB and their combinations all performed better in patients with extra-pulmonary diseases than with pulmonary disorders. False-positive T-SPOT.TB results were found to be associated with history of prior TB. In addition, concomitant bacterial infections and low CD4 counts were associated with increased ATB risk. CONCLUSIONS: T-SPOT.TB is superior in screening ATB in HIV-infected patients in China over traditional TST. Additional TST would help to confirm a positive T-SPOT.TB result. Both tests work better for patients with extra-pulmonary conditions.

  18. Simultaneous high-performance liquid chromatography assay of acetylsalicylic acid and salicylic acid in film-coated aspirin tablets.

    Science.gov (United States)

    Fogel, J; Epstein, P; Chen, P

    1984-12-28

    A reversed-phase high-performance liquid chromatography (HPLC) method has been developed for the simultaneous assay of acetylsalicylic acid (I) and salicylic acid (II) in film-coated aspirin tablets. As little as 0.1% II (relative to I) can be quantitatively determined. Using a 5-microns octadecylsilane column with water-acetonitrile-phosphoric acid (76:24:0.5) as the mobile phase enabled the chromatographic separation to be completed in 4 min. Due to the slow rate of decomposition of I to II in the extraction solvent, acetonitrile-methanol-phosphoric acid (92:8:0.5), the analysis of many samples was routinely performed by means of automated HPLC equipment. Other compounds (non-aspirin salicylates, caffeine and acetaminophen) were also separated by the chromatographic system.

  19. Performance of a methylation specific real-time PCR assay as a triage test for HPV-positive women.

    Science.gov (United States)

    Schmitz, Martina; Wunsch, Kristina; Hoyer, Heike; Scheungraber, Cornelia; Runnebaum, Ingo B; Hansel, Alfred; Dürst, Matthias

    2017-01-01

    HPV DNA testing as a primary screening marker is being implemented in several countries. Due to the high HPV prevalence in the screening population, effective triage strategies for HPV-positive cases are required. The aim of this study was to evaluate the performance of a methylation-specific real-time PCR  assay (GynTect®) comprising six marker regions as a triage test. An analytical sensitivity of 0.1 ng genomic DNA corresponding to 15 SiHa cells was achieved. Absolute specificity was observed in the presence of 20 ng unmethylated genomic DNA. In a clinical setting, cervical scrapes of 306 women showing abnormal colposcopy were tested for cytology, HPV positivity, and the GynTect markers ASTN1, DLX1, ITGA4, RXFP3, SOX17, and ZNF671. Of all women, histopathological data were available. The overall sensitivity for GynTect to detect CIN3+ was 67.7% (95% CI 57.3%-77.1%) whereas sensitivity was significantly higher for women of age ≥ 30 years (p = 0.04). All cancer cases (n = 5) were detected by GynTect. The overall false positive rate (= 1-specificity) for women with no CIN was 17.4% (95% CI 12.5-23.1%), with a higher proportion among HPV-positive women (24.0%, 95% CI 16.0-33.6%). In a triage screening setting, where all women underwent HPV testing and the HPV positives in addition GynTect testing, the overall sensitivity would slightly decline but specificity would reach the maximum value of 88.7% (95% CI 83.7-92.6%). The GynTect® assay is a robust easy to use assay with high analytical sensitivity and specificity. Moreover, the performance of the assay based on cervical scrapes provides further evidence for the usefulness of methylation markers to detect HPV-positive women with clinically relevant disease.

  20. Non-Tuberculous Mycobacteria and the Performance of Interferon Gamma Release Assays in Denmark

    DEFF Research Database (Denmark)

    Hermansen, Thomas Stig; Thomsen, Vibeke Østergaard; Lillebaek, Troels

    2014-01-01

    BACKGROUND: The QuantiFERON-TB-Gold Test (QFT) is more specific than the Mantoux skin-test to discriminate between Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacterial (NTM) infections. Here we study the performance of the QFT in patients with NTM disease. METHODS: From 2005 to 2011...... region 4% (2/50). None of the 15 children with MAC lymphadenitis had a positive QFT. CONCLUSION: This study is one of the largest assessing IGRAs in patients with NTM disease in a TB low-incidence setting. Our study showed that the QFT holds potential to discriminate between NTM and MTB infections. We...... found no positive IGRA test results among children with NTM not sharing the RD1-region of MTB resulting in a 100% specificity and we suggest that a QFT in a child presenting with cervical lymphadenitis may be helpful in distinguishing NTM from TB lymphadenitis....

  1. The Impact of Computer Simulations as Interactive Demonstration Tools on the Performance of Grade 11 Learners in Electromagnetism

    Science.gov (United States)

    Kotoka, Jonas; Kriek, Jeanne

    2014-01-01

    The impact of computer simulations on the performance of 65 grade 11 learners in electromagnetism in a South African high school in the Mpumalanga province is investigated. Learners did not use the simulations individually, but teachers used them as an interactive demonstration tool. Basic concepts in electromagnetism are difficult to understand…

  2. ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA. USEPA DEMONSTRATION PROJECT AT VALLEY VISTA, AZ FINAL PERFORMANCE EVALUATION REPORT

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at an Arizona Water Company (AWC) facility in Sedona, AZ, commonly referred to as Valley Vista. The objectives of the project were t...

  3. Arsenic Removal from Drinking Water by Adsorptive Media USEPA Demonstration Project at Rimrock AZ Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at the Arizona Water Company (AWC) facility in Rimrock, AZ. The objectives of the project were to evaluate: 1) the effectiveness of ...

  4. Arsenic Removal from Drinking Water by Adsorptive Media USEPA Demonstration Project at Bow, NH Final performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the U.S. Environmental Protection Agency (EPA) arsenic removal treatment technology demonstration project at the White Rock Water Company (WRWC) public water system, a small residential drinking w...

  5. Precision performance at low levels and 99th percentile concentration of the Access AccuTnl assay on two different platforms.

    Science.gov (United States)

    Zaninotto, Martina; Mion, Monica Maria; Novello, Enrica; Moretti, Marco; Delprete, Ernesto; Rocchi, Marco Bruno; Sisti, Davide; Plebani, Mario

    2009-01-01

    Cardiac troponins currently represent the preferred biomarkers for the detection of myocardial necrosis. The objective of the present study was to compare the performance of the Access AccuTnl assay (Beckman Coulter) measured on two different platforms, the UniCel Dxl 800 and the Access 2 (Beckman Coulter). In particular, the serum cardiac troponin I (cTnl) concentration corresponding to 10% coefficient of variation (CV), the cTnl assay minimum detectable concentration (MDC), and the serum cTnl 99th percentile in healthy subjects were calculated. The Access AccuTnl is a paramagnetic particle chemiluminescent immunoassay. Imprecision profiles were determined according to the Clinical and Laboratory Standards Institute EP5-A protocol using serum pools. The MDC was calculated as mean +3 SD of 20 determinations of the zero calibrator during one run. The 99th percentile was determined analyzing serum samples from 679 healthy blood donors (523 males, 156 females; 18-71 years old). cTnl concentrations are given in microg/L. 10% CV values (95% confidence interval, CI) were 0.0577 (0.0467-0.0750) (UniCel Dxl 800) and 0.0486 (0.0255-0.0596) (Access 2). MDC values were 0.011 (UniCel Dxl 800) and 0.012 (Access 2). The 99th percentile (95% CI) value was 0.0340 (0.0298-0.0410). Our data confirm the reliability of the evaluated cTnl assay and demonstrate the comparability of the cTnl values between the platforms studied.

  6. Performance of highly sensitive cardiac troponin T assay to detect ischaemia at PET-CT in low-risk patients with acute coronary syndrome: a prospective observational study.

    Science.gov (United States)

    Morawiec, Beata; Fournier, Stephane; Tapponnier, Maxime; Prior, John O; Monney, Pierre; Dunet, Vincent; Lauriers, Nathalie; Recordon, Frederique; Trana, Catalina; Iglesias, Juan-Fernando; Kawecki, Damian; Boulat, Olivier; Bardy, Daniel; Lamsidri, Sabine; Eeckhout, Eric; Hugli, Olivier; Muller, Olivier

    2017-07-10

    Highly sensitive troponin T (hs-TnT) assay has improved clinical decision-making for patients admitted with chest pain. However, this assay's performance in detecting myocardial ischaemia in a lowrisk population has been poorly documented. To assess hs-TnT assay's performance to detect myocardial ischaemia at positron emission tomography/CT (PET-CT) in low-risk patients admitted with chest pain. Patients admitted for chest pain with a nonconclusive ECG and negative standard cardiac troponin T results at admission and after 6 hours were prospectively enrolled. Their hs-TnT samples were at T0, T2 and T6. Physicians were blinded to hs-TnT results. All patients underwent a PET-CT at rest and during adenosine-induced stress. All patients with a positive PET-CT result underwent a coronary angiography. Forty-eight patients were included. Six had ischaemia at PET-CT. All of them had ≥1 significant stenosis at coronary angiography. Areas under the curve (95% CI) for predicting significant ischaemia at PET-CT using hs-TnT were 0.764 (0.515 to 1.000) at T0, 0.812(0.616 to 1.000) at T2 and 0.813(0.638 to 0.989) at T6. The receiver operating characteristicbased optimal cut-off value for hs-TnT at T0, T2 and T6 needed to exclude significant ischaemia at PET-CT was <4 ng/L. Using this value, sensitivity, specificity, positive and negative predictive values of hs-TnT to predict significant ischaemia were 83%/38%/16%/94% at T0, 100%/40%/19%/100% at T2 and 100%/43%/20%/100% at T6, respectively. Our findings suggest that in low-risk patients, using the hs-TnT assay with a cut-off value of 4 ng/L demonstrates excellent negative predictive value to exclude myocardial ischaemia detection at PET-CT, at the expense of weak specificity and positive predictive value. ClinicalTrials.gov Identifier: NCT01374607. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly

  7. Performance Comparison of the Versant HCV Genotype 2.0 Assay (LiPA) and the Abbott Realtime HCV Genotype II Assay for Detecting Hepatitis C Virus Genotype 6

    Science.gov (United States)

    Yang, Ruifeng; Cong, Xu; Du, Shaocai; Fei, Ran; Rao, Huiying

    2014-01-01

    The Versant HCV genotype 2.0 assay (line probe assay [LiPA] 2.0), based on reverse hybridization, and the Abbott Realtime HCV genotype II assay (Realtime II), based on genotype-specific real-time PCR, have been widely used to analyze hepatitis C virus (HCV) genotypes. However, their performances for detecting HCV genotype 6 infections have not been well studied. Here, we analyzed genotype 6 in 63 samples from the China HCV Genotyping Study that were originally identified as genotype 6 using the LiPA 2.0. The genotyping results were confirmed by nonstructural 5B (NS5B) or core sequence phylogenetic analysis. A total of 57 samples were confirmed to be genotype 6 (51 genotype 6a, 5 genotype 6n, and 1 genotype 6e). Four samples identified as a mixture of genotypes 6 and 4 by the LiPA 2.0 were confirmed to be genotype 3b. The remaining two samples classified as genotype 6 by the LiPA 2.0 were confirmed to be genotype 1b, which were intergenotypic recombinants and excluded from further comparison. In 57 genotype 6 samples detected using the Realtime II version 2.00 assay, 47 genotype 6a samples were identified as genotype 6, one 6e sample was misclassified as genotype 1, and four 6a and five 6n samples yielded indeterminate results. Nine nucleotide profiles in the 5′ untranslated region affected the performances of both assays. Therefore, our analysis shows that both assays have limitations in identifying HCV genotype 6. The LiPA 2.0 cannot distinguish some 3b samples from genotype 6 samples. The Realtime II assay fails to identify some 6a and all non-6a subtypes, and it misclassifies genotype 6e as genotype 1. PMID:25100817

  8. Performance of the Xpert MTB/RIF assay for the diagnosis of pulmonary tuberculosis and rifampin resistance in a low-incidence, high-resource setting.

    Directory of Open Access Journals (Sweden)

    Jason P Rice

    Full Text Available Performance of the Xpert MTB/RIF assay, designed to simultaneously detect Mycobacterium tuberculosis complex (MTBC and rifampin (RIF resistance, has been well documented in low-resource settings with high TB-incidence. However, few studies have assessed its accuracy in low TB incidence settings. We evaluated the performance of Xpert MTB/RIF using clinical sputum specimens routinely collected from suspect pulmonary TB patients over a 4-year time period in San Diego County, California. Xpert MTB/RIF results were compared to acid-fast bacilli (AFB smear microscopy, mycobacterial culture, and phenotypic drug susceptibility testing (DST. Of 751 sputum specimens, 134 (17.8% were MTBC culture-positive and 2 (1.5% were multidrug-resistant (MDR. For the detection of MTBC, Xpert MTB/RIF sensitivity was 89.6% (97.7% and 74.5% in smear-positive and -negative sputa, respectively and specificity was 97.2%; while AFB smear sensitivity and specificity were 64.9% and 77.8%, respectively. Xpert MTB/RIF detected 35 of 47 smear-negative culture-positive specimens, and excluded 124 of 137 smear-positive culture-negative specimens. Xpert MTB/RIF also correctly excluded 99.2% (121/122 of nontuberculous mycobacteria (NTM specimens, including all 33 NTM false-positives by smear microscopy. For the detection of RIF resistance, Xpert MTB/RIF sensitivity and specificity were 100% and 98.3%, respectively. Our findings demonstrate that Xpert MTB/RIF is able to accurately detect MTBC and RIF resistance in routinely collected respiratory specimens in a low TB-incidence setting, with comparable performance to that achieved in high-incidence settings; and suggest that under these conditions the assay has particular utility in detecting smear-negative TB cases, excluding smear-positive patients without MTBC disease, and differentiating MTBC from NTM.

  9. Performance of the Xpert MTB/RIF assay for the diagnosis of pulmonary tuberculosis and rifampin resistance in a low-incidence, high-resource setting.

    Science.gov (United States)

    Rice, Jason P; Seifert, Marva; Moser, Kathleen S; Rodwell, Timothy C

    2017-01-01

    Performance of the Xpert MTB/RIF assay, designed to simultaneously detect Mycobacterium tuberculosis complex (MTBC) and rifampin (RIF) resistance, has been well documented in low-resource settings with high TB-incidence. However, few studies have assessed its accuracy in low TB incidence settings. We evaluated the performance of Xpert MTB/RIF using clinical sputum specimens routinely collected from suspect pulmonary TB patients over a 4-year time period in San Diego County, California. Xpert MTB/RIF results were compared to acid-fast bacilli (AFB) smear microscopy, mycobacterial culture, and phenotypic drug susceptibility testing (DST). Of 751 sputum specimens, 134 (17.8%) were MTBC culture-positive and 2 (1.5%) were multidrug-resistant (MDR). For the detection of MTBC, Xpert MTB/RIF sensitivity was 89.6% (97.7% and 74.5% in smear-positive and -negative sputa, respectively) and specificity was 97.2%; while AFB smear sensitivity and specificity were 64.9% and 77.8%, respectively. Xpert MTB/RIF detected 35 of 47 smear-negative culture-positive specimens, and excluded 124 of 137 smear-positive culture-negative specimens. Xpert MTB/RIF also correctly excluded 99.2% (121/122) of nontuberculous mycobacteria (NTM) specimens, including all 33 NTM false-positives by smear microscopy. For the detection of RIF resistance, Xpert MTB/RIF sensitivity and specificity were 100% and 98.3%, respectively. Our findings demonstrate that Xpert MTB/RIF is able to accurately detect MTBC and RIF resistance in routinely collected respiratory specimens in a low TB-incidence setting, with comparable performance to that achieved in high-incidence settings; and suggest that under these conditions the assay has particular utility in detecting smear-negative TB cases, excluding smear-positive patients without MTBC disease, and differentiating MTBC from NTM.

  10. Performance of mRNA- and DNA-based high-risk human papillomavirus assays in detection of high-grade cervical lesions.

    Science.gov (United States)

    Virtanen, Elina; Kalliala, Ilkka; Dyba, Tadeusz; Nieminen, Pekka; Auvinen, Eeva

    2017-01-01

    The aim was to assess the performance of two commercial assays for the detection of high-risk human papillomavirus (hrHPV): Aptima HPV Assay (Hologic, Inc., Marlborough, MA, USA) which detects mRNA of 14 different hrHPV types, and Hybrid Capture 2 HPV DNA test (HC2; Qiagen, Gaithersburg, MD, USA), which detects the DNA of 13 different hrHPV types. Test performance was compared in the settings of a standard colposcopy clinic, among the regular patient flow. Two separate cervical cell samples for Aptima and HC2 testing were collected from women referred to colposcopy or a cervical follow-up visit. Altogether, 481 paired samples were analyzed and all positive samples were also tested using the Aptima HPV 16 18/45 Genotype Assay. Results from the two assays were compared directly and with stratification by histology and cytology from the same sampling visit. The overall agreement between HC2 and Aptima assays was 92.9% (Kappa coefficient of 0.855). The sensitivity and specificity of the assays in detecting CIN2+ were 92.5 and 58.2% for HC2, and 94.0 and 59.3% for Aptima, respectively. No significant differences between the assays were found (p-values >0.5). Both assays detected all CIN3 (n = 30) and carcinoma (n = 2) cases. The mRNA-based Aptima assay and the extensively studied DNA-based HC2 test performed equally well in detecting high-grade cervical lesions. Our data contribute to the growing evidence base indicating that the mRNA-based Aptima assay could be used for the triage of patients with HPV-associated cervical disease. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

  11. Traceability Assessment and Performance Evaluation of Results for Measurement of Abbott Clinical Chemistry Assays on 4 Chemistry Analyzers.

    Science.gov (United States)

    Lim, Jinsook; Song, Kyung Eun; Song, Sang Hoon; Choi, Hyun-Jung; Koo, Sun Hoe; Kwon, Gye Choel

    2016-05-01

    -The traceability of clinical results to internationally recognized and accepted reference materials and reference measurement procedures has become increasingly important. Therefore, the establishment of traceability has become a mandatory requirement for all in vitro diagnostics devices. -To evaluate the traceability of the Abbott Architect c8000 system (Abbott Laboratories, Abbott Park, Illinois), consisting of calibrators and reagents, across 4 different chemistry analyzers, and to evaluate its general performance on the Toshiba 2000FR NEO (Toshiba Medical Systems Corporation, Otawara-shi, Tochigi-ken, Japan). -For assessment of traceability, secondary reference materials were evaluated 5 times, and then bias was calculated. Precision, linearity, and carryover were determined according to the guidelines of the Clinical and Laboratory Standards Institute (Wayne, Pennsylvania). -The biases from 4 different analyzers ranged from -2.33% to 2.70% on the Toshiba 2000FR NEO, -2.33% to 5.12% on the Roche Hitachi 7600 (Roche Diagnostics International, Basel, Switzerland), -0.93% to 2.87% on the Roche Modular, and -2.16% to 2.86% on the Abbott Architect c16000. The total coefficients of variance of all analytes were less than 5%. The coefficients of determination (R(2)) were more than 0.9900. The carryover rate ranged from -0.54% to 0.17%. -Abbott clinical chemistry assays met the performance criteria based on desirable biological variation for precision, bias, and total error. They also showed excellent linearity and carryover. Therefore, these clinical chemistry assays were found to be accurate and reliable and are readily applicable on the various platforms used in this study.

  12. A multi-centre evaluation of the intra-assay and inter-assay variation of commercial and in-house anti-cardiolipin antibody assays.

    Science.gov (United States)

    Wong, Richard; Favaloro, Emmanuel; Pollock, Wendy; Wilson, Robert; Hendle, Michelle; Adelstein, Stephen; Baumgart, Karl; Homes, Paul; Smith, Stuart; Steele, Richard; Sturgess, Allan; Gillis, David

    2004-04-01

    To assess the intra-assay (intra-run) and inter-assay (inter-run) variation of commercial and in-house IgG and IgM anti-cardiolipin antibody (aCL) assays/kits, and to determine an appropriate maximum value for inclusion in consensus guidelines. Frozen aliquots of two patient specimens and one commercial control were sent to nine laboratories for the evaluation of eight commercial kits and one in-house assay. Intra-assay and inter-assay evaluations were performed with all three samples for IgG aCL, and one patient specimen for IgM aCL. The IgG and IgM aCL values varied considerably between the nine assays/kits. The majority of assays/kits demonstrated less than 20% intra-assay and inter-assay variation, with lower intra-assay and inter-assay variation observed with the commercial control. Single calibrator assays were not consistently associated with higher inter-assay variation than multi-point calibrator assays. An inter-assay coefficient of variation of 20% was determined to be an appropriate maximum value for inclusion in the Australasian aCL Working Party consensus guidelines. Improved standardisation between different assay/kits is still required.

  13. Clean Coal Technology III: 10 MW Demonstration of Gas Suspension Absorption final project performance and economics report

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, F.E.

    1995-08-01

    The 10 MW Demonstration of the Gas Suspension Absorption (GSA) program is a government and industry co-funded technology development. The objective of the project is to demonstrate the performance of the GSA system in treating a 10 MW slipstream of flue gas resulting from the combustion of a high sulfur coal. This project involves design, fabrication, construction and testing of the GSA system. The Project Performance and Economics Report provides the nonproprietary information for the ``10 MW Demonstration of the Gas Suspension Absorption (GSA) Project`` installed at Tennessee Valley Authority`s (TVA) Shawnee Power Station, Center for Emissions Research (CER) at Paducah, Kentucky. The program demonstrated that the GSA flue-gas-desulfurization (FGD) technology is capable of achieving high SO{sub 2} removal efficiencies (greater than 90%), while maintaining particulate emissions below the New Source Performance Standards (NSPS), without any negative environmental impact (section 6). A 28-day test demonstrated the reliability and operability of the GSA system during continuous operation. The test results and detailed discussions of the test data can be obtained from TVA`s Final Report (Appendix A). The Air Toxics Report (Appendix B), prepared by Energy and Environmental Research Corporation (EERC) characterizes air toxic emissions of selected hazardous air pollutants (HAP) from the GSA process. The results of this testing show that the GSA system can substantially reduce the emission of these HAP. With its lower capital costs and maintenance costs (section 7), as compared to conventional semi-dry scrubbers, the GSA technology commands a high potential for further commercialization in the United States. For detailed information refer to The Economic Evaluation Report (Appendix C) prepared by Raytheon Engineers and Constructors.

  14. A model for the training effects in swimming demonstrates a strong relationship between parasympathetic activity, performance and index of fatigue.

    Directory of Open Access Journals (Sweden)

    Sébastien Chalencon

    Full Text Available Competitive swimming as a physical activity results in changes to the activity level of the autonomic nervous system (ANS. However, the precise relationship between ANS activity, fatigue and sports performance remains contentious. To address this problem and build a model to support a consistent relationship, data were gathered from national and regional swimmers during two 30 consecutive-week training periods. Nocturnal ANS activity was measured weekly and quantified through wavelet transform analysis of the recorded heart rate variability. Performance was then measured through a subsequent morning 400 meters freestyle time-trial. A model was proposed where indices of fatigue were computed using Banister's two antagonistic component model of fatigue and adaptation applied to both the ANS activity and the performance. This demonstrated that a logarithmic relationship existed between performance and ANS activity for each subject. There was a high degree of model fit between the measured and calculated performance (R(2=0.84±0.14,p<0.01 and the measured and calculated High Frequency (HF power of the ANS activity (R(2=0.79±0.07, p<0.01. During the taper periods, improvements in measured performance and measured HF were strongly related. In the model, variations in performance were related to significant reductions in the level of 'Negative Influences' rather than increases in 'Positive Influences'. Furthermore, the delay needed to return to the initial performance level was highly correlated to the delay required to return to the initial HF power level (p<0.01. The delay required to reach peak performance was highly correlated to the delay required to reach the maximal level of HF power (p=0.02. Building the ANS/performance identity of a subject, including the time to peak HF, may help predict the maximal performance that could be obtained at a given time.

  15. Human skin melanocyte migration towards stromal cell-derived factor-1α demonstrated by optical real-time cell mobility assay: modulation of their chemotactic ability by α-melanocyte-stimulating hormone.

    Science.gov (United States)

    Yamauchi, Akira; Hadjur, Christophe; Takahashi, Tadahito; Suzuki, Itaru; Hirose, Kunitaka; Mahe, Yann F

    2013-10-01

    To identify potential regulators of normal human melanocyte behaviour, we have developed an in vitro human melanocyte migration assay, using the optically accessible, real-time cell motility assay device TAXIScan. Coating of the glass surface with an extracellular matrix that served as scaffolding molecule was essential to demonstrate efficient melanocyte migration. Among several chemokines tested, stromal cell-derived factor (SDF)-1α/CXCL12 was the most effective driver of human normal skin melanocytes. Incubation of melanocytes with α-melanocyte-stimulating hormone (MSH) before the assay specifically enhanced CXCR4 expression and consequently chemotaxis towards SDF-1α/CXCL12. These results suggest that α-MSH acts on melanocytes to produce melanin as well as stimulates the cells to migrate to the site where they work through CXCR4 up-regulation, which is a new dynamic mode of action of α-MSH on melanocyte physiology. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Performance of PCR-REBA assay for screening and identifying pathogens directly in whole blood of patients with suspected sepsis.

    Science.gov (United States)

    Wang, H-Y; Kim, J; Kim, S; Park, S D; Kim, H Y; Choi, H K; Uh, Y; Lee, H

    2015-11-01

    Rapid and accurate identification of a broad range of bacterial and fungal pathogens is the key to successful management of patients with bloodstream infections (BSIs). The aim of this study was to evaluate the diagnostic performance of PCR-REBA Sepsis-ID test for the detection of BSIs pathogens. EDTA anticoagulated blood for REBA Sepsis-ID assay and blood culture samples from 882 patients with suspected sepsis were simultaneously collected from January 2014 to December 2014. Of 115 patients with positive blood culture, 64 (55·7%) were Gram-positive bacteria, 35 (30·4%) were Gram-negative bacteria, 1 (0·9%) was Candida albicans and 15 (13·0%) were polymicrobial infections. The concordance rate of blood culture system and PCR-REBA Sepsis ID test was 83·0% (95% confidence interval (CI), 79·8-84·8, P detection (P = 0·002). The results of this study suggested that PCR-REBA may be helpful when added to blood culture in the diagnosis and management of sepsis. PCR-REBA Sepsis-ID test is a useful tool for the rapid identification of pathogenic isolates in whole blood to ensure adequate treatment for the causative agents of BSIs. Although the cost of molecular diagnostic assays is higher than the cost of conventional methods, clinical and economic cost-benefit analysis is still needed. PCR-REBA may provide essential information for accelerating therapeutic decisions to ensure effective treatment with antibiotics in the acute phase of pathogen infection. © 2015 The Society for Applied Microbiology.

  17. Hybrid Capture 2 and cobas human papillomavirus assays perform similarly on SurePath samples from women with abnormalities.

    Science.gov (United States)

    Fornari, D; Rebolj, M; Bjerregård, B; Lidang, M; Christensen, I; Høgdall, E; Bonde, J

    2016-08-01

    In two laboratories (Departments of Pathology, Copenhagen University Hospitals of Herlev and Hvidovre), we compared cobas and Hybrid Capture 2 (HC2) human papillomavirus (HPV) assays using SurePath® samples from women with atypical squamous cells of undetermined significance (ASCUS) at ≥30 years and women after treatment of cervical intraepithelial neoplasia (CIN). Samples from 566 women with ASCUS and 411 women after treatment were routinely tested with HC2 and, thereafter, with cobas. Histological outcomes were retrieved from the Danish Pathology Data Base. We calculated the overall agreement between the assays, and compared their sensitivity and specificity for ≥CIN2. In women with ASCUS, HC2 and cobas testing results were similar in the two laboratories. The overall agreement was 91% (95% CI, 88-93). After CIN treatment, the overall agreement was 87% (95% CI, 82-91) at Herlev and 88% (95% CI, 82-92) at Hvidovre. There were no significant differences in the sensitivity for ≥CIN2 between the two tests [Herlev, 98% (95% CI, 89-100) for HC2 versus 94% (95% CI, 82-99) for cobas; Hvidovre, 97% (95% CI, 83-100) for HC2 versus 100% (95% CI, 88-100) for cobas]. The differences were also not significant for specificity. In women with the studied well-defined clinical indications for HPV testing, cobas and HC2 performed similarly in terms of the detection of HPV and ≥CIN2. © 2016 The Authors. Cytopathology Published by John Wiley & Sons Ltd.

  18. Performance characteristics of the new ARCHITECT Toxo IgG and Toxo IgG Avidity assays.

    Science.gov (United States)

    Sickinger, Eva; Gay-Andrieu, Françoise; Jonas, Gesa; Schultess, Jan; Stieler, Myriam; Smith, Darwin; Hausmann, Michael; Stricker, René; Stricker, Reto; Dhein, Jens; Braun, Hans-Bertram

    2008-11-01

    The ARCHITECT Toxo IgG and IgG Avidity assays have been developed as a fully automated panel for immune status determination and acute infection exclusion. Resolved relative specificity and sensitivity of the ARCHITECT Toxo IgG assay were 99.6% (1359/1365) and 99.7% (1096/1099) as determined on pregnant females, blood donor, and diagnostic specimens. Seroconversion sensitivity of the ARCHITECT assay was comparable with the AxSYM Toxo IgG assay. The ARCHITECT Toxo IgG Avidity assay detected 100.0% (124/124) of acute phase specimens (ARCHITECT Toxo IgG assay, using recombinant antigens, showed excellent specificity and sensitivity for acute phase as well as past infection specimens. The ARCHITECT Toxoplasmosis panel can be reliably used to rule out acute Toxoplasma gondii infection in pregnant women.

  19. High-performance liquid chromatographic assay of parabens in wash-off cosmetic products and foods using chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qunlin [Department of Chemistry, University of Science and Technology of China, Jinzai Road 96, Hefei, Anhui 230026 (China); Lian Mei [Department of Chemistry, University of Science and Technology of China, Jinzai Road 96, Hefei, Anhui 230026 (China); Liu Lijuan [Department of Chemistry, University of Science and Technology of China, Jinzai Road 96, Hefei, Anhui 230026 (China); Cui Hua [Department of Chemistry, University of Science and Technology of China, Jinzai Road 96, Hefei, Anhui 230026 (China)]. E-mail: hcui@ustc.edu.cn

    2005-04-29

    A new method for the simultaneous determination of parabens including methylparaben, ethylparaben, propylparaben, and butylparaben by high-performance liquid chromatography (HPLC) coupled with chemiluminescence detection was developed. The procedure was based on the chemiluminescent enhancement by parabens of the cerium(IV)-rhodamine 6G system in the strong sulfuric acid medium. The good separation of parabens was carried out with an isocratic elution using a mixture of methanol and water (60:40, v/v) within 8.5 min. Under the optimized conditions, a linear working range extends three orders of magnitude with the relative standard deviations of intra- and inter-day precision below 4.5%, and the detection limits were 1.9 x 10{sup -9}, 2.7 x 10{sup -9}, 3.9 x 10{sup -9}, and 5.3 x 10{sup -9} g ml{sup -1} for methylparaben, ethylparaben, propylparaben, and butylparaben, respectively. The chemiluminescence reaction was well compatible with the mobile phase of high-performance liquid chromatography. The proposed method has been successfully applied to the assay of parabens in wash-off cosmetic products and foods with the minimal sample preparation.

  20. Performance of the CLSI Carba NP and the Rosco Carb Screen Assays Using North American Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa Isolates.

    Science.gov (United States)

    Gallagher, Lauren C; Roundtree, Sylvester S; Lancaster, Diana P; Rudin, Susan D; Bard, Jennifer Dien; Roberts, Amity L; Marshall, Steven H; Bonomo, Robert A; Sullivan, Kaede V

    2015-10-01

    This study compared the performance of the Carba NP assay, published by the Clinical and Laboratory Standards Institute, and the Rosco Rapid Carb Screen kit. Carba NP had superior sensitivity, but both assays required an increased inoculum to detect carbapenemase production in isolates with blaNDM, blaIMP, and blaOXA-48. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Performance of the Cobas® Influenza A/B Assay for Rapid Pcr-Based Detection of Influenza Compared to Prodesse ProFlu+ and Viral Culture

    Science.gov (United States)

    Chen, L.; Tian, Y.; Chen, S.; Liesenfeld, O.

    2015-01-01

    Rapid and accurate diagnosis of influenza is important for patient management and infection control. We determined the performance of the cobas® Influenza A/B assay, a rapid automated nucleic acid assay performed on the cobas® Liat System for qualitative detection of influenza A and influenza B from nasopharyngeal (NP) swab specimens. Retrospective frozen and prospectively collected NP swabs from patients with signs and symptoms of influenza collected in universal transport medium (UTM) were tested at multiple sites including CLIA-waived sites using the cobas® Influenza A/B assay. Results were compared to the Prodesse Pro-Flu+ assay and to viral culture. Compared to the Prodesse ProFlu+ Assay, sensitivities of the cobas® Influenza A/B assay for influenza A and B were 97.7 and 98.6%, respectively; specificity was 99.2 and 99.4%. Compared to viral culture, the cobas® Influenza A/B assay showed sensitivities of 97.5 and 96.9% for influenza virus A and B, respectively; specificities were 97.9% for both viruses. Polymerase chain reaction (PCR)/sequencing showed that the majority of viral culture negative but cobas® Influenza A/B positive results were true positive results, indicating that the cobas® Influenza A/B assay has higher sensitivity compared to viral culture. In conclusion, the excellent accuracy, rapid time to result, and remarkable ease of use make the cobas® Influenza A/B nucleic acid assay for use on the cobas® Liat System a highly suitable point-of-care solution for the management of patients with suspected influenza A and B infection. PMID:26716012

  2. Initial demonstration of the NRC`s capability to conduct a performance assessment for a High-Level Waste Repository

    Energy Technology Data Exchange (ETDEWEB)

    Codell, R.; Eisenberg, N.; Fehringer, D.; Ford, W.; Margulies, T.; McCartin, T.; Park, J.; Randall, J.

    1992-05-01

    In order to better review licensing submittals for a High-Level Waste Repository, the US Nuclear Regulatory Commission staff has expanded and improved its capability to conduct performance assessments. This report documents an initial demonstration of this capability. The demonstration made use of the limited data from Yucca Mountain, Nevada to investigate a small set of scenario classes. Models of release and transport of radionuclides from a repository via the groundwater and direct release pathways provided preliminary estimates of releases to the accessible environment for a 10,000 year simulation time. Latin hypercube sampling of input parameters was used to express results as distributions and to investigate model sensitivities. This methodology demonstration should not be interpreted as an estimate of performance of the proposed repository at Yucca Mountain, Nevada. By expanding and developing the NRC staff capability to conduct such analyses, NRC would be better able to conduct an independent technical review of the US Department of Energy (DOE) licensing submittals for a high-level waste (HLW) repository. These activities were divided initially into Phase 1 and Phase 2 activities. Additional phases may follow as part of a program of iterative performance assessment at the NRC. The NRC staff conducted Phase 1 activities primarily in CY 1989 with minimal participation from NRC contractors. The Phase 2 activities were to involve NRC contractors actively and to provide for the transfer of technology. The Phase 2 activities are scheduled to start in CY 1990, to allow Sandia National Laboratories to complete development and transfer of computer codes and the Center for Nuclear Waste Regulatory Analyses (CNWRA) to be in a position to assist in the acquisition of the codes.

  3. Highly sensitive reversed-phase high-performance liquid chromatography assay for the detection of Tamm-Horsfall protein in human urine.

    Science.gov (United States)

    Akimoto, Masaru; Hokazono, Eisaku; Ota, Eri; Tateishi, Takiko; Kayamori, Yuzo

    2016-01-01

    Tamm-Horsfall protein (also known as uromodulin) is the most abundant urinary protein in healthy individuals. Since initially characterized by Tamm and Horsfall, the amount of urinary excretion and structural mutations of Tamm-Horsfall protein is associated with kidney diseases. However, currently available assays for Tamm-Horsfall protein, which are mainly enzyme-linked immunosorbent assay-based, suffer from poor reproducibility and might give false negative results. We developed a novel, quantitative assay for Tamm-Horsfall protein using reversed-phase high-performance liquid chromatography. A precipitation pretreatment avoided urine matrix interference and excessive sample dilution. High-performance liquid chromatography optimization based on polarity allowed excellent separation of Tamm-Horsfall protein from other major urine components. Our method exhibited high precision (based on the relative standard deviations of intraday [≤2.77%] and interday [≤5.35%] repetitions). The Tamm-Horsfall protein recovery rate was 100.0-104.2%. The mean Tamm-Horsfall protein concentration in 25 healthy individuals was 31.6 ± 18.8 mg/g creatinine. There was a strong correlation between data obtained by high-performance liquid chromatography and enzyme-linked immunosorbent assay (r = 0.906), but enzyme-linked immunosorbent assay values tended to be lower than high-performance liquid chromatography values at low Tamm-Horsfall protein concentrations. The high sensitivity and reproducibility of our Tamm-Horsfall protein assay will reduce the number of false negative results of the sample compared with enzyme-linked immunosorbent assay. Moreover, our method is superior to other high-performance liquid chromatography methods, and a simple protocol will facilitate further research on the physiological role of Tamm-Horsfall protein. © The Author(s) 2015.

  4. Performance evaluation of the Aptima HSV-1 and 2 assay for the detection of HSV in cutaneous and mucocutaneous lesion specimens.

    Science.gov (United States)

    Sam, Soya S; Caliendo, Angela M; Ingersoll, Jessica; Abdul-Ali, Deborah; Kraft, Colleen S

    2017-12-13

    Timely and precise laboratory diagnosis of Herpes simplex viruses (HSV) is required to guide clinical management. The study evaluated limit of detection (LOD) and performance characteristics of the Aptima HSV 1 & 2 assay in comparison to four assays. The multi-center study compared qualitative detection of HSV-1 and 2 by the Aptima HSV-1 and 2 assay (Hologic) to ELVIS culture, Lyra Direct (Quidel), AmpliVue (Quidel) and a laboratory developed test (LDT). LOD was performed using VTM and STM diluted viral concentrations and clinical performance was evaluated using 505 swab specimens. The Aptima LOD studies performed showed a lower detection limit for STM specimens as 1450 copies/mL and 430 copies/mL for HSV1 and HSV-2 respectively; the LOD for VTM specimens was 9370 copies/mL and 8045 copies/mL for HSV-1 and HSV-2 respectively. When the assays were analyzed based on the positive consensus result established the Aptima had 95% of percent positive agreement (PPA) and 100% negative percent agreement (NPA) for the HSV-1. For the HSV-2, the PPA and NPA for Aptima were 96% and 100% respectively. AmpliVue had 1.8% invalid rate, while Lyra had no invalid results but an inhibition rate of 0.8%. Aptima and LDT did not have any invalid or inhibited results. The results indicate that the Aptima HSV-1 & 2 assay is sensitive and the performance characteristics of the Aptima assay is comparable to the assays analyzed for the detection and differentiation of HSV-1 and 2 from cutaneous and mucocutaneous lesions. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Performance of the high-sensitivity troponin assay in diagnosing acute myocardial infarction: systematic review and meta-analysis

    Science.gov (United States)

    Al-Saleh, Ayman; Alazzoni, Ashraf; Al Shalash, Saleh; Ye, Chenglin; Mbuagbaw, Lawrence; Thabane, Lehana; Jolly, Sanjit S.

    2014-01-01

    Background High-sensitivity cardiac troponin assays have been adopted by many clinical centres worldwide; however, clinicians are uncertain how to interpret the results. We sought to assess the utility of these assays in diagnosing acute myocardial infarction (MI). Methods We carried out a systematic review and meta-analysis of studies comparing high-sensitivity with conventional assays of cardiac troponin levels among adults with suspected acute MI in the emergency department. We searched MEDLINE, EMBASE and Cochrane databases up to April 2013 and used bivariable random-effects modelling to obtain summary parameters for diagnostic accuracy. Results We identified 9 studies that assessed the use of high-sensitivity troponin T assays (n = 9186 patients). The summary sensitivity of these tests in diagnosing acute MI at presentation to the emergency department was estimated to be 0.94 (95% confidence interval [CI] 0.89–0.97); for conventional tests, it was 0.72 (95% CI 0.63–0.79). The summary specificity was 0.73 (95% CI 0.64–0.81) for the high-sensitivity assay compared with 0.95 (95% CI 0.93–0.97) for the conventional assay. The differences in estimates of the summary sensitivity and specificity between the high-sensitivity and conventional assays were statistically significant (p sensitivity troponin I assays and showed similar results. Interpretation Used at presentation to the emergency department, the high-sensitivity cardiac troponin assay has improved sensitivity, but reduced specificity, compared with the conventional troponin assay. With repeated measurements over 6 hours, the area under the curve is similar for both tests, indicating that the major advantage of the high-sensitivity test is early diagnosis. PMID:25295240

  6. Comparison between Corchorus olitorius and Corchorus capsularis at GUS histochemical assay performance for tissue culture independent transformation

    Directory of Open Access Journals (Sweden)

    REDUANUL BARI

    2015-08-01

    Full Text Available Tissue culture independent transformation technique in crops is relatively new and of popular interest due to its faster approach and efficiency. The prospect of this technique in the production of transgenic Jute plants with new genetic properties is promising. In the present study, two varieties of each of Corchorus olitorius (var. O-72 and var. OM-1 and C. capsularis (var. CVL-1 and var. BJC-83 were used to observe their transformation ability. Agrobacterium tumefaciens strain LBA4404 was used for transformation, which harbors a binary vector pBI121 containing selectable marker gene nptII, gus (β-glucuronidase reporter gene and a stress tolerance gene GLY-1. The young shoot tip of the seedlings (20-22 cm was infected with the bacterial culture. The young leaves were collected after 20-21 days of bacterial culture transformation and thereafter histochemical GUS assay was performed. In the putatively transformed regions of the plants, gus reporter gene was expressed showing blue color in the tissues. Non-transformed plants did not show any color. Among the varieties, the percentage of matured plants showing GUS activity was higher in C. olitorious var. O-72 (80.66% and OM-1 (73.33% compared to C. capsularis var. BJC-83 (32.50% and CVL-1 (40.00%. The result of the study provides an indication that efficiency of transformation by using tissue culture independent direct genetic transformation for the two species of Jute may differ significantly.

  7. Separation and Quantification of Eight Antidiabetic Drugs on A High-Performance Liquid Chromatography: Its Application to Human Plasma Assay

    Science.gov (United States)

    Lakshmi, Karunanidhi S.; Rajesh, Tirumala

    2011-01-01

    An analytical method based on isocratic reverse phase high-performance liquid chromatography was developed and validated for the separation and quantification of eight antidiabetic drugs: rosiglitazone, pioglitazone, glipizide, gliclazide, repaglinide, nateglinide, glibenclamide, and glimepiride for their application in human plasma assay. Metformin is used as internal standard. Analysis was done on Onyx monolithic C18 column (100 × 4.6 mm, i.d., 5 μm) using a mixture of 0.05% formic acid in water and methanol in the ratio of 42 : 58 (v/v) fixed at a flow rate of 0.5 mL/min, and they were monitored at 234 nm. Separation was achieved in less than 20 min. The calibration curves were linear in the range of 50–2000 ng/mL. The method was validated for its recovery, intra- and interday precision, stability, specificity, and selectivity. Plasma samples were prepared using solid-phase extraction of analytes. Hence, the developed method was found to be suitable for the routine analysis of selected antidiabetic drugs in biological matrices. PMID:22389851

  8. Development and performance assessment of a qualitative SYBR® green real-time PCR assay for the detection of Aspergillus versicolor in indoor air.

    Science.gov (United States)

    Libert, X; Chasseur, C; Bladt, S; Packeu, A; Bureau, F; Roosens, N H; De Keersmaecker, S C J

    2015-09-01

    Currently, contamination of indoor environment by fungi and molds is considered as a public health problem. The monitoring of indoor airborne fungal contamination is a common tool to help understanding the link between fungi in houses and respiratory problems. Classical analytical monitoring methods, based on cultivation and microscopic identification, depend on the growth of the fungi. Consequently, they are biased by difficulties to grow some species on certain culture media and under certain conditions or by noncultivable or dead fungi that can consequently not be identified. However, they could have an impact on human health as they might be allergenic. Since molecular methods do not require a culture step, they seem an excellent alternative for the monitoring of indoor fungal contaminations. As a case study, we developed a SYBR® green real-time PCR-based assay for the specific detection and identification of Aspergillus versicolor, which is frequently observed in indoor environment and known to be allergenic. The developed primers amplify a short region of the internal transcribed spacer 1 from the 18S ribosomal DNA complex. Subsequently, the performance of this quantitative polymerase chain reaction (qPCR) method was assessed using specific criteria, including an evaluation of the selectivity, PCR efficiency, dynamic range, and repeatability. The limit of detection was determined to be 1 or 2 copies of genomic DNA of A. versicolor. In order to demonstrate that this SYBR® green qPCR assay is a valuable alternative for monitoring indoor fungal contamination with A. versicolor, environmental samples collected in contaminated houses were analyzed and the results were compared to the ones obtained with the traditional methods.

  9. A demonstration project of interdisciplinary dairy herd extension advising funded by industry and users. 2. Impact on herd performance.

    Science.gov (United States)

    Peters, R R; Cassel, E K; Varner, M A; Douglass, L W; Vough, L R; Manspeaker, J E; Stewart, L E; Wysong, J W; Eickelberger, R C

    1994-08-01

    The objectives of this 24-herd, demonstration project of extension advising were to measure the impact of integrated problem solving on measures of DHI performance for 2 yr during and 2 yr after the project. During project advising, increases in rolling herd average milk and fat yields and 3.5% FCM were similar for project and state herds. When rolling herd average for milk yield for state herds was adjusted for two USDA milk reduction programs, milk yield of project herds was estimated to have increased 434 lb more per cow than that of DHI state herds. Compared with state DHI trends, project producers significantly improved in percentage of low SCC, days open, and age at first calving. Two years postproject, DHI milk yield declined for project and state herds, probably because of drought. Demonstration herds did not outperform state DHI herd average in milk yield or in other efficiency parameters during the 2-yr postproject. The extension advising in the demonstration project had the most positive impact on management of low ranking herds. Only low ranking herds had an advantage in rate of improvement, compared with high ranking herds, in rolling herd average for milk yield during and after the project and in SCC and days open during the project. Gains by managers of herds ranking low and in the middle in DHI parameters were generally lost or declining postproject.

  10. FY16 Status of Immersion Phased Array Ultrasonic Probe Development and Performance Demonstration Results for Under Sodium Viewing

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Aaron A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chamberlin, Clyde E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Edwards, Matthew K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hagge, Tobias J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hughes, Michael S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Larche, Michael R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mathews, Royce A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Neill, Kevin J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Prowant, Matthew S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-08-31

    This section of the Joint summary technical letter report (TLR) describes work conducted at the Pacific Northwest National Laboratory (PNNL) during FY 2016 (FY16) on the under-sodium viewing (USV) PNNL project 58745, work package AT-16PN230102. This section of the TLR satisfies PNNL’s M3AT-16PN2301025 milestone and is focused on summarizing the design, development, and evaluation of two different phased-array ultrasonic testing (PA-UT) probe designs—a two-dimensional (2D) matrix phased-array probe, and two one-dimensional (1D) linear array probes, referred to as serial number 4 (SN4) engineering test units (ETUs). The 2D probe is a pulse-echo (PE), 32×2, 64-element matrix phased-array ETU. The 1D probes are 32×1 element linear array ETUs. This TLR also provides the results from a performance demonstration (PD) of in-sodium target detection trials at 260°C using both probe designs. This effort continues the iterative evolution supporting the longer term goal of producing and demonstrating a pre-manufacturing prototype ultrasonic probe that possesses the fundamental performance characteristics necessary to enable the development of a high-temperature sodium-cooled fast reactor (SFR) inspection system for in-sodium detection and imaging.

  11. Performances of fourth generation HIV antigen/antibody assays on filter paper for detection of early HIV infections.

    Science.gov (United States)

    Kania, Dramane; Truong, Tam Nguyen; Montoya, Ana; Nagot, Nicolas; Van de Perre, Philippe; Tuaillon, Edouard

    2015-01-01

    Point-of-care testing and diagnosis of HIV acute infections play important roles in preventing transmission, but HIV rapid diagnosis tests have poor capacity to detect early infections. Filter paper can be used for capillary blood collection and HIV testing using 4th generation immunoassays. Antigen/antibody combined immunoassays were evaluated for their capacity to identify early HIV infections using filter paper in comparison with rapid test. Thirty nine serum samples collected from HIV seroconverters were spotted onto filter paper and tested by the Roche Elecsys(®) HIV Combi PT test and the DiaSorin Liaison XL Murex HIV Ab/Ag assay. Fourth generation immunoassays identified 34 out of 39 HIV early infections using dried serum spot, whereas the Determine™ HIV-1/2 rapid test detected 24 out of 39 HIV positive serum (87.2% vs 61.5% respectively, p = 0.009). p24 antigen was detected by the Liaison XL in 19 dried serum samples (48.7%). In the group characterized by a negative western blot, 7 out of 8 (87.5%) and 6 out of 8 (75.0%) samples were found positive for HIV using the Elecsys and the Liaison XL, respectively. None of these eight samples classified in this group of early acute infections were found positive by the rapid test. Fourth generation Ag/Ab immunoassays performed on dried serum spot had good performance for HIV testing during the early phases of HIV infection. This method may be useful to detect HIV early infections in hard-to-reach populations and individuals living in remote areas before rapid tests become positive. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Factors associated with the performance of a blood-based interferon-γ release assay in diagnosing tuberculosis.

    Directory of Open Access Journals (Sweden)

    Sally Banfield

    Full Text Available BACKGROUND: Indeterminate results are a recognised limitation of interferon-γ release assays (IGRA in the diagnosis of latent tuberculosis (TB infection (LTBI and TB disease, especially in children. We investigated whether age and common co-morbidities were associated with IGRA performance in an unselected cohort of resettled refugees. METHODS: A retrospective cross-sectional study of refugees presenting for their post-resettlement health assessment during 2006 and 2007. Refugees were investigated for prevalent infectious diseases, including TB, and for common nutritional deficiencies and haematological abnormalities as part of standard clinical screening protocols. Tuberculosis screening was performed by IGRA; QuantiFERON-TB Gold in 2006 and QuantiFERON-TBGold In-Tube in 2007. RESULTS: Complete data were available on 1130 refugees, of whom 573 (51% were children less than 17 years and 1041 (92% were from sub-Saharan Africa. All individuals were HIV negative. A definitive IGRA result was obtained in 1004 (89% refugees, 264 (26% of which were positive; 256 (97% had LTBI and 8 (3% had TB disease. An indeterminate IGRA result was obtained in 126 (11% refugees (all failed positive mitogen control. In multivariate analysis, younger age (linear OR= 0.93 [95% CI 0.91-0.95], P<0.001, iron deficiency anaemia (2.69 [1.51-4.80], P = 0.001, malaria infection (3.04 [1.51-6.09], P = 0.002, and helminth infection (2.26 [1.48-3.46], P<0.001, but not vitamin D deficiency or insufficiency, were associated with an indeterminate IGRA result. CONCLUSIONS: Younger age and a number of common co-morbidities are significantly and independently associated with indeterminate IGRA results in resettled predominantly African refugees.

  13. Comparison of the performance in detection of HPV infections between the high-risk HPV genotyping real time PCR and the PCR-reverse dot blot assays.

    Science.gov (United States)

    Zhang, Lahong; Dai, Yibei; Chen, Jiahuan; Hong, Liquan; Liu, Yuhua; Ke, Qiang; Chen, Yiwen; Cai, Chengsong; Liu, Xia; Chen, Zhaojun

    2018-01-01

    A new multiplex real-time PCR assay, the high-risk HPV genotyping real time PCR assay (HR HPV RT-PCR), has been developed to detect 15 high-risk HPV types with respective viral loads. In this report, a total of 684 cervical specimens from women diagnosed with vaginitis were assessed by the HR HPV RT-PCR and the PCR reaction and reverse dot blot (PCR-RDB) assays, using a PCR-sequencing method as a reference standard. A total coincidence of 97.7% between the HR HPV RT PCR and the PCR-RDB assays was determined with a Kappa value of 0.953. The HR HPV RT PCR assay had sensitivity, specificity, and concordance rates (accuracy) of 99.7%, 99.7%, and 99.7%, respectively, as confirmed by PCR-sequencing, while the PCR-RDB assay had respective rates of 98.8%, 97.1%, and 98.0%. The overall rate of HPV infection, determined by PCR-sequencing, in women diagnosed with vaginitis was 49.85%, including 36.26% of single infection and 13.6% of multiple infections. The most common infections among the 15 high-risk HPV types in women diagnosed with vaginitis were HPV-52, HPV-16, and HPV-58, with a total detection rate of 10.23%, 7.75%, and 5.85%, respectively. We conclude that the HR HPV RT PCR assay exhibits better clinical performance than the PCR-RDB assay, and is an ideal alternative method for HPV genotyping. In addition, the HR HPV RT PCR assay provides HPV DNA viral loads, and could serve as a quantitative marker in the diagnosis and treatment of single and multiple HPV infections. © 2017 Wiley Periodicals, Inc.

  14. Demonstration of high-performance p-type tin oxide thin-film transistors using argon-plasma surface treatments

    Science.gov (United States)

    Bae, Sang-Dae; Kwon, Soo-Hun; Jeong, Hwan-Seok; Kwon, Hyuck-In

    2017-07-01

    In this work, we investigated the effects of low-temperature argon (Ar)-plasma surface treatments on the physical and chemical structures of p-type tin oxide thin-films and the electrical performance of p-type tin oxide thin-film transistors (TFTs). From the x-ray photoelectron spectroscopy measurement, we found that SnO was the dominant phase in the deposited tin oxide thin-film, and the Ar-plasma treatment partially transformed the tin oxide phase from SnO to SnO2 by oxidation. The resistivity of the tin oxide thin-film increased with the plasma-treatment time because of the reduced hole concentration. In addition, the root-mean-square roughness of the tin oxide thin-film decreased as the plasma-treatment time increased. The p-type oxide TFT with an Ar-plasma-treated tin oxide thin-film exhibited excellent electrical performance with a high current on-off ratio (5.2 × 106) and a low off-current (1.2 × 10-12 A), which demonstrates that the low-temperature Ar-plasma treatment is a simple and effective method for improving the electrical performance of p-type tin oxide TFTs.

  15. Superior early diagnostic performance of a sensitive cardiac troponin assay as compared to a standard troponin test in the diagnosis of acute myocardial infarction.

    Science.gov (United States)

    Pracoń, Radosław; Kruk, Mariusz; Jakubczak, Barbara; Demkow, Marcin; Bilińska, Zofia T

    2012-01-01

    New generation cardiac troponin assays have sufficient precision to detect and quantify plasma troponin concentrations below the lower threshold of detection of the currently employed troponin tests. However, diagnostic performance of the newer generation assays in daily clinical practice is not well established. To evaluate the diagnostic performance of a sensitive assay as compared to a standard assay in a single reading at admission in the diagnosis of acute myocardial infarction (AMI) in patients presenting to the Emergency Department with chest pain. The study comprised 187 consecutive patients admitted to the Institute of Cardiology in Warsaw in June and July 2010 with chest pain in whom the attending physician ordered troponin assay to rule AMI in or out. In all of these patients, in addition to the standard Dimension Flex Troponin I (Siemens Healthcare Diagnostics, Inc.) the sensitive Architect Stat Troponin I (Abbott Diagnostics) test was assayed. The triage of patients as well as all diagnostic and treatment decisions were left to the discretion of the attending physician who was blinded to the sensitive troponin test readings. The final diagnosis was adjudicated by a team of two cardiologists on the basis of all the available medical records except for sensitive troponin test results. Mean age of the study cohort (n = 187) was 64.3 ± 13.9 years and 119 (63.6%) were males. The final diagnosis of AMI was adjudicated in 84 (44.9%) patients (mean age 67.5 ± 12.9 years; 119 [63.6%] males). Receiver operating characteristic (ROC) analysis showed greater area under the curve (AUC) for the sensitive cardiac troponin assay compared to the standard assay (AUC = 0.916, 95% CI = 0.866-0.951 vs AUC = 0.863, 95% CI = 0.806-0.909, respectively; p = 0.02) in a single reading at admission. Sensitive assay was characterised by higher sensitivity (87%), specificity (88%), positive (86%) and negative (89%) predictive values in the detection of AMI compared to the standard

  16. FY15 Status of Immersion Phased Array Ultrasonic Probe Development and Performance Demonstration Results for Under Sodium Viewing

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Aaron A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Larche, Michael R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mathews, Royce [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Neill, Kevin J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baldwin, David L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Prowant, Matthew S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Edwards, Matthew K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chamberlin, Clyde E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-01

    This Technical Letter Report (TLR) describes work conducted at the Pacific Northwest National Laboratory (PNNL) during FY 2015 on the under-sodium viewing (USV) PNNL project 58745, Work Package AT-15PN230102. This TLR satisfies PNNL’s M3AT-15PN2301027 milestone, and is focused on summarizing the design, development, and evaluation of a two-dimensional matrix phased-array probe referred to as serial number 3 (SN3). In addition, this TLR also provides the results from a performance demonstration of in-sodium target detection trials at 260°C using a one-dimensional 22-element linear array developed in FY14 and referred to as serial number 2 (SN2).

  17. Experimental demonstration of the transmission performance for LDPC-coded multiband OFDM ultra-wideband over fiber system

    Science.gov (United States)

    He, Jing; Wen, Xuejie; Chen, Ming; Chen, Lin; Su, Jinshu

    2015-01-01

    To improve the transmission performance of multiband orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband (UWB) over optical fiber, a pre-coding scheme based on low-density parity-check (LDPC) is adopted and experimentally demonstrated in the intensity-modulation and direct-detection MB-OFDM UWB over fiber system. Meanwhile, a symbol synchronization and pilot-aided channel estimation scheme is implemented on the receiver of the MB-OFDM UWB over fiber system. The experimental results show that the LDPC pre-coding scheme can work effectively in the MB-OFDM UWB over fiber system. After 70 km standard single-mode fiber (SSMF) transmission, at the bit error rate of 1 × 10-3, the receiver sensitivities are improved about 4 dB when the LDPC code rate is 75%.

  18. Saccharification Performances of Miscanthus at the Pilot and Miniaturized Assay Scales: Genotype and Year Variabilities According to the Biomass Composition

    Directory of Open Access Journals (Sweden)

    Nassim Belmokhtar

    2017-05-01

    Full Text Available HIGHLIGHTSBiomass production and cell wall composition are differentially impacted by harvesting year and genotypes, influencing then cellulose conversion in miniaturized assay.Using a high-throughput miniaturized and semi-automated method for performing the pretreatment and saccharification steps at laboratory scale allows for the assessment of these factors on the biomass potential for producing bioethanol before moving to the industrial scale.The large genetic diversity of the perennial grass miscanthus makes it suitable for producing cellulosic ethanol in biorefineries. The saccharification potential and year variability of five genotypes belonging to Miscanthus × giganteus and Miscanthus sinensis were explored using a miniaturized and semi-automated method, allowing the application of a hot water treatment followed by an enzymatic hydrolysis. The studied genotypes highlighted distinct cellulose conversion yields due to their distinct cell wall compositions. An inter-year comparison revealed significant variations in the biomass productivity and cell wall compositions. Compared to the recalcitrant genotypes, more digestible genotypes contained higher amounts of hemicellulosic carbohydrates and lower amounts of cellulose and lignin. In contrast to hemicellulosic carbohydrates, the relationships analysis between the biomass traits and cellulose conversion clearly showed the same negative effect of cellulose and lignin on cellulose digestion. The miniaturized and semi-automated method we developed was usable at the laboratory scale and was reliable for mimicking the saccharification at the pilot scale using a steam explosion pretreatment and enzymatic hydrolysis. Therefore, this miniaturized method will allow the reliable screening of many genotypes for saccharification potential. These findings provide valuable information and tools for breeders to create genotypes combining high yield, suitable biomass composition, and high saccharification

  19. Clinical performance of the Multispot HIV-1/HIV-2 rapid test to correctly differentiate HIV-2 from HIV-1 infection in screening algorithms using third and fourth generation assays and to identify cross reactivity with the HIV-1 Western Blot.

    Science.gov (United States)

    Ramos, Eric M; Harb, Socorro; Dragavon, Joan; Coombs, Robert W

    2013-12-01

    An accurate and rapid serologic method to differentiate HIV-2 from HIV-1 infection is required since the confirmatory HIV-1 Western Blot (WB) may demonstrate cross-reactivity with HIV-2 antibodies. To evaluate the performance of the Bio-Rad Multispot HIV-1/HIV-2 rapid assay as a supplemental test to correctly identify HIV-2 infection and identify HIV-1 WB cross-reactivity with HIV-2 in clinical samples tested at an academic medical center. Between August 2008 and July 2012, clinical samples were screened for HIV using either 3rd- or 4th-generation HIV-1/2 antibody or combination antibody and HIV-1 p24 antigen assays, respectively. All repeatedly reactive samples were reflexed for Multispot rapid testing. Multispot HIV-2 and HIV-1 and HIV-2-reactive samples were further tested using an HIV-2 immunoblot assay and HIV-1 or HIV-2 RNA assays when possible. The HIV-1 WB was performed routinely for additional confirmation and to assess for HIV-2 antibody cross-reactivity. Of 46,061 samples screened, 890 (89.6%) of 993 repeatedly reactive samples were also Multispot-reactive: 882 for HIV-1; three for only HIV-2; and five for both HIV-1 and HIV-2. All three HIV-2-only Multispot-positives along with a single dually reactive HIV-1/2 Multispot-positive were also HIV-2 immunoblot-positive; the latter was HIV-1 RNA negative and HIV-2 RNA positive. The Multispot rapid test performed well as a supplemental test for HIV-1/2 diagnostic testing. Four new HIV-2 infections (0.45%) were identified from among 890 Multispot-reactive tests. The use of HIV-1 WB alone to confirm HIV-1/2 screening assays may underestimate the true prevalence of HIV-2 infection in the United States. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Performance Evaluation of the VIDAS® Measles IgG Assay and Its Diagnostic Value for Measuring IgG Antibody Avidity in Measles Virus Infection

    Directory of Open Access Journals (Sweden)

    Julia Dina

    2016-08-01

    Full Text Available The objective of this study is primarily to compare the performance of the VIDAS® Measles immunoglobulin (IgG assay to that of two other serological assays using an immunoassay technique, Enzygnost® Anti-measles Virus/IgG (Siemens and Measles IgG CAPTURE EIA® (Microimmune. The sensitivity and the agreement of the VIDAS® Measles IgG assay compared to the Enzygnost® Anti-measles Virus/IgG assay and the Measles IgG CAPTURE EIA® assay are 100%, 97.2% and 99.0%, 98.4%, respectively. The very low number of negative sera for IgG antibodies does not allow calculation of specificity. As a secondary objective, we have evaluated the ability of the VIDAS® Measles IgG assay to measure anti-measles virus IgG antibody avidity with the help of the VIDAS® CMV IgG Avidity reagent, using 76 sera from subjects with measles and 238 other sera. Different groups of populations were analyzed. In the primary infection measles group, the mean IgG avidity index was 0.16 (range of 0.07 to 0.93 compared to 0.79 (range of 0.25 to 1 in the serum group positive for IgG antibodies and negative for IgM. These data allow to define a weak anti-measles virus IgG antibody avidity as an avidity index (AI < 0.3 and a strong avidity as an AI > 0.6. The VIDAS® Measles IgG assay has a performance equivalent to that of other available products. Its use, individual and quick, is well adapted to testing for anti-measles immunity in exposed subjects.

  1. Performance of a rapid, on-site human immunodeficiency virus antibody assay in a public health setting.

    Science.gov (United States)

    Kassler, W J; Haley, C; Jones, W K; Gerber, A R; Kennedy, E J; George, J R

    1995-11-01

    Rapid, on-site human immunodeficiency virus (HIV) testing has the potential to improve the delivery of prevention services in publicly funded counseling and testing sites. The Single Use Diagnostic System (SUDS) HIV-1 is the only rapid enzyme immunoassay (EIA) approved for diagnostic use in the United States. To evaluate the feasibility of using SUDS in public clinics and to validate the test's performance in a public health laboratory, we conducted blinded SUDS testing on plasma sent for HIV testing. From 19 March through 30 June 1993, 1,923 consecutive samples from a sexually transmitted diseases clinic and an HIV counseling and testing clinic were tested on site with SUDS. Tests done in the first two weeks with a malfunctioning centrifuge n = 402) and those done when there were excessively high temperatures in the laboratory (n = 53) were analyzed separately. Of 1,466 tests, 39 were positive by both SUDS and EIA (with Western blot [immunoblot] confirmation) and 7 were SUDS positive and EIA negative. Western blotting was used as the "gold standard" to adjudicate these discrepancies. There were no SUDS-negative and EIA-positive tests. Compared with that of EIA (with Western blot confirmation), the sensitivity of SUDS was 100% (95% confidence interval, 88.8 to 100%) and the specificity was 99.5% (95% confidence interval, 98.9 to 99.8%). The positive predictive value of SUDS was 88% in the STD clinic and 81% in the HIV counseling and testing clinic. There was a 7.7-fold increase in false positives, from 0.48 to 3.7%, when there was inadequate centrifugation and when the temperature exceeded the manufacturer's recommendations. Rapid, on-site HIV testing by the SUDS assay is feasible and practical in public health settings. The test can be performed accurately, at reasonable cost, and within the time frame of a typical clinic visit. Caution should be used, however, as two conditions adversely affected the accuracy of this test: inadequate specimen preparation and

  2. Anti-citrullinated protein antibodies in the diagnosis of rheumatoid arthritis (RA): diagnostic performance of automated anti-CCP-2 and anti-CCP-3 antibodies assays

    NARCIS (Netherlands)

    Vos, I.; Van Mol, C.; Trouw, L.A.; Mahler, M.; Bakker, J.A.; Van Offel, J.; De Clerck, L.

    2017-01-01

    This study compares the diagnostic performance of a second generation anti-cyclic citrullinated peptide antibody (CCP2) with a third generation anti-CCP antibodies assay (CCP3), as well as the combination of both tests. Serum samples of 127 patients were analyzed. IgG anti-CCP 2 and IgM rheumatoid

  3. Dual Testing Algorithm of BED-CEIA and AxSYM Avidity Index Assays Performs Best in Identifying Recent HIV Infection in a Sample of Rwandan Sex Workers

    NARCIS (Netherlands)

    Braunstein, S.L.; Nash, D.; Kim, A.A.; Ford, K.; Mwambarangwe, L.; Ingabire, C.M.; Vyankandondera, J.; van de Wijgert, J.H.H.M.

    2011-01-01

    To assess the performance of BED-CEIA (BED) and AxSYM Avidity Index (Ax-AI) assays in estimating HIV incidence among female sex workers (FSW) in Kigali, Rwanda. Eight hundred FSW of unknown HIV status were HIV tested; HIV-positive women had BED and Ax-AI testing at baseline and ≥12 months later to

  4. Development and performance assessment of a luminex xMAP® direct hybridization assay for the detection and identification of indoor air fungal contamination.

    Science.gov (United States)

    Libert, Xavier; Packeu, Ann; Bureau, Fabrice; Roosens, Nancy H; De Keersmaecker, Sigrid C J

    2017-01-01

    Considered as a public health problem, indoor fungal contamination is generally monitored using classical protocols based on culturing. However, this culture dependency could influence the representativeness of the fungal population detected in an analyzed sample as this includes the dead and uncultivable fraction. Moreover, culture-based protocols are often time-consuming. In this context, molecular tools are a powerful alternative, especially those allowing multiplexing. In this study a Luminex xMAP® assay was developed for the simultaneous detection of 10 fungal species which are most frequently in indoor air and that may cause health problems. This xMAP® assay was found to be sensitive, i.e. its limit of detection is ranging between 0.05 and 0.01 ng of gDNA. The assay was subsequently tested with environmental air samples which were also analyzed with a classical protocol. All the species identified with the classical method were also detected with the xMAP® assay, however in a shorter time frame. These results demonstrate that the Luminex xMAP® fungal assay developed in this study could contribute to the improvement of public health and specifically to the indoor fungal contamination treatment.

  5. Development and performance assessment of a luminex xMAP® direct hybridization assay for the detection and identification of indoor air fungal contamination.

    Directory of Open Access Journals (Sweden)

    Xavier Libert

    Full Text Available Considered as a public health problem, indoor fungal contamination is generally monitored using classical protocols based on culturing. However, this culture dependency could influence the representativeness of the fungal population detected in an analyzed sample as this includes the dead and uncultivable fraction. Moreover, culture-based protocols are often time-consuming. In this context, molecular tools are a powerful alternative, especially those allowing multiplexing. In this study a Luminex xMAP® assay was developed for the simultaneous detection of 10 fungal species which are most frequently in indoor air and that may cause health problems. This xMAP® assay was found to be sensitive, i.e. its limit of detection is ranging between 0.05 and 0.01 ng of gDNA. The assay was subsequently tested with environmental air samples which were also analyzed with a classical protocol. All the species identified with the classical method were also detected with the xMAP® assay, however in a shorter time frame. These results demonstrate that the Luminex xMAP® fungal assay developed in this study could contribute to the improvement of public health and specifically to the indoor fungal contamination treatment.

  6. Comparison of the analytical and clinical performances of Abbott RealTime High Risk HPV, Hybrid Capture 2, and DNA Chip assays in gynecology patients.

    Science.gov (United States)

    Park, Seungman; Kang, Youjin; Kim, Dong Geun; Kim, Eui-Chong; Park, Sung Sup; Seong, Moon-Woo

    2013-08-01

    The detection of high-risk (HR) HPV in cervical cancer screening is important for early diagnosis of cervical cancer or pre-cancerous lesions. We evaluated the analytical and clinical performances of 3 HR HPV assays in Gynecology patients. A total of 991 specimens were included in this study: 787 specimens for use with a Hybrid Capture 2 (HC2) and 204 specimens for a HPV DNA microarray (DNA Chip). All specimens were tested using an Abbott RealTime High Risk HPV assay (Real-time HR), PGMY PCR, and sequence analysis. Clinical sensitivities for severe abnormal cytology (severe than high-grade squamous intraepithelial lesion) were 81.8% for Real-time HR, 77.3% for HC2, and 66.7% for DNA Chip, and clinical sensitivities for severe abnormal histology (cervical intraepithelial neoplasia grade 2+) were 91.7% for HC2, 87.5% for Real-time HR, and 73.3% for DNA Chip. As compared to results of the sequence analysis, HC2, Real-time HR, and DNA Chip showed concordance rates of 94.3% (115/122), 90.0% (117/130), and 61.5% (16/26), respectively. The HC2 assay and Real-time HR assay showed comparable results to each other in both clinical and analytical performances, while the DNA Chip assay showed poor clinical and analytical performances. The Real-time HR assay can be a good alternative option for HR HPV testing with advantages of allowing full automation and simultaneous genotyping of HR types 16 and 18. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Modification of the BAX System PCR assay for detecting Salmonella in beef, produce, and soy protein isolate. Performance Tested Method 100201.

    Science.gov (United States)

    Peng, Linda X; Wallace, Morgan; Andaloro, Bridget; Fallon, Dawn; Fleck, Lois; Delduco, Dan; Tice, George

    2011-01-01

    The BAX System PCR assay for Salmonella detection in foods was previously validated as AOAC Research Institute (RI) Performance Tested Method (PTM) 100201. New studies were conducted on beef and produce using the same media and protocol currently approved for the BAX System PCR assay for E. coli O157:H7 multiplex (MP). Additionally, soy protein isolate was tested for matrix extension using the U.S. Food and Drug Administration-Bacteriological Analytical Manual (FDA-BAM) enrichment protocols. The studies compared the BAX System method to the U.S. Department of Agriculture culture method for detecting Salmonella in beef and the FDA-BAM culture method for detecting Salmonella in produce and soy protein isolate. Method comparison studies on low-level inoculates showed that the BAX System assay for Salmonella performed as well as or better than the reference method for detecting Salmonella in beef and produce in 8-24 h enrichment when the BAX System E. coli O157:H7 MP media was used, and soy protein isolate in 20 h enrichment with lactose broth followed by 3 h regrowth in brain heart infusion broth. An inclusivity panel of 104 Salmonella strains with diverse serotypes was tested by the BAX System using the proprietary BAX System media and returned all positive results. Ruggedness factors involved in the enrichment phase were also evaluated by testing outside the specified parameters, and none of the factors examined affected the performance of the assay.

  8. Hybrid Capture 2 and cobas human papillomavirus assays perform similarly on SurePath samples from women with abnormalities

    DEFF Research Database (Denmark)

    Fornari, D; Rebolj, M; Bjerregaard, B

    2016-01-01

    OBJECTIVE: In two laboratories (Departments of Pathology, Copenhagen University Hospitals of Herlev and Hvidovre), we compared cobas and Hybrid Capture 2 (HC2) human papillomavirus (HPV) assays using SurePath® samples from women with atypical squamous cells of undetermined significance (ASCUS...

  9. Demonstration of High Performance in Layered Deuterium-Tritium Capsule Implosions in Uranium Hohlraums at the National Ignition Facility.

    Science.gov (United States)

    Döppner, T; Callahan, D A; Hurricane, O A; Hinkel, D E; Ma, T; Park, H-S; Berzak Hopkins, L F; Casey, D T; Celliers, P; Dewald, E L; Dittrich, T R; Haan, S W; Kritcher, A L; MacPhee, A; Le Pape, S; Pak, A; Patel, P K; Springer, P T; Salmonson, J D; Tommasini, R; Benedetti, L R; Bond, E; Bradley, D K; Caggiano, J; Church, J; Dixit, S; Edgell, D; Edwards, M J; Fittinghoff, D N; Frenje, J; Gatu Johnson, M; Grim, G; Hatarik, R; Havre, M; Herrmann, H; Izumi, N; Khan, S F; Kline, J L; Knauer, J; Kyrala, G A; Landen, O L; Merrill, F E; Moody, J; Moore, A S; Nikroo, A; Ralph, J E; Remington, B A; Robey, H F; Sayre, D; Schneider, M; Streckert, H; Town, R; Turnbull, D; Volegov, P L; Wan, A; Widmann, K; Wilde, C H; Yeamans, C

    2015-07-31

    We report on the first layered deuterium-tritium (DT) capsule implosions indirectly driven by a "high-foot" laser pulse that were fielded in depleted uranium hohlraums at the National Ignition Facility. Recently, high-foot implosions have demonstrated improved resistance to ablation-front Rayleigh-Taylor instability induced mixing of ablator material into the DT hot spot [Hurricane et al., Nature (London) 506, 343 (2014)]. Uranium hohlraums provide a higher albedo and thus an increased drive equivalent to an additional 25 TW laser power at the peak of the drive compared to standard gold hohlraums leading to higher implosion velocity. Additionally, we observe an improved hot-spot shape closer to round which indicates enhanced drive from the waist. In contrast to findings in the National Ignition Campaign, now all of our highest performing experiments have been done in uranium hohlraums and achieved total yields approaching 10^{16} neutrons where more than 50% of the yield was due to additional heating of alpha particles stopping in the DT fuel.

  10. Ultra-performance liquid chromatography-tandem mass spectrometry-based multiplex enzyme assay for six enzymes associated with hereditary hemolytic anemia.

    Science.gov (United States)

    Park, Chul Min; Lee, Kyunghoon; Jun, Sun-Hee; Song, Sang Hoon; Song, Junghan

    2017-08-15

    Deficiencies in erythrocyte metabolic enzymes are associated with hereditary hemolytic anemia. Here, we report the development of a novel multiplex enzyme assay for six major enzymes, namely glucose-6-phosphate dehydrogenase, pyruvate kinase, pyrimidine 5'-nucleotidase, hexokinase, triosephosphate isomerase, and adenosine deaminase, deficiencies in which are implicated in erythrocyte enzymopathies. To overcome the drawbacks of traditional spectrophotometric enzyme assays, the present assay was based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The products of the six enzymes were directly measured by using ion pairing UPLC-MS/MS, and the precision, linearity, ion suppression, optimal sample amounts, and incubation times were evaluated. Eighty-three normal individuals and 13 patients with suspected enzymopathy were analyzed. The UPLC running time was within 5min. No ion suppression was observed at the retention time for the products or internal standards. We selected an optimal dilution factor and incubation time for each enzyme system. The intra- and inter-assay imprecision values (CVs) were 2.5-12.1% and 2.9-14.3%, respectively. The linearity of each system was good, with R2 values >0.97. Patient samples showed consistently lower enzyme activities than those from normal individuals. The present ion paring UPLC-MS/MS assay enables facile and reproducible multiplex evaluation of the activity of enzymes implicated in enzymopathy-associated hemolytic anemia. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Comparison of analytical and clinical performance of CLART HPV2 genotyping assay to Linear Array and Hybrid Capture 2

    DEFF Research Database (Denmark)

    Ejegod, Ditte Møller; Rebolj, Matejka; Bonde, Jesper

    2015-01-01

    for high-grade CIN. RESULTS: The κ-coefficient for agreement in detection of genotypes 16, 18, 31, 33, 35, and 51 was ≥0.90 (overall agreement: 98-99%, positive agreement: 84-95%). The values were slightly lower, but still in the "substantial" range for genotypes 39, 45, 52, 56, 58, 59, and several low-risk...... genotypes. The relative sensitivity of CLART for ≥ CIN2 and ≥ CIN3 was not significantly lower than that of LA and HC2, although CLART showed a higher specificity than HC2. CONCLUSIONS: In Danish women with abnormal SurePath cytology, CLART and LA were highly comparable for detection of most high-risk......BACKGROUND: Human Papillomavirus (HPV) genotyping has an increasingly important role in cervical cancer screening and vaccination monitoring, however, without an internationally agreed standard reference assay. The test results from the most widely used genotyping assays are read manually and hence...

  12. Effects of visual demonstration, verbal instructions, and prompted verbal descriptions on the performance of human subjects in conditional discriminations

    OpenAIRE

    Ribes-Iñesta, Emilio; Cepeda, Ma. Luisa; Hickman, Hortencia; Moreno, Diana; Peñalosa, Eduardo

    1992-01-01

    A study was conducted to confirm prior results concerning the role of prompted verbal descriptions of visually demonstrated stimulus relations in the acquisition and transfer of identity, difference, and similarity-matching relations (Ribes et al., 1988). Four groups of human adults were trained with these three matching relations under four different procedures: (1) visual demonstration without response requirement, (2) verbal instructions, (3) visual demonstration plus prompted verbal descr...

  13. Performance of the NG OligoGen kit for the diagnosis of Neisseria gonorrhoeae: comparison with cobas 4800 assay.

    Science.gov (United States)

    Parra-Sánchez, M; García-Rey, S; Marcuello, A; Zakariya-Yousef, I; Bernal, S; Pueyo, I; Martín-Mazuelos, E; Palomares, J C

    2016-01-01

    PCR assays are nowadays between the most sensitive and reliable methods for screening and diagnosing sexually transmitted infections (STIs). The aim of this study was to analyze the reliability, accuracy, and usefulness of the new NG OligoGen kit in comparison with the cobas 4800 assay for the detection of Neisseria gonorrhoeae in clinical samples. A prospective study was designed for detection of N. gonorrhoeae including urine samples (n=152), rectal (n=80), endocervical (n=67), pharyngeal (n=41), and urethral swabs (n=5) that were sent from a regional STI clinic in Seville, Spain. Samples were collected from 255 (73.9%) men and 90 women. Sensitivity, specificity, positive and negative predicative values, and kappa value for N. gonorrhoeae detection using the NG OligoGen kit were 99.6%, 100%, 100%, 99.1%, and 0.99, respectively. Statistical data obtained in this study confirm the usefulness and reliable results of this new assay. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Assay for trenbolone and its metabolite 17 alpha-trenbolone in bovine urine based on immunoaffinity chromatographic clean-up and off-line high-performance liquid chromatography-thin-layer chromatography.

    Science.gov (United States)

    van Ginkel, L A; van Blitterswijk, H; Zoontjes, P W; van den Bosch, D; Stephany, R W

    1988-07-22

    An high-performance liquid chromatography (HPLC)-thin-layer chromatography (TLC) method was developed to detect the illegal use of the xenobiotic growth promotor Trenbolone acetate (TBA). Very effective clean-up of bovine urine was achieved by immunoaffinity chromatography (IAC). The active form of TBA, the steroid 17 beta-Trenbolone (17 beta-TB), as well as its major metabolite 17 alpha-Trenbolone (17 alpha-TB), were assayed simultaneously with HPLC and on-line UV detection. The fraction containing 17 alpha-TB and 17 beta-TB (TB-fraction) was collected, and for confirmation 17 beta- and 17 alpha-TB were subsequently separated and identified by TLC. The limit of detection by on-line HPLC-UV (350 nm) was 1-2 micrograms TB/l. Off-line TLC detection was even more sensitive, 0.5 microgram 17 beta- or 17 alpha-TB/1. The assay was validated by investigating urine samples from veal calves implanted with TBA. The presence of 17 beta- and 17 alpha-TB was clearly demonstrated. A survey of the illegal use of TBA in cattle was performed by applying the assay to urine obtained at slaughter. No residues of TBA or its metabolites were found in any of the 144 random samples from the Dutch public health surveillance programme.

  15. Through-the-Sensor Determination of AN/AQS-20 Sensor Performance Demonstration 1, December 13 through 17, 2004

    National Research Council Canada - National Science Library

    Harris, Michael; Avera, William; Steed, Chad; Sample, John; Bibee, Leonard D; Wood, Warren T; Morgerson, Dave; Robinson, Christopher S

    2005-01-01

    ...) Tactical Decision Aid (TDA). This demonstration was a representative simulation that showed the connectivity and functionality using previously collected raw AN/AQS-20 Engineering Development Model (EDM...

  16. Performance of the G4 Xpert® MTB/RIF assay for the detection of Mycobacterium tuberculosis and rifampin resistance: a retrospective case-control study of analytical and clinical samples from high- and low-tuberculosis prevalence settings.

    Science.gov (United States)

    Dharan, Nila J; Blakemore, Robert; Sloutsky, Alex; Kaur, Devinder; Alexander, Richard C; Ghajar, Minoo; Musser, Kimberlee A; Escuyer, Vincent E; Rowlinson, Marie-Claire; Crowe, Susanne; Laniado-Laborin, Rafael; Valli, Eloise; Nabeta, Pamela; Johnson, Pamela; Alland, David

    2016-12-20

    The Xpert® MTB/RIF (Xpert) assay is a rapid PCR-based assay for the detection of Mycobacterium tuberculosis complex DNA (MTBc) and mutations associated with rifampin resistance (RIF). An updated version introduced in 2011, the G4 Xpert, included modifications to probe B and updated analytic software. An analytical study was performed to assess Xpert detection of mutations associated with rifampin resistance in rifampin-susceptible and -resistant isolates. A clinical study was performed in which specimens from US and non-US persons suspected of tuberculosis (TB) were tested to determine Xpert performance characteristics. All specimens underwent smear microscopy, mycobacterial culture, conventional drug-susceptibility testing and Xpert testing; DNA from isolates with discordant rifampin resistance results was sequenced. Among 191 laboratory-prepared isolates in the analytical study, Xpert sensitivity for detection of rifampin resistance associated mutations was 97.7% and specificity was 90.8%, which increased to 99.0% after DNA sequencing analysis of the discordant samples. Of the 1,096 subjects in the four clinical studies, 49% were from the US. Overall, Xpert detected MTBc in 439 of 468 culture-positive specimens for a sensitivity of 93.8% (95% confidence interval [CI]: 91.2%-95.7%) and did not detect MTBc in 620 of 628 culture-negative specimens for a specificity of 98.7% (95% CI: 97.5%-99.4%). Sensitivity was 99.7% among smear-positive cases, and 76.1% among smear-negative cases. Non-determinate MTBc detection and false-positive RIF resistance results were low (1.2 and 0.9%, respectively). The updated Xpert assay retained the high sensitivity and specificity of the previous assay versions and demonstrated low rates of non-determinate and RIF resistance false positive results.

  17. Understanding the Effects of Roasting on Antioxidant Components of Coffee Brews by Coupling On‐line ABTS Assay to High Performance Size Exclusion Chromatography

    Science.gov (United States)

    Opitz, Sebastian E.W.; Goodman, Bernard A.; Keller, Marco; Smrke, Samo; Wellinger, Marco; Schenker, Stefan

    2016-01-01

    Abstract Introduction Coffee is a widely consumed beverage containing antioxidant active compounds. During roasting the phytochemical composition of the coffee bean changes dramatically and highly polymeric substances are produced. Besides chlorogenic acids that are already present in green coffee beans, melanoidins show antioxidant capacity as well. Objective To employ post‐column derivatisation by coupling high performance size exclusion chromatography (HPSEC) to an antioxidant assay to investigate the effect of roasting on the properties of antioxidant active compounds in coffee brews. Methodology We have investigated the antioxidant capacity of Coffea arabica (Arabica) and C. canephora (Robusta) beans that were roasted over the full spectrum of roast conditions (four roasting speeds to three roast degrees) by comparing the results from HPSEC coupled on‐line to the ABTS assay with those from two batch assays, Folin Ciocalteu (FC) and oxygen radical absorbance capacity (ORAC) assay. Results The antioxidant capacity showed a general decrease towards slower and darker roasted coffee for all three assays, indicative of heat degradation of active compounds. Hence, low molecular weight (LMW) compounds such as chlorogenic acids (CGAs) decreased progressively already from relatively mild roasting conditions. In contrast, high molecular weight (HMW) compounds (e.g. melanoidins) increased from light to dark roast degrees with lowering magnitude towards slower roasting profiles. Conclusion By coupling HPSEC on‐line to the ABTS assay we were able to separately quantify the contribution of HMW and LMW compounds to the total antioxidant capacity, increasing our understanding of the roast process. © 2016 The Authors. Phytochemical Analysis Published by John Wiley & Sons Ltd. PMID:28008674

  18. Understanding the Effects of Roasting on Antioxidant Components of Coffee Brews by Coupling On-line ABTS Assay to High Performance Size Exclusion Chromatography.

    Science.gov (United States)

    Opitz, Sebastian E W; Goodman, Bernard A; Keller, Marco; Smrke, Samo; Wellinger, Marco; Schenker, Stefan; Yeretzian, Chahan

    2017-03-01

    Coffee is a widely consumed beverage containing antioxidant active compounds. During roasting the phytochemical composition of the coffee bean changes dramatically and highly polymeric substances are produced. Besides chlorogenic acids that are already present in green coffee beans, melanoidins show antioxidant capacity as well. To employ post-column derivatisation by coupling high performance size exclusion chromatography (HPSEC) to an antioxidant assay to investigate the effect of roasting on the properties of antioxidant active compounds in coffee brews. We have investigated the antioxidant capacity of Coffea arabica (Arabica) and C. canephora (Robusta) beans that were roasted over the full spectrum of roast conditions (four roasting speeds to three roast degrees) by comparing the results from HPSEC coupled on-line to the ABTS assay with those from two batch assays, Folin Ciocalteu (FC) and oxygen radical absorbance capacity (ORAC) assay. The antioxidant capacity showed a general decrease towards slower and darker roasted coffee for all three assays, indicative of heat degradation of active compounds. Hence, low molecular weight (LMW) compounds such as chlorogenic acids (CGAs) decreased progressively already from relatively mild roasting conditions. In contrast, high molecular weight (HMW) compounds (e.g. melanoidins) increased from light to dark roast degrees with lowering magnitude towards slower roasting profiles. By coupling HPSEC on-line to the ABTS assay we were able to separately quantify the contribution of HMW and LMW compounds to the total antioxidant capacity, increasing our understanding of the roast process. © 2016 The Authors. Phytochemical Analysis Published by John Wiley & Sons Ltd. © 2016 The Authors. Phytochemical Analysis Published by John Wiley & Sons Ltd.

  19. Performance comparison of the BioSys optical assay and the violet red bile agar method for detecting coliforms in food products.

    Science.gov (United States)

    Firstenberg-Eden, Ruth; Foti, Debra; McDougal, Susan; Beck, Stephen

    2004-12-01

    Coliform counts in a variety of foods, including dairy products (raw milk, pasteurized milk, yogurt, butter, and ice cream), meats (pork sausage, ground beef, and raw chicken), raw eggs, and chocolate, were performed by the rapid automated BioSys optical assay and the conventional method with violet red bile agar (VRBA). The standard deviation (SD) among five replicate counts for the optical assay was similar to or better than that obtained with VRBA plates for all foods tested. The average SD for all foods tested was 0.21 for the optical assay and 0.30 for the VRBA plates. At very low concentrations of coliforms (1 to 10 CFU/ml for liquid products and 10 to 100 CFU/g for solid samples), the average SDs were 0.26 and 0.47, respectively. The optical assay was less susceptible to interference by noncoliform organisms. In naturally contaminated samples, bacteria such as Serratia liquefaciens, Pantoea spp., Vibrio fluvialis, Aeromonas hydrophilia, and Pseudomonas spp. formed typical colonies in VRBA, resulting in false-positive results or a need to verify colonies in brilliant green lactose broth. The optical assay appeared to be more selective than the VRBA conventional method, detecting fewer noncoliforms. There was close agreement in test results between the two methods, as indicated by correlation coefficients of 0.92 to 0.99 obtained for the regression analysis of the two methods. In most cases both methods distinguished accurately between positive samples containing coliforms and negative controls. All products tested using the automated BioSys Optical Assay for coliforms yielded results more quickly (typically 10 to 12 h) than did those tested with the conventional VRBA method (24 to 72 h with confirmation).

  20. Enzyme assays

    OpenAIRE

    Bisswanger, Hans

    2014-01-01

    The essential requirements for enzyme assays are described and frequently occurring errors and pitfalls as well as their avoidance are discussed. The main factors, which must be considered for assaying enzymes, are temperature, pH, ionic strength and the proper concentrations of the essential components like substrates and enzymes. Standardization of these parameters would be desirable, but the diversity of the features of different enzymes prevents unification of assay conditions. Neverthele...

  1. Locating sweet spots for screening hits and evaluating pan-assay interference filters from the performance analysis of two lead-like libraries.

    Science.gov (United States)

    Mok, N Yi; Maxe, Sara; Brenk, Ruth

    2013-03-25

    The efficiency of automated compound screening is heavily influenced by the design and the quality of the screening libraries used. We recently reported on the assembly of one diverse and one target-focused lead-like screening library. Using data from 15 enzyme-based screenings conducted using these libraries, their performance was investigated. Both libraries delivered screening hits across a range of targets, with the hits distributed across the entire chemical space represented by both libraries. On closer inspection, however, hit distribution was uneven across the chemical space, with enrichments observed in octants characterized by compounds at the higher end of the molecular weight and lipophilicity spectrum for lead-like compounds, while polar and sp(3)-carbon atom rich compounds were underrepresented among the screening hits. Based on these observations, we propose that screening libraries should not be evenly distributed in lead-like chemical space but be enriched in polar, aliphatic compounds. In conjunction with variable concentration screening, this could lead to more balanced hit rates across the chemical space and screening hits of higher ligand efficiency will be captured. Apart from chemical diversity, both screening libraries were shown to be clean from any pan-assay interference (PAINS) behavior. Even though some compounds were flagged to contain PAINS structural motifs, some of these motifs were demonstrated to be less problematic than previously suggested. To maximize the diversity of the chemical space sampled in a screening campaign, we therefore consider it justifiable to retain compounds containing PAINS structural motifs that were apparently clean in this analysis when assembling screening libraries.

  2. [Evaluation of a new screening assay kit for the combined detection of HIV p24 antigen and antibody--comparison of the performance of the new kit and HIV antibody assay kits].

    Science.gov (United States)

    Hayashi, T; Watanabe, S; Kondo, M; Saito, T; Imai, M

    1999-07-01

    DUO is an automated HIV infection screening test kit based on the combined detection of p24 Ag and anti-HIV-1 and anti-HIV-2 IgG in human sera or plasma using the ELFA technique (Enzyme-Linked Fluorescent Assay). The performance of DUO was compared with that of HIV-1/HIV-2 3rd generation EIA plus and particle agglutination (PA) test. A total of 141 seropositive sera, 3 seroconversion panels, 300 seronegative sera and 387 potentially cross-reactive serum samples were tested. One hundred and forty one seropositive sera in Japan and Cameroon were all positive with DUO. Three seroconversion panels (panel Q, Z, AE) were tested to evaluate sensitivity. In Panel Q, infecution was detected seven days earlier with DUO than with the 3rd generation EIA plus and PA. In Panel AE, infection was detected four days earlier with DUO than with the single antibody assays. Three hundred seronegative sera from Kanagawa prefectural public health centers were all negative with DUO as well as PA test. Three hundred and eighty seven potentially cross-reacting samples were tested to challenge the specificity of the assay. These included samples from pregnant women and hepatitis patients. In four of the 204 samples from pregnant women, false-positive results were observed with DUO. In three of the 183 samples from hepatitis patients, false-positive results were also obtained with DUO. All samples of 7 DUO positive results were negative with western blot test. Five of them were negative with RT-PCR and 2 of them were not tested because there were not enough samples. Thirty cross-reacting (false-positive) samples by PA test from blood donors were tested by DUO, and all of these were negative by DUO.

  3. Performance of four different indirect enzyme-linked immunosorbent assays (ELISAs) to detect specific IgG, IgA, and IgM in Legionnaires' disease

    DEFF Research Database (Denmark)

    Bangsborg, Jette Marie; Shand, G H; Hansen, K

    1994-01-01

    , closely followed by the corresponding SON tests. By combining two individual assays, a maximum nosographic sensitivity of 85% could be obtained. Whereas no benefit of using purified outer membrane protein or flagella instead of a sonic extract in the indirect ELISAs was found, the LPS antigen provided......Currently recommended methods in Legionnaires' disease serology are based upon crude whole-cell antigenic preparations. To investigate whether purified antigens would perform better in a given diagnostic test for antibodies against Legionella pneumophila, we compared the performance of three...... antigenic preparations of L. pneumophila serogroup 1 consisting of outer membrane protein (OMP), flagellin (FLA), and lipopolysaccharide (LPS) to a sonic extract (SON) in indirect immunosorbent assay (ELISA) measuring both IgG, IgA, and IgM. The reactivity of sera from 20 patients with culture...

  4. Comparison of Clinical Performance of Abbott RealTime High Risk HPV Test with That of Hybrid Capture 2 Assay in a Screening Setting▿

    OpenAIRE

    Carozzi, F. M.; Burroni, E.; Bisanzi, S.; Puliti, D; Confortini, M.; Giorgi Rossi, P; Sani, C; Scalisi, A.; Chini, F.

    2011-01-01

    Randomized trials have produced sound evidence about the efficacy of screening with human papillomavirus (HPV) DNA tests in reducing cervical cancer incidence and mortality. We evaluated the clinical performance and reproducibility of the Abbott RealTime High Risk (HR) HPV test compared with that of the HR hybrid capture 2 (HC2) assay as assessed by a noninferiority score test. A random sample of 998 cervical specimens (914 specimens of cervical intraepithelial neoplasia less severe than grad...

  5. Detection of enteropathogens associated with travelers' diarrhea using a multiplex Luminex-based assay performed on stool samples smeared on Whatman FTA Elute cards.

    Science.gov (United States)

    Lalani, Tahaniyat; Tisdale, Michele D; Maguire, Jason D; Wongsrichanalai, Chansuda; Riddle, Mark S; Tribble, David R

    2015-09-01

    We evaluated the limits of detection (LoD) for an 11-plex PCR-Luminex assay performed on Whatman(™) FTA Elute cards smeared with stool containing pathogens associated with travelers' diarrhea. LoDs ranged from 10(2) to 10(5)CFU, PFU, or cysts/g for most pathogens except Cryptosporidium. Campylobacter and norovirus LoDs increased with prolonged storage of cards. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Detection of enteropathogens associated with travelers’ diarrhea using a multiplex Luminex-based assay performed on stool samples smeared on Whatman FTA Elute cards

    Science.gov (United States)

    Lalani, Tahaniyat; Tisdale, Michele D; Maguire, Jason D; Wongsrichanalai, Chansuda; Riddle, Mark S; Tribble, David R

    2015-01-01

    We evaluated the limits of detection (LoD) for an 11-plex PCR-Luminex assay performed on Whatman FTA Elute cards smeared with stool containing pathogens associated with travelers’ diarrhea. LoDs ranged between 102-105 CFU, PFU or cysts/g for most pathogens except Cryptosporidium. Campylobacter and norovirus LoD increased with prolonged storage of cards. PMID:26072151

  7. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1978-01-01

    Presents the following chemistry lecture demonstrations and experiments: (1) a versatile kinetic demonstration; (2) the Bakelite Demonstration; (3) applying Beer's law; and (4) entropy calculations. (HM)

  8. Method and apparatus for purifying nucleic acids and performing polymerase chain reaction assays using an immiscible fluid

    Science.gov (United States)

    Koh, Chung-Yan; Light, Yooli Kim; Piccini, Matthew Ernest; Singh, Anup K.

    2017-10-31

    Embodiments of the present invention are directed toward devices, systems, and methods for purifying nucleic acids to conduct polymerase chain reaction (PCR) assays. In one example, a method includes generating complexes of silica beads and nucleic acids in a lysis buffer, transporting the complexes through an immiscible fluid to remove interfering compounds from the complexes, further transporting the complexes into a density medium containing components required for PCR where the nucleic acids disassociate from the silica beads, and thermocycling the contents of the density medium to achieve PCR. Signal may be detected from labeling agents in the components required for PCR.

  9. ESTCP Munitions Response Live Site Demonstrations Southwest Proving Ground, Arkansas Andersen Air Force Base, Guam Cost and Performance Report

    Science.gov (United States)

    2017-08-23

    Complete coverage of the demonstration site Footprint coverage calculated using UX-Process Footprint Coverage Quality Control (QC) tool; excludes...Complete coverage of the demonstration site Footprint coverage calculated using UX-Process Footprint Coverage QC tool; excludes inaccessible...installed  Vegetation thinned  IVS installation  37 seed items installed  Vegetation thinned  IVS installation Data Collection  11.23 acres

  10. Co-Localization of Insulin-Like Growth Factor Binding Protein-1, Casein Kinase-2β, and Mechanistic Target of Rapamycin in Human Hepatocellular Carcinoma Cells as Demonstrated by Dual Immunofluorescence and in Situ Proximity Ligation Assay.

    Science.gov (United States)

    Singal, Sahil S; Nygard, Karen; Dhruv, Manthan R; Biggar, Kyle; Abu Shehab, Majida; Shun-Cheng Li, Shawn; Jansson, Thomas; Gupta, Madhulika B

    2017-10-14

    Insulin-like growth factor binding protein (IGFBP)-1 influences fetal growth by modifying insulin-like growth factor-I (IGF-I) bioavailability. IGFBP-1 phosphorylation, which markedly increases its affinity for IGF-I, is regulated by mechanistic target of rapamycin (mTOR) and casein kinase (CSNK)-2. However, the underlying molecular mechanisms remain unknown. We examined the cellular localization and potential interactions of IGFBP-1, CSNK-2β, and mTOR as a prerequisite for protein-protein interaction. Analysis of dual immunofluorescence images indicated a potential perinuclear co-localization between IGFBP-1 and CSNK-2β and a nuclear co-localization between CSNK-2β and mTOR. Proximity ligation assay (PLA) indicated proximity between IGFBP-1 and CSNK-2β as well as mTOR and CSNK-2β but not between mTOR and IGFBP-1. Three-dimensional rendering of the PLA images validated that IGFBP-1 and CSNK-2β interactions were in the perinuclear region and mTOR and CSNK-2β interactions were predominantly perinuclear rather than nuclear as indicated by mTOR and CSNK-2β co-localization. Compared with control, hypoxia and rapamycin treatment showed markedly amplified PLA signals for IGFBP-1 and CSNK-2β (approximately 18-fold, P = 0.0002). Stable isotope labeling with multiple reaction monitoring-mass spectrometry demonstrated that hypoxia and rapamycin treatment increased IGFBP-1 phosphorylation at Ser98/Ser101/Ser119/Ser174 but most considerably (106-fold) at Ser169. We report interactions between CSNK-2β and IGFBP-1 as well as mTOR and CSNK-2β, providing strong evidence of a mechanistic link between mTOR and IGF-I signaling, two critical regulators of cell growth via CSNK-2. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  11. Development of a dose assay for a Clostridium difficile vaccine using a tandem ion exchange high performance liquid chromatography method.

    Science.gov (United States)

    Wang, Feng; Ha, Sha; Rustandi, Richard R

    2017-05-19

    Clostridium difficile is a gram-positive intestine bacterium that causes a severe diarrhea and could eventually be lethal. The main virulence factor is related to the release of two major exotoxins, toxin A (TcdA) and toxin B (TcdB). Recent C. difficile-associated disease (CDAD) outbreaks have been caused by hypervirulent strains which secrete an additional binary toxin (CDTa/CDTb). Vaccination against these toxins is considered the best way to combat the CDAD. Recently, a novel tetravalent C. difficile vaccine candidate containing all four toxins produced from a baculovirus expression system has been developed. A dose assay to release this tetravalent C. difficile vaccine was developed using tandem ion-exchange HPLC chromatography. A sequential weak cation exchange (carboxyl group) and weak anion exchange (tertiary amine group) columns were employed. The four C. difficile vaccine antigen pIs range from 4.4 to 8.6. The final optimized separation employs salt gradient elution at two different pHs. The standard analytical parameters such as LOD, LOQ, linearity, accuracy, precision and repeatability were evaluated for this method and it was deemed acceptable as a quantitative assay for vaccine release. Furthermore, the developed method was utilized for monitoring the stability of the tetravalent C. difficile vaccine in final container. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Kilowatt Isotope Power System: component test report for the ground demonstration system jet condenser orifice performance. 77-KIPS-103

    Energy Technology Data Exchange (ETDEWEB)

    Brainard, E.L.

    1977-11-08

    The purpose of these tests was to determine which orifice elements achieved satisfactory hydraulic and thermal performance prior to their incorporation into the Jet Condenser Assembly. Requirements were as set forth within the Kilowatt Isotope Power System (KIPS) Component Test Procedure number 414 for the Jet Condenser Orifice Performance testing. The results of the performance testing conducted on the Jet Condenser Orifices are presented. Part Number 720841 Jet Condenser Orifice Nozzle successfully completed the orifice screening tests.

  13. Single Doses up to 800 mg of E-52862 Do Not Prolong the QTc Interval--A Retrospective Validation by Pharmacokinetic-Pharmacodynamic Modelling of Electrocardiography Data Utilising the Effects of a Meal on QTc to Demonstrate ECG Assay Sensitivity.

    Science.gov (United States)

    Täubel, Jörg; Ferber, Georg; Lorch, Ulrike; Wang, Duolao; Sust, Mariano; Camm, A John

    2015-01-01

    E-52862 is a Sigma-1 receptor antagonist (S1RA) currently under investigation as a potential analgesic medicine. We successfully applied a concentration-effect model retrospectively to a four-way crossover Phase I single ascending dose study and utilized the QTc shortening effects of a meal to demonstrate assay sensitivity by establishing the time course effects from baseline in all four periods, independently from any potential drug effects. Thirty two healthy male and female subjects were included in four treatment periods to receive single ascending doses of 500 mg, 600 mg or 800 mg of E-52862 or placebo. PK was linear over the dose range investigated and doses up to 600 mg were well tolerated. The baseline electrocardiography (ECG) measurements on Day-1 were time-matched with ECG and pharmacokinetic (PK) samples on Day 1 (dosing day). In this conventional mean change to time-matched placebo analysis, the largest time-matched difference to placebo QTcI was 1.44 ms (90% CI: -4.04, 6.93 ms) for 500 mg; -0.39 ms (90% CI: -3.91, 3.13 ms) for 600 mg and 1.32 ms (90% CI: -1.89, 4.53 ms) for 800 mg of E-52862, thereby showing the absence of any QTc prolonging effect at the doses tested. In addition concentration-effect models, one based on the placebo corrected change from baseline and one for the change of QTcI from average baseline with time as fixed effect were fitted to the data confirming the results of the time course analysis. The sensitivity of this study to detect small changes in the QTc interval was confirmed by demonstrating a shortening of QTcF of -8.1 (90% CI: -10.4, -5.9) one hour and -7.2 (90% CI: -9.4, -5.0) three hours after a standardised meal. EU Clinical Trials Register EudraCT 2010 020343 13.

  14. The impact of HIV infection and CD4 cell count on the performance of an interferon gamma release assay in patients with pulmonary tuberculosis

    DEFF Research Database (Denmark)

    Aabye, Martine G.; Ravn, Pernille; PrayGod, George

    2009-01-01

    BACKGROUND: The performance of the tuberculosis specific Interferon Gamma Release Assays (IGRAs) has not been sufficiently documented in tuberculosis- and HIV-endemic settings. This study evaluated the sensitivity of the QuantiFERON TB-Gold In-Tube (QFT-IT) in patients with culture confirmed...... pulmonary tuberculosis (PTB) in a TB- and HIV-endemic population and the effect of HIV-infection and CD4 cell count on test performance. METHODOLOGY/PRINCIPAL FINDINGS: 161 patients with sputum culture confirmed PTB were subjected to HIV- and QFT-IT testing and measurement of CD4 cell count. The QFT......-infection is prevalent....

  15. High-performance liquid chromatography-tandem mass spectrometry assay of fatty acid amide hydrolase (FAAH) in blood: FAAH inhibition as clinical biomarker.

    Science.gov (United States)

    Yapa, Udeni; Prusakiewicz, Jeffery J; Wrightstone, Ann D; Christine, Lori J; Palandra, Joe; Groeber, Elizabeth; Wittwer, Arthur J

    2012-02-15

    Fatty acid amide hydrolase (FAAH) is one of the main enzymes responsible for the degradation of the endocannabinoid anandamide (N-arachidonoylethanolamine, AEA). FAAH inhibitors may be useful in treating many disorders involving inflammation and pain. Although brain FAAH may be the relevant target for inhibition, rat studies show a correlation between blood and brain FAAH inhibition, allowing blood FAAH activity to be used as a target biomarker. Building on experience with a rat leukocyte FAAH activity assay using [³H]AEA, we have developed a human leukocyte assay using stably labeled [²H₄]AEA as substrate. The deuterium-labeled ethanolamine reaction product ([²H₄]EA) was analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in the positive electrospray ionization (ESI) mode. The response for [²H₄]EA was linear from 10 nM to 10 μM, and the analysis time was less than 6 min/sample. Results using the [²H₄]AEA and HPLC-MS/MS method agreed well with those obtained using the [³H]AEA radiometric assay. In addition to using a nonradioactive substrate, the HPLC-MS/MS method had increased sensitivity with lower background. Importantly, the assay preserved partial FAAH inhibition resulting from ex vivo treatment with a time-dependent irreversible inhibitor, suggesting its utility with clinical samples. The assay has been used to profile the successful inhibition of FAAH in recent clinical trials. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Evaluation of the diagnostic performance of current and next-generation assays for cardiac troponin I in the BWH-TIMI ED Chest Pain Study

    Science.gov (United States)

    Ruff, Christian T; Kosowsky, Joshua; Conrad, Michael J; Murphy, Sabina A; Sabatine, Marc S; Jarolim, Petr; Morrow, David A

    2013-01-01

    Background: Rapid diagnosis of acute coronary syndrome is a clinical and operational priority in busy emergency departments (ED). We examined the performance of an investigational troponin I (TnI) assay with 10–100-times greater sensitivity than current commercial assays. Methods: Among patients with non-traumatic chest pain enrolled in the BWH-TIMI ED Chest Pain Study, we measured TnI (n=381) at baseline, 4–6 h, and 12–24 h with an investigational assay (S-TnI; Singulex, detection-limit 0.0002 µg/l, 99th percentile 0.009 µg/l) and a contemporary sensitive assay (TnI-Ultra; Siemens, detection-limit 0.006 µg/l, 99th percentile 0.04 µg/l). Final diagnosis was adjudicated using all diagnostic data and local hospital-based cardiac TnI (Siemens), blinded to investigational cardiac Tn. Results: The adjudicated diagnosis was myocardial infarction (MI) in 96 patients, unstable angina in 41, and acute non-coronary cardiovascular conditions in 50 patients. Baseline S-TnI was highly sensitive for MI (97%, 95% CI 91–99%) with specificity 81% (95% CI 76–86%) and positive predictive value 63% (95% CI 55–71%). The negative predictive value with S-TnI was 99% (95% CI 96–100%). S-TnI had better diagnostic accuracy than the local assay (area under the curve 0.976 vs. 0.916, p=0.003). Among 20 patients with negative baseline TnI and diagnosis of MI, 19 had elevated baseline S-TnI. Compared to TnI-Ultra, S-TnI trended toward higher sensitivity (97 vs. 94%, p=NS) but did not differ significantly in negative predictive value (99 vs. 98%) or area under the curve (p=0.29). Conclusion: Current and investigational Tn assays substantially increased clinical sensitivity and improved diagnostic accuracy for MI, despite a decline in specificity. A contemporary sensitive assay delivered similar overall accuracy to the investigational test, suggesting that we have reached a point of maximum diagnostic return with increasing analytical sensitivity. PMID:24222830

  17. Arsenic Removal from Drinking Water by Adsorptive Media, U.S. EPA Demonstration Project at LEADS Head Start Building in Buckeye Lake, OH - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained for the arsenic removal treatment technology demonstration project at Licking Economic Action Development Study (LEADS) Head Start School in Buckeye Lake, Ohio. The objectives of the project were to evaluate...

  18. Arsenic Removal from Drinking Water by Adsorptive Media U.S. EPA Demonstration Project at Richmond Elementary School in Susanville, CA Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained for the arsenic removal treatment technology demonstration project at Richmond Elementary School in Susanville, CA. The objectives of the project were to evaluate: (1) the effectiveness of an Aquatic Treatme...

  19. Demonstration and Evaluation of Solid Phase Microextraction for the Assessment of Bioavailability and Contaminant Mobility. ESTCP Cost and Performance Report

    Science.gov (United States)

    2012-08-01

    demonstrate the ability to place high value sorbents in a thin layer in sediments), apatite (as a phosphate- based metals control agent) and sand (as...contaminants with freshwater invertebrates. Second edition. EPA-600/R-99/064. Duluth, MN . Vinturella, A.E., R.M. Burgess, B.A. Coull, K.M. Thompson

  20. Effects of visual demonstration, verbal instructions, and prompted verbal descriptions on the performance of human subjects in conditional discriminations

    Science.gov (United States)

    Ribes-Iñesta, Emilio; Cepeda, Ma. Luisa; Hickman, Hortencia; Moreno, Diana; Peñalosa, Eduardo

    1992-01-01

    A study was conducted to confirm prior results concerning the role of prompted verbal descriptions of visually demonstrated stimulus relations in the acquisition and transfer of identity, difference, and similarity-matching relations (Ribes et al., 1988). Four groups of human adults were trained with these three matching relations under four different procedures: (1) visual demonstration without response requirement, (2) verbal instructions, (3) visual demonstration plus prompted verbal description, and (4) visual demonstration plus verbal instructions. These procedures were presented at the beginning of the training period before subjects could respond to the experimental task. Although most subjects in the four groups acquired the conditional discrimination under the three matching relations, only those in the two instruction-related groups showed some intramodal and extramodal transfer in tests with stimuli that had not been used in training. These results suggest the importance of measuring extra-situational and trans-situational generalization, and raise the need to distinguish between formal and functional verbal factors in the regulation of human behavior. ImagesFig. 3Fig. 4 PMID:22477044

  1. A lateral electrophoretic flow diagnostic assay.

    Science.gov (United States)

    Lin, Robert; Skandarajah, Arunan; Gerver, Rachel E; Neira, Hector D; Fletcher, Daniel A; Herr, Amy E

    2015-03-21

    Immunochromatographic assays are a cornerstone tool in disease screening. To complement existing lateral flow assays (based on wicking flow) we introduce a lateral flow format that employs directed electrophoretic transport. The format is termed a "lateral e-flow assay" and is designed to support multiplexed detection using immobilized reaction volumes of capture antigen. To fabricate the lateral e-flow device, we employ mask-based UV photopatterning to selectively immobilize unmodified capture antigen along the microchannel in a barcode-like pattern. The channel-filling polyacrylamide hydrogel incorporates a photoactive moiety (benzophenone) to immobilize capture antigen to the hydrogel without a priori antigen modification. We report a heterogeneous sandwich assay using low-power electrophoresis to drive biospecimen through the capture antigen barcode. Fluorescence barcode readout is collected via a low-resource appropriate imaging system (CellScope). We characterize lateral e-flow assay performance and demonstrate a serum assay for antibodies to the hepatitis C virus (HCV). In a pilot study, the lateral e-flow assay positively identifies HCV+ human sera in 60 min. The lateral e-flow assay provides a flexible format for conducting multiplexed immunoassays relevant to confirmatory diagnosis in near-patient settings.

  2. Reflectance Demonstration.

    Science.gov (United States)

    Kowalski, Frank

    1993-01-01

    Presents a demonstration in which a mirror "disappears" upon rotation. The author has used the demonstration with students from fourth grade up through college. Suggestions are given for making the demonstration into a permanent hallway display. (MVL)

  3. Thread as a matrix for biomedical assays.

    Science.gov (United States)

    Reches, Meital; Mirica, Katherine A; Dasgupta, Rohit; Dickey, Michael D; Butte, Manish J; Whitesides, George M

    2010-06-01

    This paper describes the use of thread as a matrix for the fabrication of diagnostic assay systems. The kinds of thread used for this study are inexpensive, broadly available, and lightweight; some of them are already familiar materials in healthcare. Fluids wick along these threads by capillary action; no external power source is necessary for pumping. This paper demonstrates three designs for diagnostic assays that use different characteristics of the thread. The first two designs-the "woven array" and the "branching design"-take advantage of the ease with which thread can be woven on a loom to generate fluidic pathways that enable multiple assays to be performed in parallel. The third design-the "sewn array"-takes advantage of the ease with which thread can be sewn through a hydrophobic polymer sheet to incorporate assays into bandages, diapers and similar systems. These designs lead to microfluidic devices that may be useful in performing simple colorimetric assays that require qualitative results. We demonstrate the function of thread-based microfluidic devices in the context of five different colorimetric assays: detection of ketones, nitrite, protein, and glucose in artificial urine, and detection of alkaline phosphatase in artificial plasma.

  4. Arsenic and Uranium Removal from Drinking Water by Adsorptive Media U.S. EPA Demonstration Project at Upper Bodfish in Lake Isabella, CA -Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the performance evaluation of an arsenic (As) and uranium (U) removal technology demonstrated at Upper Bodfish in Lake Isabella, CA. The objectives of the project are to evaluate: (1) the effecti...

  5. LIFAC Demonstration at Richmond Power and Light Whitewater Valley Unit No. 2 Volume II: Project Performance and Economics

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1998-04-01

    The C1ean Coal Technology (CCT) Program has been recognized in the National Energy Strategy as a major initiative whereby coal will be able to reach its full potential as a source of energy for the nation and the international marketplace. Attainment of this goal depends upon the development of highly efficient, environmentally sound, competitive coal utilization technologies responsive to diverse energy markets and varied consumer needs. The CCT Program is an effort jointly funded by government and industry whereby the most promising of the advanced coal-based technologies are being moved into the marketplace through demonstration. The CCT Program is being implemented through a total of five competitive solicitations. LIFAC North America, a joint venture partnership of ICF Kaiser Engineers, Inc., and Tampella Power Corporation, is currently demonstrating the LIFAC flue gas desulfurization technology developed by Tampella Power. This technology provides sulfur dioxide emission control for power plants, especially existing facilities with tight space limitations. Sulfur dioxide emissions are expected to be reduced by up to 85% by using limestone as a sorbent. The LIFAC technology is being demonstrated at Whitewater Valley Unit No. 2, a 60-MW coal-fired power plant owned and operated by Richmond Power and Light (RP&L) and located in Richmond, Indiana. The Whitewater plant consumes high-sulfur coals, with sulfur contents ranging from 2.0-2.9 $ZO. The project, co-funded by LIFAC North America and DOE, is being conducted with the participation of Richmond Power and Light, the State of Indiana, the Electric Power Research Institute (EPRI), and the Black Beauty Coal Company. The project has a total cost of $21.4 million and a duration of 48 months from the preliminary design phase through the testing program.

  6. Performance evaluation of three commercial molecular assays for the detection of Mycobacterium tuberculosis from clinical specimens in a high TB-HIV-burden setting.

    Science.gov (United States)

    Matabane, M M Z; Ismail, F; Strydom, K A; Onwuegbuna, O; Omar, S V; Ismail, N

    2015-11-09

    A major challenge faced by countries with a high burden of tuberculosis (TB) is early detection especially in individuals with paucibacillary disease which is common in HIV endemic settings. Remarkable efforts have been made globally to accelerate the development and expansion of new diagnostic technologies that allow better and earlier diagnosis of active tuberculosis particularly directly from clinical specimens with a few commercial options available. These include GenoType MTBDRplus Version 2.0 (Hain Lifescience), Xpert® MTB/RIF (Cepheid) and Anyplex™ plus MTB/NTM/DR-TB Real-time detection (Seegene). We evaluated the diagnostic performance of these three commercial molecular assays for the detection of Mycobacterium tuberculosis complex from clinical specimens in a high TB-HIV-burden setting. This was a retrospective laboratory-based study using stored remnant sediments from clinical specimens of presumptive pulmonary TB cases. A stratified sample of smear positive TB, smear negative TB and TB culture negatives was included. All the samples were tested on the three molecular assays following the manufacturers' instructions; except for Anyplex™plus, for which DNA extraction was performed using the NucliSENS® easyMAG® platform (bioMerieux). Samples were also processed for liquid TB culture and time-to-culture positivity was recorded. Of the 90 sediments processed, 81 were analyzable across all three systems. The overall sensitivity was highest for Xpert® MTB/RIF (89.1%) followed by GenoType MTBDRplus (70.9%) and Anyplex™ plus (65.5%). The specificity and sensitivity in smear positive cases was comparable across all systems. There was a significant difference in sensitivity between Xpert® MTB/RIF and the other two assays for smear-negative cases (P < 0.05). The performance in cases where the time-to-culture positivity was ≥ 20 days was also significantly poorer for both Anyplex™ plus and GenoType MTBDRplus compared to Xpert® MTB/RIF (P < 0

  7. Dual testing algorithm of BED-CEIA and AxSYM Avidity Index assays performs best in identifying recent HIV infection in a sample of Rwandan sex workers.

    Directory of Open Access Journals (Sweden)

    Sarah L Braunstein

    Full Text Available BACKGROUND: To assess the performance of BED-CEIA (BED and AxSYM Avidity Index (Ax-AI assays in estimating HIV incidence among female sex workers (FSW in Kigali, Rwanda. METHODOLOGY AND FINDINGS: Eight hundred FSW of unknown HIV status were HIV tested; HIV-positive women had BED and Ax-AI testing at baseline and ≥12 months later to estimate assay false-recent rates (FRR. STARHS-based HIV incidence was estimated using the McWalter/Welte formula, and adjusted with locally derived FRR and CD4 results. HIV incidence and local assay window periods were estimated from a prospective cohort of FSW. At baseline, 190 HIV-positive women were BED and Ax-AI tested; 23 were classified as recent infection (RI. Assay FRR with 95% confidence intervals were: 3.6% (1.2-8.1 (BED; 10.6% (6.1-17.0 (Ax-AI; and 2.1% (0.4-6.1 (BED/Ax-AI combined. After FRR-adjustment, incidence estimates by BED, Ax-AI, and BED/Ax-AI were: 5.5/100 person-years (95% CI 2.2-8.7; 7.7 (3.2-12.3; and 4.4 (1.4-7.3. After CD4-adjustment, BED, Ax-AI, and BED/Ax-AI incidence estimates were: 5.6 (2.6-8.6; 9.7 (5.0-14.4; and 4.7 (2.0-7.5. HIV incidence rates in the first and second 6 months of the cohort were 4.6 (1.6-7.7 and 2.2 (0.1-4.4. CONCLUSIONS: Adjusted incidence estimates by BED/Ax-AI combined were similar to incidence in the first 6 months of the cohort. Furthermore, false-recent rate on the combined BED/Ax-AI algorithm was low and substantially lower than for either assay alone. Improved assay specificity with time since seroconversion suggests that specificity would be higher in population-based testing where more individuals have long-term infection.

  8. INTERIM REPORT ON THE EVOLUTION AND PERFORMANCE OF THE EICHROM TECHNOLOGIES PROCEPT RAPID DIOXIN ASSAY FOR SOIL AND SEDIMENT SAMPLES

    Science.gov (United States)

    A demonstration of screening technologies for determining the presence of dioxin and dioxin-like compounds in soil and sediment was conducted under the U.S. Environmental Protection Agency's(EPA's) Superfund Innovative Technology Evaluation Program in Saginaw, Michigan in 2004. T...

  9. Performance of a Cartridge-Based Assay for Detection of Clinically Significant Human Papillomavirus (HPV) Infection: Lessons from VALGENT (Validation of HPV Genotyping Tests)

    Science.gov (United States)

    Geraets, Daan; Cuzick, Jack; Cadman, Louise; Moore, Catherine; Vanden Broeck, Davy; Padalko, Elisaveta; Quint, Wim; Arbyn, Marc

    2016-01-01

    The Validation of Human Papillomavirus (HPV) Genotyping Tests (VALGENT) studies offer an opportunity to clinically validate HPV assays for use in primary screening for cervical cancer and also provide a framework for the comparison of analytical and type-specific performance. Through VALGENT, we assessed the performance of the cartridge-based Xpert HPV assay (Xpert HPV), which detects 14 high-risk (HR) types and resolves HPV16 and HPV18/45. Samples from women attending the United Kingdom cervical screening program enriched with cytologically abnormal samples were collated. All had been previously tested by a clinically validated standard comparator test (SCT), the GP5+/6+ enzyme immunoassay (EIA). The clinical sensitivity and specificity of the Xpert HPV for the detection of cervical intraepithelial neoplasia grade 2 or higher (CIN2+) and CIN3+ relative to those of the SCT were assessed as were the inter- and intralaboratory reproducibilities according to international criteria for test validation. Type concordance for HPV16 and HPV18/45 between the Xpert HPV and the SCT was also analyzed. The Xpert HPV detected 94% of CIN2+ and 98% of CIN3+ lesions among all screened women and 90% of CIN2+ and 96% of CIN3+ lesions in women 30 years and older. The specificity for CIN1 or less (≤CIN1) was 83% (95% confidence interval [CI], 80 to 85%) in all women and 88% (95% CI, 86 to 91%) in women 30 years and older. Inter- and intralaboratory agreements for the Xpert HPV were 98% and 97%, respectively. The kappa agreements for HPV16 and HPV18/45 between the clinically validated reference test (GP5+/6+ LMNX) and the Xpert HPV were 0.92 and 0.91, respectively. The clinical performance and reproducibility of the Xpert HPV are comparable to those of well-established HPV assays and fulfill the criteria for use in primary cervical cancer screening. PMID:27385707

  10. The diagnostic performance of a single GeneXpert MTB/RIF assay in an intensified tuberculosis case finding survey among HIV-infected prisoners in Malaysia.

    Directory of Open Access Journals (Sweden)

    Haider Abdulrazzaq Abed Al-Darraji

    Full Text Available Delays in tuberculosis (TB diagnosis, particularly in prisons, is associated with detrimental outcomes. The new GeneXpert MTB/RIF assay (Xpert offers accurate and rapid diagnosis of active TB, but its performance in improving case detection in high-transmission congregate settings has yet to be evaluated. We assessed the diagnostic accuracy of a single Xpert assay in an intensified case finding survey among HIV-infected prisoners in Malaysia.HIV-infected prisoners at a single site provided two early-morning sputum specimens to be examined using fluorescence smear microscopy, BACTEC MGIT 960 liquid culture and a single Xpert. The sensitivity, specificity, negative and positive predictive values of Xpert were calculated relative to gold-standard results using MGIT 960 liquid culture. Relevant clinical and demographic data were used to examine correlates of active TB disease.The majority of enrolled subjects with complete data (N=125 were men (90.4%, age <40 years (61.6% and had injected drugs (75.2%. Median CD4 lymphocyte count was 337 cells/µL (IQR 149-492; only 19 (15.2% were receiving antiretroviral therapy. Of 15 culture-positive TB cases, single Xpert assay accurately detected only eight previously undiagnosed TB cases, resulting in a sensitivity, specificity, positive predictive value and negative predictive value of 53.3% (95% CI 30.12-75.2%, 100% (95% CI 96.6-100%, 100% (95% CI 67.56-100% and 94.0% (95% CI 88.2-97.1%, respectively. Only 1 of 15 (6.7% active TB cases was smear-positive. The prevalence (12% of undiagnosed active pulmonary TB (15 of 125 prisoners was high and associated with longer duration of drug use (AOR 1.14, 95% CI 1.03-1.26, for each year of drug use.Single Xpert assay improved TB case detection and outperformed AFB smear microscopy, but yielded low screening sensitivity. Further examination of the impact of HIV infection on the diagnostic performance of the new assay alongside other screening methods in correctional

  11. Clinical and analytical performance of the BD Onclarity™ HPV assay for detection of CIN2+ lesions on SurePath samples

    DEFF Research Database (Denmark)

    Ejegod, Ditte Møller; Junge, Jette; Franzmann, Maria

    2016-01-01

    using adjudicated histological outcomes from Danish women referred for colposcopy. METHODS: 276 women from Copenhagen, Denmark were referred for colposcopy with abnormal cytology and/or a positive HPV test. Two samples for HPV analysis were taken in BD SurePath™ and in the BD cervical brush diluent (CBD......%, 17%, and 22%, for HC2, Onclarity and LA, respectively. CONCLUSION: Overall, the Onclarity HPV assay performed well on SurePath LBC and CBD media, with clinical sensitivity and specificity matching those of HC2 and LA....

  12. Demonstration of the Performance of an Air-Type Photovoltaic Thermal (PVT System Coupled with a Heat-Recovery Ventilator

    Directory of Open Access Journals (Sweden)

    Jin-Hee Kim

    2016-09-01

    Full Text Available A heat-recovery ventilator (HRV effectively conducts ventilation by recovering waste heat from indoors to outdoors during heating periods. However, dew condensation associated with the HRV system may arise due to the difference between the indoor temperature and the very low outdoor temperature in winter, and this can decrease the heat exchange efficiency. These problems can be solved by the pre-heating of the incoming air, but additional energy is required when pursuing such a strategy. On the other hand, an air-type photovoltaic thermal (PVT system produces electricity and thermal energy simultaneously using air as the heat transfer medium. Moreover, the heated air from the air-type PVT system can be connected to the HRV to pre-heat the supply air instead of taking in the cold outdoor air. Thus, the ventilation efficiency can be improved and the problems arising during the heating period can be resolved. Consequentially, the heating energy required in a building can be reduced, with additional electricity acquired as well. In this paper, the performance of an air-type PVT system coupled with an HRV is assessed. To do this, air-type PVT collectors operating at 1 kWp were installed in an experimental house and coupled to an HRV system. Thermal performance and heating energy required during the winter season were analyzed experimentally. Furthermore, the electrical performances of the air-type PVT system with and without ventilation at the back side of the PV during the summer season were analyzed.

  13. Evaluation of lot-to-lot repeatability and effect of assay media choice in the recombinant Factor C assay.

    Science.gov (United States)

    McKenzie, Jennifer Helen; Alwis, K Udeni; Sordillo, Joanne E; Kalluri, Kesava Srinivas; Milton, Donald Kirby

    2011-06-01

    Measurement of environmental endotoxin exposures is complicated by variability encountered using current biological assay methods arising in part from lot-to-lot variability of the Limulus-amebocyte lysate (LAL) reagents. Therefore, we investigated the lot-to-lot repeatability of commercially available recombinant Factor C (rFC) kits as an alternative to LAL. Specifically, we compared endotoxin estimates obtained from rFC assay of twenty indoor dust samples, using four different extraction and assay media, to endotoxin estimates previously obtained by Limulus amebocyte lysate (LAL) assay and amounts of 3-hydroxy fatty acids (3-OHFA) in lipopolysaccharide (LPS) using gas-chromatography mass spectroscopy (GC-MS). We found that lot-to-lot variability of the rFC assay kits does not significantly alter endotoxin estimates in house dust samples when performed using three of the four assay media tested and that choice of assay media significantly altered endotoxin estimates obtained by rFC assay of house dust samples. Our findings demonstrate lot-to-lot reproducibility of rFC assay of environmental samples and suggest that use of rFC assay performed with Tris buffer or water as the extraction and assay medium for measurement of endotoxin in dust samples may be a suitable choice for developing a standardized methodology.

  14. Optimization process for the design of the DCLL blanket for the European DEMOnstration fusion reactor according to its nuclear performances

    Science.gov (United States)

    Palermo, Iole; Rapisarda, David; Fernández-Berceruelo, Iván; Ibarra, Angel

    2017-07-01

    The research study focuses on the neutronic design analysis and optimization of one of the options for a fusion reactor designed as DCLL (dual coolant lithium-lead). The main objective has been to develop an efficient and technologically viable modular DCLL breeding blanket (BB) using the DEMO generic design specifications established within the EUROfusion Programme. The final neutronic design has to satisfy the requirements of: tritium self-sufficiency; BB thermal efficiency; preservation of plasma confinement; temperature limits imposed by materials; and radiation limits to guarantee the largest operational life for all the components. Therefore, a 3D fully heterogeneous DCLL neutronic model has been developed for the DEMO baseline 2014 determining its behaviour under the real operational conditions of the DEMO reactor. Consequent actions have been adopted to improve its performances. Neutronic assessments have specially addressed tritium breeding ratio, multiplication energy factor, power density distributions, damage and shielding responses. The model has then been adapted to the subsequent DEMO baseline 2015 (with a more powerful and bigger plasma, smaller divertor and bigger blanket segments), implying new design choices to improve the reactor nuclear performances.

  15. First steps toward harmonized human biomonitoring in Europe: demonstration project to perform human biomonitoring on a European scale.

    Science.gov (United States)

    Den Hond, Elly; Govarts, Eva; Willems, Hanny; Smolders, Roel; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Schwedler, Gerda; Seiwert, Margarete; Fiddicke, Ulrike; Castaño, Argelia; Esteban, Marta; Angerer, Jürgen; Koch, Holger M; Schindler, Birgit K; Sepai, Ovnair; Exley, Karen; Bloemen, Louis; Horvat, Milena; Knudsen, Lisbeth E; Joas, Anke; Joas, Reinhard; Biot, Pierre; Aerts, Dominique; Koppen, Gudrun; Katsonouri, Andromachi; Hadjipanayis, Adamos; Krskova, Andrea; Maly, Marek; Mørck, Thit A; Rudnai, Peter; Kozepesy, Szilvia; Mulcahy, Maurice; Mannion, Rory; Gutleb, Arno C; Fischer, Marc E; Ligocka, Danuta; Jakubowski, Marek; Reis, M Fátima; Namorado, Sónia; Gurzau, Anca Elena; Lupsa, Ioana-Rodica; Halzlova, Katarina; Jajcaj, Michal; Mazej, Darja; Tratnik, Janja Snoj; López, Ana; Lopez, Estrella; Berglund, Marika; Larsson, Kristin; Lehmann, Andrea; Crettaz, Pierre; Schoeters, Greet

    2015-03-01

    For Europe as a whole, data on internal exposure to environmental chemicals do not yet exist. Characterization of the internal individual chemical environment is expected to enhance understanding of the environmental threats to health. We developed and applied a harmonized protocol to collect comparable human biomonitoring data all over Europe. In 17 European countries, we measured mercury in hair and cotinine, phthalate metabolites, and cadmium in urine of 1,844 children (5-11 years of age) and their mothers. Specimens were collected over a 5-month period in 2011-2012. We obtained information on personal characteristics, environment, and lifestyle. We used the resulting database to compare concentrations of exposure biomarkers within Europe, to identify determinants of exposure, and to compare exposure biomarkers with health-based guidelines. Biomarker concentrations showed a wide variability in the European population. However, levels in children and mothers were highly correlated. Most biomarker concentrations were below the health-based guidance values. We have taken the first steps to assess personal chemical exposures in Europe as a whole. Key success factors were the harmonized protocol development, intensive training and capacity building for field work, chemical analysis and communication, as well as stringent quality control programs for chemical and data analysis. Our project demonstrates the feasibility of a Europe-wide human biomonitoring framework to support the decision-making process of environmental measures to protect public health.

  16. Performance of the GeneXpert Ebola Assay for Diagnosis of Ebola Virus Disease in Sierra Leone: A Field Evaluation Study.

    Directory of Open Access Journals (Sweden)

    Amanda E Semper

    2016-03-01

    Full Text Available Throughout the Ebola virus disease (EVD epidemic in West Africa, field laboratory testing for EVD has relied on complex, multi-step real-time reverse transcription PCR (RT-PCR assays; an accurate sample-to-answer RT-PCR test would reduce time to results and potentially increase access to testing. We evaluated the performance of the Cepheid GeneXpert Ebola assay on clinical venipuncture whole blood (WB and buccal swab (BS specimens submitted to a field biocontainment laboratory in Sierra Leone for routine EVD testing by RT-PCR ("Trombley assay".This study was conducted in the Public Health England EVD diagnostic laboratory in Port Loko, Sierra Leone, using residual diagnostic specimens remaining after clinical testing. EDTA-WB specimens (n = 218 were collected from suspected or confirmed EVD patients between April 1 and July 20, 2015. BS specimens (n = 71 were collected as part of a national postmortem screening program between March 7 and July 20, 2015. EDTA-WB and BS specimens were tested with Xpert (targets: glycoprotein [GP] and nucleoprotein [NP] genes and Trombley (target: NP gene assays in parallel. All WB specimens were fresh; 84/218 were tested in duplicate on Xpert to compare WB sampling methods (pipette versus swab; 43/71 BS specimens had been previously frozen. In all, 7/218 (3.2% WB and 7/71 (9.9% BS samples had Xpert results that were reported as "invalid" or "error" and were excluded, leaving 211 WB and 64 BS samples with valid Trombley and Xpert results. For WB, 22/22 Trombley-positive samples were Xpert-positive (sensitivity 100%, 95% CI 84.6%-100%, and 181/189 Trombley-negative samples were Xpert-negative (specificity 95.8%, 95% confidence interval (CI 91.8%-98.2%. Seven of the eight Trombley-negative, Xpert-positive (Xpert cycle threshold [Ct] range 37.7-43.4 WB samples were confirmed to be follow-up submissions from previously Trombley-positive EVD patients, suggesting a revised Xpert specificity of 99.5% (95% CI 97

  17. Dataset demonstrating the modeling of a high performance Cu(In,GaSe2 absorber based thin film photovoltaic cell

    Directory of Open Access Journals (Sweden)

    Md. Asaduzzaman

    2017-04-01

    Full Text Available The physical data of the semiconductor materials used in the design of a CIGS absorber based thin film photovoltaic cell have been presented in this data article. Besides, the values of the contact parameter and operating conditions of the cell have been reported. Furthermore, by conducting the simulation with data corresponding to the device structure: soda-lime glass (SLG substrate/Mo back-contact/CIGS absorber/CdS buffer/intrinsic ZnO/Al-doped ZnO window/Al-grid front-contact, the solar cell performance parameters such as open circuit voltage (Voc, short circuit current density Jsc, fill factor (FF, efficiency (η, and collection efficiency ηc have been analyzed.

  18. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1990-01-01

    Presented are two demonstrations; "Heat of Solution and Colligative Properties: An Illustration of Enthalpy and Entropy," and "A Vapor Pressure Demonstration." Included are lists of materials and experimental procedures. Apparatus needed are illustrated. (CW)

  19. The Comet Assay: Tails of the (Unexpected. Use of the comet assay in pharmaceutical development.

    Directory of Open Access Journals (Sweden)

    Bas-jan Van Der Leede

    2015-08-01

    Full Text Available In genotoxicity testing of pharmaceuticals the rodent alkaline comet assay is being increasingly used as a second in vivo assay in addition to the in vivo micronucleus assay to mitigate in vitro positive results as recommended by regulatory guidance. In this presentation we want to give insight into the circumstances in vivo comet assay is deployed in a Genetic Toxicology Department of a pharmaceutical company. As the in vivo comet assay is a salvage assay, it means that some events have occurred in an in vitro assay and that the compound (or metabolite responsible for this signal is potentially deselected for further development. More than often the decision to perform an in vivo comet assay is at a very early stage in development and the first time that the compound will be tested in vivo at high/toxic dose levels. As almost no toxicokinetic data and tissue distribution data are available a careful design with maximizes the chances for successful mitigation is necessary. Decisions on acute or repeated dosing need to be made and arrangements for combining the in vivo comet assay with the in vivo micronucleus assay are to be considered. Often synthesis methods need to be scaled up fast to provide the required amount of compound and information on suitable formulations needs to be in place. As exposure data is crucial for interpretation of results, analytical methods need to be brought in place rapidly. An experienced multi skilled and communicative team needs to be available to deploy successfully this kind of assays at an early stage of development. We will present a few scenarios on study conduct and demonstrate how this assay can make a difference for the further development of a new drug.

  20. Proof-of-Concept Demonstrations for Computation-Based Human Reliability Analysis. Modeling Operator Performance During Flooding Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Joe, Jeffrey Clark [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boring, Ronald Laurids [Idaho National Lab. (INL), Idaho Falls, ID (United States); Herberger, Sarah Elizabeth Marie [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The United States (U.S.) Department of Energy (DOE) Light Water Reactor Sustainability (LWRS) program has the overall objective to help sustain the existing commercial nuclear power plants (NPPs). To accomplish this program objective, there are multiple LWRS “pathways,” or research and development (R&D) focus areas. One LWRS focus area is called the Risk-Informed Safety Margin and Characterization (RISMC) pathway. Initial efforts under this pathway to combine probabilistic and plant multi-physics models to quantify safety margins and support business decisions also included HRA, but in a somewhat simplified manner. HRA experts at Idaho National Laboratory (INL) have been collaborating with other experts to develop a computational HRA approach, called the Human Unimodel for Nuclear Technology to Enhance Reliability (HUNTER), for inclusion into the RISMC framework. The basic premise of this research is to leverage applicable computational techniques, namely simulation and modeling, to develop and then, using RAVEN as a controller, seamlessly integrate virtual operator models (HUNTER) with 1) the dynamic computational MOOSE runtime environment that includes a full-scope plant model, and 2) the RISMC framework PRA models already in use. The HUNTER computational HRA approach is a hybrid approach that leverages past work from cognitive psychology, human performance modeling, and HRA, but it is also a significant departure from existing static and even dynamic HRA methods. This report is divided into five chapters that cover the development of an external flooding event test case and associated statistical modeling considerations.

  1. Investigation of OMNIgene·SPUTUM performance in delayed tuberculosis testing by smear, culture, and Xpert MTB/RIF assays in Uganda

    Directory of Open Access Journals (Sweden)

    C.D. Kelly-Cirino

    2017-06-01

    Full Text Available OMNIgene·SPUTUM (OM-S is a sample transport reagent designed to work with all tuberculosis diagnostics while eliminating the need for cold chain. OM-S-treated sputum samples were assayed in several tests after multiday holds. Raw sputa from 100 patients underwent direct smear microscopy, were manually split and assigned to the OM-S group [OM-S added at collection (no other processing required and tested after 0- to 5-day holds at room temperature] or standard-of-care (SOC group (NaOH/N-acetyl l-cysteine decontamination, all tested on day of collection. Concentrated smear microscopy, Lowenstein Jensen (LJ culture, and mycobacteria growth indicator tube (MGIT culture were performed. For patients with negative direct smear, a second sample was split, with SOC (raw sputum and OM-S portions (sediment tested in the Xpert MTB/RIF (Xpert assay. OM-S group and SOC group results were strongly concordant on all four tests [range, 89% (MGIT–97% (Xpert]. OM-S MGIT, LJ, and Xpert tests were in statistical agreement with SOC MGIT as reference. OM-S specimens had lower culture contamination rates (3% vs. 10% LJ; 2% vs. 5% MGIT but required, on average, 5.6 additional days to become MGIT-positive. The findings suggest that samples held/transported in OM-S are compatible with smear microscopy, LJ or MGIT culture, and Xpert, and perform comparably to fresh sputum samples. Larger feasibility studies are warranted.

  2. Development and validation of high performance liquid chromatography with a spectrophotometric detection method for the chemical purity and assay of nepafenac.

    Science.gov (United States)

    Lipiec-Abramska, Elżbieta; Jedynak, Łukasz; Formela, Adam; Roszczyński, Jacek; Cybulski, Marcin; Puchalska, Maria; Zagrodzka, Joanna

    2014-03-01

    The study is a proposition of the application of high performance liquid chromatography (HPLC) with a spectrophotometric UV range detector to analyze the chemical purity and assay of nepafenac, an active pharmaceutical ingredient (API). During literature search only a few publications were found about nepafenac. HPLC UV methods were mainly presented in patent documents about nepafenac synthesis and chemical purity. The presented method allows to separate all potential related compounds from nepafenac and to quantitate the nepafenac amount. As there is no official monograph in the pharmacopeias about nepafenac, the performed full validation procedure makes the method ready to use in routine analysis. The composition of the mobile phase (10mM ammonium formate, pH 4.1) and the HPLC column (Phenomenex Gemini-NX C18) were selected during the development step. Presented data confirm the benefits of the developed method. Four of the most potential impurities were validated as for the quantitative test and the rest of impurities were validated as for the limit test - according to ICH Q2(R1). The accuracy/recovery results for the chemical purity method are within 90-108%, in the case of assay studies from 99% to 101%; the limit of detection is as low as 15-30ng/mL. The linearity passes all statistical tests. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Performance demonstration and personnel qualification for ultrasonic examination in service inspection of nuclear power plants; Ultraaeaenitestauksen menetelmaekokeet ja henkiloestoen paetevoeinti ydinvoimalaitosten maeaeraeaikaistarkastuksissa

    Energy Technology Data Exchange (ETDEWEB)

    Sillanpaeae, J.; Saerkiniemi, P.

    1993-02-01

    The ASME Code section XI (App. VII and VIII) requires that ultrasonic examination procedures, equipment and personnel used to detect and size flaws in reactor vessels, piping welds, bolts and studs shall be qualified by performance demonstration. The requirements for the qualifications of ultrasonic testing personnel and also the requirements for specimens, rules for the conduct of performance demonstrations and acceptance criteria have been clarified in this report. The preparation for these requirements is in progress and the situation in different countries e.g. US and England has been discussed. Also the possibilities to fulfill the requirements of Appendix VIII in Finland are dealt with. (29 refs., 7 figs., 5 tabs.).

  4. Changing Feeding Regimes To Demonstrate Flexible Biogas Production: Effects on Process Performance, Microbial Community Structure, and Methanogenesis Pathways.

    Science.gov (United States)

    Mulat, Daniel Girma; Jacobi, H Fabian; Feilberg, Anders; Adamsen, Anders Peter S; Richnow, Hans-Hermann; Nikolausz, Marcell

    2015-10-23

    Flexible biogas production that adapts biogas output to energy demand can be regulated by changing feeding regimes. In this study, the effect of changes in feeding intervals on process performance, microbial community structure, and the methanogenesis pathway was investigated. Three different feeding regimes (once daily, every second day, and every 2 h) at the same organic loading rate were studied in continuously stirred tank reactors treating distiller's dried grains with solubles. A larger amount of biogas was produced after feeding in the reactors fed less frequently (once per day and every second day), whereas the amount remained constant in the reactor fed more frequently (every 2 h), indicating the suitability of the former for the flexible production of biogas. Compared to the conventional more frequent feeding regimes, a methane yield that was up to 14% higher and an improved stability of the process against organic overloading were achieved by employing less frequent feeding regimes. The community structures of bacteria and methanogenic archaea were monitored by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA and mcrA genes, respectively. The results showed that the composition of the bacterial community varied under the different feeding regimes, and the observed T-RFLP patterns were best explained by the differences in the total ammonia nitrogen concentrations, H2 levels, and pH values. However, the methanogenic community remained stable under all feeding regimes, with the dominance of the Methanosarcina genus followed by that of the Methanobacterium genus. Stable isotope analysis showed that the average amount of methane produced during each feeding event by acetoclastic and hydrogenotrophic methanogenesis was not influenced by the three different feeding regimes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  5. Changing Feeding Regimes To Demonstrate Flexible Biogas Production: Effects on Process Performance, Microbial Community Structure, and Methanogenesis Pathways

    Science.gov (United States)

    Mulat, Daniel Girma; Jacobi, H. Fabian; Feilberg, Anders; Adamsen, Anders Peter S.; Richnow, Hans-Hermann

    2015-01-01

    Flexible biogas production that adapts biogas output to energy demand can be regulated by changing feeding regimes. In this study, the effect of changes in feeding intervals on process performance, microbial community structure, and the methanogenesis pathway was investigated. Three different feeding regimes (once daily, every second day, and every 2 h) at the same organic loading rate were studied in continuously stirred tank reactors treating distiller's dried grains with solubles. A larger amount of biogas was produced after feeding in the reactors fed less frequently (once per day and every second day), whereas the amount remained constant in the reactor fed more frequently (every 2 h), indicating the suitability of the former for the flexible production of biogas. Compared to the conventional more frequent feeding regimes, a methane yield that was up to 14% higher and an improved stability of the process against organic overloading were achieved by employing less frequent feeding regimes. The community structures of bacteria and methanogenic archaea were monitored by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA and mcrA genes, respectively. The results showed that the composition of the bacterial community varied under the different feeding regimes, and the observed T-RFLP patterns were best explained by the differences in the total ammonia nitrogen concentrations, H2 levels, and pH values. However, the methanogenic community remained stable under all feeding regimes, with the dominance of the Methanosarcina genus followed by that of the Methanobacterium genus. Stable isotope analysis showed that the average amount of methane produced during each feeding event by acetoclastic and hydrogenotrophic methanogenesis was not influenced by the three different feeding regimes. PMID:26497462

  6. A European multicientre study on the comparison of HIV-1 viral loads between VERIS HIV-1 Assay and Roche COBAS® TAQMAN® HIV-1 test, Abbott RealTime HIV-1 Assay, and Siemens VERSANT HIV-1 Assay.

    Science.gov (United States)

    Braun, Patrick; Delgado, Rafael; Drago, Monica; Fanti, Diana; Fleury, Hervé; Hofmann, Jörg; Izopet, Jacques; Kühn, Sebastian; Lombardi, Alessandra; Mancon, Alessandro; Marcos, Mª Angeles; Mileto, Davide; Sauné, Karine; O'Shea, Siobhan; Pérez-Rivilla, Alfredo; Ramble, John; Trimoulet, Pascale; Vila, Jordi; Whittaker, Duncan; Artus, Alain; Rhodes, Daniel

    2017-07-01

    Viral load monitoring is essential for patients under treatment for HIV. Beckman Coulter has developed the VERIS HIV-1 Assay for use on the novel, automated DxN VERIS Molecular Diagnostics System. ¥ OBJECTIVES: Evaluation of the clinical performance of the new quantitative VERIS HIV-1 Assay at multiple EU laboratories. Method comparison with the VERIS HIV-1 Assay was performed with 415 specimens at 5 sites tested with COBAS ® AmpliPrep/COBAS ® TaqMan ® HIV-1 Test, v2.0, 169 specimens at 3 sites tested with RealTime HIV-1 Assay, and 202 specimens from 2 sites tested with VERSANT HIV-1 Assay. Patient monitoring sample results from 4 sites were also compared. Bland-Altman analysis showed the average bias between VERIS HIV-1 Assay and COBAS HIV-1 Test, RealTime HIV-1 Assay, and VERSANT HIV-1 Assay to be 0.28, 0.39, and 0.61 log 10 cp/mL, respectively. Bias at low end levels below 1000cp/mL showed predicted bias to be HIV-1 Assay versus COBAS HIV-1 Test and RealTime HIV-1 Assay, and HIV-1 Assay. Analysis on 174 specimens tested with the 0.175mL volume VERIS HIV-1 Assay and COBAS HIV-1 Test showed average bias of 0.39 log 10 cp/mL. Patient monitoring results using VERIS HIV-1 Assay demonstrated similar viral load trends over time to all comparators. The VERIS HIV-1 Assay for use on the DxN VERIS System demonstrated comparable clinical performance to COBAS ® HIV-1 Test, RealTime HIV-1 Assay, and VERSANT HIV-1 Assay. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Paying It Forward: A Technical Assistance Guide for Developing and Implementing Performance-Based Scholarships. The Performance-Based Scholarship Demonstration

    Science.gov (United States)

    Welbeck, Rashida; Ware, Michelle; Cerna, Oscar; Valenzuela, Ireri

    2014-01-01

    Difficulties in paying for college and in maintaining good academic performance are two major hurdles to college graduation for low-income students. In recent years, state and federal budgets for postsecondary education have been cut significantly, limiting the options policymakers, education leaders, and communities have to improve rates of…

  8. Evaluation of the HOOF-Print assay for typing Brucella abortus strains isolated from cattle in the United States: results with four performance criteria

    Directory of Open Access Journals (Sweden)

    Ewalt Darla R

    2005-06-01

    Full Text Available Abstract Background A fundamental question that arises during epidemiological investigations of bacterial disease outbreaks is whether the outbreak strain is genetically related to a proposed index strain. Highly discriminating genetic markers for characterizing bacterial strains can help in clarifying the genetic relationships among strains. Under the auspices of the European Society of Clinical Microbiology and Infectious Diseases, the European Study Group for Epidemiological Markers (ESGEM established guidelines for evaluating the performance of typing systems based of a number of criteria. Recently, HOOF-Print genotype analysis, a new method for typing Brucella abortus strains based on hypervariability at eight tandem repeat loci, was described. This paper evaluates the HOOF-Print assay by four of the criteria set out by the ESGEM: typeability, reproducibility, power of discrimination, and concordance with other typing methods. Results The HOOF-Print Assay was evaluated with a test population composed of 97 unrelated field isolates and 6 common laboratory strains of B. abortus. Both typeability and reproducibility of the assay were excellent. Allele diversity and frequency varied widely among the eight loci, ranging from 1 to 13 alleles. The power of discrimination, measured by the Hunter-Gaston discrimination index (HGDI, varied by locus ranging from 0 to 0.89, where a maximal value of 1.0 indicates discrimination of all strains. The HGDI values calculated for subgroups sorted by biovar were similar to the values determined for the whole population. None of the individual loci achieved the recommended HGDI threshold of 0.95, but the HGDI of the composite profiles was 0.99 (93 unique genotypes from 97 field strains evaluated, well above the recommended threshold. By comparison, the HGDI value for biovar typing was 0.61 in a test population biased with disproportionate numbers of the less common biovars. Cluster analysis based on HOOF

  9. Analytical performance evaluation of the Elecsys® Cyclosporine and Elecsys® Tacrolimus assays on the cobas e411 analyzer

    Directory of Open Access Journals (Sweden)

    Maki Sasano

    2017-08-01

    Full Text Available Background: Cyclosporine (CsA and tacrolimus (TAC are immunosuppressant drugs that are often used to treat autoimmune diseases and as transplantation therapy; therefore, their concentrations need to be monitored carefully. We herein evaluated the analytical performance of the Elecsys® Cyclosporine and Elecsys® Tacrolimus assay kits, which have been newly developed to measure CsA and TAC concentrations in the whole blood. Methods: We used residual whole blood samples from autoimmune disease and transplantation patients who were being treated with CsA or TAC. CsA concentrations were measured using an affinity chrome-mediated immunoassay (ACMIA and an electrochemiluminescence immunoassay (ECLIA. TAC concentrations were measured using a chemiluminescence immunoassay (CLIA and ECLIA. We investigated assay precision, linearity, lower limit of quantitation (LOQ, stability of calibration, influence of interference substances and the hematocrit, correlation of ACMIA with ECLIA, and correlation of CLIA with ECLIA. Results: Within-assay coefficients of variation were 1.8−3.6% (CsA: 94−1238 ng/mL and 2.9−3.9% (TAC: 2.1−17.8 ng/mL, whereas day-to-day coefficients of variation ranged between 3.0−4.1% (CsA and 2.8−3.9% (TAC. The limits of quantitation were defined as the concentration at which the CV was approximately 10%. Each lower LOQ obtained was 16 ng/mL (CsA, and 0.95 ng/mL (TAC. CsA and TAC calibrations were stable for at least 21 days. Neither the presence of conjugated bilirubin, unconjugated bilirubin, chyle, and rheumatoid factor nor the hematocrit affected these assays. A method comparison using a standardized major axis regression analysis of ACMIA and ECLIA was r=0.995, y=0.924x −1.175, n=200 (CsA, while that of CLIA and ECLIA was r=0.994, y=1.080x −0.197, n=200 (TAC. Conclusions: The analytical performances of the Elecsys® Cyclosporine and Elecsys®Tacrolimus assays were acceptable

  10. HIV-1 serologic test results for one million newborn dried-blood specimens: assay performance and implications for screening.

    Science.gov (United States)

    Gwinn, M; Redus, M A; Granade, T C; Hannon, W H; George, J R

    1992-01-01

    In a population-based national survey conducted in 1988-90, more than one million neonatal dried-blood specimens were tested for maternal antibody to human immunodeficiency virus type 1 (HIV-1). Enzyme immunoassays (EIA) and Western blot tests were performed in 20 state laboratories following standardized procedures. The observed predictive value of a repeatedly reactive EIA results closely coincided with that expected on the basis of manufacturer's estimates of test sensitivity and specificity for dried-blood specimens. Of the 2,845 EIA-reactive specimens tested by Western blot, 1,323 (47%) were positive, 1,270 (45%) were negative, and 252 (9%) were indeterminate. False-positive EIA and indeterminate Western blot results occurred at rates independent of seroprevalence. These data help characterize the results to be expected from screening of similar low-seroprevalence populations and constitute a base line for the detection of systematic testing errors.

  11. Performance evaluation of the FDA-approved Determine™ HIV-1/2 Ag/Ab Combo assay using plasma and whole blood specimens.

    Science.gov (United States)

    Masciotra, Silvina; Luo, Wei; Westheimer, Emily; Cohen, Stephanie E; Gay, Cynthia L; Hall, Laura; Pan, Yi; Peters, Philip J; Owen, S Michele

    2017-06-01

    The Determine™ HIV-1/2 Ag/Ab Combo (DC) rapid test can identify HIV-1 infection earlier than rapid antibody-only tests in plasma specimens. We compared the performance of DC with a laboratory-based antigen/antibody (Ag/Ab) combo assay in plasma and evaluated antigen reactivity in whole blood specimens. We tested by DC 508 plasma specimens collected in a prospective study and 107 sequential plasma and simulated whole blood specimens from 20 seroconversion panels. Previous results using the ARCHITECT (ARC) Ag/Ab combo assay were compared to DC results. In seroconversion panels, the days from the first HIV1 RNA-positive test to first DC-reactive in plasma and whole blood was compared. McNemar's and Wilcoxon signed rank tests were used for statistical analysis. Of 415 HIV-positive samples, ARC detected 396 (95.4%) and DC 337 (81.2%) (pARC-reactive/MS-negative, 78.6% of ARC-reactive/MS-indeterminate, and 99.6% of ARC-reactive/MS-HIV-1-positive or -undifferentiated specimens. DC antigen reactivity was higher among ARC-reactive/MS-negative than MS-indeterminate samples. In 20 HIV-1 seroconversion panels, there was a significant difference between DC reactivity in plasma (91.1%) and whole blood (56.4%) (pplasma (p=0.008). In plasma, DC was significantly less sensitive than an instrumented laboratory-based Ag/Ab combo assay. DC in plasma was significantly more sensitive compared to whole blood in early HIV-1 infections. With the U.S. laboratory-based diagnostic algorithm, DC as the first step would likely miss a high proportion of HIV-1 infections in early stages of seroconversion. Published by Elsevier B.V.

  12. Analytical Performance of a Multiplex Real-Time PCR Assay Using TaqMan Probes for Quantification of Trypanosoma cruzi Satellite DNA in Blood Samples

    Science.gov (United States)

    Abate, Teresa; Cayo, Nelly M.; Parrado, Rudy; Bello, Zoraida Diaz; Velazquez, Elsa; Muñoz-Calderon, Arturo; Juiz, Natalia A.; Basile, Joaquín; Garcia, Lineth; Riarte, Adelina; Nasser, Julio R.; Ocampo, Susana B.; Yadon, Zaida E.; Torrico, Faustino; de Noya, Belkisyole Alarcón; Ribeiro, Isabela; Schijman, Alejandro G.

    2013-01-01

    Background The analytical validation of sensitive, accurate and standardized Real-Time PCR methods for Trypanosoma cruzi quantification is crucial to provide a reliable laboratory tool for diagnosis of recent infections as well as for monitoring treatment efficacy. Methods/Principal Findings We have standardized and validated a multiplex Real-Time quantitative PCR assay (qPCR) based on TaqMan technology, aiming to quantify T. cruzi satellite DNA as well as an internal amplification control (IAC) in a single-tube reaction. IAC amplification allows rule out false negative PCR results due to inhibitory substances or loss of DNA during sample processing. The assay has a limit of detection (LOD) of 0.70 parasite equivalents/mL and a limit of quantification (LOQ) of 1.53 parasite equivalents/mL starting from non-boiled Guanidine EDTA blood spiked with T. cruzi CL-Brener stock. The method was evaluated with blood samples collected from Chagas disease patients experiencing different clinical stages and epidemiological scenarios: 1- Sixteen Venezuelan patients from an outbreak of oral transmission, 2- Sixty three Bolivian patients suffering chronic Chagas disease, 3- Thirty four Argentinean cases with chronic Chagas disease, 4- Twenty seven newborns to seropositive mothers, 5- A seronegative receptor who got infected after transplantation with a cadaveric kidney explanted from an infected subject. Conclusions/Significance The performing parameters of this assay encourage its application to early assessment of T. cruzi infection in cases in which serological methods are not informative, such as recent infections by oral contamination or congenital transmission or after transplantation with organs from seropositive donors, as well as for monitoring Chagas disease patients under etiological treatment. PMID:23350002

  13. 'LC-electrolyte effects' improve the bioanalytical performance of liquid chromatography/tandem mass spectrometric assays in supporting pharmacokinetic study for drug discovery.

    Science.gov (United States)

    Wang, Li; Sun, Yan; Du, Feifei; Niu, Wei; Lu, Tong; Kan, Jingmin; Xu, Fang; Yuan, Kaihong; Qin, Tao; Liu, Changxiao; Li, Chuan

    2007-01-01

    The development of rapid and sensitive bioanalytical methods in a short time frame with acceptable levels of precision and accuracy is imperative for successful drug discovery. We previously reported that the use of a mobile phase containing an extremely low concentration of ammonium formate or formic acid increased analyte electrospray ionization (ESI) response and controlled against matrix effects. We designated these favorable effects 'LC-electrolyte effects'. In order to support rapid pharmacokinetic (PK) studies for drug discovery, we applied LC-electrolyte effects to the development of generic procedures that can be used to quickly generate reliable PK data for compound candidates. We herein demonstrate our approach using four model tested compounds (Compd-A, -B, -C, and -D). The analytical methods involve generic protein precipitation for sample clean-up, followed by application of fast liquid chromatographic (LC) gradients and the subsequent use of electrospray ionization tandem mass spectrometry (ESI-MS/MS) for individual measurement of the tested compounds in 20-microL plasma samples. Good linearity over the concentration range of 1.6 or 8-25000 ng/mL (r(2) > 0.99), precision (RSD, 0.45-13.1%), and accuracy (91-112%) were achieved through the use of a low dose of formic acid (0.4 mM or 0.015 per thousand) in the methanol/water-based LC mobile phase. The analytical method was quite sensitive, providing a lower limit of quantification of 1.6 pg on-column except for Compd-C (8 pg), and showed negligible ion suppression caused by matrix components. Finally, the assay suitability was demonstrated in simulated discovery PK studies of the tested compounds with i.v./p.o. dosing of rats. This new assay approach has been adopted with good results in our laboratory for many recent discovery PK studies. Copyright (c) 2007 John Wiley & Sons, Ltd.

  14. ARSENIC REMOVAL FROM DRINKING WATER BY PROCESS MODIFICATION TO COAGULATION/FILTRATION. USEPA DEMONSTRATION PROJECT AT LIDGERWOOD, ND. FINAL PERFORMANCE EVALUATION REPORT

    Science.gov (United States)

    This report documents the activities performed and the results obtained for the arsenic removal treatment technology demonstration project at the Lidgerwood, North Dakota site. The objectives of the project were to evaluate: (1) the effectiveness of process modifications to an e...

  15. Arsenic Removal from Drinking Water by Adsorptive Media - U.S. EPA Demonstration Project at Seely-Brown Village in Pomfret, CT - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed for and the results obtained from the arsenic removal treatment technology demonstration project at Seely-Brown Village in Pomfret, CT. The objectives of the project were to evaluate the effectiveness of ArsenXnp adsorption media in...

  16. Arsenic Removal from Drinking Water by Iron Removal U.S. EPA Demonstration Project at Vintage on the Ponds in Delavan, WI Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained for the arsenic removal treatment technology demonstration project at Vintage on the Ponds in Delavan, WI. The objectives of the project were to evaluate: (1) the effectiveness of a Kinetico Macrolite® press...

  17. Arsenic Removal from Drinking Water by Adsorptive Media - U.S. EPA Demonstration Project at Taos, NM, Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained for the EPA arsenic removal technology demonstration project at the Town of Taos in New Mexico. The main objective of the project was to evaluate the effectiveness of Severn Trent Services’ (STS) SORB 33™ ad...

  18. Arsenic Removal from Drinking Water by Adsorptive Media - U.S. EPA Demonstration Project at Rollinsford, NH, Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained from the arsenic removal treatment technology demonstration project at Rollinsford, New Hampshire. The objectives of the project were to evaluate: 1) the effectiveness of AdEdge Technologies’ AD -33TM media ...

  19. Arsenic Removal from Drinking Water by Adsorptive Media - U.S. EPA Demonstration Project at Hot Springs Mobile Home Park in Willard, Utah - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents activities performed for and results obtained from the arsenic removal treatment technology demonstration project at the Hot Springs Mobile Home Park (HSMHP) in Willard, UT. The objectives of the project were to evaluate the effectiveness of Adsorbsia™ GTO™...

  20. Arsenic Removal from Drinking Water by Adsorptive Media - U.S. EPA Demonstration Project at Geneseo Hills Subdivision, in Geneseo, IL Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained from the arsenic removal treatment technology demonstration project at the Geneseo Hills Subdivision in Geneseo, IL. The main objective of the project was to evaluate the effectiveness of AdEdge Technologies...

  1. Arsenic Removal from Drinking Water by Adsorptive Media - U.S. EPA Demonstration Project at Covered Wells in Tohono O’odham Nation, AZ - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained from the arsenic removal treatment technology demonstration project at Covered Wells in Tohono O’odham Nation, AZ. The main objective of the project was to evaluate the effectiveness of AdEdge Technologies’ ...

  2. ARSENIC REMOVAL FROM DRINKING WATER BY IRON REMOVAL. U.S. EPA DEMONSTRATION PROJECT AT CLIMAX, MN. FINAL PERFORMANCE EVALUATION REPORT.

    Science.gov (United States)

    This report documents the activities performed and the results obtained for the arsenic removal treatment technology demonstration project following one year of operation at the Climax, Minnesota, site. The objectives of the project were to evaluate: (1) the effectiveness of Kin...

  3. Arsenic Removal from Drinking Water by Adsorptive Media U.S. EPA Demonstration Project at Spring Brook Mobile Home Park in Wales, ME Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained for the arsenic removal treatment technology demonstration project at Spring Brook Mobile Home Park (SBMHP) in Wales, Maine. The objectives of the project were to evaluate: 1) the effectiveness of an arsenic...

  4. Arsenic Removal from Drinking Water by Coagulation/Filtration - U.S. EPA Demonstration Project at Village of Waynesville, IL - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained from the arsenic removal drinking water treatment technology demonstration project at the Village of Waynesville, IL. The main objective of the project was to evaluate the effectiveness of the Peerless coagu...

  5. Arsenic Removal from Drinking Water by Coagulation/Filtration, U.S. EPA Demonstration Project at the City of Okanogan, WA - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at the City of Okanogan, WA facility. The objectives of the project were to evaluate: (1) the effectiveness of Filtronics’ FH-13 Ele...

  6. Arsenic Removal from Drinking Water by Coagulation/Filtration - U.S. EPA Demonstration Project at Town of Arnaudville, LA - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at the United Water Systems’ facility in Arnaudville, LA. The objectives of the project were to evaluate: (1) the effectiveness of K...

  7. Arsenic Removal from Drinking Water by Adsorptive Media U.S. EPA Demonstration Project at Webb Consolidated Independent School District in Bruni, TX - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained from the arsenic removal treatment technology demonstration project at the Webb Consolidated Independent School District (Webb CISD) in Bruni, TX. The main objective of the project was to evaluate the effect...

  8. Arsenic Removal from Drinking Water by Adsorptive Media - U.S. EPA Demonstration Project at Woodstock Middle School in Woodstock, CT - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed for and the results obtained from the arsenic removal treatment technology demonstration project at the Woodstock Middle School in Woodstock, CT. The objectives of the project were to evaluate the effectiveness of Adsorbsia™ GTO™ me...

  9. Arsenic Removal from Drinking Water by Iron Removal - U.S. EPA Demonstration Project at Northeastern Elementary School in Fountain City, IN - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed and the results obtained from the arsenic removal treatment technology demonstration project at Northeastern Elementary School in Fountain City, IN. The main objective of the project was to evaluate the effectiveness of US Water Sys...

  10. ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA U.S. EPA DEMONSTRATION PROJECT AT CHATEAU ESTATES MOBILE HOME PARK IN SPRINGFIELD, OH. FINAL PERFORMANCE EVALUATION REPORT

    Science.gov (United States)

    This report documents the activities performed for and the results obtained from the first six months of the arsenic removal treatment technology demonstration project at the Chateau Estates Mobile Home Park at Springfield, OH. The objectives of the project are to evaluate the ef...

  11. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1985-01-01

    Two demonstrations are described. The first (useful as an introduction to kinetics) shows how the rate of a reaction is fast at first and then gradually decreases to zero when one reactant has been used up. The second is a gas density demonstration using 1,1,2-trichloro-1,2,2-trifluoro ethane. (JN)

  12. Application of the micronucleus assay performed by different scorers in case of large-scale radiation accidents

    Directory of Open Access Journals (Sweden)

    Rawojć Kamila

    2015-09-01

    Full Text Available Mass casualty scenarios of radiation exposure require high throughput biological dosimetry techniques for population triage, in order to rapidly identify individuals, who require clinical treatment. Accurate dose estimates can be made by biological dosimetry, to predict the acute radiation syndrome (ARS within days after a radiation accident or a malicious act involving radiation. Timely information on dose is important for the medical management of acutely irradiated persons [1]. The aim of the study was to evaluate the usefulness of the micronuclei (MNi scoring procedure in an experimental mode, where 500 binucleated cells were analyzed in different exposure dose ranges. Whole-body exposure was simulated in an in vitro experiment by irradiating whole blood collected from one healthy donor with 60 MeV protons and 250 keV X-rays, in the dose range of 0.3-4.0 Gy. For achieving meaningful results, sample scoring was performed by three independent persons, who followed guidelines described in detail by Fenech et al. [2, 3]. Compared results revealed no significant differences between scorers, which has important meaning in reducing the analysis time. Moreover, presented data based on 500 cells distribution, show that there are significant differences between MNi yields after 1.0 Gy exposure of blood for both protons and X-rays, implicating this experimental mode as appropriate for the distinction between high and low dose-exposed individuals, which allows early classification of exposed victims into clinically relevant subgroups.

  13. Beyond-use date determination of buprenorphine buccal solution using a stability-indicating high-performance liquid chromatographic assay.

    Science.gov (United States)

    Kirk, Loren Madden; Brown, Stacy D

    2015-12-01

    The objectives of this study included developing and validating a stability-indicating high-performance liquid chromatographic (HPLC) method with ultraviolet (UV) detection for the determination of buprenorphine in a buccal solution for veterinary use, and applying that method to determine the stability of a 3 mg/ml buprenorphine preparation in room temperature and refrigerated storage conditions. This preparation, intended for buccal administration in feline patients, plays an important role in pain management in cats. A stability-indicating HPLC method was developed and validated for system suitability, accuracy, repeatability, intermediate precision, specificity, linearity and robustness based on US Pharmacopeia (USP) General Chapter . The method was then applied to the study of potency changes over 90 days in a buccal buprenorphine solution stored at two temperatures. All HPLC-UV method data met acceptable criteria for the quantification of buprenorphine in a buccal solution formulation. The buprenorphine concentrations found in each stability sample remained within the 90-110% of label claim throughout the 90 days of study. All stability test bottles of the buprenorphine buccal solution retained their original appearance. For the room temperature bottles, some white particulate matter was noted in the threads of the container bottles starting at day 21. The pH of the preparations during the course of the study was in the range of 3.57-4.06 and 4.01-4.16 for the room temperature and refrigerated samples, respectively. Pharmacists have compounded a concentrated 3 mg/ml buccal solution to use easily in the home care or outpatient setting for treatment of feline pain. Prior to this investigation, pharmacists empirically assigned beyond-use dates to this formulation based on standards in USP General Chapter Pharmaceutical Compounding - Nonsterile Preparations. This study of a 3 mg/ml buprenorphine buccal solution indicates stability through 90 days. © ISFM and

  14. Stability-indicating assay of repaglinide in bulk and optimized nanoemulsion by validated high performance thin layer chromatography technique

    Directory of Open Access Journals (Sweden)

    Juber Akhtar

    2013-01-01

    Full Text Available A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatographic (HPTLC method for analysis of repaglinide both as a bulk drug and in nanoemulsion formulation was developed and validated. The method employed TLC aluminum plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of chloroform/methanol/ammonia/glacial acetic acid (7.5:1.5:0.9:0.1, v/v/v/v. This system was found to give compact spots for repaglinide (R f value of 0.38 ± 0.02. Repaglinide was subjected to acid and alkali hydrolysis, oxidation, photodegradation and dry heat treatment. Also, the degraded products were well separated from the pure drug. Densitometric analysis of repaglinide was carried out in the absorbance mode at 240 nm. The linear regression data for the calibration plots showed good linear relationship with r 2 = 0.998 ± 0.032 in the concentration range of 50-800 ng. The method was validated for precision, accuracy as recovery, robustness and specificity. The limits of detection and quantitation were 0.023 and 0.069 ng per spot, respectively. The drug undergoes degradation under acidic and basic conditions, oxidation and dry heat treatment. All the peaks of the degraded product were resolved from the standard drug with significantly different R f values. Statistical analysis proves that the method is reproducible and selective for the estimation of the said drug. As the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating one. Moreover, the proposed HPTLC method was utilized to investigate the degradation kinetics in 1M NaOH.

  15. Monitoring the Secretory Behavior of the Rat Adrenal Medulla by High-Performance Liquid Chromatography-Based Catecholamine Assay from Slice Supernatants

    Science.gov (United States)

    De Nardi, Frédéric; Lefort, Claudie; Bréard, Dimitri; Richomme, Pascal; Legros, Christian; Guérineau, Nathalie C.

    2017-01-01

    Catecholamine (CA) secretion from the adrenal medullary tissue is a key step of the adaptive response triggered by an organism to cope with stress. Whereas molecular and cellular secretory processes have been extensively studied at the single chromaffin cell level, data available for the whole gland level are much scarcer. We tackled this issue in rat by developing an easy to implement experimental strategy combining the adrenal acute slice supernatant collection with a high-performance liquid chromatography-based epinephrine and norepinephrine (NE) assay. This technique affords a convenient method for measuring basal and stimulated CA release from single acute slices, allowing thus to individually address the secretory function of the left and right glands. Our data point that the two glands are equally competent to secrete epinephrine and NE, exhibiting an equivalent epinephrine:NE ratio, both at rest and in response to a cholinergic stimulation. Nicotine is, however, more efficient than acetylcholine to evoke NE release. A pharmacological challenge with hexamethonium, an α3-containing nicotinic acetylcholine receptor antagonist, disclosed that epinephrine- and NE-secreting chromaffin cells distinctly expressed α3 nicotinic receptors, with a dominant contribution in NE cells. As such, beyond the novelty of CA assays from acute slice supernatants, our study contributes at refining the secretory behavior of the rat adrenal medullary tissue, and opens new perspectives for monitoring the release of other hormones and transmitters, especially those involved in the stress response. PMID:28993760

  16. Monitoring the Secretory Behavior of the Rat Adrenal Medulla by High-Performance Liquid Chromatography-Based Catecholamine Assay from Slice Supernatants

    Directory of Open Access Journals (Sweden)

    Frédéric De Nardi

    2017-09-01

    Full Text Available Catecholamine (CA secretion from the adrenal medullary tissue is a key step of the adaptive response triggered by an organism to cope with stress. Whereas molecular and cellular secretory processes have been extensively studied at the single chromaffin cell level, data available for the whole gland level are much scarcer. We tackled this issue in rat by developing an easy to implement experimental strategy combining the adrenal acute slice supernatant collection with a high-performance liquid chromatography-based epinephrine and norepinephrine (NE assay. This technique affords a convenient method for measuring basal and stimulated CA release from single acute slices, allowing thus to individually address the secretory function of the left and right glands. Our data point that the two glands are equally competent to secrete epinephrine and NE, exhibiting an equivalent epinephrine:NE ratio, both at rest and in response to a cholinergic stimulation. Nicotine is, however, more efficient than acetylcholine to evoke NE release. A pharmacological challenge with hexamethonium, an α3-containing nicotinic acetylcholine receptor antagonist, disclosed that epinephrine- and NE-secreting chromaffin cells distinctly expressed α3 nicotinic receptors, with a dominant contribution in NE cells. As such, beyond the novelty of CA assays from acute slice supernatants, our study contributes at refining the secretory behavior of the rat adrenal medullary tissue, and opens new perspectives for monitoring the release of other hormones and transmitters, especially those involved in the stress response.

  17. Monitoring the Secretory Behavior of the Rat Adrenal Medulla by High-Performance Liquid Chromatography-Based Catecholamine Assay from Slice Supernatants.

    Science.gov (United States)

    De Nardi, Frédéric; Lefort, Claudie; Bréard, Dimitri; Richomme, Pascal; Legros, Christian; Guérineau, Nathalie C

    2017-01-01

    Catecholamine (CA) secretion from the adrenal medullary tissue is a key step of the adaptive response triggered by an organism to cope with stress. Whereas molecular and cellular secretory processes have been extensively studied at the single chromaffin cell level, data available for the whole gland level are much scarcer. We tackled this issue in rat by developing an easy to implement experimental strategy combining the adrenal acute slice supernatant collection with a high-performance liquid chromatography-based epinephrine and norepinephrine (NE) assay. This technique affords a convenient method for measuring basal and stimulated CA release from single acute slices, allowing thus to individually address the secretory function of the left and right glands. Our data point that the two glands are equally competent to secrete epinephrine and NE, exhibiting an equivalent epinephrine:NE ratio, both at rest and in response to a cholinergic stimulation. Nicotine is, however, more efficient than acetylcholine to evoke NE release. A pharmacological challenge with hexamethonium, an α3-containing nicotinic acetylcholine receptor antagonist, disclosed that epinephrine- and NE-secreting chromaffin cells distinctly expressed α3 nicotinic receptors, with a dominant contribution in NE cells. As such, beyond the novelty of CA assays from acute slice supernatants, our study contributes at refining the secretory behavior of the rat adrenal medullary tissue, and opens new perspectives for monitoring the release of other hormones and transmitters, especially those involved in the stress response.

  18. Development of a combined in vitro cell culture--quantitative PCR assay for evaluating the disinfection performance of pulsed light for treating the waterborne enteroparasite Giardia lamblia.

    Science.gov (United States)

    Garvey, Mary; Stocca, Alessia; Rowan, Neil

    2014-09-01

    Giardia lamblia is a flagellated protozoan parasite that is recognised as a frequent cause of water-borne disease in humans and animals. We report for the first time on the use of a combined in vitro HCT-8 cell culture-quantitative PCR assay for evaluating the efficacy of using pulsed UV light for treating G. lamblia parasites. Findings showed that current methods that are limited to using vital stains before and after cyst excystation are not appropriate for monitoring or evaluating cyst destruction post PUV-treatments. Use of the human ileocecal HCT-8 cell line was superior to that of the human colon Caco-2 cell line for in vitro culture and determining PUV sensitivity of treated cysts. G. lamblia cysts were also shown to be more resistant to PUV irradiation compared to treating similar numbers of Cryptosporidium parvum oocysts. These observations also show that the use of this HCT-8 cell culture assay may replace use of animal models for determining disinfection performances of PUV for treating both C. parvum and G. lamblia. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Application of 3D Printing Technology in Increasing the Diagnostic Performance of Enzyme-Linked Immunosorbent Assay (ELISA for Infectious Diseases

    Directory of Open Access Journals (Sweden)

    Harpal Singh

    2015-07-01

    Full Text Available Enzyme-linked Immunosorbent Assay (ELISA-based diagnosis is the mainstay for measuring antibody response in infectious diseases and to support pathogen identification of potential use in infectious disease outbreaks and clinical care of individual patients. The development of laboratory diagnostics using readily available 3D printing technologies provides a timely opportunity for further expansion of this technology into immunodetection systems. Utilizing available 3D printing platforms, a ‘3D well’ was designed and developed to have an increased surface area compared to those of 96-well plates. The ease and rapidity of the development of the 3D well prototype provided an opportunity for its rapid validation through the diagnostic performance of ELISA in infectious disease without modifying current laboratory practices for ELISA. The improved sensitivity of the 3D well of up to 2.25-fold higher compared to the 96-well ELISA provides a potential for the expansion of this technology towards miniaturization and Lab-On-a-Chip platforms to reduce time, volume of reagents and samples needed for such assays in the laboratory diagnosis of infectious and other diseases including applications in other disciplines.

  20. High-performance liquid chromatography assay for the determination of the HIV-protease inhibitor tipranavir in human plasma in combination with nine other antiretroviral medications.

    Science.gov (United States)

    Choi, Sun Ok; Rezk, Naser L; Kashuba, Angela D M

    2007-03-12

    An accurate, sensitive and simple reverse-phase (RP) high-performance liquid chromatography (HPLC) assay has been developed and validated for the simultaneous quantitative determination of tipranavir with nine other antiretroviral drugs in plasma. A liquid-liquid extraction of the drugs in tert-butylmethylether (TBME) from 200 microL of plasma is followed by a reversed phase gradient HPLC assay with UV detection at 210 nm. The standard curve for the drug was linear in the range of 80-80,000 ng/mL for tipranavir; 10-10,000 ng/mL for nevirapine, indinavir, efavirenz, and saquinavir; and 25-10,000 ng/mL for amprenavir, atazanavir, ritonavir, lopinavir, and nelfinavir. The regression coefficient (r(2)) was greater than 0.998 for all analytes. This method has been fully validated and shown to be specific, accurate and precise. Due to an excellent extraction procedure giving good recovery and a clean baseline, this method is simple, rapid, accurate and provides excellent resolution and peak shape for all analytes. Thus this method is very suitable for therapeutic drug monitoring.

  1. Performance of a Cartridge-Based Assay for Detection of Clinically Significant Human Papillomavirus (HPV) Infection: Lessons from VALGENT (Validation of HPV Genotyping Tests).

    Science.gov (United States)

    Cuschieri, Kate; Geraets, Daan; Cuzick, Jack; Cadman, Louise; Moore, Catherine; Vanden Broeck, Davy; Padalko, Elisaveta; Quint, Wim; Arbyn, Marc

    2016-09-01

    The Validation of Human Papillomavirus (HPV) Genotyping Tests (VALGENT) studies offer an opportunity to clinically validate HPV assays for use in primary screening for cervical cancer and also provide a framework for the comparison of analytical and type-specific performance. Through VALGENT, we assessed the performance of the cartridge-based Xpert HPV assay (Xpert HPV), which detects 14 high-risk (HR) types and resolves HPV16 and HPV18/45. Samples from women attending the United Kingdom cervical screening program enriched with cytologically abnormal samples were collated. All had been previously tested by a clinically validated standard comparator test (SCT), the GP5+/6+ enzyme immunoassay (EIA). The clinical sensitivity and specificity of the Xpert HPV for the detection of cervical intraepithelial neoplasia grade 2 or higher (CIN2+) and CIN3+ relative to those of the SCT were assessed as were the inter- and intralaboratory reproducibilities according to international criteria for test validation. Type concordance for HPV16 and HPV18/45 between the Xpert HPV and the SCT was also analyzed. The Xpert HPV detected 94% of CIN2+ and 98% of CIN3+ lesions among all screened women and 90% of CIN2+ and 96% of CIN3+ lesions in women 30 years and older. The specificity for CIN1 or less (≤CIN1) was 83% (95% confidence interval [CI], 80 to 85%) in all women and 88% (95% CI, 86 to 91%) in women 30 years and older. Inter- and intralaboratory agreements for the Xpert HPV were 98% and 97%, respectively. The kappa agreements for HPV16 and HPV18/45 between the clinically validated reference test (GP5+/6+ LMNX) and the Xpert HPV were 0.92 and 0.91, respectively. The clinical performance and reproducibility of the Xpert HPV are comparable to those of well-established HPV assays and fulfill the criteria for use in primary cervical cancer screening. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  2. Performance of the Abbott RealTime MTB and MTB RIF/INH Assays in a Setting of High Tuberculosis and HIV Coinfection in South Africa.

    Science.gov (United States)

    Scott, Lesley; David, Anura; Noble, Lara; Nduna, Matilda; Da Silva, Pedro; Black, Andrew; Venter, Francois; Stevens, Wendy

    2017-08-01

    South Africa is a country with a high incidence of tuberculosis (TB), complicated by coinfection with human immunodeficiency virus (HIV). The Xpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) is used in South Africa as the test for the initial diagnosis of TB, and other molecular platforms such as the m 2000 (Abbott Molecular, Des Plaines, IL, USA) are widely used for molecular monitoring of HIV load. The latter platform is now also equipped with the RealTi m e (RT) MTB and RealTi m e MTB RIF/INH assays for TB and first-line drug resistance screening but has not been evaluated in settings of HIV and TB coinfection. A prospective clinical validation study was conducted at a community health center in Johannesburg, South Africa, and consenting individuals with presumptive pulmonary TB were enrolled. The performance of the Abbott assays was compared with those of the Xpert MTB/RIF, liquid culture, drug susceptibility testing, and clinical case definitions. A statistical analysis was performed on 206 individuals (73% were HIV positive). The sensitivity and specificity of the RT MTB were 82.5% (confidence interval [CI], 67.2 to 92.7) and 93.1% (CI, 86.2 to 97.2) on raw sputum and 77.5% (CI, 61.5 to 89.2) and 95.1% (CI, 88.9 to 98.4) on concentrated sputum, respectively, compared with those from liquid culture. The RT MTB correctly identified 17/35 more smear-negative culture-positive specimens than the Xpert MTB/RIF. Both the RT MTB and the Xpert MTB/RIF displayed sensitivities >70% and specificities >90% in HIV-positive individuals. The available drug resistance results concurred with MTBDR plus and drug susceptibility profiles. The RT MTB assay has similar diagnostic performance to the Xpert MTB/RIF and is suited to testing presumptive TB patients coinfected with HIV. The existing laboratory information system connectivity, training, and technical support make this a viable polyvalent option to scale up TB alongside HIV laboratory testing services in South Africa. Copyright

  3. Performance of HBsAg quantification assays for detection of Hepatitis B virus genotypes and diagnostic escape-variants in clinical samples.

    Science.gov (United States)

    Thibault, Vincent; Servant-Delmas, Annabelle; Ly, Thoai Duong; Roque-Afonso, Anne-Marie; Laperche, Syria

    2017-04-01

    The impact of hepatitis B virus (HBV) genomic variability on the measurement of HBsAg level has been poorly evaluated. This study was designed to compare the performance of all the available assays measuring HBsAg level in this setting. A large selection of wild type HBV genotypes (n=184) and HBsAg strains harboring mutations in the S gene (n=81) from clinical samples was studied with three HBsAg quantification assays: Architect HBsAg (Abbott), LiaisonXL Murex HBsAg Quant (DiaSorin) and the Elecsys HBsAgII (Roche). The overall percentage of positive results was 99.2% for Abbott, 98.9% for DiaSorin and 98.1% for Roche. Abbott and Roche assays provided an excellent concordance in HBsAg quantification (global mean bias of -0.006 logIU/mL). By contrast, DiaSorin underestimated HBsAg level with values 0.112 logIU/ml and 0.103 logIU/ml lower than Abbott and Roche, respectively. By contrast, DiaSorin slightly over quantified gtC (2.5% over the expected value) while Abbott provided values 6.2% lower than expected and 16.2% lower than what observed for the other genotypes. HBsAg quantitative assays were influenced by HBs protein substitutions irrespective to the genotype but no specific protein pattern that would particularly impair the quantification by one technique has been identified. However, Roche seemed to be particularly impacted by substitutions at 145 residue: 75% of under quantified samples carried a substituted 145 residue. This head-to-head comparison indicates a good correlation between all current systems used to quantify HBsAg but clearly shows an influence of both the genotype and the presence of "a" determinant variants in the absolute quantification of HBsAg. While these discrepancies may not translate into major clinical consequence, they may explain an absence of detection of weak concentration of HBsAg on some systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Analytical performance of newly developed multiplex human papillomavirus genotyping assay using Luminex xMAP™ technology (Mebgen™ HPV Kit).

    Science.gov (United States)

    Ozaki, Satoru; Kato, Kana; Abe, Yukiko; Hara, Hirotaka; Kubota, Hiroshi; Kubushiro, Kaneyuki; Kawahara, Ei; Inoue, Masaki

    2014-08-01

    Regional differences in human papillomavirus (HPV) genotypes and the presence of mixed HPV infections may affect adversely the efficacy of the HPV vaccine. Therefore, a simple and high-throughput HPV genotyping system is required. Recently, a novel HPV genotyping kit (the Mebgen™ HPV kit) was developed. This kit uses multiplex PCR and Luminex xMAP™ technology to detect 13 types of high-risk HPVs and an internal control in a 96-well format. In the present study, the analytical performance of the kit was examined using HPV plasmid DNA. All 13 types of HPVs were detected with a minimum detection sensitivity of 250 copies/test, and highly specific signals were observed. HPV 16 plasmid was detected in samples containing mixtures with other HPV-type plasmids in ratios ranging from 1:1 to 1:1000. No cross reactivity was observed with DNA from 27 types of other infectious microbes. A clinical evaluation was carried out using cervical samples from 356 patients with persistent abnormal smears diagnosed at mass public health screenings for cervical cancer. The samples were preserved in Tacas™ medium until analysis. HPV was detected in 162 (45.5%) samples including 110 (67.9%) with single infections and 52 (32.1%) with multiple infections. The type distribution of the 13 high-risk HPVs was as follows: 28.4% HPV 16, 11.7% HPV 18, 6.8% HPV 31, 3.1% HPV 33, 3.7% HPV 35, 9.3% HPV 39, 1.9% HPV 45, 8.6% HPV 51, 37.0% HPV 52, 9.3% HPV 56, 16.7% HPV 58, 3.7% HPV 59, and 1.9% HPV 68. To evaluate sample stability over time, changes in the detection of HPV DNA derived from HeLa and SiHa cells were measured in 3 types of liquid-based cytology media. HPV DNA was detected in Tacas and Thinprep™ samples after storage at 4°C or 30°C for 4 weeks and within 1 week of collection in Surepath™ samples. These results suggest that this newly developed HPV genotyping kit is suitable for use in both clinical applications and large-scale epidemiological studies. Copyright © 2014 The

  5. The relative test performance characteristics of two commercial assays for the detection of Mycobacterium tuberculosis complex in paraffin-fixed human biopsy specimens

    Directory of Open Access Journals (Sweden)

    Broukhanski George

    2008-09-01

    Full Text Available Abstract The Seeplex™ TB Detection-2 assay (Rockville, MD is a nested endpoint PCR for the Mycobacterium tuberculosis complex (MTBC targets IS6110 and MPB64 that utilizes dual priming oligonucleotide technology. When used to detect the presence of MTBC DNA in formalin-fixed paraffin-embedded tissue specimens, the sensitivity and specificity of this assay is equivalent to a labor-intensive traditional endpoint PCR assay and is more sensitive than a commercial real-time PCR assay.

  6. Determination of vitamin B6 vitamers and pyridoxic acid in plasma: development and evaluation of a high-performance liquid chromatographic assay

    DEFF Research Database (Denmark)

    Bisp, Marianne R; Bor, Mustafa Vakur; Heinsvig, Else-Marie

    2002-01-01

    were eluted with a gradient of acetonitrile (0.5-15%) in a potassium phosphate buffer with 1-octanesulfonic acid and triethylamine, pH 2.16. The concentration of the vitamers was determined with fluorescence detector (328 nm excitation, 393 nm emission) after postcolumn derivatization with phosphate...... vitamers pyridoxal 5'-phosphate (PLP), pyridoxal (PL), pyridoxamine 5'-phosphate (PMP), pyridoxine (PN), and pyridoxamine (PM) and the degradation product 4-pyridoxic acid (4-PA). The separation was accomplished using a C18 (ODS) analytical column and an ion-pair reversed-phase chromatography. B6 vitamers...... buffer containing 1 g/L sodium bisulfite. The performance of the assay was evaluated by analyzing six plasma samples with interrelated concentration and two control samples (unspiked and vitamer spiked) over a 3-months period. The HPLC method was able to identify PLP, 4-PA, PM, PL, PN, and PMP from all...

  7. Performance of the Molecular Alere i Influenza A&B Test Compared to That of the Xpert Flu A/B Assay

    Science.gov (United States)

    Flores-Cortez, Estefany J.

    2014-01-01

    Data on the performance of rapid molecular point-of-care use platforms for diagnosis of influenza are lacking. We validated nasopharyngeal (NP) flocked specimens in universal transport medium (UTM) and evaluated the clinical sensitivity and specificity of the Alere i influenza A&B test compared to those of the Xpert flu A/B assay. The Alere i influenza A&B test had an overall sensitivity and specificity of 93.8% and 62.5% for influenza A, respectively, and of 91.8% and 53.6% for influenza B, respectively. The poor specificity was due to influenza virus samples determined positive for both type A and B. PMID:25502527

  8. Performance of the molecular Alere I influenza A&B test compared to that of the xpert flu A/B assay.

    Science.gov (United States)

    Chapin, Kimberle C; Flores-Cortez, Estefany J

    2015-02-01

    Data on the performance of rapid molecular point-of-care use platforms for diagnosis of influenza are lacking. We validated nasopharyngeal (NP) flocked specimens in universal transport medium (UTM) and evaluated the clinical sensitivity and specificity of the Alere i influenza A&B test compared to those of the Xpert flu A/B assay. The Alere i influenza A&B test had an overall sensitivity and specificity of 93.8% and 62.5% for influenza A, respectively, and of 91.8% and 53.6% for influenza B, respectively. The poor specificity was due to influenza virus samples determined positive for both type A and B. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Development of automated brightfield double In Situ hybridization (BDISH application for HER2 gene and chromosome 17 centromere (CEN 17 for breast carcinomas and an assay performance comparison to manual dual color HER2 fluorescence In Situ hybridization (FISH

    Directory of Open Access Journals (Sweden)

    Wang Lin

    2008-10-01

    Full Text Available Abstract Background Human epidermal growth factor receptor 2 (HER2 fluorescence in situ hybridization (FISH is a quantitative assay for selecting breast cancer patients for trastuzumab therapy. However, current HER2 FISH procedures are labor intensive, manual methods that require skilled technologists and specialized fluorescence microscopy. Furthermore, FISH slides cannot be archived for long term storage and review. Our objective was to develop an automated brightfield double in situ hybridization (BDISH application for HER2 gene and chromosome 17 centromere (CEN 17 and test the assay performance with dual color HER2 FISH evaluated breast carcinomas. Methods The BDISH assay was developed with the nick translated dinitrophenyl (DNP-labeled HER2 DNA probe and DNP-labeled CEN 17 oligoprobe on the Ventana BenchMark® XT slide processing system. Detection of HER2 and CEN 17 signals was accomplished with the silver acetate, hydroquinone, and H2O2 reaction with horseradish peroxidase (HRP and the fast red and naphthol phosphate reaction with alkaline phosphatise (AP, respectively. The BDISH specificity was optimized with formalin-fixed, paraffin-embedded xenograft tumors, MCF7 (non-amplified HER2 gene and BT-474 (amplified HER2 gene. Then, the BDISH performance was evaluated with 94 routinely processed breast cancer tissues. Interpretation of HER2 and CEN 17 BDISH slides was conducted by 4 observers using a conventional brightfield microscope without oil immersion objectives. Results Sequential hybridization and signal detection for HER2 and CEN 17 ISH demonstrated both DNA targets in the same cells. HER2 signals were visualized as discrete black metallic silver dots while CEN 17 signals were detected as slightly larger red dots. Our study demonstrated a high consensus concordance between HER2 FISH and BDISH results of clinical breast carcinoma cases based on the historical scoring method (98.9%, Simple Kappa = 0.9736, 95% CI = 0.9222 – 1.0000 and

  10. The Impact of Nursing Home Pay-for-Performance on Quality and Medicare Spending: Results from the Nursing Home Value-Based Purchasing Demonstration.

    Science.gov (United States)

    Grabowski, David C; Stevenson, David G; Caudry, Daryl J; O'Malley, A James; Green, Lisa H; Doherty, Julia A; Frank, Richard G

    2017-08-01

    To evaluate the impact of the Nursing Home Value-Based Purchasing demonstration on quality of care and Medicare spending. Administrative and qualitative data from Arizona, New York, and Wisconsin nursing homes over the base-year (2008-2009) and 3-year (2009-2012) demonstration period. Nursing homes were randomized to the intervention in New York, while the comparison facilities were constructed via propensity score matching in Arizona and Wisconsin. We used a difference-in-difference analysis to compare outcomes across the base-year relative to outcomes in each of the three demonstration years. To provide context and assist with interpretation of results, we also interviewed staff members at participating facilities. Medicare savings were observed in Arizona in the first year only and Wisconsin for the first 2 years; no savings were observed in New York. The demonstration did not systematically impact any of the quality measures. Discussions with nursing home administrators suggested that facilities made few, if any, changes in response to the demonstration, leading us to conclude that the observed savings likely reflected regression to the mean rather than true savings. The Federal nursing home pay-for-performance demonstration had little impact on quality or Medicare spending. © Health Research and Educational Trust.

  11. Low-dose paroxetine exposure causes lifetime declines in male mouse body weight, reproduction and competitive ability as measured by the novel organismal performance assay.

    Science.gov (United States)

    Gaukler, Shannon M; Ruff, James S; Galland, Tessa; Kandaris, Kirstie A; Underwood, Tristan K; Liu, Nicole M; Young, Elizabeth L; Morrison, Linda C; Yost, Garold S; Potts, Wayne K

    2015-01-01

    Paroxetine is a selective serotonin reuptake inhibitor (SSRI) that is currently available on the market and is suspected of causing congenital malformations in babies born to mothers who take the drug during the first trimester of pregnancy. We utilized organismal performance assays (OPAs), a novel toxicity assessment method, to assess the safety of paroxetine during pregnancy in a rodent model. OPAs utilize genetically diverse wild mice (Mus musculus) to evaluate competitive performance between experimental and control animals as they compete among each other for limited resources in semi-natural enclosures. Performance measures included reproductive success, male competitive ability and survivorship. Paroxetine-exposed males weighed 13% less, had 44% fewer offspring, dominated 53% fewer territories and experienced a 2.5-fold increased trend in mortality, when compared with controls. Paroxetine-exposed females had 65% fewer offspring early in the study, but rebounded at later time points, presumably, because they were no longer exposed to paroxetine. In cages, paroxetine-exposed breeders took 2.3 times longer to produce their first litter and pups of both sexes experienced reduced weight when compared with controls. Low-dose paroxetine-induced health declines detected in this study that were undetected in preclinical trials with doses 2.5-8 times higher than human therapeutic doses. These data indicate that OPAs detect phenotypic adversity and provide unique information that could be useful towards safety testing during pharmaceutical development. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Possibilities to achieve better performance at the Pulp and Paper Industry bark boilers by optimised combustion control. Stage 3 Demonstration; Moejligheter till foerbaettrad drift av skogsindustrins barkpannor genom optimerad foerbraenningsteknisk styrning. Etapp 3 Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Robert [AaF-Energi och Miljoe AB, Stockholm (Sweden)

    2002-09-01

    This report presents the result of phase 3 'Full scale demonstration' of project 'Possibilities to achieve better performance at the Pulp and Paper Industry bark boilers by optimised combustion control'. The project was initiated to generate know-how for coping with the special demands that exist for the bark boilers, with rapid changes of loads and fuel quality. The fuel comprises of different types of wood chips, bark and residue fibres with a wide range of moisture contents. In the future it is expected that these boilers, working under difficult conditions, will have the same environmental requirements as district heating boilers. Phase 1 of the project 'Diagnosis and analysis of existing boilers' was published as Vaermeforsk report 660. The report contains an analysis of 21 Swedish bark boilers. Phase 2 'General solutions and possible implementation at four selected boilers' was published as Vaermeforsk report 710. The work has included measurements in- and outside the furnace, tests and mathematical simulation in two steps. The first basic simulations were made to get a good picture of the present situation and the later modification simulations to test the practical effects of different combustion solutions. The presentation in the report has been aimed at describing concrete solutions, but most of all to explain on what grounds different solutions is recommended. In phase 3 'Demonstration' most of the proposed improvement solutions have been implemented at Billerud ABs 40 t/h bark/sludge (130 t/h with oil) bark grate boiler at Karlsborg. The result has been very good with a combination of higher load capacity and large reductions of the CO- and NO{sub x} emissions at a relatively low cost. From an economical point of view has the Billerud Karlsborg AB estimated the reduction in operation cost to almost 3 MSEK annually and the investment cost to 7.7 MSEK. It is our hope that this project has proven that there

  13. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1985-01-01

    Describes two demonstrations that require almost no preparation time, are visually stimulating, and present a variety of material for class discussion (with sample questions provided). The first involves a sodium bicarbonate hydrochloric acid volcano; the second involves a dissolving polystyrene cup. Procedures used and information on…

  14. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1981-01-01

    Provides instructions and a list of materials needed to demonstrate: (1) a model of the quantum mechanical atom; (2) principles involved in metal corrosion and in the prevention of this destructive process by electrochemical means; and (3) a Thermit reaction, modified to make it more dramatic and interesting for students. (SK)

  15. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L.

    1983-01-01

    An apparatus is described in which effects of pressure, volume, and temperature changes on a gas can be observed simultaneously. Includes use of the apparatus in demonstrating Boyle's, Gay-Lussac's, and Charles' Laws, attractive forces, Dalton's Law of Partial pressures, and in illustrating measurable vapor pressures of liquids and some solids.…

  16. On the Safety and Performance Demonstration Tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and Validation and Verification of Computational Codes

    OpenAIRE

    Kim, Jong-Bum; Jeong, Ji-Young; Lee, Tae-Ho; Kim, Sungkyun; Euh, Dong-Jin; Joo, Hyung-Kook

    2016-01-01

    The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V&V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the co...

  17. Analytical Performance of Four Polymerase Chain Reaction (PCR) and Real Time PCR (qPCR) Assays for the Detection of Six Leishmania Species DNA in Colombia

    Science.gov (United States)

    León, Cielo M.; Muñoz, Marina; Hernández, Carolina; Ayala, Martha S.; Flórez, Carolina; Teherán, Aníbal; Cubides, Juan R.; Ramírez, Juan D.

    2017-01-01

    Leishmaniasis comprises a spectrum of parasitic diseases caused by protozoans of the genus Leishmania. Molecular tools have been widely employed for the detection of Leishmania due to its high sensitivity and specificity. However, the analytical performance of molecular platforms as PCR and real time PCR (qPCR) including a wide variety of molecular markers has never been evaluated. Herein, the aim was to evaluate the analytical performance of 4 PCR-based assays (designed on four different targets) and applied on conventional and real-time PCR platforms. We evaluated the analytical performance of conventional PCR and real time PCR, determining exclusivity and inclusivity, Anticipated Reportable Range (ARR), limit of detection (LoD) and accuracy using primers directed to kDNA, HSP70, 18S and ITS-1 targets. We observed that the kDNA was the most sensitive but does not meet the criterion of exclusivity. The HSP70 presented a higher LoD in conventional PCR and qPCR in comparison with the other markers (1 × 101 and 1 × 10-1 equivalent parasites/mL respectively) and had a higher coefficient of variation in qPCR. No statistically significant differences were found between the days of the test with the four molecular markers. The present study revealed that the 18S marker presented the best performance in terms of analytical sensitivity and specificity for the qPCR in the species tested (species circulating in Colombia). Therefore, we recommend to explore the analytical and diagnostic performance in future studies using a broader number of species across America. PMID:29046670

  18. Analytical Performance of Four Polymerase Chain Reaction (PCR) and Real Time PCR (qPCR) Assays for the Detection of Six Leishmania Species DNA in Colombia.

    Science.gov (United States)

    León, Cielo M; Muñoz, Marina; Hernández, Carolina; Ayala, Martha S; Flórez, Carolina; Teherán, Aníbal; Cubides, Juan R; Ramírez, Juan D

    2017-01-01

    Leishmaniasis comprises a spectrum of parasitic diseases caused by protozoans of the genus Leishmania. Molecular tools have been widely employed for the detection of Leishmania due to its high sensitivity and specificity. However, the analytical performance of molecular platforms as PCR and real time PCR (qPCR) including a wide variety of molecular markers has never been evaluated. Herein, the aim was to evaluate the analytical performance of 4 PCR-based assays (designed on four different targets) and applied on conventional and real-time PCR platforms. We evaluated the analytical performance of conventional PCR and real time PCR, determining exclusivity and inclusivity, Anticipated Reportable Range (ARR), limit of detection (LoD) and accuracy using primers directed to kDNA, HSP70, 18S and ITS-1 targets. We observed that the kDNA was the most sensitive but does not meet the criterion of exclusivity. The HSP70 presented a higher LoD in conventional PCR and qPCR in comparison with the other markers (1 × 101 and 1 × 10-1 equivalent parasites/mL respectively) and had a higher coefficient of variation in qPCR. No statistically significant differences were found between the days of the test with the four molecular markers. The present study revealed that the 18S marker presented the best performance in terms of analytical sensitivity and specificity for the qPCR in the species tested (species circulating in Colombia). Therefore, we recommend to explore the analytical and diagnostic performance in future studies using a broader number of species across America.

  19. Analytical Performance of Four Polymerase Chain Reaction (PCR and Real Time PCR (qPCR Assays for the Detection of Six Leishmania Species DNA in Colombia

    Directory of Open Access Journals (Sweden)

    Cielo M. León

    2017-10-01

    Full Text Available Leishmaniasis comprises a spectrum of parasitic diseases caused by protozoans of the genus Leishmania. Molecular tools have been widely employed for the detection of Leishmania due to its high sensitivity and specificity. However, the analytical performance of molecular platforms as PCR and real time PCR (qPCR including a wide variety of molecular markers has never been evaluated. Herein, the aim was to evaluate the analytical performance of 4 PCR-based assays (designed on four different targets and applied on conventional and real-time PCR platforms. We evaluated the analytical performance of conventional PCR and real time PCR, determining exclusivity and inclusivity, Anticipated Reportable Range (ARR, limit of detection (LoD and accuracy using primers directed to kDNA, HSP70, 18S and ITS-1 targets. We observed that the kDNA was the most sensitive but does not meet the criterion of exclusivity. The HSP70 presented a higher LoD in conventional PCR and qPCR in comparison with the other markers (1 × 101 and 1 × 10-1 equivalent parasites/mL respectively and had a higher coefficient of variation in qPCR. No statistically significant differences were found between the days of the test with the four molecular markers. The present study revealed that the 18S marker presented the best performance in terms of analytical sensitivity and specificity for the qPCR in the species tested (species circulating in Colombia. Therefore, we recommend to explore the analytical and diagnostic performance in future studies using a broader number of species across America.

  20. HBsAg blood screening and diagnosis: performance evaluation of the ARCHITECT HBsAg qualitative and ARCHITECT HBsAg qualitative confirmatory assays.

    Science.gov (United States)

    Popp, Christian; Krams, Doris; Beckert, Christian; Buenning, Carsten; Queirós, Lucinda; Piro, Loredana; Luciani, Marina; Roebbecke, Markus; Kapprell, Hans-Peter

    2011-08-01

    A low initial reactive rate for screening assays is important for time- and cost-effective infectious disease testing. Therefore, the new ARCHITECT HBsAg Qualitative screening assay, in conjunction with the new ARCHITECT HBsAg Qualitative Confirmatory assay, was introduced. As the role of hepatitis B surface antigen (HBsAg) as surrogate marker for HBV resolution and the monitoring of drug effectiveness are becoming increasingly important, the established ARCHITECT HBsAg Quantitative assay remains available on the market. Precision, sensitivity, and specificity of the newly developed screening assay were in the range of established HBsAg assays. Seroconversion sensitivity was slightly superior compared to other commercially available assays. An initial reactive rate of 0.2% (without HBsAg-confirmed positive samples of 0.17%) for the ARCHITECT HBsAg Qualitative assay was observed. As the new screening assay is a 1-step assay format, the "high-dose hook effect" was investigated to assess the risk of false-negative results, but even very high positive HBsAg samples obtained signals clearly above the cutoff. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Comparison of In-Vitro and Ex-Vivo Wound Healing Assays for the Investigation of Diabetic Wound Healing and Demonstration of a Beneficial Effect of a Triterpene Extract.

    Directory of Open Access Journals (Sweden)

    Christopher Ueck

    Full Text Available Diabetes mellitus is a frequent cause for chronic, difficult-to-treat wounds. New therapies for diabetic wounds are urgently needed and in-vitro or ex-vivo test systems are essential for the initial identification of new active molecules. The aim of this study is to compare in-vitro and ex-vivo test systems for their usability for early drug screening and to investigate the efficacy of a birch bark triterpene extract (TE that has been proven ex-vivo and clinically to accelerate non-diabetic wound healing (WH, in a diabetic context. We investigated in-vitro models for diabetic WH, i.e. scratch assays with human keratinocytes from diabetic donors or cultured under hyperglycaemic conditions and a newly developed porcine ex-vivo hyperglycaemic WH model for their potential to mimic delayed diabetic WH and for the influence of TE in these test systems. We show that keratinocytes from diabetic donors often fail to exhibit significantly delayed WH. For cells under hyperglycaemic conditions significant decrease is observed but is influenced by choice of medium and presence of supplements. Also, donor age plays a role. Interestingly, hyperglycaemic effects are mainly hyperosmolaric effects in scratch assays. Ex-vivo models under hyperglycaemic conditions show a clear and substantial decrease of WH, and here both glucose and hyperosmolarity effects are involved. Finally, we provide evidence that TE is also beneficial for ex-vivo hyperglycaemic WH, resulting in significantly increased length of regenerated epidermis to 188±16% and 183±11% (SEM; p<0.05 compared to controls when using two different TE formulations. In conclusion, our results suggest that microenvironmental influences are important in WH test systems and that therefore the more complex hyperglycaemic ex-vivo model is more suitable for early drug screening. Limitations of the in-vitro and ex-vivo models are discussed. Furthermore our data recommend TE as a promising candidate for in

  2. Assay of labile estrogen o-quinones, potent carcinogenic molecular species, by high performance liquid chromatography-electrospray ionization tandem mass spectrometry with phenazine derivatization.

    Science.gov (United States)

    Yamashita, Kouwa; Masuda, Akina; Hoshino, Yuka; Komatsu, Sachiko; Numazawa, Mitsuteru

    2010-04-01

    A sensitive and selective assay method for labile estrogen o-quinones, estrone (E(1))-2,3-quinone (Q), E(1)-3,4-Q, estradiol (E(2))-2,3-Q and E(2)-3,4-Q, based on the use of phenazine (Phz) derivatization with o-phenylenediamine and high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) was described. The Phz derivatives of four estrogen o-quinones were purified by solid phase extraction and analyzed by HPLC-ESI-MS/MS. The protonated molecule was observed as a base peak for all Phz derivatives in their ESI-mass spectra (positive mode). In multiple reaction monitoring, the transition from [M+H]+ to m/z 231 was chosen for quantification. Calibration curves for the o-quinones were obtained using standard catechol estrogens after sodium metaperiodate treatment and Phz derivatization. Using this method, these four estrogen o-quinones were analyzed with the limit of quantification of 5 ng/ml in acetonitrile (MeCN)-blank matrix (1:4, v/v), respectively, on a basis of the weight of catechol estrogens. Assay accuracy and precision for four estrogen o-quinones were 89.6-113.0% and 3.1-12.6% (5, 125 and 2000 ng/ml in MeCN-blank matrix). Applications of this method enabled to determine the catalytic activities on hydroxylation and subsequent oxidation of E(1) and E(2) of Mushroom tyrosinase and rat liver microsomal fraction. It was confirmed by this method that tyrosinase exhibited 2- and 4-hydroxylation and further oxidation activities for catechols in the ring-A of estrogens. Whereas rat liver microsomal fraction possessed only 2- and 4-hydroxylation activities, and further oxidation activity for catechol estrogens was low. 2010 Elsevier Ltd. All rights reserved.

  3. Anti-citrullinated protein antibodies in the diagnosis of rheumatoid arthritis (RA): diagnostic performance of automated anti-CCP-2 and anti-CCP-3 antibodies assays.

    Science.gov (United States)

    Vos, Ine; Van Mol, Christof; Trouw, Leendert A; Mahler, Michael; Bakker, Jaap A; Van Offel, Jan; De Clerck, Luc; Huizinga, Tom W

    2017-07-01

    This study compares the diagnostic performance of a second generation anti-cyclic citrullinated peptide antibody (CCP2) with a third generation anti-CCP antibodies assay (CCP3), as well as the combination of both tests. Serum samples of 127 patients were analyzed. IgG anti-CCP 2 and IgM rheumatoid factor were determined by EliA™ technique on a Phadia 250 instrument (Thermo Fisher Scientific), anti-CCP3 by the Quanta Flash™ anti-CCP3 IgG kit, BIO-FLASH Rapid Response Chemiluminscence Analyzer (INOVA Diagnostics). Diagnostic performance was compared using ROC-curves, sensitivity, specificity, likelihood ratios, and predictive values. Logistic regressions were used to investigate whether using both tests (anti-CCP2 and anti-CCP3) gives a better prediction of rheumatoid arthritis. At the manufacturer's cut-offs sensitivity and specificity were 79.4 and 61.0% for CCP3 and 80.9 and 69.5% for CCP2. No significant differences could be observed regarding the areas under the curve (AUC) of both ROC-curves. The optimal cut-off point for CCP2 was 10.5 U/ml (sensitivity of 75.0% and specificity of 80.0%) and 5.6 U/ml for CCP3 (sensitivity of 86.9% and specificity of 61.0%). Binary logistic regressions indicated that the likelihood of having rheumatoid arthritis (RA) is significantly higher when testing positive on both CCP2 and CCP3 compared to CCP2 or CCP3 alone. In our cohort, comparable performance was found between the two CCP assays. Positivity for both CCP2 and CCP3 resulted in the most specific identification of RA patients. In patients with joint complaints suspected of having RA and with a weakly positive CCP 2 (≥7 and ≤16 U/ml) CCP3 testing could be of additive value for diagnosing RA.

  4. [Comparison of the indirect immunofluorescence assay performance of Bartonella henselae antigens obtained by co-cultivation in Vero and HeLa cells].

    Science.gov (United States)

    Ergin, Cağrı; Akkaya, Yüksel; Kiriş Satılmış, Ozgün; Yılmaz, Cansev

    2011-07-01

    The laboratory diagnosis of Bartonella henselae infection is mainly based on serological testing by indirect immunofluorescence assay (IFA). Cell line co-cultivation with B.henselae and agar derivated antigens are the two major procedures used for evaluation of anti-Bartonella antibodies. Vero and Hep-2 cell lines are the most commonly used media for co-cultivation both in-house and commercial diagnostic kits production. However, HeLa cells which are easily supplied and grown, also can easily be infected by B.henselae. The aim of this study was to compare the performances of antigens obtained by co-cultivation of B.henselae ATCC 49882 (Houston-1) in Vero and HeLa Cells in IFA serology. Out of 381 sera samples, 127 (33.3%) were found positive and 195 (51.2%) were found negative by IFA performed by both cell line co-cultivations. The total agreement between the methods were found as 84.5% (322/381), and Cohen kappa value was calculated as 0.68 (strong, coherent). As a result, He-La cells were found to be useful for the preparation of B.henselae antigens to be used in IFA for the serologic diagnosis of B.henselae infections. However different genotype strains and cross reactions with other infectious agents should be investigated by further studies before routine applications of HeLa cell co-cultivations procedure is established.

  5. Prevalence of Anal Human Papillomavirus (HPV) and Performance of Cepheid Xpert and Hybrid Capture 2 (hc2) HPV Assays in South African HIV-Infected Women.

    Science.gov (United States)

    Mbulawa, Zizipho Z A; Wilkin, Timothy; Goeieman, Bridgette J; Jong, Eefje; Michelow, Pamela; Swarts, Avril; Smith, Jennifer S; Kegorilwe, Patricia; Firnhaber, Cynthia S; Williamson, Anna-Lise

    2017-08-01

    This study investigated anal high-risk HPV (HR-HPV) prevalence in HIV-infected women using the Cepheid Xpert HPV assay and compares its performance with that of Hybrid Capture-2 (hc2). A total of 199 HIV-infected women were recruited from Helen Joseph Hospital, Johannesburg. Stored ThinPrep anal swabs that had previously been tested using hc2 were tested for HPV using Xpert. The HR-HPV prevalence by Xpert was 40.8% and similar to hc2 (41.8%) with overall agreement of 86.7%; Cohen's kappa 0.73 (95% CI 0.63-0.82). High grade squamous intraepithelial lesions (HSIL) was associated with increasing number of multiple HPV infection (P HPV16 (OR: 14.0, 95% CI: 3.9-48.0, P HPV39/68/56/66 (OR: 4.1, 95% CI: 1.4-12, P = .01) and HPV51/59 (OR: 2.8, 95% CI: 1.1-7.6, P = .04) were independently associated with anal HSIL. Xpert HPV typing is a promising anal screening test in HIV-infected women that performs similarly to hc2.

  6. Stereospecific Assay of (R- and (S-Goitrin in Commercial Formulation of Radix Isatidis by Reversed Phase High-Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Lixing Nie

    2017-01-01

    Full Text Available Radix isatidis (Banlangen is a widely used traditional Chinese medicine for treating fever and removing toxic heat. Pharmacological studies have indicated that (R-goitrin (epigoitrin is one of the main constituents accounting for its antiviral activity, while (S-goitrin (goitrin is known as an antithyroid factor. To better control the quality of radix isatidis and its formulations, it is imperative to enantiomerically determine the contents of R- and S-goitrin. In this study, an enantioselective method based on reversed phase chromatography was developed for the assay of (R, S-goitrin enantiomers. Optimum separation was obtained on an S-Chiral A column (4.6 mm × 250 mm, 5 μm using methanol/water (30 : 70, v/v as the mobile phase. After validation, the method was applied to quantify the enantiomers in Banlangen granules, which is the most prescribed commercial formulation of radix isatidis. Compared to enantioselective resolution approaches based on normal phase chromatography, the new method could be conveniently performed using regular reversed phase high-performance liquid chromatography (RP-HPLC equipment and was found to be more suitable for the enantioselective quality control of water-extracted and soluble medicines.

  7. On the safety and performance demonstration tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and validation and verification of computational codes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Bum; Jeong, Ji Young; Lee, Tae Ho; Kim, Sung Kyun; Euh, Dong Jin; Joo, Hyung Kook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V and V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V and V, and the performance test results of the model pump in sodium showed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

  8. Minimal_Set_of_In_Vitro_ER_Agonist_Assays_Selection_RegToxPharm_Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — A dataset for the manuscript which demonstrates that it is possible to achieve levels of performance equivalent to the full 16 assay ER agonist model against both in...

  9. Lateral flow strip assay

    Science.gov (United States)

    Miles, Robin R [Danville, CA; Benett, William J [Livermore, CA; Coleman, Matthew A [Oakland, CA; Pearson, Francesca S [Livermore, CA; Nasarabadi, Shanavaz L [Livermore, CA

    2011-03-08

    A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

  10. Rover waste assay system

    Energy Technology Data Exchange (ETDEWEB)

    Akers, D.W.; Stoots, C.M.; Kraft, N.C.; Marts, D.J. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-11-01

    The Rover Waste Assay System (RWAS) is a nondestructive assay system designed for the rapid assay of highly-enriched {sup 235}U contaminated piping, tank sections, and debris from the Rover nuclear rocket fuel processing facility at the Idaho Chemical Processing Plant. A scanning system translates a NaI(Tl) detector/collimator system over the structural components where both relative and calibrated measurements for {sup 137}Cs are made. Uranium-235 concentrations are in operation and is sufficiently automated that most functions are performed by the computer system. These functions include system calibration, problem identification, collimator control, data analysis, and reporting. Calibration of the system was done through a combination of measurements on calibration standards and benchmarked modeling. A description of the system is presented along with the methods and uncertainties associated with the calibration and analysis of the system for components from the Rover facility. 4 refs., 2 figs., 4 tabs.

  11. Determination of adenosine deaminase activity in dried blood spots by a nonradiochemical assay using reversed-phase high-performance liquid chromatography

    NARCIS (Netherlands)

    van Kuilenburg, A. B. P.; Zoetekouw, L.; Meijer, J.; Kuijpers, T. W.

    2010-01-01

    Adenosine deaminase (ADA) deficiency is a rare metabolic disease causing severe combined immunodeficiency (SCID). An assay to determine ADA activity in dried blood spots was developed using reversed-phase HPLC. The assay was linear with reaction times up to at least 4 hours, and protein

  12. GASIS demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Vidas, E.H. [Energy and Environmental Analysis, Inc., Arlington, VA (United States)

    1995-04-01

    A prototype of the GASIS database and retrieval software has been developed and is the subject of this poster session and computer demonstration. The prototype consists of test or preliminary versions of the GASIS Reservoir Data System and Source Directory datasets and the software for query and retrieval. The prototype reservoir database covers the Rocky Mountain region and contains the full GASIS data matrix (all GASIS data elements) that will eventually be included on the CD-ROM. It is populated for development purposes primarily by the information included in the Rocky Mountain Gas Atlas. The software has been developed specifically for GASIS using Foxpro for Windows. The application is an executable file that does not require Foxpro to run. The reservoir database software includes query and retrieval, screen display, report generation, and data export functions. Basic queries by state, basin, or field name will be assisted by scrolling selection lists. A detailed query screen will allow record selection on the basis of any data field, such as depth, cumulative production, or geological age. Logical operators can be applied to any-numeric data element or combination of elements. Screen display includes a {open_quotes}browse{close_quotes} display with one record per row and a detailed single record display. Datasets can be exported in standard formats for manipulation with other software packages. The Source Directory software will allow record retrieval by database type or subject area.

  13. Performance of a RT-PCR Assay in Comparison to FISH and Immunohistochemistry for the Detection of ALK in Non-Small Cell Lung Cancer

    Science.gov (United States)

    Hout, David R.; Lawrence, Kasey; Morris, Stephan W.; Tucker, Tracy; Mazzola, Rosetta; Skelton, Rachel; McMahon, Frank; Handshoe, John; Lesperance, Mary; Karsan, Aly

    2017-01-01

    Patients with lung cancers harboring an activating anaplastic lymphoma kinase (ALK) rearrangement respond favorably to ALK inhibitor therapy. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) are validated and widely used screening tests for ALK rearrangements but both methods have limitations. The ALK RGQ RT-PCR Kit (RT-PCR) is a single tube quantitative real-time PCR assay for high throughput and automated interpretation of ALK expression. In this study, we performed a direct comparison of formalin-fixed paraffin-embedded (FFPE) lung cancer specimens using all three ALK detection methods. The RT-PCR test (diagnostic cut-off ΔCt of ≤8) was shown to be highly sensitive (100%) when compared to FISH and IHC. Sequencing of RNA detected full-length ALK transcripts or EML4-ALK and KIF5B-ALK fusion variants in discordant cases in which ALK expression was detected by the ALK RT-PCR test but negative by FISH and IHC. The overall specificity of the RT-PCR test for the detection of ALK in cases without full-length ALK expression was 94% in comparison to FISH and sequencing. These data support the ALK RT-PCR test as a highly efficient and reliable diagnostic screening approach to identify patients with non-small cell lung cancer whose tumors are driven by oncogenic ALK. PMID:28763012

  14. A new high-performance thin layer chromatography-based assay of detergents and surfactants commonly used in membrane protein studies.

    Science.gov (United States)

    Barret, Laurie-Anne; Polidori, Ange; Bonneté, Françoise; Bernard-Savary, Pierre; Jungas, Colette

    2013-03-15

    The hydrophobic nature of membrane proteins (MPs) necessitates the use of detergents for their extraction, solubilization and purification. Because the concentration of amphiphiles is crucial in the crystallization process, detergent quantification is essential to routine analysis. Here we describe a quantitative high-performance thin-layer chromatography (HPTLC) method we developed for the detection of small quantities of detergent bound to solubilized MPs. After optimization of aqueous deposit conditions, we show that most detergents widely used in membrane protein crystallography display distinctive mobilities in a mixture of dichloromethane, methanol and acetic acid 32:7.6:0.4 (v/v/v). Migration and derivatization conditions were optimized with n-dodecyl-β-D-maltoside (DDM), the most popular detergent for membrane protein crystallization. A linear calibration curve very well fits our data from 0.1 to 1.6 μg of DDM in water with a limit of detection of 0.05 μg. This limit of detection is the best achieved to date for a routine detergent assay, being not modified by the addition of NaCl, commonly used in protein buffers. With these chromatographic conditions, no prior treatment is required to assess the quantities of detergent bound to purified MPs, thus enabling the quantification of close structure detergents via a single procedure. This HPTLC method, which is fast and requires low sample volume, is fully suitable for routine measurements. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Reliability of mutagen sensitivity assay: an inter-laboratory comparison.

    Science.gov (United States)

    Erdei, Esther; Lee, Sang-Joon; Wei, Qingyi; Wang, Li-E; Song, Yan-S; Bovbjerg, Dana; Berwick, Marianne

    2006-07-01

    Mutagen sensitivity is regarded as a genetic susceptibility phenotype for various cancers; it is cytogenetically based and probably involves a number of genes from different DNA repair pathways. This assay has been used in a number of laboratories in the field of epidemiology, where it has been investigated and appears to be a useful susceptibility biomarker for epidemiological studies assessing cancer risks at the population level. One concern about phenotypic assays, such as the mutagen sensitivity assay, has been that there could be wide variation in results depending on the timing of the assay (within individual variation), the individual performing the assay (within observer variation) and the laboratory where the assay has been performed (inter-laboratory variation). We conducted an inter-laboratory comparison study between the Memorial Sloan-Kettering Cancer Center and M. D. Anderson, in which we assessed all these concerns. We did not find any significant variation in any of the assays. The correlation was high for all tests. The good concordance rate between laboratories supports the continued use of the mutagen sensitivity assay by different laboratories, and demonstrates its potential to identify at-risk subgroups among normal individuals and cancer patients alike.

  16. Clinical performance of LOCI™-based tumor marker assays for tumor markers CA 15-3, CA 125, CEA, CA 19-9 and AFP in gynecological cancers.

    Science.gov (United States)

    Dolscheid-Pommerich, Ramona C; Keyver-Paik, Mignon; Hecking, Thomas; Kuhn, Walther; Hartmann, Gunther; Stoffel-Wagner, Birgit; Holdenrieder, Stefan

    2017-10-01

    Evidence is sparse regarding the clinical performance of luminescent oxygen channeling immunoassays-based tumor marker assays in gynecological cancer. Analyzing serum samples of 336 patients with Dimension™Vista1500, we investigated the diagnostic power of carbohydrate antigen 15-3, carbohydrate antigen 125, carcinoembryonic antigen, carbohydrate antigen 19-9, and alpha-fetoprotein in patients suffering from different types of gynecological cancer and precancerous gynecological diseases and compared findings to appropriate control groups. The cohort comprised 177 female patients with gynecological cancers (73 breast, 22 cervical, 16 endometrial, 17 vulva, and 49 ovarian cancers), 26 patients with precancerous gynecological diseases (11 vulva, 4 cervical, and 10 breast), 109 patients with benign gynecological diseases, and 24 healthy controls. Discriminative power was assessed by areas under the curve in receiver operating characteristic curves, and sensitivities were determined at a fixed specificity of 95%. Levels of biomarkers in healthy controls were in the expected ranges and a discriminative power between gynecological cancers and healthy controls was observed for several tumor markers. Established tumor type-associated markers were elevated in specific gynecological cancers and benign controls as well as within precancerous gynecological diseases and healthy control group. In ovarian cancer, carbohydrate antigen 125 and carbohydrate antigen 15-3 were significantly elevated compared to the respective benign diseases. Carbohydrate antigen 125 was the most conclusive marker (area under the curve = 0.86% and 77.6% sensitivity at 95% specificity). In breast cancer, carcinoembryonic antigen and carbohydrate antigen 15-3 were significantly higher than in the respective benign diseases. Carcinoembryonic antigen achieved the most conclusive area under the curve (0.65) with 31.5% sensitivity at 95% specificity. None of the investigated markers was found to be of

  17. Clinical and virological factors influencing the performance of a NS1 antigen-capture assay and potential use as a marker of dengue disease severity.

    Directory of Open Access Journals (Sweden)

    Veasna Duong

    2011-07-01

    Full Text Available BACKGROUND: Detection of dengue NS1 antigen in acute infection has been proposed for early diagnosis of dengue disease. The aim of this study was to evaluate the clinical and virological factors influencing the performance of the Platelia NS1 Ag kit (BioRad and to assess the potential use of NS1 antigen and dengue viral loads as markers of dengue disease severity. METHODOLOGY/PRINCIPAL FINDINGS: Blood specimens were collected from patients hospitalized at the Kampong Cham hospital during the 2006 and 2007 dengue epidemics in Cambodia. Dengue infection was confirmed in 243/339 symptomatic patients and in 17 asymptomatic individuals out of 214 household members tested. Overall sensitivity and specificity of Platelia NS1 Ag kit were 57.5% and 100% respectively. NS1 Ag assay combined with IgM antibody capture ELISA significantly increased the sensitivity for dengue diagnosis. NS1 Ag positivity rate was found significantly higher in DF than in DHF/DSS, in primary than in secondary infections, in patients with a high viremia (>5 log/mL and in patients infected with DENV-1. In asymptomatic individuals, the NS1 Ag capture sensitivity tends to be lower than that in symptomatic patients. Milder disease severity was observed independently in patients with RNA copy number >5 log10 cDNA equivalents/mL or in high level of NS1 antigen ratio or in DENV-1 infection. CONCLUSIONS: Overall sensitivity of NS1 Ag detection kit varied widely across the various forms of dengue infection or disease. Sensitivity was highest in patients sampled during the first 3 days after onset of fever, in patients with primary infection, DENV-1 infection, with high level of viremia and in DF rather than DHF/DSS. In asymptomatic patients, RT-PCR assay has proved to be more sensitive than NS1 antigen detection. The NS1 antigen level correlated significantly with viremia and a low NS1 antigen ratio was associated with more severe disease.

  18. On the Safety and Performance Demonstration Tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and Validation and Verification of Computational Codes

    Directory of Open Access Journals (Sweden)

    Jong-Bum Kim

    2016-10-01

    Full Text Available The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR has been developed and the validation and verification (V&V activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1, produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodium showed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

  19. Improved Serodiagnostic Performance for Lyme Disease by Use of Two Recombinant Proteins in Enzyme-Linked Immunosorbent Assay Compared to Standardized Two-Tier Testing.

    Science.gov (United States)

    Bradshaw, Gary L; Thueson, R Kelley; Uriona, Todd J

    2017-10-01

    The most reliable test method for the serological confirmation of Lyme disease (LD) is a 2-tier method recommended by the CDC in 1995. The first-tier test is a low-specificity enzyme-linked immunosorbent assay (ELISA), and the second-tier tests are higher-specificity IgG and IgM Western blots. This study describes the selection of two Borrelia burgdorferi recombinant proteins and evaluation of their performance in a simple 1-tier test for the serological confirmation of LD. These two proteins were generated from (i) the full-length dbpA gene combined with the invariable region 6 of the vlsE gene (DbpA/C6) and (b) the full-length ospC gene (OspC). The expressed DbpA/C6 and OspC proteins were useful in detecting anti-Borrelia IgG and IgM antibodies, respectively. A blind study was conducted on a well-characterized panel of 279 human sera from the CDC, comparing ELISAs using these two recombinant antigens with the 2-tier test method. The two methods (DbpA/C6-OspC versus 2-tier test) were equivalent in identifying sera from negative-control subjects (99% and 100% specificity, respectively) and in detecting stage II and III LD patient sera (100% and 100% sensitivity). However, the DbpA/C6-OspC ELISA was markedly better (80% versus 63%) than the 2-tier test method in detecting anti-Borrelia antibodies in stage I LD patients. The findings suggest that these antigens could be used in a simple 1-tier ELISA that is faster to perform, easier to interpret, and less expensive than the 2-tier test method and which is better at detecting Borrelia-specific antibodies in sera from patients with stage I LD. Copyright © 2017 Bradshaw et al.

  20. Quantification of imatinib in human serum: validation of a high-performance liquid chromatography-mass spectrometry method for therapeutic drug monitoring and pharmacokinetic assays

    Directory of Open Access Journals (Sweden)

    Rezende VM

    2013-08-01

    Full Text Available Vinicius Marcondes Rezende,1 Ariane Rivellis,1 Mafalda Megumi Yoshinaga Novaes,1 Dalton de Alencar Fisher Chamone,2 Israel Bendit1,21Laboratory of Tumor Biology, 2Department of Hematology, School of Medicine, University of São Paulo, São Paulo, BrazilBackground: Imatinib mesylate has been a breakthrough treatment for chronic myeloid leukemia. It has become the ideal tyrosine kinase inhibitor and the standard treatment for chronic-phase leukemia. Striking results have recently been reported, but intolerance to imatinib and noncompliance with treatment remain to be solved. Molecular monitoring by quantitative real-time polymerase chain reaction is the gold standard for monitoring patients, and imatinib blood levels have also become an important tool for monitoring.Methods: A fast and cheap method was developed and validated using high-performance liquid chromatography-mass spectrometry for quantification of imatinib in human serum and tamsulosin as the internal standard. Remarkable advantages of the method includes use of serum instead of plasma, less time spent on processing and analysis, simpler procedures, and requiring reduced amounts of biological material, solvents, and reagents. Stability of the analyte was also studied. This research also intended to drive the validation scheme in clinical centers. The method was validated according to the requirements of the US Food and Drug Administration and Brazilian National Health Surveillance Agency within the range of 0.500–10.0 µg/mL with a limit of detection of 0.155 µg/mL. Stability data for the analyte are also presented.Conclusion: Given that the validated method has proved to be linear, accurate, precise, and robust, it is suitable for pharmacokinetic assays, such as bioavailability and bioequivalence, and is being successfully applied in routine therapeutic drug monitoring in the hospital service.Keywords: imatinib, high-performance liquid chromatography-mass spectrometry, therapeutic

  1. ARAMIS project: a more explicit demonstration of risk control through the use of bow-tie diagrams and the evaluation of safety barrier performance.

    Science.gov (United States)

    de Dianous, Valérie; Fiévez, Cécile

    2006-03-31

    Over the last two decades a growing interest for risk analysis has been noted in the industries. The ARAMIS project has defined a methodology for risk assessment. This methodology has been built to help the industrialist to demonstrate that they have a sufficient risk control on their site. Risk analysis consists first in the identification of all the major accidents, assuming that safety functions in place are inefficient. This step of identification of the major accidents uses bow-tie diagrams. Secondly, the safety barriers really implemented on the site are taken into account. The barriers are identified on the bow-ties. An evaluation of their performance (response time, efficiency, and level of confidence) is performed to validate that they are relevant for the expected safety function. At last, the evaluation of their probability of failure enables to assess the frequency of occurrence of the accident. The demonstration of the risk control based on a couple gravity/frequency of occurrence is also possible for all the accident scenarios. During the risk analysis, a practical tool called risk graph is used to assess if the number and the reliability of the safety functions for a given cause are sufficient to reach a good risk control.

  2. Dual-energy CT in vertebral compression fractures: performance of visual and quantitative analysis for bone marrow edema demonstration with comparison to MRI

    Energy Technology Data Exchange (ETDEWEB)

    Bierry, Guillaume; Venkatasamy, Aina; Kremer, Stephane; Dosch, Jean-Claude; Dietemann, Jean-Louis [University Hospital of Strasbourg, Department of Radiology, Strasbourg (France)

    2014-04-15

    To prospectively evaluate the performance of virtual non-calcium (VNC) dual-energy CT (DECT) images for the demonstration of trauma-related abnormal marrow attenuation in collapsed and non-collapsed vertebral compression fractures (VCF) with MRI as a reference standard. Twenty patients presenting with non-tumoral VCF were consecutively and prospectively included in this IRB-approved study, and underwent MRI and DECT of the spine. MR examination served as a reference standard. Two independent readers visually evaluated all vertebrae for abnormal marrow attenuation (''CT edema'') on VNC DECT images; specificity, sensitivity, predictive values, intra and inter-observer agreements were calculated. A last reader performed a quantitative evaluation of CT numbers; cut-off values were calculated using ROC analysis. In the visual analysis, VNC DECT images had an overall sensitivity of 84 %, specificity of 97 %, and accuracy of 95 %, intra- and inter-observer agreements ranged from k = 0.74 to k = 0.90. CT numbers were significantly different between vertebrae with edema on MR and those without (p < 0.0001). Cut-off values provided sensitivity of 85 % (77 %) and specificity of 82 % (74 %) for ''CT edema'' on thoracic (lumbar) vertebrae. VNC DECT images allowed an accurate demonstration of trauma-related abnormal attenuation in VCF, revealing the acute nature of the fracture, on both visual and quantitative evaluation. (orig.)

  3. Performance of the Real Fungus-ID kit based on multiplex RT-PCR assay for the rapid detection and identification of Trichophyton spp. and Microsporum spp. in clinical specimens with suspected dermatophyte infection.

    Science.gov (United States)

    Wang, H-Y; Kim, H; Choi, E H; Lee, H

    2016-01-01

    The aim of this study was to evaluate the performance of a commercially available multiplex RT-PCR assay for the rapid detection and identification of dermatophytes directly from clinical samples and cultures. The multiplex RT-PCR assay was used to evaluate 118 clinical isolates from various specimen types and a total of 140 known specimens were compared with both conventional methods, commercially available PCR-REBA, and ITS sequence analysis. In this study, multiplex RT-PCR assay yield significantly more positive results than culture (91·9 vs 39·5%) and conventional methods including KOH microscopy (91·9 vs 71·3%). Although the results among the multiplex RT-PCR, PCR-REBA and ITS sequence analysis were concordant (100%) in 118 clinical isolates, concordant results between multiplex RT-PCR assay and culture were at 66% (78/118). The overall positive rates for the PCR-REBA, multiplex RT-PCR assay and ITS sequence analysis were 98·8, 91·9, and 52·9% respectively. In addition, the concordance rate of multiplex RT-PCR assay and the PCR-REBA assay was 93% (95% confidence interval (CI), 89·9-96·1, P culture can take up to 2-3 weeks. The use of the multiplex RT-PCR molecular diagnostic assay was rapid and reliable for detecting pathogen infections. Even though the use of molecular diagnostic technology is more expensive than conventional methods, the clinical and economic benefit of saving time relative to expense remains to be elucidated. Therefore, the multiplex RT-PCR assay may provide the essential information to accelerate therapeutic decisions for earlier and adequate antibiotic treatment in the acute phase of fungal pathogen infections. © 2015 The Society for Applied Microbiology.

  4. Performance evaluation of a new fourth-generation HIV Ag/Ab combination electrochemiluminescence immunoassay - evaluation of a new HIV assay.

    Science.gov (United States)

    Wang, Tingting; Li, Dongdong; Yan, Kening; Yuan, Yu; Yang, Tingfu; Du, Xiaoqing; Yan, Xuedan; Tao, Chuanmin; Wang, Lanlan

    2014-03-01

    A new fourth-generation HIV Ag/Ab electrochemiluminescence immunoassay for screening of HIV infection, the Elecsys HIV Combi PT (Roche Diagnostics, Penzberg, Germany) assay, is going to be commercially available in clinical laboratories in China. This assay was evaluated and compared with two commonly used assays: Elecsys HIV Combi assay and the Livzon anti-HIV-1/2 ELISA. Commercially available panels and 30 established HIV infection samples were tested to evaluate the sensitivity. In addition, a total of 675 routine clinical samples were collected and tested in West China Hospital to compare the specificity. Any reactive result from a screening test was retested and all reactive retested samples were confirmed with Western blot assay, Elecsys HIV Ag test, Elecsys HIV Ag confirmatory test or HIV-1 RNA NAT testing. According to the results of the HIV seroconversion panels, the Elecsys HIV Combi PT could detect seroconversion at the same bleed or at least one bleed earlier compared to the other two assays. Among the 675 clinical samples, most results were consistent except for one specimen with a false-negative result using Elecsys HIV Combi assay. In conclusion, the Elecsys HIV Combi PT has shown satisfactory sensitivity and specificity to be a screening test for HIV infection.

  5. Evaluation of the New Siemens Tacrolimus Assay on the Dimension EXL Integrated Chemistry System Analyzer: Comparison With an Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry Method.

    Science.gov (United States)

    Bargnoux, Anne-Sophie; Sutra, Thibault; Badiou, Stéphanie; Kuster, Nils; Dupuy, Anne-Marie; Mourad, Georges; Pageaux, Georges-Philippe; Le Quintrec, Moglie; Cristol, Jean-Paul

    2016-12-01

    Many patients are maintained at the lower end of the tacrolimus (TAC) reference range (3-7 ng/mL), requiring the use of analytical methods displaying a very low limit of quantification for their follow-up. Therefore, the new Dimension TAC, based on affinity chrome-mediated immunoassay technology, was evaluated on the Dimension EXL Integrated Chemistry System (Siemens Healthcare Diagnostics Inc). The aims of this study were (1) to evaluate the analytical performances with special emphasis on sensibility at low levels of TAC, (2) to compare the results with an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS) method. Analytical performance (imprecision, linearity, limit of detection, and limit of quantification) was evaluated. Comparison to UPLC/MS/MS was performed on 106 whole blood samples from 88 transplant recipients using regression analysis and Bland-Altman plot analysis. Repeatability and within-laboratory coefficients of variation were new Dimension TAC immunoassay on the EXL analyzer demonstrated reliable and reproducible performances allowing routine monitoring in transplant patients, even at TAC concentrations at the lower end of the therapeutic range.

  6. Performance evaluation of a rapid molecular diagnostic, MultiCode based, sample-to-answer assay for the simultaneous detection of Influenza A, B and respiratory syncytial viruses

    NARCIS (Netherlands)

    J. Voermans (Jolanda); S. Seven-Deniz; P.L.A. Fraaij (Pieter); A.A. Eijck (Annemiek); M.P.G. Koopmans D.V.M. (Marion); S.D. Pas (Suzan)

    2016-01-01

    textabstractBackground Clinical signs and symptoms of different airway pathogens are generally indistinguishable, making laboratory tests essential for clinical decisions regarding isolation and antiviral therapy. Immunochromatographic tests (ICT) and direct immunofluorescence assays (DFA) have

  7. Performance and reliability of five commercial enzyme-linked immunosorbent assay kits in screening for anti-human immunodeficiency virus antibody in high-risk subjects.

    OpenAIRE

    Ozanne, G; Fauvel, M

    1988-01-01

    Anti-human immunodeficiency virus enzyme-linked immunosorbent assay kits marketed by Electro-Nucleonics Inc. (ENI), Genetic Systems Corp. (GSC), Organon Teknika Inc. (OTI), Ortho Diagnostic Systems Inc. (ODSI), and Wellcome Diagnostics (WD) were evaluated by using 289 randomly selected serum samples from a high-risk population and 53 serum samples likely to produce false-positive results. The radioimmunoprecipitation assay was used as the reference test. Sensitivities ranged from 96.51% (ODSI...

  8. Cross-reactivity of Nocardia spp. in the fungal (1-3)-β-d-glucan assay performed on cerebral spinal fluid.

    Science.gov (United States)

    Koncan, Raffaella; Favuzzi, Vincenza; Ligozzi, Marco; Sorrentino, Annarita; Cornaglia, Giuseppe; Cascio, Giuliana Lo

    2015-02-01

    Cerebral spinal fluid from a patient affected by a brain abscess caused by Nocardia abscessus gave a positive result for (1-3)-β-d-glucan (BG) assay, in absence of any fungal infection. This study aimed to assess whether Nocardia spp. show cross-reactivity with BG assay. All Nocardia spp. analyzed provided positive reactions. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Total cholesterol performance of Abell-Levy-Brodie-Kendall reference measurement procedure: Certification of Japanese in-vitro diagnostic assay manufacturers through CDC's Cholesterol Reference Method Laboratory Network.

    Science.gov (United States)

    Nakamura, Masakazu; Iso, Hiroyasu; Kitamura, Akihiko; Imano, Hironori; Kiyama, Masahiko; Yokoyama, Shinji; Kayamori, Yuzo; Koyama, Isao; Nishimura, Kunihiro; Nakai, Michikazu; Dasti, Mahnaz; Vesper, Hubert W; Teramoto, Tamio; Miyamoto, Yoshihiro

    2015-05-20

    Accurate measurement of total cholesterol (TC) is important for cardiovascular disease risk management. The US Centers for Disease Control and Prevention (CDC) and Cholesterol Reference Method Laboratory Network (CRMLN) perform Abell-Levy-Brodie-Kendall (AK) reference measurement procedure (RMP) for TC as a secondary reference method, and implement Certification Protocol for Manufacturers. Japanese CRMLN laboratory at Osaka performed the AK RMP for 22 years, and conducted TC certification for reagent/calibrator/instrument systems of six Japanese manufacturers every 2 years for 16 years. Osaka TC performance was examined and compared to CDC's reference values. AK RMP involved sample hydrolysis, cholesterol extraction, and determination of cholesterol levels by spectrophotometry. The Certification Protocol for Manufacturers includes comparison with AK RMP using at least 40 fresh specimens. Demonstration of average bias ≤3% and total coefficient of variation ≤3% qualified an analytical system for certification. In the AK RMP used in the Osaka CRMLN laboratory, the regression equation for measuring TC was y (Osaka)=1.000x (CDC)+0.032 (n=619, R(2)=1.000). Six Japanese manufacturers had allowable performance for certification. The AK RMP for TC measurement was accurate, precise, and stable for 22 years. Six Japanese manufacturers were certified for 16 years. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Performance of the tuberculin skin test and interferon-γ release assay for detection of tuberculosis infection in immunocompromised patients in a BCG-vaccinated population

    Directory of Open Access Journals (Sweden)

    Kim Young

    2009-12-01

    Full Text Available Abstract Background Interferon-γ release assay (IGRA may improve diagnostic accuracy for latent tuberculosis infection (LTBI. This study compared the performance of the tuberculin skin test (TST with that of IGRA for the diagnosis of LTBI in immunocompromised patients in an intermediate TB burden country where BCG vaccination is mandatory. Methods We conducted a retrospective observational study of patients given the TST and an IGRA, the QuantiFERON-TB Gold In-Tube (QFT-IT, at Severance Hospital, a tertiary hospital in South Korea, from December 2006 to May 2009. Results Of 211 patients who underwent TST and QFT-IT testing, 117 (55% were classified as immunocompromised. Significantly fewer immunocompromised than immunocompetent patients had positive TST results (10.3% vs. 27.7%, p 0.001, whereas the percentage of positive QFT-IT results was comparable for both groups (21.4% vs. 25.5%. However, indeterminate QFT-IT results were more frequent in immunocompromised than immunocompetent patients (21.4% vs. 9.6%, p 0.021. Agreement between the TST and QFT-IT was fair for the immunocompromised group (κ = 0.38, but moderate agreement was observed for the immunocompetent group (κ = 0.57. Indeterminate QFT-IT results were associated with anaemia, lymphocytopenia, hypoproteinemia, and hypoalbuminemia. Conclusion In immunocompromised patients, the QFT-IT may be more sensitive than the TST for detection of LTBI, but it resulted in a considerable proportion of indeterminate results. Therefore, both tests may maximise the efficacy of screening for LTBI in immunocompromised patients.

  11. High-performance liquid chromatography assay for the quantification of HIV protease inhibitors and non-nucleoside reverse transcriptase inhibitors in human plasma.

    Science.gov (United States)

    Rezk, Naser L; Tidwell, Richard R; Kashuba, Angela D M

    2004-06-15

    An accurate, sensitive, and specific reverse-phase high-performance liquid chromatography (HPLC) assay for the simultaneous quantitative determination of HIV-protease inhibitors (PIs) (indinavir, IDV; amprenavir, APV; saquinavir, SQV; nelfinavir, NFV; ritonavir, RTV; and lopinavir, LPV) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) (nevirapine, NVP; delavirdine, DLV; and efavirenz, EFV) in human blood plasma is described. The method provides excellent resolution and peak shape for nine analytes through a linear gradient (36-86%) of 25% phosphate buffer (pH 4.5), 60% acetonitrile, 15% methanol, and 0.75 ml TFA, with a gradient mobile phase flow rate (0.9-1.1 ml) over 30 min run time. The optimized solid phase extraction (SPE) extraction method using (1.0 ml, 100mg BOND ELUT-C18 Varian) column provides a clean base line and high extraction efficiency using a 550 microl plasma sample. The method was validated over the range of 10-10,000 ng/ml for NVP, IDV, and SQV; 10-5000 ng/ml for EFV; 25-10000 ng/ml for APV; and 25-5000 ng/ml for DLV, NFV, RTV, and LPV. This method is accurate (average accuracies of three different concentrations ranged from 91 to 112%), and precise (within- and between-day precision measures ranged from 0.2 to 5.7% and 0.1 to 5.4%, respectively). This method is suitable for use in clinical pharmacokinetic studies as well as in therapeutic drug monitoring (TDM).

  12. Performance of the Xpert MTB/RIF assay in the diagnosis of tuberculosis in formalin-fixed, paraffin-embedded tissues

    Directory of Open Access Journals (Sweden)

    Pascal Polepole

    2017-01-01

    Full Text Available Objective/Background: Extrapulmonary tuberculosis (EPTB, which accounts for 10%–40% of the global burden of TB, with the highest incidence in Sub-Saharan Africa, is strongly associated with human immunodeficiency virus infection. Diagnosing EPTB is challenging, and recently, there has been a concerted effort to evaluate the latest molecular diagnostics for diagnosing TB in a range of specimen types. The Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA, USA is one such technology, which simultaneously detects Mycobacterium tuberculosis and rifampicin resistance. Our objective was to evaluate the accuracy of the Xpert MTB/RIF assay for the diagnosis of EPTB and detection of rifampicin resistance in routinely processed formalin-fixed, paraffin-embedded (FFPE tissues, compared with histological detection of TB as the gold standard. Methods: A convenience set of 100 biobanked FFPE tissues, including lymph nodes (n = 64, male genital tract tissue (n = 10, abdominal tissue (n = 8, female genital tissue (n = 5, breast tissue (n = 5, synovial tissue (n = 4, skin (n = 2, tongue tissue (n = 1, and thyroid (n = 1, from routine cases of clinically suspected EPTB admitted to the University Teaching Hospital, Lusaka, Zambia, were analyzed using the Xpert MTB/RIF assay and in-house polymerase chain reaction (PCR assay targeting IS6110, in parallel with Ziehl–Neelsen (ZN staining, against histology as the gold standard. Results: Some 66% of specimens had histological evidence of TB infection. ZN staining was positive for TB in 8% of cases, and Xpert MTB/RIF was positive for TB in 25% of cases. Taking histology as the gold standard, the sensitivity and specificity were as follows: In lymph tissue the accuracy of the Xpert MTB/RIF assay was 41% (95%CI 27-57, not significantly better than ZN or the in-house PCR assay. In non-lymph tissue the sensitivity of the in-house PCR assay was 82% (95%CI: 56%-95%, significantly higher than the Xpert MTB/RIF assay (P = 0

  13. Performance of the Xpert MTB/RIF assay in the diagnosis of tuberculosis in formalin-fixed, paraffin-embedded tissues.

    Science.gov (United States)

    Polepole, Pascal; Kabwe, Mwila; Kasonde, Mpanga; Tembo, John; Shibemba, Aaron; O'Grady, Justin; Kapata, Nathan; Zumla, Alimuddin; Bates, Matthew

    2017-01-01

    Extrapulmonary tuberculosis (EPTB), which accounts for 10%-40% of the global burden of TB, with the highest incidence in Sub-Saharan Africa, is strongly associated with human immunodeficiency virus infection. Diagnosing EPTB is challenging, and recently, there has been a concerted effort to evaluate the latest molecular diagnostics for diagnosing TB in a range of specimen types. The Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA, USA) is one such technology, which simultaneously detects Mycobacterium tuberculosis and rifampicin resistance. Our objective was to evaluate the accuracy of the Xpert MTB/RIF assay for the diagnosis of EPTB and detection of rifampicin resistance in routinely processed formalin-fixed, paraffin-embedded (FFPE) tissues, compared with histological detection of TB as the gold standard. A convenience set of 100 biobanked FFPE tissues, including lymph nodes (n = 64), male genital tract tissue (n = 10), abdominal tissue (n = 8), female genital tissue (n = 5), breast tissue (n = 5), synovial tissue (n = 4), skin (n = 2), tongue tissue (n = 1), and thyroid (n = 1), from routine cases of clinically suspected EPTB admitted to the University Teaching Hospital, Lusaka, Zambia, were analyzed using the Xpert MTB/RIF assay and in-house polymerase chain reaction (PCR) assay targeting IS6110, in parallel with Ziehl-Neelsen (ZN) staining, against histology as the gold standard. Some 66% of specimens had histological evidence of TB infection. ZN staining was positive for TB in 8% of cases, and Xpert MTB/RIF was positive for TB in 25% of cases. Taking histology as the gold standard, the sensitivity and specificity were as follows: In lymph tissue the accuracy of the Xpert MTB/RIF assay was 41% (95%CI 27-57), not significantly better than ZN or the in-house PCR assay. In non-lymph tissue the sensitivity of the in-house PCR assay was 82% (95%CI: 56%-95%), significantly higher than the Xpert MTB/RIF assay (P = 0.004). The Xpert MTB/RIF assay indicated rifampicin

  14. Industry Application ECCS / LOCA Integrated Cladding/Emergency Core Cooling System Performance: Demonstration of LOTUS-Baseline Coupled Analysis of the South Texas Plant Model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongbin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Szilard, Ronaldo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Epiney, Aaron [Idaho National Lab. (INL), Idaho Falls, ID (United States); Parisi, Carlo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Vaghetto, Rodolfo [Texas A & M Univ., College Station, TX (United States); Vanni, Alessandro [Texas A & M Univ., College Station, TX (United States); Neptune, Kaleb [Texas A & M Univ., College Station, TX (United States)

    2017-06-01

    Under the auspices of the DOE LWRS Program RISMC Industry Application ECCS/LOCA, INL has engaged staff from both South Texas Project (STP) and the Texas A&M University (TAMU) to produce a generic pressurized water reactor (PWR) model including reactor core, clad/fuel design and systems thermal hydraulics based on the South Texas Project (STP) nuclear power plant, a 4-Loop Westinghouse PWR. A RISMC toolkit, named LOCA Toolkit for the U.S. (LOTUS), has been developed for use in this generic PWR plant model to assess safety margins for the proposed NRC 10 CFR 50.46c rule, Emergency Core Cooling System (ECCS) performance during LOCA. This demonstration includes coupled analysis of core design, fuel design, thermalhydraulics and systems analysis, using advanced risk analysis tools and methods to investigate a wide range of results. Within this context, a multi-physics best estimate plus uncertainty (MPBEPU) methodology framework is proposed.

  15. Performance of three automated fourth-generation combined HIV antigen/antibody assays in large-scale screening of blood donors and clinical samples.

    Science.gov (United States)

    Malm, K; von Sydow, M; Andersson, S

    2009-04-01

    Since the introduction in the mid-1980s, HIV testing has gradually improved both in terms of sensitivity and specificity. The so-called fourth generation of tests, combined HIV antigen/antibody assays, has now been introduced. This study compares three automated combined assays with older third-generation antibody assays in large-scale screening. Serum samples from routine screening of blood and plasma donors and clinical samples were investigated for specificity evaluation. Three fourth-generation combination assays from one manufacturer were compared with three older third-generation antibody assays from the same manufacturer. More than 40 000 samples per assay were included. For sensitivity, selected panels of confirmed HIV-1- and HIV-2-positive samples as well as seroconversion samples (HIV-1) from commercial panels and also from patients who appeared during the evaluation were used. The specificities of the fourth-generation tests were 99.91% (AxSYM), 99.95% (ARCHITECT) and 99.97% (PRISM) after repeated testing. Some specificity variation between reagent batches was observed. All HIV-1-positive samples were reactive by the three fourth-generation systems. HIV-1 seroconversion samples and panels were reactive earlier than by antibody-only tests. As for HIV-2 samples, AxSYM failed to detect one (n = 40), whereas PRISM and ARCHITECT detected all (n = 16 for PRISM and n = 52 for ARCHITECT). The new HIV antigen/antibody combination assay systems were found to have high sensitivity and specificity. The instruments provided a rational and easy way of testing at large scale.

  16. Evaluation of the IMMULITE® 2000 CMV IgM assay.

    Science.gov (United States)

    Bal, Tricia A; Armstrong, Glenn; Han, Xiang Y

    2012-02-29

    Diagnosis of cytomegalovirus (CMV) infection is challenging because of the high rate of asymptomatic infection and the low specificity of associated symptoms and signs. As a result, laboratory testing is an essential aid in making an accurate diagnosis. The presence of CMV IgM is indicative of primary CMV infection. In pregnancy, diagnosis of primary infection is important because primary maternal infection increases fetal infection risk substantially. Fetal infection can result in serious sequelae ranging from neurological deficits to death. Diagnosis among the immunocompromised is also critical for the timely initiation of therapy that can reduce morbidity and mortality risk. The IMMULITE® 2000 CMV IgM assay qualitatively detects CMV IgM antibodies in human serum or plasma to aid in the diagnosis of current or recent CMV infection. To determine expected values in apparently healthy subjects, 136 samples were tested. Reproducibility, normal range, and method comparison studies were also performed to evaluate the assay's performance. The assay's reproducibility was evaluated across three sites. Seven hundred and eighteen (n = 718) individual patient serum samples, which included samples from CMV IgM-positive (n = 109, determined by the Abbott IMx CMV or the Diamedix CMV IgM assays), pregnant (n = 210), HIV-positive (n = 30), immunosuppressed (n = 102), and transplant patients (n = 17) and from patients with potentially cross-reacting conditions (n = 136) were evaluated in the method comparison study. The positive, negative, and overall agreement between the IMMULITE 2000 CMV IgM assay and the VIDAS CMV IgM assay (predicate assay) were determined. The assay demonstrated excellent reproducibility with a total CV of less than 10%. The positive, negative, and overall agreement between the IMMULITE 2000 assay and the VIDAS assay were > 95% for the method comparison samples. Among potentially cross-reactive samples, the overall agreement between the two assays was 96

  17. Performance of cobas® 4800 and m2000 real-time™ assays for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in rectal and self-collected vaginal specimen

    NARCIS (Netherlands)

    Geelen, Tanja H; Rossen, John W; Beerens, Antoine M; Poort, Linda; Morré, Servaas A; Ritmeester, Wilma S; van Kruchten, Harry E; van de Pas, Masja M; Savelkoul, Paul H M

    2013-01-01

    A prospective, multicenter trial was designed to compare the performance characteristics of the cobas® 4800 (Roche Diagnostics, Indianapolis, IN, USA) and m2000 real-time™ (Abbott Molecular Inc., Des Plaines, IL, USA) assays for detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG)

  18. Smartphone instrument for portable enzyme-linked immunosorbent assays.

    Science.gov (United States)

    Long, Kenneth D; Yu, Hojeong; Cunningham, Brian T

    2014-11-01

    We demonstrate the utilization of a smartphone camera as a spectrometer that is capable of measuring Enzyme Linked Immunosorbent Assays (ELISA) at biologically-relevant concentrations with the aid of a custom cradle that aligns a diffraction grating and a collimating lens between a light source and the imaging sensor. Two example biomarkers are assayed using conventional ELISA protocols: IL-6, a protein used diagnostically for several types of cancer, and Ara h 1, one of the principle peanut allergens. In addition to the demonstration of limits of detection at medically-relevant concentrations, a screening of various cookies was completed to measure levels of peanut cross-contamination in local bakeries. The results demonstrate the utility of the instrument for quantitatively performing broad classes of homogeneous colorimetric assays, in which the endpoint readout is the color change of a liquid sample.

  19. Alternative antibody for the detection of CA19-9 antigen: a European multicenter study for the evaluation of the analytical and clinical performance of the Access GI Monitor assay on the UniCel Dxl 800 Immunoassay System.

    Science.gov (United States)

    Stieber, Petra; Molina, Rafael; Gion, Massimo; Gressner, Axel; Troalen, Frédéric; Holdenrieder, Stefan; Auge, Jose Maria; Zancan, Matelda; Wycislo, Matthias; Jarrige, Véronique

    2008-01-01

    Gastrointestinal cancer antigen CA19-9 is known as a valuable marker for the management of patients with pancreatic cancer. The analytical and clinical performance of the Access GI Monitor assay (Beckman Coulter) was evaluated on the UniCel Dxl 800 Immunoassay System at five different European sites and compared with a reference method, defined as CA19-9 on the Elecsys System (Roche Diagnostics). Total imprecision (%CV) of the GI Monitor ranged between 3.4% and 7.7%, and inter-laboratory reproducibility between 3.6% and 4.0%. Linearity upon dilution showed a mean recovery of 97.4% (SD + 7.2%). Endogenous interferents had no influence on GI Monitor levels (mean recoveries: hemoglobin 103%, bilirubin 106%, triglycerides 106%). There was no high-dose hook effect up to 115,000 kU/L. Clinical performance investigated in sera from 1811 individuals showed a good correlation between the Access GI Monitor and Elecsys CA19-9 (R = 0.959, slope = 1.004, intercept = +0.17). GI Monitor serum levels were low in healthy individuals (n = 267, median = 6.0 kU/L, 95th percentile=23.1 kU/L), higher in individuals with various benign diseases (n = 550, medians = 5.8-13.4 kU/L, 95th percentiles = 30.1-195.5 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 8.4-233.8 kU/L, 95th percentiles = 53.7-13,902 kU/L). Optimal diagnostic accuracy for cancer detection against the relevant benign control group by the GI Monitor was found for pancreatic cancer [area under the curve (AUC) 0.83]. Results for the reference CA19-9 assay were comparable (AUC 0.85). The Access GI Monitor provides very good methodological characteristics and demonstrates an excellent analytical and clinical correlation with the Elecsys CA19-9. The GI Monitor shows the best diagnostic accuracy in pancreatic cancer. Our results also suggest a clinical value of the GI Monitor in other cancers.

  20. Towards a high throughput droplet-based agglutination assay

    KAUST Repository

    Kodzius, Rimantas

    2013-10-22

    This work demonstrates the detection method for a high throughput droplet based agglutination assay system. Using simple hydrodynamic forces to mix and aggregate functionalized microbeads we avoid the need to use magnetic assistance or mixing structures. The concentration of our target molecules was estimated by agglutination strength, obtained through optical image analysis. Agglutination in droplets was performed with flow rates of 150 µl/min and occurred in under a minute, with potential to perform high-throughput measurements. The lowest target concentration detected in droplet microfluidics was 0.17 nM, which is three orders of magnitude more sensitive than a conventional card based agglutination assay.

  1. Diagnostic performance of HPV E6/E7 mRNA assay for detection of cervical high-grade intraepithelial neoplasia and cancer among women with ASCUS Papanicolaou smears.

    Science.gov (United States)

    Ren, Chenchen; Zhu, Yuanhang; Yang, Li; Zhang, Xiaoan; Liu, Ling; Ren, Chunying

    2017-11-15

    The aim of this study was to investigate the clinical performance of high risk (HR) HPV E6/E7 mRNA assay in detecting cervical high-grade intraepithelial neoplasia and cancer among women with atypical squamous cells of undetermined significance (ASCUS) Papanicolaou (Pap) smears. A total of 160 patients with ASCUS who underwent HR-HPV DNA assay, HR-HPV E6/E7 mRNA assay and colposcopy biopsy at Third Affiliated Hospital of Zhengzhou University, China, from December 2015 to March 2017, were enrolled. Logistic regression analysis was used to evaluate the relationship between pathological results with clinical biologic factors. Univariate analysis showed that the qualitative results of HR-HPV DNA, qualitative results of HR-HPV E6/E7 mRNA and expression levels of HR-HPV E6/E7 mRNA were risk factors of high-grade cervical intraepithelial neoplasia (CIN) and cervical cancer (all P mRNA was associated with high-grade CIN and cervical cancer (OR = 8.971, 95% CI = 2.572-31.289, P = 0.001). An optimal cut-off value of ≥ 558.26 copies/ml was determined using receiver operating characteristic curve, and specificity of cut-off value were higher than E6/E7 mRNA qualitative assay and DNA qualitative assay. HPV E6/E7 mRNA quantitative assay may be a valuable tool in triage of ASCUS pap smears. A high specificity of E6/E7 mRNA quantitative assay as a triage test in women with ASCUS can be translated into a low referral for colposcopy.

  2. Analytical and clinical performance of the Hologic Aptima HCV Quant Dx Assay for the quantification of HCV RNA in plasma samples

    DEFF Research Database (Denmark)

    Schønning, Kristian; Pedersen, Martin Schou; Johansen, Kim

    2017-01-01

    dilution series of four HCV genotypes (slope of the regression line: 1.00-1.02). The Aptima assay detected significantly more replicates below targeted 2 Log IU/mL than the CAPCTMv2 test, and yielded clearly interpretable results when used to analyze samples from patients treated with DAAs. CONCLUSIONS...

  3. Mistaken identity of an open reading frame proposed for PCR-based identification of Mycoplasma bovis and the effect of polymorphisms and insertions on assay performance

    Science.gov (United States)

    Mycoplasma bovis is an important cause of disease in cattle and bison. Because the bacterium requires specialized growth conditions many diagnostic laboratories routinely use PCR to replace or complement conventional isolation and identification methods. A frequently used target of such assays is th...

  4. INSM1 Demonstrates Superior Performance to the Individual and Combined Use of Synaptophysin, Chromogranin and CD56 for Diagnosing Neuroendocrine Tumors of the Thoracic Cavity.

    Science.gov (United States)

    Rooper, Lisa M; Sharma, Rajni; Li, Qing Kay; Illei, Peter B; Westra, William H

    2017-11-01

    Despite the importance of recognizing neuroendocrine differentiation when diagnosing tumors of the thoracic cavity, the sensitivity of traditional neuroendocrine markers is suboptimal, particularly for high-grade neuroendocrine carcinomas such as small cell lung carcinoma and large cell neuroendocrine carcinoma. To increase sensitivity, neuroendocrine markers are routinely ordered as panels of multiple immunostains where any single positive marker is regarded as sufficient evidence of neuroendocrine differentiation. Insulinoma-associated protein 1 (INSM1) is a well-validated transcription factor of neuroendocrine differentiation that has only recently been evaluated for diagnostic use. We performed INSM1 immunohistochemistry on a large series of thoracic neuroendocrine and non-neuroendocrine tumors and compared its performance to synaptophysin, chromogranin, and CD56. INSM1 was positive in 94.9% of small cell lung carcinomas and 91.3% of large cell neuroendocrine carcinomas, compared with 74.4% and 78.3% with the combined panel of traditional markers. INSM1 also stained all (100%) of the atypical carcinoids, typical carcinoids and mediastinal paragangliomas, but only 3.3% of adenocarcinomas and 4.2% of squamous cell carcinomas. Overall, INSM1 demonstrated a sensitivity of 96.4% across all grades of thoracic neuroendocrine tumors, significantly more than the 87.4% using the panel of traditional markers (P=0.02). INSM1 is sufficiently sensitive and specific to serve as a standalone first-line marker of neuroendocrine differentiation. A more restrained approach to immunohistochemical analysis of small thoracic biopsies is appropriate given the expanding demand on this limited material for therapeutic biomarker analysis.

  5. Review on the acute Daphnia magna toxicity test – Evaluation of the sensitivity and the precision of assays performed with organisms from laboratory cultures or hatched from dormant eggs

    Directory of Open Access Journals (Sweden)

    Persoone G.

    2009-08-01

    “Culture/maintenance free” aquatic microbiotests with species of different phylogenetic groups were developed in the early 1990s at the Laboratory for Environmental Toxicology and Aquatic Ecology at the Ghent University in Belgium. These assays which were given the generic name “Toxkits”, are unique in that they employ dormant stages (“cryptobiotic eggs” of the test species, which can be stored for long periods of time and “hatched” at the time of performance of the assays. One of these microbiotests is the Daphtoxkit F magna, which is currently used in many laboratories worldwide for research as well as for toxicity monitoring purposes. The microbiotest technology has several advantages in comparison to the “traditional” tests based on laboratory cultures, especially its independence of the stock culturing burden. However, the acceptance (or possible non-acceptance of performing assays with test organisms obtained from “dormant eggs” should be clearly dictated by the “sensitivity” and “precision” criteria of the former assays in comparison to the latter. The first part of this review therefore thoroughly reviews the scientific literature and of data obtained from various laboratories for assays performed with either D. magna test organisms obtained from lab cultures or hatched from dormant eggs. Attention has focused on data of quality control tests performed on reference chemicals, and in particular on potassium dichromate (K2Cr2O7 for which an acceptability range of 0.6–2.1 mg·L–1 has been set in ISO standard 6341 for the 24 h EC50 of the acute D. magna assay. Mean EC50s, standard deviations and variation coefficients were calculated from the collected data, all of which are presented in tables and figures and discussed in detail. The major conclusions drawn from the analysis of the large number of quality control (QC data on the acute D. magna toxicity test are that : (1 Virtually all results from assays performed with

  6. Sulforhodamine B assay and chemosensitivity.

    Science.gov (United States)

    Voigt, Wieland

    2005-01-01

    The sulforhodamine B (SRB) assay was developed by Skehan and colleagues to measure drug-induced cytotoxicity and cell proliferation for large-scale drug-screening applications. Its principle is based on the ability of the protein dye sulforhodamine B to bind electrostatically and pH dependent on protein basic amino acid residues of trichloroacetic acid-fixed cells. Under mild acidic conditions it binds to and under mild basic conditions it can be extracted from cells and solubilized for measurement. Results of the SRB assay were linear with cell number and cellular protein measured at cellular densities ranging from 1 to 200% of confluence. Its sensitivity is comparable with that of several fluorescence assays and superior to that of Lowry or Bradford. The signal-to-noise ratio is favorable and the resolution is 1000-2000 cells/well. It performed similarly compared to other cytotoxicity assays such as MTT or clonogenic assay. The SRB assay possesses a colorimetric end point and is nondestructive and indefinitely stable. These practical advances make the SRB assay an appropriate and sensitive assay to measure drug-induced cytotoxicity even at large-scale application.

  7. Performance evaluation of the Verigene® (Nanosphere) and FilmArray® (BioFire®) molecular assays for identification of causative organisms in bacterial bloodstream infections.

    Science.gov (United States)

    Ward, C; Stocker, K; Begum, J; Wade, P; Ebrahimsa, U; Goldenberg, S D

    2015-03-01

    Molecular assays designed to provide bacterial identification and detection of resistance genes directly from positive blood cultures can significantly reduce the time to definitive results. This has the potential to improve patient management and antimicrobial stewardship. However, the extent of such an impact is yet to be fully assessed. We tested two such assays, the Verigene® System Bloodstream Infection Tests (Nanosphere, Inc., Northbrook, IL, USA) (both Gram-positive and Gram-negative cartridges) and the FilmArray® Blood Culture Identification Panel (BioFire® Diagnostics, Inc., Salt Lake City, UT, USA). We compared their accuracy and speed of organism and resistance gene identification to conventional culture-based methods for 173 positive blood cultures. We also retrospectively determined, for organisms deemed not to be contaminants, the potential impact on antimicrobial prescribing. Both the Verigene® and FilmArray® assays accurately identified organisms, on average, 27.95 and 29.17 h earlier than conventional methods, respectively. There were a significant number of false-positives for Pseudomonas aeruginosa with the FilmArray® assay, which may have been related to contamination of the bioMérieux BacT standard anaerobic blood culture bottles, which the manufacturer has acknowledged. Both panels provided results significantly faster than conventional methods. In our setting, the extent of the potential positive impact on antimicrobial prescribing was modest (9 out of 173 samples). However, this may be an underestimation, since probable contaminants were not included in this analysis. In conclusion, both panels gave accurate results with significantly improved turnaround times.

  8. Review on the acute Daphnia magna toxicity test – Evaluation of the sensitivity and the precision of assays performed with organisms from laboratory cultures or hatched from dormant eggs

    Directory of Open Access Journals (Sweden)

    G. Persoone

    2009-08-01

    Full Text Available One of the most internationally used bioassays for toxicity screening of chemicals and for toxicity monitoring of effluents and contaminated waters is the acute toxicity test with daphnid crustaceans, and in particular that performed with Daphnia magna.Standard methods have been developed for this assay that were gradually endorsed by national and international organisations dealing with toxicity testing procedures, in view of its application within a regulatory framework. As for all toxicity tests, the organisms used for the acute D. magna assay have to be obtained from live stocks which are cultured in the laboratory on live food (micro-algae.Unsurprisingly the various standard protocols of this particular assay differ – at least to a certain extent – with regard to the test organism culturing conditions. In addition, some technical aspects of the toxicity test such as the effect criterion (mortality of immobility, the exposure time, the type of dilution water, etc., also vary from one standard to another.Although this particular assay is currently used in many countries, the technical and biological problems inherent in year-round culturing and availability of the biological material and the culturing/maintenance costs of live stocks restrict its application to a limited number of highly specialised laboratories.This fundamental bottleneck in toxicity testing triggered investigations which brought forward the concept of “microbiotests” or “small-scale” toxicity tests. “Culture/maintenance free” aquatic microbiotests with species of different phylogenetic groups were developed in the early 1990s at the Laboratory for Environmental Toxicology and Aquatic Ecology at the Ghent University in Belgium.These assays which were given the generic name “Toxkits”, are unique in that they employ dormant stages (“cryptobiotic eggs” of the test species, which can be stored for long periods of time and “hatched” at the time of

  9. Antibody performance in ChIP-sequencing assays: From quality scores of public data sets to quantitative certification [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Marco-Antonio Mendoza-Parra

    2016-03-01

    Full Text Available We have established a certification system for antibodies to be used in chromatin immunoprecipitation assays coupled to massive parallel sequencing (ChIP-seq. This certification comprises a standardized ChIP procedure and the attribution of a numerical quality control indicator (QCi to biological replicate experiments. The QCi computation is based on a universally applicable quality assessment that quantitates the global deviation of randomly sampled subsets of ChIP-seq dataset with the original genome-aligned sequence reads. Comparison with a QCi database for >28,000 ChIP-seq assays were used to attribute quality grades (ranging from ‘AAA’ to ‘DDD’ to a given dataset. In the present report we used the numerical QC system to assess the factors influencing the quality of ChIP-seq assays, including the nature of the target, the sequencing depth and the commercial source of the antibody.  We have used this approach specifically to certify mono and polyclonal antibodies obtained from Active Motif directed against the histone modification marks H3K4me3, H3K27ac and H3K9ac for ChIP-seq. The antibodies received the grades AAA to BBC (www.ngs-qc.org. We propose to attribute such quantitative grading of all antibodies attributed with the label “ChIP-seq grade”.

  10. Diagnostic performance of different fecal Lawsonia intracellularis-specific polymerase chain reaction assays as diagnostic tests for proliferative enteropathy in pigs: a review.

    Science.gov (United States)

    Pedersen, Ken Steen; Holyoake, Patricia; Stege, Helle; Nielsen, Jens Peter

    2010-07-01

    Traditionally, diagnosis of Lawsonia intracellularis-associated proliferative enteropathy (PE) has depended on necropsy and histology. Since the establishment of the etiologic role of L. intracellularis, a number of specific polymerase chain reaction (PCR) assays have been developed for the detection of DNA in feces. The present article is a systematic review of peer-reviewed publications on the application of L. intracellularis-specific fecal PCR as an antemortem diagnostic test for histologic lesions of PE in pigs. Based on this information, a range of diagnostic sensitivities (36-100%) and specificities (50-100%) of the published tests was calculated. Validity and confidence limits of the estimates varied considerably. The positive and negative predictive values of 6 different PCR assays were calculated for PE prevalence of 15%, 30%, 45%, 60%, 75%, and 90%, using a histologic case definition of PE and based on the reported test sensitivities and specificities. The simulated predictive values suggested that applying the fecal PCR assay as a diagnostic test is more likely to overestimate than underestimate the number of pigs having histologic lesions of PE under field conditions.

  11. ESTCP Cost and Performance Report: Field Demonstration of Rhizosphere-Enhanced Treatment of Organics-Contaminated Soils on Native American Lands with Application to Northern FUD Sites

    National Research Council Canada - National Science Library

    Reynolds, C. M

    2004-01-01

    ... can be used in other situations dealing with surface soil contamination. This project included field demonstrations of rhizosphere-enhanced bioremediation of petroleum, oils, and lubricants (POLs...

  12. Education Payload Operation - Demonstrations

    Science.gov (United States)

    Keil, Matthew

    2009-01-01

    Education Payload Operation - Demonstrations (EPO-Demos) are recorded video education demonstrations performed on the International Space Station (ISS) by crewmembers using hardware already onboard the ISS. EPO-Demos are videotaped, edited, and used to enhance existing NASA education resources and programs for educators and students in grades K-12. EPO-Demos are designed to support the NASA mission to inspire the next generation of explorers.

  13. Arsenic and Nitrate Removal from Drinking Water by Ion Exchange U.S. EPA Demonstration Project at Vale, OR - Final Performance Evaluation Report

    Science.gov (United States)

    As part of the EPA Arsenic Removal Technology Demonstration Program, a 540-gal/min (gpm) ion exchange (IX) system proposed by Kinetico was selected for demonstration at Vale, OR to remove arsenic and nitrate from a groundwater supply to meet their respective maximum contaminant l...

  14. Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in an STI population: performances of the Presto CT-NG assay, the Lightmix Kit 480 HT CT/NG and the COBAS Amplicor with urine specimens and urethral/cervicovaginal samples

    Science.gov (United States)

    Schuurs, T A; Verweij, S P; Weel, J F L; Ouburg, S; Morré, S A

    2013-01-01

    Objectives This study assessed the performances of the Presto CT-NG assay, the Lightmix Kit 480 HT CT/NG and the COBAS Amplicor for Chlamydia trachomatis and Neisseria gonorrhoeae detection. Design A cross-sectional study design. Setting Izore, Centre for Diagnosing Infectious Diseases in Friesland, the Netherlands, tested samples sent from regional sexually transmitted infection (STI) outpatient clinics and regional hospitals from the province Friesland, the Netherlands. Participants Samples were collected from 292 men and 835 women. These samples included 560 urine samples and 567 urethral/cervicovaginal samples. Primary and secondary outcome measures The primary outcome measure is C trachomatis infection. No secondary outcome measures are available. Results The sensitivity, specificity, positive predicative value (PPV) and negative predictive value (NPV) for C trachomatis detection in urine samples using the Presto CT-NG assay were 100%, 99.8%, 98.1% and 100%, respectively; for the Lightmix Kit 480 HT CT/NG: 94.2%, 99.8%, 96.1% and 99.4%, respectively; for the COBAS Amplicor: 92.3%, 99.6%, 96% and 99.2%, respectively. The sensitivity, specificity, PPV and NPV for C trachomatis detection in urethral/cervicovaginal swabs using the Presto CT-NG assay and the COBAS Amplicor were 100%, 99.8%, 97.7% and 100%, respectively; for the Lightmix Kit 480 HT CT/NG: 100%, 99.6%, 97.7% and 100%, respectively. Calculations for N gonorrhoeae could not be made due to a low prevalence. Conclusions All three assays had a high sensitivity, specificity, PPV and NPV for C trachomatis, with best performance for the Presto CT-NG assay. PMID:24381252

  15. Comparison of Antioxidant Evaluation Assays for Investigating Antioxidative Activity of Gallic Acid and Its Alkyl Esters in Different Food Matrices.

    Science.gov (United States)

    Phonsatta, Natthaporn; Deetae, Pawinee; Luangpituksa, Pairoj; Grajeda-Iglesias, Claudia; Figueroa-Espinoza, Maria Cruz; Le Comte, Jérôme; Villeneuve, Pierre; Decker, Eric A; Visessanguan, Wonnop; Panya, Atikorn

    2017-08-30

    The addition of antioxidants is one of the strategies to inhibit lipid oxidation, a major cause of lipid deterioration in foods leading to rancidity development and nutritional losses. However, several studies have been reported that conventional antioxidant assays, e.g., TPC, ABTS, FRAP, and ORAC could not predict antioxidant performance in several foods. This study aimed to investigate the performance of two recently developed assays, e.g., the conjugated autoxidizable triene (CAT) and the apolar radical-initiated conjugated autoxidizable triene (ApoCAT) assays to predict the antioxidant effectiveness of gallic acid and its esters in selected food models in comparison with the conventional antioxidant assays. The results indicated that the polarities of the antioxidants have a strong impact on antioxidant activities. In addition, different oxidant locations demonstrated by the CAT and ApoCAT assays influenced the overall antioxidant performances of the antioxidants with different polarities. To validate the predictability of the assays, the antioxidative performance of gallic acid and its alkyl esters was investigated in oil-in-water (O/W) emulsions, bulk soybean oils, and roasted peanuts as the lipid food models. The results showed that only the ApoCAT assay could be able to predict the antioxidative performances in O/W emulsions regardless of the antioxidant polarities. This study demonstrated that the relevance of antioxidant assays to food models was strongly dependent on physical similarities between the tested assays and the food structure matrices.

  16. Comparison of clinical performances among Roche Cobas HPV, RFMP HPV PapilloTyper and Hybrid Capture 2 assays for detection of high-risk types of human papillomavirus.

    Science.gov (United States)

    Yu, Shinae; Kwon, Min-Jung; Lee, Eun Hee; Park, Hyosoon; Woo, Hee-Yeon

    2015-09-01

    The cervical cancer screening guidelines suggest that early detection of HPV16 and HPV18 is helpful for identifying women with cervical intraepithelial neoplasia (CIN) grade two or higher. We comparatively evaluated three HPV DNA assays, Roche Cobas HPV, RFMP HPV PapilloTyper, and Hybrid Capture 2 (HC2). A total of 861 cervical swab samples from women over 30 years of age were classified into two groups, that is, high grade squamous intraepithelial lesion (HSIL) and non-HSIL, according to cervical cytology results and analyzed by three assays. The results of direct sequencing or Linear array HPV genotyping test were considered true when the three assays presented discrepancies. The concordance rates between Roche Cobas HPV versus RFMP HPV PapilloTyper, RFMP HPV PapilloTyper versus HC2, and Roche Cobas versus HC2 were 94.5%, 94.3%, and 95.9%, respectively. For detection of HPV16 and HPV18, Roche Cobas HPV showed the concordance rates of 98.3% (κ = 0.73) and 99.4% (κ = 0.40) with the confirmation tests, respectively; and RFMP HPV PapilloTyper showed the concordance rates of 99.5% (κ = 0.92) and 100.0% (κ = 1.00), respectively. In conclusion, Roche Cobas HPV, RFMP HPV PapilloTyper, and HC2 showed high agreement rates. Roche Cobas HPV and RFMP HPV PapilloTyper are particularly useful, since both provide HPV specific genotypes, HPV16 and HPV18. © 2015 Wiley Periodicals, Inc.

  17. Development of a lateral-flow assay for rapid screening of the performance-enhancing sympathomimetic drug clenbuterol used in animal production; food safety assessments.

    Science.gov (United States)

    Lai, Weihua; Xu, Yang; Fung, Daniel Y C; Xiong, Yonghua

    2007-01-01

    A lateral-flow assay that could provide visual evidence of the presence of clenbuterol in swine urine was developed. Colloidal gold was prepared and conjugated with anti-clenbuterol monoclonal antibody. Immunochromatographic test strips were produced, and then, 210 samples were tested on these strips. Analysis was completed in 10 min. Detection limit was 3 ppb of clenbuterol. Parallel GC-MS data indicated that clenbuterol rapid detection strip had no false negative. The false positive rate was 4.4%. Immunochromatographic strip has great applied value in the food safety field because it possesses benefits of sensitivity, stability, reproducibility, ease of use and inexpensive.

  18. Toward standardization of carbohydrate-deficient transferrin (CDT) measurements: III. Performance of native serum and serum spiked with disialotransferrin proves that harmonization of CDT assays is possible.

    Science.gov (United States)

    Weykamp, Cas; Wielders, Jos P M; Helander, Anders; Anton, Raymond F; Bianchi, Vincenza; Jeppsson, Jan-Olof; Siebelder, Carla; Whitfield, John B; Schellenberg, François

    2013-05-01

    Carbohydrate-deficient transferrin (CDT) is a generic term that refers to the transferrin glycoforms whose concentration in blood is temporarily increased by sustained alcohol consumption. Due to high clinical specificity, CDT was proposed as a biomarker of heavy alcohol use and has been available for about 20 years. A number of methods have been developed for CDT measurement based on different analytical techniques and principles and without any harmonization or calibration to a reference method. As a consequence, neither the reference limits nor the cut-off values have been similar across assays, hampering understanding of the diagnostic value of CDT and its routine use. This prompted the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) to initiate a Working Group on Standardization of CDT (WG-CDT). This third publication of the WG-CDT is devoted to testing the commutability of native and disialotransferrin-spiked serum panels as candidate secondary reference materials, in order to prove the harmonization potential of commercial CDT methods. The results showed that assay harmonization reduced the inter-laboratory imprecision in a network of reference laboratories running the HPLC candidate reference method. In the seven commercial methods evaluated in this study, the use of multi-level secondary calibrators of human serum origin significantly reduced the between-method imprecision. Thus, harmonization of CDT measurements by different methods can be achieved using this calibration system, opening the way for a full standardization of commercial methods against a reference method by use of certified reference materials.

  19. Alternative antibody for the detection of CA15-3 antigen: a European multicenter study for the evaluation of the analytical and clinical performance of the Access BR Monitor assay on the UniCel Dxl 800 Immunoassay System.

    Science.gov (United States)

    Molina, Rafael; Gion, Massimo; Gressner, Axel; Troalen, Frédéric; Auge, Jose Maria; Holdenrieder, Stefan; Zancan, Matelda; Wycislo, Matthias; Stieber, Petra

    2008-01-01

    Cancer antigen CA15-3 antigen is known as a valuable marker for the management of breast cancer. The analytical and clinical performance of the Access BR Monitor Immunoassay System (Beckman Coulter) was evaluated at five different European sites and compared with a reference system, defined as CA15-3 on the Elecsys System (Roche Diagnostics). Total imprecision (% CV) of the BR Monitor ranged between 5.5% and 11.7%, and inter-laboratory reproducibility between 3.4% and 5.1%. Linearity upon dilution showed a mean recovery of 98.5% (SD + 9.1%). Endogenous interferents had no influence on BR Monitor levels (mean recoveries: hemoglobin 112%, bilirubin 111%, triglycerides 108%). There was no high-dose hook effect up to 13,540 kU/L. Clinical performance investigated in sera from individuals showed a general correlation between the Access BR Monitor and Elecsys CA15-3 (R = 0.797), with a slope of 1.383. CA15-3 serum levels, as measured by the BR Monitor, were low in healthy individuals (n = 267, median = 11.9 kU/L, 95th percentile = 23.5 kU/L), higher in individuals with various benign diseases (n = 549, medians = 11.3-15.6 kU/L, 95th percentiles = 21.6-54.6 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 11.2-22.8 kU/L, 95th percentiles = 30.0-429.7 kU/L). Best diagnostic accuracy for cancer detection against the relevant benign control group by the BR Monitor was found for locoregional and metastatic breast cancer, as well as for ovarian cancer [area under the curve (AUC) 0.619, 0.897 and 0.774]. Results for the reference CA15-3 assay were comparable (AUC 0.611, 0.887 and 0.818). The Access BR Monitor provides accurate methodological characteristics and demonstrates an analytical and clinical correlation with Elecsys CA15-3. Best diagnostic accuracy for the BR Monitor was found in breast and ovarian cancer. Our results also suggest a clinical value of the BR Monitor in other cancers.

  20. Alternative antibody for the detection of CA125 antigen: a European multicenter study for the evaluation of the analytical and clinical performance of the Access OV Monitor assay on the UniCel Dxl 800 Immunoassay System.

    Science.gov (United States)

    Holdenrieder, Stefan; Molina, Rafael; Gion, Massimo; Gressner, Axel; Troalen, Frédéric; Auge, Jose Maria; Zancan, Matelda; Wycislo, Matthias; Stieber, Petra

    2008-01-01

    Cancer antigen CA125 is known as a valuable marker for the management of ovarian cancer. The analytical and clinical performance of the Access OV Monitor Immunoassay System (Beckman Coulter) was evaluated at five different European sites and compared with a reference system, defined as CA125 on the Elecsys System (Roche Diagnostics). Total imprecision (% CV) of the OV Monitor ranged between 3.1% and 8.8%, and inter-laboratory reproducibility between 4.7% and 5.0%. Linearity upon dilution showed a mean recovery of 100% (SD + 8.1%). Endogenous interferents had no influence on OV Monitor levels (mean recoveries: hemoglobin 107%, bilirubin 103%, triglycerides 103%). There was no high-dose hook effect up to 27,193 kU/L. Clinical performance investigated in sera from 1811 individuals showed a good correlation between the Access OV Monitor and Elecsys CA125 (R = 0.982, slope = 0.921, intercept = +1.951). OV Monitor serum levels were low in healthy individuals (n = 267, median = 9.7 kU/L, 95th percentile = 30.8 kU/L), higher in individuals with various benign diseases (n = 549, medians = 10.9-16.4 kU/L, 95th percentiles = 44.2-355 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 12.4-445 kU/L; 95th percentiles = 53.4-4664 kU/L). Optimal diagnostic accuracy for cancer detection against the relevant benign control group by the OV Monitor was found for ovarian cancer [area under the curve (AUC) 0.898]. Results for the reference CA125 assay were comparable (AUC 0.899). The Access OV Monitor provides very good methodological characteristics and demonstrates an excellent analytical and clinical correlation with Elecsys CA125. The best diagnostic accuracy for the OV Monitor was found in ovarian cancer. Our results also suggest a clinical value of the OV Monitor in other cancers.

  1. Correlation between the genotoxicity endpoints measured by two different genotoxicity assays: comet assay and CBMN assay

    Directory of Open Access Journals (Sweden)

    Carina Ladeira

    2015-06-01

    The results concerning of positive findings by micronuclei and non significant ones by comet assay, are corroborated by Deng et al. (2005 study performed in workers occupationally exposed to methotrexate, also a cytostatic drug. According to Cavallo et al. (2009, the comet assay seems to be more suitable for the prompt evaluation of the genotoxic effects, for instance, of polycyclic aromatic hydrocarbons mixtures containing volatile substances, whereas the micronucleus test seems more appropriate to evaluate the effects of exposure to antineoplastic agents. However, there are studies that observed an increase in both the comet assay and the micronucleus test in nurses handling antineoplastic drugs, although statistical significance was only seen in the comet assay, quite the opposite of our results (Maluf & Erdtmann, 2000; Laffon et al. 2005.

  2. SU-E-T-41: A Method for Performing An In-House Batch Assay of I-125 Seeds Used for Prostate Implants

    Energy Technology Data Exchange (ETDEWEB)

    Muryn, J [Cleveland State University, Cleveland, OH (United States); Wilkinson, D [Cleveland Clinic Foundation, Cleveland, OH (United States)

    2015-06-15

    Purpose: The purpose of this work is to evaluate a method for confirming source strength of I-125 seeds in a bulk assay while maintaining sterility and time efficiency. Methods: The I-125 seeds used in this study (STM 1251, Bard Brachytherapy, Inc.) were available as loose seeds or linked in 3, 4, or 5 seed configurations. A third party 10% assay (NIST traceable) is provided. Source strengths ranging from 0.395 to 0.504 U were available for this study. A stand was built out of aluminum to hold an exposure meter (Inovision (Fluke) 451P) at 25 cm above the I-125 sources to measure the exposure rate. Three different seed configurations were measured: loose, linked, and loaded needles (Bard FastFil Seed Implant Needle). The measurements were made in an operating room, and a sterile sheet was used under the non-sterile aluminum stand. Seeds and needles were placed in a sterile tray. Results: One hundred forty-two loose seeds in 5 batches (0.395, 0.395, 0.409, 0.444, 0.444 U/seed) and 902 seeds in 7 batches containing various strands (0.444, 0.444,.0444, 0.466, 0.466, 0.504, 0.504 U/seed) were measured. The average exposure rate per unit activity was measured to be 0.593 mR per hr per U with a standard deviation of 0.016. The Result for loaded needles was 0.261 mR per hr per U with a standard deviation of 0.014. Once the apparatus is set up, measurements of 180 linked sources as supplied in the Bard package requires only a few minutes. Conclusion: The proposed method can confirm the activity of a batch of loose or stranded I-125 seeds within a range of 5%.

  3. Arsenic Removal from Drinking Water by Point of Entry/Point of Use Adsorptive Media U.S. EPA Demonstration Project at Oregon Institute of Technology at Klamath Falls, OR - Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at Oregon Institute of Technology (OIT) at Klamath Falls, OR. The objectives of the project were to evaluate: (1) the effectiveness...

  4. Performance of an alternative HIV diagnostic algorithm using the ARCHITECT HIV Ag/Ab Combo assay and potential utility of sample-to-cutoff ratio to discriminate primary from established infection.

    Science.gov (United States)

    Ramos, Eric M; Harb, Socorro; Dragavon, Joan; Swenson, Paul; Stekler, Joanne D; Coombs, Robert W

    2013-12-01

    The ARCHITECT HIV Ag/Ab Combo assay has a wide dynamic range for determining the sample-to-cutoff ratio (S/CO) values compared to other diagnostic HIV antibody assays. Determine the performance of an HIV testing algorithm that uses the ARCHITECT combo assay in the clinical setting and explore the utility of the signal-to-cutoff (S/CO) ratio to predict acute HIV-1 infection status. A retrospective analysis of clinical samples from a hospital and referral population screened for HIV-1 infection between May 2011 and March 2013. Repeatedly reactive samples were tested using the Multispot HIV-1/HIV-2 rapid test and depending on that result, confirmatory orthogonal testing used the Western blot (WB) for HIV-1, Immunoblot for HIV-2 and nucleic acid amplification testing (NAAT) for HIV RNA. A total of 21,317 test results were evaluated of which 509 were ARCHITECT repeatedly reactive; of these, 422 were Multispot-reactive only for HIV-1 (413 WB-positive; 9 indeterminate), 4 were Multispot-reactive for both HIV-1 and HIV-2 (one HIV-2 immunoblot-positive with 17 HIV-2 RNA copies/mL) and 83 were Multispot-non-reactive of which 15 were HIV-1 RNA positive and represented acute HIV-1 infection. There was an association among the ARCHITECT S/CO (median; IQR) values for antibody-negative (0.14; 0.11-0.16), acute infection (33; 2.1-76) and established HIV-1 infection (794; 494-1,029) (Kruskal-Wallis, pARCHITECT combo assay with Multispot confirmation and reserved use of HIV-1 WB, HIV-2 Immunoblot and HIV NAAT for Multispot dual HIV-1/2 infection, and NAAT alone for Multispot-negative specimens, had a suitable test performance for detecting acute and established HIV infection. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Performance of an alternative HIV diagnostic algorithm using the ARCHITECT HIV Ag/Ab Combo assay and potential utility of sample-to-cutoff ratio to discriminate primary from established infection☆

    Science.gov (United States)

    Ramos, Eric M.; Harb, Socorro; Dragavon, Joan; Swenson, Paul; Stekler, Joanne D.; Coombs, Robert W.

    2014-01-01

    Background The ARCHITECT HIV Ag/Ab Combo assay has a wide dynamic range for determining the sample-to-cutoff ratio (S/CO) values compared to other diagnostic HIV antibody assays. Objectives Determine the performance of an HIV testing algorithm that uses the ARCHITECT combo assay in the clinical setting and explore the utility of the signal-to-cutoff (S/CO) ratio to predict acute HIV-1 infection status. Study design A retrospective analysis of clinical samples from a hospital and referral population screened for HIV-1 infection between May 2011 and March 2013. Repeatedly reactive samples were tested using the Multispot HIV-1/HIV-2 rapid test and depending on that result, confirmatory orthogonal testing used the Western blot (WB) for HIV-1, Immunoblot for HIV-2 and nucleic acid amplification testing (NAAT) for HIV RNA. Results A total of 21,317 test results were evaluated of which 509 were ARCHITECT repeatedly reactive; of these, 422 were Multispot-reactive only for HIV-1 (413 WB-positive; 9 indeterminate), 4 were Multispot-reactive for both HIV-1 and HIV-2 (one HIV-2 immunoblot-positive with 17 HIV-2 RNA copies/mL) and 83 were Multispot-non-reactive of which 15 were HIV-1 RNA positive and represented acute HIV-1 infection. There was an association among the ARCHITECT S/CO (median; IQR) values for antibody-negative (0.14; 0.11–0.16), acute infection (33; 2.1–76) and established HIV-1 infection (794; 494–1,029) (Kruskal–Wallis, p ARCHITECT combo assay with Multispot confirmation and reserved use of HIV-1 WB, HIV-2 Immunoblot and HIV NAAT for Multispot dual HIV-1/2 infection, and NAAT alone for Multispot-negative specimens, had a suitable test performance for detecting acute and established HIV infection. PMID:24029686

  6. An o-phthalaldehyde spectrophotometric assay for proteinases.

    Science.gov (United States)

    Church, F C; Porter, D H; Catignani, G L; Swaisgood, H E

    1985-05-01

    A rapid and convenient spectrophotometric assay has been devised to measure proteolysis. The assay is based on the reaction of o-phthalaldehyde (OPA) and 2-mercaptoethanol with amino groups released during proteolysis of a protein substrate. The reaction is specific for primary amines in amino acids, peptides, and proteins, approaches completion within 1 to 2 min at 25 degrees C (half-times of approx 10-15 s), and requires no preliminary heating or separation of the hydrolyzed products from the undegraded protein substrate prior to performing the assay. The OPA assay was relatively as successful as a 2,4,6-trinitrobenzenesulfonic acid (TNBS) procedure in predicting the extent of hydrolysis of a protein substrate. The utility of the OPA method was demonstrated by measuring the degree of proteolytic degradation caused by trypsin, subtilisin, Pronase, and chymotrypsin of various soluble protein substrates. Ethanethiol (instead of 2-mercaptoethanol) or 50% of dimethyl sulfoxide can be included in the assay solution to stabilize certain OPA-amine products. The present method approaches the sensitivity of ninhydrin and TNBS procedures, is more convenient and rapid, and could substitute for these reagents in most assay systems.

  7. FLUIDICS DEVICE FOR ASSAY

    DEFF Research Database (Denmark)

    2007-01-01

    The present invention relates to a device for use in performing assays on standard laboratory solid supports whereon chemical entities are attached. The invention furthermore relates to the use of such a device and a kit comprising such a device. The device according to the present invention...... is adapted to receive one or more replaceable solid support(s) (40) onto which chemical entities (41) are attached, said device comprising a base (1, 60, 80, 300, 400, 10, 70, 140, 20, 90, 120, 150, 30, 100), one or more inlet(s) (5), one or more outlet(s) (6). The base and the solid support (40) defines......, when operatively connected, one or more chambers (21) comprising the chemical entities (41), the inlet(s) (5) and outlet(s) (6) and chambers (21) being in fluid connection. The device further comprise means for providing differing chemical conditions in each chamber (21)....

  8. Evaluation of enzyme-linked immunosorbent assays performed on milk and serum samples for detection of neosporosis and leukosis in lactating dairy cows.

    Science.gov (United States)

    Walsh, Robert B; Kelton, David F; Hietala, Sharon K; Duffield, Todd F

    2013-04-01

    Serum and milk samples from 1229 cows on 22 Ontario dairy farms were individually tested for antibodies specific for bovine leukosis virus (BLV) and Neospora caninum by enzyme-linked immunosorbent assay (ELISA). Antibodies against BLV were present in 361 serum samples (29.4%) and 369 milk samples (30.0%). Comparing the 2 tests, agreement was almost perfect (k = 0.86; 95% CI = 0.83 to 0.90) and the proportions of samples positive were not significantly different (P = 0.56). Both tests identified the same 3 herds free of bovine leukosis virus. Antibodies against N. caninum were detected in 138 serum samples (11.2%), and 111 milk samples (9.0%). Agreement between the 2 tests was moderate (k = 0.52; 95% CI = 0.43 to 0.59). Four herds were free of neosporosis by the serum test, while 10 herds were negative by the milk test. The ELISA on milk samples facilitates sample collection to classify herds free of BLV; the milk N. caninum ELISA was less reliable in predicting herd-level infection.

  9. Development and Validation of a Specific Stability Indicating High Performance Liquid Chromatographic Methods for Related Compounds and Assay of Solifenacin Succinate

    Directory of Open Access Journals (Sweden)

    B. V. Rami Reddy

    2013-01-01

    Full Text Available Gradient, reverse phase liquid chromatographic methods were developed separately for the related compounds and solifenacin succinate, an active pharmaceutical ingredient used for the treatment of overactive bladder. Gradient LC method was employed for related compounds. The mobile phase-A contains a 0.01 M phosphate buffer pH: 3.5±0.05 with orthophosphoric acid (88% and mobile phase-B contains a mixture of acetonitrile and water in the ratio of 90 : 10(v/v. The flow rate was 1.0 mL/minute, column temperature was kept at 35°C, and detection was monitored at 220 nm. In the developed HPLC method the resolution between solifenacin succinate and its closely eluting impurity, that is, solifenacin N-oxide was found to be greater than 3.0. The drug was subjected to stress conditions such as hydrolysis, oxidation, photolysis, and thermal degradation. Considerable degradation was found to occur in only oxidative stress condition. Degradation product formed during oxidative stress condition was found to be impurity-C and it can be identified by LC-MS. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.5%. The developed RP-LC method was validated as per ICH guidelines. We also developed LC-MS/MS method for determination and identification of these impurities in solifenacin succinate.

  10. Evaluation of a particle enhanced turbidimetric assay for the measurement of neutrophil gelatinase-associated lipocalin in plasma and urine on Architect-8000: Analytical performance and establishment of reference values.

    Science.gov (United States)

    Makris, Konstantinos; Stefani, Dimitra; Makri, Eleni; Panagou, Ioannis; Lagiou, Maria; Sarli, Antonia; Lelekis, Moysis; Kroupis, Christos

    2015-12-01

    Neutrophil gelatinase-associated lipocalin (NGAL) is a promising biomarker for acute kidney injury. NGAL can be measured in both blood and urine. Apart from kidney injury, NGAL levels in both plasma and urine can be influenced by various pathological situations. Accurate evaluation and comparison of results deriving from clinical studies require robust assays, appropriate specimen handling and reference intervals that will reflect its levels in a healthy population for both biological matrices. We report the analytical validation of a latex particle-enhanced turbidimetric immunoassay (PETIA) aimed to measure NGAL in plasma and urine on an automated biochemistry analyzer (ABBOTT-Architect-8000). Assay performance characteristics were evaluated using standard protocols. Urine and plasma specimen storage requirements were determined and reference ranges for blood and urine were determined using healthy controls. The assay is precise (total CV%<4.8%), and sensitive (limit of quantification: 8.4 ng/mL for plasma and 9.0 ng/mL for urine), showing no hook effect. Calibration is stable for at least 30 days. The assay showed excellent linearity over the studied interval (20-4450 ng/mL). The analyte is stable at 4 °C for at least 5 days, and at 20 °C for 4h. Gender specific reference ranges for plasma (male: 38.7-157.6 ng/mL, female: 24.4-142.5 ng/mL) and unisex for urine (<9.0-49.41 ng/mL) are proposed. Our data indicate that NGAL can be measured with adequate precision and sensitivity on automated biochemistry analyzers and its measurement could easily be added to a standard panel to screen kidney diseases. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  11. Comparison of the performance of the NucliSENS EasyQ HPV E6/E7 mRNA assay and HPV DNA chip for testing squamous cell lesions of the uterine cervix.

    Science.gov (United States)

    Munkhdelger, Jijgee; Choi, Yeonim; Lee, Dongsup; Kim, Sunghyun; Kim, Geehyuk; Park, Sangjung; Choi, Eunhee; Jin, Hyunwoo; Jeon, Bo-Young; Lee, Hyeyoung; Park, Kwang Hwa

    2014-08-01

    This study aims to evaluate the clinical performance of the NucliSENS EasyQ assay and compare it with HPV DNA genotyping for the detection of high-grade squamous intraepithelial lesions (HSIL) and cancer in a Korean population. In 188 total thin prep samples, the remaining fluid after cytology slide preparation was tested with Goodgene HPV DNA chips and the NucliSENS EasyQ HPV E6/E7 messenger RNA (mRNA) assay. The sensitivity and specificity of each test were calculated with HSIL and squamous cell carcinoma (SCC) as the disease endpoint. Out of the 188 samples, 139 (74%) were positive for DNA of 14 HPV types, while 57 (30%) cases were positive for E6/E7 mRNA. The DNA test was positive in cytology cases of SCC, HSIL, and atypical squamous cell. The mRNA test yielded results of 75%, 74%, 60%, 56%, and 29% positivity in abnormal cytology cases of SCC, HSIL, atypical squamous cells - cannot exclude HSIL, atypical squamous cells of undetermined significance, and low-grade squamous intraepithelial lesion, respectively. In normal cytology cases, the positivity rates were 9% and 53% for the mRNA and DNA tests, respectively. For detection of HSIL and SCC, the sensitivity of the mRNA test was 74.36% and that of the DNA test was 100%, while the specificities of the tests were 85% and 40.83%, respectively. These findings suggest that the HPV E6/E7 mRNA assay can overcome the shortcoming of low specificity of DNA assays for clinical detection of high-grade cervical lesions and malignancies. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Performance of the HPV-16 L1 methylation assay and HPV E6/E7 mRNA test for the detection of squamous intraepithelial lesions in cervical cytological samples.

    Science.gov (United States)

    Qiu, Cui; Zhi, Yanfang; Shen, Yong; Gong, Jiaomei; Li, Ya; Rong, Shouhua; Okunieff, Paul; Zhang, Lulu; Li, Xiaofu

    2015-11-01

    HPV-16 L1 methylation and E6/E7 mRNA have suggested that they had close relationship with cervical neoplastic progression. This study aimed to evaluate the clinical performance of the HPV-16 L1 methylation assay and E6/E7 mRNA test for detecting high-grade cervical lesions (CIN2+). A total of 81 women with liquid-based cytology (LBC) samples, histological results, and positive HPV-DNA test for HPV type 16 only were included in this study. HPV-16 L1 methylation and E6/E7 mRNA levels were measured using methylation-sensitive high resolution melting (MS-HRM) analysis and Quantivirus®HPV E6/E7 RNA 3.0 assay (bDNA), respectively, in the same residue of LBC samples. The current date showed a positive correlation between the HPV-16 L1 methylation and the E6/E7 mRNA levels. The L1 methylation and mRNA levels both increased with disease severity. The mRNA test method showed higher sensitivity and NPV (98.0 and 91.7% vs. 89.8 and 80.8%), while lower specificity and PPV (34.4 and 69.6% vs. 65.6 and 80.0%), than the L1 methylation assay for detecting histology-confirmed CIN2+. When using the detection method of mRNA test combined with L1 methylation assay, we obtained a sensitivity of 89.8% and a specificity of 71.9%. These findings suggest that assessment of HPV-16 L1 methylation testing combined with E6/E7 mRNA testing may be a promising method for the triage of women with HPV type 16 only. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Lessons from the use of genetically modified Drosophila melanogaster in ecological studies: Hsf mutant lines show highly trait-specific performance in field and laboratory thermal assays

    DEFF Research Database (Denmark)

    Sørensen, Jesper Givskov; Loeschcke, Volker; Kristensen, Torsten Nygård

    2009-01-01

    . 2.  We have tested the importance of inducible heat shock proteins (Hsps) under different thermal conditions using two heat shock factor (Hsf) mutant lines (either able (Hsf+) or unable (Hsf0) to mount a heat stress response) and an outbred laboratory adapted wild-type line of Drosophila...... melanogaster under both laboratory and field conditions.3.  In the field, there was a tendency towards better performance of Hsf+ flies relative to Hsf0 flies, but as compared with wild-type the performance of both mutant lines was very low.4.  In the laboratory tests, Hsf+ flies had higher heat knock......-down resistance relative to Hsf0 flies but in other assays on heat, cold and desiccation resistance there was either no difference between the two mutant lines or the Hsf0 line had higher performance. Also, the superiority of the wild-type flies under field conditions was trait specific.5.  The results emphasize...

  14. Evaluation of the Thermo Scientific SureTect Listeria monocytogenes Assay.

    Science.gov (United States)

    Cloke, Jonathan; Leon-Velarde, Carlos; Larson, Nathan; Dave, Keron; Evans, Katharine; Crabtree, David; Hughes, Annette; Hopper, Craig; Simpson, Helen; Withey, Sophie; Oleksiuk, Milena; Holopainen, Jani; Wickstrand, Nina; Kauppinen, Mikko

    2014-01-01

    The Thermo Scientific SureTect Listeria monocytogenes Assay is a new real-time PCR assay for the detection of Listeria monocytogenes in food and environmental samples. This assay was validated using the AOAC Research Institute (AOAC-RI) Performance Tested Methods program in comparison to the reference method detailed in International Organization for Standardization 11290-1:1996, including Amendment 1:2004 with the following foods and food contact surfaces: smoked salmon, processed cheese, fresh bagged spinach, fresh cantaloupe, cooked prawns (chilled product), cooked sliced turkey meat (chilled product), ice cream, pork frankfurters, salami, ground raw beef meat (12% fat), plastic, and stainless steel. All matrixes were tested by Thermo Fisher Scientific, Microbiology Division, Basingstoke, UK. In addition, three matrixes (pork frankfurters, bagged lettuce, and stainless steel) were analyzed independently as part of the AOAC-RI controlled laboratory study by the University of Guelph, Canada. Using probability of detection (POD) statistical analysis, a significant difference was demonstrated between the candidate and reference methods for salami, cooked sliced turkey and ice cream in favor of the SureTect assay. For all other matrixes, no significant difference by POD was seen between the two methods during the study. Inclusivity and exclusivity testing was also conducted with 53 and 30 isolates, respectively, which demonstrated that the SureTect assay was able to detect all serotypes of L. monocytogenes. None of the exclusivity isolates analyzed were detected by the SureTect assay. Ruggedness testing was conducted to evaluate the performance of the assay with specific method deviations outside the recommended parameters open to variation, i.e., enrichment time and temperature and lysis temperature, which demonstrated that the assay gave reliable performance. Accelerated stability testing was also conducted, validating the assay shelf life.

  15. Limitations of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay when compared to three commonly used cell enumeration assays.

    Science.gov (United States)

    van Tonder, Alet; Joubert, Annie M; Cromarty, A Duncan

    2015-02-20

    The tetrazolium-based MTT assay has long been regarded as the gold standard of cytotoxicity assays as it is highly sensitive and has been miniaturised for use as a high-throughput screening assay. However, various reports refer to interference by different test compounds, including the glycolysis inhibitor 3-bromopyruvate, with the conversion of the dye to coloured formazan crystals. This study assessed the linear range and reproducibility of three commonly used cell enumeration assays; the neutral red uptake (NRU), resazurin reduction (RES) and sulforhodamine B (SRB) assays, in comparison to the MTT assay. Interference between the MTT assay and three glycolysis inhibitors, 2-deoxyglucose, 3-bromopyruvate and lonidamine, was investigated. Data indicate that the NRU, RES and SRB assays showed the smallest variability across the linear range, while the largest variation was observed for the MTT assay. This implies that these assays would more accurately detect small changes in cell number than the MTT assay. The SRB assay provided the most reproducible results as indicated by the coefficient of determination after a limited number of experiments. The SRB assay also produced the lowest variance in the derived 50% inhibitory concentration (IC50), while IC50 concentrations of 3-bromopyruvate could not be detected using either the MTT or RES assays after 24 hours incubation. Interference in the MTT assay was observed for all three tested glycolysis inhibitors in a cell-free environment. No interferences were observed for the NRU, SRB or RES assays. This study demonstrated that the MTT assay was not the best assay in a number of parameters that must be considered when a cell enumeration assay is selected: the MTT assay was less accurate in detecting changes in cell number as indicated by the variation observed in the linear range, had the highest variation when the IC50 concentrations of the glycolysis inhibitors were determined, and interference between the MTT assay and

  16. Microbead agglutination based assays

    KAUST Repository

    Kodzius, Rimantas

    2013-01-21

    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling the macroscopic observation. Such tests are most often used to explore antibody-antigen reactions. Agglutination has been used for protein assays using a biotin/streptavidin system as well as a hybridization based assay. The agglutination systems are prone to selftermination of the linking analyte, prone to active site saturation and loss of agglomeration at high analyte concentrations. We investigated the molecular target/ligand interaction, explaining the common agglutination problems related to analyte self-termination, linkage of the analyte to the same bead instead of different microbeads. We classified the agglutination process into three kinds of assays: a two- component assay, a three-component assay and a stepped three- component assay. Although we compared these three kinds of assays for recognizing DNA and protein molecules, the assay can be used for virtually any molecule, including ions and metabolites. In total, the optimized assay permits detecting analytes with high sensitivity in a short time, 5 min, at room temperature. Such a system is appropriate for POC testing.

  17. Demonstrating the effectiveness of body armour: a pilot prospective computerised surface wound mapping trial performed at the Role 3 hospital in Afghanistan.

    Science.gov (United States)

    Breeze, Johno; Allanson-Bailey, L S; Hepper, A E; Midwinter, M J

    2015-03-01

    Modern body armour clearly reduces injury incidence and severity, but evidence to actually objectively demonstrate this effect is scarce. Although the Joint Theatre Trauma Registry (JTTR) alone cannot relate injury pattern to body armour coverage, the addition of computerised Surface Wound Mapping (SWM) may enable this utility. Surface wound locations of all UK and NATO coalition soldiers, Afghan National Army and Police and local nationals injured by explosively propelled fragments and treated in the Role 3 UK-led Field Hospital in Camp Bastion, Afghanistan, between 8 July and 20 October 2012 were prospectively recorded. The Abbreviated Injury Scores (AIS) and relative risk of casualties sustaining injuries under a type of body armour were compared with those that did not wear that armour. Casualties wearing a combat helmet were 2.7 times less likely to sustain a fragmentation wound to the head than those that were unprotected (mean AIS of 2.9 compared with 4.1). Casualties wearing a body armour vest were 4.1 times less likely to sustain a fragmentation wound to the chest or abdomen than those that were unprotected (mean AIS of 2.9 compared with 3.9). Casualties wearing pelvic protection were 10 times less likely to sustain a fragmentation wound to the pelvis compared with those that were unprotected (mean AIS of 3.4 compared with 3.9). Computerised SWM has objectively demonstrated the ability of body armour worn on current operations in Afghanistan to reduce wound incidence and severity. We recognise this technique is limited in that it only records the surface wound location and may be specific to this conflict. However, gathering electronic SWM at the same time as recording injuries for the JTTR was simple, required little extra time and therefore we would recommend its collection during future conflicts. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Detailed review of transgenic rodent mutation assays.

    Science.gov (United States)

    Lambert, Iain B; Singer, Timothy M; Boucher, Sherri E; Douglas, George R

    2005-09-01

    Induced chromosomal and gene mutations play a role in carcinogenesis and may be involved in the production of birth defects and other disease conditions. While it is widely accepted that in vivo mutation assays are more relevant to the human condition than are in vitro assays, our ability to evaluate mutagenesis in vivo in a broad range of tissues has historically been quite limited. The development of transgenic rodent (TGR) mutation models has given us the ability to detect, quantify, and sequence mutations in a range of somatic and germ cells. This document provides a comprehensive review of the TGR mutation assay literature and assesses the potential use of these assays in a regulatory context. The information is arranged as follows. (1) TGR mutagenicity models and their use for the analysis of gene and chromosomal mutation are fully described. (2) The principles underlying current OECD tests for the assessment of genotoxicity in vitro and in vivo, and also nontransgenic assays available for assessment of gene mutation, are described. (3) All available information pertaining to the conduct of TGR assays and important parameters of assay performance have been tabulated and analyzed. (4) The performance of TGR assays, both in isolation and as part of a battery of in vitro and in vivo short-term genotoxicity tests, in predicting carcinogenicity is described. (5) Recommendations are made regarding the experimental parameters for TGR assays, and the use of TGR assays in a regulatory context.

  19. Enzyme activity assays within microstructured optical fibers enabled